8218c06158
We sometimes hit the DCHECK in the wasm code manager: DCHECK_IMPLIES(writable, !MemoryProtectionKeyWritable()); This is because we spawn new threads while having a {CodeSpaceWriteScope} open. In the case of PKU, this changes the PKRU register to allow writes to the code space, and the value of that register is inherited by any new thread. If this thread then tries to switch to writable code spaces, it hits the DCHECK. It would hit a similar DCHECK when trying to execute code. We fix this issue by temporarily resetting the PKRU register to non-writable while we call the {NotifyConcurrencyIncrease} method. This is not a very robust solution, as any new call that potentially happens inside a {CodeSpaceWriteScope} needs to do the same, but refactoring the code to avoid spawning new threads while being in writable state would be a lot of work with other downsides. R=jkummerow@chromium.org Bug: v8:13075 Change-Id: Ibc7270aa597902dc6d9649cb6bcdfce8b1a9bafc Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3762579 Commit-Queue: Clemens Backes <clemensb@chromium.org> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Cr-Commit-Position: refs/heads/main@{#81729} |
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include | ||
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samples | ||
src | ||
test | ||
testing | ||
third_party | ||
tools | ||
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AUTHORS | ||
BUILD.bazel | ||
BUILD.gn | ||
CODE_OF_CONDUCT.md | ||
codereview.settings | ||
COMMON_OWNERS | ||
DEPS | ||
DIR_METADATA | ||
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LICENSE | ||
LICENSE.fdlibm | ||
LICENSE.strongtalk | ||
LICENSE.v8 | ||
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MIPS_OWNERS | ||
OWNERS | ||
PPC_OWNERS | ||
PRESUBMIT.py | ||
README.md | ||
RISCV_OWNERS | ||
S390_OWNERS | ||
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WORKSPACE |
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.