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| author | Florian Weimer <fweimer@redhat.com> | 2021-09-13 11:06:08 +0200 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2021-09-13 11:06:08 +0200 |
| commit | 8af8456004edbab71f8903a60a3cae442cf6fe69 (patch) | |
| tree | 735e5c4cb622683727395fd9ec345788597c44a2 /nptl/pthread_cancel.c | |
| parent | 2fd36391be523e882f2d102063710d3cf7ee7fa8 (diff) | |
| download | glibc-8af8456004edbab71f8903a60a3cae442cf6fe69.tar.gz glibc-8af8456004edbab71f8903a60a3cae442cf6fe69.tar.xz 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.c | 9 |
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) |