Re: Question: livepatch failed for new fork() task stack unreliable

["Wangshaobo (bobo)" <bobo.shaobowang@huawei.com>]

在 2020/6/5 9:51, Josh Poimboeuf 写道:
> On Fri, Jun 05, 2020 at 09:26:42AM +0800, Wangshaobo (bobo) wrote:
>>>> So, I want to ask is there any side effects if i modify like this ? this
>>>> modification is based on
>>>>
>>>> your fix. It looks like ok with proper test.
>>>>
>>>> diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
>>>> index e9cc182aa97e..ecce5051e8fd 100644
>>>> --- a/arch/x86/kernel/unwind_orc.c
>>>> +++ b/arch/x86/kernel/unwind_orc.c
>>>> @@ -620,6 +620,7 @@ void __unwind_start(struct unwind_state *state, struct
>>>> task_struct *task,
>>>>                   state->sp = task->thread.sp;
>>>>                   state->bp = READ_ONCE_NOCHECK(frame->bp);
>>>>                   state->ip = READ_ONCE_NOCHECK(frame->ret_addr);
>>>> +              state->signal = ((void *)state->ip == ret_from_fork);
>>>>           }
>>>>
>>>> diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
>>>> index 7f969b2d240f..d7396431261a 100644
>>>> --- a/arch/x86/kernel/unwind_orc.c
>>>> +++ b/arch/x86/kernel/unwind_orc.c
>>>> @@ -540,7 +540,7 @@ bool unwind_next_frame(struct unwind_state *state)
>>>>            state->sp = sp;
>>>>            state->regs = NULL;
>>>>            state->prev_regs = NULL;
>>>> -        state->signal = ((void *)state->ip == ret_from_fork);
>>>> +        state->signal = false;
>>>>            break;
>>> Yes that's correct.
>> Hi, josh
>>
>> Could i ask when are you free to send the patch, all the tests are passed
>> by.
> I want to run some regression tests, so it will probably be next week.

Hi, josh

did you send this patch, I haven't received it up to now, so i ask u to 
confirm again.

thanks,

Wang ShaoBo