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Bug 1353763 - Baldr: handle strange Windows exception + SetThreadContext interaction (r=red)

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MozReview-Commit-ID: 4jrrBipq4xB
This commit is contained in:
Luke Wagner 2017-04-14 15:29:41 -05:00
parent 59b23525ff
commit 2e125f3d9d
1 changed files with 19 additions and 1 deletions
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20
js/src/wasm/WasmSignalHandlers.cpp
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@ -863,6 +863,18 @@ HandleFault(PEXCEPTION_POINTERS exception)
if (!IsHeapAccessAddress(*instance, faultingAddress))
return false;
// Similar to the non-atomic situation above, on Windows, an OOB fault at a
// PC can trigger *after* an async interrupt observed that PC and attempted
// to redirect to the async stub. In this unique case, interrupted() is
// already true when the OOB handler is called. Since the point of the async
// interrupt is to get out of an iloop and the OOB trap will do just that,
// we can simply clear the interrupt. (The update to CONTEXT.pc made by
// HandleMemoryAccess will clobber the interrupt's previous update.)
if (activation->interrupted()) {
MOZ_ASSERT(activation->resumePC() == pc);
activation->finishInterrupt();
}
HandleMemoryAccess(context, pc, faultingAddress, *instance, activation, ppc);
return true;
}
@ -1302,8 +1314,14 @@ RedirectJitCodeToInterruptCheck(JSContext* cx, CONTEXT* context)
uint8_t* pc = *ppc;
uint8_t* fp = ContextToFP(context);
// Only interrupt in function code so that the frame iterators have the
// invariant that resumePC always has a function CodeRange and we can't
// get into any weird interrupt-during-interrupt-stub cases. Note that
// the out-of-bounds/unaligned trap paths which call startInterrupt() go
// through function code, so test if already interrupted. All these
// paths are temporary though, so this case can be removed later.
const Code* code = activation->compartment()->wasm.lookupCode(pc);
if (code && code->segment().containsFunctionPC(pc) && fp) {
if (code && code->segment().containsFunctionPC(pc) && fp && !activation->interrupted()) {
activation->startInterrupt(pc, fp);
*ppc = code->segment().interruptCode();
return true;