From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
[ Upstream commit 51270d573a8d9dd5afdc7934de97d66c0e14b5fd ]
I'm updating __assign_str() and will be removing the second parameter. To
make sure that it does not break anything, I make sure that it matches the
__string() field, as that is where the string is actually going to be
saved in. To make sure there's nothing that breaks, I added a WARN_ON() to
make sure that what was used in __string() is the same that is used in
__assign_str().
In doing this change, an error was triggered as __assign_str() now expects
the string passed in to be a char * value. I instead had the following
warning:
include/trace/events/qdisc.h: In function ‘trace_event_raw_event_qdisc_reset’:
include/trace/events/qdisc.h:91:35: error: passing argument 1 of 'strcmp' from incompatible pointer type [-Werror=incompatible-pointer-types]
91 | __assign_str(dev, qdisc_dev(q));
That's because the qdisc_enqueue() and qdisc_reset() pass in qdisc_dev(q)
to __assign_str() and to __string(). But that function returns a pointer
to struct net_device and not a string.
It appears that these events are just saving the pointer as a string and
then reading it as a string as well.
Use qdisc_dev(q)->name to save the device instead.
Fixes: a34dac0b90552 ("net_sched: add tracepoints for qdisc_reset() and qdisc_destroy()")
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Reviewed-by: Jamal Hadi Salim <jhs@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
include/trace/events/qdisc.h | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h
index 330d32d84485b..a50df41634c58 100644
--- a/include/trace/events/qdisc.h
+++ b/include/trace/events/qdisc.h
@@ -53,14 +53,14 @@ TRACE_EVENT(qdisc_reset,
TP_ARGS(q),
TP_STRUCT__entry(
- __string( dev, qdisc_dev(q) )
- __string( kind, q->ops->id )
- __field( u32, parent )
- __field( u32, handle )
+ __string( dev, qdisc_dev(q)->name )
+ __string( kind, q->ops->id )
+ __field( u32, parent )
+ __field( u32, handle )
),
TP_fast_assign(
- __assign_str(dev, qdisc_dev(q));
+ __assign_str(dev, qdisc_dev(q)->name);
__assign_str(kind, q->ops->id);
__entry->parent = q->parent;
__entry->handle = q->handle;
@@ -78,14 +78,14 @@ TRACE_EVENT(qdisc_destroy,
TP_ARGS(q),
TP_STRUCT__entry(
- __string( dev, qdisc_dev(q) )
- __string( kind, q->ops->id )
- __field( u32, parent )
- __field( u32, handle )
+ __string( dev, qdisc_dev(q)->name )
+ __string( kind, q->ops->id )
+ __field( u32, parent )
+ __field( u32, handle )
),
TP_fast_assign(
- __assign_str(dev, qdisc_dev(q));
+ __assign_str(dev, qdisc_dev(q)->name);
__assign_str(kind, q->ops->id);
__entry->parent = q->parent;
__entry->handle = q->handle;
--
2.43.0
