Changeset 86919 in webkit for trunk/Source/JavaScriptCore/assembler/X86Assembler.h

Timestamp:

May 19, 2011, 6:33:46 PM (14 years ago)

Author:

[email protected]

Message:

2011-05-19 Oliver Hunt <​[email protected]>

Reviewed by Gavin Barraclough.

Randomise code starting location a little
​https://bugs.webkit.org/show_bug.cgi?id=61161

Add a nop() function to the Assemblers so that we
can randomise code offsets slightly at no real cost.

• assembler/ARMAssembler.h: (JSC::ARMAssembler::nop):
• assembler/ARMv7Assembler.h: (JSC::ARMv7Assembler::nop):
• assembler/MacroAssemblerARM.h: (JSC::MacroAssemblerARM::nop):
• assembler/MacroAssemblerARMv7.h: (JSC::MacroAssemblerARMv7::nop):
• assembler/MacroAssemblerMIPS.h: (JSC::MacroAssemblerMIPS::nop):
• assembler/MacroAssemblerSH4.h: (JSC::MacroAssemblerSH4::nop):
• assembler/MacroAssemblerX86Common.h: (JSC::MacroAssemblerX86Common::nop):
• assembler/X86Assembler.h: (JSC::X86Assembler::nop):
• jit/JIT.cpp: (JSC::JIT::JIT): (JSC::JIT::privateCompile):
• jit/JIT.h:
• runtime/WeakRandom.h: (JSC::WeakRandom::getUint32):

File:

• trunk/Source/JavaScriptCore/assembler/X86Assembler.h (modified) (2 diffs)

trunk/Source/JavaScriptCore/assembler/X86Assembler.h

@@ -139 +139 @@
         OP_LEA                          = 0x8D,
         OP_GROUP1A_Ev                   = 0x8F,
+        OP_NOP                          = 0x90,
         OP_CDQ                          = 0x99,
         OP_MOV_EAXOv                    = 0xA1,
@@ -1593 +1594 @@
     unsigned debugOffset() { return m_formatter.debugOffset(); }
 #endif
+
+    void nop()
+    {
+        m_formatter.oneByteOp(OP_NOP);
+    }
 
 private: