Re: [RFC PATCH] kernel/fork: fix CLONE_CHILD_CLEARTID regression in nscd
From: Oleg Nesterov <oleg@redhat.com>
Date: 2016-08-03 21:08:13
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sorry for delay, I am travelling till the end of the week. On 08/01, Michal Hocko wrote:
fec1d0115240 ("[PATCH] Disable CLONE_CHILD_CLEARTID for abnormal exit")almost 10 years ago ;)
has caused a subtle regression in nscd which uses CLONE_CHILD_CLEARTID to clear the nscd_certainly_running flag in the shared databases, so that the clients are notified when nscd is restarted.
So iiuc with this patch nscd_certainly_running should be cleared even if ncsd was killed by !sig_kernel_coredump() signal, right?
We should also check for vfork because
this is killable since d68b46fe16ad ("vfork: make it killable").Hmm, why? Can't understand... In any case this check doesn't look right, the comment says "a killed vfork parent" while tsk->vfork_done != NULL means it is a vforked child. So if we want this change, why we can't simply do - if (!(tsk->flags & PF_SIGNALED) && + if (!(tsk->signal->flags & SIGNAL_GROUP_COREDUMP) && ? And I think PF_SIGNALED must die in any case... but this is off-topic. Oleg. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>