Commit Graph

826615 Commits

Author SHA1 Message Date
Wang YanQing
5de35e3ae9 selftests/bpf: fix compile errors due to unsync linux/in6.h and netinet/in.h
I meet below compile errors:
"
In file included from test_tcpnotify_kern.c:12:
/usr/include/netinet/in.h:101:5: error: expected identifier
    IPPROTO_HOPOPTS = 0,   /* IPv6 Hop-by-Hop options.  */
    ^
/usr/include/linux/in6.h:131:26: note: expanded from macro 'IPPROTO_HOPOPTS'
                                ^
In file included from test_tcpnotify_kern.c:12:
/usr/include/netinet/in.h:103:5: error: expected identifier
    IPPROTO_ROUTING = 43,  /* IPv6 routing header.  */
    ^
/usr/include/linux/in6.h:132:26: note: expanded from macro 'IPPROTO_ROUTING'
                                ^
In file included from test_tcpnotify_kern.c:12:
/usr/include/netinet/in.h:105:5: error: expected identifier
    IPPROTO_FRAGMENT = 44, /* IPv6 fragmentation header.  */
    ^
/usr/include/linux/in6.h:133:26: note: expanded from macro 'IPPROTO_FRAGMENT'
"
The same compile errors are reported for test_tcpbpf_kern.c too.

My environment:
lsb_release -a:
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.6 LTS
Release:        16.04
Codename:       xenial

dpkg -l | grep libc-dev:
ii  libc-dev-bin              2.23-0ubuntu11           amd64        GNU C Library: Development binaries
ii  linux-libc-dev:amd64      4.4.0-145.171            amd64        Linux Kernel Headers for development.

The reason is linux/in6.h and netinet/in.h aren't synchronous about how to
handle the same definitions, IPPROTO_HOPOPTS, etc.

This patch fixes the compile errors by moving <netinet/in.h> to before the
<linux/*.h>.

Signed-off-by: Wang YanQing <udknight@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-18 16:08:40 -07:00
Magnus Karlsson
79b1b30e4c libbpf: remove compile time warning from libbpf_util.h
Having a helpful compile time warning in libbpf_util.h is not a good
idea since all warnings are treated as errors. Change this into a
comment in the code instead.

Fixes: b7e3a28019 ("libbpf: remove dependency on barrier.h in xsk.h")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-18 16:07:12 -07:00
Andrey Ignatov
da70314917 bpf: Document BPF_PROG_TYPE_CGROUP_SYSCTL
Add documentation for BPF_PROG_TYPE_CGROUP_SYSCTL, including general
info, attach type, context, return code, helpers, example and usage
considerations.

A separate file prog_cgroup_sysctl.rst is added to Documentation/bpf/.

In the future more program types can be documented in their own
prog_<name>.rst files.

Another way to place program type specific documentation would be to
group program types somehow (e.g. cgroup.rst for all cgroup-bpf
programs), but it may not scale well since some program types may belong
to different groups, e.g. BPF_PROG_TYPE_CGROUP_SKB can be documented
together with either cgroup-bpf programs or programs that access skb.

The new file is added to the index and verified by `make htmldocs` /
sanity-check by lynx.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-18 16:05:36 -07:00
Yonghong Song
ba02de1aa0 selftests/bpf: fix a compilation error
I hit the following compilation error with gcc 4.8.5.

  prog_tests/flow_dissector.c: In function ‘test_flow_dissector’:
  prog_tests/flow_dissector.c:155:2: error: ‘for’ loop initial declarations are only allowed in C99 mode
    for (int i = 0; i < ARRAY_SIZE(tests); i++) {
    ^
  prog_tests/flow_dissector.c:155:2: note: use option -std=c99 or -std=gnu99 to compile your code

Let us fix the issue by avoiding this particular c99 feature.

Fixes: a5cb33464e ("selftests/bpf: make flow dissector tests more extensible")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-17 22:29:51 -07:00
Alexei Starovoitov
193d0002ef Merge branch 'bulk-cpumap-redirect'
Jesper Dangaard Brouer says:

====================
This patchset utilize a number of different kernel bulk APIs for optimizing
the performance for the XDP cpumap redirect feature.

Benchmark details are available here:
 https://github.com/xdp-project/xdp-project/blob/master/areas/cpumap/cpumap03-optimizations.org

Performance measurements can be considered micro benchmarks, as they measure
dropping packets at different stages in the network stack.
Summary based on above:

Baseline benchmarks
- baseline-redirect: UdpNoPorts: 3,180,074
- baseline-redirect: iptables-raw drop: 6,193,534

Patch1: bpf: cpumap use ptr_ring_consume_batched
- redirect: UdpNoPorts: 3,327,729
- redirect: iptables-raw drop: 6,321,540

Patch2: net: core: introduce build_skb_around
- redirect: UdpNoPorts: 3,221,303
- redirect: iptables-raw drop: 6,320,066

Patch3: bpf: cpumap do bulk allocation of SKBs
- redirect: UdpNoPorts: 3,290,563
- redirect: iptables-raw drop: 6,650,112

Patch4: bpf: cpumap memory prefetchw optimizations for struct page
- redirect: UdpNoPorts: 3,520,250
- redirect: iptables-raw drop: 7,649,604

In this V2 submission I have chosen drop the SKB-list patch using
netif_receive_skb_list() as it was not showing a performance improvement for
these micro benchmarks.
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-17 19:09:26 -07:00
Jesper Dangaard Brouer
86d231459d bpf: cpumap memory prefetchw optimizations for struct page
A lot of the performance gain comes from this patch.

While analysing performance overhead it was found that the largest CPU
stalls were caused when touching the struct page area. It is first read with
a READ_ONCE from build_skb_around via page_is_pfmemalloc(), and when freed
written by page_frag_free() call.

Measurements show that the prefetchw (W) variant operation is needed to
achieve the performance gain. We believe this optimization it two fold,
first the W-variant saves one step in the cache-coherency protocol, and
second it helps us to avoid the non-temporal prefetch HW optimizations and
bring this into all cache-levels. It might be worth investigating if
prefetch into L2 will have the same benefit.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-17 19:09:25 -07:00
Jesper Dangaard Brouer
8f0504a97e bpf: cpumap do bulk allocation of SKBs
As cpumap now batch consume xdp_frame's from the ptr_ring, it knows how many
SKBs it need to allocate. Thus, lets bulk allocate these SKBs via
kmem_cache_alloc_bulk() API, and use the previously introduced function
build_skb_around().

Notice that the flag __GFP_ZERO asks the slab/slub allocator to clear the
memory for us. This does clear a larger area than needed, but my micro
benchmarks on Intel CPUs show that this is slightly faster due to being a
cacheline aligned area is cleared for the SKBs. (For SLUB allocator, there
is a future optimization potential, because SKBs will with high probability
originate from same page. If we can find/identify continuous memory areas
then the Intel CPU memset rep stos will have a real performance gain.)

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-17 19:09:25 -07:00
Jesper Dangaard Brouer
ba0509b688 net: core: introduce build_skb_around
The function build_skb() also have the responsibility to allocate and clear
the SKB structure. Introduce a new function build_skb_around(), that moves
the responsibility of allocation and clearing to the caller. This allows
caller to use kmem_cache (slab/slub) bulk allocation API.

Next patch use this function combined with kmem_cache_alloc_bulk.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-17 19:09:24 -07:00
Jesper Dangaard Brouer
77361825bb bpf: cpumap use ptr_ring_consume_batched
Move ptr_ring dequeue outside loop, that allocate SKBs and calls network
stack, as these operations that can take some time. The ptr_ring is a
communication channel between CPUs, where we want to reduce/limit any
cacheline bouncing.

Do a concentrated bulk dequeue via ptr_ring_consume_batched, to shorten the
period and times the remote cacheline in ptr_ring is read

Batch size 8 is both to (1) limit BH-disable period, and (2) consume one
cacheline on 64-bit archs. After reducing the BH-disable section further
then we can consider changing this, while still thinking about L1 cacheline
size being active.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-17 19:09:24 -07:00
Alexei Starovoitov
00967e84f7 Merge branch 'af_xdp-smp_mb-fixes'
Magnus Karlsson says:

====================
This patch set fixes one bug and removes two dependencies on Linux
kernel headers from the XDP socket code in libbpf. A number of people
have pointed out that these two dependencies make it hard to build the
XDP socket part of libbpf without any kernel header dependencies. The
two removed dependecies are:

* Remove the usage of likely and unlikely (compiler.h) in xsk.h. It
  has been reported that the use of these actually decreases the
  performance of the ring access code due to an increase in
  instruction cache misses, so let us just remove these.

* Remove the dependency on barrier.h as it brings in a lot of kernel
  headers. As the XDP socket code only uses two simple functions from
  it, we can reimplement these. As a bonus, the new implementation is
  faster as it uses the same barrier primitives as the kernel does
  when the same code is compiled there. Without this patch, the user
  land code uses lfence and sfence on x86, which are unnecessarily
  harsh/thorough.

In the process of removing these dependencies a missing barrier
function for at least PPC64 was discovered. For a full explanation on
the missing barrier, please refer to patch 1. So the patch set now
starts with two patches fixing this. I have also added a patch at the
end removing this full memory barrier for x86 only, as it is not
needed there.

Structure of the patch set:
Patch 1-2: Adds the missing barrier function in kernel and user space.
Patch 3-4: Removes the dependencies
Patch 5: Optimizes the added barrier from patch 2 so that it does not
         do unnecessary work on x86.

v2 -> v3:
* Added missing memory barrier in ring code
* Added an explanation on the three barriers we use in the code
* Moved barrier functions from xsk.h to libbpf_util.h
* Added comment on why we have these functions in libbpf_util.h
* Added a new barrier function in user space that makes it possible to
  remove the full memory barrier on x86.

v1 -> v2:
* Added comment about validity of ARM 32-bit barriers.
  Only armv7 and above.

/Magnus
====================

Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-16 20:13:11 -07:00
Magnus Karlsson
2c5935f1b2 libbpf: optimize barrier for XDP socket rings
The full memory barrier in the XDP socket rings on the consumer side
between the load of the data and the store of the consumer ring is
there to protect the store from being executed before the load of the
data. If this was allowed to happen, the producer might overwrite the
data field with a new entry before the consumer got the chance to read
it.

On x86, stores are guaranteed not to be reordered with older loads, so
it does not need a full memory barrier here. A compile time barrier
would be enough. This patch introdcues a new primitive in
libbpf_util.h that implements a new barrier type (libbpf_smp_rwmb)
hindering stores to be reordered with older loads. It is then used in
the XDP socket ring access code in libbpf to improve performance.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-16 20:13:10 -07:00
Magnus Karlsson
b7e3a28019 libbpf: remove dependency on barrier.h in xsk.h
The use of smp_rmb() and smp_wmb() creates a Linux header dependency
on barrier.h that is unnecessary in most parts. This patch implements
the two small defines that are needed from barrier.h. As a bonus, the
new implementations are faster than the default ones as they default
to sfence and lfence for x86, while we only need a compiler barrier in
our case. Just as it is when the same ring access code is compiled in
the kernel.

Fixes: 1cad078842 ("libbpf: add support for using AF_XDP sockets")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-16 20:13:10 -07:00
Magnus Karlsson
a06d729646 libbpf: remove likely/unlikely in xsk.h
This patch removes the use of likely and unlikely in xsk.h since they
create a dependency on Linux headers as reported by several
users. There have also been reports that the use of these decreases
performance as the compiler puts the code on two different cache lines
instead of on a single one. All in all, I think we are better off
without them.

Fixes: 1cad078842 ("libbpf: add support for using AF_XDP sockets")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-16 20:13:10 -07:00
Magnus Karlsson
d5e63fdd44 libbpf: fix XDP socket ring buffer memory ordering
The ring buffer code of	XDP sockets is missing a memory	barrier	on the
consumer side between the load of the data and the write that signals
that it is ok for the producer to put new data into the buffer. On
architectures that does not guarantee that stores are not reordered
with older loads, the producer might put data into the ring before the
consumer had the chance to read it. As IA does guarantee this
ordering, it would only need a compiler barrier here, but there are no
primitives in barrier.h for this specific case (hinder writes to be ordered
before older reads) so I had to add a smp_mb() here which will
translate into a run-time synch operation on IA.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-16 20:13:10 -07:00
Magnus Karlsson
f63666de2b xsk: fix XDP socket ring buffer memory ordering
The ring buffer code of XDP sockets is missing a memory barrier on the
consumer side between the load of the data and the write that signals
that it is ok for the producer to put new data into the buffer. On
architectures that does not guarantee that stores are not reordered
with older loads, the producer might put data into the ring before the
consumer had the chance to read it. As IA does guarantee this
ordering, it would only need a compiler barrier here, but there are no
primitives in Linux for this specific case (hinder writes to be ordered
before older reads) so I had to add a smp_mb() here which will
translate into a run-time synch operation on IA.

Added a longish comment in the code explaining what each barrier in
the ring implementation accomplishes and what would happen if we
removed one of them.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-16 20:13:10 -07:00
Prashant Bhole
d1b7725dfe tools/bpftool: show btf_id in map listing
Let's print btf id of map similar to the way we are printing it
for programs.

Sample output:
user@test# bpftool map -f
61: lpm_trie  flags 0x1
	key 20B  value 8B  max_entries 1  memlock 4096B
133: array  name test_btf_id  flags 0x0
	key 4B  value 4B  max_entries 4  memlock 4096B
	pinned /sys/fs/bpf/test100
	btf_id 174
170: array  name test_btf_id  flags 0x0
	key 4B  value 4B  max_entries 4  memlock 4096B
	btf_id 240

Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-16 19:48:26 -07:00
Prashant Bhole
d459b59ee0 tools/bpftool: re-organize newline printing for map listing
Let's move the final newline printing in show_map_close_plain() at
the end of the function because it looks correct and consistent with
prog.c. Also let's do related changes for the line which prints
pinned file name.

Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-16 19:48:26 -07:00
Andrey Ignatov
f25377ee4f bpftool: Support sysctl hook
Add support for recently added BPF_PROG_TYPE_CGROUP_SYSCTL program type
and BPF_CGROUP_SYSCTL attach type.

Example of bpftool output with sysctl program from selftests:

  # bpftool p load ./test_sysctl_prog.o /mnt/bpf/sysctl_prog type cgroup/sysctl
  # bpftool p l
  9: cgroup_sysctl  name sysctl_tcp_mem  tag 0dd05f81a8d0d52e  gpl
          loaded_at 2019-04-16T12:57:27-0700  uid 0
          xlated 1008B  jited 623B  memlock 4096B
  # bpftool c a /mnt/cgroup2/bla sysctl id 9
  # bpftool c t
  CgroupPath
  ID       AttachType      AttachFlags     Name
  /mnt/cgroup2/bla
      9        sysctl                          sysctl_tcp_mem
  # bpftool c d /mnt/cgroup2/bla sysctl id 9
  # bpftool c t
  CgroupPath
  ID       AttachType      AttachFlags     Name

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-16 19:45:47 -07:00
Andrii Nakryiko
e1d1dc4653 libbpf: fix printf formatter for ptrdiff_t argument
Using %ld for printing out value of ptrdiff_t type is not portable
between 32-bit and 64-bit archs. This is causing compilation errors for
libbpf on 32-bit platform (discovered as part of an effort to integrate
libbpf into systemd ([0])). Proper formatter is %td, which is used in
this patch.

v2->v1:
  - add Reported-by
  - provide more context on how this issue was discovered

[0] https://github.com/systemd/systemd/pull/12151

Reported-by: Evgeny Vereshchagin <evvers@ya.ru>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-16 19:44:19 -07:00
Prashant Bhole
0d306c31b2 bpf: use BPF_CAST_CALL for casting bpf call
verifier.c uses BPF_CAST_CALL for casting bpf call except at one
place in jit_subprogs(). Let's use the macro for consistency.

Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-16 19:28:31 -07:00
Viet Hoang Tran
725721a650 bpf: allow clearing all sock_ops callback flags
The helper function bpf_sock_ops_cb_flags_set() can be used to both
set and clear the sock_ops callback flags. However, its current
behavior is not consistent. BPF program may clear a flag if more than
one were set, or replace a flag with another one, but cannot clear all
flags.

This patch also updates the documentation to clarify the ability to
clear flags of this helper function.

Signed-off-by: Hoang Tran <hoang.tran@uclouvain.be>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-16 19:24:20 -07:00
Peter Oskolkov
809041e765 selftests: bpf: add VRF test cases to lwt_ip_encap test.
This patch adds tests validating that VRF and BPF-LWT
encap work together well, as requested by David Ahern.

Signed-off-by: Peter Oskolkov <posk@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-16 19:19:51 -07:00
Alban Crequy
02a8c817a3 bpf: add map helper functions push, pop, peek in more BPF programs
commit f1a2e44a3a ("bpf: add queue and stack maps") introduced new BPF
helper functions:
- BPF_FUNC_map_push_elem
- BPF_FUNC_map_pop_elem
- BPF_FUNC_map_peek_elem

but they were made available only for network BPF programs. This patch
makes them available for tracepoint, cgroup and lirc programs.

Signed-off-by: Alban Crequy <alban@kinvolk.io>
Cc: Mauricio Vasquez B <mauricio.vasquez@polito.it>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 10:24:02 +02:00
Stanislav Fomichev
a5cb33464e selftests/bpf: make flow dissector tests more extensible
Rewrite selftest to iterate over an array with input packet and
expected flow_keys. This should make it easier to extend this test
with additional cases without too much boilerplate.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 10:21:12 +02:00
Alexei Starovoitov
08de198c95 selftests/bpf: two scale tests
Add two tests to check that sequence of 1024 jumps is verifiable.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 10:18:15 +02:00
Benjamin Poirier
3da6e7e408 bpftool: Improve handling of ENOSPC on reuseport_array map dumps
avoids outputting a series of
	value:
	No space left on device

The value itself is not wrong but bpf_fd_reuseport_array_lookup_elem() can
only return it if the map was created with value_size = 8. There's nothing
bpftool can do about it. Instead of repeating this error for every key in
the map, print an explanatory warning and a specialized error.

example before:
key: 00 00 00 00
value:
No space left on device
key: 01 00 00 00
value:
No space left on device
key: 02 00 00 00
value:
No space left on device
Found 0 elements

example after:
Warning: cannot read values from reuseport_sockarray map with value_size != 8
key: 00 00 00 00  value: <cannot read>
key: 01 00 00 00  value: <cannot read>
key: 02 00 00 00  value: <cannot read>
Found 0 elements

Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 10:16:33 +02:00
Benjamin Poirier
0478c3bf81 bpftool: Use print_entry_error() in case of ENOENT when dumping
Commit bf598a8f0f ("bpftool: Improve handling of ENOENT on map dumps")
used print_entry_plain() in case of ENOENT. However, that commit introduces
dead code. Per-cpu maps are zero-filled. When reading them, it's all or
nothing. There will never be a case where some cpus have an entry and
others don't.

The truth is that ENOENT is an error case. Use print_entry_error() to
output the desired message. That function's "value" parameter is also
renamed to indicate that we never use it for an actual map value.

The output format is unchanged.

Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 10:16:33 +02:00
Quentin Monnet
25df480def tools: bpftool: add a note on program statistics in man page
Linux kernel now supports statistics for BPF programs, and bpftool is
able to dump them. However, these statistics are not enabled by default,
and administrators may not know how to access them.

Add a paragraph in bpftool documentation, under the description of the
"bpftool prog show" command, to explain that such statistics are
available and that their collection is controlled via a dedicated sysctl
knob.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 10:13:37 +02:00
Quentin Monnet
88b3eed805 tools: bpftool: fix short option name for printing version in man pages
Manual pages would tell that option "-v" (lower case) would print the
version number for bpftool. This is wrong: the short name of the option
is "-V" (upper case). Fix the documentation accordingly.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 10:13:32 +02:00
Quentin Monnet
9a487883bd tools: bpftool: fix man page documentation for "pinmaps" keyword
The "pinmaps" keyword is present in the man page, in the verbose
description of the "bpftool prog load" command. However, it is missing
from the summary of available commands at the beginning of the file. Add
it there as well.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 10:13:27 +02:00
Quentin Monnet
39c9f10639 tools: bpftool: reset errno for "bpftool cgroup tree"
When trying to dump the tree of all cgroups under a given root node,
bpftool attempts to query programs of all available attach types. Some
of those attach types do not support queries, therefore several of the
calls are actually expected to fail.

Those calls set errno to EINVAL, which has no consequence for dumping
the rest of the tree. It does have consequences however if errno is
inspected at a later time. For example, bpftool batch mode relies on
errno to determine whether a command has succeeded, and whether it
should carry on with the next command. Setting errno to EINVAL when
everything worked as expected would therefore make such command fail:

        # echo 'cgroup tree \n net show' | \
                bpftool batch file -

To improve this, reset errno when its value is EINVAL after attempting
to show programs for all existing attach types in do_show_tree_fn().

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 10:13:21 +02:00
Quentin Monnet
031ebc1aac tools: bpftool: remove blank line after btf_id when listing programs
Commit 569b0c7773 ("tools/bpftool: show btf id in program information")
made bpftool print an empty line after each program entry when listing
the BPF programs loaded on the system (plain output). This is especially
confusing when some programs have an associated BTF id, and others
don't. Let's remove the blank line.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 10:13:12 +02:00
Willem de Bruijn
43537b8e2d bpf: reserve flags in bpf_skb_net_shrink
The ENCAP flags in bpf_skb_adjust_room are ignored on decap with
bpf_skb_net_shrink. Reserve these bits for future use.

Fixes: 868d523535 ("bpf: add bpf_skb_adjust_room encap flags")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 09:56:20 +02:00
Alan Maguire
bfb35c27c6 bpf: fix whitespace for ENCAP_L2 defines in bpf.h
replace tab after #define with space in line with rest of definitions

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 09:54:21 +02:00
Stanislav Fomichev
bcbccad694 selftests/bpf: bring back (void *) cast to set_ipv4_csum in test_tc_tunnel
It was removed in commit 166b5a7f2c ("selftests_bpf: extend
test_tc_tunnel for UDP encap") without any explanation.

Otherwise I see:
progs/test_tc_tunnel.c:160:17: warning: taking address of packed member 'ip' of class or structure
      'v4hdr' may result in an unaligned pointer value [-Waddress-of-packed-member]
        set_ipv4_csum(&h_outer.ip);
                       ^~~~~~~~~~
1 warning generated.

Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Fixes: 166b5a7f2c ("selftests_bpf: extend test_tc_tunnel for UDP encap")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 09:51:48 +02:00
Andrii Nakryiko
efb2ddc4ce selftests/btf: add VAR and DATASEC case for dedup tests
Add test case verifying that dedup happens (INTs are deduped in this
case) and VAR/DATASEC types are not deduped, but have their referenced
type IDs adjusted correctly.

Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Yonghong Song <yhs@fb.com>
Cc: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 09:50:20 +02:00
Andrii Nakryiko
189cf5a4a7 btf: add support for VAR and DATASEC in btf_dedup()
This patch adds support for VAR and DATASEC in btf_dedup(). VAR/DATASEC
are never deduplicated, but they need to be processed anyway as types
they refer to might need to be remapped due to deduplication and
compaction.

Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Yonghong Song <yhs@fb.com>
Cc: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 09:50:20 +02:00
Andrii Nakryiko
68e5ab1fc8 kbuild: handle old pahole more gracefully when generating BTF
When CONFIG_DEBUG_INFO_BTF is enabled but available version of pahole is too
old to support BTF generation, build script is supposed to emit warning and
proceed with the build. Due to using exit instead of return from BASH function,
existing handling code prematurely exits exit code 0, not completing some of
the build steps. This patch fixes issue by correctly returning just from
gen_btf() function only.

Fixes: e83b9f5544 ("kbuild: add ability to generate BTF type info for vmlinux")
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-16 09:47:50 +02:00
Jiong Wang
c342dc109a bpf: refactor "check_reg_arg" to eliminate code redundancy
There are a few "regs[regno]" here are there across "check_reg_arg", this
patch factor it out into a simple "reg" pointer. The intention is to
simplify code indentation and make the later patches in this set look
cleaner.

Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12 17:06:33 -07:00
Jiong Wang
55e7f3b5ac bpf: factor out reg and stack slot propagation into "propagate_liveness_reg"
After code refactor in previous patches, the propagation logic inside the
for loop in "propagate_liveness" becomes clear that they are good enough to
be factored out into a common function "propagate_liveness_reg".

Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12 17:06:33 -07:00
Jiong Wang
3f8cafa413 bpf: refactor propagate_liveness to eliminate code redundance
Access to reg states were not factored out, the consequence is long code
for dereferencing them which made the indentation not good for reading.

This patch factor out these code so the core code in the loop could be
easier to follow.

Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12 17:06:33 -07:00
Jiong Wang
1b04aee7e2 bpf: refactor propagate_liveness to eliminate duplicated for loop
Propagation for register and stack slot are finished in separate for loop,
while they are perfect to be put into a single loop.

This could also let them share some common variables in later patches.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12 17:06:33 -07:00
Andrey Ignatov
51356ac89b bpf: Fix distinct pointer types warning for ARCH=i386
Fix a new warning reported by kbuild for make ARCH=i386:

   In file included from kernel/bpf/cgroup.c:11:0:
   kernel/bpf/cgroup.c: In function '__cgroup_bpf_run_filter_sysctl':
   include/linux/kernel.h:827:29: warning: comparison of distinct pointer types lacks a cast
      (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
                                ^
   include/linux/kernel.h:841:4: note: in expansion of macro '__typecheck'
      (__typecheck(x, y) && __no_side_effects(x, y))
       ^~~~~~~~~~~
   include/linux/kernel.h:851:24: note: in expansion of macro '__safe_cmp'
     __builtin_choose_expr(__safe_cmp(x, y), \
                           ^~~~~~~~~~
   include/linux/kernel.h:860:19: note: in expansion of macro '__careful_cmp'
    #define min(x, y) __careful_cmp(x, y, <)
                      ^~~~~~~~~~~~~
>> kernel/bpf/cgroup.c:837:17: note: in expansion of macro 'min'
      ctx.new_len = min(PAGE_SIZE, *pcount);
                    ^~~

Fixes: 4e63acdff8 ("bpf: Introduce bpf_sysctl_{get,set}_new_value helpers")
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12 16:11:55 -07:00
Alexei Starovoitov
a43d05086c Merge branch 'bpf-sysctl-hook'
Andrey Ignatov says:

====================
v2->v3:
- simplify C based selftests by relying on variable offset stack access.

v1->v2:
- add fs/proc/proc_sysctl.c mainteners to Cc:.

The patch set introduces new BPF hook for sysctl.

It adds new program type BPF_PROG_TYPE_CGROUP_SYSCTL and attach type
BPF_CGROUP_SYSCTL.

BPF_CGROUP_SYSCTL hook is placed before calling to sysctl's proc_handler so
that accesses (read/write) to sysctl can be controlled for specific cgroup
and either allowed or denied, or traced.

The hook has access to sysctl name, current sysctl value and (on write
only) to new sysctl value via corresponding helpers. New sysctl value can
be overridden by program. Both name and values (current/new) are
represented as strings same way they're visible in /proc/sys/. It is up to
program to parse these strings.

To help with parsing the most common kind of sysctl value, vector of
integers, two new helpers are provided: bpf_strtol and bpf_strtoul with
semantic similar to user space strtol(3) and strtoul(3).

The hook also provides bpf_sysctl context with two fields:
* @write indicates whether sysctl is being read (= 0) or written (= 1);
* @file_pos is sysctl file position to read from or write to, can be
  overridden.

The hook allows to make better isolation for containerized applications
that are run as root so that one container can't change a sysctl and affect
all other containers on a host, make changes to allowed sysctl in a safer
way and simplify sysctl tracing for cgroups.

Patch 1 is preliminary refactoring.
Patch 2 adds new program and attach types.
Patches 3-5 implement helpers to access sysctl name and value.
Patch 6 adds file_pos field to bpf_sysctl context.
Patch 7 updates UAPI in tools.
Patches 8-9 add support for the new hook to libbpf and corresponding test.
Patches 10-14 add selftests for the new hook.
Patch 15 adds support for new arg types to verifier: pointer to integer.
Patch 16 adds bpf_strto{l,ul} helpers to parse integers from sysctl value.
Patch 17 updates UAPI in tools.
Patch 18 updates bpf_helpers.h.
Patch 19 adds selftests for pointer to integer in verifier.
Patches 20-21 add selftests for bpf_strto{l,ul}, including integration
              C based test for sysctl value parsing.
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12 13:56:11 -07:00
Andrey Ignatov
7568f4cbbe selftests/bpf: C based test for sysctl and strtoX
Add C based test for a few bpf_sysctl_* helpers and bpf_strtoul.

Make sure that sysctl can be identified by name and that multiple
integers can be parsed from sysctl value with bpf_strtoul.

net/ipv4/tcp_mem is chosen as a testing sysctl, it contains 3 unsigned
longs, they all are parsed and compared (val[0] < val[1] < val[2]).

Example of output:
  # ./test_sysctl
  ...
  Test case: C prog: deny all writes .. [PASS]
  Test case: C prog: deny access by name .. [PASS]
  Test case: C prog: read tcp_mem .. [PASS]
  Summary: 39 PASSED, 0 FAILED

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12 13:54:59 -07:00
Andrey Ignatov
8549ddc832 selftests/bpf: Test bpf_strtol and bpf_strtoul helpers
Test that bpf_strtol and  bpf_strtoul helpers can be used to convert
provided buffer to long or unsigned long correspondingly and return both
correct result and number of consumed bytes, or proper errno.

Example of output:
  # ./test_sysctl
  ..
  Test case: bpf_strtoul one number string .. [PASS]
  Test case: bpf_strtoul multi number string .. [PASS]
  Test case: bpf_strtoul buf_len = 0, reject .. [PASS]
  Test case: bpf_strtoul supported base, ok .. [PASS]
  Test case: bpf_strtoul unsupported base, EINVAL .. [PASS]
  Test case: bpf_strtoul buf with spaces only, EINVAL .. [PASS]
  Test case: bpf_strtoul negative number, EINVAL .. [PASS]
  Test case: bpf_strtol negative number, ok .. [PASS]
  Test case: bpf_strtol hex number, ok .. [PASS]
  Test case: bpf_strtol max long .. [PASS]
  Test case: bpf_strtol overflow, ERANGE .. [PASS]
  Summary: 36 PASSED, 0 FAILED

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12 13:54:59 -07:00
Andrey Ignatov
c2d5f12e4c selftests/bpf: Test ARG_PTR_TO_LONG arg type
Test that verifier handles new argument types properly, including
uninitialized or partially initialized value, misaligned stack access,
etc.

Example of output:
  #456/p ARG_PTR_TO_LONG uninitialized OK
  #457/p ARG_PTR_TO_LONG half-uninitialized OK
  #458/p ARG_PTR_TO_LONG misaligned OK
  #459/p ARG_PTR_TO_LONG size < sizeof(long) OK
  #460/p ARG_PTR_TO_LONG initialized OK

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12 13:54:59 -07:00
Andrey Ignatov
99f57973ac selftests/bpf: Add sysctl and strtoX helpers to bpf_helpers.h
Add bpf_sysctl_* and bpf_strtoX helpers to bpf_helpers.h.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12 13:54:59 -07:00
Andrey Ignatov
b457e5534c bpf: Sync bpf.h to tools/
Sync bpf_strtoX related bpf UAPI changes to tools/.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12 13:54:59 -07:00
Andrey Ignatov
d7a4cb9b67 bpf: Introduce bpf_strtol and bpf_strtoul helpers
Add bpf_strtol and bpf_strtoul to convert a string to long and unsigned
long correspondingly. It's similar to user space strtol(3) and
strtoul(3) with a few changes to the API:

* instead of NUL-terminated C string the helpers expect buffer and
  buffer length;

* resulting long or unsigned long is returned in a separate
  result-argument;

* return value is used to indicate success or failure, on success number
  of consumed bytes is returned that can be used to identify position to
  read next if the buffer is expected to contain multiple integers;

* instead of *base* argument, *flags* is used that provides base in 5
  LSB, other bits are reserved for future use;

* number of supported bases is limited.

Documentation for the new helpers is provided in bpf.h UAPI.

The helpers are made available to BPF_PROG_TYPE_CGROUP_SYSCTL programs to
be able to convert string input to e.g. "ulongvec" output.

E.g. "net/ipv4/tcp_mem" consists of three ulong integers. They can be
parsed by calling to bpf_strtoul three times.

Implementation notes:

Implementation includes "../../lib/kstrtox.h" to reuse integer parsing
functions. It's done exactly same way as fs/proc/base.c already does.

Unfortunately existing kstrtoX function can't be used directly since
they fail if any invalid character is present right after integer in the
string. Existing simple_strtoX functions can't be used either since
they're obsolete and don't handle overflow properly.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12 13:54:59 -07:00