pkg/report: demangle rust reports

[a-nogikh]

Options are https://pkg.go.dev/github.com/ianlancetaylor/demangle or https://lore.kernel.org/rust-for-linux/20250430004128.474388-1-irogers@google.com/

I've let a local instance run on v6.15-rc7 + upstream-rust-kasan.config from #6029 and it has found a report that might be a good candidate for pkg/report/testdata:

[  492.198014][T24950] ======================================================
[  492.198599][T24950] WARNING: possible circular locking dependency detected
[  492.199166][T24950] 6.15.0-rc7-dirty #2 Not tainted
[  492.199662][T24950] ------------------------------------------------------
[  492.200243][T24950] syz.5.7376/24950 is trying to acquire lock:
[  492.200764][T24950] ffff888106a71958 (&q->elevator_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0x49a/0x1a10
[  492.201679][T24950] 
[  492.201679][T24950] but task is already holding lock:
[  492.202324][T24950] ffff888106a71428 (&q->q_usage_counter(io)#55){++++}-{0:0}, at: nbd_start_device+0x16c/0xac0
[  492.203199][T24950] 
[  492.203199][T24950] which lock already depends on the new lock.
[  492.203199][T24950] 
[  492.204282][T24950] 
[  492.204282][T24950] the existing dependency chain (in reverse order) is:
[  492.205026][T24950] 
[  492.205026][T24950] -> #2 (&q->q_usage_counter(io)#55){++++}-{0:0}:
[  492.205755][T24950]        lock_acquire+0x120/0x360
[  492.206191][T24950]        blk_alloc_queue+0x538/0x620
[  492.207668][T24950]        __blk_mq_alloc_disk+0x164/0x350
[  492.208143][T24950]        nbd_dev_add+0x478/0xb10
[  492.208580][T24950]        nbd_init+0x21a/0x2d0
[  492.208987][T24950]        do_one_initcall+0x233/0x820
[  492.209427][T24950]        do_initcall_level+0x137/0x1f0
[  492.209898][T24950]        do_initcalls+0x69/0xd0
[  492.211387][T24950]        kernel_init_freeable+0x3d9/0x570
[  492.212872][T24950]        kernel_init+0x1d/0x1d0
[  492.214106][T24950]        ret_from_fork+0x4b/0x80
[  492.215349][T24950]        ret_from_fork_asm+0x1a/0x30
[  492.216687][T24950] 
[  492.216687][T24950] -> #1 (fs_reclaim){+.+.}-{0:0}:
[  492.218501][T24950]        lock_acquire+0x120/0x360
[  492.219773][T24950]        fs_reclaim_acquire+0x72/0x100
[  492.221247][T24950]        kmem_cache_alloc_noprof+0x44/0x3c0
[  492.222382][T24950]        __kernfs_new_node+0xd7/0x7f0
[  492.223332][T24950]        kernfs_new_node+0x102/0x210
[  492.224319][T24950]        kernfs_create_dir_ns+0x44/0x130
[  492.225321][T24950]        sysfs_create_dir_ns+0x123/0x280
[  492.226310][T24950]        kobject_add_internal+0x59f/0xb40
[  492.227320][T24950]        kobject_add+0x155/0x220
[  492.228199][T24950]        elv_register_queue+0xdb/0x260
[  492.229196][T24950]        blk_register_queue+0x375/0x450
[  492.230186][T24950]        add_disk_fwnode+0x77f/0x10e0
[  492.231152][T24950]        _RNvXCsktjF9JQNZ8U_5rnullNtB2_13NullBlkModuleNtCs43vyB533jt3_6kernel13InPlaceModule4init+0x904/0xc30
[  492.232707][T24950]        __rnull_mod_init+0x1a/0x70
[  492.233328][T24950]        do_one_initcall+0x233/0x820
[  492.233954][T24950]        do_initcall_level+0x137/0x1f0
[  492.234606][T24950]        do_initcalls+0x69/0xd0
[  492.235198][T24950]        kernel_init_freeable+0x3d9/0x570
[  492.235883][T24950]        kernel_init+0x1d/0x1d0
[  492.236478][T24950]        ret_from_fork+0x4b/0x80
[  492.237083][T24950]        ret_from_fork_asm+0x1a/0x30
[  492.237709][T24950] 
[  492.237709][T24950] -> #0 (&q->elevator_lock){+.+.}-{4:4}:
[  492.238636][T24950]        validate_chain+0xb9b/0x2140
[  492.239262][T24950]        __lock_acquire+0xaac/0xd20
[  492.239881][T24950]        lock_acquire+0x120/0x360
[  492.240504][T24950]        __mutex_lock+0x182/0xe80
[  492.241103][T24950]        blk_mq_update_nr_hw_queues+0x49a/0x1a10
[  492.241900][T24950]        nbd_start_device+0x16c/0xac0
[  492.242492][T24950]        nbd_genl_connect+0x1250/0x1930
[  492.242954][T24950]        genl_family_rcv_msg_doit+0x212/0x300
[  492.243465][T24950]        genl_rcv_msg+0x60e/0x790
[  492.243901][T24950]        netlink_rcv_skb+0x21c/0x490
[  492.244352][T24950]        genl_rcv+0x28/0x40
[  492.244734][T24950]        netlink_unicast+0x758/0x8d0
[  492.245165][T24950]        netlink_sendmsg+0x805/0xb30
[  492.245611][T24950]        __sock_sendmsg+0x21c/0x270
[  492.246055][T24950]        ____sys_sendmsg+0x505/0x830
[  492.246500][T24950]        ___sys_sendmsg+0x21f/0x2a0
[  492.246948][T24950]        __x64_sys_sendmsg+0x19b/0x260
[  492.247396][T24950]        do_syscall_64+0xf6/0x210
[  492.247817][T24950]        entry_SYSCALL_64_after_hwframe+0x77/0x7f
[  492.248351][T24950] 
[  492.248351][T24950] other info that might help us debug this:
[  492.248351][T24950] 
[  492.249170][T24950] Chain exists of:
[  492.249170][T24950]   &q->elevator_lock --> fs_reclaim --> &q->q_usage_counter(io)#55
[  492.249170][T24950] 
[  492.250308][T24950]  Possible unsafe locking scenario:
[  492.250308][T24950] 
[  492.250911][T24950]        CPU0                    CPU1
[  492.251357][T24950]        ----                    ----
[  492.251804][T24950]   lock(&q->q_usage_counter(io)#55);
[  492.252287][T24950]                                lock(fs_reclaim);
[  492.252868][T24950]                                lock(&q->q_usage_counter(io)#55);
[  492.253541][T24950]   lock(&q->elevator_lock);
[  492.253948][T24950] 
[  492.253948][T24950]  *** DEADLOCK ***
[  492.253948][T24950] 
[  492.254623][T24950] 6 locks held by syz.5.7376/24950:
[  492.255064][T24950]  #0: ffffffff8f76e570 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
[  492.255786][T24950]  #1: ffffffff8f76e388 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
[  492.256540][T24950]  #2: ffff88802383a198 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_genl_connect+0x94f/0x1930
[  492.257385][T24950]  #3: ffff88802383a0d8 (&set->tag_list_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0xac/0x1a10
[  492.258321][T24950]  #4: ffff888106a71428 (&q->q_usage_counter(io)#55){++++}-{0:0}, at: nbd_start_device+0x16c/0xac0
[  492.259234][T24950]  #5: ffff888106a71460 (&q->q_usage_counter(queue)#7){+.+.}-{0:0}, at: nbd_start_device+0x16c/0xac0
[  492.260176][T24950] 
[  492.260176][T24950] stack backtrace:
[  492.260687][T24950] CPU: 0 UID: 0 PID: 24950 Comm: syz.5.7376 Not tainted 6.15.0-rc7-dirty #2 PREEMPT(full) 
[  492.260700][T24950] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[  492.260709][T24950] Call Trace:
[  492.260715][T24950]  <TASK>
[  492.260721][T24950]  dump_stack_lvl+0x189/0x250
[  492.260734][T24950]  ? __pfx_dump_stack_lvl+0x10/0x10
[  492.260746][T24950]  ? __pfx__printk+0x10/0x10
[  492.260760][T24950]  ? print_lock_name+0xde/0x100
[  492.260772][T24950]  print_circular_bug+0x2ee/0x310
[  492.260789][T24950]  check_noncircular+0x134/0x160
[  492.260806][T24950]  validate_chain+0xb9b/0x2140
[  492.260826][T24950]  __lock_acquire+0xaac/0xd20
[  492.260840][T24950]  ? blk_mq_update_nr_hw_queues+0x49a/0x1a10
[  492.260856][T24950]  lock_acquire+0x120/0x360
[  492.260867][T24950]  ? blk_mq_update_nr_hw_queues+0x49a/0x1a10
[  492.260887][T24950]  __mutex_lock+0x182/0xe80
[  492.260899][T24950]  ? blk_mq_update_nr_hw_queues+0x49a/0x1a10
[  492.260918][T24950]  ? blk_mq_update_nr_hw_queues+0x49a/0x1a10
[  492.260935][T24950]  ? __pfx___mutex_lock+0x10/0x10
[  492.260949][T24950]  ? __kasan_kmalloc+0x93/0xb0
[  492.260967][T24950]  ? blk_mq_update_nr_hw_queues+0x47b/0x1a10
[  492.260985][T24950]  blk_mq_update_nr_hw_queues+0x49a/0x1a10
[  492.261006][T24950]  ? __pfx_blk_mq_update_nr_hw_queues+0x10/0x10
[  492.261023][T24950]  ? nbd_add_socket+0x688/0x9a0
[  492.261034][T24950]  nbd_start_device+0x16c/0xac0
[  492.261045][T24950]  ? __nla_parse+0x40/0x60
[  492.261059][T24950]  nbd_genl_connect+0x1250/0x1930
[  492.261078][T24950]  ? __pfx_nbd_genl_connect+0x10/0x10
[  492.261100][T24950]  ? genl_family_rcv_msg_attrs_parse+0x1c9/0x2a0
[  492.261118][T24950]  genl_family_rcv_msg_doit+0x212/0x300
[  492.261136][T24950]  ? __pfx_genl_family_rcv_msg_doit+0x10/0x10
[  492.261156][T24950]  ? stack_depot_save_flags+0x40/0x910
[  492.261168][T24950]  genl_rcv_msg+0x60e/0x790
[  492.261185][T24950]  ? __pfx_genl_rcv_msg+0x10/0x10
[  492.261199][T24950]  ? __pfx_nbd_genl_connect+0x10/0x10
[  492.261219][T24950]  netlink_rcv_skb+0x21c/0x490
[  492.261231][T24950]  ? __pfx_genl_rcv_msg+0x10/0x10
[  492.261246][T24950]  ? __pfx_netlink_rcv_skb+0x10/0x10
[  492.261263][T24950]  ? down_read+0x1ad/0x2e0
[  492.261277][T24950]  genl_rcv+0x28/0x40
[  492.261291][T24950]  netlink_unicast+0x758/0x8d0
[  492.261304][T24950]  netlink_sendmsg+0x805/0xb30
[  492.261319][T24950]  ? __pfx_netlink_sendmsg+0x10/0x10
[  492.261332][T24950]  ? aa_sock_msg_perm+0x94/0x160
[  492.261349][T24950]  ? bpf_lsm_socket_sendmsg+0x9/0x20
[  492.261365][T24950]  ? __pfx_netlink_sendmsg+0x10/0x10
[  492.261378][T24950]  __sock_sendmsg+0x21c/0x270
[  492.261388][T24950]  ____sys_sendmsg+0x505/0x830
[  492.261404][T24950]  ? __pfx_____sys_sendmsg+0x10/0x10
[  492.261420][T24950]  ? import_iovec+0x74/0xa0
[  492.261436][T24950]  ___sys_sendmsg+0x21f/0x2a0
[  492.261450][T24950]  ? __pfx____sys_sendmsg+0x10/0x10
[  492.261474][T24950]  ? __fget_files+0x2a/0x420
[  492.261485][T24950]  ? __fget_files+0x3a0/0x420
[  492.261499][T24950]  __x64_sys_sendmsg+0x19b/0x260
[  492.261514][T24950]  ? __pfx___x64_sys_sendmsg+0x10/0x10
[  492.261532][T24950]  ? do_syscall_64+0xba/0x210
[  492.261545][T24950]  do_syscall_64+0xf6/0x210
[  492.261558][T24950]  ? clear_bhb_loop+0x60/0xb0
[  492.261571][T24950]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[  492.261582][T24950] RIP: 0033:0x7fc91838e969
[  492.261593][T24950] Code: ff ff 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
[  492.261603][T24950] RSP: 002b:00007fc9191d7038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  492.261614][T24950] RAX: ffffffffffffffda RBX: 00007fc9185b5fa0 RCX: 00007fc91838e969
[  492.261623][T24950] RDX: 0000000000004000 RSI: 0000200000000300 RDI: 0000000000000004
[  492.261631][T24950] RBP: 00007fc918410ab1 R08: 0000000000000000 R09: 0000000000000000
[  492.261638][T24950] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[  492.261646][T24950] R13: 0000000000000000 R14: 00007fc9185b5fa0 R15: 00007ffef33da528
[  492.261658][T24950]  </TASK>

After symbolization we get:

======================================================
WARNING: possible circular locking dependency detected
6.15.0-rc7-dirty #2 Not tainted
------------------------------------------------------
syz.5.7376/24950 is trying to acquire lock:
ffff888106a71958 (&q->elevator_lock){+.+.}-{4:4}, at: blk_mq_elv_switch_none block/blk-mq.c:4951 [inline]
ffff888106a71958 (&q->elevator_lock){+.+.}-{4:4}, at: __blk_mq_update_nr_hw_queues block/blk-mq.c:5031 [inline]
ffff888106a71958 (&q->elevator_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0x49a/0x1a10 block/blk-mq.c:5083

but task is already holding lock:
ffff888106a71428 (&q->q_usage_counter(io)#55){++++}-{0:0}, at: nbd_start_device+0x16c/0xac0 drivers/block/nbd.c:1476

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&q->q_usage_counter(io)#55){++++}-{0:0}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
       blk_alloc_queue+0x538/0x620 block/blk-core.c:461
       blk_mq_alloc_queue block/blk-mq.c:4348 [inline]
       __blk_mq_alloc_disk+0x164/0x350 block/blk-mq.c:4395
       nbd_dev_add+0x478/0xb10 drivers/block/nbd.c:1933
       nbd_init+0x21a/0x2d0 drivers/block/nbd.c:2670
       do_one_initcall+0x233/0x820 init/main.c:1257
       do_initcall_level+0x137/0x1f0 init/main.c:1319
       do_initcalls+0x69/0xd0 init/main.c:1335
       kernel_init_freeable+0x3d9/0x570 init/main.c:1567
       kernel_init+0x1d/0x1d0 init/main.c:1457
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #1 (fs_reclaim){+.+.}-{0:0}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
       __fs_reclaim_acquire mm/page_alloc.c:4060 [inline]
       fs_reclaim_acquire+0x72/0x100 mm/page_alloc.c:4074
       might_alloc include/linux/sched/mm.h:318 [inline]
       slab_pre_alloc_hook mm/slub.c:4098 [inline]
       slab_alloc_node mm/slub.c:4176 [inline]
       kmem_cache_alloc_noprof+0x44/0x3c0 mm/slub.c:4203
       __kernfs_new_node+0xd7/0x7f0 fs/kernfs/dir.c:637
       kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:713
       kernfs_create_dir_ns+0x44/0x130 fs/kernfs/dir.c:1081
       sysfs_create_dir_ns+0x123/0x280 fs/sysfs/dir.c:59
       create_dir lib/kobject.c:73 [inline]
       kobject_add_internal+0x59f/0xb40 lib/kobject.c:240
       kobject_add_varg lib/kobject.c:374 [inline]
       kobject_add+0x155/0x220 lib/kobject.c:426
       elv_register_queue+0xdb/0x260 block/elevator.c:462
       blk_register_queue+0x375/0x450 block/blk-sysfs.c:874
       add_disk_fwnode+0x77f/0x10e0 block/genhd.c:505
       _RINvMs_NtNtNtCs43vyB533jt3_6kernel5block2mq8gen_diskNtB5_14GenDiskBuilder5buildNtCsktjF9JQNZ8U_5rnull13NullBlkDeviceEB1h_ rust/kernel/block/mq/gen_disk.rs:160 [inline]
       _RNCNvXCsktjF9JQNZ8U_5rnullNtB4_13NullBlkModuleNtCs43vyB533jt3_6kernel13InPlaceModule4init0B4_ drivers/block/rnull.rs:49 [inline]
       _RNvXCsktjF9JQNZ8U_5rnullNtB2_13NullBlkModuleNtCs43vyB533jt3_6kernel13InPlaceModule4init+0x904/0xc30 drivers/block/rnull.rs:46
       _RNvNtNtCsktjF9JQNZ8U_5rnull13___module_init13___module_init6___init drivers/block/rnull.rs:27 [inline]
       __rnull_mod_init+0x1a/0x70 drivers/block/rnull.rs:27
       do_one_initcall+0x233/0x820 init/main.c:1257
       do_initcall_level+0x137/0x1f0 init/main.c:1319
       do_initcalls+0x69/0xd0 init/main.c:1335
       kernel_init_freeable+0x3d9/0x570 init/main.c:1567
       kernel_init+0x1d/0x1d0 init/main.c:1457
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #0 (&q->elevator_lock){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3166 [inline]
       check_prevs_add kernel/locking/lockdep.c:3285 [inline]
       validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3909
       __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
       __mutex_lock_common kernel/locking/mutex.c:601 [inline]
       __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746
       blk_mq_elv_switch_none block/blk-mq.c:4951 [inline]
       __blk_mq_update_nr_hw_queues block/blk-mq.c:5031 [inline]
       blk_mq_update_nr_hw_queues+0x49a/0x1a10 block/blk-mq.c:5083
       nbd_start_device+0x16c/0xac0 drivers/block/nbd.c:1476
       nbd_genl_connect+0x1250/0x1930 drivers/block/nbd.c:2201
       genl_family_rcv_msg_doit+0x212/0x300 net/netlink/genetlink.c:1115
       genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
       genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
       netlink_rcv_skb+0x21c/0x490 net/netlink/af_netlink.c:2534
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
       netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
       netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
       netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
       sock_sendmsg_nosec net/socket.c:712 [inline]
       __sock_sendmsg+0x21c/0x270 net/socket.c:727
       ____sys_sendmsg+0x505/0x830 net/socket.c:2566
       ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
       __sys_sendmsg net/socket.c:2652 [inline]
       __do_sys_sendmsg net/socket.c:2657 [inline]
       __se_sys_sendmsg net/socket.c:2655 [inline]
       __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &q->elevator_lock --> fs_reclaim --> &q->q_usage_counter(io)#55

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&q->q_usage_counter(io)#55);
                               lock(fs_reclaim);
                               lock(&q->q_usage_counter(io)#55);
  lock(&q->elevator_lock);

 *** DEADLOCK ***

6 locks held by syz.5.7376/24950:
 #0: ffffffff8f76e570 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffffffff8f76e388 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff8f76e388 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff8f76e388 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209
 #2: ffff88802383a198 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_genl_connect+0x94f/0x1930 drivers/block/nbd.c:2111
 #3: ffff88802383a0d8 (&set->tag_list_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0xac/0x1a10 block/blk-mq.c:5082
 #4: ffff888106a71428 (&q->q_usage_counter(io)#55){++++}-{0:0}, at: nbd_start_device+0x16c/0xac0 drivers/block/nbd.c:1476
 #5: ffff888106a71460 (&q->q_usage_counter(queue)#7){+.+.}-{0:0}, at: nbd_start_device+0x16c/0xac0 drivers/block/nbd.c:1476

stack backtrace:
CPU: 0 UID: 0 PID: 24950 Comm: syz.5.7376 Not tainted 6.15.0-rc7-dirty #2 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2079
 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2211
 check_prev_add kernel/locking/lockdep.c:3166 [inline]
 check_prevs_add kernel/locking/lockdep.c:3285 [inline]
 validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3909
 __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
 __mutex_lock_common kernel/locking/mutex.c:601 [inline]
 __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746
 blk_mq_elv_switch_none block/blk-mq.c:4951 [inline]
 __blk_mq_update_nr_hw_queues block/blk-mq.c:5031 [inline]
 blk_mq_update_nr_hw_queues+0x49a/0x1a10 block/blk-mq.c:5083
 nbd_start_device+0x16c/0xac0 drivers/block/nbd.c:1476
 nbd_genl_connect+0x1250/0x1930 drivers/block/nbd.c:2201
 genl_family_rcv_msg_doit+0x212/0x300 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x21c/0x490 net/netlink/af_netlink.c:2534
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:727
 ____sys_sendmsg+0x505/0x830 net/socket.c:2566
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
 __sys_sendmsg net/socket.c:2652 [inline]
 __do_sys_sendmsg net/socket.c:2657 [inline]
 __se_sys_sendmsg net/socket.c:2655 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc91838e969
Code: ff ff 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc9191d7038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc9185b5fa0 RCX: 00007fc91838e969
RDX: 0000000000004000 RSI: 0000200000000300 RDI: 0000000000000004
RBP: 00007fc918410ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc9185b5fa0 R15: 00007ffef33da528
 </TASK>
nbd5: detected capacity change from 0 to 64

[a-nogikh]

We could do it in symbolizeLine():

syzkaller/pkg/report/linux.go

Lines 492 to 496 in 0919b50

	modified := append([]byte{}, line...)
	if buildID != "" {
	modified = replace(modified, match[8], match[9], []byte(" ["+modName+"]"))
	}
	modified = replace(modified, match[7], match[7], []byte(info))

replace(modified, match[2], match[3], newName) would correspond to replacing _RNvXCsktjF9JQNZ8U_5rnullNtB2_13NullBlkModuleNtCs43vyB533jt3_6kernel13InPlaceModule4init here:

[  492.231152][T24950]        _RNvXCsktjF9JQNZ8U_5rnullNtB2_13NullBlkModuleNtCs43vyB533jt3_6kernel13InPlaceModule4init+0x904/0xc30

=>

[  492.231152][T24950]        <rnull[ee75c4b3859c3ff6]::NullBlkModule as kernel[2f3febcca69aaa0f]::InPlaceModule>::init+0x904/0xc30

Or we could always replace it with frame.Func (not just for inline functions) and do demangling in pkg/symbolize

---

On the other hand, we don't really need full symbolization here - demangling can be done also in the absence of vmlinux. So it should probably be another pass somewhere after symbolize() here?

syzkaller/pkg/report/linux.go

Lines 383 to 388 in 0919b50

	if ctx.vmlinux != "" {
	if err := ctx.symbolize(rep); err != nil {
	return err
	}
	}
	rep.Report = ctx.decompileOpcodes(rep.Report, rep)