1734612 - Startup Crash in [@ mozilla::ScriptPreloader::InitCacheInternal]

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect, P1)

Description

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

Crash report: https://crash-stats.mozilla.org/report/index/e3259484-a527-4128-b916-504690211007

MOZ_CRASH Reason: MOZ_RELEASE_ASSERT(JS::IsTranscodingBytecodeAligned(scriptData.get()))

Top 10 frames of crashing thread:

0 xul.dll mozilla::ScriptPreloader::InitCacheInternal js/xpconnect/loader/ScriptPreloader.cpp:540
1 xul.dll mozilla::ScriptPreloader::InitCache js/xpconnect/loader/ScriptPreloader.cpp:440
2 xul.dll static mozilla::ScriptPreloader::GetSingleton js/xpconnect/loader/ScriptPreloader.cpp:115
3 xul.dll xpc::InitializeJSContext js/xpconnect/src/nsXPConnect.cpp:99
4 xul.dll XREMain::XRE_mainRun toolkit/xre/nsAppRunner.cpp:5013
5 xul.dll XREMain::XRE_main toolkit/xre/nsAppRunner.cpp:5477
6 xul.dll XRE_main toolkit/xre/nsAppRunner.cpp:5536
7 firefox.exe wmain toolkit/xre/nsWindowsWMain.cpp:138
8 firefox.exe __scrt_common_main_seh /builds/worker/workspace/obj-build/browser/app/d:/agent/_work/1/s/src/vctools/crt/vcstartup/src/startup/exe_common.inl:288
9 kernel32.dll BaseThreadInitThunk 

Comment 1

[Tooru Fujisawa [:arai]]

so far I cannot find any case that it doesn't align there, unless we accidentally support module in preloader cache.
I can add more asserts to see if it's file corruption, and if that's the case we can add fallback path.

Comment 2

[Ryan VanderMeulen [:RyanVM]]

No diagnostic assert hits so far in DevEdition 94.0b4 :(. How practical is a backout if we don't make headway on this soon? We don't want to ship a new startup crash in 94.

Comment 3

[Tooru Fujisawa [:arai]]

Attachment: Bug 1734612 - Use soft error and stop reading startup cache file if the content is unexpected. r?tcampbell!

Comment 4

[Tooru Fujisawa [:arai]]

Thank you for checking crash reports :)

the above patch replaces the assertion with soft error.
if the unexpected content is found in the cache file, we ignore such content and stop reading from the cache.

Comment 5

[Tooru Fujisawa [:arai]]

Comment on attachment 9245642 [details]
Bug 1734612 - Use soft error and stop reading startup cache file if the content is unexpected. r?tcampbell!

Beta/Release Uplift Approval Request

• User impact if declined: Startup crash if the cache file is corrupted.
  This has no automated tests or manual tests, since it's basically caused by corrupted file.
• Is this code covered by automated tests?: No
• Has the fix been verified in Nightly?: No
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): This changes assertion to soft error for file corruption case.
  and ignore the remaining of the cache file.
• String changes made/needed:

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8f3257e6d425
Use soft error and stop reading startup cache file if the content is unexpected. r=tcampbell

Comment 7

[Cristina Cozmuta (:CrissCozmuta)]

https://hg.mozilla.org/mozilla-central/rev/8f3257e6d425

Comment 8

[Dianna Smith [:diannaS]]

Comment on attachment 9245642 [details]
Bug 1734612 - Use soft error and stop reading startup cache file if the content is unexpected. r?tcampbell!

Approved for 94.0b6

Comment 9

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-beta/rev/96bf9bcf5a5f