Re: [PATCH] kbuild: lto: add _mcount to list of used symbols

From: Kees Cook
Date: Thu Feb 25 2021 - 15:15:44 EST


On Thu, Feb 25, 2021 at 03:34:49PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> Some randconfig builds fail with undefined references to _mcount
> when CONFIG_TRIM_UNUSED_KSYMS is set:
>
> ERROR: modpost: "_mcount" [drivers/tee/optee/optee.ko] undefined!
> ERROR: modpost: "_mcount" [drivers/fsi/fsi-occ.ko] undefined!
> ERROR: modpost: "_mcount" [drivers/fpga/dfl-pci.ko] undefined!
>
> Since there is already a list of symbols that get generated at link
> time, add this one as well.
>
> Fixes: fbe078d397b4 ("kbuild: lto: add a default list of used symbols")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Thanks!

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

--
Kees Cook