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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* Generate assembler source containing symbol information
2 *
3 * Copyright 2002 by Kai Germaschewski
4 *
5 * This software may be used and distributed according to the terms
6 * of the GNU General Public License, incorporated herein by reference.
7 *
8 * Usage: nm -n vmlinux | scripts/kallsyms [--all-symbols] > symbols.S
9 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 * Table compression uses all the unused char codes on the symbols and
11 * maps these to the most used substrings (tokens). For instance, it might
12 * map char code 0xF7 to represent "write_" and then in every symbol where
13 * "write_" appears it can be replaced by 0xF7, saving 5 bytes.
14 * The used codes themselves are also placed in the table so that the
15 * decompresion can work without "special cases".
16 * Applied to kernel symbols, this usually produces a compression ratio
17 * of about 50%.
18 *
19 */
20
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <ctype.h>
Ard Biesheuvel2213e9a2016-03-15 14:58:19 -070025#include <limits.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
Mike Frysinger17b1f0d2009-06-08 19:12:13 -040027#ifndef ARRAY_SIZE
28#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
29#endif
30
Tejun Heo9281ace2007-07-17 04:03:51 -070031#define KSYM_NAME_LEN 128
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
Linus Torvalds1da177e2005-04-16 15:20:36 -070033struct sym_entry {
34 unsigned long long addr;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -070035 unsigned int len;
Paulo Marquesf2df3f62008-02-06 01:37:33 -080036 unsigned int start_pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -070037 unsigned char *sym;
Ard Biesheuvel8c996942016-03-15 14:58:15 -070038 unsigned int percpu_absolute;
Linus Torvalds1da177e2005-04-16 15:20:36 -070039};
40
Kees Cook78eb7152014-03-17 13:18:27 +103041struct addr_range {
42 const char *start_sym, *end_sym;
Mike Frysinger17b1f0d2009-06-08 19:12:13 -040043 unsigned long long start, end;
44};
45
46static unsigned long long _text;
Ard Biesheuvel2213e9a2016-03-15 14:58:19 -070047static unsigned long long relative_base;
Kees Cook78eb7152014-03-17 13:18:27 +103048static struct addr_range text_ranges[] = {
Mike Frysinger17b1f0d2009-06-08 19:12:13 -040049 { "_stext", "_etext" },
50 { "_sinittext", "_einittext" },
51 { "_stext_l1", "_etext_l1" }, /* Blackfin on-chip L1 inst SRAM */
52 { "_stext_l2", "_etext_l2" }, /* Blackfin on-chip L2 SRAM */
53};
54#define text_range_text (&text_ranges[0])
55#define text_range_inittext (&text_ranges[1])
56
Rusty Russellc6bda7c2014-03-17 14:05:46 +103057static struct addr_range percpu_range = {
58 "__per_cpu_start", "__per_cpu_end", -1ULL, 0
59};
60
Linus Torvalds1da177e2005-04-16 15:20:36 -070061static struct sym_entry *table;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -070062static unsigned int table_size, table_cnt;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063static int all_symbols = 0;
Rusty Russellc6bda7c2014-03-17 14:05:46 +103064static int absolute_percpu = 0;
Yoshinori Sato41f11a42005-05-01 08:59:06 -070065static char symbol_prefix_char = '\0';
Ard Biesheuvel2213e9a2016-03-15 14:58:19 -070066static int base_relative = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -070068int token_profit[0x10000];
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
70/* the table that holds the result of the compression */
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -070071unsigned char best_table[256][2];
Linus Torvalds1da177e2005-04-16 15:20:36 -070072unsigned char best_table_len[256];
73
74
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -070075static void usage(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070076{
Ming Leif6537f22013-11-02 09:11:33 +103077 fprintf(stderr, "Usage: kallsyms [--all-symbols] "
78 "[--symbol-prefix=<prefix char>] "
79 "[--page-offset=<CONFIG_PAGE_OFFSET>] "
Ard Biesheuvel2213e9a2016-03-15 14:58:19 -070080 "[--base-relative] < in.map > out.S\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 exit(1);
82}
83
84/*
85 * This ignores the intensely annoying "mapping symbols" found
86 * in ARM ELF files: $a, $t and $d.
87 */
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -070088static inline int is_arm_mapping_symbol(const char *str)
Linus Torvalds1da177e2005-04-16 15:20:36 -070089{
Kyle McMartin6c34f1f2014-09-16 22:37:18 +010090 return str[0] == '$' && strchr("axtd", str[1])
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 && (str[2] == '\0' || str[2] == '.');
92}
93
Kees Cook78eb7152014-03-17 13:18:27 +103094static int check_symbol_range(const char *sym, unsigned long long addr,
95 struct addr_range *ranges, int entries)
Mike Frysinger17b1f0d2009-06-08 19:12:13 -040096{
97 size_t i;
Kees Cook78eb7152014-03-17 13:18:27 +103098 struct addr_range *ar;
Mike Frysinger17b1f0d2009-06-08 19:12:13 -040099
Kees Cook78eb7152014-03-17 13:18:27 +1030100 for (i = 0; i < entries; ++i) {
101 ar = &ranges[i];
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400102
Kees Cook78eb7152014-03-17 13:18:27 +1030103 if (strcmp(sym, ar->start_sym) == 0) {
104 ar->start = addr;
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400105 return 0;
Kees Cook78eb7152014-03-17 13:18:27 +1030106 } else if (strcmp(sym, ar->end_sym) == 0) {
107 ar->end = addr;
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400108 return 0;
109 }
110 }
111
112 return 1;
113}
114
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700115static int read_symbol(FILE *in, struct sym_entry *s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116{
117 char str[500];
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700118 char *sym, stype;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 int rc;
120
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700121 rc = fscanf(in, "%llx %c %499s\n", &s->addr, &stype, str);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 if (rc != 3) {
Jean Sacrenef894872010-09-10 23:13:33 -0600123 if (rc != EOF && fgets(str, 500, in) == NULL)
124 fprintf(stderr, "Read error or end of file.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 return -1;
126 }
Andi Kleenf3462aa2013-10-23 15:07:53 +0200127 if (strlen(str) > KSYM_NAME_LEN) {
Fabio Estevam6f622592013-11-08 00:45:01 -0200128 fprintf(stderr, "Symbol %s too long for kallsyms (%zu vs %d).\n"
Masahiro Yamadabb66fc62014-06-10 19:08:13 +0900129 "Please increase KSYM_NAME_LEN both in kernel and kallsyms.c\n",
Andi Kleenf3462aa2013-10-23 15:07:53 +0200130 str, strlen(str), KSYM_NAME_LEN);
131 return -1;
132 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700134 sym = str;
135 /* skip prefix char */
136 if (symbol_prefix_char && str[0] == symbol_prefix_char)
137 sym++;
138
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 /* Ignore most absolute/undefined (?) symbols. */
Eric W. Biedermanfd593d12006-12-07 02:14:04 +0100140 if (strcmp(sym, "_text") == 0)
141 _text = s->addr;
Kees Cook78eb7152014-03-17 13:18:27 +1030142 else if (check_symbol_range(sym, s->addr, text_ranges,
143 ARRAY_SIZE(text_ranges)) == 0)
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400144 /* nothing to do */;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700145 else if (toupper(stype) == 'A')
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 {
147 /* Keep these useful absolute symbols */
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700148 if (strcmp(sym, "__kernel_syscall_via_break") &&
149 strcmp(sym, "__kernel_syscall_via_epc") &&
150 strcmp(sym, "__kernel_sigtramp") &&
151 strcmp(sym, "__gp"))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 return -1;
153
154 }
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700155 else if (toupper(stype) == 'U' ||
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700156 is_arm_mapping_symbol(sym))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 return -1;
Ralf Baechle6f00df22005-09-06 15:16:41 -0700158 /* exclude also MIPS ELF local symbols ($L123 instead of .L123) */
159 else if (str[0] == '$')
160 return -1;
Sam Ravnborgaab34ac2008-05-19 20:07:58 +0200161 /* exclude debugging symbols */
162 else if (stype == 'N')
163 return -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
165 /* include the type field in the symbol name, so that it gets
166 * compressed together */
167 s->len = strlen(str) + 1;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700168 s->sym = malloc(s->len + 1);
Jesper Juhlf1a136e2006-03-25 03:07:46 -0800169 if (!s->sym) {
170 fprintf(stderr, "kallsyms failure: "
171 "unable to allocate required amount of memory\n");
172 exit(EXIT_FAILURE);
173 }
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700174 strcpy((char *)s->sym + 1, str);
175 s->sym[0] = stype;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
Ard Biesheuvel8c996942016-03-15 14:58:15 -0700177 s->percpu_absolute = 0;
178
Rusty Russellc6bda7c2014-03-17 14:05:46 +1030179 /* Record if we've found __per_cpu_start/end. */
180 check_symbol_range(sym, s->addr, &percpu_range, 1);
181
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 return 0;
183}
184
Kees Cook78eb7152014-03-17 13:18:27 +1030185static int symbol_in_range(struct sym_entry *s, struct addr_range *ranges,
186 int entries)
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400187{
188 size_t i;
Kees Cook78eb7152014-03-17 13:18:27 +1030189 struct addr_range *ar;
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400190
Kees Cook78eb7152014-03-17 13:18:27 +1030191 for (i = 0; i < entries; ++i) {
192 ar = &ranges[i];
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400193
Kees Cook78eb7152014-03-17 13:18:27 +1030194 if (s->addr >= ar->start && s->addr <= ar->end)
Mike Frysingerac6ca5c2009-06-15 07:52:48 -0400195 return 1;
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400196 }
197
Mike Frysingerac6ca5c2009-06-15 07:52:48 -0400198 return 0;
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400199}
200
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700201static int symbol_valid(struct sym_entry *s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202{
203 /* Symbols which vary between passes. Passes 1 and 2 must have
Sam Ravnborg2ea03892009-01-14 21:38:20 +0100204 * identical symbol lists. The kallsyms_* symbols below are only added
205 * after pass 1, they would be included in pass 2 when --all-symbols is
206 * specified so exclude them to get a stable symbol list.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 */
208 static char *special_symbols[] = {
Sam Ravnborg2ea03892009-01-14 21:38:20 +0100209 "kallsyms_addresses",
Ard Biesheuvel2213e9a2016-03-15 14:58:19 -0700210 "kallsyms_offsets",
211 "kallsyms_relative_base",
Sam Ravnborg2ea03892009-01-14 21:38:20 +0100212 "kallsyms_num_syms",
213 "kallsyms_names",
214 "kallsyms_markers",
215 "kallsyms_token_table",
216 "kallsyms_token_index",
217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 /* Exclude linker generated symbols which vary between passes */
219 "_SDA_BASE_", /* ppc */
220 "_SDA2_BASE_", /* ppc */
221 NULL };
Ard Biesheuvelbd8b22d2015-03-30 15:20:31 +0200222
223 static char *special_suffixes[] = {
Ard Biesheuvelbd8b22d2015-03-30 15:20:31 +0200224 "_veneer", /* arm */
Ard Biesheuvelb9b74be2016-04-01 14:33:48 +0100225 "_from_arm", /* arm */
226 "_from_thumb", /* arm */
Ard Biesheuvelbd8b22d2015-03-30 15:20:31 +0200227 NULL };
228
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 int i;
Ard Biesheuvelbd8b22d2015-03-30 15:20:31 +0200230 char *sym_name = (char *)s->sym + 1;
231
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700232 /* skip prefix char */
Ard Biesheuvelbd8b22d2015-03-30 15:20:31 +0200233 if (symbol_prefix_char && *sym_name == symbol_prefix_char)
234 sym_name++;
235
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236
237 /* if --all-symbols is not specified, then symbols outside the text
238 * and inittext sections are discarded */
239 if (!all_symbols) {
Kees Cook78eb7152014-03-17 13:18:27 +1030240 if (symbol_in_range(s, text_ranges,
241 ARRAY_SIZE(text_ranges)) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 return 0;
243 /* Corner case. Discard any symbols with the same value as
Robin Getza3b81112008-02-06 01:36:26 -0800244 * _etext _einittext; they can move between pass 1 and 2 when
245 * the kallsyms data are added. If these symbols move then
246 * they may get dropped in pass 2, which breaks the kallsyms
247 * rules.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 */
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400249 if ((s->addr == text_range_text->end &&
Ard Biesheuvelbd8b22d2015-03-30 15:20:31 +0200250 strcmp(sym_name,
Kees Cook78eb7152014-03-17 13:18:27 +1030251 text_range_text->end_sym)) ||
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400252 (s->addr == text_range_inittext->end &&
Ard Biesheuvelbd8b22d2015-03-30 15:20:31 +0200253 strcmp(sym_name,
Kees Cook78eb7152014-03-17 13:18:27 +1030254 text_range_inittext->end_sym)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 return 0;
256 }
257
258 /* Exclude symbols which vary between passes. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 for (i = 0; special_symbols[i]; i++)
Ard Biesheuvelbd8b22d2015-03-30 15:20:31 +0200260 if (strcmp(sym_name, special_symbols[i]) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 return 0;
262
Ard Biesheuvelbd8b22d2015-03-30 15:20:31 +0200263 for (i = 0; special_suffixes[i]; i++) {
264 int l = strlen(sym_name) - strlen(special_suffixes[i]);
265
266 if (l >= 0 && strcmp(sym_name + l, special_suffixes[i]) == 0)
267 return 0;
268 }
269
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 return 1;
271}
272
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700273static void read_map(FILE *in)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274{
275 while (!feof(in)) {
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700276 if (table_cnt >= table_size) {
277 table_size += 10000;
278 table = realloc(table, sizeof(*table) * table_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 if (!table) {
280 fprintf(stderr, "out of memory\n");
281 exit (1);
282 }
283 }
Paulo Marquesf2df3f62008-02-06 01:37:33 -0800284 if (read_symbol(in, &table[table_cnt]) == 0) {
285 table[table_cnt].start_pos = table_cnt;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700286 table_cnt++;
Paulo Marquesf2df3f62008-02-06 01:37:33 -0800287 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 }
289}
290
291static void output_label(char *label)
292{
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700293 if (symbol_prefix_char)
294 printf(".globl %c%s\n", symbol_prefix_char, label);
295 else
296 printf(".globl %s\n", label);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 printf("\tALGN\n");
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700298 if (symbol_prefix_char)
299 printf("%c%s:\n", symbol_prefix_char, label);
300 else
301 printf("%s:\n", label);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302}
303
304/* uncompress a compressed symbol. When this function is called, the best table
305 * might still be compressed itself, so the function needs to be recursive */
306static int expand_symbol(unsigned char *data, int len, char *result)
307{
308 int c, rlen, total=0;
309
310 while (len) {
311 c = *data;
312 /* if the table holds a single char that is the same as the one
313 * we are looking for, then end the search */
314 if (best_table[c][0]==c && best_table_len[c]==1) {
315 *result++ = c;
316 total++;
317 } else {
318 /* if not, recurse and expand */
319 rlen = expand_symbol(best_table[c], best_table_len[c], result);
320 total += rlen;
321 result += rlen;
322 }
323 data++;
324 len--;
325 }
326 *result=0;
327
328 return total;
329}
330
Kees Cook78eb7152014-03-17 13:18:27 +1030331static int symbol_absolute(struct sym_entry *s)
332{
Ard Biesheuvel8c996942016-03-15 14:58:15 -0700333 return s->percpu_absolute;
Kees Cook78eb7152014-03-17 13:18:27 +1030334}
335
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700336static void write_src(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337{
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700338 unsigned int i, k, off;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 unsigned int best_idx[256];
340 unsigned int *markers;
Tejun Heo9281ace2007-07-17 04:03:51 -0700341 char buf[KSYM_NAME_LEN];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342
343 printf("#include <asm/types.h>\n");
344 printf("#if BITS_PER_LONG == 64\n");
345 printf("#define PTR .quad\n");
346 printf("#define ALGN .align 8\n");
347 printf("#else\n");
348 printf("#define PTR .long\n");
349 printf("#define ALGN .align 4\n");
350 printf("#endif\n");
351
Jan Beulichaad09472006-12-08 02:35:57 -0800352 printf("\t.section .rodata, \"a\"\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353
Ard Biesheuvel2213e9a2016-03-15 14:58:19 -0700354 /* Provide proper symbols relocatability by their relativeness
355 * to a fixed anchor point in the runtime image, either '_text'
356 * for absolute address tables, in which case the linker will
357 * emit the final addresses at build time. Otherwise, use the
358 * offset relative to the lowest value encountered of all relative
359 * symbols, and emit non-relocatable fixed offsets that will be fixed
360 * up at runtime.
361 *
362 * The symbol names cannot be used to construct normal symbol
363 * references as the list of symbols contains symbols that are
364 * declared static and are private to their .o files. This prevents
365 * .tmp_kallsyms.o or any other object from referencing them.
Eric W. Biedermanfd593d12006-12-07 02:14:04 +0100366 */
Ard Biesheuvel2213e9a2016-03-15 14:58:19 -0700367 if (!base_relative)
368 output_label("kallsyms_addresses");
369 else
370 output_label("kallsyms_offsets");
371
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700372 for (i = 0; i < table_cnt; i++) {
Ard Biesheuvel2213e9a2016-03-15 14:58:19 -0700373 if (base_relative) {
374 long long offset;
375 int overflow;
376
377 if (!absolute_percpu) {
378 offset = table[i].addr - relative_base;
379 overflow = (offset < 0 || offset > UINT_MAX);
380 } else if (symbol_absolute(&table[i])) {
381 offset = table[i].addr;
382 overflow = (offset < 0 || offset > INT_MAX);
383 } else {
384 offset = relative_base - table[i].addr - 1;
385 overflow = (offset < INT_MIN || offset >= 0);
386 }
387 if (overflow) {
388 fprintf(stderr, "kallsyms failure: "
389 "%s symbol value %#llx out of range in relative mode\n",
390 symbol_absolute(&table[i]) ? "absolute" : "relative",
391 table[i].addr);
392 exit(EXIT_FAILURE);
393 }
394 printf("\t.long\t%#x\n", (int)offset);
395 } else if (!symbol_absolute(&table[i])) {
Vivek Goyal2c22d8b2006-12-07 02:14:10 +0100396 if (_text <= table[i].addr)
397 printf("\tPTR\t_text + %#llx\n",
398 table[i].addr - _text);
399 else
Andrew Morton2930ffc2014-03-10 15:49:48 -0700400 printf("\tPTR\t_text - %#llx\n",
401 _text - table[i].addr);
Eric W. Biedermanfd593d12006-12-07 02:14:04 +0100402 } else {
403 printf("\tPTR\t%#llx\n", table[i].addr);
404 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 }
406 printf("\n");
407
Ard Biesheuvel2213e9a2016-03-15 14:58:19 -0700408 if (base_relative) {
409 output_label("kallsyms_relative_base");
410 printf("\tPTR\t_text - %#llx\n", _text - relative_base);
411 printf("\n");
412 }
413
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 output_label("kallsyms_num_syms");
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700415 printf("\tPTR\t%d\n", table_cnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 printf("\n");
417
418 /* table of offset markers, that give the offset in the compressed stream
419 * every 256 symbols */
Jesper Juhlf1a136e2006-03-25 03:07:46 -0800420 markers = malloc(sizeof(unsigned int) * ((table_cnt + 255) / 256));
421 if (!markers) {
422 fprintf(stderr, "kallsyms failure: "
423 "unable to allocate required memory\n");
424 exit(EXIT_FAILURE);
425 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426
427 output_label("kallsyms_names");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 off = 0;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700429 for (i = 0; i < table_cnt; i++) {
430 if ((i & 0xFF) == 0)
431 markers[i >> 8] = off;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432
433 printf("\t.byte 0x%02x", table[i].len);
434 for (k = 0; k < table[i].len; k++)
435 printf(", 0x%02x", table[i].sym[k]);
436 printf("\n");
437
438 off += table[i].len + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 }
440 printf("\n");
441
442 output_label("kallsyms_markers");
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700443 for (i = 0; i < ((table_cnt + 255) >> 8); i++)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 printf("\tPTR\t%d\n", markers[i]);
445 printf("\n");
446
447 free(markers);
448
449 output_label("kallsyms_token_table");
450 off = 0;
451 for (i = 0; i < 256; i++) {
452 best_idx[i] = off;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700453 expand_symbol(best_table[i], best_table_len[i], buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 printf("\t.asciz\t\"%s\"\n", buf);
455 off += strlen(buf) + 1;
456 }
457 printf("\n");
458
459 output_label("kallsyms_token_index");
460 for (i = 0; i < 256; i++)
461 printf("\t.short\t%d\n", best_idx[i]);
462 printf("\n");
463}
464
465
466/* table lookup compression functions */
467
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468/* count all the possible tokens in a symbol */
469static void learn_symbol(unsigned char *symbol, int len)
470{
471 int i;
472
473 for (i = 0; i < len - 1; i++)
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700474 token_profit[ symbol[i] + (symbol[i + 1] << 8) ]++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475}
476
477/* decrease the count for all the possible tokens in a symbol */
478static void forget_symbol(unsigned char *symbol, int len)
479{
480 int i;
481
482 for (i = 0; i < len - 1; i++)
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700483 token_profit[ symbol[i] + (symbol[i + 1] << 8) ]--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484}
485
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700486/* remove all the invalid symbols from the table and do the initial token count */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487static void build_initial_tok_table(void)
488{
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700489 unsigned int i, pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700491 pos = 0;
492 for (i = 0; i < table_cnt; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 if ( symbol_valid(&table[i]) ) {
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700494 if (pos != i)
495 table[pos] = table[i];
496 learn_symbol(table[pos].sym, table[pos].len);
497 pos++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 }
499 }
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700500 table_cnt = pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501}
502
Paulo Marques7c5d2492007-06-20 18:09:00 +0100503static void *find_token(unsigned char *str, int len, unsigned char *token)
504{
505 int i;
506
507 for (i = 0; i < len - 1; i++) {
508 if (str[i] == token[0] && str[i+1] == token[1])
509 return &str[i];
510 }
511 return NULL;
512}
513
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514/* replace a given token in all the valid symbols. Use the sampled symbols
515 * to update the counts */
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700516static void compress_symbols(unsigned char *str, int idx)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517{
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700518 unsigned int i, len, size;
519 unsigned char *p1, *p2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700521 for (i = 0; i < table_cnt; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522
523 len = table[i].len;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700524 p1 = table[i].sym;
525
526 /* find the token on the symbol */
Paulo Marques7c5d2492007-06-20 18:09:00 +0100527 p2 = find_token(p1, len, str);
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700528 if (!p2) continue;
529
530 /* decrease the counts for this symbol's tokens */
531 forget_symbol(table[i].sym, len);
532
533 size = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534
535 do {
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700536 *p2 = idx;
537 p2++;
538 size -= (p2 - p1);
539 memmove(p2, p2 + 1, size);
540 p1 = p2;
541 len--;
542
543 if (size < 2) break;
544
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 /* find the token on the symbol */
Paulo Marques7c5d2492007-06-20 18:09:00 +0100546 p2 = find_token(p1, size, str);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700548 } while (p2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700550 table[i].len = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700552 /* increase the counts for this symbol's new tokens */
553 learn_symbol(table[i].sym, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 }
555}
556
557/* search the token with the maximum profit */
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700558static int find_best_token(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559{
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700560 int i, best, bestprofit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561
562 bestprofit=-10000;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700563 best = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700565 for (i = 0; i < 0x10000; i++) {
566 if (token_profit[i] > bestprofit) {
567 best = i;
568 bestprofit = token_profit[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 return best;
572}
573
574/* this is the core of the algorithm: calculate the "best" table */
575static void optimize_result(void)
576{
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700577 int i, best;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578
579 /* using the '\0' symbol last allows compress_symbols to use standard
580 * fast string functions */
581 for (i = 255; i >= 0; i--) {
582
583 /* if this table slot is empty (it is not used by an actual
584 * original char code */
585 if (!best_table_len[i]) {
586
587 /* find the token with the breates profit value */
588 best = find_best_token();
Xiaochen Wange0a04b12011-05-01 11:41:41 +0800589 if (token_profit[best] == 0)
590 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591
592 /* place it in the "best" table */
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700593 best_table_len[i] = 2;
594 best_table[i][0] = best & 0xFF;
595 best_table[i][1] = (best >> 8) & 0xFF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596
597 /* replace this token in all the valid symbols */
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700598 compress_symbols(best_table[i], i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 }
600 }
601}
602
603/* start by placing the symbols that are actually used on the table */
604static void insert_real_symbols_in_table(void)
605{
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700606 unsigned int i, j, c;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607
608 memset(best_table, 0, sizeof(best_table));
609 memset(best_table_len, 0, sizeof(best_table_len));
610
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700611 for (i = 0; i < table_cnt; i++) {
612 for (j = 0; j < table[i].len; j++) {
613 c = table[i].sym[j];
614 best_table[c][0]=c;
615 best_table_len[c]=1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 }
617 }
618}
619
620static void optimize_token_table(void)
621{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 build_initial_tok_table();
623
624 insert_real_symbols_in_table();
625
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700626 /* When valid symbol is not registered, exit to error */
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700627 if (!table_cnt) {
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700628 fprintf(stderr, "No valid symbol.\n");
629 exit(1);
630 }
631
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 optimize_result();
633}
634
Lai Jiangshanb478b782009-03-13 15:10:26 +0800635/* guess for "linker script provide" symbol */
636static int may_be_linker_script_provide_symbol(const struct sym_entry *se)
637{
638 const char *symbol = (char *)se->sym + 1;
639 int len = se->len - 1;
640
641 if (len < 8)
642 return 0;
643
644 if (symbol[0] != '_' || symbol[1] != '_')
645 return 0;
646
647 /* __start_XXXXX */
648 if (!memcmp(symbol + 2, "start_", 6))
649 return 1;
650
651 /* __stop_XXXXX */
652 if (!memcmp(symbol + 2, "stop_", 5))
653 return 1;
654
655 /* __end_XXXXX */
656 if (!memcmp(symbol + 2, "end_", 4))
657 return 1;
658
659 /* __XXXXX_start */
660 if (!memcmp(symbol + len - 6, "_start", 6))
661 return 1;
662
663 /* __XXXXX_end */
664 if (!memcmp(symbol + len - 4, "_end", 4))
665 return 1;
666
667 return 0;
668}
669
670static int prefix_underscores_count(const char *str)
671{
672 const char *tail = str;
673
Paul Mundta9ece532009-09-22 16:44:12 -0700674 while (*tail == '_')
Lai Jiangshanb478b782009-03-13 15:10:26 +0800675 tail++;
676
677 return tail - str;
678}
679
Paulo Marquesf2df3f62008-02-06 01:37:33 -0800680static int compare_symbols(const void *a, const void *b)
681{
682 const struct sym_entry *sa;
683 const struct sym_entry *sb;
684 int wa, wb;
685
686 sa = a;
687 sb = b;
688
689 /* sort by address first */
690 if (sa->addr > sb->addr)
691 return 1;
692 if (sa->addr < sb->addr)
693 return -1;
694
695 /* sort by "weakness" type */
696 wa = (sa->sym[0] == 'w') || (sa->sym[0] == 'W');
697 wb = (sb->sym[0] == 'w') || (sb->sym[0] == 'W');
698 if (wa != wb)
699 return wa - wb;
700
Lai Jiangshanb478b782009-03-13 15:10:26 +0800701 /* sort by "linker script provide" type */
702 wa = may_be_linker_script_provide_symbol(sa);
703 wb = may_be_linker_script_provide_symbol(sb);
704 if (wa != wb)
705 return wa - wb;
706
707 /* sort by the number of prefix underscores */
708 wa = prefix_underscores_count((const char *)sa->sym + 1);
709 wb = prefix_underscores_count((const char *)sb->sym + 1);
710 if (wa != wb)
711 return wa - wb;
712
Paulo Marquesf2df3f62008-02-06 01:37:33 -0800713 /* sort by initial order, so that other symbols are left undisturbed */
714 return sa->start_pos - sb->start_pos;
715}
716
717static void sort_symbols(void)
718{
719 qsort(table, table_cnt, sizeof(struct sym_entry), compare_symbols);
720}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721
Rusty Russellc6bda7c2014-03-17 14:05:46 +1030722static void make_percpus_absolute(void)
723{
724 unsigned int i;
725
726 for (i = 0; i < table_cnt; i++)
Ard Biesheuvel8c996942016-03-15 14:58:15 -0700727 if (symbol_in_range(&table[i], &percpu_range, 1)) {
728 /*
729 * Keep the 'A' override for percpu symbols to
730 * ensure consistent behavior compared to older
731 * versions of this tool.
732 */
Rusty Russellc6bda7c2014-03-17 14:05:46 +1030733 table[i].sym[0] = 'A';
Ard Biesheuvel8c996942016-03-15 14:58:15 -0700734 table[i].percpu_absolute = 1;
735 }
Rusty Russellc6bda7c2014-03-17 14:05:46 +1030736}
737
Ard Biesheuvel2213e9a2016-03-15 14:58:19 -0700738/* find the minimum non-absolute symbol address */
739static void record_relative_base(void)
740{
741 unsigned int i;
742
743 relative_base = -1ULL;
744 for (i = 0; i < table_cnt; i++)
745 if (!symbol_absolute(&table[i]) &&
746 table[i].addr < relative_base)
747 relative_base = table[i].addr;
748}
749
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700750int main(int argc, char **argv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751{
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700752 if (argc >= 2) {
753 int i;
754 for (i = 1; i < argc; i++) {
755 if(strcmp(argv[i], "--all-symbols") == 0)
756 all_symbols = 1;
Rusty Russellc6bda7c2014-03-17 14:05:46 +1030757 else if (strcmp(argv[i], "--absolute-percpu") == 0)
758 absolute_percpu = 1;
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700759 else if (strncmp(argv[i], "--symbol-prefix=", 16) == 0) {
760 char *p = &argv[i][16];
761 /* skip quote */
762 if ((*p == '"' && *(p+2) == '"') || (*p == '\'' && *(p+2) == '\''))
763 p++;
764 symbol_prefix_char = *p;
Ard Biesheuvel2213e9a2016-03-15 14:58:19 -0700765 } else if (strcmp(argv[i], "--base-relative") == 0)
766 base_relative = 1;
767 else
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700768 usage();
769 }
770 } else if (argc != 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 usage();
772
773 read_map(stdin);
Rusty Russellc6bda7c2014-03-17 14:05:46 +1030774 if (absolute_percpu)
775 make_percpus_absolute();
Ard Biesheuvel2213e9a2016-03-15 14:58:19 -0700776 if (base_relative)
777 record_relative_base();
Sam Ravnborg2ea03892009-01-14 21:38:20 +0100778 sort_symbols();
779 optimize_token_table();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 write_src();
781
782 return 0;
783}