go/test/fixedbugs/issue14636.go
Rhys Hiltner 3375974e0d cmd/link/internal/ld: don't panic on short buildid
When the linker was written in C, command line arguments were passed
around as null-terminated byte arrays which encouraged checking
characters one at a time. In Go, that can easily lead to
out-of-bounds panics.

Use the more idiomatic strings.HasPrefix when checking cmd/link's -B
argument to avoid the panic, and replace the manual hex decode with
use of the encoding/hex package.

Fixes #14636

Change-Id: I45f765bbd8cf796fee1a9a3496178bf76b117827
Reviewed-on: https://go-review.googlesource.com/20211
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-03-04 21:20:09 +00:00

44 lines
1.2 KiB
Go

// +build !nacl,!android,!darwin darwin,!arm
// run
// Copyright 2016 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"
"log"
"os/exec"
"strings"
)
func main() {
checkLinkOutput("", "-B argument must start with 0x")
checkLinkOutput("0", "-B argument must start with 0x")
checkLinkOutput("0x", "usage")
checkLinkOutput("0x0", "-B argument must have even number of digits")
checkLinkOutput("0x00", "usage")
checkLinkOutput("0xYZ", "-B argument contains invalid hex digit")
checkLinkOutput("0x"+strings.Repeat("00", 32), "usage")
checkLinkOutput("0x"+strings.Repeat("00", 33), "-B option too long (max 32 digits)")
}
func checkLinkOutput(buildid string, message string) {
cmd := exec.Command("go", "tool", "link", "-B", buildid)
out, err := cmd.CombinedOutput()
if err == nil {
log.Fatalf("expected cmd/link to fail")
}
firstLine := string(bytes.SplitN(out, []byte("\n"), 2)[0])
if strings.HasPrefix(firstLine, "panic") {
log.Fatalf("cmd/link panicked:\n%s", out)
}
if !strings.Contains(firstLine, message) {
log.Fatalf("cmd/link output did not include expected message %q: %s", message, firstLine)
}
}