FYI, we noticed the following commit: commit: ceed73a2cf4aff2921802aa3d21d45280677547d ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation") https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master in testcase: boot on test machine: qemu-system-i386 -enable-kvm -cpu Haswell,+smep,+smap -m 360M caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +---------------------------------------------------------------------------------------------+------------+------------+ | | cdf4969c42 | ceed73a2cf | +---------------------------------------------------------------------------------------------+------------+------------+ | boot_successes | 52 | 44 | | boot_failures | 0 | 8 | | drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c:#suspicious_rcu_dereference_check()usage | 0 | 8 | +---------------------------------------------------------------------------------------------+------------+------------+ [ 101.364846] WARNING: suspicious RCU usage [ 101.365654] 4.13.0-rc6-01701-gceed73a #1 Not tainted [ 101.370873] ----------------------------- [ 101.372472] drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c:57 suspicious rcu_dereference_check() usage! [ 101.374427] [ 101.374427] other info that might help us debug this: [ 101.374427] [ 101.387491] [ 101.387491] rcu_scheduler_active = 2, debug_locks = 1 [ 101.389368] 1 lock held by trinity-main/2809: [ 101.390736] #0: (rtnl_mutex){+.+.+.}, at: [<8146085b>] rtnl_lock+0xf/0x11 [ 101.395482] [ 101.395482] stack backtrace: [ 101.396948] CPU: 0 PID: 2809 Comm: trinity-main Not tainted 4.13.0-rc6-01701-gceed73a #1 [ 101.398857] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014 [ 101.401079] Call Trace: [ 101.401656] dump_stack+0xa1/0xeb [ 101.402871] lockdep_rcu_suspicious+0xc7/0xd0 [ 101.403665] rmnet_is_real_dev_registered+0x40/0x4e [ 101.405199] rmnet_config_notify_cb+0x2c/0x142 [ 101.406344] ? wireless_nlevent_flush+0x47/0x71 [ 101.407385] notifier_call_chain+0x2d/0x47 [ 101.408645] raw_notifier_call_chain+0xc/0xe [ 101.409882] call_netdevice_notifiers_info+0x41/0x49 [ 101.411402] call_netdevice_notifiers+0xc/0xe [ 101.412713] rollback_registered_many+0x268/0x36e [ 101.413702] rollback_registered+0x39/0x56 [ 101.414965] unregister_netdevice_queue+0x79/0x88 [ 101.415908] unregister_netdev+0x16/0x1d [ 101.417030] gprs_attach+0x129/0x133 [ 101.417700] pep_setsockopt+0xa2/0x118 [ 101.418851] sock_common_setsockopt+0x13/0x18 [ 101.420462] SyS_setsockopt+0x59/0x77 [ 101.421196] SyS_socketcall+0x16c/0x1cf [ 101.422148] do_int80_syscall_32+0x57/0x11d [ 101.423137] entry_INT80_32+0x33/0x33 [ 101.423827] EIP: 0x77fc61b2 [ 101.424802] EFLAGS: 00000206 CPU: 0 [ 101.425465] EAX: ffffffda EBX: 0000000e ECX: 7fc2cc50 EDX: 7fc2ccd0 [ 101.426928] ESI: 00000005 EDI: 00000152 EBP: 77da037c ESP: 7fc2cc48 [ 101.428482] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b [main] Setsockopt(116 7f 80d3000 4) on fd 339 [37:5:3] [main] Setsockopt(1 1d 80d3000 b0) on fd 340 [1:1:1] [main] Setsockopt(1 d 80d3000 8) on fd 341 [5:3:63] [main] Setsockopt(10c 4 80d3000 4) on fd 342 [12:1:192] [main] Setsockopt(1 6 80d3000 e3) on fd 343 [16:3:21] [main] Setsockopt(1 e 80d3000 4) on fd 344 [35:2:0] [main] Setsockopt(116 7f 80d3000 f5) on fd 345 [37:5:5] [main] Setsockopt(1 24 80d3000 4) on fd 346 [1:1:1] [main] Setsockopt(1 1 80d3000 d9) on fd 347 [5:2:0] [main] Setsockopt(1 2d 80d3000 80) on fd 348 [12:5:2] [main] Setsockopt(116 7f 80d3000 dd) on fd 350 [37:1:5] [main] Setsockopt(1 20 80d3000 4) on fd 351 [1:5:1] [main] Setsockopt(1 2f 80d3000 4) on fd 352 [5:2:0] [main] Setsockopt(10b 4 80d3000 4) on fd 353 [12:1:151] [main] Setsockopt(1 28 80d3000 4) on fd 354 [35:2:0] [main] Setsockopt(1 9 80d3000 9a) on fd 356 [1:2:1] [main] Setsockopt(1 f 80d3000 7) on fd 358 [12:1:67] [main] Setsockopt(1 23 80d3000 cf) on fd 359 [35:2:0] [main] Setsockopt(1 b 80d3000 a9) on fd 360 [37:1:5] [main] Setsockopt(1 d 80d3000 8) on fd 362 [5:2:0] [main] Setsockopt(10e 4 80d3000 4) on fd 363 [12:1:98] [main] Setsockopt(1 22 80d3000 b6) on fd 364 [35:2:0] [main] Setsockopt(116 7f 80d3000 4) on fd 365 [37:1:1] [main] Setsockopt(1 8 80d3000 f2) on fd 367 [5:2:0] [main] Setsockopt(1 8 80d3000 bb) on fd 368 [12:5:2] [main] Setsockopt(1 29 80d3000 20) on fd 369 [35:5:0] [main] Setsockopt(1 2 80d3000 4) on fd 370 [37:1:5] [main] Setsockopt(107 c 80d3000 4) on fd 373 [12:1:121] [main] Setsockopt(1 10 80d3000 4) on fd 374 [35:5:0] [main] Setsockopt(1 6 80d3000 4) on fd 375 [37:1:1] [main] Setsockopt(1 e 80d3000 4) on fd 376 [1:1:1] [main] Setsockopt(1 20 80d3000 4) on fd 377 [5:2:0] [main] Setsockopt(105 c 80d3000 4) on fd 378 [12:5:2] [main] Setsockopt(1 9 80d3000 4) on fd 379 [35:2:0] [main] 375 sockets created based on info from socket cachefile. [main] Generating file descriptors [main] Added 291 filenames from /dev [main] Added 9059 filenames from /proc [main] Added 12972 filenames from /sys [child0:2818] get_mempolicy (275) returned ENOSYS, marking as inactive. [child0:2818] setreuid16 (70) returned ENOSYS, marking as inactive. [child0:2818] set_mempolicy (276) returned ENOSYS, marking as inactive. [child0:2818] getegid16 (50) returned ENOSYS, marking as inactive. [child0:2818] setregid16 (71) returned ENOSYS, marking as inactive. [child0:2818] setresgid16 (170) returned ENOSYS, marking as inactive. [child0:2818] setfsuid16 (138) returned ENOSYS, marking as inactive. [child0:2818] fanotify_mark (339) returned ENOSYS, marking as inactive. [child0:2818] uid changed! Was: 0, now -1744521016 Bailing main loop. Exit reason: UID changed. [ 102.510858] caif:caif_disconnect_client(): nothing to disconnect [ 102.512444] caif:caif_disconnect_client(): nothing to disconnect [ 102.513745] caif:caif_disconnect_client(): nothing to disconnect [ 102.516225] caif:caif_disconnect_client(): nothing to disconnect [ 102.517669] caif:caif_disconnect_client(): nothing to disconnect [ 102.519318] caif:caif_disconnect_client(): nothing to disconnect [ 102.520613] caif:caif_disconnect_client(): nothing to disconnect [ 102.521859] caif:caif_disconnect_client(): nothing to disconnect [ 102.523465] caif:caif_disconnect_client(): nothing to disconnect [ 102.524768] caif:caif_disconnect_client(): nothing to disconnect [ 102.526079] caif:caif_disconnect_client(): nothing to disconnect To reproduce: git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k job-script # job-script is attached in this email Thanks, Xiaolong