[PATCH 1/2] sched: fix stale get_pref_llc() stub for !CONFIG_SCHED_CACHE

[Yafang Shao]

Commit b636fef85bda ("sched/cache: Introduce task_struct->sched_cache_grp
to fix UAF") switched get_pref_llc() from taking a struct mm_struct * to
taking the task's struct sched_cache_group *, but only updated the
CONFIG_SCHED_CACHE definition and its caller: the stub in the
!CONFIG_SCHED_CACHE branch kept the old mm_struct parameter.

Fixes: b636fef85bda ("sched/cache: Introduce task_struct->sched_cache_grp to fix UAF")
Cc: <stable@xxxxxxxxxxxxxxx> #v7.2.x
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
Reviewed-by: Gregory Price (Meta) <gourry@xxxxxxxxxx>
Reviewed-by: Chen Yu <yu.c.chen@xxxxxxxxx>
Reviewed-by: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
---
 kernel/sched/fair.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 57360f5cdde4..973647ad6c2d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2194,7 +2194,7 @@ void init_sched_mm(struct task_struct *p) { }
 static void task_tick_cache(struct rq *rq, struct task_struct *p) { }
 
 static inline int get_pref_llc(struct task_struct *p,
-			       struct mm_struct *mm)
+			       struct sched_cache_group *grp)
 {
 	return -1;
 }
-- 
2.52.0