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Re: Question about signal syscalls !

To: "David Daney" <ddaney@avtrex.com>
Subject: Re: Question about signal syscalls !
From: "Franck Bui-Huu" <vagabon.xyz@gmail.com>
Date: Fri, 2 Feb 2007 20:58:31 +0100
Cc: "Ralf Baechle" <ralf@linux-mips.org>, linux-mips <linux-mips@linux-mips.org>
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On 2/2/07, David Daney <ddaney@avtrex.com> wrote:
Franck Bui-Huu wrote:
> David Daney wrote:
>> The entire user context (i.e. the value of *all* registers) is replaced
>> with the values stored in the sigcontext structure on the caller's
>> stack.  If all registers are being restored from the sigcontext, then
>> there is no need to save the current values of the registers, because
>> they will never be used.
>>
>

Again, why do you think that all values of the registers are saved on
sys_sigreturn() ?


> And now I'm starting to think that we don't need to save static regs in
> setup_sigcontext() either...
>
All registers *must* be saved in the sigcontext.  That is part of the
contract the kernel has with user code.


I'm just talking about _static_ registers which are s0-s7...

On return from an asynchronous signal, *all* registers must contain the
same values they had before the process was interrupted.


yes I agree and I've never said the contrary.
--
              Franck

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