From 804c4a2209bcf6ed4c45386f033e4d0f7c5bfda5 Mon Sep 17 00:00:00 2001 From: "Masami Hiramatsu (Google)" Date: Tue, 10 Feb 2026 17:43:43 +0900 Subject: [PATCH] tracing: Reset last_boot_info if ring buffer is reset Commit 32dc0042528d ("tracing: Reset last-boot buffers when reading out all cpu buffers") resets the last_boot_info when user read out all data via trace_pipe* files. But it is not reset when user resets the buffer from other files. (e.g. write `trace` file) Reset it when the corresponding ring buffer is reset too. Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers Link: https://patch.msgid.link/177071302364.2293046.17895165659153977720.stgit@mhiramat.tok.corp.google.com Fixes: 32dc0042528d ("tracing: Reset last-boot buffers when reading out all cpu buffers") Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index fd470675809b..e884d32b7895 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4127,6 +4127,8 @@ static int tracing_single_release_tr(struct inode *inode, struct file *file) return single_release(inode, file); } +static bool update_last_data_if_empty(struct trace_array *tr); + static int tracing_open(struct inode *inode, struct file *file) { struct trace_array *tr = inode->i_private; @@ -4151,6 +4153,8 @@ static int tracing_open(struct inode *inode, struct file *file) tracing_reset_online_cpus(trace_buf); else tracing_reset_cpu(trace_buf, cpu); + + update_last_data_if_empty(tr); } if (file->f_mode & FMODE_READ) { @@ -5215,6 +5219,7 @@ tracing_set_trace_read(struct file *filp, char __user *ubuf, int tracer_init(struct tracer *t, struct trace_array *tr) { tracing_reset_online_cpus(&tr->array_buffer); + update_last_data_if_empty(tr); return t->init(tr); } @@ -7028,6 +7033,7 @@ int tracing_set_clock(struct trace_array *tr, const char *clockstr) ring_buffer_set_clock(tr->snapshot_buffer.buffer, trace_clocks[i].func); tracing_reset_online_cpus(&tr->snapshot_buffer); #endif + update_last_data_if_empty(tr); if (tr->scratch && !(tr->flags & TRACE_ARRAY_FL_LAST_BOOT)) { struct trace_scratch *tscratch = tr->scratch; -- 2.47.3