Never seen this before, sounds like a recent regression. It seems
some wifi related module try to create same file under sysfs.


[   12.853956] ------------[ cut here ]------------
[   12.856064] WARNING: CPU: 1 PID: 1634 at ../../../../../tmp/portage/sys-kernel/chromeos-kernel-4_4-4.4.114-r1354/work/chromeos-kernel-4_4-4.4.114/fs/sysfs/dir.c:31 sysfs_warn_dup+0x64/0x73
[   12.860498] sysfs: cannot create duplicate filename '/class/ieee80211'
[   12.862250] Modules linked in: uinput cfg80211(+) iwl7000_cfg80211 ip6table_filter snd_hda_codec_generic bridge stp llc ipt_MASQUERADE nf_nat_masquerade_ipv4 snd_hda_intel xt_mark zram snd_hda_codec snd_hwdep snd_hda_core i2c_piix4 fuse snd_seq_dummy snd_seq snd_seq_device virtio_net joydev
[   12.870044] CPU: 1 PID: 1634 Comm: modprobe Not tainted 4.4.114-13025-ge03072ba6450 #1
[   12.871010] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014
[   12.871010]  0000000000000286 771d18b865e9338f ffff88001f90fb60 ffffffff8f1343a3
[   12.871010]  ffff88001f90fbb0 0000000000000000 ffff88001f90fba0 ffffffff8eeabe7d
[   12.871010]  0000001f1f90fc20 ffff880042bc7000 ffff88003d4a9820 ffff88005d9a6618
[   12.871010] Call Trace:
[   12.871010]  [<ffffffff8f1343a3>] dump_stack+0x4d/0x63
[   12.871010]  [<ffffffff8eeabe7d>] __warn+0xca/0xe5
[   12.871010]  [<ffffffff8eeabf80>] warn_slowpath_fmt+0x5a/0x76
[   12.871010]  [<ffffffff8f02cfbf>] sysfs_warn_dup+0x64/0x73
[   12.871010]  [<ffffffff8f02d07c>] sysfs_create_dir_ns+0x69/0x7b
[   12.871010]  [<ffffffff8f136a3c>] kobject_add_internal+0xd2/0x267
[   12.871010]  [<ffffffff8f136bf7>] kset_register+0x26/0x3f
[   12.871010]  [<ffffffff8f3ed82f>] __class_register+0xdd/0x178
[   12.871010]  [<ffffffffc054c68a>] wiphy_sysfs_init+0x1c/0x1e [cfg80211]
[   12.871010]  [<ffffffffc05ae020>] cfg80211_init+0x20/0xd8 [cfg80211]
[   12.871010]  [<ffffffffc05ae000>] ? 0xffffffffc05ae000
[   12.871010]  [<ffffffff8ee004a3>] do_one_initcall+0x186/0x19b
[   12.871010]  [<ffffffff8ef043e5>] do_init_module+0x5f/0x1cd
[   12.871010]  [<ffffffff8ef0642f>] load_module+0x1c6b/0x1c8f
[   12.871010]  [<ffffffff8ef064d3>] SYSC_finit_module+0x80/0xa7
[   12.871010]  [<ffffffff8ef064d3>] ? SYSC_finit_module+0x80/0xa7
[   12.871010]  [<ffffffff8ef0668b>] SyS_finit_module+0xe/0x10
[   12.871010]  [<ffffffff8f706f8d>] entry_SYSCALL_64_fastpath+0x21/0x95
[   12.908350] ---[ end trace 441c88b26bd1f3bc ]---
[   12.909451] ------------[ cut here ]------------
[   12.910421] WARNING: CPU: 1 PID: 1634 at ../../../../../tmp/portage/sys-kernel/chromeos-kernel-4_4-4.4.114-r1354/work/chromeos-kernel-4_4-4.4.114/lib/kobject.c:240 kobject_add_internal+0x21a/0x267
[   12.913940] kobject_add_internal failed for ieee80211 with -EEXIST, don't try to register things with the same name in the same directory.
[   12.916999] Modules linked in: uinput cfg80211(+) iwl7000_cfg80211 ip6table_filter snd_hda_codec_generic bridge stp llc ipt_MASQUERADE nf_nat_masquerade_ipv4 snd_hda_intel xt_mark zram snd_hda_codec snd_hwdep snd_hda_core i2c_piix4 fuse snd_seq_dummy snd_seq snd_seq_device virtio_net joydev
[   12.922896] CPU: 1 PID: 1634 Comm: modprobe Tainted: G        W       4.4.114-13025-ge03072ba6450 #1
[   12.923160] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014
[   12.923160]  0000000000000286 771d18b865e9338f ffff88001f90fbb0 ffffffff8f1343a3
[   12.923160]  ffff88001f90fc00 0000000000000000 ffff88001f90fbf0 ffffffff8eeabe7d
[   12.923160]  000000f01f90fc70 ffff880038e34c28 00000000ffffffef ffff88005db165a8
[   12.923160] Call Trace:
[   12.923160]  [<ffffffff8f1343a3>] dump_stack+0x4d/0x63
[   12.923160]  [<ffffffff8eeabe7d>] __warn+0xca/0xe5
[   12.923160]  [<ffffffff8eeabf80>] warn_slowpath_fmt+0x5a/0x76
[   12.923160]  [<ffffffff8f02cfc7>] ? sysfs_warn_dup+0x6c/0x73
[   12.923160]  [<ffffffff8f136b84>] kobject_add_internal+0x21a/0x267
[   12.923160]  [<ffffffff8f136bf7>] kset_register+0x26/0x3f
[   12.923160]  [<ffffffff8f3ed82f>] __class_register+0xdd/0x178
[   12.923160]  [<ffffffffc054c68a>] wiphy_sysfs_init+0x1c/0x1e [cfg80211]
[   12.923160]  [<ffffffffc05ae020>] cfg80211_init+0x20/0xd8 [cfg80211]
[   12.923160]  [<ffffffffc05ae000>] ? 0xffffffffc05ae000
[   12.923160]  [<ffffffff8ee004a3>] do_one_initcall+0x186/0x19b
[   12.923160]  [<ffffffff8ef043e5>] do_init_module+0x5f/0x1cd
[   12.923160]  [<ffffffff8ef0642f>] load_module+0x1c6b/0x1c8f
[   12.923160]  [<ffffffff8ef064d3>] SYSC_finit_module+0x80/0xa7
[   12.923160]  [<ffffffff8ef064d3>] ? SYSC_finit_module+0x80/0xa7
[   12.923160]  [<ffffffff8ef0668b>] SyS_finit_module+0xe/0x10
[   12.923160]  [<ffffffff8f706f8d>] entry_SYSCALL_64_fastpath+0x21/0x95
[   12.958449] ---[ end trace 441c88b26bd1f3bd ]---