Title: [252661] trunk/Source/_javascript_Core
- Revision
- 252661
- Author
- ysuz...@apple.com
- Date
- 2019-11-19 16:56:39 -0800 (Tue, 19 Nov 2019)
Log Message
[JSC] Work-around Leaks' false-positive report about memory leaking
https://bugs.webkit.org/show_bug.cgi?id=204384
<rdar://problem/56950932>
Reviewed by Mark Lam.
According to the radar, Leaks start reporting false-positive memory leaks about ExecutableAllocator and FixedVMPoolExecutableAllocator,
while they are per-process singleton and reachable through g_jscConfig. I'm guessing this is because Leaks start skipping scan for
readonly memory region. (g_jscConfig is now mprotected to readonly).
To work-around this, we anchor these heap allocated things to global variables to help Leaks scan. Once it is fixed, we should remove it.
* jit/ExecutableAllocator.cpp:
(JSC::ExecutableAllocator::initializeUnderlyingAllocator):
(JSC::ExecutableAllocator::initialize):
Modified Paths
Diff
Modified: trunk/Source/_javascript_Core/ChangeLog (252660 => 252661)
--- trunk/Source/_javascript_Core/ChangeLog 2019-11-20 00:50:51 UTC (rev 252660)
+++ trunk/Source/_javascript_Core/ChangeLog 2019-11-20 00:56:39 UTC (rev 252661)
@@ -1,3 +1,21 @@
+2019-11-19 Yusuke Suzuki <ysuz...@apple.com>
+
+ [JSC] Work-around Leaks' false-positive report about memory leaking
+ https://bugs.webkit.org/show_bug.cgi?id=204384
+ <rdar://problem/56950932>
+
+ Reviewed by Mark Lam.
+
+ According to the radar, Leaks start reporting false-positive memory leaks about ExecutableAllocator and FixedVMPoolExecutableAllocator,
+ while they are per-process singleton and reachable through g_jscConfig. I'm guessing this is because Leaks start skipping scan for
+ readonly memory region. (g_jscConfig is now mprotected to readonly).
+
+ To work-around this, we anchor these heap allocated things to global variables to help Leaks scan. Once it is fixed, we should remove it.
+
+ * jit/ExecutableAllocator.cpp:
+ (JSC::ExecutableAllocator::initializeUnderlyingAllocator):
+ (JSC::ExecutableAllocator::initialize):
+
2019-11-18 Mark Lam <mark....@apple.com>
Always enable Optional<OptionsStorage::Size> parse(const char* string) for OS(DARWIN).
Modified: trunk/Source/_javascript_Core/jit/ExecutableAllocator.cpp (252660 => 252661)
--- trunk/Source/_javascript_Core/jit/ExecutableAllocator.cpp 2019-11-20 00:50:51 UTC (rev 252660)
+++ trunk/Source/_javascript_Core/jit/ExecutableAllocator.cpp 2019-11-20 00:56:39 UTC (rev 252661)
@@ -414,10 +414,14 @@
m_reservation.deallocate();
}
+// Keep this pointer in a mutable global variable to help Leaks find it.
+// But we do not use this pointer.
+static FixedVMPoolExecutableAllocator* globalFixedVMPoolExecutableAllocatorToWorkAroundLeaks = nullptr;
void ExecutableAllocator::initializeUnderlyingAllocator()
{
RELEASE_ASSERT(!g_jscConfig.fixedVMPoolExecutableAllocator);
g_jscConfig.fixedVMPoolExecutableAllocator = new FixedVMPoolExecutableAllocator();
+ globalFixedVMPoolExecutableAllocatorToWorkAroundLeaks = g_jscConfig.fixedVMPoolExecutableAllocator;
CodeProfiling::notifyAllocator(g_jscConfig.fixedVMPoolExecutableAllocator);
}
@@ -642,9 +646,13 @@
namespace JSC {
+// Keep this pointer in a mutable global variable to help Leaks find it.
+// But we do not use this pointer.
+static ExecutableAllocator* globalExecutableAllocatorToWorkAroundLeaks = nullptr;
void ExecutableAllocator::initialize()
{
g_jscConfig.executableAllocator = new ExecutableAllocator;
+ globalExecutableAllocatorToWorkAroundLeaks = g_jscConfig.executableAllocator;
}
ExecutableAllocator& ExecutableAllocator::singleton()
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