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, 2 insertions, 0 deletions

diff --git a/src/internal/pthread_impl.h b/src/internal/pthread_impl.h
index 3c2bd767..58e06136 100644
--- a/src/internal/pthread_impl.h
+++ b/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