nptl: add pthread_getname_np/pthread_setname_np from GNU libc

These functions are used by firefox for example.
Tested with running firefox on x86 system.

libc/sysdeps/linux/common/not-cancel.h

@@ -70,7 +70,7 @@ extern int __openat64_nocancel (int fd, const char *fname, int oflag,
 #define read_not_cancel(fd, buf, n) \
   INLINE_SYSCALL (read, 3, (fd), (buf), (n))
 
-#ifdef __UCLIBC_HAS_LINUXTHREADS__
+#ifdef __UCLIBC_HAS_THREADS__
 /* Uncancelable write.  */
 #define write_not_cancel(fd, buf, n) \
   INLINE_SYSCALL (write, 3, (fd), (buf), (n))

libpthread/nptl/pthread_getname.c

@@ -0,0 +1,69 @@
+/* pthread_getname_np -- Get  thread name.  Linux version
+   Copyright (C) 2010-2016 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; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <pthreadP.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/prctl.h>
+
+#include <not-cancel.h>
+
+
+int
+pthread_getname_np (pthread_t th, char *buf, size_t len)
+{
+  const struct pthread *pd = (const struct pthread *) th;
+
+  /* Unfortunately the kernel headers do not export the TASK_COMM_LEN
+     macro.  So we have to define it here.  */
+#define TASK_COMM_LEN 16
+  if (len < TASK_COMM_LEN)
+    return ERANGE;
+
+  if (pd == THREAD_SELF)
+    return prctl (PR_GET_NAME, buf) ? errno : 0;
+
+#define FMT "/proc/self/task/%u/comm"
+  char fname[sizeof (FMT) + 8];
+  sprintf (fname, FMT, (unsigned int) pd->tid);
+
+  int fd = open_not_cancel_2 (fname, O_RDONLY);
+  if (fd == -1)
+    return errno;
+
+  int res = 0;
+  ssize_t n = TEMP_FAILURE_RETRY (read_not_cancel (fd, buf, len));
+  if (n < 0)
+    res = errno;
+  else
+    {
+      if (buf[n - 1] == '\n')
+	buf[n - 1] = '\0';
+      else if (n == len)
+	res = ERANGE;
+      else
+	buf[n] = '\0';
+    }
+
+  close_not_cancel_no_status (fd);
+
+  return res;
+}

libpthread/nptl/pthread_setname.c

@@ -0,0 +1,63 @@
+/* pthread_setname_np -- Set  thread name.  Linux version
+   Copyright (C) 2010-2016 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; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <pthreadP.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/prctl.h>
+
+#include <not-cancel.h>
+
+
+int
+pthread_setname_np (pthread_t th, const char *name)
+{
+  const struct pthread *pd = (const struct pthread *) th;
+
+  /* Unfortunately the kernel headers do not export the TASK_COMM_LEN
+     macro.  So we have to define it here.  */
+#define TASK_COMM_LEN 16
+  size_t name_len = strlen (name);
+  if (name_len >= TASK_COMM_LEN)
+    return ERANGE;
+
+  if (pd == THREAD_SELF)
+    return prctl (PR_SET_NAME, name) ? errno : 0;
+
+#define FMT "/proc/self/task/%u/comm"
+  char fname[sizeof (FMT) + 8];
+  sprintf (fname, FMT, (unsigned int) pd->tid);
+
+  int fd = open_not_cancel_2 (fname, O_RDWR);
+  if (fd == -1)
+    return errno;
+
+  int res = 0;
+  ssize_t n = TEMP_FAILURE_RETRY (write_not_cancel (fd, name, name_len));
+  if (n < 0)
+    res = errno;
+  else if (n != name_len)
+    res = EIO;
+
+  close_not_cancel_no_status (fd);
+
+  return res;
+}

libpthread/nptl/sysdeps/pthread/pthread.h

@@ -428,6 +428,16 @@ extern int pthread_getschedparam (pthread_t __target_thread,
 extern int pthread_setschedprio (pthread_t __target_thread, int __prio)
      __THROW;
 
+#ifdef __USE_GNU
+/* Get thread name visible in the kernel and its interfaces.  */
+extern int pthread_getname_np (pthread_t __target_thread, char *__buf,
+			       size_t __buflen)
+     __THROW __nonnull ((2));
+
+/* Set thread name visible in the kernel and its interfaces.  */
+extern int pthread_setname_np (pthread_t __target_thread, const char *__name)
+     __THROW __nonnull ((2));
+#endif
 
 #if defined __USE_UNIX98 && defined __UCLIBC_SUSV4_LEGACY__
 /* Determine level of concurrency.  */