as_pool_build_search_tokens sometimes crashes on strcmp()

[luk1337]

Hello, I originally reported this issue to KDE, but I was told to report it here instead. I'm not quite sure what's in the pool that makes this issue happen, but if necessary, I can try add some logging messages for that.

Version: 0.15.5-1.fc37
GDB backtrace:

(gdb) bt
#0  __strcmp_avx2 () at ../sysdeps/x86_64/multiarch/strcmp-avx2.S:287
#1  0x00007f1b385d042d in as_pool_build_search_tokens (pool=<optimized out>, search=0x7f1aa97cedb8 "androidstudio")
    at ../src/as-pool.c:2154
#2  0x00007f1b385d0814 in as_pool_search (pool=0x560b08632060, search=0x7f1aa97cedb8 "androidstudio") at ../src/as-pool.c:2226
#3  0x00007f1b3988f584 in AppStream::Pool::search(QString const&) const (this=this@entry=0x560b086247f8, term=...)
    at ../qt/pool.cpp:172
#4  0x00007f1b69bf72b1 in InstallerRunner::findComponentsByString(QString const&) (query=..., this=0x560b086247e0)
    at /usr/src/debug/plasma-workspace-5.26.1-1.fc37.x86_64/runners/appstream/appstreamrunner.cpp:163
#5  InstallerRunner::match(Plasma::RunnerContext&) (this=0x560b086247e0, context=...)
    at /usr/src/debug/plasma-workspace-5.26.1-1.fc37.x86_64/runners/appstream/appstreamrunner.cpp:93
#6  0x00007f1ba015404f in Plasma::FindMatchesJob::run(QSharedPointer<ThreadWeaver::JobInterface>, ThreadWeaver::Thread*)
    (this=0x560b08b7e990, self=...) at /usr/src/debug/kf5-krunner-5.99.0-1.fc37.x86_64/src/runnerjobs.cpp:140
#7  0x00007f1ba011ea4e in ThreadWeaver::Executor::run(QSharedPointer<ThreadWeaver::JobInterface> const&, ThreadWeaver::Thread*)
    (this=<optimized out>, job=<optimized out>, thread=<optimized out>)
    at /usr/src/debug/kf5-threadweaver-5.99.0-1.fc37.x86_64/src/executor.cpp:33
#8  0x00007f1ba011f885 in ThreadWeaver::Job::execute(QSharedPointer<ThreadWeaver::JobInterface> const&, ThreadWeaver::Thread*)
    (this=<optimized out>, self=..., th=0x560b085e1970) at /usr/src/debug/kf5-threadweaver-5.99.0-1.fc37.x86_64/src/job.cpp:64
#9  0x00007f1ba0123458 in ThreadWeaver::Thread::run() (this=0x560b085e1970)
    at /usr/src/debug/kf5-threadweaver-5.99.0-1.fc37.x86_64/src/thread.cpp:98
#10 0x00007f1bbb8e8487 in QThreadPrivate::start(void*) (arg=0x560b085e1970) at thread/qthread_unix.cpp:330
#11 0x00007f1bba8af14d in start_thread (arg=<optimized out>) at pthread_create.c:442
#12 0x00007f1bba930950 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

[ximion]

Do you have any way to reproduce this? The point where it crashes makes very little sense, as it's in the middle of a section that compares strings that should all be valid at that point. Might be some threading issue (could even be in KRunner...), but having a way to reproduce this would help a lot!

[luk1337]

The issue was supposedly fixed @ KDE, so maybe it was just race condition on their end. I'll close this issue for now, and maybe reopen again if I ever get the same backtrace.

[ximion]

Possibly the string the passed in was freed at a bad time by a different thread. Thanks for the follow-up and closing this issue :-)