Gilles Chanteperdrix wrote:
> Jan Kiszka wrote:
>> Gilles Chanteperdrix wrote:
>>> Jan Kiszka wrote:
>>>> Gilles Chanteperdrix wrote:
>>>>> Ok for returning -EINTR, it is documented. Kernel-space is not so
>>>>> different from user-space, rt_task_unblock could wake-up a kernel-space
>>>>> task blocked in a call to rt_cond_wait.
>>>>> However, if the epilogue returns an error, we must return it.
>>>> OK for this. Pushed an update, but I also modified it further to avoid
>>>> returning without the mutex lock unless that one is also failing. Maybe
>>>> in-kernel POSIX requires the same fix, will check.
>>> Still not OK. You should reacquire the mutex only if the error is 0,
>>> -ETIMEDOUT or -EINTR. With any other error, we do not know if we can
>>> call the epilogue safely.
>> We _must_ reacquire the mutex - but, granted, we actually have to take
>> care of invalid cond objects. Lot's of bugs...
> No. If the error is another error than 0, -ETIMEDOUT, or -EINTR, it
> means that the error was detected prior to freeing the mutex. So, we do
> not have to re-acquire the mutex. Quoting POSIX:
> "Except in the case of [ETIMEDOUT], all these error checks shall act as
> if they were performed immediately at the beginning of processing for
> the function and shall cause an error return, in effect, prior to
> modifying the state of the mutex specified by mutex or the condition
> variable specified by cond."
> POSIX does not talk about -EINTR, because it states that in this case,
> we should return 0 to the application.

OK, but EIDRM was missing in your list. Will adjust both patches.


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Corporate Competence Center Embedded Linux

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