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| author | Richard Musiol <mail@richard-musiol.de> | 2018-05-07 16:18:19 +0200 |
|---|---|---|
| committer | Cherry Zhang <cherryyz@google.com> | 2018-05-10 12:05:17 +0000 |
| commit | bf23a4e61ddceb26744da8f462ce6351fca66089 (patch) | |
| tree | d8729a64a59e3d2b0fcbea43ff1a6239bb26e594 /src/cmd/internal/obj | |
| parent | 10529a01fd8b0d5cc07eb3f6aa00a0272597684b (diff) | |
| download | go-bf23a4e61ddceb26744da8f462ce6351fca66089.tar.xz | |
cmd/internal/obj/wasm: avoid invalid offsets for Load/Store
Offsets for Load and Store instructions have type i32. Bad index
expression offsets can cause an offset to be larger than MaxUint32,
which is not allowed. One example for this is the test test/index0.go.
Generate valid code by adding a guard to the responsible rewrite rule.
Also emit a proper error when using such a bad index in assembly code.
Change-Id: Ie90adcbf3ae3861c26680eb81790f28692913ccf
Reviewed-on: https://go-review.googlesource.com/111955
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Diffstat (limited to 'src/cmd/internal/obj')
| -rw-r--r-- | src/cmd/internal/obj/wasm/wasmobj.go | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/cmd/internal/obj/wasm/wasmobj.go b/src/cmd/internal/obj/wasm/wasmobj.go index 2b7e12a93f..ca09b3fa0b 100644 --- a/src/cmd/internal/obj/wasm/wasmobj.go +++ b/src/cmd/internal/obj/wasm/wasmobj.go @@ -870,6 +870,9 @@ func assemble(ctxt *obj.Link, s *obj.LSym, newprog obj.ProgAlloc) { if p.From.Type != obj.TYPE_CONST { panic("bad type for *Load") } + if p.From.Offset > math.MaxUint32 { + ctxt.Diag("bad offset in %v", p) + } writeUleb128(w, align(p.As)) writeUleb128(w, uint64(p.From.Offset)) @@ -877,6 +880,9 @@ func assemble(ctxt *obj.Link, s *obj.LSym, newprog obj.ProgAlloc) { if p.To.Offset < 0 { panic("negative offset") } + if p.From.Offset > math.MaxUint32 { + ctxt.Diag("bad offset in %v", p) + } writeUleb128(w, align(p.As)) writeUleb128(w, uint64(p.To.Offset)) |