This source file includes following definitions.
- get_exec_path
- fprintf_json
- disasm_print_insn
- disasm_init
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14 #define _GNU_SOURCE
15 #include <stdio.h>
16 #include <stdarg.h>
17 #include <stdint.h>
18 #include <stdio.h>
19 #include <stdlib.h>
20 #include <assert.h>
21 #include <unistd.h>
22 #include <string.h>
23 #include <bfd.h>
24 #include <dis-asm.h>
25 #include <sys/stat.h>
26 #include <limits.h>
27 #include <libbpf.h>
28
29 #include "json_writer.h"
30 #include "main.h"
31
32 static void get_exec_path(char *tpath, size_t size)
33 {
34 const char *path = "/proc/self/exe";
35 ssize_t len;
36
37 len = readlink(path, tpath, size - 1);
38 assert(len > 0);
39 tpath[len] = 0;
40 }
41
42 static int oper_count;
43 static int fprintf_json(void *out, const char *fmt, ...)
44 {
45 va_list ap;
46 char *s;
47
48 va_start(ap, fmt);
49 if (vasprintf(&s, fmt, ap) < 0)
50 return -1;
51 va_end(ap);
52
53 if (!oper_count) {
54 int i;
55
56
57 i = strlen(s) - 1;
58 while (s[i] == ' ')
59 s[i--] = '\0';
60
61 jsonw_string_field(json_wtr, "operation", s);
62 jsonw_name(json_wtr, "operands");
63 jsonw_start_array(json_wtr);
64 oper_count++;
65 } else if (!strcmp(fmt, ",")) {
66
67 } else {
68 jsonw_string(json_wtr, s);
69 oper_count++;
70 }
71 free(s);
72 return 0;
73 }
74
75 void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,
76 const char *arch, const char *disassembler_options,
77 const struct btf *btf,
78 const struct bpf_prog_linfo *prog_linfo,
79 __u64 func_ksym, unsigned int func_idx,
80 bool linum)
81 {
82 const struct bpf_line_info *linfo = NULL;
83 disassembler_ftype disassemble;
84 struct disassemble_info info;
85 unsigned int nr_skip = 0;
86 int count, i, pc = 0;
87 char tpath[PATH_MAX];
88 bfd *bfdf;
89
90 if (!len)
91 return;
92
93 memset(tpath, 0, sizeof(tpath));
94 get_exec_path(tpath, sizeof(tpath));
95
96 bfdf = bfd_openr(tpath, NULL);
97 assert(bfdf);
98 assert(bfd_check_format(bfdf, bfd_object));
99
100 if (json_output)
101 init_disassemble_info(&info, stdout,
102 (fprintf_ftype) fprintf_json);
103 else
104 init_disassemble_info(&info, stdout,
105 (fprintf_ftype) fprintf);
106
107
108 if (arch) {
109 const bfd_arch_info_type *inf = bfd_scan_arch(arch);
110
111 if (inf) {
112 bfdf->arch_info = inf;
113 } else {
114 p_err("No libbfd support for %s", arch);
115 return;
116 }
117 }
118
119 info.arch = bfd_get_arch(bfdf);
120 info.mach = bfd_get_mach(bfdf);
121 if (disassembler_options)
122 info.disassembler_options = disassembler_options;
123 info.buffer = image;
124 info.buffer_length = len;
125
126 disassemble_init_for_target(&info);
127
128 #ifdef DISASM_FOUR_ARGS_SIGNATURE
129 disassemble = disassembler(info.arch,
130 bfd_big_endian(bfdf),
131 info.mach,
132 bfdf);
133 #else
134 disassemble = disassembler(bfdf);
135 #endif
136 assert(disassemble);
137
138 if (json_output)
139 jsonw_start_array(json_wtr);
140 do {
141 if (prog_linfo) {
142 linfo = bpf_prog_linfo__lfind_addr_func(prog_linfo,
143 func_ksym + pc,
144 func_idx,
145 nr_skip);
146 if (linfo)
147 nr_skip++;
148 }
149
150 if (json_output) {
151 jsonw_start_object(json_wtr);
152 oper_count = 0;
153 if (linfo)
154 btf_dump_linfo_json(btf, linfo, linum);
155 jsonw_name(json_wtr, "pc");
156 jsonw_printf(json_wtr, "\"0x%x\"", pc);
157 } else {
158 if (linfo)
159 btf_dump_linfo_plain(btf, linfo, "; ",
160 linum);
161 printf("%4x:\t", pc);
162 }
163
164 count = disassemble(pc, &info);
165 if (json_output) {
166
167
168
169
170 if (oper_count == 1)
171 jsonw_null(json_wtr);
172 jsonw_end_array(json_wtr);
173 }
174
175 if (opcodes) {
176 if (json_output) {
177 jsonw_name(json_wtr, "opcodes");
178 jsonw_start_array(json_wtr);
179 for (i = 0; i < count; ++i)
180 jsonw_printf(json_wtr, "\"0x%02hhx\"",
181 (uint8_t)image[pc + i]);
182 jsonw_end_array(json_wtr);
183 } else {
184 printf("\n\t");
185 for (i = 0; i < count; ++i)
186 printf("%02x ",
187 (uint8_t)image[pc + i]);
188 }
189 }
190 if (json_output)
191 jsonw_end_object(json_wtr);
192 else
193 printf("\n");
194
195 pc += count;
196 } while (count > 0 && pc < len);
197 if (json_output)
198 jsonw_end_array(json_wtr);
199
200 bfd_close(bfdf);
201 }
202
203 int disasm_init(void)
204 {
205 bfd_init();
206 return 0;
207 }