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// Copyright 2012 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 darwin dragonfly freebsd linux netbsd openbsd
package runtime
import "unsafe"
//go:noescape
func sigfwd(fn uintptr, sig uint32, info *siginfo, ctx unsafe.Pointer)
// Determines if the signal should be handled by Go and if not, forwards the
// signal to the handler that was installed before Go's. Returns whether the
// signal was forwarded.
// This is called by the signal handler, and the world may be stopped.
//go:nosplit
//go:nowritebarrierrec
func sigfwdgo(sig uint32, info *siginfo, ctx unsafe.Pointer) bool {
if sig >= uint32(len(sigtable)) {
return false
}
fwdFn := fwdSig[sig]
if !signalsOK {
// The only way we can get here is if we are in a
// library or archive, we installed a signal handler
// at program startup, but the Go runtime has not yet
// been initialized.
if fwdFn == _SIG_DFL {
dieFromSignal(int32(sig))
} else {
sigfwd(fwdFn, sig, info, ctx)
}
return true
}
flags := sigtable[sig].flags
// If there is no handler to forward to, no need to forward.
if fwdFn == _SIG_DFL {
return false
}
// If we aren't handling the signal, forward it.
if flags&_SigHandling == 0 {
sigfwd(fwdFn, sig, info, ctx)
return true
}
// Only forward synchronous signals.
c := &sigctxt{info, ctx}
if c.sigcode() == _SI_USER || flags&_SigPanic == 0 {
return false
}
// Determine if the signal occurred inside Go code. We test that:
// (1) we were in a goroutine (i.e., m.curg != nil), and
// (2) we weren't in CGO (i.e., m.curg.syscallsp == 0).
g := getg()
if g != nil && g.m != nil && g.m.curg != nil && g.m.curg.syscallsp == 0 {
return false
}
// Signal not handled by Go, forward it.
if fwdFn != _SIG_IGN {
sigfwd(fwdFn, sig, info, ctx)
}
return true
}
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