eBPF programs passed from userspace are using pseudo BPF_LD_IMM64 instructions
to refer to process-local map_fd. Scan the program for such instructions and
if FDs are valid, convert them to 'struct bpf_map' pointers which will be used
by verifier to check access to maps in bpf_map_lookup/update() calls.
If program passes verifier, convert pseudo BPF_LD_IMM64 into generic by dropping
BPF_PSEUDO_MAP_FD flag.

Note that eBPF interpreter is generic and knows nothing about pseudo insns.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

add optional attributes for BPF_PROG_LOAD syscall:
union bpf_attr {
    struct {
	...
	__u32         log_level; /* verbosity level of eBPF verifier */
	__u32         log_size;  /* size of user buffer */
	__aligned_u64 log_buf;   /* user supplied 'char *buffer' */
    };
};

when log_level > 0 the verifier will return its verification log in the user
supplied buffer 'log_buf' which can be used by program author to analyze why
verifier rejected given program.

'Understanding eBPF verifier messages' section of Documentation/networking/filter.txt
provides several examples of these messages, like the program:

  BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
  BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
  BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
  BPF_LD_MAP_FD(BPF_REG_1, 0),
  BPF_CALL_FUNC(BPF_FUNC_map_lookup_elem),
  BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
  BPF_ST_MEM(BPF_DW, BPF_REG_0, 4, 0),
  BPF_EXIT_INSN(),

will be rejected with the following multi-line message in log_buf:

  0: (7a) *(u64 *)(r10 -8) = 0
  1: (bf) r2 = r10
  2: (07) r2 += -8
  3: (b7) r1 = 0
  4: (85) call 1
  5: (15) if r0 == 0x0 goto pc+1
   R0=map_ptr R10=fp
  6: (7a) *(u64 *)(r0 +4) = 0
  misaligned access off 4 size 8

The format of the output can change at any time as verifier evolves.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

this patch adds all of eBPF verfier documentation and empty bpf_check()

The end goal for the verifier is to statically check safety of the program.

Verifier will catch:
- loops
- out of range jumps
- unreachable instructions
- invalid instructions
- uninitialized register access
- uninitialized stack access
- misaligned stack access
- out of range stack access
- invalid calling convention

More details in Documentation/networking/filter.txt
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

in native eBPF programs userspace is using pseudo BPF_CALL instructions
which encode one of 'enum bpf_func_id' inside insn->imm field.
Verifier checks that program using correct function arguments to given func_id.
If all checks passed, kernel needs to fixup BPF_CALL->imm fields by
replacing func_id with in-kernel function pointer.
eBPF interpreter just calls the function.

In-kernel eBPF users continue to use generic BPF_CALL.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

eBPF programs are similar to kernel modules. They are loaded by the user
process and automatically unloaded when process exits. Each eBPF program is
a safe run-to-completion set of instructions. eBPF verifier statically
determines that the program terminates and is safe to execute.

The following syscall wrapper can be used to load the program:
int bpf_prog_load(enum bpf_prog_type prog_type,
                  const struct bpf_insn *insns, int insn_cnt,
                  const char *license)
{
    union bpf_attr attr = {
        .prog_type = prog_type,
        .insns = ptr_to_u64(insns),
        .insn_cnt = insn_cnt,
        .license = ptr_to_u64(license),
    };

    return bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
}
where 'insns' is an array of eBPF instructions and 'license' is a string
that must be GPL compatible to call helper functions marked gpl_only

Upon succesful load the syscall returns prog_fd.
Use close(prog_fd) to unload the program.

User space tests and examples follow in the later patches
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

'maps' is a generic storage of different types for sharing data between kernel
and userspace.

The maps are accessed from user space via BPF syscall, which has commands:

- create a map with given type and attributes
  fd = bpf(BPF_MAP_CREATE, union bpf_attr *attr, u32 size)
  returns fd or negative error

- lookup key in a given map referenced by fd
  err = bpf(BPF_MAP_LOOKUP_ELEM, union bpf_attr *attr, u32 size)
  using attr->map_fd, attr->key, attr->value
  returns zero and stores found elem into value or negative error

- create or update key/value pair in a given map
  err = bpf(BPF_MAP_UPDATE_ELEM, union bpf_attr *attr, u32 size)
  using attr->map_fd, attr->key, attr->value
  returns zero or negative error

- find and delete element by key in a given map
  err = bpf(BPF_MAP_DELETE_ELEM, union bpf_attr *attr, u32 size)
  using attr->map_fd, attr->key

- iterate map elements (based on input key return next_key)
  err = bpf(BPF_MAP_GET_NEXT_KEY, union bpf_attr *attr, u32 size)
  using attr->map_fd, attr->key, attr->next_key

- close(fd) deletes the map
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

done as separate commit to ease conflict resolution
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

BPF syscall is a multiplexor for a range of different operations on eBPF.
This patch introduces syscall with single command to create a map.
Next patch adds commands to access maps.

'maps' is a generic storage of different types for sharing data between kernel
and userspace.

Userspace example:
/* this syscall wrapper creates a map with given type and attributes
 * and returns map_fd on success.
 * use close(map_fd) to delete the map
 */
int bpf_create_map(enum bpf_map_type map_type, int key_size,
                   int value_size, int max_entries)
{
    union bpf_attr attr = {
        .map_type = map_type,
        .key_size = key_size,
        .value_size = value_size,
        .max_entries = max_entries
    };

    return bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
}

'union bpf_attr' is backwards compatible with future extensions.

More details in Documentation/networking/filter.txt and in manpage
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

While using a MQ + NETEM setup, I had confirmation that the default
timer migration ( /proc/sys/kernel/timer_migration ) is killing us.

Installing this on a receiver side of a TCP_STREAM test, (NIC has 8 TX
queues) :

EST="est 1sec 4sec"
for ETH in eth1
do
 tc qd del dev $ETH root 2>/dev/null
 tc qd add dev $ETH root handle 1: mq
 tc qd add dev $ETH parent 1:1 $EST netem limit 70000 delay 6ms
 tc qd add dev $ETH parent 1:2 $EST netem limit 70000 delay 8ms
 tc qd add dev $ETH parent 1:3 $EST netem limit 70000 delay 10ms
 tc qd add dev $ETH parent 1:4 $EST netem limit 70000 delay 12ms
 tc qd add dev $ETH parent 1:5 $EST netem limit 70000 delay 14ms
 tc qd add dev $ETH parent 1:6 $EST netem limit 70000 delay 16ms
 tc qd add dev $ETH parent 1:7 $EST netem limit 80000 delay 18ms
 tc qd add dev $ETH parent 1:8 $EST netem limit 90000 delay 20ms
done

We can see that timers get migrated into a single cpu, presumably idle
at the time timers are set up.
Then all qdisc dequeues run from this cpu and huge lock contention
happens. This single cpu is stuck in softirq mode and cannot dequeue
fast enough.

    39.24%  [kernel]          [k] _raw_spin_lock
     2.65%  [kernel]          [k] netem_enqueue
     1.80%  [kernel]          [k] netem_dequeue
     1.63%  [kernel]          [k] copy_user_enhanced_fast_string
     1.45%  [kernel]          [k] _raw_spin_lock_bh

By pinning qdisc timers on the cpu running the qdisc, we respect proper
XPS setting and remove this lock contention.

     5.84%  [kernel]          [k] netem_enqueue
     4.83%  [kernel]          [k] _raw_spin_lock
     2.92%  [kernel]          [k] copy_user_enhanced_fast_string

Current Qdiscs that benefit from this change are :

	netem, cbq, fq, hfsc, tbf, htb.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Tom Herbert says:

====================
net: Eliminate gso_send_check

gso_send_check presents a lot of complexity for what it is being used
for. It seems that there are only two cases where it might be effective:
TCP and UFO paths. In these cases, the gso_send_check function
initializes the TCP or UDP checksum respectively to the pseudo header
checksum so that the checksum computation is appropriately offloaded or
computed in the gso_segment functions. The gso_send_check functions
are only called from dev.c in skb_mac_gso_segment when ip_summed !=
CHECKSUM_PARTIAL (which seems very unlikely in TCP case). We can move
the logic of this into the respective gso_segment functions where the
checksum is initialized if ip_summed != CHECKSUM_PARTIAL.

With the above cases handled, gso_send_check is no longer needed, so
we can remove all uses of it and the fields in the offload callbacks.
With this change, ip_summed in the skb should be preserved though all
the layers of gso_segment calls.

In follow-on patches, we may be able to remove the check setup code in
tcp_gso_segment if we can guarantee that ip_summed will always be
CHECKSUM_PARTIAL (verify all paths and probably add an assert in
tcp_gro_segment).

Tested these patches by:
  - netperf TCP_STREAM test with GSO enabled
  - Forced ip_summed != CHECKSUM_PARTIAL with above
  - Ran UDP_RR with 10000 request size over GRE tunnel. This exercised
    UFO path.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The send_check logic was only interesting in cases of TCP offload and
UDP UFO where the checksum needed to be initialized to the pseudo
header checksum. Now we've moved that logic into the related
gso_segment functions so gso_send_check is no longer needed.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In udp[46]_ufo_send_check the UDP checksum initialized to the pseudo
header checksum. We can move this logic into udp[46]_ufo_fragment.
After this change udp[64]_ufo_send_check is a no-op.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In tcp_v[46]_gso_send_check the TCP checksum is initialized to the
pseudo header checksum using __tcp_v[46]_send_check. We can move this
logic into new tcp[46]_gso_segment functions to be done when
ip_summed != CHECKSUM_PARTIAL (ip_summed == CHECKSUM_PARTIAL should be
the common case, possibly always true when taking GSO path). After this
change tcp_v[46]_gso_send_check is no-op.
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Beniamino Galvani says:

====================
net: stmmac glue layer for Amlogic Meson SoCs

the Ethernet controller available in Amlogic Meson6 and Meson8 SoCs is
a Synopsys DesignWare MAC IP core, already supported by the stmmac
driver.

These patches add a glue layer to the driver for the platform-specific
settings required by the Amlogic variant.

This has been tested on a Amlogic S802 device with the initial Meson
support submitted by Carlo Caione [1].

[1] http://lwn.net/Articles/612000/
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add the device tree bindings documentation for the Amlogic Meson
variant of the Synopsys DesignWare MAC.
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The Ethernet controller available in Meson6 and Meson8 SoCs is a
Synopsys DesignWare MAC IP core, already supported by the stmmac
driver.

This glue layer implements some platform-specific settings needed by
the Amlogic variant.
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull networking fixes from David Miller:
 "Here is a quick pull request primarily meant to address the deconfig
  fallout from changing SCSI_NETLINK from being used via 'select' to
  being used via 'depends'.

  I applied a set of 5 patches written by Michal Marek, and then I
  carefully audited all of the remaining config files, basically:

   1) I scanned every arch config file, and if it mentioned CONFIG_INET
      or CONFIG_UNIX, I made sure it had CONFIG_NET=y

   2) After that, I scanned every arch config file, and if it did not
      have CONFIG_NET=y I made sure it did not reference any networking
      config options.

  Finally, we have some late breaking wireless fixes in here from John
  Linville and co"

[ And there's a sparc bpf fix snuck in too ]

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  sparc: bpf_jit: fix loads from negative offsets
  parisc: Update defconfigs which were missing CONFIG_NET.
  powerpc: Update defconfigs which were missing CONFIG_NET.
  s390: Update defconfigs which were missing CONFIG_NET.
  mips: Update some more defconfigs which were missing CONFIG_NET.
  sparc: Set CONFIG_NET=y in defconfigs
  sh: Set CONFIG_NET=y in defconfigs
  powerpc: Set CONFIG_NET=y in defconfigs
  parisc: Set CONFIG_NET=y in defconfigs
  mips: Set CONFIG_NET=y in defconfigs
  brcmfmac: Fix off by one bug in brcmf_count_20mhz_channels()
  ath9k: Fix NULL pointer dereference on early irq
  net: rfkill: gpio: Fix clock status
  NFC: st21nfca: Fix potential depmod dependency cycle
  NFC: st21nfcb: Fix depmod dependency cycle
  NFC: microread: Potential overflows in microread_target_discovered()

- fix BPF_LD|ABS|IND from negative offsets:
  make sure to sign extend lower 32 bits in 64-bit register
  before calling C helpers from JITed code, otherwise 'int k'
  argument of bpf_internal_load_pointer_neg_helper() function
  will be added as large unsigned integer, causing packet size
  check to trigger and abort the program.

  It's worth noting that JITed code for 'A = A op K' will affect
  upper 32 bits differently depending whether K is simm13 or not.
  Since small constants are sign extended, whereas large constants
  are stored in temp register and zero extended.
  That is ok and we don't have to pay a penalty of sign extension
  for every sethi, since all classic BPF instructions have 32-bit
  semantics and we only need to set correct upper bits when
  transitioning from JITed code into C.

- though instructions 'A &= 0' and 'A *= 0' are odd, JIT compiler
  should not optimize them out
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

John W. Linville says:

====================
pull request: wireless 2014-09-23

Please consider pulling this one last batch of fixes intended for the 3.17 stream!

For the NFC bits, Samuel says:

"Hopefully not too late for a handful of NFC fixes:

- 2 potential build failures for ST21NFCA and ST21NFCB, triggered by a
  depmod dependenyc cycle.
- One potential buffer overflow in the microread driver."

On top of that...

Emil Goode provides a fix for a brcmfmac off-by-one regression which
was introduced in the 3.17 cycle.

Loic Poulain fixes a polarity mismatch for a variable assignment
inside of rfkill-gpio.

Wojciech Dubowik prevents a NULL pointer dereference in ath9k.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit df568d8e ("scsi: Use 'depends' with LIBFC instead of
'select'.")  removed what happened to be the only instance of 'select
NET'. Defconfigs that were relying on the select now lack networking
support.
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit df568d8e ("scsi: Use 'depends' with LIBFC instead of
'select'.")  removed what happened to be the only instance of 'select
NET'. Defconfigs that were relying on the select now lack networking
support.
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit df568d8e ("scsi: Use 'depends' with LIBFC instead of
'select'.")  removed what happened to be the only instance of 'select
NET'. Defconfigs that were relying on the select now lack networking
support.
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit df568d8e ("scsi: Use 'depends' with LIBFC instead of
'select'.")  removed what happened to be the only instance of 'select
NET'. Defconfigs that were relying on the select now lack networking
support.
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 5d6be6a5 ("scsi_netlink : Make SCSI_NETLINK dependent on NET
instead of selecting NET") removed what happened to be the only instance
of 'select NET'. Defconfigs that were relying on the select now lack
networking support.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: sparclinux@vger.kernel.org
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 5d6be6a5 ("scsi_netlink : Make SCSI_NETLINK dependent on NET
instead of selecting NET") removed what happened to be the only instance
of 'select NET'. Defconfigs that were relying on the select now lack
networking support.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: linux-sh@vger.kernel.org
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 5d6be6a5 ("scsi_netlink : Make SCSI_NETLINK dependent on NET
instead of selecting NET") removed what happened to be the only instance
of 'select NET'. Defconfigs that were relying on the select now lack
networking support.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 5d6be6a5 ("scsi_netlink : Make SCSI_NETLINK dependent on NET
instead of selecting NET") removed what happened to be the only instance
of 'select NET'. Defconfigs that were relying on the select now lack
networking support.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 5d6be6a5 ("scsi_netlink : Make SCSI_NETLINK dependent on NET
instead of selecting NET") removed what happened to be the only instance
of 'select NET'. Defconfigs that were relying on the select now lack
networking support.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: linux-mips@linux-mips.org
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull one last block fix from Jens Axboe:
 "We've had an issue with scsi-mq where probing takes forever.  This was
  bisected down to the percpu changes for blk_mq_queue_enter(), and the
  fact we now suffer an RCU grace period when killing a queue.  SCSI
  creates and destroys tons of queues, so this let to 10s of seconds of
  stalls at boot for some.

  Tejun has a real fix for this, but it's too involved for 3.17.  So
  this is a temporary workaround to expedite the queue killing until we
  can fold in the real fix for 3.18 when that merge window opens"

* 'for-linus' of git://git.kernel.dk/linux-block:
  blk-mq, percpu_ref: implement a kludge for SCSI blk-mq stall during probe

Pull PCI fixes from Bjorn Helgaas:
 "Here are a few fixes that should be in v3.17.

   - Reverting "Don't scan random busses" covers up a CardBus regression
     having to do with allocating CardBus bus numbers.

   - Reverting "Make sure bus numbers stay within parents bounds" covers
     up an ACPI _CRS bug that makes us reconfigure a bridge, causing a
     broken device behind it to stop responding.

   - The pciehp timeout change fixes some code we added in v3.17.
     Without the fix, we can send a new hotplug command too early,
     before the timeout has expired.

  I hope for better fixes for the reverts, but those will have to come
  after v3.17"

* tag 'pci-v3.17-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: pciehp: Fix pcie_wait_cmd() timeout
  Revert "PCI: Make sure bus number resources stay within their parents bounds"
  Revert "PCI: Don't scan random busses in pci_scan_bridge()"

Pull crypto fixes from Herbert Xu:
 "This fixes three issues:

   - if ccp is loaded on a machine without ccp, it will incorrectly
     activate causing all requests to fail.  Fixed by preventing ccp
     from loading if hardware isn't available.

   - not all IRQs were enabled for the qat driver, leading to potential
     stalls when it is used

   - disabled buggy AVX CTR implementation in aesni"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: aesni - disable "by8" AVX CTR optimization
  crypto: ccp - Check for CCP before registering crypto algs
  crypto: qat - Enable all 32 IRQs

Pull media fixes from Mauro Carvalho Chehab:
 "For some last time fixes:
   - a regression detected on Kernel 3.16 related to VBI Teletext
     application breakage on drivers using videobuf2 (see
     https://bugzilla.kernel.org/show_bug.cgi?id=84401).  The bug was
     noticed on saa7134 (migrated to VB2 on 3.16), but also affects
     em28xx (migrated on 3.9 to VB2);
   - two additional sanity checks at videobuf2;
   - two fixups to restore proper VBI support at the em28xx driver;
   - two Kernel oops fixups (at cx24123 and cx2341x drivers);
   - a bug at adv7604 where an if was doing just the opposite as it
     would be expected;
   - some documentation fixups to match the behavior defined at the
     Kernel"

* tag 'media/v3.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  [media] em28xx-v4l: get rid of field "users" in struct em28xx_v4l2"
  [media] em28xx: fix VBI handling logic
  [media] DocBook media: improve the poll() documentation
  [media] DocBook media: fix the poll() 'no QBUF' documentation
  [media] vb2: fix VBI/poll regression
  [media] cx2341x: fix kernel oops
  [media] cx24123: fix kernel oops due to missing parent pointer
  [media] adv7604: fix inverted condition
  [media] media/radio: fix radio-miropcm20.c build with io.h header file
  [media] vb2: fix plane index sanity check in vb2_plane_cookie()
  [media] DocBook media: update version number and V4L2 changes
  [media] DocBook media: fix fieldname in struct v4l2_subdev_selection
  [media] vb2: fix vb2 state check when start_streaming fails
  [media] videobuf2-core.h: fix comment
  [media] videobuf2-core: add comments before the WARN_ON
  [media] videobuf2-dma-sg: fix for wrong GFP mask to sg_alloc_table_from_pages

Pull bugfixes for md/raid1 from Neil Brown:
 "It is amazing how much easier it is to find bugs when you know one is
  there.  Two bug reports resulted in finding 7 bugs!

  All are tagged for -stable.  Those that can't cause (rare) data
  corruption, cause lockups.

  Particularly, but not only, fixing new "resync" code"

* tag 'md/3.17-more-fixes' of git://git.neil.brown.name/md:
  md/raid1: fix_read_error should act on all non-faulty devices.
  md/raid1: count resync requests in nr_pending.
  md/raid1: update next_resync under resync_lock.
  md/raid1: Don't use next_resync to determine how far resync has progressed
  md/raid1: make sure resync waits for conflicting writes to complete.
  md/raid1: clean up request counts properly in close_sync()
  md/raid1:  be more cautious where we read-balance during resync.
  md/raid1: intialise start_next_window for READ case to avoid hang

blk-mq uses percpu_ref for its usage counter which tracks the number
of in-flight commands and used to synchronously drain the queue on
freeze.  percpu_ref shutdown takes measureable wallclock time as it
involves a sched RCU grace period.  This means that draining a blk-mq
takes measureable wallclock time.  One would think that this shouldn't
matter as queue shutdown should be a rare event which takes place
asynchronously w.r.t. userland.

Unfortunately, SCSI probing involves synchronously setting up and then
tearing down a lot of request_queues back-to-back for non-existent
LUNs.  This means that SCSI probing may take more than ten seconds
when scsi-mq is used.

This will be properly fixed by implementing a mechanism to keep
q->mq_usage_counter in atomic mode till genhd registration; however,
that involves rather big updates to percpu_ref which is difficult to
apply late in the devel cycle (v3.17-rc6 at the moment).  As a
stop-gap measure till the proper fix can be implemented in the next
cycle, this patch introduces __percpu_ref_kill_expedited() and makes
blk_mq_freeze_queue() use it.  This is heavy-handed but should work
for testing the experimental SCSI blk-mq implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Christoph Hellwig <hch@infradead.org>
Link: http://lkml.kernel.org/g/20140919113815.GA10791@lst.de
Fixes: add703fd ("blk-mq: use percpu_ref for mq usage count")
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Tested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

The "by8" implementation introduced in commit 22cddcc7 ("crypto: aes
- AES CTR x86_64 "by8" AVX optimization") is failing crypto tests as it
handles counter block overflows differently. It only accounts the right
most 32 bit as a counter -- not the whole block as all other
implementations do. This makes it fail the cryptomgr test #4 that
specifically tests this corner case.

As we're quite late in the release cycle, just disable the "by8" variant
for now.
Reported-by: Romain Francoise <romain@orebokech.com>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Chandramouli Narayanan <mouli@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

If the ccp is built as a built-in module, then ccp-crypto (whether
built as a module or a built-in module) will be able to load and
it will register its crypto algorithms.  If the system does not have
a CCP this will result in -ENODEV being returned whenever a command
is attempted to be queued by the registered crypto algorithms.

Add an API, ccp_present(), that checks for the presence of a CCP
on the system.  The ccp-crypto module can use this to determine if it
should register it's crypto alogorithms.

Cc: stable@vger.kernel.org
Reported-by: Scot Doyle <lkml14@scotdoyle.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Tested-by: Scot Doyle <lkml14@scotdoyle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Pull infiniband/rdma fixes from Roland Dreier:
 "Last late set of InfiniBand/RDMA fixes for 3.17:

   - fixes for the new memory region re-registration support
   - iSER initiator error path fixes
   - grab bag of small fixes for the qib and ocrdma hardware drivers
   - larger set of fixes for mlx4, especially in RoCE mode"

* tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband: (26 commits)
  IB/mlx4: Fix VF mac handling in RoCE
  IB/mlx4: Do not allow APM under RoCE
  IB/mlx4: Don't update QP1 in native mode
  IB/mlx4: Avoid accessing netdevice when building RoCE qp1 header
  mlx4: Fix mlx4 reg/unreg mac to work properly with 0-mac addresses
  IB/core: When marshaling uverbs path, clear unused fields
  IB/mlx4: Avoid executing gid task when device is being removed
  IB/mlx4: Fix lockdep splat for the iboe lock
  IB/mlx4: Get upper dev addresses as RoCE GIDs when port comes up
  IB/mlx4: Reorder steps in RoCE GID table initialization
  IB/mlx4: Don't duplicate the default RoCE GID
  IB/mlx4: Avoid null pointer dereference in mlx4_ib_scan_netdevs()
  IB/iser: Bump version to 1.4.1
  IB/iser: Allow bind only when connection state is UP
  IB/iser: Fix RX/TX CQ resource leak on error flow
  RDMA/ocrdma: Use right macro in query AH
  RDMA/ocrdma: Resolve L2 address when creating user AH
  mlx4: Correct error flows in rereg_mr
  IB/qib: Correct reference counting in debugfs qp_stats
  IPoIB: Remove unnecessary port query
  ...

Pull sound fixes from Takashi Iwai:
 "One fix is about a buggy computation in PCM API function Clemens
  spotted out, but the impact must be really small as no one really uses
  it in user-space side.

  The rest are a trivial fix for a HD-audio model and a USB-audio
  device-specific regression fix, so all look fairly safe to apply"

* tag 'sound-3.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: snd-usb-caiaq: Fix LED commands for Kore controller
  ALSA: pcm: fix fifo_size frame calculation
  ALSA: hda - Add fixup model name lookup for Lemote A1205

Pull final block fixes from Jens Axboe:
 "This week and last we've been fixing some corner cases related to
  blk-mq, mostly.  I ended up pulling most of that out of for-linus
  yesterday, which is why the branch looks fresh.  The rest were
  postponed for 3.18.

  This pull request contains:

   - Fix from Christoph, avoiding a stack overflow when FUA insertion
     would recursive infinitely.

   - Fix from David Hildenbrand on races between the timeout handler and
     uninitialized requests.  Fixes a real issue that virtio_blk has run
     into.

   - A few fixes from me:

        - Ensure that request deadline/timeout is ordered before the
          request is marked as started.

        - A potential oops on out-of-memory, when we scale the queue
          depth of the device and retry.

        - A hang fix on requeue from SCSI, where the hardware queue
          would be stopped when we attempt to re-run it (and hence
          nothing would happen, stalling progress).

        - A fix for commit 2da78092, where the cleanup path was moved
          to RCU, but a debug might_sleep() was inadvertently left in
          the code.  This causes warnings for people"

* 'for-linus' of git://git.kernel.dk/linux-block:
  genhd: fix leftover might_sleep() in blk_free_devt()
  blk-mq: use blk_mq_start_hw_queues() when running requeue work
  blk-mq: fix potential oops on out-of-memory in __blk_mq_alloc_rq_maps()
  blk-mq: avoid infinite recursion with the FUA flag
  blk-mq: Avoid race condition with uninitialized requests
  blk-mq: request deadline must be visible before marking rq as started