There is a possible race between the read operations of the `registers'
file and the `range' file. Close that down by taking the appropriate
locks when modifying/accessing the list.
Signed-off-by: Dimitris Papastamos <d...@opensource.wolfsonmicro.com>
---
drivers/base/regmap/internal.h | 1 +
drivers/base/regmap/regmap-debugfs.c | 7 +++++++
2 files changed, 8 insertions(+)
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 5a22bd3..dc23508 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -76,6 +76,7 @@ struct regmap {
unsigned int debugfs_tot_len;
struct list_head debugfs_off_cache;
+ struct mutex cache_lock;
#endif
unsigned int max_register;
diff --git a/drivers/base/regmap/regmap-debugfs.c
b/drivers/base/regmap/regmap-debugfs.c
index e14cb2d..a6b5606 100644
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -88,6 +88,7 @@ static unsigned int regmap_debugfs_get_dump_start(struct
regmap *map,
* If we don't have a cache build one so we don't have to do a
* linear scan each time.
*/
+ mutex_lock(&map->cache_lock);
i = base;
if (list_empty(&map->debugfs_off_cache)) {
for (; i <= map->max_register; i += map->reg_stride) {
@@ -110,6 +111,7 @@ static unsigned int regmap_debugfs_get_dump_start(struct
regmap *map,
c = kzalloc(sizeof(*c), GFP_KERNEL);
if (!c) {
regmap_debugfs_free_dump_cache(map);
+ mutex_unlock(&map->cache_lock);
return base;
}
c->min = p;
@@ -142,12 +144,14 @@ static unsigned int regmap_debugfs_get_dump_start(struct
regmap *map,
fpos_offset = from - c->min;
reg_offset = fpos_offset / map->debugfs_tot_len;
*pos = c->min + (reg_offset * map->debugfs_tot_len);
+ mutex_unlock(&map->cache_lock);
return c->base_reg + reg_offset;
}
*pos = c->max;
ret = c->max_reg;
}
+ mutex_unlock(&map->cache_lock);
return ret;
}
@@ -382,6 +386,7 @@ void regmap_debugfs_init(struct regmap *map, const char
*name)
struct regmap_range_node *range_node;
INIT_LIST_HEAD(&map->debugfs_off_cache);
+ mutex_init(&map->cache_lock);
if (name) {
map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
@@ -432,7 +437,9 @@ void regmap_debugfs_init(struct regmap *map, const char
*name)
void regmap_debugfs_exit(struct regmap *map)
{
debugfs_remove_recursive(map->debugfs);
+ mutex_lock(&map->cache_lock);
regmap_debugfs_free_dump_cache(map);
+ mutex_unlock(&map->cache_lock);
kfree(map->debugfs_name);
}
--
1.8.1.3
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