1 // SPDX-License-Identifier: GPL-2.0-only <<
2 /* 1 /*
3 * recordmcount.c: construct a table of the lo 2 * recordmcount.c: construct a table of the locations of calls to 'mcount'
4 * so that ftrace can find them quickly. 3 * so that ftrace can find them quickly.
5 * Copyright 2009 John F. Reiser <jreiser@BitW 4 * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.
>> 5 * Licensed under the GNU General Public License, version 2 (GPLv2).
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 <setjmp.h>
30 #include <stdio.h> 31 #include <stdio.h>
31 #include <stdlib.h> 32 #include <stdlib.h>
32 #include <string.h> 33 #include <string.h>
33 #include <unistd.h> 34 #include <unistd.h>
34 35
35 #ifndef EM_AARCH64 36 #ifndef EM_AARCH64
36 #define EM_AARCH64 183 37 #define EM_AARCH64 183
37 #define R_AARCH64_NONE 0 38 #define R_AARCH64_NONE 0
38 #define R_AARCH64_ABS64 257 39 #define R_AARCH64_ABS64 257
39 #endif 40 #endif
40 41
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 <<
50 #define R_ARM_THM_CALL 10 <<
51 #define R_ARM_CALL 28 <<
52 <<
53 #define R_AARCH64_CALL26 283 <<
54 <<
55 static int fd_map; /* File descriptor for 42 static int fd_map; /* File descriptor for file being modified. */
56 static int mmap_failed; /* Boolean flag. */ 43 static int mmap_failed; /* Boolean flag. */
57 static char gpfx; /* prefix for global s 44 static char gpfx; /* prefix for global symbol name (sometimes '_') */
58 static struct stat sb; /* Remember .st_size, 45 static struct stat sb; /* Remember .st_size, etc. */
>> 46 static jmp_buf jmpenv; /* setjmp/longjmp per-file error escape */
59 static const char *altmcount; /* alternate m 47 static const char *altmcount; /* alternate mcount symbol name */
60 static int warn_on_notrace_sect; /* warn when 48 static int warn_on_notrace_sect; /* warn when section has mcount not being recorded */
61 static void *file_map; /* pointer of the mapp 49 static void *file_map; /* pointer of the mapped file */
62 static void *file_end; /* pointer to the end 50 static void *file_end; /* pointer to the end of the mapped file */
63 static int file_updated; /* flag to state file 51 static int file_updated; /* flag to state file was changed */
64 static void *file_ptr; /* current file pointe 52 static void *file_ptr; /* current file pointer location */
65 <<
66 static void *file_append; /* added to the end 53 static void *file_append; /* added to the end of the file */
67 static size_t file_append_size; /* how much is 54 static size_t file_append_size; /* how much is added to end of file */
68 55
>> 56 /* setjmp() return values */
>> 57 enum {
>> 58 SJ_SETJMP = 0, /* hardwired first return */
>> 59 SJ_FAIL,
>> 60 SJ_SUCCEED
>> 61 };
>> 62
69 /* Per-file resource cleanup when multiple fil 63 /* Per-file resource cleanup when multiple files. */
70 static void file_append_cleanup(void) !! 64 static void
>> 65 cleanup(void)
71 { 66 {
>> 67 if (!mmap_failed)
>> 68 munmap(file_map, sb.st_size);
>> 69 else
>> 70 free(file_map);
>> 71 file_map = NULL;
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 __attribute__((noreturn))
>> 79 fail_file(void)
79 { 80 {
80 if (!mmap_failed) !! 81 cleanup();
81 munmap(file_map, sb.st_size); !! 82 longjmp(jmpenv, SJ_FAIL);
82 else !! 83 }
83 free(file_map); !! 84
84 file_map = NULL; !! 85 static void __attribute__((noreturn))
>> 86 succeed_file(void)
>> 87 {
>> 88 cleanup();
>> 89 longjmp(jmpenv, SJ_SUCCEED);
85 } 90 }
86 91
87 /* ulseek, uwrite, ...: Check return value fo !! 92 /* ulseek, uread, ...: Check return value for errors. */
88 93
89 static off_t ulseek(off_t const offset, int co !! 94 static off_t
>> 95 ulseek(int const fd, off_t const offset, int const whence)
90 { 96 {
91 switch (whence) { 97 switch (whence) {
92 case SEEK_SET: 98 case SEEK_SET:
93 file_ptr = file_map + offset; 99 file_ptr = file_map + offset;
94 break; 100 break;
95 case SEEK_CUR: 101 case SEEK_CUR:
96 file_ptr += offset; 102 file_ptr += offset;
97 break; 103 break;
98 case SEEK_END: 104 case SEEK_END:
99 file_ptr = file_map + (sb.st_s 105 file_ptr = file_map + (sb.st_size - offset);
100 break; 106 break;
101 } 107 }
102 if (file_ptr < file_map) { 108 if (file_ptr < file_map) {
103 fprintf(stderr, "lseek: seek b 109 fprintf(stderr, "lseek: seek before file\n");
104 return -1; !! 110 fail_file();
105 } 111 }
106 return file_ptr - file_map; 112 return file_ptr - file_map;
107 } 113 }
108 114
109 static ssize_t uwrite(void const *const buf, s !! 115 static size_t
>> 116 uread(int const fd, void *const buf, size_t const count)
>> 117 {
>> 118 size_t const n = read(fd, buf, count);
>> 119 if (n != count) {
>> 120 perror("read");
>> 121 fail_file();
>> 122 }
>> 123 return n;
>> 124 }
>> 125
>> 126 static size_t
>> 127 uwrite(int const fd, void const *const buf, size_t const count)
110 { 128 {
111 size_t cnt = count; 129 size_t cnt = count;
112 off_t idx = 0; 130 off_t idx = 0;
113 void *p = NULL; <<
114 131
115 file_updated = 1; 132 file_updated = 1;
116 133
117 if (file_ptr + count >= file_end) { 134 if (file_ptr + count >= file_end) {
118 off_t aoffset = (file_ptr + co 135 off_t aoffset = (file_ptr + count) - file_end;
119 136
120 if (aoffset > file_append_size 137 if (aoffset > file_append_size) {
121 p = realloc(file_appen !! 138 file_append = realloc(file_append, aoffset);
122 if (!p) <<
123 free(file_appe <<
124 file_append = p; <<
125 file_append_size = aof 139 file_append_size = aoffset;
126 } 140 }
127 if (!file_append) { 141 if (!file_append) {
128 perror("write"); 142 perror("write");
129 file_append_cleanup(); !! 143 fail_file();
130 mmap_cleanup(); <<
131 return -1; <<
132 } 144 }
133 if (file_ptr < file_end) { 145 if (file_ptr < file_end) {
134 cnt = file_end - file_ 146 cnt = file_end - file_ptr;
135 } else { 147 } else {
136 cnt = 0; 148 cnt = 0;
137 idx = aoffset - count; 149 idx = aoffset - count;
138 } 150 }
139 } 151 }
140 152
141 if (cnt) 153 if (cnt)
142 memcpy(file_ptr, buf, cnt); 154 memcpy(file_ptr, buf, cnt);
143 155
144 if (cnt < count) 156 if (cnt < count)
145 memcpy(file_append + idx, buf 157 memcpy(file_append + idx, buf + cnt, count - cnt);
146 158
147 file_ptr += count; 159 file_ptr += count;
148 return count; 160 return count;
149 } 161 }
150 162
151 static void * umalloc(size_t size) !! 163 static void *
>> 164 umalloc(size_t size)
152 { 165 {
153 void *const addr = malloc(size); 166 void *const addr = malloc(size);
154 if (addr == 0) { 167 if (addr == 0) {
155 fprintf(stderr, "malloc failed 168 fprintf(stderr, "malloc failed: %zu bytes\n", size);
156 file_append_cleanup(); !! 169 fail_file();
157 mmap_cleanup(); <<
158 return NULL; <<
159 } 170 }
160 return addr; 171 return addr;
161 } 172 }
162 173
163 /* <<
164 * Get the whole file as a programming conveni <<
165 * malloc+lseek+read+free of many pieces. If <<
166 * avoids copying unused pieces; else just rea <<
167 * Open for both read and write; new info will <<
168 * Use MAP_PRIVATE so that a few changes to th <<
169 * do not propagate to the file until an expli <<
170 * This preserves most aspects of consistency <<
171 * for simultaneous readers of the file while <<
172 * However, multiple writers still are bad. W <<
173 * locking because it is expensive and the use <<
174 * makes multiple writers unlikely. <<
175 */ <<
176 static void *mmap_file(char const *fname) <<
177 { <<
178 /* Avoid problems if early cleanup() * <<
179 fd_map = -1; <<
180 mmap_failed = 1; <<
181 file_map = NULL; <<
182 file_ptr = NULL; <<
183 file_updated = 0; <<
184 sb.st_size = 0; <<
185 <<
186 fd_map = open(fname, O_RDONLY); <<
187 if (fd_map < 0) { <<
188 perror(fname); <<
189 return NULL; <<
190 } <<
191 if (fstat(fd_map, &sb) < 0) { <<
192 perror(fname); <<
193 goto out; <<
194 } <<
195 if (!S_ISREG(sb.st_mode)) { <<
196 fprintf(stderr, "not a regular <<
197 goto out; <<
198 } <<
199 file_map = mmap(0, sb.st_size, PROT_RE <<
200 fd_map, 0); <<
201 if (file_map == MAP_FAILED) { <<
202 mmap_failed = 1; <<
203 file_map = umalloc(sb.st_size) <<
204 if (!file_map) { <<
205 perror(fname); <<
206 goto out; <<
207 } <<
208 if (read(fd_map, file_map, sb. <<
209 perror(fname); <<
210 free(file_map); <<
211 file_map = NULL; <<
212 goto out; <<
213 } <<
214 } else <<
215 mmap_failed = 0; <<
216 out: <<
217 close(fd_map); <<
218 fd_map = -1; <<
219 <<
220 file_end = file_map + sb.st_size; <<
221 <<
222 return file_map; <<
223 } <<
224 <<
225 <<
226 static unsigned char ideal_nop5_x86_64[5] = { 174 static unsigned char ideal_nop5_x86_64[5] = { 0x0f, 0x1f, 0x44, 0x00, 0x00 };
227 static unsigned char ideal_nop5_x86_32[5] = { 175 static unsigned char ideal_nop5_x86_32[5] = { 0x3e, 0x8d, 0x74, 0x26, 0x00 };
228 static unsigned char *ideal_nop; 176 static unsigned char *ideal_nop;
229 177
230 static char rel_type_nop; 178 static char rel_type_nop;
231 179
232 static int (*make_nop)(void *map, size_t const 180 static int (*make_nop)(void *map, size_t const offset);
233 181
234 static int make_nop_x86(void *map, size_t cons 182 static int make_nop_x86(void *map, size_t const offset)
235 { 183 {
236 uint32_t *ptr; 184 uint32_t *ptr;
237 unsigned char *op; 185 unsigned char *op;
238 186
239 /* Confirm we have 0xe8 0x0 0x0 0x0 0x 187 /* Confirm we have 0xe8 0x0 0x0 0x0 0x0 */
240 ptr = map + offset; 188 ptr = map + offset;
241 if (*ptr != 0) 189 if (*ptr != 0)
242 return -1; 190 return -1;
243 191
244 op = map + offset - 1; 192 op = map + offset - 1;
245 if (*op != 0xe8) 193 if (*op != 0xe8)
246 return -1; 194 return -1;
247 195
248 /* convert to nop */ 196 /* convert to nop */
249 if (ulseek(offset - 1, SEEK_SET) < 0) !! 197 ulseek(fd_map, offset - 1, SEEK_SET);
250 return -1; !! 198 uwrite(fd_map, ideal_nop, 5);
251 if (uwrite(ideal_nop, 5) < 0) <<
252 return -1; <<
253 return 0; 199 return 0;
254 } 200 }
255 201
256 static unsigned char ideal_nop4_arm_le[4] = { 202 static unsigned char ideal_nop4_arm_le[4] = { 0x00, 0x00, 0xa0, 0xe1 }; /* mov r0, r0 */
257 static unsigned char ideal_nop4_arm_be[4] = { 203 static unsigned char ideal_nop4_arm_be[4] = { 0xe1, 0xa0, 0x00, 0x00 }; /* mov r0, r0 */
258 static unsigned char *ideal_nop4_arm; 204 static unsigned char *ideal_nop4_arm;
259 205
260 static unsigned char bl_mcount_arm_le[4] = { 0 206 static unsigned char bl_mcount_arm_le[4] = { 0xfe, 0xff, 0xff, 0xeb }; /* bl */
261 static unsigned char bl_mcount_arm_be[4] = { 0 207 static unsigned char bl_mcount_arm_be[4] = { 0xeb, 0xff, 0xff, 0xfe }; /* bl */
262 static unsigned char *bl_mcount_arm; 208 static unsigned char *bl_mcount_arm;
263 209
264 static unsigned char push_arm_le[4] = { 0x04, 210 static unsigned char push_arm_le[4] = { 0x04, 0xe0, 0x2d, 0xe5 }; /* push {lr} */
265 static unsigned char push_arm_be[4] = { 0xe5, 211 static unsigned char push_arm_be[4] = { 0xe5, 0x2d, 0xe0, 0x04 }; /* push {lr} */
266 static unsigned char *push_arm; 212 static unsigned char *push_arm;
267 213
268 static unsigned char ideal_nop2_thumb_le[2] = 214 static unsigned char ideal_nop2_thumb_le[2] = { 0x00, 0xbf }; /* nop */
269 static unsigned char ideal_nop2_thumb_be[2] = 215 static unsigned char ideal_nop2_thumb_be[2] = { 0xbf, 0x00 }; /* nop */
270 static unsigned char *ideal_nop2_thumb; 216 static unsigned char *ideal_nop2_thumb;
271 217
272 static unsigned char push_bl_mcount_thumb_le[6 218 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[6 219 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; 220 static unsigned char *push_bl_mcount_thumb;
275 221
276 static int make_nop_arm(void *map, size_t cons 222 static int make_nop_arm(void *map, size_t const offset)
277 { 223 {
278 char *ptr; 224 char *ptr;
279 int cnt = 1; 225 int cnt = 1;
280 int nop_size; 226 int nop_size;
281 size_t off = offset; 227 size_t off = offset;
282 228
283 ptr = map + offset; 229 ptr = map + offset;
284 if (memcmp(ptr, bl_mcount_arm, 4) == 0 230 if (memcmp(ptr, bl_mcount_arm, 4) == 0) {
285 if (memcmp(ptr - 4, push_arm, 231 if (memcmp(ptr - 4, push_arm, 4) == 0) {
286 off -= 4; 232 off -= 4;
287 cnt = 2; 233 cnt = 2;
288 } 234 }
289 ideal_nop = ideal_nop4_arm; 235 ideal_nop = ideal_nop4_arm;
290 nop_size = 4; 236 nop_size = 4;
291 } else if (memcmp(ptr - 2, push_bl_mco 237 } else if (memcmp(ptr - 2, push_bl_mcount_thumb, 6) == 0) {
292 cnt = 3; 238 cnt = 3;
293 nop_size = 2; 239 nop_size = 2;
294 off -= 2; 240 off -= 2;
295 ideal_nop = ideal_nop2_thumb; 241 ideal_nop = ideal_nop2_thumb;
296 } else 242 } else
297 return -1; 243 return -1;
298 244
299 /* Convert to nop */ 245 /* Convert to nop */
300 if (ulseek(off, SEEK_SET) < 0) !! 246 ulseek(fd_map, off, SEEK_SET);
301 return -1; <<
302 247
303 do { 248 do {
304 if (uwrite(ideal_nop, nop_size !! 249 uwrite(fd_map, ideal_nop, nop_size);
305 return -1; <<
306 } while (--cnt > 0); 250 } while (--cnt > 0);
307 251
308 return 0; 252 return 0;
309 } 253 }
310 254
311 static unsigned char ideal_nop4_arm64[4] = {0x 255 static unsigned char ideal_nop4_arm64[4] = {0x1f, 0x20, 0x03, 0xd5};
312 static int make_nop_arm64(void *map, size_t co 256 static int make_nop_arm64(void *map, size_t const offset)
313 { 257 {
314 uint32_t *ptr; 258 uint32_t *ptr;
315 259
316 ptr = map + offset; 260 ptr = map + offset;
317 /* bl <_mcount> is 0x94000000 before r 261 /* bl <_mcount> is 0x94000000 before relocation */
318 if (*ptr != 0x94000000) 262 if (*ptr != 0x94000000)
319 return -1; 263 return -1;
320 264
321 /* Convert to nop */ 265 /* Convert to nop */
322 if (ulseek(offset, SEEK_SET) < 0) !! 266 ulseek(fd_map, offset, SEEK_SET);
323 return -1; !! 267 uwrite(fd_map, ideal_nop, 4);
324 if (uwrite(ideal_nop, 4) < 0) <<
325 return -1; <<
326 return 0; 268 return 0;
327 } 269 }
328 270
329 static int write_file(const char *fname) !! 271 /*
>> 272 * Get the whole file as a programming convenience in order to avoid
>> 273 * malloc+lseek+read+free of many pieces. If successful, then mmap
>> 274 * avoids copying unused pieces; else just read the whole file.
>> 275 * Open for both read and write; new info will be appended to the file.
>> 276 * Use MAP_PRIVATE so that a few changes to the in-memory ElfXX_Ehdr
>> 277 * do not propagate to the file until an explicit overwrite at the last.
>> 278 * This preserves most aspects of consistency (all except .st_size)
>> 279 * for simultaneous readers of the file while we are appending to it.
>> 280 * However, multiple writers still are bad. We choose not to use
>> 281 * locking because it is expensive and the use case of kernel build
>> 282 * makes multiple writers unlikely.
>> 283 */
>> 284 static void *mmap_file(char const *fname)
>> 285 {
>> 286 fd_map = open(fname, O_RDONLY);
>> 287 if (fd_map < 0 || fstat(fd_map, &sb) < 0) {
>> 288 perror(fname);
>> 289 fail_file();
>> 290 }
>> 291 if (!S_ISREG(sb.st_mode)) {
>> 292 fprintf(stderr, "not a regular file: %s\n", fname);
>> 293 fail_file();
>> 294 }
>> 295 file_map = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
>> 296 fd_map, 0);
>> 297 mmap_failed = 0;
>> 298 if (file_map == MAP_FAILED) {
>> 299 mmap_failed = 1;
>> 300 file_map = umalloc(sb.st_size);
>> 301 uread(fd_map, file_map, sb.st_size);
>> 302 }
>> 303 close(fd_map);
>> 304
>> 305 file_end = file_map + sb.st_size;
>> 306
>> 307 return file_map;
>> 308 }
>> 309
>> 310 static void write_file(const char *fname)
330 { 311 {
331 char tmp_file[strlen(fname) + 4]; 312 char tmp_file[strlen(fname) + 4];
332 size_t n; 313 size_t n;
333 314
334 if (!file_updated) 315 if (!file_updated)
335 return 0; !! 316 return;
336 317
337 sprintf(tmp_file, "%s.rc", fname); 318 sprintf(tmp_file, "%s.rc", fname);
338 319
339 /* 320 /*
340 * After reading the entire file into 321 * After reading the entire file into memory, delete it
341 * and write it back, to prevent weird 322 * and write it back, to prevent weird side effects of modifying
342 * an object file in place. 323 * an object file in place.
343 */ 324 */
344 fd_map = open(tmp_file, O_WRONLY | O_T 325 fd_map = open(tmp_file, O_WRONLY | O_TRUNC | O_CREAT, sb.st_mode);
345 if (fd_map < 0) { 326 if (fd_map < 0) {
346 perror(fname); 327 perror(fname);
347 return -1; !! 328 fail_file();
348 } 329 }
349 n = write(fd_map, file_map, sb.st_size 330 n = write(fd_map, file_map, sb.st_size);
350 if (n != sb.st_size) { 331 if (n != sb.st_size) {
351 perror("write"); 332 perror("write");
352 close(fd_map); !! 333 fail_file();
353 return -1; <<
354 } 334 }
355 if (file_append_size) { 335 if (file_append_size) {
356 n = write(fd_map, file_append, 336 n = write(fd_map, file_append, file_append_size);
357 if (n != file_append_size) { 337 if (n != file_append_size) {
358 perror("write"); 338 perror("write");
359 close(fd_map); !! 339 fail_file();
360 return -1; <<
361 } 340 }
362 } 341 }
363 close(fd_map); 342 close(fd_map);
364 if (rename(tmp_file, fname) < 0) { 343 if (rename(tmp_file, fname) < 0) {
365 perror(fname); 344 perror(fname);
366 return -1; !! 345 fail_file();
367 } 346 }
368 return 0; <<
369 } 347 }
370 348
371 /* w8rev, w8nat, ...: Handle endianness. */ 349 /* w8rev, w8nat, ...: Handle endianness. */
372 350
373 static uint64_t w8rev(uint64_t const x) 351 static uint64_t w8rev(uint64_t const x)
374 { 352 {
375 return ((0xff & (x >> (0 * 8))) << ( 353 return ((0xff & (x >> (0 * 8))) << (7 * 8))
376 | ((0xff & (x >> (1 * 8))) << ( 354 | ((0xff & (x >> (1 * 8))) << (6 * 8))
377 | ((0xff & (x >> (2 * 8))) << ( 355 | ((0xff & (x >> (2 * 8))) << (5 * 8))
378 | ((0xff & (x >> (3 * 8))) << ( 356 | ((0xff & (x >> (3 * 8))) << (4 * 8))
379 | ((0xff & (x >> (4 * 8))) << ( 357 | ((0xff & (x >> (4 * 8))) << (3 * 8))
380 | ((0xff & (x >> (5 * 8))) << ( 358 | ((0xff & (x >> (5 * 8))) << (2 * 8))
381 | ((0xff & (x >> (6 * 8))) << ( 359 | ((0xff & (x >> (6 * 8))) << (1 * 8))
382 | ((0xff & (x >> (7 * 8))) << ( 360 | ((0xff & (x >> (7 * 8))) << (0 * 8));
383 } 361 }
384 362
385 static uint32_t w4rev(uint32_t const x) 363 static uint32_t w4rev(uint32_t const x)
386 { 364 {
387 return ((0xff & (x >> (0 * 8))) << ( 365 return ((0xff & (x >> (0 * 8))) << (3 * 8))
388 | ((0xff & (x >> (1 * 8))) << ( 366 | ((0xff & (x >> (1 * 8))) << (2 * 8))
389 | ((0xff & (x >> (2 * 8))) << ( 367 | ((0xff & (x >> (2 * 8))) << (1 * 8))
390 | ((0xff & (x >> (3 * 8))) << ( 368 | ((0xff & (x >> (3 * 8))) << (0 * 8));
391 } 369 }
392 370
393 static uint32_t w2rev(uint16_t const x) 371 static uint32_t w2rev(uint16_t const x)
394 { 372 {
395 return ((0xff & (x >> (0 * 8))) << ( 373 return ((0xff & (x >> (0 * 8))) << (1 * 8))
396 | ((0xff & (x >> (1 * 8))) << ( 374 | ((0xff & (x >> (1 * 8))) << (0 * 8));
397 } 375 }
398 376
399 static uint64_t w8nat(uint64_t const x) 377 static uint64_t w8nat(uint64_t const x)
400 { 378 {
401 return x; 379 return x;
402 } 380 }
403 381
404 static uint32_t w4nat(uint32_t const x) 382 static uint32_t w4nat(uint32_t const x)
405 { 383 {
406 return x; 384 return x;
407 } 385 }
408 386
409 static uint32_t w2nat(uint16_t const x) 387 static uint32_t w2nat(uint16_t const x)
410 { 388 {
411 return x; 389 return x;
412 } 390 }
413 391
414 static uint64_t (*w8)(uint64_t); 392 static uint64_t (*w8)(uint64_t);
415 static uint32_t (*w)(uint32_t); 393 static uint32_t (*w)(uint32_t);
416 static uint32_t (*w2)(uint16_t); 394 static uint32_t (*w2)(uint16_t);
417 395
418 /* Names of the sections that could contain ca 396 /* Names of the sections that could contain calls to mcount. */
419 static int is_mcounted_section_name(char const !! 397 static int
>> 398 is_mcounted_section_name(char const *const txtname)
420 { 399 {
421 return strncmp(".text", txtna !! 400 return strcmp(".text", txtname) == 0 ||
422 strcmp(".init.text", txtna 401 strcmp(".init.text", txtname) == 0 ||
423 strcmp(".ref.text", txtna 402 strcmp(".ref.text", txtname) == 0 ||
424 strcmp(".sched.text", txtna 403 strcmp(".sched.text", txtname) == 0 ||
425 strcmp(".spinlock.text", txtna 404 strcmp(".spinlock.text", txtname) == 0 ||
426 strcmp(".irqentry.text", txtna 405 strcmp(".irqentry.text", txtname) == 0 ||
427 strcmp(".softirqentry.text", t 406 strcmp(".softirqentry.text", txtname) == 0 ||
428 strcmp(".kprobes.text", txtnam 407 strcmp(".kprobes.text", txtname) == 0 ||
429 strcmp(".cpuidle.text", txtnam !! 408 strcmp(".cpuidle.text", txtname) == 0 ||
>> 409 strcmp(".text.unlikely", txtname) == 0;
430 } 410 }
431 411
432 static char const *already_has_rel_mcount = "s <<
433 <<
434 /* 32 bit and 64 bit are very similar */ 412 /* 32 bit and 64 bit are very similar */
435 #include "recordmcount.h" 413 #include "recordmcount.h"
436 #define RECORD_MCOUNT_64 414 #define RECORD_MCOUNT_64
437 #include "recordmcount.h" 415 #include "recordmcount.h"
438 416
439 static int arm_is_fake_mcount(Elf32_Rel const <<
440 { <<
441 switch (ELF32_R_TYPE(w(rp->r_info))) { <<
442 case R_ARM_THM_CALL: <<
443 case R_ARM_CALL: <<
444 case R_ARM_PC24: <<
445 return 0; <<
446 } <<
447 <<
448 return 1; <<
449 } <<
450 <<
451 static int arm64_is_fake_mcount(Elf64_Rel cons <<
452 { <<
453 return ELF64_R_TYPE(w8(rp->r_info)) != <<
454 } <<
455 <<
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. 417 /* 64-bit EM_MIPS has weird ELF64_Rela.r_info.
479 * http://techpubs.sgi.com/library/manuals/400 418 * http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf
480 * We interpret Table 29 Relocation Operation 419 * We interpret Table 29 Relocation Operation (Elf64_Rel, Elf64_Rela) [p.40]
481 * to imply the order of the members; the spec 420 * to imply the order of the members; the spec does not say so.
482 * typedef unsigned char Elf64_Byte; 421 * typedef unsigned char Elf64_Byte;
483 * fails on MIPS64 because their <elf.h> alrea 422 * fails on MIPS64 because their <elf.h> already has it!
484 */ 423 */
485 424
486 typedef uint8_t myElf64_Byte; /* Typ 425 typedef uint8_t myElf64_Byte; /* Type for a 8-bit quantity. */
487 426
488 union mips_r_info { 427 union mips_r_info {
489 Elf64_Xword r_info; 428 Elf64_Xword r_info;
490 struct { 429 struct {
491 Elf64_Word r_sym; 430 Elf64_Word r_sym; /* Symbol index. */
492 myElf64_Byte r_ssym; 431 myElf64_Byte r_ssym; /* Special symbol. */
493 myElf64_Byte r_type3; 432 myElf64_Byte r_type3; /* Third relocation. */
494 myElf64_Byte r_type2; 433 myElf64_Byte r_type2; /* Second relocation. */
495 myElf64_Byte r_type; 434 myElf64_Byte r_type; /* First relocation. */
496 } r_mips; 435 } r_mips;
497 }; 436 };
498 437
499 static uint64_t MIPS64_r_sym(Elf64_Rel const * 438 static uint64_t MIPS64_r_sym(Elf64_Rel const *rp)
500 { 439 {
501 return w(((union mips_r_info){ .r_info 440 return w(((union mips_r_info){ .r_info = rp->r_info }).r_mips.r_sym);
502 } 441 }
503 442
504 static void MIPS64_r_info(Elf64_Rel *const rp, 443 static void MIPS64_r_info(Elf64_Rel *const rp, unsigned sym, unsigned type)
505 { 444 {
506 rp->r_info = ((union mips_r_info){ 445 rp->r_info = ((union mips_r_info){
507 .r_mips = { .r_sym = w(sym), . 446 .r_mips = { .r_sym = w(sym), .r_type = type }
508 }).r_info; 447 }).r_info;
509 } 448 }
510 449
511 static int do_file(char const *const fname) !! 450 static void
>> 451 do_file(char const *const fname)
512 { 452 {
>> 453 Elf32_Ehdr *const ehdr = mmap_file(fname);
513 unsigned int reltype = 0; 454 unsigned int reltype = 0;
514 Elf32_Ehdr *ehdr; <<
515 int rc = -1; <<
516 <<
517 ehdr = mmap_file(fname); <<
518 if (!ehdr) <<
519 goto out; <<
520 455
521 w = w4nat; 456 w = w4nat;
522 w2 = w2nat; 457 w2 = w2nat;
523 w8 = w8nat; 458 w8 = w8nat;
524 switch (ehdr->e_ident[EI_DATA]) { 459 switch (ehdr->e_ident[EI_DATA]) {
525 static unsigned int const endi 460 static unsigned int const endian = 1;
526 default: 461 default:
527 fprintf(stderr, "unrecognized 462 fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
528 ehdr->e_ident[EI_DATA] 463 ehdr->e_ident[EI_DATA], fname);
529 goto out; !! 464 fail_file();
>> 465 break;
530 case ELFDATA2LSB: 466 case ELFDATA2LSB:
531 if (*(unsigned char const *)&e 467 if (*(unsigned char const *)&endian != 1) {
532 /* main() is big endia 468 /* main() is big endian, file.o is little endian. */
533 w = w4rev; 469 w = w4rev;
534 w2 = w2rev; 470 w2 = w2rev;
535 w8 = w8rev; 471 w8 = w8rev;
536 } 472 }
537 ideal_nop4_arm = ideal_nop4_ar 473 ideal_nop4_arm = ideal_nop4_arm_le;
538 bl_mcount_arm = bl_mcount_arm_ 474 bl_mcount_arm = bl_mcount_arm_le;
539 push_arm = push_arm_le; 475 push_arm = push_arm_le;
540 ideal_nop2_thumb = ideal_nop2_ 476 ideal_nop2_thumb = ideal_nop2_thumb_le;
541 push_bl_mcount_thumb = push_bl 477 push_bl_mcount_thumb = push_bl_mcount_thumb_le;
542 break; 478 break;
543 case ELFDATA2MSB: 479 case ELFDATA2MSB:
544 if (*(unsigned char const *)&e 480 if (*(unsigned char const *)&endian != 0) {
545 /* main() is little en 481 /* main() is little endian, file.o is big endian. */
546 w = w4rev; 482 w = w4rev;
547 w2 = w2rev; 483 w2 = w2rev;
548 w8 = w8rev; 484 w8 = w8rev;
549 } 485 }
550 ideal_nop4_arm = ideal_nop4_ar 486 ideal_nop4_arm = ideal_nop4_arm_be;
551 bl_mcount_arm = bl_mcount_arm_ 487 bl_mcount_arm = bl_mcount_arm_be;
552 push_arm = push_arm_be; 488 push_arm = push_arm_be;
553 ideal_nop2_thumb = ideal_nop2_ 489 ideal_nop2_thumb = ideal_nop2_thumb_be;
554 push_bl_mcount_thumb = push_bl 490 push_bl_mcount_thumb = push_bl_mcount_thumb_be;
555 break; 491 break;
556 } /* end switch */ 492 } /* end switch */
557 if (memcmp(ELFMAG, ehdr->e_ident, SELF !! 493 if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
558 w2(ehdr->e_type) != ET_REL || !! 494 || w2(ehdr->e_type) != ET_REL
559 ehdr->e_ident[EI_VERSION] != EV_CU !! 495 || ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
560 fprintf(stderr, "unrecognized 496 fprintf(stderr, "unrecognized ET_REL file %s\n", fname);
561 goto out; !! 497 fail_file();
562 } 498 }
563 499
564 gpfx = '_'; !! 500 gpfx = 0;
565 switch (w2(ehdr->e_machine)) { 501 switch (w2(ehdr->e_machine)) {
566 default: 502 default:
567 fprintf(stderr, "unrecognized 503 fprintf(stderr, "unrecognized e_machine %u %s\n",
568 w2(ehdr->e_machine), f 504 w2(ehdr->e_machine), fname);
569 goto out; !! 505 fail_file();
>> 506 break;
570 case EM_386: 507 case EM_386:
571 reltype = R_386_32; 508 reltype = R_386_32;
572 rel_type_nop = R_386_NONE; 509 rel_type_nop = R_386_NONE;
573 make_nop = make_nop_x86; 510 make_nop = make_nop_x86;
574 ideal_nop = ideal_nop5_x86_32; 511 ideal_nop = ideal_nop5_x86_32;
575 mcount_adjust_32 = -1; 512 mcount_adjust_32 = -1;
576 gpfx = 0; <<
577 break; <<
578 case EM_ARM: <<
579 reltype = R_ARM_ABS32; <<
580 altmcount = "__gnu_mcount_nc"; <<
581 make_nop = make_nop_arm; <<
582 rel_type_nop = R_ARM_NONE; <<
583 is_fake_mcount32 = arm_is_fake <<
584 gpfx = 0; <<
585 break; 513 break;
>> 514 case EM_ARM: reltype = R_ARM_ABS32;
>> 515 altmcount = "__gnu_mcount_nc";
>> 516 make_nop = make_nop_arm;
>> 517 rel_type_nop = R_ARM_NONE;
>> 518 break;
586 case EM_AARCH64: 519 case EM_AARCH64:
587 reltype = R_AARCH64_ABS64; !! 520 reltype = R_AARCH64_ABS64;
588 make_nop = make_nop_arm64; !! 521 make_nop = make_nop_arm64;
589 rel_type_nop = R_AARCH64_NONE; !! 522 rel_type_nop = R_AARCH64_NONE;
590 ideal_nop = ideal_nop4_arm64; !! 523 ideal_nop = ideal_nop4_arm64;
591 is_fake_mcount64 = arm64_is_fa !! 524 gpfx = '_';
592 break; !! 525 break;
593 case EM_MIPS: /* reltype: e_class !! 526 case EM_IA_64: reltype = R_IA64_IMM64; gpfx = '_'; break;
594 case EM_LOONGARCH: /* reltype: e_ !! 527 case EM_MIPS: /* reltype: e_class */ gpfx = '_'; break;
595 case EM_PPC: reltype = R_PPC_ADDR32 !! 528 case EM_PPC: reltype = R_PPC_ADDR32; gpfx = '_'; break;
596 case EM_PPC64: reltype = R_PPC64_ADDR !! 529 case EM_PPC64: reltype = R_PPC64_ADDR64; gpfx = '_'; break;
597 case EM_S390: /* reltype: e_class !! 530 case EM_S390: /* reltype: e_class */ gpfx = '_'; break;
598 case EM_SH: reltype = R_SH_DIR32; !! 531 case EM_SH: reltype = R_SH_DIR32; break;
599 case EM_SPARCV9: reltype = R_SPARC_64; !! 532 case EM_SPARCV9: reltype = R_SPARC_64; gpfx = '_'; break;
600 case EM_X86_64: 533 case EM_X86_64:
601 make_nop = make_nop_x86; 534 make_nop = make_nop_x86;
602 ideal_nop = ideal_nop5_x86_64; 535 ideal_nop = ideal_nop5_x86_64;
603 reltype = R_X86_64_64; 536 reltype = R_X86_64_64;
604 rel_type_nop = R_X86_64_NONE; 537 rel_type_nop = R_X86_64_NONE;
605 mcount_adjust_64 = -1; 538 mcount_adjust_64 = -1;
606 gpfx = 0; <<
607 break; 539 break;
608 } /* end switch */ 540 } /* end switch */
609 541
610 switch (ehdr->e_ident[EI_CLASS]) { 542 switch (ehdr->e_ident[EI_CLASS]) {
611 default: 543 default:
612 fprintf(stderr, "unrecognized 544 fprintf(stderr, "unrecognized ELF class %d %s\n",
613 ehdr->e_ident[EI_CLASS 545 ehdr->e_ident[EI_CLASS], fname);
614 goto out; !! 546 fail_file();
>> 547 break;
615 case ELFCLASS32: 548 case ELFCLASS32:
616 if (w2(ehdr->e_ehsize) != size 549 if (w2(ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
617 || w2(ehdr->e_shentsize) != s 550 || w2(ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
618 fprintf(stderr, 551 fprintf(stderr,
619 "unrecognized 552 "unrecognized ET_REL file: %s\n", fname);
620 goto out; !! 553 fail_file();
621 } 554 }
622 if (w2(ehdr->e_machine) == EM_ 555 if (w2(ehdr->e_machine) == EM_MIPS) {
623 reltype = R_MIPS_32; 556 reltype = R_MIPS_32;
624 is_fake_mcount32 = MIP 557 is_fake_mcount32 = MIPS32_is_fake_mcount;
625 } 558 }
626 if (w2(ehdr->e_machine) == EM_ !! 559 do32(ehdr, fname, reltype);
627 reltype = R_LARCH_32; <<
628 is_fake_mcount32 = LAR <<
629 } <<
630 if (do32(ehdr, fname, reltype) <<
631 goto out; <<
632 break; 560 break;
633 case ELFCLASS64: { 561 case ELFCLASS64: {
634 Elf64_Ehdr *const ghdr = (Elf6 562 Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
635 if (w2(ghdr->e_ehsize) != size 563 if (w2(ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
636 || w2(ghdr->e_shentsize) != s 564 || w2(ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
637 fprintf(stderr, 565 fprintf(stderr,
638 "unrecognized 566 "unrecognized ET_REL file: %s\n", fname);
639 goto out; !! 567 fail_file();
640 } 568 }
641 if (w2(ghdr->e_machine) == EM_ 569 if (w2(ghdr->e_machine) == EM_S390) {
642 reltype = R_390_64; 570 reltype = R_390_64;
643 mcount_adjust_64 = -14 571 mcount_adjust_64 = -14;
644 } 572 }
645 if (w2(ghdr->e_machine) == EM_ 573 if (w2(ghdr->e_machine) == EM_MIPS) {
646 reltype = R_MIPS_64; 574 reltype = R_MIPS_64;
647 Elf64_r_sym = MIPS64_r 575 Elf64_r_sym = MIPS64_r_sym;
648 Elf64_r_info = MIPS64_ 576 Elf64_r_info = MIPS64_r_info;
649 is_fake_mcount64 = MIP 577 is_fake_mcount64 = MIPS64_is_fake_mcount;
650 } 578 }
651 if (w2(ghdr->e_machine) == EM_ !! 579 do64(ghdr, fname, reltype);
652 reltype = R_LARCH_64; <<
653 is_fake_mcount64 = LAR <<
654 } <<
655 if (do64(ghdr, fname, reltype) <<
656 goto out; <<
657 break; 580 break;
658 } 581 }
659 } /* end switch */ 582 } /* end switch */
660 583
661 rc = write_file(fname); !! 584 write_file(fname);
662 out: !! 585 cleanup();
663 file_append_cleanup(); <<
664 mmap_cleanup(); <<
665 return rc; <<
666 } 586 }
667 587
668 int main(int argc, char *argv[]) !! 588 int
>> 589 main(int argc, char *argv[])
669 { 590 {
670 const char ftrace[] = "/ftrace.o"; 591 const char ftrace[] = "/ftrace.o";
671 int ftrace_size = sizeof(ftrace) - 1; 592 int ftrace_size = sizeof(ftrace) - 1;
672 int n_error = 0; /* gcc-4.3.0 false p 593 int n_error = 0; /* gcc-4.3.0 false positive complaint */
673 int c; 594 int c;
674 int i; 595 int i;
675 596
676 while ((c = getopt(argc, argv, "w")) > 597 while ((c = getopt(argc, argv, "w")) >= 0) {
677 switch (c) { 598 switch (c) {
678 case 'w': 599 case 'w':
679 warn_on_notrace_sect = 600 warn_on_notrace_sect = 1;
680 break; 601 break;
681 default: 602 default:
682 fprintf(stderr, "usage 603 fprintf(stderr, "usage: recordmcount [-w] file.o...\n");
683 return 0; 604 return 0;
684 } 605 }
685 } 606 }
686 607
687 if ((argc - optind) < 1) { 608 if ((argc - optind) < 1) {
688 fprintf(stderr, "usage: record 609 fprintf(stderr, "usage: recordmcount [-w] file.o...\n");
689 return 0; 610 return 0;
690 } 611 }
691 612
692 /* Process each file in turn, allowing 613 /* Process each file in turn, allowing deep failure. */
693 for (i = optind; i < argc; i++) { 614 for (i = optind; i < argc; i++) {
694 char *file = argv[i]; 615 char *file = argv[i];
>> 616 int const sjval = setjmp(jmpenv);
695 int len; 617 int len;
696 618
697 /* 619 /*
698 * The file kernel/trace/ftrac 620 * The file kernel/trace/ftrace.o references the mcount
699 * function but does not call 621 * function but does not call it. Since ftrace.o should
700 * not be traced anyway, we ju 622 * not be traced anyway, we just skip it.
701 */ 623 */
702 len = strlen(file); 624 len = strlen(file);
703 if (len >= ftrace_size && 625 if (len >= ftrace_size &&
704 strcmp(file + (len - ftrac 626 strcmp(file + (len - ftrace_size), ftrace) == 0)
705 continue; 627 continue;
706 628
707 if (do_file(file)) { !! 629 switch (sjval) {
>> 630 default:
>> 631 fprintf(stderr, "internal error: %s\n", file);
>> 632 exit(1);
>> 633 break;
>> 634 case SJ_SETJMP: /* normal sequence */
>> 635 /* Avoid problems if early cleanup() */
>> 636 fd_map = -1;
>> 637 mmap_failed = 1;
>> 638 file_map = NULL;
>> 639 file_ptr = NULL;
>> 640 file_updated = 0;
>> 641 do_file(file);
>> 642 break;
>> 643 case SJ_FAIL: /* error in do_file or below */
708 fprintf(stderr, "%s: f 644 fprintf(stderr, "%s: failed\n", file);
709 ++n_error; 645 ++n_error;
710 } !! 646 break;
>> 647 case SJ_SUCCEED: /* premature success */
>> 648 /* do nothing */
>> 649 break;
>> 650 } /* end switch */
711 } 651 }
712 return !!n_error; 652 return !!n_error;
713 } 653 }
714 654
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