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).

1 files changed, 4 insertions, 5 deletions

diff --git a/arch/or1k/pthread_arch.h b/arch/or1k/pthread_arch.h
index 76d0a8bc..f75ea7e4 100644
--- a/arch/or1k/pthread_arch.h
+++ b/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