| Message ID | 20210601093614.245873-2-egorenar@linux.ibm.com |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [1/2] clock_settime03: fix type of time | expand |
Hi! > Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com> > --- > lib/tst_wallclock.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/lib/tst_wallclock.c b/lib/tst_wallclock.c > index 838dde8b3..37d3005ef 100644 > --- a/lib/tst_wallclock.c > +++ b/lib/tst_wallclock.c > @@ -60,6 +60,8 @@ void tst_wallclock_restore(void) > > if (tst_clock_settime(CLOCK_REALTIME, &adjust)) > tst_brk(TBROK | TERRNO, "tst_clock_settime() realtime failed"); > + > + SAFE_TOUCH("/etc/localtime", 0, NULL); I would prefer not to break the test here if the file is not present on a system, there may be embedded systems where this file does not exists and SAFE_TOUCH() will exit the test with TBROK in that case. Also the problem is access time here, so opening and closing the file should be enough to fix it right? What about something as: int fd = open("/etc/localtime", O_RDWR); if (fd > 0) SAFE_CLOSE(fd); That should fix the access time without breaking the test on systems that does not have the /etc/localtime file installed. > } > > void tst_rtc_clock_save(const char *rtc_dev) > -- > 2.31.1 > > > -- > Mailing list info: https://lists.linux.it/listinfo/ltp
Hi, Cyril Hrubis <chrubis@suse.cz> writes: > I would prefer not to break the test here if the file is not present on > a system, there may be embedded systems where this file does not exists > and SAFE_TOUCH() will exit the test with TBROK in that case. Good point, thanks, fixed in v2. > > Also the problem is access time here, so opening and closing the file > should be enough to fix it right? > > What about something as: > > int fd = open("/etc/localtime", O_RDWR); > if (fd > 0) > SAFE_CLOSE(fd); > > That should fix the access time without breaking the test on systems > that does not have the /etc/localtime file installed. > According to some manpage (which i sadly don't remember) the access time of a file never changes with just an open, one have to read some data at least. But even reading won't help in this case, see example below and my explanation in the patch v2. $ stat /usr/share/zoneinfo/Europe/Berlin File: /usr/share/zoneinfo/Europe/Berlin Size: 2298 Blocks: 8 IO Block: 4096 regular file Device: fd01h/64769d Inode: 2623067 Links: 1 Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root) Context: system_u:object_r:locale_t:s0 Access: 2038-01-19 04:14:06.076000270 +0100 <---------- !!! Modify: 2021-06-01 13:48:50.751160745 +0200 Change: 2021-06-01 13:48:50.751160745 +0200 Birth: 2021-04-28 22:06:08.389017197 +0200 $ od -N1 /usr/share/zoneinfo/Europe/Berlin 0000000 000124 0000001 $ stat /usr/share/zoneinfo/Europe/Berlin File: /usr/share/zoneinfo/Europe/Berlin Size: 2298 Blocks: 8 IO Block: 4096 regular file Device: fd01h/64769d Inode: 2623067 Links: 1 Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root) Context: system_u:object_r:locale_t:s0 Access: 2038-01-19 04:14:06.076000270 +0100 <---------- !!! Modify: 2021-06-01 13:48:50.751160745 +0200 Change: 2021-06-01 13:48:50.751160745 +0200 Birth: 2021-04-28 22:06:08.389017197 +0200 Thanks for feedback Regards Alex
diff --git a/lib/tst_wallclock.c b/lib/tst_wallclock.c index 838dde8b3..37d3005ef 100644 --- a/lib/tst_wallclock.c +++ b/lib/tst_wallclock.c @@ -60,6 +60,8 @@ void tst_wallclock_restore(void) if (tst_clock_settime(CLOCK_REALTIME, &adjust)) tst_brk(TBROK | TERRNO, "tst_clock_settime() realtime failed"); + + SAFE_TOUCH("/etc/localtime", 0, NULL); } void tst_rtc_clock_save(const char *rtc_dev)
The test clock_settime03 temporarily changes the wallclock to a date in the year 2038. This has a negative side-effect of changing the access time of the time zone file to which /etc/localtime refers. This causes a nasty issue with glibc-2.33 for applications built with -m32 compiler flag. An access time from the year 2038 leads to an overflow error in glibc-2.33 in * https://elixir.bootlin.com/glibc/glibc-2.33/source/time/tzfile.c#L167 * https://elixir.bootlin.com/glibc/glibc-2.33/source/sysdeps/unix/sysv/linux/stat_t64_cp.c#L29 when a call to localtime() is made in 32bit mode. This issue causes e.g. some of strace 32-bit tests to fail because they use localtime() in 32-bit mode (reproducible on s390x) when we execute it after the LTP test suite. To fix this issue, touch the /etc/localtime after the wallclock was restored. Test on x86_64 Fedora 34 ------------------------ $ stat /usr/share/zoneinfo/Europe/Berlin File: /usr/share/zoneinfo/Europe/Berlin Size: 2298 Blocks: 8 IO Block: 4096 regular file Device: fd01h/64769d Inode: 2623067 Links: 1 Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root) Context: system_u:object_r:locale_t:s0 Access: 2021-06-01 11:10:14.341921070 +0200 <---- watch this !!! Modify: 2021-06-01 11:10:14.192920508 +0200 Change: 2021-06-01 11:10:14.192920508 +0200 Birth: 2021-04-28 22:06:08.389017197 +0200 $ sudo ./clock_settime03 tst_test.c:1311: TINFO: Timeout per run is 0h 05m 00s clock_settime03.c:35: TINFO: Testing variant: syscall with old kernel spec clock_settime03.c:103: TPASS: clock_settime(): Y2038 test passed Summary: passed 1 failed 0 broken 0 skipped 0 warnings 0 $ stat /usr/share/zoneinfo/Europe/Berlin File: /usr/share/zoneinfo/Europe/Berlin Size: 2298 Blocks: 8 IO Block: 4096 regular file Device: fd01h/64769d Inode: 2623067 Links: 1 Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root) Context: system_u:object_r:locale_t:s0 Access: 2038-01-19 04:14:06.067000237 +0100 <---- watch this !!! Modify: 2021-06-01 11:10:14.192920508 +0200 Change: 2021-06-01 11:10:14.192920508 +0200 Birth: 2021-04-28 22:06:08.389017197 +0200 $ ~/test-localtime 2021-06-0109:22:31 +0000 # before this fix %z is wrong, it should be +0200 $ ~/test-localtime 2021-06-0111:24:30 +0200 # after this fix %z is correct Source of test-localtime: --------------------------------------------------------- int main(int argc, char *argv[]) { time_t t; struct tm *tm; char buf[256]; t = time(NULL); tm = localtime(&t); strftime(buf, sizeof(buf), "%F%T %z", tm); fprintf(stdout, "%s\n", buf); return 0; } --------------------------------------------------------- Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com> --- lib/tst_wallclock.c | 2 ++ 1 file changed, 2 insertions(+)