tracing/mmiotrace: Reset dropped_count in mmio_reset_data()

mmio_reset_data() is called during tracer initialization, reset, and
start. While it resets overrun_detected and prev_overruns, it neglects
to reset dropped_count. Consequently, dropped event counts from prior
tracing sessions persist in dropped_count and corrupt overrun reports
in subsequent runs.

Fix this by explicitly calling atomic_set(&dropped_count, 0) in
mmio_reset_data().

Link: https://patch.msgid.link/178524299122.56416.16277704230639425172.stgit@devnote2
Fixes: 173ed24ee2d6 ("mmiotrace: count events lost due to not recording")
Assisted-by: Antigravity:gemini-3.6-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index b88b8d9923adbd6e7cb4c321ff4ee16487e4b108..e064ba3f28cb95d409a9bffe7a00abe0960cf882 100644 (file)
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -29,6 +29,7 @@ static void mmio_reset_data(struct trace_array *tr)
 {
        overrun_detected = false;
        prev_overruns = 0;
+       atomic_set(&dropped_count, 0);
 
        tracing_reset_online_cpus(&tr->array_buffer);
 }