Thread (10 messages) read the whole thread 10 messages, 6 authors, 2021-03-18

Re: [vdpa_sim_net] 79991caf52: net/ipv4/ipmr.c:#RCU-list_traversed_in_non-reader_section

From: Oliver Sang <hidden>
Date: 2021-03-18 06:33:56
Also in: kvm, lkml, oe-lkp

Hi Joe and Dongli,

On Mon, Feb 08, 2021 at 08:10:21AM -0800, Joe Jin wrote:
On 2/7/21 12:15 PM, Dongli Zhang wrote:
quoted
Is it possible that the issue is not due to this change?
Looks this issue does not related your change, from dmesg output, when issue occurred, virtio was not loaded:

[  502.508450] ------------[ cut here ]------------
[  502.511859] WARNING: CPU: 0 PID: 1 at drivers/gpu/drm/vkms/vkms_crtc.c:21 vkms_vblank_simulate+0x22a/0x240
[  502.524018] Modules linked in:
[  502.539642] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.11.0-rc4-00008-g79991caf5202 #1
thanks for explanation and sorry for false positive.
we will investigate further to avoid such kind of false positive in the future.

quoted
This change is just to call different API to allocate memory, which is
equivalent to kzalloc()+vzalloc().

Before the change:

try kzalloc(sizeof(*vs), GFP_KERNEL | __GFP_NOWARN | __GFP_RETRY_MAYFAIL);

... and then below if the former is failed.

vzalloc(sizeof(*vs));


After the change:

try kmalloc_node(size, FP_KERNEL|GFP_ZERO|__GFP_NOWARN|__GFP_NORETRY, node);

... and then below if the former is failed

__vmalloc_node(size, 1, GFP_KERNEL|GFP_ZERO, node, __builtin_return_address(0));


The below is the first WARNING in uploaded dmesg. I assume it was called before
to open /dev/vhost-scsi.

Will this test try to open /dev/vhost-scsi?

[    5.095515] =============================
[    5.095515] WARNING: suspicious RCU usage
[    5.095515] 5.11.0-rc4-00008-g79991caf5202 #1 Not tainted
[    5.095534] -----------------------------
[    5.096041] security/smack/smack_lsm.c:351 RCU-list traversed in non-reader
section!!
[    5.096982]
[    5.096982] other info that might help us debug this:
[    5.096982]
[    5.097953]
[    5.097953] rcu_scheduler_active = 1, debug_locks = 1
[    5.098739] no locks held by kthreadd/2.
[    5.099237]
[    5.099237] stack backtrace:
[    5.099537] CPU: 0 PID: 2 Comm: kthreadd Not tainted
5.11.0-rc4-00008-g79991caf5202 #1
[    5.100470] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.12.0-1 04/01/2014
[    5.101442] Call Trace:
[    5.101807]  dump_stack+0x15f/0x1bf
[    5.102298]  smack_cred_prepare+0x400/0x420
[    5.102840]  ? security_prepare_creds+0xd4/0x120
[    5.103441]  security_prepare_creds+0x84/0x120
[    5.103515]  prepare_creds+0x3f1/0x580
[    5.103515]  copy_creds+0x65/0x480
[    5.103515]  copy_process+0x7b4/0x3600
[    5.103515]  ? check_prev_add+0xa40/0xa40
[    5.103515]  ? lockdep_enabled+0xd/0x60
[    5.103515]  ? lock_is_held_type+0x1a/0x100
[    5.103515]  ? __cleanup_sighand+0xc0/0xc0
[    5.103515]  ? lockdep_unlock+0x39/0x160
[    5.103515]  kernel_clone+0x165/0xd20
[    5.103515]  ? copy_init_mm+0x20/0x20
[    5.103515]  ? pvclock_clocksource_read+0xd9/0x1a0
[    5.103515]  ? sched_clock_local+0x99/0xc0
[    5.103515]  ? kthread_insert_work_sanity_check+0xc0/0xc0
[    5.103515]  kernel_thread+0xba/0x100
[    5.103515]  ? __ia32_sys_clone3+0x40/0x40
[    5.103515]  ? kthread_insert_work_sanity_check+0xc0/0xc0
[    5.103515]  ? do_raw_spin_unlock+0xa9/0x160
[    5.103515]  kthreadd+0x68f/0x7a0
[    5.103515]  ? kthread_create_on_cpu+0x160/0x160
[    5.103515]  ? lockdep_hardirqs_on+0x77/0x100
[    5.103515]  ? _raw_spin_unlock_irq+0x24/0x60
[    5.103515]  ? kthread_create_on_cpu+0x160/0x160
[    5.103515]  ret_from_fork+0x22/0x30

Thank you very much!

Dongli Zhang


On 2/6/21 7:03 PM, kernel test robot wrote:
quoted
Greeting,

FYI, we noticed the following commit (built with gcc-9):

commit: 79991caf5202c7989928be534727805f8f68bb8d ("vdpa_sim_net: Add support for user supported devices")
https://urldefense.com/v3/__https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git__;!!GqivPVa7Brio!LfgrgVVtPAjwjqTZX8yANgsix4f3cJmAA_CcMeCVymh5XYcamWdR9dnbIQA-p61PJtI$  Dongli-Zhang/vhost-scsi-alloc-vhost_scsi-with-kvzalloc-to-avoid-delay/20210129-191605


in testcase: trinity
version: trinity-static-x86_64-x86_64-f93256fb_2019-08-28
with following parameters:

	runtime: 300s

test-description: Trinity is a linux system call fuzz tester.
test-url: https://urldefense.com/v3/__http://codemonkey.org.uk/projects/trinity/__;!!GqivPVa7Brio!LfgrgVVtPAjwjqTZX8yANgsix4f3cJmAA_CcMeCVymh5XYcamWdR9dnbIQA-6Y4x88c$ 


on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 8G

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):


+-------------------------------------------------------------------------+------------+------------+
|                                                                         | 39502d042a | 79991caf52 |
+-------------------------------------------------------------------------+------------+------------+
| boot_successes                                                          | 0          | 0          |
| boot_failures                                                           | 62         | 57         |
| WARNING:suspicious_RCU_usage                                            | 62         | 57         |
| security/smack/smack_lsm.c:#RCU-list_traversed_in_non-reader_section    | 62         | 57         |
| security/smack/smack_access.c:#RCU-list_traversed_in_non-reader_section | 62         | 57         |
| BUG:workqueue_lockup-pool                                               | 33         | 40         |
| BUG:kernel_hang_in_boot_stage                                           | 6          | 2          |
| net/mac80211/util.c:#RCU-list_traversed_in_non-reader_section           | 23         | 15         |
| WARNING:SOFTIRQ-safe->SOFTIRQ-unsafe_lock_order_detected                | 18         |            |
| WARNING:inconsistent_lock_state                                         | 5          |            |
| inconsistent{SOFTIRQ-ON-W}->{IN-SOFTIRQ-W}usage                         | 5          |            |
| calltrace:asm_call_irq_on_stack                                         | 2          |            |
| RIP:lock_acquire                                                        | 2          |            |
| RIP:check_kcov_mode                                                     | 1          |            |
| RIP:native_safe_halt                                                    | 2          |            |
| INFO:rcu_sched_self-detected_stall_on_CPU                               | 2          |            |
| RIP:clear_page_rep                                                      | 1          |            |
| WARNING:at_drivers/gpu/drm/vkms/vkms_crtc.c:#vkms_vblank_simulate       | 9          | 7          |
| RIP:vkms_vblank_simulate                                                | 9          | 7          |
| RIP:__slab_alloc                                                        | 3          | 3          |
| RIP:__do_softirq                                                        | 2          |            |
| RIP:console_unlock                                                      | 6          | 3          |
| invoked_oom-killer:gfp_mask=0x                                          | 1          |            |
| Mem-Info                                                                | 1          |            |
| RIP:vprintk_emit                                                        | 1          |            |
| RIP:__asan_load4                                                        | 1          |            |
| kernel_BUG_at_kernel/sched/core.c                                       | 0          | 1          |
| invalid_opcode:#[##]                                                    | 0          | 1          |
| RIP:sched_cpu_dying                                                     | 0          | 1          |
| WARNING:possible_circular_locking_dependency_detected                   | 0          | 1          |
| Kernel_panic-not_syncing:Fatal_exception                                | 0          | 1          |
| net/ipv4/ipmr.c:#RCU-list_traversed_in_non-reader_section               | 0          | 8          |
| RIP:arch_local_irq_restore                                              | 0          | 1          |
| RIP:idr_get_free                                                        | 0          | 1          |
| net/ipv6/ip6mr.c:#RCU-list_traversed_in_non-reader_section              | 0          | 2          |
+-------------------------------------------------------------------------+------------+------------+


If you fix the issue, kindly add following tag
Reported-by: kernel test robot <redacted>


[  890.196279] =============================
[  890.212608] WARNING: suspicious RCU usage
[  890.228281] 5.11.0-rc4-00008-g79991caf5202 #1 Tainted: G        W
[  890.244087] -----------------------------
[  890.259417] net/ipv4/ipmr.c:138 RCU-list traversed in non-reader section!!
[  890.275043]
[  890.275043] other info that might help us debug this:
[  890.275043]
[  890.318497]
[  890.318497] rcu_scheduler_active = 2, debug_locks = 1
[  890.346089] 2 locks held by trinity-c1/2476:
[  890.360897]  #0: ffff888149d6f400 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xc0/0xe0
[  890.375165]  #1: ffff8881cabfd5c8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xa0/0x9c0
[  890.389706]
[  890.389706] stack backtrace:
[  890.416375] CPU: 1 PID: 2476 Comm: trinity-c1 Tainted: G        W         5.11.0-rc4-00008-g79991caf5202 #1
[  890.430706] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
[  890.444971] Call Trace:
[  890.458554]  dump_stack+0x15f/0x1bf
[  890.471996]  ipmr_get_table+0x140/0x160
[  890.485328]  ipmr_vif_seq_start+0x4d/0xe0
[  890.498620]  seq_read_iter+0x1b2/0x9c0
[  890.511469]  ? kvm_sched_clock_read+0x14/0x40
[  890.524008]  ? sched_clock+0x1b/0x40
[  890.536095]  ? iov_iter_init+0x7c/0xa0
[  890.548028]  seq_read+0x2fd/0x3e0
[  890.559948]  ? seq_hlist_next_percpu+0x140/0x140
[  890.572204]  ? should_fail+0x78/0x2a0
[  890.584189]  ? write_comp_data+0x2a/0xa0
[  890.596235]  ? __sanitizer_cov_trace_pc+0x1d/0x60
[  890.608134]  ? seq_hlist_next_percpu+0x140/0x140
[  890.620042]  proc_reg_read+0x14e/0x180
[  890.631585]  do_iter_read+0x397/0x420
[  890.642843]  vfs_readv+0xf5/0x160
[  890.653833]  ? vfs_iter_read+0x80/0x80
[  890.664229]  ? __fdget_pos+0xc0/0xe0
[  890.674236]  ? pvclock_clocksource_read+0xd9/0x1a0
[  890.684259]  ? kvm_sched_clock_read+0x14/0x40
[  890.693852]  ? sched_clock+0x1b/0x40
[  890.702898]  ? sched_clock_cpu+0x18/0x120
[  890.711648]  ? write_comp_data+0x2a/0xa0
[  890.720243]  ? __sanitizer_cov_trace_pc+0x1d/0x60
[  890.729290]  do_readv+0x111/0x260
[  890.738205]  ? vfs_readv+0x160/0x160
[  890.747154]  ? lockdep_hardirqs_on+0x77/0x100
[  890.756100]  ? syscall_enter_from_user_mode+0x8a/0x100
[  890.765126]  do_syscall_64+0x34/0x80
[  890.773795]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  890.782630] RIP: 0033:0x453b29
[  890.791189] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 84 00 00 c3 66 2e 0f 1f 84 00 00 00 00
[  890.810866] RSP: 002b:00007ffcda44fb18 EFLAGS: 00000246 ORIG_RAX: 0000000000000013
[  890.820764] RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 0000000000453b29
[  890.830792] RDX: 000000000000009a RSI: 0000000001de1c00 RDI: 00000000000000b9
[  890.840626] RBP: 00007ffcda44fbc0 R08: 722c279d69ffc468 R09: 0000000000000400
[  890.850366] R10: 0098d82a42c63c22 R11: 0000000000000246 R12: 0000000000000002
[  890.860001] R13: 00007f042ae6f058 R14: 00000000010a2830 R15: 00007f042ae6f000



To reproduce:

        # build kernel
	cd linux
	cp config-5.11.0-rc4-00008-g79991caf5202 .config
	make HOSTCC=gcc-9 CC=gcc-9 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage

        git clone https://urldefense.com/v3/__https://github.com/intel/lkp-tests.git__;!!GqivPVa7Brio!LfgrgVVtPAjwjqTZX8yANgsix4f3cJmAA_CcMeCVymh5XYcamWdR9dnbIQA-Qkr9TyI$ 
        cd lkp-tests
        bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email



Thanks,
Oliver Sang
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