From: Paolo Bonzini <pbonzini@redhat.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
Anthony Liguori <anthony@codemonkey.ws>
Subject: Re: [Qemu-devel] audit needed for signal handlers
Date: Mon, 11 Nov 2013 18:47:14 +0100 [thread overview]
Message-ID: <52811822.6040401@redhat.com> (raw)
In-Reply-To: <CAFEAcA_3e5RK2Dz2D6x3mGnE+MZ6BohLVtkiUJ+_ktz5dASNcg@mail.gmail.com>
Il 11/11/2013 18:13, Peter Maydell ha scritto:
>> > That said, aren't all signals in QEMU (except SIG_IPI) caught with
>> > signalfd and the handlers run synchronously in the iothread?
> Eric specifically points out one which is not.
> (I'm pretty sure that 'reinstall signal handler at
> end of signal handler' is ancient voodoo that we don't
> want either, incidentally.)
Yeah, I was convinced it was---I still cannot find a reason why SIGWINCH
needs to be handled synchronously.
resize_term is definitely not signal safe; the man page reflects
10-year-old (or more) signal handling lore: "While these functions are
intended to be used to support a signal handler (i.e., for SIGWINCH),
care should be taken to avoid invoking them in a context where malloc or
realloc may have been interrupted, since it uses those functions".
Calling malloc/realloc from a signal handler is taboo these days...
Paolo
next prev parent reply other threads:[~2013-11-11 17:47 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-11 16:50 [Qemu-devel] audit needed for signal handlers Eric Blake
2013-11-11 16:56 ` Anthony Liguori
2013-11-11 17:03 ` Eric Blake
2013-11-11 17:05 ` Paolo Bonzini
2013-11-11 17:08 ` Eric Blake
2013-11-11 17:11 ` Paolo Bonzini
2013-11-11 17:13 ` Peter Maydell
2013-11-11 17:22 ` Eric Blake
2013-11-11 17:47 ` Paolo Bonzini [this message]
2013-11-12 8:18 ` Gerd Hoffmann
2013-11-12 12:07 ` Laszlo Ersek
2013-11-11 17:11 ` Peter Maydell
2013-11-11 18:03 ` Max Filippov
2013-11-12 12:24 ` Laszlo Ersek
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