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* [PATCH v6 0/9] Add generated modalias to modules.builtin.modinfo
@ 2025-08-14 13:07 Alexey Gladkov
  2025-08-14 13:07 ` [PATCH v6 1/9] kbuild: always create intermediate vmlinux.unstripped Alexey Gladkov
                   ` (8 more replies)
  0 siblings, 9 replies; 27+ messages in thread
From: Alexey Gladkov @ 2025-08-14 13:07 UTC (permalink / raw)
  To: Nathan Chancellor, Nicolas Schier, Masahiro Yamada, Petr Pavlu,
	Luis Chamberlain, Sami Tolvanen, Daniel Gomez
  Cc: linux-kernel, linux-modules, linux-kbuild, Alexey Gladkov

The modules.builtin.modinfo file is used by userspace (kmod to be specific) to
get information about builtin modules. Among other information about the module,
information about module aliases is stored. This is very important to determine
that a particular modalias will be handled by a module that is inside the
kernel.

There are several mechanisms for creating modalias for modules:

The first is to explicitly specify the MODULE_ALIAS of the macro. In this case,
the aliases go into the '.modinfo' section of the module if it is compiled
separately or into vmlinux.o if it is builtin into the kernel.

The second is the use of MODULE_DEVICE_TABLE followed by the use of the
modpost utility. In this case, vmlinux.o no longer has this information and
does not get it into modules.builtin.modinfo.

For example:

$ modinfo pci:v00008086d0000A36Dsv00001043sd00008694bc0Csc03i30
modinfo: ERROR: Module pci:v00008086d0000A36Dsv00001043sd00008694bc0Csc03i30 not found.

$ modinfo xhci_pci
name:           xhci_pci
filename:       (builtin)
license:        GPL
file:           drivers/usb/host/xhci-pci
description:    xHCI PCI Host Controller Driver

The builtin module is missing alias "pci:v*d*sv*sd*bc0Csc03i30*" which will be
generated by modpost if the module is built separately.

To fix this it is necessary to add the generated by modpost modalias to
modules.builtin.modinfo. Fortunately modpost already generates .vmlinux.export.c
for exported symbols. It is possible to add `.modinfo` for builtin modules and
modify the build system so that `.modinfo` section is extracted from the
intermediate vmlinux after modpost is executed.

---
Notes:
- v6:
  * Rebase to v6.17-rc1-16-g8742b2d8935f to pick up the fixes made by Masahiro Yamada.
  * Fix an issue on i386 configs caused by the use of string_32.h.
  * v5: https://lore.kernel.org/all/cover.1753354215.git.legion@kernel.org/

- v5:
  * Rebase to v6.16-rc6-281-gf4a40a4282f4 to pick up the fixes made by Masahiro Yamada.
  * Attempt to fix linker warning on s390.
  * Fix typo in pinctrl/meson found by the kernel test robot.
  * v4: https://lore.kernel.org/all/cover.1750511018.git.legion@kernel.org/

- v4:
  * Rework the patchset based on top of Masahiro Yamada's patches.
  * Add removal of unnecessary __mod_device_table__* symbols to avoid symbol
    table growth in vmlinux.
  * rust code takes into account changes in __mod_device_table__*.
  * v3: https://lore.kernel.org/all/cover.1748335606.git.legion@kernel.org/

- v3:
  * Add `Reviewed-by` tag to patches from Petr Pavlu.
  * Rebase to v6.15.
  * v2: https://lore.kernel.org/all/20250509164237.2886508-1-legion@kernel.org/

- v2:
  * Drop patch for mfd because it was already applied and is in linux-next.
  * The generation of aliases for builtin modules has been redone as
    suggested by Masahiro Yamada.
  * Rebase to v6.15-rc5-136-g9c69f8884904
  * v1: https://lore.kernel.org/all/cover.1745591072.git.legion@kernel.org/


Alexey Gladkov (6):
  scsi: Always define blogic_pci_tbl structure
  pinctrl: meson: Fix typo in device table macro
  modpost: Add modname to mod_device_table alias
  modpost: Create modalias for builtin modules
  kbuild: vmlinux.unstripped should always depend on .vmlinux.export.o
  s390: vmlinux.lds.S: Reorder sections

Masahiro Yamada (3):
  kbuild: always create intermediate vmlinux.unstripped
  kbuild: keep .modinfo section in vmlinux.unstripped
  kbuild: extract modules.builtin.modinfo from vmlinux.unstripped

 arch/s390/kernel/vmlinux.lds.S             | 10 +--
 drivers/pinctrl/meson/pinctrl-amlogic-a4.c |  2 +-
 drivers/scsi/BusLogic.c                    |  4 +-
 include/asm-generic/vmlinux.lds.h          |  2 +-
 include/linux/module.h                     | 18 +++--
 rust/kernel/device_id.rs                   |  8 +--
 scripts/Makefile.vmlinux                   | 77 ++++++++++++++--------
 scripts/Makefile.vmlinux_o                 | 26 +-------
 scripts/link-vmlinux.sh                    |  5 +-
 scripts/mksysmap                           |  6 ++
 scripts/mod/file2alias.c                   | 34 ++++++++--
 scripts/mod/modpost.c                      | 15 +++++
 scripts/mod/modpost.h                      |  2 +
 13 files changed, 130 insertions(+), 79 deletions(-)

-- 
2.50.1


^ permalink raw reply	[flat|nested] 27+ messages in thread

end of thread, other threads:[~2025-08-25 16:56 UTC | newest]

Thread overview: 27+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-08-14 13:07 [PATCH v6 0/9] Add generated modalias to modules.builtin.modinfo Alexey Gladkov
2025-08-14 13:07 ` [PATCH v6 1/9] kbuild: always create intermediate vmlinux.unstripped Alexey Gladkov
2025-08-14 13:07 ` [PATCH v6 2/9] kbuild: keep .modinfo section in vmlinux.unstripped Alexey Gladkov
2025-08-14 13:07 ` [PATCH v6 3/9] kbuild: extract modules.builtin.modinfo from vmlinux.unstripped Alexey Gladkov
2025-08-17 12:34   ` Masahiro Yamada
2025-08-17 12:52     ` Alexey Gladkov
2025-08-18  6:43       ` Nathan Chancellor
2025-08-14 13:07 ` [PATCH v6 4/9] scsi: Always define blogic_pci_tbl structure Alexey Gladkov
2025-08-19  2:04   ` Martin K. Petersen
2025-08-19  7:18     ` Nathan Chancellor
2025-08-20  1:52       ` Martin K. Petersen
2025-08-20 16:11         ` Nathan Chancellor
2025-08-25 10:09           ` Alexey Gladkov
2025-08-25 16:56             ` Nathan Chancellor
2025-08-14 13:07 ` [PATCH v6 5/9] pinctrl: meson: Fix typo in device table macro Alexey Gladkov
2025-08-18  9:11   ` Linus Walleij
2025-08-14 13:07 ` [PATCH v6 6/9] modpost: Add modname to mod_device_table alias Alexey Gladkov
2025-08-14 13:26   ` Danilo Krummrich
2025-08-14 13:54     ` Alexey Gladkov
2025-08-14 14:03       ` Danilo Krummrich
2025-08-14 21:46         ` Alexey Gladkov
2025-08-14 22:17           ` Danilo Krummrich
2025-08-14 13:07 ` [PATCH v6 7/9] modpost: Create modalias for builtin modules Alexey Gladkov
2025-08-14 13:07 ` [PATCH v6 8/9] kbuild: vmlinux.unstripped should always depend on .vmlinux.export.o Alexey Gladkov
2025-08-14 13:07 ` [PATCH v6 9/9] s390: vmlinux.lds.S: Reorder sections Alexey Gladkov
2025-08-14 14:16   ` Heiko Carstens
2025-08-14 21:51     ` Alexey Gladkov

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