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David Howells cdfbabfb2f net: Work around lockdep limitation in sockets that use sockets 
Lockdep issues a circular dependency warning when AFS issues an operation
through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem.

The theory lockdep comes up with is as follows:

 (1) If the pagefault handler decides it needs to read pages from AFS, it
     calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but
     creating a call requires the socket lock:

	mmap_sem must be taken before sk_lock-AF_RXRPC

 (2) afs_open_socket() opens an AF_RXRPC socket and binds it.  rxrpc_bind()
     binds the underlying UDP socket whilst holding its socket lock.
     inet_bind() takes its own socket lock:

	sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET

 (3) Reading from a TCP socket into a userspace buffer might cause a fault
     and thus cause the kernel to take the mmap_sem, but the TCP socket is
     locked whilst doing this:

	sk_lock-AF_INET must be taken before mmap_sem

However, lockdep's theory is wrong in this instance because it deals only
with lock classes and not individual locks.  The AF_INET lock in (2) isn't
really equivalent to the AF_INET lock in (3) as the former deals with a
socket entirely internal to the kernel that never sees userspace.  This is
a limitation in the design of lockdep.

Fix the general case by:

 (1) Double up all the locking keys used in sockets so that one set are
     used if the socket is created by userspace and the other set is used
     if the socket is created by the kernel.

 (2) Store the kern parameter passed to sk_alloc() in a variable in the
     sock struct (sk_kern_sock).  This informs sock_lock_init(),
     sock_init_data() and sk_clone_lock() as to the lock keys to be used.

     Note that the child created by sk_clone_lock() inherits the parent's
     kern setting.

 (3) Add a 'kern' parameter to ->accept() that is analogous to the one
     passed in to ->create() that distinguishes whether kernel_accept() or
     sys_accept4() was the caller and can be passed to sk_alloc().

     Note that a lot of accept functions merely dequeue an already
     allocated socket.  I haven't touched these as the new socket already
     exists before we get the parameter.

     Note also that there are a couple of places where I've made the accepted
     socket unconditionally kernel-based:

	irda_accept()
	rds_rcp_accept_one()
	tcp_accept_from_sock()

     because they follow a sock_create_kern() and accept off of that.

Whilst creating this, I noticed that lustre and ocfs don't create sockets
through sock_create_kern() and thus they aren't marked as for-kernel,
though they appear to be internal.  I wonder if these should do that so
that they use the new set of lock keys.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 		2017-03-09 18:23:27 -08:00
..
accessibility
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acpi Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 2017-03-03 16:48:48 -08:00
amba
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android sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
ata SCSI misc on 20170303 2017-03-03 21:36:56 -08:00
atm sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
auxdisplay
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base Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-03-03 11:38:56 -08:00
bcma
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block SCSI misc on 20170303 2017-03-03 21:36:56 -08:00
bluetooth btmrvl: fix spelling mistake: "actived" -> "activated" 2017-02-19 00:26:37 +01:00
bus ARM: SoC driver updates 2017-02-23 15:57:04 -08:00
cdrom Merge branch 'for-4.11/next' into for-4.11/linus-merge 2017-02-17 14:08:19 -07:00
char Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
clk ARM: SoC: late DT updates for v4.11 2017-03-03 16:15:48 -08:00
clocksource sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h> 2017-03-02 08:42:27 +01:00
connector
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cpufreq Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
cpuidle Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-03-04 10:42:53 -08:00
dax sched/headers: Prepare to remove the <linux/magic.h> include from <linux/sched/task_stack.h> 2017-03-02 08:42:40 +01:00
dca
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devfreq scripts/spelling.txt: add "followings" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
dio
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dma sched/headers: Prepare to move the get_task_struct()/put_task_struct() and related APIs from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:40 +01:00
dma-buf sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
edac Merge branch 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-02-20 12:47:44 -08:00
eisa
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extcon scripts/spelling.txt: add "swithc" pattern and fix typo instances 2017-02-27 18:43:46 -08:00
firewire Merge branch 'idr-4.11' of git://git.infradead.org/users/willy/linux-dax 2017-02-28 20:29:41 -08:00
firmware sched/headers: Prepare for new header dependencies before moving code to <uapi/linux/sched/types.h> 2017-03-02 08:42:27 +01:00
fmc
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fpga
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fsi
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gpio This is the bulk of GPIO changes for the v4.11 cycle 2017-02-23 08:46:04 -08:00
gpu Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
hid sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
hsi sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
hv sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
hwmon scripts/spelling.txt: add "followings" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
hwspinlock
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hwtracing mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmf 2017-02-24 17:46:54 -08:00
i2c sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
ide sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
idle Power management turbostat utility updates for v4.11-rc1 2017-03-02 17:41:27 -08:00
iio Staging/IIO driver fixes for 4.11-rc1 2017-03-04 11:26:18 -08:00
infiniband sched/headers: Prepare to move the get_task_struct()/put_task_struct() and related APIs from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:40 +01:00
input Input: rmi4 - f30: detect INPUT_PROP_BUTTONPAD from the button count 2017-03-01 10:01:56 -08:00
iommu sched/headers: Prepare for new header dependencies before moving code to <linux/sched/mm.h> 2017-03-02 08:42:28 +01:00
ipack
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irqchip IOMMU Updates for Linux v4.11 2017-02-20 16:42:43 -08:00
isdn sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h> 2017-03-02 08:42:39 +01:00
leds sched/headers: Prepare for new header dependencies before moving code to <linux/sched/loadavg.h> 2017-03-02 08:42:27 +01:00
lguest sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
lightnvm lightnvm: set default lun range when no luns are specified 2017-02-15 08:27:21 -07:00
macintosh sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
mailbox sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
mcb
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md Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
media sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
memory ARM: SoC driver updates 2017-02-23 15:57:04 -08:00
memstick Merge branch 'for-4.11/next' into for-4.11/linus-merge 2017-02-17 14:08:19 -07:00
message SCSI misc on 20170220 2017-02-21 11:51:42 -08:00
mfd staging/iio driver patches for 4.11-rc1 2017-02-22 12:14:01 -08:00
misc Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
mmc sched/headers: Prepare for new header dependencies before moving code to <uapi/linux/sched/types.h> 2017-03-02 08:42:27 +01:00
mtd Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-03-03 11:38:56 -08:00
net bnxt_en: Ignore 0 value in autoneg supported speed from firmware. 2017-03-09 17:38:31 -08:00
nfc scripts/spelling.txt: add "omited" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
ntb ntb: ntb_hw_intel: link_poll isn't clearing the pending status properly 2017-02-16 23:11:26 -05:00
nubus
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nvdimm nfit, libnvdimm: fix interleave set cookie calculation 2017-03-01 00:49:42 -08:00
nvme Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2017-03-03 10:53:35 -08:00
nvmem
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of DeviceTree updates for 4.11: 2017-02-22 19:23:14 -08:00
oprofile sched/headers: Prepare to move the get_task_struct()/put_task_struct() and related APIs from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:40 +01:00
parisc Merge branch 'parisc-4.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2017-03-03 16:20:06 -08:00
parport sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
pci pci-v4.11-fixes-1 2017-03-03 16:44:21 -08:00
pcmcia
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perf sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h> 2017-03-02 08:42:27 +01:00
phy pci-v4.11-changes 2017-02-23 11:53:22 -08:00
pinctrl scripts/spelling.txt: add "overrided" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
platform sched/headers: Prepare for new header dependencies before moving code to <linux/sched/loadavg.h> 2017-03-02 08:42:27 +01:00
pnp
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power scripts/spelling.txt: add "intialization" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
powercap
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pps
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ps3 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
ptp 4.11 is going to be a relatively large release for KVM, with a little over 2017-02-22 18:22:53 -08:00
pwm pwm: Changes for v4.11-rc1 2017-03-01 09:46:02 -08:00
rapidio rapidio: use get_user_pages_unlocked() 2017-02-27 18:43:45 -08:00
ras
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regulator regulator: Updates for v4.11 2017-02-20 17:23:57 -08:00
remoteproc virtio, vhost: optimizations, fixes 2017-03-02 13:53:13 -08:00
reset ARM: SoC driver updates 2017-02-23 15:57:04 -08:00
rpmsg virtio, vhost: optimizations, fixes 2017-03-02 13:53:13 -08:00
rtc sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
s390 Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
sbus
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scsi SCSI misc on 20170303 2017-03-03 21:36:56 -08:00
sfi
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sh
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sn
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soc sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
spi sched/headers: Prepare for new header dependencies before moving code to <uapi/linux/sched/types.h> 2017-03-02 08:42:27 +01:00
spmi
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ssb
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staging net: Work around lockdep limitation in sockets that use sockets 2017-03-09 18:23:27 -08:00
target Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
tc
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thermal sched/headers: Prepare for new header dependencies before moving code to <uapi/linux/sched/types.h> 2017-03-02 08:42:27 +01:00
thunderbolt
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tty sched/headers: Prepare to move the get_task_struct()/put_task_struct() and related APIs from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:40 +01:00
uio sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
usb Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
uwb
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vfio sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
vhost Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
video sched/headers: Remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-03 01:45:16 +01:00
virt
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virtio Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
vlynq
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vme
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w1 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
watchdog watchdog: retu: restore MFD dependency 2017-03-01 06:15:10 -08:00
xen sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h> 2017-03-02 08:42:31 +01:00
zorro
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Kconfig
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Makefile pci-v4.11-changes 2017-02-23 11:53:22 -08:00