a0a5aeec7b
To enforce W^X for the WebAssembly code space, we want to explore using
Intel memory protection keys for userspace, also known as MPK, PKEYs, or
PKU. Instead of flipping page protection flags with mprotect (which
incurs a high syscall overhead; and which switches flags for the whole
process), with PKU we associate a key with each page once and then
change the permissions of that key with a fast thread-local register
write. That is, this gives both finger-grained permissions (per-thread)
and more performance.
This CL is starts experimenting with PKUs by
(1) adding a flag to turn on prototype PKU support; and if set to true
(2) allocates a protection key once per {WasmCodeManager} in x64 Linux
systems.
This is a partial reland of https://crrev.com/c/2850932, which was
reverted due to an added histogram failing Chromium integration.
Since the histogram (to record PKU support) is independent of the
functionality in this CL, we split it out into its own CL (to come).
R=clemensb@chromium.org
CC=jkummerow@chromium.org
Bug: v8:11714
Change-Id: I67c8679495c55fa51da8243582963649abde660b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2878738
Commit-Queue: Daniel Lehmann <dlehmann@google.com>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74435}
|
||
|---|---|---|
| .github | ||
| build_overrides | ||
| custom_deps | ||
| docs | ||
| gni | ||
| include | ||
| infra | ||
| samples | ||
| src | ||
| test | ||
| testing | ||
| third_party | ||
| tools | ||
| .clang-format | ||
| .clang-tidy | ||
| .editorconfig | ||
| .flake8 | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| .gn | ||
| .vpython | ||
| .ycm_extra_conf.py | ||
| AUTHORS | ||
| BUILD.gn | ||
| CODE_OF_CONDUCT.md | ||
| codereview.settings | ||
| COMMON_OWNERS | ||
| DEPS | ||
| DIR_METADATA | ||
| ENG_REVIEW_OWNERS | ||
| INFRA_OWNERS | ||
| INTL_OWNERS | ||
| LICENSE | ||
| LICENSE.fdlibm | ||
| LICENSE.strongtalk | ||
| LICENSE.v8 | ||
| MIPS_OWNERS | ||
| OWNERS | ||
| PPC_OWNERS | ||
| PRESUBMIT.py | ||
| README.md | ||
| RISCV_OWNERS | ||
| S390_OWNERS | ||
| WATCHLISTS | ||
V8 JavaScript Engine
V8 is Google's open source JavaScript engine.
V8 implements ECMAScript as specified in ECMA-262.
V8 is written in C++ and is used in Google Chrome, the open source browser from Google.
V8 can run standalone, or can be embedded into any C++ application.
V8 Project page: https://v8.dev/docs
Getting the Code
Checkout depot tools, and run
fetch v8
This will checkout V8 into the directory v8 and fetch all of its dependencies.
To stay up to date, run
git pull origin
gclient sync
For fetching all branches, add the following into your remote
configuration in .git/config:
fetch = +refs/branch-heads/*:refs/remotes/branch-heads/*
fetch = +refs/tags/*:refs/tags/*
Contributing
Please follow the instructions mentioned at v8.dev/docs/contribute.