<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - Xwayland crashes with SIGBUS when processing PutImage" href="https://bugs.freedesktop.org/show_bug.cgi?id=93750#c5">Comment # 5</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - Xwayland crashes with SIGBUS when processing PutImage" href="https://bugs.freedesktop.org/show_bug.cgi?id=93750">bug 93750</a> from <a class="email" href="mailto:jadahl@gmail.com" title="Jonas Ådahl <jadahl@gmail.com>"> Jonas Ådahl</a> <pre>(In reply to Pekka Paalanen from <a href="show_bug.cgi?id=93750#c4">comment #4</a>) > (In reply to Jonas Ådahl from <a href="show_bug.cgi?id=93750#c2">comment #2</a>) > > One thing I noticed was that /run/user/1000/ was 100% full when SIGBUS was > > hit, but I couldn't see any error messages about failed allocation, but not > > sure that has anything to do with it. > > I think this is the cause. For an explanation why a full fs causes a SIGBUS, > see: > <a href="http://cgit.freedesktop.org/wayland/wayland/commit/">http://cgit.freedesktop.org/wayland/wayland/commit/</a> > ?id=011b6954031a25de8d9eb39631b6837553bb3cfb > > Can you somehow check if the target memory is indeed mmapped from that fs > and if so, how does the file get created? This would allow a graceful > failure at least. Seems my xwayland is building without posix_fallocate support, so it is most likely the "on-the-fly ENOSPC" SIGBUS then. It also seems xwayland will never build with posix_fallocate because it is missing the configure.ac rule. Will send a patch fixing that, and see if we managed to fail gracefully. Should ftruncate even be supported? To support it while being able to fail gracefully (i.e. not crash) we'd need to add sigbus handlers here and there I assume. > > I think the next question would be whether the mmap is of the expected size, > and should something throttle/reclaim somewhere to avoid filling the fs. We already throttle wl_surface_attach right? So maybe we could just throttle buffer creation as well will work just fine.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>