• Victor Gomes's avatar
    [heap] Support mprotect off thread · 8a6b7d8b
    Victor Gomes authored
    While compiling concurrently, we change the permissions of the page
    containing the new code object to RWX, so the main thread can continue
    executing a potential code in the same page.
    
    If no thread is compiling the new code, we change the permissions
    of all pages affected back to RX.
    
    We also initialises code object page to immediately RWX by default.
    Otherwise, a new code could be allocated in the same page, it will call
    UnprotectAndRegister, and since write_unprotect_counter_ is now at
    least 2, the code ignores the permission change. We then sigfault
    when trying to run the new code.
    
    Change-Id: Id18bcb9a44843b4ff747b1e4ac91913e80b74d80
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3257606Reviewed-by: 's avatarDominik Inführ <dinfuehr@chromium.org>
    Commit-Queue: Victor Gomes <victorgomes@chromium.org>
    Cr-Commit-Position: refs/heads/main@{#77827}
    8a6b7d8b
memory-allocator.cc 25.6 KB