nptl: Define __PTHREAD_MUTEX_{NUSERS_AFTER_KIND,USE_UNION}

This patch adds two new internal defines to set the internal
pthread_mutex_t layout required by the supported ABIS:

  1. __PTHREAD_MUTEX_NUSERS_AFTER_KIND which control whether to define
     __nusers fields before or after __kind.  The preferred value for
     is 0 for new ports and it sets __nusers before __kind.

  2. __PTHREAD_MUTEX_USE_UNION which control whether internal __spins and
     __list members will be place inside an union for linuxthreads
     compatibility.  The preferred value is 0 for ports and it sets
     to not use an union to define both fields.

It fixes the wrong offsets value for __kind value on x86_64-linux-gnu-x32.
Checked with a make check run-built-tests=no on all afected ABIs.

	[BZ #22298]
	* nptl/allocatestack.c (allocate_stack): Check if
	__PTHREAD_MUTEX_HAVE_PREV is non-zero, instead if
	__PTHREAD_MUTEX_HAVE_PREV is defined.
	* nptl/descr.h (pthread): Likewise.
	* nptl/nptl-init.c (__pthread_initialize_minimal_internal):
	Likewise.
	* nptl/pthread_create.c (START_THREAD_DEFN): Likewise.
	* sysdeps/nptl/fork.c (__libc_fork): Likewise.
	* sysdeps/nptl/pthread.h (PTHREAD_MUTEX_INITIALIZER): Likewise.
	* sysdeps/nptl/bits/thread-shared-types.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): New
	defines.
	(__pthread_internal_list): Check __PTHREAD_MUTEX_USE_UNION instead
	of __WORDSIZE for internal layout.
	(__pthread_mutex_s): Check __PTHREAD_MUTEX_NUSERS_AFTER_KIND instead
	of __WORDSIZE for internal __nusers layout and __PTHREAD_MUTEX_USE_UNION
	instead of __WORDSIZE whether to use an union for __spins and __list
	fields.
	(__PTHREAD_MUTEX_HAVE_PREV): Define also for __PTHREAD_MUTEX_USE_UNION
	case.
	* sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): New
	defines.
	* sysdeps/alpha/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/arm/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/hppa/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/ia64/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/m68k/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/mips/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/nios2/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/powerpc/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/s390/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/sh/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/sparc/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/tile/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/x86/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.

Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

3 files changed, 29 insertions, 7 deletions

diff --git a/sysdeps/nptl/bits/thread-shared-types.h b/sysdeps/nptl/bits/thread-shared-types.h
index 68b82b6bd6..da4358a965 100644
--- a/sysdeps/nptl/bits/thread-shared-types.h
+++ b/sysdeps/nptl/bits/thread-shared-types.h
@@ -42,6 +42,25 @@
 				    the internal structure.
    __PTHREAD_MUTEX_LOCK_ELISION   - 1 if the architecture supports lock
 				    elision or 0 otherwise.
+   __PTHREAD_MUTEX_NUSERS_AFTER_KIND - control where to put __nusers.  The
+				       preferred value for new architectures
+				       is 0.
+   __PTHREAD_MUTEX_USE_UNION      - control whether internal __spins and
+				    __list will be place inside a union for
+				    linuxthreads compatibility.
+				    The preferred value for new architectures
+				    is 0.
+
+   For a new port the preferred values for the required defines are:
+
+   #define __PTHREAD_COMPAT_PADDING_MID
+   #define __PTHREAD_COMPAT_PADDING_END
+   #define __PTHREAD_MUTEX_LOCK_ELISION         0
+   #define __PTHREAD_MUTEX_NUSERS_AFTER_KIND    0
+   #define __PTHREAD_MUTEX_USE_UNION            0
+
+   __PTHREAD_MUTEX_LOCK_ELISION can be set to 1 if the hardware plans to
+   eventually support lock elision using transactional memory.
 
    The additional macro defines any constraint for the lock alignment
    inside the thread structures:
@@ -59,7 +78,7 @@
 
 /* Common definition of pthread_mutex_t. */
 
-#if __WORDSIZE == 64
+#if !__PTHREAD_MUTEX_USE_UNION
 typedef struct __pthread_internal_list
 {
   struct __pthread_internal_list *__prev;
@@ -74,7 +93,7 @@ typedef struct __pthread_internal_slist
 
 /* Lock elision support.  */
 #if __PTHREAD_MUTEX_LOCK_ELISION
-# if __WORDSIZE == 64
+# if !__PTHREAD_MUTEX_USE_UNION
 #  define __PTHREAD_SPINS_DATA	\
   short __spins;		\
   short __elision
@@ -101,24 +120,27 @@ struct __pthread_mutex_s
   int __lock __LOCK_ALIGNMENT;
   unsigned int __count;
   int __owner;
-#if __WORDSIZE == 64
+#if !__PTHREAD_MUTEX_NUSERS_AFTER_KIND
   unsigned int __nusers;
 #endif
   /* KIND must stay at this position in the structure to maintain
      binary compatibility with static initializers.  */
   int __kind;
   __PTHREAD_COMPAT_PADDING_MID
-#if __WORDSIZE == 64
+#if __PTHREAD_MUTEX_NUSERS_AFTER_KIND
+  unsigned int __nusers;
+#endif
+#if !__PTHREAD_MUTEX_USE_UNION
   __PTHREAD_SPINS_DATA;
   __pthread_list_t __list;
 # define __PTHREAD_MUTEX_HAVE_PREV      1
 #else
-  unsigned int __nusers;
   __extension__ union
   {
     __PTHREAD_SPINS_DATA;
     __pthread_slist_t __list;
   };
+# define __PTHREAD_MUTEX_HAVE_PREV      0
 #endif
   __PTHREAD_COMPAT_PADDING_END
 };
diff --git a/sysdeps/nptl/fork.c b/sysdeps/nptl/fork.c
index 4bb87e2331..48676c2f48 100644
--- a/sysdeps/nptl/fork.c
+++ b/sysdeps/nptl/fork.c
@@ -166,7 +166,7 @@ __libc_fork (void)
 	 inherit the correct value from the parent.  We do not need to clear
 	 the pending operation because it must have been zero when fork was
 	 called.  */
-# ifdef __PTHREAD_MUTEX_HAVE_PREV
+# if __PTHREAD_MUTEX_HAVE_PREV
       self->robust_prev = &self->robust_head;
 # endif
       self->robust_head.list = &self->robust_head;
diff --git a/sysdeps/nptl/pthread.h b/sysdeps/nptl/pthread.h
index 632ea7bc36..2b2b386ab3 100644
--- a/sysdeps/nptl/pthread.h
+++ b/sysdeps/nptl/pthread.h
@@ -83,7 +83,7 @@ enum
 #endif
 
 
-#ifdef __PTHREAD_MUTEX_HAVE_PREV
+#if __PTHREAD_MUTEX_HAVE_PREV
 # define PTHREAD_MUTEX_INITIALIZER \
   { { 0, 0, 0, 0, 0, __PTHREAD_SPINS, { 0, 0 } } }
 # ifdef __USE_GNU