user_events: Add trace event call as root for low permission cases

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Tracefs by default is locked down heavily. System operators can open up
some files, such as user_events to a broader set of users. These users
do not have access within tracefs beyond just the user_event files. Due
to this restriction the trace_add_event_call/remove calls will silently
fail since the caller does not have permissions to create directories.

To fix this trace_add_event_call/remove calls will be issued with
override creds of the global root UID. Creds are reverted immediately
afterward.

Link: https://lkml.kernel.org/r/20220308222807.2040-1-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

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Beau Belgrave 2022-03-08 14:28:07 -08:00 • committed by Steven Rostedt (Google)

parent bc47ee4844

commit 089331d473

1 changed files with 37 additions and 2 deletions

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39

kernel/trace/trace_events_user.c

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