[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH] linux-user/signal.c: Use frame->retcode instead
From: |
Richard Henderson |
Subject: |
Re: [Qemu-devel] [PATCH] linux-user/signal.c: Use frame->retcode instead of frame address for alpha target restorer |
Date: |
Tue, 29 Mar 2016 08:42:59 -0700 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 |
On 03/29/2016 07:25 AM, Laurent Vivier wrote:
>
>
> Le 29/03/2016 16:01, address@hidden a écrit :
>> From: Chen Gang <address@hidden>
>>
>> The restorer needs the return code address which is frame->retcode, not
>> frame itself.
>>
>> Signed-off-by: Chen Gang <address@hidden>
>> ---
>> linux-user/signal.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/linux-user/signal.c b/linux-user/signal.c
>> index e487f9e..4157154 100644
>> --- a/linux-user/signal.c
>> +++ b/linux-user/signal.c
>> @@ -5455,7 +5455,7 @@ static void setup_rt_frame(int sig, struct
>> target_sigaction *ka,
>> &frame->retcode[1]);
>> __put_user(INSN_CALLSYS, &frame->retcode[2]);
>> /* imb(); */
>> - r26 = frame_addr;
>> + r26 = frame_addr + offsetof(struct target_rt_sigframe, retcode);
>> }
>>
>> if (err) {
>>
>
> If you change setup_rt_frame(), you must update setup_frame() too.
>
> It seems correct.
>
> Richard, as you have written the original code, could you check this is
> correct?
Yes, it's correct, and yes both functions need fixing.
In practice, this path is historical and will never be used;
it was now a very old glibc that didn't supply a restorer.
r~