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Commit b053b439 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

bpf: libbpf: bpftool: Print bpf_line_info during prog dump 



This patch adds print bpf_line_info function in 'prog dump jitted'
and 'prog dump xlated':

[root@arch-fb-vm1 bpf]# ~/devshare/fb-kernel/linux/tools/bpf/bpftool/bpftool prog dump jited pinned /sys/fs/bpf/test_btf_haskv
[...]
int test_long_fname_2(struct dummy_tracepoint_args * arg):
bpf_prog_44a040bf25481309_test_long_fname_2:
; static int test_long_fname_2(struct dummy_tracepoint_args *arg)
   0:	push   %rbp
   1:	mov    %rsp,%rbp
   4:	sub    $0x30,%rsp
   b:	sub    $0x28,%rbp
   f:	mov    %rbx,0x0(%rbp)
  13:	mov    %r13,0x8(%rbp)
  17:	mov    %r14,0x10(%rbp)
  1b:	mov    %r15,0x18(%rbp)
  1f:	xor    %eax,%eax
  21:	mov    %rax,0x20(%rbp)
  25:	xor    %esi,%esi
; int key = 0;
  27:	mov    %esi,-0x4(%rbp)
; if (!arg->sock)
  2a:	mov    0x8(%rdi),%rdi
; if (!arg->sock)
  2e:	cmp    $0x0,%rdi
  32:	je     0x0000000000000070
  34:	mov    %rbp,%rsi
; counts = bpf_map_lookup_elem(&btf_map, &key);
  37:	add    $0xfffffffffffffffc,%rsi
  3b:	movabs $0xffff8881139d7480,%rdi
  45:	add    $0x110,%rdi
  4c:	mov    0x0(%rsi),%eax
  4f:	cmp    $0x4,%rax
  53:	jae    0x000000000000005e
  55:	shl    $0x3,%rax
  59:	add    %rdi,%rax
  5c:	jmp    0x0000000000000060
  5e:	xor    %eax,%eax
; if (!counts)
  60:	cmp    $0x0,%rax
  64:	je     0x0000000000000070
; counts->v6++;
  66:	mov    0x4(%rax),%edi
  69:	add    $0x1,%rdi
  6d:	mov    %edi,0x4(%rax)
  70:	mov    0x0(%rbp),%rbx
  74:	mov    0x8(%rbp),%r13
  78:	mov    0x10(%rbp),%r14
  7c:	mov    0x18(%rbp),%r15
  80:	add    $0x28,%rbp
  84:	leaveq
  85:	retq
[...]

With linum:
[root@arch-fb-vm1 bpf]# ~/devshare/fb-kernel/linux/tools/bpf/bpftool/bpftool prog dump jited pinned /sys/fs/bpf/test_btf_haskv linum
int _dummy_tracepoint(struct dummy_tracepoint_args * arg):
bpf_prog_b07ccb89267cf242__dummy_tracepoint:
; return test_long_fname_1(arg); [file:/data/users/kafai/fb-kernel/linux/tools/testing/selftests/bpf/test_btf_haskv.c line_num:54 line_col:9]
   0:	push   %rbp
   1:	mov    %rsp,%rbp
   4:	sub    $0x28,%rsp
   b:	sub    $0x28,%rbp
   f:	mov    %rbx,0x0(%rbp)
  13:	mov    %r13,0x8(%rbp)
  17:	mov    %r14,0x10(%rbp)
  1b:	mov    %r15,0x18(%rbp)
  1f:	xor    %eax,%eax
  21:	mov    %rax,0x20(%rbp)
  25:	callq  0x000000000000851e
; return test_long_fname_1(arg); [file:/data/users/kafai/fb-kernel/linux/tools/testing/selftests/bpf/test_btf_haskv.c line_num:54 line_col:2]
  2a:	xor    %eax,%eax
  2c:	mov    0x0(%rbp),%rbx
  30:	mov    0x8(%rbp),%r13
  34:	mov    0x10(%rbp),%r14
  38:	mov    0x18(%rbp),%r15
  3c:	add    $0x28,%rbp
  40:	leaveq
  41:	retq
[...]

Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 3d650141

tools/bpf/bpftool/Documentation/bpftool-prog.rst

+12 −4
Original line number Diff line number Diff line
@@ -22,8 +22,8 @@ MAP COMMANDS 
=============



|	**bpftool** **prog { show | list }** [*PROG*]

|	**bpftool** **prog dump xlated** *PROG* [{**file** *FILE* | **opcodes** | **visual**}]

|	**bpftool** **prog dump jited**  *PROG* [{**file** *FILE* | **opcodes**}]

|	**bpftool** **prog dump xlated** *PROG* [{**file** *FILE* | **opcodes** | **visual** | **linum**}]

|	**bpftool** **prog dump jited**  *PROG* [{**file** *FILE* | **opcodes** | **linum**}]

|	**bpftool** **prog pin** *PROG* *FILE*

|	**bpftool** **prog { load | loadall }** *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*]

|	**bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*]
@@ -56,7 +56,7 @@ DESCRIPTION 
		  Output will start with program ID followed by program type and

		  zero or more named attributes (depending on kernel version).



	**bpftool prog dump xlated** *PROG* [{ **file** *FILE* | **opcodes** | **visual** }]

	**bpftool prog dump xlated** *PROG* [{ **file** *FILE* | **opcodes** | **visual** | **linum** }]

		  Dump eBPF instructions of the program from the kernel. By

		  default, eBPF will be disassembled and printed to standard

		  output in human-readable format. In this case, **opcodes**
@@ -69,13 +69,21 @@ DESCRIPTION 
		  built instead, and eBPF instructions will be presented with

		  CFG in DOT format, on standard output.



	**bpftool prog dump jited**  *PROG* [{ **file** *FILE* | **opcodes** }]

		  If the prog has line_info available, the source line will

		  be displayed by default.  If **linum** is specified,

		  the filename, line number and line column will also be

		  displayed on top of the source line.

	**bpftool prog dump jited**  *PROG* [{ **file** *FILE* | **opcodes** | **linum** }]

		  Dump jited image (host machine code) of the program.

		  If *FILE* is specified image will be written to a file,

		  otherwise it will be disassembled and printed to stdout.



		  **opcodes** controls if raw opcodes will be printed.



		  If the prog has line_info available, the source line will

		  be displayed by default.  If **linum** is specified,

		  the filename, line number and line column will also be

		  displayed on top of the source line.

	**bpftool prog pin** *PROG* *FILE*

		  Pin program *PROG* as *FILE*.

tools/bpf/bpftool/bash-completion/bpftool

+3 −3
Original line number Diff line number Diff line
@@ -191,7 +191,7 @@ _bpftool() 


    # Deal with simplest keywords

    case $prev in

        help|hex|opcodes|visual)

        help|hex|opcodes|visual|linum)

            return 0

            ;;

        tag)
@@ -278,10 +278,10 @@ _bpftool() 
                    *)

                        _bpftool_once_attr 'file'

                        if _bpftool_search_list 'xlated'; then

                            COMPREPLY+=( $( compgen -W 'opcodes visual' -- \

                            COMPREPLY+=( $( compgen -W 'opcodes visual linum' -- \

                                "$cur" ) )

                        else

                            COMPREPLY+=( $( compgen -W 'opcodes' -- \

                            COMPREPLY+=( $( compgen -W 'opcodes linum' -- \

                                "$cur" ) )

                        fi

                        return 0

tools/bpf/bpftool/btf_dumper.c

+64 −0
Original line number Diff line number Diff line
@@ -385,3 +385,67 @@ void btf_dumper_type_only(const struct btf *btf, __u32 type_id, char *func_sig, 
	if (err < 0)

		func_sig[0] = '\0';

}



static const char *ltrim(const char *s)

{

	while (isspace(*s))

		s++;



	return s;

}



void btf_dump_linfo_plain(const struct btf *btf,

			  const struct bpf_line_info *linfo,

			  const char *prefix, bool linum)

{

	const char *line = btf__name_by_offset(btf, linfo->line_off);



	if (!line)

		return;

	line = ltrim(line);



	if (!prefix)

		prefix = "";



	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("%s%s [file:%s line_num:%u line_col:%u]\n",

		       prefix, line, file,

		       BPF_LINE_INFO_LINE_NUM(linfo->line_col),

		       BPF_LINE_INFO_LINE_COL(linfo->line_col));

	} else {

		printf("%s%s\n", prefix, line);

	}

}



void btf_dump_linfo_json(const struct btf *btf,

			 const struct bpf_line_info *linfo, bool linum)

{

	const char *line = btf__name_by_offset(btf, linfo->line_off);



	if (line)

		jsonw_string_field(json_wtr, "src", ltrim(line));



	if (linum) {

		const char *file = btf__name_by_offset(btf, linfo->file_name_off);



		if (file)

			jsonw_string_field(json_wtr, "file", file);



		if (BPF_LINE_INFO_LINE_NUM(linfo->line_col))

			jsonw_int_field(json_wtr, "line_num",

					BPF_LINE_INFO_LINE_NUM(linfo->line_col));



		if (BPF_LINE_INFO_LINE_COL(linfo->line_col))

			jsonw_int_field(json_wtr, "line_col",

					BPF_LINE_INFO_LINE_COL(linfo->line_col));

	}

}

tools/bpf/bpftool/jit_disasm.c

+22 −1
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <dis-asm.h>

#include <sys/stat.h>

#include <limits.h>

#include <libbpf.h>



#include "json_writer.h"

#include "main.h"
@@ -68,10 +69,16 @@ static int fprintf_json(void *out, const char *fmt, ...) 
}



void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,

		       const char *arch, const char *disassembler_options)

		       const char *arch, const char *disassembler_options,

		       const struct btf *btf,

		       const struct bpf_prog_linfo *prog_linfo,

		       __u64 func_ksym, unsigned int func_idx,

		       bool linum)

{

	const struct bpf_line_info *linfo = NULL;

	disassembler_ftype disassemble;

	struct disassemble_info info;

	unsigned int nr_skip = 0;

	int count, i, pc = 0;

	char tpath[PATH_MAX];

	bfd *bfdf;
@@ -127,12 +134,26 @@ void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes, 
	if (json_output)

		jsonw_start_array(json_wtr);

	do {

		if (prog_linfo) {

			linfo = bpf_prog_linfo__lfind_addr_func(prog_linfo,

								func_ksym + pc,

								func_idx,

								nr_skip);

			if (linfo)

				nr_skip++;

		}



		if (json_output) {

			jsonw_start_object(json_wtr);

			oper_count = 0;

			if (linfo)

				btf_dump_linfo_json(btf, linfo, linum);

			jsonw_name(json_wtr, "pc");

			jsonw_printf(json_wtr, "\"0x%x\"", pc);

		} else {

			if (linfo)

				btf_dump_linfo_plain(btf, linfo, "; ",

						     linum);

			printf("%4x:\t", pc);

		}

tools/bpf/bpftool/main.h

+21 −2
Original line number Diff line number Diff line
@@ -138,6 +138,9 @@ struct pinned_obj { 
	struct hlist_node hash;

};



struct btf;

struct bpf_line_info;



int build_pinned_obj_table(struct pinned_obj_table *table,

			   enum bpf_obj_type type);

void delete_pinned_obj_table(struct pinned_obj_table *tab);
@@ -175,13 +178,23 @@ int map_parse_fd(int *argc, char ***argv); 
int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len);



#ifdef HAVE_LIBBFD_SUPPORT

struct bpf_prog_linfo;

void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,

		       const char *arch, const char *disassembler_options);

		       const char *arch, const char *disassembler_options,

		       const struct btf *btf,

		       const struct bpf_prog_linfo *prog_linfo,

		       __u64 func_ksym, unsigned int func_idx,

		       bool linum);

int disasm_init(void);

#else

static inline

void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,

		       const char *arch, const char *disassembler_options)

		       const char *arch, const char *disassembler_options,

		       const struct btf *btf,

		       const struct bpf_prog_linfo *prog_linfo,

		       __u64 func_ksym, unsigned int func_idx,

		       bool linum)



{

}

static inline int disasm_init(void)
@@ -217,6 +230,12 @@ int btf_dumper_type(const struct btf_dumper *d, __u32 type_id, 
void btf_dumper_type_only(const struct btf *btf, __u32 func_type_id,

			  char *func_only, int size);



void btf_dump_linfo_plain(const struct btf *btf,

			  const struct bpf_line_info *linfo,

			  const char *prefix, bool linum);

void btf_dump_linfo_json(const struct btf *btf,

			 const struct bpf_line_info *linfo, bool linum);



struct nlattr;

struct ifinfomsg;

struct tcmsg;