Re: [IPV6]: Audit all ip6_dst_lookup/ip6_dst_store calls

From: Matt Domsch
Date: Mon Jul 31 2006 - 00:23:50 EST


On Sun, Jul 30, 2006 at 10:32:10PM -0500, Matt Domsch wrote:
> On Sun, Jul 30, 2006 at 03:44:16PM -0700, David Miller wrote:
> > From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> > Date: Sat, 29 Jul 2006 14:33:25 +1000
> >
> > > [IPV6]: Audit all ip6_dst_lookup/ip6_dst_store calls
> > >
> > > The current users of ip6_dst_lookup can be divided into two classes:
> > >
> > > 1) The caller holds no locks and is in user-context (UDP).
> > > 2) The caller does not want to lookup the dst cache at all.
> > >
> > > The second class covers everyone except UDP because most people do
> > > the cache lookup directly before calling ip6_dst_lookup. This patch
> > > adds ip6_sk_dst_lookup for the first class.
> > >
> > > Similarly ip6_dst_store users can be divded into those that need to
> > > take the socket dst lock and those that don't. This patch adds
> > > __ip6_dst_store for those (everyone except UDP/datagram) that don't
> > > need an extra lock.
> > >
> > > Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> >
> > Applied, thanks Herbert.
>
> I applied this on 2.6.18-rc3, and it panics immediately as the first
> IPv6 TCP (ssh) session is initiated to the system.

I backed out this patch, and get a somewhat different failure then
with 2.6.18-rc3 plain. The oops repeat continuously with <EOI> after
each. Again, this occurs as soon as I start an IPv6 ssh session.

--
Matt Domsch
Software Architect
Dell Linux Solutions linux.dell.com & www.dell.com/linux
Linux on Dell mailing lists @ http://lists.us.dell.com

Linux version 2.6.18-rc3 (mdomsch@xxxxxxxxxxxxxxxxxxxxx) (gcc version 4.1.1 20060721 (Red Hat 4.1.1-13)) #2 SMP Sun Jul 30 23:06:48 CDT 2006
=================================
[ INFO: inconsistent lock state ]
---------------------------------
inconsistent {softirq-on-W} -> {in-softirq-R} usage.
swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
(&sk->sk_dst_lock){---?}, at: [<ffffffff80415827>] sk_dst_check+0x26/0x113
{softirq-on-W} state was registered at:
[<ffffffff802a8231>] lock_acquire+0x4a/0x69
[<ffffffff802688a1>] _write_lock+0x24/0x31
[<ffffffff8044d9a4>] inet_bind+0x198/0x20b
[<ffffffff80412ed4>] sys_bind+0x75/0x9c
[<ffffffff8026144d>] system_call+0x7d/0x83
irq event stamp: 604084
hardirqs last enabled at (604084): [<ffffffff8020aab2>] kmem_cache_alloc+0xd3/0xf7
hardirqs last disabled at (604083): [<ffffffff8020aa2a>] kmem_cache_alloc+0x4b/0xf7
softirqs last enabled at (604026): [<ffffffff8021288d>] __do_softirq+0xec/0xf5
softirqs last disabled at (604029): [<ffffffff802626fa>] call_softirq+0x1e/0x28

other info that might help us debug this:
1 lock held by swapper/0:
#0: (slock-AF_INET6){-+..}, at: [<ffffffff883d91df>] tcp_v6_rcv+0x30e/0x76f [ipv6]

stack backtrace:

Call Trace:
[<ffffffff8026f861>] show_trace+0xae/0x30e
[<ffffffff8026fad6>] dump_stack+0x15/0x17
[<ffffffff802a634f>] print_usage_bug+0x259/0x26a
[<ffffffff802a6b38>] mark_lock+0x1d5/0x3db
[<ffffffff802a76b8>] __lock_acquire+0x412/0xa18
[<ffffffff802a8232>] lock_acquire+0x4b/0x69
[<ffffffff802689b8>] _read_lock+0x28/0x34
[<ffffffff80415827>] sk_dst_check+0x26/0x113
[<ffffffff883ba986>] :ipv6:ip6_dst_lookup+0x3a/0x192
[<ffffffff883d6c2f>] :ipv6:tcp_v6_send_synack+0x185/0x2e4
[<ffffffff883d7a5a>] :ipv6:tcp_v6_conn_request+0x291/0x2f3
[<ffffffff802455c2>] tcp_rcv_state_process+0x5f/0xe7c
[<ffffffff883d7015>] :ipv6:tcp_v6_do_rcv+0x268/0x372
[<ffffffff883d95f0>] :ipv6:tcp_v6_rcv+0x71f/0x76f
[<ffffffff883bc48f>] :ipv6:ip6_input+0x223/0x315
[<ffffffff883bcb3d>] :ipv6:ipv6_rcv+0x254/0x2af
[<ffffffff80221883>] netif_receive_skb+0x260/0x2dd
[<ffffffff88194292>] :e1000:e1000_clean_rx_irq+0x423/0x4c2
[<ffffffff88192752>] :e1000:e1000_clean+0x88/0x17d
[<ffffffff8020caed>] net_rx_action+0xac/0x1d1
[<ffffffff80212809>] __do_softirq+0x68/0xf5
[<ffffffff802626fa>] call_softirq+0x1e/0x28
DWARF2 unwinder stuck at call_softirq+0x1e/0x28
Leftover inexact backtrace:
<IRQ> [<ffffffff80270b48>] do_softirq+0x39/0x9f
[<ffffffff802960b6>] irq_exit+0x57/0x59
[<ffffffff80270cab>] do_IRQ+0xfd/0x107
[<ffffffff8025b612>] mwait_idle+0x0/0x54
[<ffffffff80261985>] ret_from_intr+0x0/0xf
<EOI>

<1>Unable to handle kernel paging request at ffffffff82800000 RIP:
[<ffffffff8026fa5c>] show_trace+0x2a9/0x30e
PGD 203027 PUD 205027 PMD 0
Oops: 0000 [1] SMP
CPU 0
Modules linked in: ipv6 ipmi_devintf ipmi_si ipmi_msghandler hidp rfcomm l2cap bluetooth sunrpc ip_conntrack_netbios_ns ipt_REJECT xt_state ip_conntrack nfnetlink xt_tcpudp iptable_filter ip_tables x_tables acpi_cpufreq video sbs i2c_ec i2c_core button battery asus_acpi ac parport_pc lp parport intel_rng e1000 sg ehci_hcd ide_cd cdrom pcspkr serio_raw e752x_edac edac_mc uhci_hcd dm_snapshot dm_zero dm_mirror dm_mod ext3 jbd ata_piix libata sd_mod scsi_mod
Pid: 0, comm: swapper Not tainted 2.6.18-rc3 #2
RIP: 0010:[<ffffffff8026fa5c>] [<ffffffff8026fa5c>] show_trace+0x2a9/0x30e
RSP: 0018:ffffffff8066a850 EFLAGS: 00010002
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000a4ec
RDX: ffffffff80561e60 RSI: 0000000000000000 RDI: ffffffff8056e020
RBP: ffffffff8066a940 R08: ffffffff8066a5a0 R09: ffffffff802abf75
R10: ffffffff802abf75 R11: 0000000000000000 R12: ffffffff827ffffd
R13: ffffffff8066a860 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffffffff80922000(0000) knlGS:0000000000000000
CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: ffffffff82800000 CR3: 0000000072e0b000 CR4: 00000000000006e0
Process swapper (pid: 0, threadinfo ffffffff80952000, task ffffffff80561e60)
Stack: ffffffff8066a860 0000000080725708 0000000000000000 0000000000000000
0000000000000000 ffffffff80953ec8 ffffffff8066af80 0000000000000046
0000000000000000 0000000000000000 0000000000000000 0000000000000000
Call Trace:
[<ffffffff8026fad6>] dump_stack+0x15/0x17
[<ffffffff802a634f>] print_usage_bug+0x259/0x26a
[<ffffffff802a6b38>] mark_lock+0x1d5/0x3db
[<ffffffff802a76b8>] __lock_acquire+0x412/0xa18
[<ffffffff802a8232>] lock_acquire+0x4b/0x69
[<ffffffff802689b8>] _read_lock+0x28/0x34
[<ffffffff80415827>] sk_dst_check+0x26/0x113
[<ffffffff883ba986>] :ipv6:ip6_dst_lookup+0x3a/0x192
[<ffffffff883d6c2f>] :ipv6:tcp_v6_send_synack+0x185/0x2e4
[<ffffffff883d7a5a>] :ipv6:tcp_v6_conn_request+0x291/0x2f3
[<ffffffff802455c2>] tcp_rcv_state_process+0x5f/0xe7c
[<ffffffff883d7015>] :ipv6:tcp_v6_do_rcv+0x268/0x372
[<ffffffff883d95f0>] :ipv6:tcp_v6_rcv+0x71f/0x76f
[<ffffffff883bc48f>] :ipv6:ip6_input+0x223/0x315
[<ffffffff883bcb3d>] :ipv6:ipv6_rcv+0x254/0x2af
[<ffffffff80221883>] netif_receive_skb+0x260/0x2dd
[<ffffffff88194292>] :e1000:e1000_clean_rx_irq+0x423/0x4c2
[<ffffffff88192752>] :e1000:e1000_clean+0x88/0x17d
[<ffffffff8020caed>] net_rx_action+0xac/0x1d1
[<ffffffff80212809>] __do_softirq+0x68/0xf5
[<ffffffff802626fa>] call_softirq+0x1e/0x28
DWARF2 unwinder stuck at call_softirq+0x1e/0x28
Leftover inexact backtrace:
<IRQ> [<ffffffff80270b48>] do_softirq+0x39/0x9f
[<ffffffff802960b6>] irq_exit+0x57/0x59
[<ffffffff80270cab>] do_IRQ+0xfd/0x107
[<ffffffff8025b612>] mwait_idle+0x0/0x54
[<ffffffff80261985>] ret_from_intr+0x0/0xf
<EOI>
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