github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-06-05 04:56:13 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

kselftest: vm: fix mdwe's mmap_FIXED test case

Browse Source 
[ Upstream commit a27e2e2d46 ]

I checked with the original author, the mmap_FIXED test case wasn't
properly tested and fails.  Currently, it maps two consecutive (non
overlapping) pages and expects the second mapping to be denied by MDWE but
these two pages have nothing to do with each other so MDWE is actually out
of the picture here.

What the test actually intended to do was to remap a virtual address using
MAP_FIXED.  However, this operation unmaps the existing mapping and
creates a new one so the va is backed by a new page and MDWE is again out
of the picture, all remappings should succeed.

This patch keeps the test case to make it clear that this situation is
expected to work: MDWE shouldn't block a MAP_FIXED replacement.

Link: https://lkml.kernel.org/r/20230828150858.393570-3-revest@chromium.org
Fixes: 4cf1fe34fd ("kselftest: vm: add tests for memory-deny-write-execute")
Signed-off-by: Florent Revest <revest@chromium.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Tested-by: Ryan Roberts <ryan.roberts@arm.com>
Tested-by: Ayush Jain <ayush.jain3@amd.com>
Cc: Alexey Izbyshev <izbyshev@ispras.ru>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com>
Cc: Topi Miettinen <toiwoton@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Florent Revest 2023-08-28 17:08:54 +02:00 committed by Greg Kroah-Hartman
parent 11d05f01cf
commit 9c74367665
1 changed files with 3 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
tools/testing/selftests/mm/mdwe_test.c
View File

@ -168,13 +168,10 @@ TEST_F(mdwe, mmap_FIXED)
self->p = mmap(NULL, self->size, PROT_READ, self->flags, 0, 0);
ASSERT_NE(self->p, MAP_FAILED);
p = mmap(self->p + self->size, self->size, PROT_READ | PROT_EXEC,
/* MAP_FIXED unmaps the existing page before mapping which is allowed */
p = mmap(self->p, self->size, PROT_READ | PROT_EXEC,
self->flags | MAP_FIXED, 0, 0);
if (variant->enabled) {
EXPECT_EQ(p, MAP_FAILED);
} else {
EXPECT_EQ(p, self->p);
}
EXPECT_EQ(p, self->p);
}
TEST_F(mdwe, arm64_BTI)