user/sven/linux.git/fs/debugfs, branch v6.8.12

debugfs: fix wait/cancellation handling during remove

2024-04-03T13:32:17Z

[ Upstream commit 952c3fce297f12c7ff59380adb66b564e2bc9b64 ] Ben Greear further reports deadlocks during concurrent debugfs remove while files are being accessed, even though the code in question now uses debugfs cancellations. Turns out that despite all the review on the locking, we missed completely that the logic is wrong: if the refcount hits zero we can finish (and need not wait for the completion), but if it doesn't we have to trigger all the cancellations. As written, we can _never_ get into the loop triggering the cancellations. Fix this, and explain it better while at it. Cc: stable@vger.kernel.org Fixes: 8c88a474357e ("debugfs: add API to allow debugfs operations cancellation") Reported-by: Ben Greear Closes: https://lore.kernel.org/r/1c9fa9e5-09f1-0522-fdbc-dbcef4d255ca@candelatech.com Tested-by: Madhan Sai Signed-off-by: Johannes Berg Link: https://lore.kernel.org/r/20240229153635.6bfab7eb34d3.I6c7aeff8c9d6628a8bc1ddcf332205a49d801f17@changeid Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

Merge branches 'acpi-pm', 'acpi-video', 'acpi-apei' and 'acpi-extlog'

2024-01-04T12:19:40Z

Merge an ACPI power management change, ACPI backlight driver changes, APEI updates and ACPI extlog driver changes for 6.8-rc1: - Modify the ACPI LPIT table handling code to avoid u32 multiplication overflows in state residency computations (Nikita Kiryushin). - Drop an unused helper function from the ACPI backlight (video) driver and add a clarifying comment to it (Hans de Goede). - Update the ACPI backlight driver to avoid using uninitialized memory in some cases (Nikita Kiryushin). - Add ACPI backlight quirk for the Colorful X15 AT 23 laptop (Yuluo Qiu). - Add support for vendor-defined error types to the ACPI APEI error injection code (Avadhut Naik). - Adjust APEI to properly set MF_ACTION_REQUIRED on synchronous memory failure events, so they are handled differently from the asynchronous ones (Shuai Xue). - Fix NULL pointer dereference check in the ACPI extlog driver (Prarit Bhargava). - Adjust the ACPI extlog driver to clear the Extended Error Log status when RAS_CEC handled the error (Tony Luck). * acpi-pm: ACPI: LPIT: Avoid u32 multiplication overflow * acpi-video: ACPI: video: Add quirk for the Colorful X15 AT 23 Laptop ACPI: video: check for error while searching for backlight device parent ACPI: video: Drop should_check_lcd_flag() ACPI: video: Add comment about acpi_video_backlight_use_native() usage * acpi-apei: ACPI: APEI: set memory failure flags as MF_ACTION_REQUIRED on synchronous events ACPI: APEI: EINJ: Add support for vendor defined error types platform/chrome: cros_ec_debugfs: Fix permissions for panicinfo fs: debugfs: Add write functionality to debugfs blobs ACPI: APEI: EINJ: Refactor available_error_type_show() * acpi-extlog: ACPI: extlog: Clear Extended Error Log status when RAS_CEC handled the error ACPI: extlog: fix NULL pointer dereference check

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

fs: debugfs: Add write functionality to debugfs blobs

2023-11-21T20:10:44Z

Currently, debugfs_create_blob() creates read-only debugfs binary blob files. In some cases, however, userspace tools need to write variable length data structures into predetermined memory addresses. An example is when injecting Vendor-defined error types through the einj module. In such cases, the functionality to write to these blob files in debugfs would be desired since the mapping aspect can be handled within the modules with userspace tools only needing to write into the blob files. Implement a write callback to enable writing to these blob files, created in debugfs, by owners only. Signed-off-by: Avadhut Naik Reviewed-by: Alexey Kardashevskiy Reviewed-by: Greg Kroah-Hartman Reviewed-by: Tony Luck Signed-off-by: Rafael J. Wysocki

Merge tag 'driver-core-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2023-11-04T01:15:47Z

Pull driver core updates from Greg KH: "Here is the set of driver core updates for 6.7-rc1. Nothing major in here at all, just a small number of changes including: - minor cleanups and updates from Andy Shevchenko - __counted_by addition - firmware_loader update for aborting loads cleaner - other minor changes, details in the shortlog - documentation update All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (21 commits) firmware_loader: Abort all upcoming firmware load request once reboot triggered firmware_loader: Refactor kill_pending_fw_fallback_reqs() Documentation: security-bugs.rst: linux-distros relaxed their rules driver core: Release all resources during unbind before updating device links driver core: class: remove boilerplate code driver core: platform: Annotate struct irq_affinity_devres with __counted_by resource: Constify resource crosscheck APIs resource: Unify next_resource() and next_resource_skip_children() resource: Reuse for_each_resource() macro PCI: Implement custom llseek for sysfs resource entries kernfs: sysfs: support custom llseek method for sysfs entries debugfs: Fix __rcu type comparison warning device property: Replace custom implementation of COUNT_ARGS() drivers: base: test: Make property entry API test modular driver core: Add missing parameter description to __fwnode_link_add() device property: Clarify usage scope of some struct fwnode_handle members devres: rename the first parameter of devm_add_action(_or_reset) driver core: platform: Unify the firmware node type check driver core: platform: Use temporary variable in platform_device_add() driver core: platform: Refactor error path in a couple places ...