linux_dsm_epyc7002/include
Eric Dumazet 2695578b89 net: usbnet: fix potential deadlock on 32bit hosts
Marek reported a LOCKDEP issue occurring on 32bit host,
that we tracked down to the fact that usbnet could either
run from soft or hard irqs.

This patch adds u64_stats_update_begin_irqsave() and
u64_stats_update_end_irqrestore() helpers to solve this case.

[   17.768040] ================================
[   17.772239] WARNING: inconsistent lock state
[   17.776511] 4.16.0-rc3-next-20180227-00007-g876c53a7493c #453 Not tainted
[   17.783329] --------------------------------
[   17.787580] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
[   17.793607] swapper/0/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
[   17.798751]  (&syncp->seq#5){?.-.}, at: [<9b22e5f0>]
asix_rx_fixup_internal+0x188/0x288
[   17.806790] {IN-HARDIRQ-W} state was registered at:
[   17.811677]   tx_complete+0x100/0x208
[   17.815319]   __usb_hcd_giveback_urb+0x60/0xf0
[   17.819770]   xhci_giveback_urb_in_irq+0xa8/0x240
[   17.824469]   xhci_td_cleanup+0xf4/0x16c
[   17.828367]   xhci_irq+0xe74/0x2240
[   17.831827]   usb_hcd_irq+0x24/0x38
[   17.835343]   __handle_irq_event_percpu+0x98/0x510
[   17.840111]   handle_irq_event_percpu+0x1c/0x58
[   17.844623]   handle_irq_event+0x38/0x5c
[   17.848519]   handle_fasteoi_irq+0xa4/0x138
[   17.852681]   generic_handle_irq+0x18/0x28
[   17.856760]   __handle_domain_irq+0x6c/0xe4
[   17.860941]   gic_handle_irq+0x54/0xa0
[   17.864666]   __irq_svc+0x70/0xb0
[   17.867964]   arch_cpu_idle+0x20/0x3c
[   17.871578]   arch_cpu_idle+0x20/0x3c
[   17.875190]   do_idle+0x144/0x218
[   17.878468]   cpu_startup_entry+0x18/0x1c
[   17.882454]   start_kernel+0x394/0x400
[   17.886177] irq event stamp: 161912
[   17.889616] hardirqs last  enabled at (161912): [<7bedfacf>]
__netdev_alloc_skb+0xcc/0x140
[   17.897893] hardirqs last disabled at (161911): [<d58261d0>]
__netdev_alloc_skb+0x94/0x140
[   17.904903] exynos5-hsi2c 12ca0000.i2c: tx timeout
[   17.906116] softirqs last  enabled at (161904): [<387102ff>]
irq_enter+0x78/0x80
[   17.906123] softirqs last disabled at (161905): [<cf4c628e>]
irq_exit+0x134/0x158
[   17.925722].
[   17.925722] other info that might help us debug this:
[   17.933435]  Possible unsafe locking scenario:
[   17.933435].
[   17.940331]        CPU0
[   17.942488]        ----
[   17.944894]   lock(&syncp->seq#5);
[   17.948274]   <Interrupt>
[   17.950847]     lock(&syncp->seq#5);
[   17.954386].
[   17.954386]  *** DEADLOCK ***
[   17.954386].
[   17.962422] no locks held by swapper/0/0.

Fixes: c8b5d129ee ("net: usbnet: support 64bit stats")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-07 11:46:39 -05:00
..
acpi ACPICA: Update version to 20180105 2018-02-06 10:32:13 +01:00
asm-generic bug.h: work around GCC PR82365 in BUG() 2018-02-21 15:35:43 -08:00
clocksource
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-01-31 14:22:45 -08:00
drm drm/nouveau: prefer XBGR2101010 for addfb ioctl 2018-02-23 13:51:42 +01:00
dt-bindings MIPS changes for 4.16 2018-02-07 11:22:44 -08:00
keys
kvm KVM changes for 4.16 2018-02-10 13:16:35 -08:00
linux net: usbnet: fix potential deadlock on 32bit hosts 2018-03-07 11:46:39 -05:00
math-emu
media media: dvb: update buffer mmaped flags and frame counter 2018-02-23 11:44:08 -05:00
memory
misc powerpc updates for 4.16 2018-02-02 10:01:04 -08:00
net sch_netem: fix skb leak in netem_enqueue() 2018-03-07 11:18:14 -05:00
pcmcia
ras
rdma IB/uverbs: Use u64_to_user_ptr() not a union 2018-02-15 14:59:45 -07:00
scsi SCSI postmerge on 20180202 2018-02-03 13:07:56 -08:00
soc ARC fixes for 4.16-rc4 2018-03-01 14:32:23 -08:00
sound Merge branch 'topic/fixes' into for-linus 2018-02-12 09:36:26 +01:00
target
trace Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-02-14 17:02:15 -08:00
uapi media fixes for v4.16-rc4 2018-03-03 10:27:14 -08:00
video fbdev changes for v4.16: 2018-02-07 13:10:43 -08:00
xen