linux-toradex.git/include/linux/skbuff.h, branch v3.4.16 Linux kernel for Apalis and Colibri modules net: remove skb_orphan_try() 2012-07-16T16:03:48+00:00 Eric Dumazet edumazet@google.com 2012-06-14T06:42:44+00:00 993772c70fda9d05299fc3a8ed9d1cba268870f1 [ Upstream commit 62b1a8ab9b3660bb820d8dfe23148ed6cda38574 ] 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 <jhautbois@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Oliver Hartkopp <socketcan@hartkopp.net> Acked-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 62b1a8ab9b3660bb820d8dfe23148ed6cda38574 ]

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 <jhautbois@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
skb: avoid unnecessary reallocations in __skb_cow 2012-06-09T15:36:15+00:00 Felix Fietkau nbd@openwrt.org 2012-05-29T03:35:08+00:00 010589e2bce841733dc989fd56c5c3aba41a759c [ Upstream commit 617c8c11236716dcbda877e764b7bf37c6fd8063 ] At the beginning of __skb_cow, headroom gets set to a minimum of NET_SKB_PAD. This causes unnecessary reallocations if the buffer was not cloned and the headroom is just below NET_SKB_PAD, but still more than the amount requested by the caller. This was showing up frequently in my tests on VLAN tx, where vlan_insert_tag calls skb_cow_head(skb, VLAN_HLEN). Locally generated packets should have enough headroom, and for forward paths, we already have NET_SKB_PAD bytes of headroom, so we don't need to add any extra space here. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 617c8c11236716dcbda877e764b7bf37c6fd8063 ]

At the beginning of __skb_cow, headroom gets set to a minimum of
NET_SKB_PAD. This causes unnecessary reallocations if the buffer was not
cloned and the headroom is just below NET_SKB_PAD, but still more than the
amount requested by the caller.
This was showing up frequently in my tests on VLAN tx, where
vlan_insert_tag calls skb_cow_head(skb, VLAN_HLEN).

Locally generated packets should have enough headroom, and for forward
paths, we already have NET_SKB_PAD bytes of headroom, so we don't need to
add any extra space here.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: fix two typos in skbuff.h 2012-05-01T13:40:19+00:00 Eric Dumazet edumazet@google.com 2012-04-30T21:29:16+00:00 d961949660fa1c1b7eb0c3a3c157989c90f14e8e fix kernel doc typos in function names Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
fix kernel doc typos in function names

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
skbuff: struct ubuf_info callback type safety 2012-04-13T17:09:19+00:00 Michael S. Tsirkin mst@redhat.com 2012-04-09T00:24:02+00:00 ca8f4fb21d08747013cce9cf1840aa5bfc31f2d8 The skb struct ubuf_info callback gets passed struct ubuf_info itself, not the arg value as the field name and the function signature seem to imply. Rename the arg field to ctx to match usage, add documentation and change the callback argument type to make usage clear and to have compiler check correctness. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
The skb struct ubuf_info callback gets passed struct ubuf_info
itself, not the arg value as the field name and the function signature
seem to imply. Rename the arg field to ctx to match usage,
add documentation and change the callback argument type
to make usage clear and to have compiler check correctness.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp: avoid order-1 allocations on wifi and tx path 2012-04-11T14:11:12+00:00 Eric Dumazet eric.dumazet@gmail.com 2012-04-10T20:30:48+00:00 a21d45726acacc963d8baddf74607d9b74e2b723 Marc Merlin reported many order-1 allocations failures in TX path on its wireless setup, that dont make any sense with MTU=1500 network, and non SG capable hardware. After investigation, it turns out TCP uses sk_stream_alloc_skb() and used as a convention skb_tailroom(skb) to know how many bytes of data payload could be put in this skb (for non SG capable devices) Note : these skb used kmalloc-4096 (MTU=1500 + MAX_HEADER + sizeof(struct skb_shared_info) being above 2048) Later, mac80211 layer need to add some bytes at the tail of skb (IEEE80211_ENCRYPT_TAILROOM = 18 bytes) and since no more tailroom is available has to call pskb_expand_head() and request order-1 allocations. This patch changes sk_stream_alloc_skb() so that only sk->sk_prot->max_header bytes of headroom are reserved, and use a new skb field, avail_size to hold the data payload limit. This way, order-0 allocations done by TCP stack can leave more than 2 KB of tailroom and no more allocation is performed in mac80211 layer (or any layer needing some tailroom) avail_size is unioned with mark/dropcount, since mark will be set later in IP stack for output packets. Therefore, skb size is unchanged. Reported-by: Marc MERLIN <marc@merlins.org> Tested-by: Marc MERLIN <marc@merlins.org> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Marc Merlin reported many order-1 allocations failures in TX path on its
wireless setup, that dont make any sense with MTU=1500 network, and non
SG capable hardware.

After investigation, it turns out TCP uses sk_stream_alloc_skb() and
used as a convention skb_tailroom(skb) to know how many bytes of data
payload could be put in this skb (for non SG capable devices)

Note : these skb used kmalloc-4096 (MTU=1500 + MAX_HEADER +
sizeof(struct skb_shared_info) being above 2048)

Later, mac80211 layer need to add some bytes at the tail of skb
(IEEE80211_ENCRYPT_TAILROOM = 18 bytes) and since no more tailroom is
available has to call pskb_expand_head() and request order-1
allocations.

This patch changes sk_stream_alloc_skb() so that only
sk->sk_prot->max_header bytes of headroom are reserved, and use a new
skb field, avail_size to hold the data payload limit.

This way, order-0 allocations done by TCP stack can leave more than 2 KB
of tailroom and no more allocation is performed in mac80211 layer (or
any layer needing some tailroom)

avail_size is unioned with mark/dropcount, since mark will be set later
in IP stack for output packets. Therefore, skb size is unchanged.

Reported-by: Marc MERLIN <marc@merlins.org>
Tested-by: Marc MERLIN <marc@merlins.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system 2012-03-28T22:58:21+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-03-28T22:58:21+00:00 0195c00244dc2e9f522475868fa278c473ba7339 Pull "Disintegrate and delete asm/system.h" from David Howells: "Here are a bunch of patches to disintegrate asm/system.h into a set of separate bits to relieve the problem of circular inclusion dependencies. I've built all the working defconfigs from all the arches that I can and made sure that they don't break. The reason for these patches is that I recently encountered a circular dependency problem that came about when I produced some patches to optimise get_order() by rewriting it to use ilog2(). This uses bitops - and on the SH arch asm/bitops.h drags in asm-generic/get_order.h by a circuituous route involving asm/system.h. The main difficulty seems to be asm/system.h. It holds a number of low level bits with no/few dependencies that are commonly used (eg. memory barriers) and a number of bits with more dependencies that aren't used in many places (eg. switch_to()). These patches break asm/system.h up into the following core pieces: (1) asm/barrier.h Move memory barriers here. This already done for MIPS and Alpha. (2) asm/switch_to.h Move switch_to() and related stuff here. (3) asm/exec.h Move arch_align_stack() here. Other process execution related bits could perhaps go here from asm/processor.h. (4) asm/cmpxchg.h Move xchg() and cmpxchg() here as they're full word atomic ops and frequently used by atomic_xchg() and atomic_cmpxchg(). (5) asm/bug.h Move die() and related bits. (6) asm/auxvec.h Move AT_VECTOR_SIZE_ARCH here. Other arch headers are created as needed on a per-arch basis." Fixed up some conflicts from other header file cleanups and moving code around that has happened in the meantime, so David's testing is somewhat weakened by that. We'll find out anything that got broken and fix it.. * tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits) Delete all instances of asm/system.h Remove all #inclusions of asm/system.h Add #includes needed to permit the removal of asm/system.h Move all declarations of free_initmem() to linux/mm.h Disintegrate asm/system.h for OpenRISC Split arch_align_stack() out from asm-generic/system.h Split the switch_to() wrapper out of asm-generic/system.h Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h Create asm-generic/barrier.h Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h Disintegrate asm/system.h for Xtensa Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt] Disintegrate asm/system.h for Tile Disintegrate asm/system.h for Sparc Disintegrate asm/system.h for SH Disintegrate asm/system.h for Score Disintegrate asm/system.h for S390 Disintegrate asm/system.h for PowerPC Disintegrate asm/system.h for PA-RISC Disintegrate asm/system.h for MN10300 ... 
Pull "Disintegrate and delete asm/system.h" from David Howells:
 "Here are a bunch of patches to disintegrate asm/system.h into a set of
  separate bits to relieve the problem of circular inclusion
  dependencies.

  I've built all the working defconfigs from all the arches that I can
  and made sure that they don't break.

  The reason for these patches is that I recently encountered a circular
  dependency problem that came about when I produced some patches to
  optimise get_order() by rewriting it to use ilog2().

  This uses bitops - and on the SH arch asm/bitops.h drags in
  asm-generic/get_order.h by a circuituous route involving asm/system.h.

  The main difficulty seems to be asm/system.h.  It holds a number of
  low level bits with no/few dependencies that are commonly used (eg.
  memory barriers) and a number of bits with more dependencies that
  aren't used in many places (eg.  switch_to()).

  These patches break asm/system.h up into the following core pieces:

    (1) asm/barrier.h

        Move memory barriers here.  This already done for MIPS and Alpha.

    (2) asm/switch_to.h

        Move switch_to() and related stuff here.

    (3) asm/exec.h

        Move arch_align_stack() here.  Other process execution related bits
        could perhaps go here from asm/processor.h.

    (4) asm/cmpxchg.h

        Move xchg() and cmpxchg() here as they're full word atomic ops and
        frequently used by atomic_xchg() and atomic_cmpxchg().

    (5) asm/bug.h

        Move die() and related bits.

    (6) asm/auxvec.h

        Move AT_VECTOR_SIZE_ARCH here.

  Other arch headers are created as needed on a per-arch basis."

Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that.  We'll find out anything that got broken and fix it..

* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
  Delete all instances of asm/system.h
  Remove all #inclusions of asm/system.h
  Add #includes needed to permit the removal of asm/system.h
  Move all declarations of free_initmem() to linux/mm.h
  Disintegrate asm/system.h for OpenRISC
  Split arch_align_stack() out from asm-generic/system.h
  Split the switch_to() wrapper out of asm-generic/system.h
  Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
  Create asm-generic/barrier.h
  Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
  Disintegrate asm/system.h for Xtensa
  Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
  Disintegrate asm/system.h for Tile
  Disintegrate asm/system.h for Sparc
  Disintegrate asm/system.h for SH
  Disintegrate asm/system.h for Score
  Disintegrate asm/system.h for S390
  Disintegrate asm/system.h for PowerPC
  Disintegrate asm/system.h for PA-RISC
  Disintegrate asm/system.h for MN10300
  ...
Remove all #inclusions of asm/system.h 2012-03-28T17:30:03+00:00 David Howells dhowells@redhat.com 2012-03-28T17:30:03+00:00 9ffc93f203c18a70623f21950f1dd473c9ec48cd Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com> 
Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`

Signed-off-by: David Howells <dhowells@redhat.com>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-03-27T23:52:32+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-03-27T23:52:32+00:00 de8856d2c11f562c60ed9340a83db4a4f829a6e6 Pull networking fixes from David Miller: 1) Name string overrun fix in gianfar driver from Joe Perches. 2) VHOST bug fixes from Michael S. Tsirkin and Nadav Har'El 3) Fix dependencies on xt_LOG netfilter module, from Pablo Neira Ayuso. 4) Fix RCU locking in xt_CT, also from Pablo Neira Ayuso. 5) Add a parameter to skb_add_rx_frag() so we can fix the truesize adjustments in the drivers that use it. The individual drivers aren't fixed by this commit, but will be dealt with using follow-on commits. From Eric Dumazet. 6) Add some device IDs to qmi_wwan driver, from Andrew Bird. 7) Fix a potential rcu_read_lock() imbalancein rt6_fill_node(). From Eric Dumazet. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: net: fix a potential rcu_read_lock() imbalance in rt6_fill_node() net: add a truesize parameter to skb_add_rx_frag() gianfar: Fix possible overrun and simplify interrupt name field creation USB: qmi_wwan: Add ZTE (Vodafone) K3570-Z and K3571-Z net interfaces USB: option: Ignore ZTE (Vodafone) K3570/71 net interfaces USB: qmi_wwan: Add ZTE (Vodafone) K3565-Z and K4505-Z net interfaces qlcnic: Bug fix for LRO netfilter: nf_conntrack: permanently attach timeout policy to conntrack netfilter: xt_CT: fix assignation of the generic protocol tracker netfilter: xt_CT: missing rcu_read_lock section in timeout assignment netfilter: cttimeout: fix dependency with l4protocol conntrack module netfilter: xt_LOG: use CONFIG_IP6_NF_IPTABLES instead of CONFIG_IPV6 vhost: fix release path lockdep checks vhost: don't forget to schedule() tools/virtio: stub out strong barriers tools/virtio: add linux/hrtimer.h stub tools/virtio: add linux/module.h stub 
Pull networking fixes from David Miller:
 1) Name string overrun fix in gianfar driver from Joe Perches.

 2) VHOST bug fixes from Michael S. Tsirkin and Nadav Har'El

 3) Fix dependencies on xt_LOG netfilter module, from Pablo Neira Ayuso.

 4) Fix RCU locking in xt_CT, also from Pablo Neira Ayuso.

 5) Add a parameter to skb_add_rx_frag() so we can fix the truesize
    adjustments in the drivers that use it.  The individual drivers
    aren't fixed by this commit, but will be dealt with using follow-on
    commits.  From Eric Dumazet.

 6) Add some device IDs to qmi_wwan driver, from Andrew Bird.

 7) Fix a potential rcu_read_lock() imbalancein rt6_fill_node().  From
    Eric Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  net: fix a potential rcu_read_lock() imbalance in rt6_fill_node()
  net: add a truesize parameter to skb_add_rx_frag()
  gianfar: Fix possible overrun and simplify interrupt name field creation
  USB: qmi_wwan: Add ZTE (Vodafone) K3570-Z and K3571-Z net interfaces
  USB: option: Ignore ZTE (Vodafone) K3570/71 net interfaces
  USB: qmi_wwan: Add ZTE (Vodafone) K3565-Z and K4505-Z net interfaces
  qlcnic: Bug fix for LRO
  netfilter: nf_conntrack: permanently attach timeout policy to conntrack
  netfilter: xt_CT: fix assignation of the generic protocol tracker
  netfilter: xt_CT: missing rcu_read_lock section in timeout assignment
  netfilter: cttimeout: fix dependency with l4protocol conntrack module
  netfilter: xt_LOG: use CONFIG_IP6_NF_IPTABLES instead of CONFIG_IPV6
  vhost: fix release path lockdep checks
  vhost: don't forget to schedule()
  tools/virtio: stub out strong barriers
  tools/virtio: add linux/hrtimer.h stub
  tools/virtio: add linux/module.h stub
net: add a truesize parameter to skb_add_rx_frag() 2012-03-25T17:29:58+00:00 Eric Dumazet eric.dumazet@gmail.com 2012-03-23T23:59:33+00:00 50269e19ad990e79eeda101fc6df80cffd5d4831 skb_add_rx_frag() API is misleading. Network skbs built with this helper can use uncharged kernel memory and eventually stress/crash machine in OOM. Add a 'truesize' parameter and then fix drivers in followup patches. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Wey-Yi Guy <wey-yi.w.guy@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
skb_add_rx_frag() API is misleading.

Network skbs built with this helper can use uncharged kernel memory and
eventually stress/crash machine in OOM.

Add a 'truesize' parameter and then fix drivers in followup patches.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2012-03-24T17:08:39+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-03-24T17:08:39+00:00 ed2d265d1266736bd294332d7f649003943ae36e Pull <linux/bug.h> cleanup from Paul Gortmaker: "The changes shown here are to unify linux's BUG support under the one <linux/bug.h> file. Due to historical reasons, we have some BUG code in bug.h and some in kernel.h -- i.e. the support for BUILD_BUG in linux/kernel.h predates the addition of linux/bug.h, but old code in kernel.h wasn't moved to bug.h at that time. As a band-aid, kernel.h was including <asm/bug.h> to pseudo link them. This has caused confusion[1] and general yuck/WTF[2] reactions. Here is an example that violates the principle of least surprise: CC lib/string.o lib/string.c: In function 'strlcat': lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON' make[2]: *** [lib/string.o] Error 1 $ $ grep linux/bug.h lib/string.c #include <linux/bug.h> $ We've included <linux/bug.h> for the BUG infrastructure and yet we still get a compile fail! [We've not kernel.h for BUILD_BUG_ON.] Ugh - very confusing for someone who is new to kernel development. With the above in mind, the goals of this changeset are: 1) find and fix any include/*.h files that were relying on the implicit presence of BUG code. 2) find and fix any C files that were consuming kernel.h and hence relying on implicitly getting some/all BUG code. 3) Move the BUG related code living in kernel.h to <linux/bug.h> 4) remove the asm/bug.h from kernel.h to finally break the chain. During development, the order was more like 3-4, build-test, 1-2. But to ensure that git history for bisect doesn't get needless build failures introduced, the commits have been reorderd to fix the problem areas in advance. [1] https://lkml.org/lkml/2012/1/3/90 [2] https://lkml.org/lkml/2012/1/17/414" Fix up conflicts (new radeon file, reiserfs header cleanups) as per Paul and linux-next. * tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: kernel.h: doesn't explicitly use bug.h, so don't include it. bug: consolidate BUILD_BUG_ON with other bug code BUG: headers with BUG/BUG_ON etc. need linux/bug.h bug.h: add include of it to various implicit C users lib: fix implicit users of kernel.h for TAINT_WARN spinlock: macroize assert_spin_locked to avoid bug.h dependency x86: relocate get/set debugreg fcns to include/asm/debugreg. 
Pull <linux/bug.h> cleanup from Paul Gortmaker:
 "The changes shown here are to unify linux's BUG support under the one
  <linux/bug.h> file.  Due to historical reasons, we have some BUG code
  in bug.h and some in kernel.h -- i.e.  the support for BUILD_BUG in
  linux/kernel.h predates the addition of linux/bug.h, but old code in
  kernel.h wasn't moved to bug.h at that time.  As a band-aid, kernel.h
  was including <asm/bug.h> to pseudo link them.

  This has caused confusion[1] and general yuck/WTF[2] reactions.  Here
  is an example that violates the principle of least surprise:

      CC      lib/string.o
      lib/string.c: In function 'strlcat':
      lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON'
      make[2]: *** [lib/string.o] Error 1
      $
      $ grep linux/bug.h lib/string.c
      #include <linux/bug.h>
      $

  We've included <linux/bug.h> for the BUG infrastructure and yet we
  still get a compile fail! [We've not kernel.h for BUILD_BUG_ON.] Ugh -
  very confusing for someone who is new to kernel development.

  With the above in mind, the goals of this changeset are:

  1) find and fix any include/*.h files that were relying on the
     implicit presence of BUG code.
  2) find and fix any C files that were consuming kernel.h and hence
     relying on implicitly getting some/all BUG code.
  3) Move the BUG related code living in kernel.h to <linux/bug.h>
  4) remove the asm/bug.h from kernel.h to finally break the chain.

  During development, the order was more like 3-4, build-test, 1-2.  But
  to ensure that git history for bisect doesn't get needless build
  failures introduced, the commits have been reorderd to fix the problem
  areas in advance.

	[1]  https://lkml.org/lkml/2012/1/3/90
	[2]  https://lkml.org/lkml/2012/1/17/414"

Fix up conflicts (new radeon file, reiserfs header cleanups) as per Paul
and linux-next.

* tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
  kernel.h: doesn't explicitly use bug.h, so don't include it.
  bug: consolidate BUILD_BUG_ON with other bug code
  BUG: headers with BUG/BUG_ON etc. need linux/bug.h
  bug.h: add include of it to various implicit C users
  lib: fix implicit users of kernel.h for TAINT_WARN
  spinlock: macroize assert_spin_locked to avoid bug.h dependency
  x86: relocate get/set debugreg fcns to include/asm/debugreg.