| // 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); |
| } |