Error injection is sloppy and very ad-hoc.  BPF could fill this niche
perfectly with it's kprobe functionality.  We could make sure errors are
only triggered in specific call chains that we care about with very
specific situations.  Accomplish this with the bpf_override_funciton
helper.  This will modify the probe'd callers return value to the
specified value and set the PC to an override function that simply
returns, bypassing the originally probed function.  This gives us a nice
clean way to implement systematic error injection for all of our code
paths.
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

This allows us to do error injection with BPF for open_ctree.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Using BPF we can override kprob'ed functions and return arbitrary
values.  Obviously this can be a bit unsafe, so make this feature opt-in
for functions.  Simply tag a function with KPROBE_ERROR_INJECT_SYMBOL in
order to give BPF access to that function for error injection purposes.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Yonghong Song says:

====================
Commit e87c6bc3 ("bpf: permit multiple bpf attachments
for a single perf event") added support to attach multiple
bpf programs to a single perf event. Given a perf event
(kprobe, uprobe, or kernel tracepoint), the perf ioctl interface
is used to query bpf programs attached to the same trace event.

There already exists a BPF_PROG_QUERY command for introspection
currently used by cgroup+bpf. We did have an implementation for
querying tracepoint+bpf through the same interface. However, it
looks cleaner to use ioctl() style of api here, since attaching
bpf prog to tracepoint/kuprobe is also done via ioctl.

Patch #1 had the core implementation and patch #2 added
a test case in tools bpf selftests suite.

Changelogs:
v3 -> v4:
  - Fix a compilation error with newer gcc like 6.3.1 while
    old gcc 4.8.5 is okay. I was using &uquery->ids to represent
    the address to the ids array to make it explicit that the
    address is passed, and this syntax is rightly rejected
    by gcc 6.3.1.
v2 -> v3:
  - Change uapi structure perf_event_query_bpf to be more
    clearer based on Peter's suggestion, and adjust
    other codes accordingly.
v1 -> v2:
  - Rebase on top of net-next.
  - Use existing bpf_prog_array_length function instead of
    implementing the same functionality in function
    bpf_prog_array_copy_info.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Added a subtest in test_progs. The tracepoint is
sched/sched_switch. Multiple bpf programs are attached to
this tracepoint and the query interface is exercised.
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Commit e87c6bc3 ("bpf: permit multiple bpf attachments
for a single perf event") added support to attach multiple
bpf programs to a single perf event.
Although this provides flexibility, users may want to know
what other bpf programs attached to the same tp interface.
Besides getting visibility for the underlying bpf system,
such information may also help consolidate multiple bpf programs,
understand potential performance issues due to a large array,
and debug (e.g., one bpf program which overwrites return code
may impact subsequent program results).

Commit 2541517c ("tracing, perf: Implement BPF programs
attached to kprobes") utilized the existing perf ioctl
interface and added the command PERF_EVENT_IOC_SET_BPF
to attach a bpf program to a tracepoint. This patch adds a new
ioctl command, given a perf event fd, to query the bpf program
array attached to the same perf tracepoint event.

The new uapi ioctl command:
  PERF_EVENT_IOC_QUERY_BPF

The new uapi/linux/perf_event.h structure:
  struct perf_event_query_bpf {
       __u32	ids_len;
       __u32	prog_cnt;
       __u32	ids[0];
  };

User space provides buffer "ids" for kernel to copy to.
When returning from the kernel, the number of available
programs in the array is set in "prog_cnt".

The usage:
  struct perf_event_query_bpf *query =
    malloc(sizeof(*query) + sizeof(u32) * ids_len);
  query.ids_len = ids_len;
  err = ioctl(pmu_efd, PERF_EVENT_IOC_QUERY_BPF, query);
  if (err == 0) {
    /* query.prog_cnt is the number of available progs,
     * number of progs in ids: (ids_len == 0) ? 0 : query.prog_cnt
     */
  } else if (errno == ENOSPC) {
    /* query.ids_len number of progs copied,
     * query.prog_cnt is the number of available progs
     */
  } else {
      /* other errors */
  }
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

CONFIG_CGROUP_BPF=y is required for test_dev_cgroup test case.
Signed-off-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Quentin Monnet says:

====================
First patch of this series cleans up the two Makefiles (Makefile and
Documentation/Makefile) and make their contents more consistent.

The second one add "uninstall" and "doc-uninstall" targets, to remove
files previously installed on the system with "install" and "doc-install"
targets.
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Create two targets to remove executable and documentation that would
have been previously installed with `make install` and `make
doc-install`.

Also create a "QUIET_UNINST" helper in tools/scripts/Makefile.include.

Do not attempt to remove directories /usr/local/sbin and
/usr/share/bash-completions/completions, even if they are empty, as
those specific directories probably already existed on the system before
we installed the program, and we do not wish to break other makefiles
that might assume their existence. Do remvoe /usr/local/share/man/man8
if empty however, as this directory does not seem to exist by default.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Several minor fixes and harmonisation items for Makefiles:

* Use the same mechanism for verbose/non-verbose output in two files
  ("$(Q)"), for all commands.
* Use calls to "QUIET_INSTALL" and equivalent in Makefile. In
  particular, use "call(descend, ...)" instead of "make -C" to run
  documentation targets.
* Add a "doc-clean" target, aligned on "doc" and "doc-install".
* Make "install" target in Makefile depend on "bpftool".
* Remove condition on DESTDIR to initialise prefix in doc Makefile.
* Remove modification of VPATH based on OUTPUT, it is unused.
* Formatting: harmonise spaces around equal signs.
* Make install path for man pages /usr/local/man instead of
  /usr/local/share/man (respects the Makefile conventions, and the
  latter is usually a symbolic link to the former anyway).
* Do not erase prefix if set by user in bpftool Makefile.
* Fix install target for bpftool: append DESTDIR to install path.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Alexei Starovoitov says:

====================
pull-request: bpf-next 2017-12-07

The following pull-request contains BPF updates for your net-next tree.

The main changes are:

1) Detailed documentation of BPF development process from Daniel.

2) Addition of is_fullsock, snd_cwnd and srtt_us fields to bpf_sock_ops
   from Lawrence.

3) Minor follow up for bpf_skb_set_tunnel_key() from William.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Private destructor could be called when register_netdev() fail with
rtnl lock held. This will lead deadlock in tun_free_netdev() who tries
to hold rtnl_lock. Fixing this by switching to use spinlock to
synchronize.

Fixes: 96f84061 ("tun: add eBPF based queue selection method")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ursula Braun says:

====================
smc: fixes 2017-12-07

here are some smc-patches. The initial 4 patches are cleanups.
Patch 5 gets rid of ib_post_sends in tasklet context to avoid peer drops due
to out-of-order receivals.
Patch 6 makes sure, the Linux SMC code understands variable sized CLC proposal
messages built according to RFC7609.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

According to RFC7609 [1] the CLC proposal message contains an area of
unknown length for future growth. Additionally it may contain up to
8 IPv6 prefixes. The current version of the SMC-code does not
understand CLC proposal messages using these variable length fields and,
thus, is incompatible with SMC implementations in other operating
systems.

This patch makes sure, SMC understands incoming CLC proposals
* with arbitrary length values for future growth
* with up to 8 IPv6 prefixes

[1] SMC-R Informational RFC: http://www.rfc-editor.org/info/rfc7609Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Reviewed-by: Hans Wippel <hwippel@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The SMC protocol requires to send a separate consumer cursor update,
if it cannot be piggybacked to updates of the producer cursor.
When receiving a blocked signal from the sender, this update is sent
already in tasklet context. In addition consumer cursor updates are
sent after data receival.
Sending of cursor updates is controlled by sequence numbers.
Assuming receiving stray messages the receiver drops updates with older
sequence numbers than an already received cursor update with a higher
sequence number.
Sending consumer cursor updates in tasklet context may result in
wrong order sends and its corresponding drops at the receiver. Since
it is sufficient to send consumer cursor updates once the data is
received, this patch gets rid of the consumer cursor update in tasklet
context to guarantee in-sequence arrival of cursor updates.
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When waiting for data to be received it must be checked if the
peer signals shutdown. The SMC code uses two different checks
for this purpose, even though just one check is sufficient.
This patch removes the superfluous test for SOCK_DONE.
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The smc code never checks the sk_write_pending sock field.
Thus there is no need to update it.
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Let smc_clc_send_decline() return with an error, if the amount
sent is smaller than the length of an smc decline message.
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

smc_close_active_abort() is used in smc_close.c only.
Make it static.
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Introduce a configuration option: CONFIG_NET_DSA_LEGACY allowing to compile out
support for the old platform device and Device Tree binding registration.
Support for these configurations is scheduled to be removed in 4.17.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

On some dual port NICs, the 2 ports have to be configured with compatible
link speeds.  Under some conditions, a port's configured speed may no
longer be supported.  The firmware will send a message to the driver
when this happens.

Improve this logic that prints out the warning by only printing it if
we can determine the link speed that is no longer supported.  If the
speed is unknown or it is in autoneg mode, skip the warning message.
Reported-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Tested-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
Few BPF doc updates

Two changes, i) add BPF trees into maintainers file, and ii) add
a BPF doc around the development process, similarly as we have
with netdev FAQ, but just describing BPF specifics. Thanks!
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

In the same spirit of netdev FAQ, start a BPF FAQ as a collection
of expectations and/or workflow details in the context of BPF patch
processing.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

i) Add the bpf and bpf-next trees to the maintainers entry
   so they can be found easily and picked up by test bots
   etc that would integrate all trees from maintainers file.
   Suggested by Stephen while integrating the trees into
   linux-next.

ii) Add the two headers defining BPF/XDP tracepoints to the
    list of files as well.
Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

The recv flow of ipvlan l2 mode performs as same as l3 mode for
non-multicast packet, so use the existing func ipvlan_handle_mode_l3
instead of these duplicated statements in non-multicast case.
Signed-off-by: Gao Feng <gfree.wind@vip.163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, whenever the NETIF_F_HW_TC feature changes, we silently
always allow it, but we actually do not disable the flows in HW
on disable. That breaks user's expectations. So just forbid
the feature disable in case there are any filters offloaded.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The statement no longer serves a purpose.

Commit fa35864e ("tuntap: Fix for a race in accessing numqueues")
added the ACCESS_ONCE to avoid a race condition with skb_queue_len.

Commit 436acceb ("tuntap: remove unnecessary sk_receive_queue
length check during xmit") removed the affected skb_queue_len check.

Commit 96f84061 ("tun: add eBPF based queue selection method")
split the function, reading the field a second time in the callee.
The temp variable is now only read once, so just remove it.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

t_name cannot be NULL since it is an array field of a struct.
Replacing null check on static array with string length check using
strnlen()
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

TC actions are no longer freed in RCU callbacks and we should
always have RTNL lock, so this spinlock is no longer needed.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tcfm_dev always points to the correct netdev and we already
hold a refcnt, so no need to use tcfm_ifindex to lookup again.

If we would support moving target netdev across netns, using
pointer would be better than ifindex.

This also fixes dumping obsolete ifindex, now after the
target device is gone we just dump 0 as ifindex.

Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

William Tu says:

====================
ipv6: add ip6erspan collect_md mode

Similar to erspan collect_md mode in ipv4, the first patch adds
support for ip6erspan collect metadata mode.  The second patch
adds the test case using bpf_skb_[gs]et_tunnel_key helpers.

The corresponding iproute2 patch:
https://marc.info/?l=linux-netdev&m=151251545410047&w=2
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Extend the existing tests for ip6erspan.
Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Similar to ip6 gretap and ip4 gretap, the patch allows
erspan tunnel to operate in collect metadata mode.
bpf_skb_[gs]et_tunnel_key() helpers can make use of
it right away.
Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Smatch warns that:

    drivers/net/ethernet/broadcom/bnxt/bnxt_tc.c:160 bnxt_tc_parse_actions()
    error: uninitialized symbol 'rc'.

"rc" is either uninitialized or set to zero here so we can just remove
the check.

Fixes: 8c95f773 ("bnxt_en: add support for Flower based vxlan encap/decap offload")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Julia Cartwright says:

====================
macb rx filter cleanups

Here's a proper patchset based on net-next.

v1 -> v2:
  - Rebased on net-next
  - Add Nicolas's Acks
  - Reorder commits, putting the list_empty() cleanups prior to the
    others.
  - Added commit reverting the GFP_ATOMIC change.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that the rx_fs_lock is no longer held across allocation, it's safe
to use GFP_KERNEL for allocating new entries.

This reverts commit 81da3bf6 ("net: macb: change GFP_KERNEL to
GFP_ATOMIC").

Cc: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Julia Cartwright <julia@ni.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit ae8223de ("net: macb: Added support for RX filtering")
introduces a lock, rx_fs_lock which is intended to protect the list of
rx_flow items and synchronize access to the hardware rx filtering
registers.

However, the region protected by this lock is overscoped, unnecessarily
including things like slab allocation.  Reduce this lock scope to only
include operations which must be performed atomically: list traversal,
addition, and removal, and hitting the macb filtering registers.

This fixes the use of kmalloc w/ GFP_KERNEL in atomic context.

Fixes: ae8223de ("net: macb: Added support for RX filtering")
Cc: Rafal Ozieblo <rafalo@cadence.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Julia Cartwright <julia@ni.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The list_for_each_entry() macro already handles the case where the list
is empty (by not executing the loop body).  It's not necessary to handle
this case specially, so stop doing so.

Cc: Rafal Ozieblo <rafalo@cadence.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Julia Cartwright <julia@ni.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

No one actually uses it.

Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Vivien Didelot says:

====================
net: dsa: use per-port upstream port

An upstream port is a local switch port used to reach a CPU port.

DSA still considers a unique CPU port in the whole switch fabric and
thus return a unique upstream port for a given switch. This is wrong in
a multiple CPU ports environment.

We are now switching to using the dedicated CPU port assigned to each
port in order to get rid of the deprecated unique tree CPU port.

This patchset makes the dsa_upstream_port() helper take a port argument
and goes one step closer complete support for multiple CPU ports.

Changes in v2:
  - reverse-christmas-tree-fy variables
====================
Signed-off-by: David S. Miller <davem@davemloft.net>