1 // SPDX-License-Identifier: GPL-2.0-only 1 // SPDX-License-Identifier: GPL-2.0-only
2 /* 2 /*
3 * recordmcount.c: construct a table of the lo 3 * recordmcount.c: construct a table of the locations of calls to 'mcount'
4 * so that ftrace can find them quickly. 4 * so that ftrace can find them quickly.
5 * Copyright 2009 John F. Reiser <jreiser@BitW 5 * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.
6 * 6 *
7 * Restructured to fit Linux format, as well a 7 * Restructured to fit Linux format, as well as other updates:
8 * Copyright 2010 Steven Rostedt <srostedt@re 8 * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
9 */ 9 */
10 10
11 /* 11 /*
12 * Strategy: alter the .o file in-place. 12 * Strategy: alter the .o file in-place.
13 * 13 *
14 * Append a new STRTAB that has the new sectio 14 * Append a new STRTAB that has the new section names, followed by a new array
15 * ElfXX_Shdr[] that has the new section heade 15 * ElfXX_Shdr[] that has the new section headers, followed by the section
16 * contents for __mcount_loc and its relocatio 16 * contents for __mcount_loc and its relocations. The old shstrtab strings,
17 * and the old ElfXX_Shdr[] array, remain as " 17 * and the old ElfXX_Shdr[] array, remain as "garbage" (commonly, a couple
18 * kilobytes.) Subsequent processing by /bin/ 18 * kilobytes.) Subsequent processing by /bin/ld (or the kernel module loader)
19 * will ignore the garbage regions, because th 19 * will ignore the garbage regions, because they are not designated by the
20 * new .e_shoff nor the new ElfXX_Shdr[]. [In 20 * new .e_shoff nor the new ElfXX_Shdr[]. [In order to remove the garbage,
21 * then use "ld -r" to create a new file that 21 * then use "ld -r" to create a new file that omits the garbage.]
22 */ 22 */
23 23
24 #include <sys/types.h> 24 #include <sys/types.h>
25 #include <sys/mman.h> 25 #include <sys/mman.h>
26 #include <sys/stat.h> 26 #include <sys/stat.h>
27 #include <getopt.h> 27 #include <getopt.h>
28 #include <elf.h> 28 #include <elf.h>
29 #include <fcntl.h> 29 #include <fcntl.h>
30 #include <stdio.h> 30 #include <stdio.h>
31 #include <stdlib.h> 31 #include <stdlib.h>
32 #include <string.h> 32 #include <string.h>
33 #include <unistd.h> 33 #include <unistd.h>
34 34
35 #ifndef EM_AARCH64 35 #ifndef EM_AARCH64
36 #define EM_AARCH64 183 36 #define EM_AARCH64 183
37 #define R_AARCH64_NONE 0 37 #define R_AARCH64_NONE 0
38 #define R_AARCH64_ABS64 257 38 #define R_AARCH64_ABS64 257
39 #endif 39 #endif
40 40
41 #ifndef EM_LOONGARCH 41 #ifndef EM_LOONGARCH
42 #define EM_LOONGARCH 258 42 #define EM_LOONGARCH 258
43 #define R_LARCH_32 1 43 #define R_LARCH_32 1
44 #define R_LARCH_64 2 44 #define R_LARCH_64 2
45 #define R_LARCH_MARK_LA 20 45 #define R_LARCH_MARK_LA 20
46 #define R_LARCH_SOP_PUSH_PLT_PCREL 29 46 #define R_LARCH_SOP_PUSH_PLT_PCREL 29
47 #endif 47 #endif
48 48
49 #define R_ARM_PC24 1 49 #define R_ARM_PC24 1
50 #define R_ARM_THM_CALL 10 50 #define R_ARM_THM_CALL 10
51 #define R_ARM_CALL 28 51 #define R_ARM_CALL 28
52 52
53 #define R_AARCH64_CALL26 283 53 #define R_AARCH64_CALL26 283
54 54
55 static int fd_map; /* File descriptor for 55 static int fd_map; /* File descriptor for file being modified. */
56 static int mmap_failed; /* Boolean flag. */ 56 static int mmap_failed; /* Boolean flag. */
57 static char gpfx; /* prefix for global s 57 static char gpfx; /* prefix for global symbol name (sometimes '_') */
58 static struct stat sb; /* Remember .st_size, 58 static struct stat sb; /* Remember .st_size, etc. */
59 static const char *altmcount; /* alternate m 59 static const char *altmcount; /* alternate mcount symbol name */
60 static int warn_on_notrace_sect; /* warn when 60 static int warn_on_notrace_sect; /* warn when section has mcount not being recorded */
61 static void *file_map; /* pointer of the mapp 61 static void *file_map; /* pointer of the mapped file */
62 static void *file_end; /* pointer to the end 62 static void *file_end; /* pointer to the end of the mapped file */
63 static int file_updated; /* flag to state file 63 static int file_updated; /* flag to state file was changed */
64 static void *file_ptr; /* current file pointe 64 static void *file_ptr; /* current file pointer location */
65 65
66 static void *file_append; /* added to the end 66 static void *file_append; /* added to the end of the file */
67 static size_t file_append_size; /* how much is 67 static size_t file_append_size; /* how much is added to end of file */
68 68
69 /* Per-file resource cleanup when multiple fil 69 /* Per-file resource cleanup when multiple files. */
70 static void file_append_cleanup(void) 70 static void file_append_cleanup(void)
71 { 71 {
72 free(file_append); 72 free(file_append);
73 file_append = NULL; 73 file_append = NULL;
74 file_append_size = 0; 74 file_append_size = 0;
75 file_updated = 0; 75 file_updated = 0;
76 } 76 }
77 77
78 static void mmap_cleanup(void) 78 static void mmap_cleanup(void)
79 { 79 {
80 if (!mmap_failed) 80 if (!mmap_failed)
81 munmap(file_map, sb.st_size); 81 munmap(file_map, sb.st_size);
82 else 82 else
83 free(file_map); 83 free(file_map);
84 file_map = NULL; 84 file_map = NULL;
85 } 85 }
86 86
87 /* ulseek, uwrite, ...: Check return value fo 87 /* ulseek, uwrite, ...: Check return value for errors. */
88 88
89 static off_t ulseek(off_t const offset, int co 89 static off_t ulseek(off_t const offset, int const whence)
90 { 90 {
91 switch (whence) { 91 switch (whence) {
92 case SEEK_SET: 92 case SEEK_SET:
93 file_ptr = file_map + offset; 93 file_ptr = file_map + offset;
94 break; 94 break;
95 case SEEK_CUR: 95 case SEEK_CUR:
96 file_ptr += offset; 96 file_ptr += offset;
97 break; 97 break;
98 case SEEK_END: 98 case SEEK_END:
99 file_ptr = file_map + (sb.st_s 99 file_ptr = file_map + (sb.st_size - offset);
100 break; 100 break;
101 } 101 }
102 if (file_ptr < file_map) { 102 if (file_ptr < file_map) {
103 fprintf(stderr, "lseek: seek b 103 fprintf(stderr, "lseek: seek before file\n");
104 return -1; 104 return -1;
105 } 105 }
106 return file_ptr - file_map; 106 return file_ptr - file_map;
107 } 107 }
108 108
109 static ssize_t uwrite(void const *const buf, s 109 static ssize_t uwrite(void const *const buf, size_t const count)
110 { 110 {
111 size_t cnt = count; 111 size_t cnt = count;
112 off_t idx = 0; 112 off_t idx = 0;
113 void *p = NULL; <<
114 113
115 file_updated = 1; 114 file_updated = 1;
116 115
117 if (file_ptr + count >= file_end) { 116 if (file_ptr + count >= file_end) {
118 off_t aoffset = (file_ptr + co 117 off_t aoffset = (file_ptr + count) - file_end;
119 118
120 if (aoffset > file_append_size 119 if (aoffset > file_append_size) {
121 p = realloc(file_appen !! 120 file_append = realloc(file_append, aoffset);
122 if (!p) <<
123 free(file_appe <<
124 file_append = p; <<
125 file_append_size = aof 121 file_append_size = aoffset;
126 } 122 }
127 if (!file_append) { 123 if (!file_append) {
128 perror("write"); 124 perror("write");
129 file_append_cleanup(); 125 file_append_cleanup();
130 mmap_cleanup(); 126 mmap_cleanup();
131 return -1; 127 return -1;
132 } 128 }
133 if (file_ptr < file_end) { 129 if (file_ptr < file_end) {
134 cnt = file_end - file_ 130 cnt = file_end - file_ptr;
135 } else { 131 } else {
136 cnt = 0; 132 cnt = 0;
137 idx = aoffset - count; 133 idx = aoffset - count;
138 } 134 }
139 } 135 }
140 136
141 if (cnt) 137 if (cnt)
142 memcpy(file_ptr, buf, cnt); 138 memcpy(file_ptr, buf, cnt);
143 139
144 if (cnt < count) 140 if (cnt < count)
145 memcpy(file_append + idx, buf 141 memcpy(file_append + idx, buf + cnt, count - cnt);
146 142
147 file_ptr += count; 143 file_ptr += count;
148 return count; 144 return count;
149 } 145 }
150 146
151 static void * umalloc(size_t size) 147 static void * umalloc(size_t size)
152 { 148 {
153 void *const addr = malloc(size); 149 void *const addr = malloc(size);
154 if (addr == 0) { 150 if (addr == 0) {
155 fprintf(stderr, "malloc failed 151 fprintf(stderr, "malloc failed: %zu bytes\n", size);
156 file_append_cleanup(); 152 file_append_cleanup();
157 mmap_cleanup(); 153 mmap_cleanup();
158 return NULL; 154 return NULL;
159 } 155 }
160 return addr; 156 return addr;
161 } 157 }
162 158
163 /* 159 /*
164 * Get the whole file as a programming conveni 160 * Get the whole file as a programming convenience in order to avoid
165 * malloc+lseek+read+free of many pieces. If 161 * malloc+lseek+read+free of many pieces. If successful, then mmap
166 * avoids copying unused pieces; else just rea 162 * avoids copying unused pieces; else just read the whole file.
167 * Open for both read and write; new info will 163 * Open for both read and write; new info will be appended to the file.
168 * Use MAP_PRIVATE so that a few changes to th 164 * Use MAP_PRIVATE so that a few changes to the in-memory ElfXX_Ehdr
169 * do not propagate to the file until an expli 165 * do not propagate to the file until an explicit overwrite at the last.
170 * This preserves most aspects of consistency 166 * This preserves most aspects of consistency (all except .st_size)
171 * for simultaneous readers of the file while 167 * for simultaneous readers of the file while we are appending to it.
172 * However, multiple writers still are bad. W 168 * However, multiple writers still are bad. We choose not to use
173 * locking because it is expensive and the use 169 * locking because it is expensive and the use case of kernel build
174 * makes multiple writers unlikely. 170 * makes multiple writers unlikely.
175 */ 171 */
176 static void *mmap_file(char const *fname) 172 static void *mmap_file(char const *fname)
177 { 173 {
178 /* Avoid problems if early cleanup() * 174 /* Avoid problems if early cleanup() */
179 fd_map = -1; 175 fd_map = -1;
180 mmap_failed = 1; 176 mmap_failed = 1;
181 file_map = NULL; 177 file_map = NULL;
182 file_ptr = NULL; 178 file_ptr = NULL;
183 file_updated = 0; 179 file_updated = 0;
184 sb.st_size = 0; 180 sb.st_size = 0;
185 181
186 fd_map = open(fname, O_RDONLY); 182 fd_map = open(fname, O_RDONLY);
187 if (fd_map < 0) { 183 if (fd_map < 0) {
188 perror(fname); 184 perror(fname);
189 return NULL; 185 return NULL;
190 } 186 }
191 if (fstat(fd_map, &sb) < 0) { 187 if (fstat(fd_map, &sb) < 0) {
192 perror(fname); 188 perror(fname);
193 goto out; 189 goto out;
194 } 190 }
195 if (!S_ISREG(sb.st_mode)) { 191 if (!S_ISREG(sb.st_mode)) {
196 fprintf(stderr, "not a regular 192 fprintf(stderr, "not a regular file: %s\n", fname);
197 goto out; 193 goto out;
198 } 194 }
199 file_map = mmap(0, sb.st_size, PROT_RE 195 file_map = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
200 fd_map, 0); 196 fd_map, 0);
201 if (file_map == MAP_FAILED) { 197 if (file_map == MAP_FAILED) {
202 mmap_failed = 1; 198 mmap_failed = 1;
203 file_map = umalloc(sb.st_size) 199 file_map = umalloc(sb.st_size);
204 if (!file_map) { 200 if (!file_map) {
205 perror(fname); 201 perror(fname);
206 goto out; 202 goto out;
207 } 203 }
208 if (read(fd_map, file_map, sb. 204 if (read(fd_map, file_map, sb.st_size) != sb.st_size) {
209 perror(fname); 205 perror(fname);
210 free(file_map); 206 free(file_map);
211 file_map = NULL; 207 file_map = NULL;
212 goto out; 208 goto out;
213 } 209 }
214 } else 210 } else
215 mmap_failed = 0; 211 mmap_failed = 0;
216 out: 212 out:
217 close(fd_map); 213 close(fd_map);
218 fd_map = -1; 214 fd_map = -1;
219 215
220 file_end = file_map + sb.st_size; 216 file_end = file_map + sb.st_size;
221 217
222 return file_map; 218 return file_map;
223 } 219 }
224 220
225 221
226 static unsigned char ideal_nop5_x86_64[5] = { 222 static unsigned char ideal_nop5_x86_64[5] = { 0x0f, 0x1f, 0x44, 0x00, 0x00 };
227 static unsigned char ideal_nop5_x86_32[5] = { 223 static unsigned char ideal_nop5_x86_32[5] = { 0x3e, 0x8d, 0x74, 0x26, 0x00 };
228 static unsigned char *ideal_nop; 224 static unsigned char *ideal_nop;
229 225
230 static char rel_type_nop; 226 static char rel_type_nop;
231 227
232 static int (*make_nop)(void *map, size_t const 228 static int (*make_nop)(void *map, size_t const offset);
233 229
234 static int make_nop_x86(void *map, size_t cons 230 static int make_nop_x86(void *map, size_t const offset)
235 { 231 {
236 uint32_t *ptr; 232 uint32_t *ptr;
237 unsigned char *op; 233 unsigned char *op;
238 234
239 /* Confirm we have 0xe8 0x0 0x0 0x0 0x 235 /* Confirm we have 0xe8 0x0 0x0 0x0 0x0 */
240 ptr = map + offset; 236 ptr = map + offset;
241 if (*ptr != 0) 237 if (*ptr != 0)
242 return -1; 238 return -1;
243 239
244 op = map + offset - 1; 240 op = map + offset - 1;
245 if (*op != 0xe8) 241 if (*op != 0xe8)
246 return -1; 242 return -1;
247 243
248 /* convert to nop */ 244 /* convert to nop */
249 if (ulseek(offset - 1, SEEK_SET) < 0) 245 if (ulseek(offset - 1, SEEK_SET) < 0)
250 return -1; 246 return -1;
251 if (uwrite(ideal_nop, 5) < 0) 247 if (uwrite(ideal_nop, 5) < 0)
252 return -1; 248 return -1;
253 return 0; 249 return 0;
254 } 250 }
255 251
256 static unsigned char ideal_nop4_arm_le[4] = { 252 static unsigned char ideal_nop4_arm_le[4] = { 0x00, 0x00, 0xa0, 0xe1 }; /* mov r0, r0 */
257 static unsigned char ideal_nop4_arm_be[4] = { 253 static unsigned char ideal_nop4_arm_be[4] = { 0xe1, 0xa0, 0x00, 0x00 }; /* mov r0, r0 */
258 static unsigned char *ideal_nop4_arm; 254 static unsigned char *ideal_nop4_arm;
259 255
260 static unsigned char bl_mcount_arm_le[4] = { 0 256 static unsigned char bl_mcount_arm_le[4] = { 0xfe, 0xff, 0xff, 0xeb }; /* bl */
261 static unsigned char bl_mcount_arm_be[4] = { 0 257 static unsigned char bl_mcount_arm_be[4] = { 0xeb, 0xff, 0xff, 0xfe }; /* bl */
262 static unsigned char *bl_mcount_arm; 258 static unsigned char *bl_mcount_arm;
263 259
264 static unsigned char push_arm_le[4] = { 0x04, 260 static unsigned char push_arm_le[4] = { 0x04, 0xe0, 0x2d, 0xe5 }; /* push {lr} */
265 static unsigned char push_arm_be[4] = { 0xe5, 261 static unsigned char push_arm_be[4] = { 0xe5, 0x2d, 0xe0, 0x04 }; /* push {lr} */
266 static unsigned char *push_arm; 262 static unsigned char *push_arm;
267 263
268 static unsigned char ideal_nop2_thumb_le[2] = 264 static unsigned char ideal_nop2_thumb_le[2] = { 0x00, 0xbf }; /* nop */
269 static unsigned char ideal_nop2_thumb_be[2] = 265 static unsigned char ideal_nop2_thumb_be[2] = { 0xbf, 0x00 }; /* nop */
270 static unsigned char *ideal_nop2_thumb; 266 static unsigned char *ideal_nop2_thumb;
271 267
272 static unsigned char push_bl_mcount_thumb_le[6 268 static unsigned char push_bl_mcount_thumb_le[6] = { 0x00, 0xb5, 0xff, 0xf7, 0xfe, 0xff }; /* push {lr}, bl */
273 static unsigned char push_bl_mcount_thumb_be[6 269 static unsigned char push_bl_mcount_thumb_be[6] = { 0xb5, 0x00, 0xf7, 0xff, 0xff, 0xfe }; /* push {lr}, bl */
274 static unsigned char *push_bl_mcount_thumb; 270 static unsigned char *push_bl_mcount_thumb;
275 271
276 static int make_nop_arm(void *map, size_t cons 272 static int make_nop_arm(void *map, size_t const offset)
277 { 273 {
278 char *ptr; 274 char *ptr;
279 int cnt = 1; 275 int cnt = 1;
280 int nop_size; 276 int nop_size;
281 size_t off = offset; 277 size_t off = offset;
282 278
283 ptr = map + offset; 279 ptr = map + offset;
284 if (memcmp(ptr, bl_mcount_arm, 4) == 0 280 if (memcmp(ptr, bl_mcount_arm, 4) == 0) {
285 if (memcmp(ptr - 4, push_arm, 281 if (memcmp(ptr - 4, push_arm, 4) == 0) {
286 off -= 4; 282 off -= 4;
287 cnt = 2; 283 cnt = 2;
288 } 284 }
289 ideal_nop = ideal_nop4_arm; 285 ideal_nop = ideal_nop4_arm;
290 nop_size = 4; 286 nop_size = 4;
291 } else if (memcmp(ptr - 2, push_bl_mco 287 } else if (memcmp(ptr - 2, push_bl_mcount_thumb, 6) == 0) {
292 cnt = 3; 288 cnt = 3;
293 nop_size = 2; 289 nop_size = 2;
294 off -= 2; 290 off -= 2;
295 ideal_nop = ideal_nop2_thumb; 291 ideal_nop = ideal_nop2_thumb;
296 } else 292 } else
297 return -1; 293 return -1;
298 294
299 /* Convert to nop */ 295 /* Convert to nop */
300 if (ulseek(off, SEEK_SET) < 0) 296 if (ulseek(off, SEEK_SET) < 0)
301 return -1; 297 return -1;
302 298
303 do { 299 do {
304 if (uwrite(ideal_nop, nop_size 300 if (uwrite(ideal_nop, nop_size) < 0)
305 return -1; 301 return -1;
306 } while (--cnt > 0); 302 } while (--cnt > 0);
307 303
308 return 0; 304 return 0;
309 } 305 }
310 306
311 static unsigned char ideal_nop4_arm64[4] = {0x 307 static unsigned char ideal_nop4_arm64[4] = {0x1f, 0x20, 0x03, 0xd5};
312 static int make_nop_arm64(void *map, size_t co 308 static int make_nop_arm64(void *map, size_t const offset)
313 { 309 {
314 uint32_t *ptr; 310 uint32_t *ptr;
315 311
316 ptr = map + offset; 312 ptr = map + offset;
317 /* bl <_mcount> is 0x94000000 before r 313 /* bl <_mcount> is 0x94000000 before relocation */
318 if (*ptr != 0x94000000) 314 if (*ptr != 0x94000000)
319 return -1; 315 return -1;
320 316
321 /* Convert to nop */ 317 /* Convert to nop */
322 if (ulseek(offset, SEEK_SET) < 0) 318 if (ulseek(offset, SEEK_SET) < 0)
323 return -1; 319 return -1;
324 if (uwrite(ideal_nop, 4) < 0) 320 if (uwrite(ideal_nop, 4) < 0)
325 return -1; 321 return -1;
326 return 0; 322 return 0;
327 } 323 }
328 324
329 static int write_file(const char *fname) 325 static int write_file(const char *fname)
330 { 326 {
331 char tmp_file[strlen(fname) + 4]; 327 char tmp_file[strlen(fname) + 4];
332 size_t n; 328 size_t n;
333 329
334 if (!file_updated) 330 if (!file_updated)
335 return 0; 331 return 0;
336 332
337 sprintf(tmp_file, "%s.rc", fname); 333 sprintf(tmp_file, "%s.rc", fname);
338 334
339 /* 335 /*
340 * After reading the entire file into 336 * After reading the entire file into memory, delete it
341 * and write it back, to prevent weird 337 * and write it back, to prevent weird side effects of modifying
342 * an object file in place. 338 * an object file in place.
343 */ 339 */
344 fd_map = open(tmp_file, O_WRONLY | O_T 340 fd_map = open(tmp_file, O_WRONLY | O_TRUNC | O_CREAT, sb.st_mode);
345 if (fd_map < 0) { 341 if (fd_map < 0) {
346 perror(fname); 342 perror(fname);
347 return -1; 343 return -1;
348 } 344 }
349 n = write(fd_map, file_map, sb.st_size 345 n = write(fd_map, file_map, sb.st_size);
350 if (n != sb.st_size) { 346 if (n != sb.st_size) {
351 perror("write"); 347 perror("write");
352 close(fd_map); 348 close(fd_map);
353 return -1; 349 return -1;
354 } 350 }
355 if (file_append_size) { 351 if (file_append_size) {
356 n = write(fd_map, file_append, 352 n = write(fd_map, file_append, file_append_size);
357 if (n != file_append_size) { 353 if (n != file_append_size) {
358 perror("write"); 354 perror("write");
359 close(fd_map); 355 close(fd_map);
360 return -1; 356 return -1;
361 } 357 }
362 } 358 }
363 close(fd_map); 359 close(fd_map);
364 if (rename(tmp_file, fname) < 0) { 360 if (rename(tmp_file, fname) < 0) {
365 perror(fname); 361 perror(fname);
366 return -1; 362 return -1;
367 } 363 }
368 return 0; 364 return 0;
369 } 365 }
370 366
371 /* w8rev, w8nat, ...: Handle endianness. */ 367 /* w8rev, w8nat, ...: Handle endianness. */
372 368
373 static uint64_t w8rev(uint64_t const x) 369 static uint64_t w8rev(uint64_t const x)
374 { 370 {
375 return ((0xff & (x >> (0 * 8))) << ( 371 return ((0xff & (x >> (0 * 8))) << (7 * 8))
376 | ((0xff & (x >> (1 * 8))) << ( 372 | ((0xff & (x >> (1 * 8))) << (6 * 8))
377 | ((0xff & (x >> (2 * 8))) << ( 373 | ((0xff & (x >> (2 * 8))) << (5 * 8))
378 | ((0xff & (x >> (3 * 8))) << ( 374 | ((0xff & (x >> (3 * 8))) << (4 * 8))
379 | ((0xff & (x >> (4 * 8))) << ( 375 | ((0xff & (x >> (4 * 8))) << (3 * 8))
380 | ((0xff & (x >> (5 * 8))) << ( 376 | ((0xff & (x >> (5 * 8))) << (2 * 8))
381 | ((0xff & (x >> (6 * 8))) << ( 377 | ((0xff & (x >> (6 * 8))) << (1 * 8))
382 | ((0xff & (x >> (7 * 8))) << ( 378 | ((0xff & (x >> (7 * 8))) << (0 * 8));
383 } 379 }
384 380
385 static uint32_t w4rev(uint32_t const x) 381 static uint32_t w4rev(uint32_t const x)
386 { 382 {
387 return ((0xff & (x >> (0 * 8))) << ( 383 return ((0xff & (x >> (0 * 8))) << (3 * 8))
388 | ((0xff & (x >> (1 * 8))) << ( 384 | ((0xff & (x >> (1 * 8))) << (2 * 8))
389 | ((0xff & (x >> (2 * 8))) << ( 385 | ((0xff & (x >> (2 * 8))) << (1 * 8))
390 | ((0xff & (x >> (3 * 8))) << ( 386 | ((0xff & (x >> (3 * 8))) << (0 * 8));
391 } 387 }
392 388
393 static uint32_t w2rev(uint16_t const x) 389 static uint32_t w2rev(uint16_t const x)
394 { 390 {
395 return ((0xff & (x >> (0 * 8))) << ( 391 return ((0xff & (x >> (0 * 8))) << (1 * 8))
396 | ((0xff & (x >> (1 * 8))) << ( 392 | ((0xff & (x >> (1 * 8))) << (0 * 8));
397 } 393 }
398 394
399 static uint64_t w8nat(uint64_t const x) 395 static uint64_t w8nat(uint64_t const x)
400 { 396 {
401 return x; 397 return x;
402 } 398 }
403 399
404 static uint32_t w4nat(uint32_t const x) 400 static uint32_t w4nat(uint32_t const x)
405 { 401 {
406 return x; 402 return x;
407 } 403 }
408 404
409 static uint32_t w2nat(uint16_t const x) 405 static uint32_t w2nat(uint16_t const x)
410 { 406 {
411 return x; 407 return x;
412 } 408 }
413 409
414 static uint64_t (*w8)(uint64_t); 410 static uint64_t (*w8)(uint64_t);
415 static uint32_t (*w)(uint32_t); 411 static uint32_t (*w)(uint32_t);
416 static uint32_t (*w2)(uint16_t); 412 static uint32_t (*w2)(uint16_t);
417 413
418 /* Names of the sections that could contain ca 414 /* Names of the sections that could contain calls to mcount. */
419 static int is_mcounted_section_name(char const 415 static int is_mcounted_section_name(char const *const txtname)
420 { 416 {
421 return strncmp(".text", txtna 417 return strncmp(".text", txtname, 5) == 0 ||
422 strcmp(".init.text", txtna 418 strcmp(".init.text", txtname) == 0 ||
423 strcmp(".ref.text", txtna 419 strcmp(".ref.text", txtname) == 0 ||
424 strcmp(".sched.text", txtna 420 strcmp(".sched.text", txtname) == 0 ||
425 strcmp(".spinlock.text", txtna 421 strcmp(".spinlock.text", txtname) == 0 ||
426 strcmp(".irqentry.text", txtna 422 strcmp(".irqentry.text", txtname) == 0 ||
427 strcmp(".softirqentry.text", t 423 strcmp(".softirqentry.text", txtname) == 0 ||
428 strcmp(".kprobes.text", txtnam 424 strcmp(".kprobes.text", txtname) == 0 ||
429 strcmp(".cpuidle.text", txtnam 425 strcmp(".cpuidle.text", txtname) == 0;
430 } 426 }
431 427
432 static char const *already_has_rel_mcount = "s 428 static char const *already_has_rel_mcount = "success"; /* our work here is done! */
433 429
434 /* 32 bit and 64 bit are very similar */ 430 /* 32 bit and 64 bit are very similar */
435 #include "recordmcount.h" 431 #include "recordmcount.h"
436 #define RECORD_MCOUNT_64 432 #define RECORD_MCOUNT_64
437 #include "recordmcount.h" 433 #include "recordmcount.h"
438 434
439 static int arm_is_fake_mcount(Elf32_Rel const 435 static int arm_is_fake_mcount(Elf32_Rel const *rp)
440 { 436 {
441 switch (ELF32_R_TYPE(w(rp->r_info))) { 437 switch (ELF32_R_TYPE(w(rp->r_info))) {
442 case R_ARM_THM_CALL: 438 case R_ARM_THM_CALL:
443 case R_ARM_CALL: 439 case R_ARM_CALL:
444 case R_ARM_PC24: 440 case R_ARM_PC24:
445 return 0; 441 return 0;
446 } 442 }
447 443
448 return 1; 444 return 1;
449 } 445 }
450 446
451 static int arm64_is_fake_mcount(Elf64_Rel cons 447 static int arm64_is_fake_mcount(Elf64_Rel const *rp)
452 { 448 {
453 return ELF64_R_TYPE(w8(rp->r_info)) != 449 return ELF64_R_TYPE(w8(rp->r_info)) != R_AARCH64_CALL26;
454 } 450 }
455 451
456 static int LARCH32_is_fake_mcount(Elf32_Rel co 452 static int LARCH32_is_fake_mcount(Elf32_Rel const *rp)
457 { 453 {
458 switch (ELF64_R_TYPE(w(rp->r_info))) { 454 switch (ELF64_R_TYPE(w(rp->r_info))) {
459 case R_LARCH_MARK_LA: 455 case R_LARCH_MARK_LA:
460 case R_LARCH_SOP_PUSH_PLT_PCREL: 456 case R_LARCH_SOP_PUSH_PLT_PCREL:
461 return 0; 457 return 0;
462 } 458 }
463 459
464 return 1; 460 return 1;
465 } 461 }
466 462
467 static int LARCH64_is_fake_mcount(Elf64_Rel co 463 static int LARCH64_is_fake_mcount(Elf64_Rel const *rp)
468 { 464 {
469 switch (ELF64_R_TYPE(w(rp->r_info))) { 465 switch (ELF64_R_TYPE(w(rp->r_info))) {
470 case R_LARCH_MARK_LA: 466 case R_LARCH_MARK_LA:
471 case R_LARCH_SOP_PUSH_PLT_PCREL: 467 case R_LARCH_SOP_PUSH_PLT_PCREL:
472 return 0; 468 return 0;
473 } 469 }
474 470
475 return 1; 471 return 1;
476 } 472 }
477 473
478 /* 64-bit EM_MIPS has weird ELF64_Rela.r_info. 474 /* 64-bit EM_MIPS has weird ELF64_Rela.r_info.
479 * http://techpubs.sgi.com/library/manuals/400 475 * http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf
480 * We interpret Table 29 Relocation Operation 476 * We interpret Table 29 Relocation Operation (Elf64_Rel, Elf64_Rela) [p.40]
481 * to imply the order of the members; the spec 477 * to imply the order of the members; the spec does not say so.
482 * typedef unsigned char Elf64_Byte; 478 * typedef unsigned char Elf64_Byte;
483 * fails on MIPS64 because their <elf.h> alrea 479 * fails on MIPS64 because their <elf.h> already has it!
484 */ 480 */
485 481
486 typedef uint8_t myElf64_Byte; /* Typ 482 typedef uint8_t myElf64_Byte; /* Type for a 8-bit quantity. */
487 483
488 union mips_r_info { 484 union mips_r_info {
489 Elf64_Xword r_info; 485 Elf64_Xword r_info;
490 struct { 486 struct {
491 Elf64_Word r_sym; 487 Elf64_Word r_sym; /* Symbol index. */
492 myElf64_Byte r_ssym; 488 myElf64_Byte r_ssym; /* Special symbol. */
493 myElf64_Byte r_type3; 489 myElf64_Byte r_type3; /* Third relocation. */
494 myElf64_Byte r_type2; 490 myElf64_Byte r_type2; /* Second relocation. */
495 myElf64_Byte r_type; 491 myElf64_Byte r_type; /* First relocation. */
496 } r_mips; 492 } r_mips;
497 }; 493 };
498 494
499 static uint64_t MIPS64_r_sym(Elf64_Rel const * 495 static uint64_t MIPS64_r_sym(Elf64_Rel const *rp)
500 { 496 {
501 return w(((union mips_r_info){ .r_info 497 return w(((union mips_r_info){ .r_info = rp->r_info }).r_mips.r_sym);
502 } 498 }
503 499
504 static void MIPS64_r_info(Elf64_Rel *const rp, 500 static void MIPS64_r_info(Elf64_Rel *const rp, unsigned sym, unsigned type)
505 { 501 {
506 rp->r_info = ((union mips_r_info){ 502 rp->r_info = ((union mips_r_info){
507 .r_mips = { .r_sym = w(sym), . 503 .r_mips = { .r_sym = w(sym), .r_type = type }
508 }).r_info; 504 }).r_info;
509 } 505 }
510 506
511 static int do_file(char const *const fname) 507 static int do_file(char const *const fname)
512 { 508 {
513 unsigned int reltype = 0; 509 unsigned int reltype = 0;
514 Elf32_Ehdr *ehdr; 510 Elf32_Ehdr *ehdr;
515 int rc = -1; 511 int rc = -1;
516 512
517 ehdr = mmap_file(fname); 513 ehdr = mmap_file(fname);
518 if (!ehdr) 514 if (!ehdr)
519 goto out; 515 goto out;
520 516
521 w = w4nat; 517 w = w4nat;
522 w2 = w2nat; 518 w2 = w2nat;
523 w8 = w8nat; 519 w8 = w8nat;
524 switch (ehdr->e_ident[EI_DATA]) { 520 switch (ehdr->e_ident[EI_DATA]) {
525 static unsigned int const endi 521 static unsigned int const endian = 1;
526 default: 522 default:
527 fprintf(stderr, "unrecognized 523 fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
528 ehdr->e_ident[EI_DATA] 524 ehdr->e_ident[EI_DATA], fname);
529 goto out; 525 goto out;
530 case ELFDATA2LSB: 526 case ELFDATA2LSB:
531 if (*(unsigned char const *)&e 527 if (*(unsigned char const *)&endian != 1) {
532 /* main() is big endia 528 /* main() is big endian, file.o is little endian. */
533 w = w4rev; 529 w = w4rev;
534 w2 = w2rev; 530 w2 = w2rev;
535 w8 = w8rev; 531 w8 = w8rev;
536 } 532 }
537 ideal_nop4_arm = ideal_nop4_ar 533 ideal_nop4_arm = ideal_nop4_arm_le;
538 bl_mcount_arm = bl_mcount_arm_ 534 bl_mcount_arm = bl_mcount_arm_le;
539 push_arm = push_arm_le; 535 push_arm = push_arm_le;
540 ideal_nop2_thumb = ideal_nop2_ 536 ideal_nop2_thumb = ideal_nop2_thumb_le;
541 push_bl_mcount_thumb = push_bl 537 push_bl_mcount_thumb = push_bl_mcount_thumb_le;
542 break; 538 break;
543 case ELFDATA2MSB: 539 case ELFDATA2MSB:
544 if (*(unsigned char const *)&e 540 if (*(unsigned char const *)&endian != 0) {
545 /* main() is little en 541 /* main() is little endian, file.o is big endian. */
546 w = w4rev; 542 w = w4rev;
547 w2 = w2rev; 543 w2 = w2rev;
548 w8 = w8rev; 544 w8 = w8rev;
549 } 545 }
550 ideal_nop4_arm = ideal_nop4_ar 546 ideal_nop4_arm = ideal_nop4_arm_be;
551 bl_mcount_arm = bl_mcount_arm_ 547 bl_mcount_arm = bl_mcount_arm_be;
552 push_arm = push_arm_be; 548 push_arm = push_arm_be;
553 ideal_nop2_thumb = ideal_nop2_ 549 ideal_nop2_thumb = ideal_nop2_thumb_be;
554 push_bl_mcount_thumb = push_bl 550 push_bl_mcount_thumb = push_bl_mcount_thumb_be;
555 break; 551 break;
556 } /* end switch */ 552 } /* end switch */
557 if (memcmp(ELFMAG, ehdr->e_ident, SELF 553 if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0 ||
558 w2(ehdr->e_type) != ET_REL || 554 w2(ehdr->e_type) != ET_REL ||
559 ehdr->e_ident[EI_VERSION] != EV_CU 555 ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
560 fprintf(stderr, "unrecognized 556 fprintf(stderr, "unrecognized ET_REL file %s\n", fname);
561 goto out; 557 goto out;
562 } 558 }
563 559
564 gpfx = '_'; 560 gpfx = '_';
565 switch (w2(ehdr->e_machine)) { 561 switch (w2(ehdr->e_machine)) {
566 default: 562 default:
567 fprintf(stderr, "unrecognized 563 fprintf(stderr, "unrecognized e_machine %u %s\n",
568 w2(ehdr->e_machine), f 564 w2(ehdr->e_machine), fname);
569 goto out; 565 goto out;
570 case EM_386: 566 case EM_386:
571 reltype = R_386_32; 567 reltype = R_386_32;
572 rel_type_nop = R_386_NONE; 568 rel_type_nop = R_386_NONE;
573 make_nop = make_nop_x86; 569 make_nop = make_nop_x86;
574 ideal_nop = ideal_nop5_x86_32; 570 ideal_nop = ideal_nop5_x86_32;
575 mcount_adjust_32 = -1; 571 mcount_adjust_32 = -1;
576 gpfx = 0; 572 gpfx = 0;
577 break; 573 break;
578 case EM_ARM: 574 case EM_ARM:
579 reltype = R_ARM_ABS32; 575 reltype = R_ARM_ABS32;
580 altmcount = "__gnu_mcount_nc"; 576 altmcount = "__gnu_mcount_nc";
581 make_nop = make_nop_arm; 577 make_nop = make_nop_arm;
582 rel_type_nop = R_ARM_NONE; 578 rel_type_nop = R_ARM_NONE;
583 is_fake_mcount32 = arm_is_fake 579 is_fake_mcount32 = arm_is_fake_mcount;
584 gpfx = 0; 580 gpfx = 0;
585 break; 581 break;
586 case EM_AARCH64: 582 case EM_AARCH64:
587 reltype = R_AARCH64_ABS64; 583 reltype = R_AARCH64_ABS64;
588 make_nop = make_nop_arm64; 584 make_nop = make_nop_arm64;
589 rel_type_nop = R_AARCH64_NONE; 585 rel_type_nop = R_AARCH64_NONE;
590 ideal_nop = ideal_nop4_arm64; 586 ideal_nop = ideal_nop4_arm64;
591 is_fake_mcount64 = arm64_is_fa 587 is_fake_mcount64 = arm64_is_fake_mcount;
592 break; 588 break;
>> 589 case EM_IA_64: reltype = R_IA64_IMM64; break;
593 case EM_MIPS: /* reltype: e_class 590 case EM_MIPS: /* reltype: e_class */ break;
594 case EM_LOONGARCH: /* reltype: e_ 591 case EM_LOONGARCH: /* reltype: e_class */ break;
595 case EM_PPC: reltype = R_PPC_ADDR32 592 case EM_PPC: reltype = R_PPC_ADDR32; break;
596 case EM_PPC64: reltype = R_PPC64_ADDR 593 case EM_PPC64: reltype = R_PPC64_ADDR64; break;
597 case EM_S390: /* reltype: e_class 594 case EM_S390: /* reltype: e_class */ break;
598 case EM_SH: reltype = R_SH_DIR32; 595 case EM_SH: reltype = R_SH_DIR32; gpfx = 0; break;
599 case EM_SPARCV9: reltype = R_SPARC_64; 596 case EM_SPARCV9: reltype = R_SPARC_64; break;
600 case EM_X86_64: 597 case EM_X86_64:
601 make_nop = make_nop_x86; 598 make_nop = make_nop_x86;
602 ideal_nop = ideal_nop5_x86_64; 599 ideal_nop = ideal_nop5_x86_64;
603 reltype = R_X86_64_64; 600 reltype = R_X86_64_64;
604 rel_type_nop = R_X86_64_NONE; 601 rel_type_nop = R_X86_64_NONE;
605 mcount_adjust_64 = -1; 602 mcount_adjust_64 = -1;
606 gpfx = 0; 603 gpfx = 0;
607 break; 604 break;
608 } /* end switch */ 605 } /* end switch */
609 606
610 switch (ehdr->e_ident[EI_CLASS]) { 607 switch (ehdr->e_ident[EI_CLASS]) {
611 default: 608 default:
612 fprintf(stderr, "unrecognized 609 fprintf(stderr, "unrecognized ELF class %d %s\n",
613 ehdr->e_ident[EI_CLASS 610 ehdr->e_ident[EI_CLASS], fname);
614 goto out; 611 goto out;
615 case ELFCLASS32: 612 case ELFCLASS32:
616 if (w2(ehdr->e_ehsize) != size 613 if (w2(ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
617 || w2(ehdr->e_shentsize) != s 614 || w2(ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
618 fprintf(stderr, 615 fprintf(stderr,
619 "unrecognized 616 "unrecognized ET_REL file: %s\n", fname);
620 goto out; 617 goto out;
621 } 618 }
622 if (w2(ehdr->e_machine) == EM_ 619 if (w2(ehdr->e_machine) == EM_MIPS) {
623 reltype = R_MIPS_32; 620 reltype = R_MIPS_32;
624 is_fake_mcount32 = MIP 621 is_fake_mcount32 = MIPS32_is_fake_mcount;
625 } 622 }
626 if (w2(ehdr->e_machine) == EM_ 623 if (w2(ehdr->e_machine) == EM_LOONGARCH) {
627 reltype = R_LARCH_32; 624 reltype = R_LARCH_32;
628 is_fake_mcount32 = LAR 625 is_fake_mcount32 = LARCH32_is_fake_mcount;
629 } 626 }
630 if (do32(ehdr, fname, reltype) 627 if (do32(ehdr, fname, reltype) < 0)
631 goto out; 628 goto out;
632 break; 629 break;
633 case ELFCLASS64: { 630 case ELFCLASS64: {
634 Elf64_Ehdr *const ghdr = (Elf6 631 Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
635 if (w2(ghdr->e_ehsize) != size 632 if (w2(ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
636 || w2(ghdr->e_shentsize) != s 633 || w2(ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
637 fprintf(stderr, 634 fprintf(stderr,
638 "unrecognized 635 "unrecognized ET_REL file: %s\n", fname);
639 goto out; 636 goto out;
640 } 637 }
641 if (w2(ghdr->e_machine) == EM_ 638 if (w2(ghdr->e_machine) == EM_S390) {
642 reltype = R_390_64; 639 reltype = R_390_64;
643 mcount_adjust_64 = -14 640 mcount_adjust_64 = -14;
644 } 641 }
645 if (w2(ghdr->e_machine) == EM_ 642 if (w2(ghdr->e_machine) == EM_MIPS) {
646 reltype = R_MIPS_64; 643 reltype = R_MIPS_64;
647 Elf64_r_sym = MIPS64_r 644 Elf64_r_sym = MIPS64_r_sym;
648 Elf64_r_info = MIPS64_ 645 Elf64_r_info = MIPS64_r_info;
649 is_fake_mcount64 = MIP 646 is_fake_mcount64 = MIPS64_is_fake_mcount;
650 } 647 }
651 if (w2(ghdr->e_machine) == EM_ 648 if (w2(ghdr->e_machine) == EM_LOONGARCH) {
652 reltype = R_LARCH_64; 649 reltype = R_LARCH_64;
653 is_fake_mcount64 = LAR 650 is_fake_mcount64 = LARCH64_is_fake_mcount;
654 } 651 }
655 if (do64(ghdr, fname, reltype) 652 if (do64(ghdr, fname, reltype) < 0)
656 goto out; 653 goto out;
657 break; 654 break;
658 } 655 }
659 } /* end switch */ 656 } /* end switch */
660 657
661 rc = write_file(fname); 658 rc = write_file(fname);
662 out: 659 out:
663 file_append_cleanup(); 660 file_append_cleanup();
664 mmap_cleanup(); 661 mmap_cleanup();
665 return rc; 662 return rc;
666 } 663 }
667 664
668 int main(int argc, char *argv[]) 665 int main(int argc, char *argv[])
669 { 666 {
670 const char ftrace[] = "/ftrace.o"; 667 const char ftrace[] = "/ftrace.o";
671 int ftrace_size = sizeof(ftrace) - 1; 668 int ftrace_size = sizeof(ftrace) - 1;
672 int n_error = 0; /* gcc-4.3.0 false p 669 int n_error = 0; /* gcc-4.3.0 false positive complaint */
673 int c; 670 int c;
674 int i; 671 int i;
675 672
676 while ((c = getopt(argc, argv, "w")) > 673 while ((c = getopt(argc, argv, "w")) >= 0) {
677 switch (c) { 674 switch (c) {
678 case 'w': 675 case 'w':
679 warn_on_notrace_sect = 676 warn_on_notrace_sect = 1;
680 break; 677 break;
681 default: 678 default:
682 fprintf(stderr, "usage 679 fprintf(stderr, "usage: recordmcount [-w] file.o...\n");
683 return 0; 680 return 0;
684 } 681 }
685 } 682 }
686 683
687 if ((argc - optind) < 1) { 684 if ((argc - optind) < 1) {
688 fprintf(stderr, "usage: record 685 fprintf(stderr, "usage: recordmcount [-w] file.o...\n");
689 return 0; 686 return 0;
690 } 687 }
691 688
692 /* Process each file in turn, allowing 689 /* Process each file in turn, allowing deep failure. */
693 for (i = optind; i < argc; i++) { 690 for (i = optind; i < argc; i++) {
694 char *file = argv[i]; 691 char *file = argv[i];
695 int len; 692 int len;
696 693
697 /* 694 /*
698 * The file kernel/trace/ftrac 695 * The file kernel/trace/ftrace.o references the mcount
699 * function but does not call 696 * function but does not call it. Since ftrace.o should
700 * not be traced anyway, we ju 697 * not be traced anyway, we just skip it.
701 */ 698 */
702 len = strlen(file); 699 len = strlen(file);
703 if (len >= ftrace_size && 700 if (len >= ftrace_size &&
704 strcmp(file + (len - ftrac 701 strcmp(file + (len - ftrace_size), ftrace) == 0)
705 continue; 702 continue;
706 703
707 if (do_file(file)) { 704 if (do_file(file)) {
708 fprintf(stderr, "%s: f 705 fprintf(stderr, "%s: failed\n", file);
709 ++n_error; 706 ++n_error;
710 } 707 }
711 } 708 }
712 return !!n_error; 709 return !!n_error;
713 } 710 }
714 711
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