Re: [Qemu-devel] [PATCH] linux-user: avoid treading on gprof's SIGPROF signals

[Laurent Vivier]

On 02/05/2019 18:27, Laurent Desnogues wrote:
> On Thu, May 2, 2019 at 6:17 PM Laurent Vivier <address@hidden> wrote:
>>
>> On 02/05/2019 16:58, Alex Bennée wrote:
>>> The guest tends to get confused when it receives signals it doesn't
>>> know about. Given the gprof magic has also set up it's own handler we
>>> would do well to avoid stomping on it as well.
>>>
>>> Signed-off-by: Alex Bennée <address@hidden>
>>> ---
>>>  linux-user/signal.c | 5 +++++
>>>  1 file changed, 5 insertions(+)
>>>
>>> diff --git a/linux-user/signal.c b/linux-user/signal.c
>>> index e2c0b37173..44b2d3b35a 100644
>>> --- a/linux-user/signal.c
>>> +++ b/linux-user/signal.c
>>> @@ -508,6 +508,11 @@ void signal_init(void)
>>>      act.sa_flags = SA_SIGINFO;
>>>      act.sa_sigaction = host_signal_handler;
>>>      for(i = 1; i <= TARGET_NSIG; i++) {
>>> +#ifdef TARGET_GPROF
>>> +        if (i == SIGPROF) {
>>> +            continue;
>>> +        }
>>> +#endif
>>>          host_sig = target_to_host_signal(i);
>>>          sigaction(host_sig, NULL, &oact);
>>>          if (oact.sa_sigaction == (void *)SIG_IGN) {
>>>
>>
>> Perhaps merge this with the previous one and send a v2: it will ease
>> bisecting.
> 
> I agree it would be better, though it should be noted that the signal
> issue has existed for at least 8 years (that's when I had to add a
> specific patch in my private repository).

I can also apply the second first, and the first then...

Thanks,
Laurent