1892132 - Crash in [@ mozilla::detail::RWLockImpl::readLock]

Status: RESOLVED DUPLICATE of bug 1892131

(Core :: Widget: Gtk, defect)

Description

[BugBot [:suhaib / :marco/ :calixte]]

Crash report: https://crash-stats.mozilla.org/report/index/0006bb45-d1af-4547-8c56-4f75d0240417

Reason: SIGSEGV / SEGV_MAPERR

Top 10 frames of crashing thread:

0  libc.so.6  __pthread_rwlock_rdlock_full64  nptl/nptl/pthread_rwlock_common.c:298
0  libc.so.6  ___pthread_rwlock_rdlock  nptl/nptl/pthread_rwlock_rdlock.c:26
1  firefox-bin  mozilla::detail::RWLockImpl::readLock  mozglue/misc/RWLock_posix.cpp:38
2  libxul.so  mozilla::RWLock::ReadLock  xpcom/threads/RWLock.h:60
2  libxul.so  mozilla::BaseAutoReadLock<mozilla::RWLock>::BaseAutoReadLock  xpcom/threads/RWLock.h:111
2  libxul.so  nsWindow::GetOpaqueRegion const  widget/gtk/nsWindow.cpp:6931
3  libxul.so  mozilla::widget::GtkCompositorWidget::GetTransparentRegion  widget/gtk/GtkCompositorWidget.cpp:146
4  libxul.so  mozilla::wr::RenderCompositorSWGL::AllocateMappedBuffer  gfx/webrender_bindings/RenderCompositorSWGL.cpp:155
5  libxul.so  mozilla::wr::RenderCompositorSWGL::StartCompositing  gfx/webrender_bindings/RenderCompositorSWGL.cpp:193
6  libxul.so  <webrender::compositor::sw_compositor::SwCompositor as webrender::composite::Compositor>::start_compositing  gfx/wr/webrender/src/compositor/sw_compositor.rs:1462

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

• First crash report: 2024-04-17
• Process type: GPU
• Is startup crash: No
• Has user comments: No
• Is null crash: Yes - all crashes happened on null or near null memory address

By analyzing the backtrace, the regression may have been introduced by a patch [1] to fix Bug 1891414.

[1] https://hg.mozilla.org/mozilla-central/rev?node=e7acb510da15

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