Re: pt_regs leak into userspace (was Re: [PATCH v3 20/71] ARC: Signal handling)

From: Jonas Bonn
Date: Fri Feb 15 2013 - 02:25:18 EST


On 11 February 2013 15:07, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:

> I'd suggest asking itanic folks; they do *not* put callee-saved stuff into
> sigcontext. AFAICS, they don't have setcontext() implemented as a syscall
> at all - it's done as sigprocmask() + doing to callee-saved registers what
> longjmp() does.


Just to round off this discussion, after giving it some more thought I
agree that the case where you would need callee-saved registers
restored is probably rather pathological. Any sane use of
get/set/swapcontext is manageable without this.

So, Vineet, I'm now convinced your approach is sound. I will probably
amend the OpenRISC arch to behave similarly. Consider your entire
patch Acked now.

/Jonas
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