go/src/runtime/sigpanic_unix.go

// Copyright 2014 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 solaris

package runtime

func sigpanic() {
	g := getg()
	if !canpanic(g) {
		throw("unexpected signal during runtime execution")
	}

	switch g.sig {
	case _SIGBUS:
		if g.sigcode0 == _BUS_ADRERR && g.sigcode1 < 0x1000 || g.paniconfault {
			panicmem()
		}
		print("unexpected fault address ", hex(g.sigcode1), "\n")
		throw("fault")
	case _SIGSEGV:
		if (g.sigcode0 == 0 || g.sigcode0 == _SEGV_MAPERR || g.sigcode0 == _SEGV_ACCERR) && g.sigcode1 < 0x1000 || g.paniconfault {
			panicmem()
		}
		print("unexpected fault address ", hex(g.sigcode1), "\n")
		throw("fault")
	case _SIGFPE:
		switch g.sigcode0 {
		case _FPE_INTDIV:
			panicdivide()
		case _FPE_INTOVF:
			panicoverflow()
		}
		panicfloat()
	}

	if g.sig >= uint32(len(sigtable)) {
		// can't happen: we looked up g.sig in sigtable to decide to call sigpanic
		throw("unexpected signal value")
	}
	panic(errorString(sigtable[g.sig].name))
}

// setsigsegv is used on darwin/arm{,64} to fake a segmentation fault.
//go:nosplit
func setsigsegv(pc uintptr) {
	g := getg()
	g.sig = _SIGSEGV
	g.sigpc = pc
	g.sigcode0 = _SEGV_MAPERR
	g.sigcode1 = 0 // TODO: emulate si_addr
}