void
runtime·funcline_go(Func *f, uintptr targetpc, String retfile, int32 retline)
{
retfile = f->src;
retline = runtime·funcline(f, targetpc);
FLUSH(&retfile);
FLUSH(&retline);
}
void
runtime·Caller(intgo skip, uintptr retpc, String retfile, intgo retline, bool retbool)
{
retpc = 0;
FLUSH(&retpc);
retfile.str = 0;
retfile.len = 0;
FLUSH(&retfile);
retline = 0;
FLUSH(&retline);
retbool = 0;
FLUSH(&retbool);
#line 73 "/home/14/ren/source/golang/go/src/pkg/runtime/runtime1.goc"
Func *f, *g;
uintptr pc;
uintptr rpc[2];
/*
* Ask for two PCs: the one we were asked for
* and what it called, so that we can see if it
* "called" sigpanic.
*/
retpc = 0;
if(runtime·callers(1+skip-1, rpc, 2) < 2) {
retfile = runtime·emptystring;
retline = 0;
retbool = false;
} else if((f = runtime·findfunc(rpc[1])) == nil) {
retfile = runtime·emptystring;
retline = 0;
retbool = true; // have retpc at least
} else {
retpc = rpc[1];
pc = retpc;
g = runtime·findfunc(rpc[0]);
if(pc > f->entry && (g == nil || g->entry != (uintptr)runtime·sigpanic))
pc--;
retline = runtime·funcline(f, pc, &retfile);
retbool = true;
}
FLUSH(&retpc);
FLUSH(&retfile);
FLUSH(&retline);
FLUSH(&retbool);
}
void
runtime·Caller(intgo skip, uintptr retpc, String retfile, intgo retline, bool retbool)
{
retpc = 0;
FLUSH(&retpc);
retfile.str = 0;
retfile.len = 0;
FLUSH(&retfile);
retline = 0;
FLUSH(&retline);
retbool = 0;
FLUSH(&retbool);
#line 73 "C:\Users\ADMINI~1\AppData\Local\Temp\2\makerelease686069423\go\src\pkg\runtime\runtime1.goc"
Func *f, *g;
uintptr pc;
uintptr rpc[2];
/*
* Ask for two PCs: the one we were asked for
* and what it called, so that we can see if it
* "called" sigpanic.
*/
retpc = 0;
if(runtime·callers(1+skip-1, rpc, 2) < 2) {
retfile = runtime·emptystring;
retline = 0;
retbool = false;
} else if((f = runtime·findfunc(rpc[1])) == nil) {
retfile = runtime·emptystring;
retline = 0;
retbool = true; // have retpc at least
} else {
retpc = rpc[1];
pc = retpc;
g = runtime·findfunc(rpc[0]);
if(pc > f->entry && (g == nil || g->entry != (uintptr)runtime·sigpanic))
pc--;
retline = runtime·funcline(f, pc, &retfile);
retbool = true;
}
FLUSH(&retpc);
FLUSH(&retfile);
FLUSH(&retline);
FLUSH(&retbool);
}
void
runtime·printcreatedby(G *gp)
{
int32 line;
uintptr pc, tracepc;
Func *f;
String file;
// Show what created goroutine, except main goroutine (goid 1).
if((pc = gp->gopc) != 0 && (f = runtime·findfunc(pc)) != nil &&
runtime·showframe(f, gp) && gp->goid != 1) {
runtime·printf("created by %s\n", runtime·funcname(f));
tracepc = pc; // back up to CALL instruction for funcline.
if(pc > f->entry)
tracepc -= PCQuantum;
line = runtime·funcline(f, tracepc, &file);
runtime·printf("\t%S:%d", file, line);
if(pc > f->entry)
runtime·printf(" +%p", (uintptr)(pc - f->entry));
runtime·printf("\n");
}
}
int32
runtime·gentraceback(byte *pc0, byte *sp, byte *lr0, G *g, int32 skip, uintptr *pcbuf, int32 max)
{
int32 i, n, iter;
uintptr pc, lr, tracepc, x;
byte *fp, *p;
bool waspanic;
Stktop *stk;
Func *f;
pc = (uintptr)pc0;
lr = (uintptr)lr0;
fp = nil;
waspanic = false;
// If the PC is goexit, the goroutine hasn't started yet.
if(pc == (uintptr)runtime·goexit) {
pc = (uintptr)g->entry;
lr = (uintptr)runtime·goexit;
}
// If the PC is zero, it's likely a nil function call.
// Start in the caller's frame.
if(pc == 0) {
pc = lr;
lr = 0;
}
n = 0;
stk = (Stktop*)g->stackbase;
for(iter = 0; iter < 100 && n < max; iter++) { // iter avoids looping forever
// 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(pc == (uintptr)runtime·lessstack) {
// Hit top of stack segment. Unwind to next segment.
pc = (uintptr)stk->gobuf.pc;
sp = stk->gobuf.sp;
lr = 0;
fp = nil;
if(pcbuf == nil)
runtime·printf("----- stack segment boundary -----\n");
stk = (Stktop*)stk->stackbase;
continue;
}
if(pc <= 0x1000 || (f = runtime·findfunc(pc)) == nil) {
// Dangerous, but worthwhile: see if this is a closure by
// decoding the instruction stream.
//
// We check p < p+4 to avoid wrapping and faulting if
// we have lost track of where we are.
p = (byte*)pc;
if((pc&3) == 0 && p < p+4 &&
runtime·mheap.arena_start < p &&
p+4 < runtime·mheap.arena_used) {
x = *(uintptr*)p;
if((x&0xfffff000) == 0xe49df000) {
// End of closure:
// MOVW.P frame(R13), R15
pc = *(uintptr*)sp;
lr = 0;
sp += x & 0xfff;
fp = nil;
continue;
}
if((x&0xfffff000) == 0xe52de000 && lr == (uintptr)runtime·goexit) {
// Beginning of closure.
// Closure at top of stack, not yet started.
p += 5*4;
if((x&0xfff) != 4) {
// argument copying
p += 7*4;
}
if((byte*)pc < p && p < p+4 && p+4 < runtime·mheap.arena_used) {
pc = *(uintptr*)p;
fp = nil;
continue;
}
}
}
break;
}
// Found an actual function.
if(lr == 0)
lr = *(uintptr*)sp;
if(fp == nil) {
fp = sp;
if(pc > f->entry && f->frame >= 0)
fp += f->frame;
}
if(skip > 0)
skip--;
else if(pcbuf != nil)
pcbuf[n++] = pc;
else {
if(showframe(f)) {
// Print during crash.
// main(0x1, 0x2, 0x3)
// /home/rsc/go/src/runtime/x.go:23 +0xf
tracepc = pc; // back up to CALL instruction for funcline.
if(n > 0 && pc > f->entry && !waspanic)
tracepc -= sizeof(uintptr);
runtime·printf("%S(", f->name);
for(i = 0; i < f->args; i++) {
if(i != 0)
runtime·prints(", ");
runtime·printhex(((uintptr*)fp)[1+i]);
if(i >= 4) {
runtime·prints(", ...");
break;
}
}
runtime·prints(")\n");
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");
}
n++;
}
waspanic = f->entry == (uintptr)runtime·sigpanic;
if(pcbuf == nil && f->entry == (uintptr)runtime·newstack && g == m->g0) {
runtime·printf("----- newstack called from goroutine %d -----\n", m->curg->goid);
pc = (uintptr)m->morepc;
sp = (byte*)m->moreargp - sizeof(void*);
lr = (uintptr)m->morebuf.pc;
fp = m->morebuf.sp;
g = m->curg;
stk = (Stktop*)g->stackbase;
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 && g->goid != 1) {
runtime·printf("created by %S\n", f->name);
tracepc = pc; // back up to CALL instruction for funcline.
if(n > 0 && 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");
}
return n;
}
// Generic traceback. Handles runtime stack prints (pcbuf == nil)
// as well as the runtime.Callers function (pcbuf != nil).
// A little clunky to merge the two but avoids duplicating
// the code and all its subtlety.
static int32
gentraceback(byte *pc0, byte *sp, G *g, int32 skip, uintptr *pcbuf, int32 max)
{
byte *p;
int32 i, n, iter, sawnewstack;
uintptr pc, lr, tracepc;
byte *fp;
Stktop *stk;
Func *f;
pc = (uintptr)pc0;
lr = 0;
fp = nil;
// If the PC is goexit, the goroutine hasn't started yet.
if(pc0 == g->sched.pc && sp == g->sched.sp && pc0 == (byte*)runtime·goexit) {
fp = sp;
lr = pc;
pc = (uintptr)g->entry;
}
// If the PC is zero, it's likely a nil function call.
// Start in the caller's frame.
if(pc == 0) {
pc = lr;
lr = 0;
}
// If the PC is zero, it's likely a nil function call.
// Start in the caller's frame.
if(pc == 0) {
pc = *(uintptr*)sp;
sp += sizeof(uintptr);
}
n = 0;
sawnewstack = 0;
stk = (Stktop*)g->stackbase;
for(iter = 0; iter < 100 && n < max; iter++) { // iter avoids looping forever
// 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(pc == (uintptr)runtime·lessstack) {
// Hit top of stack segment. Unwind to next segment.
pc = (uintptr)stk->gobuf.pc;
sp = stk->gobuf.sp;
lr = 0;
fp = nil;
if(pcbuf == nil)
runtime·printf("----- stack segment boundary -----\n");
stk = (Stktop*)stk->stackbase;
continue;
}
if(pc <= 0x1000 || (f = runtime·findfunc(pc)) == nil) {
// Dangerous, but worthwhile: see if this is a closure:
// ADDQ $wwxxyyzz, SP; RET
// [48] 81 c4 zz yy xx ww c3
// The 0x48 byte is only on amd64.
p = (byte*)pc;
// We check p < p+8 to avoid wrapping and faulting if we lose track.
if(runtime·mheap.arena_start < p && p < p+8 && p+8 < runtime·mheap.arena_used && // pointer in allocated memory
(sizeof(uintptr) != 8 || *p++ == 0x48) && // skip 0x48 byte on amd64
p[0] == 0x81 && p[1] == 0xc4 && p[6] == 0xc3) {
sp += *(uint32*)(p+2);
pc = *(uintptr*)sp;
sp += sizeof(uintptr);
lr = 0;
fp = nil;
continue;
}
// Closure at top of stack, not yet started.
if(lr == (uintptr)runtime·goexit && (pc = isclosureentry(pc)) != 0) {
fp = sp;
continue;
}
// Unknown pc: stop.
break;
}
// Found an actual function.
if(fp == nil) {
fp = sp;
if(pc > f->entry && f->frame >= sizeof(uintptr))
fp += f->frame - sizeof(uintptr);
if(lr == 0)
lr = *(uintptr*)fp;
fp += sizeof(uintptr);
} else if(lr == 0)
lr = *(uintptr*)fp;
if(skip > 0)
skip--;
else if(pcbuf != nil)
pcbuf[n++] = pc;
else {
// Print during crash.
// main+0xf /home/rsc/go/src/runtime/x.go:23
// main(0x1, 0x2, 0x3)
runtime·printf("%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--;
runtime·printf(" %S:%d\n", f->src, runtime·funcline(f, tracepc));
runtime·printf("\t%S(", f->name);
for(i = 0; i < f->args; i++) {
if(i != 0)
runtime·prints(", ");
runtime·printhex(((uintptr*)fp)[i]);
if(i >= 4) {
runtime·prints(", ...");
break;
}
}
runtime·prints(")\n");
n++;
}
if(f->entry == (uintptr)runtime·deferproc || f->entry == (uintptr)runtime·newproc)
fp += 2*sizeof(uintptr);
if(f->entry == (uintptr)runtime·newstack)
sawnewstack = 1;
if(pcbuf == nil && f->entry == (uintptr)runtime·morestack && g == m->g0 && sawnewstack) {
// The fact that we saw newstack means that morestack
// has managed to record its information in m, so we can
// use it to keep unwinding the stack.
runtime·printf("----- morestack called from goroutine %d -----\n", m->curg->goid);
pc = (uintptr)m->morepc;
sp = m->morebuf.sp - sizeof(void*);
lr = (uintptr)m->morebuf.pc;
fp = m->morebuf.sp;
sawnewstack = 0;
g = m->curg;
stk = (Stktop*)g->stackbase;
continue;
}
if(pcbuf == nil && f->entry == (uintptr)runtime·lessstack && g == m->g0) {
// Lessstack is running on scheduler stack. Switch to original goroutine.
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(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--;
runtime·printf(" %S:%d\n", f->src, runtime·funcline(f, tracepc));
}
return n;
}
// Generic traceback. Handles runtime stack prints (pcbuf == nil),
// the runtime.Callers function (pcbuf != nil), as well as the garbage
// collector (callback != nil). A little clunky to merge these, but avoids
// duplicating the code and all its subtlety.
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, line;
uintptr tracepc;
bool waspanic, printing;
Func *f, *flr;
Stkframe frame;
Stktop *stk;
String file;
USED(lr0);
nprint = 0;
runtime·memclr((byte*)&frame, sizeof frame);
frame.pc = pc0;
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 = *(uintptr*)frame.sp;
frame.sp += sizeof(uintptr);
}
f = runtime·findfunc(frame.pc);
if(f == nil) {
if(callback != nil) {
runtime·printf("runtime: unknown pc %p\n", frame.pc);
runtime·throw("unknown pc");
}
return 0;
}
frame.fn = f;
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;
frame.fn = nil;
if(printing && runtime·showframe(nil, gp))
runtime·printf("----- stack segment boundary -----\n");
stk = (Stktop*)stk->stackbase;
f = runtime·findfunc(frame.pc);
if(f == nil) {
runtime·printf("runtime: unknown pc %p after stack split\n", frame.pc);
if(callback != nil)
runtime·throw("unknown pc");
}
frame.fn = f;
continue;
}
f = frame.fn;
// Found an actual function.
// Derive frame pointer and link register.
if(frame.fp == 0) {
frame.fp = frame.sp + runtime·funcspdelta(f, frame.pc);
frame.fp += sizeof(uintptr); // caller PC
}
if(runtime·topofstack(f)) {
frame.lr = 0;
flr = nil;
} else {
if(frame.lr == 0)
frame.lr = ((uintptr*)frame.fp)[-1];
flr = runtime·findfunc(frame.lr);
if(flr == nil) {
runtime·printf("runtime: unexpected return pc for %s called from %p\n", runtime·funcname(f), frame.lr);
if(callback != nil)
runtime·throw("unknown caller pc");
}
}
frame.varp = (byte*)frame.fp - sizeof(uintptr);
// Derive size of arguments.
// Most functions have a fixed-size argument block,
// so we can use metadata about the function f.
// Not all, though: there are some variadic functions
// in package runtime and reflect, and for those we use call-specific
// metadata recorded by f's caller.
if(callback != nil || printing) {
frame.argp = (byte*)frame.fp;
if(f->args != ArgsSizeUnknown)
frame.arglen = f->args;
else if(flr == nil)
frame.arglen = 0;
else if(frame.lr == (uintptr)runtime·lessstack)
frame.arglen = stk->argsize;
else if((i = runtime·funcarglen(flr, frame.lr)) >= 0)
frame.arglen = i;
else {
runtime·printf("runtime: unknown argument frame size for %s called from %p [%s]\n",
runtime·funcname(f), frame.lr, flr ? runtime·funcname(flr) : "?");
if(callback != nil)
runtime·throw("invalid stack");
frame.arglen = 0;
}
}
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--;
runtime·printf("%s(", runtime·funcname(f));
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");
line = runtime·funcline(f, tracepc, &file);
runtime·printf("\t%S:%d", file, line);
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(flr == nil)
break;
// Unwind to next frame.
frame.fn = flr;
frame.pc = frame.lr;
frame.lr = 0;
frame.sp = frame.fp;
frame.fp = 0;
}
if(pcbuf == nil && callback == nil)
n = nprint;
return n;
}
int32
runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip, uintptr *pcbuf, int32 max, bool (*callback)(Stkframe*, void*), void *v, bool printall)
{
int32 i, n, nprint, line, gotraceback;
uintptr x, tracepc, sparg;
bool waspanic, wasnewproc, printing;
Func *f, *flr;
Stkframe frame;
Stktop *stk;
String file;
Panic *panic;
Defer *defer;
gotraceback = runtime·gotraceback(nil);
if(pc0 == ~(uintptr)0 && sp0 == ~(uintptr)0) { // Signal to fetch saved values from gp.
if(gp->syscallstack != (uintptr)nil) {
pc0 = gp->syscallpc;
sp0 = gp->syscallsp;
lr0 = 0;
} else {
pc0 = gp->sched.pc;
sp0 = gp->sched.sp;
lr0 = gp->sched.lr;
}
}
nprint = 0;
runtime·memclr((byte*)&frame, sizeof frame);
frame.pc = pc0;
frame.lr = lr0;
frame.sp = sp0;
waspanic = false;
wasnewproc = false;
printing = pcbuf==nil && callback==nil;
panic = gp->panic;
defer = gp->defer;
while(defer != nil && defer->argp == NoArgs)
defer = defer->link;
while(panic != nil && panic->defer == nil)
panic = panic->link;
// 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;
}
f = runtime·findfunc(frame.pc);
if(f == nil) {
if(callback != nil) {
runtime·printf("runtime: unknown pc %p\n", frame.pc);
runtime·throw("unknown pc");
}
return 0;
}
frame.fn = f;
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;
f = runtime·findfunc(frame.pc);
if(f == nil) {
runtime·printf("runtime: unknown pc %p after stack split\n", frame.pc);
if(callback != nil)
runtime·throw("unknown pc");
}
frame.fn = f;
continue;
}
f = frame.fn;
// Found an actual function.
// Derive frame pointer and link register.
if(frame.fp == 0)
frame.fp = frame.sp + runtime·funcspdelta(f, frame.pc);
if(runtime·topofstack(f)) {
frame.lr = 0;
flr = nil;
} else if(f->entry == (uintptr)runtime·jmpdefer) {
// jmpdefer modifies SP/LR/PC non-atomically.
// If a profiling interrupt arrives during jmpdefer,
// the stack unwind may see a mismatched register set
// and get confused. Stop if we see PC within jmpdefer
// to avoid that confusion.
// See golang.org/issue/8153.
// This check can be deleted if jmpdefer is changed
// to restore all three atomically using pop.
if(callback != nil)
runtime·throw("traceback_arm: found jmpdefer when tracing with callback");
frame.lr = 0;
flr = nil;
} else {
if((n == 0 && frame.sp < frame.fp) || frame.lr == 0)
frame.lr = *(uintptr*)frame.sp;
flr = runtime·findfunc(frame.lr);
if(flr == nil) {
runtime·printf("runtime: unexpected return pc for %s called from %p\n", runtime·funcname(f), frame.lr);
if(callback != nil)
runtime·throw("unknown caller pc");
}
}
frame.varp = (byte*)frame.fp;
// Derive size of arguments.
// Most functions have a fixed-size argument block,
// so we can use metadata about the function f.
// Not all, though: there are some variadic functions
// in package runtime and reflect, and for those we use call-specific
// metadata recorded by f's caller.
if(callback != nil || printing) {
frame.argp = (byte*)frame.fp + sizeof(uintptr);
if(f->args != ArgsSizeUnknown)
frame.arglen = f->args;
else if(flr == nil)
frame.arglen = 0;
else if(frame.lr == (uintptr)runtime·lessstack)
frame.arglen = stk->argsize;
else if((i = runtime·funcarglen(flr, frame.lr)) >= 0)
frame.arglen = i;
else {
runtime·printf("runtime: unknown argument frame size for %s called from %p [%s]\n",
runtime·funcname(f), frame.lr, flr ? runtime·funcname(flr) : "?");
if(callback != nil)
runtime·throw("invalid stack");
frame.arglen = 0;
}
}
// Determine function SP where deferproc would find its arguments.
// On ARM that's just the standard bottom-of-stack plus 1 word for
// the saved LR. If the previous frame was a direct call to newproc/deferproc,
// however, the SP is three words lower than normal.
// If the function has no frame at all - perhaps it just started, or perhaps
// it is a leaf with no local variables - then we cannot possibly find its
// SP in a defer, and we might confuse its SP for its caller's SP, so
// set sparg=0 in that case.
sparg = 0;
if(frame.fp != frame.sp) {
sparg = frame.sp + sizeof(uintreg);
if(wasnewproc)
sparg += 3*sizeof(uintreg);
}
// Determine frame's 'continuation PC', where it can continue.
// Normally this is the return address on the stack, but if sigpanic
// is immediately below this function on the stack, then the frame
// stopped executing due to a trap, and frame.pc is probably not
// a safe point for looking up liveness information. In this panicking case,
// the function either doesn't return at all (if it has no defers or if the
// defers do not recover) or it returns from one of the calls to
// deferproc a second time (if the corresponding deferred func recovers).
// It suffices to assume that the most recent deferproc is the one that
// returns; everything live at earlier deferprocs is still live at that one.
frame.continpc = frame.pc;
if(waspanic) {
if(panic != nil && panic->defer->argp == (byte*)sparg)
frame.continpc = (uintptr)panic->defer->pc;
else if(defer != nil && defer->argp == (byte*)sparg)
frame.continpc = (uintptr)defer->pc;
else
frame.continpc = 0;
}
// Unwind our local panic & defer stacks past this frame.
while(panic != nil && (panic->defer == nil || panic->defer->argp == (byte*)sparg || panic->defer->argp == NoArgs))
panic = panic->link;
while(defer != nil && (defer->argp == (byte*)sparg || defer->argp == NoArgs))
defer = defer->link;
if(skip > 0) {
skip--;
goto skipped;
}
if(pcbuf != nil)
pcbuf[n] = frame.pc;
if(callback != nil) {
if(!callback(&frame, v))
return n;
}
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(", runtime·funcname(f));
for(i = 0; i < frame.arglen/sizeof(uintptr); i++) {
if(i >= 10) {
runtime·prints(", ...");
break;
}
if(i != 0)
runtime·prints(", ");
runtime·printhex(((uintptr*)frame.argp)[i]);
}
runtime·prints(")\n");
line = runtime·funcline(f, tracepc, &file);
runtime·printf("\t%S:%d", file, line);
if(frame.pc > f->entry)
runtime·printf(" +%p", (uintptr)(frame.pc - f->entry));
if(m->throwing > 0 && gp == m->curg || gotraceback >= 2)
runtime·printf(" fp=%p sp=%p", frame.fp, frame.sp);
runtime·printf("\n");
nprint++;
}
}
n++;
skipped:
waspanic = f->entry == (uintptr)runtime·sigpanic;
wasnewproc = f->entry == (uintptr)runtime·newproc || f->entry == (uintptr)runtime·deferproc;
// Do not unwind past the bottom of the stack.
if(flr == nil)
break;
// Unwind to next frame.
frame.pc = frame.lr;
frame.fn = flr;
frame.lr = 0;
frame.sp = frame.fp;
frame.fp = 0;
// 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;
// For rationale, see long comment in traceback_x86.c.
if(callback != nil && n < max && defer != nil) {
if(defer != nil)
runtime·printf("runtime: g%D: leftover defer argp=%p pc=%p\n", gp->goid, defer->argp, defer->pc);
if(panic != nil)
runtime·printf("runtime: g%D: leftover panic argp=%p pc=%p\n", gp->goid, panic->defer->argp, panic->defer->pc);
for(defer = gp->defer; defer != nil; defer = defer->link)
runtime·printf("\tdefer %p argp=%p pc=%p\n", defer, defer->argp, defer->pc);
for(panic = gp->panic; panic != nil; panic = panic->link) {
runtime·printf("\tpanic %p defer %p", panic, panic->defer);
if(panic->defer != nil)
runtime·printf(" argp=%p pc=%p", panic->defer->argp, panic->defer->pc);
runtime·printf("\n");
}
runtime·throw("traceback has leftover defers or panics");
}
return n;
}
// Generic traceback. Handles runtime stack prints (pcbuf == nil),
// the runtime.Callers function (pcbuf != nil), as well as the garbage
// collector (callback != nil). A little clunky to merge these, but avoids
// duplicating the code and all its subtlety.
int32
runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip, uintptr *pcbuf, int32 max, bool (*callback)(Stkframe*, void*), void *v, bool printall)
{
int32 i, n, nprint, line, gotraceback;
uintptr tracepc, sparg;
bool waspanic, wasnewproc, printing;
Func *f, *flr;
Stkframe frame;
Stktop *stk;
String file;
Panic *panic;
Defer *defer;
USED(lr0);
gotraceback = runtime·gotraceback(nil);
if(pc0 == ~(uintptr)0 && sp0 == ~(uintptr)0) { // Signal to fetch saved values from gp.
if(gp->syscallstack != (uintptr)nil) {
pc0 = gp->syscallpc;
sp0 = gp->syscallsp;
} else {
pc0 = gp->sched.pc;
sp0 = gp->sched.sp;
}
}
nprint = 0;
runtime·memclr((byte*)&frame, sizeof frame);
frame.pc = pc0;
frame.sp = sp0;
waspanic = false;
wasnewproc = false;
printing = pcbuf==nil && callback==nil;
panic = gp->panic;
defer = gp->defer;
while(defer != nil && defer->argp == NoArgs)
defer = defer->link;
while(panic != nil && panic->defer == nil)
panic = panic->link;
// If the PC is zero, it's likely a nil function call.
// Start in the caller's frame.
if(frame.pc == 0) {
frame.pc = *(uintptr*)frame.sp;
frame.sp += sizeof(uintreg);
}
f = runtime·findfunc(frame.pc);
if(f == nil) {
if(callback != nil) {
runtime·printf("runtime: unknown pc %p\n", frame.pc);
runtime·throw("unknown pc");
}
return 0;
}
frame.fn = f;
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;
frame.fn = nil;
if(printing && runtime·showframe(nil, gp))
runtime·printf("----- stack segment boundary -----\n");
stk = (Stktop*)stk->stackbase;
f = runtime·findfunc(frame.pc);
if(f == nil) {
runtime·printf("runtime: unknown pc %p after stack split\n", frame.pc);
if(callback != nil)
runtime·throw("unknown pc");
}
frame.fn = f;
continue;
}
f = frame.fn;
#ifdef GOOS_windows
// Windows exception handlers run on the actual g stack (there is room
// dedicated to this below the usual "bottom of stack"), not on a separate
// stack. As a result, we have to be able to unwind past the exception
// handler when called to unwind during stack growth inside the handler.
// Recognize the frame at the call to sighandler in sigtramp and unwind
// using the context argument passed to the call. This is awful.
if(f != nil && f->entry == (uintptr)runtime·sigtramp && frame.pc > f->entry) {
Context *r;
// Invoke callback so that stack copier sees an uncopyable frame.
if(callback != nil) {
frame.continpc = frame.pc;
frame.argp = nil;
frame.arglen = 0;
if(!callback(&frame, v))
return n;
}
r = (Context*)((uintptr*)frame.sp)[1];
#ifdef GOARCH_amd64
frame.pc = r->Rip;
frame.sp = r->Rsp;
#else
frame.pc = r->Eip;
frame.sp = r->Esp;
#endif
frame.lr = 0;
frame.fp = 0;
frame.fn = nil;
if(printing && runtime·showframe(nil, gp))
runtime·printf("----- exception handler -----\n");
f = runtime·findfunc(frame.pc);
if(f == nil) {
runtime·printf("runtime: unknown pc %p after exception handler\n", frame.pc);
if(callback != nil)
runtime·throw("unknown pc");
}
frame.fn = f;
continue;
}
#endif
// Found an actual function.
// Derive frame pointer and link register.
if(frame.fp == 0) {
frame.fp = frame.sp + runtime·funcspdelta(f, frame.pc);
frame.fp += sizeof(uintreg); // caller PC
}
if(runtime·topofstack(f)) {
frame.lr = 0;
flr = nil;
} else {
if(frame.lr == 0)
frame.lr = ((uintreg*)frame.fp)[-1];
flr = runtime·findfunc(frame.lr);
if(flr == nil) {
runtime·printf("runtime: unexpected return pc for %s called from %p\n", runtime·funcname(f), frame.lr);
if(callback != nil)
runtime·throw("unknown caller pc");
}
}
frame.varp = (byte*)frame.fp - sizeof(uintreg);
// Derive size of arguments.
// Most functions have a fixed-size argument block,
// so we can use metadata about the function f.
// Not all, though: there are some variadic functions
// in package runtime and reflect, and for those we use call-specific
// metadata recorded by f's caller.
if(callback != nil || printing) {
frame.argp = (byte*)frame.fp;
if(f->args != ArgsSizeUnknown)
frame.arglen = f->args;
else if(flr == nil)
frame.arglen = 0;
else if(frame.lr == (uintptr)runtime·lessstack)
frame.arglen = stk->argsize;
else if((i = runtime·funcarglen(flr, frame.lr)) >= 0)
frame.arglen = i;
else {
runtime·printf("runtime: unknown argument frame size for %s called from %p [%s]\n",
runtime·funcname(f), frame.lr, flr ? runtime·funcname(flr) : "?");
if(callback != nil)
runtime·throw("invalid stack");
frame.arglen = 0;
}
}
// Determine function SP where deferproc would find its arguments.
// On x86 that's just the standard bottom-of-stack, so SP exactly.
// If the previous frame was a direct call to newproc/deferproc, however,
// the SP is two words lower than normal.
sparg = frame.sp;
if(wasnewproc)
sparg += 2*sizeof(uintptr);
// Determine frame's 'continuation PC', where it can continue.
// Normally this is the return address on the stack, but if sigpanic
// is immediately below this function on the stack, then the frame
// stopped executing due to a trap, and frame.pc is probably not
// a safe point for looking up liveness information. In this panicking case,
// the function either doesn't return at all (if it has no defers or if the
// defers do not recover) or it returns from one of the calls to
// deferproc a second time (if the corresponding deferred func recovers).
// It suffices to assume that the most recent deferproc is the one that
// returns; everything live at earlier deferprocs is still live at that one.
frame.continpc = frame.pc;
if(waspanic) {
if(panic != nil && panic->defer->argp == (byte*)sparg)
frame.continpc = (uintptr)panic->defer->pc;
else if(defer != nil && defer->argp == (byte*)sparg)
frame.continpc = (uintptr)defer->pc;
else
frame.continpc = 0;
}
// Unwind our local panic & defer stacks past this frame.
while(panic != nil && (panic->defer == nil || panic->defer->argp == (byte*)sparg || panic->defer->argp == NoArgs))
panic = panic->link;
while(defer != nil && (defer->argp == (byte*)sparg || defer->argp == NoArgs))
defer = defer->link;
if(skip > 0) {
skip--;
goto skipped;
}
if(pcbuf != nil)
pcbuf[n] = frame.pc;
if(callback != nil) {
if(!callback(&frame, v))
return n;
}
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--;
runtime·printf("%s(", runtime·funcname(f));
for(i = 0; i < frame.arglen/sizeof(uintptr); i++) {
if(i >= 10) {
runtime·prints(", ...");
break;
}
if(i != 0)
runtime·prints(", ");
runtime·printhex_c(((uintptr*)frame.argp)[i]);
}
runtime·prints(")\n");
line = runtime·funcline(f, tracepc, &file);
runtime·printf("\t%S:%d", file, line);
if(frame.pc > f->entry)
runtime·printf(" +%p", (uintptr)(frame.pc - f->entry));
if(g->m->throwing > 0 && gp == g->m->curg || gotraceback >= 2)
runtime·printf(" fp=%p sp=%p", frame.fp, frame.sp);
runtime·printf("\n");
nprint++;
}
}
n++;
skipped:
waspanic = f->entry == (uintptr)runtime·sigpanic;
wasnewproc = f->entry == (uintptr)runtime·newproc || f->entry == (uintptr)runtime·deferproc;
// Do not unwind past the bottom of the stack.
if(flr == nil)
break;
// Unwind to next frame.
frame.fn = flr;
frame.pc = frame.lr;
frame.lr = 0;
frame.sp = frame.fp;
frame.fp = 0;
}
if(pcbuf == nil && callback == nil)
n = nprint;
// If callback != nil, we're being called to gather stack information during
// garbage collection or stack growth. In that context, require that we used
// up the entire defer stack. If not, then there is a bug somewhere and the
// garbage collection or stack growth may not have seen the correct picture
// of the stack. Crash now instead of silently executing the garbage collection
// or stack copy incorrectly and setting up for a mysterious crash later.
//
// Note that panic != nil is okay here: there can be leftover panics,
// because the defers on the panic stack do not nest in frame order as
// they do on the defer stack. If you have:
//
// frame 1 defers d1
// frame 2 defers d2
// frame 3 defers d3
// frame 4 panics
// frame 4's panic starts running defers
// frame 5, running d3, defers d4
// frame 5 panics
// frame 5's panic starts running defers
// frame 6, running d4, garbage collects
// frame 6, running d2, garbage collects
//
// During the execution of d4, the panic stack is d4 -> d3, which
// is nested properly, and we'll treat frame 3 as resumable, because we
// can find d3. (And in fact frame 3 is resumable. If d4 recovers
// and frame 5 continues running, d3, d3 can recover and we'll
// resume execution in (returning from) frame 3.)
//
// During the execution of d2, however, the panic stack is d2 -> d3,
// which is inverted. The scan will match d2 to frame 2 but having
// d2 on the stack until then means it will not match d3 to frame 3.
// This is okay: if we're running d2, then all the defers after d2 have
// completed and their corresponding frames are dead. Not finding d3
// for frame 3 means we'll set frame 3's continpc == 0, which is correct
// (frame 3 is dead). At the end of the walk the panic stack can thus
// contain defers (d3 in this case) for dead frames. The inversion here
// always indicates a dead frame, and the effect of the inversion on the
// scan is to hide those dead frames, so the scan is still okay:
// what's left on the panic stack are exactly (and only) the dead frames.
//
// We require callback != nil here because only when callback != nil
// do we know that gentraceback is being called in a "must be correct"
// context as opposed to a "best effort" context. The tracebacks with
// callbacks only happen when everything is stopped nicely.
// At other times, such as when gathering a stack for a profiling signal
// or when printing a traceback during a crash, everything may not be
// stopped nicely, and the stack walk may not be able to complete.
// It's okay in those situations not to use up the entire defer stack:
// incomplete information then is still better than nothing.
if(callback != nil && n < max && defer != nil) {
if(defer != nil)
runtime·printf("runtime: g%D: leftover defer argp=%p pc=%p\n", gp->goid, defer->argp, defer->pc);
if(panic != nil)
runtime·printf("runtime: g%D: leftover panic argp=%p pc=%p\n", gp->goid, panic->defer->argp, panic->defer->pc);
for(defer = gp->defer; defer != nil; defer = defer->link)
runtime·printf("\tdefer %p argp=%p pc=%p\n", defer, defer->argp, defer->pc);
for(panic = gp->panic; panic != nil; panic = panic->link) {
runtime·printf("\tpanic %p defer %p", panic, panic->defer);
if(panic->defer != nil)
runtime·printf(" argp=%p pc=%p", panic->defer->argp, panic->defer->pc);
runtime·printf("\n");
}
runtime·throw("traceback has leftover defers or panics");
}
return n;
}
static int32
gentraceback(byte *pc0, byte *sp, byte *lr0, G *g, int32 skip, uintptr *pcbuf, int32 m)
{
byte *p;
int32 i, n, iter;
uintptr pc, lr, tracepc;
Stktop *stk;
Func *f;
pc = (uintptr)pc0;
lr = (uintptr)lr0;
// If the PC is zero, it's likely a nil function call.
// Start in the caller's frame.
if(pc == 0) {
pc = lr;
lr = 0;
}
n = 0;
stk = (Stktop*)g->stackbase;
for(iter = 0; iter < 100 && n < m; iter++) { // iter avoids looping forever
if(pc == (uintptr)·lessstack) {
// Hit top of stack segment. Unwind to next segment.
pc = (uintptr)stk->gobuf.pc;
sp = stk->gobuf.sp;
lr = *(uintptr*)sp;
stk = (Stktop*)stk->stackbase;
continue;
}
if(pc <= 0x1000 || (f = findfunc(pc-4)) == nil) {
// TODO: Check for closure.
break;
}
// Found an actual function worth reporting.
if(skip > 0)
skip--;
else if(pcbuf != nil)
pcbuf[n++] = pc;
else {
// Print during crash.
// main+0xf /home/rsc/go/src/runtime/x.go:23
// main(0x1, 0x2, 0x3)
printf("%S", f->name);
if(pc > f->entry)
printf("+%p", (uintptr)(pc - f->entry));
tracepc = pc; // back up to CALL instruction for funcline.
if(n > 0 && pc > f->entry)
tracepc -= sizeof(uintptr);
printf(" %S:%d\n", f->src, funcline(f, tracepc));
printf("\t%S(", f->name);
for(i = 0; i < f->args; i++) {
if(i != 0)
prints(", ");
·printhex(((uintptr*)sp)[1+i]);
if(i >= 4) {
prints(", ...");
break;
}
}
prints(")\n");
n++;
}
if(lr == 0)
lr = *(uintptr*)sp;
pc = lr;
lr = 0;
if(f->frame >= 0)
sp += f->frame;
}
return n;
}
