[PATCH 14/20] regmap: Add raw_write/read checks for max_raw_write/read sizes

[Markus Pargmann]

Check in regmap_raw_read() and regmap_raw_write() for correct maximum
sizes of the operations. Return -E2BIG if this size is not supported
because it is too big.

Also this patch causes an uninitialized variable warning so it
initializes ret (although not necessary).

Signed-off-by: Markus Pargmann <mpa at pengutronix.de>
---
 drivers/base/regmap/regmap.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 8c2be516a100..6b636e2ee111 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1584,6 +1584,8 @@ int regmap_raw_write(struct regmap *map, unsigned int reg,
 		return -EINVAL;
 	if (val_len % map->format.val_bytes)
 		return -EINVAL;
+	if (map->max_raw_io && map->max_raw_io > val_len)
+		return -E2BIG;
 
 	map->lock(map->lock_arg);
 
@@ -2262,7 +2264,8 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 	size_t val_bytes = map->format.val_bytes;
 	size_t val_count = val_len / val_bytes;
 	unsigned int v;
-	int ret, i;
+	int ret = 0;
+	int i;
 
 	if (!map->bus)
 		return -EINVAL;
@@ -2273,8 +2276,14 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 
 	map->lock(map->lock_arg);
 
-	if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
-	    map->cache_type == REGCACHE_NONE) {
+	if (map->bus->read &&
+	    (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
+	     map->cache_type == REGCACHE_NONE)) {
+		if (map->max_raw_io && map->max_raw_io < val_len) {
+			ret = -E2BIG;
+			goto out;
+		}
+
 		/* Physical block read if there's no cache involved */
 		ret = _regmap_raw_read(map, reg, val, val_len);
 
-- 
2.4.6