root/src/pkg/runtime/signal_arm.c

DEFINITIONS

1. runtime·dumpregs
2. runtime·sighandler

// 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.

// +build darwin dragonfly freebsd linux netbsd openbsd

#include "runtime.h"
#include "defs_GOOS_GOARCH.h"
#include "os_GOOS.h"
#include "signal_GOOS_GOARCH.h"
#include "signals_GOOS.h"

void
runtime·dumpregs(Siginfo *info, void *ctxt)
{
        USED(info);
        USED(ctxt);

        runtime·printf("trap    %x\n", SIG_TRAP(info, ctxt));
        runtime·printf("error   %x\n", SIG_ERROR(info, ctxt));
        runtime·printf("oldmask %x\n", SIG_OLDMASK(info, ctxt));
        runtime·printf("r0      %x\n", SIG_R0(info, ctxt));
        runtime·printf("r1      %x\n", SIG_R1(info, ctxt));
        runtime·printf("r2      %x\n", SIG_R2(info, ctxt));
        runtime·printf("r3      %x\n", SIG_R3(info, ctxt));
        runtime·printf("r4      %x\n", SIG_R4(info, ctxt));
        runtime·printf("r5      %x\n", SIG_R5(info, ctxt));
        runtime·printf("r6      %x\n", SIG_R6(info, ctxt));
        runtime·printf("r7      %x\n", SIG_R7(info, ctxt));
        runtime·printf("r8      %x\n", SIG_R8(info, ctxt));
        runtime·printf("r9      %x\n", SIG_R9(info, ctxt));
        runtime·printf("r10     %x\n", SIG_R10(info, ctxt));
        runtime·printf("fp      %x\n", SIG_FP(info, ctxt));
        runtime·printf("ip      %x\n", SIG_IP(info, ctxt));
        runtime·printf("sp      %x\n", SIG_SP(info, ctxt));
        runtime·printf("lr      %x\n", SIG_LR(info, ctxt));
        runtime·printf("pc      %x\n", SIG_PC(info, ctxt));
        runtime·printf("cpsr    %x\n", SIG_CPSR(info, ctxt));
        runtime·printf("fault   %x\n", SIG_FAULT(info, ctxt));
}

void
runtime·sighandler(int32 sig, Siginfo *info, void *ctxt, G *gp)
{
        SigTab *t;
        bool crash;

        if(sig == SIGPROF) {
                runtime·sigprof((uint8*)SIG_PC(info, ctxt), (uint8*)SIG_SP(info, ctxt), (uint8*)SIG_LR(info, ctxt), gp, m);
                return;
        }

        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_FAULT(info, ctxt);
                gp->sigpc = SIG_PC(info, ctxt);

                // 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.
                SIG_SP(info, ctxt) -= 4;
                *(uint32*)SIG_SP(info, ctxt) = SIG_LR(info, ctxt);
                // 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(gp->sigpc != 0)
                        SIG_LR(info, ctxt) = gp->sigpc;
                // In case we are panicking from external C code
                SIG_R10(info, ctxt) = (uintptr)gp;
                SIG_R9(info, ctxt) = (uintptr)m;
                SIG_PC(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;

        m->throwing = 1;
        m->caughtsig = gp;
        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", SIG_PC(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·goroutineheader(gp);
                runtime·traceback(SIG_PC(info, ctxt), SIG_SP(info, ctxt), SIG_LR(info, ctxt), gp);
                runtime·tracebackothers(gp);
                runtime·printf("\n");
                runtime·dumpregs(info, ctxt);
        }
        
        if(crash)
                runtime·crash();

        runtime·exit(2);
}