From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Mon, 23 Aug 2021 16:51:54 +0000 (-0300)
Subject: nptl: Use exit_lock when accessing TID on pthread_getaffinity_np
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a75cd1e3afbc742970c3b9edb486ddaa120eb8c5;p=thirdparty%2Fglibc.git

nptl: Use exit_lock when accessing TID on pthread_getaffinity_np

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.
---

diff --git a/nptl/pthread_getaffinity.c b/nptl/pthread_getaffinity.c
index 0828185fbd..ec5d2dc2cc 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.  */
+  internal_sigset_t old_mask;
+  internal_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);
+  internal_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 de146dddeb..0532b367de 100644
--- a/sysdeps/pthread/Makefile
+++ b/sysdeps/pthread/Makefile
@@ -217,6 +217,7 @@ tests += \
   tst-pt-vfork1 \
   tst-pt-vfork2 \
   tst-pthread-exit-signal \
+  tst-pthread-exited \
   tst-pthread-mutexattr \
   tst-pthread-mutexattr-2 \
   tst-pthread-raise-blocked-self \
diff --git a/sysdeps/pthread/tst-pthread-exited.c b/sysdeps/pthread/tst-pthread-exited.c
new file mode 100644
index 0000000000..8997752528
--- /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) 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 <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>