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| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-06-29 23:45:56 -0400 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-06-30 14:29:33 -0400 |
| commit | 7ef282e05132d56b6f6b71e3873f317664bea78b (patch) | |
| tree | 8784d94d60792f48e068b83b21fd00db73dfb512 /kernel/trace/trace.h | |
| parent | e6bc5b3f423825220a3232ddf08399658c918671 (diff) | |
| download | linux-7ef282e05132d56b6f6b71e3873f317664bea78b.tar.gz linux-7ef282e05132d56b6f6b71e3873f317664bea78b.tar.bz2 linux-7ef282e05132d56b6f6b71e3873f317664bea78b.zip | |
tracing: Move pipe reference to trace array instead of current_tracer
If a process has the trace_pipe open on a trace_array, the current tracer
for that trace array should not be changed. This was original enforced by a
global lock, but when instances were introduced, it was moved to the
current_trace. But this structure is shared by all instances, and a
trace_pipe is for a single instance. There's no reason that a process that
has trace_pipe open on one instance should prevent another instance from
changing its current tracer. Move the reference counter to the trace_array
instead.
This is marked as "Fixes" but is more of a clean up than a true fix.
Backport if you want, but its not critical.
Fixes: cf6ab6d9143b1 ("tracing: Add ref count to tracer for when they are being read by pipe")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.h')
| -rw-r--r-- | kernel/trace/trace.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 13db4000af3f..f21607f87189 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -356,6 +356,7 @@ struct trace_array { struct trace_event_file *trace_marker_file; cpumask_var_t tracing_cpumask; /* only trace on set CPUs */ int ref; + int trace_ref; #ifdef CONFIG_FUNCTION_TRACER struct ftrace_ops *ops; struct trace_pid_list __rcu *function_pids; @@ -547,7 +548,6 @@ struct tracer { struct tracer *next; struct tracer_flags *flags; int enabled; - int ref; bool print_max; bool allow_instances; #ifdef CONFIG_TRACER_MAX_TRACE |