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53fd522c0d
Follows suit with https://go-review.googlesource.com/#/c/20111. Generated by running $ grep -R 'Go Authors. All' * | cut -d":" -f1 | while read F;do perl -pi -e 's/Go Authors. All/Go Authors. All/g' $F;done The code in cmd/internal/unvendor wasn't changed. Fixes #15213 Change-Id: I4f235cee0a62ec435f9e8540a1ec08ae03b1a75f Reviewed-on: https://go-review.googlesource.com/21819 Reviewed-by: Ian Lance Taylor <iant@golang.org> Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
108 lines
2 KiB
Go
108 lines
2 KiB
Go
// run
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// Copyright 2014 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Issue 8048. Incorrect handling of liveness when walking stack
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// containing faulting frame.
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package main
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import "runtime"
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func main() {
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test1()
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test2()
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test3()
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}
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func test1() {
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// test1f will panic without its own defer.
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// The runtime.GC checks that we can walk the stack
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// at that point and not get confused.
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// The recover lets test1 exit normally.
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defer func() {
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runtime.GC()
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recover()
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}()
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test1f()
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}
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func test1f() {
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// Because b == false, the if does not execute,
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// so x == nil, so the println(*x) faults reading
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// from nil. The compiler will lay out the code
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// so that the if body occurs above the *x,
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// so if the liveness info at the *x is used, it will
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// find the liveness at the call to runtime.GC.
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// It will think y is live, but y is uninitialized,
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// and the runtime will crash detecting a bad slice.
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// The runtime should see that there are no defers
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// corresponding to this panicked frame and ignore
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// the frame entirely.
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var x *int
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var b bool
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if b {
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y := make([]int, 1)
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runtime.GC()
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x = &y[0]
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}
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println(*x)
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}
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func test2() {
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// Same as test1, but the fault happens in the function with the defer.
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// The runtime should see the defer and garbage collect the frame
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// as if the PC were immediately after the defer statement.
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defer func() {
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runtime.GC()
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recover()
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}()
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var x *int
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var b bool
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if b {
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y := make([]int, 1)
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runtime.GC()
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x = &y[0]
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}
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println(*x)
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}
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func test3() {
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// Like test1 but avoid array index, which does not
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// move to end of function on ARM.
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defer func() {
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runtime.GC()
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recover()
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}()
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test3setup()
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test3f()
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}
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func test3setup() {
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var x uintptr
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var b bool
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b = true
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if b {
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y := uintptr(123)
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runtime.GC()
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x = y
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}
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runtime.GC()
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globl = x
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}
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var globl uintptr
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func test3f() {
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var x *int
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var b bool
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if b {
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y := new(int)
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runtime.GC()
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x = y
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}
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println(*x)
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}
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