ASoC: SOF: ipc4-loader: remove the CPC check warnings
[platform/kernel/linux-starfive.git] / tools / bpf / bpf_jit_disasm.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Minimal BPF JIT image disassembler
4  *
5  * Disassembles BPF JIT compiler emitted opcodes back to asm insn's for
6  * debugging or verification purposes.
7  *
8  * To get the disassembly of the JIT code, do the following:
9  *
10  *  1) `echo 2 > /proc/sys/net/core/bpf_jit_enable`
11  *  2) Load a BPF filter (e.g. `tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24`)
12  *  3) Run e.g. `bpf_jit_disasm -o` to read out the last JIT code
13  *
14  * Copyright 2013 Daniel Borkmann <borkmann@redhat.com>
15  */
16
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 <regex.h>
26 #include <fcntl.h>
27 #include <sys/klog.h>
28 #include <sys/types.h>
29 #include <sys/stat.h>
30 #include <limits.h>
31 #include <tools/dis-asm-compat.h>
32
33 #define CMD_ACTION_SIZE_BUFFER          10
34 #define CMD_ACTION_READ_ALL             3
35
36 static void get_exec_path(char *tpath, size_t size)
37 {
38         char *path;
39         ssize_t len;
40
41         snprintf(tpath, size, "/proc/%d/exe", (int) getpid());
42         tpath[size - 1] = 0;
43
44         path = strdup(tpath);
45         assert(path);
46
47         len = readlink(path, tpath, size);
48         tpath[len] = 0;
49
50         free(path);
51 }
52
53 static void get_asm_insns(uint8_t *image, size_t len, int opcodes)
54 {
55         int count, i, pc = 0;
56         char tpath[PATH_MAX];
57         struct disassemble_info info;
58         disassembler_ftype disassemble;
59         bfd *bfdf;
60
61         memset(tpath, 0, sizeof(tpath));
62         get_exec_path(tpath, sizeof(tpath));
63
64         bfdf = bfd_openr(tpath, NULL);
65         assert(bfdf);
66         assert(bfd_check_format(bfdf, bfd_object));
67
68         init_disassemble_info_compat(&info, stdout,
69                                      (fprintf_ftype) fprintf,
70                                      fprintf_styled);
71         info.arch = bfd_get_arch(bfdf);
72         info.mach = bfd_get_mach(bfdf);
73         info.buffer = image;
74         info.buffer_length = len;
75
76         disassemble_init_for_target(&info);
77
78 #ifdef DISASM_FOUR_ARGS_SIGNATURE
79         disassemble = disassembler(info.arch,
80                                    bfd_big_endian(bfdf),
81                                    info.mach,
82                                    bfdf);
83 #else
84         disassemble = disassembler(bfdf);
85 #endif
86         assert(disassemble);
87
88         do {
89                 printf("%4x:\t", pc);
90
91                 count = disassemble(pc, &info);
92
93                 if (opcodes) {
94                         printf("\n\t");
95                         for (i = 0; i < count; ++i)
96                                 printf("%02x ", (uint8_t) image[pc + i]);
97                 }
98                 printf("\n");
99
100                 pc += count;
101         } while(count > 0 && pc < len);
102
103         bfd_close(bfdf);
104 }
105
106 static char *get_klog_buff(unsigned int *klen)
107 {
108         int ret, len;
109         char *buff;
110
111         len = klogctl(CMD_ACTION_SIZE_BUFFER, NULL, 0);
112         if (len < 0)
113                 return NULL;
114
115         buff = malloc(len);
116         if (!buff)
117                 return NULL;
118
119         ret = klogctl(CMD_ACTION_READ_ALL, buff, len);
120         if (ret < 0) {
121                 free(buff);
122                 return NULL;
123         }
124
125         *klen = ret;
126         return buff;
127 }
128
129 static char *get_flog_buff(const char *file, unsigned int *klen)
130 {
131         int fd, ret, len;
132         struct stat fi;
133         char *buff;
134
135         fd = open(file, O_RDONLY);
136         if (fd < 0)
137                 return NULL;
138
139         ret = fstat(fd, &fi);
140         if (ret < 0 || !S_ISREG(fi.st_mode))
141                 goto out;
142
143         len = fi.st_size + 1;
144         buff = malloc(len);
145         if (!buff)
146                 goto out;
147
148         memset(buff, 0, len);
149         ret = read(fd, buff, len - 1);
150         if (ret <= 0)
151                 goto out_free;
152
153         close(fd);
154         *klen = ret;
155         return buff;
156 out_free:
157         free(buff);
158 out:
159         close(fd);
160         return NULL;
161 }
162
163 static char *get_log_buff(const char *file, unsigned int *klen)
164 {
165         return file ? get_flog_buff(file, klen) : get_klog_buff(klen);
166 }
167
168 static void put_log_buff(char *buff)
169 {
170         free(buff);
171 }
172
173 static uint8_t *get_last_jit_image(char *haystack, size_t hlen,
174                                    unsigned int *ilen)
175 {
176         char *ptr, *pptr, *tmp;
177         off_t off = 0;
178         unsigned int proglen;
179         int ret, flen, pass, ulen = 0;
180         regmatch_t pmatch[1];
181         unsigned long base;
182         regex_t regex;
183         uint8_t *image;
184
185         if (hlen == 0)
186                 return NULL;
187
188         ret = regcomp(&regex, "flen=[[:alnum:]]+ proglen=[[:digit:]]+ "
189                       "pass=[[:digit:]]+ image=[[:xdigit:]]+", REG_EXTENDED);
190         assert(ret == 0);
191
192         ptr = haystack;
193         memset(pmatch, 0, sizeof(pmatch));
194
195         while (1) {
196                 ret = regexec(&regex, ptr, 1, pmatch, 0);
197                 if (ret == 0) {
198                         ptr += pmatch[0].rm_eo;
199                         off += pmatch[0].rm_eo;
200                         assert(off < hlen);
201                 } else
202                         break;
203         }
204
205         ptr = haystack + off - (pmatch[0].rm_eo - pmatch[0].rm_so);
206         ret = sscanf(ptr, "flen=%d proglen=%u pass=%d image=%lx",
207                      &flen, &proglen, &pass, &base);
208         if (ret != 4) {
209                 regfree(&regex);
210                 return NULL;
211         }
212         if (proglen > 1000000) {
213                 printf("proglen of %d too big, stopping\n", proglen);
214                 return NULL;
215         }
216
217         image = malloc(proglen);
218         if (!image) {
219                 printf("Out of memory\n");
220                 return NULL;
221         }
222         memset(image, 0, proglen);
223
224         tmp = ptr = haystack + off;
225         while ((ptr = strtok(tmp, "\n")) != NULL && ulen < proglen) {
226                 tmp = NULL;
227                 if (!strstr(ptr, "JIT code"))
228                         continue;
229                 pptr = ptr;
230                 while ((ptr = strstr(pptr, ":")))
231                         pptr = ptr + 1;
232                 ptr = pptr;
233                 do {
234                         image[ulen++] = (uint8_t) strtoul(pptr, &pptr, 16);
235                         if (ptr == pptr) {
236                                 ulen--;
237                                 break;
238                         }
239                         if (ulen >= proglen)
240                                 break;
241                         ptr = pptr;
242                 } while (1);
243         }
244
245         assert(ulen == proglen);
246         printf("%u bytes emitted from JIT compiler (pass:%d, flen:%d)\n",
247                proglen, pass, flen);
248         printf("%lx + <x>:\n", base);
249
250         regfree(&regex);
251         *ilen = ulen;
252         return image;
253 }
254
255 static void usage(void)
256 {
257         printf("Usage: bpf_jit_disasm [...]\n");
258         printf("       -o          Also display related opcodes (default: off).\n");
259         printf("       -O <file>   Write binary image of code to file, don't disassemble to stdout.\n");
260         printf("       -f <file>   Read last image dump from file or stdin (default: klog).\n");
261         printf("       -h          Display this help.\n");
262 }
263
264 int main(int argc, char **argv)
265 {
266         unsigned int len, klen, opt, opcodes = 0;
267         char *kbuff, *file = NULL;
268         char *ofile = NULL;
269         int ofd;
270         ssize_t nr;
271         uint8_t *pos;
272         uint8_t *image = NULL;
273
274         while ((opt = getopt(argc, argv, "of:O:")) != -1) {
275                 switch (opt) {
276                 case 'o':
277                         opcodes = 1;
278                         break;
279                 case 'O':
280                         ofile = optarg;
281                         break;
282                 case 'f':
283                         file = optarg;
284                         break;
285                 default:
286                         usage();
287                         return -1;
288                 }
289         }
290
291         bfd_init();
292
293         kbuff = get_log_buff(file, &klen);
294         if (!kbuff) {
295                 fprintf(stderr, "Could not retrieve log buffer!\n");
296                 return -1;
297         }
298
299         image = get_last_jit_image(kbuff, klen, &len);
300         if (!image) {
301                 fprintf(stderr, "No JIT image found!\n");
302                 goto done;
303         }
304         if (!ofile) {
305                 get_asm_insns(image, len, opcodes);
306                 goto done;
307         }
308
309         ofd = open(ofile, O_WRONLY | O_CREAT | O_TRUNC, DEFFILEMODE);
310         if (ofd < 0) {
311                 fprintf(stderr, "Could not open file %s for writing: ", ofile);
312                 perror(NULL);
313                 goto done;
314         }
315         pos = image;
316         do {
317                 nr = write(ofd, pos, len);
318                 if (nr < 0) {
319                         fprintf(stderr, "Could not write data to %s: ", ofile);
320                         perror(NULL);
321                         goto done;
322                 }
323                 len -= nr;
324                 pos += nr;
325         } while (len);
326         close(ofd);
327
328 done:
329         put_log_buff(kbuff);
330         free(image);
331         return 0;
332 }