tracing: Two fixes for 5.16
Subsystems (2)
Steven Rostedt
maintainercover tracing: Two fixes for 5.16
[ Resending because my email server was not connecting to mail.kernel.org ]
Two fixes to event pid filtering:
- Have created events reflect the current state of pid filtering
- Test pid filtering on discard test of recorded logic. (Also clean up the if statement to be cleaner).
Steven Rostedt (VMware) (2):
tracing: Check pid filtering when creating events
tracing: Fix pid filtering when triggers are attached
----
kernel/trace/trace.h | 24 ++++++++++++++++++------ kernel/trace/trace_events.c | 12 ++++++++++++ 2 files changed, 30 insertions(+), 6 deletions(-)
Steven Rostedt
maintainerPATCH 1/2 tracing: Check pid filtering when creating events
From: "Steven Rostedt (VMware)" <[email protected]>
When pid filtering is activated in an instance, all of the events trace files for that instance has the PID_FILTER flag set. This determines whether or not pid filtering needs to be done on the event, otherwise the event is executed as normal.
If pid filtering is enabled when an event is created (via a dynamic event or modules), its flag is not updated to reflect the current state, and the events are not filtered properly.
--- kernel/trace/trace_events.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
kernel/trace/trace_events.c +12 -0
@@ -2678,12 +2678,24 @@ static struct trace_event_file * trace_create_new_event(struct trace_event_call *call, struct trace_array *tr) { + struct trace_pid_list *no_pid_list; +struct trace_pid_list *pid_list;struct trace_event_file *file; +unsigned int first; file =kmem_cache_alloc (file_cachep,GFP_TRACE );if (!file)return NULL ; + pid_list =rcu_dereference_protected (tr->filtered_pids, +lockdep_is_held (&event_mutex)); + no_pid_list =rcu_dereference_protected (tr->filtered_no_pids, +lockdep_is_held (&event_mutex)); + +if (!trace_pid_list_first (pid_list, &first) || + !trace_pid_list_first (pid_list, &first)) + file->flags |=EVENT_FILE_FL_PID_FILTER ; + file->event_call = call; file->tr = tr;atomic_set (&file->sm_ref,0 );
Signature · 1 line
2.33.0
Steven Rostedt
maintainerPATCH 2/2 tracing: Fix pid filtering when triggers are attached
In reply to Steven RostedtFrom: "Steven Rostedt (VMware)" <[email protected]>
If a event is filtered by pid and a trigger that requires processing of the event to happen is a attached to the event, the discard portion does not take the pid filtering into account, and the event will then be recorded when it should not have been.
--- kernel/trace/trace.h | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-)
kernel/trace/trace.h +18 -6
@@ -1366,14 +1366,26 @@ __event_trigger_test_discard(struct trace_event_file *file,if (eflags &EVENT_FILE_FL_TRIGGER_COND ) *tt =event_triggers_call (file, buffer, entry, event); -if (test_bit (EVENT_FILE_FL_SOFT_DISABLED_BIT , &file->flags) || - (unlikely (file->flags &EVENT_FILE_FL_FILTERED ) && - !filter_match_preds (file->filter, entry))) { -__trace_event_discard_commit (buffer, event); -return true; - } +if (likely (!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED | +EVENT_FILE_FL_FILTERED | +EVENT_FILE_FL_PID_FILTER )))) +return false; + +if (file->flags &EVENT_FILE_FL_SOFT_DISABLED ) + goto discard; + +if (file->flags &EVENT_FILE_FL_FILTERED && + !filter_match_preds (file->filter, entry)) + goto discard; + +if ((file->flags &EVENT_FILE_FL_PID_FILTER ) && +trace_event_ignore_this_pid (file)) + goto discard;return false; + discard: +__trace_event_discard_commit (buffer, event); +return true; }/**
Signature · 1 line
2.33.0