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

[Jim Cromie <jim.cromie@gmail.com>]

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>