[nrf fromlist] settings: zms: fix a bug related to the name's ID

To avoid collisions between IDs used by settings and IDs used directly
by subsystems using ZMS API, the MSB is always set to 1 for Setting's
name ID written to ZMS backend

Upstream PR #: 86170

Signed-off-by: Riadh Ghaddab <[email protected]>
(cherry picked from commit c9a33bbefabb262411985ee7237d040bb3cf2fa4)

Author: rghaddab

subsys/settings/include/settings/settings_zms.h

@@ -60,10 +60,9 @@ extern "C" {
 #define ZMS_COLLISIONS_MASK GENMASK(CONFIG_SETTINGS_ZMS_MAX_COLLISIONS_BITS, 1)
 #define ZMS_HASH_TOTAL_MASK GENMASK(29, 1)
 #define ZMS_MAX_COLLISIONS  (BIT(CONFIG_SETTINGS_ZMS_MAX_COLLISIONS_BITS) - 1)
-#define ZMS_HEADER_HASH     0x80000000
 
 /* some useful macros */
-#define ZMS_NAME_HASH_ID(x) (x & ZMS_HASH_TOTAL_MASK)
+#define ZMS_NAME_HASH_ID(x) ((x & ZMS_HASH_TOTAL_MASK) | BIT(31))
 #define ZMS_UPDATE_COLLISION_NUM(x, y)                                                             \
 	((x & ~ZMS_COLLISIONS_MASK) | ((y << 1) & ZMS_COLLISIONS_MASK))
 #define ZMS_COLLISION_NUM(x) ((x & ZMS_COLLISIONS_MASK) >> 1)

subsys/settings/src/settings_zms.c

@@ -232,6 +232,8 @@ static int settings_zms_save(struct settings_store *cs, const char *name, const
 	delete = ((value == NULL) || (val_len == 0));
 
 	name_hash = sys_hash32(name, strlen(name)) & ZMS_HASH_MASK;
+	/* MSB is always 1 */
+	name_hash |= BIT(31);
 
 	/* Let's find out if there is no hash collisions in the storage */
 	write_name = true;