diff --git a/mozilla/gc/boehm/os_dep.c b/mozilla/gc/boehm/os_dep.c
index 29eb5bf17e7..ce4780b2857 100644
--- a/mozilla/gc/boehm/os_dep.c
+++ b/mozilla/gc/boehm/os_dep.c
@@ -2429,8 +2429,6 @@ void GC_save_callers(struct callinfo info[NFRAMES])
 
 #if defined(SAVE_CALL_CHAIN) && defined(LINUX)
 
-#include <setjmp.h>
-
 #include "call_tree.h"
 
 typedef struct stack_frame stack_frame;
@@ -2443,10 +2441,8 @@ struct stack_frame {
 
 static stack_frame* getStackFrame()
 {
-  jmp_buf jb;
   stack_frame* currentFrame;
-  setjmp(jb);
-  currentFrame = (stack_frame*)(jb[0].__jmpbuf[JB_BP]);
+  currentFrame = (stack_frame*)__builtin_frame_address(0);
   currentFrame = currentFrame->next;
   return currentFrame;
 }
diff --git a/mozilla/js/src/jsutil.c b/mozilla/js/src/jsutil.c
index 9f052c7446e..02ba56a021d 100644
--- a/mozilla/js/src/jsutil.c
+++ b/mozilla/js/src/jsutil.c
@@ -66,7 +66,6 @@ JS_PUBLIC_API(void) JS_Assert(const char *s, const char *file, JSIntn ln)
 
 #define __USE_GNU 1
 #include <dlfcn.h>
-#include <setjmp.h>
 #include <string.h>
 #include "jshash.h"
 #include "jsprf.h"
@@ -170,13 +169,10 @@ CallTree(uint32 *bp)
 JSCallsite *
 JS_Backtrace(int skip)
 {
-    jmp_buf jb;
     uint32 *bp, *bpdown;
 
-    setjmp(jb);
-
     /* Stack walking code adapted from Kipp's "leaky". */
-    bp = (uint32*) jb[0].__jmpbuf[JB_BP];
+    bp = (uint32*) __builtin_frame_address(0);
     while (--skip >= 0) {
         bpdown = (uint32*) *bp++;
         if (bpdown < bp)
diff --git a/mozilla/tools/trace-malloc/lib/nsTraceMalloc.c b/mozilla/tools/trace-malloc/lib/nsTraceMalloc.c
index 2092ad03d31..283f5feaca9 100644
--- a/mozilla/tools/trace-malloc/lib/nsTraceMalloc.c
+++ b/mozilla/tools/trace-malloc/lib/nsTraceMalloc.c
@@ -51,7 +51,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <setjmp.h>
 #ifdef XP_UNIX
 #include <unistd.h>
 #include <sys/stat.h>
@@ -1339,7 +1338,6 @@ backtrace(int skip)
 callsite *
 backtrace(int skip)
 {
-    jmp_buf jb;
     uint32 *bp, *bpdown;
     callsite *site, **key;
     PLHashNumber hash;
@@ -1348,10 +1346,9 @@ backtrace(int skip)
 
     tmstats.backtrace_calls++;
     suppress_tracing++;
-    setjmp(jb);
 
     /* Stack walking code adapted from Kipp's "leaky". */
-    bp = (uint32*) jb[0].__jmpbuf[JB_BP];
+    bp = (uint32*) __builtin_frame_address(0);
     while (--skip >= 0) {
         bpdown = (uint32*) *bp++;
         if (bpdown < bp)