Re: [Qemu-devel] audit needed for signal handlers

[Paolo Bonzini]

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