6.1-stable review patch. If anyone has any objections, please let me know.
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From: Ryan Roberts ryan.roberts@arm.com
[ Upstream commit d021b442cf312664811783e92b3d5e4548e92a53 ]
ksm_tests was previously mmapping a region of memory, aligning the returned pointer to a PMD boundary, then setting MADV_HUGEPAGE, but was setting it past the end of the mmapped area due to not taking the pointer alignment into consideration. Fix this behaviour.
Up until commit efa7df3e3bb5 ("mm: align larger anonymous mappings on THP boundaries"), this buggy behavior was (usually) masked because the alignment difference was always less than PMD-size. But since the mentioned commit, `ksm_tests -H -s 100` started failing.
Link: https://lkml.kernel.org/r/20240122120554.3108022-1-ryan.roberts@arm.com Fixes: 325254899684 ("selftests: vm: add KSM huge pages merging time test") Signed-off-by: Ryan Roberts ryan.roberts@arm.com Cc: Pedro Demarchi Gomes pedrodemargomes@gmail.com Cc: Shuah Khan shuah@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/vm/ksm_tests.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/vm/ksm_tests.c b/tools/testing/selftests/vm/ksm_tests.c index 0d85be2350fa..a81165930785 100644 --- a/tools/testing/selftests/vm/ksm_tests.c +++ b/tools/testing/selftests/vm/ksm_tests.c @@ -470,7 +470,7 @@ static int ksm_merge_hugepages_time(int mapping, int prot, int timeout, size_t m if (map_ptr_orig == MAP_FAILED) err(2, "initial mmap");
- if (madvise(map_ptr, len + HPAGE_SIZE, MADV_HUGEPAGE)) + if (madvise(map_ptr, len, MADV_HUGEPAGE)) err(2, "MADV_HUGEPAGE");
pagemap_fd = open("/proc/self/pagemap", O_RDONLY);