From bde71f2565dabc8e567e3c8351097094052c0031 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Mon, 27 Mar 2023 12:06:55 +0100 Subject: [PATCH] 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. Signed-off-by: Quentin Monnet Acked-by: Stanislav Fomichev --- tools/bpf/bpftool/btf_dumper.c | 19 ++++++++++++++++++- tools/bpf/bpftool/cfg.c | 22 ++++++++++++++-------- tools/bpf/bpftool/cfg.h | 3 ++- tools/bpf/bpftool/main.h | 2 +- tools/bpf/bpftool/prog.c | 2 +- tools/bpf/bpftool/xlated_dumper.c | 15 +++++++++++++-- tools/bpf/bpftool/xlated_dumper.h | 3 ++- 7 files changed, 51 insertions(+), 15 deletions(-) diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c index 8bfc1b69497db..24835c3f9a1cf 100644 --- a/tools/bpf/bpftool/btf_dumper.c +++ b/tools/bpf/bpftool/btf_dumper.c @@ -841,7 +841,7 @@ static void dotlabel_puts(const char *s) } void btf_dump_linfo_dotlabel(const struct btf *btf, - const struct bpf_line_info *linfo) + const struct bpf_line_info *linfo, bool linum) { const char *line = btf__name_by_offset(btf, linfo->line_off); @@ -849,6 +849,23 @@ void btf_dump_linfo_dotlabel(const struct btf *btf, return; line = ltrim(line); + if (linum) { + const char *file = btf__name_by_offset(btf, linfo->file_name_off); + + /* More forgiving on file because linum option is + * expected to provide more info than the already + * available src line. + */ + if (!file) + file = ""; + + printf("; [file:"); + dotlabel_puts(file); + printf("line_num:%u line_col:%u]\\l\\\n", + BPF_LINE_INFO_LINE_NUM(linfo->line_col), + BPF_LINE_INFO_LINE_COL(linfo->line_col)); + } + printf("; "); dotlabel_puts(line); printf("\\l\\\n"); diff --git a/tools/bpf/bpftool/cfg.c b/tools/bpf/bpftool/cfg.c index 9fdc1f0cdd6e6..eec437cca2ea7 100644 --- a/tools/bpf/bpftool/cfg.c +++ b/tools/bpf/bpftool/cfg.c @@ -381,7 +381,8 @@ static void cfg_destroy(struct cfg *cfg) } static void -draw_bb_node(struct func_node *func, struct bb_node *bb, struct dump_data *dd) +draw_bb_node(struct func_node *func, struct bb_node *bb, struct dump_data *dd, + bool opcodes, bool linum) { const char *shape; @@ -401,7 +402,8 @@ draw_bb_node(struct func_node *func, struct bb_node *bb, struct dump_data *dd) unsigned int start_idx; printf("{\\\n"); start_idx = bb->head - func->start; - dump_xlated_for_graph(dd, bb->head, bb->tail, start_idx); + dump_xlated_for_graph(dd, bb->head, bb->tail, start_idx, + opcodes, linum); printf("}"); } @@ -427,12 +429,14 @@ static void draw_bb_succ_edges(struct func_node *func, struct bb_node *bb) } } -static void func_output_bb_def(struct func_node *func, struct dump_data *dd) +static void +func_output_bb_def(struct func_node *func, struct dump_data *dd, + bool opcodes, bool linum) { struct bb_node *bb; list_for_each_entry(bb, &func->bbs, l) { - draw_bb_node(func, bb, dd); + draw_bb_node(func, bb, dd, opcodes, linum); } } @@ -452,7 +456,8 @@ static void func_output_edges(struct func_node *func) func_idx, ENTRY_BLOCK_INDEX, func_idx, EXIT_BLOCK_INDEX); } -static void cfg_dump(struct cfg *cfg, struct dump_data *dd) +static void +cfg_dump(struct cfg *cfg, struct dump_data *dd, bool opcodes, bool linum) { struct func_node *func; @@ -460,14 +465,15 @@ static void cfg_dump(struct cfg *cfg, struct dump_data *dd) list_for_each_entry(func, &cfg->funcs, l) { printf("subgraph \"cluster_%d\" {\n\tstyle=\"dashed\";\n\tcolor=\"black\";\n\tlabel=\"func_%d ()\";\n", func->idx, func->idx); - func_output_bb_def(func, dd); + func_output_bb_def(func, dd, opcodes, linum); func_output_edges(func); printf("}\n"); } printf("}\n"); } -void dump_xlated_cfg(struct dump_data *dd, void *buf, unsigned int len) +void dump_xlated_cfg(struct dump_data *dd, void *buf, unsigned int len, + bool opcodes, bool linum) { struct bpf_insn *insn = buf; struct cfg cfg; @@ -476,7 +482,7 @@ void dump_xlated_cfg(struct dump_data *dd, void *buf, unsigned int len) if (cfg_build(&cfg, insn, len)) return; - cfg_dump(&cfg, dd); + cfg_dump(&cfg, dd, opcodes, linum); cfg_destroy(&cfg); } diff --git a/tools/bpf/bpftool/cfg.h b/tools/bpf/bpftool/cfg.h index 909d17e6d4c2a..b3793f4e17832 100644 --- a/tools/bpf/bpftool/cfg.h +++ b/tools/bpf/bpftool/cfg.h @@ -6,6 +6,7 @@ #include "xlated_dumper.h" -void dump_xlated_cfg(struct dump_data *dd, void *buf, unsigned int len); +void dump_xlated_cfg(struct dump_data *dd, void *buf, unsigned int len, + bool opcodes, bool linum); #endif /* __BPF_TOOL_CFG_H */ diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index e9ee514b22d41..00d11ca6d3f2b 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; diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index 567ac37dbd86a..848f57a7d7623 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -854,7 +854,7 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode, else if (json_output) dump_xlated_json(&dd, buf, member_len, opcodes, linum); else if (visual) - dump_xlated_cfg(&dd, buf, member_len); + dump_xlated_cfg(&dd, buf, member_len, opcodes, linum); else dump_xlated_plain(&dd, buf, member_len, opcodes, linum); kernel_syms_destroy(&dd); diff --git a/tools/bpf/bpftool/xlated_dumper.c b/tools/bpf/bpftool/xlated_dumper.c index 5fbe94aa85891..c5e03833fadfa 100644 --- a/tools/bpf/bpftool/xlated_dumper.c +++ b/tools/bpf/bpftool/xlated_dumper.c @@ -361,7 +361,8 @@ void dump_xlated_plain(struct dump_data *dd, void *buf, unsigned int len, } void dump_xlated_for_graph(struct dump_data *dd, void *buf_start, void *buf_end, - unsigned int start_idx) + unsigned int start_idx, + bool opcodes, bool linum) { const struct bpf_insn_cbs cbs = { .cb_print = print_insn_for_graph, @@ -405,7 +406,7 @@ void dump_xlated_for_graph(struct dump_data *dd, void *buf_start, void *buf_end, linfo = bpf_prog_linfo__lfind(prog_linfo, insn_off, 0); if (linfo && linfo != last_linfo) { - btf_dump_linfo_dotlabel(btf, linfo); + btf_dump_linfo_dotlabel(btf, linfo, linum); last_linfo = linfo; } } @@ -413,6 +414,16 @@ void dump_xlated_for_graph(struct dump_data *dd, void *buf_start, void *buf_end, printf("%d: ", insn_off); print_bpf_insn(&cbs, cur, true); + if (opcodes) { + printf(" "); + fprint_hex(stdout, cur, 8, " "); + if (double_insn && cur <= insn_end - 1) { + printf(" "); + fprint_hex(stdout, cur + 1, 8, " "); + } + printf("\\l\\\n"); + } + if (cur != insn_end) printf(" | "); } diff --git a/tools/bpf/bpftool/xlated_dumper.h b/tools/bpf/bpftool/xlated_dumper.h index 54847e1742737..9a946377b0e63 100644 --- a/tools/bpf/bpftool/xlated_dumper.h +++ b/tools/bpf/bpftool/xlated_dumper.h @@ -34,6 +34,7 @@ void dump_xlated_json(struct dump_data *dd, void *buf, unsigned int len, void dump_xlated_plain(struct dump_data *dd, void *buf, unsigned int len, bool opcodes, bool linum); void dump_xlated_for_graph(struct dump_data *dd, void *buf, void *buf_end, - unsigned int start_index); + unsigned int start_index, + bool opcodes, bool linum); #endif