From 9fd496848b1c4cd04fee5f152bb7bcec11e1b901 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Wed, 5 Apr 2023 14:21:16 +0100 Subject: bpftool: Support inline annotations when dumping the CFG of a program 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 --- tools/bpf/bpftool/main.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'tools/bpf/bpftool/main.h') diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index 0ef373cef4c7..e9ee514b22d4 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -229,6 +229,8 @@ void btf_dump_linfo_plain(const struct btf *btf, const char *prefix, bool linum); void btf_dump_linfo_json(const struct btf *btf, const struct bpf_line_info *linfo, bool linum); +void btf_dump_linfo_dotlabel(const struct btf *btf, + const struct bpf_line_info *linfo); struct nlattr; struct ifinfomsg; -- cgit From 7483a7a70a12d7c00c9f80574d533b01689d39a7 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Wed, 5 Apr 2023 14:21:19 +0100 Subject: bpftool: Support printing opcodes and source file references in CFG 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 --- tools/bpf/bpftool/main.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/bpf/bpftool/main.h') diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index e9ee514b22d4..00d11ca6d3f2 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -230,7 +230,7 @@ void btf_dump_linfo_plain(const struct btf *btf, void btf_dump_linfo_json(const struct btf *btf, const struct bpf_line_info *linfo, bool linum); void btf_dump_linfo_dotlabel(const struct btf *btf, - const struct bpf_line_info *linfo); + const struct bpf_line_info *linfo, bool linum); struct nlattr; struct ifinfomsg; -- cgit From 0232b788978652571c4f4e57dc26ff8e4837926a Mon Sep 17 00:00:00 2001 From: Kui-Feng Lee Date: Wed, 19 Apr 2023 17:28:21 -0700 Subject: bpftool: Register struct_ops with a link. 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 --- tools/bpf/bpftool/main.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'tools/bpf/bpftool/main.h') diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index 00d11ca6d3f2..9a95788e654d 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -264,4 +264,7 @@ static inline bool hashmap__empty(struct hashmap *map) return map ? hashmap__size(map) == 0 : true; } +int pathname_concat(char *buf, int buf_sz, const char *path, + const char *name); + #endif -- cgit From d0fe92fb5e3df6991c640fb9205d880b68603259 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 21 Apr 2023 19:02:58 +0200 Subject: tools: bpftool: print netfilter link info 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 --- tools/bpf/bpftool/main.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'tools/bpf/bpftool/main.h') diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index 9a95788e654d..a49534d7eafa 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -267,4 +267,7 @@ static inline bool hashmap__empty(struct hashmap *map) int pathname_concat(char *buf, int buf_sz, const char *path, const char *name); +/* print netfilter bpf_link info */ +void netfilter_dump_plain(const struct bpf_link_info *info); +void netfilter_dump_json(const struct bpf_link_info *info, json_writer_t *wtr); #endif -- cgit