The operations on sys_tz, so far known to me in sys_settimeofday and
sys_gettimeofday, is neither atomic nor protected by any lock. I
suspect it probably causes unpredictable behavior when multiple
processes try to set the system time zone simultaneously.
Following is the code fragment extracted from do_sys_settimeofday().
The function is invoked by sys_settimeofday() without locking. At
least two non-atomic operations:
1. struct copy between *tz and sys_tz.
2. The test-and-operate over firsttime.
if (tz) {
/* SMP safe, global irq locking makes it work. */
sys_tz = *tz;
if (firsttime) {
firsttime = 0;
if (!tv)
warp_clock();
}
}
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
