Changeset 199950 in webkit

Timestamp:

Apr 23, 2016 10:05:54 AM (8 years ago)

Author:

barraclough@apple.com

Message:

bmalloc: vm allocations should plant guard pages
​https://bugs.webkit.org/show_bug.cgi?id=156937

Rolling out - looks like this is memory regression.

• bmalloc/Object.h:

(bmalloc::Object::operator+):
(bmalloc::Object::operator<=):
(bmalloc::Object::operator-): Deleted.

• bmalloc/VMAllocate.h:

(bmalloc::vmDeallocate):
(bmalloc::vmRevokePermissions): Deleted.

• bmalloc/VMHeap.cpp:

(bmalloc::VMHeap::allocateSmallChunk):

Location:

trunk/Source/bmalloc

Files:

• ChangeLog (modified) (1 diff)
• bmalloc/Object.h (modified) (2 diffs)
• bmalloc/VMAllocate.h (modified) (1 diff)
• bmalloc/VMHeap.cpp (modified) (1 diff)

trunk/Source/bmalloc/ChangeLog

@@ +1 @@
+2016-04-23  Gavin Barraclough  <barraclough@apple.com>
+
+        bmalloc: vm allocations should plant guard pages
+        https://bugs.webkit.org/show_bug.cgi?id=156937
+
+        Rolling out - looks like this is memory regression.
+
+        * bmalloc/Object.h:
+        (bmalloc::Object::operator+):
+        (bmalloc::Object::operator<=):
+        (bmalloc::Object::operator-): Deleted.
+        * bmalloc/VMAllocate.h:
+        (bmalloc::vmDeallocate):
+        (bmalloc::vmRevokePermissions): Deleted.
+        * bmalloc/VMHeap.cpp:
+        (bmalloc::VMHeap::allocateSmallChunk):
+
 2016-04-22  Geoffrey Garen  <ggaren@apple.com>
 

trunk/Source/bmalloc/bmalloc/Object.h

@@ -53 +53 @@
     
     Object operator+(size_t);
-    Object operator-(size_t);
     bool operator<=(const Object&);
 
@@ -66 +65 @@
 }
 
-inline Object Object::operator-(size_t offset)
-{
-    return Object(m_chunk, m_offset - offset);
-}
-
 inline bool Object::operator<=(const Object& other)
 {

trunk/Source/bmalloc/bmalloc/VMAllocate.h

@@ -138 +138 @@
 }
 
-inline void vmRevokePermissions(void* p, size_t vmSize)
-{
-    vmValidate(p, vmSize);
-    mprotect(p, vmSize, PROT_NONE);
-}
-
 // Allocates vmSize bytes at a specified power-of-two alignment.
 // Use this function to create maskable memory regions.

trunk/Source/bmalloc/bmalloc/VMHeap.cpp

@@ -76 +76 @@
     Object end(chunk, chunkSize);
 
-    vmRevokePermissions(begin.begin(), pageSize);
-    vmRevokePermissions(end.begin() - pageSize, pageSize);
-
-    begin = begin + pageSize;
-    end = end - pageSize;
-
     for (Object it = begin; it + pageSize <= end; it = it + pageSize) {
         SmallPage* page = it.page();