diff options
| author | Shenghou Ma <minux.ma@gmail.com> | 2013-02-06 01:18:37 +0800 |
|---|---|---|
| committer | Shenghou Ma <minux.ma@gmail.com> | 2013-02-06 01:18:37 +0800 |
| commit | 7de3d71797a0e6f25975fa5c3c69c7b0e27d23d2 (patch) | |
| tree | 3daf55454737287eb5c38a00e12608a6c0f94596 /src/pkg | |
| parent | 4360ef8de295ee7929ed408e044e14c8a1044a73 (diff) | |
| download | go-7de3d71797a0e6f25975fa5c3c69c7b0e27d23d2.tar.xz | |
runtime: save LR to stack when panicking to handle leaf function traceback
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7289047
Diffstat (limited to 'src/pkg')
| -rw-r--r-- | src/pkg/runtime/signal_linux_arm.c | 16 | ||||
| -rw-r--r-- | src/pkg/runtime/traceback_arm.c | 6 |
2 files changed, 17 insertions, 5 deletions
diff --git a/src/pkg/runtime/signal_linux_arm.c b/src/pkg/runtime/signal_linux_arm.c index 31444a7243..c425696d56 100644 --- a/src/pkg/runtime/signal_linux_arm.c +++ b/src/pkg/runtime/signal_linux_arm.c @@ -68,11 +68,17 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp) gp->sigcode1 = r->fault_address; gp->sigpc = r->arm_pc; - // If this is a leaf function, we do smash LR, - // but we're not going back there anyway. - // Don't bother smashing if r->arm_pc is 0, - // which is probably a call to a nil func: the - // old link register is more useful in the stack trace. + // We arrange lr, and pc to pretend the panicking + // function calls sigpanic directly. + // Always save LR to stack so that panics in leaf + // functions are correctly handled. This smashes + // the stack frame but we're not going back there + // anyway. + r->arm_sp -= 4; + *(uint32 *)r->arm_sp = r->arm_lr; + // Don't bother saving PC if it's zero, which is + // probably a call to a nil func: the old link register + // is more useful in the stack trace. if(r->arm_pc != 0) r->arm_lr = r->arm_pc; // In case we are panicking from external C code diff --git a/src/pkg/runtime/traceback_arm.c b/src/pkg/runtime/traceback_arm.c index fd60490ae4..39dc6fd22c 100644 --- a/src/pkg/runtime/traceback_arm.c +++ b/src/pkg/runtime/traceback_arm.c @@ -182,6 +182,12 @@ runtime·gentraceback(byte *pc0, byte *sp, byte *lr0, G *gp, int32 skip, uintptr // 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; + + // sighandler saves the lr on stack before fake a call to sigpanic + if(waspanic) { + pc = *(uintptr *)sp; + sp += 4; + } } if(pcbuf == nil && (pc = gp->gopc) != 0 && (f = runtime·findfunc(pc)) != nil |