diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-05-29 19:33:28 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-05-29 19:33:28 +0300 |
commit | e1a9e3db3bb59c2fa0c0de0b3381c64b3b6ffba7 (patch) | |
tree | ccb7cab00ab983b242c7c4c52aa0a8507929a7b4 | |
parent | 494b99f712d00fee7e0927067081954fc493b6d9 (diff) | |
parent | 0c8713153fbf7ba4e45172e139d501c86006dc03 (diff) | |
download | linux-e1a9e3db3bb59c2fa0c0de0b3381c64b3b6ffba7.tar.xz |
Merge tag 'driver-core-5.13-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fixes from Greg KH:
"Here are three small driver core / debugfs fixes for 5.13-rc4:
- debugfs fix for incorrect "lockdown" mode for selinux accesses
- two device link changes, one bugfix and one cleanup
All of these have been in linux-next for over a week with no reported
problems"
* tag 'driver-core-5.13-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
drivers: base: Reduce device link removal code duplication
drivers: base: Fix device link removal
debugfs: fix security_locked_down() call for SELinux
-rw-r--r-- | drivers/base/core.c | 68 | ||||
-rw-r--r-- | fs/debugfs/inode.c | 9 | ||||
-rw-r--r-- | include/linux/device.h | 6 |
3 files changed, 44 insertions, 39 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index 628e33939aca..54ba506e5a89 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -194,6 +194,17 @@ int device_links_read_lock_held(void) { return srcu_read_lock_held(&device_links_srcu); } + +static void device_link_synchronize_removal(void) +{ + synchronize_srcu(&device_links_srcu); +} + +static void device_link_remove_from_lists(struct device_link *link) +{ + list_del_rcu(&link->s_node); + list_del_rcu(&link->c_node); +} #else /* !CONFIG_SRCU */ static DECLARE_RWSEM(device_links_lock); @@ -224,6 +235,16 @@ int device_links_read_lock_held(void) return lockdep_is_held(&device_links_lock); } #endif + +static inline void device_link_synchronize_removal(void) +{ +} + +static void device_link_remove_from_lists(struct device_link *link) +{ + list_del(&link->s_node); + list_del(&link->c_node); +} #endif /* !CONFIG_SRCU */ static bool device_is_ancestor(struct device *dev, struct device *target) @@ -445,8 +466,13 @@ static struct attribute *devlink_attrs[] = { }; ATTRIBUTE_GROUPS(devlink); -static void device_link_free(struct device_link *link) +static void device_link_release_fn(struct work_struct *work) { + struct device_link *link = container_of(work, struct device_link, rm_work); + + /* Ensure that all references to the link object have been dropped. */ + device_link_synchronize_removal(); + while (refcount_dec_not_one(&link->rpm_active)) pm_runtime_put(link->supplier); @@ -455,24 +481,19 @@ static void device_link_free(struct device_link *link) kfree(link); } -#ifdef CONFIG_SRCU -static void __device_link_free_srcu(struct rcu_head *rhead) -{ - device_link_free(container_of(rhead, struct device_link, rcu_head)); -} - static void devlink_dev_release(struct device *dev) { struct device_link *link = to_devlink(dev); - call_srcu(&device_links_srcu, &link->rcu_head, __device_link_free_srcu); -} -#else -static void devlink_dev_release(struct device *dev) -{ - device_link_free(to_devlink(dev)); + INIT_WORK(&link->rm_work, device_link_release_fn); + /* + * It may take a while to complete this work because of the SRCU + * synchronization in device_link_release_fn() and if the consumer or + * supplier devices get deleted when it runs, so put it into the "long" + * workqueue. + */ + queue_work(system_long_wq, &link->rm_work); } -#endif static struct class devlink_class = { .name = "devlink", @@ -846,7 +867,6 @@ out: } EXPORT_SYMBOL_GPL(device_link_add); -#ifdef CONFIG_SRCU static void __device_link_del(struct kref *kref) { struct device_link *link = container_of(kref, struct device_link, kref); @@ -856,25 +876,9 @@ static void __device_link_del(struct kref *kref) pm_runtime_drop_link(link); - list_del_rcu(&link->s_node); - list_del_rcu(&link->c_node); - device_unregister(&link->link_dev); -} -#else /* !CONFIG_SRCU */ -static void __device_link_del(struct kref *kref) -{ - struct device_link *link = container_of(kref, struct device_link, kref); - - dev_info(link->consumer, "Dropping the link to %s\n", - dev_name(link->supplier)); - - pm_runtime_drop_link(link); - - list_del(&link->s_node); - list_del(&link->c_node); + device_link_remove_from_lists(link); device_unregister(&link->link_dev); } -#endif /* !CONFIG_SRCU */ static void device_link_put_kref(struct device_link *link) { diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 1d252164d97b..8129a430d789 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -45,10 +45,13 @@ static unsigned int debugfs_allow __ro_after_init = DEFAULT_DEBUGFS_ALLOW_BITS; static int debugfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, struct iattr *ia) { - int ret = security_locked_down(LOCKDOWN_DEBUGFS); + int ret; - if (ret && (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID))) - return ret; + if (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) { + ret = security_locked_down(LOCKDOWN_DEBUGFS); + if (ret) + return ret; + } return simple_setattr(&init_user_ns, dentry, ia); } diff --git a/include/linux/device.h b/include/linux/device.h index 38a2071cf776..f1a00040fa53 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -570,7 +570,7 @@ struct device { * @flags: Link flags. * @rpm_active: Whether or not the consumer device is runtime-PM-active. * @kref: Count repeated addition of the same link. - * @rcu_head: An RCU head to use for deferred execution of SRCU callbacks. + * @rm_work: Work structure used for removing the link. * @supplier_preactivated: Supplier has been made active before consumer probe. */ struct device_link { @@ -583,9 +583,7 @@ struct device_link { u32 flags; refcount_t rpm_active; struct kref kref; -#ifdef CONFIG_SRCU - struct rcu_head rcu_head; -#endif + struct work_struct rm_work; bool supplier_preactivated; /* Owned by consumer probe. */ }; |