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  1. 26 Apr, 2019 6 commits
    • Alexei Starovoitov's avatar
      Merge branch 'btf-dump' · 0c0cad2c
      Alexei Starovoitov authored 
      Andrii Nakryiko says:

====================
This patch set adds a new `bpftool btf dump` sub-command, which allows to dump
BTF contents (only types for now). Currently it only outputs low-level
content, almost 1:1 with binary BTF format, but follow up patches will add
ability to dump BTF types as a compilable C header file. JSON output is
supported as well.

Patch #1 adds `btf` sub-command, dumping BTF types in human-readable format.
It also implements reading .BTF data from ELF file.
Patch #2 adds minimal documentation with output format examples and different
ways to specify source of BTF data.
Patch #3 adds support for btf command in bash-completion/bpftool script.
Patch #4 fixes minor indentation issue in bash-completion script.

Output format is mostly following existing format of BPF verifier log, but
deviates from it in few places. More details are in commit message for patch 1.

Example of output for all supported BTF kinds are in patch #2 as part of
documentation. Some field names are quite verbose and I'd rather shorten them,
if we don't feel like being very close to BPF verifier names is a necessity,
but in this patch I left them exactly the same as in verifier log.

v3->v4:
  - reverse Christmas tree (Quentin)
  - better docs (Quentin)

v2->v3:
  - make map's key|value|kv|all suggestion more precise (Quentin)
  - fix default case indentations (Quentin)

v1->v2:
  - fix unnecessary trailing whitespaces in bpftool-btf.rst (Yonghong)
  - add btf in main.c for a list of possible OBJECTs
  - handle unknown keyword under `bpftool btf dump` (Yonghong)
====================
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      0c0cad2c
    • Andrii Nakryiko's avatar
      bpftool: fix indendation in bash-completion/bpftool · 8ed1875b
      Andrii Nakryiko authored 
      Fix misaligned default case branch for `prog dump` sub-command.
Reported-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Cc: Yonghong Song <yhs@fb.com>
Reviewed-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      8ed1875b
    • Andrii Nakryiko's avatar
      bpftool: add bash completions for btf command · 4a714fee
      Andrii Nakryiko authored 
      Add full support for btf command in bash-completion script.

Cc: Quentin Monnet <quentin.monnet@netronome.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      4a714fee
    • Andrii Nakryiko's avatar
      bpftool/docs: add btf sub-command documentation · ca253339
      Andrii Nakryiko authored 
      Document usage and sample output format for `btf dump` sub-command.

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>
Cc: Song Liu <songliubraving@fb.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      ca253339
    • Andrii Nakryiko's avatar
      bpftool: add ability to dump BTF types · c93cc690
      Andrii Nakryiko authored 
      Add new `btf dump` sub-command to bpftool. It allows to dump
human-readable low-level BTF types representation of BTF types. BTF can
be retrieved from few different sources:
  - from BTF object by ID;
  - from PROG, if it has associated BTF;
  - from MAP, if it has associated BTF data; it's possible to narrow
    down types to either key type, value type, both, or all BTF types;
  - from ELF file (.BTF section).

Output format mostly follows BPF verifier log format with few notable
exceptions:
  - all the type/field/param/etc names are enclosed in single quotes to
    allow easier grepping and to stand out a little bit more;
  - FUNC_PROTO output follows STRUCT/UNION/ENUM format of having one
    line per each argument; this is more uniform and allows easy
    grepping, as opposed to succinct, but inconvenient format that BPF
    verifier log is using.

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>
Cc: Song Liu <songliubraving@fb.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      c93cc690
    • Benjamin Poirier's avatar
      bpftool: Fix errno variable usage · 77d76426
      Benjamin Poirier authored 
      The test meant to use the saved value of errno. Given the current code, it
makes no practical difference however.

Fixes: bf598a8f ("bpftool: Improve handling of ENOENT on map dumps")
Signed-off-by: default avatarBenjamin Poirier <bpoirier@suse.com>
Reviewed-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      77d76426
  3. 25 Apr, 2019 7 commits
    • Stanislav Fomichev's avatar
      bpftool: show flow_dissector attachment status · 7f0c57fe
      Stanislav Fomichev authored 
      Right now there is no way to query whether BPF flow_dissector program
is attached to a network namespace or not. In previous commit, I added
support for querying that info, show it when doing `bpftool net`:

$ bpftool prog loadall ./bpf_flow.o \
	/sys/fs/bpf/flow type flow_dissector \
	pinmaps /sys/fs/bpf/flow
$ bpftool prog
3: flow_dissector  name _dissect  tag 8c9e917b513dd5cc  gpl
        loaded_at 2019-04-23T16:14:48-0700  uid 0
        xlated 656B  jited 461B  memlock 4096B  map_ids 1,2
        btf_id 1
...

$ bpftool net -j
[{"xdp":[],"tc":[],"flow_dissector":[]}]

$ bpftool prog attach pinned \
	/sys/fs/bpf/flow/flow_dissector flow_dissector
$ bpftool net -j
[{"xdp":[],"tc":[],"flow_dissector":["id":3]}]

Doesn't show up in a different net namespace:
$ ip netns add test
$ ip netns exec test bpftool net -j
[{"xdp":[],"tc":[],"flow_dissector":[]}]

Non-json output:
$ bpftool net
xdp:

tc:

flow_dissector:
id 3

v2:
* initialization order (Jakub Kicinski)
* clear errno for batch mode (Quentin Monnet)
Signed-off-by: default avatarStanislav Fomichev <sdf@google.com>
Reviewed-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      7f0c57fe
    • Stanislav Fomichev's avatar
      bpf: support BPF_PROG_QUERY for BPF_FLOW_DISSECTOR attach_type · 118c8e9a
      Stanislav Fomichev authored 
      target_fd is target namespace. If there is a flow dissector BPF program
attached to that namespace, its (single) id is returned.

v5:
* drop net ref right after rcu unlock (Daniel Borkmann)

v4:
* add missing put_net (Jann Horn)

v3:
* add missing inline to skb_flow_dissector_prog_query static def
  (kbuild test robot <lkp@intel.com>)

v2:
* don't sleep in rcu critical section (Jakub Kicinski)
* check input prog_cnt (exit early)

Cc: Jann Horn <jannh@google.com>
Signed-off-by: default avatarStanislav Fomichev <sdf@google.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      118c8e9a
    • Daniel T. Lee's avatar
      samples: bpf: add hbm sample to .gitignore · ead442a0
      Daniel T. Lee authored 
      This commit adds hbm to .gitignore which is
currently ommited from the ignore file.
Signed-off-by: default avatarDaniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      ead442a0
    • Daniel T. Lee's avatar
      libbpf: fix samples/bpf build failure due to undefined UINT32_MAX · 32e621e5
      Daniel T. Lee authored 
      Currently, building bpf samples will cause the following error.

    ./tools/lib/bpf/bpf.h:132:27: error: 'UINT32_MAX' undeclared here (not in a function) ..
     #define BPF_LOG_BUF_SIZE (UINT32_MAX >> 8) /* verifier maximum in kernels <= 5.1 */
                               ^
    ./samples/bpf/bpf_load.h:31:25: note: in expansion of macro 'BPF_LOG_BUF_SIZE'
     extern char bpf_log_buf[BPF_LOG_BUF_SIZE];
                             ^~~~~~~~~~~~~~~~

Due to commit 4519efa6 ("libbpf: fix BPF_LOG_BUF_SIZE off-by-one error")
hard-coded size of BPF_LOG_BUF_SIZE has been replaced with UINT32_MAX which is
defined in <stdint.h> header.

Even with this change, bpf selftests are running fine since these are built
with clang and it includes header(-idirafter) from clang/6.0.0/include.
(it has <stdint.h>)

    clang -I. -I./include/uapi -I../../../include/uapi -idirafter /usr/local/include -idirafter /usr/include \
    -idirafter /usr/lib/llvm-6.0/lib/clang/6.0.0/include -idirafter /usr/include/x86_64-linux-gnu \
    -Wno-compare-distinct-pointer-types -O2 -target bpf -emit-llvm -c progs/test_sysctl_prog.c -o - | \
    llc -march=bpf -mcpu=generic  -filetype=obj -o /linux/tools/testing/selftests/bpf/test_sysctl_prog.o

But bpf samples are compiled with GCC, and it only searches and includes
headers declared at the target file. As '#include <stdint.h>' hasn't been
declared in tools/lib/bpf/bpf.h, it causes build failure of bpf samples.

    gcc -Wp,-MD,./samples/bpf/.sockex3_user.o.d -Wall -Wmissing-prototypes -Wstrict-prototypes \
    -O2 -fomit-frame-pointer -std=gnu89 -I./usr/include -I./tools/lib/ -I./tools/testing/selftests/bpf/ \
    -I./tools/  lib/ -I./tools/include -I./tools/perf -c -o ./samples/bpf/sockex3_user.o ./samples/bpf/sockex3_user.c;

This commit add declaration of '#include <stdint.h>' to tools/lib/bpf/bpf.h
to fix this problem.
Signed-off-by: default avatarDaniel T. Lee <danieltimlee@gmail.com>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      32e621e5
    • Alexei Starovoitov's avatar
      Merge branch 'libbpf-fixes' · 0e33d334
      Alexei Starovoitov authored 
      Daniel Borkmann says:

====================
Two small fixes in relation to global data handling. Thanks!
====================
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      0e33d334
    • Daniel Borkmann's avatar
      bpf, libbpf: fix segfault in bpf_object__init_maps' pr_debug statement · 4f8827d2
      Daniel Borkmann authored 
      Ran into it while testing; in bpf_object__init_maps() data can be NULL
in the case where no map section is present. Therefore we simply cannot
access data->d_size before NULL test. Move the pr_debug() where it's
safe to access.

Fixes: d859900c ("bpf, libbpf: support global data/bss/rodata sections")
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      4f8827d2
    • Daniel Borkmann's avatar
      bpf, libbpf: handle old kernels more graceful wrt global data sections · 8837fe5d
      Daniel Borkmann authored 
      Andrii reported a corner case where e.g. global static data is present
in the BPF ELF file in form of .data/.bss/.rodata section, but without
any relocations to it. Such programs could be loaded before commit
d859900c ("bpf, libbpf: support global data/bss/rodata sections"),
whereas afterwards if kernel lacks support then loading would fail.

Add a probing mechanism which skips setting up libbpf internal maps
in case of missing kernel support. In presence of relocation entries,
we abort the load attempt.

Fixes: d859900c ("bpf, libbpf: support global data/bss/rodata sections")
Reported-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      8837fe5d
  5. 23 Apr, 2019 27 commits
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