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deps: V8: cherry-pick 0c8b6e415c30
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Original commit message:

    [mac][wasm] Work around MacOS 11.2 code page decommit failures

    MacOS 11.2 refuses to set "no access" permissions on memory that
    we previously used for JIT-compiled code. It is still unclear
    whether this is WAI on the part of the kernel. In the meantime,
    as a workaround, we use madvise(..., MADV_FREE_REUSABLE) instead
    of mprotect(..., NONE) when discarding code pages. This is inspired
    by what Chromium's gin platform does.

    Fixed: v8:11389
    Change-Id: I866586932573b4253002436ae5eee4e0411c45fc
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2679688
    Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
    Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
    Auto-Submit: Jakob Kummerow <jkummerow@chromium.org>
    Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#72559}

Backport-PR-URL: #38051
Co-authored-by: BoHong Li <a60814billy@gmail.com>

Refs: v8/v8@0c8b6e4
Fixes: #37061
PR-URL: #37276
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Ash Cripps <acripps@redhat.com>
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matinzd authored and targos committed Apr 11, 2021
1 parent db04ae6 commit 5707ada
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2 changes: 1 addition & 1 deletion common.gypi
Expand Up @@ -36,7 +36,7 @@

# Reset this number to 0 on major V8 upgrades.
# Increment by one for each non-official patch applied to deps/v8.
'v8_embedder_string': '-node.24',
'v8_embedder_string': '-node.25',

##### V8 defaults for Node.js #####

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10 changes: 10 additions & 0 deletions deps/v8/src/base/platform/platform-posix.cc
Expand Up @@ -390,6 +390,16 @@ bool OS::SetPermissions(void* address, size_t size, MemoryPermission access) {

int prot = GetProtectionFromMemoryPermission(access);
int ret = mprotect(address, size, prot);

// MacOS 11.2 on Apple Silicon refuses to switch permissions from
// rwx to none. Just use madvise instead.
#if defined(V8_OS_MACOSX)
if (ret != 0 && access == OS::MemoryPermission::kNoAccess) {
ret = madvise(address, size, MADV_FREE_REUSABLE);
return ret == 0;
}
#endif

if (ret == 0 && access == OS::MemoryPermission::kNoAccess) {
// This is advisory; ignore errors and continue execution.
USE(DiscardSystemPages(address, size));
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