From c20a7d50c47e9448604a3fe643ca2bcac305c66e Mon Sep 17 00:00:00 2001 From: "Masami Hiramatsu (Google)" Date: Tue, 28 Jul 2026 21:49:51 +0900 Subject: [PATCH] tracing/mmiotrace: Reset dropped_count in mmio_reset_data() [ Upstream commit c786d2bdf1f3964deee192ad942dee2a741c1e2c ] 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) Signed-off-by: Steven Rostedt Signed-off-by: Sasha Levin --- kernel/trace/trace_mmiotrace.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index 4d9e5c830dbe..c523ce5aa495 100644 --- 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); }