From mboxrd@z Thu Jan 1 00:00:00 1970 From: Petr Vorel Date: Fri, 16 Jul 2021 11:51:27 +0200 Subject: [LTP] [PATCH] crypto/af_alg02: use pthread_tryjoin_np() instead of pthread_kill() In-Reply-To: References: <20210715102813.106843-1-aleksei.kodanev@bell-sw.com> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ltp@lists.linux.it > Hi Alexey, > On Thu, Jul 15, 2021 at 6:29 PM Alexey Kodanev > wrote: > > musl doesn't return ESRCH for pthread_kill() if thread id is not found. Maybe ask on MUSL mailing list? > > POSIX only recommends to return ESRCH, and also says that pthread_kill() > > produces undefined behavior if tid lifetime has ended [1]. > > [1]: https://man7.org/linux/man-pages/man3/pthread_kill.3.html > > Signed-off-by: Alexey Kodanev > > --- > > testcases/kernel/crypto/af_alg02.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/testcases/kernel/crypto/af_alg02.c > > b/testcases/kernel/crypto/af_alg02.c > > index 31d30777c..0f5793c16 100644 > > --- a/testcases/kernel/crypto/af_alg02.c > > +++ b/testcases/kernel/crypto/af_alg02.c > > @@ -60,7 +60,7 @@ static void run(void) > > TST_CHECKPOINT_WAIT(0); > > - while (pthread_kill(thr, 0) != ESRCH) { > > + while (pthread_tryjoin_np(thr, NULL) == EBUSY) { > I'm not sure if safe enough to use because it is nonstandard GNU extensions > and the "_np" means nonportable. Others please double check, but pthread_tryjoin_np() seems to be in uclibc-ng and musl (+ of course in glibc). It's only missing in bionic (it looks like people would like to have it [1]). > Maybe another workaround is to define a volatile flag 'thread_complete', > initialize it to '0' when thread_B starts and reset to '1' while exit, and > just > do a value check in the while loop of thread_A should acquire thread_B > status. > Is this way a bit better? Sounds as reasonable workaround for me. Kind regards, Petr [1] https://github.com/kito-cheng/android-checkpoint/blob/master/bionic/0003-bionic-Implement-pthread_tryjoin_np.patch