linux/lib
Alistair Popple af69016dab lib: test_hmm: implement a device release method
Unloading the HMM test module produces the following warning:

[ 3782.224783] ------------[ cut here ]------------
[ 3782.226323] Device 'hmm_dmirror0' does not have a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.
[ 3782.230570] WARNING: drivers/base/core.c:2567 at device_release+0x185/0x210, CPU#20: rmmod/1924
[ 3782.233949] Modules linked in: test_hmm(-) nvidia_uvm(O) nvidia(O)
[ 3782.236321] CPU: 20 UID: 0 PID: 1924 Comm: rmmod Tainted: G           O        7.0.0-rc1+ #374 PREEMPT(full)
[ 3782.240226] Tainted: [O]=OOT_MODULE
[ 3782.241639] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
[ 3782.246193] RIP: 0010:device_release+0x185/0x210
[ 3782.247860] Code: 00 00 fc ff df 48 8d 7b 50 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 86 00 00 00 48 8b 73 50 48 85 f6 74 11 48 8d 3d db 25 29 03 <67> 48 0f b9 3a e9 0d ff ff ff 48 b8 00 00 00 00 00 fc ff df 48 89
[ 3782.254211] RSP: 0018:ffff888126577d98 EFLAGS: 00010246
[ 3782.256054] RAX: dffffc0000000000 RBX: ffffffffc2b70310 RCX: ffffffff8fe61ba1
[ 3782.258512] RDX: 1ffffffff856e062 RSI: ffff88811341eea0 RDI: ffffffff91bbacb0
[ 3782.261041] RBP: ffff888111475000 R08: 0000000000000001 R09: fffffbfff856e069
[ 3782.263471] R10: ffffffffc2b7034b R11: 00000000ffffffff R12: 0000000000000000
[ 3782.265983] R13: dffffc0000000000 R14: ffff88811341eea0 R15: 0000000000000000
[ 3782.268443] FS:  00007fd5a3689040(0000) GS:ffff88842c8d0000(0000) knlGS:0000000000000000
[ 3782.271236] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 3782.273251] CR2: 00007fd5a36d2c10 CR3: 00000001242b8000 CR4: 00000000000006f0
[ 3782.275362] Call Trace:
[ 3782.276071]  <TASK>
[ 3782.276678]  kobject_put+0x146/0x270
[ 3782.277731]  hmm_dmirror_exit+0x7a/0x130 [test_hmm]
[ 3782.279135]  __do_sys_delete_module+0x341/0x510
[ 3782.280438]  ? module_flags+0x300/0x300
[ 3782.281547]  do_syscall_64+0x111/0x670
[ 3782.282620]  entry_SYSCALL_64_after_hwframe+0x4b/0x53
[ 3782.284091] RIP: 0033:0x7fd5a3793b37
[ 3782.285303] Code: 73 01 c3 48 8b 0d c9 82 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 99 82 0c 00 f7 d8 64 89 01 48
[ 3782.290708] RSP: 002b:00007ffd68b7dc68 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[ 3782.292817] RAX: ffffffffffffffda RBX: 000055e3c0d1c770 RCX: 00007fd5a3793b37
[ 3782.294735] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055e3c0d1c7d8
[ 3782.296661] RBP: 0000000000000000 R08: 1999999999999999 R09: 0000000000000000
[ 3782.298622] R10: 00007fd5a3806ac0 R11: 0000000000000206 R12: 00007ffd68b7deb0
[ 3782.300576] R13: 00007ffd68b7e781 R14: 000055e3c0d1b2a0 R15: 00007ffd68b7deb8
[ 3782.301963]  </TASK>
[ 3782.302371] irq event stamp: 5019
[ 3782.302987] hardirqs last  enabled at (5027): [<ffffffff8cf1f062>] __up_console_sem+0x52/0x60
[ 3782.304507] hardirqs last disabled at (5036): [<ffffffff8cf1f047>] __up_console_sem+0x37/0x60
[ 3782.306086] softirqs last  enabled at (4940): [<ffffffff8cd9a4b0>] __irq_exit_rcu+0xc0/0xf0
[ 3782.307567] softirqs last disabled at (4929): [<ffffffff8cd9a4b0>] __irq_exit_rcu+0xc0/0xf0
[ 3782.309105] ---[ end trace 0000000000000000 ]---

This is because the test module doesn't have a device.release method.  In
this case one probably isn't needed for correctness - the device structs
are in a static array so don't need freeing when the final reference goes
away.

However some device state is freed on exit, so to ensure this happens at
the right time and to silence the warning move the deinitialisation to a
release method and assign that as the device release callback.  Whilst
here also fix a minor error handling bug where cdev_device_del() wasn't
being called if allocation failed.

Link: https://lore.kernel.org/20260331063445.3551404-4-apopple@nvidia.com
Fixes: 6a760f58c7 ("mm/hmm/test: use char dev with struct device to get device node")
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Acked-by: Balbir Singh <balbirs@nvidia.com>
Tested-by: Zenghui Yu (Huawei) <zenghui.yu@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: <stable@vger,kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-18 00:10:52 -07:00
..
842
crc
crypto lib/crypto: powerpc: Add powerpc/aesp8-ppc.S to clean-files 2026-03-17 09:27:11 -07:00
dim Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
fonts
kunit kunit: reduce stack usage in kunit_run_tests() 2026-03-02 10:11:06 -07:00
lz4
lzo
math
pldmfw Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
raid6
reed_solomon Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
test_fortify fortify: Cleanup temp file also on non-successful exit 2026-01-14 19:49:55 -08:00
tests liveupdate: remove liveupdate_test_unregister() 2026-04-18 00:10:50 -07:00
vdso mm: rename zap_vma_pages() to zap_vma() 2026-04-05 13:53:14 -07:00
xz Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
zlib_deflate
zlib_dfltcc
zlib_inflate Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
zstd
.gitignore
Kconfig lib/glob: convert selftest to KUnit 2026-01-26 19:07:13 -08:00
Kconfig.debug A single fix for debugobjects. 2026-03-01 13:32:32 -08:00
Kconfig.kasan
Kconfig.kcsan
Kconfig.kfence
Kconfig.kgdb
Kconfig.kmsan
Kconfig.ubsan
Makefile ubsan: turn off kmsan inside of ubsan instrumentation 2026-04-05 13:53:19 -07:00
alloc_tag.c mm/alloc_tag: clear codetag for pages allocated before page_ext initialization 2026-04-18 00:10:50 -07:00
argv_split.c
ashldi3.c
ashrdi3.c
asn1_decoder.c
asn1_encoder.c
assoc_array.c Convert more 'alloc_obj' cases to default GFP_KERNEL arguments 2026-02-21 20:03:00 -08:00
atomic64.c
atomic64_test.c
audit.c
base64.c
bcd.c
bch.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
bitmap-str.c
bitmap.c
bitrev.c
bootconfig-data.S
bootconfig.c lib/bootconfig: check xbc_init_node() return in override path 2026-03-19 08:43:05 +09:00
bsearch.c
btree.c
bucket_locks.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
bug.c bug: avoid format attribute warning for clang as well 2026-04-05 13:53:37 -07:00
build_OID_registry oid_registry: allow arbitrary size OIDs 2026-01-20 19:44:15 -08:00
buildid.c procfs: avoid fetching build ID while holding VMA lock 2026-02-05 14:10:00 -08:00
bust_spinlocks.c
cache_maint.c
check_signature.c
checksum.c
closure.c
clz_ctz.c
clz_tab.c
cmdline.c
cmpdi2.c
cmpxchg-emu.c
codetag.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
compat_audit.c
cpu_rmap.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
cpumask.c
ctype.c
debug_info.c
debug_locks.c
debugobjects.c debugobject: Make it work with deferred page initialization - again 2026-02-10 13:26:19 +01:00
dec_and_lock.c
decompress.c
decompress_bunzip2.c
decompress_inflate.c
decompress_unlz4.c
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c xz: fix arm fdt compile error for kmalloc replacement 2026-02-22 12:05:31 -08:00
decompress_unzstd.c
devmem_is_allowed.c
devres.c
dhry.h
dhry_1.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
dhry_2.c
dhry_run.c
digsig.c
dump_stack.c
dynamic_debug.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
dynamic_queue_limits.c
earlycpio.c
errname.c
error-inject.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
errseq.c
extable.c
fault-inject-usercopy.c
fault-inject.c
fdt.c
fdt_addresses.c
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
find_bit.c lib/find_bit: fix uninitialized variable use in FIND_NTH_BIT 2026-02-08 18:47:29 -05:00
find_bit_benchmark.c
find_bit_benchmark_rust.rs
flex_proportions.c flex_proportions: make fprop_new_period() hardirq safe 2026-01-26 19:03:46 -08:00
fw_table.c
genalloc.c
generic-radix-tree.c
glob.c
group_cpus.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
hexdump.c kernel.h: drop hex.h and update all hex.h users 2026-01-20 19:44:19 -08:00
hweight.c
idr.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
inflate.c
interval_tree.c
interval_tree_test.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
iomap.c
iomap_copy.c
iomem_copy.c
iommu-helper.c
iov_iter.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
irq_poll.c
irq_regs.c
is_single_threaded.c
kasprintf.c
kfifo.c kfifo: fix kmalloc_array_node() argument order 2026-01-26 19:07:09 -08:00
klist.c
kobject.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
kobject_uevent.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
kstrtox.c lib/kstrtox: fix kstrtobool() docstring to mention enabled/disabled 2026-01-26 19:07:10 -08:00
kstrtox.h
linear_ranges.c
list_debug.c
list_sort.c
llist.c
locking-selftest-hardirq.h
locking-selftest-mutex.h
locking-selftest-rlock-hardirq.h
locking-selftest-rlock-softirq.h
locking-selftest-rlock.h
locking-selftest-rsem.h
locking-selftest-rtmutex.h
locking-selftest-softirq.h
locking-selftest-spin-hardirq.h
locking-selftest-spin-softirq.h
locking-selftest-spin.h
locking-selftest-wlock-hardirq.h
locking-selftest-wlock-softirq.h
locking-selftest-wlock.h
locking-selftest-wsem.h
locking-selftest.c
lockref.c
logic_iomem.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
logic_pio.c
lru_cache.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
lshrdi3.c
lwq.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
maple_tree.c maple_tree: clean up mas_wr_node_store() 2026-04-05 13:52:57 -07:00
memcat_p.c
memory-notifier-error-inject.c
memregion.c
memweight.c
min_heap.c
muldi3.c
net_utils.c
netdev-notifier-error-inject.c
nlattr.c
nmi_backtrace.c
notifier-error-inject.c
notifier-error-inject.h
objagg.c Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses 2026-02-22 08:26:33 -08:00
objpool.c objpool: fix the overestimation of object pooling metadata size 2026-02-12 15:45:57 -08:00
of-reconfig-notifier-error-inject.c
oid_registry.c
once.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
packing.c
packing_test.c
parman.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
parser.c
percpu-refcount.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
percpu_counter.c
percpu_test.c
plist.c
pm-notifier-error-inject.c
polynomial.c
radix-tree.c
radix-tree.h
random32.c
ratelimit.c
rbtree.c
rbtree_test.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
rcuref.c
ref_tracker.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
refcount.c
rhashtable.c
sbitmap.c
scatterlist.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
seq_buf.c
sg_pool.c
sg_split.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
siphash.c
smp_processor_id.c
sort.c
stackdepot.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
stmp_device.c
string.c
string_helpers.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
strncpy_from_user.c
strnlen_user.c
sys_info.c
syscall.c
test-kstrtox.c
test_bitmap.c
test_bitops.c
test_bpf.c Convert 'alloc_flex' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
test_context-analysis.c compiler-context-analysis: Remove __assume_ctx_lock from initializers 2026-01-28 20:45:25 +01:00
test_debug_virtual.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
test_dynamic_debug.c
test_firmware.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
test_fpu.h
test_fpu_glue.c
test_fpu_impl.c
test_free_pages.c
test_hexdump.c
test_hmm.c lib: test_hmm: implement a device release method 2026-04-18 00:10:52 -07:00
test_hmm_uapi.h
test_ida.c
test_kho.c kho: persist blob size in KHO FDT 2026-04-18 00:10:48 -07:00
test_kmod.c
test_lockup.c
test_maple_tree.c maple_tree: use maple copy node for mas_wr_split() 2026-04-05 13:52:56 -07:00
test_memcat_p.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
test_meminit.c
test_module.c
test_objagg.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
test_objpool.c
test_parman.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
test_ref_tracker.c
test_rhashtable.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
test_static_key_base.c
test_static_keys.c
test_sysctl.c
test_ubsan.c
test_vmalloc.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
test_xarray.c
textsearch.c
timerqueue.c
trace_readwrite.c
ts_bm.c
ts_fsm.c
ts_kmp.c
ubsan.c
ubsan.h
ucmpdi2.c
ucs2_string.c
union_find.c
usercopy.c
uuid.c kernel.h: drop hex.h and update all hex.h users 2026-01-20 19:44:19 -08:00
vsprintf.c kernel.h: drop hex.h and update all hex.h users 2026-01-20 19:44:19 -08:00
win_minmax.c
xarray.c
xxhash.c