[PATCH 1/2] tracing: Have tracing_snapshot_instance_cond() write errors to the appropriate instance

From: Steven Rostedt
Date: Tue Apr 04 2023 - 19:03:17 EST


From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>

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.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 2824f50332486 ("tracing: Make the snapshot trigger work with instances")
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 937e9676dfd4..ed1d1093f5e9 100644
--- 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;
}

--
2.39.2