proc: make collect_sigign_sigcatch() rcu-safe
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From: Roland McGrath on 9 Apr 2010 16:00 > In theory, this ->sighand can be re-used under us (but it can't go away). > We could check task->sighand == sighand once again after the main loop > to prevent the race with exit/exec, but I don't think this is really > needed for fs/proc. In v2.6.34-rc3-500-g0eddb51 this isn't possible because the calls from task_sig() and do_task_stat() are under siglock. Is that locking removed by another pending change? Thanks, Roland -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Oleg Nesterov on 12 Apr 2010 16:50
On 04/09, Roland McGrath wrote: > > > In theory, this ->sighand can be re-used under us (but it can't go away). > > We could check task->sighand == sighand once again after the main loop > > to prevent the race with exit/exec, but I don't think this is really > > needed for fs/proc. > > In v2.6.34-rc3-500-g0eddb51 this isn't possible because the calls from > task_sig() and do_task_stat() are under siglock. Yes sure. If it is called under ->siglock we have no races we should worry about. > Is that locking removed > by another pending change? Yes, the next 3/3 patch. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |