Commit 8f854244 authored by Keith Randall's avatar Keith Randall Committed by Keith Randall

cmd/compile: fix crash when memmove argument is not the right type

Make sure the argument to memmove is of pointer type before we try to
get the element type.

This has been noticed for code that uses unsafe+linkname so it can
call runtime.memmove. Probably not the best thing to allow, but the
code is out there and we'd rather not break it unnecessarily.

Fixes #30061

Change-Id: I334a8453f2e293959fd742044c43fbe93f0b3d31
Reviewed-on: https://go-review.googlesource.com/c/160826
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: default avatarIan Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
parent 7e987b7b
......@@ -1354,6 +1354,7 @@
// Inline small or disjoint runtime.memmove calls with constant length.
(StaticCall {sym} s1:(Store _ (Const(64|32) [sz]) s2:(Store _ src s3:(Store {t} _ dst mem))))
&& isSameSym(sym,"runtime.memmove")
&& t.(*types.Type).IsPtr() // avoids TUINTPTR, see issue 30061
&& s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1
&& isInlinableMemmove(dst,src,sz,config)
&& clobber(s1) && clobber(s2) && clobber(s3)
......
......@@ -27397,7 +27397,7 @@ func rewriteValuegeneric_OpStaticCall_0(v *Value) bool {
config := b.Func.Config
_ = config
// match: (StaticCall {sym} s1:(Store _ (Const64 [sz]) s2:(Store _ src s3:(Store {t} _ dst mem))))
// cond: isSameSym(sym,"runtime.memmove") && s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1 && isInlinableMemmove(dst,src,sz,config) && clobber(s1) && clobber(s2) && clobber(s3)
// cond: isSameSym(sym,"runtime.memmove") && t.(*types.Type).IsPtr() && s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1 && isInlinableMemmove(dst,src,sz,config) && clobber(s1) && clobber(s2) && clobber(s3)
// result: (Move {t.(*types.Type).Elem()} [sz] dst src mem)
for {
sym := v.Aux
......@@ -27425,7 +27425,7 @@ func rewriteValuegeneric_OpStaticCall_0(v *Value) bool {
_ = s3.Args[2]
dst := s3.Args[1]
mem := s3.Args[2]
if !(isSameSym(sym, "runtime.memmove") && s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1 && isInlinableMemmove(dst, src, sz, config) && clobber(s1) && clobber(s2) && clobber(s3)) {
if !(isSameSym(sym, "runtime.memmove") && t.(*types.Type).IsPtr() && s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1 && isInlinableMemmove(dst, src, sz, config) && clobber(s1) && clobber(s2) && clobber(s3)) {
break
}
v.reset(OpMove)
......@@ -27437,7 +27437,7 @@ func rewriteValuegeneric_OpStaticCall_0(v *Value) bool {
return true
}
// match: (StaticCall {sym} s1:(Store _ (Const32 [sz]) s2:(Store _ src s3:(Store {t} _ dst mem))))
// cond: isSameSym(sym,"runtime.memmove") && s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1 && isInlinableMemmove(dst,src,sz,config) && clobber(s1) && clobber(s2) && clobber(s3)
// cond: isSameSym(sym,"runtime.memmove") && t.(*types.Type).IsPtr() && s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1 && isInlinableMemmove(dst,src,sz,config) && clobber(s1) && clobber(s2) && clobber(s3)
// result: (Move {t.(*types.Type).Elem()} [sz] dst src mem)
for {
sym := v.Aux
......@@ -27465,7 +27465,7 @@ func rewriteValuegeneric_OpStaticCall_0(v *Value) bool {
_ = s3.Args[2]
dst := s3.Args[1]
mem := s3.Args[2]
if !(isSameSym(sym, "runtime.memmove") && s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1 && isInlinableMemmove(dst, src, sz, config) && clobber(s1) && clobber(s2) && clobber(s3)) {
if !(isSameSym(sym, "runtime.memmove") && t.(*types.Type).IsPtr() && s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1 && isInlinableMemmove(dst, src, sz, config) && clobber(s1) && clobber(s2) && clobber(s3)) {
break
}
v.reset(OpMove)
......
// compile
// 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.
// Make sure we can linkname to memmove with an unsafe.Pointer argument.
package p
import "unsafe"
//go:linkname memmove runtime.memmove
func memmove(to, from unsafe.Pointer, n uintptr)
var V1, V2 int
func F() {
memmove(unsafe.Pointer(&V1), unsafe.Pointer(&V2), unsafe.Sizeof(int(0)))
}
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