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