[webkit-changes] [WebKit/WebKit] 6063bc: Skip JIT memory allocation in ExecutableAllocator:...

[Commit Queue]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 6063bc484b4f523c354231080d5bc2fca0b536f1
      https://github.com/WebKit/WebKit/commit/6063bc484b4f523c354231080d5bc2fca0b536f1
  Author: Mark Lam <mark.lam at apple.com>
  Date:   2023-06-22 (Thu, 22 Jun 2023)

  Changed paths:
    M Source/JavaScriptCore/assembler/CPU.cpp
    M Source/JavaScriptCore/assembler/CPU.h
    M Source/JavaScriptCore/jit/ExecutableAllocator.cpp

  Log Message:
  -----------
  Skip JIT memory allocation in ExecutableAllocator::disableJIT() when running on an open source XNU.
https://bugs.webkit.org/show_bug.cgi?id=258409
rdar://111170164

Reviewed by Yusuke Suzuki.

The open source XNU does not support special handling of JIT memory.  However, macOS Safari and
WebKit binaries still need to be able to run on the open source XNU, albeit without JIT.

However, ExecutableAllocator::disableJIT() is still trying to allocated JIT memory if the JIT
entitlement is present (which is defined by the WebKit binary, not the kernel), and currently,
will assert that the allocation succeeds.  We need to skip this allocation and assertion when
running on open source XNU because the allocation is not necessary, and the assertion is invalid
for the open source kernel and will fail every time.  This patch implements this skipping.

* Source/JavaScriptCore/assembler/CPU.cpp:
(JSC::isKernOpenSource):
* Source/JavaScriptCore/assembler/CPU.h:
* Source/JavaScriptCore/jit/ExecutableAllocator.cpp:
(JSC::ExecutableAllocator::disableJIT):

Canonical link: https://commits.webkit.org/265435@main