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Mao Wenan cafe8df8b9 net: phy: Fix lack of reference count on PHY driver
There is currently no reference count being held on the PHY driver,
which makes it possible to remove the PHY driver module while the PHY
state machine is running and polling the PHY. This could cause crashes
similar to this one to show up:

[   43.361162] BUG: unable to handle kernel NULL pointer dereference at 0000000000000140
[   43.361162] IP: phy_state_machine+0x32/0x490
[   43.361162] PGD 59dc067
[   43.361162] PUD 0
[   43.361162]
[   43.361162] Oops: 0000 [#1] SMP
[   43.361162] Modules linked in: dsa_loop [last unloaded: broadcom]
[   43.361162] CPU: 0 PID: 1299 Comm: kworker/0:3 Not tainted 4.10.0-rc5+ #415
[   43.361162] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS Ubuntu-1.8.2-1ubuntu2 04/01/2014
[   43.361162] Workqueue: events_power_efficient phy_state_machine
[   43.361162] task: ffff880006782b80 task.stack: ffffc90000184000
[   43.361162] RIP: 0010:phy_state_machine+0x32/0x490
[   43.361162] RSP: 0018:ffffc90000187e18 EFLAGS: 00000246
[   43.361162] RAX: 0000000000000000 RBX: ffff8800059e53c0 RCX:
ffff880006a15c60
[   43.361162] RDX: ffff880006782b80 RSI: 0000000000000000 RDI:
ffff8800059e5428
[   43.361162] RBP: ffffc90000187e48 R08: ffff880006a15c40 R09:
0000000000000000
[   43.361162] R10: 0000000000000000 R11: 0000000000000000 R12:
ffff8800059e5428
[   43.361162] R13: ffff8800059e5000 R14: 0000000000000000 R15:
ffff880006a15c40
[   43.361162] FS:  0000000000000000(0000) GS:ffff880006a00000(0000)
knlGS:0000000000000000
[   43.361162] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   43.361162] CR2: 0000000000000140 CR3: 0000000005979000 CR4:
00000000000006f0
[   43.361162] Call Trace:
[   43.361162]  process_one_work+0x1b4/0x3e0
[   43.361162]  worker_thread+0x43/0x4d0
[   43.361162]  ? __schedule+0x17f/0x4e0
[   43.361162]  kthread+0xf7/0x130
[   43.361162]  ? process_one_work+0x3e0/0x3e0
[   43.361162]  ? kthread_create_on_node+0x40/0x40
[   43.361162]  ret_from_fork+0x29/0x40
[   43.361162] Code: 56 41 55 41 54 4c 8d 67 68 53 4c 8d af 40 fc ff ff
48 89 fb 4c 89 e7 48 83 ec 08 e8 c9 9d 27 00 48 8b 83 60 ff ff ff 44 8b
73 98 <48> 8b 90 40 01 00 00 44 89 f0 48 85 d2 74 08 4c 89 ef ff d2 8b

Keep references on the PHY driver module right before we are going to
utilize it in phy_attach_direct(), and conversely when we don't use it
anymore in phy_detach().

Signed-off-by: Mao Wenan <maowenan@huawei.com>
[florian: rebase, rework commit message]
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-02 22:59:43 -05:00
arch Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-02-01 09:24:00 -08:00
block blk-mq: Remove unused variable 2017-01-18 15:14:15 -07:00
certs certs: Add a secondary system keyring that can be added to dynamically 2016-04-11 22:48:09 +01:00
crypto crypto: api - Clear CRYPTO_ALG_DEAD bit before registering an alg 2017-01-23 22:41:32 +08:00
Documentation ARC fixes for 4.10-rc6 2017-01-28 11:00:08 -08:00
drivers net: phy: Fix lack of reference count on PHY driver 2017-02-02 22:59:43 -05:00
firmware WHENCE: use https://linuxtv.org for LinuxTV URLs 2015-12-04 10:35:11 -02:00
fs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-02-01 10:30:56 -08:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-02-01 11:52:27 -08:00
init cgroup: move CONFIG_SOCK_CGROUP_DATA to init/Kconfig 2017-01-11 09:47:10 -05:00
ipc ipc/sem.c: fix incorrect sem_lock pairing 2017-01-10 18:31:55 -08:00
kernel It was reported to me that the thread created by the hwlat tracer does 2017-01-31 16:32:40 -08:00
lib mm: do not export ioremap_page_range symbol for external module 2017-01-24 16:26:14 -08:00
mm mm, page_alloc: fix premature OOM when racing with cpuset mems update 2017-01-24 16:26:14 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-02-01 11:52:27 -08:00
samples bpf: fix samples xdp_tx_iptunnel and tc_l2_redirect with fake KBUILD_MODNAME 2017-01-20 12:04:07 -05:00
scripts gcc-plugins: update gcc-common.h for gcc-7 2017-01-03 12:08:59 -08:00
security Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
sound ASoC: Fixes for v4.10 2017-01-11 19:49:27 +01:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-27 12:54:16 -08:00
usr kbuild: initramfs cleanup, set target from Kconfig 2017-01-05 09:40:16 -08:00
virt KVM/ARM updates for 4.10-rc4 2017-01-17 15:04:59 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-08-02 16:48:52 -04:00
.mailmap mailmap: add codeaurora.org names for nameless email commits 2017-01-10 18:31:55 -08:00
COPYING
CREDITS CREDITS: Remove outdated address information 2016-12-21 15:21:29 -08:00
Kbuild scripts/gdb: provide linux constants 2016-05-23 17:04:14 -07:00
Kconfig
MAINTAINERS wireless-drivers fixes for 4.10 2017-01-30 15:19:23 -05:00
Makefile Linux 4.10-rc6 2017-01-29 14:25:17 -08:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.