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From: Roland McGrath <roland@redhat.com>
To: Daniel Jacobowitz <drow@false.org>
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Cc: Jan Kratochvil <jan.kratochvil@redhat.com>, 	Doug Evans <dje@google.com>, 	GDB Patches <gdb-patches@sourceware.org>, mark.kettenis@xs4all.nl
Subject: Re: [patch] Fix Linux attach to signalled/stopped processes
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> > In practice you will 99.44% of the time be able to find some RT signal
> > that is not blocked.  But to worry about the 0.66% you still have to
> > fall back to SIGSTOP, and in that case you can't rely on queuing.
> 
> Wouldn't this be racy, again?  If the process is running, it might be
> about to block the signal we chose to stop it.

Yes.