Re: [PATCH AUTOSEL 6.8 69/98] sparc: vdso: Disable UBSAN instrumentation

From: Kees Cook
Date: Fri Mar 29 2024 - 22:05:49 EST


On Fri, Mar 29, 2024 at 08:37:40AM -0400, Sasha Levin wrote:
> From: Kees Cook <keescook@xxxxxxxxxxxx>
>
> [ Upstream commit d4be85d068b4418c341f79b654399f7f0891069a ]
>
> The UBSAN instrumentation cannot work in the vDSO since it is executing
> in userspace, so disable it in the Makefile. Fixes the build failures
> such as:
>
> arch/sparc/vdso/vclock_gettime.c:217: undefined reference to `__ubsan_handle_shift_out_of_bounds'
>
> Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
> Link: https://lore.kernel.org/all/20240224073617.GA2959352@xxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

This is harmless to backport, but doesn't do anything. (The UBSAN
changes needing this are only in Linus's tree.)

-Kees

--
Kees Cook