To correctly detect whether mmap is successful, must use if
(map_ptr == MAP_FAILED)to avoid incorrectly handling a valid mapping.
Signed-off-by: Yang Ruibin <11162571@xxxxxxxx>
---
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");
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);
--
2.34.1
