As compared with skb_to_sgvec, skb_to_sgvec_nomark only map skb to given sglist
without mark the sg which contain last skb data as the end. So the caller can
mannipulate sg list as will when padding new data after the first call without
calling sg_unmark_end to expend sg list.
Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

Pull microblaze fixes from Michal Simek:
 - Fix two compilation issues - HZ, readq/writeq
 - Fix stack protection support

* tag 'microblaze-3.14-rc3' of git://git.monstr.eu/linux-2.6-microblaze:
  microblaze: Fix a typo when disabling stack protection
  microblaze: Define readq and writeq IO helper function
  microblaze: Fix missing HZ macro

Pull s390 bugfixes from Martin Schwidefsky:
 "A collection a bug fixes.  Most of them are minor but two of them are
  more severe.  The linkage stack bug can be used by user space to force
  an oops, with panic_on_oops this is a denial-of-service.  And the dump
  memory detection issue can cause incomplete memory dumps"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/cio: improve cio_commit_config
  s390: fix kernel crash due to linkage stack instructions
  s390/dump: Fix dump memory detection
  s390/appldata: restore missing init_virt_timer()
  s390/qdio: correct program-controlled interruption checking
  s390/qdio: for_each macro correctness

Pull networking updates from David Miller:

 1) Fix flexcan build on big endian, from Arnd Bergmann

 2) Correctly attach cpsw to GPIO bitbang MDIO drive, from Stefan Roese

 3) udp_add_offload has to use GFP_ATOMIC since it can be invoked from
    non-sleepable contexts.  From Or Gerlitz

 4) vxlan_gro_receive() does not iterate over all possible flows
    properly, fix also from Or Gerlitz

 5) CAN core doesn't use a proper SKB destructor when it hooks up
    sockets to SKBs.  Fix from Oliver Hartkopp

 6) ip_tunnel_xmit() can use an uninitialized route pointer, fix from
    Eric Dumazet

 7) Fix address family assignment in IPVS, from Michal Kubecek

 8) Fix ath9k build on ARM, from Sujith Manoharan

 9) Make sure fail_over_mac only applies for the correct bonding modes,
    from Ding Tianhong

10) The udp offload code doesn't use RCU correctly, from Shlomo Pongratz

11) Handle gigabit features properly in generic PHY code, from Florian
    Fainelli

12) Don't blindly invoke link operations in
    rtnl_link_get_slave_info_data_size, they are optional.  Fix from
    Fernando Luis Vazquez Cao

13) Add USB IDs for Netgear Aircard 340U, from Bjørn Mork

14) Handle netlink packet padding properly in openvswitch, from Thomas
    Graf

15) Fix oops when deleting chains in nf_tables, from Patrick McHardy

16) Fix RX stalls in xen-netback driver, from Zoltan Kiss

17) Fix deadlock in mac80211 stack, from Emmanuel Grumbach

18) inet_nlmsg_size() forgets to consider ifa_cacheinfo, fix from Geert
    Uytterhoeven

19) tg3_change_mtu() can deadlock, fix from Nithin Sujir

20) Fix regression in setting SCTP local source addresses on accepted
    sockets, caused by some generic ipv6 socket changes.  Fix from
    Matija Glavinic Pecotic

21) IPPROTO_* must be pure defines, otherwise module aliases don't get
    constructed properly.  Fix from Jan Moskyto

22) IPV6 netconsole setup doesn't work properly unless an explicit
    source address is specified, fix from Sabrina Dubroca

23) Use __GFP_NORETRY for high order skb page allocations in
    sock_alloc_send_pskb and skb_page_frag_refill.  From Eric Dumazet

24) Fix a regression added in netconsole over bridging, from Cong Wang

25) TCP uses an artificial offset of 1ms for SRTT, but this doesn't jive
    well with TCP pacing which needs the SRTT to be accurate.  Fix from
    Eric Dumazet

26) Several cases of missing header file includes from Rashika Kheria

27) Add ZTE MF667 device ID to qmi_wwan driver, from Raymond Wanyoike

28) TCP Small Queues doesn't handle nonagle properly in some corner
    cases, fix from Eric Dumazet

29) Remove extraneous read_unlock in bond_enslave, whoops.  From Ding
    Tianhong

30) Fix 9p trans_virtio handling of vmalloc buffers, from Richard Yao

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (136 commits)
  6lowpan: fix lockdep splats
  alx: add missing stats_lock spinlock init
  9p/trans_virtio.c: Fix broken zero-copy on vmalloc() buffers
  bonding: remove unwanted bond lock for enslave processing
  USB2NET : SR9800 : One chip USB2.0 USB2NET SR9800 Device Driver Support
  tcp: tsq: fix nonagle handling
  bridge: Prevent possible race condition in br_fdb_change_mac_address
  bridge: Properly check if local fdb entry can be deleted when deleting vlan
  bridge: Properly check if local fdb entry can be deleted in br_fdb_delete_by_port
  bridge: Properly check if local fdb entry can be deleted in br_fdb_change_mac_address
  bridge: Fix the way to check if a local fdb entry can be deleted
  bridge: Change local fdb entries whenever mac address of bridge device changes
  bridge: Fix the way to find old local fdb entries in br_fdb_change_mac_address
  bridge: Fix the way to insert new local fdb entries in br_fdb_changeaddr
  bridge: Fix the way to find old local fdb entries in br_fdb_changeaddr
  tcp: correct code comment stating 3 min timeout for FIN_WAIT2, we only do 1 min
  net: vxge: Remove unused device pointer
  net: qmi_wwan: add ZTE MF667
  3c59x: Remove unused pointer in vortex_eisa_cleanup()
  net: fix 'ip rule' iif/oif device rename
  ...

When a device ndo_start_xmit() calls again dev_queue_xmit(),
lockdep can complain because dev_queue_xmit() is re-entered and the
spinlocks protecting tx queues share a common lockdep class.

Same issue was fixed for bonding/l2tp/ppp in commits

0daa2303 ("[PATCH] bonding: lockdep annotation")
49ee4920 ("bonding: set qdisc_tx_busylock to avoid LOCKDEP splat")
23d3b8bf ("net: qdisc busylock needs lockdep annotations ")
303c07db ("ppp: set qdisc_tx_busylock to avoid LOCKDEP splat ")
Reported-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Trivial fix for init time stack trace occuring in
alx_get_stats64 upon start up. Should have been part of
commit adding the spinlock:
f1b6b106 alx: add alx_get_stats64 operation
Signed-off-by: John Greene <jogreene@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The 9p-virtio transport does zero copy on things larger than 1024 bytes
in size. It accomplishes this by returning the physical addresses of
pages to the virtio-pci device. At present, the translation is usually a
bit shift.

That approach produces an invalid page address when we read/write to
vmalloc buffers, such as those used for Linux kernel modules. Any
attempt to load a Linux kernel module from 9p-virtio produces the
following stack.

[<ffffffff814878ce>] p9_virtio_zc_request+0x45e/0x510
[<ffffffff814814ed>] p9_client_zc_rpc.constprop.16+0xfd/0x4f0
[<ffffffff814839dd>] p9_client_read+0x15d/0x240
[<ffffffff811c8440>] v9fs_fid_readn+0x50/0xa0
[<ffffffff811c84a0>] v9fs_file_readn+0x10/0x20
[<ffffffff811c84e7>] v9fs_file_read+0x37/0x70
[<ffffffff8114e3fb>] vfs_read+0x9b/0x160
[<ffffffff81153571>] kernel_read+0x41/0x60
[<ffffffff810c83ab>] copy_module_from_fd.isra.34+0xfb/0x180

Subsequently, QEMU will die printing:

qemu-system-x86_64: virtio: trying to map MMIO memory

This patch enables 9p-virtio to correctly handle this case. This not
only enables us to load Linux kernel modules off virtfs, but also
enables ZFS file-based vdevs on virtfs to be used without killing QEMU.

Special thanks to both Avi Kivity and Alexander Graf for their
interpretation of QEMU backtraces. Without their guidence, tracking down
this bug would have taken much longer. Also, special thanks to Linus
Torvalds for his insightful explanation of why this should use
is_vmalloc_addr() instead of is_vmalloc_or_module_addr():

https://lkml.org/lkml/2014/2/8/272Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The bond enslave processing don't hold bond->lock anymore,
so release an unlocked rw lock will cause warning message,
remove the unwanted read_unlock(&bond->lock).

Cc: Jay Vosburgh <fubar@us.ibm.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Acked-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Liu Junliang <liujunliang_ljl@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge misc fixes from Andrew Morton:
 "A bunch of fixes"

* emailed patches fron Andrew Morton <akpm@linux-foundation.org>:
  ocfs2: check existence of old dentry in ocfs2_link()
  ocfs2: update inode size after zeroing the hole
  ocfs2: fix issue that ocfs2_setattr() does not deal with new_i_size==i_size
  mm/memory-failure.c: move refcount only in !MF_COUNT_INCREASED
  smp.h: fix x86+cpu.c sparse warnings about arch nonboot CPU calls
  mm: fix page leak at nfs_symlink()
  slub: do not assert not having lock in removing freed partial
  gitignore: add all.config
  ocfs2: fix ocfs2_sync_file() if filesystem is readonly
  drivers/edac/edac_mc_sysfs.c: poll timeout cannot be zero
  fs/file.c:fdtable: avoid triggering OOMs from alloc_fdmem
  xen: properly account for _PAGE_NUMA during xen pte translations
  mm/slub.c: list_lock may not be held in some circumstances
  drivers/md/bcache/extents.c: use %zi to format size_t
  vmcore: prevent PT_NOTE p_memsz overflow during header update
  drivers/message/i2o/i2o_config.c: fix deadlock in compat_ioctl(I2OGETIOPS)
  Documentation/: update 00-INDEX files
  checkpatch: fix detection of git repository
  get_maintainer: fix detection of git repository
  drivers/misc/sgi-gru/grukdump.c: unlocking should be conditional in gru_dump_context()

System call linkat first calls user_path_at(), check the existence of
old dentry, and then calls vfs_link()->ocfs2_link() to do the actual
work.  There may exist a race when Node A create a hard link for file
while node B rm it.

         Node A                          Node B
user_path_at()
  ->ocfs2_lookup(),
find old dentry exist
                                rm file, add inode say inodeA
                                to orphan_dir

call ocfs2_link(),create a
hard link for inodeA.

                                rm the link, add inodeA to orphan_dir
                                again

When orphan_scan work start, it calls ocfs2_queue_orphans() to do the
main work.  It first tranverses entrys in orphan_dir, linking all inodes
in this orphan_dir to a list look like this:

	inodeA->inodeB->...->inodeA

When tranvering this list, it will fall into loop, calling iput() again
and again.  And finally trigger BUG_ON(inode->i_state & I_CLEAR).
Signed-off-by: joyce <xuejiufei@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs-writeback will release the dirty pages without page lock whose offset
are over inode size, the release happens at
block_write_full_page_endio().  If not update, dirty pages in file holes
may be released before flushed to the disk, then file holes will contain
some non-zero data, this will cause sparse file md5sum error.

To reproduce the bug, find a big sparse file with many holes, like vm
image file, its actual size should be bigger than available mem size to
make writeback work more frequently, tar it with -S option, then keep
untar it and check its md5sum again and again until you get a wrong
md5sum.
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Younger Liu <younger.liu@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The issue scenario is as following:

- Create a small file and fallocate a large disk space for a file with
  FALLOC_FL_KEEP_SIZE option.

- ftruncate the file back to the original size again.  but the disk free
  space is not changed back.  This is a real bug that be fixed in this
  patch.

In order to solve the issue above, we modified ocfs2_setattr(), if
attr->ia_size != i_size_read(inode), It calls ocfs2_truncate_file(), and
truncate disk space to attr->ia_size.
Signed-off-by: Younger Liu <younger.liu@huawei.com>
Reviewed-by: Jie Liu <jeff.liu@oracle.com>
Tested-by: Jie Liu <jeff.liu@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Sunil Mushran <sunil.mushran@gmail.com>
Reviewed-by: Jensen <shencanquan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mce-test detected a test failure when injecting error to a thp tail
page.  This is because we take page refcount of the tail page in
madvise_hwpoison() while the fix in commit a3e0f9e4
("mm/memory-failure.c: transfer page count from head page to tail page
after split thp") assumes that we always take refcount on the head page.

When a real memory error happens we take refcount on the head page where
memory_failure() is called without MF_COUNT_INCREASED set, so it seems
to me that testing memory error on thp tail page using madvise makes
little sense.

This patch cancels moving refcount in !MF_COUNT_INCREASED for valid
testing.

[akpm@linux-foundation.org: s/&&/&/]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Chen Gong <gong.chen@linux.intel.com>
Cc: <stable@vger.kernel.org>	[3.9+: a3e0f9e4]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use what we already do for arch_disable_smp_support() to fix these:

  arch/x86/kernel/smpboot.c:1155:6: warning: symbol 'arch_enable_nonboot_cpus_begin' was not declared. Should it be static?
  arch/x86/kernel/smpboot.c:1160:6: warning: symbol 'arch_enable_nonboot_cpus_end' was not declared. Should it be static?
  kernel/cpu.c:512:13: warning: symbol 'arch_enable_nonboot_cpus_begin' was not declared. Should it be static?
  kernel/cpu.c:516:13: warning: symbol 'arch_enable_nonboot_cpus_end' was not declared. Should it be static?
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Changes in commit a0b8cab3 ("mm: remove lru parameter from
__pagevec_lru_add and remove parts of pagevec API") have introduced a
call to add_to_page_cache_lru() which causes a leak in nfs_symlink() as
now the page gets an extra refcount that is not dropped.

Jan Stancek observed and reported the leak effect while running test8
from Connectathon Testsuite.  After several iterations over the test
case, which creates several symlinks on a NFS mountpoint, the test
system was quickly getting into an out-of-memory scenario.

This patch fixes the page leak by dropping that extra refcount
add_to_page_cache_lru() is grabbing.
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: <stable@vger.kernel.org>	[3.11.x+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Vladimir reported the following issue:

Commit c65c1877 ("slub: use lockdep_assert_held") requires
remove_partial() to be called with n->list_lock held, but free_partial()
called from kmem_cache_close() on cache destruction does not follow this
rule, leading to a warning:

  WARNING: CPU: 0 PID: 2787 at mm/slub.c:1536 __kmem_cache_shutdown+0x1b2/0x1f0()
  Modules linked in:
  CPU: 0 PID: 2787 Comm: modprobe Tainted: G        W    3.14.0-rc1-mm1+ #1
  Hardware name:
   0000000000000600 ffff88003ae1dde8 ffffffff816d9583 0000000000000600
   0000000000000000 ffff88003ae1de28 ffffffff8107c107 0000000000000000
   ffff880037ab2b00 ffff88007c240d30 ffffea0001ee5280 ffffea0001ee52a0
  Call Trace:
    __kmem_cache_shutdown+0x1b2/0x1f0
    kmem_cache_destroy+0x43/0xf0
    xfs_destroy_zones+0x103/0x110 [xfs]
    exit_xfs_fs+0x38/0x4e4 [xfs]
    SyS_delete_module+0x19a/0x1f0
    system_call_fastpath+0x16/0x1b

His solution was to add a spinlock in order to quiet lockdep.  Although
there would be no contention to adding the lock, that lock also requires
disabling of interrupts which will have a larger impact on the system.

Instead of adding a spinlock to a location where it is not needed for
lockdep, make a __remove_partial() function that does not test if the
list_lock is held, as no one should have it due to it being freed.

Also added a __add_partial() function that does not do the lock
validation either, as it is not needed for the creation of the cache.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Vladimir Davydov <vdavydov@parallels.com>
Suggested-by: David Rientjes <rientjes@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is used by kbuild to load preset Kconfig options.  We need to
ignore it, otherwise git clean kills it.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If filesystem is readonly, there is no need to flush drive's caches or
force any uncommitted transactions.

[akpm@linux-foundation.org: return -EROFS, not 0]
Signed-off-by: Younger Liu <younger.liucn@gmail.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If you do

  echo 0 > /sys/module/edac_core/parameters/edac_mc_poll_msec

the following stack trace is output because the edac module is not
designed to poll with a timeout of zero.

  WARNING: CPU: 12 PID: 0 at lib/list_debug.c:33 __list_add+0xac/0xc0()
  list_add corruption. prev->next should be next (ffff8808291dd1b8), but was           (null). (prev=ffff8808286fe3f8).
  Modules linked in: sg nfsv3 rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache cfg80211 rfkill x86_pkg_temp_thermal coretemp kvm_intel kvm ixgbe e1000e crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd iTCO_wdt ptp sb_edac iTCO_vendor_support pps_core mdio ipmi_devintf edac_core ioatdma microcode shpchp lpc_ich pcspkr i2c_i801 dca mfd_core ipmi_si wmi ipmi_msghandler nfsd auth_rpcgss nfs_acl lockd sunrpc xfs libcrc32c sd_mod sr_mod cdrom crc_t10dif crct10dif_common mgag200 syscopyarea sysfillrect sysimgblt isci i2c_algo_bit drm_kms_helper ttm drm libsas ahci libahci scsi_transport_sas libata i2c_core dm_mirror dm_region_hash dm_log dm_mod
  CPU: 12 PID: 0 Comm: swapper/12 Not tainted 3.13.0+ #1
  Hardware name: Intel Corporation LH Pass ........../SVRBD-ROW_T, BIOS SE5C600.86B.01.08.0003.022620131521 02/26/2013
  Call Trace:
   <IRQ>
    __list_add+0xac/0xc0
    __internal_add_timer+0xab/0x130
    internal_add_timer+0x17/0x40
    mod_timer_pinned+0xca/0x170
    intel_pstate_timer_func+0x28a/0x380
    call_timer_fn+0x36/0x100
    run_timer_softirq+0x1ff/0x2f0
    __do_softirq+0xf5/0x2e0
    irq_exit+0x10d/0x120
    smp_apic_timer_interrupt+0x45/0x60
    apic_timer_interrupt+0x6d/0x80
   <EOI>
    cpuidle_idle_call+0xb9/0x1f0
    arch_cpu_idle+0xe/0x30
    cpu_startup_entry+0x9e/0x240
    start_secondary+0x1e4/0x290

  kernel BUG at kernel/timer.c:1084!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: sg nfsv3 rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache cfg80211 rfkill x86_pkg_temp_thermal coretemp kvm_intel kvm ixgbe e1000e crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd iTCO_wdt ptp sb_edac iTCO_vendor_support pps_core mdio ipmi_devintf edac_core ioatdma microcode shpchp lpc_ich pcspkr i2c_i801 dca mfd_core ipmi_si wmi ipmi_msghandler nfsd auth_rpcgss nfs_acl lockd sunrpc xfs libcrc32c sd_mod sr_mod cdrom crc_t10dif crct10dif_common mgag200 syscopyarea sysfillrect sysimgblt isci i2c_algo_bit drm_kms_helper ttm drm libsas ahci libahci scsi_transport_sas libata i2c_core dm_mirror dm_region_hash dm_log dm_mod
  CPU: 12 PID: 0 Comm: swapper/12 Tainted: G        W    3.13.0+ #1
  Hardware name: Intel Corporation LH Pass ........../SVRBD-ROW_T, BIOS SE5C600.86B.01.08.0003.022620131521 02/26/2013
  Call Trace:
   <IRQ>
    run_timer_softirq+0x245/0x2f0
    __do_softirq+0xf5/0x2e0
    irq_exit+0x10d/0x120
    smp_apic_timer_interrupt+0x45/0x60
    apic_timer_interrupt+0x6d/0x80
   <EOI>
    cpuidle_idle_call+0xb9/0x1f0
    arch_cpu_idle+0xe/0x30
    cpu_startup_entry+0x9e/0x240
    start_secondary+0x1e4/0x290
  RIP   cascade+0x93/0xa0

  WARNING: CPU: 36 PID: 1154 at kernel/workqueue.c:1461 __queue_delayed_work+0xed/0x1a0()
  Modules linked in: sg nfsv3 rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache cfg80211 rfkill x86_pkg_temp_thermal coretemp kvm_intel kvm ixgbe e1000e crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd iTCO_wdt ptp sb_edac iTCO_vendor_support pps_core mdio ipmi_devintf edac_core ioatdma microcode shpchp lpc_ich pcspkr i2c_i801 dca mfd_core ipmi_si wmi ipmi_msghandler nfsd auth_rpcgss nfs_acl lockd sunrpc xfs libcrc32c sd_mod sr_mod cdrom crc_t10dif crct10dif_common mgag200 syscopyarea sysfillrect sysimgblt isci i2c_algo_bit drm_kms_helper ttm drm libsas ahci libahci scsi_transport_sas libata i2c_core dm_mirror dm_region_hash dm_log dm_mod
  CPU: 36 PID: 1154 Comm: kworker/u481:3 Tainted: G        W    3.13.0+ #1
  Hardware name: Intel Corporation LH Pass ........../SVRBD-ROW_T, BIOS SE5C600.86B.01.08.0003.022620131521 02/26/2013
  Workqueue: edac-poller edac_mc_workq_function [edac_core]
  Call Trace:
    dump_stack+0x45/0x56
    warn_slowpath_common+0x7d/0xa0
    warn_slowpath_null+0x1a/0x20
    __queue_delayed_work+0xed/0x1a0
    queue_delayed_work_on+0x27/0x50
    edac_mc_workq_function+0x72/0xa0 [edac_core]
    process_one_work+0x17b/0x460
    worker_thread+0x11b/0x400
    kthread+0xd2/0xf0
    ret_from_fork+0x7c/0xb0

This patch adds a range check in the edac_mc_poll_msec code to check for 0.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Recently due to a spike in connections per second memcached on 3
separate boxes triggered the OOM killer from accept.  At the time the
OOM killer was triggered there was 4GB out of 36GB free in zone 1.  The
problem was that alloc_fdtable was allocating an order 3 page (32KiB) to
hold a bitmap, and there was sufficient fragmentation that the largest
page available was 8KiB.

I find the logic that PAGE_ALLOC_COSTLY_ORDER can't fail pretty dubious
but I do agree that order 3 allocations are very likely to succeed.

There are always pathologies where order > 0 allocations can fail when
there are copious amounts of free memory available.  Using the pigeon
hole principle it is easy to show that it requires 1 page more than 50%
of the pages being free to guarantee an order 1 (8KiB) allocation will
succeed, 1 page more than 75% of the pages being free to guarantee an
order 2 (16KiB) allocation will succeed and 1 page more than 87.5% of
the pages being free to guarantee an order 3 allocate will succeed.

A server churning memory with a lot of small requests and replies like
memcached is a common case that if anything can will skew the odds
against large pages being available.

Therefore let's not give external applications a practical way to kill
linux server applications, and specify __GFP_NORETRY to the kmalloc in
alloc_fdmem.  Unless I am misreading the code and by the time the code
reaches should_alloc_retry in __alloc_pages_slowpath (where
__GFP_NORETRY becomes signification).  We have already tried everything
reasonable to allocate a page and the only thing left to do is wait.  So
not waiting and falling back to vmalloc immediately seems like the
reasonable thing to do even if there wasn't a chance of triggering the
OOM killer.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Cong Wang <cwang@twopensource.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Steven Noonan forwarded a users report where they had a problem starting
vsftpd on a Xen paravirtualized guest, with this in dmesg:

  BUG: Bad page map in process vsftpd  pte:8000000493b88165 pmd:e9cc01067
  page:ffffea00124ee200 count:0 mapcount:-1 mapping:     (null) index:0x0
  page flags: 0x2ffc0000000014(referenced|dirty)
  addr:00007f97eea74000 vm_flags:00100071 anon_vma:ffff880e98f80380 mapping:          (null) index:7f97eea74
  CPU: 4 PID: 587 Comm: vsftpd Not tainted 3.12.7-1-ec2 #1
  Call Trace:
    dump_stack+0x45/0x56
    print_bad_pte+0x22e/0x250
    unmap_single_vma+0x583/0x890
    unmap_vmas+0x65/0x90
    exit_mmap+0xc5/0x170
    mmput+0x65/0x100
    do_exit+0x393/0x9e0
    do_group_exit+0xcc/0x140
    SyS_exit_group+0x14/0x20
    system_call_fastpath+0x1a/0x1f
  Disabling lock debugging due to kernel taint
  BUG: Bad rss-counter state mm:ffff880e9ca60580 idx:0 val:-1
  BUG: Bad rss-counter state mm:ffff880e9ca60580 idx:1 val:1

The issue could not be reproduced under an HVM instance with the same
kernel, so it appears to be exclusive to paravirtual Xen guests.  He
bisected the problem to commit 1667918b ("mm: numa: clear numa
hinting information on mprotect") that was also included in 3.12-stable.

The problem was related to how xen translates ptes because it was not
accounting for the _PAGE_NUMA bit.  This patch splits pte_present to add
a pteval_present helper for use by xen so both bare metal and xen use
the same code when checking if a PTE is present.

[mgorman@suse.de: wrote changelog, proposed minor modifications]
[akpm@linux-foundation.org: fix typo in comment]
Reported-by: Steven Noonan <steven@uplinklabs.net>
Tested-by: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Elena Ufimtseva <ufimtseva@gmail.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org>	[3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit c65c1877 ("slub: use lockdep_assert_held") incorrectly
required that add_full() and remove_full() hold n->list_lock.  The lock
is only taken when kmem_cache_debug(s), since that's the only time it
actually does anything.

Require that the lock only be taken under such a condition.
Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

  drivers/md/bcache/extents.c: In function `btree_ptr_bad_expensive':
  drivers/md/bcache/extents.c:196: warning: format `%li' expects type `long int', but argument 4 has type `size_t'
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Currently, update_note_header_size_elf64() and
update_note_header_size_elf32() will add the size of a PT_NOTE entry to
real_sz even if that causes real_sz to exceeds max_sz.  This patch
corrects the while loop logic in those routines to ensure that does not
happen and prints a warning if a PT_NOTE entry is dropped.  If zero
PT_NOTE entries are found or this condition is encountered because the
only entry was dropped, a warning is printed and an error is returned.

One possible negative side effect of exceeding the max_sz limit is an
allocation failure in merge_note_headers_elf64() or
merge_note_headers_elf32() which would produce console output such as
the following while booting the crash kernel.

  vmalloc: allocation failure: 14076997632 bytes
  swapper/0: page allocation failure: order:0, mode:0x80d2
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.10.0-gbp1 #7
  Call Trace:
    dump_stack+0x19/0x1b
    warn_alloc_failed+0xf0/0x160
    __vmalloc_node_range+0x19e/0x250
    vmalloc_user+0x4c/0x70
    merge_note_headers_elf64.constprop.9+0x116/0x24a
    vmcore_init+0x2d4/0x76c
    do_one_initcall+0xe2/0x190
    kernel_init_freeable+0x17c/0x207
    kernel_init+0xe/0x180
    ret_from_fork+0x7c/0xb0

  Kdump: vmcore not initialized

  kdump: dump target is /dev/sda4
  kdump: saving to /sysroot//var/crash/127.0.0.1-2014.01.28-13:58:52/
  kdump: saving vmcore-dmesg.txt
  Cannot open /proc/vmcore: No such file or directory
  kdump: saving vmcore-dmesg.txt failed
  kdump: saving vmcore
  kdump: saving vmcore failed

This type of failure has been seen on a four socket prototype system
with certain memory configurations.  Most PT_NOTE sections have a single
entry similar to:

  n_namesz = 0x5
  n_descsz = 0x150
  n_type   = 0x1

Occasionally, a second entry is encountered with very large n_namesz and
n_descsz sizes:

  n_namesz = 0x80000008
  n_descsz = 0x510ae163
  n_type   = 0x80000008

Not yet sure of the source of these extra entries, they seem bogus, but
they shouldn't cause crash dump to fail.
Signed-off-by: Greg Pearson <greg.pearson@hp.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

i2o_cfg_compat_ioctl(I2OGETIOPS) locks i2o_cfg_mutex and then calls
i2o_cfg_ioctl(I2OGETIOPS) that locks i2o_cfg_mutex as well.  A deadlock
is guaranteed.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Some of the 00-INDEX files are somewhat outdated and some folders does
not contain 00-INDEX at all.  Only outdated (with the notably exception
of spi) indexes are touched here, the 169 folders without 00-INDEX has
not been touched.

New 00-INDEX
 - spi/* was added in a series of commits dating back to 2006

Added files (missing in (*/)00-INDEX)
 - dmatest.txt was added by commit 851b7e16 ("dmatest: run test via
   debugfs")
 - this_cpu_ops.txt was added by commit a1b2a555 ("percpu: add
   documentation on this_cpu operations")
 - ww-mutex-design.txt was added by commit 040a0a37 ("mutex: Add
   support for wound/wait style locks")
 - bcache.txt was added by commit cafe5635 ("bcache: A block layer
   cache")
 - kernel-per-CPU-kthreads.txt was added by commit 49717cb4
   ("kthread: Document ways of reducing OS jitter due to per-CPU
   kthreads")
 - phy.txt was added by commit ff764963 ("drivers: phy: add generic
   PHY framework")
 - block/null_blk was added by commit 12f8f4fc ("null_blk:
   documentation")
 - module-signing.txt was added by commit 3cafea30 ("Add
   Documentation/module-signing.txt file")
 - assoc_array.txt was added by commit 3cb98950 ("Add a generic
   associative array implementation.")
 - arm/IXP4xx was part of the initial repo
 - arm/cluster-pm-race-avoidance.txt was added by commit 7fe31d28
   ("ARM: mcpm: introduce helpers for platform coherency exit/setup")
 - arm/firmware.txt was added by commit 7366b92a ("ARM: Add
   interface for registering and calling firmware-specific operations")
 - arm/kernel_mode_neon.txt was added by commit 2afd0a05 ("ARM:
   7825/1: document the use of NEON in kernel mode")
 - arm/tcm.txt was added by commit bc581770 ("ARM: 5580/2: ARM TCM
   (Tightly-Coupled Memory) support v3")
 - arm/vlocks.txt was added by commit 9762f12d ("ARM: mcpm: Add
   baremetal voting mutexes")
 - blackfin/gptimers-example.c, Makefile was added by commit
   4b60779d ("Blackfin: add an example showing how to use the
   gptimers API")
 - devicetree/usage-model.txt was added by commit 31134efc ("dt:
   Linux DT usage model documentation")
 - fb/api.txt was added by commit fb21c2f4 ("fbdev: Add FOURCC-based
   format configuration API")
 - fb/sm501.txt was added by commit e6a04980 ("video, sm501: add
   edid and commandline support")
 - fb/udlfb.txt was added by commit 96f8d864 ("fbdev: move udlfb out
   of staging.")
 - filesystems/Makefile was added by commit 1e0051ae
   ("Documentation/fs/: split txt and source files")
 - filesystems/nfs/nfsd-admin-interfaces.txt was added by commit
   8a4c6e19 ("nfsd: document kernel interfaces for nfsd
   configuration")
 - ide/warm-plug-howto.txt was added by commit f74c9141 ("ide: add
   warm-plug support for IDE devices (take 2)")
 - laptops/Makefile was added by commit d49129ac
   ("Documentation/laptop/: split txt and source files")
 - leds/leds-blinkm.txt was added by commit b54cf35a ("LEDS: add
   BlinkM RGB LED driver, documentation and update MAINTAINERS")
 - leds/ledtrig-oneshot.txt was added by commit 5e417281 ("leds: add
   oneshot trigger")
 - leds/ledtrig-transient.txt was added by commit 44e1e9f8 ("leds:
   add new transient trigger for one shot timer activation")
 - m68k/README.buddha was part of the initial repo
 - networking/LICENSE.(qla3xxx|qlcnic|qlge) was added by commits
   40839129, c4e84bde, 5a4faa87
 - networking/Makefile was added by commit 3794f3e8 ("docsrc: build
   Documentation/ sources")
 - networking/i40evf.txt was added by commit 105bf2fe ("i40evf: add
   driver to kernel build system")
 - networking/ipsec.txt was added by commit b3c6efbc ("xfrm: Add
   file to document IPsec corner case")
 - networking/mac80211-auth-assoc-deauth.txt was added by commit
   3cd7920a ("mac80211: add auth/assoc/deauth flow diagram")
 - networking/netlink_mmap.txt was added by commit 5683264c
   ("netlink: add documentation for memory mapped I/O")
 - networking/nf_conntrack-sysctl.txt was added by commit c9f9e0e1
   ("netfilter: doc: add nf_conntrack sysctl api documentation") lan)
 - networking/team.txt was added by commit 3d249d4c ("net: introduce
   ethernet teaming device")
 - networking/vxlan.txt was added by commit d342894c ("vxlan:
   virtual extensible lan")
 - power/runtime_pm.txt was added by commit 5e928f77 ("PM: Introduce
   core framework for run-time PM of I/O devices (rev.  17)")
 - power/charger-manager.txt was added by commit 3bb3dbbd
   ("power_supply: Add initial Charger-Manager driver")
 - RCU/lockdep-splat.txt was added by commit d7bd2d68 ("rcu:
   Document interpretation of RCU-lockdep splats")
 - s390/kvm.txt was added by 5ecee4ba (KVM: s390: API documentation)
 - s390/qeth.txt was added by commit b4d72c08 ("qeth: bridgeport
   support - basic control")
 - scheduler/sched-bwc.txt was added by commit 88ebc08e ("sched: Add
   documentation for bandwidth control")
 - scsi/advansys.txt was added by commit 4bd6d7f3 ("[SCSI] advansys:
   Move documentation to Documentation/scsi")
 - scsi/bfa.txt was added by commit 1ec90174 ("[SCSI] bfa: add
   readme file")
 - scsi/bnx2fc.txt was added by commit 12b8fc10 ("[SCSI] bnx2fc: Add
   driver documentation")
 - scsi/cxgb3i.txt was added by commit c3673464 ("[SCSI] cxgb3i: Add
   cxgb3i iSCSI driver.")
 - scsi/hpsa.txt was added by commit 992ebcf1 ("[SCSI] hpsa: Add
   hpsa.txt to Documentation/scsi")
 - scsi/link_power_management_policy.txt was added by commit
   ca77329f ("[libata] Link power management infrastructure")
 - scsi/osd.txt was added by commit 78e0c621 ("[SCSI] osd:
   Documentation for OSD library")
 - scsi/scsi-parameter.txt was created/moved by commit 163475fb
   ("Documentation: move SCSI parameters to their own text file")
 - serial/driver was part of the initial repo
 - serial/n_gsm.txt was added by commit 323e8412 ("n_gsm: add a
   documentation")
 - timers/Makefile was added by commit 3794f3e8 ("docsrc: build
   Documentation/ sources")
 - virt/kvm/s390.txt was added by commit d9101fca ("KVM: s390:
   diagnose call documentation")
 - vm/split_page_table_lock was added by commit 49076ec2 ("mm:
   dynamically allocate page->ptl if it cannot be embedded to struct
   page")
 - w1/slaves/w1_ds28e04 was added by commit fbf7f7b4 ("w1: Add
   1-wire slave device driver for DS28E04-100")
 - w1/masters/omap-hdq was added by commit e0a29382 ("hdq:
   documentation for OMAP HDQ")
 - x86/early-microcode.txt was added by commit 0d91ea86 ("x86, doc:
   Documentation for early microcode loading")
 - x86/earlyprintk.txt was added by commit a1aade47 ("x86/doc:
   mini-howto for using earlyprintk=dbgp")
 - x86/entry_64.txt was added by commit 8b4777a4 ("x86-64: Document
   some of entry_64.S")
 - x86/pat.txt was added by commit d27554d8 ("x86: PAT
   documentation")

Moved files
 - arm/kernel_user_helpers.txt was moved out of arch/arm/kernel by
   commit 37b83046 ("ARM: kuser: move interface documentation out of
   the source code")
 - efi-stub.txt was moved out of x86/ and down into Documentation/ in
   commit 4172fe2f ("EFI stub documentation updates")
 - laptops/hpfall.c was moved out of hwmon/ and into laptops/ in commit
   efcfed9b ("Move hp_accel to drivers/platform/x86")
 - commit 5616c23a ("x86: doc: move x86-generic documentation from
   Doc/x86/i386"):
   * x86/usb-legacy-support.txt
   * x86/boot.txt
   * x86/zero_page.txt
 - power/video_extension.txt was moved to acpi in commit 70e66e4d
   ("ACPI / video: move video_extension.txt to Documentation/acpi")

Removed files (left in 00-INDEX)
 - memory.txt was removed by commit 00ea8990 ("memory.txt: remove
   stray information")
 - gpio.txt was moved to gpio/ in commit fd8e198c ("Documentation:
   gpiolib: document new interface")
 - networking/DLINK.txt was removed by commit 168e06ae
   ("drivers/net: delete old parallel port de600/de620 drivers")
 - serial/hayes-esp.txt was removed by commit f53a2ade ("tty: esp:
   remove broken driver")
 - s390/TAPE was removed by commit 9e280f66 ("[S390] remove tape
   block docu")
 - vm/locking was removed by commit 57ea8171 ("mm: documentation:
   remove hopelessly out-of-date locking doc")
 - laptops/acer-wmi.txt was remvoed by commit 02003667 ("acer-wmi:
   Delete out-of-date documentation")

Typos/misc issues
 - rpc-server-gss.txt was added as knfsd-rpcgss.txt in commit
   030d794b ("SUNRPC: Use gssproxy upcall for server RPCGSS
   authentication.")
 - commit b88cf73d ("net: add missing entries to
   Documentation/networking/00-INDEX")
   * generic-hdlc.txt was added as generic_hdlc.txt
   * spider_net.txt was added as spider-net.txt
 - w1/master/mxc-w1 was added as mxc_w1 by commit a5fd9139 ("w1: add
   1-wire master driver for i.MX27 / i.MX31")
 - s390/zfcpdump.txt was added as zfcpdump by commit 6920c12a
   ("[S390] Add Documentation/s390/00-INDEX.")
Signed-off-by: Henrik Austad <henrik@austad.us>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>	[rcu bits]
Acked-by: Rob Landley <rob@landley.net>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Mark Brown <broonie@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Len Brown <len.brown@intel.com>
Cc: James Bottomley <JBottomley@parallels.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Since git v1.7.7, the .git directory can be a file when, for example,
the kernel is a submodule of another git super project.  So, the check
"-d .git" is not working anymore in this case.  Using a more generic
check like "-e .git" corrects this behaviour.
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Since git v1.7.7, the .git directory can be a file when, for example,
the kernel is a submodule of another git super project.  So, the check
"-d .git" is not working anymore in this case.  Using a more generic
check like "-e .git" corrects this behaviour.
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

I was reviewing this and noticed that unlocking should be conditional on
the error path.  I've changed it to unlock and return directly since we
only do it once and it seems unlikely to change in the near future.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 46d3ceab ("tcp: TCP Small Queues") introduced a possible
regression for applications using TCP_NODELAY.

If TCP session is throttled because of tsq, we should consult
tp->nonagle when TX completion is done and allow us to send additional
segment, especially if this segment is not a full MSS.
Otherwise this segment is sent after an RTO.

[edumazet] : Cooked the changelog, added another fix about testing
sk_wmem_alloc twice because TX completion can happen right before
setting TSQ_THROTTLED bit.

This problem is particularly visible with recent auto corking,
but might also be triggered with low tcp_limit_output_bytes
values or NIC drivers delaying TX completion by hundred of usec,
and very low rtt.

Thomas Glanzmann for example reported an iscsi regression, caused
by tcp auto corking making this bug quite visible.

Fixes: 46d3ceab ("tcp: TCP Small Queues")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Thomas Glanzmann <thomas@glanzmann.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Toshiaki Makita says:

====================
bridge: Fix corner case problems around local fdb entries

There are so many corner cases that are not handled properly around local
fdb entries.
- We might fail to delete the old entry and might delete an arbitrary local
  entry when changing mac address of a bridge port.
- We always fail to delete the old entry when changing mac address of the
  bridge device.
- We might incorrectly delete a necessary entry when detaching a bridge port.
- We might incorrectly delete a necessary entry when deleting a vlan.
and so on.

This is a patch series to fix these issues.

v3:
- Handle NTF_USE case in patch 1/9, commented by Vlad Yasevich.

- Tested port detach/attach and didn't find any problem with patch 5/9,
  suggested by Stephen Hemminger.

- Add comments about possible inconsistent state in current implementation
  into commit log of patch 5/9, found by the above test.

- Reword unintensive changelog of patch 7/9, commented by Vlad Yasevich.

v2:
- Change the way to find the old entry in br_fdb_changeaddr() from memorizing
  previous port address to introducing a new flag indicating whether a fdb
  entry is added by user or not, commented by Stephen Hemminger.

- Add a fix for the way to insert a new address in br_fdb_changeaddr().

- Prevent creating an entry such that its dst is NULL in br_add_if() to
  preserve old behavior, commented by Vlad Yasevich.

- Add more comments about slight behavior change, where the bridge device
  come to be able to receive traffic to an address it has during short
  window, to changelogs, commented by Vlad Yasevich.

- Add a fix for possible race in br_fdb_change_mac_address().
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

br_fdb_change_mac_address() calls fdb_insert()/fdb_delete() without
br->hash_lock.

These hash list updates are racy with br_fdb_update()/br_fdb_cleanup().
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Vlan codes unconditionally delete local fdb entries.
We should consider the possibility that other ports have the same
address and vlan.

Example of problematic case:
  ip link set eth0 address 12:34:56:78:90:ab
  ip link set eth1 address aa:bb:cc:dd:ee:ff
  brctl addif br0 eth0
  brctl addif br0 eth1 # br0 will have mac address 12:34:56:78:90:ab
  bridge vlan add dev eth0 vid 10
  bridge vlan add dev eth1 vid 10
  bridge vlan add dev br0 vid 10 self
We will have fdb entry such that f->dst == eth0, f->vlan_id == 10 and
f->addr == 12:34:56:78:90:ab at this time.
Next, delete eth0 vlan 10.
  bridge vlan del dev eth0 vid 10
In this case, we still need the entry for br0, but it will be deleted.

Note that br0 needs the entry even though its mac address is not set
manually. To delete the entry with proper condition checking,
fdb_delete_local() is suitable to use.
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

br_fdb_delete_by_port() doesn't care about vlan and mac address of the
bridge device.

As the check is almost the same as mac address changing, slightly modify
fdb_delete_local() and use it.

Note that we can always set added_by_user to 0 in fdb_delete_local() because
- br_fdb_delete_by_port() calls fdb_delete_local() for local entries
  regardless of its added_by_user. In this case, we have to check if another
  port has the same address and vlan, and if found, we have to create the
  entry (by changing dst). This is kernel-added entry, not user-added.
- br_fdb_changeaddr() doesn't call fdb_delete_local() for user-added entry.
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

br_fdb_change_mac_address() doesn't check if the local entry has the
same address as any of bridge ports.
Although I'm not sure when it is beneficial, current implementation allow
the bridge device to receive any mac address of its ports.
To preserve this behavior, we have to check if the mac address of the
entry being deleted is identical to that of any port.

As this check is almost the same as that in br_fdb_changeaddr(), create
a common function fdb_delete_local() and call it from
br_fdb_changeadddr() and br_fdb_change_mac_address().
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We should take into account the followings when deleting a local fdb
entry.

- nbp_vlan_find() can be used only when vid != 0 to check if an entry is
  deletable, because a fdb entry with vid 0 can exist at any time while
  nbp_vlan_find() always return false with vid 0.

  Example of problematic case:
    ip link set eth0 address 12:34:56:78:90:ab
    ip link set eth1 address 12:34:56:78:90:ab
    brctl addif br0 eth0
    brctl addif br0 eth1
    ip link set eth0 address aa:bb:cc:dd:ee:ff
  Then, the fdb entry 12:34:56:78:90:ab will be deleted even though the
  bridge port eth1 still has that address.

- The port to which the bridge device is attached might needs a local entry
  if its mac address is set manually.

  Example of problematic case:
    ip link set eth0 address 12:34:56:78:90:ab
    brctl addif br0 eth0
    ip link set br0 address 12:34:56:78:90:ab
    ip link set eth0 address aa:bb:cc:dd:ee:ff
  Then, the fdb still must have the entry 12:34:56:78:90:ab, but it will be
  deleted.

We can use br->dev->addr_assign_type to check if the address is manually
set or not, but I propose another approach.

Since we delete and insert local entries whenever changing mac address
of the bridge device, we can change dst of the entry to NULL regardless of
addr_assign_type when deleting an entry associated with a certain port,
and if it is found to be unnecessary later, then delete it.
That is, if changing mac address of a port, the entry might be changed
to its dst being NULL first, but is eventually deleted when recalculating
and changing bridge id.

This approach is especially useful when we want to share the code with
deleting vlan in which the bridge device might want such an entry regardless
of addr_assign_type, and makes things easy because we don't have to consider
if mac address of the bridge device will be changed or not at the time we
delete a local entry of a port, which means fdb code will not be bothered
even if the bridge id calculating logic is changed in the future.

Also, this change reduces inconsistent state, where frames whose dst is the
mac address of the bridge, can't reach the bridge because of premature fdb
entry deletion. This change reduces the possibility that the bridge device
replies unreachable mac address to arp requests, which could occur during
the short window between calling del_nbp() and br_stp_recalculate_bridge_id()
in br_del_if(). This will effective after br_fdb_delete_by_port() starts to
use the same code by following patch.
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Vlan code may need fdb change when changing mac address of bridge device
even if it is caused by the mac address changing of a bridge port.

Example configuration:
  ip link set eth0 address 12:34:56:78:90:ab
  ip link set eth1 address aa:bb:cc:dd:ee:ff
  brctl addif br0 eth0
  brctl addif br0 eth1 # br0 will have mac address 12:34:56:78:90:ab
  bridge vlan add dev br0 vid 10 self
  bridge vlan add dev eth0 vid 10
We will have fdb entry such that f->dst == NULL, f->vlan_id == 10 and
f->addr == 12:34:56:78:90:ab at this time.
Next, change the mac address of eth0 to greater value.
  ip link set eth0 address ee:ff:12:34:56:78
Then, mac address of br0 will be recalculated and set to aa:bb:cc:dd:ee:ff.
However, an entry aa:bb:cc:dd:ee:ff will not be created and we will be not
able to communicate using br0 on vlan 10.

Address this issue by deleting and adding local entries whenever
changing the mac address of the bridge device.

If there already exists an entry that has the same address, for example,
in case that br_fdb_changeaddr() has already inserted it,
br_fdb_change_mac_address() will simply fail to insert it and no
duplicated entry will be made, as it was.

This approach also needs br_add_if() to call br_fdb_insert() before
br_stp_recalculate_bridge_id() so that we don't create an entry whose
dst == NULL in this function to preserve previous behavior.

Note that this is a slight change in behavior where the bridge device can
receive the traffic to the new address before calling
br_stp_recalculate_bridge_id() in br_add_if().
However, it is not a problem because we have already the address on the
new port and such a way to insert new one before recalculating bridge id
is taken in br_device_event() as well.
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We have been always failed to delete the old entry at
br_fdb_change_mac_address() because br_set_mac_address() updates
dev->dev_addr before calling br_fdb_change_mac_address() and
br_fdb_change_mac_address() uses dev->dev_addr to find the old entry.

That update of dev_addr is completely unnecessary because the same work
is done in br_stp_change_bridge_id() which is called right away after
calling br_fdb_change_mac_address().
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since commit bc9a25d2 ("bridge: Add vlan support for local fdb entries"),
br_fdb_changeaddr() has inserted a new local fdb entry only if it can
find old one. But if we have two ports where they have the same address
or user has deleted a local entry, there will be no entry for one of the
ports.

Example of problematic case:
  ip link set eth0 address aa:bb:cc:dd:ee:ff
  ip link set eth1 address aa:bb:cc:dd:ee:ff
  brctl addif br0 eth0
  brctl addif br0 eth1 # eth1 will not have a local entry due to dup.
  ip link set eth1 address 12:34:56:78:90:ab
Then, the new entry for the address 12:34:56:78:90:ab will not be
created, and the bridge device will not be able to communicate.

Insert new entries regardless of whether we can find old entries or not.
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>