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: Martin KaFai Lau <kafai@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
mariux64 · Dec 9, 2018 · b053b43 · b053b43
1 parent 3d65014
commit b053b43
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Showing 12 changed files with 516 additions and 25 deletions.
diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
@@ -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*.
 

diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool
@@ -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

diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c
@@ -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));
+	}
+}
diff --git a/tools/bpf/bpftool/jit_disasm.c b/tools/bpf/bpftool/jit_disasm.c
@@ -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);
 		}
 

diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
@@ -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;