Plan 9 from Bell Labs’s /usr/web/sources/contrib/stallion/root/arm/go/src/runtime/signal_386.go

Copyright © 2021 Plan 9 Foundation.
Distributed under the MIT License.
Download the Plan 9 distribution.


// Copyright 2013 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 nacl netbsd openbsd

package runtime

import (
	"runtime/internal/sys"
	"unsafe"
)

func dumpregs(c *sigctxt) {
	print("eax    ", hex(c.eax()), "\n")
	print("ebx    ", hex(c.ebx()), "\n")
	print("ecx    ", hex(c.ecx()), "\n")
	print("edx    ", hex(c.edx()), "\n")
	print("edi    ", hex(c.edi()), "\n")
	print("esi    ", hex(c.esi()), "\n")
	print("ebp    ", hex(c.ebp()), "\n")
	print("esp    ", hex(c.esp()), "\n")
	print("eip    ", hex(c.eip()), "\n")
	print("eflags ", hex(c.eflags()), "\n")
	print("cs     ", hex(c.cs()), "\n")
	print("fs     ", hex(c.fs()), "\n")
	print("gs     ", hex(c.gs()), "\n")
}

//go:nosplit
//go:nowritebarrierrec
func (c *sigctxt) sigpc() uintptr { return uintptr(c.eip()) }

func (c *sigctxt) sigsp() uintptr { return uintptr(c.esp()) }
func (c *sigctxt) siglr() uintptr { return 0 }
func (c *sigctxt) fault() uintptr { return uintptr(c.sigaddr()) }

// preparePanic sets up the stack to look like a call to sigpanic.
func (c *sigctxt) preparePanic(sig uint32, gp *g) {
	if GOOS == "darwin" {
		// Work around Leopard bug that doesn't set FPE_INTDIV.
		// Look at instruction to see if it is a divide.
		// Not necessary in Snow Leopard (si_code will be != 0).
		if sig == _SIGFPE && gp.sigcode0 == 0 {
			pc := (*[4]byte)(unsafe.Pointer(gp.sigpc))
			i := 0
			if pc[i] == 0x66 { // 16-bit instruction prefix
				i++
			}
			if pc[i] == 0xF6 || pc[i] == 0xF7 {
				gp.sigcode0 = _FPE_INTDIV
			}
		}
	}

	pc := uintptr(c.eip())
	sp := uintptr(c.esp())

	if shouldPushSigpanic(gp, pc, *(*uintptr)(unsafe.Pointer(sp))) {
		// Make it look like the faulting PC called sigpanic.
		if sys.RegSize > sys.PtrSize {
			sp -= sys.PtrSize
			*(*uintptr)(unsafe.Pointer(sp)) = 0
		}
		sp -= sys.PtrSize
		*(*uintptr)(unsafe.Pointer(sp)) = pc
		c.set_esp(uint32(sp))
	}
	c.set_eip(uint32(funcPC(sigpanic)))
}

Bell Labs OSI certified Powered by Plan 9

(Return to Plan 9 Home Page)

Copyright © 2021 Plan 9 Foundation. All Rights Reserved.
Comments to [email protected].