nptl: Add EOVERFLOW checks for futex calls
authorAdhemerval Zanella <adhemerval.zanella@linaro.org>
Thu, 26 Nov 2020 13:54:04 +0000 (10:54 -0300)
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>
Fri, 27 Nov 2020 12:59:13 +0000 (09:59 -0300)
commitaa69f19a937b679816ef10e8620ea1141bb1734b
treefda886e3c6899912d8ebb5e65ace4710075bbc0f
parent71eeae0325a95f5e5d7ec4a27a6a6c357e0c8ef4
nptl: Add EOVERFLOW checks for futex calls

Some futex-internal calls require additional check for EOVERFLOW (as
indicated by [1] [2] [3]).  For both mutex and rwlock code, EOVERFLOW is
handle as ETIMEDOUT; since it indicate to the caller that the blocking
operation could not be issued.

For mutex it avoids a possible issue where PTHREAD_MUTEX_ROBUST_* might
assume EOVERFLOW indicate futex has succeed, and for PTHREAD_MUTEX_PP_*
it avoid a potential busy infinite loop.  For rwlock and semaphores, it
also avoids potential busy infinite loops.

Checked on x86_64-linux-gnu and i686-linux-gnu, although EOVERFLOW
won't be possible with current usage (since all timeouts on 32-bit
architectures with 32-bit time_t support will be in the range of
32-bit time_t).

[1] https://sourceware.org/pipermail/libc-alpha/2020-November/120079.html
[2] https://sourceware.org/pipermail/libc-alpha/2020-November/120080.html
[3] https://sourceware.org/pipermail/libc-alpha/2020-November/120127.html
nptl/pthread_cond_wait.c
nptl/pthread_mutex_timedlock.c
nptl/pthread_rwlock_common.c
nptl/sem_waitcommon.c