[webkit-changes] [WebKit/WebKit] 370d7a: IPInt should decode LEB for extended opcodes

[Keith Miller]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 370d7ae576389f08b9d9e4ae477c35dff89e4d08
      https://github.com/WebKit/WebKit/commit/370d7ae576389f08b9d9e4ae477c35dff89e4d08
  Author: Keith Miller <keith_miller at apple.com>
  Date:   2023-09-21 (Thu, 21 Sep 2023)

  Changed paths:
    A JSTests/wasm/stress/non-canonical-extended-ops.js
    M Source/JavaScriptCore/llint/InPlaceInterpreter.asm
    M Source/JavaScriptCore/wasm/WasmFunctionParser.h
    M Source/JavaScriptCore/wasm/WasmIPIntGenerator.cpp

  Log Message:
  -----------
  IPInt should decode LEB for extended opcodes
https://bugs.webkit.org/show_bug.cgi?id=261894

Reviewed by Yusuke Suzuki.

Right now it assumes they are 1 byte, which 99.9% of the time they will be.
It's technically correct, however, to non-canonically encode them as more
than one byte. This patch adds a simple LEB UInt32 decoder to IPInt
and uses it to decode the extended opcode.

* JSTests/wasm/stress/non-canonical-extended-ops.js: Added.
(instance):
* Source/JavaScriptCore/llint/InPlaceInterpreter.asm:
* Source/JavaScriptCore/wasm/WasmFunctionParser.h:
(JSC::Wasm::FunctionParser<Context>::truncSaturated):
* Source/JavaScriptCore/wasm/WasmIPIntGenerator.cpp:
(JSC::Wasm::IPIntGenerator::addMemoryFill):
(JSC::Wasm::IPIntGenerator::addMemoryCopy):
(JSC::Wasm::IPIntGenerator::truncSaturated):

Canonical link: https://commits.webkit.org/268300@main