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+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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+From: deepak1556 <[email protected]>
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+Date: Mon, 8 Feb 2021 13:20:09 -0800
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+Subject: Work around MacOS 11.2 code page decommit failures
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+
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+MacOS 11.2 refuses to set "no access" permissions on memory that
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+we previously used for JIT-compiled code. It is still unclear
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+whether this is WAI on the part of the kernel. In the meantime,
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+as a workaround, we use madvise(..., MADV_FREE_REUSABLE) instead
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+of mprotect(..., NONE) when discarding code pages. This is inspired
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+by what Chromium's gin platform does.
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+
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+Fixed: v8:11389
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+Change-Id: I866586932573b4253002436ae5eee4e0411c45fc
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+Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2679688
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+Commit-Queue: Jakob Kummerow <[email protected]>
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+Commit-Queue: Michael Lippautz <[email protected]>
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+Auto-Submit: Jakob Kummerow <[email protected]>
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+Reviewed-by: Michael Lippautz <[email protected]>
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+Cr-Commit-Position: refs/heads/master@{#72559}
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+
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+diff --git a/src/base/platform/platform-posix.cc b/src/base/platform/platform-posix.cc
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+index ab0d7839a453d87a8404ca791c1022871e8fd606..67746173d582c5c404083be8ef3fa36c7dfc8cfe 100644
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+--- a/src/base/platform/platform-posix.cc
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++++ b/src/base/platform/platform-posix.cc
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+@@ -415,6 +415,16 @@ bool OS::SetPermissions(void* address, size_t size, MemoryPermission access) {
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+
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+ int prot = GetProtectionFromMemoryPermission(access);
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+ int ret = mprotect(address, size, prot);
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++
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++ // MacOS 11.2 on Apple Silicon refuses to switch permissions from
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++ // rwx to none. Just use madvise instead.
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++#if defined(V8_OS_MACOSX)
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++ if (ret != 0 && access == OS::MemoryPermission::kNoAccess) {
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++ ret = madvise(address, size, MADV_FREE_REUSABLE);
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++ return ret == 0;
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++ }
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++#endif
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++
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+ if (ret == 0 && access == OS::MemoryPermission::kNoAccess) {
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+ // This is advisory; ignore errors and continue execution.
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+ USE(DiscardSystemPages(address, size));
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