linux.git/scripts/mod/modpost.c, branch v6.1.168

modpost: Amend ppc64 save/restfpr symnames for -Os build

2026-03-04T12:20:24+00:00

[ Upstream commit 3cd9763ce4ad999d015cf0734e6b968cead95077 ]

Building a size optimized ppc64 kernel (-Os), gcc emits more FP
save/restore symbols, that the linker generates on demand into the
.sfpr section. Explicitly allow-list those in scripts/mod/modpost.c,
too. They are needed for the amdgpu in-kernel floating point support.

MODPOST Module.symvers
ERROR: modpost: "_restfpr_20" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
ERROR: modpost: "_restfpr_26" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
ERROR: modpost: "_restfpr_22" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
ERROR: modpost: "_savegpr1_27" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
ERROR: modpost: "_savegpr1_25" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
ERROR: modpost: "_restfpr_28" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
ERROR: modpost: "_savegpr1_29" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
ERROR: modpost: "_savefpr_20" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
ERROR: modpost: "_savefpr_22" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
ERROR: modpost: "_restfpr_15" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
WARNING: modpost: suppressed 56 unresolved symbol warnings because there were too many)

Signed-off-by: René Rebe 
Link: https://patch.msgid.link/20251123.131330.407910684435629198.rene@exactco.de
Signed-off-by: Nathan Chancellor 
Signed-off-by: Sasha Levin

modpost: Add .irqentry.text to OTHER_SECTIONS

2024-12-14T18:54:35+00:00

commit 7912405643a14b527cd4a4f33c1d4392da900888 upstream.

The compiler can fully inline the actual handler function of an interrupt
entry into the .irqentry.text entry point. If such a function contains an
access which has an exception table entry, modpost complains about a
section mismatch:

  WARNING: vmlinux.o(__ex_table+0x447c): Section mismatch in reference ...

  The relocation at __ex_table+0x447c references section ".irqentry.text"
  which is not in the list of authorized sections.

Add .irqentry.text to OTHER_SECTIONS to cure the issue.

Reported-by: Sergey Senozhatsky 
Signed-off-by: Thomas Gleixner 
Cc: stable@vger.kernel.org # needed for linux-5.4-y
Link: https://lore.kernel.org/all/20241128111844.GE10431@google.com/
Signed-off-by: Masahiro Yamada 
[ bump the size of good_tosec[] to prevent overflow - gregkh ]
Signed-off-by: Greg Kroah-Hartman

modpost: Add '.ltext' and '.ltext.*' to TEXT_SECTIONS

2024-02-23T08:12:38+00:00

commit 397586506c3da005b9333ce5947ad01e8018a3be upstream.

After the linked LLVM change, building ARCH=um defconfig results in a
segmentation fault in modpost. Prior to commit a23e7584ecf3 ("modpost:
unify 'sym' and 'to' in default_mismatch_handler()"), there was a
warning:

  WARNING: modpost: vmlinux.o(__ex_table+0x88): Section mismatch in reference to the .ltext:(unknown)
  WARNING: modpost: The relocation at __ex_table+0x88 references
  section ".ltext" which is not in the list of
  authorized sections.  If you're adding a new section
  and/or if this reference is valid, add ".ltext" to the
  list of authorized sections to jump to on fault.
  This can be achieved by adding ".ltext" to
  OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.

The linked LLVM change moves global objects to the '.ltext' (and
'.ltext.*' with '-ffunction-sections') sections with '-mcmodel=large',
which ARCH=um uses. These sections should be handled just as '.text'
and '.text.*' are, so add them to TEXT_SECTIONS.

Cc: stable@vger.kernel.org
Closes: https://github.com/ClangBuiltLinux/linux/issues/1981
Link: https://github.com/llvm/llvm-project/commit/4bf8a688956a759b7b6b8d94f42d25c13c7af130
Signed-off-by: Nathan Chancellor 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Nathan Chancellor 
Signed-off-by: Greg Kroah-Hartman

modpost: Include '.text.*' in TEXT_SECTIONS

2024-02-23T08:12:38+00:00

commit 19331e84c3873256537d446afec1f6c507f8c4ef upstream.

Commit 6c730bfc894f ("modpost: handle -ffunction-sections") added
".text.*" to the OTHER_TEXT_SECTIONS macro to fix certain section
mismatch warnings. Unfortunately, this makes it impossible for modpost
to warn about section mismatches with LTO, which implies
'-ffunction-sections', as all functions are put in their own
'.text.' sections, which may still reference functions in
sections they are not supposed to, such as __init.

Fix this by moving ".text.*" into TEXT_SECTIONS, so that configurations
with '-ffunction-sections' will see warnings about mismatched sections.

Link: https://lore.kernel.org/Y39kI3MOtVI5BAnV@google.com/
Reported-by: Vincent Donnefort 
Reviewed-and-tested-by: Alexander Lobakin 
Reviewed-by: Sami Tolvanen 
Tested-by: Vincent Donnefort 
Signed-off-by: Nathan Chancellor 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Nathan Chancellor 
Stable-dep-of: 846cfbeed09b ("um: Fix adding '-no-pie' for clang")
Signed-off-by: Greg Kroah-Hartman

linux/init: remove __memexit* annotations

2024-02-23T08:12:38+00:00

commit 6a4e59eeedc3018cb57722eecfcbb49431aeb05f upstream.

We have never used __memexit, __memexitdata, or __memexitconst.

These were unneeded.

Signed-off-by: Masahiro Yamada 
Acked-by: Arnd Bergmann 
[nathan: Remove additional case of XXXEXIT_TO_SOME_EXIT due to lack of
         78dac1a22944 in 6.1]
Signed-off-by: Nathan Chancellor 
Stable-dep-of: 846cfbeed09b ("um: Fix adding '-no-pie' for clang")
Signed-off-by: Greg Kroah-Hartman

modpost: Don't let "driver"s reference .exit.*

2024-02-23T08:12:38+00:00

commit f177cd0c15fcc7bdbb68d8d1a3166dead95314c8 upstream.

Drivers must not reference functions marked with __exit as these likely
are not available when the code is built-in.

There are few creative offenders uncovered for example in ARCH=amd64
allmodconfig builds. So only trigger the section mismatch warning for
W=1 builds.

The dual rule that drivers must not reference .init.* is implemented
since commit 0db252452378 ("modpost: don't allow *driver to reference
.init.*") which however missed that .exit.* should be handled in the
same way.

Thanks to Masahiro Yamada and Arnd Bergmann who gave valuable hints to
find this improvement.

Signed-off-by: Uwe Kleine-König 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Nathan Chancellor 
Stable-dep-of: 846cfbeed09b ("um: Fix adding '-no-pie' for clang")
Signed-off-by: Greg Kroah-Hartman

modpost: propagate W=1 build option to modpost

2024-02-23T08:12:38+00:00

commit 20ff36856fe00879f82de71fe6f1482ca1b72334 upstream.

"No build warning" is a strong requirement these days, so you must fix
all issues before enabling a new warning flag.

We often add a new warning to W=1 first so that the kbuild test robot
blocks new breakages.

This commit allows modpost to show extra warnings only when W=1
(or KBUILD_EXTRA_WARN=1) is given.

Signed-off-by: Masahiro Yamada 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Nathan Chancellor 
Stable-dep-of: 846cfbeed09b ("um: Fix adding '-no-pie' for clang")
Signed-off-by: Greg Kroah-Hartman

modpost: fix off by one in is_executable_section()

2023-07-19T14:21:42+00:00

[ Upstream commit 3a3f1e573a105328a2cca45a7cfbebabbf5e3192 ]

The > comparison should be >= to prevent an out of bounds array
access.

Fixes: 52dc0595d540 ("modpost: handle relocations mismatch in __ex_table.")
Signed-off-by: Dan Carpenter 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Sasha Levin

modpost: fix section mismatch message for R_ARM_{PC24,CALL,JUMP24}

2023-07-19T14:21:41+00:00

[ Upstream commit 56a24b8ce6a7f9c4a21b2276a8644f6f3d8fc14d ]

addend_arm_rel() processes R_ARM_PC24, R_ARM_CALL, R_ARM_JUMP24 in a
wrong way.

Here, test code.

[test code for R_ARM_JUMP24]

  .section .init.text,"ax"
  bar:
          bx      lr

  .section .text,"ax"
  .globl foo
  foo:
          b       bar

[test code for R_ARM_CALL]

  .section .init.text,"ax"
  bar:
          bx      lr

  .section .text,"ax"
  .globl foo
  foo:
          push    {lr}
          bl      bar
          pop     {pc}

If you compile it with ARM multi_v7_defconfig, modpost will show the
symbol name, (unknown).

  WARNING: modpost: vmlinux.o: section mismatch in reference: foo (section: .text) -> (unknown) (section: .init.text)

(You need to use GNU linker instead of LLD to reproduce it.)

Fix the code to make modpost show the correct symbol name.

I imported (with adjustment) sign_extend32() from include/linux/bitops.h.

The '+8' is the compensation for pc-relative instruction. It is
documented in "ELF for the Arm Architecture" [1].

  "If the relocation is pc-relative then compensation for the PC bias
  (the PC value is 8 bytes ahead of the executing instruction in Arm
  state and 4 bytes in Thumb state) must be encoded in the relocation
  by the object producer."

[1]: https://github.com/ARM-software/abi-aa/blob/main/aaelf32/aaelf32.rst

Fixes: 56a974fa2d59 ("kbuild: make better section mismatch reports on arm")
Fixes: 6e2e340b59d2 ("ARM: 7324/1: modpost: Fix section warnings for ARM for many compilers")
Signed-off-by: Masahiro Yamada 
Signed-off-by: Sasha Levin

modpost: fix section mismatch message for R_ARM_ABS32

2023-07-19T14:21:41+00:00

[ Upstream commit b7c63520f6703a25eebb4f8138fed764fcae1c6f ]

addend_arm_rel() processes R_ARM_ABS32 in a wrong way.

Here, test code.

  [test code 1]

    #include 

    int __initdata foo;
    int get_foo(void) { return foo; }

If you compile it with ARM versatile_defconfig, modpost will show the
symbol name, (unknown).

  WARNING: modpost: vmlinux.o: section mismatch in reference: get_foo (section: .text) -> (unknown) (section: .init.data)

(You need to use GNU linker instead of LLD to reproduce it.)

If you compile it for other architectures, modpost will show the correct
symbol name.

  WARNING: modpost: vmlinux.o: section mismatch in reference: get_foo (section: .text) -> foo (section: .init.data)

For R_ARM_ABS32, addend_arm_rel() sets r->r_addend to a wrong value.

I just mimicked the code in arch/arm/kernel/module.c.

However, there is more difficulty for ARM.

Here, test code.

  [test code 2]

    #include 

    int __initdata foo;
    int get_foo(void) { return foo; }

    int __initdata bar;
    int get_bar(void) { return bar; }

With this commit applied, modpost will show the following messages
for ARM versatile_defconfig:

  WARNING: modpost: vmlinux.o: section mismatch in reference: get_foo (section: .text) -> foo (section: .init.data)
  WARNING: modpost: vmlinux.o: section mismatch in reference: get_bar (section: .text) -> foo (section: .init.data)

The reference from 'get_bar' to 'foo' seems wrong.

I have no solution for this because it is true in assembly level.

In the following output, relocation at 0x1c is no longer associated
with 'bar'. The two relocation entries point to the same symbol, and
the offset to 'bar' is encoded in the instruction 'r0, [r3, #4]'.

  Disassembly of section .text:

  00000000 :
     0: e59f3004          ldr     r3, [pc, #4]   @ c 
     4: e5930000          ldr     r0, [r3]
     8: e12fff1e          bx      lr
     c: 00000000          .word   0x00000000

  00000010 :
    10: e59f3004          ldr     r3, [pc, #4]   @ 1c 
    14: e5930004          ldr     r0, [r3, #4]
    18: e12fff1e          bx      lr
    1c: 00000000          .word   0x00000000

  Relocation section '.rel.text' at offset 0x244 contains 2 entries:
   Offset     Info    Type            Sym.Value  Sym. Name
  0000000c  00000c02 R_ARM_ABS32       00000000   .init.data
  0000001c  00000c02 R_ARM_ABS32       00000000   .init.data

When find_elf_symbol() gets into a situation where relsym->st_name is
zero, there is no guarantee to get the symbol name as written in C.

I am keeping the current logic because it is useful in many architectures,
but the symbol name is not always correct depending on the optimization.
I left some comments in find_tosym().

Fixes: 56a974fa2d59 ("kbuild: make better section mismatch reports on arm")
Signed-off-by: Masahiro Yamada 
Signed-off-by: Sasha Levin