what the hell is op_mutex for, BTW?
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

* sanity checks belong before risky operation, not after it
* don't quit as soon as we'd found an entry
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

new helper: dir_relax(inode).  Call when you are in location that will
_not_ be invalidated by directory modifications (block boundary, in case
of ext*).  Returns whether the directory has survived (dropping i_mutex
allows rmdir to kill the sucker; if it returns false to us, ->iterate()
is obviously done)
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

new helpers - dir_emit_dot(file, ctx, dentry), dir_emit_dotdot(file, ctx),
dir_emit_dots(file, ctx).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

ext2, ufs, minix, sysv
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

New method - ->iterate(file, ctx).  That's the replacement for ->readdir();
it takes callback from ctx->actor, uses ctx->pos instead of file->f_pos and
calls dir_emit(ctx, ...) instead of filldir(data, ...).  It does *not*
update file->f_pos (or look at it, for that matter); iterate_dir() does the
update.

Note that dir_emit() takes the offset from ctx->pos (and eventually
filldir_t will lose that argument).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

iterate_dir(): new helper, replacing vfs_readdir().

struct dir_context: contains the readdir callback (and will get more stuff
in it), embedded into whatever data that callback wants to deal with;
eventually, we'll be passing it to ->readdir() replacement instead of
(data,filldir) pair.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and single return is quite sufficient to get out of function, TYVM
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

io_remap_pfn_range() does all we need
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

io_remap_pfn_range() sets it
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

io_remap_pfn_range() will set it just fine
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Al Viro pointed me to the fact that '->readdir()' and '->llseek()' have no
mutual exclusion, which means the 'ubifs_dir_llseek()' can be run while we are
in the middle of 'ubifs_readdir()'.

This means that 'file->private_data' can be freed while 'ubifs_readdir()' uses
it, and this is a very bad bug: not only 'ubifs_readdir()' can return garbage,
but this may corrupt memory and lead to all kinds of problems like crashes an
security holes.

This patch fixes the problem by using the 'file->f_version' field, which
'->llseek()' always unconditionally sets to zero. We set it to 1 in
'ubifs_readdir()' and whenever we detect that it became 0, we know there was a
seek and it is time to clear the state saved in 'file->private_data'.

I tested this patch by writing a user-space program which runds readdir and
seek in parallell. I could easily crash the kernel without these patches, but
could not crash it with these patches.

Cc: stable@vger.kernel.org
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Tested-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Al Viro pointed me to the fact that '->readdir()' and '->llseek()' have no
mutual exclusion, which means the 'ubifs_dir_llseek()' can be run while we are
in the middle of 'ubifs_readdir()'.

First of all, this means that 'file->private_data' can be freed while
'ubifs_readdir()' uses it.  But this particular patch does not fix the problem.
This patch is only a preparation, and the fix will follow next.

In this patch we make 'ubifs_readdir()' stop using 'file->f_pos' directly,
because 'file->f_pos' can be changed by '->llseek()' at any point. This may
lead 'ubifs_readdir()' to returning inconsistent data: directory entry names
may correspond to incorrect file positions.

So here we introduce a local variable 'pos', read 'file->f_pose' once at very
the beginning, and then stick to 'pos'. The result of this is that when
'ubifs_dir_llseek()' changes 'file->f_pos' while we are in the middle of
'ubifs_readdir()', the latter "wins".

Cc: stable@vger.kernel.org
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Tested-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

dump_seek() does SEEK_CUR, not SEEK_SET; native binfmt_aout
handles it correctly (seeks by PAGE_SIZE - sizeof(struct user),
getting the current position to PAGE_SIZE), compat one seeks
by PAGE_SIZE and ends up at PAGE_SIZE + already written...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

When you copy some code, you are supposed to read it.  If nothing else,
there's a chance to spot and fix an obvious bug instead of sharing it...

X-Song: "I Got It From Agnes", by Tom Lehrer
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
[ Tom Lehrer? You're dating yourself, Al ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull ARM SoC fixes from Olof Johansson:
 "These are a little later than I planned on since I got caught up with
  handling merges for 3.11 most of the week.

  Another week, another batch of fixes for arm-soc platforms.

  Again, nothing controversial.  A few more than would be ideal, but all
  are valid fixes.  In particular the prima2 panic patch is critical
  since it fixes a problem where multiplatform kernels panic on all but
  prima2 hardware."

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: SAMSUNG: pm: Adjust for pinctrl- and DT-enabled platforms
  ARM: prima2: fix incorrect panic usage
  arm: mvebu: armada-xp-{gp,openblocks-ax3-4}: specify PCIe range
  ARM: Kirkwood: handle mv88f6282 cpu in __kirkwood_variant().
  ARM: omap3: clock: fix wrong container_of in clock36xx.c
  ARM: dts: OMAP5: Fix missing PWM capability to timer nodes
  ARM: dts: omap4-panda|sdp: Fix mux for twl6030 IRQ pin and msecure line
  ARM: dts: AM33xx: Fix properties on gpmc node
  arm: omap2: fix AM33xx hwmod infos for UART2
  ARM: OMAP3: Fix iva2_pwrdm settings for 3703

Pull networking fixes from David Miller:

 1) Fix RTNL locking in batman-adv, from Matthias Schiffer.

 2) Don't allow non-passthrough macvlan devices to set NOPROMISC via
    netlink, otherwise we can end up with corrupted promisc counter
    values on the device.  From Michael S Tsirkin.

 3) Fix stmmac driver build with debugging defines enabled, from Dinh
    Nguyen.

 4) Make sure name string we give in socket address in AF_PACKET is NULL
    terminated, from Daniel Borkmann.

 5) Fix leaking of two uninitialized bytes of memory to userspace in
    l2tp, from Guillaume Nault.

 6) Clear IPCB(skb) before tunneling otherwise we touch dangling IP
    options state and crash.  From Saurabh Mohan.

 7) Fix suspend/resume for davinci_mdio by using suspend_late and
    resume_early.  From Mugunthan V N.

 8) Don't tag ip_tunnel_init_net and ip_tunnel_delete_net with
    __net_{init,exit}, they can be called outside of those contexts.
    From Eric Dumazet.

 9) Fix RX length error in sh_eth driver, from Yoshihiro Shimoda.

10) Fix missing sctp_outq initialization in some code paths of SCTP
    stack, from Neil Horman.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (21 commits)
  sctp: fully initialize sctp_outq in sctp_outq_init
  netiucv: Hold rtnl between name allocation and device registration.
  tulip: Properly check dma mapping result
  net: sh_eth: fix incorrect RX length error if R8A7740
  ip_tunnel: remove __net_init/exit from exported functions
  drivers: net: davinci_mdio: restore mdio clk divider in mdio resume
  drivers: net: davinci_mdio: moving mdio resume earlier than cpsw ethernet driver
  net/ipv4: ip_vti clear skb cb before tunneling.
  tg3: Wait for boot code to finish after power on
  l2tp: Fix sendmsg() return value
  l2tp: Fix PPP header erasure and memory leak
  bonding: fix igmp_retrans type and two related races
  bonding: reset master mac on first enslave failure
  packet: packet_getname_spkt: make sure string is always 0-terminated
  net: ethernet: stmicro: stmmac: Fix compile error when STMMAC_XMIT_DEBUG used
  be2net: Fix 32-bit DMA Mask handling
  xen-netback: don't de-reference vif pointer after having called xenvif_put()
  macvlan: don't touch promisc without passthrough
  batman-adv: Don't handle address updates when bla is disabled
  batman-adv: forward late OGMs from best next hop
  ...

Pull powerpc fixes from Benjamin Herrenschmidt:
 "So here are 3 fixes still for 3.10.  Fixes are simple, bugs are nasty
  (though not recent regressions, nasty enough) and all targeted at
  stable"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: Fix missing/delayed calls to irq_work
  powerpc: Fix emulation of illegal instructions on PowerNV platform
  powerpc: Fix stack overflow crash in resume_kernel when ftracing

Thanks to commit f91eb62f ("init: scream bloody murder if interrupts
are enabled too early"), "bloody murder" is now being screamed.

With a MIPS OCTEON config, we use on_each_cpu() in our
irq_chip.irq_bus_sync_unlock() function.  This gets called in early as a
result of the time_init() call.  Because the !SMP version of
on_each_cpu() unconditionally enables irqs, we get:

    WARNING: at init/main.c:560 start_kernel+0x250/0x410()
    Interrupts were enabled early
    CPU: 0 PID: 0 Comm: swapper Not tainted 3.10.0-rc5-Cavium-Octeon+ #801
    Call Trace:
      show_stack+0x68/0x80
      warn_slowpath_common+0x78/0xb0
      warn_slowpath_fmt+0x38/0x48
      start_kernel+0x250/0x410

Suggested fix: Do what we already do in the SMP version of
on_each_cpu(), and use local_irq_save/local_irq_restore.  Because we
need a flags variable, make it a static inline to avoid name space
issues.

[ Change from v1: Convert on_each_cpu to a static inline function, add
  #include <linux/irqflags.h> to avoid build breakage on some files.

  on_each_cpu_mask() and on_each_cpu_cond() suffer the same problem as
  on_each_cpu(), but they are not causing !SMP bugs for me, so I will
  defer changing them to a less urgent patch. ]
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull VFS fixes from Al Viro:
 "Several fixes + obvious cleanup (you've missed a couple of open-coded
  can_lookup() back then)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  snd_pcm_link(): fix a leak...
  use can_lookup() instead of direct checks of ->i_op->lookup
  move exit_task_namespaces() outside of exit_notify()
  fput: task_work_add() can fail if the caller has passed exit_task_work()
  ncpfs: fix rmdir returns Device or resource busy

Pull xfs fixes from Ben Myers:
 - Remove noisy warnings about experimental support which spams the logs
 - Add padding to align directory and attr structures correctly
 - Set block number on child buffer on a root btree split
 - Disable verifiers during log recovery for non-CRC filesystems

* tag 'for-linus-v3.10-rc6' of git://oss.sgi.com/xfs/xfs:
  xfs: don't shutdown log recovery on validation errors
  xfs: ensure btree root split sets blkno correctly
  xfs: fix implicit padding in directory and attr CRC formats
  xfs: don't emit v5 superblock warnings on write

Pull char / misc fixes from Greg Kroah-Hartman:
 "Here are some small mei driver fixes for 3.10-rc6 that fix some
  reported problems"

* tag 'char-misc-3.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  mei: me: clear interrupts on the resume path
  mei: nfc: fix nfc device freeing
  mei: init: Flush scheduled work before resetting the device

Pull USB fixes from Greg Kroah-Hartman:
 "Here are some small USB driver fixes that resolve some reported
  problems for 3.10-rc6

  Nothing major, just 3 USB serial driver fixes, and two chipidea fixes"

* tag 'usb-3.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: chipidea: fix id change handling
  usb: chipidea: fix no transceiver case
  USB: pl2303: fix device initialisation at open
  USB: spcp8x5: fix device initialisation at open
  USB: f81232: fix device initialisation at open