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authorRich Felker <dalias@aerifal.cx>2020-08-24 22:23:08 -0400
committerRich Felker <dalias@aerifal.cx>2020-08-27 18:36:45 -0400
commit3a5b9ae7cf656648c80fe155a5239d9b4fb4c485 (patch)
treefaef753db71ebd66802f84034478dd5c982bdd92 /arch/arm
parentea71a9004e08030a15d45186e263fd2b0c51cc25 (diff)
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deduplicate __pthread_self thread pointer adjustment out of each arch
the adjustment made is entirely a function of TLS_ABOVE_TP and
TP_OFFSET. aside from avoiding repetition of the TP_OFFSET value and
arithmetic, this change makes pthread_arch.h independent of the
definition of struct __pthread from pthread_impl.h. this in turn will
allow inclusion of pthread_arch.h to be moved to the top of
pthread_impl.h so that it can influence the definition of the
structure.

previously, arch files were very inconsistent about the type used for
the thread pointer. this change unifies the new __get_tp interface to
always use uintptr_t, which is the most correct when performing
arithmetic that may involve addresses outside the actual pointed-to
object (due to TP_OFFSET).
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/pthread_arch.h16
1 files changed, 8 insertions, 8 deletions
diff --git a/arch/arm/pthread_arch.h b/arch/arm/pthread_arch.h
index 48640985..157e2eae 100644
--- a/arch/arm/pthread_arch.h
+++ b/arch/arm/pthread_arch.h
@@ -1,11 +1,11 @@
 #if ((__ARM_ARCH_6K__ || __ARM_ARCH_6KZ__ || __ARM_ARCH_6ZK__) && !__thumb__) \
  || __ARM_ARCH_7A__ || __ARM_ARCH_7R__ || __ARM_ARCH >= 7
 
-static inline pthread_t __pthread_self()
+static inline uintptr_t __get_tp()
 {
-	char *p;
-	__asm__ ( "mrc p15,0,%0,c13,c0,3" : "=r"(p) );
-	return (void *)(p-sizeof(struct pthread));
+	uintptr_t tp;
+	__asm__ ( "mrc p15,0,%0,c13,c0,3" : "=r"(tp) );
+	return tp;
 }
 
 #else
@@ -16,12 +16,12 @@ static inline pthread_t __pthread_self()
 #define BLX "blx"
 #endif
 
-static inline pthread_t __pthread_self()
+static inline uintptr_t __get_tp()
 {
 	extern hidden uintptr_t __a_gettp_ptr;
-	register uintptr_t p __asm__("r0");
-	__asm__ ( BLX " %1" : "=r"(p) : "r"(__a_gettp_ptr) : "cc", "lr" );
-	return (void *)(p-sizeof(struct pthread));
+	register uintptr_t tp __asm__("r0");
+	__asm__ ( BLX " %1" : "=r"(tp) : "r"(__a_gettp_ptr) : "cc", "lr" );
+	return tp;
 }
 
 #endif