android_kernel_oneplus_msm8998/drivers
Roland Dreier 5909ce545d IB/uverbs: Lock SRQ / CQ / PD objects in a consistent order
Since XRC support was added, the uverbs code has locked SRQ, CQ and PD
objects needed during QP and SRQ creation in different orders
depending on the the code path.  This leads to the (at least
theoretical) possibility of deadlock, and triggers the lockdep splat
below.

Fix this by making sure we always lock the SRQ first, then CQs and
finally the PD.

    ======================================================
    [ INFO: possible circular locking dependency detected ]
    3.4.0-rc5+ #34 Not tainted
    -------------------------------------------------------
    ibv_srq_pingpon/2484 is trying to acquire lock:
     (SRQ-uobj){+++++.}, at: [<ffffffffa00af51b>] idr_read_uobj+0x2f/0x4d [ib_uverbs]

    but task is already holding lock:
     (CQ-uobj){+++++.}, at: [<ffffffffa00af51b>] idr_read_uobj+0x2f/0x4d [ib_uverbs]

    which lock already depends on the new lock.

    the existing dependency chain (in reverse order) is:

    -> #2 (CQ-uobj){+++++.}:
           [<ffffffff81070fd0>] lock_acquire+0xbf/0xfe
           [<ffffffff81384f28>] down_read+0x34/0x43
           [<ffffffffa00af51b>] idr_read_uobj+0x2f/0x4d [ib_uverbs]
           [<ffffffffa00af542>] idr_read_obj+0x9/0x19 [ib_uverbs]
           [<ffffffffa00b16c3>] ib_uverbs_create_qp+0x180/0x684 [ib_uverbs]
           [<ffffffffa00ae3dd>] ib_uverbs_write+0xb7/0xc2 [ib_uverbs]
           [<ffffffff810fe47f>] vfs_write+0xa7/0xee
           [<ffffffff810fe65f>] sys_write+0x45/0x69
           [<ffffffff8138cdf9>] system_call_fastpath+0x16/0x1b

    -> #1 (PD-uobj){++++++}:
           [<ffffffff81070fd0>] lock_acquire+0xbf/0xfe
           [<ffffffff81384f28>] down_read+0x34/0x43
           [<ffffffffa00af51b>] idr_read_uobj+0x2f/0x4d [ib_uverbs]
           [<ffffffffa00af542>] idr_read_obj+0x9/0x19 [ib_uverbs]
           [<ffffffffa00af8ad>] __uverbs_create_xsrq+0x96/0x386 [ib_uverbs]
           [<ffffffffa00b31b9>] ib_uverbs_detach_mcast+0x1cd/0x1e6 [ib_uverbs]
           [<ffffffffa00ae3dd>] ib_uverbs_write+0xb7/0xc2 [ib_uverbs]
           [<ffffffff810fe47f>] vfs_write+0xa7/0xee
           [<ffffffff810fe65f>] sys_write+0x45/0x69
           [<ffffffff8138cdf9>] system_call_fastpath+0x16/0x1b

    -> #0 (SRQ-uobj){+++++.}:
           [<ffffffff81070898>] __lock_acquire+0xa29/0xd06
           [<ffffffff81070fd0>] lock_acquire+0xbf/0xfe
           [<ffffffff81384f28>] down_read+0x34/0x43
           [<ffffffffa00af51b>] idr_read_uobj+0x2f/0x4d [ib_uverbs]
           [<ffffffffa00af542>] idr_read_obj+0x9/0x19 [ib_uverbs]
           [<ffffffffa00b1728>] ib_uverbs_create_qp+0x1e5/0x684 [ib_uverbs]
           [<ffffffffa00ae3dd>] ib_uverbs_write+0xb7/0xc2 [ib_uverbs]
           [<ffffffff810fe47f>] vfs_write+0xa7/0xee
           [<ffffffff810fe65f>] sys_write+0x45/0x69
           [<ffffffff8138cdf9>] system_call_fastpath+0x16/0x1b

    other info that might help us debug this:

    Chain exists of:
      SRQ-uobj --> PD-uobj --> CQ-uobj

     Possible unsafe locking scenario:

           CPU0                    CPU1
           ----                    ----
      lock(CQ-uobj);
                                   lock(PD-uobj);
                                   lock(CQ-uobj);
      lock(SRQ-uobj);

     *** DEADLOCK ***

    3 locks held by ibv_srq_pingpon/2484:
     #0:  (QP-uobj){+.+...}, at: [<ffffffffa00b162c>] ib_uverbs_create_qp+0xe9/0x684 [ib_uverbs]
     #1:  (PD-uobj){++++++}, at: [<ffffffffa00af51b>] idr_read_uobj+0x2f/0x4d [ib_uverbs]
     #2:  (CQ-uobj){+++++.}, at: [<ffffffffa00af51b>] idr_read_uobj+0x2f/0x4d [ib_uverbs]

    stack backtrace:
    Pid: 2484, comm: ibv_srq_pingpon Not tainted 3.4.0-rc5+ #34
    Call Trace:
     [<ffffffff8137eff0>] print_circular_bug+0x1f8/0x209
     [<ffffffff81070898>] __lock_acquire+0xa29/0xd06
     [<ffffffffa00af37c>] ? __idr_get_uobj+0x20/0x5e [ib_uverbs]
     [<ffffffffa00af51b>] ? idr_read_uobj+0x2f/0x4d [ib_uverbs]
     [<ffffffff81070fd0>] lock_acquire+0xbf/0xfe
     [<ffffffffa00af51b>] ? idr_read_uobj+0x2f/0x4d [ib_uverbs]
     [<ffffffff81070eee>] ? lock_release+0x166/0x189
     [<ffffffff81384f28>] down_read+0x34/0x43
     [<ffffffffa00af51b>] ? idr_read_uobj+0x2f/0x4d [ib_uverbs]
     [<ffffffffa00af51b>] idr_read_uobj+0x2f/0x4d [ib_uverbs]
     [<ffffffffa00af542>] idr_read_obj+0x9/0x19 [ib_uverbs]
     [<ffffffffa00b1728>] ib_uverbs_create_qp+0x1e5/0x684 [ib_uverbs]
     [<ffffffff81070fec>] ? lock_acquire+0xdb/0xfe
     [<ffffffff81070c09>] ? lock_release_non_nested+0x94/0x213
     [<ffffffff810d470f>] ? might_fault+0x40/0x90
     [<ffffffff810d470f>] ? might_fault+0x40/0x90
     [<ffffffffa00ae3dd>] ib_uverbs_write+0xb7/0xc2 [ib_uverbs]
     [<ffffffff810fe47f>] vfs_write+0xa7/0xee
     [<ffffffff810ff736>] ? fget_light+0x3b/0x99
     [<ffffffff810fe65f>] sys_write+0x45/0x69
     [<ffffffff8138cdf9>] system_call_fastpath+0x16/0x1b

Reported-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-05-08 11:17:34 -07:00
..
accessibility
acpi Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-05-05 10:06:06 -07:00
amba ARM: 7366/3: amba: Remove AMBA level regulator support 2012-04-13 14:04:08 +01:00
ata Change summary: 2012-05-03 17:16:52 -07:00
atm
auxdisplay
base drivers/base: fix compiler warning in SoC export driver - idr should be ida 2012-04-09 14:54:22 -07:00
bcma bcma: use fallback sprom if no on chip sprom is available 2012-04-16 13:32:01 -04:00
block Fixes in various components: 2012-04-20 11:31:00 -07:00
bluetooth Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth 2012-04-27 15:16:43 -04:00
cdrom
char tty and serial fixes for 3.4-rc2 2012-04-12 15:36:33 -07:00
clk
clocksource Revert "clocksource: Load the ACPI PM clocksource asynchronously" 2012-04-12 00:05:05 +02:00
connector
cpufreq cpufreq: OMAP: fix build errors: depends on ARCH_OMAP2PLUS 2012-04-13 17:57:40 -07:00
cpuidle Merge branches 'idle-fix' and 'misc' into release 2012-04-06 21:48:59 -04:00
crypto crypto: talitos - properly lock access to global talitos registers 2012-04-09 15:13:40 +08:00
dca
devfreq
dio
dma Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma 2012-04-26 15:33:36 -07:00
edac Merge branch 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2012-04-06 17:56:20 -07:00
eisa
firewire
firmware efivars: Improve variable validation 2012-05-03 17:19:19 -07:00
gpio ARM: pxa: fix gpio wakeup setting 2012-04-27 10:46:45 +08:00
gpu drm/radeon: clarify and extend wb setup on APUs and NI+ asics 2012-05-04 09:36:11 +01:00
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2012-04-20 10:39:33 -07:00
hsi HSI: hsi_char: Remove max_data_size from sysfs 2012-04-23 14:23:32 +03:00
hv
hwmon hwmon: (coretemp) Increase CPU core limit 2012-05-01 09:16:14 -07:00
hwspinlock
i2c i2c: mxs: disable QUEUE when sending is done 2012-04-27 16:13:29 +02:00
ide
idle simple_open: automatically convert to simple_open() 2012-04-05 15:25:50 -07:00
ieee802154
infiniband IB/uverbs: Lock SRQ / CQ / PD objects in a consistent order 2012-05-08 11:17:34 -07:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2012-04-30 10:13:48 -07:00
iommu Merge branch 'akpm' (Andrew's patch-bomb) 2012-04-05 15:30:34 -07:00
isdn tty and serial fixes for 3.4-rc2 2012-04-12 15:36:33 -07:00
leds leds-atmel-pwm.c: Make pwmled_probe() __devinit 2012-04-17 16:29:31 +02:00
lguest
macintosh
mca
md md/bitmap: fix calculation of 'chunks' - missing shift. 2012-05-04 17:03:18 +10:00
media Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-04-21 12:43:23 -07:00
memstick
message
mfd mfd: Fix build breakage in omap-usb-host.c 2012-05-01 11:55:04 +02:00
misc Merge branch 'akpm' (Andrew's patch-bomb) 2012-04-05 15:30:34 -07:00
mmc Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma 2012-04-26 15:33:36 -07:00
mtd Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma 2012-04-26 15:33:36 -07:00
net sungem: Fix WakeOnLan 2012-05-03 01:42:55 -04:00
nfc
nubus
of gpio: Fix range check in of_gpio_simple_xlate() 2012-04-10 14:20:56 -06:00
oprofile simple_open: automatically convert to simple_open() 2012-04-05 15:25:50 -07:00
parisc
parport
pci Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-05-05 10:06:06 -07:00
pcmcia Merge git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia 2012-03-29 16:00:48 -07:00
pinctrl pinctrl: implement pinctrl_check_ops 2012-04-11 09:31:02 +02:00
platform Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-05-06 12:19:38 -07:00
pnp Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-03-30 16:45:39 -07:00
power Various small bugfixes and enhancements, plus two new drivers: 2012-03-30 16:09:02 -07:00
pps
ps3
ptp
rapidio
regulator regulator: Fix a build warning in the anatop driver for 3.4 2012-04-10 10:26:41 -07:00
remoteproc simple_open: automatically convert to simple_open() 2012-04-05 15:25:50 -07:00
rpmsg
rtc Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-05-04 15:35:09 -07:00
s390 qeth: Use blkt defaults for OSA Express 4 2012-04-24 00:33:17 -04:00
sbus
scsi [SCSI] libfc: update mfs boundry checking 2012-04-25 08:46:29 +01:00
sfi
sh SuperH updates for 3.4 merge window 2012-03-30 00:09:17 -07:00
sn
spi spi/spi-bfin5xx: Fix flush of last bit after each spi transfer 2012-04-27 12:20:39 -06:00
ssb
staging staging: ozwpan: Fix bug where kfree is called twice. 2012-04-26 12:40:53 -07:00
target tcm_fc: Do not free tpg structure during wq allocation failure 2012-04-06 18:57:05 -07:00
tc
thermal
tty TTY fix for 3.4-rc5 2012-05-02 13:47:49 -07:00
uio
usb USB: ehci-tegra: remove redundant gpio_set_value 2012-05-01 14:11:51 -04:00
uwb uwb: fix error handling 2012-04-18 13:15:51 -07:00
vhost Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-04-22 21:02:57 -07:00
video blackfin: fix compile error in bfin-lq035q1-fb.c 2012-04-26 14:46:51 -04:00
virt
virtio virtio_balloon: fix handling of PAGE_SIZE != 4k 2012-04-15 11:51:06 +03:00
vlynq
w1
watchdog hpwdt: Only BYTE reads/writes to WD Timer port 0x72 2012-04-26 14:38:07 +02:00
xen xen/acpi: Workaround broken BIOSes exporting non-existing C-states. 2012-04-26 22:07:28 -04:00
zorro
Kconfig Merge branch 'for-next' of git://gitorious.org/kernel-hsi/kernel-hsi 2012-04-02 09:50:40 -07:00
Makefile Merge branch 'for-next' of git://gitorious.org/kernel-hsi/kernel-hsi 2012-04-02 09:50:40 -07:00