--- Libc/Libc-1272.200.26/gen/thread_stack_pcs.c
+++ Libc/Libc-1353.100.2/gen/thread_stack_pcs.c
@@ -27,15 +27,8 @@
 #include <mach/mach.h>
 #include <mach/vm_statistics.h>
 #include <stdlib.h>
+#include <pthread/stack_np.h>
 #include "stack_logging.h"
-
-
-#if defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__arm64__)
-#define FP_LINK_OFFSET 1
-#else
-#error ********** Unimplemented architecture
-#endif
-
 
 #define	INSTACK(a)	((a) >= stackbot && (a) <= stacktop)
 #if defined(__x86_64__)
@@ -46,9 +39,9 @@
 #define	ISALIGNED(a)	((((uintptr_t)(a)) & 0x1) == 0)
 #endif
 
-__private_extern__  __attribute__((noinline))
-void
-_thread_stack_pcs(vm_address_t *buffer, unsigned max, unsigned *nb,
+__attribute__((noinline))
+static void
+__thread_stack_pcs(vm_address_t *buffer, unsigned max, unsigned *nb,
 		unsigned skip, void *startfp)
 {
 	void *frame, *next;
@@ -58,42 +51,57 @@
 
 	*nb = 0;
 
+	// Rely on the fact that our caller has an empty stackframe (no local vars)
+	// to determine the minimum size of a stackframe (frame ptr & return addr)
+	frame = __builtin_frame_address(0);
+	next = (void*)pthread_stack_frame_decode_np((uintptr_t)frame, NULL);
+
 	/* make sure return address is never out of bounds */
-	stacktop -= (FP_LINK_OFFSET + 1) * sizeof(void *);
+	stacktop -= (next - frame);
 
-	frame = __builtin_frame_address(0);
 	if(!INSTACK(frame) || !ISALIGNED(frame))
 		return;
-	while ((startfp && startfp >= *(void **)frame) || skip--) {
-		next = *(void **)frame;
+	while (startfp || skip--) {
+		if (startfp && startfp < next) break;
 		if(!INSTACK(next) || !ISALIGNED(next) || next <= frame)
 			return;
 		frame = next;
+		next = (void*)pthread_stack_frame_decode_np((uintptr_t)frame, NULL);
 	}
 	while (max--) {
-		void *retaddr = (void *)*(vm_address_t *)
-				(((void **)frame) + FP_LINK_OFFSET);
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wint-conversion"
+		uintptr_t retaddr;
+		next = (void*)pthread_stack_frame_decode_np((uintptr_t)frame, &retaddr);
 		buffer[*nb] = retaddr;
-#pragma clang diagnostic pop
 		(*nb)++;
-		next = *(void **)frame;
 		if(!INSTACK(next) || !ISALIGNED(next) || next <= frame)
 			return;
 		frame = next;
 	}
 }
 
+// Note that callee relies on this function having a minimal stackframe
+// to introspect (i.e. no tailcall and no local variables)
+__private_extern__ __attribute__((disable_tail_calls))
+void
+_thread_stack_pcs(vm_address_t *buffer, unsigned max, unsigned *nb,
+		unsigned skip, void *startfp)
+{
+	// skip this frame
+	__thread_stack_pcs(buffer, max, nb, skip + 1, startfp);
+}
+
 // Prevent thread_stack_pcs() from getting tail-call-optimized into
-// _thread_stack_pcs() on 64-bit environments, thus making the "number of hot
+// __thread_stack_pcs() on 64-bit environments, thus making the "number of hot
 // frames to skip" be more predictable, giving more consistent backtraces.
 //
 // See <rdar://problem/5364825> "stack logging: frames keep getting truncated"
 // for why this is necessary.
+//
+// Note that callee relies on this function having a minimal stackframe
+// to introspect (i.e. no tailcall and no local variables)
 __attribute__((disable_tail_calls))
 void
 thread_stack_pcs(vm_address_t *buffer, unsigned max, unsigned *nb)
 {
-	_thread_stack_pcs(buffer, max, nb, 0, NULL);
+	__thread_stack_pcs(buffer, max, nb, 0, NULL);
 }