linux/fs/debugfs/file.c, branch v6.7

debugfs: initialize cancellations earlier

2023-12-22T06:33:02Z

Tetsuo Handa pointed out that in the (now reverted) lockdep commit I initialized the data too late. The same is true for the cancellation data, it must be initialized before the cmpxchg(), otherwise it may be done twice and possibly even overwriting data in there already when there's a race. Fix that, which also requires destroying the mutex in case we lost the race. Fixes: 8c88a474357e ("debugfs: add API to allow debugfs operations cancellation") Reported-by: Tetsuo Handa Signed-off-by: Johannes Berg Link: https://lore.kernel.org/r/20231221150444.1e47a0377f80.If7e8ba721ba2956f12c6e8405e7d61e154aa7ae7@changeid Signed-off-by: Greg Kroah-Hartman

Revert "debugfs: annotate debugfs handlers vs. removal with lockdep"

2023-12-04T06:43:16Z

This reverts commit f4acfcd4deb1 ("debugfs: annotate debugfs handlers vs. removal with lockdep"), it appears to have false positives and really shouldn't have been in the -rc series with the fixes anyway. Signed-off-by: Johannes Berg Link: https://lore.kernel.org/r/20231202114936.fd55431ab160.I911aa53abeeca138126f690d383a89b13eb05667@changeid Signed-off-by: Greg Kroah-Hartman

Merge tag 'wireless-2023-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless

2023-11-30T03:43:34Z

Johannes Berg says: ==================== wireless fixes: - debugfs had a deadlock (removal vs. use of files), fixes going through wireless ACKed by Greg - support for HT STAs on 320 MHz channels, even if it's not clear that should ever happen (that's 6 GHz), best not to WARN() - fix for the previous CQM fix that broke most cases - various wiphy locking fixes - various small driver fixes * tag 'wireless-2023-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless: wifi: mac80211: use wiphy locked debugfs for sdata/link wifi: mac80211: use wiphy locked debugfs helpers for agg_status wifi: cfg80211: add locked debugfs wrappers debugfs: add API to allow debugfs operations cancellation debugfs: annotate debugfs handlers vs. removal with lockdep debugfs: fix automount d_fsdata usage wifi: mac80211: handle 320 MHz in ieee80211_ht_cap_ie_to_sta_ht_cap wifi: avoid offset calculation on NULL pointer wifi: cfg80211: hold wiphy mutex for send_interface wifi: cfg80211: lock wiphy mutex for rfkill poll wifi: cfg80211: fix CQM for non-range use wifi: mac80211: do not pass AP_VLAN vif pointer to drivers during flush wifi: iwlwifi: mvm: fix an error code in iwl_mvm_mld_add_sta() wifi: mt76: mt7925: fix typo in mt7925_init_he_caps wifi: mt76: mt7921: fix 6GHz disabled by the missing default CLC config ==================== Link: https://lore.kernel.org/r/20231129150809.31083-3-johannes@sipsolutions.net Signed-off-by: Jakub Kicinski

debugfs: add API to allow debugfs operations cancellation

2023-11-27T10:24:55Z

In some cases there might be longer-running hardware accesses in debugfs files, or attempts to acquire locks, and we want to still be able to quickly remove the files. Introduce a cancellations API to use inside the debugfs handler functions to be able to cancel such operations on a per-file basis. Acked-by: Greg Kroah-Hartman Signed-off-by: Johannes Berg

debugfs: annotate debugfs handlers vs. removal with lockdep

2023-11-27T10:24:50Z

When you take a lock in a debugfs handler but also try to remove the debugfs file under that lock, things can deadlock since the removal has to wait for all users to finish. Add lockdep annotations in debugfs_file_get()/_put() to catch such issues. Acked-by: Greg Kroah-Hartman Signed-off-by: Johannes Berg

debugfs: fix automount d_fsdata usage

2023-11-27T10:24:45Z

debugfs_create_automount() stores a function pointer in d_fsdata, but since commit 7c8d469877b1 ("debugfs: add support for more elaborate ->d_fsdata") debugfs_release_dentry() will free it, now conditionally on DEBUGFS_FSDATA_IS_REAL_FOPS_BIT, but that's not set for the function pointer in automount. As a result, removing an automount dentry would attempt to free the function pointer. Luckily, the only user of this (tracing) never removes it. Nevertheless, it's safer if we just handle the fsdata in one way, namely either DEBUGFS_FSDATA_IS_REAL_FOPS_BIT or allocated. Thus, change the automount to allocate it, and use the real_fops in the data to indicate whether or not automount is filled, rather than adding a type tag. At least for now this isn't actually needed, but the next changes will require it. Also check in debugfs_file_get() that it gets only called on regular files, just to make things clearer. Acked-by: Greg Kroah-Hartman Signed-off-by: Johannes Berg

debugfs: Fix __rcu type comparison warning

2023-10-05T11:18:18Z

Sparse reports the following: fs/debugfs/file.c:942:9: sparse: sparse: incompatible types in comparison expression (different address spaces): fs/debugfs/file.c:942:9: sparse: char [noderef] __rcu * fs/debugfs/file.c:942:9: sparse: char * rcu_assign_pointer() expects that it's assigning to pointers annotated with __rcu. We can't annotate the generic struct file::private_data, so cast it instead. Fixes: 86b5488121db ("debugfs: Add write support to debugfs_create_str()") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202309091933.BRWlSnCq-lkp@intel.com/ Signed-off-by: Mike Tipton Link: https://lore.kernel.org/r/20230922134512.5126-1-quic_mdtipton@quicinc.com Signed-off-by: Greg Kroah-Hartman

debugfs: Add write support to debugfs_create_str()

2023-08-22T18:04:07Z

Currently, debugfs_create_str() only supports reading strings from debugfs. Add support for writing them as well. Based on original implementation by Peter Zijlstra [0]. Write support was present in the initial patch version, but dropped in v2 due to lack of users. We have a user now, so reintroduce it. [0] https://lore.kernel.org/all/YF3Hv5zXb%2F6lauzs@hirez.programming.kicks-ass.net/ Signed-off-by: Mike Tipton Acked-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20230807142914.12480-2-quic_mdtipton@quicinc.com Signed-off-by: Georgi Djakov

debugfs: Correct the 'debugfs_create_str' docs

2023-05-31T18:02:14Z

The documentation of the 'debugfs_create_str' says that the function returns a pointer to a dentry created, or an ERR_PTR in case of error. Actually, this is not true: this function doesn't return anything at all. Correct the documentation correspondingly. Signed-off-by: Ivan Orlov Link: https://lore.kernel.org/r/20230514172353.52878-1-ivan.orlov0322@gmail.com Signed-off-by: Greg Kroah-Hartman

debugfs: Export debugfs_create_str symbol

2023-01-20T11:41:00Z

Needed by SCMI Raw mode support when compiled as a loadable module. Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Signed-off-by: Cristian Marussi Tested-by: Florian Fainelli Tested-by: Vincent Guittot Acked-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20230118121426.492864-10-cristian.marussi@arm.com Signed-off-by: Sudeep Holla