Title: [195578] trunk/Source/_javascript_Core
- Revision
- 195578
- Author
- [email protected]
- Date
- 2016-01-25 20:01:33 -0800 (Mon, 25 Jan 2016)
Log Message
[JSC] We should never use x18 on iOS ARM64
https://bugs.webkit.org/show_bug.cgi?id=153461
Patch by Benjamin Poulain <[email protected]> on 2016-01-25
Reviewed by Filip Pizlo.
The register x18 is reserved in the iOS variant of the ARM64 ABI.
The weird thing is: if you use it, its value will change completely
randomly. It looks like it is changed by the system on interrupts.
This patch adds x18 to the reserved register and add assertions
to the assembler to prevent similar problems in the future.
* assembler/ARM64Assembler.h:
(JSC::ARM64Assembler::xOrSp):
(JSC::ARM64Assembler::xOrZr):
* assembler/AbstractMacroAssembler.h:
(JSC::isIOS): Deleted.
* assembler/AssemblerCommon.h:
(JSC::isIOS):
* jit/RegisterSet.cpp:
(JSC::RegisterSet::reservedHardwareRegisters):
Modified Paths
Diff
Modified: trunk/Source/_javascript_Core/ChangeLog (195577 => 195578)
--- trunk/Source/_javascript_Core/ChangeLog 2016-01-26 03:13:03 UTC (rev 195577)
+++ trunk/Source/_javascript_Core/ChangeLog 2016-01-26 04:01:33 UTC (rev 195578)
@@ -1,3 +1,28 @@
+2016-01-25 Benjamin Poulain <[email protected]>
+
+ [JSC] We should never use x18 on iOS ARM64
+ https://bugs.webkit.org/show_bug.cgi?id=153461
+
+ Reviewed by Filip Pizlo.
+
+ The register x18 is reserved in the iOS variant of the ARM64 ABI.
+
+ The weird thing is: if you use it, its value will change completely
+ randomly. It looks like it is changed by the system on interrupts.
+
+ This patch adds x18 to the reserved register and add assertions
+ to the assembler to prevent similar problems in the future.
+
+ * assembler/ARM64Assembler.h:
+ (JSC::ARM64Assembler::xOrSp):
+ (JSC::ARM64Assembler::xOrZr):
+ * assembler/AbstractMacroAssembler.h:
+ (JSC::isIOS): Deleted.
+ * assembler/AssemblerCommon.h:
+ (JSC::isIOS):
+ * jit/RegisterSet.cpp:
+ (JSC::RegisterSet::reservedHardwareRegisters):
+
2016-01-25 Commit Queue <[email protected]>
Unreviewed, rolling out r195550.
Modified: trunk/Source/_javascript_Core/assembler/ARM64Assembler.h (195577 => 195578)
--- trunk/Source/_javascript_Core/assembler/ARM64Assembler.h 2016-01-26 03:13:03 UTC (rev 195577)
+++ trunk/Source/_javascript_Core/assembler/ARM64Assembler.h 2016-01-26 04:01:33 UTC (rev 195578)
@@ -3276,8 +3276,18 @@
return (insn & 0x7c000000) == 0x14000000;
}
- static int xOrSp(RegisterID reg) { ASSERT(!isZr(reg)); return reg; }
- static int xOrZr(RegisterID reg) { ASSERT(!isSp(reg)); return reg & 31; }
+ static int xOrSp(RegisterID reg)
+ {
+ ASSERT(!isZr(reg));
+ ASSERT(!isIOS() || reg != ARM64Registers::x18);
+ return reg;
+ }
+ static int xOrZr(RegisterID reg)
+ {
+ ASSERT(!isSp(reg));
+ ASSERT(!isIOS() || reg != ARM64Registers::x18);
+ return reg & 31;
+ }
static FPRegisterID xOrZrAsFPR(RegisterID reg) { return static_cast<FPRegisterID>(xOrZr(reg)); }
static int xOrZrOrSp(bool useZr, RegisterID reg) { return useZr ? xOrZr(reg) : xOrSp(reg); }
Modified: trunk/Source/_javascript_Core/assembler/AbstractMacroAssembler.h (195577 => 195578)
--- trunk/Source/_javascript_Core/assembler/AbstractMacroAssembler.h 2016-01-26 03:13:03 UTC (rev 195577)
+++ trunk/Source/_javascript_Core/assembler/AbstractMacroAssembler.h 2016-01-26 04:01:33 UTC (rev 195578)
@@ -76,15 +76,6 @@
#endif
}
-inline bool isIOS()
-{
-#if PLATFORM(IOS)
- return true;
-#else
- return false;
-#endif
-}
-
inline bool optimizeForARMv7IDIVSupported()
{
return isARMv7IDIVSupported() && Options::useArchitectureSpecificOptimizations();
Modified: trunk/Source/_javascript_Core/assembler/AssemblerCommon.h (195577 => 195578)
--- trunk/Source/_javascript_Core/assembler/AssemblerCommon.h 2016-01-26 03:13:03 UTC (rev 195577)
+++ trunk/Source/_javascript_Core/assembler/AssemblerCommon.h 2016-01-26 04:01:33 UTC (rev 195578)
@@ -28,6 +28,15 @@
namespace JSC {
+ALWAYS_INLINE bool isIOS()
+{
+#if PLATFORM(IOS)
+ return true;
+#else
+ return false;
+#endif
+}
+
ALWAYS_INLINE bool isInt9(int32_t value)
{
return value == ((value << 23) >> 23);
Modified: trunk/Source/_javascript_Core/jit/RegisterSet.cpp (195577 => 195578)
--- trunk/Source/_javascript_Core/jit/RegisterSet.cpp 2016-01-26 03:13:03 UTC (rev 195577)
+++ trunk/Source/_javascript_Core/jit/RegisterSet.cpp 2016-01-26 04:01:33 UTC (rev 195578)
@@ -45,7 +45,11 @@
RegisterSet RegisterSet::reservedHardwareRegisters()
{
#if CPU(ARM64)
+#if PLATFORM(IOS)
+ return RegisterSet(ARM64Registers::x18, ARM64Registers::lr);
+#else
return RegisterSet(ARM64Registers::lr);
+#endif // PLATFORM(IOS)
#else
return RegisterSet();
#endif
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