1// Copyright 2016 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 aix darwin dragonfly freebsd hurd linux netbsd openbsd solaris 6 7package runtime 8 9import ( 10 "unsafe" 11) 12 13// Functions for gccgo to support signal handling. In the gc runtime 14// these are written in OS-specific files and in assembler. 15 16//go:noescape 17//extern sigaction 18func sigaction(signum uint32, act *_sigaction, oact *_sigaction) int32 19 20//go:noescape 21//extern sigprocmask 22func sigprocmask(how int32, set *sigset, oldset *sigset) int32 23 24//go:noescape 25//extern sigfillset 26func sigfillset(set *sigset) int32 27 28//go:noescape 29//extern sigemptyset 30func sigemptyset(set *sigset) int32 31 32//go:noescape 33//extern sigaddset 34func c_sigaddset(set *sigset, signum uint32) int32 35 36//go:noescape 37//extern sigdelset 38func c_sigdelset(set *sigset, signum uint32) int32 39 40//go:noescape 41//extern sigaltstack 42func sigaltstack(ss *_stack_t, oss *_stack_t) int32 43 44//extern raise 45func raise(sig uint32) int32 46 47//extern getpid 48func getpid() _pid_t 49 50//extern kill 51func kill(pid _pid_t, sig uint32) int32 52 53//go:noescape 54//extern setitimer 55func setitimer(which int32, new *_itimerval, old *_itimerval) int32 56 57type sigctxt struct { 58 info *_siginfo_t 59 ctxt unsafe.Pointer 60} 61 62func (c *sigctxt) sigcode() uint64 { 63 return uint64(getSiginfoCode(c.info)) 64} 65 66//go:nosplit 67//go:nowritebarrierrec 68func setsig(i uint32, fn uintptr) { 69 var sa _sigaction 70 sa.sa_flags = _SA_SIGINFO | _SA_RESTART 71 72 // For gccgo we do not set SA_ONSTACK for a signal that can 73 // cause a panic. Instead, we trust that the split stack has 74 // enough room to start the signal handler. This is because 75 // otherwise we have no good way to switch back to the 76 // original stack before panicing. 77 if sigtable[i].flags&_SigPanic == 0 { 78 sa.sa_flags |= _SA_ONSTACK 79 } 80 81 sigfillset((*sigset)(unsafe.Pointer(&sa.sa_mask))) 82 setSigactionHandler(&sa, fn) 83 sigaction(i, &sa, nil) 84} 85 86//go:nosplit 87//go:nowritebarrierrec 88func setsigstack(i uint32) { 89 var sa _sigaction 90 sigaction(i, nil, &sa) 91 handler := getSigactionHandler(&sa) 92 if handler == 0 || handler == _SIG_DFL || handler == _SIG_IGN || sa.sa_flags&_SA_ONSTACK != 0 { 93 return 94 } 95 if sigtable[i].flags&_SigPanic != 0 { 96 return 97 } 98 sa.sa_flags |= _SA_ONSTACK 99 sigaction(i, &sa, nil) 100} 101 102//go:nosplit 103//go:nowritebarrierrec 104func getsig(i uint32) uintptr { 105 var sa _sigaction 106 if sigaction(i, nil, &sa) < 0 { 107 // On GNU/Linux glibc rejects attempts to call 108 // sigaction with signal 32 (SIGCANCEL) or 33 (SIGSETXID). 109 if GOOS == "linux" && (i == 32 || i == 33) { 110 return _SIG_DFL 111 } 112 throw("sigaction read failure") 113 } 114 return getSigactionHandler(&sa) 115} 116 117func signalstack(p unsafe.Pointer, n uintptr) 118 119//go:nosplit 120//go:nowritebarrierrec 121func raiseproc(sig uint32) { 122 kill(getpid(), sig) 123} 124 125//go:nosplit 126//go:nowritebarrierrec 127func sigfwd(fn uintptr, sig uint32, info *_siginfo_t, ctx unsafe.Pointer) { 128 f1 := [1]uintptr{fn} 129 f2 := &f1 130 f3 := *(*func(uint32, *_siginfo_t, unsafe.Pointer))(unsafe.Pointer(&f2)) 131 f3(sig, info, ctx) 132} 133 134//go:nosplit 135//go:nowritebarrierrec 136func sigaddset(mask *sigset, i int) { 137 c_sigaddset(mask, uint32(i)) 138} 139 140func sigdelset(mask *sigset, i int) { 141 c_sigdelset(mask, uint32(i)) 142} 143