[PATCH] landlock: Drop "const" argument qualifier to avoid GCC 4.9 warnings

From: Kees Cook
Date: Fri Sep 10 2021 - 18:36:19 EST


When building under GCC 4.9, the compiler warns about const mismatches:

security/landlock/ruleset.c: In function 'insert_rule':
security/landlock/ruleset.c:196:34: error: passing argument 2 of 'create_rule' from incompatible pointer type [-Werror]
new_rule = create_rule(object, &this->layers, this->num_layers,
^
security/landlock/ruleset.c:69:30: note: expected 'const struct landlock_layer ** const' but argument is of type 'struct landlock_layer (*)[]'
static struct landlock_rule *create_rule(
^
security/landlock/ruleset.c: In function 'landlock_insert_rule':
security/landlock/ruleset.c:240:38: error: passing argument 3 of 'insert_rule' from incompatible pointer type [-Werror]
return insert_rule(ruleset, object, &layers, ARRAY_SIZE(layers));
^
security/landlock/ruleset.c:144:12: note: expected 'const struct landlock_layer ** const' but argument is of type 'struct landlock_layer (*)[1]'
static int insert_rule(struct landlock_ruleset *const ruleset,
^

Drop "const" from the function definition.

Cc: "Mickaël Salaün" <mic@xxxxxxxxxxx>
Cc: James Morris <jmorris@xxxxxxxxx>
Cc: "Serge E. Hallyn" <serge@xxxxxxxxxx>
Cc: linux-security-module@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
security/landlock/ruleset.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c
index ec72b9262bf3..64c37af88ee7 100644
--- a/security/landlock/ruleset.c
+++ b/security/landlock/ruleset.c
@@ -68,7 +68,7 @@ static void build_check_rule(void)

static struct landlock_rule *create_rule(
struct landlock_object *const object,
- const struct landlock_layer (*const layers)[],
+ struct landlock_layer (*layers)[],
const u32 num_layers,
const struct landlock_layer *const new_layer)
{
@@ -143,7 +143,7 @@ static void build_check_ruleset(void)
*/
static int insert_rule(struct landlock_ruleset *const ruleset,
struct landlock_object *const object,
- const struct landlock_layer (*const layers)[],
+ struct landlock_layer (*layers)[],
size_t num_layers)
{
struct rb_node **walker_node;
--
2.30.2