[LTP] [PATCH] cve-2015-3290: Bump up stack boundary requirement

[Martin Doucha]

Hello,
I've tested the new compile options with a buggy kernel and the test can 
still reproduce the issue.

Reviewed-by: Martin Doucha <mdoucha@suse.cz>

On 02. 04. 25 19:07, Siddhesh Poyarekar wrote:
> When the input compiler defaults to AVX enabled, stack realignment
> requirements causes gcc to fail to omit %rbp use, due to which the test
> fails to clobber %rbp in inline asm.  Bump up the preferred stack
> boundary to avoid this stack realignment for AVX, so the frame pointer
> omission goes through.
> 
> Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org>
> ---
>   testcases/cve/Makefile | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/testcases/cve/Makefile b/testcases/cve/Makefile
> index 01b9b9ccb..06bd1b3db 100644
> --- a/testcases/cve/Makefile
> +++ b/testcases/cve/Makefile
> @@ -22,6 +22,9 @@ ifneq (,$(filter $(HOST_CPU),x86 x86_64))
>   meltdown: CFLAGS += -msse2
>   endif
>   
> -cve-2015-3290:	CFLAGS += -pthread -fomit-frame-pointer
> +# The test needs to clobber %rbp, which requires frame pointer omission.  Also
> +# bump up the preferred stack boundary to ensure that the compiler manages to
> +# omit the frame pointer even with AVX enabled.
> +cve-2015-3290:	CFLAGS += -pthread -fomit-frame-pointer -mpreferred-stack-boundary=5
>   
>   include $(top_srcdir)/include/mk/generic_leaf_target.mk


-- 
Martin Doucha   mdoucha@suse.cz
SW Quality Engineer
SUSE LINUX, s.r.o.
CORSO IIa
Krizikova 148/34
186 00 Prague 8
Czech Republic