1 // Copyright 2014 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // +build linux darwin 6 7 package runtime 8 9 import "unsafe" 10 11 func dumpregs(c *sigctxt) { 12 print("r0 ", hex(c.r0()), "\n") 13 print("r1 ", hex(c.r1()), "\n") 14 print("r2 ", hex(c.r2()), "\n") 15 print("r3 ", hex(c.r3()), "\n") 16 print("r4 ", hex(c.r4()), "\n") 17 print("r5 ", hex(c.r5()), "\n") 18 print("r6 ", hex(c.r6()), "\n") 19 print("r7 ", hex(c.r7()), "\n") 20 print("r8 ", hex(c.r8()), "\n") 21 print("r9 ", hex(c.r9()), "\n") 22 print("r10 ", hex(c.r10()), "\n") 23 print("r11 ", hex(c.r11()), "\n") 24 print("r12 ", hex(c.r12()), "\n") 25 print("r13 ", hex(c.r13()), "\n") 26 print("r14 ", hex(c.r14()), "\n") 27 print("r15 ", hex(c.r15()), "\n") 28 print("r16 ", hex(c.r16()), "\n") 29 print("r17 ", hex(c.r17()), "\n") 30 print("r18 ", hex(c.r18()), "\n") 31 print("r19 ", hex(c.r19()), "\n") 32 print("r20 ", hex(c.r20()), "\n") 33 print("r21 ", hex(c.r21()), "\n") 34 print("r22 ", hex(c.r22()), "\n") 35 print("r23 ", hex(c.r23()), "\n") 36 print("r24 ", hex(c.r24()), "\n") 37 print("r25 ", hex(c.r25()), "\n") 38 print("r26 ", hex(c.r26()), "\n") 39 print("r27 ", hex(c.r27()), "\n") 40 print("r28 ", hex(c.r28()), "\n") 41 print("r29 ", hex(c.r29()), "\n") 42 print("lr ", hex(c.lr()), "\n") 43 print("sp ", hex(c.sp()), "\n") 44 print("pc ", hex(c.pc()), "\n") 45 print("fault ", hex(c.fault()), "\n") 46 } 47 48 var crashing int32 49 50 // May run during STW, so write barriers are not allowed. 51 //go:nowritebarrier 52 func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) { 53 _g_ := getg() 54 c := &sigctxt{info, ctxt} 55 56 if sig == _SIGPROF { 57 sigprof(uintptr(c.pc()), uintptr(c.sp()), uintptr(c.lr()), gp, _g_.m) 58 return 59 } 60 61 flags := int32(_SigThrow) 62 if sig < uint32(len(sigtable)) { 63 flags = sigtable[sig].flags 64 } 65 if c.sigcode() != _SI_USER && flags&_SigPanic != 0 { 66 // Make it look like a call to the signal func. 67 // Have to pass arguments out of band since 68 // augmenting the stack frame would break 69 // the unwinding code. 70 gp.sig = sig 71 gp.sigcode0 = uintptr(c.sigcode()) 72 gp.sigcode1 = uintptr(c.fault()) 73 gp.sigpc = uintptr(c.pc()) 74 75 // We arrange lr, and pc to pretend the panicking 76 // function calls sigpanic directly. 77 // Always save LR to stack so that panics in leaf 78 // functions are correctly handled. This smashes 79 // the stack frame but we're not going back there 80 // anyway. 81 sp := c.sp() - spAlign // needs only sizeof uint64, but must align the stack 82 c.set_sp(sp) 83 *(*uint64)(unsafe.Pointer(uintptr(sp))) = c.lr() 84 85 pc := uintptr(gp.sigpc) 86 87 // If we don't recognize the PC as code 88 // but we do recognize the link register as code, 89 // then assume this was a call to non-code and treat like 90 // pc == 0, to make unwinding show the context. 91 if pc != 0 && findfunc(pc) == nil && findfunc(uintptr(c.lr())) != nil { 92 pc = 0 93 } 94 95 // Don't bother saving PC if it's zero, which is 96 // probably a call to a nil func: the old link register 97 // is more useful in the stack trace. 98 if pc != 0 { 99 c.set_lr(uint64(pc)) 100 } 101 102 // In case we are panicking from external C code 103 c.set_r28(uint64(uintptr(unsafe.Pointer(gp)))) 104 c.set_pc(uint64(funcPC(sigpanic))) 105 return 106 } 107 108 if c.sigcode() == _SI_USER || flags&_SigNotify != 0 { 109 if sigsend(sig) { 110 return 111 } 112 } 113 114 if flags&_SigKill != 0 { 115 exit(2) 116 } 117 118 if flags&_SigThrow == 0 { 119 return 120 } 121 122 _g_.m.throwing = 1 123 _g_.m.caughtsig.set(gp) 124 125 if crashing == 0 { 126 startpanic() 127 } 128 129 if sig < uint32(len(sigtable)) { 130 print(sigtable[sig].name, "\n") 131 } else { 132 print("Signal ", sig, "\n") 133 } 134 135 print("PC=", hex(c.pc()), " m=", _g_.m.id, "\n") 136 if _g_.m.lockedg != nil && _g_.m.ncgo > 0 && gp == _g_.m.g0 { 137 print("signal arrived during cgo execution\n") 138 gp = _g_.m.lockedg 139 } 140 print("\n") 141 142 var docrash bool 143 if gotraceback(&docrash) > 0 { 144 goroutineheader(gp) 145 tracebacktrap(uintptr(c.pc()), uintptr(c.sp()), uintptr(c.lr()), gp) 146 if crashing > 0 && gp != _g_.m.curg && _g_.m.curg != nil && readgstatus(_g_.m.curg)&^_Gscan == _Grunning { 147 // tracebackothers on original m skipped this one; trace it now. 148 goroutineheader(_g_.m.curg) 149 traceback(^uintptr(0), ^uintptr(0), 0, gp) 150 } else if crashing == 0 { 151 tracebackothers(gp) 152 print("\n") 153 } 154 dumpregs(c) 155 } 156 157 if docrash { 158 crashing++ 159 if crashing < sched.mcount { 160 // There are other m's that need to dump their stacks. 161 // Relay SIGQUIT to the next m by sending it to the current process. 162 // All m's that have already received SIGQUIT have signal masks blocking 163 // receipt of any signals, so the SIGQUIT will go to an m that hasn't seen it yet. 164 // When the last m receives the SIGQUIT, it will fall through to the call to 165 // crash below. Just in case the relaying gets botched, each m involved in 166 // the relay sleeps for 5 seconds and then does the crash/exit itself. 167 // In expected operation, the last m has received the SIGQUIT and run 168 // crash/exit and the process is gone, all long before any of the 169 // 5-second sleeps have finished. 170 print("\n-----\n\n") 171 raiseproc(_SIGQUIT) 172 usleep(5 * 1000 * 1000) 173 } 174 crash() 175 } 176 177 exit(2) 178 } 179
