evie/android_kernel_oneplus_msm8998
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
android_kernel_oneplus_msm8998/include
History
Michal Hocko 1c0f4e0ebb hotplug: Make register and unregister notifier API symmetric 
commit 777c6e0daebb3fcefbbd6f620410a946b07ef6d0 upstream.

Yu Zhao has noticed that __unregister_cpu_notifier only unregisters its
notifiers when HOTPLUG_CPU=y while the registration might succeed even
when HOTPLUG_CPU=n if MODULE is enabled. This means that e.g. zswap
might keep a stale notifier on the list on the manual clean up during
the pool tear down and thus corrupt the list. Resulting in the following

[  144.964346] BUG: unable to handle kernel paging request at ffff880658a2be78
[  144.971337] IP: [<ffffffffa290b00b>] raw_notifier_chain_register+0x1b/0x40
<snipped>
[  145.122628] Call Trace:
[  145.125086]  [<ffffffffa28e5cf8>] __register_cpu_notifier+0x18/0x20
[  145.131350]  [<ffffffffa2a5dd73>] zswap_pool_create+0x273/0x400
[  145.137268]  [<ffffffffa2a5e0fc>] __zswap_param_set+0x1fc/0x300
[  145.143188]  [<ffffffffa2944c1d>] ? trace_hardirqs_on+0xd/0x10
[  145.149018]  [<ffffffffa2908798>] ? kernel_param_lock+0x28/0x30
[  145.154940]  [<ffffffffa2a3e8cf>] ? __might_fault+0x4f/0xa0
[  145.160511]  [<ffffffffa2a5e237>] zswap_compressor_param_set+0x17/0x20
[  145.167035]  [<ffffffffa2908d3c>] param_attr_store+0x5c/0xb0
[  145.172694]  [<ffffffffa290848d>] module_attr_store+0x1d/0x30
[  145.178443]  [<ffffffffa2b2b41f>] sysfs_kf_write+0x4f/0x70
[  145.183925]  [<ffffffffa2b2a5b9>] kernfs_fop_write+0x149/0x180
[  145.189761]  [<ffffffffa2a99248>] __vfs_write+0x18/0x40
[  145.194982]  [<ffffffffa2a9a412>] vfs_write+0xb2/0x1a0
[  145.200122]  [<ffffffffa2a9a732>] SyS_write+0x52/0xa0
[  145.205177]  [<ffffffffa2ff4d97>] entry_SYSCALL_64_fastpath+0x12/0x17

This can be even triggered manually by changing
/sys/module/zswap/parameters/compressor multiple times.

Fix this issue by making unregister APIs symmetric to the register so
there are no surprises.

Fixes: 47e627bc8c ("[PATCH] hotplug: Allow modules to use the cpu hotplug notifiers even if !CONFIG_HOTPLUG_CPU")
Reported-and-tested-by: Yu Zhao <yuzhao@google.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: linux-mm@kvack.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Link: http://lkml.kernel.org/r/20161207135438.4310-1-mhocko@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-15 08:49:23 -08:00
..
acpi Merge branch 'acpi-pci' 2015-11-07 01:30:10 +01:00
asm-generic asm-generic: make copy_from_user() zero the destination properly 2016-09-24 10:07:45 +02:00
clocksource
crypto crypto: ghash-generic - move common definitions to a new header file 2016-10-22 12:26:56 +02:00
drm drm/prime: Pass the right module owner through to dma_buf_export() 2016-10-31 04:13:57 -06:00
dt-bindings ARM: DT updates for v4.4 2015-11-10 15:06:26 -08:00
keys KEYS: Merge the type-specific data with the payload data 2015-10-21 15:18:36 +01:00
kvm KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.active 2015-11-24 18:07:40 +01:00
linux hotplug: Make register and unregister notifier API symmetric 2016-12-15 08:49:23 -08:00
math-emu
media videobuf2-core: Check user space planes array in dqbuf 2016-05-04 14:48:50 -07:00
memory
misc
net tcp: take care of truncations done by sk_filter() 2016-11-21 10:06:40 +01:00
pcmcia
ras
rdma IB/security: Restrict use of the write() interface 2016-05-04 14:48:48 -07:00
rxrpc
scsi scsi: Add intermediate STARGET_REMOVE state to scsi_target_state 2016-06-01 12:15:54 -07:00
soc ARM: SoC driver updates for v4.4 2015-11-10 15:00:03 -08:00
sound ALSA: rawmidi: Make snd_rawmidi_transmit() race-free 2016-02-17 12:30:58 -08:00
target target: Make EXTENDED_COPY 0xe4 failure return COPY TARGET DEVICE NOT REACHABLE 2016-10-28 03:01:36 -04:00
trace SUNRPC: Don't allocate a full sockaddr_storage for tracing 2016-08-20 18:09:26 +02:00
uapi can: raw: raw_setsockopt: limit number of can_filter that can be set 2016-12-15 08:49:22 -08:00
video drm/imx: Match imx-ipuv3-crtc components using device node in platform data 2016-06-07 18:14:37 -07:00
xen xen: Fix page <-> pfn conversion on 32 bit systems 2016-05-11 11:21:14 +02:00
Kbuild