Changeset 193648 in webkit

Timestamp:

Dec 7, 2015 1:35:02 PM (8 years ago)

Author:

berto@igalia.com

Message:

Crashes on PPC64 due to mprotect() on address not aligned to the page size
​https://bugs.webkit.org/show_bug.cgi?id=130237

Reviewed by Mark Lam.

Make sure that commitSize is at least as big as the page size.

• interpreter/JSStack.cpp:

(JSC::commitSize):
(JSC::JSStack::JSStack):
(JSC::JSStack::growSlowCase):

• interpreter/JSStack.h:

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• interpreter/JSStack.cpp (modified) (3 diffs)
• interpreter/JSStack.h (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2015-12-07  Alberto Garcia  <berto@igalia.com>
+
+        Crashes on PPC64 due to mprotect() on address not aligned to the page size
+        https://bugs.webkit.org/show_bug.cgi?id=130237
+
+        Reviewed by Mark Lam.
+
+        Make sure that commitSize is at least as big as the page size.
+
+        * interpreter/JSStack.cpp:
+        (JSC::commitSize):
+        (JSC::JSStack::JSStack):
+        (JSC::JSStack::growSlowCase):
+        * interpreter/JSStack.h:
+
 2015-12-06  Filip Pizlo  <fpizlo@apple.com>
 

trunk/Source/JavaScriptCore/interpreter/JSStack.cpp

@@ -41 +41 @@
 static size_t committedBytesCount = 0;
 
+static size_t commitSize()
+{
+    static size_t size = 0;
+    if (!size)
+        size = std::max(16 * 1024, getpagesize());
+    return size;
+}
+
 static StaticLock stackStatisticsMutex;
 #endif // !ENABLE(JIT)
@@ -56 +64 @@
     ASSERT(capacity && isPageAligned(capacity));
 
-    m_reservation = PageReservation::reserve(WTF::roundUpToMultipleOf(commitSize, capacity), OSAllocator::JSVMStackPages);
+    m_reservation = PageReservation::reserve(WTF::roundUpToMultipleOf(commitSize(), capacity), OSAllocator::JSVMStackPages);
     setStackLimit(highAddress());
     m_commitTop = highAddress();
@@ -90 +98 @@
     // return false.
     ptrdiff_t delta = reinterpret_cast<char*>(m_commitTop) - reinterpret_cast<char*>(newTopOfStackWithReservedZone);
-    delta = WTF::roundUpToMultipleOf(commitSize, delta);
+    delta = WTF::roundUpToMultipleOf(commitSize(), delta);
     Register* newCommitTop = m_commitTop - (delta / sizeof(Register));
     if (newCommitTop < reservationTop())

trunk/Source/JavaScriptCore/interpreter/JSStack.h

@@ -68 +68 @@
         };
 
-        static const size_t commitSize = 16 * 1024;
         // Allow 8k of excess registers before we start trying to reap the stack
         static const ptrdiff_t maxExcessCapacity = 8 * 1024;