diff options
| author | Vineet Agarwal <agarwal.vineet2006@gmail.com> | 2026-05-04 13:43:13 +0530 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-05-28 21:31:01 -0700 |
| commit | 81ff95710c2dce47da9da4112a78743b2b23e108 (patch) | |
| tree | 1a3ce176f91e40a435cd9e2f77067a355d319b0c /tools | |
| parent | d0689faba7c4de83d31aa80828cc99737289979e (diff) | |
| download | linux-next-history-81ff95710c2dce47da9da4112a78743b2b23e108.tar.gz | |
selftests/mm: ksm-functional-tests: fix partial write handling
Update write() checks to properly detect and handle partial writes.
Previously, the write() calls used <= 0 to detect failure. This condition
is never true for partial writes (ret > 0 but ret < len), so partial
writes were silently treated as success.
Fix this by verifying that write() returns the full expected length and
treating any mismatch as failure.
Link: https://lore.kernel.org/20260504081638.683223-1-agarwal.vineet2006@gmail.com
Signed-off-by: Vineet Agarwal <agarwal.vineet2006@gmail.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Liam Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/mm/ksm_functional_tests.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c b/tools/testing/selftests/mm/ksm_functional_tests.c index 8d874c4754f38..31c06c72203fd 100644 --- a/tools/testing/selftests/mm/ksm_functional_tests.c +++ b/tools/testing/selftests/mm/ksm_functional_tests.c @@ -498,6 +498,7 @@ static void test_prctl_fork(void) static int start_ksmd_and_set_frequency(char *pages_to_scan, char *sleep_ms) { int ksm_fd; + size_t len; ksm_fd = open("/sys/kernel/mm/ksm/run", O_RDWR); if (ksm_fd < 0) @@ -506,11 +507,13 @@ static int start_ksmd_and_set_frequency(char *pages_to_scan, char *sleep_ms) if (write(ksm_fd, "1", 1) != 1) return -errno; - if (write(pages_to_scan_fd, pages_to_scan, strlen(pages_to_scan)) <= 0) - return -errno; + len = strlen(pages_to_scan); + if (write(pages_to_scan_fd, pages_to_scan, len) != len) + return -1; - if (write(sleep_millisecs_fd, sleep_ms, strlen(sleep_ms)) <= 0) - return -errno; + len = strlen(sleep_ms); + if (write(sleep_millisecs_fd, sleep_ms, len) != len) + return -1; return 0; } @@ -526,11 +529,11 @@ static int stop_ksmd_and_restore_frequency(void) if (write(ksm_fd, "2", 1) != 1) return -errno; - if (write(pages_to_scan_fd, "100", 3) <= 0) - return -errno; + if (write(pages_to_scan_fd, "100", 3) != 3) + return -1; - if (write(sleep_millisecs_fd, "20", 2) <= 0) - return -errno; + if (write(sleep_millisecs_fd, "20", 2) != 2) + return -1; return 0; } |