[PATCH v3 00/24] dynamic-debug cleanups refactors maintenance + alignment fix

[PATCH v3 00/24] dynamic-debug cleanups refactors maintenance + alignment fix

[Jim Cromie]

This series starts with 2 doc-only patches updating the current state
of dynamic-debug, they were posted separately here, without pushback.

https://lore.kernel.org/linux-doc/20260502-dyndbg-doc-v1-0-67cc4a93a77e@gmail.com/
    
Next 5 are a fix to a linker-script alignment problem in 32bit arches
causing a null-ptr scanning dyndbg-descriptor section on i386.  These
were reviewed by Petr Pavlu.

The remaining patches are cleanups, refactors in preparation for an
API change needed to fix a regression in DRM when it uses classmaps.
I split these out for easier review, I will follow up with the API
change afterwards.

The biggest revision vs V2 is the new patch: 25.  It addresses a flaw
detected by sashiko which is best described by example.

Dyndbg uses KBUILD_MODNAME to provide module-name, this works well for
loadable modules (module loader requires unique module names), but for
builtin modules, is effectively kbasename, and not unique.

So we get 4 modules named "main": init/main, kernel/power/main,
kernel/base/poser/main.  This ambiguity is visible in user-space since
the beginning of dyndbg.

Now suppose kernel/{,base}/power/main want to define classmaps to
categorize the various pr-debugs they have.  The current code finds a
module's classmaps by strcmp on modname, so init/main will match
against classmaps defined by both kernel/{,base}/power/main.

The current code will also map "main" classes to kernel/*/power/main,
so they will probably work at first, but 2 independent classmaps can
both use class-ids 0-N, but will conflict if they're both used by a
module.  Then we have classmap overlaps and unpredictable results.

patch-25 eliminates the ambiguity by using KBUILD_MODFILE to provide a
unique module-name, then adds matching against kbasename(modname) to
restore the legacy query behavior.  It *does* change the modname
exposed in /proc/dynamic_debug/control, but not the result of a query
like "module main +p".

OLDER VERSIONS:

V2 primarily revises:
 https://lore.kernel.org/lkml/20260504-dd-cleanups-2-v1-0-6fdd24040642@gmail.com/
    
V2 addressed most of sashiko's feedback on V1:
 https://sashiko.dev/#/patchset/20260504-dd-cleanups-2-v1-0-6fdd24040642%40gmail.com
    
It dropped the pr-fmt patch, as not reproducible,
advanced the drop-NAMES patch to reduce subsequent churn,
and fixed the classmaps PARAMs to u64 to avoid 32bit flags on 32bit arches
    
For easy one-stop-shopping, V2 also included 2 smaller series:
    
1st fixes a section alignment problem, with Reviewed-by from Petr Pavlu
 https://lore.kernel.org/lkml/20260515-asm-generic-1-v3-0-680b273666d4@gmail.com/
    
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
    

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
Changes in v3:
- EDITME: describe what is new in this series revision.
- EDITME: use bulletpoints and terse descriptions.
- Link to v2: https://lore.kernel.org/r/20260523-dd-maint-2-v2-0-b937312aa083@gmail.com

---
Jim Cromie (24):
      docs/dyndbg: update examples \012 to \n
      docs/dyndbg: explain flags parse 1st
      vmlinux.lds.h: refactor BOUNDED_SECTION_* macros into bounded_sections.lds.h
      vmlinux.lds.h: drop unused HEADERED_SECTION* macros
      vmlinux.lds.h: Fix ALIGN(8) omission causing NULL ptr on i386
      vmlinux.lds.h: remove redundant ALIGN(8) directives
      dyndbg.lds.S: fix lost dyndbg sections in modules
      dyndbg: factor ddebug_match_desc out from ddebug_change
      dyndbg: add stub macro for DECLARE_DYNDBG_CLASSMAP
      dyndbg: reword "class unknown," to "class:_UNKNOWN_"
      dyndbg-API: remove DD_CLASS_TYPE_(DISJOINT|LEVEL)_NAMES and code
      dyndbg: drop NUM_TYPE_ARGS
      dyndbg: reduce verbose/debug clutter
      dyndbg: refactor param_set_dyndbg_classes and below
      dyndbg: tighten fn-sig of ddebug_apply_class_bitmap
      dyndbg: replace classmap list with an array-slice
      dyndbg: macrofy a 2-index for-loop pattern
      dyndbg: Upgrade class param storage to u64 for 64-bit classmaps
      dyndbg,module: make proper substructs in _ddebug_info
      dyndbg: move mod_name down from struct ddebug_table to _ddebug_info
      dyndbg: hoist classmap-filter-by-modname up to ddebug_add_module
      selftests-dyndbg: add a dynamic_debug run_tests target
      dyndbg: change __dynamic_func_call_cls* macros into expressions
      dynamic_debug: use KBUILD_MODFILE for unique builtin module names

 Documentation/admin-guide/dynamic-debug-howto.rst  |  55 ++-
 MAINTAINERS                                        |   2 +
 drivers/gpu/drm/drm_print.c                        |   6 +-
 include/asm-generic/bounded_sections.lds.h         |  32 ++
 include/asm-generic/dyndbg.lds.h                   |  18 +
 include/asm-generic/vmlinux.lds.h                  |  68 +--
 include/drm/drm_print.h                            |   2 +-
 include/linux/dynamic_debug.h                      | 133 +++---
 kernel/module/main.c                               |  12 +-
 lib/dynamic_debug.c                                | 501 ++++++++++-----------
 lib/test_dynamic_debug.c                           |  30 +-
 scripts/module.lds.S                               |   2 +
 tools/testing/selftests/Makefile                   |   1 +
 tools/testing/selftests/dynamic_debug/Makefile     |   9 +
 tools/testing/selftests/dynamic_debug/config       |   8 +
 .../selftests/dynamic_debug/dyndbg_selftest.sh     | 294 ++++++++++++
 16 files changed, 736 insertions(+), 437 deletions(-)
---
base-commit: e43ffb69e0438cddd72aaa30898b4dc446f664f8
change-id: 20260521-dd-maint-2-76c542079420

Best regards,
-- 
Jim Cromie <jim.cromie@gmail.com>

[PATCH v3 01/24] docs/dyndbg: update examples \012 to \n

[Jim Cromie]

commit 47ea6f99d06e ("dyndbg: use ESCAPE_SPACE for cat control")
changed the control-file to display format strings with "\n" rather
than "\012".  Update the docs to match the new reality.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Tested-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 Documentation/admin-guide/dynamic-debug-howto.rst | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 095a63892257..4b14d9fd0300 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -38,12 +38,12 @@ You can view the currently configured behaviour in the *prdbg* catalog::
 
   :#> head -n7 /proc/dynamic_debug/control
   # filename:lineno [module]function flags format
-  init/main.c:1179 [main]initcall_blacklist =_ "blacklisting initcall %s\012
-  init/main.c:1218 [main]initcall_blacklisted =_ "initcall %s blacklisted\012"
-  init/main.c:1424 [main]run_init_process =_ "  with arguments:\012"
-  init/main.c:1426 [main]run_init_process =_ "    %s\012"
-  init/main.c:1427 [main]run_init_process =_ "  with environment:\012"
-  init/main.c:1429 [main]run_init_process =_ "    %s\012"
+  init/main.c:1179 [main]initcall_blacklist =_ "blacklisting initcall %s\n"
+  init/main.c:1218 [main]initcall_blacklisted =_ "initcall %s blacklisted\n"
+  init/main.c:1424 [main]run_init_process =_ "  with arguments:\n"
+  init/main.c:1426 [main]run_init_process =_ "    %s\n"
+  init/main.c:1427 [main]run_init_process =_ "  with environment:\n"
+  init/main.c:1429 [main]run_init_process =_ "    %s\n"
 
 The 3rd space-delimited column shows the current flags, preceded by
 a ``=`` for easy use with grep/cut. ``=p`` shows enabled callsites.
@@ -59,10 +59,10 @@ query/commands to the control file.  Example::
 
   :#> ddcmd '-p; module main func run* +p'
   :#> grep =p /proc/dynamic_debug/control
-  init/main.c:1424 [main]run_init_process =p "  with arguments:\012"
-  init/main.c:1426 [main]run_init_process =p "    %s\012"
-  init/main.c:1427 [main]run_init_process =p "  with environment:\012"
-  init/main.c:1429 [main]run_init_process =p "    %s\012"
+  init/main.c:1424 [main]run_init_process =p "  with arguments:\n"
+  init/main.c:1426 [main]run_init_process =p "    %s\n"
+  init/main.c:1427 [main]run_init_process =p "  with environment:\n"
+  init/main.c:1429 [main]run_init_process =p "    %s\n"
 
 Error messages go to console/syslog::
 

-- 
2.54.0

Claude review: docs/dyndbg: update examples \012 to \n

[Claude Code Review Bot]

Patch Review

Straightforward doc update matching commit 47ea6f99d06e. Reviewed-by and Tested-by from Louis Chauvet. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 02/24] docs/dyndbg: explain flags parse 1st

[Jim Cromie]

When writing queries to >control, flags are parsed 1st, since they are
the only required field, and they require specific compositions.  So
if the flags draw an error (on those specifics), then keyword errors
aren't reported.  This can be mildly confusing/annoying, so explain it
instead.

cc: linux-doc@vger.kernel.org
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 Documentation/admin-guide/dynamic-debug-howto.rst | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 4b14d9fd0300..9c2f096ed1d8 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -109,10 +109,19 @@ The match-spec's select *prdbgs* from the catalog, upon which to apply
 the flags-spec, all constraints are ANDed together.  An absent keyword
 is the same as keyword "*".
 
-
-A match specification is a keyword, which selects the attribute of
-the callsite to be compared, and a value to compare against.  Possible
-keywords are:::
+Note that since the match-spec can be empty, the flags are checked 1st,
+then the pairs of keyword and value.  Flag errs will hide keyword errs::
+
+  bash-5.2# ddcmd mod bar +foo
+  dyndbg: read 13 bytes from userspace
+  dyndbg: query 0: "mod bar +foo" mod:*
+  dyndbg: unknown flag 'o'
+  dyndbg: flags parse failed
+  dyndbg: processed 1 queries, with 0 matches, 1 errs
+
+So a match-spec is a keyword, which selects the attribute of the
+callsite to be compared, and a value to compare against.  Possible
+keywords are::
 
   match-spec ::= 'func' string |
 		 'file' string |

-- 
2.54.0

Claude review: docs/dyndbg: explain flags parse 1st

[Claude Code Review Bot]

Patch Review

Good documentation improvement explaining non-obvious parsing order. The fix from `:::` to `::` in the RST syntax is correct. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 03/24] vmlinux.lds.h: refactor BOUNDED_SECTION_* macros into bounded_sections.lds.h

[Jim Cromie]

Move BOUNDED_SECTION_* macros to a new helper file:
include/asm-generic/bounded_sections.lds.h and include it back into
vmlinux.lds.h.  This allows its reuse later to fix a failure to keep
dyndbg sections in some circumstances.

NOTES:

These macros are only for use in vmlinux.lds.h, where the _start &
_end symbols are needed.  Modules keep sections separate in ELF
sections, with their boundaries known, so the _start and _end are not
useful, and may confuse tools not expecting them.

This patch ignores a checkpatch warning, because new file is covered
by "GENERIC INCLUDE/ASM HEADER FILES" in MAINTAINERS

CC: Arnd Bergmann <arnd@arndb.de>
CC: linux-arch@vger.kernel.org
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
v3: move include to top
---
 include/asm-generic/bounded_sections.lds.h | 36 ++++++++++++++++++++++++++++++
 include/asm-generic/vmlinux.lds.h          | 31 +------------------------
 2 files changed, 37 insertions(+), 30 deletions(-)

diff --git a/include/asm-generic/bounded_sections.lds.h b/include/asm-generic/bounded_sections.lds.h
new file mode 100644
index 000000000000..8c29293ca7fb
--- /dev/null
+++ b/include/asm-generic/bounded_sections.lds.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _ASM_GENERIC_BOUNDED_SECTIONS_H
+#define _ASM_GENERIC_BOUNDED_SECTIONS_H
+
+#define BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_)	\
+	_BEGIN_##_label_ = .;						\
+	KEEP(*(_sec_))							\
+	_END_##_label_ = .;
+
+#define BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_)	\
+	_label_##_BEGIN_ = .;						\
+	KEEP(*(_sec_))							\
+	_label_##_END_ = .;
+
+#define BOUNDED_SECTION_BY(_sec_, _label_)				\
+	BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop)
+
+#define BOUNDED_SECTION(_sec)	 BOUNDED_SECTION_BY(_sec, _sec)
+
+#define HEADERED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_, _HDR_) \
+	_HDR_##_label_	= .;						\
+	KEEP(*(.gnu.linkonce.##_sec_))					\
+	BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_)
+
+#define HEADERED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_, _HDR_) \
+	_label_##_HDR_ = .;						\
+	KEEP(*(.gnu.linkonce.##_sec_))					\
+	BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_)
+
+#define HEADERED_SECTION_BY(_sec_, _label_)				\
+	HEADERED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop)
+
+#define HEADERED_SECTION(_sec)	 HEADERED_SECTION_BY(_sec, _sec)
+
+#endif /* _ASM_GENERIC_BOUNDED_SECTIONS_H */
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 60c8c22fd3e4..9c61dd083f26 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -50,6 +50,7 @@
  *               [__nosave_begin, __nosave_end] for the nosave data
  */
 
+#include <asm-generic/bounded_sections.lds.h>
 #include <asm-generic/codetag.lds.h>
 
 #ifndef LOAD_OFFSET
@@ -211,36 +212,6 @@
 # endif
 #endif
 
-#define BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_)	\
-	_BEGIN_##_label_ = .;						\
-	KEEP(*(_sec_))							\
-	_END_##_label_ = .;
-
-#define BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_)	\
-	_label_##_BEGIN_ = .;						\
-	KEEP(*(_sec_))							\
-	_label_##_END_ = .;
-
-#define BOUNDED_SECTION_BY(_sec_, _label_)				\
-	BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop)
-
-#define BOUNDED_SECTION(_sec)	 BOUNDED_SECTION_BY(_sec, _sec)
-
-#define HEADERED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_, _HDR_) \
-	_HDR_##_label_	= .;						\
-	KEEP(*(.gnu.linkonce.##_sec_))					\
-	BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_)
-
-#define HEADERED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_, _HDR_) \
-	_label_##_HDR_ = .;						\
-	KEEP(*(.gnu.linkonce.##_sec_))					\
-	BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_)
-
-#define HEADERED_SECTION_BY(_sec_, _label_)				\
-	HEADERED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop)
-
-#define HEADERED_SECTION(_sec)	 HEADERED_SECTION_BY(_sec, _sec)
-
 #ifdef CONFIG_TRACE_BRANCH_PROFILING
 #define LIKELY_PROFILE()						\
 	BOUNDED_SECTION_BY(_ftrace_annotated_branch, _annotated_branch_profile)

-- 
2.54.0

Claude review: vmlinux.lds.h: refactor BOUNDED_SECTION_* macros into bounded_sections.lds.h

[Claude Code Review Bot]

Patch Review

Clean code-motion refactoring. Moves macros to a new header for reuse. The HEADERED_SECTION macros are moved here but immediately removed in patch 4, which is slightly wasteful but makes the refactoring easier to review. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 04/24] vmlinux.lds.h: drop unused HEADERED_SECTION* macros

[Jim Cromie]

These macros are unused, no point in carrying them any more.

NB: these macros were just moved to bounded_sections.lds.h, from
vmlinux.lds.h, which is the known entity, and therefore more
meaningful in the 1-line summary, so thats what I used as the topic.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/asm-generic/bounded_sections.lds.h | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/include/asm-generic/bounded_sections.lds.h b/include/asm-generic/bounded_sections.lds.h
index 8c29293ca7fb..268cdc34389b 100644
--- a/include/asm-generic/bounded_sections.lds.h
+++ b/include/asm-generic/bounded_sections.lds.h
@@ -18,19 +18,4 @@
 
 #define BOUNDED_SECTION(_sec)	 BOUNDED_SECTION_BY(_sec, _sec)
 
-#define HEADERED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_, _HDR_) \
-	_HDR_##_label_	= .;						\
-	KEEP(*(.gnu.linkonce.##_sec_))					\
-	BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_)
-
-#define HEADERED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_, _HDR_) \
-	_label_##_HDR_ = .;						\
-	KEEP(*(.gnu.linkonce.##_sec_))					\
-	BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_)
-
-#define HEADERED_SECTION_BY(_sec_, _label_)				\
-	HEADERED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop)
-
-#define HEADERED_SECTION(_sec)	 HEADERED_SECTION_BY(_sec, _sec)
-
 #endif /* _ASM_GENERIC_BOUNDED_SECTIONS_H */

-- 
2.54.0

Claude review: vmlinux.lds.h: drop unused HEADERED_SECTION* macros

[Claude Code Review Bot]

Patch Review

Good cleanup of unused macros. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 05/24] vmlinux.lds.h: Fix ALIGN(8) omission causing NULL ptr on i386

[Jim Cromie]

Almost all uses of the BOUNDED_SECTION macros are ALIGN(8), either
explicitly, or by being below an aligned section containing x*8 byte
objects.  The noteworthy exception is BOUNDED_SECTION(__dyndbg), which
immediately follows BOUNDED_SECTION(__dyndbg_classes).

On i386, struct _ddebug_classmap is 28 bytes, so without an explicit
ALIGN(8) in the macro, the following __dyndbg section gets misaligned,
causing a NULL ptr deref in dynamic_debug_init().

So fix this with an explicit ALIGN(8) in the existing BOUNDED_SECTION
macros, and introduce _ALIGNED variants to handle the cases with an
explicit . = ALIGN(x)

Also add explicit alignments for: EXCEPTION_TABLE, ORC_UNWIND_TABLE,
TRACEDATA, INIT_SETUP, and NOTES.

update BOUNDED_SECTION uses inside . = ALIGN(x) stanzas to use
_ALIGNED variants, but keep the outer ALIGNs so the symbols between
them are not "re-aligned".

In particular, scripts/sorttable.c does not tolerate sloppy padding.

At the top of ORC_UNWIND_TABLE, add . = ALIGN(4) to match the struct
orc_header __align() call in the code:

commit b9f174c811e3 ("x86/unwind/orc: Add ELF section with ORC version identifier")

Suggested-by: Louis Chauvet <louis.chauvet@bootlin.com>  # _ALIGNED variants.
Link: https://lore.kernel.org/lkml/177402491426.6181.12855763650074831089.b4-review@b4/
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
v3:

sashiko complained about NOTES and .BTF_ids.
gemini asserts that NOTES are natively 4-byte aligned, add comment repeating it.
.BTF_ids doesnt use BOUNDED_BY, since start/end isnt needed;
sashiko evidently got confused by immediately preceding usage.

v2:

sashiko picked up 2 cases, added to the explicit list above
https://sashiko.dev/#/patchset/20260515-asm-generic-1-v3-0-680b273666d4%40gmail.com
---
 include/asm-generic/bounded_sections.lds.h | 17 ++++++++++++++---
 include/asm-generic/vmlinux.lds.h          | 18 ++++++++++--------
 2 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/include/asm-generic/bounded_sections.lds.h b/include/asm-generic/bounded_sections.lds.h
index 268cdc34389b..8ff3e3420f60 100644
--- a/include/asm-generic/bounded_sections.lds.h
+++ b/include/asm-generic/bounded_sections.lds.h
@@ -3,19 +3,30 @@
 #ifndef _ASM_GENERIC_BOUNDED_SECTIONS_H
 #define _ASM_GENERIC_BOUNDED_SECTIONS_H
 
-#define BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_)	\
+#define BOUNDED_SECTION_PRE_LABEL_ALIGNED(_sec_, _label_, _BEGIN_, _END_, _ALIGNED_) \
+	. = ALIGN(_ALIGNED_);						\
 	_BEGIN_##_label_ = .;						\
 	KEEP(*(_sec_))							\
 	_END_##_label_ = .;
 
-#define BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_)	\
+#define BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_)	\
+	BOUNDED_SECTION_PRE_LABEL_ALIGNED(_sec_, _label_, _BEGIN_, _END_, 8)
+
+#define BOUNDED_SECTION_POST_LABEL_ALIGNED(_sec_, _label_, _BEGIN_, _END_, _ALIGNED_) \
+	. = ALIGN(_ALIGNED_);						\
 	_label_##_BEGIN_ = .;						\
 	KEEP(*(_sec_))							\
 	_label_##_END_ = .;
 
+#define BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_)	\
+	BOUNDED_SECTION_POST_LABEL_ALIGNED(_sec_, _label_, _BEGIN_, _END_, 8)
+
 #define BOUNDED_SECTION_BY(_sec_, _label_)				\
 	BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop)
 
-#define BOUNDED_SECTION(_sec)	 BOUNDED_SECTION_BY(_sec, _sec)
+#define BOUNDED_SECTION_BY_ALIGNED(_sec_, _label_, _ALIGNED_)		\
+	BOUNDED_SECTION_PRE_LABEL_ALIGNED(_sec_, _label_, __start, __stop, _ALIGNED_)
+
+#define BOUNDED_SECTION(_sec)   BOUNDED_SECTION_BY(_sec, _sec)
 
 #endif /* _ASM_GENERIC_BOUNDED_SECTIONS_H */
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 9c61dd083f26..145beb14b94b 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -640,7 +640,7 @@
 #define EXCEPTION_TABLE(align)						\
 	. = ALIGN(align);						\
 	__ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {		\
-		BOUNDED_SECTION_BY(__ex_table, ___ex_table)		\
+		BOUNDED_SECTION_BY_ALIGNED(__ex_table, ___ex_table, align) \
 	}
 
 /*
@@ -650,7 +650,7 @@
 #define BTF								\
 	. = ALIGN(PAGE_SIZE);						\
 	.BTF : AT(ADDR(.BTF) - LOAD_OFFSET) {				\
-		BOUNDED_SECTION_BY(.BTF, _BTF)				\
+		BOUNDED_SECTION_BY_ALIGNED(.BTF, _BTF, PAGE_SIZE)	\
 	}								\
 	. = ALIGN(PAGE_SIZE);						\
 	.BTF_ids : AT(ADDR(.BTF_ids) - LOAD_OFFSET) {			\
@@ -832,16 +832,17 @@
 
 #ifdef CONFIG_UNWINDER_ORC
 #define ORC_UNWIND_TABLE						\
+	. = ALIGN(4);							\
 	.orc_header : AT(ADDR(.orc_header) - LOAD_OFFSET) {		\
-		BOUNDED_SECTION_BY(.orc_header, _orc_header)		\
+		BOUNDED_SECTION_BY_ALIGNED(.orc_header, _orc_header, 4)	\
 	}								\
 	. = ALIGN(4);							\
 	.orc_unwind_ip : AT(ADDR(.orc_unwind_ip) - LOAD_OFFSET) {	\
-		BOUNDED_SECTION_BY(.orc_unwind_ip, _orc_unwind_ip)	\
+		BOUNDED_SECTION_BY_ALIGNED(.orc_unwind_ip, _orc_unwind_ip, 4)\
 	}								\
 	. = ALIGN(2);							\
 	.orc_unwind : AT(ADDR(.orc_unwind) - LOAD_OFFSET) {		\
-		BOUNDED_SECTION_BY(.orc_unwind, _orc_unwind)		\
+		BOUNDED_SECTION_BY_ALIGNED(.orc_unwind, _orc_unwind, 2)	\
 	}								\
 	text_size = _etext - _stext;					\
 	. = ALIGN(4);							\
@@ -869,7 +870,7 @@
 #define TRACEDATA							\
 	. = ALIGN(4);							\
 	.tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) {		\
-		BOUNDED_SECTION_POST_LABEL(.tracedata, __tracedata, _start, _end) \
+		BOUNDED_SECTION_POST_LABEL_ALIGNED(.tracedata, __tracedata, _start, _end, 4) \
 	}
 #else
 #define TRACEDATA
@@ -898,13 +899,14 @@
 		*(.note.gnu.property)					\
 	}								\
 	.notes : AT(ADDR(.notes) - LOAD_OFFSET) {			\
-		BOUNDED_SECTION_BY(.note.*, _notes)			\
+		/* *(.note.*) are natively 4-byte aligned */		\
+		BOUNDED_SECTION_BY_ALIGNED(.note.*, _notes, 4)		\
 	} NOTES_HEADERS							\
 	NOTES_HEADERS_RESTORE
 
 #define INIT_SETUP(initsetup_align)					\
 		. = ALIGN(initsetup_align);				\
-		BOUNDED_SECTION_POST_LABEL(.init.setup, __setup, _start, _end)
+		BOUNDED_SECTION_POST_LABEL_ALIGNED(.init.setup, __setup, _start, _end, initsetup_align)
 
 #define INIT_CALLS_LEVEL(level)						\
 		__initcall##level##_start = .;				\

-- 
2.54.0

Claude review: vmlinux.lds.h: Fix ALIGN(8) omission causing NULL ptr on i386

[Claude Code Review Bot]

Patch Review

This is the key bug fix in the series. On i386, `struct _ddebug_classmap` is 28 bytes, so the `__dyndbg` section after `__dyndbg_classes` gets misaligned, causing a NULL ptr deref. The fix adds ALIGN to the base macros and introduces `_ALIGNED` variants. The approach of making ALIGN(8) the default and adding `_ALIGNED` variants for explicit overrides is sound. The ORC table `ALIGN(4)` addition matches the code's `__align()` attribute. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 06/24] vmlinux.lds.h: remove redundant ALIGN(8) directives

[Jim Cromie]

The BOUNDED_SECTION_PRE_LABEL and BOUNDED_SECTION_POST_LABEL macros
were recently updated to inherently enforce an 8-byte alignment. This
makes the explicit '. = ALIGN(8);' statements preceding 'naked' macro
calls in vmlinux.lds.h redundant.

Remove these redundant alignment directives to clean up the file and
clarify that the macros handle their own alignment padding.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/asm-generic/vmlinux.lds.h | 13 -------------
 1 file changed, 13 deletions(-)

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 145beb14b94b..2b1becd809be 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -228,7 +228,6 @@
 
 #ifdef CONFIG_KPROBES
 #define KPROBE_BLACKLIST()				\
-	. = ALIGN(8);					\
 	BOUNDED_SECTION(_kprobe_blacklist)
 #else
 #define KPROBE_BLACKLIST()
@@ -244,7 +243,6 @@
 
 #ifdef CONFIG_EVENT_TRACING
 #define FTRACE_EVENTS()							\
-	. = ALIGN(8);							\
 	BOUNDED_SECTION(_ftrace_events)					\
 	BOUNDED_SECTION_BY(_ftrace_eval_map, _ftrace_eval_maps)
 #else
@@ -261,7 +259,6 @@
 
 #ifdef CONFIG_FTRACE_SYSCALLS
 #define TRACE_SYSCALLS()			\
-	. = ALIGN(8);				\
 	BOUNDED_SECTION_BY(__syscalls_metadata, _syscalls_metadata)
 #else
 #define TRACE_SYSCALLS()
@@ -276,7 +273,6 @@
 
 #ifdef CONFIG_SERIAL_EARLYCON
 #define EARLYCON_TABLE()						\
-	. = ALIGN(8);							\
 	BOUNDED_SECTION_POST_LABEL(__earlycon_table, __earlycon_table, , _end)
 #else
 #define EARLYCON_TABLE()
@@ -284,11 +280,9 @@
 
 #ifdef CONFIG_SECURITY
 #define LSM_TABLE()					\
-	. = ALIGN(8);					\
 	BOUNDED_SECTION_PRE_LABEL(.lsm_info.init, _lsm_info, __start, __end)
 
 #define EARLY_LSM_TABLE()						\
-	. = ALIGN(8);							\
 	BOUNDED_SECTION_PRE_LABEL(.early_lsm_info.init, _early_lsm_info, __start, __end)
 #else
 #define LSM_TABLE()
@@ -314,7 +308,6 @@
 
 #ifdef CONFIG_ACPI
 #define ACPI_PROBE_TABLE(name)						\
-	. = ALIGN(8);							\
 	BOUNDED_SECTION_POST_LABEL(__##name##_acpi_probe_table,		\
 				   __##name##_acpi_probe_table,, _end)
 #else
@@ -323,7 +316,6 @@
 
 #ifdef CONFIG_THERMAL
 #define THERMAL_TABLE(name)						\
-	. = ALIGN(8);							\
 	BOUNDED_SECTION_POST_LABEL(__##name##_thermal_table,		\
 				   __##name##_thermal_table,, _end)
 #else
@@ -403,12 +395,10 @@
 	__end_init_stack = .;
 
 #define JUMP_TABLE_DATA							\
-	. = ALIGN(8);							\
 	BOUNDED_SECTION_BY(__jump_table, ___jump_table)
 
 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
 #define STATIC_CALL_DATA						\
-	. = ALIGN(8);							\
 	BOUNDED_SECTION_BY(.static_call_sites, _static_call_sites)	\
 	BOUNDED_SECTION_BY(.static_call_tramp_key, _static_call_tramp_key)
 #else
@@ -453,7 +443,6 @@
 		*(.rodata) *(.rodata.*) *(.data.rel.ro*)		\
 		SCHED_DATA						\
 		RO_AFTER_INIT_DATA	/* Read only after init */	\
-		. = ALIGN(8);						\
 		BOUNDED_SECTION_BY(__tracepoints_ptrs, ___tracepoints_ptrs) \
 		*(__tracepoints_strings)/* Tracepoints: strings */	\
 	}								\
@@ -947,12 +936,10 @@
 
 /* Alignment must be consistent with (kunit_suite *) in include/kunit/test.h */
 #define KUNIT_TABLE()							\
-		. = ALIGN(8);						\
 		BOUNDED_SECTION_POST_LABEL(.kunit_test_suites, __kunit_suites, _start, _end)
 
 /* Alignment must be consistent with (kunit_suite *) in include/kunit/test.h */
 #define KUNIT_INIT_TABLE()						\
-		. = ALIGN(8);						\
 		BOUNDED_SECTION_POST_LABEL(.kunit_init_test_suites, \
 				__kunit_init_suites, _start, _end)
 

-- 
2.54.0

Claude review: vmlinux.lds.h: remove redundant ALIGN(8) directives

[Claude Code Review Bot]

Patch Review

Logical follow-up removing now-redundant explicit alignments since the macros handle them. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 07/24] dyndbg.lds.S: fix lost dyndbg sections in modules

[Jim Cromie]

With CONFIG_DRM_USE_DYNAMIC_DEBUG=y, several build configs had
problems with __dyndbg* sections getting lost in drm drivers.  Fix
this by following the model demonstrated in codetag.lds.h.

Introduce include/asm-generic/dyndbg.lds.h, to bundle dynamic-debug's
multiple sections together, into 2 macros:

vmlinux.lds.h DATA_DATA: move the 2 BOUNDED_SECTION_BY(__dyndbg*)
calls into dyndbg.lds.h DYNDBG_SECTIONS(). vmlinux.lds.h now includes
the new file and calls the new macro.

MOD_DYNDBG_SECTIONS keeps the 2 sections by name, aligns them and sets
the output address to 0 when the sections are empty.

dyndbg.lds.h includes (reuses) bounded-section.lds.h

scripts/module.lds.S: now calls MOD_DYNDBG_SECTIONS right before the
CODETAG macro (consistent with their placements in vmlinux.lds.h), and
also includes dyndbg.lds.h

This isolates vmlinux.lds.h from further __dyndbg section additions.

CC: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
---
v3: move #includes to top, drop extra ALIGN(8) in DYNDBG_SECTIONS, add RvBy

v2: Address linker script review feedback for relocatable modules.

MOD_DYNDBG_SECTIONS() used the BOUNDED_SECTION_BY() macro, which
proved problematic for kernel modules for two reasons:

1. Unwanted Empty Sections:
   BOUNDED_SECTION_BY() automatically generates `__start` and `__stop`
   symbols. When applied to `MOD_DYNDBG_SECTIONS()`, the linker assumes
   the sections are populated due to the symbol definitions, forcing an
   empty `__dyndbg` and `__dyndbg_classes` output section in every
   compiled module, even those without dynamic debug configuration.
   Since the module loader uses `section_objs()` to locate data via
   ELF headers instead of relying on `__start`/`__stop` symbols, these
   assignments are completely unnecessary.

2. Non-zero Output Addresses:
   During relocatable linking (e.g., `ld.bfd -r`), omitting an explicit
   base address causes the section to inherit the current location
   counter. This results in non-zero sh_addr values in `.ko` files,
   which is confusing, degrades compressibility, and can cause issues
   with external tools parsing the ELF.

Fix both issues by dropping `BOUNDED_SECTION_BY()` in favor of a simple
`KEEP(*(...))` constraint and explicitly defining the sections with a `0`
base address: `__dyndbg 0 : ALIGN(8) { ... }`.

fixup-inc-vml
---
 MAINTAINERS                       |  1 +
 include/asm-generic/dyndbg.lds.h  | 18 ++++++++++++++++++
 include/asm-generic/vmlinux.lds.h |  6 ++----
 scripts/module.lds.S              |  2 ++
 4 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 9ec290e38b44..6cf80e7ac039 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9083,6 +9083,7 @@ DYNAMIC DEBUG
 M:	Jason Baron <jbaron@akamai.com>
 M:	Jim Cromie <jim.cromie@gmail.com>
 S:	Maintained
+F:	include/asm-generic/dyndbg.lds.h
 F:	include/linux/dynamic_debug.h
 F:	lib/dynamic_debug.c
 F:	lib/test_dynamic_debug.c
diff --git a/include/asm-generic/dyndbg.lds.h b/include/asm-generic/dyndbg.lds.h
new file mode 100644
index 000000000000..9d8951bef688
--- /dev/null
+++ b/include/asm-generic/dyndbg.lds.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_GENERIC_DYNDBG_LDS_H
+#define __ASM_GENERIC_DYNDBG_LDS_H
+
+#include <asm-generic/bounded_sections.lds.h>
+#define DYNDBG_SECTIONS()					\
+	BOUNDED_SECTION_BY(__dyndbg, ___dyndbg)			\
+	BOUNDED_SECTION_BY(__dyndbg_classes, ___dyndbg_classes)
+
+#define MOD_DYNDBG_SECTIONS()						\
+	__dyndbg 0 : ALIGN(8) {						\
+		KEEP(*(__dyndbg))					\
+	}								\
+	__dyndbg_classes 0 : ALIGN(8) {					\
+		KEEP(*(__dyndbg_classes))				\
+	}
+
+#endif /* __ASM_GENERIC_DYNDBG_LDS_H */
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 2b1becd809be..0a1994bb8793 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -52,6 +52,7 @@
 
 #include <asm-generic/bounded_sections.lds.h>
 #include <asm-generic/codetag.lds.h>
+#include <asm-generic/dyndbg.lds.h>
 
 #ifndef LOAD_OFFSET
 #define LOAD_OFFSET 0
@@ -344,10 +345,7 @@
 	*(.data..do_once)						\
 	STRUCT_ALIGN();							\
 	*(__tracepoints)						\
-	/* implement dynamic printk debug */				\
-	. = ALIGN(8);							\
-	BOUNDED_SECTION_BY(__dyndbg_classes, ___dyndbg_classes)		\
-	BOUNDED_SECTION_BY(__dyndbg, ___dyndbg)				\
+	DYNDBG_SECTIONS()						\
 	CODETAG_SECTIONS()						\
 	LIKELY_PROFILE()		       				\
 	BRANCH_PROFILE()						\
diff --git a/scripts/module.lds.S b/scripts/module.lds.S
index b62683061d79..2e62dc5bd5d4 100644
--- a/scripts/module.lds.S
+++ b/scripts/module.lds.S
@@ -10,6 +10,7 @@
 #endif
 
 #include <asm-generic/codetag.lds.h>
+#include <asm-generic/dyndbg.lds.h>
 
 SECTIONS {
 	/DISCARD/ : {
@@ -61,6 +62,7 @@ SECTIONS {
 		*(.rodata..L*)
 	}
 
+	MOD_DYNDBG_SECTIONS()
 	MOD_SEPARATE_CODETAG_SECTIONS()
 }
 

-- 
2.54.0

Claude review: dyndbg.lds.S: fix lost dyndbg sections in modules

[Claude Code Review Bot]

Patch Review

Fixes `CONFIG_DRM_USE_DYNAMIC_DEBUG=y` breakage where __dyndbg sections were lost in DRM drivers. The `MOD_DYNDBG_SECTIONS` approach using explicit `0` base address for modules is well-explained and follows the codetag.lds.h model. Reviewed-by from Petr Pavlu. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 08/24] dyndbg: factor ddebug_match_desc out from ddebug_change

[Jim Cromie]

ddebug_change() is a big (~100 lines) function with a nested for loop.

The outer loop walks the per-module ddebug_tables list, and does
module stuff: it filters on a query's "module FOO*" and "class BAR",
failures here skip the entire inner loop.

The inner loop (60 lines) scans a module's descriptors.  It starts
with a long block of filters on function, line, format, and the
validated "BAR" class (or the legacy/_DPRINTK_CLASS_DFLT).

These filters "continue" past pr_debugs that don't match the query
criteria, before it falls through the code below that counts matches,
then adjusts the flags and static-keys.  This is unnecessarily hard to
think about.

So move the per-descriptor filter-block into a boolean function:
ddebug_match_desc(desc), and change each "continue" to "return false".
This puts a clear interface in place, so any future changes are either
inside, outside, or across this interface.

also fix checkpatch complaints about spaces and braces.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 lib/dynamic_debug.c | 83 ++++++++++++++++++++++++++++++-----------------------
 1 file changed, 47 insertions(+), 36 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 18a71a9108d3..6b1e983cfedc 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -172,6 +172,52 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons
  * callsites, normally the same as number of changes.  If verbose,
  * logs the changes.  Takes ddebug_lock.
  */
+static bool ddebug_match_desc(const struct ddebug_query *query,
+			      struct _ddebug *dp,
+			      int valid_class)
+{
+	/* match site against query-class */
+	if (dp->class_id != valid_class)
+		return false;
+
+	/* match against the source filename */
+	if (query->filename &&
+	    !match_wildcard(query->filename, dp->filename) &&
+	    !match_wildcard(query->filename,
+			    kbasename(dp->filename)) &&
+	    !match_wildcard(query->filename,
+			    trim_prefix(dp->filename)))
+		return false;
+
+	/* match against the function */
+	if (query->function &&
+	    !match_wildcard(query->function, dp->function))
+		return false;
+
+	/* match against the format */
+	if (query->format) {
+		if (*query->format == '^') {
+			char *p;
+			/* anchored search. match must be at beginning */
+			p = strstr(dp->format, query->format + 1);
+			if (p != dp->format)
+				return false;
+		} else if (!strstr(dp->format, query->format)) {
+			return false;
+		}
+	}
+
+	/* match against the line number range */
+	if (query->first_lineno &&
+	    dp->lineno < query->first_lineno)
+		return false;
+	if (query->last_lineno &&
+	    dp->lineno > query->last_lineno)
+		return false;
+
+	return true;
+}
+
 static int ddebug_change(const struct ddebug_query *query,
 			 struct flag_settings *modifiers)
 {
@@ -204,42 +250,7 @@ static int ddebug_change(const struct ddebug_query *query,
 		for (i = 0; i < dt->num_ddebugs; i++) {
 			struct _ddebug *dp = &dt->ddebugs[i];
 
-			/* match site against query-class */
-			if (dp->class_id != valid_class)
-				continue;
-
-			/* match against the source filename */
-			if (query->filename &&
-			    !match_wildcard(query->filename, dp->filename) &&
-			    !match_wildcard(query->filename,
-					   kbasename(dp->filename)) &&
-			    !match_wildcard(query->filename,
-					   trim_prefix(dp->filename)))
-				continue;
-
-			/* match against the function */
-			if (query->function &&
-			    !match_wildcard(query->function, dp->function))
-				continue;
-
-			/* match against the format */
-			if (query->format) {
-				if (*query->format == '^') {
-					char *p;
-					/* anchored search. match must be at beginning */
-					p = strstr(dp->format, query->format+1);
-					if (p != dp->format)
-						continue;
-				} else if (!strstr(dp->format, query->format))
-					continue;
-			}
-
-			/* match against the line number range */
-			if (query->first_lineno &&
-			    dp->lineno < query->first_lineno)
-				continue;
-			if (query->last_lineno &&
-			    dp->lineno > query->last_lineno)
+			if (!ddebug_match_desc(query, dp, valid_class))
 				continue;
 
 			nfound++;

-- 
2.54.0

Claude review: dyndbg: factor ddebug_match_desc out from ddebug_change

[Claude Code Review Bot]

Patch Review

Clean refactoring extracting the per-descriptor filter block into a boolean function. Makes the code much more readable. Reviewed-by from Louis Chauvet. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 09/24] dyndbg: add stub macro for DECLARE_DYNDBG_CLASSMAP

[Jim Cromie]

Add the stub macro for !DYNAMIC_DEBUG builds, after moving the
original macro-defn down under the big ifdef.  Do it now so future
changes have a cleaner starting point.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h | 43 ++++++++++++++++++++++---------------------
 1 file changed, 22 insertions(+), 21 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 05743900a116..a10adac8e8f0 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -93,27 +93,6 @@ struct ddebug_class_map {
 	enum class_map_type map_type;
 };
 
-/**
- * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
- * @_var:   a struct ddebug_class_map, passed to module_param_cb
- * @_type:  enum class_map_type, chooses bits/verbose, numeric/symbolic
- * @_base:  offset of 1st class-name. splits .class_id space
- * @classes: class-names used to control class'd prdbgs
- */
-#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...)		\
-	static const char *_var##_classnames[] = { __VA_ARGS__ };	\
-	static struct ddebug_class_map __aligned(8) __used		\
-		__section("__dyndbg_classes") _var = {			\
-		.mod = THIS_MODULE,					\
-		.mod_name = KBUILD_MODNAME,				\
-		.base = _base,						\
-		.map_type = _maptype,					\
-		.length = NUM_TYPE_ARGS(char*, __VA_ARGS__),		\
-		.class_names = _var##_classnames,			\
-	}
-#define NUM_TYPE_ARGS(eltype, ...)				\
-        (sizeof((eltype[]){__VA_ARGS__}) / sizeof(eltype))
-
 /* encapsulate linker provided built-in (or module) dyndbg data */
 struct _ddebug_info {
 	struct _ddebug *descs;
@@ -138,6 +117,27 @@ struct ddebug_class_param {
 #if defined(CONFIG_DYNAMIC_DEBUG) || \
 	(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
 
+/**
+ * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
+ * @_var:   a struct ddebug_class_map, passed to module_param_cb
+ * @_type:  enum class_map_type, chooses bits/verbose, numeric/symbolic
+ * @_base:  offset of 1st class-name. splits .class_id space
+ * @classes: class-names used to control class'd prdbgs
+ */
+#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...)		\
+	static const char *_var##_classnames[] = { __VA_ARGS__ };	\
+	static struct ddebug_class_map __aligned(8) __used		\
+		__section("__dyndbg_classes") _var = {			\
+		.mod = THIS_MODULE,					\
+		.mod_name = KBUILD_MODNAME,				\
+		.base = _base,						\
+		.map_type = _maptype,					\
+		.length = NUM_TYPE_ARGS(char*, __VA_ARGS__),		\
+		.class_names = _var##_classnames,			\
+	}
+#define NUM_TYPE_ARGS(eltype, ...)				\
+	(sizeof((eltype[]) {__VA_ARGS__}) / sizeof(eltype))
+
 extern __printf(2, 3)
 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
 
@@ -314,6 +314,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
 
 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)
 #define DYNAMIC_DEBUG_BRANCH(descriptor) false
+#define DECLARE_DYNDBG_CLASSMAP(...)
 
 #define dynamic_pr_debug(fmt, ...)					\
 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)

-- 
2.54.0

Claude review: dyndbg: add stub macro for DECLARE_DYNDBG_CLASSMAP

[Claude Code Review Bot]

Patch Review

Adds the missing `!DYNAMIC_DEBUG` stub. The move of the macro definition under the ifdef is correct. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 10/24] dyndbg: reword "class unknown," to "class:_UNKNOWN_"

[Jim Cromie]

When a dyndbg classname is unknown to a kernel module, the callsite is
un-addressable via >control queries.

The control-file displays this condition as "class unknown,"
currently.  That spelling is sub-optimal/too-generic, so change it to
"class:_UNKNOWN_" to loudly announce the erroneous situation, and to
make it uniquely greppable.

NB: while this might be seen as a user-visible change, this shouldn't
disqualify the change:

a- it reports classmap coding error condition, which should be
   detected before review.
b- SHOUTING the error makes it uniquely greppable.
c- the classmap feature is marked BROKEN for its only current user.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 lib/dynamic_debug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 6b1e983cfedc..a9caf84ddb22 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -1166,7 +1166,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
 		if (class)
 			seq_printf(m, " class:%s", class);
 		else
-			seq_printf(m, " class unknown, _id:%d", dp->class_id);
+			seq_printf(m, " class:_UNKNOWN_ _id:%d", dp->class_id);
 	}
 	seq_putc(m, '\n');
 

-- 
2.54.0

Claude review: dyndbg: reword "class unknown," to "class:_UNKNOWN_"

[Claude Code Review Bot]

Patch Review

Minor user-visible output change for a coding error condition. The reasoning (grep-ability, BROKEN status of feature) is sound. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 11/24] dyndbg-API: remove DD_CLASS_TYPE_(DISJOINT|LEVEL)_NAMES and code

[Jim Cromie]

Remove the DD_CLASS_TYPE_*_NAMES classmap types and code.

These 2 classmap types accept class names at the PARAM interface, for
example:

  echo +DRM_UT_CORE,-DRM_UT_KMS > /sys/module/drm/parameters/debug_names

The code works, but its only used by test-dynamic-debug, and wasn't
asked for by anyone else, so reduce LOC & test-surface; simplify things.

Also rename enum class_map_type to enum ddebug_class_map_type.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v3:

fix name of enum in kdoc
also change name of struct (to future name)

v2:

move RvB after SoB

respect const instr in param_set_dyndbg_module_classes, return -EINVAL on classtype err.
---
 include/linux/dynamic_debug.h | 27 ++++--------
 lib/dynamic_debug.c           | 99 +++----------------------------------------
 lib/test_dynamic_debug.c      | 26 ------------
 3 files changed, 14 insertions(+), 138 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index a10adac8e8f0..78c22c6d2312 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -59,27 +59,16 @@ struct _ddebug {
 #endif
 } __attribute__((aligned(8)));
 
-enum class_map_type {
+enum ddebug_class_map_type {
 	DD_CLASS_TYPE_DISJOINT_BITS,
 	/**
-	 * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, one per bit.
-	 * expecting hex input. Built for drm.debug, basis for other types.
+	 * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, mapped to bits[0..N].
+	 * Expects hex input. Built for drm.debug, basis for other types.
 	 */
 	DD_CLASS_TYPE_LEVEL_NUM,
 	/**
-	 * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0-N.
-	 * N turns on just bits N-1 .. 0, so N=0 turns all bits off.
-	 */
-	DD_CLASS_TYPE_DISJOINT_NAMES,
-	/**
-	 * DD_CLASS_TYPE_DISJOINT_NAMES: input is a CSV of [+-]CLASS_NAMES,
-	 * classes are independent, like _DISJOINT_BITS.
-	 */
-	DD_CLASS_TYPE_LEVEL_NAMES,
-	/**
-	 * DD_CLASS_TYPE_LEVEL_NAMES: input is a CSV of [+-]CLASS_NAMES,
-	 * intended for names like: INFO,DEBUG,TRACE, with a module prefix
-	 * avoid EMERG,ALERT,CRIT,ERR,WARNING: they're not debug
+	 * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0..N.
+	 * Input N turns on bits 0..N-1
 	 */
 };
 
@@ -90,7 +79,7 @@ struct ddebug_class_map {
 	const char **class_names;
 	const int length;
 	const int base;		/* index of 1st .class_id, allows split/shared space */
-	enum class_map_type map_type;
+	enum ddebug_class_map_type map_type;
 };
 
 /* encapsulate linker provided built-in (or module) dyndbg data */
@@ -119,8 +108,8 @@ struct ddebug_class_param {
 
 /**
  * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
- * @_var:   a struct ddebug_class_map, passed to module_param_cb
- * @_type:  enum class_map_type, chooses bits/verbose, numeric/symbolic
+ * @_var:   a struct _ddebug_class_map, passed to module_param_cb
+ * @_maptype: enum ddebug_class_map_type, chooses bits/verbose
  * @_base:  offset of 1st class-name. splits .class_id space
  * @classes: class-names used to control class'd prdbgs
  */
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index a9caf84ddb22..0377d9f8dcd1 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -646,76 +646,6 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 
 #define CLASSMAP_BITMASK(width) ((1UL << (width)) - 1)
 
-/* accept comma-separated-list of [+-] classnames */
-static int param_set_dyndbg_classnames(const char *instr, const struct kernel_param *kp)
-{
-	const struct ddebug_class_param *dcp = kp->arg;
-	const struct ddebug_class_map *map = dcp->map;
-	unsigned long curr_bits, old_bits;
-	char *cl_str, *p, *tmp;
-	int cls_id, totct = 0;
-	bool wanted;
-
-	cl_str = tmp = kstrdup_and_replace(instr, '\n', '\0', GFP_KERNEL);
-	if (!tmp)
-		return -ENOMEM;
-
-	/* start with previously set state-bits, then modify */
-	curr_bits = old_bits = *dcp->bits;
-	vpr_info("\"%s\" > %s:0x%lx\n", cl_str, KP_NAME(kp), curr_bits);
-
-	for (; cl_str; cl_str = p) {
-		p = strchr(cl_str, ',');
-		if (p)
-			*p++ = '\0';
-
-		if (*cl_str == '-') {
-			wanted = false;
-			cl_str++;
-		} else {
-			wanted = true;
-			if (*cl_str == '+')
-				cl_str++;
-		}
-		cls_id = match_string(map->class_names, map->length, cl_str);
-		if (cls_id < 0) {
-			pr_err("%s unknown to %s\n", cl_str, KP_NAME(kp));
-			continue;
-		}
-
-		/* have one or more valid class_ids of one *_NAMES type */
-		switch (map->map_type) {
-		case DD_CLASS_TYPE_DISJOINT_NAMES:
-			/* the +/- pertains to a single bit */
-			if (test_bit(cls_id, &curr_bits) == wanted) {
-				v3pr_info("no change on %s\n", cl_str);
-				continue;
-			}
-			curr_bits ^= BIT(cls_id);
-			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits);
-			*dcp->bits = curr_bits;
-			v2pr_info("%s: changed bit %d:%s\n", KP_NAME(kp), cls_id,
-				  map->class_names[cls_id]);
-			break;
-		case DD_CLASS_TYPE_LEVEL_NAMES:
-			/* cls_id = N in 0..max. wanted +/- determines N or N-1 */
-			old_bits = CLASSMAP_BITMASK(*dcp->lvl);
-			curr_bits = CLASSMAP_BITMASK(cls_id + (wanted ? 1 : 0 ));
-
-			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits);
-			*dcp->lvl = (cls_id + (wanted ? 1 : 0));
-			v2pr_info("%s: changed bit-%d: \"%s\" %lx->%lx\n", KP_NAME(kp), cls_id,
-				  map->class_names[cls_id], old_bits, curr_bits);
-			break;
-		default:
-			pr_err("illegal map-type value %d\n", map->map_type);
-		}
-	}
-	kfree(tmp);
-	vpr_info("total matches: %d\n", totct);
-	return 0;
-}
-
 /**
  * param_set_dyndbg_classes - class FOO >control
  * @instr: string echo>d to sysfs, input depends on map_type
@@ -734,28 +664,14 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
 	unsigned long inrep, new_bits, old_bits;
 	int rc, totct = 0;
 
-	switch (map->map_type) {
-
-	case DD_CLASS_TYPE_DISJOINT_NAMES:
-	case DD_CLASS_TYPE_LEVEL_NAMES:
-		/* handle [+-]classnames list separately, we are done here */
-		return param_set_dyndbg_classnames(instr, kp);
-
-	case DD_CLASS_TYPE_DISJOINT_BITS:
-	case DD_CLASS_TYPE_LEVEL_NUM:
-		/* numeric input, accept and fall-thru */
-		rc = kstrtoul(instr, 0, &inrep);
-		if (rc) {
-			pr_err("expecting numeric input: %s > %s\n", instr, KP_NAME(kp));
-			return -EINVAL;
-		}
-		break;
-	default:
-		pr_err("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
+	rc = kstrtoul(instr, 0, &inrep);
+	if (rc) {
+		int len = strcspn(instr, "\n");
+		pr_err("expecting numeric input, not: %.*s > %s\n",
+		       len, instr, KP_NAME(kp));
 		return -EINVAL;
 	}
 
-	/* only _BITS,_NUM (numeric) map-types get here */
 	switch (map->map_type) {
 	case DD_CLASS_TYPE_DISJOINT_BITS:
 		/* expect bits. mask and warn if too many */
@@ -783,6 +699,7 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
 		break;
 	default:
 		pr_warn("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
+		return -EINVAL;
 	}
 	vpr_info("%s: total matches: %d\n", KP_NAME(kp), totct);
 	return 0;
@@ -804,12 +721,8 @@ int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
 	const struct ddebug_class_map *map = dcp->map;
 
 	switch (map->map_type) {
-
-	case DD_CLASS_TYPE_DISJOINT_NAMES:
 	case DD_CLASS_TYPE_DISJOINT_BITS:
 		return scnprintf(buffer, PAGE_SIZE, "0x%lx\n", *dcp->bits);
-
-	case DD_CLASS_TYPE_LEVEL_NAMES:
 	case DD_CLASS_TYPE_LEVEL_NUM:
 		return scnprintf(buffer, PAGE_SIZE, "%d\n", *dcp->lvl);
 	default:
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 77c2a669b6af..74d183ebf3e0 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -74,13 +74,6 @@ DECLARE_DYNDBG_CLASSMAP(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS, 0,
 DD_SYS_WRAP(disjoint_bits, p);
 DD_SYS_WRAP(disjoint_bits, T);
 
-/* symbolic input, independent bits */
-enum cat_disjoint_names { LOW = 11, MID, HI };
-DECLARE_DYNDBG_CLASSMAP(map_disjoint_names, DD_CLASS_TYPE_DISJOINT_NAMES, 10,
-			"LOW", "MID", "HI");
-DD_SYS_WRAP(disjoint_names, p);
-DD_SYS_WRAP(disjoint_names, T);
-
 /* numeric verbosity, V2 > V1 related */
 enum cat_level_num { V0 = 14, V1, V2, V3, V4, V5, V6, V7 };
 DECLARE_DYNDBG_CLASSMAP(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, 14,
@@ -88,13 +81,6 @@ DECLARE_DYNDBG_CLASSMAP(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, 14,
 DD_SYS_WRAP(level_num, p);
 DD_SYS_WRAP(level_num, T);
 
-/* symbolic verbosity */
-enum cat_level_names { L0 = 22, L1, L2, L3, L4, L5, L6, L7 };
-DECLARE_DYNDBG_CLASSMAP(map_level_names, DD_CLASS_TYPE_LEVEL_NAMES, 22,
-			"L0", "L1", "L2", "L3", "L4", "L5", "L6", "L7");
-DD_SYS_WRAP(level_names, p);
-DD_SYS_WRAP(level_names, T);
-
 /* stand-in for all pr_debug etc */
 #define prdbg(SYM) __pr_debug_cls(SYM, #SYM " msg\n")
 
@@ -102,10 +88,6 @@ static void do_cats(void)
 {
 	pr_debug("doing categories\n");
 
-	prdbg(LOW);
-	prdbg(MID);
-	prdbg(HI);
-
 	prdbg(D2_CORE);
 	prdbg(D2_DRIVER);
 	prdbg(D2_KMS);
@@ -129,14 +111,6 @@ static void do_levels(void)
 	prdbg(V5);
 	prdbg(V6);
 	prdbg(V7);
-
-	prdbg(L1);
-	prdbg(L2);
-	prdbg(L3);
-	prdbg(L4);
-	prdbg(L5);
-	prdbg(L6);
-	prdbg(L7);
 }
 
 static void do_prints(void)

-- 
2.54.0

Claude review: dyndbg-API: remove DD_CLASS_TYPE_(DISJOINT|LEVEL)_NAMES and code

[Claude Code Review Bot]

Patch Review

Significant API simplification removing unused symbolic-name classmap types. The `default:` case now properly returns `-EINVAL`, which is a correctness improvement. Reviewed-by from Louis Chauvet. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 12/24] dyndbg: drop NUM_TYPE_ARGS

[Jim Cromie]

ARRAY_SIZE works here, since array decl is complete.

no functional change

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2: include linux/array_size.h, correct commit subject
    review after sob
---
 include/linux/dynamic_debug.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 78c22c6d2312..867e3978675f 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -121,11 +121,9 @@ struct ddebug_class_param {
 		.mod_name = KBUILD_MODNAME,				\
 		.base = _base,						\
 		.map_type = _maptype,					\
-		.length = NUM_TYPE_ARGS(char*, __VA_ARGS__),		\
+		.length = ARRAY_SIZE(_var##_classnames),		\
 		.class_names = _var##_classnames,			\
 	}
-#define NUM_TYPE_ARGS(eltype, ...)				\
-	(sizeof((eltype[]) {__VA_ARGS__}) / sizeof(eltype))
 
 extern __printf(2, 3)
 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);

-- 
2.54.0

Claude review: dyndbg: drop NUM_TYPE_ARGS

[Claude Code Review Bot]

Patch Review

Simple cleanup replacing custom macro with `ARRAY_SIZE`. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 13/24] dyndbg: reduce verbose/debug clutter

[Jim Cromie]

currently, for verbose=3, these are logged (blank lines for clarity):

 dyndbg: query 0: "class DRM_UT_CORE +p" mod:*
 dyndbg: split into words: "class" "DRM_UT_CORE" "+p"

 dyndbg: op='+'
 dyndbg: flags=0x1
 dyndbg: *flagsp=0x1 *maskp=0xffffffff

 dyndbg: parsed: func="" file="" module="" format="" lineno=0-0 class=...
 dyndbg: no matches for query
 dyndbg: no-match: func="" file="" module="" format="" lineno=0-0 class=...
 dyndbg: processed 1 queries, with 0 matches, 0 errs

That is excessive, so this patch:
 - shrinks 3 lines of 2nd stanza to single line
 - drops 1st 2 lines of 3rd stanza
   3rd line is like 1st, with result, not procedure.
   2nd line is just status, retold in 4th, with more info.

New output:

 dyndbg: query 0: "class DRM_UT_CORE +p"
 dyndbg: split into words: "class" "DRM_UT_CORE" "+p"
 dyndbg: op='+' flags=0x1 maskp=0xffffffff
 dyndbg: processed 1 queries, with 0 matches, 0 errs

Also drop several verbose=3 messages in ddebug_add_module

When modprobing a module, dyndbg currently logs/says "add-module", and
then "skipping" if the module has no prdbgs.  Instead just check 1st
and return quietly.

no functional change

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2:

RvB after SoB

trivial change to verbose-debug output line to output the actual
"module" keyword rather than "mod:", and do so only when the module is
constrained by the callchain (ie as part of a modprobe).

 was:   query X: "(keyword value)* [+-=]flags" mod:*
 now:   query X: "(keyword value)* [+-=]flags"
   or   query X: module FOO "keyword value)* [+-=]flags"

IOW, adjust output to reflect the input grammar more closely.

drop-info-parsed

vinfo-applied-nomatch
---
 lib/dynamic_debug.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 0377d9f8dcd1..bacb55f960fa 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -276,9 +276,6 @@ static int ddebug_change(const struct ddebug_query *query,
 	}
 	mutex_unlock(&ddebug_lock);
 
-	if (!nfound && verbose)
-		pr_info("no matches for query\n");
-
 	return nfound;
 }
 
@@ -487,7 +484,6 @@ static int ddebug_parse_query(char *words[], int nwords,
 		 */
 		query->module = modname;
 
-	vpr_info_dq(query, "parsed");
 	return 0;
 }
 
@@ -511,7 +507,6 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
 		pr_err("bad flag-op %c, at start of %s\n", *str, str);
 		return -EINVAL;
 	}
-	v3pr_info("op='%c'\n", op);
 
 	for (; *str ; ++str) {
 		for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
@@ -525,7 +520,6 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
 			return -EINVAL;
 		}
 	}
-	v3pr_info("flags=0x%x\n", modifiers->flags);
 
 	/* calculate final flags, mask based upon op */
 	switch (op) {
@@ -541,7 +535,7 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
 		modifiers->flags = 0;
 		break;
 	}
-	v3pr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);
+	v3pr_info("op='%c' flags=0x%x maskp=0x%x\n", op, modifiers->flags, modifiers->mask);
 
 	return 0;
 }
@@ -593,7 +587,8 @@ static int ddebug_exec_queries(char *query, const char *modname)
 		if (!query || !*query || *query == '#')
 			continue;
 
-		vpr_info("query %d: \"%s\" mod:%s\n", i, query, modname ?: "*");
+		vpr_info("query %d: %s%s \"%s\"\n", i,
+			 modname ? "module " : "", modname ?: "", query);
 
 		rc = ddebug_exec_query(query, modname);
 		if (rc < 0) {
@@ -1159,11 +1154,10 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 {
 	struct ddebug_table *dt;
 
-	v3pr_info("add-module: %s.%d sites\n", modname, di->num_descs);
-	if (!di->num_descs) {
-		v3pr_info(" skip %s\n", modname);
+	if (!di->num_descs)
 		return 0;
-	}
+
+	v3pr_info("add-module: %s %d sites\n", modname, di->num_descs);
 
 	dt = kzalloc_obj(*dt);
 	if (dt == NULL) {

-- 
2.54.0

Claude review: dyndbg: reduce verbose/debug clutter

[Claude Code Review Bot]

Patch Review

Good cleanup of verbose logging. The consolidation of three separate v3pr_info calls into one is cleaner. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 14/24] dyndbg: refactor param_set_dyndbg_classes and below

[Jim Cromie]

Refactor callchain below param_set_dyndbg_classes(1) to allow mod-name
specific settings.  Split (1) into upper/lower fns, adding modname
param to lower, and passing NULL in from upper.  Below that, add the
same param to ddebug_apply_class_bitmap(), and pass it thru to
_ddebug_queries(), replacing NULL with the param.

This allows the callchain to update the classmap in just one module,
vs just all as currently done.  While the sysfs param is unlikely to
ever update just one module, the callchain will be used for modprobe
handling, which should update only that just-probed module.

In ddebug_apply_class_bitmap(), also check for actual changes to the
bits before announcing them, to declutter logs.

No functional change.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2: move RvB after SoB
---
 lib/dynamic_debug.c | 51 +++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 39 insertions(+), 12 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index bacb55f960fa..182b84b6f6c5 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -608,9 +608,10 @@ static int ddebug_exec_queries(char *query, const char *modname)
 	return nfound;
 }
 
-/* apply a new bitmap to the sys-knob's current bit-state */
+/* apply a new class-param setting */
 static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
-				     unsigned long *new_bits, unsigned long *old_bits)
+				     unsigned long *new_bits, unsigned long *old_bits,
+				     const char *query_modname)
 {
 #define QUERY_SIZE 128
 	char query[QUERY_SIZE];
@@ -618,7 +619,9 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 	int matches = 0;
 	int bi, ct;
 
-	v2pr_info("apply: 0x%lx to: 0x%lx\n", *new_bits, *old_bits);
+	if (*new_bits != *old_bits)
+		v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
+			  *old_bits, query_modname ?: "'*'");
 
 	for (bi = 0; bi < map->length; bi++) {
 		if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
@@ -627,12 +630,16 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 		snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
 			 test_bit(bi, new_bits) ? '+' : '-', dcp->flags);
 
-		ct = ddebug_exec_queries(query, NULL);
+		ct = ddebug_exec_queries(query, query_modname);
 		matches += ct;
 
 		v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
 			  ct, map->class_names[bi], *new_bits);
 	}
+	if (*new_bits != *old_bits)
+		v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
+			  *old_bits, query_modname ?: "'*'");
+
 	return matches;
 }
 
@@ -645,6 +652,7 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
  * param_set_dyndbg_classes - class FOO >control
  * @instr: string echo>d to sysfs, input depends on map_type
  * @kp:    kp->arg has state: bits/lvl, map, map_type
+ * @mod_name: module name or null for all modules with the classes
  *
  * Enable/disable prdbgs by their class, as given in the arguments to
  * DECLARE_DYNDBG_CLASSMAP.  For LEVEL map-types, enforce relative
@@ -652,7 +660,9 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
  *
  * Returns: 0 or <0 if error.
  */
-int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
+static int param_set_dyndbg_module_classes(const char *instr,
+					   const struct kernel_param *kp,
+					   const char *mod_name)
 {
 	const struct ddebug_class_param *dcp = kp->arg;
 	const struct ddebug_class_map *map = dcp->map;
@@ -675,8 +685,8 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
 				KP_NAME(kp), inrep, CLASSMAP_BITMASK(map->length));
 			inrep &= CLASSMAP_BITMASK(map->length);
 		}
-		v2pr_info("bits:%lx > %s\n", inrep, KP_NAME(kp));
-		totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits);
+		v2pr_info("bits:0x%lx > %s.%s\n", inrep, mod_name ?: "*", KP_NAME(kp));
+		totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits, mod_name);
 		*dcp->bits = inrep;
 		break;
 	case DD_CLASS_TYPE_LEVEL_NUM:
@@ -689,7 +699,7 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
 		old_bits = CLASSMAP_BITMASK(*dcp->lvl);
 		new_bits = CLASSMAP_BITMASK(inrep);
 		v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
-		totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits);
+		totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits, mod_name);
 		*dcp->lvl = inrep;
 		break;
 	default:
@@ -699,16 +709,33 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
 	vpr_info("%s: total matches: %d\n", KP_NAME(kp), totct);
 	return 0;
 }
+
+/**
+ * param_set_dyndbg_classes - classmap kparam setter
+ * @instr: string echo>d to sysfs, input depends on map_type
+ * @kp:    kp->arg has state: bits/lvl, map, map_type
+ *
+ * enable/disable all class'd pr_debugs in the classmap. For LEVEL
+ * map-types, enforce * relative levels by bitpos.
+ *
+ * Returns: 0 or <0 if error.
+ */
+int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
+{
+	return param_set_dyndbg_module_classes(instr, kp, NULL);
+}
 EXPORT_SYMBOL(param_set_dyndbg_classes);
 
 /**
- * param_get_dyndbg_classes - classes reader
+ * param_get_dyndbg_classes - classmap kparam getter
  * @buffer: string description of controlled bits -> classes
  * @kp:     kp->arg has state: bits, map
  *
- * Reads last written state, underlying prdbg state may have been
- * altered by direct >control.  Displays 0x for DISJOINT, 0-N for
- * LEVEL Returns: #chars written or <0 on error
+ * Reads last written state, underlying pr_debug states may have been
+ * altered by direct >control.  Displays 0x for DISJOINT classmap
+ * types, 0-N for LEVEL types.
+ *
+ * Returns: ct of chars written or <0 on error
  */
 int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
 {

-- 
2.54.0

Claude review: dyndbg: refactor param_set_dyndbg_classes and below

[Claude Code Review Bot]

Patch Review

Splits the function to add `mod_name` parameter to the lower function, preparing for per-module classmap application. The added change-detection in `ddebug_apply_class_bitmap` is useful. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 15/24] dyndbg: tighten fn-sig of ddebug_apply_class_bitmap

[Jim Cromie]

old_bits arg is currently a pointer to the input bits, but this could
allow inadvertent changes to the input by the fn.  Disallow this.
And constify new_bits while here.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2: move RvB after SoB
---
 lib/dynamic_debug.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 182b84b6f6c5..bb7e16d38f19 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -610,7 +610,8 @@ static int ddebug_exec_queries(char *query, const char *modname)
 
 /* apply a new class-param setting */
 static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
-				     unsigned long *new_bits, unsigned long *old_bits,
+				     const unsigned long *new_bits,
+				     const unsigned long old_bits,
 				     const char *query_modname)
 {
 #define QUERY_SIZE 128
@@ -619,12 +620,12 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 	int matches = 0;
 	int bi, ct;
 
-	if (*new_bits != *old_bits)
+	if (*new_bits != old_bits)
 		v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
-			  *old_bits, query_modname ?: "'*'");
+			  old_bits, query_modname ?: "'*'");
 
 	for (bi = 0; bi < map->length; bi++) {
-		if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
+		if (test_bit(bi, new_bits) == test_bit(bi, &old_bits))
 			continue;
 
 		snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
@@ -636,9 +637,9 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 		v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
 			  ct, map->class_names[bi], *new_bits);
 	}
-	if (*new_bits != *old_bits)
+	if (*new_bits != old_bits)
 		v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
-			  *old_bits, query_modname ?: "'*'");
+			  old_bits, query_modname ?: "'*'");
 
 	return matches;
 }
@@ -686,7 +687,7 @@ static int param_set_dyndbg_module_classes(const char *instr,
 			inrep &= CLASSMAP_BITMASK(map->length);
 		}
 		v2pr_info("bits:0x%lx > %s.%s\n", inrep, mod_name ?: "*", KP_NAME(kp));
-		totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits, mod_name);
+		totct += ddebug_apply_class_bitmap(dcp, &inrep, *dcp->bits, mod_name);
 		*dcp->bits = inrep;
 		break;
 	case DD_CLASS_TYPE_LEVEL_NUM:
@@ -699,7 +700,7 @@ static int param_set_dyndbg_module_classes(const char *instr,
 		old_bits = CLASSMAP_BITMASK(*dcp->lvl);
 		new_bits = CLASSMAP_BITMASK(inrep);
 		v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
-		totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits, mod_name);
+		totct += ddebug_apply_class_bitmap(dcp, &new_bits, old_bits, mod_name);
 		*dcp->lvl = inrep;
 		break;
 	default:

-- 
2.54.0

Claude review: dyndbg: tighten fn-sig of ddebug_apply_class_bitmap

[Claude Code Review Bot]

Patch Review

Changes `old_bits` from pointer to value parameter, preventing inadvertent modification. Good defensive coding. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 16/24] dyndbg: replace classmap list with an array-slice

[Jim Cromie]

Classmaps are stored in an elf section/array, but currently are
individually list-linked onto dyndbg's per-module ddebug_table for
operation. This is unnecessary.

Just like dyndbg's descriptors, classes are packed in compile order;
so even with many builtin modules employing multiple classmaps, each
modules' maps are packed contiguously, and can be treated as a
array-start-address & array-length.

So this drops the whole list building operation done in
ddebug_attach_module_classes(), and removes the list-head members of
the classmap structs.  The "select-by-modname" condition is reused to
find the start,end of the subrange of classmaps belonging to the module.

NOTES:

There are multiple modules named "main" but thats an artifact of how
KBUILD_MODNAME gets its value, and none of those repeats are
contiguous.  The legacy code segmenting the builtin descriptors
depends upon this, we are "reusing" that dependency.

The "filter-by-modname" on classmaps should really be done in
ddebug_add_module(1); ie closer to dynamic_debug_init(2), which
already splits up pr-debug descriptors into subranges by modname, then
calls (1) on each.  (2) knows nothing of classmaps currently, and
doesn't need to.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2: RvB after SoB
---
 include/linux/dynamic_debug.h |  1 -
 lib/dynamic_debug.c           | 65 +++++++++++++++++++++++--------------------
 2 files changed, 35 insertions(+), 31 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 867e3978675f..0443781ed95b 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -73,7 +73,6 @@ enum ddebug_class_map_type {
 };
 
 struct ddebug_class_map {
-	struct list_head link;
 	struct module *mod;
 	const char *mod_name;	/* needed for builtins */
 	const char **class_names;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index bb7e16d38f19..34d002e0a08c 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -45,10 +45,11 @@ extern struct ddebug_class_map __start___dyndbg_classes[];
 extern struct ddebug_class_map __stop___dyndbg_classes[];
 
 struct ddebug_table {
-	struct list_head link, maps;
+	struct list_head link;
 	const char *mod_name;
-	unsigned int num_ddebugs;
 	struct _ddebug *ddebugs;
+	struct ddebug_class_map *classes;
+	unsigned int num_ddebugs, num_classes;
 };
 
 struct ddebug_query {
@@ -149,12 +150,13 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
 }
 
 static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
-							  const char *class_string, int *class_id)
+							const char *class_string,
+							int *class_id)
 {
 	struct ddebug_class_map *map;
-	int idx;
+	int i, idx;
 
-	list_for_each_entry(map, &dt->maps, link) {
+	for (map = dt->classes, i = 0; i < dt->num_classes; i++, map++) {
 		idx = match_string(map->class_names, map->length, class_string);
 		if (idx >= 0) {
 			*class_id = idx + map->base;
@@ -165,7 +167,6 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons
 	return NULL;
 }
 
-#define __outvar /* filled by callee */
 /*
  * Search the tables for _ddebug's which match the given `query' and
  * apply the `flags' and `mask' to them.  Returns number of matching
@@ -227,7 +228,7 @@ static int ddebug_change(const struct ddebug_query *query,
 	unsigned int nfound = 0;
 	struct flagsbuf fbuf, nbuf;
 	struct ddebug_class_map *map = NULL;
-	int __outvar valid_class;
+	int valid_class;
 
 	/* search for matching ddebugs */
 	mutex_lock(&ddebug_lock);
@@ -1062,9 +1063,10 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
 
 static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp)
 {
-	struct ddebug_class_map *map;
+	struct ddebug_class_map *map = iter->table->classes;
+	int i, nc = iter->table->num_classes;
 
-	list_for_each_entry(map, &iter->table->maps, link)
+	for (i = 0; i < nc; i++, map++)
 		if (class_in_range(dp->class_id, map))
 			return map->class_names[dp->class_id - map->base];
 
@@ -1148,30 +1150,34 @@ static const struct proc_ops proc_fops = {
 	.proc_write = ddebug_proc_write
 };
 
-static void ddebug_attach_module_classes(struct ddebug_table *dt,
-					 struct ddebug_class_map *classes,
-					 int num_classes)
+static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug_info *di)
 {
 	struct ddebug_class_map *cm;
-	int i, j, ct = 0;
+	int i, nc = 0;
 
-	for (cm = classes, i = 0; i < num_classes; i++, cm++) {
+	/*
+	 * Find this module's classmaps in a subrange/wholerange of
+	 * the builtin/modular classmap vector/section.  Save the start
+	 * and length of the subrange at its edges.
+	 */
+	for (cm = di->classes, i = 0; i < di->num_classes; i++, cm++) {
 
 		if (!strcmp(cm->mod_name, dt->mod_name)) {
-
-			v2pr_info("class[%d]: module:%s base:%d len:%d ty:%d\n", i,
-				  cm->mod_name, cm->base, cm->length, cm->map_type);
-
-			for (j = 0; j < cm->length; j++)
-				v3pr_info(" %d: %d %s\n", j + cm->base, j,
-					  cm->class_names[j]);
-
-			list_add(&cm->link, &dt->maps);
-			ct++;
+			if (!nc) {
+				v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
+					  i, cm->mod_name, cm->base, cm->length, cm->map_type);
+				dt->classes = cm;
+			}
+			nc++;
+		} else if (nc) {
+			/* end of matching classmaps */
+			break;
 		}
 	}
-	if (ct)
-		vpr_info("module:%s attached %d classes\n", dt->mod_name, ct);
+	if (nc) {
+		dt->num_classes = nc;
+		vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
+	}
 }
 
 /*
@@ -1203,10 +1209,9 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 	dt->num_ddebugs = di->num_descs;
 
 	INIT_LIST_HEAD(&dt->link);
-	INIT_LIST_HEAD(&dt->maps);
 
 	if (di->classes && di->num_classes)
-		ddebug_attach_module_classes(dt, di->classes, di->num_classes);
+		ddebug_attach_module_classes(dt, di);
 
 	mutex_lock(&ddebug_lock);
 	list_add_tail(&dt->link, &ddebug_tables);
@@ -1319,8 +1324,8 @@ static void ddebug_remove_all_tables(void)
 	mutex_lock(&ddebug_lock);
 	while (!list_empty(&ddebug_tables)) {
 		struct ddebug_table *dt = list_entry(ddebug_tables.next,
-						      struct ddebug_table,
-						      link);
+						     struct ddebug_table,
+						     link);
 		ddebug_table_free(dt);
 	}
 	mutex_unlock(&ddebug_lock);

-- 
2.54.0

Claude review: dyndbg: replace classmap list with an array-slice

[Claude Code Review Bot]

Patch Review

Removes list_head from classmap structs and uses array-slice (pointer + count) instead. This is a significant simplification. The reliance on contiguous module ordering is inherited from the existing descriptor segmentation in `dynamic_debug_init()`. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 17/24] dyndbg: macrofy a 2-index for-loop pattern

[Jim Cromie]

dynamic-debug currently has 2 __sections (__dyndbg, __dyndb_classes),
struct _ddebug_info keeps track of them both, with 2 members each:
_vec and _vec#_len.

We need to loop over these sections, with index and record pointer,
making ref to both _vec and _vec_len.  This is already fiddly and
error-prone, and will get worse as we add a 3rd section.

Lets instead embed/abstract the fiddly-ness in the `for_subvec()`
macro, and avoid repeating it going forward.

This is a for-loop macro expander, so it syntactically expects to
precede either a single statement or a { block } of them, and the
usual typeof or do-while-0 tricks are unavailable to fix the
multiple-expansion warning.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2: move RvB after SoB
---
 lib/dynamic_debug.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 34d002e0a08c..41bbb72ef730 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -129,6 +129,20 @@ do {								\
 #define v3pr_info(fmt, ...)	vnpr_info(3, fmt, ##__VA_ARGS__)
 #define v4pr_info(fmt, ...)	vnpr_info(4, fmt, ##__VA_ARGS__)
 
+/*
+ * simplify a repeated for-loop pattern walking N steps in a T _vec
+ * member inside a struct _box.  It expects int i and T *_sp to be
+ * declared in the caller.
+ * @_i:  caller provided counter.
+ * @_sp: cursor into _vec, to examine each item.
+ * @_box: ptr to a struct containing @_vec member
+ * @_vec: name of a member in @_box
+ */
+#define for_subvec(_i, _sp, _box, _vec)			\
+	for ((_i) = 0, (_sp) = (_box)->_vec;		\
+	     (_i) < (_box)->num_##_vec;			\
+	     (_i)++, (_sp)++)		/* { block } */
+
 static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
 {
 	/* trim any trailing newlines */
@@ -156,7 +170,7 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons
 	struct ddebug_class_map *map;
 	int i, idx;
 
-	for (map = dt->classes, i = 0; i < dt->num_classes; i++, map++) {
+	for_subvec(i, map, dt, classes) {
 		idx = match_string(map->class_names, map->length, class_string);
 		if (idx >= 0) {
 			*class_id = idx + map->base;
@@ -1160,8 +1174,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
 	 * the builtin/modular classmap vector/section.  Save the start
 	 * and length of the subrange at its edges.
 	 */
-	for (cm = di->classes, i = 0; i < di->num_classes; i++, cm++) {
-
+	for_subvec(i, cm, di, classes) {
 		if (!strcmp(cm->mod_name, dt->mod_name)) {
 			if (!nc) {
 				v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",

-- 
2.54.0

Claude review: dyndbg: macrofy a 2-index for-loop pattern

[Claude Code Review Bot]

Patch Review

The `for_subvec` macro is somewhat unusual -- it expects caller-declared variables `i` and a pointer, and uses token pasting for `num_##_vec`. The naming convention dependency makes it fragile if struct members are renamed. This is partially addressed in patch 19 which changes the paste to `.len`. The comment `/* { block } */` is a nice reminder of usage. No major issues, though the macro could be considered over-engineering for just 2 use sites.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 18/24] dyndbg: Upgrade class param storage to u64 for 64-bit classmaps

[Jim Cromie]

Currently, `struct ddebug_class_param` uses `unsigned long` pointers
to store the state of `bits` and `lvl`. On 32-bit architectures, this
limits the bit-vector to 32 bits, which truncates 64-bit classmaps
(such as the one needed by `__drm_debug`).

To guarantee support for 64-bit debug categories across all
architectures, upgrade the internal storage types in `struct
_ddebug_class_param` to `u64`. This inherently makes both union
members the same size while safely avoiding truncation.

This includes:
- Changing union members `bits` and `lvl` to `u64 *`.
- Using `kstrtou64()` for sysfs input parsing.
- Replacing array-based `test_bit()` operations with safe `u64` scalar
  bitwise logic (`!!(val & (1ULL << bi))`).
- adjusting lib/test_dynamic_debug.c too

- Updating `drm_print`'s `__drm_debug` refs to `u64`
  further changes to drm later, when BROKEN is fixed.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
v3:

fix undefd behavior when classmaps is all 64 bits.
change struct ddebug_class_param to _ddebug_class_param
change module_param_named( type-arg from ulong to ullong)

in drivers/gpu/drm/drm_print.{c,h}
api change later

v2:

patch was "make bits & lvl same size"
but that size was unsigned long, only 32 bits on i386 etc
use u64 for all bits, and %llu %llx

u64-fix

u64-drm-dbg

_ddebug-cl-parm-drm
---
 drivers/gpu/drm/drm_print.c   |  6 +++---
 include/drm/drm_print.h       |  2 +-
 include/linux/dynamic_debug.h |  4 ++--
 lib/dynamic_debug.c           | 34 ++++++++++++++++++----------------
 lib/test_dynamic_debug.c      |  2 +-
 5 files changed, 25 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
index ded9461df5f2..9b4d8e3baacc 100644
--- a/drivers/gpu/drm/drm_print.c
+++ b/drivers/gpu/drm/drm_print.c
@@ -40,7 +40,7 @@
  * __drm_debug: Enable debug output.
  * Bitmask of DRM_UT_x. See include/drm/drm_print.h for details.
  */
-unsigned long __drm_debug;
+u64 __drm_debug;
 EXPORT_SYMBOL(__drm_debug);
 
 MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug category.\n"
@@ -54,7 +54,7 @@ MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug cat
 "\t\tBit 8 (0x100) will enable DP messages (displayport code)");
 
 #if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
-module_param_named(debug, __drm_debug, ulong, 0600);
+module_param_named(debug, __drm_debug, ullong, 0600);
 #else
 /* classnames must match vals of enum drm_debug_category */
 DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
@@ -69,7 +69,7 @@ DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
 			"DRM_UT_DP",
 			"DRM_UT_DRMRES");
 
-static struct ddebug_class_param drm_debug_bitmap = {
+static struct _ddebug_class_param drm_debug_bitmap = {
 	.bits = &__drm_debug,
 	.flags = "p",
 	.map = &drm_debug_classes,
diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index ab017b05e175..21a0ced0b2f2 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -39,7 +39,7 @@ struct drm_device;
 struct seq_file;
 
 /* Do *not* use outside of drm_print.[ch]! */
-extern unsigned long __drm_debug;
+extern u64 __drm_debug;
 
 /**
  * DOC: print
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 0443781ed95b..91546a99014b 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -91,8 +91,8 @@ struct _ddebug_info {
 
 struct ddebug_class_param {
 	union {
-		unsigned long *bits;
-		unsigned int *lvl;
+		u64 *bits;
+		u64 *lvl;
 	};
 	char flags[8];
 	const struct ddebug_class_map *map;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 41bbb72ef730..7298520a89dc 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -625,8 +625,7 @@ static int ddebug_exec_queries(char *query, const char *modname)
 
 /* apply a new class-param setting */
 static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
-				     const unsigned long *new_bits,
-				     const unsigned long old_bits,
+				     const u64 *new_bits, const u64 old_bits,
 				     const char *query_modname)
 {
 #define QUERY_SIZE 128
@@ -636,24 +635,27 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 	int bi, ct;
 
 	if (*new_bits != old_bits)
-		v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
+		v2pr_info("apply bitmap: 0x%llx to: 0x%llx for %s\n", *new_bits,
 			  old_bits, query_modname ?: "'*'");
 
 	for (bi = 0; bi < map->length; bi++) {
-		if (test_bit(bi, new_bits) == test_bit(bi, &old_bits))
+		bool new_b = !!(*new_bits & (1ULL << bi));
+		bool old_b = !!(old_bits & (1ULL << bi));
+
+		if (new_b == old_b)
 			continue;
 
 		snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
-			 test_bit(bi, new_bits) ? '+' : '-', dcp->flags);
+			 new_b ? '+' : '-', dcp->flags);
 
 		ct = ddebug_exec_queries(query, query_modname);
 		matches += ct;
 
-		v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
+		v2pr_info("bit_%d: %d matches on class: %s -> 0x%llx\n", bi,
 			  ct, map->class_names[bi], *new_bits);
 	}
 	if (*new_bits != old_bits)
-		v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
+		v2pr_info("applied bitmap: 0x%llx to: 0x%llx for %s\n", *new_bits,
 			  old_bits, query_modname ?: "'*'");
 
 	return matches;
@@ -662,7 +664,7 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 /* stub to later conditionally add "$module." prefix where not already done */
 #define KP_NAME(kp)	kp->name
 
-#define CLASSMAP_BITMASK(width) ((1UL << (width)) - 1)
+#define CLASSMAP_BITMASK(width) ((width) == 64 ? ~0ULL : (1ULL << (width)) - 1)
 
 /**
  * param_set_dyndbg_classes - class FOO >control
@@ -682,10 +684,10 @@ static int param_set_dyndbg_module_classes(const char *instr,
 {
 	const struct ddebug_class_param *dcp = kp->arg;
 	const struct ddebug_class_map *map = dcp->map;
-	unsigned long inrep, new_bits, old_bits;
+	u64 inrep, new_bits, old_bits;
 	int rc, totct = 0;
 
-	rc = kstrtoul(instr, 0, &inrep);
+	rc = kstrtou64(instr, 0, &inrep);
 	if (rc) {
 		int len = strcspn(instr, "\n");
 		pr_err("expecting numeric input, not: %.*s > %s\n",
@@ -697,24 +699,24 @@ static int param_set_dyndbg_module_classes(const char *instr,
 	case DD_CLASS_TYPE_DISJOINT_BITS:
 		/* expect bits. mask and warn if too many */
 		if (inrep & ~CLASSMAP_BITMASK(map->length)) {
-			pr_warn("%s: input: 0x%lx exceeds mask: 0x%lx, masking\n",
+			pr_warn("%s: input: 0x%llx exceeds mask: 0x%llx, masking\n",
 				KP_NAME(kp), inrep, CLASSMAP_BITMASK(map->length));
 			inrep &= CLASSMAP_BITMASK(map->length);
 		}
-		v2pr_info("bits:0x%lx > %s.%s\n", inrep, mod_name ?: "*", KP_NAME(kp));
+		v2pr_info("bits:0x%llx > %s.%s\n", inrep, mod_name ?: "*", KP_NAME(kp));
 		totct += ddebug_apply_class_bitmap(dcp, &inrep, *dcp->bits, mod_name);
 		*dcp->bits = inrep;
 		break;
 	case DD_CLASS_TYPE_LEVEL_NUM:
 		/* input is bitpos, of highest verbosity to be enabled */
 		if (inrep > map->length) {
-			pr_warn("%s: level:%ld exceeds max:%d, clamping\n",
+			pr_warn("%s: level:%llu exceeds max:%d, clamping\n",
 				KP_NAME(kp), inrep, map->length);
 			inrep = map->length;
 		}
 		old_bits = CLASSMAP_BITMASK(*dcp->lvl);
 		new_bits = CLASSMAP_BITMASK(inrep);
-		v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
+		v2pr_info("lvl:%llu bits:0x%llx > %s\n", inrep, new_bits, KP_NAME(kp));
 		totct += ddebug_apply_class_bitmap(dcp, &new_bits, old_bits, mod_name);
 		*dcp->lvl = inrep;
 		break;
@@ -760,9 +762,9 @@ int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
 
 	switch (map->map_type) {
 	case DD_CLASS_TYPE_DISJOINT_BITS:
-		return scnprintf(buffer, PAGE_SIZE, "0x%lx\n", *dcp->bits);
+		return scnprintf(buffer, PAGE_SIZE, "0x%llx\n", *dcp->bits);
 	case DD_CLASS_TYPE_LEVEL_NUM:
-		return scnprintf(buffer, PAGE_SIZE, "%d\n", *dcp->lvl);
+		return scnprintf(buffer, PAGE_SIZE, "%llu\n", *dcp->lvl);
 	default:
 		return -1;
 	}
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 74d183ebf3e0..c049580d2152 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -40,7 +40,7 @@ module_param_cb(do_prints, &param_ops_do_prints, NULL, 0600);
  * - tie together sysname, mapname, bitsname, flagsname
  */
 #define DD_SYS_WRAP(_model, _flags)					\
-	static unsigned long bits_##_model;				\
+	static u64 bits_##_model;					\
 	static struct ddebug_class_param _flags##_model = {		\
 		.bits = &bits_##_model,					\
 		.flags = #_flags,					\

-- 
2.54.0

Claude review: dyndbg: Upgrade class param storage to u64 for 64-bit classmaps

[Claude Code Review Bot]

Patch Review

Important fix for 32-bit architectures where `unsigned long` truncates 64-bit classmaps. The `CLASSMAP_BITMASK` macro:
```c
#define CLASSMAP_BITMASK(width) ((width) == 64 ? ~0ULL : (1ULL << (width)) - 1)
```
correctly handles the width==64 case to avoid undefined behavior. The DRM changes (`__drm_debug` to `u64`, `struct ddebug_class_param` to `struct _ddebug_class_param`) are straightforward. Minor nit: the operator precedence in `CLASSMAP_BITMASK` -- `(1ULL << (width)) - 1` -- is technically correct since `<<` binds tighter than `-`, but adding parens around the subtraction `((1ULL << (width)) - 1)` would be clearer.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 19/24] dyndbg,module: make proper substructs in _ddebug_info

[Jim Cromie]

recompose struct _ddebug_info, inserting proper sub-structs.

The struct _ddebug_info has 2 pairs of _vec, num_##_vec fields, for
descs and classes respectively.  for_subvec() makes walking these
vectors less cumbersome, now lets move those field pairs into their
own "vec" structs: _ddebug_descs & _ddebug_class_maps, and re-compose
struct _ddebug_info to contain them cleanly.  This also lets us get
rid of for_subvec()'s num_##_vec paste-up.

Also recompose struct ddebug_table to contain a _ddebug_info.  This
reinforces its use as a cursor into relevant data for a builtin
module, and access to the full _ddebug state for modules.

NOTES:

Fixup names: Normalize all struct names to "struct _ddebug_*"
eliminating the minor/stupid variations created in classmaps-v1.

Change section names together, for more obvious name pairing.

Invariant: These vectors ref a contiguous subrange of __section memory
in builtin/DATA or in loadable modules via mod->dyndbg_info; with
guaranteed life-time for us.

struct module contains a _ddebug_info field and module/main.c sets it
up, so that gets adjusted rather obviously.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---

v3: squash in section name changes.

v2:

Move RvB after SoB
In structs _ddebug_descs & _ddebug_class_maps, change int length to unsigned int
No use of <0 vals is contemplated.

dyndbg: improve section names

change __dyndbg to __dyndbg_descs
change __dyndbg_classes to __dyndbg_class_maps

this sets up for adding __dyndbg_class_users
---
 include/asm-generic/dyndbg.lds.h |  14 ++---
 include/linux/dynamic_debug.h    |  40 +++++++++-----
 kernel/module/main.c             |  12 ++--
 lib/dynamic_debug.c              | 116 +++++++++++++++++++--------------------
 lib/test_dynamic_debug.c         |   2 +-
 5 files changed, 98 insertions(+), 86 deletions(-)

diff --git a/include/asm-generic/dyndbg.lds.h b/include/asm-generic/dyndbg.lds.h
index 9d8951bef688..ec661f9f3793 100644
--- a/include/asm-generic/dyndbg.lds.h
+++ b/include/asm-generic/dyndbg.lds.h
@@ -3,16 +3,16 @@
 #define __ASM_GENERIC_DYNDBG_LDS_H
 
 #include <asm-generic/bounded_sections.lds.h>
-#define DYNDBG_SECTIONS()					\
-	BOUNDED_SECTION_BY(__dyndbg, ___dyndbg)			\
-	BOUNDED_SECTION_BY(__dyndbg_classes, ___dyndbg_classes)
+#define DYNDBG_SECTIONS()						\
+	BOUNDED_SECTION_BY(__dyndbg_descs, ___dyndbg_descs)		\
+	BOUNDED_SECTION_BY(__dyndbg_class_maps, ___dyndbg_class_maps)
 
 #define MOD_DYNDBG_SECTIONS()						\
-	__dyndbg 0 : ALIGN(8) {						\
-		KEEP(*(__dyndbg))					\
+	__dyndbg_descs 0 : ALIGN(8) {					\
+		KEEP(*(__dyndbg_descs))					\
 	}								\
-	__dyndbg_classes 0 : ALIGN(8) {					\
-		KEEP(*(__dyndbg_classes))				\
+	__dyndbg_class_maps 0 : ALIGN(8) {				\
+		KEEP(*(__dyndbg_class_maps))				\
 	}
 
 #endif /* __ASM_GENERIC_DYNDBG_LDS_H */
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 91546a99014b..8fc315d0e5a5 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -72,8 +72,8 @@ enum ddebug_class_map_type {
 	 */
 };
 
-struct ddebug_class_map {
-	struct module *mod;
+struct _ddebug_class_map {
+	struct module *mod;	/* NULL for builtins */
 	const char *mod_name;	/* needed for builtins */
 	const char **class_names;
 	const int length;
@@ -81,21 +81,33 @@ struct ddebug_class_map {
 	enum ddebug_class_map_type map_type;
 };
 
-/* encapsulate linker provided built-in (or module) dyndbg data */
+/*
+ * @_ddebug_info: gathers module/builtin dyndbg_* __sections together.
+ * For builtins, it is used as a cursor, with the inner structs
+ * marking sub-vectors of the builtin __sections in DATA.
+ */
+struct _ddebug_descs {
+	struct _ddebug *start;
+	unsigned int len;
+};
+
+struct _ddebug_class_maps {
+	struct _ddebug_class_map *start;
+	unsigned int len;
+};
+
 struct _ddebug_info {
-	struct _ddebug *descs;
-	struct ddebug_class_map *classes;
-	unsigned int num_descs;
-	unsigned int num_classes;
+	struct _ddebug_descs descs;
+	struct _ddebug_class_maps maps;
 };
 
-struct ddebug_class_param {
+struct _ddebug_class_param {
 	union {
 		u64 *bits;
 		u64 *lvl;
 	};
 	char flags[8];
-	const struct ddebug_class_map *map;
+	const struct _ddebug_class_map *map;
 };
 
 /*
@@ -114,8 +126,8 @@ struct ddebug_class_param {
  */
 #define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...)		\
 	static const char *_var##_classnames[] = { __VA_ARGS__ };	\
-	static struct ddebug_class_map __aligned(8) __used		\
-		__section("__dyndbg_classes") _var = {			\
+	static struct _ddebug_class_map __aligned(8) __used		\
+		__section("__dyndbg_class_maps") _var = {			\
 		.mod = THIS_MODULE,					\
 		.mod_name = KBUILD_MODNAME,				\
 		.base = _base,						\
@@ -155,7 +167,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
 
 #define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt)	\
 	static struct _ddebug  __aligned(8)			\
-	__section("__dyndbg") name = {				\
+	__section("__dyndbg_descs") name = {			\
 		.modname = KBUILD_MODNAME,			\
 		.function = __func__,				\
 		.filename = __FILE__,				\
@@ -242,7 +254,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
  * macro.
  */
 #define _dynamic_func_call_cls(cls, fmt, func, ...)			\
-	__dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__)
+	__dynamic_func_call_cls(__UNIQUE_ID(_ddebug), cls, fmt, func, ##__VA_ARGS__)
 #define _dynamic_func_call(fmt, func, ...)				\
 	_dynamic_func_call_cls(_DPRINTK_CLASS_DFLT, fmt, func, ##__VA_ARGS__)
 
@@ -252,7 +264,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
  * with precisely the macro's varargs.
  */
 #define _dynamic_func_call_cls_no_desc(cls, fmt, func, ...)		\
-	__dynamic_func_call_cls_no_desc(__UNIQUE_ID(ddebug), cls, fmt,	\
+	__dynamic_func_call_cls_no_desc(__UNIQUE_ID(_ddebug), cls, fmt,	\
 					func, ##__VA_ARGS__)
 #define _dynamic_func_call_no_desc(fmt, func, ...)			\
 	_dynamic_func_call_cls_no_desc(_DPRINTK_CLASS_DFLT, fmt,	\
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 46dd8d25a605..bd7899a91755 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2774,12 +2774,12 @@ static int find_module_sections(struct module *mod, struct load_info *info)
 		pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
 
 #ifdef CONFIG_DYNAMIC_DEBUG_CORE
-	mod->dyndbg_info.descs = section_objs(info, "__dyndbg",
-					      sizeof(*mod->dyndbg_info.descs),
-					      &mod->dyndbg_info.num_descs);
-	mod->dyndbg_info.classes = section_objs(info, "__dyndbg_classes",
-						sizeof(*mod->dyndbg_info.classes),
-						&mod->dyndbg_info.num_classes);
+	mod->dyndbg_info.descs.start = section_objs(info, "__dyndbg_descs",
+						    sizeof(*mod->dyndbg_info.descs.start),
+						    &mod->dyndbg_info.descs.len);
+	mod->dyndbg_info.maps.start = section_objs(info, "__dyndbg_class_maps",
+						   sizeof(*mod->dyndbg_info.maps.start),
+						   &mod->dyndbg_info.maps.len);
 #endif
 
 	return 0;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 7298520a89dc..0995cbef6f47 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -39,17 +39,15 @@
 
 #include <rdma/ib_verbs.h>
 
-extern struct _ddebug __start___dyndbg[];
-extern struct _ddebug __stop___dyndbg[];
-extern struct ddebug_class_map __start___dyndbg_classes[];
-extern struct ddebug_class_map __stop___dyndbg_classes[];
+extern struct _ddebug __start___dyndbg_descs[];
+extern struct _ddebug __stop___dyndbg_descs[];
+extern struct _ddebug_class_map __start___dyndbg_class_maps[];
+extern struct _ddebug_class_map __stop___dyndbg_class_maps[];
 
 struct ddebug_table {
 	struct list_head link;
 	const char *mod_name;
-	struct _ddebug *ddebugs;
-	struct ddebug_class_map *classes;
-	unsigned int num_ddebugs, num_classes;
+	struct _ddebug_info info;
 };
 
 struct ddebug_query {
@@ -136,11 +134,11 @@ do {								\
  * @_i:  caller provided counter.
  * @_sp: cursor into _vec, to examine each item.
  * @_box: ptr to a struct containing @_vec member
- * @_vec: name of a member in @_box
+ * @_vec: name of a vector member in @_box
  */
 #define for_subvec(_i, _sp, _box, _vec)			\
-	for ((_i) = 0, (_sp) = (_box)->_vec;		\
-	     (_i) < (_box)->num_##_vec;			\
+	for ((_i) = 0, (_sp) = (_box)->_vec.start;	\
+	     (_i) < (_box)->_vec.len;			\
 	     (_i)++, (_sp)++)		/* { block } */
 
 static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
@@ -163,14 +161,14 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
 		  query->first_lineno, query->last_lineno, query->class_string);
 }
 
-static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
+static struct _ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
 							const char *class_string,
 							int *class_id)
 {
-	struct ddebug_class_map *map;
+	struct _ddebug_class_map *map;
 	int i, idx;
 
-	for_subvec(i, map, dt, classes) {
+	for_subvec(i, map, &dt->info, maps) {
 		idx = match_string(map->class_names, map->length, class_string);
 		if (idx >= 0) {
 			*class_id = idx + map->base;
@@ -241,7 +239,7 @@ static int ddebug_change(const struct ddebug_query *query,
 	unsigned int newflags;
 	unsigned int nfound = 0;
 	struct flagsbuf fbuf, nbuf;
-	struct ddebug_class_map *map = NULL;
+	struct _ddebug_class_map *map = NULL;
 	int valid_class;
 
 	/* search for matching ddebugs */
@@ -262,8 +260,8 @@ static int ddebug_change(const struct ddebug_query *query,
 			valid_class = _DPRINTK_CLASS_DFLT;
 		}
 
-		for (i = 0; i < dt->num_ddebugs; i++) {
-			struct _ddebug *dp = &dt->ddebugs[i];
+		for (i = 0; i < dt->info.descs.len; i++) {
+			struct _ddebug *dp = &dt->info.descs.start[i];
 
 			if (!ddebug_match_desc(query, dp, valid_class))
 				continue;
@@ -624,13 +622,13 @@ static int ddebug_exec_queries(char *query, const char *modname)
 }
 
 /* apply a new class-param setting */
-static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
+static int ddebug_apply_class_bitmap(const struct _ddebug_class_param *dcp,
 				     const u64 *new_bits, const u64 old_bits,
 				     const char *query_modname)
 {
 #define QUERY_SIZE 128
 	char query[QUERY_SIZE];
-	const struct ddebug_class_map *map = dcp->map;
+	const struct _ddebug_class_map *map = dcp->map;
 	int matches = 0;
 	int bi, ct;
 
@@ -682,8 +680,8 @@ static int param_set_dyndbg_module_classes(const char *instr,
 					   const struct kernel_param *kp,
 					   const char *mod_name)
 {
-	const struct ddebug_class_param *dcp = kp->arg;
-	const struct ddebug_class_map *map = dcp->map;
+	const struct _ddebug_class_param *dcp = kp->arg;
+	const struct _ddebug_class_map *map = dcp->map;
 	u64 inrep, new_bits, old_bits;
 	int rc, totct = 0;
 
@@ -757,8 +755,8 @@ EXPORT_SYMBOL(param_set_dyndbg_classes);
  */
 int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
 {
-	const struct ddebug_class_param *dcp = kp->arg;
-	const struct ddebug_class_map *map = dcp->map;
+	const struct _ddebug_class_param *dcp = kp->arg;
+	const struct _ddebug_class_map *map = dcp->map;
 
 	switch (map->map_type) {
 	case DD_CLASS_TYPE_DISJOINT_BITS:
@@ -1005,8 +1003,8 @@ static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
 	}
 	iter->table = list_entry(ddebug_tables.next,
 				 struct ddebug_table, link);
-	iter->idx = iter->table->num_ddebugs;
-	return &iter->table->ddebugs[--iter->idx];
+	iter->idx = iter->table->info.descs.len;
+	return &iter->table->info.descs.start[--iter->idx];
 }
 
 /*
@@ -1027,10 +1025,10 @@ static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
 		}
 		iter->table = list_entry(iter->table->link.next,
 					 struct ddebug_table, link);
-		iter->idx = iter->table->num_ddebugs;
+		iter->idx = iter->table->info.descs.len;
 		--iter->idx;
 	}
-	return &iter->table->ddebugs[iter->idx];
+	return &iter->table->info.descs.start[iter->idx];
 }
 
 /*
@@ -1074,16 +1072,19 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
 	return dp;
 }
 
-#define class_in_range(class_id, map)					\
-	(class_id >= map->base && class_id < map->base + map->length)
+static bool ddebug_class_in_range(const int class_id, const struct _ddebug_class_map *map)
+{
+	return (class_id >= map->base &&
+		class_id < map->base + map->length);
+}
 
-static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp)
+static const char *ddebug_class_name(struct ddebug_table *dt, struct _ddebug *dp)
 {
-	struct ddebug_class_map *map = iter->table->classes;
-	int i, nc = iter->table->num_classes;
+	struct _ddebug_class_map *map;
+	int i;
 
-	for (i = 0; i < nc; i++, map++)
-		if (class_in_range(dp->class_id, map))
+	for_subvec(i, map, &dt->info, maps)
+		if (ddebug_class_in_range(dp->class_id, map))
 			return map->class_names[dp->class_id - map->base];
 
 	return NULL;
@@ -1116,7 +1117,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
 	seq_putc(m, '"');
 
 	if (dp->class_id != _DPRINTK_CLASS_DFLT) {
-		class = ddebug_class_name(iter, dp);
+		class = ddebug_class_name(iter->table, dp);
 		if (class)
 			seq_printf(m, " class:%s", class);
 		else
@@ -1168,7 +1169,7 @@ static const struct proc_ops proc_fops = {
 
 static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug_info *di)
 {
-	struct ddebug_class_map *cm;
+	struct _ddebug_class_map *cm;
 	int i, nc = 0;
 
 	/*
@@ -1176,12 +1177,12 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
 	 * the builtin/modular classmap vector/section.  Save the start
 	 * and length of the subrange at its edges.
 	 */
-	for_subvec(i, cm, di, classes) {
+	for_subvec(i, cm, di, maps) {
 		if (!strcmp(cm->mod_name, dt->mod_name)) {
 			if (!nc) {
 				v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
 					  i, cm->mod_name, cm->base, cm->length, cm->map_type);
-				dt->classes = cm;
+				dt->info.maps.start = cm;
 			}
 			nc++;
 		} else if (nc) {
@@ -1190,7 +1191,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
 		}
 	}
 	if (nc) {
-		dt->num_classes = nc;
+		dt->info.maps.len = nc;
 		vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
 	}
 }
@@ -1203,10 +1204,10 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 {
 	struct ddebug_table *dt;
 
-	if (!di->num_descs)
+	if (!di->descs.len)
 		return 0;
 
-	v3pr_info("add-module: %s %d sites\n", modname, di->num_descs);
+	v3pr_info("add-module: %s %d sites\n", modname, di->descs.len);
 
 	dt = kzalloc_obj(*dt);
 	if (dt == NULL) {
@@ -1220,19 +1221,18 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 	 * this struct ddebug_table.
 	 */
 	dt->mod_name = modname;
-	dt->ddebugs = di->descs;
-	dt->num_ddebugs = di->num_descs;
+	dt->info = *di;
 
 	INIT_LIST_HEAD(&dt->link);
 
-	if (di->classes && di->num_classes)
+	if (di->maps.len)
 		ddebug_attach_module_classes(dt, di);
 
 	mutex_lock(&ddebug_lock);
 	list_add_tail(&dt->link, &ddebug_tables);
 	mutex_unlock(&ddebug_lock);
 
-	vpr_info("%3u debug prints in module %s\n", di->num_descs, modname);
+	vpr_info("%3u debug prints in module %s\n", di->descs.len, modname);
 	return 0;
 }
 
@@ -1379,10 +1379,10 @@ static int __init dynamic_debug_init(void)
 	char *cmdline;
 
 	struct _ddebug_info di = {
-		.descs = __start___dyndbg,
-		.classes = __start___dyndbg_classes,
-		.num_descs = __stop___dyndbg - __start___dyndbg,
-		.num_classes = __stop___dyndbg_classes - __start___dyndbg_classes,
+		.descs.start = __start___dyndbg_descs,
+		.maps.start  = __start___dyndbg_class_maps,
+		.descs.len = __stop___dyndbg_descs - __start___dyndbg_descs,
+		.maps.len  = __stop___dyndbg_class_maps - __start___dyndbg_class_maps,
 	};
 
 #ifdef CONFIG_MODULES
@@ -1393,7 +1393,7 @@ static int __init dynamic_debug_init(void)
 	}
 #endif /* CONFIG_MODULES */
 
-	if (&__start___dyndbg == &__stop___dyndbg) {
+	if (&__start___dyndbg_descs == &__stop___dyndbg_descs) {
 		if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
 			pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
 			return 1;
@@ -1403,16 +1403,16 @@ static int __init dynamic_debug_init(void)
 		return 0;
 	}
 
-	iter = iter_mod_start = __start___dyndbg;
+	iter = iter_mod_start = __start___dyndbg_descs;
 	modname = iter->modname;
 	i = mod_sites = mod_ct = 0;
 
-	for (; iter < __stop___dyndbg; iter++, i++, mod_sites++) {
+	for (; iter < __stop___dyndbg_descs; iter++, i++, mod_sites++) {
 
 		if (strcmp(modname, iter->modname)) {
 			mod_ct++;
-			di.num_descs = mod_sites;
-			di.descs = iter_mod_start;
+			di.descs.len = mod_sites;
+			di.descs.start = iter_mod_start;
 			ret = ddebug_add_module(&di, modname);
 			if (ret)
 				goto out_err;
@@ -1422,19 +1422,19 @@ static int __init dynamic_debug_init(void)
 			iter_mod_start = iter;
 		}
 	}
-	di.num_descs = mod_sites;
-	di.descs = iter_mod_start;
+	di.descs.len = mod_sites;
+	di.descs.start = iter_mod_start;
 	ret = ddebug_add_module(&di, modname);
 	if (ret)
 		goto out_err;
 
 	ddebug_init_success = 1;
-	vpr_info("%d prdebugs in %d modules, %d KiB in ddebug tables, %d kiB in __dyndbg section\n",
+	vpr_info("%d prdebugs in %d modules, %d KiB in ddebug tables, %d kiB in __dyndbg_descs section\n",
 		 i, mod_ct, (int)((mod_ct * sizeof(struct ddebug_table)) >> 10),
 		 (int)((i * sizeof(struct _ddebug)) >> 10));
 
-	if (di.num_classes)
-		v2pr_info("  %d builtin ddebug class-maps\n", di.num_classes);
+	if (di.maps.len)
+		v2pr_info("  %d builtin ddebug class-maps\n", di.maps.len);
 
 	/* now that ddebug tables are loaded, process all boot args
 	 * again to find and activate queries given in dyndbg params.
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index c049580d2152..e6b2422ca671 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -41,7 +41,7 @@ module_param_cb(do_prints, &param_ops_do_prints, NULL, 0600);
  */
 #define DD_SYS_WRAP(_model, _flags)					\
 	static u64 bits_##_model;					\
-	static struct ddebug_class_param _flags##_model = {		\
+	static struct _ddebug_class_param _flags##_model = {		\
 		.bits = &bits_##_model,					\
 		.flags = #_flags,					\
 		.map = &map_##_model,					\

-- 
2.54.0

Claude review: dyndbg,module: make proper substructs in _ddebug_info

[Claude Code Review Bot]

Patch Review

Large but mechanical refactoring. Section renames (`__dyndbg` -> `__dyndbg_descs`, `__dyndbg_classes` -> `__dyndbg_class_maps`) are a breaking change for any out-of-tree modules using dynamic debug, but the old names were somewhat generic. The struct reorganization with `_ddebug_descs` and `_ddebug_class_maps` sub-structs is clean. The `__UNIQUE_ID(ddebug)` -> `__UNIQUE_ID(_ddebug)` change is unrelated cleanup that should ideally be in its own patch or at least mentioned in the commit message. No blocking issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 20/24] dyndbg: move mod_name down from struct ddebug_table to _ddebug_info

[Jim Cromie]

struct _ddebug_info already has most of dyndbg's info for a module;
push debug_table.mod_name down into it, finishing the encapsulation.

This allows refactoring several callchains, passing &_ddebug_info
instead of &ddebug_table, and hoisting the "&dt->info" deref up
instead of repeating it thru the callchans

ddebug_table contains a _ddebug_info member, so its users keep access
to mod_name, just now with "->info." added in.

In static ddebug_add_module(&di), reinforce the cursor-model by
dropping the modname arg, and setting di->mod_name at each caller.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2: move RvB after SoB

old-v12
. moved up 1 position in series, ahead of hoist...
---
 include/linux/dynamic_debug.h |  1 +
 lib/dynamic_debug.c           | 50 ++++++++++++++++++++++---------------------
 2 files changed, 27 insertions(+), 24 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 8fc315d0e5a5..e4a62cb73267 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -97,6 +97,7 @@ struct _ddebug_class_maps {
 };
 
 struct _ddebug_info {
+	const char *mod_name;
 	struct _ddebug_descs descs;
 	struct _ddebug_class_maps maps;
 };
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 0995cbef6f47..ebfff48c4a6c 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -46,7 +46,6 @@ extern struct _ddebug_class_map __stop___dyndbg_class_maps[];
 
 struct ddebug_table {
 	struct list_head link;
-	const char *mod_name;
 	struct _ddebug_info info;
 };
 
@@ -245,10 +244,11 @@ static int ddebug_change(const struct ddebug_query *query,
 	/* search for matching ddebugs */
 	mutex_lock(&ddebug_lock);
 	list_for_each_entry(dt, &ddebug_tables, link) {
+		struct _ddebug_info *di = &dt->info;
 
 		/* match against the module name */
 		if (query->module &&
-		    !match_wildcard(query->module, dt->mod_name))
+		    !match_wildcard(query->module, di->mod_name))
 			continue;
 
 		if (query->class_string) {
@@ -260,8 +260,8 @@ static int ddebug_change(const struct ddebug_query *query,
 			valid_class = _DPRINTK_CLASS_DFLT;
 		}
 
-		for (i = 0; i < dt->info.descs.len; i++) {
-			struct _ddebug *dp = &dt->info.descs.start[i];
+		for (i = 0; i < di->descs.len; i++) {
+			struct _ddebug *dp = &di->descs.start[i];
 
 			if (!ddebug_match_desc(query, dp, valid_class))
 				continue;
@@ -281,7 +281,7 @@ static int ddebug_change(const struct ddebug_query *query,
 #endif
 			v4pr_info("changed %s:%d [%s]%s %s => %s\n",
 				  trim_prefix(dp->filename), dp->lineno,
-				  dt->mod_name, dp->function,
+				  di->mod_name, dp->function,
 				  ddebug_describe_flags(dp->flags, &fbuf),
 				  ddebug_describe_flags(newflags, &nbuf));
 			dp->flags = newflags;
@@ -1078,12 +1078,12 @@ static bool ddebug_class_in_range(const int class_id, const struct _ddebug_class
 		class_id < map->base + map->length);
 }
 
-static const char *ddebug_class_name(struct ddebug_table *dt, struct _ddebug *dp)
+static const char *ddebug_class_name(struct _ddebug_info *di, struct _ddebug *dp)
 {
 	struct _ddebug_class_map *map;
 	int i;
 
-	for_subvec(i, map, &dt->info, maps)
+	for_subvec(i, map, di, maps)
 		if (ddebug_class_in_range(dp->class_id, map))
 			return map->class_names[dp->class_id - map->base];
 
@@ -1111,13 +1111,13 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
 
 	seq_printf(m, "%s:%u [%s]%s =%s \"",
 		   trim_prefix(dp->filename), dp->lineno,
-		   iter->table->mod_name, dp->function,
+		   iter->table->info.mod_name, dp->function,
 		   ddebug_describe_flags(dp->flags, &flags));
 	seq_escape_str(m, dp->format, ESCAPE_SPACE, "\t\r\n\"");
 	seq_putc(m, '"');
 
 	if (dp->class_id != _DPRINTK_CLASS_DFLT) {
-		class = ddebug_class_name(iter->table, dp);
+		class = ddebug_class_name(&iter->table->info, dp);
 		if (class)
 			seq_printf(m, " class:%s", class);
 		else
@@ -1178,7 +1178,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
 	 * and length of the subrange at its edges.
 	 */
 	for_subvec(i, cm, di, maps) {
-		if (!strcmp(cm->mod_name, dt->mod_name)) {
+		if (!strcmp(cm->mod_name, dt->info.mod_name)) {
 			if (!nc) {
 				v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
 					  i, cm->mod_name, cm->base, cm->length, cm->map_type);
@@ -1192,7 +1192,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
 	}
 	if (nc) {
 		dt->info.maps.len = nc;
-		vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
+		vpr_info("module:%s attached %d classes\n", dt->info.mod_name, nc);
 	}
 }
 
@@ -1200,27 +1200,26 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
  * Allocate a new ddebug_table for the given module
  * and add it to the global list.
  */
-static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
+static int ddebug_add_module(struct _ddebug_info *di)
 {
 	struct ddebug_table *dt;
 
 	if (!di->descs.len)
 		return 0;
 
-	v3pr_info("add-module: %s %d sites\n", modname, di->descs.len);
+	v3pr_info("add-module: %s %d sites\n", di->mod_name, di->descs.len);
 
 	dt = kzalloc_obj(*dt);
 	if (dt == NULL) {
-		pr_err("error adding module: %s\n", modname);
+		pr_err("error adding module: %s\n", di->mod_name);
 		return -ENOMEM;
 	}
 	/*
-	 * For built-in modules, name lives in .rodata and is
-	 * immortal. For loaded modules, name points at the name[]
-	 * member of struct module, which lives at least as long as
-	 * this struct ddebug_table.
+	 * For built-in modules, name (as supplied in di by its
+	 * callers) lives in .rodata and is immortal. For loaded
+	 * modules, name points at the name[] member of struct module,
+	 * which lives at least as long as this struct ddebug_table.
 	 */
-	dt->mod_name = modname;
 	dt->info = *di;
 
 	INIT_LIST_HEAD(&dt->link);
@@ -1232,7 +1231,7 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 	list_add_tail(&dt->link, &ddebug_tables);
 	mutex_unlock(&ddebug_lock);
 
-	vpr_info("%3u debug prints in module %s\n", di->descs.len, modname);
+	vpr_info("%3u debug prints in module %s\n", di->descs.len, di->mod_name);
 	return 0;
 }
 
@@ -1295,7 +1294,7 @@ static int ddebug_remove_module(const char *mod_name)
 
 	mutex_lock(&ddebug_lock);
 	list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
-		if (dt->mod_name == mod_name) {
+		if (dt->info.mod_name == mod_name) {
 			ddebug_table_free(dt);
 			ret = 0;
 			break;
@@ -1315,7 +1314,8 @@ static int ddebug_module_notify(struct notifier_block *self, unsigned long val,
 
 	switch (val) {
 	case MODULE_STATE_COMING:
-		ret = ddebug_add_module(&mod->dyndbg_info, mod->name);
+		mod->dyndbg_info.mod_name = mod->name;
+		ret = ddebug_add_module(&mod->dyndbg_info);
 		if (ret)
 			WARN(1, "Failed to allocate memory: dyndbg may not work properly.\n");
 		break;
@@ -1413,7 +1413,8 @@ static int __init dynamic_debug_init(void)
 			mod_ct++;
 			di.descs.len = mod_sites;
 			di.descs.start = iter_mod_start;
-			ret = ddebug_add_module(&di, modname);
+			di.mod_name = modname;
+			ret = ddebug_add_module(&di);
 			if (ret)
 				goto out_err;
 
@@ -1424,7 +1425,8 @@ static int __init dynamic_debug_init(void)
 	}
 	di.descs.len = mod_sites;
 	di.descs.start = iter_mod_start;
-	ret = ddebug_add_module(&di, modname);
+	di.mod_name = modname;
+	ret = ddebug_add_module(&di);
 	if (ret)
 		goto out_err;
 

-- 
2.54.0

Claude review: dyndbg: move mod_name down from struct ddebug_table to _ddebug_info

[Claude Code Review Bot]

Patch Review

Clean encapsulation completing the struct reorganization. The change to set `di->mod_name` at each caller rather than passing it as a parameter is a reasonable API simplification. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 21/24] dyndbg: hoist classmap-filter-by-modname up to ddebug_add_module

[Jim Cromie]

The body of ddebug_attach_module_classes() is just a code-block that
finds the contiguous subrange of classmaps matching on modname, and
saves it into the ddebug_table's info record.

Implement this block in a macro to accommodate different component
vectors in the "box" (as named in the for_subvec macro).  We will
reuse this macro shortly.

And hoist its invocation out of ddebug_attach_module_classes() up into
ddebug_add_module().  This moves the filtering step up closer to
dynamic_debug_init(), which already segments the builtin pr_debug
descriptors on their mod_name boundaries.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v3: expand block-comment in ddebug_add_module

v2: move RvB after SoB

finish hoist - drop old fn - ddebug_attach_module_classes

the v1 rev left the old ddebug_attach_module_classes in place, but it
is completely redundant now, since it already lost the list-linking
job it was doing.

It was being cut out later in the patchset (in the unsent API
adaptation phase), but for cleaner review, lets excise it now.

OLD all-in-1-series (pre split into reviewable chunks)

v10?- reordered params to match kdoc

v12- refactor/rename: s/dd_mark_vector_subrange/dd_set_module_subrange/

1. Renamed the macro from dd_mark_vector_subrange to
   dd_set_module_subrange to better reflect its purpose of narrowing a
   vector to a module-specific subrange.

2. Simplified the arguments by removing the redundant _dst, as the _di
   pointer already provides access to the target _ddebug_info struct.

3. Refactored for Clarity: Instead of overwriting the struct's start
   pointer while the for_subvec loop is using it to iterate, I
   introduced a temporary __start variable. This avoids the "subtle"
   side effect and makes the logic easier to follow.

4. Updated Documentation: Improved the comment block to explicitly
   state that the macro scans for the first match and counts
   contiguous elements.

fiuxp
---
 lib/dynamic_debug.c | 84 ++++++++++++++++++++++++++++-------------------------
 1 file changed, 45 insertions(+), 39 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index ebfff48c4a6c..fdb730db385e 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -161,8 +161,8 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
 }
 
 static struct _ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
-							const char *class_string,
-							int *class_id)
+							 const char *class_string,
+							 int *class_id)
 {
 	struct _ddebug_class_map *map;
 	int i, idx;
@@ -1167,34 +1167,34 @@ static const struct proc_ops proc_fops = {
 	.proc_write = ddebug_proc_write
 };
 
-static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug_info *di)
-{
-	struct _ddebug_class_map *cm;
-	int i, nc = 0;
-
-	/*
-	 * Find this module's classmaps in a subrange/wholerange of
-	 * the builtin/modular classmap vector/section.  Save the start
-	 * and length of the subrange at its edges.
-	 */
-	for_subvec(i, cm, di, maps) {
-		if (!strcmp(cm->mod_name, dt->info.mod_name)) {
-			if (!nc) {
-				v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
-					  i, cm->mod_name, cm->base, cm->length, cm->map_type);
-				dt->info.maps.start = cm;
-			}
-			nc++;
-		} else if (nc) {
-			/* end of matching classmaps */
-			break;
-		}
-	}
-	if (nc) {
-		dt->info.maps.len = nc;
-		vpr_info("module:%s attached %d classes\n", dt->info.mod_name, nc);
-	}
-}
+/*
+ * dd_set_module_subrange - find matching subrange of classmaps
+ * @_i:   caller-provided index var
+ * @_sp:  cursor into @_vec
+ * @_di:  pointer to the struct _ddebug_info to be narrowed
+ * @_vec: name of the vector member (must have .start and .len)
+ *
+ * Narrow a _ddebug_info's vector (@_vec) of classmaps to the
+ * contiguous subrange of elements where ->mod_name matches
+ * @__di->mod_name.  This is primarily for builtins, loadable modules
+ * have only their classmaps, and dont need this sub-selection.
+ */
+#define dd_set_module_subrange(_i, _sp, _di, _vec) ({			\
+	struct _ddebug_info *__di = (_di);				\
+	typeof(__di->_vec.start) __start = NULL;			\
+	int __nc = 0;							\
+	for_subvec(_i, _sp, __di, _vec) {				\
+		if (!strcmp((_sp)->mod_name, __di->mod_name)) {		\
+			if (!__nc++)					\
+				__start = (_sp);			\
+		} else if (__nc) {					\
+			break; /* end of consecutive matches */		\
+		}							\
+	}								\
+	if (__nc)							\
+		__di->_vec.start = __start;				\
+	__di->_vec.len = __nc;						\
+})
 
 /*
  * Allocate a new ddebug_table for the given module
@@ -1203,6 +1203,8 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
 static int ddebug_add_module(struct _ddebug_info *di)
 {
 	struct ddebug_table *dt;
+	struct _ddebug_class_map *cm;
+	int i;
 
 	if (!di->descs.len)
 		return 0;
@@ -1215,17 +1217,21 @@ static int ddebug_add_module(struct _ddebug_info *di)
 		return -ENOMEM;
 	}
 	/*
-	 * For built-in modules, name (as supplied in di by its
-	 * callers) lives in .rodata and is immortal. For loaded
-	 * modules, name points at the name[] member of struct module,
-	 * which lives at least as long as this struct ddebug_table.
+	 * For built-in modules, di is a partial cursor into the
+	 * builtin dyndbg data; the descriptors are the subrange
+	 * matching the modname, but the classmaps are the full set.
+	 * We find and set the relevant subrange of classmaps here.
+	 *
+	 * The modname string is in .rodata, the descriptors and
+	 * classmaps are in writable .data. All are immortal.
+	 *
+	 * For loaded modules, mod_name points at the name[] member
+	 * of struct module, and the descriptors and classmaps point
+	 * at the module's ELF sections; all have lifetimes matching
+	 * the module's presence.
 	 */
 	dt->info = *di;
-
-	INIT_LIST_HEAD(&dt->link);
-
-	if (di->maps.len)
-		ddebug_attach_module_classes(dt, di);
+	dd_set_module_subrange(i, cm, &dt->info, maps);
 
 	mutex_lock(&ddebug_lock);
 	list_add_tail(&dt->link, &ddebug_tables);

-- 
2.54.0

Claude review: dyndbg: hoist classmap-filter-by-modname up to ddebug_add_module

[Claude Code Review Bot]

Patch Review

The `dd_set_module_subrange` macro is complex but well-documented. It uses statement-expression `({ })` syntax and a temporary `__start` variable to avoid modifying the iteration pointer. The `INIT_LIST_HEAD(&dt->link)` removal appears to be a bug -- the list_head should still be initialized before `list_add_tail`. Let me check... actually, `kzalloc` zeroes the struct, and `list_add_tail` doesn't require pre-initialization since it directly sets both `next` and `prev`. So this is technically safe, though `INIT_LIST_HEAD` is conventional.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 22/24] selftests-dyndbg: add a dynamic_debug run_tests target

[Jim Cromie]

Add a selftest script for dynamic-debug.  The config requires
CONFIG_TEST_DYNAMIC_DEBUG=m and CONFIG_TEST_DYNAMIC_DEBUG_SUBMOD=m,
which tacitly requires either CONFIG_DYNAMIC_DEBUG=y or
CONFIG_DYNAMIC_DEBUG_CORE=y

ATM this has just basic_tests(), which modify pr_debug() flags in the
builtin params module.  This means they're available to manipulate and
observe the effects in "cat control".

This is backported from another feature branch; the support-fns (thx
Lukas) have unused features at the moment, they'll get used shortly.

The script enables simple virtme-ng testing:

   [jimc@gandalf b0-ftrace]$ vrun_t
   virtme-ng 1.32+115.g07b109d
   doing: vng --name v6.14-rc4-60-gd5f48427de0c \
	  --user root -v -p 4 -a dynamic_debug.verbose=3 V=1 \
	  -- ../tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
   virtme: waiting for virtiofsd to start
   ..

And add dynamic_debug to TARGETS, so `make run_tests` sees it properly.
For the impatient, set TARGETS explicitly:

  [root@v6 selftests]# make TARGETS=dynamic_debug run_tests
  make[1]: Nothing to be done for 'all'.
  TAP version 13
  1..1
  # timeout set to 45
  # selftests: dynamic_debug: dyndbg_selftest.sh
  # # BASIC_TESTS    95.422122] dyndbg: query 0: 0"=_" mod:*
  ...

NOTES

check KCONFIG_CONFIG to avoid silly fails.  Several tests are
dependent upon config choices. Lets avoid failing where that is noise.

The KCONFIG_CONFIG var exists to convey the config-file around.  If
the var names a file, read it and extract the relevant CONFIG items,
and use them to skip the dependent tests, thus avoiding the fails that
would follow, and the disruption to whatever CI is running these
selftests.

If the envar doesn't name a config-file, ".config" is assumed.

CONFIG_DYNAMIC_DEBUG=y:

basic-tests() and comma-terminator-tests() test for the presence of
the builtin pr_debugs in module/main.c, which I deemed stable and
therefore safe to count.  That said, the test fails if only
CONFIG_DYNAMIC_DEBUG_CORE=y is set.  It could be rewritten to test
against test-dynamic-debug.ko, but that just trades one config
dependence for another.

Co-developed-by: Łukasz Bartosik <ukaszb@chromium.org>
Signed-off-by: Łukasz Bartosik <ukaszb@chromium.org>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---

v3: use ksft_* exit codes

v2:
drop commit-msg mention of yet-to-be-submitted tests
move RvB after SoB

script fixups per sashiko review

   1. CONFIG_DYNAMIC_DEBUG=y is set correctly.
   2. All subshell captures $( ( ... ) 2>&1 ) are fixed.
   3. All echo variables are safely quoted to prevent word-splitting.
   4. Standardized on modern /sys/kernel/tracing/ paths.
   5. exit $exp_exit_code correctly propagates failure status.
---
 MAINTAINERS                                        |   1 +
 tools/testing/selftests/Makefile                   |   1 +
 tools/testing/selftests/dynamic_debug/Makefile     |   9 +
 tools/testing/selftests/dynamic_debug/config       |   8 +
 .../selftests/dynamic_debug/dyndbg_selftest.sh     | 258 +++++++++++++++++++++
 5 files changed, 277 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 6cf80e7ac039..b3d41824220a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9087,6 +9087,7 @@ F:	include/asm-generic/dyndbg.lds.h
 F:	include/linux/dynamic_debug.h
 F:	lib/dynamic_debug.c
 F:	lib/test_dynamic_debug.c
+F:	tools/testing/selftests/dynamic_debug/*
 
 DYNAMIC INTERRUPT MODERATION
 M:	Tal Gilboa <talgi@nvidia.com>
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 6e59b8f63e41..17c4ddbcee89 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -27,6 +27,7 @@ TARGETS += drivers/net/team
 TARGETS += drivers/net/virtio_net
 TARGETS += drivers/platform/x86/intel/ifs
 TARGETS += dt
+TARGETS += dynamic_debug
 TARGETS += efivarfs
 TARGETS += exec
 TARGETS += fchmodat2
diff --git a/tools/testing/selftests/dynamic_debug/Makefile b/tools/testing/selftests/dynamic_debug/Makefile
new file mode 100644
index 000000000000..6d06fa7f1040
--- /dev/null
+++ b/tools/testing/selftests/dynamic_debug/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# borrowed from Makefile for user memory selftests
+
+# No binaries, but make sure arg-less "make" doesn't trigger "run_tests"
+all:
+
+TEST_PROGS := dyndbg_selftest.sh
+
+include ../lib.mk
diff --git a/tools/testing/selftests/dynamic_debug/config b/tools/testing/selftests/dynamic_debug/config
new file mode 100644
index 000000000000..ec478b17873d
--- /dev/null
+++ b/tools/testing/selftests/dynamic_debug/config
@@ -0,0 +1,8 @@
+
+# basic tests ref the builtin params module
+CONFIG_DYNAMIC_DEBUG=y
+
+# more testing is possible with these,
+# but insisting on them here skips testing entirely for such configs
+# CONFIG_TEST_DYNAMIC_DEBUG=m
+# CONFIG_TEST_DYNAMIC_DEBUG_SUBMOD=m
diff --git a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
new file mode 100755
index 000000000000..8b2b7388678e
--- /dev/null
+++ b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
@@ -0,0 +1,258 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0-only
+
+V=${V:=0}  # invoke as V=1 $0  for global verbose
+RED="\033[0;31m"
+GREEN="\033[0;32m"
+YELLOW="\033[0;33m"
+BLUE="\033[0;34m"
+MAGENTA="\033[0;35m"
+CYAN="\033[0;36m"
+NC="\033[0;0m"
+error_msg=""
+
+# Standard kselftest exit codes
+ksft_pass=0
+ksft_fail=1
+ksft_skip=4
+
+[ -e /proc/dynamic_debug/control ] || {
+    echo -e "${RED}: this test requires CONFIG_DYNAMIC_DEBUG=y ${NC}"
+    exit $ksft_skip # nothing to test here, no good reason to fail.
+}
+
+# need info to avoid failures due to untestable configs
+
+[ -f "$KCONFIG_CONFIG" ] || KCONFIG_CONFIG=".config"
+if [ -f "$KCONFIG_CONFIG" ]; then
+    echo "# consulting KCONFIG_CONFIG: $KCONFIG_CONFIG"
+    grep -q "CONFIG_DYNAMIC_DEBUG=y" $KCONFIG_CONFIG ; LACK_DD_BUILTIN=$?
+    grep -q "CONFIG_TEST_DYNAMIC_DEBUG=m" $KCONFIG_CONFIG ; LACK_TMOD=$?
+else
+    # if no config, try runtime probes
+    modprobe -n test_dynamic_debug 2>/dev/null ; LACK_TMOD=$?
+    # assume builtin dyndbg if control exists (checked above)
+    LACK_DD_BUILTIN=0
+fi
+
+function vx () {
+    echo "$1" > /sys/module/dynamic_debug/parameters/verbose
+}
+
+function ddgrep () {
+    grep "$1" /proc/dynamic_debug/control
+}
+
+function doprints () {
+    cat /sys/module/test_dynamic_debug/parameters/do_prints
+}
+
+function ddcmd () {
+    exp_exit_code=0
+    num_args=$#
+    if [ "${@:$#}" = "pass" ]; then
+	num_args=$#-1
+    elif [ "${@:$#}" = "fail" ]; then
+        num_args=$#-1
+	exp_exit_code=1
+    fi
+    args=${@:1:$num_args}
+    output=$( (echo "$args" > /proc/dynamic_debug/control) 2>&1)
+    exit_code=$?
+    error_msg=$(echo "$output" | cut -d ":" -f 5 | sed -e 's/^[[:space:]]*//')
+    handle_exit_code $BASH_LINENO $FUNCNAME $exit_code $exp_exit_code
+}
+
+function handle_exit_code() {
+    local exp_exit_code=0
+    [ $# == 4 ] && exp_exit_code=$4
+    if [ $3 -ne $exp_exit_code ]; then
+        echo -e "${RED}: $BASH_SOURCE:$1 $2() expected to exit with code $exp_exit_code, got $3"
+	[ $3 == 1 ] && echo "Error: '$error_msg'"
+        exit $ksft_fail
+    fi
+}
+
+# $1 - pattern to match, pattern in $1 is enclosed by spaces for a match ""\s$1\s"
+# $2 - number of times the pattern passed in $1 is expected to match
+# $3 - optional can be set either to "-r" or "-v"
+#       "-r" means relaxed matching in this case pattern provided in $1 is passed
+#       as is without enclosing it with spaces
+#       "-v" prints matching lines
+# $4 - optional when $3 is set to "-r" then $4 can be used to pass "-v"
+function check_match_ct {
+    pattern="\s$1\s"
+    exp_cnt=0
+
+    [ "$3" == "-r" ] && pattern="$1"
+    let cnt=$(ddgrep "$pattern" | wc -l)
+    if [ $V -eq 1 ] || [ "$3" == "-v" ] || [ "$4" == "-v" ]; then
+        echo -ne "${BLUE}" && ddgrep "$pattern" && echo -ne "${NC}"
+    fi
+    [ $# -gt 1 ] && exp_cnt=$2
+    if [ $cnt -ne $exp_cnt ]; then
+        echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO check failed expected $exp_cnt on $1, got $cnt"
+        exit $ksft_fail
+    else
+        echo ": $cnt matches on $1"
+    fi
+}
+
+# $1 - trace instance name
+# #2 - if > 0 then directory is expected to exist, if <= 0 then otherwise
+# $3 - "-v" for verbose
+function check_trace_instance_dir {
+    if [ -e /sys/kernel/tracing/instances/$1 ]; then
+        if [ "$3" == "-v" ] ; then
+            echo "ls -l /sys/kernel/tracing/instances/$1: "
+            ls -l /sys/kernel/tracing/instances/$1
+        fi
+	if [ $2 -le 0 ]; then
+            echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO error trace instance \
+		    '/sys/kernel/tracing/instances/$1' does exist"
+	    exit $ksft_fail
+	fi
+    else
+	if [ $2 -gt 0 ]; then
+            echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO error trace instance \
+		    '/sys/kernel/tracing/instances/$1' does not exist"
+	    exit $ksft_fail
+        fi
+    fi
+}
+
+function tmark {
+    echo $* > /sys/kernel/tracing/trace_marker
+}
+
+# $1 - trace instance name
+# $2 - line number
+# $3 - if > 0 then the instance is expected to be opened, otherwise
+# the instance is expected to be closed
+function check_trace_instance {
+    output=$(tail -n9 /proc/dynamic_debug/control | grep ": Opened trace instances" \
+	    | xargs -n1 | grep $1)
+    if [ "$output" != $1 ] && [ $3 -gt 0 ]; then
+        echo -e "${RED}: $BASH_SOURCE:$2 trace instance $1 is not opened"
+        exit $ksft_fail
+    fi
+    if [ "$output" == $1 ] && [ $3 -le 0 ]; then
+        echo -e "${RED}: $BASH_SOURCE:$2 trace instance $1 is not closed"
+        exit $ksft_fail
+    fi
+}
+
+function is_trace_instance_opened {
+    check_trace_instance $1 $BASH_LINENO 1
+}
+
+function is_trace_instance_closed {
+    check_trace_instance $1 $BASH_LINENO 0
+}
+
+# $1 - trace instance directory to delete
+# $2 - if > 0 then directory is expected to be deleted successfully, if <= 0 then otherwise
+function del_trace_instance_dir() {
+    exp_exit_code=1
+    [ $2 -gt 0 ] && exp_exit_code=0
+    output=$( (rmdir /sys/kernel/tracing/instances/$1) 2>&1)
+    exit_code=$?
+    error_msg=$(echo "$output" | cut -d ":" -f 3 | sed -e 's/^[[:space:]]*//')
+    handle_exit_code $BASH_LINENO $FUNCNAME $exit_code $exp_exit_code
+}
+
+function error_log_ref {
+    # to show what I got
+    : echo "# error-log-ref: $1"
+    : echo cat \$2
+}
+
+function ifrmmod {
+    lsmod | grep $1 2>&1>/dev/null && rmmod $1
+}
+
+# $1 - text to search for
+function search_trace() {
+    search_trace_name 0 1 $1
+}
+
+# $1 - trace instance name, 0 for global event trace
+# $2 - line number counting from the bottom
+# $3 - text to search for
+function search_trace_name() {
+	if [ "$1" = "0" ]; then
+	    buf=$(cat /sys/kernel/tracing/trace)
+	    line=$(tail -$2 /sys/kernel/tracing/trace | head -1 | sed -e 's/^[[:space:]]*//')
+	else
+	    buf=$(cat /sys/kernel/tracing/instances/$1/trace)
+	    line=$(tail -$2 /sys/kernel/tracing/instances/$1/trace | head -1 | \
+		   sed -e 's/^[[:space:]]*//')
+	fi
+	if [ $2 = 0 ]; then
+	    # whole-buf check
+	    output=$(echo "$buf" | grep "$3")
+	else
+	    output=$(echo "$line" | grep "$3")
+	fi
+	if [ "$output" = "" ]; then
+            echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO search for '$3' failed \
+		    in line '$line' or '$buf'"
+	    exit $ksft_fail
+	fi
+	if [ $V = 1 ]; then
+	    echo -e "${MAGENTA}: search_trace_name in $1 found: \n$output \nin:${BLUE} $buf ${NC}"
+        fi
+}
+
+# $1 - error message to check
+function check_err_msg() {
+    if [ "$error_msg" != "$1" ]; then
+        echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO error message '$error_msg' \
+		does not match with '$1'"
+        exit $ksft_fail
+    fi
+}
+
+function basic_tests {
+    echo -e "${GREEN}# BASIC_TESTS ${NC}"
+    if [ $LACK_DD_BUILTIN -eq 1 ]; then
+	echo "SKIP"
+	exit $ksft_skip
+    fi
+    ddcmd =_ # zero everything
+    check_match_ct =p 0
+
+    # module params are builtin to handle boot args
+    check_match_ct '\[params\]' 4 -r
+    ddcmd module params +mpf
+    check_match_ct =pmf 4
+
+    # multi-cmd input, newline separated, with embedded comments
+    cat <<"EOF" > /proc/dynamic_debug/control
+      module params =_				# clear params
+      module params +mf				# set flags
+      module params func parse_args +sl		# other flags
+EOF
+    check_match_ct =mf 3
+    check_match_ct =mfsl 1
+    ddcmd =_
+}
+
+tests_list=(
+    basic_tests
+)
+
+# Run tests
+
+ifrmmod test_dynamic_debug
+
+for test in "${tests_list[@]}"
+do
+    $test
+    echo ""
+done
+echo -en "${GREEN}# Done on: "
+date
+echo -en "${NC}"
+
+exit $ksft_pass

-- 
2.54.0

Claude review: selftests-dyndbg: add a dynamic_debug run_tests target

[Claude Code Review Bot]

Patch Review

Good addition of selftests. The config check and ksft exit codes are properly used. The test is well-structured with helper functions. Minor: there are many unused helper functions (trace-related) that are "backported from another feature branch" -- these add noise but aren't harmful.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 23/24] dyndbg: change __dynamic_func_call_cls* macros into expressions

[Jim Cromie]

The Xe driver's XE_IOCTL_DBG macro calls drm_dbg() from inside an if
(expression).  This breaks when CONFIG_DRM_USE_DYNAMIC_DEBUG=y because
the invoked macro has a do-while-0 wrapper, and is not an expression.

   if (cond && (drm_dbg("expr-form"),1)) {
      ... do some more stuff
   }

Fix for this usage by changing __dynamic_func_call_cls{,_no_desc}
macros into expressions, by replacing the do-while-0s with a ({ })
wrapper.  In the common usage, the trailing ';' converts the
expression into a statement.

   drm_dbg("statement form");

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2:

fix statement-expressions to return 0 (not void) like their respective fallbacks

   1. Add 0; to __dynamic_func_call_cls
   2. Add 0; to __dynamic_func_call_cls_no_desc
   3. Convert the disabled fallback of dynamic_hex_dump from do { ... } while(0) to ({ ... 0; })

move RvB after SoB
---
 include/linux/dynamic_debug.h | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index e4a62cb73267..2d6983186f37 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -224,24 +224,26 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
  * (|_cls):	adds in _DPRINT_CLASS_DFLT as needed
  * (|_no_desc):	former gets callsite descriptor as 1st arg (for prdbgs)
  */
-#define __dynamic_func_call_cls(id, cls, fmt, func, ...) do {	\
+#define __dynamic_func_call_cls(id, cls, fmt, func, ...) ({	\
 	DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt);	\
 	if (DYNAMIC_DEBUG_BRANCH(id)) {				\
 		func(&id, ##__VA_ARGS__);			\
 		__dynamic_dump_stack(id);			\
 	}							\
-} while (0)
+	0; /* match no_printk return value */			\
+})
 #define __dynamic_func_call(id, fmt, func, ...)				\
 	__dynamic_func_call_cls(id, _DPRINTK_CLASS_DFLT, fmt,		\
 				func, ##__VA_ARGS__)
 
-#define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) do {	\
+#define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) ({	\
 	DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt);		\
 	if (DYNAMIC_DEBUG_BRANCH(id)) {					\
 		func(__VA_ARGS__);					\
 		__dynamic_dump_stack(id);				\
 	}								\
-} while (0)
+	0; /* match no_printk return value */				\
+})
 #define __dynamic_func_call_no_desc(id, fmt, func, ...)			\
 	__dynamic_func_call_cls_no_desc(id, _DPRINTK_CLASS_DFLT,	\
 					fmt, func, ##__VA_ARGS__)
@@ -321,10 +323,12 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
 	dev_no_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__)
 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize,		\
 			 groupsize, buf, len, ascii)			\
-	do { if (0)							\
+({									\
+	if (0)								\
 		print_hex_dump(KERN_DEBUG, prefix_str, prefix_type,	\
-				rowsize, groupsize, buf, len, ascii);	\
-	} while (0)
+			       rowsize, groupsize, buf, len, ascii);	\
+	0;								\
+})
 
 #endif /* CONFIG_DYNAMIC_DEBUG || (CONFIG_DYNAMIC_DEBUG_CORE && DYNAMIC_DEBUG_MODULE) */
 

-- 
2.54.0

Claude review: dyndbg: change __dynamic_func_call_cls* macros into expressions

[Claude Code Review Bot]

Patch Review

Important fix for Xe driver's `XE_IOCTL_DBG` pattern that uses `drm_dbg()` inside an if-expression. Converting `do { } while(0)` to `({ })` is the standard solution. The `0;` return value matching `no_printk` is correct. The `dynamic_hex_dump` fallback stub also gets converted. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v3 24/24] dynamic_debug: use KBUILD_MODFILE for unique builtin module names

[Jim Cromie]

Historically dynamic-debug gets its module names from KBUILD_MODNAME.
This works well for loadable modules, as the module loader has always
required them to have unique names, but for builtins it is basically
kbasename(srcfile), which sadly gives us many modules named "main".

This makes the following ambiguous:
  bash-5.3# echo module main +m > /proc/dynamic_debug/control

since it would affect 4 independent modules named main:
  bash-5.3# ddgrep =m
  init/main.c:1265 [main]initcall_blacklist =m "blacklisting initcall %s\n"
  kernel/power/main.c:49 [main]pm_restore_gfp_mask =m "GFP mask restored\n"
  kernel/module/main.c:2862 [main]move_module =m "\t0x%lx 0x%.8lx %s\n"
  drivers/base/power/main.c:149 [main]device_pm_add =m "Adding info for %s:%s\n"

We can improve this by using KBUILD_MODFILE for dyndbg's modname in
builtins, and KBUILD_MODNAME for loadables.

The above control-file entries then become:
  init/main.c:1265 [init/main]initcall_blacklist ...
  kernel/power/main.c:49 [kernel/power/main]pm_restore_gfp_mask ...
  kernel/module/main.c:2862 [kernel/module/main]move_module ...
  drivers/base/power/main.c:149 [drivers/base/power/main]device_pm_add ...

While this is a user visible change; [params] becomes [kernel/params],
it is not a behavior change; we now match the query-module against the
subsystem/module name or its kbasename (the simple-modname), which as
before, matches all 4 modules.

This allows queries to be specific when desired: "module init/main",
while preserving the existing meaning of "module main"

The deeper reason for this change is not obvious.  If any builtin
"main" module were to add a classmap, it would attach to all "main"
modules.  If 2 "main" modules defined separate classmaps, both modules
would inadvertently share both classmaps.  Since classmaps map
classnames to 0..62, and independently defined classmaps are most
likely to start at 0 (unless author is planning to share the 0..62
range with other classmaps), we have a setup for later reserved range
conflicts.  Having unique names prevents future conflicts.

This solution isn't perfect:
1. it changes displayed [params] to [kernel/params] etc
2. its mostly redundant with "filename */main.*"
3. "module power", "module module", "module base/power" might be better
   but would break old queries.

Adapt dynamic-debug selftest:
1- Add 'test_subsystem_module_queries' to verify path-based module matching.
2- Use dynamic counting with precise regexes to determine expectations.
3- Reorder tests to run slash-query verification immediately after
   basic tests.
4- Update basic_tests and comma_terminator_tests to use 'kernel/params'
   instead of 'params' to match new path-based names for built-ins.

And adjust Documentation

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
v3: new patch in rev-3
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 Documentation/admin-guide/dynamic-debug-howto.rst  | 40 ++++++++++----------
 include/linux/dynamic_debug.h                      | 17 +++++++--
 lib/dynamic_debug.c                                |  3 +-
 .../selftests/dynamic_debug/dyndbg_selftest.sh     | 44 ++++++++++++++++++++--
 4 files changed, 77 insertions(+), 27 deletions(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 9c2f096ed1d8..8befb69575b7 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -38,12 +38,12 @@ You can view the currently configured behaviour in the *prdbg* catalog::
 
   :#> head -n7 /proc/dynamic_debug/control
   # filename:lineno [module]function flags format
-  init/main.c:1179 [main]initcall_blacklist =_ "blacklisting initcall %s\n"
-  init/main.c:1218 [main]initcall_blacklisted =_ "initcall %s blacklisted\n"
-  init/main.c:1424 [main]run_init_process =_ "  with arguments:\n"
-  init/main.c:1426 [main]run_init_process =_ "    %s\n"
-  init/main.c:1427 [main]run_init_process =_ "  with environment:\n"
-  init/main.c:1429 [main]run_init_process =_ "    %s\n"
+  init/main.c:1179 [init/main]initcall_blacklist =_ "blacklisting initcall %s\n"
+  init/main.c:1218 [init/main]initcall_blacklisted =_ "initcall %s blacklisted\n"
+  init/main.c:1424 [init/main]run_init_process =_ "  with arguments:\n"
+  init/main.c:1426 [init/main]run_init_process =_ "    %s\n"
+  init/main.c:1427 [init/main]run_init_process =_ "  with environment:\n"
+  init/main.c:1429 [init/main]run_init_process =_ "    %s\n"
 
 The 3rd space-delimited column shows the current flags, preceded by
 a ``=`` for easy use with grep/cut. ``=p`` shows enabled callsites.
@@ -59,10 +59,10 @@ query/commands to the control file.  Example::
 
   :#> ddcmd '-p; module main func run* +p'
   :#> grep =p /proc/dynamic_debug/control
-  init/main.c:1424 [main]run_init_process =p "  with arguments:\n"
-  init/main.c:1426 [main]run_init_process =p "    %s\n"
-  init/main.c:1427 [main]run_init_process =p "  with environment:\n"
-  init/main.c:1429 [main]run_init_process =p "    %s\n"
+  init/main.c:1424 [init/main]run_init_process =p "  with arguments:\n"
+  init/main.c:1426 [init/main]run_init_process =p "    %s\n"
+  init/main.c:1427 [init/main]run_init_process =p "  with environment:\n"
+  init/main.c:1429 [init/main]run_init_process =p "    %s\n"
 
 Error messages go to console/syslog::
 
@@ -161,17 +161,19 @@ file
 	file kernel/freezer.c	# ie column 1 of control file
 	file drivers/usb/*	# all callsites under it
 	file inode.c:start_*	# parse :tail as a func (above)
-	file inode.c:1-100	# parse :tail as a line-range (above)
+	file inode.c:1-100	# parse :tail as a line-range (below)
 
 module
-    The given string is compared against the module name
-    of each callsite.  The module name is the string as
-    seen in ``lsmod``, i.e. without the directory or the ``.ko``
-    suffix and with ``-`` changed to ``_``.  Examples::
-
-	module sunrpc
-	module nfsd
-	module drm*	# both drm, drm_kms_helper
+    The query string is compared against the subsystem module name of
+    each callsite, as shown in the control file.  The simple module
+    name is the string as seen in ``lsmod``, i.e. without the
+    directory or the ``.ko`` suffix and with ``-`` changed to ``_``.
+
+    Examples::
+
+	module nfsd        # simple modname (as from lsmod)
+	module init/main   # subsystem modname (as in control file)
+	module drm*	   # both drm, drm_kms_helper
 
 format
     The given string is searched for in the dynamic debug format
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 2d6983186f37..aee6f3d0916f 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -8,6 +8,17 @@
 
 #include <linux/build_bug.h>
 
+/*
+ * Pick the best name for the module:
+ * KBUILD_MODFILE includes the path (e.g., drivers/usb/core/usbcore) for built-ins.
+ * Fall back to KBUILD_MODNAME for modules (loader requires unique names).
+ */
+#ifdef KBUILD_MODFILE
+# define DDEBUG_MODNAME KBUILD_MODFILE
+#else
+# define DDEBUG_MODNAME KBUILD_MODNAME
+#endif
+
 /*
  * An instance of this structure is created in a special
  * ELF section at every dynamic debug callsite.  At runtime,
@@ -128,9 +139,9 @@ struct _ddebug_class_param {
 #define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...)		\
 	static const char *_var##_classnames[] = { __VA_ARGS__ };	\
 	static struct _ddebug_class_map __aligned(8) __used		\
-		__section("__dyndbg_class_maps") _var = {			\
+	__section("__dyndbg_class_maps") _var = {			\
 		.mod = THIS_MODULE,					\
-		.mod_name = KBUILD_MODNAME,				\
+		.mod_name = DDEBUG_MODNAME,				\
 		.base = _base,						\
 		.map_type = _maptype,					\
 		.length = ARRAY_SIZE(_var##_classnames),		\
@@ -169,7 +180,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
 #define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt)	\
 	static struct _ddebug  __aligned(8)			\
 	__section("__dyndbg_descs") name = {			\
-		.modname = KBUILD_MODNAME,			\
+		.modname = DDEBUG_MODNAME,			\
 		.function = __func__,				\
 		.filename = __FILE__,				\
 		.format = (fmt),				\
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index fdb730db385e..7f78c6b3eeaf 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -248,7 +248,8 @@ static int ddebug_change(const struct ddebug_query *query,
 
 		/* match against the module name */
 		if (query->module &&
-		    !match_wildcard(query->module, di->mod_name))
+		    !match_wildcard(query->module, di->mod_name) &&
+		    !match_wildcard(query->module, kbasename(di->mod_name)))
 			continue;
 
 		if (query->class_string) {
diff --git a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
index 8b2b7388678e..541a2ea7bcb3 100755
--- a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
+++ b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
@@ -76,9 +76,9 @@ function handle_exit_code() {
 # $1 - pattern to match, pattern in $1 is enclosed by spaces for a match ""\s$1\s"
 # $2 - number of times the pattern passed in $1 is expected to match
 # $3 - optional can be set either to "-r" or "-v"
-#       "-r" means relaxed matching in this case pattern provided in $1 is passed
-#       as is without enclosing it with spaces
-#       "-v" prints matching lines
+#       "-r" means relaxed matching in this case pattern provided in
+#       $1 is passed as is without enclosing it with spaces "-v"
+#       prints matching lines
 # $4 - optional when $3 is set to "-r" then $4 can be used to pass "-v"
 function check_match_ct {
     pattern="\s$1\s"
@@ -223,7 +223,7 @@ function basic_tests {
     check_match_ct =p 0
 
     # module params are builtin to handle boot args
-    check_match_ct '\[params\]' 4 -r
+    check_match_ct '\[kernel/params\]' 4 -r
     ddcmd module params +mpf
     check_match_ct =pmf 4
 
@@ -238,8 +238,44 @@ EOF
     ddcmd =_
 }
 
+function test_subsystem_module_queries {
+    echo -e "${GREEN}# TEST_SUBSYTEM_MODULE_QUERIES ${NC}"
+    ddcmd =_
+
+    # Find how many 'main' modules we have in total (by basename)
+    # Use a more precise regex to avoid false positives like [irqdomain]
+    local total_main=$(grep -c "\[\([^]]*/\)\?main\]" /proc/dynamic_debug/control)
+    echo "# found $total_main total 'main' modules"
+
+    if [ $total_main -eq 0 ]; then
+        echo "SKIP - no 'main' modules found to test slashes"
+        return
+    fi
+
+    echo "# testing 'module */main'"
+    ddcmd module "*/main" +p
+    # This should match modules that HAVE a slash and end in /main
+    local slash_main=$(grep -c "\[[^]]*/main\]" /proc/dynamic_debug/control)
+    check_match_ct =p $slash_main -r
+
+    echo "# testing 'module init/main' (specific path)"
+    ddcmd =_
+    ddcmd module "init/main" +p
+    local init_main=$(grep -c "\[init/main\]" /proc/dynamic_debug/control)
+    check_match_ct =p $init_main
+
+    echo "# testing 'module main' (basename match)"
+    ddcmd =_
+    ddcmd module main +p
+    # This should match ALL $total_main entries due to kbasename matching
+    check_match_ct =p $total_main
+
+    ddcmd =_
+}
+
 tests_list=(
     basic_tests
+    test_subsystem_module_queries
 )
 
 # Run tests

-- 
2.54.0

Claude review: dynamic_debug: use KBUILD_MODFILE for unique builtin module names

[Claude Code Review Bot]

Patch Review

The most impactful user-visible change. The backward-compatibility via `kbasename()` matching is well-handled:
```c
if (query->module &&
    !match_wildcard(query->module, di->mod_name) &&
    !match_wildcard(query->module, kbasename(di->mod_name)))
```
This preserves existing `module main` queries while allowing `module init/main` for precision. The `DDEBUG_MODNAME` ifdef falling back to `KBUILD_MODNAME` for loadable modules is correct since `KBUILD_MODFILE` isn't always defined. The selftest updates are appropriate. The cover letter already explains the deeper motivation (classmap ambiguity prevention). The documentation updates are good. One concern: the cover letter mentions this is patch-25 but it's actually patch 24 in the series -- numbering was likely adjusted between cover letter writing and posting.

---
Generated by Claude Code Patch Reviewer

Claude review: dynamic-debug cleanups refactors maintenance + alignment fix

[Claude Code Review Bot]

Overall Series Review

Subject: dynamic-debug cleanups refactors maintenance + alignment fix
Author: Jim Cromie <jim.cromie@gmail.com>
Patches: 25
Reviewed: 2026-06-04T14:06:55.467449

---

This is a substantial 24-patch series from Jim Cromie for dynamic-debug (dyndbg) maintenance, cleanup, refactoring, and a bug fix. The series is well-structured in a logical progression:

1. **Patches 1-2**: Documentation updates
2. **Patches 3-7**: Linker script alignment fix (the actual bug fix for NULL ptr on i386)
3. **Patches 8-21**: Dyndbg internals cleanup and refactoring (code factoring, API simplification, struct reorganization, u64 upgrade)
4. **Patch 22**: Selftest addition
5. **Patches 23-24**: Expression macro fix for Xe driver, and KBUILD_MODFILE for unique builtin names

The DRM-relevant portions are relatively small: patch 18 changes `__drm_debug` from `unsigned long` to `u64` and renames `struct ddebug_class_param` to `struct _ddebug_class_param` in drm_print.c, and patch 19 renames section names (__dyndbg -> __dyndbg_descs). These are reasonable changes tied to the broader refactoring.

Most patches have Reviewed-by from Louis Chauvet, and the linker script patches have Reviewed-by from Petr Pavlu.

**Concerns**: The cover letter still has the "EDITME" placeholders in the v3 changes section. The `for_subvec` macro (patch 17) and `dd_set_module_subrange` macro (patch 21) are somewhat unusual/complex macro patterns that may be harder to maintain. The KBUILD_MODFILE change (patch 24) is a user-visible change that alters `/proc/dynamic_debug/control` output format for builtins.

Overall this is a well-organized cleanup series. The section alignment fix (patches 3-7) is the most important functional change.

---
Generated by Claude Code Patch Reviewer

[PATCH v4 00/25] dynamic-debug cleanups refactors maintenance + alignment fix

[Jim Cromie]

V4 of this series drops 2 doc-only patches in v3, recently picked up
by linux-doc, thx Jonathan

So new 1st 5 are a fix to a linker-script alignment problem in 32bit
arches causing a null-ptr scanning dyndbg-descriptor section on i386.
These were reviewed by Petr Pavlu.

V4 main change is addition and use of match_wildcard_hyphen(), which
allows that "i2c_hid" is same as "i2c-hid" wrt to modname comparison.
This addresses sashiko-dev's feedback on V3.

v3:

The remaining patches are cleanups, refactors in preparation for an
API change needed to fix a regression in DRM when it uses classmaps.
I split these out for easier review, I will follow up with the API
change afterwards.

The biggest revision vs V2 is the new patch: 25.  It addresses a flaw
detected by sashiko which is best described by example.

Dyndbg uses KBUILD_MODNAME to provide module-name, this works well for
loadable modules (module loader requires unique module names), but for
builtin modules, is effectively kbasename, and not unique.

So we get 4 modules named "main": init/main, kernel/power/main,
kernel/base/poser/main.  This ambiguity is visible in user-space since
the beginning of dyndbg.

Now suppose kernel/{,base}/power/main want to define classmaps to
categorize the various pr-debugs they have.  The current code finds a
module's classmaps by strcmp on modname, so init/main will match
against classmaps defined by both kernel/{,base}/power/main.

The current code will also map "main" classes to kernel/*/power/main,
so they will probably work at first, but 2 independent classmaps can
both use class-ids 0-N, but will conflict if they're both used by a
module.  Then we have classmap overlaps and unpredictable results.

patch-24 eliminates the ambiguity by using KBUILD_MODFILE to provide a
unique module-name, then adds matching against kbasename(modname) to
restore the legacy query behavior.  It *does* change the modname
exposed in /proc/dynamic_debug/control, but not the result of a query
like "module main +p".

OLDER VERSIONS:

V2 primarily revises:
 https://lore.kernel.org/lkml/20260504-dd-cleanups-2-v1-0-6fdd24040642@gmail.com/
    
V2 addressed most of sashiko's feedback on V1:
 https://sashiko.dev/#/patchset/20260504-dd-cleanups-2-v1-0-6fdd24040642%40gmail.com
    
It dropped the pr-fmt patch, as not reproducible,
advanced the drop-NAMES patch to reduce subsequent churn,
and fixed the classmaps PARAMs to u64 to avoid 32bit flags on 32bit arches
    
For easy one-stop-shopping, V2 also included 2 smaller series:
    
1st fixes a section alignment problem, with Reviewed-by from Petr Pavlu
 https://lore.kernel.org/lkml/20260515-asm-generic-1-v3-0-680b273666d4@gmail.com/
    
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
    

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
Changes in v4:
- EDITME: describe what is new in this series revision.
- EDITME: use bulletpoints and terse descriptions.
- Link to v3: https://lore.kernel.org/r/20260601-dd-maint-2-v3-0-4a15b241bd3c@gmail.com

Changes in v3:
- EDITME: describe what is new in this series revision.
- EDITME: use bulletpoints and terse descriptions.
- Link to v2: https://lore.kernel.org/r/20260523-dd-maint-2-v2-0-b937312aa083@gmail.com

---
Jim Cromie (25):
      docs/dyndbg: update examples \012 to \n
      docs/dyndbg: explain flags parse 1st
      vmlinux.lds.h: refactor BOUNDED_SECTION_* macros into bounded_sections.lds.h
      vmlinux.lds.h: drop unused HEADERED_SECTION* macros
      vmlinux.lds.h: Fix ALIGN(8) omission causing NULL ptr on i386
      vmlinux.lds.h: remove redundant ALIGN(8) directives
      dyndbg.lds.S: fix lost dyndbg sections in modules
      dyndbg: factor ddebug_match_desc out from ddebug_change
      dyndbg: add stub macro for DECLARE_DYNDBG_CLASSMAP
      dyndbg: reword "class unknown," to "class:_UNKNOWN_"
      dyndbg-API: remove DD_CLASS_TYPE_(DISJOINT|LEVEL)_NAMES and code
      dyndbg: drop NUM_TYPE_ARGS
      dyndbg: reduce verbose/debug clutter
      dyndbg: refactor param_set_dyndbg_classes and below
      dyndbg: tighten fn-sig of ddebug_apply_class_bitmap
      dyndbg: replace classmap list with an array-slice
      dyndbg: macrofy a 2-index for-loop pattern
      dyndbg: Upgrade class param storage to u64 for 64-bit classmaps
      dyndbg,module: make proper substructs in _ddebug_info
      dyndbg: move mod_name down from struct ddebug_table to _ddebug_info
      dyndbg: hoist classmap-filter-by-modname up to ddebug_add_module
      selftests-dyndbg: add a dynamic_debug run_tests target
      dyndbg: change __dynamic_func_call_cls* macros into expressions
      lib/parser: add match_wildcard_hyphen() for agnostic matching
      dynamic_debug: use KBUILD_MODFILE for unique builtin module names

 Documentation/admin-guide/dynamic-debug-howto.rst  |  55 ++-
 MAINTAINERS                                        |   2 +
 drivers/gpu/drm/drm_print.c                        |   6 +-
 include/asm-generic/bounded_sections.lds.h         |  32 ++
 include/asm-generic/dyndbg.lds.h                   |  18 +
 include/asm-generic/vmlinux.lds.h                  |  68 +--
 include/drm/drm_print.h                            |   2 +-
 include/linux/dynamic_debug.h                      | 133 +++---
 include/linux/parser.h                             |   1 +
 kernel/module/main.c                               |  12 +-
 lib/dynamic_debug.c                                | 507 ++++++++++-----------
 lib/parser.c                                       |  58 ++-
 lib/test_dynamic_debug.c                           |  30 +-
 scripts/module.lds.S                               |   2 +
 tools/testing/selftests/Makefile                   |   1 +
 tools/testing/selftests/dynamic_debug/Makefile     |   9 +
 tools/testing/selftests/dynamic_debug/config       |   8 +
 .../selftests/dynamic_debug/dyndbg_selftest.sh     | 343 ++++++++++++++
 18 files changed, 833 insertions(+), 454 deletions(-)
---
base-commit: e43ffb69e0438cddd72aaa30898b4dc446f664f8
change-id: 20260521-dd-maint-2-76c542079420

Best regards,
-- 
Jim Cromie <jim.cromie@gmail.com>

[PATCH v4 01/25] docs/dyndbg: update examples \012 to \n

[Jim Cromie]

commit 47ea6f99d06e ("dyndbg: use ESCAPE_SPACE for cat control")
changed the control-file to display format strings with "\n" rather
than "\012".  Update the docs to match the new reality.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Tested-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 Documentation/admin-guide/dynamic-debug-howto.rst | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 095a63892257..4b14d9fd0300 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -38,12 +38,12 @@ You can view the currently configured behaviour in the *prdbg* catalog::
 
   :#> head -n7 /proc/dynamic_debug/control
   # filename:lineno [module]function flags format
-  init/main.c:1179 [main]initcall_blacklist =_ "blacklisting initcall %s\012
-  init/main.c:1218 [main]initcall_blacklisted =_ "initcall %s blacklisted\012"
-  init/main.c:1424 [main]run_init_process =_ "  with arguments:\012"
-  init/main.c:1426 [main]run_init_process =_ "    %s\012"
-  init/main.c:1427 [main]run_init_process =_ "  with environment:\012"
-  init/main.c:1429 [main]run_init_process =_ "    %s\012"
+  init/main.c:1179 [main]initcall_blacklist =_ "blacklisting initcall %s\n"
+  init/main.c:1218 [main]initcall_blacklisted =_ "initcall %s blacklisted\n"
+  init/main.c:1424 [main]run_init_process =_ "  with arguments:\n"
+  init/main.c:1426 [main]run_init_process =_ "    %s\n"
+  init/main.c:1427 [main]run_init_process =_ "  with environment:\n"
+  init/main.c:1429 [main]run_init_process =_ "    %s\n"
 
 The 3rd space-delimited column shows the current flags, preceded by
 a ``=`` for easy use with grep/cut. ``=p`` shows enabled callsites.
@@ -59,10 +59,10 @@ query/commands to the control file.  Example::
 
   :#> ddcmd '-p; module main func run* +p'
   :#> grep =p /proc/dynamic_debug/control
-  init/main.c:1424 [main]run_init_process =p "  with arguments:\012"
-  init/main.c:1426 [main]run_init_process =p "    %s\012"
-  init/main.c:1427 [main]run_init_process =p "  with environment:\012"
-  init/main.c:1429 [main]run_init_process =p "    %s\012"
+  init/main.c:1424 [main]run_init_process =p "  with arguments:\n"
+  init/main.c:1426 [main]run_init_process =p "    %s\n"
+  init/main.c:1427 [main]run_init_process =p "  with environment:\n"
+  init/main.c:1429 [main]run_init_process =p "    %s\n"
 
 Error messages go to console/syslog::
 

-- 
2.54.0

Claude review: docs/dyndbg: update examples \012 to \n

[Claude Code Review Bot]

Patch Review

Straightforward doc update replacing `\012` with `\n` to match reality after commit 47ea6f99d06e. Has Reviewed-by and Tested-by from Louis Chauvet. No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH v11 00/65] Fix DRM_USE_DYNAMIC_DEBUG=y

[Jim Cromie]

resend - apologies, faf'g with --cc-cover & to: lists

The drm subsystem has *lots* of debug statements, in 11 categories

 $> ack '\w*_dbg' drivers/gpu/drm/ | wc
    5532   29318  553806
 $> ack 'DRM_DEBUG\w*' drivers/gpu/drm/ | wc
    2208   12856  212035

All of these are bit-tests on __drm_debug, exposed to users as
/sys/module/drm/parameters/debug.  Many of these are done often,
vblank is done ~100/sec for some displays.  Over the uptime of many
boxes, this is a lot of cpu cycles, on bits that are almost always
off.

Dynamic-debug excels at replacing such tests with NOOPS.  Classmaps
was devised to bring that 0-off-cost to drm's categories.

Classmaps-v1 went into the kernel in Sept 2022, in 2 chunks:
  b7b4eebdba7b..6ea3bf466ac6    # core dyndbg changes
  0406faf25fb1..ee7d633f2dfb    # drm adoption

Sadly DRM-CI found a regression during init with drm.debug=<initval>;
the static-keys underneath the drm-dbgs in drm.ko got enabled, but
those in drivers & helpers did not.

Root Problem:

DECLARE_DYNDBG_CLASSMAP defined the classmap, but it repeated use in
both core and drivers violated a K&R rule "define once, refer
afterwards".  This flaw resulted in a regression; with drm.debug=0xFF
boot arg, drm-core got enabled, but drivers,etc did not.

So in feb 2023, this resulted in:
commit bb2ff6c27bc9 ("drm: Disable dynamic debug as broken")

This patchset replaces it with DYNDBG_CLASSMAP_DEFINE (invoked once in
drm-core) and DYNDBG_CLASSMAP_USE (invoked repeatedly, in drivers &
helpers).

_DEFINE exports the classmap it creates (in drm.ko), other modules
_USE the classmap.  The _USE adds a record ref'g the _DEFINEd (&
exported) classmap, in a 2nd __dyndbg_class_users section.

So now at modprobe, dyndbg scans the new section after the 1st
__dyndbg_class_maps section, follows the linkage to the _DEFINEr
module, finds the (optional) kernel-param controlling the classmap,
examines its drm.debug=<initval>, and applies it to the module being
initialized.

Savings effect:

No real effort was made to quantify the savings; bit-tests are almost
unmeasurable individually, and [1] DRM_USE_DYNAMIC_DEBUG=y purposely
depends upon JUMP_LABEL to avoid its use where it cannot help.

That said, Ive booted one box with drm.debug=0x1ff on the boot-line,
with a script run by systemd to turn it off once boot completes. It
issued ~25k messages in that time.

Status-v11:

Now rebased on drm-misc-next, to allow grinding on DRM-CI.
https://gitlab.freedesktop.org/jim.cromie/kernel-drm-next-dd/-/pipelines/1622778

DRM-CI revealed 2 bugs, fixes now included:
1. drm_buddy had 32bit truncation error, causing unexpected pass
2. drm_printer_debug_fn disregarded drm.debug, spewing msgs, causing timeout.

Also tuned vblank* to avoid drm_debug_enabled() bit-test.
Probably should defer this until [1]=y is default. It isnt yet.

Up to this point, classmaps-v2 has been stuck, straddled on the fence
between drm and dynamic-debug; it needs a little help towards one side
or the other.  ISTM that drm is the actual user, and the acid-test of
its proper function; the dyndbg selftest recaps the 2-module scenario,
but this cannot finally prove anything absent drm.

Verification: DRM-CI Pipeline #1622778
  - KUnit (arm32, arm64, x86_64): All 621 tests PASSED.
    Specifically confirms the 64-bit truncation fixes in drm_buddy.
  - i915-CML: 370 tests PASSED, 0 FAIL.
    Confirms the quelling of the UART storm in shared print callbacks.
  - Overall: No regressions found in dyndbg or buddy allocator logic.

Future:

Lukas Bartosik has been patiently waiting for classmaps to land, so he
can add dyndbg-to-ftrace functionality.  This new feature will allow
steering any/all drm.debug messages to a private ftrace buffer, and
also to mix in other pr_debug messages.  Other ftrace streams could
also be sent there (possibly w/o code changes, tbd).  It could be a
big step towards a featureful crash-buffer.

Ive also cobbled together a maple-tree based replacement for the
__dyndbg_descriptors linker section; it copies the section contents
into 3 maple trees, then drops the section in __init.  By eliminating
the redundant columns (module, file, function) it reduces the storage
needed by 40%.  Early measurements show no net runtime costs, maple
trees make good furniture.

Given that progress, I also hacked up a maple-tree based dynamic
prefix cache.  Currently the dynamic-prefix is re-written for every
prefixed callsite; this can get expensive.  By careful keying (flags
on top, descriptor address underneath), a single prefix string can
span an entire range (smallest of enabled module, file, function).

That last one doesn't help DRM, cuz it doesnt use dynamic-prefixes,
but with this optimization in place, it could be adapted to do so.

Lastly, I have an RFC jump-label patchset that dramatically cuts IPIs,
currently 1 per pr_debug (to ~1/140), by sorting the (existing) queue,
rather than flushing it when a non-increasing patch-addr is queued.

I'd like to move forward with all these, but I anticipate a "fix
classmaps 1st" response.

Jim Cromie (65):
  dyndbg: fix NULL ptr on i386 due to section alignment
  dyndbg: factor ddebug_match_desc out from ddebug_change
  dyndbg: add stub macro for DECLARE_DYNDBG_CLASSMAP
  docs/dyndbg: update examples \012 to \n
  docs/dyndbg: explain flags parse 1st
  test-dyndbg: fixup CLASSMAP usage error
  dyndbg: reword "class unknown," to "class:_UNKNOWN_"
  dyndbg: make ddebug_class_param union members same size
  dyndbg: drop NUM_TYPE_ARRAY
  dyndbg: tweak pr_fmt to avoid expansion conflicts
  dyndbg: reduce verbose/debug clutter
  dyndbg: refactor param_set_dyndbg_classes and below
  dyndbg: tighten fn-sig of ddebug_apply_class_bitmap
  dyndbg: replace classmap list with a vector
  dyndbg: macrofy a 2-index for-loop pattern
  dyndbg,module: make proper substructs in _ddebug_info
  dyndbg: hoist classmap-filter-by-modname up to ddebug_add_module
  dyndbg: move mod_name down from struct ddebug_table to _ddebug_info
  dyndbg-API: remove DD_CLASS_TYPE_(DISJOINT|LEVEL)_NAMES and code
  selftests-dyndbg: add a dynamic_debug run_tests target
  dyndbg: change __dynamic_func_call_cls* macros into expressions
  dyndbg-API: replace DECLARE_DYNDBG_CLASSMAP
  dyndbg: detect class_id reservation conflicts
  dyndbg: check DYNAMIC_DEBUG_CLASSMAP_DEFINE args at compile-time
  dyndbg-test: change do_prints testpoint to accept a loopct
  dyndbg-API: promote DYNAMIC_DEBUG_CLASSMAP_PARAM to API
  dyndbg: treat comma as a token separator
  dyndbg: split multi-query strings with %
  selftests-dyndbg: add test_mod_submod
  dyndbg: resolve "protection" of class'd pr_debug
  dyndbg: add DYNAMIC_DEBUG_CLASSMAP_USE_(dd_class_name, offset)
  dyndbg: Harden classmap and callsite validation
  docs/dyndbg: add classmap info to howto
  drm: use correct ccflags-y spelling
  drm-dyndbg: adapt drm core to use dyndbg classmaps-v2
  drm-dyndbg: adapt DRM to invoke DYNAMIC_DEBUG_CLASSMAP_PARAM
  drm-print: modernize an archaic comment
  drm-print: fix config-dependent unused variable
  drm-dyndbg: DRM_CLASSMAP_USE in amdgpu driver
  drm-dyndbg: DRM_CLASSMAP_USE in i915 driver
  drm-dyndbg: DRM_CLASSMAP_USE in drm_crtc_helper
  drm-dyndbg: DRM_CLASSMAP_USE in drm_dp_helper
  drm-dyndbg: DRM_CLASSMAP_USE in nouveau
  drm-dyndbg: add DRM_CLASSMAP_USE to Xe driver
  drm-dyndbg: add DRM_CLASSMAP_USE to virtio_gpu
  drm-dyndbg: add DRM_CLASSMAP_USE to simpledrm
  drm-dyndbg: add DRM_CLASSMAP_USE to bochs
  drm-dyndbg: add DRM_CLASSMAP_USE to etnaviv
  drm-dyndbg: add DRM_CLASSMAP_USE to gma500 driver
  drm-dyndbg: add DRM_CLASSMAP_USE to radeon
  drm-dyndbg: add DRM_CLASSMAP_USE to vmwgfx driver
  drm-dyndbg: add DRM_CLASSMAP_USE to vkms driver
  drm-dyndbg: add DRM_CLASSMAP_USE to udl driver
  drm-dyndbg: add DRM_CLASSMAP_USE to mgag200 driver
  drm-dyndbg: add DRM_CLASSMAP_USE to the gud driver
  drm-dyndbg: add DRM_CLASSMAP_USE to the qxl driver
  drm-dyndbg: add DRM_CLASSMAP_USE to the drm_gem_shmem_helper driver
  accel: add -DDYNAMIC_DEBUG_MODULE to subdir-ccflags
  accel/ivpu: implement IVPU_DBG_* as a dyndbg classmap
  drm: restore CONFIG_DRM_USE_DYNAMIC_DEBUG un-BROKEN
  accel/ethosu: enable drm.debug control
  accel/rocket: enable drm.debug control
  drm_buddy: fix 64-bit truncation in power-of-2 rounding
  drm_print: fix drm_printer dynamic debug bypass
  drm_vblank: use dyndbg's static-key to avoid flag-check

 .../admin-guide/dynamic-debug-howto.rst       | 184 +++-
 MAINTAINERS                                   |   3 +-
 drivers/accel/Makefile                        |   7 +-
 drivers/accel/ethosu/ethosu_drv.c             |   3 +
 drivers/accel/ivpu/ivpu_drv.c                 |  27 +-
 drivers/accel/ivpu/ivpu_drv.h                 |  45 +-
 drivers/accel/rocket/rocket_gem.c             |   2 +
 drivers/gpu/buddy.c                           |   4 +-
 drivers/gpu/drm/Kconfig.debug                 |   1 -
 drivers/gpu/drm/Makefile                      |   3 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c       |  12 +-
 drivers/gpu/drm/display/drm_dp_helper.c       |  12 +-
 drivers/gpu/drm/drm_crtc_helper.c             |  12 +-
 drivers/gpu/drm/drm_gem_shmem_helper.c        |   1 +
 drivers/gpu/drm/drm_print.c                   |  38 +-
 drivers/gpu/drm/drm_vblank.c                  |  10 +-
 drivers/gpu/drm/etnaviv/etnaviv_drv.c         |   2 +
 drivers/gpu/drm/gma500/psb_drv.c              |   2 +
 drivers/gpu/drm/gud/gud_drv.c                 |   2 +
 drivers/gpu/drm/i915/i915_params.c            |  12 +-
 drivers/gpu/drm/mgag200/mgag200_drv.c         |   2 +
 drivers/gpu/drm/nouveau/nouveau_drm.c         |  12 +-
 drivers/gpu/drm/qxl/qxl_drv.c                 |   2 +
 drivers/gpu/drm/radeon/radeon_drv.c           |   2 +
 drivers/gpu/drm/sysfb/simpledrm.c             |   2 +
 drivers/gpu/drm/tiny/bochs.c                  |   2 +
 drivers/gpu/drm/udl/udl_main.c                |   2 +
 drivers/gpu/drm/virtio/virtgpu_drv.c          |   2 +
 drivers/gpu/drm/vkms/vkms_drv.c               |   2 +
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c           |   2 +
 drivers/gpu/drm/xe/xe_drm_client.c            |   2 +
 include/asm-generic/vmlinux.lds.h             |  19 +-
 include/drm/drm_print.h                       |  22 +-
 include/linux/dynamic_debug.h                 | 304 +++++--
 kernel/module/main.c                          |  15 +-
 lib/Kconfig.debug                             |  24 +-
 lib/Makefile                                  |   5 +
 lib/dynamic_debug.c                           | 814 ++++++++++++------
 lib/test_dynamic_debug.c                      | 198 +++--
 lib/test_dynamic_debug_submod.c               |  21 +
 tools/testing/selftests/Makefile              |   1 +
 .../testing/selftests/dynamic_debug/Makefile  |   9 +
 tools/testing/selftests/dynamic_debug/config  |   7 +
 .../dynamic_debug/dyndbg_selftest.sh          | 373 ++++++++
 44 files changed, 1665 insertions(+), 561 deletions(-)
 create mode 100644 lib/test_dynamic_debug_submod.c
 create mode 100644 tools/testing/selftests/dynamic_debug/Makefile
 create mode 100644 tools/testing/selftests/dynamic_debug/config
 create mode 100755 tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh

-- 
2.53.0

[PATCH v11 04/65] docs/dyndbg: update examples \012 to \n

[Jim Cromie]

commit 47ea6f99d06e ("dyndbg: use ESCAPE_SPACE for cat control")
changed the control-file to display format strings with "\n" rather
than "\012".  Update the docs to match the new reality.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Tested-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 .../admin-guide/dynamic-debug-howto.rst       | 20 +++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 095a63892257..4b14d9fd0300 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -38,12 +38,12 @@ You can view the currently configured behaviour in the *prdbg* catalog::
 
   :#> head -n7 /proc/dynamic_debug/control
   # filename:lineno [module]function flags format
-  init/main.c:1179 [main]initcall_blacklist =_ "blacklisting initcall %s\012
-  init/main.c:1218 [main]initcall_blacklisted =_ "initcall %s blacklisted\012"
-  init/main.c:1424 [main]run_init_process =_ "  with arguments:\012"
-  init/main.c:1426 [main]run_init_process =_ "    %s\012"
-  init/main.c:1427 [main]run_init_process =_ "  with environment:\012"
-  init/main.c:1429 [main]run_init_process =_ "    %s\012"
+  init/main.c:1179 [main]initcall_blacklist =_ "blacklisting initcall %s\n"
+  init/main.c:1218 [main]initcall_blacklisted =_ "initcall %s blacklisted\n"
+  init/main.c:1424 [main]run_init_process =_ "  with arguments:\n"
+  init/main.c:1426 [main]run_init_process =_ "    %s\n"
+  init/main.c:1427 [main]run_init_process =_ "  with environment:\n"
+  init/main.c:1429 [main]run_init_process =_ "    %s\n"
 
 The 3rd space-delimited column shows the current flags, preceded by
 a ``=`` for easy use with grep/cut. ``=p`` shows enabled callsites.
@@ -59,10 +59,10 @@ query/commands to the control file.  Example::
 
   :#> ddcmd '-p; module main func run* +p'
   :#> grep =p /proc/dynamic_debug/control
-  init/main.c:1424 [main]run_init_process =p "  with arguments:\012"
-  init/main.c:1426 [main]run_init_process =p "    %s\012"
-  init/main.c:1427 [main]run_init_process =p "  with environment:\012"
-  init/main.c:1429 [main]run_init_process =p "    %s\012"
+  init/main.c:1424 [main]run_init_process =p "  with arguments:\n"
+  init/main.c:1426 [main]run_init_process =p "    %s\n"
+  init/main.c:1427 [main]run_init_process =p "  with environment:\n"
+  init/main.c:1429 [main]run_init_process =p "    %s\n"
 
 Error messages go to console/syslog::
 
-- 
2.53.0

Claude review: docs/dyndbg: update examples \012 to \n

[Claude Code Review Bot]

Patch Review

Trivial doc update to match reality after `47ea6f99d06e`. Fine.

---
Generated by Claude Code Patch Reviewer