regmap: fix a NULL pointer dereference in __regmap_init

__regmap_init() may receive a NULL `struct regmap_bus *bus' pointer,
for example, from snd_hdac_regmap_init(), and it make sure that it
does not NULL deference `bus`, except around ->max_raw_read and
->max_raw_write initialisation. Add missing check.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Sergey SENOZHATSKY 2015-08-31 18:54:58 +09:00 коммит произвёл Mark Brown
Родитель 29332534e2
Коммит 17649c90ff
1 изменённых файлов: 4 добавлений и 2 удалений

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@ -579,8 +579,10 @@ struct regmap *regmap_init(struct device *dev,
map->use_single_read = config->use_single_rw || !bus || !bus->read;
map->use_single_write = config->use_single_rw || !bus || !bus->write;
map->can_multi_write = config->can_multi_write && bus && bus->write;
map->max_raw_read = bus->max_raw_read;
map->max_raw_write = bus->max_raw_write;
if (bus) {
map->max_raw_read = bus->max_raw_read;
map->max_raw_write = bus->max_raw_write;
}
map->dev = dev;
map->bus = bus;
map->bus_context = bus_context;