1991804 - Startup crash in [@ mozilla::MozPromise<T>::CreateAndResolve]

Status: NEW

(Core :: MFBT, defect)

Description

[BugBot [:suhaib / :marco]]

Crash report: https://crash-stats.mozilla.org/report/index/191a713a-c8c3-41db-83d6-7f5a20250927

Reason: EXCEPTION_ACCESS_VIOLATION_WRITE

Top 10 frames of crashing thread:

0  xul.dll  mozilla::MozPromise<mozilla::ipc::LaunchResults, mozilla::ipc::LaunchError, 1>::CreateAndResolve  xpcom/threads/MozPromise.h:267
0  xul.dll  mozilla::ipc::WindowsProcessLauncher::DoLaunch  ipc/glue/GeckoChildProcessHost.cpp
1  xul.dll  mozilla::ipc::BaseProcessLauncher::PerformAsyncLaunch  ipc/glue/GeckoChildProcessHost.cpp:1075
2  xul.dll  mozilla::detail::RunnableMethodArguments<>::apply<mozilla::ipc::BaseProcessLauncher, RefPtr<mozilla::MozPromise<mozilla::ipc::LaunchResults, mozilla::ipc::LaunchError, 1> >  const  xpcom/threads/nsThreadUtils.h:1083
2  xul.dll  std::invoke  /builds/worker/fetches/vs/VC/Tools/MSVC/14.39.33519/include/type_traits:1729
2  xul.dll  std::_Apply_impl  /builds/worker/fetches/vs/VC/Tools/MSVC/14.39.33519/include/tuple:1077
2  xul.dll  std::apply  /builds/worker/fetches/vs/VC/Tools/MSVC/14.39.33519/include/tuple:1088
2  xul.dll  mozilla::detail::RunnableMethodArguments<>::apply  xpcom/threads/nsThreadUtils.h:1081
2  xul.dll  mozilla::detail::MethodCall<mozilla::MozPromise<mozilla::ipc::LaunchResults, mozilla::ipc::LaunchError, 1>, RefPtr<mozilla::MozPromise<mozilla::ipc::LaunchResults, mozilla::ipc::LaunchError, 1> >   xpcom/threads/MozPromise.h:1711
2  xul.dll  mozilla::detail::ProxyRunnable<mozilla::MozPromise<mozilla::ipc::LaunchResults, mozilla::ipc::LaunchError, 1>, RefPtr<mozilla::MozPromise<mozilla::ipc::LaunchResults, mozilla::ipc::LaunchError, 1> >   xpcom/threads/MozPromise.h:1731

By querying Nightly crashes reported within the last 2 months, here are some insights about the signature:

• First crash report: 2025-09-27
• Process type: Parent
• Is startup crash: Yes - 8 out of 12 crashes happened during startup
• Has user comments: No
• Is null crash: No

By analyzing the backtrace, the regression may have been introduced by a patch [1] to fix Bug 1990641.

[1] https://hg.mozilla.org/mozilla-central/rev?node=8d66d2c44db4

:sergesanspaille, since you are the author of the potential regressor, could you please take a look?

Comment 1

[[:sergesanspaille]]

The mentionned bug is a no-op. As showcased by https://godbolt.org/z/fsGfWdsnG the three syntaxes to add a noreturn attribute are equivalent and lead to the same LLVM IR