Messages in this thread | | | Date | Mon, 2 May 2011 18:42:09 -0400 | From | Chris Metcalf <> | Subject | Re: [PATCH 1/1] tile: do_hardwall_trap: do not play with task->sighand |
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On 4/26/2011 4:37 PM, Oleg Nesterov wrote: > 1. do_hardwall_trap() checks ->sighand != NULL and then takes ->siglock. > > This is unsafe even if the task can't run (I assume it is pinned to > the same CPU), its parent can reap the task and set ->sighand = NULL > right after this check. Even if the compiler dosn't read ->sighand > twice and this memory can't to away __group_send_sig_info() is wrong > after that. Use do_send_sig_info(). > > 2. Send SIGILL to the thread, not to the whole process. Unless it has > the handler or blocked this kills the whole thread-group as before. > IIUC, different threads can be bound to different rect's. > > 3. Check PF_EXITING instead of ->sighand. A zombie thread can go away > but its ->sighand can be !NULL. > > Reported-by: Matt Fleming <matt@console-pimps.org> > Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Thanks, I've taken this change into the tile tree.
-- Chris Metcalf, Tilera Corp. http://www.tilera.com
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