[REGRESSION 6.0.x / 6.1.x] NULL dereferencing at tracing

[Takashi Iwai]

Hi Steven,

we've got a bug report indicating the NULL dereference at the recent
tracing changes, showing at the start of KDE.  The details including
the dmesg are found at:
  https://bugzilla.opensuse.org/show_bug.cgi?id=1204705

It was reported at first for 6.0.3, and confirmed that the problem
persists with 6.1-rc, too.

The culprit seems to be the commit
f3ddb74ad0790030c9592229fb14d8c451f4e9a8
    tracing: Wake up ring buffer waiters on closing of the file
and reverting it seems fixing the problem.

Could you take a look?


thanks,

Takashi