[PATCH 09/17] lib/list_sort: fix function type mismatches

Sami Tolvanen
2021-03-12T00:50:21Z

Casting the comparison function to a different type trips indirect
call Control-Flow Integrity (CFI) checking. Remove the additional
consts from cmp_func, and the now unneeded casts.

Fixes: 043b3f7b6388 ("lib/list_sort: simplify and remove MAX_LIST_LENGTH_BITS")
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
lib/list_sort.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/list_sort.c b/lib/list_sort.c
index 52f0c258c895..b14accf4ef83 100644
--- a/lib/list_sort.c
+++ b/lib/list_sort.c
@@ -8,7 +8,7 @@
#include <linux/list.h>

typedef int __attribute__((nonnull(2,3))) (*cmp_func)(void *,
- struct list_head const *, struct list_head const *);
+ struct list_head *, struct list_head *);

/*
* Returns a list organized in an intermediate format suited
@@ -227,7 +227,7 @@ void list_sort(void *priv, struct list_head *head,
if (likely(bits)) {
struct list_head *a = *tail, *b = a->prev;

- a = merge(priv, (cmp_func)cmp, b, a);
+ a = merge(priv, cmp, b, a);
/* Install the merged result in place of the inputs */
a->prev = b->prev;
*tail = a;
@@ -249,10 +249,10 @@ void list_sort(void *priv, struct list_head *head,

if (!next)
break;
- list = merge(priv, (cmp_func)cmp, pending, list);
+ list = merge(priv, cmp, pending, list);
pending = next;
}
/* The final merge, rebuilding prev links */
- merge_final(priv, (cmp_func)cmp, head, pending, list);
+ merge_final(priv, cmp, head, pending, list);
}
EXPORT_SYMBOL(list_sort);
--
2.31.0.rc2.261.g7f71774620-goog