diff mbox series

[bpf-next,v2,5/5] bpftool: Support printing opcodes and source file references in CFG

Message ID 20230327110655.58363-6-quentin@isovalent.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series bpftool: Add inline annotations when dumping program CFGs | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR success PR summary
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for bpf-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 20 this patch: 20
netdev/cc_maintainers warning 2 maintainers not CCed: martin.lau@linux.dev song@kernel.org
netdev/build_clang success Errors and warnings before: 18 this patch: 18
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 20 this patch: 20
netdev/checkpatch warning WARNING: line length of 82 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
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Commit Message

Quentin Monnet March 27, 2023, 11:06 a.m. UTC 
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 <quentin@isovalent.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
---
 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(-)

Comments

Eduard Zingerman March 27, 2023, 5:04 p.m. UTC | #1 
On Mon, 2023-03-27 at 12:06 +0100, Quentin Monnet wrote:
> 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 <quentin@isovalent.com>
> Acked-by: Stanislav Fomichev <sdf@google.com>
> ---
>  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 8bfc1b69497d..24835c3f9a1c 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",

Space between file name and 'line_num' is missing.

Also, at-least for BPF test-cases the labels might become quite long,
which makes graph unnecessarily wide, e.g.:

  ; [file:/home/eddy/work/bpf-next/tools/testing/selftests/bpf/progs/bpf_flow.cline_num:97 line_col:34]\l\

The file names are encoded in full during compilation, but maybe
shorten long file names by removing some preceding levels
(and use shorter tags 'line:', 'col:', is 'file:' tag necessary at all?).
For example:

  ; [.../progs/bpf_flow.c line:97 col:34]\l\.

> +		       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 9fdc1f0cdd6e..eec437cca2ea 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 909d17e6d4c2..b3793f4e1783 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 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;
> diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
> index 567ac37dbd86..848f57a7d762 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 5fbe94aa8589..c5e03833fadf 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("       ");

These spaces are treated as a single space by the dot renderer, as [1]
says: "Spaces are interpreted as separators between tokens, so they
must be escaped if you want spaces in the text."

[1] https://graphviz.org/doc/info/shapes.html#record

> +			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 54847e174273..9a946377b0e6 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
Quentin Monnet March 31, 2023, 2:52 p.m. UTC | #2 
2023-03-27 20:04 UTC+0300 ~ Eduard Zingerman <eddyz87@gmail.com>
> On Mon, 2023-03-27 at 12:06 +0100, Quentin Monnet wrote:
>> 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 <quentin@isovalent.com>
>> Acked-by: Stanislav Fomichev <sdf@google.com>
>> ---
>>  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 8bfc1b69497d..24835c3f9a1c 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",
> 
> Space between file name and 'line_num' is missing.

My bad, thanks!

> 
> Also, at-least for BPF test-cases the labels might become quite long,
> which makes graph unnecessarily wide, e.g.:
> 
>   ; [file:/home/eddy/work/bpf-next/tools/testing/selftests/bpf/progs/bpf_flow.cline_num:97 line_col:34]\l\
> 
> The file names are encoded in full during compilation, but maybe
> shorten long file names by removing some preceding levels
> (and use shorter tags 'line:', 'col:', is 'file:' tag necessary at all?).
> For example:
> 
>   ; [.../progs/bpf_flow.c line:97 col:34]\l\.

I thought about that but was unsure. But yeah, I suppose the risk of
users getting confused about where the file is located is limited,
especially given that we still have regular program dump that will keep
the full path. OK I'll look into that for the next version.

> 
>> +		       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 9fdc1f0cdd6e..eec437cca2ea 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 909d17e6d4c2..b3793f4e1783 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 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;
>> diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
>> index 567ac37dbd86..848f57a7d762 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 5fbe94aa8589..c5e03833fadf 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("       ");
> 
> These spaces are treated as a single space by the dot renderer, as [1]
> says: "Spaces are interpreted as separators between tokens, so they
> must be escaped if you want spaces in the text."
> 
> [1] https://graphviz.org/doc/info/shapes.html#record

I noticed, I kept the multiple spaces to make the DOT output slightly
more readable. But it would maybe make sense to indent more in the graph
as well, if it doesn't make opcode sequences wider than instructions.
I'll have a look at this.
Eduard Zingerman March 31, 2023, 3:03 p.m. UTC | #3 
On Fri, 2023-03-31 at 15:52 +0100, Quentin Monnet wrote:
[...]
> > > @@ -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("       ");
> > 
> > These spaces are treated as a single space by the dot renderer, as [1]
> > says: "Spaces are interpreted as separators between tokens, so they
> > must be escaped if you want spaces in the text."
> > 
> > [1] https://graphviz.org/doc/info/shapes.html#record
> 
> I noticed, I kept the multiple spaces to make the DOT output slightly
> more readable. But it would maybe make sense to indent more in the graph
> as well, if it doesn't make opcode sequences wider than instructions.
> I'll have a look at this.

Oh, sorry, that did not occur to me, making DOT itself more readable
makes total sense.
diff mbox series

Patch

diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c
index 8bfc1b69497d..24835c3f9a1c 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 9fdc1f0cdd6e..eec437cca2ea 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 909d17e6d4c2..b3793f4e1783 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 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;
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 567ac37dbd86..848f57a7d762 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 5fbe94aa8589..c5e03833fadf 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 54847e174273..9a946377b0e6 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