linux-stable.git/tools/bpf/bpftool, branch v6.4

tools: bpftool: print netfilter link info

2023-04-21T18:34:49+00:00

Dump protocol family, hook and priority value:
$ bpftool link
2: netfilter  prog 14
        ip input prio -128
        pids install(3264)
5: netfilter  prog 14
        ip6 forward prio 21
        pids a.out(3387)
9: netfilter  prog 14
        ip prerouting prio 123
        pids a.out(5700)
10: netfilter  prog 14
        ip input prio 21
        pids test2(5701)

v2: Quentin Monnet suggested to also add 'bpftool net' support:

$ bpftool net
xdp:

tc:

flow_dissector:

netfilter:

        ip prerouting prio 21 prog_id 14
        ip input prio -128 prog_id 14
        ip input prio 21 prog_id 14
        ip forward prio 21 prog_id 14
        ip output prio 21 prog_id 14
        ip postrouting prio 21 prog_id 14

'bpftool net' only dumps netfilter link type, links are sorted by protocol
family, hook and priority.

v5: fix bpf ci failure: libbpf needs small update to prog_type_name[]
    and probe_prog_load helper.
v4: don't fail with -EOPNOTSUPP in libbpf probe_prog_load, update
    prog_type_name[] with "netfilter" entry (bpf ci)
v3: fix bpf.h copy, 'reserved' member was removed (Alexei)
    use p_err, not fprintf (Quentin)

Suggested-by: Quentin Monnet 
Link: https://lore.kernel.org/bpf/eeeaac99-9053-90c2-aa33-cc1ecb1ae9ca@isovalent.com/
Reviewed-by: Quentin Monnet 
Signed-off-by: Florian Westphal 
Link: https://lore.kernel.org/r/20230421170300.24115-6-fw@strlen.de
Signed-off-by: Alexei Starovoitov

bpftool: Update doc to explain struct_ops register subcommand.

2023-04-21T18:10:10+00:00

The "struct_ops register" subcommand now allows for an optional *LINK_DIR*
to be included. This specifies the directory path where bpftool will pin
struct_ops links with the same name as their corresponding map names.

Signed-off-by: Kui-Feng Lee 
Reviewed-by: Quentin Monnet 
Link: https://lore.kernel.org/r/20230420002822.345222-2-kuifeng@meta.com
Signed-off-by: Alexei Starovoitov

bpftool: Register struct_ops with a link.

2023-04-21T18:10:10+00:00

You can include an optional path after specifying the object name for the
'struct_ops register' subcommand.

Since the commit 226bc6ae6405 ("Merge branch 'Transit between BPF TCP
congestion controls.'") has been accepted, it is now possible to create a
link for a struct_ops. This can be done by defining a struct_ops in
SEC(".struct_ops.link") to make libbpf returns a real link. If we don't pin
the links before leaving bpftool, they will disappear. To instruct bpftool
to pin the links in a directory with the names of the maps, we need to
provide the path of that directory.

Signed-off-by: Kui-Feng Lee 
Reviewed-by: Quentin Monnet 
Link: https://lore.kernel.org/r/20230420002822.345222-1-kuifeng@meta.com
Signed-off-by: Alexei Starovoitov

bpftool: Replace "__fallthrough" by a comment to address merge conflict

2023-04-20T23:38:10+00:00

The recent support for inline annotations in control flow graphs
generated by bpftool introduced the usage of the "__fallthrough" macro
in a switch/case block in btf_dumper.c. This change went through the
bpf-next tree, but resulted in a merge conflict in linux-next, because
this macro has been renamed "fallthrough" (no underscores) in the
meantime.

To address the conflict, we temporarily switch to a simple comment
instead of a macro.

Related: commit f7a858bffcdd ("tools: Rename __fallthrough to fallthrough")

Fixes: 9fd496848b1c ("bpftool: Support inline annotations when dumping the CFG of a program")
Reported-by: Sven Schnelle 
Reported-by: Thomas Richter 
Suggested-by: Daniel Borkmann 
Signed-off-by: Quentin Monnet 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/all/yt9dttxlwal7.fsf@linux.ibm.com/
Link: https://lore.kernel.org/bpf/20230412123636.2358949-1-tmricht@linux.ibm.com/
Link: https://lore.kernel.org/bpf/20230420003333.90901-1-quentin@isovalent.com

bpftool: Set program type only if it differs from the desired one

2023-04-07T22:28:12+00:00

After commit d6e6286a12e7 ("libbpf: disassociate section handler on explicit
bpf_program__set_type() call"), bpf_program__set_type() will force cleanup
the program's SEC() definition, this commit fixed the test helper but missed
the bpftool, which leads to bpftool prog autoattach broken as follows:

  $ bpftool prog load spi-xfer-r1v1.o /sys/fs/bpf/test autoattach
  Program spi_xfer_r1v1 does not support autoattach, falling back to pinning

This patch fix bpftool to set program type only if it differs.

Fixes: d6e6286a12e7 ("libbpf: disassociate section handler on explicit bpf_program__set_type() call")
Signed-off-by: Wei Yongjun 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20230407081427.2621590-1-weiyongjun@huaweicloud.com

bpftool: Clean up _bpftool_once_attr() calls in bash completion

2023-04-06T04:27:27+00:00

In bpftool's bash completion file, function _bpftool_once_attr() is able
to process multiple arguments. There are a few locations where this
function is called multiple times in a row, each time for a single
argument; let's pass all arguments instead to minimize the number of
function calls required for the completion.

Signed-off-by: Quentin Monnet 
Link: https://lore.kernel.org/r/20230405132120.59886-8-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov

bpftool: Support printing opcodes and source file references in CFG

2023-04-06T04:27:27+00:00

Add support for displaying opcodes or/and file references (filepath,
line and column numbers) when dumping the control flow graphs of loaded
BPF programs with bpftool.

The filepaths in the records are absolute. To avoid blocks on the graph
to get too wide, we truncate them when they get too long (but we always
keep the entire file name). In the unlikely case where the resulting
file name is ambiguous, it remains possible to get the full path with a
regular dump (no CFG).

Signed-off-by: Quentin Monnet 
Link: https://lore.kernel.org/r/20230405132120.59886-7-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov

bpftool: Support "opcodes", "linum", "visual" simultaneously

2023-04-06T04:27:27+00:00

When dumping a program, the keywords "opcodes" (for printing the raw
opcodes), "linum" (for displaying the filename, line number, column
number along with the source code), and "visual" (for generating the
control flow graph for translated programs) are mutually exclusive. But
there's no reason why they should be. Let's make it possible to pass
several of them at once. The "file FILE" option, which makes bpftool
output a binary image to a file, remains incompatible with the others.

Signed-off-by: Quentin Monnet 
Link: https://lore.kernel.org/r/20230405132120.59886-6-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov

bpftool: Return an error on prog dumps if both CFG and JSON are required

2023-04-06T04:27:27+00:00

We do not support JSON output for control flow graphs of programs with
bpftool. So far, requiring both the CFG and JSON output would result in
producing a null JSON object. It makes more sense to raise an error
directly when parsing command line arguments and options, so that users
know they won't get any output they might expect.

If JSON is required for the graph, we leave it to Graphviz instead:

    # bpftool prog dump xlated  visual | dot -Tjson

Suggested-by: Eduard Zingerman 
Signed-off-by: Quentin Monnet 
Link: https://lore.kernel.org/r/20230405132120.59886-5-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov

bpftool: Support inline annotations when dumping the CFG of a program

2023-04-06T04:27:27+00:00

We support dumping the control flow graph of loaded programs to the DOT
format with bpftool, but so far this feature wouldn't display the source
code lines available through BTF along with the eBPF bytecode. Let's add
support for these annotations, to make it easier to read the graph.

In prog.c, we move the call to dump_xlated_cfg() in order to pass and
use the full struct dump_data, instead of creating a minimal one in
draw_bb_node().

We pass the pointer to this struct down to dump_xlated_for_graph() in
xlated_dumper.c, where most of the logics is added. We deal with BTF
mostly like we do for plain or JSON output, except that we cannot use a
"nr_skip" value to skip a given number of linfo records (we don't
process the BPF instructions linearly, and apart from the root of the
graph we don't know how many records we should skip, so we just store
the last linfo and make sure the new one we find is different before
printing it).

When printing the source instructions to the label of a DOT graph node,
there are a few subtleties to address. We want some special newline
markers, and there are some characters that we must escape. To deal with
them, we introduce a new dedicated function btf_dump_linfo_dotlabel() in
btf_dumper.c. We'll reuse this function in a later commit to format the
filepath, line, and column references as well.

Signed-off-by: Quentin Monnet 
Link: https://lore.kernel.org/r/20230405132120.59886-4-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov