nptl: Add __pthread_attr_copy for copying pthread_attr_t objects

Also add the private type union pthread_attr_transparent, to reduce

the amount of casting that is required.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

Tested-by: Carlos O'Donell <carlos@redhat.com>

(cherry picked from commit 331c6e8a184167dd21a9f0b3fc165aeefea6eeca)

Difference from upstream:

Unlike upstream, __pthread_attr_copy is in libpthread.so.

# Conflicts:

#	nptl/Makefile

#	nptl/Versions

diff --git a/nptl/Makefile b/nptl/Makefile

index d6b37b6efd3b7d78..b14de3ffb330c10b 100644

--- a/nptl/Makefile

+++ b/nptl/Makefile

@@ -54,7 +54,8 @@ libpthread-routines = nptl-init nptlfreeres vars events version pt-interp \

 		      pthread_getconcurrency pthread_setconcurrency \

 		      pthread_getschedparam pthread_setschedparam \

 		      pthread_setschedprio \

-		      pthread_attr_init pthread_attr_destroy \

+		      pthread_attr_init pthread_attr_copy \

+		      pthread_attr_destroy \

 		      pthread_attr_getdetachstate pthread_attr_setdetachstate \

 		      pthread_attr_getguardsize pthread_attr_setguardsize \

 		      pthread_attr_getschedparam pthread_attr_setschedparam \

diff --git a/nptl/Versions b/nptl/Versions

index 6007fd03e7ed117c..e38272aa187fbe78 100644

--- a/nptl/Versions

+++ b/nptl/Versions

@@ -283,5 +283,6 @@ libpthread {

     __pthread_barrier_init; __pthread_barrier_wait;

     __shm_directory;

     __libpthread_freeres;

+    __pthread_attr_copy;

   }

 }

diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h

index 00be8f92793e8710..a2d48b2015cd385c 100644

--- a/nptl/pthreadP.h

+++ b/nptl/pthreadP.h

@@ -464,6 +464,9 @@ extern int __pthread_attr_getstack (const pthread_attr_t *__restrict __attr,

 				    size_t *__restrict __stacksize);

 extern int __pthread_attr_setstack (pthread_attr_t *__attr, void *__stackaddr,

 				    size_t __stacksize);

+extern int __pthread_attr_setaffinity_np (pthread_attr_t *attr,

+					  size_t cpusetsize,

+					  const cpu_set_t *cpuset);

 extern int __pthread_rwlock_init (pthread_rwlock_t *__restrict __rwlock,

 				  const pthread_rwlockattr_t *__restrict

 				  __attr);

@@ -605,6 +608,11 @@ extern void __wait_lookup_done (void) attribute_hidden;

 # define PTHREAD_STATIC_FN_REQUIRE(name) __asm (".globl " #name);

 #endif

+/* Make a deep copy of the attribute *SOURCE in *TARGET.  *TARGET is

+   not assumed to have been initialized.  Returns 0 on success, or a

+   positive error code otherwise.  */

+int __pthread_attr_copy (pthread_attr_t *target, const pthread_attr_t *source);

+

 /* Returns 0 if POL is a valid scheduling policy.  */

 static inline int

 check_sched_policy_attr (int pol)

diff --git a/nptl/pthread_attr_copy.c b/nptl/pthread_attr_copy.c

new file mode 100644

index 0000000000000000..67f272acf297100c

--- /dev/null

+++ b/nptl/pthread_attr_copy.c

@@ -0,0 +1,56 @@

+/* Deep copy of a pthread_attr_t object.

+   Copyright (C) 2020 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 <pthreadP.h>

+#include <stdlib.h>

+

+int

+__pthread_attr_copy (pthread_attr_t *target, const pthread_attr_t *source)

+{

+  /* Avoid overwriting *TARGET until all allocations have

+     succeeded.  */

+  union pthread_attr_transparent temp;

+  temp.external = *source;

+

+  /* Force new allocation.  This function has full ownership of temp.  */

+  temp.internal.cpuset = NULL;

+  temp.internal.cpusetsize = 0;

+

+  int ret = 0;

+

+  struct pthread_attr *isource = (struct pthread_attr *) source;

+

+  /* Propagate affinity mask information.  */

+  if (isource->cpusetsize > 0)

+    ret = __pthread_attr_setaffinity_np (&temp.external,

+					 isource->cpusetsize,

+					 isource->cpuset);

+

+  if (ret != 0)

+    {

+      /* Deallocate because we have ownership.  */

+      __pthread_attr_destroy (&temp.external);

+      return ret;

+    }

+

+  /* Transfer ownership.  *target is not assumed to have been

+     initialized.  */

+  *target = temp.external;

+  return 0;

+}

diff --git a/nptl/pthread_attr_setaffinity.c b/nptl/pthread_attr_setaffinity.c

index 545b72c91e290216..914ebf6f9cbfd5ff 100644

--- a/nptl/pthread_attr_setaffinity.c

+++ b/nptl/pthread_attr_setaffinity.c

@@ -55,6 +55,7 @@ __pthread_attr_setaffinity_new (pthread_attr_t *attr, size_t cpusetsize,

   return 0;

 }

+strong_alias (__pthread_attr_setaffinity_new, __pthread_attr_setaffinity_np)

 versioned_symbol (libpthread, __pthread_attr_setaffinity_new,

 		  pthread_attr_setaffinity_np, GLIBC_2_3_4);

diff --git a/sysdeps/nptl/internaltypes.h b/sysdeps/nptl/internaltypes.h

index b78ad99a888b4e3b..d3dce1278de989e2 100644

--- a/sysdeps/nptl/internaltypes.h

+++ b/sysdeps/nptl/internaltypes.h

@@ -49,6 +49,13 @@ struct pthread_attr

 #define ATTR_FLAG_SCHED_SET		0x0020

 #define ATTR_FLAG_POLICY_SET		0x0040

+/* Used to allocate a pthread_attr_t object which is also accessed

+   internally.  */

+union pthread_attr_transparent

+{

+  pthread_attr_t external;

+  struct pthread_attr internal;

+};

 /* Mutex attribute data structure.  */

 struct pthread_mutexattr