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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2022-04-06 12:24:42 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2022-04-14 12:48:31 -0300 |
| commit | 404656009b459658138ed1bd18f3c6cf3863e6a6 (patch) | |
| tree | 3cbfb1da2b0f8e657f72a53abf1c5bf85b8d43c3 /nptl/pthread_join_common.c | |
| parent | 2376944b9e5c0364b9fb473e4d8dabca31b57167 (diff) | |
| download | glibc-404656009b459658138ed1bd18f3c6cf3863e6a6.tar.gz glibc-404656009b459658138ed1bd18f3c6cf3863e6a6.tar.xz glibc-404656009b459658138ed1bd18f3c6cf3863e6a6.zip | |
nptl: Handle spurious EINTR when thread cancellation is disabled (BZ#29029)
Some Linux interfaces never restart after being interrupted by a signal handler, regardless of the use of SA_RESTART [1]. It means that for pthread cancellation, if the target thread disables cancellation with pthread_setcancelstate and calls such interfaces (like poll or select), it should not see spurious EINTR failures due the internal SIGCANCEL. However recent changes made pthread_cancel to always sent the internal signal, regardless of the target thread cancellation status or type. To fix it, the previous semantic is restored, where the cancel signal is only sent if the target thread has cancelation enabled in asynchronous mode. The cancel state and cancel type is moved back to cancelhandling and atomic operation are used to synchronize between threads. The patch essentially revert the following commits: 8c1c0aae20 nptl: Move cancel type out of cancelhandling 2b51742531 nptl: Move cancel state out of cancelhandling 26cfbb7162 nptl: Remove CANCELING_BITMASK However I changed the atomic operation to follow the internal C11 semantic and removed the MACRO usage, it simplifies a bit the resulting code (and removes another usage of the old atomic macros). Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu, and powerpc64-linux-gnu. [1] https://man7.org/linux/man-pages/man7/signal.7.html Reviewed-by: Florian Weimer <fweimer@redhat.com> Tested-by: Aurelien Jarno <aurelien@aurel32.net>
Diffstat (limited to 'nptl/pthread_join_common.c')
| -rw-r--r-- | nptl/pthread_join_common.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/nptl/pthread_join_common.c b/nptl/pthread_join_common.c index a8e884f341..ca3245b0af 100644 --- a/nptl/pthread_join_common.c +++ b/nptl/pthread_join_common.c @@ -57,12 +57,9 @@ __pthread_clockjoin_ex (pthread_t threadid, void **thread_return, if ((pd == self || (self->joinid == pd && (pd->cancelhandling - & (CANCELED_BITMASK | EXITING_BITMASK + & (CANCELING_BITMASK | CANCELED_BITMASK | EXITING_BITMASK | TERMINATED_BITMASK)) == 0)) - && !(self->cancelstate == PTHREAD_CANCEL_ENABLE - && (pd->cancelhandling & (CANCELED_BITMASK | EXITING_BITMASK - | TERMINATED_BITMASK)) - == CANCELED_BITMASK)) + && !cancel_enabled_and_canceled (self->cancelhandling)) /* This is a deadlock situation. The threads are waiting for each other to finish. Note that this is a "may" error. To be 100% sure we catch this error we would have to lock the data |