kernel/linux.git/drivers/nvdimm/dimm_devs.c, branch v6.2

libnvdimm: Introduce CONFIG_NVDIMM_SECURITY_TEST flag

2022-12-01T20:42:35+00:00

nfit_test overrode the security_show() sysfs attribute function in nvdimm dimm_devs in order to allow testing of security unlock. With the introduction of CXL security commands, the trick to override security_show() becomes significantly more complicated. By introdcing a security flag CONFIG_NVDIMM_SECURITY_TEST, libnvdimm can just toggle the check via a compile option. In addition the original override can can be removed from tools/testing/nvdimm/. The flag will also be used to bypass cpu_cache_invalidate_memregion() when set in a different commit. This allows testing on QEMU with nfit_test or cxl_test since cpu_cache_has_invalidate_memregion() checks whether X86_FEATURE_HYPERVISOR cpu feature flag is set on x86. Reviewed-by: Jonathan Cameron Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/166983618758.2734609.18031639517065867138.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dan Williams

nvdimm: Drop nd_device_lock()

2022-04-28T21:01:55+00:00

Now that all NVDIMM subsystem locking is validated with custom lock classes, there is no need for the custom usage of the lockdep_mutex. Cc: Vishal Verma Cc: Dave Jiang Cc: Ira Weiny Reviewed-by: Ira Weiny Link: https://lore.kernel.org/r/165055521979.3745911.10751769706032029999.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

nvdimm: Replace lockdep_mutex with local lock classes

2022-04-28T21:01:55+00:00

In response to an attempt to expand dev->lockdep_mutex for device_lock() validation [1], Peter points out [2] that the lockdep API already has the ability to assign a dedicated lock class per subsystem device-type. Use lockdep_set_class() to override the default device_lock() '__lockdep_no_validate__' class for each NVDIMM subsystem device-type. This enables lockdep to detect deadlocks and recursive locking within the device-driver core and the subsystem. Link: https://lore.kernel.org/r/164982968798.684294.15817853329823976469.stgit@dwillia2-desk3.amr.corp.intel.com [1] Link: https://lore.kernel.org/r/Ylf0dewci8myLvoW@hirez.programming.kicks-ass.net [2] Suggested-by: Peter Zijlstra Cc: Vishal Verma Cc: Dave Jiang Cc: Ira Weiny Reviewed-by: Ira Weiny Link: https://lore.kernel.org/r/165055520896.3745911.8021255583475547548.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

nvdimm/region: Delete nd_blk_region infrastructure

2022-03-11T23:53:13+00:00

Now that the nd_namespace_blk infrastructure is removed, delete all the region machinery to coordinate provisioning aliased capacity between PMEM and BLK. Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/164688418803.2879318.1302315202397235855.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

libnvdimm: Export nvdimm shutdown helper, nvdimm_delete()

2021-06-15T23:47:22+00:00

CXL is a hotplug bus and arranges for nvdimm devices to be dynamically discovered and removed. The libnvdimm core manages shutdown of nvdimm security operations when the device is unregistered. That functionality is moved to nvdimm_delete() and invoked by the CXL-to-nvdimm glue code. Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/162379910271.2993820.2955889139842401250.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

libnvdimm/dimm: Avoid race between probe and available_slots_show()

2021-02-02T00:20:40+00:00

Richard reports that the following test: (while true; do cat /sys/bus/nd/devices/nmem*/available_slots 2>&1 > /dev/null done) & while true; do for i in $(seq 0 4); do echo nmem$i > /sys/bus/nd/drivers/nvdimm/bind done for i in $(seq 0 4); do echo nmem$i > /sys/bus/nd/drivers/nvdimm/unbind done done ...fails with a crash signature like: divide error: 0000 [#1] SMP KASAN PTI RIP: 0010:nd_label_nfree+0x134/0x1a0 [libnvdimm] [..] Call Trace: available_slots_show+0x4e/0x120 [libnvdimm] dev_attr_show+0x42/0x80 ? memset+0x20/0x40 sysfs_kf_seq_show+0x218/0x410 The root cause is that available_slots_show() consults driver-data, but fails to synchronize against device-unbind setting up a TOCTOU race to access uninitialized memory. Validate driver-data under the device-lock. Fixes: 4d88a97aa9e8 ("libnvdimm, nvdimm: dimm driver and base libnvdimm device-driver infrastructure") Cc: Cc: Vishal Verma Cc: Dave Jiang Cc: Ira Weiny Cc: Coly Li Reported-by: Richard Palethorpe Acked-by: Richard Palethorpe Signed-off-by: Dan Williams

libnvdimm: KASAN: global-out-of-bounds Read in internal_create_group

2020-08-17T20:47:38+00:00

Because the last member of the "nvdimm_firmware_attributes" array was not assigned a null ptr, when traversal of "grp->attrs" array is out of bounds in "create_files" func. func: create_files: ->for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) ->.... BUG: KASAN: global-out-of-bounds in create_files fs/sysfs/group.c:43 [inline] BUG: KASAN: global-out-of-bounds in internal_create_group+0x9d8/0xb20 fs/sysfs/group.c:149 Read of size 8 at addr ffffffff8a2e4cf0 by task kworker/u17:10/959 CPU: 2 PID: 959 Comm: kworker/u17:10 Not tainted 5.8.0-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 Workqueue: events_unbound async_run_entry_fn Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0x5/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 create_files fs/sysfs/group.c:43 [inline] internal_create_group+0x9d8/0xb20 fs/sysfs/group.c:149 internal_create_groups.part.0+0x90/0x140 fs/sysfs/group.c:189 internal_create_groups fs/sysfs/group.c:185 [inline] sysfs_create_groups+0x25/0x50 fs/sysfs/group.c:215 device_add_groups drivers/base/core.c:2024 [inline] device_add_attrs drivers/base/core.c:2178 [inline] device_add+0x7fd/0x1c40 drivers/base/core.c:2881 nd_async_device_register+0x12/0x80 drivers/nvdimm/bus.c:506 async_run_entry_fn+0x121/0x530 kernel/async.c:123 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 The buggy address belongs to the variable: nvdimm_firmware_attributes+0x10/0x40 Link: https://lore.kernel.org/r/20200812085501.30963-1-qiang.zhang@windriver.com Link: https://lore.kernel.org/r/20200814150509.225615-1-vaibhav@linux.ibm.com Fixes: 48001ea50d17f ("PM, libnvdimm: Add runtime firmware activation support") Reported-by: syzbot+1cf0ffe61aecf46f588f@syzkaller.appspotmail.com Reported-by: Sandipan Das Reported-by: Vaibhav Jain Reviewed-by: Ira Weiny Signed-off-by: Zqiang Signed-off-by: Vishal Verma

libnvdimm/security: the 'security' attr never show 'overwrite' state

2020-08-04T00:54:13+00:00

'security' attribute displays the security state of an nvdimm. During normal operation, the nvdimm state maybe one of 'disabled', 'unlocked' or 'locked'. When an admin issues # ndctl sanitize-dimm nmem0 --overwrite the attribute is expected to change to 'overwrite' until the overwrite operation completes. But tests on our systems show that 'overwrite' is never shown during the overwrite operation. i.e. # cat /sys/devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0012:00/ndbus0/nmem0/security unlocked the attribute remain 'unlocked' through out the operation, consequently "ndctl wait-overwrite nmem0" command doesn't wait at all. The driver tracks the state in 'nvdimm->sec.flags': when the operation starts, it adds an overwrite bit to the flags; and when the operation completes, it removes the bit. Hence security_show() should check the 'overwrite' bit first, in order to indicate the actual state when multiple bits are set in the flags. Link: https://lore.kernel.org/r/1596494499-9852-2-git-send-email-jane.chu@oracle.com Reviewed-by: Dave Jiang Signed-off-by: Jane Chu Signed-off-by: Vishal Verma

ACPI: NFIT: Add runtime firmware activate support

2020-07-29T01:29:22+00:00

Plumb the platform specific backend for the generic libnvdimm firmware activate interface. Register dimm level operations to arm/disarm activation, and register bus level operations to report the dynamic platform-quiesce time relative to the number of dimms armed for firmware activation. A new nfit-specific bus attribute "firmware_activate_noidle" is added to allow the activation to switch between platform enforced, and OS opportunistic device quiesce. In other words, let the hibernate cycle handle in-flight device-dma rather than the platform attempting to increase PCI-E timeouts and the like. Cc: Dave Jiang Cc: Ira Weiny Cc: Vishal Verma Signed-off-by: Dan Williams Signed-off-by: Vishal Verma

PM, libnvdimm: Add runtime firmware activation support

2020-07-29T01:28:32+00:00

Abstract platform specific mechanics for nvdimm firmware activation behind a handful of generic ops. At the bus level ->activate_state() indicates the unified state (idle, busy, armed) of all DIMMs on the bus, and ->capability() indicates the system state expectations for activate. At the DIMM level ->activate_state() indicates the per-DIMM state, ->activate_result() indicates the outcome of the last activation attempt, and ->arm() attempts to transition the DIMM from 'idle' to 'armed'. A new hibernate_quiet_exec() facility is added to support firmware activation in an OS defined system quiesce state. It leverages the fact that the hibernate-freeze state wants to assert that a memory hibernation snapshot can be taken. This is in contrast to a platform firmware defined quiesce state that may forcefully quiet the memory controller independent of whether an individual device-driver properly supports hibernate-freeze. The libnvdimm sysfs interface is extended to support detection of a firmware activate capability. The mechanism supports enumeration and triggering of firmware activate, optionally in the hibernate_quiet_exec() context. [rafael: hibernate_quiet_exec() proposal] [vishal: fix up sparse warning, grammar in Documentation/] Cc: Pavel Machek Cc: Ira Weiny Cc: Len Brown Cc: Jonathan Corbet Cc: Dave Jiang Cc: Vishal Verma Reported-by: kernel test robot Co-developed-by: "Rafael J. Wysocki" Signed-off-by: "Rafael J. Wysocki" Signed-off-by: Dan Williams Signed-off-by: Vishal Verma