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go/src/pkg/runtime/traceback_arm.c
Dmitriy Vyukov eac6bee7c1 runtime: fix argument printing during traceback
Current code can print more arguments than necessary
and also incorrectly prints "...".
Update #5723.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/10689043
2013-06-27 20:43:43 +04:00

250 lines
7.1 KiB
C

// 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 "runtime.h"
#include "arch_GOARCH.h"
#include "malloc.h"
void runtime·deferproc(void);
void runtime·newproc(void);
void runtime·morestack(void);
void runtime·sigpanic(void);
void _div(void);
void _mod(void);
void _divu(void);
void _modu(void);
int32
runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip, uintptr *pcbuf, int32 max, void (*callback)(Stkframe*, void*), void *v, bool printall)
{
int32 i, n, nprint, skip0;
uintptr x, tracepc;
bool waspanic, printing;
Func *f, *f2;
Stkframe frame;
Stktop *stk;
skip0 = skip;
nprint = 0;
runtime·memclr((byte*)&frame, sizeof frame);
frame.pc = pc0;
frame.lr = lr0;
frame.sp = sp0;
waspanic = false;
printing = pcbuf==nil && callback==nil;
// If the PC is zero, it's likely a nil function call.
// Start in the caller's frame.
if(frame.pc == 0) {
frame.pc = frame.lr;
frame.lr = 0;
}
n = 0;
stk = (Stktop*)gp->stackbase;
while(n < max) {
// Typically:
// pc is the PC of the running function.
// sp is the stack pointer at that program counter.
// fp is the frame pointer (caller's stack pointer) at that program counter, or nil if unknown.
// stk is the stack containing sp.
// The caller's program counter is lr, unless lr is zero, in which case it is *(uintptr*)sp.
if(frame.pc == (uintptr)runtime·lessstack) {
// Hit top of stack segment. Unwind to next segment.
frame.pc = stk->gobuf.pc;
frame.sp = stk->gobuf.sp;
frame.lr = 0;
frame.fp = 0;
if(printing && runtime·showframe(nil, gp))
runtime·printf("----- stack segment boundary -----\n");
stk = (Stktop*)stk->stackbase;
continue;
}
if(frame.pc <= 0x1000 || (frame.fn = f = runtime·findfunc(frame.pc)) == nil) {
if(callback != nil) {
runtime·printf("runtime: unknown pc %p at frame %d\n", frame.pc, skip0-skip+n);
runtime·throw("invalid stack");
}
break;
}
// Found an actual function.
// Derive frame pointer and link register.
if(frame.lr == 0)
frame.lr = *(uintptr*)frame.sp;
if(frame.fp == 0) {
frame.fp = frame.sp;
if(frame.pc > f->entry && f->frame >= sizeof(uintptr))
frame.fp += f->frame;
}
// Derive size of arguments.
frame.argp = (byte*)frame.fp + sizeof(uintptr);
frame.arglen = 0;
if(f->args != ArgsSizeUnknown)
frame.arglen = f->args;
else if(runtime·haszeroargs(f->entry))
frame.arglen = 0;
else if(frame.lr == (uintptr)runtime·lessstack)
frame.arglen = stk->argsize;
else if(f->entry == (uintptr)runtime·deferproc || f->entry == (uintptr)runtime·newproc)
frame.arglen = 3*sizeof(uintptr) + *(int32*)frame.argp;
else if((f2 = runtime·findfunc(frame.lr)) != nil && f2->frame >= sizeof(uintptr))
frame.arglen = f2->frame; // conservative overestimate
else {
runtime·printf("runtime: unknown argument frame size for %S\n", f->name);
if(!printing)
runtime·throw("invalid stack");
}
// Derive location and size of local variables.
if(frame.fp == frame.sp) {
// Function has not created a frame for itself yet.
frame.varp = nil;
frame.varlen = 0;
} else if(f->locals == 0) {
// Assume no information, so use whole frame.
// TODO: Distinguish local==0 from local==unknown.
frame.varp = (byte*)frame.sp;
frame.varlen = frame.fp - frame.sp;
} else {
if(f->locals > frame.fp - frame.sp) {
runtime·printf("runtime: inconsistent locals=%p frame=%p fp=%p sp=%p for %S\n", (uintptr)f->locals, (uintptr)f->frame, frame.fp, frame.sp, f->name);
runtime·throw("invalid stack");
}
frame.varp = (byte*)frame.fp - f->locals;
frame.varlen = f->locals;
}
if(skip > 0) {
skip--;
goto skipped;
}
if(pcbuf != nil)
pcbuf[n] = frame.pc;
if(callback != nil)
callback(&frame, v);
if(printing) {
if(printall || runtime·showframe(f, gp)) {
// Print during crash.
// main(0x1, 0x2, 0x3)
// /home/rsc/go/src/runtime/x.go:23 +0xf
tracepc = frame.pc; // back up to CALL instruction for funcline.
if(n > 0 && frame.pc > f->entry && !waspanic)
tracepc -= sizeof(uintptr);
runtime·printf("%S(", f->name);
for(i = 0; i < frame.arglen/sizeof(uintptr); i++) {
if(i >= 5) {
runtime·prints(", ...");
break;
}
if(i != 0)
runtime·prints(", ");
runtime·printhex(((uintptr*)frame.argp)[i]);
}
runtime·prints(")\n");
runtime·printf("\t%S:%d", f->src, runtime·funcline(f, tracepc));
if(frame.pc > f->entry)
runtime·printf(" +%p", (uintptr)(frame.pc - f->entry));
if(m->throwing && gp == m->curg)
runtime·printf(" fp=%p", frame.fp);
runtime·printf("\n");
nprint++;
}
}
n++;
skipped:
waspanic = f->entry == (uintptr)runtime·sigpanic;
// Do not unwind past the bottom of the stack.
if(frame.pc == (uintptr)runtime·goexit || f->entry == (uintptr)runtime·mstart || f->entry == (uintptr)_rt0_go)
break;
// Unwind to next frame.
frame.pc = frame.lr;
frame.lr = 0;
frame.sp = frame.fp;
frame.fp = 0;
// 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)
frame.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)
frame.sp += 12;
// sighandler saves the lr on stack before faking a call to sigpanic
if(waspanic) {
x = *(uintptr*)frame.sp;
frame.sp += 4;
frame.fn = f = runtime·findfunc(frame.pc);
if(f == nil)
frame.pc = x;
else if (f->frame == 0)
frame.lr = x;
}
}
if(pcbuf == nil && callback == nil)
n = nprint;
return n;
}
static void
printcreatedby(G *gp)
{
uintptr pc, tracepc;
Func *f;
if((pc = gp->gopc) != 0 && (f = runtime·findfunc(pc)) != nil
&& runtime·showframe(f, gp) && gp->goid != 1) {
runtime·printf("created by %S\n", f->name);
tracepc = pc; // back up to CALL instruction for funcline.
if(pc > f->entry)
tracepc -= sizeof(uintptr);
runtime·printf("\t%S:%d", f->src, runtime·funcline(f, tracepc));
if(pc > f->entry)
runtime·printf(" +%p", (uintptr)(pc - f->entry));
runtime·printf("\n");
}
}
void
runtime·traceback(uintptr pc, uintptr sp, uintptr lr, G *gp)
{
if(gp->status == Gsyscall) {
// Override signal registers if blocked in system call.
pc = gp->sched.pc;
sp = gp->sched.sp;
lr = 0;
}
// Print traceback. By default, omits runtime frames.
// If that means we print nothing at all, repeat forcing all frames printed.
if(runtime·gentraceback(pc, sp, lr, gp, 0, nil, 100, nil, nil, false) == 0)
runtime·gentraceback(pc, sp, lr, gp, 0, nil, 100, nil, nil, true);
printcreatedby(gp);
}
// func caller(n int) (pc uintptr, file string, line int, ok bool)
int32
runtime·callers(int32 skip, uintptr *pcbuf, int32 m)
{
uintptr pc, sp;
sp = runtime·getcallersp(&skip);
pc = (uintptr)runtime·getcallerpc(&skip);
return runtime·gentraceback(pc, sp, 0, g, skip, pcbuf, m, nil, nil, false);
}