On 8/20/24 21:50, Yang Ruibin wrote:

To correctly detect whether mmap is successful, must use if (map_ptr == MAP_FAILED)to avoid incorrectly handling a valid mapping.

Add "Fix mmap() error paths to check for MAP_FAILED" at the end of the changelog

Change short log to say "selftests:mm: Fix mmap() error paths to check for MAP_FAILED" selftests is the right subsystem tag for this change.

"Fix" in the short log will make it easier for this change to be picked up by stables.

Signed-off-by: Yang Ruibin 11162571@vivo.com

tools/testing/selftests/mm/ksm_tests.c | 2 +- tools/testing/selftests/mm/madv_populate.c | 2 +- tools/testing/selftests/mm/soft-dirty.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/mm/ksm_tests.c b/tools/testing/selftests/mm/ksm_tests.c index b748c48908d9..dad54840f32e 100644 --- a/tools/testing/selftests/mm/ksm_tests.c +++ b/tools/testing/selftests/mm/ksm_tests.c @@ -201,7 +201,7 @@ static void *allocate_memory(void *ptr, int prot, int mapping, char data, size_ { void *map_ptr = mmap(ptr, map_size, PROT_WRITE, mapping, -1, 0);

• if (!map_ptr) {

• if (map_ptr == MAP_FAILED) { perror("mmap");

Use ksft_exit_fail_msg("mmap failed\n") to be consistent with the rest.

return NULL;

} diff --git a/tools/testing/selftests/mm/madv_populate.c b/tools/testing/selftests/mm/madv_populate.c index ef7d911da13e..b89cb83ca5c5 100644 --- a/tools/testing/selftests/mm/madv_populate.c +++ b/tools/testing/selftests/mm/madv_populate.c @@ -34,7 +34,7 @@ static void sense_support(void) addr = mmap(0, pagesize, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);

• if (!addr)

• if (addr == MAP_FAILED) ksft_exit_fail_msg("mmap failed\n");

ret = madvise(addr, pagesize, MADV_POPULATE_READ); diff --git a/tools/testing/selftests/mm/soft-dirty.c b/tools/testing/selftests/mm/soft-dirty.c index bdfa5d085f00..4ccbc053bcce 100644 --- a/tools/testing/selftests/mm/soft-dirty.c +++ b/tools/testing/selftests/mm/soft-dirty.c @@ -134,7 +134,7 @@ static void test_mprotect(int pagemap_fd, int pagesize, bool anon) if (anon) { map = mmap(NULL, pagesize, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);

• if (!map)
  

• if (map == MAP_FAILED)
  ksft_exit_fail_msg("anon mmap failed\n");
  

  } else { test_fd = open(fname, O_RDWR | O_CREAT, 0664);

With the above fixed:

Reviewed-by: Shuah Khan skhan@linuxfoundation.org

thanks, -- Shuah