[PATCH v4 03/30] landlock: Factor out check_access_path()

["Mickaël Salaün" <mic@digikod.net>]

Merge check_access_path() into current_check_access_path() and make
hook_path_mknod() use it.

Cc: Günther Noack <gnoack@google.com>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Link: https://lore.kernel.org/r/20250108154338.1129069-4-mic@digikod.net
---

Changes since v1:
- Rebased on the TCP patch series.
- Remove inlining removal which was merged.
---
 security/landlock/fs.c | 32 +++++++++++---------------------
 1 file changed, 11 insertions(+), 21 deletions(-)

diff --git a/security/landlock/fs.c b/security/landlock/fs.c
index e31b97a9f175..d911c924843f 100644
--- a/security/landlock/fs.c
+++ b/security/landlock/fs.c
@@ -908,28 +908,22 @@ static bool is_access_to_paths_allowed(
 	return allowed_parent1 && allowed_parent2;
 }
 
-static int check_access_path(const struct landlock_ruleset *const domain,
-			     const struct path *const path,
-			     access_mask_t access_request)
-{
-	layer_mask_t layer_masks[LANDLOCK_NUM_ACCESS_FS] = {};
-
-	access_request = landlock_init_layer_masks(
-		domain, access_request, &layer_masks, LANDLOCK_KEY_INODE);
-	if (is_access_to_paths_allowed(domain, path, access_request,
-				       &layer_masks, NULL, 0, NULL, NULL))
-		return 0;
-	return -EACCES;
-}
-
 static int current_check_access_path(const struct path *const path,
-				     const access_mask_t access_request)
+				     access_mask_t access_request)
 {
 	const struct landlock_ruleset *const dom = get_current_fs_domain();
+	layer_mask_t layer_masks[LANDLOCK_NUM_ACCESS_FS] = {};
 
 	if (!dom)
 		return 0;
-	return check_access_path(dom, path, access_request);
+
+	access_request = landlock_init_layer_masks(
+		dom, access_request, &layer_masks, LANDLOCK_KEY_INODE);
+	if (is_access_to_paths_allowed(dom, path, access_request, &layer_masks,
+				       NULL, 0, NULL, NULL))
+		return 0;
+
+	return -EACCES;
 }
 
 static access_mask_t get_mode_access(const umode_t mode)
@@ -1414,11 +1408,7 @@ static int hook_path_mknod(const struct path *const dir,
 			   struct dentry *const dentry, const umode_t mode,
 			   const unsigned int dev)
 {
-	const struct landlock_ruleset *const dom = get_current_fs_domain();
-
-	if (!dom)
-		return 0;
-	return check_access_path(dom, dir, get_mode_access(mode));
+	return current_check_access_path(dir, get_mode_access(mode));
 }
 
 static int hook_path_symlink(const struct path *const dir,
-- 
2.47.1