[PATCH 2/2] rv: Fix wrong type cast in reactors_show() and monitor_reactor_show()

From: Nam Cao
Date: Sun Jul 27 2025 - 13:31:40 EST


Argument 'p' of reactors_show() and monitor_reactor_show() is not a pointer
to struct rv_reactor, it is actually a pointer to the list_head inside
struct rv_reactor. Therefore it's wrong to cast 'p' to struct rv_reactor *.

This wrong type cast has been there since the beginning. But it still
worked because the list_head was the first field in struct rv_reactor_def.
This is no longer true since commit 3d3c376118b5 ("rv: Merge struct
rv_reactor_def into struct rv_reactor") moved the list_head, and this wrong
type cast became a functional problem.

Properly use container_of() instead.

Fixes: 3d3c376118b5 ("rv: Merge struct rv_reactor_def into struct rv_reactor")
Signed-off-by: Nam Cao <namcao@xxxxxxxxxxxxx>
---
kernel/trace/rv/rv_reactors.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/rv/rv_reactors.c b/kernel/trace/rv/rv_reactors.c
index 106f2c4740f2..d32859fec238 100644
--- a/kernel/trace/rv/rv_reactors.c
+++ b/kernel/trace/rv/rv_reactors.c
@@ -86,7 +86,7 @@ static struct rv_reactor *get_reactor_rdef_by_name(char *name)
*/
static int reactors_show(struct seq_file *m, void *p)
{
- struct rv_reactor *reactor = p;
+ struct rv_reactor *reactor = container_of(p, struct rv_reactor, list);

seq_printf(m, "%s\n", reactor->name);
return 0;
@@ -139,7 +139,7 @@ static const struct file_operations available_reactors_ops = {
static int monitor_reactor_show(struct seq_file *m, void *p)
{
struct rv_monitor *mon = m->private;
- struct rv_reactor *reactor = p;
+ struct rv_reactor *reactor = container_of(p, struct rv_reactor, list);

if (mon->reactor == reactor)
seq_printf(m, "[%s]\n", reactor->name);
--
2.39.5