diff options
author | Linus Torvalds | 2022-11-18 10:49:53 -0800 |
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committer | Linus Torvalds | 2022-11-18 10:49:53 -0800 |
commit | 63c8c0d7dcb687c123ec6dc7e958cd54ebf956b6 (patch) | |
tree | 7d31f95b32fefe0ff0934d404aeb54200ad6efec /fs | |
parent | 1f63d1a106e98db5cd378b21a471f7ddd710d1b5 (diff) | |
parent | 1edfe4ea16ca2c9e91ec6cecd446b13636724e4f (diff) |
Merge tag 'driver-core-6.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fixes from Greg KH:
"Here are two small driver core fixes for 6.1-rc6:
- utsname fix, this one should already be in your tree as it came
from a different tree earlier.
- kernfs bugfix for a much reported syzbot report that seems to keep
getting triggered.
Both of these have been in linux-next for a while with no reported
issues"
* tag 'driver-core-6.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
kernfs: Fix spurious lockdep warning in kernfs_find_and_get_node_by_id()
kernel/utsname_sysctl.c: Add missing enum uts_proc value
Diffstat (limited to 'fs')
-rw-r--r-- | fs/kernfs/dir.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 3990f3e270cb..f33b3baad07c 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -31,10 +31,15 @@ static DEFINE_SPINLOCK(kernfs_idr_lock); /* root->ino_idr */ #define rb_to_kn(X) rb_entry((X), struct kernfs_node, rb) +static bool __kernfs_active(struct kernfs_node *kn) +{ + return atomic_read(&kn->active) >= 0; +} + static bool kernfs_active(struct kernfs_node *kn) { lockdep_assert_held(&kernfs_root(kn)->kernfs_rwsem); - return atomic_read(&kn->active) >= 0; + return __kernfs_active(kn); } static bool kernfs_lockdep(struct kernfs_node *kn) @@ -705,7 +710,12 @@ struct kernfs_node *kernfs_find_and_get_node_by_id(struct kernfs_root *root, goto err_unlock; } - if (unlikely(!kernfs_active(kn) || !atomic_inc_not_zero(&kn->count))) + /* + * We should fail if @kn has never been activated and guarantee success + * if the caller knows that @kn is active. Both can be achieved by + * __kernfs_active() which tests @kn->active without kernfs_rwsem. + */ + if (unlikely(!__kernfs_active(kn) || !atomic_inc_not_zero(&kn->count))) goto err_unlock; spin_unlock(&kernfs_idr_lock); |