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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2019-11-07 20:58:41 +0000
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2019-11-26 13:53:36 +0000
commit71d260c1077ce7ab1530809fc826756bdcd032b0 (patch)
treedbd30cdc6015415b34e6fd483c6a6186093c75ba /nptl
parent7fc8c286e31a336caa008a8bcfb00aac1e47cdc8 (diff)
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nptl: Cleanup mutex internal offset tests
The offsets of pthread_mutex_t __data.__nusers, __data.__spins,
__data.elision, __data.list are not required to be constant over
the releases.  Only the __data.__kind is used for static
initializers.

This patch also adds an additional size check for __data.__kind.

Checked with a build against affected ABIs.

Change-Id: I7a4e48cc91b4c4ada57e9a5d1b151fb702bfaa9f
Diffstat (limited to 'nptl')
-rw-r--r--nptl/pthreadP.h3
-rw-r--r--nptl/pthread_mutex_init.c13
2 files changed, 6 insertions, 10 deletions
diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h
index bbb2bf0222..9c200673a0 100644
--- a/nptl/pthreadP.h
+++ b/nptl/pthreadP.h
@@ -617,5 +617,8 @@ check_stacksize_attr (size_t st)
   _Static_assert (offsetof (type, member) == offset,			\
 		  "offset of " #member " field of " #type " != "	\
 		  ASSERT_PTHREAD_STRING (offset))
+#define ASSERT_PTHREAD_INTERNAL_MEMBER_SIZE(type, member, mtype)	\
+  _Static_assert (sizeof (((type) { 0 }).member) != 8,	\
+		  "sizeof (" #type "." #member ") != sizeof (" #mtype "))")
 
 #endif	/* pthreadP.h */
diff --git a/nptl/pthread_mutex_init.c b/nptl/pthread_mutex_init.c
index 20800b80f5..daef8b4bcc 100644
--- a/nptl/pthread_mutex_init.c
+++ b/nptl/pthread_mutex_init.c
@@ -55,18 +55,11 @@ __pthread_mutex_init (pthread_mutex_t *mutex,
 
   ASSERT_TYPE_SIZE (pthread_mutex_t, __SIZEOF_PTHREAD_MUTEX_T);
 
-  ASSERT_PTHREAD_INTERNAL_OFFSET (pthread_mutex_t, __data.__nusers,
-				  __PTHREAD_MUTEX_NUSERS_OFFSET);
+  /* __kind is the only field where its offset should be checked to
+     avoid ABI breakage with static initializers.  */
   ASSERT_PTHREAD_INTERNAL_OFFSET (pthread_mutex_t, __data.__kind,
 				  __PTHREAD_MUTEX_KIND_OFFSET);
-  ASSERT_PTHREAD_INTERNAL_OFFSET (pthread_mutex_t, __data.__spins,
-				  __PTHREAD_MUTEX_SPINS_OFFSET);
-#if __PTHREAD_MUTEX_LOCK_ELISION
-  ASSERT_PTHREAD_INTERNAL_OFFSET (pthread_mutex_t, __data.__elision,
-				  __PTHREAD_MUTEX_ELISION_OFFSET);
-#endif
-  ASSERT_PTHREAD_INTERNAL_OFFSET (pthread_mutex_t, __data.__list,
-				  __PTHREAD_MUTEX_LIST_OFFSET);
+  ASSERT_PTHREAD_INTERNAL_MEMBER_SIZE (pthread_mutex_t, __data.__kind, int);
 
   imutexattr = ((const struct pthread_mutexattr *) mutexattr
 		?: &default_mutexattr);