On Wed, Jan 24, 2024 at 8:00 AM Nathan Chancellor <nathan@xxxxxxxxxx> wrote:
>
> After the linked LLVM change, building ARCH=um defconfig results in a
> segmentation fault in modpost.
Yeah, this is a mistake in my commits.
The NULL pointer access should be fixed, but that is a separate issue.
Anyway, I applied this patch.
> 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@xxxxxxxxxxxxxxx
> Closes: https://github.com/ClangBuiltLinux/linux/issues/1981
> Link: https://github.com/llvm/llvm-project/commit/4bf8a688956a759b7b6b8d94f42d25c13c7af130
> Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> ---
> scripts/mod/modpost.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index cb6406f485a9..f7c4d3fe4381 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -807,7 +807,8 @@ static void check_section(const char *modname, struct elf_info *elf,
>
> #define DATA_SECTIONS ".data", ".data.rel"
> #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
> - ".kprobes.text", ".cpuidle.text", ".noinstr.text"
> + ".kprobes.text", ".cpuidle.text", ".noinstr.text", \
> + ".ltext", ".ltext.*"
> #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
> ".fixup", ".entry.text", ".exception.text", \
> ".coldtext", ".softirqentry.text"
>
> --
> 2.43.0
>
--
Best Regards
Masahiro Yamada
