runtime: handle non-standard call sequences in arm traceback
R=r
CC=golang-dev
https://golang.org/cl/4191048
diff --git a/src/pkg/runtime/arm/traceback.c b/src/pkg/runtime/arm/traceback.c
index 2307e98..28d39dc 100644
--- a/src/pkg/runtime/arm/traceback.c
+++ b/src/pkg/runtime/arm/traceback.c
@@ -9,6 +9,10 @@
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 @@
// 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.
@@ -150,6 +154,15 @@
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;
}
return n;
}
