[v3,04/12] nptl: Use exit_lock when accessing TID on pthread_getaffinity_np

Message ID 20220531175255.1513396-5-adhemerval.zanella@linaro.org
State Superseded
Headers
Series Fix various NPTL synchronization issues |

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent

Commit Message

Adhemerval Zanella May 31, 2022, 5:52 p.m. UTC
  Also return EINVAL if the thread is already terminated at the time of
the call.  This is slight better than returning the calling thread
affinity (current behaviour), since the thread lifetime is defined.

Checked on x86_64-linux-gnu.
---
 nptl/pthread_getaffinity.c           | 30 ++++++++++------
 sysdeps/pthread/Makefile             |  1 +
 sysdeps/pthread/tst-pthread-exited.c | 51 ++++++++++++++++++++++++++++
 3 files changed, 71 insertions(+), 11 deletions(-)
 create mode 100644 sysdeps/pthread/tst-pthread-exited.c
  

Patch

diff --git a/nptl/pthread_getaffinity.c b/nptl/pthread_getaffinity.c
index c91fb37343..79f346326d 100644
--- a/nptl/pthread_getaffinity.c
+++ b/nptl/pthread_getaffinity.c
@@ -15,25 +15,33 @@ 
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
-#include <limits.h>
+#include <libc-lock.h>
 #include <pthreadP.h>
-#include <string.h>
-#include <sysdep.h>
-#include <sys/param.h>
-#include <sys/types.h>
 #include <shlib-compat.h>
 
 
 int
 __pthread_getaffinity_np (pthread_t th, size_t cpusetsize, cpu_set_t *cpuset)
 {
-  const struct pthread *pd = (const struct pthread *) th;
+  struct pthread *pd = (struct pthread *) th;
 
-  int res = INTERNAL_SYSCALL_CALL (sched_getaffinity, pd->tid,
-				   MIN (INT_MAX, cpusetsize), cpuset);
-  if (INTERNAL_SYSCALL_ERROR_P (res))
-    return INTERNAL_SYSCALL_ERRNO (res);
+  /* Block all signals, as required by pd->exit_lock.  */
+  sigset_t old_mask;
+  __libc_signal_block_all (&old_mask);
+  __libc_lock_lock (pd->exit_lock);
+
+  int res= 0;
+  if (pd->tid > 0)
+    res = INTERNAL_SYSCALL_CALL (sched_getaffinity, pd->tid,
+				 MIN (INT_MAX, cpusetsize), cpuset);
+  else
+    res = -EINVAL;
+
+  __libc_lock_unlock (pd->exit_lock);
+  __libc_signal_restore_set (&old_mask);
+
+  if (res < 0)
+    return -res;
 
   /* Clean the rest of the memory the kernel didn't do.  */
   memset ((char *) cpuset + res, '\0', cpusetsize - res);
diff --git a/sysdeps/pthread/Makefile b/sysdeps/pthread/Makefile
index 8cebe7a784..6a1debaf30 100644
--- a/sysdeps/pthread/Makefile
+++ b/sysdeps/pthread/Makefile
@@ -126,6 +126,7 @@  tests += tst-cnd-basic tst-mtx-trylock tst-cnd-broadcast \
 	 tst-pthread-raise-blocked-self \
 	 tst-pthread_kill-exited \
 	 tst-pthread_kill-exiting \
+	 tst-pthread-exited
 	 # tests
 
 tests-time64 += \
diff --git a/sysdeps/pthread/tst-pthread-exited.c b/sysdeps/pthread/tst-pthread-exited.c
new file mode 100644
index 0000000000..6fca37d7c2
--- /dev/null
+++ b/sysdeps/pthread/tst-pthread-exited.c
@@ -0,0 +1,51 @@ 
+/* Test pthread interface which should return ESRCH when issues along
+   with a terminated pthread_t.
+   Copyright (C) 2021 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 <signal.h>
+#include <stddef.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xthread.h>
+
+static void *
+noop_thread (void *closure)
+{
+  return NULL;
+}
+
+static int
+do_test (void)
+{
+  pthread_t thr = xpthread_create (NULL, noop_thread, NULL);
+
+  support_wait_for_thread_exit ();
+
+  {
+    cpu_set_t cpuset;
+    int r = pthread_getaffinity_np (thr, sizeof (cpuset), &cpuset);
+    TEST_COMPARE (r, EINVAL);
+  }
+
+  xpthread_join (thr);
+
+  return 0;
+}
+
+#include <support/test-driver.c>