workaround clang deficiency affecting thread pointer access on powerpc

based on patch by Richard Pennington, who initially reported the
issue.

diff --git a/arch/powerpc/pthread_arch.h b/arch/powerpc/pthread_arch.h
index cb2a70b..2d1ee43 100644 (file)
--- a/arch/powerpc/pthread_arch.h
+++ b/arch/powerpc/pthread_arch.h
@@ -1,6 +1,11 @@
 static inline struct pthread *__pthread_self()
 {
-       register char* tp __asm__("r2");
+#ifdef __clang__
+       char *tp;
+       __asm__ __volatile__ ("mr %0, 2" : "=r"(tp) : : );
+#else
+       register char *tp __asm__("r2");
+#endif
        return (pthread_t)(tp - 0x7000 - sizeof(struct pthread));
 }