From 109be507377fe7f6e8819ac94041d3fdcdf6fd2f Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 28 Apr 2024 15:18:25 +0200 Subject: Adding upstream version 1.19.8. Signed-off-by: Daniel Baumann --- test/fixedbugs/issue30041.go | 63 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 test/fixedbugs/issue30041.go (limited to 'test/fixedbugs/issue30041.go') diff --git a/test/fixedbugs/issue30041.go b/test/fixedbugs/issue30041.go new file mode 100644 index 0000000..7d8a169 --- /dev/null +++ b/test/fixedbugs/issue30041.go @@ -0,0 +1,63 @@ +// run + +// Copyright 2019 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. + +// Issue 30041: copying results of a reflect-generated +// call on stack should not have write barrier. + +package main + +import ( + "reflect" + "runtime" + "unsafe" +) + +var badPtr uintptr + +var sink []byte + +func init() { + // Allocate large enough to use largeAlloc. + b := make([]byte, 1<<16-1) + sink = b // force heap allocation + // Any space between the object and the end of page is invalid to point to. + badPtr = uintptr(unsafe.Pointer(&b[len(b)-1])) + 1 +} + +type ft func() *int + +var fn ft + +func rf([]reflect.Value) []reflect.Value { + a := reflect.ValueOf((*int)(nil)) + return []reflect.Value{a} +} + +const N = 1000 + +func main() { + fn = reflect.MakeFunc(reflect.TypeOf(fn), rf).Interface().(ft) + + // Keep running GC so the write barrier is on. + go func() { + for i := 0; i < N; i++ { + runtime.GC() + } + }() + + var x [10]uintptr + for i := range x { + x[i] = badPtr + } + for i := 0; i < N; i++ { + runtime.Gosched() + use(x) // prepare bad pointers on stack + fn() + } +} + +//go:noinline +func use([10]uintptr) {} -- cgit v1.2.3