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-rw-r--r-- | js/xpconnect/tests/chrome/test_bug732665.xhtml | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/js/xpconnect/tests/chrome/test_bug732665.xhtml b/js/xpconnect/tests/chrome/test_bug732665.xhtml new file mode 100644 index 0000000000..0ffba66ebc --- /dev/null +++ b/js/xpconnect/tests/chrome/test_bug732665.xhtml @@ -0,0 +1,92 @@ +<?xml version="1.0"?> +<?xml-stylesheet type="text/css" href="chrome://global/skin"?> +<?xml-stylesheet type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"?> +<!-- +https://bugzilla.mozilla.org/show_bug.cgi?id=732665 +--> +<window title="Mozilla Bug 732665" + xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"> + <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"/> + + <!-- test results are displayed in the html:body --> + <body xmlns="http://www.w3.org/1999/xhtml"> + <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=732665" + target="_blank">Mozilla Bug 732665</a> + </body> + + <!-- test code goes here --> + <script type="application/javascript"> + <![CDATA[ + +add_task(async () => { + await SpecialPowers.pushPrefEnv({"set": [["security.allow_eval_with_system_principal", + true]]}); + // + // Important! If this test starts failing after a tricky platform-y change, + // the stack quota numbers in XPCJSContext probably need twiddling. We want + // to maintain the invariants in this test (at least to some approximation) + // for security reasons. + // + + // Executes f() d steps from the probed native stack limit, and returns + // the number of steps to the recursion limit from the caller. + function nearNativeStackLimit(d, f) { + f = f || function() {}; + let failed = null; + function inner() { + try { + // eslint-disable-next-line no-eval + var stepsFromLimit = eval("inner()"); // Use eval to force a number of native stackframes to be created. + if (stepsFromLimit == d) { + try { + f(); + } catch(e) { + // If we didn't have enough stack space to call the (possibly + // trivial) test function above, we obviously can't expect to call + // into the test harness assertion code successfully. + failed = e; + } + } + return stepsFromLimit + 1; + } catch(e) { + // It would be nice to check here that the exception is actually an + // over-recursion here. But doing so would require toString()ing the + // exception, which we may not have the stack space to do. + return 0; + } + } + let result = inner(); + ok(!failed, `nearNativeStackLimit callback threw: ${failed}`); + return result; + } + + var contentSb = new Cu.Sandbox("https://www.example.com"); + var chromeSb = new Cu.Sandbox(window); + chromeSb.ok = contentSb.ok = ok; + Cu.evalInSandbox(nearNativeStackLimit.toSource(), chromeSb); + Cu.evalInSandbox(nearNativeStackLimit.toSource(), contentSb); + var chromeLimit = Cu.evalInSandbox("nearNativeStackLimit(0);", chromeSb); + var contentLimit = Cu.evalInSandbox("nearNativeStackLimit(0)", contentSb); + ok(chromeLimit >= contentLimit + 10, + "Chrome should be able to have at least 10 heavy frames more stack than content: " + chromeLimit + ", " + contentLimit); + + // Exhaust the stack space in content, and then make sure we can still get 10 + // heavy frames in chrome. + // + // Note that sometimes, if we pass |0| to nearNativeStackLimit, we can end up + // so close to the border in content that we can't even get ourselves together + // enough to make the cross-compartment call. So rather than exhausting the + // stack entirely and then checking for 10 chrome frames, we leave ourselves + // one frame's worth, and check for 11. + // + // If this assertion fails, the current work-around so far is to measure + // again the worst frame size, by using the JS Shell to run + // test_bug732665_meta.js . This script will output numbers to update + // XPCJSContext.cpp comment, as well as the kTrustedScriptBuffer constant. + contentSb.nnslChrome = chromeSb.nearNativeStackLimit; + var nestedLimit = Cu.evalInSandbox("nearNativeStackLimit(1, function() { nestedLimit = nnslChrome(0);}); nestedLimit;", contentSb); + ok(nestedLimit >= 11, "Chrome should be invokable from content script with an exhausted stack: " + nestedLimit); +}); + ]]> + </script> +</window> |