From f72e77c33e4b5657af35125e75bab249256030f3 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Tue, 17 Mar 2026 09:01:20 -0700 Subject: device property: Make modifications of fwnode "flags" thread safe In various places in the kernel, we modify the fwnode "flags" member by doing either: fwnode->flags |= SOME_FLAG; fwnode->flags &= ~SOME_FLAG; This type of modification is not thread-safe. If two threads are both mucking with the flags at the same time then one can clobber the other. While flags are often modified while under the "fwnode_link_lock", this is not universally true. Create some accessor functions for setting, clearing, and testing the FWNODE flags and move all users to these accessor functions. New accessor functions use set_bit() and clear_bit(), which are thread-safe. Cc: stable@vger.kernel.org Fixes: c2c724c868c4 ("driver core: Add fw_devlink_parse_fwtree()") Reviewed-by: Andy Shevchenko Acked-by: Mark Brown Reviewed-by: Wolfram Sang Signed-off-by: Douglas Anderson Reviewed-by: Rafael J. Wysocki (Intel) Reviewed-by: Saravana Kannan Link: https://patch.msgid.link/20260317090112.v2.1.I0a4d03104ecd5103df3d76f66c8d21b1d15a2e38@changeid [ Fix fwnode_clear_flag() argument alignment, restore dropped blank line in fwnode_dev_initialized(), and remove unnecessary parentheses around fwnode_test_flag() calls. - Danilo ] Signed-off-by: Danilo Krummrich --- include/linux/fwnode.h | 44 +++++++++++++++++++++++++++++++++----------- 1 file changed, 33 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h index 097be89487bf..80b38fbf2121 100644 --- a/include/linux/fwnode.h +++ b/include/linux/fwnode.h @@ -15,6 +15,7 @@ #define _LINUX_FWNODE_H_ #include +#include #include #include #include @@ -42,12 +43,12 @@ struct device; * suppliers. Only enforce ordering with suppliers that have * drivers. */ -#define FWNODE_FLAG_LINKS_ADDED BIT(0) -#define FWNODE_FLAG_NOT_DEVICE BIT(1) -#define FWNODE_FLAG_INITIALIZED BIT(2) -#define FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD BIT(3) -#define FWNODE_FLAG_BEST_EFFORT BIT(4) -#define FWNODE_FLAG_VISITED BIT(5) +#define FWNODE_FLAG_LINKS_ADDED 0 +#define FWNODE_FLAG_NOT_DEVICE 1 +#define FWNODE_FLAG_INITIALIZED 2 +#define FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD 3 +#define FWNODE_FLAG_BEST_EFFORT 4 +#define FWNODE_FLAG_VISITED 5 struct fwnode_handle { struct fwnode_handle *secondary; @@ -57,7 +58,7 @@ struct fwnode_handle { struct device *dev; struct list_head suppliers; struct list_head consumers; - u8 flags; + unsigned long flags; }; /* @@ -212,16 +213,37 @@ static inline void fwnode_init(struct fwnode_handle *fwnode, INIT_LIST_HEAD(&fwnode->suppliers); } +static inline void fwnode_set_flag(struct fwnode_handle *fwnode, + unsigned int bit) +{ + set_bit(bit, &fwnode->flags); +} + +static inline void fwnode_clear_flag(struct fwnode_handle *fwnode, + unsigned int bit) +{ + clear_bit(bit, &fwnode->flags); +} + +static inline void fwnode_assign_flag(struct fwnode_handle *fwnode, + unsigned int bit, bool value) +{ + assign_bit(bit, &fwnode->flags, value); +} + +static inline bool fwnode_test_flag(struct fwnode_handle *fwnode, + unsigned int bit) +{ + return test_bit(bit, &fwnode->flags); +} + static inline void fwnode_dev_initialized(struct fwnode_handle *fwnode, bool initialized) { if (IS_ERR_OR_NULL(fwnode)) return; - if (initialized) - fwnode->flags |= FWNODE_FLAG_INITIALIZED; - else - fwnode->flags &= ~FWNODE_FLAG_INITIALIZED; + fwnode_assign_flag(fwnode, FWNODE_FLAG_INITIALIZED, initialized); } int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup, -- cgit v1.2.3