github.com/4ad/go@v0.0.0-20161219182952-69a12818b605/src/runtime/signal_sigtramp.go (about) 1 // Copyright 2009 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 dragonfly linux netbsd 6 7 package runtime 8 9 import "unsafe" 10 11 // Continuation of the (assembly) sigtramp() logic. 12 // This may be called with the world stopped. 13 //go:nosplit 14 //go:nowritebarrierrec 15 func sigtrampgo(sig uint32, info *siginfo, ctx unsafe.Pointer) { 16 if sigfwdgo(sig, info, ctx) { 17 return 18 } 19 g := getg() 20 if g == nil { 21 if sig == _SIGPROF { 22 // Ignore profiling signals that arrive on 23 // non-Go threads. On some systems they will 24 // be handled directly by the signal handler, 25 // by calling sigprofNonGo, in which case we won't 26 // get here anyhow. 27 return 28 } 29 badsignal(uintptr(sig), &sigctxt{info, ctx}) 30 return 31 } 32 33 // If some non-Go code called sigaltstack, adjust. 34 sp := uintptr(unsafe.Pointer(&sig)) 35 if sp < g.m.gsignal.stack.lo || sp >= g.m.gsignal.stack.hi { 36 var st sigaltstackt 37 sigaltstack(nil, &st) 38 if st.ss_flags&_SS_DISABLE != 0 { 39 setg(nil) 40 cgocallback(unsafe.Pointer(funcPC(noSignalStack)), noescape(unsafe.Pointer(&sig)), unsafe.Sizeof(sig), 0) 41 } 42 stsp := uintptr(unsafe.Pointer(st.ss_sp)) 43 if sp < stsp || sp >= stsp+st.ss_size { 44 setg(nil) 45 cgocallback(unsafe.Pointer(funcPC(sigNotOnStack)), noescape(unsafe.Pointer(&sig)), unsafe.Sizeof(sig), 0) 46 } 47 g.m.gsignal.stack.lo = stsp 48 g.m.gsignal.stack.hi = stsp + st.ss_size 49 g.m.gsignal.stackguard0 = stsp + _StackGuard 50 g.m.gsignal.stackguard1 = stsp + _StackGuard 51 g.m.gsignal.stackAlloc = st.ss_size 52 g.m.gsignal.stktopsp = getcallersp(unsafe.Pointer(&sig)) 53 } 54 55 setg(g.m.gsignal) 56 sighandler(sig, info, ctx, g) 57 setg(g) 58 }