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Revert "Reland: [wasm] Check correctness of thread-local write protection"

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This reverts commit 1c0cca0f56.

Reason for revert: this made tree closed. (https://crbug.com/1238174)

Original change's description:
> Reland: [wasm] Check correctness of thread-local write protection
>
> The fix landed as a separate CL: https://crrev.com/c/3081522
> This is an unmodified reland.
>
> Original description:
> We make an undocumented assumption in {CodeSpaceWriteScope} that a
> single thread will only work on one module at a time. If this is
> violated, the thread-local {code_space_write_nesting_level_} would
> prevent the second module from being switched to writable.
>
> This CL adds a second thread local (in debug only) to check that if
> there is already a {CodeSpaceWriteScope} open that it contains the same
> {NativeModule} as any nested scope.
>
> R=​jkummerow@chromium.org
>
> Bug: v8:11974
> Cq-Include-Trybots: luci.v8.try:v8_linux_gc_stress_dbg_ng
> Cq-Include-Trybots: luci.v8.try:v8_mac64_gc_stress_dbg_ng
> Change-Id: Id827b6ca472f695e4500584349aba159aa07eed1
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3080578
> Commit-Queue: Clemens Backes <clemensb@chromium.org>
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#76177}

Bug: v8:11974, 1238174
Change-Id: I74d8723344e4b9015d956ebfe3fda492280356b6
Cq-Include-Trybots: luci.v8.try:v8_linux_gc_stress_dbg_ng
Cq-Include-Trybots: luci.v8.try:v8_mac64_gc_stress_dbg_ng
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3084041
Auto-Submit: Minoru Chikamune <chikamune@google.com>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#76184}
This commit is contained in:
Minoru Chikamune 2021-08-10 01:03:05 +00:00 committed by V8 LUCI CQ
parent 3eb90f6945
commit 996e03809c
2 changed files with 0 additions and 15 deletions
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12
src/wasm/code-space-access.cc
View File

@ -12,12 +12,6 @@ namespace internal {
namespace wasm {
thread_local int CodeSpaceWriteScope::code_space_write_nesting_level_ = 0;
// The thread-local counter (above) is only valid if a single thread only works
// on one module at a time. This second thread-local checks that.
#if defined(DEBUG) && (!defined(V8_OS_MACOSX) || !defined(V8_HOST_ARCH_ARM64))
thread_local NativeModule* CodeSpaceWriteScope::current_native_module_ =
nullptr;
#endif
// TODO(jkummerow): Background threads could permanently stay in
// writable mode; only the main thread has to switch back and forth.
@ -26,12 +20,6 @@ CodeSpaceWriteScope::CodeSpaceWriteScope(NativeModule*) {
#else // !V8_HAS_PTHREAD_JIT_WRITE_PROTECT
CodeSpaceWriteScope::CodeSpaceWriteScope(NativeModule* native_module)
: native_module_(native_module) {
#ifdef DEBUG
if (code_space_write_nesting_level_ == 0) {
current_native_module_ = native_module;
}
DCHECK_EQ(native_module, current_native_module_);
#endif // DEBUG
#endif // !V8_HAS_PTHREAD_JIT_WRITE_PROTECT
if (code_space_write_nesting_level_ == 0) SetWritable();
code_space_write_nesting_level_++;

3
src/wasm/code-space-access.h
View File

@ -55,9 +55,6 @@ class V8_NODISCARD CodeSpaceWriteScope final {
private:
static thread_local int code_space_write_nesting_level_;
#if defined(DEBUG) && (!defined(V8_OS_MACOSX) || !defined(V8_HOST_ARCH_ARM64))
static thread_local NativeModule* current_native_module_;
#endif
void SetWritable() const;
void SetExecutable() const;