Bug 1365309 - Part 3: Disable ThreadStackHelper on x86 linux due to a LUL crash, r=froydnj

MozReview-Commit-ID: 2kBBFftnJEd

toolkit/components/telemetry/tests/unit/xpcshell.ini

@@ -52,7 +52,7 @@ tags = addons
 tags = addons
 [test_TelemetrySession_activeTicks.js]
 [test_ThreadHangStats.js]
-skip-if = os == "android" || os == "linux" # BHR is disabled on linux (bug 1365309)
+skip-if = os == "android" || (os == "linux" && bits == 32) # BHR is disabled on 32-bit linux
 run-sequentially = Bug 1046307, test can fail intermittently when CPU load is high
 [test_TelemetrySend.js]
 [test_ChildHistograms.js]

xpcom/threads/ThreadStackHelper.h

@@ -22,8 +22,10 @@
 #include <mach/mach.h>
 #endif
 
-// Support pseudostack and native stack on these platforms.
-#if defined(XP_LINUX) || defined(XP_WIN) || defined(XP_MACOSX)
+// Support pseudostack and native stack on these platforms. We don't support
+// collecting this information on x86 linux builds, as our LUL stackwalking
+// initialization code can occasionally crash. (see bug 1365309 comment 8).
+#if (defined(XP_LINUX) && defined(HAVE_64BIT_BUILD)) || defined(XP_WIN) || defined(XP_MACOSX)
 #  ifdef MOZ_GECKO_PROFILER
 #    define MOZ_THREADSTACKHELPER_PSEUDO
 #    define MOZ_THREADSTACKHELPER_NATIVE