4 files changed, 72 insertions, 78 deletions

diff --git a/src/pkg/runtime/arm/asm.s b/src/pkg/runtime/arm/asm.s
index a4e4b3283..f9fe7e628 100644
--- a/src/pkg/runtime/arm/asm.s
+++ b/src/pkg/runtime/arm/asm.s
@@ -12,10 +12,10 @@ TEXT _rt0_arm(SB),7,$-4
 	// use R13 instead of SP to avoid linker rewriting the offsets
 	MOVW	0(R13), R0		// argc
 	MOVW	$4(R13), R1		// argv
-	SUB	$128, R13		// plenty of scratch
+	SUB	$64, R13		// plenty of scratch
 	AND	$~7, R13
-	MOVW	R0, 120(R13)		// save argc, argv away
-	MOVW	R1, 124(R13)
+	MOVW	R0, 60(R13)		// save argc, argv away
+	MOVW	R1, 64(R13)
 
 	// set up m and g registers
 	// g is R10, m is R9
@@ -34,9 +34,9 @@ TEXT _rt0_arm(SB),7,$-4
 	BL	runtime·check(SB)
 
 	// saved argc, argv
-	MOVW	120(R13), R0
+	MOVW	60(R13), R0
 	MOVW	R0, 4(R13)
-	MOVW	124(R13), R1
+	MOVW	64(R13), R1
 	MOVW	R1, 8(R13)
 	BL	runtime·args(SB)
 	BL	runtime·osinit(SB)
@@ -274,3 +274,34 @@ TEXT runtime·abort(SB),7,$-4
 TEXT runtime·runcgocallback(SB),7,$0
 	MOVW	$0, R0
 	MOVW	(R0), R1
+
+// bool armcas(int32 *val, int32 old, int32 new)
+// Atomically:
+//	if(*val == old){
+//		*val = new;
+//		return 1;
+//	}else
+//		return 0;
+//
+// To implement runtime·cas in ../$GOOS/arm/sys.s
+// using the native instructions, use:
+//
+//	TEXT runtime·cas(SB),7,$0
+//		B	runtime·armcas(SB)
+//
+TEXT runtime·armcas(SB),7,$0
+	MOVW	valptr+0(FP), R1
+	MOVW	old+4(FP), R2
+	MOVW	new+8(FP), R3
+casl:
+	LDREX	(R1), R0
+	CMP		R0, R2
+	BNE		casfail
+	STREX	R3, (R1), R0
+	CMP		$0, R0
+	BNE		casl
+	MOVW	$1, R0
+	RET
+casfail:
+	MOVW	$0, R0
+	RET
diff --git a/src/pkg/runtime/arm/cas5.s b/src/pkg/runtime/arm/cas5.s
deleted file mode 100644
index 20bd3c3e2..000000000
--- a/src/pkg/runtime/arm/cas5.s
+++ /dev/null
@@ -1,43 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-#include "arm/asm.h"
-
-// This version works on pre v6 architectures
-
-// bool cas(int32 *val, int32 old, int32 new)
-// Atomically:
-//	if(*val == old){
-//		*val = new;
-//		return 1;
-//	}else
-//		return 0;
-
-TEXT runtime·cas(SB),7,$0
-	MOVW	0(FP), R0	// *val
-	MOVW	4(FP), R1	// old
-	MOVW	8(FP), R2	// new
-	MOVW	$1, R3
-	MOVW	$runtime·cas_mutex(SB), R4
-l:
-	SWPW	(R4), R3	// acquire mutex
-	CMP		$0, R3
-	BNE		fail0
-	
-	MOVW	(R0), R5
-	CMP		R1, R5
-	BNE		fail1
-	
-	MOVW	R2, (R0)	
-	MOVW	R3, (R4)	// release mutex
-	MOVW	$1, R0
-	RET
-fail1:	
-	MOVW	R3, (R4)	// release mutex
-fail0:
-	MOVW	$0, R0
-	RET
- 
-DATA runtime·cas_mutex(SB)/4, $0
-GLOBL runtime·cas_mutex(SB), $4
diff --git a/src/pkg/runtime/arm/cas6.s b/src/pkg/runtime/arm/cas6.s
deleted file mode 100644
index 43788b28a..000000000
--- a/src/pkg/runtime/arm/cas6.s
+++ /dev/null
@@ -1,29 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// bool cas(int32 *val, int32 old, int32 new)
-// Atomically:
-//	if(*val == old){
-//		*val = new;
-//		return 1;
-//	}else
-//		return 0;
-
-TEXT runtime·cas(SB),7,$0
-	MOVW	0(FP), R1	// *val
-	MOVW	4(FP), R2	// old
-	MOVW	8(FP), R3	// new
-l:
-	LDREX	(R1), R0
-	CMP		R0, R2
-	BNE		fail
-	STREX	R3, (R1), R0
-	CMP		$0, R0
-	BNE		l
-	MOVW	$1, R0
-	RET
-fail:
-	MOVW	$0, R0
-	RET
-
diff --git a/src/pkg/runtime/arm/traceback.c b/src/pkg/runtime/arm/traceback.c
index 2307e98e8..ad3096823 100644
--- a/src/pkg/runtime/arm/traceback.c
+++ b/src/pkg/runtime/arm/traceback.c
@@ -9,6 +9,10 @@ void runtime·deferproc(void);
 void runtime·newproc(void);
 void runtime·newstack(void);
 void runtime·morestack(void);
+void _div(void);
+void _mod(void);
+void _divu(void);
+void _modu(void);
 
 static int32
 gentraceback(byte *pc0, byte *sp, byte *lr0, G *g, int32 skip, uintptr *pcbuf, int32 max)
@@ -113,7 +117,7 @@ gentraceback(byte *pc0, byte *sp, byte *lr0, G *g, int32 skip, uintptr *pcbuf, i
 			// Print during crash.
 			//	main+0xf /home/rsc/go/src/runtime/x.go:23
 			//		main(0x1, 0x2, 0x3)
-			runtime·printf("%S", f->name);
+			runtime·printf("[%p] %S", fp, f->name);
 			if(pc > f->entry)
 				runtime·printf("+%p", (uintptr)(pc - f->entry));
 			tracepc = pc;	// back up to CALL instruction for funcline.
@@ -145,12 +149,43 @@ gentraceback(byte *pc0, byte *sp, byte *lr0, G *g, int32 skip, uintptr *pcbuf, i
 			continue;
 		}
 		
+		if(pcbuf == nil && f->entry == (uintptr)runtime·lessstack && g == m->g0) {
+			runtime·printf("----- lessstack called from goroutine %d -----\n", m->curg->goid);
+			g = m->curg;
+			stk = (Stktop*)g->stackbase;
+			sp = stk->gobuf.sp;
+			pc = (uintptr)stk->gobuf.pc;
+			fp = nil;
+			lr = 0;
+			continue;
+		}	
+		
 		// Unwind to next frame.
 		pc = lr;
 		lr = 0;
 		sp = fp;
 		fp = nil;
+		
+		// If this was div or divu or mod or modu, the caller had
+		// an extra 8 bytes on its stack.  Adjust sp.
+		if(f->entry == (uintptr)_div || f->entry == (uintptr)_divu || f->entry == (uintptr)_mod || f->entry == (uintptr)_modu)
+			sp += 8;
+		
+		// If this was deferproc or newproc, the caller had an extra 12.
+		if(f->entry == (uintptr)runtime·deferproc || f->entry == (uintptr)runtime·newproc)
+			sp += 12;
 	}
+	
+	if(pcbuf == nil && (pc = g->gopc) != 0 && (f = runtime·findfunc(pc)) != nil) {
+		runtime·printf("----- goroutine created by -----\n%S", f->name);
+		if(pc > f->entry)
+			runtime·printf("+%p", (uintptr)(pc - f->entry));
+		tracepc = pc;	// back up to CALL instruction for funcline.
+		if(n > 0 && pc > f->entry)
+			tracepc -= sizeof(uintptr);
+		runtime·printf(" %S:%d\n", f->src, runtime·funcline(f, tracepc));
+	}
+
 	return n;		
 }