Re: [Devel] Re: [PATCH 08/10] Introduce functions to restart a process
From: Cedric Le Goater
Date: Wed Oct 22 2008 - 08:48:27 EST
>>> + CFI_STARTPROC
>>> + pushl %eax
>>> + CFI_ADJUST_CFA_OFFSET 4
>>> + call schedule_tail
>>> + GET_THREAD_INFO(%ebp)
>>> + popl %eax
>>> + CFI_ADJUST_CFA_OFFSET -4
>>> + movl (%esp), %eax
>>> + testl %eax, %eax
>>> + jz 1f
>>> + pushl %esp
>>> + call *%eax
>>> + addl $4, %esp
>>> + addl $256, %esp
>>> + jmp ret_from_fork_tail
>>> + CFI_ENDPROC
>> Could you explain why you need to do this
>> call *%eax
>> is it related to the freezer code ?
> It is not related to the freezer code actually.
> That is needed to restart syscalls. Right now I don't have a code in my
> patchset which restarts a syscall, but later I plan to add it.
> In OpenVZ checkpointing we restart syscalls if process was caught in syscall
> during checkpointing.
ok. I get it now. why 256 bytes of extra stack ? I'm sure it's not random.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/