From aa30f47cf666111f6bbfd15f290a27e8a7b9d854 Mon Sep 17 00:00:00 2001 From: Kimberly Brown Date: Mon, 1 Apr 2019 22:51:18 -0400 Subject: kobject: Add support for default attribute groups to kobj_type MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit kobj_type currently uses a list of individual attributes to store default attributes. Attribute groups are more flexible than a list of attributes because groups provide support for attribute visibility. So, add support for default attribute groups to kobj_type. In future patches, the existing uses of kobj_type’s attribute list will be converted to attribute groups. When that is complete, kobj_type’s attribute list, “default_attrs”, will be removed. Signed-off-by: Kimberly Brown Signed-off-by: Greg Kroah-Hartman --- lib/kobject.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'lib/kobject.c') diff --git a/lib/kobject.c b/lib/kobject.c index aa89edcd2b63..ede40005db28 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -82,6 +82,7 @@ static int populate_dir(struct kobject *kobj) static int create_dir(struct kobject *kobj) { + const struct kobj_type *ktype = get_ktype(kobj); const struct kobj_ns_type_operations *ops; int error; @@ -95,6 +96,14 @@ static int create_dir(struct kobject *kobj) return error; } + if (ktype) { + error = sysfs_create_groups(kobj, ktype->default_groups); + if (error) { + sysfs_remove_dir(kobj); + return error; + } + } + /* * @kobj->sd may be deleted by an ancestor going away. Hold an * extra reference so that it stays until @kobj is gone. @@ -584,11 +593,16 @@ EXPORT_SYMBOL_GPL(kobject_move); void kobject_del(struct kobject *kobj) { struct kernfs_node *sd; + const struct kobj_type *ktype = get_ktype(kobj); if (!kobj) return; sd = kobj->sd; + + if (ktype) + sysfs_remove_groups(kobj, ktype->default_groups); + sysfs_remove_dir(kobj); sysfs_put(sd); -- cgit v1.2.3 From 92067f843854be0eef1e41ff00cb465247a83c42 Mon Sep 17 00:00:00 2001 From: "Tobin C. Harding" Date: Sun, 28 Apr 2019 10:48:10 +1000 Subject: kobject: Improve docs for kobject_add/del There is currently some confusion on how to wind back kobject_init_and_add() during the error paths in code that uses this function. Add documentation to kobject_add() and kobject_del() to help clarify the usage. Signed-off-by: Tobin C. Harding Signed-off-by: Greg Kroah-Hartman --- lib/kobject.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) (limited to 'lib/kobject.c') diff --git a/lib/kobject.c b/lib/kobject.c index ede40005db28..c97b5729f94d 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -406,15 +406,19 @@ static __printf(3, 0) int kobject_add_varg(struct kobject *kobj, * is assigned to the kobject, then the kobject will be located in the * root of the sysfs tree. * - * If this function returns an error, kobject_put() must be called to - * properly clean up the memory associated with the object. - * Under no instance should the kobject that is passed to this function - * be directly freed with a call to kfree(), that can leak memory. - * * Note, no "add" uevent will be created with this call, the caller should set * up all of the necessary sysfs files for the object and then call * kobject_uevent() with the UEVENT_ADD parameter to ensure that * userspace is properly notified of this kobject's creation. + * + * Return: If this function returns an error, kobject_put() must be + * called to properly clean up the memory associated with the + * object. Under no instance should the kobject that is passed + * to this function be directly freed with a call to kfree(), + * that can leak memory. + * + * If this call returns successfully and you later need to unwind + * kobject_add() for the error path you should call kobject_del(). */ int kobject_add(struct kobject *kobj, struct kobject *parent, const char *fmt, ...) @@ -589,6 +593,9 @@ EXPORT_SYMBOL_GPL(kobject_move); /** * kobject_del - unlink kobject from hierarchy. * @kobj: object. + * + * This is the function that should be called to delete an object + * successfully added via kobject_add(). */ void kobject_del(struct kobject *kobj) { -- cgit v1.2.3 From 1fd7c3b438a2e4741435ed4d45546c03abf045b2 Mon Sep 17 00:00:00 2001 From: "Tobin C. Harding" Date: Sun, 28 Apr 2019 09:56:52 +1000 Subject: kobject: Improve doc clarity kobject_init_and_add() Function kobject_init_and_add() is currently misused in a number of places in the kernel. On error return kobject_put() must be called but is at times not. Make the function documentation more explicit about calling kobject_put() in the error path. Signed-off-by: Tobin C. Harding Signed-off-by: Greg Kroah-Hartman --- lib/kobject.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'lib/kobject.c') diff --git a/lib/kobject.c b/lib/kobject.c index c97b5729f94d..a30ee0467942 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -450,9 +450,12 @@ EXPORT_SYMBOL(kobject_add); * @parent: pointer to the parent of this kobject. * @fmt: the name of the kobject. * - * This function combines the call to kobject_init() and - * kobject_add(). The same type of error handling after a call to - * kobject_add() and kobject lifetime rules are the same here. + * This function combines the call to kobject_init() and kobject_add(). + * + * If this function returns an error, kobject_put() must be called to + * properly clean up the memory associated with the object. This is the + * same type of error handling after a call to kobject_add() and kobject + * lifetime rules are the same here. */ int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype, struct kobject *parent, const char *fmt, ...) -- cgit v1.2.3 From 3d378dc713f3ff4951d9a50c6a815f011e59da10 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Wed, 1 May 2019 13:43:17 +0100 Subject: kobject: fix dereference before null check on kobj The kobj pointer is being null-checked so potentially it could be null, however, the ktype declaration before the null check is dereferencing kobj hence we have a potential null pointer deference. Fix this by moving the assignment of ktype after kobj has been null checked. Addresses-Coverity: ("Dereference before null check") Fixes: aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") Signed-off-by: Colin Ian King Signed-off-by: Greg Kroah-Hartman --- lib/kobject.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'lib/kobject.c') diff --git a/lib/kobject.c b/lib/kobject.c index a30ee0467942..095bcb55c2ba 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -603,12 +603,13 @@ EXPORT_SYMBOL_GPL(kobject_move); void kobject_del(struct kobject *kobj) { struct kernfs_node *sd; - const struct kobj_type *ktype = get_ktype(kobj); + const struct kobj_type *ktype; if (!kobj) return; sd = kobj->sd; + ktype = get_ktype(kobj); if (ktype) sysfs_remove_groups(kobj, ktype->default_groups); -- cgit v1.2.3 From 8fd7c302b37099670b5d793375da10a40da7edf5 Mon Sep 17 00:00:00 2001 From: "Tobin C. Harding" Date: Thu, 2 May 2019 12:31:39 +1000 Subject: kobject: Remove docstring reference to kset Currently the docstring for kobject_get_path() mentions 'kset'. The kset is not used in the function callchain starting from this function. Remove docstring reference to kset from the function kobject_get_path(). Signed-off-by: Tobin C. Harding Signed-off-by: Greg Kroah-Hartman --- lib/kobject.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'lib/kobject.c') diff --git a/lib/kobject.c b/lib/kobject.c index 095bcb55c2ba..09e3ac329e92 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -162,12 +162,11 @@ static void fill_kobj_path(struct kobject *kobj, char *path, int length) } /** - * kobject_get_path - generate and return the path associated with a given kobj and kset pair. - * + * kobject_get_path() - Allocate memory and fill in the path for @kobj. * @kobj: kobject in question, with which to build the path * @gfp_mask: the allocation type used to allocate the path * - * The result must be freed by the caller with kfree(). + * Return: The newly allocated memory, caller must free with kfree(). */ char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask) { -- cgit v1.2.3 From ed856349dc0886a97e91fd4ce6ba5ff5312fc0f1 Mon Sep 17 00:00:00 2001 From: "Tobin C. Harding" Date: Thu, 2 May 2019 12:31:40 +1000 Subject: kobject: Fix kernel-doc comment first line kernel-doc comments have a prescribed format. This includes parenthesis on the function name. To be _particularly_ correct we should also capitalise the brief description and terminate it with a period. In preparation for adding/updating kernel-doc function comments clean up the ones currently present. Signed-off-by: Tobin C. Harding Signed-off-by: Greg Kroah-Hartman --- lib/kobject.c | 43 ++++++++++++++++++++++--------------------- 1 file changed, 22 insertions(+), 21 deletions(-) (limited to 'lib/kobject.c') diff --git a/lib/kobject.c b/lib/kobject.c index 09e3ac329e92..3f4b7e95b0c2 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -18,7 +18,7 @@ #include /** - * kobject_namespace - return @kobj's namespace tag + * kobject_namespace() - Return @kobj's namespace tag. * @kobj: kobject in question * * Returns namespace tag of @kobj if its parent has namespace ops enabled @@ -36,7 +36,7 @@ const void *kobject_namespace(struct kobject *kobj) } /** - * kobject_get_ownership - get sysfs ownership data for @kobj + * kobject_get_ownership() - Get sysfs ownership data for @kobj. * @kobj: kobject in question * @uid: kernel user ID for sysfs objects * @gid: kernel group ID for sysfs objects @@ -273,7 +273,7 @@ static int kobject_add_internal(struct kobject *kobj) } /** - * kobject_set_name_vargs - Set the name of an kobject + * kobject_set_name_vargs() - Set the name of a kobject. * @kobj: struct kobject to set the name of * @fmt: format string used to build the name * @vargs: vargs to format the string. @@ -313,7 +313,7 @@ int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, } /** - * kobject_set_name - Set the name of a kobject + * kobject_set_name() - Set the name of a kobject. * @kobj: struct kobject to set the name of * @fmt: format string used to build the name * @@ -335,7 +335,7 @@ int kobject_set_name(struct kobject *kobj, const char *fmt, ...) EXPORT_SYMBOL(kobject_set_name); /** - * kobject_init - initialize a kobject structure + * kobject_init() - Initialize a kobject structure. * @kobj: pointer to the kobject to initialize * @ktype: pointer to the ktype for this kobject. * @@ -391,7 +391,7 @@ static __printf(3, 0) int kobject_add_varg(struct kobject *kobj, } /** - * kobject_add - the main kobject add function + * kobject_add() - The main kobject add function. * @kobj: the kobject to add * @parent: pointer to the parent of the kobject. * @fmt: format to name the kobject with. @@ -443,7 +443,8 @@ int kobject_add(struct kobject *kobj, struct kobject *parent, EXPORT_SYMBOL(kobject_add); /** - * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy + * kobject_init_and_add() - Initialize a kobject structure and add it to + * the kobject hierarchy. * @kobj: pointer to the kobject to initialize * @ktype: pointer to the ktype for this kobject. * @parent: pointer to the parent of this kobject. @@ -473,7 +474,7 @@ int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype, EXPORT_SYMBOL_GPL(kobject_init_and_add); /** - * kobject_rename - change the name of an object + * kobject_rename() - Change the name of an object. * @kobj: object in question. * @new_name: object's new name * @@ -540,7 +541,7 @@ out: EXPORT_SYMBOL_GPL(kobject_rename); /** - * kobject_move - move object to another parent + * kobject_move() - Move object to another parent. * @kobj: object in question. * @new_parent: object's new parent (can be NULL) */ @@ -593,7 +594,7 @@ out: EXPORT_SYMBOL_GPL(kobject_move); /** - * kobject_del - unlink kobject from hierarchy. + * kobject_del() - Unlink kobject from hierarchy. * @kobj: object. * * This is the function that should be called to delete an object @@ -624,7 +625,7 @@ void kobject_del(struct kobject *kobj) EXPORT_SYMBOL(kobject_del); /** - * kobject_get - increment refcount for object. + * kobject_get() - Increment refcount for object. * @kobj: object. */ struct kobject *kobject_get(struct kobject *kobj) @@ -717,7 +718,7 @@ static void kobject_release(struct kref *kref) } /** - * kobject_put - decrement refcount for object. + * kobject_put() - Decrement refcount for object. * @kobj: object. * * Decrement the refcount, and if 0, call kobject_cleanup(). @@ -746,7 +747,7 @@ static struct kobj_type dynamic_kobj_ktype = { }; /** - * kobject_create - create a struct kobject dynamically + * kobject_create() - Create a struct kobject dynamically. * * This function creates a kobject structure dynamically and sets it up * to be a "dynamic" kobject with a default release function set up. @@ -769,8 +770,8 @@ struct kobject *kobject_create(void) } /** - * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs - * + * kobject_create_and_add() - Create a struct kobject dynamically and + * register it with sysfs. * @name: the name for the kobject * @parent: the parent kobject of this kobject, if any. * @@ -801,7 +802,7 @@ struct kobject *kobject_create_and_add(const char *name, struct kobject *parent) EXPORT_SYMBOL_GPL(kobject_create_and_add); /** - * kset_init - initialize a kset for use + * kset_init() - Initialize a kset for use. * @k: kset */ void kset_init(struct kset *k) @@ -843,7 +844,7 @@ const struct sysfs_ops kobj_sysfs_ops = { EXPORT_SYMBOL_GPL(kobj_sysfs_ops); /** - * kset_register - initialize and add a kset. + * kset_register() - Initialize and add a kset. * @k: kset. */ int kset_register(struct kset *k) @@ -863,7 +864,7 @@ int kset_register(struct kset *k) EXPORT_SYMBOL(kset_register); /** - * kset_unregister - remove a kset. + * kset_unregister() - Remove a kset. * @k: kset. */ void kset_unregister(struct kset *k) @@ -876,7 +877,7 @@ void kset_unregister(struct kset *k) EXPORT_SYMBOL(kset_unregister); /** - * kset_find_obj - search for object in kset. + * kset_find_obj() - Search for object in kset. * @kset: kset we're looking in. * @name: object's name. * @@ -924,7 +925,7 @@ static struct kobj_type kset_ktype = { }; /** - * kset_create - create a struct kset dynamically + * kset_create() - Create a struct kset dynamically. * * @name: the name for the kset * @uevent_ops: a struct kset_uevent_ops for the kset @@ -968,7 +969,7 @@ static struct kset *kset_create(const char *name, } /** - * kset_create_and_add - create a struct kset dynamically and add it to sysfs + * kset_create_and_add() - Create a struct kset dynamically and add it to sysfs. * * @name: the name for the kset * @uevent_ops: a struct kset_uevent_ops for the kset -- cgit v1.2.3 From 70e16a620e075cb916644e06012766639b58b2fb Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 2 May 2019 12:22:24 +0200 Subject: kobject: clean up the kobject add documentation a bit more Commit 1fd7c3b438a2 ("kobject: Improve doc clarity kobject_init_and_add()") tried to provide more clarity, but the reference to kobject_del() was incorrect. Fix that up by removing that line, and hopefully be more explicit as to exactly what needs to happen here once you register a kobject with the kobject core. Acked-by: Tobin C. Harding Fixes: 1fd7c3b438a2 ("kobject: Improve doc clarity kobject_init_and_add()") Signed-off-by: Greg Kroah-Hartman --- lib/kobject.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'lib/kobject.c') diff --git a/lib/kobject.c b/lib/kobject.c index 3f4b7e95b0c2..f2ccdbac8ed9 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -416,8 +416,12 @@ static __printf(3, 0) int kobject_add_varg(struct kobject *kobj, * to this function be directly freed with a call to kfree(), * that can leak memory. * - * If this call returns successfully and you later need to unwind - * kobject_add() for the error path you should call kobject_del(). + * If this function returns success, kobject_put() must also be called + * in order to properly clean up the memory associated with the object. + * + * In short, once this function is called, kobject_put() MUST be called + * when the use of the object is finished in order to properly free + * everything. */ int kobject_add(struct kobject *kobj, struct kobject *parent, const char *fmt, ...) -- cgit v1.2.3