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