// Copyright 2024 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.

//go:build msan

package msan

import (
	"unsafe"
)

const Enabled = true

//go:linkname Read runtime.msanread
func Read(addr unsafe.Pointer, sz uintptr)

//go:linkname Write runtime.msanwrite
func Write(addr unsafe.Pointer, sz uintptr)

// Copyright 2015 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.

//go:build msan && ((linux && (amd64 || arm64 || loong64)) || (freebsd && amd64))

package msan

/*
#cgo CFLAGS: -fsanitize=memory
#cgo LDFLAGS: -fsanitize=memory

#include <stdint.h>
#include <sanitizer/msan_interface.h>

void __msan_read_go(void *addr, uintptr_t sz) {

// Copyright 2015 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.

//go:build msan

package runtime

import (
	"unsafe"
)

// Public memory sanitizer API.

func MSanRead(addr unsafe.Pointer, len int) {
	msanread(addr, uintptr(len))
}

func MSanWrite(addr unsafe.Pointer, len int) {
	msanwrite(addr, uintptr(len))
}

Austin Clements <******@****.***> 1683216807 -0400

		wantErr     bool
		experiments []string
	}{
		{src: "msan.go"},
		{src: "msan2.go"},
		{src: "msan2_cmsan.go"},
		{src: "msan3.go"},
		{src: "msan4.go"},
		{src: "msan5.go"},
		{src: "msan6.go"},
		{src: "msan7.go"},
		{src: "msan8.go"},
		{src: "msan_fail.go", wantErr: true},
		// This may not always fail specifically due to MSAN. It may sometimes

[!GOOS:darwin] [race] ! stderr '-msan'

[msan] ! go install -msan triv.go
[msan] stderr '-msan requires cgo'
[msan] ! stderr '-race'

[asan] ! go install -asan triv.go
[asan] stderr '(-asan: the version of $(go env CC) could not be parsed)|(-asan: C compiler is not gcc or clang)|(-asan is not supported with [A-Za-z]+ compiler (\d+)\.(\d+))|(-asan requires cgo)'
[asan] ! stderr '-msan'

-- triv.go --
package main

//go:build !msan

// Dummy MSan support API, used when not built with -msan.

package runtime

import (
	"unsafe"
)

const msanenabled = false

// Because msanenabled is false, none of these functions should be called.

func msanread(addr unsafe.Pointer, sz uintptr)     { throw("msan") }
func msanwrite(addr unsafe.Pointer, sz uintptr)    { throw("msan") }

        arg->buf[0] = 0;
}

// msanGoWait will be called with all registers undefined as far as
// msan is concerned. It just waits for a signal.
// Because the registers are msan-undefined, the signal handler will
// be invoked with all registers msan-undefined.
__attribute__((noinline))

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package msan contains helper functions for manually instrumenting code
// for the memory sanitizer.
// This package exports the private msan routines in runtime unconditionally
// but without the "msan" build tag they are no-ops.

	x := arena.New[[200]byte](a)
	x[0] = 9
	a.Free()
	// Use after free.
	//
	// ASAN should detect this deterministically as Free
	// should poison the arena memory.
	//
	// MSAN should detect that this access is to freed
	// memory. This may crash with an "accessed freed arena
	// memory" error before MSAN gets a chance, but if MSAN
	// was not enabled there would be a chance that this
	// could fail to crash on its own.