FYI, we noticed the following commit (built with gcc-7): commit: f89a997ccb24701b4c24615c1275ac1ef80cc016 ("idr: Fix idr_get_next race with idr_remove") git://git.infradead.org/users/willy/linux-dax.git xarray in testcase: trinity with following parameters: runtime: 300s test-description: Trinity is a linux system call fuzz tester. test-url: http://codemonkey.org.uk/projects/trinity/ on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 2G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +---------------------------------------------------------------------+------------+------------+ | | 7b785645e8 | f89a997ccb | +---------------------------------------------------------------------+------------+------------+ | boot_successes | 8 | 0 | | boot_failures | 2 | 8 | | BUG:kernel_reboot-without-warning_in_test_stage | 2 | | | WARNING:suspicious_RCU_usage | 0 | 8 | | include/linux/radix-tree.h:#suspicious_rcu_dereference_check()usage | 0 | 8 | | BUG:kernel_NULL_pointer_dereference,address | 0 | 1 | | Oops:#[##] | 0 | 1 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 1 | +---------------------------------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot <lkp(a)intel.com&gt; [ 3.173218] WARNING: suspicious RCU usage [ 3.174559] 5.2.0-rc2-00160-gf89a997 #1 Tainted: G T [ 3.176636] ----------------------------- [ 3.178408] include/linux/radix-tree.h:180 suspicious rcu_dereference_check() usage! [ 3.178759] [ 3.178759] other info that might help us debug this: [ 3.178759] [ 3.182172] [ 3.182172] rcu_scheduler_active = 2, debug_locks = 1 [ 3.184903] 2 locks held by swapper/1: [ 3.188761] #0: (____ptrval____) (cb_lock){+.+.}, at: genl_register_family+0x87/0x56e [ 3.192131] #1: (____ptrval____) (genl_mutex){+.+.}, at: genl_lock+0x12/0x14 [ 3.194838] [ 3.194838] stack backtrace: [ 3.196871] CPU: 0 PID: 1 Comm: swapper Tainted: G T 5.2.0-rc2-00160-gf89a997 #1 [ 3.198759] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 3.202062] Call Trace: [ 3.203234] dump_stack+0x19/0x1b [ 3.204715] lockdep_rcu_suspicious+0xd9/0xe2 [ 3.206552] idr_get_next+0x8c/0x13e [ 3.208105] genl_family_find_byname+0x34/0x6f [ 3.208768] ? genl_pernet_init+0xc0/0xc0 [ 3.210483] genl_register_family+0x94/0x56e [ 3.212277] ? genl_pernet_init+0xc0/0xc0 [ 3.213956] genl_init+0x28/0x71 [ 3.215416] do_one_initcall+0xdb/0x251 [ 3.217057] kernel_init_freeable+0x4c0/0x5d8 [ 3.218766] ? rest_init+0x1f9/0x1f9 [ 3.220324] kernel_init+0x9/0xf0 [ 3.221783] ret_from_fork+0x3a/0x50 [ 3.224920] clocksource: Switched to clocksource kvm-clock [ 3.342361] VFS: Disk quotas dquot_6.6.0 [ 3.343813] VFS: Dquot-cache hash table entries: 512 (order 0, 4096 bytes) [ 3.346243] pnp: PnP ACPI init [ 3.347675] pnp 00:00: Plug and Play ACPI device, IDs PNP0b00 (active) [ 3.349938] pnp 00:01: Plug and Play ACPI device, IDs PNP0303 (active) [ 3.352114] pnp 00:02: Plug and Play ACPI device, IDs PNP0f13 (active) [ 3.354207] pnp 00:03: [dma 2] [ 3.355354] pnp 00:03: Plug and Play ACPI device, IDs PNP0700 (active) [ 3.357646] pnp 00:04: Plug and Play ACPI device, IDs PNP0400 (active) [ 3.359857] pnp 00:05: Plug and Play ACPI device, IDs PNP0501 (active) [ 3.362171] pnp 00:06: Plug and Play ACPI device, IDs PNP0501 (active) [ 3.364967] pnp: PnP ACPI: found 7 devices [ 3.376968] clocksource: acpi_pm: mask: 0xffffff max_cycles: 0xffffff, max_idle_ns: 2085701024 ns [ 3.379856] pci_bus 0000:00: resource 4 [io 0x0000-0x0cf7 window] [ 3.381792] pci_bus 0000:00: resource 5 [io 0x0d00-0xffff window] [ 3.383742] pci_bus 0000:00: resource 6 [mem 0x000a0000-0x000bffff window] [ 3.385899] pci_bus 0000:00: resource 7 [mem 0x80000000-0xfebfffff window] [ 3.388048] pci_bus 0000:00: resource 8 [mem 0x100000000-0x17fffffff window] [ 3.390552] NET: Registered protocol family 2 [ 3.392063] _warn_unseeded_randomness: 2 callbacks suppressed [ 3.392077] random: get_random_u32 called from neigh_hash_alloc+0x8e/0xaa with crng_init=0 [ 3.396934] random: get_random_u32 called from rt_genid_init+0x2a/0x5a with crng_init=0 [ 3.399576] tcp_listen_portaddr_hash hash table entries: 1024 (order: 4, 73728 bytes) [ 3.402195] TCP established hash table entries: 16384 (order: 5, 131072 bytes) [ 3.405440] TCP bind hash table entries: 16384 (order: 8, 1048576 bytes) [ 3.408169] TCP: Hash tables configured (established 16384 bind 16384) [ 3.410367] UDP hash table entries: 1024 (order: 5, 163840 bytes) [ 3.412448] UDP-Lite hash table entries: 1024 (order: 5, 163840 bytes) [ 3.414669] random: get_random_u32 called from bucket_table_alloc+0xfc/0x124 with crng_init=0 [ 3.417453] NET: Registered protocol family 1 [ 3.419474] RPC: Registered named UNIX socket transport module. [ 3.421380] RPC: Registered udp transport module. [ 3.422939] RPC: Registered tcp transport module. [ 3.424552] RPC: Registered tcp NFSv4.1 backchannel transport module. [ 3.426580] NET: Registered protocol family 44 [ 3.428190] pci 0000:00:01.0: PIIX3: Enabling Passive Release [ 3.430166] pci 0000:00:00.0: Limiting direct PCI/PCI transfers [ 3.432176] pci 0000:00:01.0: Activating ISA DMA hang workarounds [ 3.435024] pci 0000:00:02.0: Video device with shadowed ROM at [mem 0x000c0000-0x000dffff] [ 3.438650] PCI: CLS 0 bytes, default 64 [ 3.440845] Trying to unpack rootfs image as initramfs... [ 8.060474] Freeing initrd memory: 138036K [ 8.063608] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x1eac813fa53, max_idle_ns: 440795210049 ns [ 8.068162] random: get_random_u64 called from arch_rnd+0x1f/0x35 with crng_init=0 [ 8.070719] random: get_random_u64 called from load_elf_binary+0x346/0x1373 with crng_init=0 [ 8.073357] random: get_random_u32 called from arch_align_stack+0x27/0x39 with crng_init=0 [ 8.094797] AVX or AES-NI instructions are not detected. [ 8.096505] CPU feature 'AVX registers' is not supported. [ 8.099818] Initialise system trusted keyrings [ 8.101442] workingset: timestamp_bits=62 max_order=19 bucket_order=0 [ 8.114258] zbud: loaded [ 8.117649] fuse: init (API version 7.30) [ 8.119710] JFS: nTxBlock = 8192, nTxLock = 65536 [ 8.125157] SGI XFS with ACLs, security attributes, realtime, scrub, debug enabled [ 8.129628] OCFS2 User DLM kernel interface loaded [ 8.134039] NET: Registered protocol family 38 [ 8.137425] Key type asymmetric registered [ 8.138977] Asymmetric key parser 'x509' registered [ 8.141307] Asymmetric key parser 'pkcs8' registered [ 8.143553] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 246) [ 8.146520] io scheduler mq-deadline registered [ 8.148339] io scheduler bfq registered [ 8.491154] String selftests succeeded [ 8.493171] crc32: CRC_LE_BITS = 32, CRC_BE BITS = 32 [ 8.494764] crc32: self tests passed, processed 225944 bytes in 280465 nsec [ 8.497161] crc32c: CRC_LE_BITS = 32 [ 8.498365] crc32c: self tests passed, processed 225944 bytes in 140450 nsec [ 8.521489] crc32_combine: 8373 self tests passed [ 8.545703] crc32c_combine: 8373 self tests passed [ 8.547631] gpio_it87: no device To reproduce: # build kernel cd linux cp config-5.2.0-rc2-00160-gf89a997 .config make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 olddefconfig make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 prepare make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 modules_prepare make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 SHELL=/bin/bash make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 bzImage git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email Thanks, lkp