2006/9/30, Christoph Lameter <clameter@xxxxxxx>:
On Fri, 29 Sep 2006, Dong Feng wrote:
> If the comments mean the subsequent code is SMP-safe and can prevent
> nest-kernel-path, how does it achieves that?
It relies on locking outside of do_sys_settimeofday(). Seems that this
indicates locking is to be performed by the arch before calling
do_sys_settimeofday. Looks suspicious to me. Check that this function is
always called with the same lock.
Yes, that is the question. The whole invocation path is
sys_settimeofday() -> do_sys_settimeofday()
I do not find a lock embracing do_sys_settimeofday().
Moreover, seems neither write operations nor read operations on sys_tz
is protected by any locks, in sys_gettimeofday() and