lkml.org 
[lkml]   [2007]   [Jun]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: Fix signalfd interaction with thread-private signals
    On 06/21, Linus Torvalds wrote:
    >
    > On Thu, 21 Jun 2007, Oleg Nesterov wrote:
    > >
    > > Yes, force_sig() unblocks and un-ignores the signal. However, unlike group-wide
    > > signals, thread-specific signals do not convert themselves to SIGKILL on delivery.
    > > The target thread should dequeue SIGSEGV and then it calls do_group_exit().
    >
    > No it couldn't.
    >
    > Why? Because the target thread is the one that *caused* the SIGSEGV in the
    > first place. It's not going to dequeue *anything*. It's either going to
    > take the SIGSEGV,

    Hmm, can't understand.

    Yes, the target thread is the one that caused the SIGSEGV, it sends the signal
    to itself. entry.S:ret_from_exception should notice this signal and _dequeue_
    it, no? This signal could be stealed by signal(SIG_IGN) which runs after it
    was delivered.

    > or it's going to get another SIGSEGV and now it's no
    > longer masked/handled and it's going to die.

    Yes sure. As I said,

    > and the target thread will take page fault again.

    My point was that it is _possible_ to steal a thread-local SIGSEGV even without
    signalfd, nothing bad should happen.

    Oleg.

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-06-21 20:27    [W:0.035 / U:0.688 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site