diff options
author | Mark Brown <broonie@kernel.org> | 2017-12-12 16:56:43 +0000 |
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committer | Mark Brown <broonie@kernel.org> | 2017-12-13 16:22:31 +0000 |
commit | 72465736adf2aade263a9475a1d42007fd49e703 (patch) | |
tree | ddc19ef33b47c55b130e78cca79b3f6b064cd2c4 | |
parent | 81e30b189f593afbf10a7bf47f18f030f8aea3b5 (diff) | |
download | op-kernel-dev-72465736adf2aade263a9475a1d42007fd49e703.zip op-kernel-dev-72465736adf2aade263a9475a1d42007fd49e703.tar.gz |
regmap: Disable debugfs when locking is disabled
The recently added support for disabling the regmap internal locking left
debugfs enabled for devices with the locking disabled. This is a problem
since debugfs allows userspace to do things like initiate reads from the
hardware which will use the scratch buffers protected by the regmap locking
so could cause data corruption.
For safety address this by just disabling debugfs for these devices. That
is overly conservative since some of the debugfs files just read internal
data structures but it's much simpler to implmement and less likely to
lead to problems with tooling that works with debugfs.
Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
-rw-r--r-- | drivers/base/regmap/internal.h | 8 | ||||
-rw-r--r-- | drivers/base/regmap/regmap-debugfs.c | 3 | ||||
-rw-r--r-- | drivers/base/regmap/regmap.c | 1 |
3 files changed, 12 insertions, 0 deletions
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h index 8641183..53785e0 100644 --- a/drivers/base/regmap/internal.h +++ b/drivers/base/regmap/internal.h @@ -77,6 +77,7 @@ struct regmap { int async_ret; #ifdef CONFIG_DEBUG_FS + bool debugfs_disable; struct dentry *debugfs; const char *debugfs_name; @@ -215,10 +216,17 @@ struct regmap_field { extern void regmap_debugfs_initcall(void); extern void regmap_debugfs_init(struct regmap *map, const char *name); extern void regmap_debugfs_exit(struct regmap *map); + +static inline void regmap_debugfs_disable(struct regmap *map) +{ + map->debugfs_disable = true; +} + #else static inline void regmap_debugfs_initcall(void) { } static inline void regmap_debugfs_init(struct regmap *map, const char *name) { } static inline void regmap_debugfs_exit(struct regmap *map) { } +static inline void regmap_debugfs_disable(struct regmap *map) { } #endif /* regcache core declarations */ diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c index 36ce351..c8ecefd 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -529,6 +529,9 @@ void regmap_debugfs_init(struct regmap *map, const char *name) struct regmap_range_node *range_node; const char *devname = "dummy"; + if (map->debugfs_disable) + return; + /* If we don't have the debugfs root yet, postpone init */ if (!regmap_debugfs_root) { struct regmap_debugfs_node *node; diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 54b1aa3..df9ca36 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -676,6 +676,7 @@ struct regmap *__regmap_init(struct device *dev, if (config->disable_locking) { map->lock = map->unlock = regmap_lock_unlock_none; + regmap_debugfs_disable(map); } else if (config->lock && config->unlock) { map->lock = config->lock; map->unlock = config->unlock; |