From 8f854244ad5165c4ef9aa5760316b13233514e06 Mon Sep 17 00:00:00 2001 From: Keith Randall Date: Fri, 1 Feb 2019 15:27:53 -0800 Subject: [PATCH] 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 Reviewed-by: Ian Lance Taylor TryBot-Result: Gobot Gobot --- .../compile/internal/ssa/gen/generic.rules | 1 + .../compile/internal/ssa/rewritegeneric.go | 8 ++++---- test/fixedbugs/issue30061.go | 20 +++++++++++++++++++ 3 files changed, 25 insertions(+), 4 deletions(-) create mode 100644 test/fixedbugs/issue30061.go diff --git a/src/cmd/compile/internal/ssa/gen/generic.rules b/src/cmd/compile/internal/ssa/gen/generic.rules index 89fbfdc6bd..61451891a5 100644 --- a/src/cmd/compile/internal/ssa/gen/generic.rules +++ b/src/cmd/compile/internal/ssa/gen/generic.rules @@ -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) diff --git a/src/cmd/compile/internal/ssa/rewritegeneric.go b/src/cmd/compile/internal/ssa/rewritegeneric.go index 79f0fd434a..f2c7529e02 100644 --- a/src/cmd/compile/internal/ssa/rewritegeneric.go +++ b/src/cmd/compile/internal/ssa/rewritegeneric.go @@ -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) diff --git a/test/fixedbugs/issue30061.go b/test/fixedbugs/issue30061.go new file mode 100644 index 0000000000..5092b01799 --- /dev/null +++ b/test/fixedbugs/issue30061.go @@ -0,0 +1,20 @@ +// 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))) +}