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Re: [Qemu-devel] [RFC] Continuous work on sandboxing
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [RFC] Continuous work on sandboxing |
Date: |
Sat, 27 Apr 2013 00:17:30 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4 |
Il 26/04/2013 23:07, Paul Moore ha scritto:
>> > 3. Debugging and/or learning mode - third party libraries still have the
>> > problem of interfering in the Qemu's signal mask. According to some
>> > previous discussions, perhaps patch all external libraries that mass up
>> > with this mask (spice, for example) is a way to solve it. But not sure
>> > if it worth the time spent. Would like to hear you guys.
> I think patching all the libraries is a losing battle, I think we need to
> pursue alternate debugging techniques.
It is really only about patching libraries that create threads _and_
block all signals in the newly-created thread (to not interfere with the
program's own handling of the signals). In this case, the per-thread
signals (SIGFPE/SIGSEGV/SIGBUS/SIGSYS/SIGILL) should be left unblocked,
but SIGSYS is often forgotten.
I don't think there are many libraries like this, but fixing SPICE at
least should definitely be welcome.
In fact QEMU's own util/qemu-thread-posix.c does not unblock those
signals. Eduardo, can you submit a patch for that?
Paolo
Re: [Qemu-devel] [RFC] Continuous work on sandboxing, Corey Bryant, 2013/04/29