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Diffstat (limited to 'src/pkg/runtime/signal_amd64x.c')
-rw-r--r-- | src/pkg/runtime/signal_amd64x.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/src/pkg/runtime/signal_amd64x.c b/src/pkg/runtime/signal_amd64x.c new file mode 100644 index 000000000..04026f32f --- /dev/null +++ b/src/pkg/runtime/signal_amd64x.c @@ -0,0 +1,156 @@ +// Copyright 2013 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 amd64 amd64p32 +// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris + +#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("rax %X\n", SIG_RAX(info, ctxt)); + runtime·printf("rbx %X\n", SIG_RBX(info, ctxt)); + runtime·printf("rcx %X\n", SIG_RCX(info, ctxt)); + runtime·printf("rdx %X\n", SIG_RDX(info, ctxt)); + runtime·printf("rdi %X\n", SIG_RDI(info, ctxt)); + runtime·printf("rsi %X\n", SIG_RSI(info, ctxt)); + runtime·printf("rbp %X\n", SIG_RBP(info, ctxt)); + runtime·printf("rsp %X\n", SIG_RSP(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("r11 %X\n", SIG_R11(info, ctxt)); + runtime·printf("r12 %X\n", SIG_R12(info, ctxt)); + runtime·printf("r13 %X\n", SIG_R13(info, ctxt)); + runtime·printf("r14 %X\n", SIG_R14(info, ctxt)); + runtime·printf("r15 %X\n", SIG_R15(info, ctxt)); + runtime·printf("rip %X\n", SIG_RIP(info, ctxt)); + runtime·printf("rflags %X\n", SIG_RFLAGS(info, ctxt)); + runtime·printf("cs %X\n", SIG_CS(info, ctxt)); + runtime·printf("fs %X\n", SIG_FS(info, ctxt)); + runtime·printf("gs %X\n", SIG_GS(info, ctxt)); +} + +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, 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; + + 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·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); +} |