uint32
runtime·sighandler(ExceptionRecord *info, Context *r, G *gp)
{
uintptr *sp;
switch(info->ExceptionCode) {
case EXCEPTION_BREAKPOINT:
r->Eip--; // because 8l generates 2 bytes for INT3
return 1;
}
if(gp != nil && runtime·issigpanic(info->ExceptionCode)) {
// Make it look like a call to the signal func.
// Have to pass arguments out of band since
// augmenting the stack frame would break
// the unwinding code.
gp->sig = info->ExceptionCode;
gp->sigcode0 = info->ExceptionInformation[0];
gp->sigcode1 = info->ExceptionInformation[1];
gp->sigpc = r->Eip;
// Only push runtime·sigpanic if r->eip != 0.
// If r->eip == 0, probably panicked because of a
// call to a nil func. Not pushing that onto sp will
// make the trace look like a call to runtime·sigpanic instead.
// (Otherwise the trace will end at runtime·sigpanic and we
// won't get to see who faulted.)
if(r->Eip != 0) {
sp = (uintptr*)r->Esp;
*--sp = r->Eip;
r->Esp = (uintptr)sp;
}
r->Eip = (uintptr)runtime·sigpanic;
return 0;
}
if(runtime·panicking) // traceback already printed
runtime·exit(2);
runtime·panicking = 1;
runtime·printf("Exception %x %p %p\n", info->ExceptionCode,
info->ExceptionInformation[0], info->ExceptionInformation[1]);
runtime·printf("PC=%x\n", r->Eip);
if(m->lockedg != nil && m->ncgo > 0 && gp == m->g0) {
runtime·printf("signal arrived during cgo execution\n");
gp = m->lockedg;
}
runtime·printf("\n");
if(runtime·gotraceback()){
runtime·traceback((void*)r->Eip, (void*)r->Esp, 0, gp);
runtime·tracebackothers(gp);
runtime·dumpregs(r);
}
runtime·exit(2);
return 0;
}
bool
runtime·showframe(Func *f)
{
static int32 traceback = -1;
if(traceback < 0)
traceback = runtime·gotraceback();
return traceback > 1 || contains(f->name, ".") && !hasprefix(f->name, "runtime.");
}
bool
runtime·showframe(Func *f, bool current)
{
static int32 traceback = -1;
if(current && m->throwing > 0)
return 1;
if(traceback < 0)
traceback = runtime·gotraceback();
return traceback > 1 || f != nil && contains(f->name, ".") && !hasprefix(f->name, "runtime.");
}
void
runtime·tracebackothers(G *me)
{
G *gp;
int32 traceback;
traceback = runtime·gotraceback();
for(gp = runtime·allg; gp != nil; gp = gp->alllink) {
if(gp == me || gp->status == Gdead)
continue;
if(gp->issystem && traceback < 2)
continue;
runtime·printf("\n");
runtime·goroutineheader(gp);
runtime·traceback(gp->sched.pc, (byte*)gp->sched.sp, 0, gp);
}
}
void
runtime·dopanic(int32 unused)
{
static bool didothers;
bool crash;
int32 t;
if(g->sig != 0)
runtime·printf("[signal %x code=%p addr=%p pc=%p]\n",
g->sig, g->sigcode0, g->sigcode1, g->sigpc);
if((t = runtime·gotraceback(&crash)) > 0){
if(g != m->g0) {
runtime·printf("\n");
runtime·goroutineheader(g);
runtime·traceback((uintptr)runtime·getcallerpc(&unused), (uintptr)runtime·getcallersp(&unused), 0, g);
} else if(t >= 2 || m->throwing > 0) {
runtime·printf("\nruntime stack:\n");
runtime·traceback((uintptr)runtime·getcallerpc(&unused), (uintptr)runtime·getcallersp(&unused), 0, g);
}
if(!didothers) {
didothers = true;
runtime·tracebackothers(g);
}
}
runtime·unlock(&paniclk);
if(runtime·xadd(&runtime·panicking, -1) != 0) {
// Some other m is panicking too.
// Let it print what it needs to print.
// Wait forever without chewing up cpu.
// It will exit when it's done.
static Lock deadlock;
runtime·lock(&deadlock);
runtime·lock(&deadlock);
}
if(crash)
runtime·crash();
runtime·exit(2);
}
void
sighandler(int32 sig, Siginfo *info, void *context)
{
Ucontext *uc;
Mcontext *mc;
Regs *r;
if(sigtab[sig].flags & SigQueue) {
if(sigsend(sig) || (sigtab[sig].flags & SigIgnore))
return;
exit(2); // SIGINT, SIGTERM, etc
}
if(panicking) // traceback already printed
exit(2);
panicking = 1;
if(sig < 0 || sig >= NSIG){
printf("Signal %d\n", sig);
}else{
printf("%s\n", sigtab[sig].name);
}
uc = context;
mc = uc->uc_mcontext;
r = &mc->ss;
printf("Faulting address: %p\n", info->si_addr);
printf("pc: %X\n", r->rip);
printf("\n");
if(gotraceback()){
traceback((void*)r->rip, (void*)r->rsp, (void*)r->r15);
tracebackothers((void*)r->r15);
dumpregs(r);
}
breakpoint();
exit(2);
}
void
sighandler(int32 sig, Siginfo* info, void* context)
{
Ucontext *uc;
Mcontext *mc;
if(sigtab[sig].flags & SigQueue) {
if(sigsend(sig) || (sigtab[sig].flags & SigIgnore))
return;
exit(2); // SIGINT, SIGTERM, etc
}
if(panicking) // traceback already printed
exit(2);
panicking = 1;
uc = context;
mc = &uc->uc_mcontext;
if(sig < 0 || sig >= NSIG)
printf("Signal %d\n", sig);
else
printf("%s\n", sigtab[sig].name);
printf("Faulting address: %p\n", info->si_addr);
printf("PC=%X\n", mc->mc_eip);
printf("\n");
if(gotraceback()){
traceback((void*)mc->mc_eip, (void*)mc->mc_esp, m->curg);
tracebackothers(m->curg);
dumpregs(mc);
}
breakpoint();
exit(2);
}
void
sighandler(int32 sig, Siginfo *info, void *context)
{
Ucontext *uc;
Mcontext *mc;
Regs *r;
G *gp;
uintptr *sp;
byte *pc;
uc = context;
mc = uc->uc_mcontext;
r = &mc->ss;
if((gp = m->curg) != nil && (sigtab[sig].flags & SigPanic)) {
// Work around Leopard bug that doesn't set FPE_INTDIV.
// Look at instruction to see if it is a divide.
// Not necessary in Snow Leopard (si_code will be != 0).
if(sig == SIGFPE && info->si_code == 0) {
pc = (byte*)r->rip;
if((pc[0]&0xF0) == 0x40) // 64-bit REX prefix
pc++;
if(pc[0] == 0xF7)
info->si_code = FPE_INTDIV;
}
// Make it look like a call to the signal func.
// Have to pass arguments out of band since
// augmenting the stack frame would break
// the unwinding code.
gp->sig = sig;
gp->sigcode0 = info->si_code;
gp->sigcode1 = (uintptr)info->si_addr;
// Only push sigpanic if r->rip != 0.
// If r->rip == 0, probably panicked because of a
// call to a nil func. Not pushing that onto sp will
// make the trace look like a call to sigpanic instead.
// (Otherwise the trace will end at sigpanic and we
// won't get to see who faulted.)
if(r->rip != 0) {
sp = (uintptr*)r->rsp;
*--sp = r->rip;
r->rsp = (uintptr)sp;
}
r->rip = (uintptr)sigpanic;
return;
}
if(sigtab[sig].flags & SigQueue) {
if(sigsend(sig) || (sigtab[sig].flags & SigIgnore))
return;
exit(2); // SIGINT, SIGTERM, etc
}
if(panicking) // traceback already printed
exit(2);
panicking = 1;
if(sig < 0 || sig >= NSIG){
printf("Signal %d\n", sig);
}else{
printf("%s\n", sigtab[sig].name);
}
printf("pc: %X\n", r->rip);
printf("\n");
if(gotraceback()){
traceback((void*)r->rip, (void*)r->rsp, 0, (void*)r->r15);
tracebackothers((void*)r->r15);
dumpregs(r);
}
breakpoint();
exit(2);
}
void
runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
{
Ucontext *uc;
Sigcontext *r;
SigTab *t;
uc = context;
r = &uc->uc_mcontext;
if(sig == SIGPROF) {
runtime·sigprof((uint8*)r->arm_pc, (uint8*)r->arm_sp, (uint8*)r->arm_lr, gp);
return;
}
t = &runtime·sigtab[sig];
if(info->si_code != SI_USER && (t->flags & SigPanic)) {
if(gp == nil)
goto Throw;
// Make it look like a call to the signal func.
// Have to pass arguments out of band since
// augmenting the stack frame would break
// the unwinding code.
gp->sig = sig;
gp->sigcode0 = info->si_code;
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.
if(r->arm_pc != 0)
r->arm_lr = r->arm_pc;
// In case we are panicking from external C code
r->arm_r10 = (uintptr)gp;
r->arm_r9 = (uintptr)m;
r->arm_pc = (uintptr)runtime·sigpanic;
return;
}
if(info->si_code == SI_USER || (t->flags & SigNotify))
if(runtime·sigsend(sig))
return;
if(t->flags & SigKill)
runtime·exit(2);
if(!(t->flags & SigThrow))
return;
Throw:
if(runtime·panicking) // traceback already printed
runtime·exit(2);
runtime·panicking = 1;
if(sig < 0 || sig >= NSIG)
runtime·printf("Signal %d\n", sig);
else
runtime·printf("%s\n", runtime·sigtab[sig].name);
runtime·printf("PC=%x\n", r->arm_pc);
runtime·printf("\n");
if(runtime·gotraceback()){
runtime·traceback((void*)r->arm_pc, (void*)r->arm_sp, (void*)r->arm_lr, gp);
runtime·tracebackothers(gp);
runtime·printf("\n");
runtime·dumpregs(r);
}
// breakpoint();
runtime·exit(2);
}
int32
runtime·sighandler(void *v, int8 *note, G *gp)
{
uintptr *sp;
SigTab *t;
bool crash;
Ureg *ureg;
intgo len, n;
int32 sig, flags;
ureg = (Ureg*)v;
// The kernel will never pass us a nil note or ureg so we probably
// made a mistake somewhere in runtime·sigtramp.
if(ureg == nil || note == nil) {
runtime·printf("sighandler: ureg %p note %p\n", ureg, note);
goto Throw;
}
// Check that the note is no more than ERRMAX bytes (including
// the trailing NUL). We should never receive a longer note.
len = runtime·findnull((byte*)note);
if(len > ERRMAX-1) {
runtime·printf("sighandler: note is longer than ERRMAX\n");
goto Throw;
}
// See if the note matches one of the patterns in runtime·sigtab.
// Notes that do not match any pattern can be handled at a higher
// level by the program but will otherwise be ignored.
flags = SigNotify;
for(sig = 0; sig < nelem(runtime·sigtab); sig++) {
t = &runtime·sigtab[sig];
n = runtime·findnull((byte*)t->name);
if(len < n)
continue;
if(runtime·strncmp((byte*)note, (byte*)t->name, n) == 0) {
flags = t->flags;
break;
}
}
if(flags & SigGoExit)
runtime·exits(note+9); // Strip "go: exit " prefix.
if(flags & SigPanic) {
// Copy the error string from sigtramp's stack into m->notesig so
// we can reliably access it from the panic routines.
runtime·memmove(g->m->notesig, note, len+1);
gp->sig = sig;
gp->sigpc = ureg->ip;
// Only push runtime·sigpanic if PC != 0.
//
// If PC == 0, probably panicked because of a call to a nil func.
// Not pushing that onto SP will make the trace look like a call
// to runtime·sigpanic instead. (Otherwise the trace will end at
// runtime·sigpanic and we won't get to see who faulted).
if(ureg->ip != 0) {
sp = (uintptr*)ureg->sp;
*--sp = ureg->ip;
ureg->sp = (uint64)sp;
}
ureg->ip = (uintptr)runtime·sigpanic;
return NCONT;
}
if(flags & SigNotify) {
// TODO(ality): See if os/signal wants it.
//if(runtime·sigsend(...))
// return NCONT;
}
if(flags & SigKill)
goto Exit;
if(!(flags & SigThrow))
return NCONT;
Throw:
g->m->throwing = 1;
g->m->caughtsig = gp;
runtime·startpanic();
runtime·printf("%s\n", note);
runtime·printf("PC=%X\n", ureg->ip);
runtime·printf("\n");
if(runtime·gotraceback(&crash)) {
runtime·goroutineheader(gp);
runtime·traceback(ureg->ip, ureg->sp, 0, gp);
runtime·tracebackothers(gp);
runtime·printf("\n");
runtime·dumpregs(ureg);
}
if(crash)
runtime·crash();
Exit:
runtime·goexitsall(note);
runtime·exits(note);
return NDFLT; // not reached
}
void
runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
{
Ucontext *uc;
Sigcontext *r;
uintptr *sp;
SigTab *t;
uc = context;
r = &uc->uc_mcontext;
if(sig == SIGPROF) {
runtime·sigprof((uint8*)r->eip, (uint8*)r->esp, nil, gp);
return;
}
t = &runtime·sigtab[sig];
if(info->si_code != SI_USER && (t->flags & SigPanic)) {
if(gp == nil)
goto Throw;
// Make it look like a call to the signal func.
// Have to pass arguments out of band since
// augmenting the stack frame would break
// the unwinding code.
gp->sig = sig;
gp->sigcode0 = info->si_code;
gp->sigcode1 = ((uintptr*)info)[3];
gp->sigpc = r->eip;
// Only push runtime·sigpanic if r->eip != 0.
// If r->eip == 0, probably panicked because of a
// call to a nil func. Not pushing that onto sp will
// make the trace look like a call to runtime·sigpanic instead.
// (Otherwise the trace will end at runtime·sigpanic and we
// won't get to see who faulted.)
if(r->eip != 0) {
sp = (uintptr*)r->esp;
*--sp = r->eip;
r->esp = (uintptr)sp;
}
r->eip = (uintptr)runtime·sigpanic;
return;
}
if(info->si_code == SI_USER || (t->flags & SigNotify))
if(runtime·sigsend(sig))
return;
if(t->flags & SigKill)
runtime·exit(2);
if(!(t->flags & SigThrow))
return;
Throw:
runtime·startpanic();
if(sig < 0 || sig >= NSIG)
runtime·printf("Signal %d\n", sig);
else
runtime·printf("%s\n", runtime·sigtab[sig].name);
runtime·printf("PC=%X\n", r->eip);
runtime·printf("\n");
if(runtime·gotraceback()){
runtime·traceback((void*)r->eip, (void*)r->esp, 0, gp);
runtime·tracebackothers(gp);
runtime·dumpregs(r);
}
runtime·exit(2);
}
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;
}
void
runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
{
Ucontext *uc;
Mcontext32 *mc;
Regs32 *r;
uintptr *sp;
byte *pc;
SigTab *t;
uc = context;
mc = uc->uc_mcontext;
r = &mc->ss;
if(sig == SIGPROF) {
if(gp != m->g0 && gp != m->gsignal)
runtime·sigprof((uint8*)r->eip, (uint8*)r->esp, nil, gp);
return;
}
t = &runtime·sigtab[sig];
if(info->si_code != SI_USER && (t->flags & SigPanic)) {
if(gp == nil || gp == m->g0)
goto Throw;
// Work around Leopard bug that doesn't set FPE_INTDIV.
// Look at instruction to see if it is a divide.
// Not necessary in Snow Leopard (si_code will be != 0).
if(sig == SIGFPE && info->si_code == 0) {
pc = (byte*)r->eip;
if(pc[0] == 0x66) // 16-bit instruction prefix
pc++;
if(pc[0] == 0xF6 || pc[0] == 0xF7)
info->si_code = FPE_INTDIV;
}
// Make it look like a call to the signal func.
// Have to pass arguments out of band since
// augmenting the stack frame would break
// the unwinding code.
gp->sig = sig;
gp->sigcode0 = info->si_code;
gp->sigcode1 = (uintptr)info->si_addr;
gp->sigpc = r->eip;
// Only push runtime·sigpanic if r->eip != 0.
// If r->eip == 0, probably panicked because of a
// call to a nil func. Not pushing that onto sp will
// make the trace look like a call to runtime·sigpanic instead.
// (Otherwise the trace will end at runtime·sigpanic and we
// won't get to see who faulted.)
if(r->eip != 0) {
sp = (uintptr*)r->esp;
*--sp = r->eip;
r->esp = (uintptr)sp;
}
r->eip = (uintptr)runtime·sigpanic;
return;
}
if(info->si_code == SI_USER || (t->flags & SigNotify))
if(runtime·sigsend(sig))
return;
if(t->flags & SigKill)
runtime·exit(2);
if(!(t->flags & SigThrow))
return;
Throw:
runtime·startpanic();
if(sig < 0 || sig >= NSIG){
runtime·printf("Signal %d\n", sig);
}else{
runtime·printf("%s\n", runtime·sigtab[sig].name);
}
runtime·printf("PC=%x\n", r->eip);
if(m->lockedg != nil && m->ncgo > 0 && gp == m->g0) {
runtime·printf("signal arrived during cgo execution\n");
gp = m->lockedg;
}
runtime·printf("\n");
if(runtime·gotraceback()){
runtime·traceback((void*)r->eip, (void*)r->esp, 0, gp);
runtime·tracebackothers(gp);
runtime·dumpregs(r);
}
runtime·exit(2);
}
void
runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
{
Ucontext *uc;
Sigcontext *r;
SigTab *t;
uc = context;
r = &uc->uc_mcontext;
if(sig == SIGPROF) {
runtime·sigprof((uint8*)r->arm_pc, (uint8*)r->arm_sp, (uint8*)r->arm_lr, gp);
return;
}
t = &runtime·sigtab[sig];
if(info->si_code != SI_USER && (t->flags & SigPanic)) {
if(gp == nil || gp == m->g0)
goto Throw;
// Make it look like a call to the signal func.
// Have to pass arguments out of band since
// augmenting the stack frame would break
// the unwinding code.
gp->sig = sig;
gp->sigcode0 = info->si_code;
gp->sigcode1 = r->fault_address;
gp->sigpc = r->arm_pc;
// 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
r->arm_r10 = (uintptr)gp;
r->arm_r9 = (uintptr)m;
r->arm_pc = (uintptr)runtime·sigpanic;
return;
}
if(info->si_code == SI_USER || (t->flags & SigNotify))
if(runtime·sigsend(sig))
return;
if(t->flags & SigKill)
runtime·exit(2);
if(!(t->flags & SigThrow))
return;
Throw:
if(runtime·panicking) // traceback already printed
runtime·exit(2);
runtime·panicking = 1;
if(sig < 0 || sig >= NSIG)
runtime·printf("Signal %d\n", sig);
else
runtime·printf("%s\n", runtime·sigtab[sig].name);
runtime·printf("PC=%x\n", r->arm_pc);
if(m->lockedg != nil && m->ncgo > 0 && gp == m->g0) {
runtime·printf("signal arrived during cgo execution\n");
gp = m->lockedg;
}
runtime·printf("\n");
if(runtime·gotraceback()) {
runtime·traceback((void*)r->arm_pc, (void*)r->arm_sp, (void*)r->arm_lr, gp);
runtime·tracebackothers(gp);
runtime·printf("\n");
runtime·dumpregs(r);
}
// breakpoint();
runtime·exit(2);
}
void
runtime·sighandler(int32 sig, Siginfo *info, void *ctxt, G *gp)
{
uintptr *sp;
SigTab *t;
bool crash;
if(sig == SIGPROF) {
if(gp != m->g0 && gp != m->gsignal)
runtime·sigprof((byte*)SIG_RIP(info, ctxt), (byte*)SIG_RSP(info, ctxt), nil, gp);
return;
}
t = &runtime·sigtab[sig];
if(SIG_CODE0(info, ctxt) != SI_USER && (t->flags & SigPanic)) {
if(gp == nil || gp == m->g0)
goto Throw;
// Make it look like a call to the signal func.
// Have to pass arguments out of band since
// augmenting the stack frame would break
// the unwinding code.
gp->sig = sig;
gp->sigcode0 = SIG_CODE0(info, ctxt);
gp->sigcode1 = SIG_CODE1(info, ctxt);
gp->sigpc = SIG_RIP(info, ctxt);
#ifdef GOOS_darwin
// Work around Leopard bug that doesn't set FPE_INTDIV.
// Look at instruction to see if it is a divide.
// Not necessary in Snow Leopard (si_code will be != 0).
if(sig == SIGFPE && gp->sigcode0 == 0) {
byte *pc;
pc = (byte*)gp->sigpc;
if((pc[0]&0xF0) == 0x40) // 64-bit REX prefix
pc++;
else if(pc[0] == 0x66) // 16-bit instruction prefix
pc++;
if(pc[0] == 0xF6 || pc[0] == 0xF7)
gp->sigcode0 = FPE_INTDIV;
}
#endif
// Only push runtime·sigpanic if rip != 0.
// If rip == 0, probably panicked because of a
// call to a nil func. Not pushing that onto sp will
// make the trace look like a call to runtime·sigpanic instead.
// (Otherwise the trace will end at runtime·sigpanic and we
// won't get to see who faulted.)
if(SIG_RIP(info, ctxt) != 0) {
sp = (uintptr*)SIG_RSP(info, ctxt);
*--sp = SIG_RIP(info, ctxt);
SIG_RSP(info, ctxt) = (uintptr)sp;
}
SIG_RIP(info, ctxt) = (uintptr)runtime·sigpanic;
return;
}
if(SIG_CODE0(info, ctxt) == SI_USER || (t->flags & SigNotify))
if(runtime·sigsend(sig))
return;
if(t->flags & SigKill)
runtime·exit(2);
if(!(t->flags & SigThrow))
return;
Throw:
m->throwing = 1;
m->caughtsig = gp;
runtime·startpanic();
if(sig < 0 || sig >= NSIG)
runtime·printf("Signal %d\n", sig);
else
runtime·printf("%s\n", runtime·sigtab[sig].name);
runtime·printf("PC=%X\n", SIG_RIP(info, ctxt));
if(m->lockedg != nil && m->ncgo > 0 && gp == m->g0) {
runtime·printf("signal arrived during cgo execution\n");
gp = m->lockedg;
}
runtime·printf("\n");
if(runtime·gotraceback(&crash)){
runtime·traceback(SIG_RIP(info, ctxt), SIG_RSP(info, ctxt), 0, gp);
runtime·tracebackothers(gp);
runtime·printf("\n");
runtime·dumpregs(info, ctxt);
}
if(crash)
runtime·crash();
runtime·exit(2);
}
void
runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
{
UcontextT *uc = context;
McontextT *mc = &uc->uc_mcontext;
uintptr *sp;
SigTab *t;
if(sig == SIGPROF) {
runtime·sigprof((uint8*)mc->__gregs[REG_EIP],
(uint8*)mc->__gregs[REG_UESP], nil, gp);
return;
}
t = &runtime·sigtab[sig];
if(info->_code != SI_USER && (t->flags & SigPanic)) {
if(gp == nil || gp == m->g0)
goto Throw;
// Make it look like a call to the signal func.
// We need to pass arguments out of band since
// augmenting the stack frame would break
// the unwinding code.
gp->sig = sig;
gp->sigcode0 = info->_code;
gp->sigcode1 = *(uintptr*)&info->_reason[0]; /* _addr */
gp->sigpc = mc->__gregs[REG_EIP];
// Only push runtime·sigpanic if __gregs[REG_EIP] != 0.
// If __gregs[REG_EIP] == 0, probably panicked because of a
// call to a nil func. Not pushing that onto sp will make the
// trace look like a call to runtime·sigpanic instead.
// (Otherwise the trace will end at runtime·sigpanic
// and we won't get to see who faulted.)
if(mc->__gregs[REG_EIP] != 0) {
sp = (uintptr*)mc->__gregs[REG_UESP];
*--sp = mc->__gregs[REG_EIP];
mc->__gregs[REG_UESP] = (uintptr)sp;
}
mc->__gregs[REG_EIP] = (uintptr)runtime·sigpanic;
return;
}
if(info->_code == SI_USER || (t->flags & SigNotify))
if(runtime·sigsend(sig))
return;
if(t->flags & SigKill)
runtime·exit(2);
if(!(t->flags & SigThrow))
return;
Throw:
runtime·startpanic();
if(sig < 0 || sig >= NSIG)
runtime·printf("Signal %d\n", sig);
else
runtime·printf("%s\n", runtime·sigtab[sig].name);
runtime·printf("PC=%X\n", mc->__gregs[REG_EIP]);
if(m->lockedg != nil && m->ncgo > 0 && gp == m->g0) {
runtime·printf("signal arrived during cgo execution\n");
gp = m->lockedg;
}
runtime·printf("\n");
if(runtime·gotraceback()){
runtime·traceback((void*)mc->__gregs[REG_EIP],
(void*)mc->__gregs[REG_UESP], 0, gp);
runtime·tracebackothers(gp);
runtime·dumpregs(mc);
}
runtime·exit(2);
}
int32
runtime·sighandler(void *v, int8 *s, G *gp)
{
Ureg *ureg;
uintptr *sp;
SigTab *sig, *nsig;
int32 len, i;
if(!s)
return NCONT;
len = runtime·findnull((byte*)s);
if(len <= 4 || runtime·mcmp((byte*)s, (byte*)"sys:", 4) != 0)
return NDFLT;
nsig = nil;
sig = runtime·sigtab;
for(i=0; i < NSIG; i++) {
if(runtime·strstr((byte*)s, (byte*)sig->name)) {
nsig = sig;
break;
}
sig++;
}
if(nsig == nil)
return NDFLT;
ureg = v;
if(nsig->flags & SigPanic) {
if(gp == nil || m->notesig == 0)
goto Throw;
// Save error string from sigtramp's stack,
// into gsignal->sigcode0, so we can reliably
// access it from the panic routines.
if(len > ERRMAX)
len = ERRMAX;
runtime·memmove((void*)m->notesig, (void*)s, len);
gp->sig = i;
gp->sigpc = ureg->pc;
// Only push runtime·sigpanic if ureg->pc != 0.
// If ureg->pc == 0, probably panicked because of a
// call to a nil func. Not pushing that onto sp will
// make the trace look like a call to runtime·sigpanic instead.
// (Otherwise the trace will end at runtime·sigpanic and we
// won't get to see who faulted.)
if(ureg->pc != 0) {
sp = (uintptr*)ureg->sp;
*--sp = ureg->pc;
ureg->sp = (uint32)sp;
}
ureg->pc = (uintptr)runtime·sigpanic;
return NCONT;
}
if(!(nsig->flags & SigThrow))
return NDFLT;
Throw:
runtime·startpanic();
runtime·printf("%s\n", s);
runtime·printf("PC=%X\n", ureg->pc);
runtime·printf("\n");
if(runtime·gotraceback()) {
runtime·traceback((void*)ureg->pc, (void*)ureg->sp, 0, gp);
runtime·tracebackothers(gp);
runtime·dumpregs(ureg);
}
runtime·goexitsall("");
runtime·exits(s);
return 0;
}
// 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;
}
// Called by sigtramp from Windows VEH handler.
// Return value signals whether the exception has been handled (-1)
// or should be made available to other handlers in the chain (0).
uint32
runtime·sighandler(ExceptionRecord *info, Context *r, G *gp)
{
bool crash;
uintptr *sp;
extern byte text[], etext[];
if(info->ExceptionCode == DBG_PRINTEXCEPTION_C) {
// This exception is intended to be caught by debuggers.
// There is a not-very-informational message like
// "Invalid parameter passed to C runtime function"
// sitting at info->ExceptionInformation[0] (a wchar_t*),
// with length info->ExceptionInformation[1].
// The default behavior is to ignore this exception,
// but somehow returning 0 here (meaning keep going)
// makes the program crash instead. Maybe Windows has no
// other handler registered? In any event, ignore it.
return -1;
}
// Only handle exception if executing instructions in Go binary
// (not Windows library code).
if(r->Rip < (uint64)text || (uint64)etext < r->Rip)
return 0;
switch(info->ExceptionCode) {
case EXCEPTION_BREAKPOINT:
// It is unclear whether this is needed, unclear whether it
// would work, and unclear how to test it. Leave out for now.
// This only handles breakpoint instructions written in the
// assembly sources, not breakpoints set by a debugger, and
// there are very few of the former.
break;
}
if(gp != nil && runtime·issigpanic(info->ExceptionCode)) {
// Make it look like a call to the signal func.
// Have to pass arguments out of band since
// augmenting the stack frame would break
// the unwinding code.
gp->sig = info->ExceptionCode;
gp->sigcode0 = info->ExceptionInformation[0];
gp->sigcode1 = info->ExceptionInformation[1];
gp->sigpc = r->Rip;
// Only push runtime·sigpanic if r->rip != 0.
// If r->rip == 0, probably panicked because of a
// call to a nil func. Not pushing that onto sp will
// make the trace look like a call to runtime·sigpanic instead.
// (Otherwise the trace will end at runtime·sigpanic and we
// won't get to see who faulted.)
if(r->Rip != 0) {
sp = (uintptr*)r->Rsp;
*--sp = r->Rip;
r->Rsp = (uintptr)sp;
}
r->Rip = (uintptr)runtime·sigpanic;
return -1;
}
if(runtime·panicking) // traceback already printed
runtime·exit(2);
runtime·panicking = 1;
runtime·printf("Exception %x %p %p %p\n", info->ExceptionCode,
info->ExceptionInformation[0], info->ExceptionInformation[1], r->Rip);
runtime·printf("PC=%X\n", r->Rip);
if(m->lockedg != nil && m->ncgo > 0 && gp == m->g0) {
runtime·printf("signal arrived during cgo execution\n");
gp = m->lockedg;
}
runtime·printf("\n");
if(runtime·gotraceback(&crash)){
runtime·traceback(r->Rip, r->Rsp, 0, gp);
runtime·tracebackothers(gp);
runtime·dumpregs(r);
}
if(crash)
runtime·crash();
runtime·exit(2);
return -1; // not reached
}
void
runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
{
Ucontext *uc;
Mcontext *mc;
Sigcontext *r;
uintptr *sp;
uc = context;
mc = &uc->uc_mcontext;
r = (Sigcontext*)mc; // same layout, more conveient names
if(sig == SIGPROF) {
runtime·sigprof((uint8*)r->rip, (uint8*)r->rsp, nil, gp);
return;
}
if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
// Make it look like a call to the signal func.
// Have to pass arguments out of band since
// augmenting the stack frame would break
// the unwinding code.
gp->sig = sig;
gp->sigcode0 = info->si_code;
gp->sigcode1 = ((uintptr*)info)[2];
gp->sigpc = r->rip;
// Only push runtime·sigpanic if r->rip != 0.
// If r->rip == 0, probably panicked because of a
// call to a nil func. Not pushing that onto sp will
// make the trace look like a call to runtime·sigpanic instead.
// (Otherwise the trace will end at runtime·sigpanic and we
// won't get to see who faulted.)
if(r->rip != 0) {
sp = (uintptr*)r->rsp;
*--sp = r->rip;
r->rsp = (uintptr)sp;
}
r->rip = (uintptr)runtime·sigpanic;
return;
}
if(runtime·sigtab[sig].flags & SigQueue) {
if(runtime·sigsend(sig) || (runtime·sigtab[sig].flags & SigIgnore))
return;
runtime·exit(2); // SIGINT, SIGTERM, etc
}
if(runtime·panicking) // traceback already printed
runtime·exit(2);
runtime·panicking = 1;
if(sig < 0 || sig >= NSIG)
runtime·printf("Signal %d\n", sig);
else
runtime·printf("%s\n", runtime·sigtab[sig].name);
runtime·printf("PC=%X\n", r->rip);
runtime·printf("\n");
if(runtime·gotraceback()){
runtime·traceback((void*)r->rip, (void*)r->rsp, 0, gp);
runtime·tracebackothers(gp);
runtime·dumpregs(r);
}
runtime·exit(2);
}
void
runtime·sighandler(int32 sig, Siginfo *info, void *ctxt, G *gp)
{
uintptr *sp;
SigTab *t;
bool crash;
if(sig == SIGPROF) {
runtime·sigprof((byte*)SIG_RIP(info, ctxt), (byte*)SIG_RSP(info, ctxt), nil, gp, g->m);
return;
}
#ifdef GOOS_darwin
// x86-64 has 48-bit virtual addresses. The top 16 bits must echo bit 47.
// The hardware delivers a different kind of fault for a malformed address
// than it does for an attempt to access a valid but unmapped address.
// OS X 10.9.2 mishandles the malformed address case, making it look like
// a user-generated signal (like someone ran kill -SEGV ourpid).
// We pass user-generated signals to os/signal, or else ignore them.
// Doing that here - and returning to the faulting code - results in an
// infinite loop. It appears the best we can do is rewrite what the kernel
// delivers into something more like the truth. The address used below
// has very little chance of being the one that caused the fault, but it is
// malformed, it is clearly not a real pointer, and if it does get printed
// in real life, people will probably search for it and find this code.
// There are no Google hits for b01dfacedebac1e or 0xb01dfacedebac1e
// as I type this comment.
if(sig == SIGSEGV && SIG_CODE0(info, ctxt) == SI_USER) {
SIG_CODE0(info, ctxt) = SI_USER+1;
info->si_addr = (void*)(uintptr)0xb01dfacedebac1eULL;
}
#endif
t = &runtime·sigtab[sig];
if(SIG_CODE0(info, ctxt) != SI_USER && (t->flags & SigPanic)) {
// Make it look like a call to the signal func.
// Have to pass arguments out of band since
// augmenting the stack frame would break
// the unwinding code.
gp->sig = sig;
gp->sigcode0 = SIG_CODE0(info, ctxt);
gp->sigcode1 = SIG_CODE1(info, ctxt);
gp->sigpc = SIG_RIP(info, ctxt);
#ifdef GOOS_darwin
// Work around Leopard bug that doesn't set FPE_INTDIV.
// Look at instruction to see if it is a divide.
// Not necessary in Snow Leopard (si_code will be != 0).
if(sig == SIGFPE && gp->sigcode0 == 0) {
byte *pc;
pc = (byte*)gp->sigpc;
if((pc[0]&0xF0) == 0x40) // 64-bit REX prefix
pc++;
else if(pc[0] == 0x66) // 16-bit instruction prefix
pc++;
if(pc[0] == 0xF6 || pc[0] == 0xF7)
gp->sigcode0 = FPE_INTDIV;
}
#endif
// Only push runtime·sigpanic if rip != 0.
// If rip == 0, probably panicked because of a
// call to a nil func. Not pushing that onto sp will
// make the trace look like a call to runtime·sigpanic instead.
// (Otherwise the trace will end at runtime·sigpanic and we
// won't get to see who faulted.)
if(SIG_RIP(info, ctxt) != 0) {
sp = (uintptr*)SIG_RSP(info, ctxt);
if(sizeof(uintreg) > sizeof(uintptr))
*--sp = 0;
*--sp = SIG_RIP(info, ctxt);
SIG_RSP(info, ctxt) = (uintptr)sp;
}
SIG_RIP(info, ctxt) = (uintptr)runtime·sigpanic;
return;
}
if(SIG_CODE0(info, ctxt) == SI_USER || (t->flags & SigNotify))
if(runtime·sigsend(sig))
return;
if(t->flags & SigKill)
runtime·exit(2);
if(!(t->flags & SigThrow))
return;
g->m->throwing = 1;
g->m->caughtsig = gp;
runtime·startpanic();
if(sig < 0 || sig >= NSIG)
runtime·printf("Signal %d\n", sig);
else
runtime·printf("%s\n", runtime·sigtab[sig].name);
runtime·printf("PC=%X\n", SIG_RIP(info, ctxt));
if(g->m->lockedg != nil && g->m->ncgo > 0 && gp == g->m->g0) {
runtime·printf("signal arrived during cgo execution\n");
gp = g->m->lockedg;
}
runtime·printf("\n");
if(runtime·gotraceback(&crash)){
runtime·goroutineheader(gp);
runtime·traceback(SIG_RIP(info, ctxt), SIG_RSP(info, ctxt), 0, gp);
runtime·tracebackothers(gp);
runtime·printf("\n");
runtime·dumpregs(info, ctxt);
}
if(crash)
runtime·crash();
runtime·exit(2);
}
int32
runtime·sighandler(void *v, int8 *s, G *gp)
{
bool crash;
Ureg *ureg;
uintptr *sp;
SigTab *sig, *nsig;
intgo len, i;
if(!s)
return NCONT;
len = runtime·findnull((byte*)s);
if(len <= 4 || runtime·mcmp((byte*)s, (byte*)"sys:", 4) != 0)
return NDFLT;
nsig = nil;
sig = runtime·sigtab;
for(i=0; i < NSIG; i++) {
if(runtime·strstr((byte*)s, (byte*)sig->name)) {
nsig = sig;
break;
}
sig++;
}
if(nsig == nil)
return NDFLT;
ureg = v;
if(nsig->flags & SigPanic) {
if(gp == nil || m->notesig == 0)
goto Throw;
// Copy the error string from sigtramp's stack into m->notesig so
// we can reliably access it from the panic routines. We can't use
// runtime·memmove here since it will use SSE instructions for big
// copies. The Plan 9 kernel doesn't allow floating point in note
// handlers.
//
// TODO(ality): revert back to memmove when the kernel is fixed.
if(len >= ERRMAX)
len = ERRMAX-1;
for(i = 0; i < len; i++)
m->notesig[i] = s[i];
m->notesig[i] = '\0';
gp->sig = i;
gp->sigpc = ureg->pc;
// Only push runtime·sigpanic if ureg->pc != 0.
// If ureg->pc == 0, probably panicked because of a
// call to a nil func. Not pushing that onto sp will
// make the trace look like a call to runtime·sigpanic instead.
// (Otherwise the trace will end at runtime·sigpanic and we
// won't get to see who faulted.)
if(ureg->pc != 0) {
sp = (uintptr*)ureg->sp;
*--sp = ureg->pc;
ureg->sp = (uint32)sp;
}
ureg->pc = (uintptr)runtime·sigpanic;
return NCONT;
}
if(!(nsig->flags & SigThrow))
return NDFLT;
Throw:
m->throwing = 1;
m->caughtsig = gp;
runtime·startpanic();
runtime·printf("%s\n", s);
runtime·printf("PC=%X\n", ureg->pc);
runtime·printf("\n");
if(runtime·gotraceback(&crash)) {
runtime·traceback(ureg->pc, ureg->sp, 0, gp);
runtime·tracebackothers(gp);
runtime·dumpregs(ureg);
}
if(crash)
runtime·crash();
runtime·goexitsall("");
runtime·exits(s);
return 0;
}
void
sighandler(int32 sig, Siginfo* info, void* context)
{
Ucontext *uc;
Mcontext *r;
G *gp;
uintptr *sp;
uc = context;
r = &uc->uc_mcontext;
if((gp = m->curg) != nil && (sigtab[sig].flags & SigPanic)) {
// Make it look like a call to the signal func.
// Have to pass arguments out of band since
// augmenting the stack frame would break
// the unwinding code.
gp->sig = sig;
gp->sigcode0 = info->si_code;
gp->sigcode1 = (uintptr)info->si_addr;
// Only push sigpanic if r->mc_rip != 0.
// If r->mc_rip == 0, probably panicked because of a
// call to a nil func. Not pushing that onto sp will
// make the trace look like a call to sigpanic instead.
// (Otherwise the trace will end at sigpanic and we
// won't get to see who faulted.)
if(r->mc_rip != 0) {
sp = (uintptr*)r->mc_rsp;
*--sp = r->mc_rip;
r->mc_rsp = (uintptr)sp;
}
r->mc_rip = (uintptr)sigpanic;
return;
}
if(sigtab[sig].flags & SigQueue) {
if(sigsend(sig) || (sigtab[sig].flags & SigIgnore))
return;
exit(2); // SIGINT, SIGTERM, etc
}
if(panicking) // traceback already printed
exit(2);
panicking = 1;
if(sig < 0 || sig >= NSIG)
printf("Signal %d\n", sig);
else
printf("%s\n", sigtab[sig].name);
printf("PC=%X\n", r->mc_rip);
printf("\n");
if(gotraceback()){
traceback((void*)r->mc_rip, (void*)r->mc_rsp, 0, (void*)r->mc_r15);
tracebackothers((void*)r->mc_r15);
dumpregs(r);
}
breakpoint();
exit(2);
}
