On 10/16/25 08:03, Alex Bennée wrote:
From: Peter Maydell<[email protected]>The linux-test test includes an attempt to check the utime and stat syscalls by setting the atime and mtime of a file to specific values, and then calling stat() to check that the values read back correctly. Unfortunately this is flaky, as it will fail if some other process (for instance a virus scanner, backup program, etc) gets in and reads the file between the utime() and stat() call, resulting in a host syscall sequence like this: utimensat(AT_FDCWD, "file2", [{tv_sec=1001, tv_nsec=0} /* 1970-01-01T01:16:41+0100 */, {tv_sec=1000, tv_nsec=0} /* 1970-01-01T01:16:40+0100 */], 0) = 0 # successfully set atime to 1001 and mtime to 1000 statx(AT_FDCWD, "file2", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT, STATX_BASIC_STATS, {stx_mask=STATX_BASIC_STATS|STATX_MNT_ID, stx_blksize=4096, stx_attributes=0, stx_nlink=1, stx_uid=32808, stx_gid=32808, stx_mode=S_IFREG|0600, stx_ino=21659016, stx_size=100, stx_blocks=8, stx_attributes_mask=STATX_ATTR_COMPRESSED|STATX_ATTR_IMMUTABLE| STATX_ATTR_APPEND|STATX_ATTR_NODUMP|STATX_ATTR_ENCRYPTED| STATX_ATTR_AUTOMOUNT|STATX_ATTR_MOUNT_ROOT|STATX_ATTR_VERITY| STATX_ATTR_DAX, stx_atime={tv_sec=1760091862, tv_nsec=63509009} /* 2025-10-10T11:24:22.063509009+0100 */, stx_ctime={tv_sec=1760091862, tv_nsec=63509009} /* 2025-10-10T11:24:22.063509009+0100 */, stx_mtime={tv_sec=1000, tv_nsec=0} /* 1970-01-01T01:16:40+0100 */, stx_rdev_major=0, stx_rdev_minor=0, stx_dev_major=252, stx_dev_minor=0, stx_mnt_id=0x1f}) = 0 # but when we statx the file, we get back an mtime of 1000 # but an atime corresponding to when the other process read it and which will cause the test program to fail with the error message "stat time". In theory we could defend against this by e.g. operating on files in a dummy loopback mount filesystem which we mounted as 'noatime', but this isn't worth the hassle. Just drop the check on atime. Cc:[email protected] Signed-off-by: Peter Maydell<[email protected]> Reviewed-by: Thomas Huth<[email protected]> Signed-off-by: Alex Bennée<[email protected]> --- tests/tcg/multiarch/linux/linux-test.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
Reviewed-by: Richard Henderson <[email protected]> r~
