• Georgia Kouveli's avatar
    [arm64] Fix CFI issue with short builtin calls · fb235844
    Georgia Kouveli authored
    The allowlist used for `Deoptimizer::IsValidReturnAddress` depends on
    fixed embedded builtin addresses. Pass a pointer to the isolate to
    this method, so that it can discover the actual builtin code start
    (which may have been remapped) and calculate the offset from the start
    of the builtins' code in order to check if the return address is
    allowed.
    
    After this change, do not disable short builtin calls when CFI is
    enabled.
    
    There's an important TODO for this change:
    Since the builtin code pointer that's used to check whether a return
    address is allowed is now writable, we should use pointer authentication
    to protect it.
    
    Bug: v8:10026
    Change-Id: Iafd31d3ad7e10cb17faf33e76e78d3df36edeefd
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3667506Reviewed-by: 's avatarToon Verwaest <verwaest@chromium.org>
    Reviewed-by: 's avatarIgor Sheludko <ishell@chromium.org>
    Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
    Cr-Commit-Position: refs/heads/main@{#81049}
    fb235844