linux-toradex.git/net, branch v3.2.27

drop_monitor: dont sleep in atomic context

2012-08-09T23:25:17+00:00

commit bec4596b4e6770c7037f21f6bd27567b152dc0d6 upstream.

drop_monitor calls several sleeping functions while in atomic context.

 BUG: sleeping function called from invalid context at mm/slub.c:943
 in_atomic(): 1, irqs_disabled(): 0, pid: 2103, name: kworker/0:2
 Pid: 2103, comm: kworker/0:2 Not tainted 3.5.0-rc1+ #55
 Call Trace:
  [] __might_sleep+0xca/0xf0
  [] kmem_cache_alloc_node+0x1b3/0x1c0
  [] ? queue_delayed_work_on+0x11c/0x130
  [] __alloc_skb+0x4b/0x230
  [] ? reset_per_cpu_data+0x160/0x160 [drop_monitor]
  [] reset_per_cpu_data+0x2f/0x160 [drop_monitor]
  [] send_dm_alert+0x4b/0xb0 [drop_monitor]
  [] process_one_work+0x130/0x4c0
  [] worker_thread+0x159/0x360
  [] ? manage_workers.isra.27+0x240/0x240
  [] kthread+0x93/0xa0
  [] kernel_thread_helper+0x4/0x10
  [] ? kthread_freezable_should_stop+0x80/0x80
  [] ? gs_change+0xb/0xb

Rework the logic to call the sleeping functions in right context.

Use standard timer/workqueue api to let system chose any cpu to perform
the allocation and netlink send.

Also avoid a loop if reset_per_cpu_data() cannot allocate memory :
use mod_timer() to wait 1/10 second before next try.

Signed-off-by: Eric Dumazet 
Cc: Neil Horman 
Reviewed-by: Neil Horman 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

drop_monitor: prevent init path from scheduling on the wrong cpu

2012-08-09T23:25:16+00:00

commit 4fdcfa12843bca38d0c9deff70c8720e4e8f515f upstream.

I just noticed after some recent updates, that the init path for the drop
monitor protocol has a minor error.  drop monitor maintains a per cpu structure,
that gets initalized from a single cpu.  Normally this is fine, as the protocol
isn't in use yet, but I recently made a change that causes a failed skb
allocation to reschedule itself .  Given the current code, the implication is
that this workqueue reschedule will take place on the wrong cpu.  If drop
monitor is used early during the boot process, its possible that two cpus will
access a single per-cpu structure in parallel, possibly leading to data
corruption.

This patch fixes the situation, by storing the cpu number that a given instance
of this per-cpu data should be accessed from.  In the case of a need for a
reschedule, the cpu stored in the struct is assigned the rescheule, rather than
the currently executing cpu

Tested successfully by myself.

Signed-off-by: Neil Horman 
CC: David Miller 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

drop_monitor: Make updating data->skb smp safe

2012-08-09T23:25:15+00:00

commit 3885ca785a3618593226687ced84f3f336dc3860 upstream.

Eric Dumazet pointed out to me that the drop_monitor protocol has some holes in
its smp protections.  Specifically, its possible to replace data->skb while its
being written.  This patch corrects that by making data->skb an rcu protected
variable.  That will prevent it from being overwritten while a tracepoint is
modifying it.

Signed-off-by: Neil Horman 
Reported-by: Eric Dumazet 
CC: David Miller 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

drop_monitor: fix sleeping in invalid context warning

2012-08-09T23:25:15+00:00

commit cde2e9a651b76d8db36ae94cd0febc82b637e5dd upstream.

Eric Dumazet pointed out this warning in the drop_monitor protocol to me:

[   38.352571] BUG: sleeping function called from invalid context at kernel/mutex.c:85
[   38.352576] in_atomic(): 1, irqs_disabled(): 0, pid: 4415, name: dropwatch
[   38.352580] Pid: 4415, comm: dropwatch Not tainted 3.4.0-rc2+ #71
[   38.352582] Call Trace:
[   38.352592]  [] ? trace_napi_poll_hit+0xd0/0xd0
[   38.352599]  [] __might_sleep+0xca/0xf0
[   38.352606]  [] mutex_lock+0x26/0x50
[   38.352610]  [] ? trace_napi_poll_hit+0xd0/0xd0
[   38.352616]  [] tracepoint_probe_register+0x29/0x90
[   38.352621]  [] set_all_monitor_traces+0x105/0x170
[   38.352625]  [] net_dm_cmd_trace+0x2a/0x40
[   38.352630]  [] genl_rcv_msg+0x21a/0x2b0
[   38.352636]  [] ? zone_statistics+0x99/0xc0
[   38.352640]  [] ? genl_rcv+0x30/0x30
[   38.352645]  [] netlink_rcv_skb+0xa9/0xd0
[   38.352649]  [] genl_rcv+0x20/0x30
[   38.352653]  [] netlink_unicast+0x1ae/0x1f0
[   38.352658]  [] netlink_sendmsg+0x2b6/0x310
[   38.352663]  [] sock_sendmsg+0x10f/0x130
[   38.352668]  [] ? move_addr_to_kernel+0x60/0xb0
[   38.352673]  [] ? verify_iovec+0x64/0xe0
[   38.352677]  [] __sys_sendmsg+0x386/0x390
[   38.352682]  [] ? handle_mm_fault+0x139/0x210
[   38.352687]  [] ? do_page_fault+0x1ec/0x4f0
[   38.352693]  [] ? set_next_entity+0x9d/0xb0
[   38.352699]  [] ? tty_ldisc_deref+0x9/0x10
[   38.352703]  [] ? pick_next_task_fair+0x63/0x140
[   38.352708]  [] sys_sendmsg+0x44/0x80
[   38.352713]  [] system_call_fastpath+0x16/0x1b

It stems from holding a spinlock (trace_state_lock) while attempting to register
or unregister tracepoint hooks, making in_atomic() true in this context, leading
to the warning when the tracepoint calls might_sleep() while its taking a mutex.
Since we only use the trace_state_lock to prevent trace protocol state races, as
well as hardware stat list updates on an rcu write side, we can just convert the
spinlock to a mutex to avoid this problem.

Signed-off-by: Neil Horman 
Reported-by: Eric Dumazet 
CC: David Miller 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

SUNRPC: return negative value in case rpcbind client creation error

2012-08-09T23:25:02+00:00

commit caea33da898e4e14f0ba58173e3b7689981d2c0b upstream.

Without this patch kernel will panic on LockD start, because lockd_up() checks
lockd_up_net() result for negative value.
From my pow it's better to return negative value from rpcbind routines instead
of replacing all such checks like in lockd_up().

Signed-off-by: Stanislav Kinsbursky 
Signed-off-by: Trond Myklebust 
Signed-off-by: Ben Hutchings

nfs: skip commit in releasepage if we're freeing memory for fs-related reasons

2012-08-09T23:24:59+00:00

commit 5cf02d09b50b1ee1c2d536c9cf64af5a7d433f56 upstream.

We've had some reports of a deadlock where rpciod ends up with a stack
trace like this:

    PID: 2507   TASK: ffff88103691ab40  CPU: 14  COMMAND: "rpciod/14"
     #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9
     #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs]
     #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f
     #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8
     #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs]
     #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs]
     #6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670
     #7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271
     #8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638
     #9 [ffff8810343bf818] shrink_zone at ffffffff8112788f
    #10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e
    #11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f
    #12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad
    #13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942
    #14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a
    #15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9
    #16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b
    #17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808
    #18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c
    #19 [ffff8810343bfce8] inet_create at ffffffff81483ba6
    #20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7
    #21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc]
    #22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc]
    #23 [ffff8810343bfe38] worker_thread at ffffffff810887d0
    #24 [ffff8810343bfee8] kthread at ffffffff8108dd96
    #25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca

rpciod is trying to allocate memory for a new socket to talk to the
server. The VM ends up calling ->releasepage to get more memory, and it
tries to do a blocking commit. That commit can't succeed however without
a connected socket, so we deadlock.

Fix this by setting PF_FSTRANS on the workqueue task prior to doing the
socket allocation, and having nfs_release_page check for that flag when
deciding whether to do a commit call. Also, set PF_FSTRANS
unconditionally in rpc_async_schedule since that function can also do
allocations sometimes.

Signed-off-by: Jeff Layton 
Signed-off-by: Trond Myklebust 
Signed-off-by: Ben Hutchings

net: feed /dev/random with the MAC address when registering a device

2012-08-09T23:24:44+00:00

commit 7bf2357524408b97fec58344caf7397f8140c3fd upstream.

Cc: David Miller 
Cc: Linus Torvalds 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Ben Hutchings

cfg80211: fix interface combinations check for ADHOC(IBSS)

2012-08-09T23:24:37+00:00

partial of commit 8e8b41f9d8c8e63fc92f899ace8da91a490ac573 upstream.

As part of commit 463454b5dbd8 ("cfg80211: fix interface
combinations check"), this extra check was introduced:

       if ((all_iftypes & used_iftypes) != used_iftypes)
               goto cont;

However, most wireless NIC drivers did not advertise ADHOC in
wiphy.iface_combinations[i].limits[] and hence we'll get -EBUSY
when we bring up a ADHOC wlan with commands similar to:

 # iwconfig wlan0 mode ad-hoc && ifconfig wlan0 up

In commit 8e8b41f9d8c8e ("cfg80211: enforce lack of interface
combinations"), the change below fixes the issue:

       if (total == 1)
               return 0;

But it also introduces other dependencies for stable. For example,
a full cherry pick of 8e8b41f9d8c8e would introduce additional
regressions unless we also start cherry picking driver specific
fixes like the following:

  9b4760e  ath5k: add possible wiphy interface combinations
  1ae2fc2  mac80211_hwsim: advertise interface combinations
  20c8e8d  ath9k: add possible wiphy interface combinations

And the purpose of the 'if (total == 1)' is to cover the specific
use case (IBSS, adhoc) that was mentioned above. So we just pick
the specific part out from 8e8b41f9d8c8e here.

Doing so gives stable kernels a way to fix the change introduced
by 463454b5dbd8, without having to make cherry picks specific to
various NIC drivers.

Signed-off-by: Liang Li 
Signed-off-by: Paul Gortmaker 
Signed-off-by: Ben Hutchings

net: remove skb_orphan_try()

2012-07-25T03:11:40+00:00

commit 62b1a8ab9b3660bb820d8dfe23148ed6cda38574 upstream.

Orphaning skb in dev_hard_start_xmit() makes bonding behavior
unfriendly for applications sending big UDP bursts : Once packets
pass the bonding device and come to real device, they might hit a full
qdisc and be dropped. Without orphaning, the sender is automatically
throttled because sk->sk_wmemalloc reaches sk->sk_sndbuf (assuming
sk_sndbuf is not too big)

We could try to defer the orphaning adding another test in
dev_hard_start_xmit(), but all this seems of little gain,
now that BQL tends to make packets more likely to be parked
in Qdisc queues instead of NIC TX ring, in cases where performance
matters.

Reverts commits :
fc6055a5ba31 net: Introduce skb_orphan_try()
87fd308cfc6b net: skb_tx_hash() fix relative to skb_orphan_try()
and removes SKBTX_DRV_NEEDS_SK_REF flag

Reported-and-bisected-by: Jean-Michel Hautbois 
Signed-off-by: Eric Dumazet 
Tested-by: Oliver Hartkopp 
Acked-by: Oliver Hartkopp 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2:
 - Adjust context
 - SKBTX_WIFI_STATUS is not defined]
Signed-off-by: Ben Hutchings

cfg80211: check iface combinations only when iface is running

2012-07-25T03:11:20+00:00

commit f8cdddb8d61d16a156229f0910f7ecfc7a82c003 upstream.

Don't validate interface combinations on a stopped
interface. Otherwise we might end up being able to
create a new interface with a certain type, but
won't be able to change an existing interface
into that type.

This also skips some other functions when
interface is stopped and changing interface type.

Signed-off-by: Michal Kazior 
Signed-off-by: Johannes Berg 
Signed-off-by: Ben Hutchings