* Why does MIPS/Linux always reserve 32 bytes in the top of each process's kernel stack space
@ 2005-01-28 2:59 zhan rongkai
2005-01-29 0:03 ` Ralf Baechle
0 siblings, 1 reply; 5+ messages in thread
From: zhan rongkai @ 2005-01-28 2:59 UTC (permalink / raw)
To: linux-mips
Hi, everyone:
Why does MIPS/Linux always reserve 32 bytes in the top of each
process's kernel stack space.
See arch/mips/kernel/process.c:
int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
unsigned long unused, struct task_struct *p, struct pt_regs *regs)
{
struct thread_info *ti = p->thread_info;
struct pt_regs *childregs;
long childksp;
childksp = (unsigned long)ti + THREAD_SIZE - 32;
......
}
--
Rongkai Zhan
^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: Why does MIPS/Linux always reserve 32 bytes in the top of each process's kernel stack space
@ 2005-01-28 4:54 ` David Daney
0 siblings, 0 replies; 5+ messages in thread
From: David Daney @ 2005-01-28 4:54 UTC (permalink / raw)
To: zhan rongkai, linux-mips
zhan rongkai wrote:
>Why does MIPS/Linux always reserve 32 bytes in the top of each
>process's kernel stack space.
Perhaps because the kernel's ABI requires it? I beleive that o64 requires stack space for a0 - a3 to be stored there.
David Daney
^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: Why does MIPS/Linux always reserve 32 bytes in the top of each process's kernel stack space
@ 2005-01-28 4:54 ` David Daney
0 siblings, 0 replies; 5+ messages in thread
From: David Daney @ 2005-01-28 4:54 UTC (permalink / raw)
To: zhan rongkai, linux-mips
zhan rongkai wrote:
>Why does MIPS/Linux always reserve 32 bytes in the top of each
>process's kernel stack space.
Perhaps because the kernel's ABI requires it? I beleive that o64 requires stack space for a0 - a3 to be stored there.
David Daney
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Why does MIPS/Linux always reserve 32 bytes in the top of each process's kernel stack space
2005-01-28 4:54 ` David Daney
(?)
@ 2005-01-29 0:02 ` Ralf Baechle
-1 siblings, 0 replies; 5+ messages in thread
From: Ralf Baechle @ 2005-01-29 0:02 UTC (permalink / raw)
To: David Daney; +Cc: zhan rongkai, linux-mips
On Thu, Jan 27, 2005 at 08:54:48PM -0800, David Daney wrote:
> >Why does MIPS/Linux always reserve 32 bytes in the top of each
> >process's kernel stack space.
>
> Perhaps because the kernel's ABI requires it? I beleive that o64 requires stack space for a0 - a3 to be stored there.
Except we don't use o64.
Ralf
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Why does MIPS/Linux always reserve 32 bytes in the top of each process's kernel stack space
2005-01-28 2:59 Why does MIPS/Linux always reserve 32 bytes in the top of each process's kernel stack space zhan rongkai
@ 2005-01-29 0:03 ` Ralf Baechle
0 siblings, 0 replies; 5+ messages in thread
From: Ralf Baechle @ 2005-01-29 0:03 UTC (permalink / raw)
To: zhan rongkai; +Cc: linux-mips
On Fri, Jan 28, 2005 at 10:59:26AM +0800, zhan rongkai wrote:
> Why does MIPS/Linux always reserve 32 bytes in the top of each
> process's kernel stack space.
Paranoia.
Ralf
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2005-01-29 0:03 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2005-01-28 2:59 Why does MIPS/Linux always reserve 32 bytes in the top of each process's kernel stack space zhan rongkai
2005-01-29 0:03 ` Ralf Baechle
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2005-01-28 4:54 David Daney
2005-01-28 4:54 ` David Daney
2005-01-29 0:02 ` Ralf Baechle
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