tracing: Have tracing_snapshot_instance_cond() write errors to the appropriate instance

[ Upstream commit 9d52727f8043cfda241ae96896628d92fa9c50bb ]

If a trace instance has a failure with its snapshot code, the error
message is to be written to that instance's buffer. But currently, the
message is written to the top level buffer. Worse yet, it may also disable
the top level buffer and not the instance that had the issue.

Link: https://lkml.kernel.org/r/20230405022341.688730321@goodmis.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ross Zwisler <zwisler@google.com>
Fixes: 2824f50332 ("tracing: Make the snapshot trigger work with instances")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Steven Rostedt (Google) 2023-04-04 22:21:14 -04:00 committed by Greg Kroah-Hartman
parent 5620eeb379
commit f58574f238

View File

@ -1112,22 +1112,22 @@ static void tracing_snapshot_instance_cond(struct trace_array *tr,
unsigned long flags;
if (in_nmi()) {
internal_trace_puts("*** SNAPSHOT CALLED FROM NMI CONTEXT ***\n");
internal_trace_puts("*** snapshot is being ignored ***\n");
trace_array_puts(tr, "*** SNAPSHOT CALLED FROM NMI CONTEXT ***\n");
trace_array_puts(tr, "*** snapshot is being ignored ***\n");
return;
}
if (!tr->allocated_snapshot) {
internal_trace_puts("*** SNAPSHOT NOT ALLOCATED ***\n");
internal_trace_puts("*** stopping trace here! ***\n");
tracing_off();
trace_array_puts(tr, "*** SNAPSHOT NOT ALLOCATED ***\n");
trace_array_puts(tr, "*** stopping trace here! ***\n");
tracer_tracing_off(tr);
return;
}
/* Note, snapshot can not be used when the tracer uses it */
if (tracer->use_max_tr) {
internal_trace_puts("*** LATENCY TRACER ACTIVE ***\n");
internal_trace_puts("*** Can not use snapshot (sorry) ***\n");
trace_array_puts(tr, "*** LATENCY TRACER ACTIVE ***\n");
trace_array_puts(tr, "*** Can not use snapshot (sorry) ***\n");
return;
}