Bug 1208819 - Fix irregexp overrecursion check to ignore interrupts. r=bhackett

js/src/irregexp/NativeRegExpMacroAssembler.cpp

@@ -154,9 +154,11 @@ NativeRegExpMacroAssembler::GenerateCode(JSContext* cx, bool match_only)
     masm.reserveStack(frameSize);
     masm.checkStackAlignment();
 
-    // Check if we have space on the stack.
+    // Check if we have space on the stack. Use the *NoInterrupt stack limit to
+    // avoid failing repeatedly when the regex code is called from Ion JIT code,
+    // see bug 1208819.
     Label stack_ok;
-    void* stack_limit = runtime->addressOfJitStackLimit();
+    void* stack_limit = runtime->addressOfJitStackLimitNoInterrupt();
     masm.branchStackPtrRhs(Assembler::Below, AbsoluteAddress(stack_limit), &stack_ok);
 
     // Exit with an exception. There is not enough space on the stack

js/src/vm/Runtime.cpp

@@ -130,6 +130,7 @@ JSRuntime::JSRuntime(JSRuntime* parentRuntime)
     jitJSContext(nullptr),
     jitActivation(nullptr),
     jitStackLimit_(0xbad),
+    jitStackLimitNoInterrupt_(0xbad),
     activation_(nullptr),
     profilingActivation_(nullptr),
     profilerSampleBufferGen_(0),
@@ -623,6 +624,7 @@ JSRuntime::resetJitStackLimit()
 #else
     jitStackLimit_ = mainThread.nativeStackLimit[StackForUntrustedScript];
 #endif
+    jitStackLimitNoInterrupt_ = jitStackLimit_;
 }
 
 void

js/src/vm/Runtime.h

@@ -632,6 +632,9 @@ struct JSRuntime : public JS::shadow::Runtime,
     mozilla::Atomic<uintptr_t, mozilla::Relaxed> jitStackLimit_;
     void resetJitStackLimit();
 
+    // Like jitStackLimit_, but not reset to trigger interrupts.
+    uintptr_t jitStackLimitNoInterrupt_;
+
   public:
     void initJitStackLimit();
 
@@ -641,6 +644,8 @@ struct JSRuntime : public JS::shadow::Runtime,
     void* addressOfJitStackLimit() { return &jitStackLimit_; }
     static size_t offsetOfJitStackLimit() { return offsetof(JSRuntime, jitStackLimit_); }
 
+    void* addressOfJitStackLimitNoInterrupt() { return &jitStackLimitNoInterrupt_; }
+
     // Information about the heap allocated backtrack stack used by RegExp JIT code.
     js::irregexp::RegExpStack regexpStack;