[PATCH v2 2/3] Replace invocation of weak PRNG inside mm/slab_common.c

[david.keisarschm@mail.huji.ac.il]

From: David <david.keisarschm@mail.huji.ac.il>

We changed the invocation
 of prandom_u32_state to
 get_random_u32. We also omitted
the initial seeding for the state,
since get_random_u32 maintains
 its own, so there is no need
 to keep storing the state of
 prandom_u32_state here.

Signed-off-by: David <david.keisarschm@mail.huji.ac.il>
---
 mm/slab_common.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/mm/slab_common.c b/mm/slab_common.c
index b79755716..6ac68b9a6 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -1130,7 +1130,7 @@ EXPORT_SYMBOL(kmalloc_large_node);
 
 #ifdef CONFIG_SLAB_FREELIST_RANDOM
 /* Randomize a generic freelist */
-static void freelist_randomize(struct rnd_state *state, unsigned int *list,
+static void freelist_randomize(unsigned int *list,
 			       unsigned int count)
 {
 	unsigned int rand;
@@ -1141,7 +1141,7 @@ static void freelist_randomize(struct rnd_state *state, unsigned int *list,
 
 	/* Fisher-Yates shuffle */
 	for (i = count - 1; i > 0; i--) {
-		rand = prandom_u32_state(state);
+		rand = get_random_u32();
 		rand %= (i + 1);
 		swap(list[i], list[rand]);
 	}
@@ -1151,7 +1151,6 @@ static void freelist_randomize(struct rnd_state *state, unsigned int *list,
 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
 				    gfp_t gfp)
 {
-	struct rnd_state state;
 
 	if (count < 2 || cachep->random_seq)
 		return 0;
@@ -1160,10 +1159,7 @@ int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
 	if (!cachep->random_seq)
 		return -ENOMEM;
 
-	/* Get best entropy at this stage of boot */
-	prandom_seed_state(&state, get_random_long());
-
-	freelist_randomize(&state, cachep->random_seq, count);
+	freelist_randomize(cachep->random_seq, count);
 	return 0;
 }
 
-- 
2.38.0