SUBDIRS has been kept as a backward compatibility since
commit ("[PATCH] kbuild: external module support") in 2002.

We do not need multiple ways to do the same thing, so I will remove
SUBDIRS after the Linux 5.3 release. I cleaned up in-tree code, and
updated the document so that nobody would try to use it.

Meanwhile, display the following warning if SUBDIRS is used.

Makefile:189: ================= WARNING ================
Makefile:190: 'SUBDIRS' will be removed after Linux 5.3
Makefile:191: Please use 'M=' or 'KBUILD_EXTMOD' instead
Makefile:192: ==========================================

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Boris Brezillon <boris.brezillon@bootlin.com> # for scx200_docflash.c
Acked-by: Guenter Roeck <linux@roeck-us.net> # for scx200_wdt.c

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Some samples require headers installation, so commit 3fca1700
("kbuild: make samples really depend on headers_install") added
such dependency in the top Makefile. However, UML fails to build
with CONFIG_SAMPLES=y because UML does not support headers_install.

Fixes: 3fca1700 ("kbuild: make samples really depend on headers_install")
Reported-by: Kees Cook <keescook@chromium.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

There is a warning when compiling bpf sample programs in sample/bpf:

  make -C /home/foo/bpf/samples/bpf/../../tools/lib/bpf/ RM='rm -rf' LDFLAGS= srctree=/home/foo/bpf/samples/bpf/../../ O=
    HOSTCC  /home/foo/bpf/samples/bpf/tracex3_user.o
  /home/foo/bpf/samples/bpf/tracex3_user.c:20:0: warning: "ARRAY_SIZE" redefined
   #define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))

  In file included from /home/foo/bpf/samples/bpf/tracex3_user.c:18:0:
  ./tools/testing/selftests/bpf/bpf_util.h:48:0: note: this is the location of the previous definition
   # define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))

Signed-off-by: Bo YU <tsu.yubo@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

"out_buf_sz" needs to be signed for the error handling to work.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This commit extends the test_cgrp2_attach2 test to cover per-cpu
cgroup storage. Bpf program will use shared and per-cpu cgroup
storages simultaneously, so a better coverage of corresponding
core code will be achieved.

Expected output:
  $ ./test_cgrp2_attach2
  Attached DROP prog. This ping in cgroup /foo should fail...
  ping: sendmsg: Operation not permitted
  Attached DROP prog. This ping in cgroup /foo/bar should fail...
  ping: sendmsg: Operation not permitted
  Attached PASS prog. This ping in cgroup /foo/bar should pass...
  Detached PASS from /foo/bar while DROP is attached to /foo.
  This ping in cgroup /foo/bar should fail...
  ping: sendmsg: Operation not permitted
  Attached PASS from /foo/bar and detached DROP from /foo.
  This ping in cgroup /foo/bar should pass...
  ### override:PASS
  ### multi:PASS

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

following commit:
commit d58e468b ("flow_dissector: implements flow dissector BPF hook")
added struct bpf_flow_keys which conflicts with the struct with
same name in sockex2_kern.c and sockex3_kern.c

similar to commit:
commit 534e0e52 ("samples/bpf: fix a compilation failure")
we tried the rename it "flow_keys" but it also conflicted with struct
having same name in include/net/flow_dissector.h. Hence renaming the
struct to "flow_key_record". Also, this commit doesn't fix the
compilation error completely because the similar struct is present in
sockex3_kern.c. Hence renaming it in both files sockex3_user.c and
sockex3_kern.c

Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

samples/bpf build failed with the following errors:

  $ make samples/bpf/
  ...
  HOSTCC  samples/bpf/sockex3_user.o
  /data/users/yhs/work/net-next/samples/bpf/sockex3_user.c:16:8: error: redefinition of ‘struct bpf_flow_keys’
   struct bpf_flow_keys {
          ^
  In file included from /data/users/yhs/work/net-next/samples/bpf/sockex3_user.c:4:0:
  ./usr/include/linux/bpf.h:2338:9: note: originally defined here
    struct bpf_flow_keys *flow_keys;
           ^
  make[3]: *** [samples/bpf/sockex3_user.o] Error 1

Commit d58e468b ("flow_dissector: implements flow dissector BPF hook")
introduced struct bpf_flow_keys in include/uapi/linux/bpf.h and hence
caused the naming conflict with samples/bpf/sockex3_user.c.

The fix is to rename struct bpf_flow_keys in samples/bpf/sockex3_user.c
to flow_keys to avoid the conflict.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Remove duplicated includes.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

- xsks_map size was fixed to 4, changed it MAX_SOCKS
- Remove redundant definition of MAX_SOCKS in xdpsock_user.c
- In dump_stats(), add NULL check for xsks[i]

Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Sample program which shows TCP_SAVE_SYN/TCP_SAVED_SYN usage example:
bpf program which is doing TOS/TCLASS reflection (server would reply
with a same TOS/TCLASS as client).

Signed-off-by: Nikita V. Shirokov <tehnerd@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

The -c/--copy -z/--zero-copy flags enforces either copy or zero-copy
mode.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

It is common XDP practice to unload/deattach the XDP bpf program,
when the XDP sample program is Ctrl-C interrupted (SIGINT) or
killed (SIGTERM).

The samples/bpf programs xdp_redirect_cpu and xdp_rxq_info,
forgot to trap signal SIGTERM (which is the default signal used
by the kill command).

This was discovered by Red Hat QA, which automated scripts depend
on killing the XDP sample program after a timeout period.

Fixes: fad3917e ("samples/bpf: add cpumap sample program xdp_redirect_cpu")
Fixes: 0fca931a ("samples/bpf: program demonstrating access to xdp_rxq_info")
Reported-by: Jean-Tsung Hsiao <jhsiao@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

This implement XDP CPU redirection load-balancing across available
CPUs, based on the hashing IP-pairs + L4-protocol.  This equivalent to
xdp-cpu-redirect feature in Suricata, which is inspired by the
Suricata 'ippair' hashing code.

An important property is that the hashing is flow symmetric, meaning
that if the source and destination gets swapped then the selected CPU
will remain the same.  This is helps locality by placing both directions
of a flows on the same CPU, in a forwarding/routing scenario.

The hashing INITVAL (15485863 the 10^6th prime number) was fairly
arbitrary choosen, but experiments with kernel tree pktgen scripts
(pktgen_sample04_many_flows.sh +pktgen_sample05_flow_per_thread.sh)
showed this improved the distribution.

This patch also change the default loaded XDP program to be this
load-balancer.  As based on different user feedback, this seems to be
the expected behavior of the sample xdp_redirect_cpu.

Link: https://github.com/OISF/suricata/commit/796ec08dd7a63


Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Adjusted function call API to take an initval. This allow the API
user to set the initial value, as a seed. This could also be used for
inputting the previous hash.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

The teardown race in cpumap is really hard to reproduce.  These changes
makes it easier to reproduce, for QA.

The --stress-mode now have a case of a very small queue size of 8, that helps
to trigger teardown flush to encounter a full queue, which results in calling
xdp_return_frame API, in a non-NAPI protect context.

Also increase MAX_CPUS, as my QA department have larger machines than me.

Tested-by: Jean-Tsung Hsiao <jhsiao@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

The test_cgrp2_attach test covers bpf cgroup attachment code well,
so let's re-use it for testing allocation/releasing of cgroup storage.

The extension is pretty straightforward: the bpf program will use
the cgroup storage to save the number of transmitted bytes.

Expected output:
  $ ./test_cgrp2_attach2
  Attached DROP prog. This ping in cgroup /foo should fail...
  ping: sendmsg: Operation not permitted
  Attached DROP prog. This ping in cgroup /foo/bar should fail...
  ping: sendmsg: Operation not permitted
  Attached PASS prog. This ping in cgroup /foo/bar should pass...
  Detached PASS from /foo/bar while DROP is attached to /foo.
  This ping in cgroup /foo/bar should fail...
  ping: sendmsg: Operation not permitted
  Attached PASS from /foo/bar and detached DROP from /foo.
  This ping in cgroup /foo/bar should pass...
  ### override:PASS
  ### multi:PASS

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Convert xdpsock_user.c to use libbpf instead of bpf_load.o.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Convert xdp_fwd_user.c to use libbpf instead of bpf_load.o.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

To smoothly test BTF supported binary on samples/bpf,
let samples/bpf/Makefile probe llc, pahole and
llvm-objcopy for BPF support and use them
like tools/testing/selftests/bpf/Makefile
changed from the commit c0fa1b6c ("bpf: btf:
Add BTF tests").

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Define u_smp_rmb() and u_smp_wmb() to respective barrier instructions.
This ensures the processor will order accesses to queue indices against
accesses to queue ring entries.

Signed-off-by: Brian Brooks <brian.brooks@linaro.org>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

In preparation for enabling command line LDLIBS, re-name HOST_LOADLIBES
to KBUILD_HOSTLDLIBS as the internal use only flags. Also rename
existing usage to HOSTLDLIBS for consistency. This should not have any
visible effects.

Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

In preparation for enabling command line CFLAGS, re-name HOSTCFLAGS to
KBUILD_HOSTCFLAGS as the internal use only flags. This should not have
any visible effects.

Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

"prog_cnt" is the number of elements which are filled out in prog_fd[]
so the test should be >= instead of >.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

I can't see that we check prog_cnt to ensure it doesn't go over
MAX_PROGS.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

People noticed that the code match on IEEE 802.1ad (ETH_P_8021AD) ethertype,
and this implies Q-in-Q or double tagged VLANs.  Thus, we better parse
the next VLAN header too.  It is even marked as a TODO.

This is relevant for real world use-cases, as XDP cpumap redirect can be
used when the NIC RSS hashing is broken.  E.g. the ixgbe driver HW cannot
handle double tagged VLAN packets, and places everything into a single
RX queue.  Using cpumap redirect, users can redistribute traffic across
CPUs to solve this, which is faster than the network stacks RPS solution.

It is left as an exerise how to distribute the packets across CPUs.  It
would be convenient to use the RX hash, but that is not _yet_ exposed
to XDP programs. For now, users can code their own hash, as I've demonstrated
in the Suricata code (where Q-in-Q is handled correctly).

Reported-by: Florian Maury <florian.maury-cv@x-cli.eu>
Reported-by: Marek Majkowski <marek@cloudflare.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

mdev_access() calls mbochs_get_page() with mdev_state->ops_lock held,
while mbochs_get_page() locks the mutex by itself.
It leads to unavoidable deadlock.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

The below path error can occur:

  # ./xdp2skb_meta.sh --dev eth0 --list
  ./xdp2skb_meta.sh: line 61: /usr/sbin/tc: No such file or directory

So just use command names instead of absolute paths of tc and ip.
In addition, it allow callers to redefine $TC and $IP paths

Fixes: 36e04a2d ("samples/bpf: xdp2skb_meta shows transferring info from XDP to SKB")
Reviewed-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

For untracked executables of samples/bpf, add this.

  Untracked files:
    (use "git add <file>..." to include in what will be committed)

  	samples/bpf/cpustat
  	samples/bpf/fds_example
  	samples/bpf/lathist
  	samples/bpf/load_sock_ops
	...

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

test_task_rename() and test_urandom_read()
can be failed during write() and read(),
So check the result of them.

Reviewed-by: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

To avoid the below build warning message,
use new generate_load() checking the return value.

  ignoring return value of ‘system’, declared with attribute warn_unused_result

And it also refactors the duplicate code of both
test_perf_event_all_cpu() and test_perf_event_task()

Cc: Teng Qin <qinteng@fb.com>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

This fixes build error regarding redefinition:

    CLANG-bpf  samples/bpf/parse_varlen.o
  samples/bpf/parse_varlen.c:111:8: error: redefinition of 'vlan_hdr'
  struct vlan_hdr {
         ^
  ./include/linux/if_vlan.h:38:8: note: previous definition is here

So remove duplicate 'struct vlan_hdr' in sample code and include if_vlan.h

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

convert mbochs_region_vm_fault and mbochs_dmabuf_vm_fault
to return vm_fault_t type.

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Sendmsg in the SKB path of AF_XDP can now return EBUSY when a packet
was discarded and completed by the driver. Just ignore this message
in the sample application.

Fixes: b4b8faa1 ("samples/bpf: sample application and documentation for AF_XDP sockets")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Reported-by: Pavel Odintsov <pavel@fastnetmon.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

For ACLs implemented using either FIB rules or FIB entries, the BPF
program needs the FIB lookup status to be able to drop the packet.
Since the bpf_fib_lookup API has not reached a released kernel yet,
change the return code to contain an encoding of the FIB lookup
result and return the nexthop device index in the params struct.

In addition, inform the BPF program of any post FIB lookup reason as
to why the packet needs to go up the stack.

The fib result for unicast routes must have an egress device, so remove
the check that it is non-NULL.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

XDP_TX requires also changing the MAC-addrs, else some hardware
may drop the TX packet before reaching the wire.  This was
observed with driver mlx5.

If xdp_rxq_info select --action XDP_TX the swapmac functionality
is activated.  It is also possible to manually enable via cmdline
option --swapmac.  This is practical if wanting to measure the
overhead of writing/updating payload for other action types.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

There is a cost associated with reading the packet data payload
that this test ignored.  Add option --read to allow enabling
reading part of the payload.

This sample/tool helps us analyse an issue observed with a NIC
mlx5 (ConnectX-5 Ex) and an Intel(R) Xeon(R) CPU E5-1650 v4.

With no_touch of data:

Running XDP on dev:mlx5p1 (ifindex:8) action:XDP_DROP options:no_touch
XDP stats       CPU     pps         issue-pps
XDP-RX CPU      0       14,465,157  0
XDP-RX CPU      1       14,464,728  0
XDP-RX CPU      2       14,465,283  0
XDP-RX CPU      3       14,465,282  0
XDP-RX CPU      4       14,464,159  0
XDP-RX CPU      5       14,465,379  0
XDP-RX CPU      total   86,789,992

When not touching data, we observe that the CPUs have idle cycles.
When reading data the CPUs are 100% busy in softirq.

With reading data:

Running XDP on dev:mlx5p1 (ifindex:8) action:XDP_DROP options:read
XDP stats       CPU     pps         issue-pps
XDP-RX CPU      0       9,620,639   0
XDP-RX CPU      1       9,489,843   0
XDP-RX CPU      2       9,407,854   0
XDP-RX CPU      3       9,422,289   0
XDP-RX CPU      4       9,321,959   0
XDP-RX CPU      5       9,395,242   0
XDP-RX CPU      total   56,657,828

The effect seen above is a result of cache-misses occuring when
more RXQs are being used.  Based on perf-event observations, our
conclusion is that the CPUs DDIO (Direct Data I/O) choose to
deliver packet into main memory, instead of L3-cache.  We also
found, that this can be mitigated by either using less RXQs or by
reducing NICs the RX-ring size.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Add an example program showing how to sample packets from XDP using the
perf event buffer. The example userspace program just prints the ethernet
header for every packet sampled.

Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

There is no default implementation for dma_buf_ops->unmap.
So add a function unmapping the page, otherwise we'll leak them.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Atomic mapping interface for dmabufs will be removed.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>