kernel.git/drivers/acpi/nfit, branch linux-5.4.y

ACPI: NFIT: fix a potential deadlock during NFIT teardown

2023-03-03T10:41:47Z

[ Upstream commit fb6df4366f86dd252bfa3049edffa52d17e7b895 ] Lockdep reports that acpi_nfit_shutdown() may deadlock against an opportune acpi_nfit_scrub(). acpi_nfit_scrub () is run from inside a 'work' and therefore has already acquired workqueue-internal locks. It also acquiires acpi_desc->init_mutex. acpi_nfit_shutdown() first acquires init_mutex, and was subsequently attempting to cancel any pending workqueue items. This reversed locking order causes a potential deadlock: ====================================================== WARNING: possible circular locking dependency detected 6.2.0-rc3 #116 Tainted: G O N ------------------------------------------------------ libndctl/1958 is trying to acquire lock: ffff888129b461c0 ((work_completion)(&(&acpi_desc->dwork)->work)){+.+.}-{0:0}, at: __flush_work+0x43/0x450 but task is already holding lock: ffff888129b460e8 (&acpi_desc->init_mutex){+.+.}-{3:3}, at: acpi_nfit_shutdown+0x87/0xd0 [nfit] which lock already depends on the new lock. ... Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&acpi_desc->init_mutex); lock((work_completion)(&(&acpi_desc->dwork)->work)); lock(&acpi_desc->init_mutex); lock((work_completion)(&(&acpi_desc->dwork)->work)); *** DEADLOCK *** Since the workqueue manipulation is protected by its own internal locking, the cancellation of pending work doesn't need to be done under acpi_desc->init_mutex. Move cancel_delayed_work_sync() outside the init_mutex to fix the deadlock. Any work that starts after acpi_nfit_shutdown() drops the lock will see ARS_CANCEL, and the cancel_delayed_work_sync() will safely flush it out. Reported-by: Dan Williams Signed-off-by: Vishal Verma Link: https://lore.kernel.org/r/20230112-acpi_nfit_lockdep-v1-1-660be4dd10be@intel.com Signed-off-by: Dan Williams Signed-off-by: Sasha Levin

ACPI: NFIT: Fix support for virtual SPA ranges

2021-08-18T06:56:57Z

commit b93dfa6bda4d4e88e5386490f2b277a26958f9d3 upstream. Fix the NFIT parsing code to treat a 0 index in a SPA Range Structure as a special case and not match Region Mapping Structures that use 0 to indicate that they are not mapped. Without this fix some platform BIOS descriptions of "virtual disk" ranges do not result in the pmem driver attaching to the range. Details: In addition to typical persistent memory ranges, the ACPI NFIT may also convey "virtual" ranges. These ranges are indicated by a UUID in the SPA Range Structure of UUID_VOLATILE_VIRTUAL_DISK, UUID_VOLATILE_VIRTUAL_CD, UUID_PERSISTENT_VIRTUAL_DISK, or UUID_PERSISTENT_VIRTUAL_CD. The critical difference between virtual ranges and UUID_PERSISTENT_MEMORY, is that virtual do not support associations with Region Mapping Structures. For this reason the "index" value of virtual SPA Range Structures is allowed to be 0. If a platform BIOS decides to represent NVDIMMs with disconnected "Region Mapping Structures" (range-index == 0), the kernel may falsely associate them with standalone ranges where the "SPA Range Structure Index" is also zero. When this happens the driver may falsely require labels where "virtual disks" are expected to be label-less. I.e. "label-less" is where the namespace-range == region-range and the pmem driver attaches with no user action to create a namespace. Cc: Jacek Zloch Cc: Lukasz Sobieraj Cc: "Lee, Chun-Yi" Cc: Fixes: c2f32acdf848 ("acpi, nfit: treat virtual ramdisk SPA as pmem region") Reported-by: Krzysztof Rusocki Reported-by: Damian Bassa Reviewed-by: Jeff Moyer Link: https://lore.kernel.org/r/162870796589.2521182.1240403310175570220.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

ACPI: NFIT: Fix comparison to '-ENXIO'

2020-11-10T11:37:31Z

[ Upstream commit 85f971b65a692b68181438e099b946cc06ed499b ] Initial value of rc is '-ENXIO', and we should use the initial value to check it. Signed-off-by: Zhang Qilong Reviewed-by: Pankaj Gupta Reviewed-by: Vishal Verma [ rjw: Subject edit ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

acpi/nfit: improve bounds checking for 'func'

2020-04-21T07:04:52Z

commit 01091c496f920e634ea84b689f480c39016752a8 upstream. The 'func' variable can come from the user in the __nd_ioctl(). If it's too high then the (1 << func) shift in acpi_nfit_clear_to_send() is undefined. In acpi_nfit_ctl() we pass 'func' to test_bit(func, &dsm_mask) which could result in an out of bounds access. To fix these issues, I introduced the NVDIMM_CMD_MAX (31) define and updated nfit_dsm_revid() to use that define as well instead of magic numbers. Fixes: 11189c1089da ("acpi/nfit: Fix command-supported detection") Signed-off-by: Dan Carpenter Reviewed-by: Dan Williams Link: https://lore.kernel.org/r/20200225161927.hvftuq7kjn547fyj@kili.mountain Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

ACPI: NFIT: Fix unlock on error in scrub_show()

2019-10-22T09:37:13Z

We change the locking in this function and forgot to update this error path so we are accidentally still holding the "dev->lockdep_mutex". Fixes: 87a30e1f05d7 ("driver-core, libnvdimm: Let device subsystems add local lockdep coverage") Signed-off-by: Dan Carpenter Reviewed-by: Ira Weiny Acked-by: Dan Williams Cc: 5.3+ # 5.3+ Signed-off-by: Rafael J. Wysocki

libnvdimm/security: Introduce a 'frozen' attribute

2019-08-29T20:49:13Z

In the process of debugging a system with an NVDIMM that was failing to unlock it was found that the kernel is reporting 'locked' while the DIMM security interface is 'frozen'. Unfortunately the security state is tracked internally as an enum which prevents it from communicating the difference between 'locked' and 'locked + frozen'. It follows that the enum also prevents the kernel from communicating 'unlocked + frozen' which would be useful for debugging why security operations like 'change passphrase' are disabled. Ditch the security state enum for a set of flags and introduce a new sysfs attribute explicitly for the 'frozen' state. The regression risk is low because the 'frozen' state was already blocked behind the 'locked' state, but will need to revisit if there were cases where applications need 'frozen' to show up in the primary 'security' attribute. The expectation is that communicating 'frozen' is mostly a helper for debug and status monitoring. Reviewed-by: Dave Jiang Reported-by: Jeff Moyer Reviewed-by: Jeff Moyer Link: https://lore.kernel.org/r/156686729474.184120.5835135644278860826.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

Merge tag 'libnvdimm-fixes-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2019-07-27T15:25:51Z

Pull libnvdimm fixes from Dan Williams: "A collection of locking and async operations fixes for v5.3-rc2. These had been soaking in a branch targeting the merge window, but missed due to a regression hunt. This fixed up version has otherwise been in -next this past week with no reported issues. In order to gain confidence in the locking changes the pull also includes a debug / instrumentation patch to enable lockdep coverage for libnvdimm subsystem operations that depend on the device_lock for exclusion. As mentioned in the changelog it is a hack, but it works and documents the locking expectations of the sub-system in a way that others can use lockdep to verify. The driver core touches got an ack from Greg. Summary: - Fix duplicate device_unregister() calls (multiple threads competing to do unregister work when scheduling device removal from a sysfs attribute of the self-same device). - Fix badblocks registration order bug. Ensure region badblocks are initialized in advance of namespace registration. - Fix a deadlock between the bus lock and probe operations. - Export device-core infrastructure to coordinate async operations via the device ->dead state. - Add device-core infrastructure to validate device_lock() usage with lockdep" * tag 'libnvdimm-fixes-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: driver-core, libnvdimm: Let device subsystems add local lockdep coverage libnvdimm/bus: Fix wait_nvdimm_bus_probe_idle() ABBA deadlock libnvdimm/bus: Stop holding nvdimm_bus_list_mutex over __nd_ioctl() libnvdimm/bus: Prepare the nd_ioctl() path to be re-entrant libnvdimm/region: Register badblocks before namespaces libnvdimm/bus: Prevent duplicate device_unregister() calls drivers/base: Introduce kill_device()

driver-core, libnvdimm: Let device subsystems add local lockdep coverage

2019-07-18T23:23:27Z

For good reason, the standard device_lock() is marked lockdep_set_novalidate_class() because there is simply no sane way to describe the myriad ways the device_lock() ordered with other locks. However, that leaves subsystems that know their own local device_lock() ordering rules to find lock ordering mistakes manually. Instead, introduce an optional / additional lockdep-enabled lock that a subsystem can acquire in all the same paths that the device_lock() is acquired. A conversion of the NFIT driver and NVDIMM subsystem to a lockdep-validate device_lock() scheme is included. The debug_nvdimm_lock() implementation implements the correct lock-class and stacking order for the libnvdimm device topology hierarchy. Yes, this is a hack, but hopefully it is a useful hack for other subsystems device_lock() debug sessions. Quoting Greg: "Yeah, it feels a bit hacky but it's really up to a subsystem to mess up using it as much as anything else, so user beware :) I don't object to it if it makes things easier for you to debug." Cc: Ingo Molnar Cc: Ira Weiny Cc: Will Deacon Cc: Dave Jiang Cc: Keith Busch Cc: Peter Zijlstra Cc: Vishal Verma Cc: "Rafael J. Wysocki" Cc: Greg Kroah-Hartman Signed-off-by: Dan Williams Acked-by: Greg Kroah-Hartman Reviewed-by: Ira Weiny Link: https://lore.kernel.org/r/156341210661.292348.7014034644265455704.stgit@dwillia2-desk3.amr.corp.intel.com

libnvdimm: nd_region flush callback support

2019-07-05T22:19:10Z

This patch adds functionality to perform flush from guest to host over VIRTIO. We are registering a callback based on 'nd_region' type. virtio_pmem driver requires this special flush function. For rest of the region types we are registering existing flush function. Report error returned by host fsync failure to userspace. Signed-off-by: Pankaj Gupta Signed-off-by: Dan Williams

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 295

2019-06-05T15:36:38Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of version 2 of the gnu general public license as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 64 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Alexios Zavras Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.894819585@linutronix.de Signed-off-by: Greg Kroah-Hartman