Commit 804c4a22 authored by Masami Hiramatsu (Google)'s avatar Masami Hiramatsu (Google) Committed by Steven Rostedt (Google)
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tracing: Reset last_boot_info if ring buffer is reset 

Commit 32dc0042 ("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 <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/177071302364.2293046.17895165659153977720.stgit@mhiramat.tok.corp.google.com


Fixes: 32dc0042 ("tracing: Reset last-boot buffers when reading out all cpu buffers")
Signed-off-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent f844282d

kernel/trace/trace.c

+6 −0
Original line number Diff line number Diff line
@@ -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;