mirror of
https://github.com/golang/go
synced 2024-11-24 20:30:14 -07:00
aa9c1a8f80
When the slice/string length is very large, probably artifically large as in CL 97523, adding BX (length) to R11 (pointer) overflows. As a result, checking DI < R11 yields the wrong result. Since they will be equal when the loop is done, just check DI != R11 instead. Yes, the pointer itself could overflow, but if that happens, something else has gone pretty wrong; not our concern here. Fixes #24187 Change-Id: I2f60fc6ccae739345d01bc80528560726ad4f8c6 Reviewed-on: https://go-review.googlesource.com/97802 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
34 lines
602 B
Go
34 lines
602 B
Go
// +build amd64p32
|
|
// run
|
|
|
|
// Copyright 2018 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 main
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"unsafe"
|
|
)
|
|
|
|
func main() {
|
|
b := make([]byte, 128)
|
|
for i := range b {
|
|
b[i] = 1
|
|
}
|
|
if bytes.IndexByte(b, 0) != -1 {
|
|
panic("found 0")
|
|
}
|
|
for i := range b {
|
|
b[i] = 0
|
|
c := b
|
|
*(*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&c)) + unsafe.Sizeof(uintptr(0)))) = 1<<31 - 1
|
|
if bytes.IndexByte(c, 0) != i {
|
|
panic(fmt.Sprintf("missing 0 at %d\n", i))
|
|
}
|
|
b[i] = 1
|
|
}
|
|
}
|