src/runtime/signal_linux_amd64.go

// 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.

package runtime

import (
	"internal/goarch"
	"unsafe"
)

type sigctxt struct {
	info *siginfo
	ctxt unsafe.Pointer
}

//go:nosplit
//go:nowritebarrierrec
func (c *sigctxt) regs() *sigcontext {
	return (*sigcontext)(unsafe.Pointer(&(*ucontext)(c.ctxt).uc_mcontext))
}

func (c *sigctxt) rax() uint64 { return c.regs().rax }
func (c *sigctxt) rbx() uint64 { return c.regs().rbx }
func (c *sigctxt) rcx() uint64 { return c.regs().rcx }
func (c *sigctxt) rdx() uint64 { return c.regs().rdx }
func (c *sigctxt) rdi() uint64 { return c.regs().rdi }
func (c *sigctxt) rsi() uint64 { return c.regs().rsi }
func (c *sigctxt) rbp() uint64 { return c.regs().rbp }
func (c *sigctxt) rsp() uint64 { return c.regs().rsp }
func (c *sigctxt) r8() uint64  { return c.regs().r8 }
func (c *sigctxt) r9() uint64  { return c.regs().r9 }
func (c *sigctxt) r10() uint64 { return c.regs().r10 }
func (c *sigctxt) r11() uint64 { return c.regs().r11 }
func (c *sigctxt) r12() uint64 { return c.regs().r12 }
func (c *sigctxt) r13() uint64 { return c.regs().r13 }
func (c *sigctxt) r14() uint64 { return c.regs().r14 }
func (c *sigctxt) r15() uint64 { return c.regs().r15 }

//go:nosplit
//go:nowritebarrierrec
func (c *sigctxt) rip() uint64 { return c.regs().rip }

func (c *sigctxt) rflags() uint64  { return c.regs().eflags }
func (c *sigctxt) cs() uint64      { return uint64(c.regs().cs) }
func (c *sigctxt) fs() uint64      { return uint64(c.regs().fs) }
func (c *sigctxt) gs() uint64      { return uint64(c.regs().gs) }
func (c *sigctxt) sigcode() uint64 { return uint64(c.info.si_code) }
func (c *sigctxt) sigaddr() uint64 { return c.info.si_addr }

func (c *sigctxt) set_rip(x uint64)     { c.regs().rip = x }
func (c *sigctxt) set_rsp(x uint64)     { c.regs().rsp = x }
func (c *sigctxt) set_sigcode(x uint64) { c.info.si_code = int32(x) }
func (c *sigctxt) set_sigaddr(x uint64) {
	*(*uintptr)(add(unsafe.Pointer(c.info), 2*goarch.PtrSize)) = uintptr(x)
}

// dumpSigStack prints a signal stack with the context, fpstate pointer field within that context and
// the beginning of the fpstate annotated by C/F/S respectively
func dumpSigStack(s string, sp uintptr, stackhi uintptr, ctx uintptr) {
	println(s)
	println("SP:\t", hex(sp))
	println("ctx:\t", hex(ctx))
	fpfield := ctx + unsafe.Offsetof(ucontext{}.uc_mcontext) + unsafe.Offsetof(mcontext{}.fpregs)
	println("fpfield:\t", hex(fpfield))
	fpbegin := uintptr(unsafe.Pointer((&sigctxt{nil, unsafe.Pointer(ctx)}).regs().fpstate))
	println("fpstate:\t", hex(fpbegin))
	hexdumpWords(sp, stackhi, func(p uintptr, hm hexdumpMarker) {
		switch p {
		case ctx:
			hm.start()
			print("C")
			println()
		case fpfield:
			hm.start()
			print("F")
			println()
		case fpbegin:
			hm.start()
			print("S")
			println()
		}
	})
}