2024-03-11 03:08:07

by I Hsin Cheng

Subject: [PATCH] lru_cache: Initialize hlist_head in lc_create

Use INIT_HLIST_HEAD to perform the initialization for each pointer to
struct list_head in the variable "slot" to provide more safety and
prevent possible bugs from uninitialized behavior.

Signed-off-by: I-HSIN CHENG <[email protected]>
---
lib/lru_cache.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/lib/lru_cache.c b/lib/lru_cache.c
index b3d918761..f2197aae1 100644
--- a/lib/lru_cache.c
+++ b/lib/lru_cache.c
@@ -105,6 +105,9 @@ struct lru_cache *lc_create(const char *name, struct kmem_cache *cache,
if (!lc)
goto out_fail;

+ for (int i = 0; i < e_count; i++)
+ INIT_HLIST_HEAD(slot + (i * sizeof(struct hlist_head)));
+
INIT_LIST_HEAD(&lc->in_use);
INIT_LIST_HEAD(&lc->lru);
INIT_LIST_HEAD(&lc->free);
--
2.34.1

2024-04-16 13:42:29

by Lars Ellenberg

Subject: Re: [PATCH] lru_cache: Initialize hlist_head in lc_create

On Mon, Mar 11, 2024 at 11:07:35AM +0800, I-HSIN CHENG wrote:
> Use INIT_HLIST_HEAD to perform the initialization for each pointer to
> struct list_head in the variable "slot" to provide more safety and
> prevent possible bugs from uninitialized behavior.

Completely pointless. It is kcalloc'd. Why explicitly zero-out something
that was already explicitly zeroed out to begin with.

Lars