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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2020-11-26 10:54:04 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2020-11-27 09:59:13 -0300 |
| commit | aa69f19a937b679816ef10e8620ea1141bb1734b (patch) | |
| tree | fda886e3c6899912d8ebb5e65ace4710075bbc0f /nptl/pthread_mutex_timedlock.c | |
| parent | 71eeae0325a95f5e5d7ec4a27a6a6c357e0c8ef4 (diff) | |
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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
Diffstat (limited to 'nptl/pthread_mutex_timedlock.c')
| -rw-r--r-- | nptl/pthread_mutex_timedlock.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/nptl/pthread_mutex_timedlock.c b/nptl/pthread_mutex_timedlock.c index 74adffe790..6c72a36b2b 100644 --- a/nptl/pthread_mutex_timedlock.c +++ b/nptl/pthread_mutex_timedlock.c @@ -270,7 +270,7 @@ __pthread_mutex_clocklock_common (pthread_mutex_t *mutex, oldval, clockid, abstime, PTHREAD_ROBUST_MUTEX_PSHARED (mutex)); /* The futex call timed out. */ - if (err == ETIMEDOUT) + if (err == ETIMEDOUT || err == EOVERFLOW) return err; /* Reload current lock value. */ oldval = mutex->__data.__lock; @@ -550,8 +550,8 @@ __pthread_mutex_clocklock_common (pthread_mutex_t *mutex, int e = __futex_abstimed_wait64 ( (unsigned int *) &mutex->__data.__lock, ceilval | 2, clockid, abstime, PTHREAD_MUTEX_PSHARED (mutex)); - if (e == ETIMEDOUT) - return ETIMEDOUT; + if (e == ETIMEDOUT || e == EOVERFLOW) + return e; } } while (atomic_compare_and_exchange_val_acq (&mutex->__data.__lock, |