| Message ID | 20221129190123.872394-3-nathan@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix lack of section mismatch warnings with LTO | expand |
On Tue, Nov 29, 2022 at 12:01:23PM -0700, Nathan Chancellor wrote: > 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 mismatchs with LTO, which implies > '-ffunction-sections', as all functions are put in their own > '.text.<func_name>' 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 <vdonnefort@google.com> > Signed-off-by: Nathan Chancellor <nathan@kernel.org> Thanks! Tested-by: Vincent Donnefort <vdonnefort@google.com> > --- > scripts/mod/modpost.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c > index 2c80da0220c3..c861beabc128 100644 > --- a/scripts/mod/modpost.c > +++ b/scripts/mod/modpost.c > @@ -823,10 +823,10 @@ static void check_section(const char *modname, struct elf_info *elf, > #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS > > #define DATA_SECTIONS ".data", ".data.rel" > -#define TEXT_SECTIONS ".text", ".text.unlikely", ".sched.text", \ > +#define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ > ".kprobes.text", ".cpuidle.text", ".noinstr.text" > #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ > - ".fixup", ".entry.text", ".exception.text", ".text.*", \ > + ".fixup", ".entry.text", ".exception.text", \ > ".coldtext", ".softirqentry.text" > > #define INIT_SECTIONS ".init.*" > -- > 2.38.1 >
From: Nathan Chancellor <nathan@kernel.org> Date: Tue, 29 Nov 2022 12:01:23 -0700 > 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 mismatchs with LTO, which implies > '-ffunction-sections', as all functions are put in their own > '.text.<func_name>' 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 <vdonnefort@google.com> > Signed-off-by: Nathan Chancellor <nathan@kernel.org> This revealed a couple issues in the FG-KASLR kernel. None of them are false-positive although FG-KASLR doesn't merge text.* into one section in the final vmlinux. Nice! Reviewed-and-tested-by: Alexander Lobakin <alexandr.lobakin@intel.com> > --- > scripts/mod/modpost.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) [...] > -- > 2.38.1 Thanks, Olek
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 2c80da0220c3..c861beabc128 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -823,10 +823,10 @@ static void check_section(const char *modname, struct elf_info *elf, #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS #define DATA_SECTIONS ".data", ".data.rel" -#define TEXT_SECTIONS ".text", ".text.unlikely", ".sched.text", \ +#define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \ ".kprobes.text", ".cpuidle.text", ".noinstr.text" #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ - ".fixup", ".entry.text", ".exception.text", ".text.*", \ + ".fixup", ".entry.text", ".exception.text", \ ".coldtext", ".softirqentry.text" #define INIT_SECTIONS ".init.*"
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 mismatchs with LTO, which implies '-ffunction-sections', as all functions are put in their own '.text.<func_name>' 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 <vdonnefort@google.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> --- scripts/mod/modpost.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)