Changeset 166732 in webkit for trunk/Source/JavaScriptCore/assembler/MacroAssemblerARMv7.cpp

Timestamp:

Apr 3, 2014, 11:25:26 AM (11 years ago)

Author:

[email protected]

Message:

Fix bit rot in ARMv7 JIT probe mechanism.
<​https://webkit.org/b/131167>

Reviewed by Geoffrey Garen.

1. The macro assembler does not support pushing the SP register. Worked around this by pushing the LR register as a placeholder, and then writing the original SP value to that slot.
2. The CPUState field in the ProbeContext needs to be aligned on a 4 byte boundary, not an 8 byte boundary.

• assembler/MacroAssemblerARMv7.cpp:

(JSC::MacroAssemblerARMv7::probe):

• jit/JITStubsARMv7.h:

File:

• trunk/Source/JavaScriptCore/assembler/MacroAssemblerARMv7.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/assembler/MacroAssemblerARMv7.cpp

@@ -83 +83 @@
 void MacroAssemblerARMv7::probe(MacroAssemblerARMv7::ProbeFunction function, void* arg1, void* arg2)
 {
-    push(RegisterID::sp);
     push(RegisterID::lr);
+    push(RegisterID::lr);
+    add32(TrustedImm32(8), RegisterID::sp, RegisterID::lr);
+    store32(RegisterID::lr, ArmAddress(RegisterID::sp, 4));
     push(RegisterID::ip);
     push(RegisterID::r0);