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

[Peter Xu]

On Thu, Jan 19, 2023 at 04:03:44PM +0000, Joey Gouly wrote:
> From: Kees Cook <keescook at chromium.org>
> 
> Add some tests to cover the new PR_SET_MDWE prctl.
> 
> Co-developed-by: Joey Gouly <joey.gouly at arm.com>
> Signed-off-by: Joey Gouly <joey.gouly at arm.com>
> Signed-off-by: Kees Cook <keescook at chromium.org>
> Cc: Shuah Khan <shuah at 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
-------------- next part --------------
>From ce8e17c244fcc743c7006316dd431c5650480756 Mon Sep 17 00:00:00 2001
From: Peter Xu <peterx at 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 at 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