Re: [rfa:NetBSD/ppc] Implement signal trampoline unwinder

Andrew Cagney
2004-03-01T01:33:16Z

> On Sun, Feb 29, 2004 at 08:05:28PM -0500, Andrew Cagney wrote:
>
>>> It appears to work (but doesn't have much effect without an rs6000
>>> unwinder).
>>>
>>> One question (and to follow up my earlier post) is there a better way of
>>> doing this:
>>>
>>> + if (frame_pc_unwind (next_frame) > 0x7f000000)
>>> + /* Assume anything that is vaguely on the stack is a signal
>>> + trampoline. */
>>> + return &ppcnbsd_sigtramp_unwind;
>>>
>>> ok?, eventually for 6.1?
>
>
> For other targets, we grub in the code for the sigtramp instruction
> sequence. I'm betting it's fixed for NetBSD too? ppc_linux_in_sigtramp
> does this.

That's potentially expensive - there should also be a predicate like the
above before the stack is read checked.

Andrew