Re: [PATCH v2 2/2] kselftest: vm: add tests for memory-deny-write-execute

[Joey Gouly <joey.gouly@arm.com>]

Hi Peter,

On Wed, Mar 01, 2023 at 11:35:56AM -0500, Peter Xu wrote:
> On Thu, Jan 19, 2023 at 04:03:44PM +0000, Joey Gouly wrote:
> > From: Kees Cook <keescook@chromium.org>
> > 
> > Add some tests to cover the new PR_SET_MDWE prctl.
> > 
> > Co-developed-by: Joey Gouly <joey.gouly@arm.com>
> > Signed-off-by: Joey Gouly <joey.gouly@arm.com>
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > Cc: Shuah Khan <shuah@kernel.org>
> 
> May need to sync prctl.h into tools/include/uapi?  Otherwise selftests/mm
> build fails here.  There's also one compiler report.  A fixup attached
> which works for me.
> 
> Thanks,
> 
> -- 
> Peter Xu

I've CC'd Arnaldo because they seem to update the tools version of prctl.h a lot.

Sorry about the 'p2' variable in the test, was there for some experiments but seems
I accidentally included it.

Acked-by: Joey Gouly <joey.gouly@arm.com>

Thanks,
Joey

> >From ce8e17c244fcc743c7006316dd431c5650480756 Mon Sep 17 00:00:00 2001
> From: Peter Xu <peterx@redhat.com>
> Date: Wed, 1 Mar 2023 11:33:34 -0500
> Subject: [PATCH] fixup! kselftest: vm: add tests for memory-deny-write-execute
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>  tools/include/uapi/linux/prctl.h       | 6 ++++++
>  tools/testing/selftests/mm/mdwe_test.c | 3 +--
>  2 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/include/uapi/linux/prctl.h b/tools/include/uapi/linux/prctl.h
> index e4c629c1f1b0..759b3f53e53f 100644
> --- a/tools/include/uapi/linux/prctl.h
> +++ b/tools/include/uapi/linux/prctl.h
> @@ -281,6 +281,12 @@ struct prctl_mm_map {
>  # define PR_SME_VL_LEN_MASK		0xffff
>  # define PR_SME_VL_INHERIT		(1 << 17) /* inherit across exec */
>  
> +/* Memory deny write / execute */
> +#define PR_SET_MDWE			65
> +# define PR_MDWE_REFUSE_EXEC_GAIN	1
> +
> +#define PR_GET_MDWE			66
> +
>  #define PR_SET_VMA		0x53564d41
>  # define PR_SET_VMA_ANON_NAME		0
>  
> diff --git a/tools/testing/selftests/mm/mdwe_test.c b/tools/testing/selftests/mm/mdwe_test.c
> index f466a099f1bf..bc91bef5d254 100644
> --- a/tools/testing/selftests/mm/mdwe_test.c
> +++ b/tools/testing/selftests/mm/mdwe_test.c
> @@ -163,9 +163,8 @@ TEST_F(mdwe, mprotect_WRITE_EXEC)
>  
>  TEST_F(mdwe, mmap_FIXED)
>  {
> -	void *p, *p2;
> +	void *p;
>  
> -	p2 = mmap(NULL, self->size, PROT_READ | PROT_EXEC, self->flags, 0, 0);
>  	self->p = mmap(NULL, self->size, PROT_READ, self->flags, 0, 0);
>  	ASSERT_NE(self->p, MAP_FAILED);
>  
> -- 
> 2.39.1
>