Nikolay Aleksandrov 18041e3174 vrf: vrf_master_ifindex_rcu is not always called with rcu read lock ... While running net-next I hit this: [ 634.073119] =============================== [ 634.073150] [ INFO: suspicious RCU usage. ] [ 634.073182] 4.2.0-rc6+ #45 Not tainted [ 634.073213] ------------------------------- [ 634.073244] include/net/vrf.h:38 suspicious rcu_dereference_check() usage! [ 634.073274] other info that might help us debug this: [ 634.073307] rcu_scheduler_active = 1, debug_locks = 1 [ 634.073338] 2 locks held by swapper/0/0: [ 634.073369] #0: (((&n->timer))){+.-...}, at: [<ffffffff8112bc35>] call_timer_fn+0x5/0x480 [ 634.073412] #1: (slock-AF_INET){+.-...}, at: [<ffffffff8174f0f5>] icmp_send+0x155/0x5f0 [ 634.073450] stack backtrace: [ 634.073483] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.2.0-rc6+ #45 [ 634.073514] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 634.073545] 0000000000000000 0593ba8242d9ace4 ffff88002fc03b48 ffffffff81803f1b [ 634.073612] 0000000000000000 ffffffff81e12500 ffff88002fc03b78 ffffffff811003c5 [ 634.073642] 0000000000000000 ffff88002ec4e600 ffffffff81f00f80 ffff88002fc03cf0 [ 634.073669] Call Trace: [ 634.073694] <IRQ> [<ffffffff81803f1b>] dump_stack+0x4c/0x65 [ 634.073728] [<ffffffff811003c5>] lockdep_rcu_suspicious+0xc5/0x100 [ 634.073763] [<ffffffff8174eb56>] icmp_route_lookup+0x176/0x5c0 [ 634.073793] [<ffffffff8174f2fb>] ? icmp_send+0x35b/0x5f0 [ 634.073818] [<ffffffff8174f274>] ? icmp_send+0x2d4/0x5f0 [ 634.073844] [<ffffffff8174f3ce>] icmp_send+0x42e/0x5f0 [ 634.073873] [<ffffffff8170b662>] ipv4_link_failure+0x22/0xa0 [ 634.073899] [<ffffffff8174bdda>] arp_error_report+0x3a/0x80 [ 634.073926] [<ffffffff816d6100>] ? neigh_lookup+0x2c0/0x2c0 [ 634.073952] [<ffffffff816d396e>] neigh_invalidate+0x8e/0x110 [ 634.073984] [<ffffffff816d62ae>] neigh_timer_handler+0x1ae/0x290 [ 634.074013] [<ffffffff816d6100>] ? neigh_lookup+0x2c0/0x2c0 [ 634.074013] [<ffffffff8112bce3>] call_timer_fn+0xb3/0x480 [ 634.074013] [<ffffffff8112bc35>] ? call_timer_fn+0x5/0x480 [ 634.074013] [<ffffffff816d6100>] ? neigh_lookup+0x2c0/0x2c0 [ 634.074013] [<ffffffff8112c2bc>] run_timer_softirq+0x20c/0x430 [ 634.074013] [<ffffffff810af50e>] __do_softirq+0xde/0x630 [ 634.074013] [<ffffffff810afc97>] irq_exit+0x117/0x120 [ 634.074013] [<ffffffff81810976>] smp_apic_timer_interrupt+0x46/0x60 [ 634.074013] [<ffffffff8180e950>] apic_timer_interrupt+0x70/0x80 [ 634.074013] <EOI> [<ffffffff8106b9d6>] ? native_safe_halt+0x6/0x10 [ 634.074013] [<ffffffff81101d8d>] ? trace_hardirqs_on+0xd/0x10 [ 634.074013] [<ffffffff81027d43>] default_idle+0x23/0x200 [ 634.074013] [<ffffffff8102852f>] arch_cpu_idle+0xf/0x20 [ 634.074013] [<ffffffff810f89ba>] default_idle_call+0x2a/0x40 [ 634.074013] [<ffffffff810f8dcc>] cpu_startup_entry+0x39c/0x4c0 [ 634.074013] [<ffffffff817f9cad>] rest_init+0x13d/0x150 [ 634.074013] [<ffffffff81f69038>] start_kernel+0x4a8/0x4c9 [ 634.074013] [<ffffffff81f68120>] ? early_idt_handler_array+0x120/0x120 [ 634.074013] [<ffffffff81f68339>] x86_64_start_reservations+0x2a/0x2c [ 634.074013] [<ffffffff81f68485>] x86_64_start_kernel+0x14a/0x16d It would seem vrf_master_ifindex_rcu() can be called without RCU held in other contexts as well so introduce a new helper which acquires rcu and returns the ifindex. Also add curly braces around both the "if" and "else" parts as per the style guide. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2015-08-19 22:13:20 -07:00
..
acpi	Additional ACPICA material for v4.2-rc1	2015-07-02 17:11:28 -07:00
asm-generic	mm: clean up per architecture MM hook header files	2015-07-17 16:39:53 -07:00
clocksource
crypto	crypto: rng - Do not free default RNG when it becomes unused	2015-06-22 15:49:18 +08:00
drm	drm/radeon: add new OLAND pci id	2015-08-12 12:24:05 -04:00
dt-bindings	The changes to the common clock framework for 4.2 are dominated by new	2015-07-01 19:22:00 -07:00
keys
kvm
linux	net: Fix docbook warning for IFF_VRF_MASTER enum	2015-08-17 15:56:35 -07:00
math-emu
media	Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds	2015-07-01 19:09:11 -07:00
memory
misc
net	vrf: vrf_master_ifindex_rcu is not always called with rcu read lock	2015-08-19 22:13:20 -07:00
pcmcia
ras	tracing: add trace event for memory-failure	2015-06-24 17:49:43 -07:00
rdma	IB: Add rdma_cap_ib_switch helper and use where appropriate	2015-07-14 13:20:08 -04:00
rxrpc
scsi	IB/srp: Avoid using uninitialized variable	2015-07-14 13:20:09 -04:00
soc	Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm	2015-06-26 12:20:00 -07:00
sound	ASoC: Further updates for v4.2	2015-06-22 11:32:41 +02:00
target	iscsi-target: Fix iscsit_start_kthreads failure OOPs	2015-07-24 14:19:43 -07:00
trace	Merge branch 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs	2015-06-30 20:07:45 -07:00
uapi	net: Identifier Locator Addressing module	2015-08-17 21:33:06 -07:00
video	Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux	2015-06-26 13:18:51 -07:00
xen
Kbuild