ndisc_notify is used to send unsolicited neighbor advertisements
(e.g., on a link up). Currently, the ndisc notifier is run before the
addrconf notifer which means NA's are not sent for link-local addresses
which are added by the addrconf notifier.

Fix by lowering the priority of the ndisc notifier. Setting the priority
to ADDRCONF_NOTIFY_PRIORITY - 5 means it runs after addrconf and before
the route notifier which is ADDRCONF_NOTIFY_PRIORITY - 10.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit a248878d ("ibmvnic: Check for transport event on driver resume")
removed the loop to kick irqs on driver resume but didn't remove the now
unused loop variable 'i'.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To ease debugging of the ibmvnic driver add a series of netdev_dbg()
statements to track driver status, especially during initialization,
removal, and resetting of the driver.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ensure that any resources allocated during probe are released if the
probe of the driver fails.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Florian Westphal says:

====================
rtnetlink: allow selected handlers to run without rtnl

Changes since v1:
 In patch 6, don't make ipv6 route handlers lockless, they all have
 assumptions on rtnl being held.  Other patches are unchanged.

The RTNL mutex is used to serialize both rtnetlink calls and
dump requests.
Its also used to protect other things such as the list of current
net namespaces.

Unfortunately RTNL mutex is a performance issue, e.g. a cpu adding an
ip address prevents other cpus from seemingly unrelated tasks such as
dumping tc classifiers or doing rtnetlink route lookups.

This patch set adds basic infrastructure to start pushing the rtnl lock
down to those places that need it, or even elide it entirely in some cases.

Subsystems can now indicate that their doit() callback can run without
RTNL mutex, such callbacks can then run in parallel.

This will obviously need a lot of followup work; all current
users need to be audited/changed to benefit from this.
Initial no-rtnl spot is netns new/getid.

We have various 'get' handlers that are also a tempting target,
however, several of these depend on rtnl mutex to prevent information
from changing while objects are being read by rtnl handlers; however,
it doesn't appear impossible to change this.

Dumps are another problem entirely, see
commit 2907c35f ("net: hold rtnl again in dump callbacks"),
this patchset doesn't touch dump requests.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Both functions take nsid_lock and don't rely on rtnl lock.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Reviewed-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow callers to tell rtnetlink core that its doit callback
should be invoked without holding rtnl mutex.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Reviewed-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Note that netlink dumps still acquire rtnl mutex via the netlink
dump infrastructure.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Reviewed-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

instead of rtnl lock/unload at the top level, push it down
to the called function.

This is just an intermediate step, next commit switches protection
of the rtnl_link ops table to rcu, in which case (for dumps) the
rtnl lock is acquired only by the netlink dumper infrastructure
(current lock/unlock/dump/lock/unlock rtnl sequence becomes
 rcu lock/rcu unlock/dump).
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Reviewed-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I don't see what prevents rmmod (unregister_all is called) while a dump
is active.

Even if we'd add rtnl lock/unlock pair to unregister_all (as done here),
thats not enough either as rtnl_lock is released right before the dump
process starts.

So this adds a refcount:
 * acquire rtnl mutex
 * bump refcount
 * release mutex
 * start the dump

... and make unregister_all remove the callbacks (no new dumps possible)
and then wait until refcount is 0.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Reviewed-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change allows us to later indicate to rtnetlink core that certain
doit functions should be called without acquiring rtnl_mutex.

This change should have no effect, we simply replace the last (now
unused) calcit argument with the new flag.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Reviewed-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is only a single place in the kernel that regisers the "calcit"
callback (to determine min allocation for dumps).

This is in rtnetlink.c for PF_UNSPEC RTM_GETLINK.
The function that checks for calcit presence at run time will first check
the requested family (which will always fail for !PF_UNSPEC as no callsite
registers this), then falls back to checking PF_UNSPEC.

Therefore we can just check if type is RTM_GETLINK and then do a direct
call.  Because of fallback to PF_UNSPEC all RTM_GETLINK types used this
regardless of family.

This has the advantage that we don't need to allocate space for
the function pointer for all the other families.

A followup patch will drop the calcit function pointer from the
rtnl_link callback structure.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Reviewed-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
bpf: Add BPF_J{LT,LE,SLT,SLE} instructions

This set adds BPF_J{LT,LE,SLT,SLE} instructions to the BPF
insn set, interpreter, JIT hardening code and all JITs are
also updated to support the new instructions. Basic idea is
to reduce register pressure by avoiding BPF_J{GT,GE,SGT,SGE}
rewrites. Removing the workaround for the rewrites in LLVM,
this can result in shorter BPF programs, less stack usage
and less verification complexity. First patch provides some
more details on rationale and integration.

Thanks a lot!

v1 -> v2:
  - Reworded commit msg in patch 1
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add test cases to the verifier selftest suite in order to verify that
i) direct packet access, and ii) dynamic map value access is working
with the changes related to the new instructions.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Enable the newly added jump opcodes, main parts are in two
different areas, namely direct packet access and dynamic map
value access. For the direct packet access, we now allow for
the following two new patterns to match in order to trigger
markings with find_good_pkt_pointers():

Variant 1 (access ok when taking the branch):

  0: (61) r2 = *(u32 *)(r1 +76)
  1: (61) r3 = *(u32 *)(r1 +80)
  2: (bf) r0 = r2
  3: (07) r0 += 8
  4: (ad) if r0 < r3 goto pc+2
  R0=pkt(id=0,off=8,r=0) R1=ctx R2=pkt(id=0,off=0,r=0)
  R3=pkt_end R10=fp
  5: (b7) r0 = 0
  6: (95) exit

  from 4 to 7: R0=pkt(id=0,off=8,r=8) R1=ctx
               R2=pkt(id=0,off=0,r=8) R3=pkt_end R10=fp
  7: (71) r0 = *(u8 *)(r2 +0)
  8: (05) goto pc-4
  5: (b7) r0 = 0
  6: (95) exit
  processed 11 insns, stack depth 0

Variant 2 (access ok on fall-through):

  0: (61) r2 = *(u32 *)(r1 +76)
  1: (61) r3 = *(u32 *)(r1 +80)
  2: (bf) r0 = r2
  3: (07) r0 += 8
  4: (bd) if r3 <= r0 goto pc+1
  R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8)
  R3=pkt_end R10=fp
  5: (71) r0 = *(u8 *)(r2 +0)
  6: (b7) r0 = 1
  7: (95) exit

  from 4 to 6: R0=pkt(id=0,off=8,r=0) R1=ctx
               R2=pkt(id=0,off=0,r=0) R3=pkt_end R10=fp
  6: (b7) r0 = 1
  7: (95) exit
  processed 10 insns, stack depth 0

The above two basically just swap the branches where we need
to handle an exception and allow packet access compared to the
two already existing variants for find_good_pkt_pointers().

For the dynamic map value access, we add the new instructions
to reg_set_min_max() and reg_set_min_max_inv() in order to
learn bounds. Verifier test cases for both are added in a
follow-up patch.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This work implements jiting of BPF_J{LT,LE} instructions with
BPF_X/BPF_K variants for the nfp eBPF JIT. The two BPF_J{SLT,SLE}
instructions have not been added yet given BPF_J{SGT,SGE} are
not supported yet either.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This work implements jiting of BPF_J{LT,LE,SLT,SLE} instructions
with BPF_X/BPF_K variants for the ppc64 eBPF JIT.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Tested-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This work implements jiting of BPF_J{LT,LE,SLT,SLE} instructions
with BPF_X/BPF_K variants for the s390x eBPF JIT.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This work implements jiting of BPF_J{LT,LE,SLT,SLE} instructions
with BPF_X/BPF_K variants for the sparc64 eBPF JIT.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This work implements jiting of BPF_J{LT,LE,SLT,SLE} instructions
with BPF_X/BPF_K variants for the arm64 eBPF JIT.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This work implements jiting of BPF_J{LT,LE,SLT,SLE} instructions
with BPF_X/BPF_K variants for the x86_64 eBPF JIT.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, eBPF only understands BPF_JGT (>), BPF_JGE (>=),
BPF_JSGT (s>), BPF_JSGE (s>=) instructions, this means that
particularly *JLT/*JLE counterparts involving immediates need
to be rewritten from e.g. X < [IMM] by swapping arguments into
[IMM] > X, meaning the immediate first is required to be loaded
into a register Y := [IMM], such that then we can compare with
Y > X. Note that the destination operand is always required to
be a register.

This has the downside of having unnecessarily increased register
pressure, meaning complex program would need to spill other
registers temporarily to stack in order to obtain an unused
register for the [IMM]. Loading to registers will thus also
affect state pruning since we need to account for that register
use and potentially those registers that had to be spilled/filled
again. As a consequence slightly more stack space might have
been used due to spilling, and BPF programs are a bit longer
due to extra code involving the register load and potentially
required spill/fills.

Thus, add BPF_JLT (<), BPF_JLE (<=), BPF_JSLT (s<), BPF_JSLE (s<=)
counterparts to the eBPF instruction set. Modifying LLVM to
remove the NegateCC() workaround in a PoC patch at [1] and
allowing it to also emit the new instructions resulted in
cilium's BPF programs that are injected into the fast-path to
have a reduced program length in the range of 2-3% (e.g.
accumulated main and tail call sections from one of the object
file reduced from 4864 to 4729 insns), reduced complexity in
the range of 10-30% (e.g. accumulated sections reduced in one
of the cases from 116432 to 88428 insns), and reduced stack
usage in the range of 1-5% (e.g. accumulated sections from one
of the object files reduced from 824 to 784b).

The modification for LLVM will be incorporated in a backwards
compatible way. Plan is for LLVM to have i) a target specific
option to offer a possibility to explicitly enable the extension
by the user (as we have with -m target specific extensions today
for various CPU insns), and ii) have the kernel checked for
presence of the extensions and enable them transparently when
the user is selecting more aggressive options such as -march=native
in a bpf target context. (Other frontends generating BPF byte
code, e.g. ply can probe the kernel directly for its code
generation.)

  [1] https://github.com/borkmann/llvm/tree/bpf-insnsSigned-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Willem de Bruijn says:

====================
net: zerocopy fixes

Fix two issues introduced in the msg_zerocopy patchset.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Do not use uarg->zerocopy outside msg_zerocopy. In other paths the
field is not explicitly initialized and aliases another field.

Those paths have only one reference so do not need this intermediate
variable. Call uarg->callback directly.

Fixes: 1f8b977a ("sock: enable MSG_ZEROCOPY")
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Only call mm_unaccount_pinned_pages when releasing a struct ubuf_info
that has initialized its field uarg->mmp.

Before this patch, a vhost-net with experimental_zcopytx can crash in

  mm_unaccount_pinned_pages
  sock_zerocopy_put
  skb_zcopy_clear
  skb_release_data

Only sock_zerocopy_alloc initializes this field. Move the unaccount
call from generic sock_zerocopy_put to its specific callback
sock_zerocopy_callback.

Fixes: a91dbff5 ("sock: ulimit on MSG_ZEROCOPY pages")
Reported-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
1GbE Intel Wired LAN Driver Updates 2017-08-08

This series contains updates to e1000e and igb/igbvf.

Gangfeng Huang fixes an issue with receive network flow classification,
where igb_nfc_filter_exit() was not being called in igb_down() which
would cause the filter tables to "fill up" if a user where to change
the adapter settings (such as speed) which requires a reset of the
adapter.

Cliff Spradlin fixes a timestamping issue, where igb was allowing requests
for hardware timestamping even if it was not configured for hardware
transmit timestamping.

Corinna Vinschen removes the error message that there was an "unexpected
SYS WRAP", when it is actually expected.  So remove the message to not
confuse users.

Greg Edwards provides several patches for the mailbox interface between
the PF and VF drivers.  Added a mailbox unlock method to be used to unlock
the PF/VF mailbox by the PF.  Added a lock around the VF mailbox ops to
prevent the VF from sending another message while the PF is still
processing the previous message.  Fixed a "scheduling while atomic" issue
by changing msleep() to mdelay().

Sasha adds support for the next LOM generations i219 (v8 & v9) which
will be available in the next Intel client platform IceLake.

John Linville adds support for a Broadcom PHY to the igb driver, since
there are designs out in the world which use the igb MAC and a third
party PHY.  This allows the driver to load and function as expected on
these designs.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The UDP offload conflict is dealt with by simply taking what is
in net-next where we have removed all of the UFO handling code
entirely.

The TCP conflict was a case of local variables in a function
being removed from both net and net-next.

In netvsc we had an assignment right next to where a missing
set of u64 stats sync object inits were added.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 65d8fc77 ("futex: Remove requirement for lock_page() in
get_futex_key()") removed an unnecessary lock_page() with the
side-effect that page->mapping needed to be treated very carefully.

Two defensive warnings were added in case any assumption was missed and
the first warning assumed a correct application would not alter a
mapping backing a futex key.  Since merging, it has not triggered for
any unexpected case but Mark Rutland reported the following bug
triggering due to the first warning.

  kernel BUG at kernel/futex.c:679!
  Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 0 PID: 3695 Comm: syz-executor1 Not tainted 4.13.0-rc3-00020-g307fec773ba3 #3
  Hardware name: linux,dummy-virt (DT)
  task: ffff80001e271780 task.stack: ffff000010908000
  PC is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679
  LR is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679
  pc : [<ffff00000821ac14>] lr : [<ffff00000821ac14>] pstate: 80000145

The fact that it's a bug instead of a warning was due to an unrelated
arm64 problem, but the warning itself triggered because the underlying
mapping changed.

This is an application issue but from a kernel perspective it's a
recoverable situation and the warning is unnecessary so this patch
removes the warning.  The warning may potentially be triggered with the
following test program from Mark although it may be necessary to adjust
NR_FUTEX_THREADS to be a value smaller than the number of CPUs in the
system.

    #include <linux/futex.h>
    #include <pthread.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <sys/mman.h>
    #include <sys/syscall.h>
    #include <sys/time.h>
    #include <unistd.h>

    #define NR_FUTEX_THREADS 16
    pthread_t threads[NR_FUTEX_THREADS];

    void *mem;

    #define MEM_PROT  (PROT_READ | PROT_WRITE)
    #define MEM_SIZE  65536

    static int futex_wrapper(int *uaddr, int op, int val,
                             const struct timespec *timeout,
                             int *uaddr2, int val3)
    {
        syscall(SYS_futex, uaddr, op, val, timeout, uaddr2, val3);
    }

    void *poll_futex(void *unused)
    {
        for (;;) {
            futex_wrapper(mem, FUTEX_CMP_REQUEUE_PI, 1, NULL, mem + 4, 1);
        }
    }

    int main(int argc, char *argv[])
    {
        int i;

        mem = mmap(NULL, MEM_SIZE, MEM_PROT,
               MAP_SHARED | MAP_ANONYMOUS, -1, 0);

        printf("Mapping @ %p\n", mem);

        printf("Creating futex threads...\n");

        for (i = 0; i < NR_FUTEX_THREADS; i++)
            pthread_create(&threads[i], NULL, poll_futex, NULL);

        printf("Flipping mapping...\n");
        for (;;) {
            mmap(mem, MEM_SIZE, MEM_PROT,
                 MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS, -1, 0);
        }

        return 0;
    }
Reported-and-tested-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NMel Gorman <mgorman@suse.de>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull i2c fixes from Wolfram Sang:
 "The main thing is to allow empty id_tables for ACPI to make some
  drivers get probed again. It looks a bit bigger than usual because it
  needs some internal renaming, too.

  Other than that, there is a fix for broken DSTDs, a super simple
  enablement for ARM MPS, and two documentation fixes which I'd like to
  see in v4.13 already"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: rephrase explanation of I2C_CLASS_DEPRECATED
  i2c: allow i2c-versatile for ARM MPS platforms
  i2c: designware: Some broken DSTDs use 1MiHz instead of 1MHz
  i2c: designware: Print clock freq on invalid clock freq error
  i2c: core: Allow empty id_table in ACPI case as well
  i2c: mux: pinctrl: mention correct module name in Kconfig help text

Pull block fixes from Jens Axboe:
 "Three patches that should go into this release.

  Two of them are from Paolo and fix up some corner cases with BFQ, and
  the last patch is from Ming and fixes up a potential usage count
  imbalance regression due to the recent NOWAIT work"

* 'for-linus' of git://git.kernel.dk/linux-block:
  blk-mq: don't leak preempt counter/q_usage_counter when allocating rq failed
  block, bfq: consider also in_service_entity to state whether an entity is active
  block, bfq: reset in_service_entity if it becomes idle

Pull crypto fixes from Herbert Xu:
 "Fix two regressions in the inside-secure driver with respect to
  hmac(sha1)"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: inside-secure - fix the sha state length in hmac_sha1_setkey
  crypto: inside-secure - fix invalidation check in hmac_sha1_setkey

Pull networking fixes from David Miller:
 "The pull requests are getting smaller, that's progress I suppose :-)

   1) Fix infinite loop in CIPSO option parsing, from Yujuan Qi.

   2) Fix remote checksum handling in VXLAN and GUE tunneling drivers,
      from Koichiro Den.

   3) Missing u64_stats_init() calls in several drivers, from Florian
      Fainelli.

   4) TCP can set the congestion window to an invalid ssthresh value
      after congestion window reductions, from Yuchung Cheng.

   5) Fix BPF jit branch generation on s390, from Daniel Borkmann.

   6) Correct MIPS ebpf JIT merge, from David Daney.

   7) Correct byte order test in BPF test_verifier.c, from Daniel
      Borkmann.

   8) Fix various crashes and leaks in ASIX driver, from Dean Jenkins.

   9) Handle SCTP checksums properly in mlx4 driver, from Davide
      Caratti.

  10) We can potentially enter tcp_connect() with a cached route
      already, due to fastopen, so we have to explicitly invalidate it.

  11) skb_warn_bad_offload() can bark in legitimate situations, fix from
      Willem de Bruijn"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (52 commits)
  net: avoid skb_warn_bad_offload false positives on UFO
  qmi_wwan: fix NULL deref on disconnect
  ppp: fix xmit recursion detection on ppp channels
  rds: Reintroduce statistics counting
  tcp: fastopen: tcp_connect() must refresh the route
  net: sched: set xt_tgchk_param par.net properly in ipt_init_target
  net: dsa: mediatek: add adjust link support for user ports
  net/mlx4_en: don't set CHECKSUM_COMPLETE on SCTP packets
  qed: Fix a memory allocation failure test in 'qed_mcp_cmd_init()'
  hysdn: fix to a race condition in put_log_buffer
  s390/qeth: fix L3 next-hop in xmit qeth hdr
  asix: Fix small memory leak in ax88772_unbind()
  asix: Ensure asix_rx_fixup_info members are all reset
  asix: Add rx->ax_skb = NULL after usbnet_skb_return()
  bpf: fix selftest/bpf/test_pkt_md_access on s390x
  netvsc: fix race on sub channel creation
  bpf: fix byte order test in test_verifier
  xgene: Always get clk source, but ignore if it's missing for SGMII ports
  MIPS: Add missing file for eBPF JIT.
  bpf, s390: fix build for libbpf and selftest suite
  ...

If the user hasn't installed any custom rules, don't go through the
whole FIB rules layer. This is pretty similar to f4530fa5 (ipv4:
Avoid overhead when no custom FIB rules are installed).

Using a micro-benchmark module [1], timing ip6_route_output() with
get_cycles(), with 40,000 routes in the main routing table, before this
patch:

    min=606 max=12911 count=627 average=1959 95th=4903 90th=3747 50th=1602 mad=821
    table=254 avgdepth=21.8 maxdepth=39
    value │                         ┊                            count
      600 │▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒                                         199
      880 │▒▒▒░░░░░░░░░░░░░░░░                                      43
     1160 │▒▒▒░░░░░░░░░░░░░░░░░░░░                                  48
     1440 │▒▒▒░░░░░░░░░░░░░░░░░░░░░░░                               43
     1720 │▒▒▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░                          59
     2000 │▒▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░                      50
     2280 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░                    26
     2560 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░                  31
     2840 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░               28
     3120 │▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░              17
     3400 │▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░             17
     3680 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░             8
     3960 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░           11
     4240 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░            6
     4520 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░           6
     4800 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░           9

After:

    min=544 max=11687 count=627 average=1776 95th=4546 90th=3585 50th=1227 mad=565
    table=254 avgdepth=21.8 maxdepth=39
    value │                         ┊                            count
      540 │▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒                                        201
      800 │▒▒▒▒▒░░░░░░░░░░░░░░░░                                    63
     1060 │▒▒▒▒▒░░░░░░░░░░░░░░░░░░░░░                               68
     1320 │▒▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░                            39
     1580 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░                         32
     1840 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░                       32
     2100 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░                    34
     2360 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░                 33
     2620 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░               26
     2880 │▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░              22
     3140 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░              9
     3400 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░             8
     3660 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░             9
     3920 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░            8
     4180 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░           8
     4440 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░           8

At the frequency of the host during the bench (~ 3.7 GHz), this is
about a 100 ns difference on the median value.

A next step would be to collapse local and main tables, as in
0ddcf43d (ipv4: FIB Local/MAIN table collapse).

[1]: https://github.com/vincentbernat/network-lab/blob/master/lab-routes-ipv6/kbench_mod.cSigned-off-by: NVincent Bernat <vincent@bernat.im>
Reviewed-by: NJiri Pirko <jiri@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

skb_warn_bad_offload triggers a warning when an skb enters the GSO
stack at __skb_gso_segment that does not have CHECKSUM_PARTIAL
checksum offload set.

Commit b2504a5d ("net: reduce skb_warn_bad_offload() noise")
observed that SKB_GSO_DODGY producers can trigger the check and
that passing those packets through the GSO handlers will fix it
up. But, the software UFO handler will set ip_summed to
CHECKSUM_NONE.

When __skb_gso_segment is called from the receive path, this
triggers the warning again.

Make UFO set CHECKSUM_UNNECESSARY instead of CHECKSUM_NONE. On
Tx these two are equivalent. On Rx, this better matches the
skb state (checksum computed), as CHECKSUM_NONE here means no
checksum computed.

See also this thread for context:
http://patchwork.ozlabs.org/patch/799015/

Fixes: b2504a5d ("net: reduce skb_warn_bad_offload() noise")
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qmi_wwan_disconnect is called twice when disconnecting devices with
separate control and data interfaces.  The first invocation will set
the interface data to NULL for both interfaces to flag that the
disconnect has been handled.  But the matching NULL check was left
out when qmi_wwan_disconnect was added, resulting in this oops:

  usb 2-1.4: USB disconnect, device number 4
  qmi_wwan 2-1.4:1.6 wwp0s29u1u4i6: unregister 'qmi_wwan' usb-0000:00:1d.0-1.4, WWAN/QMI device
  BUG: unable to handle kernel NULL pointer dereference at 00000000000000e0
  IP: qmi_wwan_disconnect+0x25/0xc0 [qmi_wwan]
  PGD 0
  P4D 0
  Oops: 0000 [#1] SMP
  Modules linked in: <stripped irrelevant module list>
  CPU: 2 PID: 33 Comm: kworker/2:1 Tainted: G            E   4.12.3-nr44-normandy-r1500619820+ #1
  Hardware name: LENOVO 4291LR7/4291LR7, BIOS CBET4000 4.6-810-g50522254fb 07/21/2017
  Workqueue: usb_hub_wq hub_event [usbcore]
  task: ffff8c882b716040 task.stack: ffffb8e800d84000
  RIP: 0010:qmi_wwan_disconnect+0x25/0xc0 [qmi_wwan]
  RSP: 0018:ffffb8e800d87b38 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
  RDX: 0000000000000001 RSI: ffff8c8824f3f1d0 RDI: ffff8c8824ef6400
  RBP: ffff8c8824ef6400 R08: 0000000000000000 R09: 0000000000000000
  R10: ffffb8e800d87780 R11: 0000000000000011 R12: ffffffffc07ea0e8
  R13: ffff8c8824e2e000 R14: ffff8c8824e2e098 R15: 0000000000000000
  FS:  0000000000000000(0000) GS:ffff8c8835300000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000000000e0 CR3: 0000000229ca5000 CR4: 00000000000406e0
  Call Trace:
   ? usb_unbind_interface+0x71/0x270 [usbcore]
   ? device_release_driver_internal+0x154/0x210
   ? qmi_wwan_unbind+0x6d/0xc0 [qmi_wwan]
   ? usbnet_disconnect+0x6c/0xf0 [usbnet]
   ? qmi_wwan_disconnect+0x87/0xc0 [qmi_wwan]
   ? usb_unbind_interface+0x71/0x270 [usbcore]
   ? device_release_driver_internal+0x154/0x210
Reported-and-tested-by: NNathaniel Roach <nroach44@gmail.com>
Fixes: c6adf779 ("net: usb: qmi_wwan: add qmap mux protocol support")
Cc: Daniele Palmas <dnlplm@gmail.com>
Signed-off-by: NBjørn Mork <bjorn@mork.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qmi_wwan_disconnect is called twice when disconnecting devices with
separate control and data interfaces.  The first invocation will set
the interface data to NULL for both interfaces to flag that the
disconnect has been handled.  But the matching NULL check was left
out when qmi_wwan_disconnect was added, resulting in this oops:

  usb 2-1.4: USB disconnect, device number 4
  qmi_wwan 2-1.4:1.6 wwp0s29u1u4i6: unregister 'qmi_wwan' usb-0000:00:1d.0-1.4, WWAN/QMI device
  BUG: unable to handle kernel NULL pointer dereference at 00000000000000e0
  IP: qmi_wwan_disconnect+0x25/0xc0 [qmi_wwan]
  PGD 0
  P4D 0
  Oops: 0000 [#1] SMP
  Modules linked in: <stripped irrelevant module list>
  CPU: 2 PID: 33 Comm: kworker/2:1 Tainted: G            E   4.12.3-nr44-normandy-r1500619820+ #1
  Hardware name: LENOVO 4291LR7/4291LR7, BIOS CBET4000 4.6-810-g50522254fb 07/21/2017
  Workqueue: usb_hub_wq hub_event [usbcore]
  task: ffff8c882b716040 task.stack: ffffb8e800d84000
  RIP: 0010:qmi_wwan_disconnect+0x25/0xc0 [qmi_wwan]
  RSP: 0018:ffffb8e800d87b38 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
  RDX: 0000000000000001 RSI: ffff8c8824f3f1d0 RDI: ffff8c8824ef6400
  RBP: ffff8c8824ef6400 R08: 0000000000000000 R09: 0000000000000000
  R10: ffffb8e800d87780 R11: 0000000000000011 R12: ffffffffc07ea0e8
  R13: ffff8c8824e2e000 R14: ffff8c8824e2e098 R15: 0000000000000000
  FS:  0000000000000000(0000) GS:ffff8c8835300000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000000000e0 CR3: 0000000229ca5000 CR4: 00000000000406e0
  Call Trace:
   ? usb_unbind_interface+0x71/0x270 [usbcore]
   ? device_release_driver_internal+0x154/0x210
   ? qmi_wwan_unbind+0x6d/0xc0 [qmi_wwan]
   ? usbnet_disconnect+0x6c/0xf0 [usbnet]
   ? qmi_wwan_disconnect+0x87/0xc0 [qmi_wwan]
   ? usb_unbind_interface+0x71/0x270 [usbcore]
   ? device_release_driver_internal+0x154/0x210
Reported-and-tested-by: NNathaniel Roach <nroach44@gmail.com>
Fixes: c6adf779 ("net: usb: qmi_wwan: add qmap mux protocol support")
Cc: Daniele Palmas <dnlplm@gmail.com>
Signed-off-by: NBjørn Mork <bjorn@mork.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change post-decrement compare to pre-decrement to avoid an
unsigned integer wrap-around on timeout. This leads to the following
!timeout check to never to be true so -ETIMEDOUT is never returned.

Detected by CoverityScan, CID#1452623 ("Logically dead code")

Fixes: 69a60b05 ("net: phy: mdio-bcm-unimac: factor busy polling loop")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit e5dadc65 ("ppp: Fix false xmit recursion detect with two ppp
devices") dropped the xmit_recursion counter incrementation in
ppp_channel_push() and relied on ppp_xmit_process() for this task.
But __ppp_channel_push() can also send packets directly (using the
.start_xmit() channel callback), in which case the xmit_recursion
counter isn't incremented anymore. If such packets get routed back to
the parent ppp unit, ppp_xmit_process() won't notice the recursion and
will call ppp_channel_push() on the same channel, effectively creating
the deadlock situation that the xmit_recursion mechanism was supposed
to prevent.

This patch re-introduces the xmit_recursion counter incrementation in
ppp_channel_push(). Since the xmit_recursion variable is now part of
the parent ppp unit, incrementation is skipped if the channel doesn't
have any. This is fine because only packets routed through the parent
unit may enter the channel recursively.

Finally, we have to ensure that pch->ppp is not going to be modified
while executing ppp_channel_push(). Instead of taking this lock only
while calling ppp_xmit_process(), we now have to hold it for the full
ppp_channel_push() execution. This respects the ppp locks ordering
which requires locking ->upl before ->downl.

Fixes: e5dadc65 ("ppp: Fix false xmit recursion detect with two ppp devices")
Signed-off-by: NGuillaume Nault <g.nault@alphalink.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>