chore: cherry-pick 0c8b6e41 from v8 (#27672)

* chore: cherry-pick 0c8b6e41 from v8

Backports https://chromium-review.googlesource.com/c/v8/v8/+/2679688

* update patches

Co-authored-by: Electron Bot <electron@github.com>
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Robo 2021-02-09 09:21:49 -08:00 committed by GitHub
parent af4a050a1b
commit 44460e84c0
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2 changed files with 43 additions and 0 deletions

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@ -8,3 +8,4 @@ do_not_export_private_v8_symbols_on_windows.patch
revert_cleanup_switch_offset_of_to_offsetof_where_possible.patch
fix_build_deprecated_attirbute_for_older_msvc_versions.patch
chore_disallow_copying_cppheapcreateparams.patch
mac_wasm_work_around_macos_11_2_code_page_decommit_failures.patch

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@ -0,0 +1,42 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: deepak1556 <hop2deep@gmail.com>
Date: Mon, 8 Feb 2021 13:20:09 -0800
Subject: 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}
diff --git a/src/base/platform/platform-posix.cc b/src/base/platform/platform-posix.cc
index ab0d7839a453d87a8404ca791c1022871e8fd606..67746173d582c5c404083be8ef3fa36c7dfc8cfe 100644
--- a/src/base/platform/platform-posix.cc
+++ b/src/base/platform/platform-posix.cc
@@ -415,6 +415,16 @@ 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));