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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-12-01 08:24:46 +0900 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-12-01 08:24:46 +0900 |
commit | 6172a5180fcc65170bfa2d49e55427567860f2a7 (patch) | |
tree | 54617c32c60bdbd06ab0cde16f8c56d913ef68ba /fs/debugfs/file.c | |
parent | e8f60209d6cf652a9cfda64371acea69f62770aa (diff) | |
parent | 777f245eec8152926b411e3d4f4545310f52cbed (diff) | |
download | lwn-6172a5180fcc65170bfa2d49e55427567860f2a7.tar.gz lwn-6172a5180fcc65170bfa2d49e55427567860f2a7.zip |
Merge tag 'net-6.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Including fixes from bpf and wifi.
Current release - regressions:
- neighbour: fix __randomize_layout crash in struct neighbour
- r8169: fix deadlock on RTL8125 in jumbo mtu mode
Previous releases - regressions:
- wifi:
- mac80211: fix warning at station removal time
- cfg80211: fix CQM for non-range use
- tools: ynl-gen: fix unexpected response handling
- octeontx2-af: fix possible buffer overflow
- dpaa2: recycle the RX buffer only after all processing done
- rswitch: fix missing dev_kfree_skb_any() in error path
Previous releases - always broken:
- ipv4: fix uaf issue when receiving igmp query packet
- wifi: mac80211: fix debugfs deadlock at device removal time
- bpf:
- sockmap: af_unix stream sockets need to hold ref for pair sock
- netdevsim: don't accept device bound programs
- selftests: fix a char signedness issue
- dsa: mv88e6xxx: fix marvell 6350 probe crash
- octeontx2-pf: restore TC ingress police rules when interface is up
- wangxun: fix memory leak on msix entry
- ravb: keep reverse order of operations in ravb_remove()"
* tag 'net-6.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (51 commits)
net: ravb: Keep reverse order of operations in ravb_remove()
net: ravb: Stop DMA in case of failures on ravb_open()
net: ravb: Start TX queues after HW initialization succeeded
net: ravb: Make write access to CXR35 first before accessing other EMAC registers
net: ravb: Use pm_runtime_resume_and_get()
net: ravb: Check return value of reset_control_deassert()
net: libwx: fix memory leak on msix entry
ice: Fix VF Reset paths when interface in a failed over aggregate
bpf, sockmap: Add af_unix test with both sockets in map
bpf, sockmap: af_unix stream sockets need to hold ref for pair sock
tools: ynl-gen: always construct struct ynl_req_state
ethtool: don't propagate EOPNOTSUPP from dumps
ravb: Fix races between ravb_tx_timeout_work() and net related ops
r8169: prevent potential deadlock in rtl8169_close
r8169: fix deadlock on RTL8125 in jumbo mtu mode
neighbour: Fix __randomize_layout crash in struct neighbour
octeontx2-pf: Restore TC ingress police rules when interface is up
octeontx2-pf: Fix adding mbox work queue entry when num_vfs > 64
net: stmmac: xgmac: Disable FPE MMC interrupts
octeontx2-af: Fix possible buffer overflow
...
Diffstat (limited to 'fs/debugfs/file.c')
-rw-r--r-- | fs/debugfs/file.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index c45e8c2d62e1..a5ade8c16375 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -84,6 +84,14 @@ int debugfs_file_get(struct dentry *dentry) struct debugfs_fsdata *fsd; void *d_fsd; + /* + * This could only happen if some debugfs user erroneously calls + * debugfs_file_get() on a dentry that isn't even a file, let + * them know about it. + */ + if (WARN_ON(!d_is_reg(dentry))) + return -EINVAL; + d_fsd = READ_ONCE(dentry->d_fsdata); if (!((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) { fsd = d_fsd; @@ -100,6 +108,14 @@ int debugfs_file_get(struct dentry *dentry) kfree(fsd); fsd = READ_ONCE(dentry->d_fsdata); } +#ifdef CONFIG_LOCKDEP + fsd->lock_name = kasprintf(GFP_KERNEL, "debugfs:%pd", dentry); + lockdep_register_key(&fsd->key); + lockdep_init_map(&fsd->lockdep_map, fsd->lock_name ?: "debugfs", + &fsd->key, 0); +#endif + INIT_LIST_HEAD(&fsd->cancellations); + mutex_init(&fsd->cancellations_mtx); } /* @@ -116,6 +132,8 @@ int debugfs_file_get(struct dentry *dentry) if (!refcount_inc_not_zero(&fsd->active_users)) return -EIO; + lock_map_acquire_read(&fsd->lockdep_map); + return 0; } EXPORT_SYMBOL_GPL(debugfs_file_get); @@ -133,11 +151,93 @@ void debugfs_file_put(struct dentry *dentry) { struct debugfs_fsdata *fsd = READ_ONCE(dentry->d_fsdata); + lock_map_release(&fsd->lockdep_map); + if (refcount_dec_and_test(&fsd->active_users)) complete(&fsd->active_users_drained); } EXPORT_SYMBOL_GPL(debugfs_file_put); +/** + * debugfs_enter_cancellation - enter a debugfs cancellation + * @file: the file being accessed + * @cancellation: the cancellation object, the cancel callback + * inside of it must be initialized + * + * When a debugfs file is removed it needs to wait for all active + * operations to complete. However, the operation itself may need + * to wait for hardware or completion of some asynchronous process + * or similar. As such, it may need to be cancelled to avoid long + * waits or even deadlocks. + * + * This function can be used inside a debugfs handler that may + * need to be cancelled. As soon as this function is called, the + * cancellation's 'cancel' callback may be called, at which point + * the caller should proceed to call debugfs_leave_cancellation() + * and leave the debugfs handler function as soon as possible. + * Note that the 'cancel' callback is only ever called in the + * context of some kind of debugfs_remove(). + * + * This function must be paired with debugfs_leave_cancellation(). + */ +void debugfs_enter_cancellation(struct file *file, + struct debugfs_cancellation *cancellation) +{ + struct debugfs_fsdata *fsd; + struct dentry *dentry = F_DENTRY(file); + + INIT_LIST_HEAD(&cancellation->list); + + if (WARN_ON(!d_is_reg(dentry))) + return; + + if (WARN_ON(!cancellation->cancel)) + return; + + fsd = READ_ONCE(dentry->d_fsdata); + if (WARN_ON(!fsd || + ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT))) + return; + + mutex_lock(&fsd->cancellations_mtx); + list_add(&cancellation->list, &fsd->cancellations); + mutex_unlock(&fsd->cancellations_mtx); + + /* if we're already removing wake it up to cancel */ + if (d_unlinked(dentry)) + complete(&fsd->active_users_drained); +} +EXPORT_SYMBOL_GPL(debugfs_enter_cancellation); + +/** + * debugfs_leave_cancellation - leave cancellation section + * @file: the file being accessed + * @cancellation: the cancellation previously registered with + * debugfs_enter_cancellation() + * + * See the documentation of debugfs_enter_cancellation(). + */ +void debugfs_leave_cancellation(struct file *file, + struct debugfs_cancellation *cancellation) +{ + struct debugfs_fsdata *fsd; + struct dentry *dentry = F_DENTRY(file); + + if (WARN_ON(!d_is_reg(dentry))) + return; + + fsd = READ_ONCE(dentry->d_fsdata); + if (WARN_ON(!fsd || + ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT))) + return; + + mutex_lock(&fsd->cancellations_mtx); + if (!list_empty(&cancellation->list)) + list_del(&cancellation->list); + mutex_unlock(&fsd->cancellations_mtx); +} +EXPORT_SYMBOL_GPL(debugfs_leave_cancellation); + /* * Only permit access to world-readable files when the kernel is locked down. * We also need to exclude any file that has ways to write or alter it as root |