aboutsummaryrefslogtreecommitdiff
path: root/nptl/pthread_cancel.c
diff options
context:
space:
mode:
authorFlorian Weimer <fweimer@redhat.com>2021-09-13 11:06:08 +0200
committerFlorian Weimer <fweimer@redhat.com>2021-09-13 11:06:08 +0200
commit8af8456004edbab71f8903a60a3cae442cf6fe69 (patch)
tree735e5c4cb622683727395fd9ec345788597c44a2 /nptl/pthread_cancel.c
parent2fd36391be523e882f2d102063710d3cf7ee7fa8 (diff)
downloadglibc-8af8456004edbab71f8903a60a3cae442cf6fe69.tar
glibc-8af8456004edbab71f8903a60a3cae442cf6fe69.tar.gz
glibc-8af8456004edbab71f8903a60a3cae442cf6fe69.tar.bz2
glibc-8af8456004edbab71f8903a60a3cae442cf6fe69.zip
nptl: pthread_kill, pthread_cancel should not fail after exit (bug 19193)
This closes one remaining race condition related to bug 12889: if the thread already exited on the kernel side, returning ESRCH is not correct because that error is reserved for the thread IDs (pthread_t values) whose lifetime has ended. In case of a kernel-side exit and a valid thread ID, no signal needs to be sent and cancellation does not have an effect, so just return 0. sysdeps/pthread/tst-kill4.c triggers undefined behavior and is removed with this commit. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Diffstat (limited to 'nptl/pthread_cancel.c')
-rw-r--r--nptl/pthread_cancel.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/nptl/pthread_cancel.c b/nptl/pthread_cancel.c
index 2bb523c0ec..a8aa3b3d15 100644
--- a/nptl/pthread_cancel.c
+++ b/nptl/pthread_cancel.c
@@ -61,10 +61,11 @@ __pthread_cancel (pthread_t th)
{
volatile struct pthread *pd = (volatile struct pthread *) th;
- /* Make sure the descriptor is valid. */
- if (INVALID_TD_P (pd))
- /* Not a valid thread handle. */
- return ESRCH;
+ if (pd->tid == 0)
+ /* The thread has already exited on the kernel side. Its outcome
+ (regular exit, other cancelation) has already been
+ determined. */
+ return 0;
static int init_sigcancel = 0;
if (atomic_load_relaxed (&init_sigcancel) == 0)