kernel/drivers/dax, branch linux-5.15.y

dax/kmem: Pass valid argument to memory_group_register_static

2023-07-23T11:47:17Z

[ Upstream commit 46e66dab8565f742374e9cc4ff7d35f344d774e2 ] memory_group_register_static takes maximum number of pages as the argument while dev_dax_kmem_probe passes total_len (in bytes) as the argument. IIUC, I don't see any crash/panic impact as such. As, memory_group_register_static just set the max_pages limit which is used in auto_movable_zone_for_pfn to determine the zone. which might cause these condition to behave differently, This will be true always so jump will happen to kernel_zone ... if (!auto_movable_can_online_movable(NUMA_NO_NODE, group, nr_pages)) goto kernel_zone; ... kernel_zone: return default_kernel_zone_for_pfn(nid, pfn, nr_pages); Here, In below, zone_intersects compare range will be larger as nr_pages will be higher (derived from total_len passed in dev_dax_kmem_probe). ... static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn, unsigned long nr_pages) { struct pglist_data *pgdat = NODE_DATA(nid); int zid; for (zid = 0; zid < ZONE_NORMAL; zid++) { struct zone *zone = &pgdat->node_zones[zid]; if (zone_intersects(zone, start_pfn, nr_pages)) return zone; } return &pgdat->node_zones[ZONE_NORMAL]; } Incorrect zone will be returned here, which in later time might cause bigger problem. Fixes: eedf634aac3b ("dax/kmem: use a single static memory group for a single probed unit") Signed-off-by: Tarun Sahu Link: https://lore.kernel.org/r/20230621155025.370672-1-tsahu@linux.ibm.com Reviewed-by: Vishal Verma Signed-off-by: Vishal Verma Signed-off-by: Sasha Levin

dax: Introduce alloc_dev_dax_id()

2023-07-23T11:47:17Z

[ Upstream commit 70aab281e18c68a1284bc387de127c2fc0bed3f8 ] The reference counting of dax_region objects is needlessly complicated, has lead to confusion [1], and has hidden a bug [2]. Towards cleaning up that mess introduce alloc_dev_dax_id() to minimize the holding of a dax_region reference to only what dev_dax_release() needs, the dax_region->ida. Part of the reason for the mess was the design to dereference a dax_region in all cases in free_dev_dax_id() even if the id was statically assigned by the upper level dax_region driver. Remove the need to call "is_static(dax_region)" by tracking whether the id is dynamic directly in the dev_dax instance itself. With that flag the dax_region pinning and release per dev_dax instance can move to alloc_dev_dax_id() and free_dev_dax_id() respectively. A follow-on cleanup address the unnecessary references in the dax_region setup and drivers. Fixes: 0f3da14a4f05 ("device-dax: introduce 'seed' devices") Link: http://lore.kernel.org/r/20221203095858.612027-1-liuyongqiang13@huawei.com [1] Link: http://lore.kernel.org/r/3cf0890b-4eb0-e70e-cd9c-2ecc3d496263@hpe.com [2] Reported-by: Yongqiang Liu Reported-by: Paul Cassella Reported-by: Ira Weiny Signed-off-by: Dan Williams Link: https://lore.kernel.org/r/168577284563.1672036.13493034988900989554.stgit@dwillia2-xfh.jf.intel.com Reviewed-by: Ira Weiny Signed-off-by: Vishal Verma Signed-off-by: Sasha Levin

dax: Fix dax_mapping_release() use after free

2023-07-23T11:47:17Z

[ Upstream commit 6d24b170a9db0456f577b1ab01226a2254c016a8 ] A CONFIG_DEBUG_KOBJECT_RELEASE test of removing a device-dax region provider (like modprobe -r dax_hmem) yields: kobject: 'mapping0' (ffff93eb460e8800): kobject_release, parent 0000000000000000 (delayed 2000) [..] DEBUG_LOCKS_WARN_ON(1) WARNING: CPU: 23 PID: 282 at kernel/locking/lockdep.c:232 __lock_acquire+0x9fc/0x2260 [..] RIP: 0010:__lock_acquire+0x9fc/0x2260 [..] Call Trace: [..] lock_acquire+0xd4/0x2c0 ? ida_free+0x62/0x130 _raw_spin_lock_irqsave+0x47/0x70 ? ida_free+0x62/0x130 ida_free+0x62/0x130 dax_mapping_release+0x1f/0x30 device_release+0x36/0x90 kobject_delayed_cleanup+0x46/0x150 Due to attempting ida_free() on an ida object that has already been freed. Devices typically only hold a reference on their parent while registered. If a child needs a parent object to complete its release it needs to hold a reference that it drops from its release callback. Arrange for a dax_mapping to pin its parent dev_dax instance until dax_mapping_release(). Fixes: 0b07ce872a9e ("device-dax: introduce 'mapping' devices") Signed-off-by: Dan Williams Link: https://lore.kernel.org/r/168577283412.1672036.16111545266174261446.stgit@dwillia2-xfh.jf.intel.com Reviewed-by: Dave Jiang Reviewed-by: Fan Ni Reviewed-by: Ira Weiny Signed-off-by: Vishal Verma Signed-off-by: Sasha Levin

dax/kmem: Fix leak of memory-hotplug resources

2023-03-10T08:40:08Z

commit e686c32590f40bffc45f105c04c836ffad3e531a upstream. While experimenting with CXL region removal the following corruption of /proc/iomem appeared. Before: f010000000-f04fffffff : CXL Window 0 f010000000-f02fffffff : region4 f010000000-f02fffffff : dax4.0 f010000000-f02fffffff : System RAM (kmem) After (modprobe -r cxl_test): f010000000-f02fffffff : **redacted binary garbage** f010000000-f02fffffff : System RAM (kmem) ...and testing further the same is visible with persistent memory assigned to kmem: Before: 480000000-243fffffff : Persistent Memory 480000000-57e1fffff : namespace3.0 580000000-243fffffff : dax3.0 580000000-243fffffff : System RAM (kmem) After (ndctl disable-region all): 480000000-243fffffff : Persistent Memory 580000000-243fffffff : ***redacted binary garbage*** 580000000-243fffffff : System RAM (kmem) The corrupted data is from a use-after-free of the "dax4.0" and "dax3.0" resources, and it also shows that the "System RAM (kmem)" resource is not being removed. The bug does not appear after "modprobe -r kmem", it requires the parent of "dax4.0" and "dax3.0" to be removed which re-parents the leaked "System RAM (kmem)" instances. Those in turn reference the freed resource as a parent. First up for the fix is release_mem_region_adjustable() needs to reliably delete the resource inserted by add_memory_driver_managed(). That is thwarted by a check for IORESOURCE_SYSRAM that predates the dax/kmem driver, from commit: 65c78784135f ("kernel, resource: check for IORESOURCE_SYSRAM in release_mem_region_adjustable") That appears to be working around the behavior of HMM's "MEMORY_DEVICE_PUBLIC" facility that has since been deleted. With that check removed the "System RAM (kmem)" resource gets removed, but corruption still occurs occasionally because the "dax" resource is not reliably removed. The dax range information is freed before the device is unregistered, so the driver can not reliably recall (another use after free) what it is meant to release. Lastly if that use after free got lucky, the driver was covering up the leak of "System RAM (kmem)" due to its use of release_resource() which detaches, but does not free, child resources. The switch to remove_resource() forces remove_memory() to be responsible for the deletion of the resource added by add_memory_driver_managed(). Fixes: c2f3011ee697 ("device-dax: add an allocation interface for device-dax instances") Cc: Cc: Oscar Salvador Cc: David Hildenbrand Cc: Pavel Tatashin Reviewed-by: Vishal Verma Reviewed-by: Pasha Tatashin Reviewed-by: Dave Jiang Link: https://lore.kernel.org/r/167653656244.3147810.5705900882794040229.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

devdax: Fix soft-reservation memory description

2022-09-28T09:11:57Z

commit 67feaba413ec68daf4124e9870878899b4ed9a0e upstream. The "hmem" platform-devices that are created to represent the platform-advertised "Soft Reserved" memory ranges end up inserting a resource that causes the iomem_resource tree to look like this: 340000000-43fffffff : hmem.0 340000000-43fffffff : Soft Reserved 340000000-43fffffff : dax0.0 This is because insert_resource() reparents ranges when they completely intersect an existing range. This matters because code that uses region_intersects() to scan for a given IORES_DESC will only check that top-level 'hmem.0' resource and not the 'Soft Reserved' descendant. So, to support EINJ (via einj_error_inject()) to inject errors into memory hosted by a dax-device, be sure to describe the memory as IORES_DESC_SOFT_RESERVED. This is a follow-on to: commit b13a3e5fd40b ("ACPI: APEI: Fix _EINJ vs EFI_MEMORY_SP") ...that fixed EINJ support for "Soft Reserved" ranges in the first instance. Fixes: 262b45ae3ab4 ("x86/efi: EFI soft reservation to E820 enumeration") Reported-by: Ricardo Sandoval Torres Tested-by: Ricardo Sandoval Torres Cc: Cc: Tony Luck Cc: Omar Avelar Cc: Rafael J. Wysocki Cc: Mark Gross Link: https://lore.kernel.org/r/166397075670.389916.7435722208896316387.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

dax: make sure inodes are flushed before destroy cache

2022-04-08T12:23:31Z

[ Upstream commit a7e8de822e0b1979f08767c751f6c8a9c1d4ad86 ] A bug can be triggered by following command $ modprobe nd_pmem && modprobe -r nd_pmem [ 10.060014] BUG dax_cache (Not tainted): Objects remaining in dax_cache on __kmem_cache_shutdown() [ 10.060938] Slab 0x0000000085b729ac objects=9 used=1 fp=0x000000004f5ae469 flags=0x200000000010200(slab|head|node) [ 10.062433] Call Trace: [ 10.062673] dump_stack_lvl+0x34/0x44 [ 10.062865] slab_err+0x90/0xd0 [ 10.063619] __kmem_cache_shutdown+0x13b/0x2f0 [ 10.063848] kmem_cache_destroy+0x4a/0x110 [ 10.064058] __x64_sys_delete_module+0x265/0x300 This is caused by dax_fs_exit() not flushing inodes before destroy cache. To fix this issue, call rcu_barrier() before destroy cache. Signed-off-by: Tong Zhang Reviewed-by: Ira Weiny Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220212071111.148575-1-ztong0001@gmail.com Fixes: 7b6be8444e0f ("dax: refactor dax-fs into a generic provider of 'struct dax_device' instances") Signed-off-by: Dan Williams Signed-off-by: Sasha Levin

Merge tag 'libnvdimm-for-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2021-09-09T18:39:57Z

Pull libnvdimm updates from Dan Williams: - Fix a race condition in the teardown path of raw mode pmem namespaces. - Cleanup the code that filesystems use to detect filesystem-dax capabilities of their underlying block device. * tag 'libnvdimm-for-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: dax: remove bdev_dax_supported xfs: factor out a xfs_buftarg_is_dax helper dax: stub out dax_supported for !CONFIG_FS_DAX dax: remove __generic_fsdax_supported dax: move the dax_read_lock() locking into dax_supported dax: mark dax_get_by_host static dm: use fs_dax_get_by_bdev instead of dax_get_by_host dax: stop using bdevname fsdax: improve the FS_DAX Kconfig description and help text libnvdimm/pmem: Fix crash triggered when I/O in-flight during unbind

Merge branch 'akpm' (patches from Andrew)

2021-09-08T19:55:35Z

Merge more updates from Andrew Morton: "147 patches, based on 7d2a07b769330c34b4deabeed939325c77a7ec2f. Subsystems affected by this patch series: mm (memory-hotplug, rmap, ioremap, highmem, cleanups, secretmem, kfence, damon, and vmscan), alpha, percpu, procfs, misc, core-kernel, MAINTAINERS, lib, checkpatch, epoll, init, nilfs2, coredump, fork, pids, criu, kconfig, selftests, ipc, and scripts" * emailed patches from Andrew Morton : (94 commits) scripts: check_extable: fix typo in user error message mm/workingset: correct kernel-doc notations ipc: replace costly bailout check in sysvipc_find_ipc() selftests/memfd: remove unused variable Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH configs: remove the obsolete CONFIG_INPUT_POLLDEV prctl: allow to setup brk for et_dyn executables pid: cleanup the stale comment mentioning pidmap_init(). kernel/fork.c: unexport get_{mm,task}_exe_file coredump: fix memleak in dump_vma_snapshot() fs/coredump.c: log if a core dump is aborted due to changed file permissions nilfs2: use refcount_dec_and_lock() to fix potential UAF nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_group nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_group nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_group nilfs2: fix memory leak in nilfs_sysfs_create_##name##_group nilfs2: fix NULL pointer in nilfs_##name##_attr_release nilfs2: fix memory leak in nilfs_sysfs_create_device_group trap: cleanup trap_init() init: move usermodehelper_enable() to populate_rootfs() ...

dax/kmem: use a single static memory group for a single probed unit

2021-09-08T18:50:23Z

Although dax/kmem users often disable auto-onlining and instead online memory manually (usually to ZONE_MOVABLE), there is still value in having auto-onlining be aware of the relationship of memory blocks. Let's treat one probed unit as a single static memory device, similar to a single ACPI memory device. Link: https://lkml.kernel.org/r/20210806124715.17090-7-david@redhat.com Signed-off-by: David Hildenbrand Cc: Anshuman Khandual Cc: Dan Williams Cc: Dave Hansen Cc: Greg Kroah-Hartman Cc: Hui Zhu Cc: Jason Wang Cc: Len Brown Cc: Marek Kedzierski Cc: "Michael S. Tsirkin" Cc: Michal Hocko Cc: Mike Rapoport Cc: Oscar Salvador Cc: Pankaj Gupta Cc: Pavel Tatashin Cc: Rafael J. Wysocki Cc: "Rafael J. Wysocki" Cc: Vitaly Kuznetsov Cc: Vlastimil Babka Cc: Wei Yang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/memory_hotplug: remove nid parameter from remove_memory() and friends

2021-09-08T18:50:23Z

There is only a single user remaining. We can simply lookup the nid only used for node offlining purposes when walking our memory blocks. We don't expect to remove multi-nid ranges; and if we'd ever do, we most probably don't care about removing multi-nid ranges that actually result in empty nodes. If ever required, we can detect the "multi-nid" scenario and simply try offlining all online nodes. Link: https://lkml.kernel.org/r/20210712124052.26491-4-david@redhat.com Signed-off-by: David Hildenbrand Acked-by: Michael Ellerman (powerpc) Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Dan Williams Cc: Vishal Verma Cc: Dave Jiang Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Nathan Lynch Cc: Laurent Dufour Cc: "Aneesh Kumar K.V" Cc: Scott Cheloha Cc: Anton Blanchard Cc: Andy Lutomirski Cc: Anshuman Khandual Cc: Ard Biesheuvel Cc: Baoquan He Cc: Borislav Petkov Cc: Catalin Marinas Cc: Christian Borntraeger Cc: Christophe Leroy Cc: Dave Hansen Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jia He Cc: Joe Perches Cc: Kefeng Wang Cc: Michal Hocko Cc: Michel Lespinasse Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Pankaj Gupta Cc: Pankaj Gupta Cc: Pavel Tatashin Cc: Peter Zijlstra Cc: Pierre Morel Cc: "Rafael J. Wysocki" Cc: Rich Felker Cc: Sergei Trofimovich Cc: Thiago Jung Bauermann Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Vitaly Kuznetsov Cc: Vlastimil Babka Cc: Wei Yang Cc: Will Deacon Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds