1031284 - Fix assertion failures for pseudostack unwinds using SPS+LUL

Status: RESOLVED FIXED

(Core :: Gecko Profiler, defect)

Description

[Julian Seward [:jseward]]

After applying the patch for bug 1022583, which enables LUL by
default on desktop linux, startups of debug builds done thusly

MOZ_PROFILER_MODE=pseudo ./ff-linux64-dbg/dist/bin/firefox-bin

quickly assert thusly
Assertion failure: !isJs(), at ../../dist/include/js/ProfilingStack.h:127

The failure stack (one of two) is

#0  js::ProfileEntry::stackAddress   js/public/ProfilingStack.h:127
#1  genProfileEntry           tools/profiler/BreakpadSampler.cpp:76
#2  genPseudoBacktraceEntries tools/profiler/BreakpadSampler.cpp:141
#3  populateBuffer            tools/profiler/BreakpadSampler.cpp:219

The failure happens because genProfileEntry calls entry.stackAddress()
without knowing whether the entry is a JS or CPP entry, and the same
for a call of entry.line().

Comment 1

[Julian Seward [:jseward]]

Attachment: bug1031284-1.diff

Guard calls to entry.stackAddress()/line() with entry.isCpp().

Comment 2

[Julian Seward [:jseward]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/e8aa304c209b

Comment 3

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/e8aa304c209b