[PATCH 1/6] nptl: Use __futex_abstimed_wait64 on pthread_create (BZ 33715)

Adhemerval Zanella adhemerval.zanella@linaro.org
Thu Dec 11 20:47:17 GMT 2025


The pthread_create is annotated as __THROWNL.

Checked on x86_64-linux-gnu.

Suggested-by: Florian Weimer <fweimer@redhat.com>
---
 nptl/Makefile         |  1 +
 nptl/pthread_create.c |  4 +--
 nptl/tst-cancel33.c   | 79 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 82 insertions(+), 2 deletions(-)
 create mode 100644 nptl/tst-cancel33.c

diff --git a/nptl/Makefile b/nptl/Makefile
index 81d6a5482c..bfce63427b 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -277,6 +277,7 @@ tests = \
   tst-cancel17 \
   tst-cancel24 \
   tst-cancel31 \
+  tst-cancel33 \
   tst-cond26 \
   tst-context1 \
   tst-default-attr \
diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index 19e4ec8064..08a67ebd81 100644
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -867,8 +867,8 @@ __pthread_create_2_1 (pthread_t *newthread, const pthread_attr_t *attr,
 	     startup there is no need to handle all the steps.  */
 	  pid_t tid;
 	  while ((tid = atomic_load_acquire (&pd->tid)) != 0)
-	    __futex_abstimed_wait_cancelable64 ((unsigned int *) &pd->tid,
-						tid, 0, NULL, LLL_SHARED);
+	    __futex_abstimed_wait64 ((unsigned int *) &pd->tid, tid, 0, NULL,
+				     LLL_SHARED);
         }
 
       /* State (c) or (d) and we have ownership of PD (see CONCURRENCY
diff --git a/nptl/tst-cancel33.c b/nptl/tst-cancel33.c
new file mode 100644
index 0000000000..3a736d18df
--- /dev/null
+++ b/nptl/tst-cancel33.c
@@ -0,0 +1,79 @@
+/* Check if pthread_create does not act as cancellation entrypoint (BZ 33715)
+   Copyright (C) 2025 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <support/check.h>
+#include <support/xunistd.h>
+#include <support/xthread.h>
+#include <stdlib.h>
+
+static pthread_barrier_t b;
+
+static void *
+thr_func2 (void *arg)
+{
+  abort ();
+  return NULL;
+}
+
+static void *
+thr_func1 (void *closure)
+{
+  int max_cpu = xsysconf (_SC_NPROCESSORS_CONF) + 1;
+  /* Set a affinity mask with an invalid CPU.  */
+  cpu_set_t *cpuset = CPU_ALLOC (max_cpu);
+  TEST_VERIFY_EXIT (cpuset != NULL);
+  size_t cpusetsize = CPU_ALLOC_SIZE (max_cpu);
+  CPU_ZERO_S (cpusetsize, cpuset);
+  CPU_SET_S (max_cpu, cpusetsize, cpuset);
+
+  /* Check if the affinity mask does trigger an error.  */
+  TEST_COMPARE (sched_setaffinity (0, cpusetsize, cpuset), -1);
+  TEST_COMPARE (errno, EINVAL);
+
+  pthread_attr_t attr;
+  xpthread_attr_init (&attr);
+  xpthread_attr_setaffinity_np (&attr, cpusetsize, cpuset);
+
+  xpthread_barrier_wait (&b);
+
+  pthread_t thr;
+  TEST_COMPARE (pthread_create (&thr, &attr, thr_func2, NULL), EINVAL);
+  xpthread_attr_destroy (&attr);
+
+  return NULL;
+}
+
+static int
+do_test (void)
+{
+  xpthread_barrier_init (&b, NULL, 2);
+
+  pthread_t thr = xpthread_create (NULL, thr_func1, NULL);
+
+  xpthread_cancel (thr);
+
+  xpthread_barrier_wait (&b);
+
+  void *r = xpthread_join (thr);
+  TEST_VERIFY_EXIT (r == NULL);
+
+  return 0;
+}
+
+#include <support/test-driver.c>
-- 
2.43.0



More information about the Libc-alpha mailing list