[PATCH v2] tracing: Report every TP_printk double dereference
David Carlier <[email protected]>
| Newsgroups | org.kernel.vger.linux-kernel,org.kernel.vger.linux-trace-kernel |
|---|---|
| Message-ID | <[email protected]> |
WARN_ONCE() splats once per call site, so only the first offending event
registered is ever reported. The tree currently has six:
ice_{rx,tx}_dim_template, two hfi1 txq events, mtu3_ep and edma_log_io.
Whichever registers first hides the rest, and each has to be found again
on the next boot.
Add a pr_warn() next to the WARN_ONCE() so every offender is listed, the
same way test_event_printk() already pairs WARN_ON_ONCE() with pr_warn()
for unsafe %p* dereferences. The WARN_ONCE() stays so the condition still
fails tests and panics under panic_on_warn.
Suggested-by: Steven Rostedt <[email protected]>
Signed-off-by: David Carlier <[email protected]>
---
kernel/trace/trace_events.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index a8590d2394e3..ce902482ec7c 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -415,6 +415,8 @@ static void test_double_dereference(const char *str, int len,
ptr += 5;
for (; ptr < end; ptr++) {
if (ptr[0] == '-' && ptr[1] == '>') {
+ pr_warn("TRACE EVENT ERROR: Event %s has double dereference in TP_printk: %.*s\n",
+ trace_event_name(call), len, str);
WARN_ONCE(1, "Event %s has double dereference in TP_printk: %.*s\n",
trace_event_name(call), len, str);
return;
--
2.55.0