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

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: 2824f50332486 ("tracing: Make the snapshot trigger work with instances")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 937e9676dfd42fbff3e4efa02aab169325f10d84..ed1d1093f5e9d81b1e6c1702b360f306086342e4 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1149,22 +1149,22 @@ 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;
        }