Commit 81f27884 authored by Jan de Mooij's avatar Jan de Mooij
Browse files

Bug 1782003 - Set lastProfilingFrame correctly in GeckoProfilerRuntime::enable. r=iain 

If the top activation is a C++ interpreter activation, the code would incorrectly use
`nullptr` as `lastProfilingFrame` for the first `JitActivation`.

Differential Revision: https://phabricator.services.mozilla.com/D153061
parent 9e84990d

js/src/jit-test/tests/profiler/bug1782003.js

0 → 100644
+28 −0
Original line number Diff line number Diff line 
function getStack() {

    enableGeckoProfiling();

    let stack = readGeckoProfilingStack();

    // The number of frames depends on JIT flags, but there must be at least

    // one frame for the caller and at most 3 total (the global script, 'testFun'

    // and 'getStack').

    assertEq(stack.length > 0, true);

    assertEq(stack.length <= 3, true);

    assertEq(JSON.stringify(stack).includes('"testFun ('), true);

    disableGeckoProfiling();

}

function testFun() {

    // Loop until this is a JIT frame.

    while (true) {

        let isJitFrame = inJit();

        if (typeof isJitFrame === "string") {

            return; // JIT disabled.

        }

        if (isJitFrame) {

            break;

        }

    }



    // Now call getStack to check this frame is on the profiler's JIT stack.

    getStack();

    getStack();

}

testFun();

js/src/vm/GeckoProfiler.cpp

+4 −14
Original line number Diff line number Diff line
@@ -51,20 +51,14 @@ void GeckoProfilerRuntime::setEventMarker(void (*fn)(const char*, 
}



// Get a pointer to the top-most profiling frame, given the exit frame pointer.

static jit::JitFrameLayout* GetTopProfilingJitFrame(Activation* act) {

  if (!act || !act->isJit()) {

    return nullptr;

  }



  jit::JitActivation* jitActivation = act->asJit();



static jit::JitFrameLayout* GetTopProfilingJitFrame(jit::JitActivation* act) {

  // If there is no exit frame set, just return.

  if (!jitActivation->hasExitFP()) {

  if (!act->hasExitFP()) {

    return nullptr;

  }



  // Skip wasm frames that might be in the way.

  OnlyJSJitFrameIter iter(jitActivation);

  OnlyJSJitFrameIter iter(act);

  if (iter.done()) {

    return nullptr;

  }
@@ -118,16 +112,12 @@ void GeckoProfilerRuntime::enable(bool enabled) { 
    // Walk through all activations, and set their lastProfilingFrame

    // appropriately.

    if (enabled) {

      Activation* act = cx->activation();

      auto* lastProfilingFrame = GetTopProfilingJitFrame(act);



      jit::JitActivation* jitActivation = cx->jitActivation;

      while (jitActivation) {

        auto* lastProfilingFrame = GetTopProfilingJitFrame(jitActivation);

        jitActivation->setLastProfilingFrame(lastProfilingFrame);

        jitActivation->setLastProfilingCallSite(nullptr);



        jitActivation = jitActivation->prevJitActivation();

        lastProfilingFrame = GetTopProfilingJitFrame(jitActivation);

      }

    } else {

      jit::JitActivation* jitActivation = cx->jitActivation;