6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: levi.yun <yeoreum.yun@xxxxxxx>
commit 7dc836187f7c6f70a82b4521503e9f9f96194581 upstream.
pid_list_fill_irq() runs via irq_work.
When CONFIG_PREEMPT_RT is disabled, it would run in irq_context.
so it shouldn't sleep while memory allocation.
Change gfp flags from GFP_KERNEL to GFP_NOWAIT to prevent sleep in
irq_work.
This change wouldn't impact functionality in practice because the worst-size
is 2K.
Cc: stable@xxxxxxxxxxx
Fixes: 8d6e90983ade2 ("tracing: Create a sparse bitmask for pid filtering")
Link: https://lore.kernel.org/20240704150226.1359936-1-yeoreum.yun@xxxxxxx
Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Signed-off-by: levi.yun <yeoreum.yun@xxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/trace/pid_list.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/kernel/trace/pid_list.c
+++ b/kernel/trace/pid_list.c
@@ -354,7 +354,7 @@ static void pid_list_refill_irq(struct i
while (upper_count-- > 0) {
union upper_chunk *chunk;
- chunk = kzalloc(sizeof(*chunk), GFP_KERNEL);
+ chunk = kzalloc(sizeof(*chunk), GFP_NOWAIT);
if (!chunk)
break;
*upper_next = chunk;
@@ -365,7 +365,7 @@ static void pid_list_refill_irq(struct i
while (lower_count-- > 0) {
union lower_chunk *chunk;
- chunk = kzalloc(sizeof(*chunk), GFP_KERNEL);
+ chunk = kzalloc(sizeof(*chunk), GFP_NOWAIT);
if (!chunk)
break;
*lower_next = chunk;
