Reviewed-by: Pavel Tikhomirov <[email protected]> On 6/25/26 09:46, Vasileios Almpanis wrote: > Reviewed-by: Vasileios Almpanis <[email protected]> > > On 6/25/26 12:42 AM, Eva Kurchatova wrote: >> The ofdlocks test installs an OFD read lock at offset 5..7 and then >> issues two F_OFD_GETLK queries (one starting at offset 5 with length 1, >> one starting at offset 0 with length 0) expecting them to report the >> same lock. It then compares the two struct flock results with memcmp(). >> >> Because 'fl' and 'fl2' live on the stack and are only partially >> initialized by the caller (l_type, l_whence, l_start, l_len, l_pid), >> the implicit padding bytes that 'struct flock' has on x86_64 are left >> with whatever happens to be on the stack. The kernel does not touch >> those padding bytes on the F_OFD_GETLK return path, so memcmp() of the >> full sizeof(struct flock) compares uninitialized padding from two >> different stack frames and intermittently reports them as different: >> >> [SUCCESS] F_UNLCK test returns: locked, type 0 pid -1 len 3 >> [FAIL] F_UNLCK test returns: locked, type 0 pid -1 len 3 >> >> i.e. the printed fields are identical but memcmp() still fails. >> >> Zero-initialize both structs at declaration so the padding is >> deterministic and the comparison is meaningful. >> >> Signed-off-by: Eva Kurchatova <[email protected]> >> >> https://virtuozzo.atlassian.net/browse/VSTOR-134203 >> Feature: fix selftests >> >> --- >> tools/testing/selftests/filelock/ofdlocks.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/tools/testing/selftests/filelock/ofdlocks.c >> b/tools/testing/selftests/filelock/ofdlocks.c >> index a55b79810ab2..45dc417dae89 100644 >> --- a/tools/testing/selftests/filelock/ofdlocks.c >> +++ b/tools/testing/selftests/filelock/ofdlocks.c >> @@ -35,7 +35,7 @@ static int lock_get(int fd, struct flock *fl) >> int main(void) >> { >> int rc; >> - struct flock fl, fl2; >> + struct flock fl = {0}, fl2 = {0}; >> int fd = open("/tmp/aa", O_RDWR | O_CREAT | O_EXCL, 0600); >> int fd2 = open("/tmp/aa", O_RDONLY); >> >
-- Best regards, Pavel Tikhomirov Senior Software Developer, Virtuozzo. _______________________________________________ Devel mailing list [email protected] https://lists.openvz.org/mailman/listinfo/devel
