projects/linux·blob 4563243e · refs

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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * sorttable.h
4 *
5 * Added ORC unwind tables sort support and other updates:
6 * Copyright (C) 1999-2019 Alibaba Group Holding Limited. by:
7 * Shile Zhang <[email protected]>
8 *
9 * Copyright 2011 - 2012 Cavium, Inc.
10 *
11 * Some of code was taken out of arch/x86/kernel/unwind_orc.c, written by:
12 * Copyright (C) 2017 Josh Poimboeuf <[email protected]>
13 *
14 * Some of this code was taken out of recordmcount.h written by:
15 *
16 * Copyright 2009 John F. Reiser <[email protected]>. All rights reserved.
17 * Copyright 2010 Steven Rostedt <[email protected]>, Red Hat Inc.
18 */
19
20#undef extable_ent_size
21#undef compare_extable
22#undef get_mcount_loc
23#undef sort_mcount_loc
24#undef elf_mcount_loc
25#undef do_sort
26#undef Elf_Addr
27#undef Elf_Ehdr
28#undef Elf_Shdr
29#undef Elf_Rel
30#undef Elf_Rela
31#undef Elf_Sym
32#undef ELF_R_SYM
33#undef Elf_r_sym
34#undef ELF_R_INFO
35#undef Elf_r_info
36#undef ELF_ST_BIND
37#undef ELF_ST_TYPE
38#undef fn_ELF_R_SYM
39#undef fn_ELF_R_INFO
40#undef uint_t
41#undef _r
42#undef _w
43
44#ifdef SORTTABLE_64
45# define extable_ent_size 16
46# define compare_extable compare_extable_64
47# define get_mcount_loc get_mcount_loc_64
48# define sort_mcount_loc sort_mcount_loc_64
49# define elf_mcount_loc elf_mcount_loc_64
50# define do_sort do_sort_64
51# define Elf_Addr Elf64_Addr
52# define Elf_Ehdr Elf64_Ehdr
53# define Elf_Shdr Elf64_Shdr
54# define Elf_Rel Elf64_Rel
55# define Elf_Rela Elf64_Rela
56# define Elf_Sym Elf64_Sym
57# define ELF_R_SYM ELF64_R_SYM
58# define Elf_r_sym Elf64_r_sym
59# define ELF_R_INFO ELF64_R_INFO
60# define Elf_r_info Elf64_r_info
61# define ELF_ST_BIND ELF64_ST_BIND
62# define ELF_ST_TYPE ELF64_ST_TYPE
63# define fn_ELF_R_SYM fn_ELF64_R_SYM
64# define fn_ELF_R_INFO fn_ELF64_R_INFO
65# define uint_t uint64_t
66# define _r r8
67# define _w w8
68#else
69# define extable_ent_size 8
70# define compare_extable compare_extable_32
71# define get_mcount_loc get_mcount_loc_32
72# define sort_mcount_loc sort_mcount_loc_32
73# define elf_mcount_loc elf_mcount_loc_32
74# define do_sort do_sort_32
75# define Elf_Addr Elf32_Addr
76# define Elf_Ehdr Elf32_Ehdr
77# define Elf_Shdr Elf32_Shdr
78# define Elf_Rel Elf32_Rel
79# define Elf_Rela Elf32_Rela
80# define Elf_Sym Elf32_Sym
81# define ELF_R_SYM ELF32_R_SYM
82# define Elf_r_sym Elf32_r_sym
83# define ELF_R_INFO ELF32_R_INFO
84# define Elf_r_info Elf32_r_info
85# define ELF_ST_BIND ELF32_ST_BIND
86# define ELF_ST_TYPE ELF32_ST_TYPE
87# define fn_ELF_R_SYM fn_ELF32_R_SYM
88# define fn_ELF_R_INFO fn_ELF32_R_INFO
89# define uint_t uint32_t
90# define _r r
91# define _w w
92#endif
93
94#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
95/* ORC unwinder only support X86_64 */
96#include <asm/orc_types.h>
97
98#define ERRSTR_MAXSZ 256
99
100char g_err[ERRSTR_MAXSZ];
101int *g_orc_ip_table;
102struct orc_entry *g_orc_table;
103
104pthread_t orc_sort_thread;
105
106static inline unsigned long orc_ip(const int *ip)
107{
108 return (unsigned long)ip + *ip;
109}
110
111static int orc_sort_cmp(const void *_a, const void *_b)
112{
113 struct orc_entry *orc_a;
114 const int *a = g_orc_ip_table + *(int *)_a;
115 const int *b = g_orc_ip_table + *(int *)_b;
116 unsigned long a_val = orc_ip(a);
117 unsigned long b_val = orc_ip(b);
118
119 if (a_val > b_val)
120 return 1;
121 if (a_val < b_val)
122 return -1;
123
124 /*
125 * The "weak" section terminator entries need to always be on the left
126 * to ensure the lookup code skips them in favor of real entries.
127 * These terminator entries exist to handle any gaps created by
128 * whitelisted .o files which didn't get objtool generation.
129 */
130 orc_a = g_orc_table + (a - g_orc_ip_table);
131 return orc_a->type == ORC_TYPE_UNDEFINED ? -1 : 1;
132}
133
134static void *sort_orctable(void *arg)
135{
136 int i;
137 int *idxs = NULL;
138 int *tmp_orc_ip_table = NULL;
139 struct orc_entry *tmp_orc_table = NULL;
140 unsigned int *orc_ip_size = (unsigned int *)arg;
141 unsigned int num_entries = *orc_ip_size / sizeof(int);
142 unsigned int orc_size = num_entries * sizeof(struct orc_entry);
143
144 idxs = (int *)malloc(*orc_ip_size);
145 if (!idxs) {
146 snprintf(g_err, ERRSTR_MAXSZ, "malloc idxs: %s",
147 strerror(errno));
148 pthread_exit(g_err);
149 }
150
151 tmp_orc_ip_table = (int *)malloc(*orc_ip_size);
152 if (!tmp_orc_ip_table) {
153 snprintf(g_err, ERRSTR_MAXSZ, "malloc tmp_orc_ip_table: %s",
154 strerror(errno));
155 pthread_exit(g_err);
156 }
157
158 tmp_orc_table = (struct orc_entry *)malloc(orc_size);
159 if (!tmp_orc_table) {
160 snprintf(g_err, ERRSTR_MAXSZ, "malloc tmp_orc_table: %s",
161 strerror(errno));
162 pthread_exit(g_err);
163 }
164
165 /* initialize indices array, convert ip_table to absolute address */
166 for (i = 0; i < num_entries; i++) {
167 idxs[i] = i;
168 tmp_orc_ip_table[i] = g_orc_ip_table[i] + i * sizeof(int);
169 }
170 memcpy(tmp_orc_table, g_orc_table, orc_size);
171
172 qsort(idxs, num_entries, sizeof(int), orc_sort_cmp);
173
174 for (i = 0; i < num_entries; i++) {
175 if (idxs[i] == i)
176 continue;
177
178 /* convert back to relative address */
179 g_orc_ip_table[i] = tmp_orc_ip_table[idxs[i]] - i * sizeof(int);
180 g_orc_table[i] = tmp_orc_table[idxs[i]];
181 }
182
183 free(idxs);
184 free(tmp_orc_ip_table);
185 free(tmp_orc_table);
186 pthread_exit(NULL);
187}
188#endif
189
190static int compare_extable(const void *a, const void *b)
191{
192 Elf_Addr av = _r(a);
193 Elf_Addr bv = _r(b);
194
195 if (av < bv)
196 return -1;
197 if (av > bv)
198 return 1;
199 return 0;
200}
201#ifdef MCOUNT_SORT_ENABLED
202pthread_t mcount_sort_thread;
203
204struct elf_mcount_loc {
205 Elf_Ehdr *ehdr;
206 Elf_Shdr *init_data_sec;
207 uint_t start_mcount_loc;
208 uint_t stop_mcount_loc;
209};
210
211/* Sort the addresses stored between __start_mcount_loc to __stop_mcount_loc in vmlinux */
212static void *sort_mcount_loc(void *arg)
213{
214 struct elf_mcount_loc *emloc = (struct elf_mcount_loc *)arg;
215 uint_t offset = emloc->start_mcount_loc - _r(&(emloc->init_data_sec)->sh_addr)
216 + _r(&(emloc->init_data_sec)->sh_offset);
217 uint_t count = emloc->stop_mcount_loc - emloc->start_mcount_loc;
218 unsigned char *start_loc = (void *)emloc->ehdr + offset;
219
220 qsort(start_loc, count/sizeof(uint_t), sizeof(uint_t), compare_extable);
221 return NULL;
222}
223
224/* Get the address of __start_mcount_loc and __stop_mcount_loc in System.map */
225static void get_mcount_loc(uint_t *_start, uint_t *_stop)
226{
227 FILE *file_start, *file_stop;
228 char start_buff[20];
229 char stop_buff[20];
230 int len = 0;
231
232 file_start = popen(" grep start_mcount System.map | awk '{print $1}' ", "r");
233 if (!file_start) {
234 fprintf(stderr, "get start_mcount_loc error!");
235 return;
236 }
237
238 file_stop = popen(" grep stop_mcount System.map | awk '{print $1}' ", "r");
239 if (!file_stop) {
240 fprintf(stderr, "get stop_mcount_loc error!");
241 pclose(file_start);
242 return;
243 }
244
245 while (fgets(start_buff, sizeof(start_buff), file_start) != NULL) {
246 len = strlen(start_buff);
247 start_buff[len - 1] = '\0';
248 }
249 *_start = strtoul(start_buff, NULL, 16);
250
251 while (fgets(stop_buff, sizeof(stop_buff), file_stop) != NULL) {
252 len = strlen(stop_buff);
253 stop_buff[len - 1] = '\0';
254 }
255 *_stop = strtoul(stop_buff, NULL, 16);
256
257 pclose(file_start);
258 pclose(file_stop);
259}
260#endif
261static int do_sort(Elf_Ehdr *ehdr,
262 char const *const fname,
263 table_sort_t custom_sort)
264{
265 int rc = -1;
266 Elf_Shdr *s, *shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff));
267 Elf_Shdr *strtab_sec = NULL;
268 Elf_Shdr *symtab_sec = NULL;
269 Elf_Shdr *extab_sec = NULL;
270 Elf_Sym *sym;
271 const Elf_Sym *symtab;
272 Elf32_Word *symtab_shndx = NULL;
273 Elf_Sym *sort_needed_sym = NULL;
274 Elf_Shdr *sort_needed_sec;
275 Elf_Rel *relocs = NULL;
276 int relocs_size = 0;
277 uint32_t *sort_needed_loc;
278 const char *secstrings;
279 const char *strtab;
280 char *extab_image;
281 int extab_index = 0;
282 int i;
283 int idx;
284 unsigned int shnum;
285 unsigned int shstrndx;
286#ifdef MCOUNT_SORT_ENABLED
287 struct elf_mcount_loc mstruct = {0};
288 uint_t _start_mcount_loc = 0;
289 uint_t _stop_mcount_loc = 0;
290#endif
291#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
292 unsigned int orc_ip_size = 0;
293 unsigned int orc_size = 0;
294 unsigned int orc_num_entries = 0;
295#endif
296
297 shstrndx = r2(&ehdr->e_shstrndx);
298 if (shstrndx == SHN_XINDEX)
299 shstrndx = r(&shdr[0].sh_link);
300 secstrings = (const char *)ehdr + _r(&shdr[shstrndx].sh_offset);
301
302 shnum = r2(&ehdr->e_shnum);
303 if (shnum == SHN_UNDEF)
304 shnum = _r(&shdr[0].sh_size);
305
306 for (i = 0, s = shdr; s < shdr + shnum; i++, s++) {
307 idx = r(&s->sh_name);
308 if (!strcmp(secstrings + idx, "__ex_table")) {
309 extab_sec = s;
310 extab_index = i;
311 }
312 if (!strcmp(secstrings + idx, ".symtab"))
313 symtab_sec = s;
314 if (!strcmp(secstrings + idx, ".strtab"))
315 strtab_sec = s;
316
317 if ((r(&s->sh_type) == SHT_REL ||
318 r(&s->sh_type) == SHT_RELA) &&
319 r(&s->sh_info) == extab_index) {
320 relocs = (void *)ehdr + _r(&s->sh_offset);
321 relocs_size = _r(&s->sh_size);
322 }
323 if (r(&s->sh_type) == SHT_SYMTAB_SHNDX)
324 symtab_shndx = (Elf32_Word *)((const char *)ehdr +
325 _r(&s->sh_offset));
326
327#ifdef MCOUNT_SORT_ENABLED
328 /* locate the .init.data section in vmlinux */
329 if (!strcmp(secstrings + idx, ".init.data")) {
330 get_mcount_loc(&_start_mcount_loc, &_stop_mcount_loc);
331 mstruct.ehdr = ehdr;
332 mstruct.init_data_sec = s;
333 mstruct.start_mcount_loc = _start_mcount_loc;
334 mstruct.stop_mcount_loc = _stop_mcount_loc;
335 }
336#endif
337
338#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
339 /* locate the ORC unwind tables */
340 if (!strcmp(secstrings + idx, ".orc_unwind_ip")) {
341 orc_ip_size = s->sh_size;
342 g_orc_ip_table = (int *)((void *)ehdr +
343 s->sh_offset);
344 }
345 if (!strcmp(secstrings + idx, ".orc_unwind")) {
346 orc_size = s->sh_size;
347 g_orc_table = (struct orc_entry *)((void *)ehdr +
348 s->sh_offset);
349 }
350#endif
351 } /* for loop */
352
353#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
354 if (!g_orc_ip_table || !g_orc_table) {
355 fprintf(stderr,
356 "incomplete ORC unwind tables in file: %s\n", fname);
357 goto out;
358 }
359
360 orc_num_entries = orc_ip_size / sizeof(int);
361 if (orc_ip_size % sizeof(int) != 0 ||
362 orc_size % sizeof(struct orc_entry) != 0 ||
363 orc_num_entries != orc_size / sizeof(struct orc_entry)) {
364 fprintf(stderr,
365 "inconsistent ORC unwind table entries in file: %s\n",
366 fname);
367 goto out;
368 }
369
370 /* create thread to sort ORC unwind tables concurrently */
371 if (pthread_create(&orc_sort_thread, NULL,
372 sort_orctable, &orc_ip_size)) {
373 fprintf(stderr,
374 "pthread_create orc_sort_thread failed '%s': %s\n",
375 strerror(errno), fname);
376 goto out;
377 }
378#endif
379
380#ifdef MCOUNT_SORT_ENABLED
381 if (!mstruct.init_data_sec || !_start_mcount_loc || !_stop_mcount_loc) {
382 fprintf(stderr,
383 "incomplete mcount's sort in file: %s\n",
384 fname);
385 goto out;
386 }
387
388 /* create thread to sort mcount_loc concurrently */
389 if (pthread_create(&mcount_sort_thread, NULL, &sort_mcount_loc, &mstruct)) {
390 fprintf(stderr,
391 "pthread_create mcount_sort_thread failed '%s': %s\n",
392 strerror(errno), fname);
393 goto out;
394 }
395#endif
396 if (!extab_sec) {
397 fprintf(stderr, "no __ex_table in file: %s\n", fname);
398 goto out;
399 }
400
401 if (!symtab_sec) {
402 fprintf(stderr, "no .symtab in file: %s\n", fname);
403 goto out;
404 }
405
406 if (!strtab_sec) {
407 fprintf(stderr, "no .strtab in file: %s\n", fname);
408 goto out;
409 }
410
411 extab_image = (void *)ehdr + _r(&extab_sec->sh_offset);
412 strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset);
413 symtab = (const Elf_Sym *)((const char *)ehdr +
414 _r(&symtab_sec->sh_offset));
415
416 if (custom_sort) {
417 custom_sort(extab_image, _r(&extab_sec->sh_size));
418 } else {
419 int num_entries = _r(&extab_sec->sh_size) / extable_ent_size;
420 qsort(extab_image, num_entries,
421 extable_ent_size, compare_extable);
422 }
423
424 /* If there were relocations, we no longer need them. */
425 if (relocs)
426 memset(relocs, 0, relocs_size);
427
428 /* find the flag main_extable_sort_needed */
429 for (sym = (void *)ehdr + _r(&symtab_sec->sh_offset);
430 sym < sym + _r(&symtab_sec->sh_size) / sizeof(Elf_Sym);
431 sym++) {
432 if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
433 continue;
434 if (!strcmp(strtab + r(&sym->st_name),
435 "main_extable_sort_needed")) {
436 sort_needed_sym = sym;
437 break;
438 }
439 }
440
441 if (!sort_needed_sym) {
442 fprintf(stderr,
443 "no main_extable_sort_needed symbol in file: %s\n",
444 fname);
445 goto out;
446 }
447
448 sort_needed_sec = &shdr[get_secindex(r2(&sym->st_shndx),
449 sort_needed_sym - symtab,
450 symtab_shndx)];
451 sort_needed_loc = (void *)ehdr +
452 _r(&sort_needed_sec->sh_offset) +
453 _r(&sort_needed_sym->st_value) -
454 _r(&sort_needed_sec->sh_addr);
455
456 /* extable has been sorted, clear the flag */
457 w(0, sort_needed_loc);
458 rc = 0;
459
460out:
461#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
462 if (orc_sort_thread) {
463 void *retval = NULL;
464 /* wait for ORC tables sort done */
465 rc = pthread_join(orc_sort_thread, &retval);
466 if (rc) {
467 fprintf(stderr,
468 "pthread_join failed '%s': %s\n",
469 strerror(errno), fname);
470 } else if (retval) {
471 rc = -1;
472 fprintf(stderr,
473 "failed to sort ORC tables '%s': %s\n",
474 (char *)retval, fname);
475 }
476 }
477#endif
478
479#ifdef MCOUNT_SORT_ENABLED
480 if (mcount_sort_thread) {
481 void *retval = NULL;
482 /* wait for mcount sort done */
483 rc = pthread_join(mcount_sort_thread, &retval);
484 if (rc) {
485 fprintf(stderr,
486 "pthread_join failed '%s': %s\n",
487 strerror(errno), fname);
488 } else if (retval) {
489 rc = -1;
490 fprintf(stderr,
491 "failed to sort mcount '%s': %s\n",
492 (char *)retval, fname);
493 }
494 }
495#endif
496 return rc;
497}