Merge tag 'trace-v6.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix timerlat with use of FORTIFY_SOURCE
FORTIFY_SOURCE was added to the stack tracer where it compares the
entry->caller array to having entry->size elements.
timerlat has the following:
memcpy(&entry->caller, fstack->calls, size);
entry->size = size;
Which triggers FORTIFY_SOURCE as the caller is populated before the
entry->size is initialized.
Swap the order to satisfy FORTIFY_SOURCE logic.
- Add down_write(trace_event_sem) when adding trace events in modules
Trace events being added to the ftrace_events array are protected by
the trace_event_sem semaphore. But when loading modules that have
trace events, the addition of the events are not protected by the
semaphore and loading two modules that have events at the same time
can corrupt the list.
Also add a lockdep_assert_held(trace_event_sem) to
_trace_add_event_dirs() to confirm it is held when iterating the
list.
* tag 'trace-v6.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Add down_write(trace_event_sem) when adding trace event
tracing/osnoise: Fix crash in timerlat_dump_stack()
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 1205312..d01e5c9 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -3136,7 +3136,10 @@ __register_event(struct trace_event_call *call, struct module *mod)
if (ret < 0)
return ret;
+ down_write(&trace_event_sem);
list_add(&call->list, &ftrace_events);
+ up_write(&trace_event_sem);
+
if (call->flags & TRACE_EVENT_FL_DYNAMIC)
atomic_set(&call->refcnt, 0);
else
@@ -3750,6 +3753,8 @@ __trace_add_event_dirs(struct trace_array *tr)
struct trace_event_call *call;
int ret;
+ lockdep_assert_held(&trace_event_sem);
+
list_for_each_entry(call, &ftrace_events, list) {
ret = __trace_add_new_event(call, tr);
if (ret < 0)
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 6819b93..fd259da 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -637,8 +637,8 @@ __timerlat_dump_stack(struct trace_buffer *buffer, struct trace_stack *fstack, u
entry = ring_buffer_event_data(event);
- memcpy(&entry->caller, fstack->calls, size);
entry->size = fstack->nr_entries;
+ memcpy(&entry->caller, fstack->calls, size);
trace_buffer_unlock_commit_nostack(buffer, event);
}
