From: David Daney <ddaney@avtrex.com>
To: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>,
linux-mips <linux-mips@linux-mips.org>
Subject: Re: Question about signal syscalls !
Date: Fri, 02 Feb 2007 08:04:45 -0800 [thread overview]
Message-ID: <45C3611D.7000702@avtrex.com> (raw)
In-Reply-To: <cda58cb80702020055t6eb2578fn5d1e4370e9ebda08@mail.gmail.com>
Franck Bui-Huu wrote:
> On 2/1/07, David Daney <ddaney@avtrex.com> wrote:
>> I don't think *any* registers *need* to be saved on sys_sigreturn().
>> The values in sigcontext on the user stack associated with the system
>> call are all used instead of the actual register values.
>>
>
> Sorry but I don't understand what you mean. Could you explain ?
sys_sigreturn does not return to the caller in the conventional sense.
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.
David Daney
next prev parent reply other threads:[~2007-02-02 16:05 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-02-01 10:43 Question about signal syscalls ! Franck Bui-Huu
2007-02-01 13:57 ` Ralf Baechle
2007-02-01 14:54 ` Franck Bui-Huu
2007-02-01 17:01 ` David Daney
2007-02-02 8:55 ` Franck Bui-Huu
2007-02-02 16:04 ` David Daney [this message]
2007-02-02 16:36 ` Franck Bui-Huu
2007-02-02 16:53 ` Daniel Jacobowitz
2007-02-02 20:03 ` Franck Bui-Huu
2007-02-02 20:18 ` Franck Bui-Huu
2007-02-02 16:56 ` David Daney
2007-02-02 19:58 ` Franck Bui-Huu
2007-02-02 20:41 ` David Daney
2007-02-05 0:55 ` Daniel Jacobowitz
2007-02-05 1:10 ` Ralf Baechle
2007-02-05 2:30 ` Daniel Jacobowitz
2007-02-05 6:00 ` David Daney
2007-02-05 9:17 ` Franck Bui-Huu
2007-02-05 9:08 ` Franck Bui-Huu
2007-02-01 18:10 ` Ralf Baechle
2007-02-02 8:54 ` Franck Bui-Huu
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