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Revert "tty: hvc: Fix data abort due to race in hvc_open"
[linux/fpc-iii.git] / tools / bpf / bpftool / gen.c
blobf5960b48c8615a700275d67c9fa4269b09fc055b
1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (C) 2019 Facebook */
3
4 #ifndef _GNU_SOURCE
5 #define _GNU_SOURCE
6 #endif
7 #include <ctype.h>
8 #include <errno.h>
9 #include <fcntl.h>
10 #include <linux/err.h>
11 #include <stdbool.h>
12 #include <stdio.h>
13 #include <string.h>
14 #include <unistd.h>
15 #include <bpf/bpf.h>
16 #include <bpf/libbpf.h>
17 #include <sys/types.h>
18 #include <sys/stat.h>
19 #include <sys/mman.h>
20 #include <unistd.h>
21 #include <bpf/btf.h>
22
23 #include "bpf/libbpf_internal.h"
24 #include "json_writer.h"
25 #include "main.h"
26
27
28 #define MAX_OBJ_NAME_LEN 64
29
30 static void sanitize_identifier(char *name)
31 {
32 int i;
33
34 for (i = 0; name[i]; i++)
35 if (!isalnum(name[i]) && name[i] != '_')
36 name[i] = '_';
37 }
38
39 static bool str_has_suffix(const char *str, const char *suffix)
40 {
41 size_t i, n1 = strlen(str), n2 = strlen(suffix);
42
43 if (n1 < n2)
44 return false;
45
46 for (i = 0; i < n2; i++) {
47 if (str[n1 - i - 1] != suffix[n2 - i - 1])
48 return false;
49 }
50
51 return true;
52 }
53
54 static void get_obj_name(char *name, const char *file)
55 {
56 /* Using basename() GNU version which doesn't modify arg. */
57 strncpy(name, basename(file), MAX_OBJ_NAME_LEN - 1);
58 name[MAX_OBJ_NAME_LEN - 1] = '\0';
59 if (str_has_suffix(name, ".o"))
60 name[strlen(name) - 2] = '\0';
61 sanitize_identifier(name);
62 }
63
64 static void get_header_guard(char *guard, const char *obj_name)
65 {
66 int i;
67
68 sprintf(guard, "__%s_SKEL_H__", obj_name);
69 for (i = 0; guard[i]; i++)
70 guard[i] = toupper(guard[i]);
71 }
72
73 static const char *get_map_ident(const struct bpf_map *map)
74 {
75 const char *name = bpf_map__name(map);
76
77 if (!bpf_map__is_internal(map))
78 return name;
79
80 if (str_has_suffix(name, ".data"))
81 return "data";
82 else if (str_has_suffix(name, ".rodata"))
83 return "rodata";
84 else if (str_has_suffix(name, ".bss"))
85 return "bss";
86 else if (str_has_suffix(name, ".kconfig"))
87 return "kconfig";
88 else
89 return NULL;
90 }
91
92 static void codegen_btf_dump_printf(void *ct, const char *fmt, va_list args)
93 {
94 vprintf(fmt, args);
95 }
96
97 static int codegen_datasec_def(struct bpf_object *obj,
98 struct btf *btf,
99 struct btf_dump *d,
100 const struct btf_type *sec,
101 const char *obj_name)
102 {
103 const char *sec_name = btf__name_by_offset(btf, sec->name_off);
104 const struct btf_var_secinfo *sec_var = btf_var_secinfos(sec);
105 int i, err, off = 0, pad_cnt = 0, vlen = btf_vlen(sec);
106 const char *sec_ident;
107 char var_ident[256];
108
109 if (strcmp(sec_name, ".data") == 0)
110 sec_ident = "data";
111 else if (strcmp(sec_name, ".bss") == 0)
112 sec_ident = "bss";
113 else if (strcmp(sec_name, ".rodata") == 0)
114 sec_ident = "rodata";
115 else if (strcmp(sec_name, ".kconfig") == 0)
116 sec_ident = "kconfig";
117 else
118 return 0;
119
120 printf(" struct %s__%s {\n", obj_name, sec_ident);
121 for (i = 0; i < vlen; i++, sec_var++) {
122 const struct btf_type *var = btf__type_by_id(btf, sec_var->type);
123 const char *var_name = btf__name_by_offset(btf, var->name_off);
124 DECLARE_LIBBPF_OPTS(btf_dump_emit_type_decl_opts, opts,
125 .field_name = var_ident,
126 .indent_level = 2,
127 );
128 int need_off = sec_var->offset, align_off, align;
129 __u32 var_type_id = var->type;
130 const struct btf_type *t;
131
132 t = btf__type_by_id(btf, var_type_id);
133 while (btf_is_mod(t)) {
134 var_type_id = t->type;
135 t = btf__type_by_id(btf, var_type_id);
136 }
137
138 if (off > need_off) {
139 p_err("Something is wrong for %s's variable #%d: need offset %d, already at %d.\n",
140 sec_name, i, need_off, off);
141 return -EINVAL;
142 }
143
144 align = btf__align_of(btf, var->type);
145 if (align <= 0) {
146 p_err("Failed to determine alignment of variable '%s': %d",
147 var_name, align);
148 return -EINVAL;
149 }
150
151 align_off = (off + align - 1) / align * align;
152 if (align_off != need_off) {
153 printf("\t\tchar __pad%d[%d];\n",
154 pad_cnt, need_off - off);
155 pad_cnt++;
156 }
157
158 /* sanitize variable name, e.g., for static vars inside
159 * a function, it's name is '<function name>.<variable name>',
160 * which we'll turn into a '<function name>_<variable name>'
161 */
162 var_ident[0] = '\0';
163 strncat(var_ident, var_name, sizeof(var_ident) - 1);
164 sanitize_identifier(var_ident);
165
166 printf("\t\t");
167 err = btf_dump__emit_type_decl(d, var_type_id, &opts);
168 if (err)
169 return err;
170 printf(";\n");
171
172 off = sec_var->offset + sec_var->size;
173 }
174 printf(" } *%s;\n", sec_ident);
175 return 0;
176 }
177
178 static int codegen_datasecs(struct bpf_object *obj, const char *obj_name)
179 {
180 struct btf *btf = bpf_object__btf(obj);
181 int n = btf__get_nr_types(btf);
182 struct btf_dump *d;
183 int i, err = 0;
184
185 d = btf_dump__new(btf, NULL, NULL, codegen_btf_dump_printf);
186 if (IS_ERR(d))
187 return PTR_ERR(d);
188
189 for (i = 1; i <= n; i++) {
190 const struct btf_type *t = btf__type_by_id(btf, i);
191
192 if (!btf_is_datasec(t))
193 continue;
194
195 err = codegen_datasec_def(obj, btf, d, t, obj_name);
196 if (err)
197 goto out;
198 }
199 out:
200 btf_dump__free(d);
201 return err;
202 }
203
204 static int codegen(const char *template, ...)
205 {
206 const char *src, *end;
207 int skip_tabs = 0, n;
208 char *s, *dst;
209 va_list args;
210 char c;
211
212 n = strlen(template);
213 s = malloc(n + 1);
214 if (!s)
215 return -ENOMEM;
216 src = template;
217 dst = s;
218
219 /* find out "baseline" indentation to skip */
220 while ((c = *src++)) {
221 if (c == '\t') {
222 skip_tabs++;
223 } else if (c == '\n') {
224 break;
225 } else {
226 p_err("unrecognized character at pos %td in template '%s'",
227 src - template - 1, template);
228 free(s);
229 return -EINVAL;
230 }
231 }
232
233 while (*src) {
234 /* skip baseline indentation tabs */
235 for (n = skip_tabs; n > 0; n--, src++) {
236 if (*src != '\t') {
237 p_err("not enough tabs at pos %td in template '%s'",
238 src - template - 1, template);
239 free(s);
240 return -EINVAL;
241 }
242 }
243 /* trim trailing whitespace */
244 end = strchrnul(src, '\n');
245 for (n = end - src; n > 0 && isspace(src[n - 1]); n--)
246 ;
247 memcpy(dst, src, n);
248 dst += n;
249 if (*end)
250 *dst++ = '\n';
251 src = *end ? end + 1 : end;
252 }
253 *dst++ = '\0';
254
255 /* print out using adjusted template */
256 va_start(args, template);
257 n = vprintf(s, args);
258 va_end(args);
259
260 free(s);
261 return n;
262 }
263
264 static int do_skeleton(int argc, char **argv)
265 {
266 char header_guard[MAX_OBJ_NAME_LEN + sizeof("__SKEL_H__")];
267 size_t i, map_cnt = 0, prog_cnt = 0, file_sz, mmap_sz;
268 DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts);
269 char obj_name[MAX_OBJ_NAME_LEN], *obj_data;
270 struct bpf_object *obj = NULL;
271 const char *file, *ident;
272 struct bpf_program *prog;
273 int fd, len, err = -1;
274 struct bpf_map *map;
275 struct btf *btf;
276 struct stat st;
277
278 if (!REQ_ARGS(1)) {
279 usage();
280 return -1;
281 }
282 file = GET_ARG();
283
284 if (argc) {
285 p_err("extra unknown arguments");
286 return -1;
287 }
288
289 if (stat(file, &st)) {
290 p_err("failed to stat() %s: %s", file, strerror(errno));
291 return -1;
292 }
293 file_sz = st.st_size;
294 mmap_sz = roundup(file_sz, sysconf(_SC_PAGE_SIZE));
295 fd = open(file, O_RDONLY);
296 if (fd < 0) {
297 p_err("failed to open() %s: %s", file, strerror(errno));
298 return -1;
299 }
300 obj_data = mmap(NULL, mmap_sz, PROT_READ, MAP_PRIVATE, fd, 0);
301 if (obj_data == MAP_FAILED) {
302 obj_data = NULL;
303 p_err("failed to mmap() %s: %s", file, strerror(errno));
304 goto out;
305 }
306 get_obj_name(obj_name, file);
307 opts.object_name = obj_name;
308 obj = bpf_object__open_mem(obj_data, file_sz, &opts);
309 if (IS_ERR(obj)) {
310 obj = NULL;
311 p_err("failed to open BPF object file: %ld", PTR_ERR(obj));
312 goto out;
313 }
314
315 bpf_object__for_each_map(map, obj) {
316 ident = get_map_ident(map);
317 if (!ident) {
318 p_err("ignoring unrecognized internal map '%s'...",
319 bpf_map__name(map));
320 continue;
321 }
322 map_cnt++;
323 }
324 bpf_object__for_each_program(prog, obj) {
325 prog_cnt++;
326 }
327
328 get_header_guard(header_guard, obj_name);
329 codegen("\
330 \n\
331 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ \n\
332 \n\
333 /* THIS FILE IS AUTOGENERATED! */ \n\
334 #ifndef %2$s \n\
335 #define %2$s \n\
336 \n\
337 #include <stdlib.h> \n\
338 #include <bpf/libbpf.h> \n\
339 \n\
340 struct %1$s { \n\
341 struct bpf_object_skeleton *skeleton; \n\
342 struct bpf_object *obj; \n\
343 ",
344 obj_name, header_guard
345 );
346
347 if (map_cnt) {
348 printf("\tstruct {\n");
349 bpf_object__for_each_map(map, obj) {
350 ident = get_map_ident(map);
351 if (!ident)
352 continue;
353 printf("\t\tstruct bpf_map *%s;\n", ident);
354 }
355 printf("\t} maps;\n");
356 }
357
358 if (prog_cnt) {
359 printf("\tstruct {\n");
360 bpf_object__for_each_program(prog, obj) {
361 printf("\t\tstruct bpf_program *%s;\n",
362 bpf_program__name(prog));
363 }
364 printf("\t} progs;\n");
365 printf("\tstruct {\n");
366 bpf_object__for_each_program(prog, obj) {
367 printf("\t\tstruct bpf_link *%s;\n",
368 bpf_program__name(prog));
369 }
370 printf("\t} links;\n");
371 }
372
373 btf = bpf_object__btf(obj);
374 if (btf) {
375 err = codegen_datasecs(obj, obj_name);
376 if (err)
377 goto out;
378 }
379
380 codegen("\
381 \n\
382 }; \n\
383 \n\
384 static void \n\
385 %1$s__destroy(struct %1$s *obj) \n\
386 { \n\
387 if (!obj) \n\
388 return; \n\
389 if (obj->skeleton) \n\
390 bpf_object__destroy_skeleton(obj->skeleton);\n\
391 free(obj); \n\
392 } \n\
393 \n\
394 static inline int \n\
395 %1$s__create_skeleton(struct %1$s *obj); \n\
396 \n\
397 static inline struct %1$s * \n\
398 %1$s__open_opts(const struct bpf_object_open_opts *opts) \n\
399 { \n\
400 struct %1$s *obj; \n\
401 \n\
402 obj = (typeof(obj))calloc(1, sizeof(*obj)); \n\
403 if (!obj) \n\
404 return NULL; \n\
405 if (%1$s__create_skeleton(obj)) \n\
406 goto err; \n\
407 if (bpf_object__open_skeleton(obj->skeleton, opts)) \n\
408 goto err; \n\
409 \n\
410 return obj; \n\
411 err: \n\
412 %1$s__destroy(obj); \n\
413 return NULL; \n\
414 } \n\
415 \n\
416 static inline struct %1$s * \n\
417 %1$s__open(void) \n\
418 { \n\
419 return %1$s__open_opts(NULL); \n\
420 } \n\
421 \n\
422 static inline int \n\
423 %1$s__load(struct %1$s *obj) \n\
424 { \n\
425 return bpf_object__load_skeleton(obj->skeleton); \n\
426 } \n\
427 \n\
428 static inline struct %1$s * \n\
429 %1$s__open_and_load(void) \n\
430 { \n\
431 struct %1$s *obj; \n\
432 \n\
433 obj = %1$s__open(); \n\
434 if (!obj) \n\
435 return NULL; \n\
436 if (%1$s__load(obj)) { \n\
437 %1$s__destroy(obj); \n\
438 return NULL; \n\
439 } \n\
440 return obj; \n\
441 } \n\
442 \n\
443 static inline int \n\
444 %1$s__attach(struct %1$s *obj) \n\
445 { \n\
446 return bpf_object__attach_skeleton(obj->skeleton); \n\
447 } \n\
448 \n\
449 static inline void \n\
450 %1$s__detach(struct %1$s *obj) \n\
451 { \n\
452 return bpf_object__detach_skeleton(obj->skeleton); \n\
453 } \n\
454 ",
455 obj_name
456 );
457
458 codegen("\
459 \n\
460 \n\
461 static inline int \n\
462 %1$s__create_skeleton(struct %1$s *obj) \n\
463 { \n\
464 struct bpf_object_skeleton *s; \n\
465 \n\
466 s = (typeof(s))calloc(1, sizeof(*s)); \n\
467 if (!s) \n\
468 return -1; \n\
469 obj->skeleton = s; \n\
470 \n\
471 s->sz = sizeof(*s); \n\
472 s->name = \"%1$s\"; \n\
473 s->obj = &obj->obj; \n\
474 ",
475 obj_name
476 );
477 if (map_cnt) {
478 codegen("\
479 \n\
480 \n\
481 /* maps */ \n\
482 s->map_cnt = %zu; \n\
483 s->map_skel_sz = sizeof(*s->maps); \n\
484 s->maps = (typeof(s->maps))calloc(s->map_cnt, s->map_skel_sz);\n\
485 if (!s->maps) \n\
486 goto err; \n\
487 ",
488 map_cnt
489 );
490 i = 0;
491 bpf_object__for_each_map(map, obj) {
492 ident = get_map_ident(map);
493
494 if (!ident)
495 continue;
496
497 codegen("\
498 \n\
499 \n\
500 s->maps[%zu].name = \"%s\"; \n\
501 s->maps[%zu].map = &obj->maps.%s; \n\
502 ",
503 i, bpf_map__name(map), i, ident);
504 /* memory-mapped internal maps */
505 if (bpf_map__is_internal(map) &&
506 (bpf_map__def(map)->map_flags & BPF_F_MMAPABLE)) {
507 printf("\ts->maps[%zu].mmaped = (void **)&obj->%s;\n",
508 i, ident);
509 }
510 i++;
511 }
512 }
513 if (prog_cnt) {
514 codegen("\
515 \n\
516 \n\
517 /* programs */ \n\
518 s->prog_cnt = %zu; \n\
519 s->prog_skel_sz = sizeof(*s->progs); \n\
520 s->progs = (typeof(s->progs))calloc(s->prog_cnt, s->prog_skel_sz);\n\
521 if (!s->progs) \n\
522 goto err; \n\
523 ",
524 prog_cnt
525 );
526 i = 0;
527 bpf_object__for_each_program(prog, obj) {
528 codegen("\
529 \n\
530 \n\
531 s->progs[%1$zu].name = \"%2$s\"; \n\
532 s->progs[%1$zu].prog = &obj->progs.%2$s;\n\
533 s->progs[%1$zu].link = &obj->links.%2$s;\n\
534 ",
535 i, bpf_program__name(prog));
536 i++;
537 }
538 }
539 codegen("\
540 \n\
541 \n\
542 s->data_sz = %d; \n\
543 s->data = (void *)\"\\ \n\
544 ",
545 file_sz);
546
547 /* embed contents of BPF object file */
548 for (i = 0, len = 0; i < file_sz; i++) {
549 int w = obj_data[i] ? 4 : 2;
550
551 len += w;
552 if (len > 78) {
553 printf("\\\n");
554 len = w;
555 }
556 if (!obj_data[i])
557 printf("\\0");
558 else
559 printf("\\x%02x", (unsigned char)obj_data[i]);
560 }
561
562 codegen("\
563 \n\
564 \"; \n\
565 \n\
566 return 0; \n\
567 err: \n\
568 bpf_object__destroy_skeleton(s); \n\
569 return -1; \n\
570 } \n\
571 \n\
572 #endif /* %s */ \n\
573 ",
574 header_guard);
575 err = 0;
576 out:
577 bpf_object__close(obj);
578 if (obj_data)
579 munmap(obj_data, mmap_sz);
580 close(fd);
581 return err;
582 }
583
584 static int do_help(int argc, char **argv)
585 {
586 if (json_output) {
587 jsonw_null(json_wtr);
588 return 0;
589 }
590
591 fprintf(stderr,
592 "Usage: %1$s gen skeleton FILE\n"
593 " %1$s gen help\n"
594 "\n"
595 " " HELP_SPEC_OPTIONS "\n"
596 "",
597 bin_name);
598
599 return 0;
600 }
601
602 static const struct cmd cmds[] = {
603 { "skeleton", do_skeleton },
604 { "help", do_help },
605 { 0 }
606 };
607
608 int do_gen(int argc, char **argv)
609 {
610 return cmd_select(cmds, argc, argv, do_help);
611 }
Linux with added FPC-III support