[libc-dev] [musl] Re: Powerpc Linux 'scv' system call ABI proposal take 2

Nicholas Piggin via libc-dev libc-dev at lists.llvm.org
Wed Apr 22 00:31:07 PDT 2020

Excerpts from Florian Weimer's message of April 22, 2020 5:15 pm:
> * Nicholas Piggin:
>> Another option would be to use a different signal. I don't see that any 
>> are more suitable.
> SIGSYS comes to my mind.  But I don't know how exclusively it is
> associated with seccomp these days.

SIGSYS is entirely seccomp now. There looks like a single obscure MIPS 
user of it in Linux that's not seccomp, but it would be entirely new for 
powerpc (or any of the common platforms, arm, x86 etc).

So I would be disinclined to use SIGSYS unless there are no other better 
signal types, and we don't want to use SIGILL for some good reason -- is 
there a good reason to add complexity for userspace by differentiating 
these two situations?


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