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).

arch/aarch64/pthread_arch.h

@@ -1,8 +1,8 @@
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
-	char *self;
-	__asm__ ("mrs %0,tpidr_el0" : "=r"(self));
-	return (void*)(self - sizeof(struct pthread));
+	uintptr_t tp;
+	__asm__ ("mrs %0,tpidr_el0" : "=r"(tp));
+	return tp;
 }
 
 #define TLS_ABOVE_TP

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

arch/i386/pthread_arch.h

@@ -1,8 +1,8 @@
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
-	struct pthread *self;
-	__asm__ ("movl %%gs:0,%0" : "=r" (self) );
-	return self;
+	uintptr_t tp;
+	__asm__ ("movl %%gs:0,%0" : "=r" (tp) );
+	return tp;
 }
 
 #define MC_PC gregs[REG_EIP]

arch/m68k/pthread_arch.h

@@ -1,7 +1,6 @@
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
-	uintptr_t tp = __syscall(SYS_get_thread_area);
-	return (pthread_t)(tp - 0x7000 - sizeof(struct pthread));
+	return __syscall(SYS_get_thread_area);
 }
 
 #define TLS_ABOVE_TP

arch/microblaze/pthread_arch.h

@@ -1,8 +1,8 @@
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
-	struct pthread *self;
-	__asm__ ("ori %0, r21, 0" : "=r" (self) );
-	return self;
+	uintptr_t tp;
+	__asm__ ("ori %0, r21, 0" : "=r" (tp) );
+	return tp;
 }
 
 #define MC_PC regs.pc

arch/mips/pthread_arch.h

@@ -1,13 +1,13 @@
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
 #if __mips_isa_rev < 2
-	register char *tp __asm__("$3");
+	register uintptr_t tp __asm__("$3");
 	__asm__ (".word 0x7c03e83b" : "=r" (tp) );
 #else
-	char *tp;
+	uintptr_t tp;
 	__asm__ ("rdhwr %0, $29" : "=r" (tp) );
 #endif
-	return (pthread_t)(tp - 0x7000 - sizeof(struct pthread));
+	return tp;
 }
 
 #define TLS_ABOVE_TP

arch/mips64/pthread_arch.h

@@ -1,13 +1,13 @@
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
 #if __mips_isa_rev < 2
-	register char *tp __asm__("$3");
+	register uintptr_t tp __asm__("$3");
 	__asm__ (".word 0x7c03e83b" : "=r" (tp) );
 #else
-	char *tp;
+	uintptr_t tp;
 	__asm__ ("rdhwr %0, $29" : "=r" (tp) );
 #endif
-	return (pthread_t)(tp - 0x7000 - sizeof(struct pthread));
+	return tp;
 }
 
 #define TLS_ABOVE_TP

arch/mipsn32/pthread_arch.h

@@ -1,13 +1,13 @@
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
 #if __mips_isa_rev < 2
-	register char *tp __asm__("$3");
+	register uintptr_t tp __asm__("$3");
 	__asm__ (".word 0x7c03e83b" : "=r" (tp) );
 #else
-	char *tp;
+	uintptr_t tp;
 	__asm__ ("rdhwr %0, $29" : "=r" (tp) );
 #endif
-	return (pthread_t)(tp - 0x7000 - sizeof(struct pthread));
+	return tp;
 }
 
 #define TLS_ABOVE_TP

arch/or1k/pthread_arch.h

@@ -1,14 +1,13 @@
-/* or1k use variant I, but with the twist that tp points to the end of TCB */
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
 #ifdef __clang__
-	char *tp;
+	uintptr_t tp;
 	__asm__ ("l.ori %0, r10, 0" : "=r" (tp) );
 #else
-	register char *tp __asm__("r10");
+	register uintptr_t tp __asm__("r10");
 	__asm__ ("" : "=r" (tp) );
 #endif
-	return (struct pthread *) (tp - sizeof(struct pthread));
+	return tp;
 }
 
 #define TLS_ABOVE_TP

arch/powerpc/pthread_arch.h

@@ -1,8 +1,8 @@
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
-	register char *tp __asm__("r2");
+	register uintptr_t tp __asm__("r2");
 	__asm__ ("" : "=r" (tp) );
-	return (pthread_t)(tp - 0x7000 - sizeof(struct pthread));
+	return tp;
 }
                         
 #define TLS_ABOVE_TP

arch/powerpc64/pthread_arch.h

@@ -1,8 +1,8 @@
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
-	register char *tp __asm__("r13");
+	register uintptr_t tp __asm__("r13");
 	__asm__ ("" : "=r" (tp) );
-	return (pthread_t)(tp - 0x7000 - sizeof(struct pthread));
+	return tp;
 }
 
 #define TLS_ABOVE_TP

arch/riscv64/pthread_arch.h

@@ -1,8 +1,8 @@
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
-	char *tp;
+	uintptr_t tp;
 	__asm__ __volatile__("mv %0, tp" : "=r"(tp));
-	return (void *)(tp - sizeof(struct pthread));
+	return tp;
 }
 
 #define TLS_ABOVE_TP

arch/s390x/pthread_arch.h

@@ -1,12 +1,12 @@
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
-	struct pthread *self;
+	uintptr_t tp;
 	__asm__ (
 		"ear  %0, %%a0\n"
 		"sllg %0, %0, 32\n"
 		"ear  %0, %%a1\n"
-		: "=r"(self));
-	return self;
+		: "=r"(tp));
+	return tp;
 }
 
 #define MC_PC psw.addr

arch/sh/pthread_arch.h

@@ -1,8 +1,8 @@
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
-	char *self;
-	__asm__ ("stc gbr,%0" : "=r" (self) );
-	return (struct pthread *) (self - sizeof(struct pthread));
+	uintptr_t tp;
+	__asm__ ("stc gbr,%0" : "=r" (tp) );
+	return tp;
 }
 
 #define TLS_ABOVE_TP

arch/x32/pthread_arch.h

@@ -1,8 +1,8 @@
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
-	struct pthread *self;
-	__asm__ ("mov %%fs:0,%0" : "=r" (self) );
-	return self;
+	uintptr_t tp;
+	__asm__ ("mov %%fs:0,%0" : "=r" (tp) );
+	return tp;
 }
 
 #define MC_PC gregs[REG_RIP]

arch/x86_64/pthread_arch.h

@@ -1,8 +1,8 @@
-static inline struct pthread *__pthread_self()
+static inline uintptr_t __get_tp()
 {
-	struct pthread *self;
-	__asm__ ("mov %%fs:0,%0" : "=r" (self) );
-	return self;
+	uintptr_t tp;
+	__asm__ ("mov %%fs:0,%0" : "=r" (tp) );
+	return tp;
 }
 
 #define MC_PC gregs[REG_RIP]

src/internal/pthread_impl.h

@@ -115,8 +115,10 @@ struct __timer {
 
 #ifdef TLS_ABOVE_TP
 #define TP_ADJ(p) ((char *)(p) + sizeof(struct pthread) + TP_OFFSET)
+#define __pthread_self() ((pthread_t)(__get_tp() - sizeof(struct __pthread) - TP_OFFSET))
 #else
 #define TP_ADJ(p) (p)
+#define __pthread_self() ((pthread_t)__get_tp())
 #endif
 
 #ifndef tls_mod_off_t