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1 | /* |
2 | * linux/fs/binfmt_elf.c |
3 | * |
4 | * These are the functions used to load ELF format executables as used |
5 | * on SVr4 machines. Information on the format may be found in the book |
6 | * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support |
7 | * Tools". |
8 | * |
9 | * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com). |
10 | */ |
11 | |
12 | #include <linux/module.h> |
13 | #include <linux/kernel.h> |
14 | #include <linux/fs.h> |
15 | #include <linux/mm.h> |
16 | #include <linux/mman.h> |
17 | #include <linux/errno.h> |
18 | #include <linux/signal.h> |
19 | #include <linux/binfmts.h> |
20 | #include <linux/string.h> |
21 | #include <linux/file.h> |
22 | #include <linux/slab.h> |
23 | #include <linux/personality.h> |
24 | #include <linux/elfcore.h> |
25 | #include <linux/init.h> |
26 | #include <linux/highuid.h> |
27 | #include <linux/compiler.h> |
28 | #include <linux/highmem.h> |
29 | #include <linux/pagemap.h> |
30 | #include <linux/security.h> |
31 | #include <linux/random.h> |
32 | #include <linux/elf.h> |
33 | #include <linux/utsname.h> |
34 | #include <asm/uaccess.h> |
35 | #include <asm/param.h> |
36 | #include <asm/page.h> |
37 | |
38 | static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs); |
39 | static int load_elf_library(struct file *); |
40 | static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *, |
41 | int, int, unsigned long); |
42 | |
43 | /* |
44 | * If we don't support core dumping, then supply a NULL so we |
45 | * don't even try. |
46 | */ |
47 | #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) |
48 | static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit); |
49 | #else |
50 | #define elf_core_dump NULL |
51 | #endif |
52 | |
53 | #if ELF_EXEC_PAGESIZE > PAGE_SIZE |
54 | #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE |
55 | #else |
56 | #define ELF_MIN_ALIGN PAGE_SIZE |
57 | #endif |
58 | |
59 | #ifndef ELF_CORE_EFLAGS |
60 | #define ELF_CORE_EFLAGS 0 |
61 | #endif |
62 | |
63 | #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1)) |
64 | #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1)) |
65 | #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1)) |
66 | |
67 | static struct linux_binfmt elf_format = { |
68 | .module = THIS_MODULE, |
69 | .load_binary = load_elf_binary, |
70 | .load_shlib = load_elf_library, |
71 | .core_dump = elf_core_dump, |
72 | .min_coredump = ELF_EXEC_PAGESIZE, |
73 | .hasvdso = 1 |
74 | }; |
75 | |
76 | #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) |
77 | |
78 | static int set_brk(unsigned long start, unsigned long end) |
79 | { |
80 | start = ELF_PAGEALIGN(start); |
81 | end = ELF_PAGEALIGN(end); |
82 | if (end > start) { |
83 | unsigned long addr; |
84 | down_write(¤t->mm->mmap_sem); |
85 | addr = do_brk(start, end - start); |
86 | up_write(¤t->mm->mmap_sem); |
87 | if (BAD_ADDR(addr)) |
88 | return addr; |
89 | } |
90 | current->mm->start_brk = current->mm->brk = end; |
91 | return 0; |
92 | } |
93 | |
94 | /* We need to explicitly zero any fractional pages |
95 | after the data section (i.e. bss). This would |
96 | contain the junk from the file that should not |
97 | be in memory |
98 | */ |
99 | static int padzero(unsigned long elf_bss) |
100 | { |
101 | unsigned long nbyte; |
102 | |
103 | nbyte = ELF_PAGEOFFSET(elf_bss); |
104 | if (nbyte) { |
105 | nbyte = ELF_MIN_ALIGN - nbyte; |
106 | if (clear_user((void __user *) elf_bss, nbyte)) |
107 | return -EFAULT; |
108 | } |
109 | return 0; |
110 | } |
111 | |
112 | /* Let's use some macros to make this stack manipulation a little clearer */ |
113 | #ifdef CONFIG_STACK_GROWSUP |
114 | #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items)) |
115 | #define STACK_ROUND(sp, items) \ |
116 | ((15 + (unsigned long) ((sp) + (items))) &~ 15UL) |
117 | #define STACK_ALLOC(sp, len) ({ \ |
118 | elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \ |
119 | old_sp; }) |
120 | #else |
121 | #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items)) |
122 | #define STACK_ROUND(sp, items) \ |
123 | (((unsigned long) (sp - items)) &~ 15UL) |
124 | #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; }) |
125 | #endif |
126 | |
127 | #ifndef ELF_BASE_PLATFORM |
128 | /* |
129 | * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. |
130 | * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value |
131 | * will be copied to the user stack in the same manner as AT_PLATFORM. |
132 | */ |
133 | #define ELF_BASE_PLATFORM NULL |
134 | #endif |
135 | |
136 | static int |
137 | create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, |
138 | unsigned long load_addr, unsigned long interp_load_addr) |
139 | { |
140 | unsigned long p = bprm->p; |
141 | int argc = bprm->argc; |
142 | int envc = bprm->envc; |
143 | elf_addr_t __user *argv; |
144 | elf_addr_t __user *envp; |
145 | elf_addr_t __user *sp; |
146 | elf_addr_t __user *u_platform; |
147 | elf_addr_t __user *u_base_platform; |
148 | elf_addr_t __user *u_rand_bytes; |
149 | const char *k_platform = ELF_PLATFORM; |
150 | const char *k_base_platform = ELF_BASE_PLATFORM; |
151 | unsigned char k_rand_bytes[16]; |
152 | int items; |
153 | elf_addr_t *elf_info; |
154 | int ei_index = 0; |
155 | const struct cred *cred = current_cred(); |
156 | struct vm_area_struct *vma; |
157 | |
158 | /* |
159 | * In some cases (e.g. Hyper-Threading), we want to avoid L1 |
160 | * evictions by the processes running on the same package. One |
161 | * thing we can do is to shuffle the initial stack for them. |
162 | */ |
163 | |
164 | p = arch_align_stack(p); |
165 | |
166 | /* |
167 | * If this architecture has a platform capability string, copy it |
168 | * to userspace. In some cases (Sparc), this info is impossible |
169 | * for userspace to get any other way, in others (i386) it is |
170 | * merely difficult. |
171 | */ |
172 | u_platform = NULL; |
173 | if (k_platform) { |
174 | size_t len = strlen(k_platform) + 1; |
175 | |
176 | u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); |
177 | if (__copy_to_user(u_platform, k_platform, len)) |
178 | return -EFAULT; |
179 | } |
180 | |
181 | /* |
182 | * If this architecture has a "base" platform capability |
183 | * string, copy it to userspace. |
184 | */ |
185 | u_base_platform = NULL; |
186 | if (k_base_platform) { |
187 | size_t len = strlen(k_base_platform) + 1; |
188 | |
189 | u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); |
190 | if (__copy_to_user(u_base_platform, k_base_platform, len)) |
191 | return -EFAULT; |
192 | } |
193 | |
194 | /* |
195 | * Generate 16 random bytes for userspace PRNG seeding. |
196 | */ |
197 | get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes)); |
198 | u_rand_bytes = (elf_addr_t __user *) |
199 | STACK_ALLOC(p, sizeof(k_rand_bytes)); |
200 | if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes))) |
201 | return -EFAULT; |
202 | |
203 | /* Create the ELF interpreter info */ |
204 | elf_info = (elf_addr_t *)current->mm->saved_auxv; |
205 | /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */ |
206 | #define NEW_AUX_ENT(id, val) \ |
207 | do { \ |
208 | elf_info[ei_index++] = id; \ |
209 | elf_info[ei_index++] = val; \ |
210 | } while (0) |
211 | |
212 | #ifdef ARCH_DLINFO |
213 | /* |
214 | * ARCH_DLINFO must come first so PPC can do its special alignment of |
215 | * AUXV. |
216 | * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in |
217 | * ARCH_DLINFO changes |
218 | */ |
219 | ARCH_DLINFO; |
220 | #endif |
221 | NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); |
222 | NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE); |
223 | NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); |
224 | NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff); |
225 | NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); |
226 | NEW_AUX_ENT(AT_PHNUM, exec->e_phnum); |
227 | NEW_AUX_ENT(AT_BASE, interp_load_addr); |
228 | NEW_AUX_ENT(AT_FLAGS, 0); |
229 | NEW_AUX_ENT(AT_ENTRY, exec->e_entry); |
230 | NEW_AUX_ENT(AT_UID, cred->uid); |
231 | NEW_AUX_ENT(AT_EUID, cred->euid); |
232 | NEW_AUX_ENT(AT_GID, cred->gid); |
233 | NEW_AUX_ENT(AT_EGID, cred->egid); |
234 | NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); |
235 | NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes); |
236 | NEW_AUX_ENT(AT_EXECFN, bprm->exec); |
237 | if (k_platform) { |
238 | NEW_AUX_ENT(AT_PLATFORM, |
239 | (elf_addr_t)(unsigned long)u_platform); |
240 | } |
241 | if (k_base_platform) { |
242 | NEW_AUX_ENT(AT_BASE_PLATFORM, |
243 | (elf_addr_t)(unsigned long)u_base_platform); |
244 | } |
245 | if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { |
246 | NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); |
247 | } |
248 | #undef NEW_AUX_ENT |
249 | /* AT_NULL is zero; clear the rest too */ |
250 | memset(&elf_info[ei_index], 0, |
251 | sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]); |
252 | |
253 | /* And advance past the AT_NULL entry. */ |
254 | ei_index += 2; |
255 | |
256 | sp = STACK_ADD(p, ei_index); |
257 | |
258 | items = (argc + 1) + (envc + 1) + 1; |
259 | bprm->p = STACK_ROUND(sp, items); |
260 | |
261 | /* Point sp at the lowest address on the stack */ |
262 | #ifdef CONFIG_STACK_GROWSUP |
263 | sp = (elf_addr_t __user *)bprm->p - items - ei_index; |
264 | bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */ |
265 | #else |
266 | sp = (elf_addr_t __user *)bprm->p; |
267 | #endif |
268 | |
269 | |
270 | /* |
271 | * Grow the stack manually; some architectures have a limit on how |
272 | * far ahead a user-space access may be in order to grow the stack. |
273 | */ |
274 | vma = find_extend_vma(current->mm, bprm->p); |
275 | if (!vma) |
276 | return -EFAULT; |
277 | |
278 | /* Now, let's put argc (and argv, envp if appropriate) on the stack */ |
279 | if (__put_user(argc, sp++)) |
280 | return -EFAULT; |
281 | argv = sp; |
282 | envp = argv + argc + 1; |
283 | |
284 | /* Populate argv and envp */ |
285 | p = current->mm->arg_end = current->mm->arg_start; |
286 | while (argc-- > 0) { |
287 | size_t len; |
288 | if (__put_user((elf_addr_t)p, argv++)) |
289 | return -EFAULT; |
290 | len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); |
291 | if (!len || len > MAX_ARG_STRLEN) |
292 | return -EINVAL; |
293 | p += len; |
294 | } |
295 | if (__put_user(0, argv)) |
296 | return -EFAULT; |
297 | current->mm->arg_end = current->mm->env_start = p; |
298 | while (envc-- > 0) { |
299 | size_t len; |
300 | if (__put_user((elf_addr_t)p, envp++)) |
301 | return -EFAULT; |
302 | len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); |
303 | if (!len || len > MAX_ARG_STRLEN) |
304 | return -EINVAL; |
305 | p += len; |
306 | } |
307 | if (__put_user(0, envp)) |
308 | return -EFAULT; |
309 | current->mm->env_end = p; |
310 | |
311 | /* Put the elf_info on the stack in the right place. */ |
312 | sp = (elf_addr_t __user *)envp + 1; |
313 | if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t))) |
314 | return -EFAULT; |
315 | return 0; |
316 | } |
317 | |
318 | #ifndef elf_map |
319 | |
320 | static unsigned long elf_map(struct file *filep, unsigned long addr, |
321 | struct elf_phdr *eppnt, int prot, int type, |
322 | unsigned long total_size) |
323 | { |
324 | unsigned long map_addr; |
325 | unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr); |
326 | unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr); |
327 | addr = ELF_PAGESTART(addr); |
328 | size = ELF_PAGEALIGN(size); |
329 | |
330 | /* mmap() will return -EINVAL if given a zero size, but a |
331 | * segment with zero filesize is perfectly valid */ |
332 | if (!size) |
333 | return addr; |
334 | |
335 | down_write(¤t->mm->mmap_sem); |
336 | /* |
337 | * total_size is the size of the ELF (interpreter) image. |
338 | * The _first_ mmap needs to know the full size, otherwise |
339 | * randomization might put this image into an overlapping |
340 | * position with the ELF binary image. (since size < total_size) |
341 | * So we first map the 'big' image - and unmap the remainder at |
342 | * the end. (which unmap is needed for ELF images with holes.) |
343 | */ |
344 | if (total_size) { |
345 | total_size = ELF_PAGEALIGN(total_size); |
346 | map_addr = do_mmap(filep, addr, total_size, prot, type, off); |
347 | if (!BAD_ADDR(map_addr)) |
348 | do_munmap(current->mm, map_addr+size, total_size-size); |
349 | } else |
350 | map_addr = do_mmap(filep, addr, size, prot, type, off); |
351 | |
352 | up_write(¤t->mm->mmap_sem); |
353 | return(map_addr); |
354 | } |
355 | |
356 | #endif /* !elf_map */ |
357 | |
358 | static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr) |
359 | { |
360 | int i, first_idx = -1, last_idx = -1; |
361 | |
362 | for (i = 0; i < nr; i++) { |
363 | if (cmds[i].p_type == PT_LOAD) { |
364 | last_idx = i; |
365 | if (first_idx == -1) |
366 | first_idx = i; |
367 | } |
368 | } |
369 | if (first_idx == -1) |
370 | return 0; |
371 | |
372 | return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz - |
373 | ELF_PAGESTART(cmds[first_idx].p_vaddr); |
374 | } |
375 | |
376 | |
377 | /* This is much more generalized than the library routine read function, |
378 | so we keep this separate. Technically the library read function |
379 | is only provided so that we can read a.out libraries that have |
380 | an ELF header */ |
381 | |
382 | static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex, |
383 | struct file *interpreter, unsigned long *interp_map_addr, |
384 | unsigned long no_base) |
385 | { |
386 | struct elf_phdr *elf_phdata; |
387 | struct elf_phdr *eppnt; |
388 | unsigned long load_addr = 0; |
389 | int load_addr_set = 0; |
390 | unsigned long last_bss = 0, elf_bss = 0; |
391 | unsigned long error = ~0UL; |
392 | unsigned long total_size; |
393 | int retval, i, size; |
394 | |
395 | /* First of all, some simple consistency checks */ |
396 | if (interp_elf_ex->e_type != ET_EXEC && |
397 | interp_elf_ex->e_type != ET_DYN) |
398 | goto out; |
399 | if (!elf_check_arch(interp_elf_ex)) |
400 | goto out; |
401 | if (!interpreter->f_op || !interpreter->f_op->mmap) |
402 | goto out; |
403 | |
404 | /* |
405 | * If the size of this structure has changed, then punt, since |
406 | * we will be doing the wrong thing. |
407 | */ |
408 | if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr)) |
409 | goto out; |
410 | if (interp_elf_ex->e_phnum < 1 || |
411 | interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr)) |
412 | goto out; |
413 | |
414 | /* Now read in all of the header information */ |
415 | size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum; |
416 | if (size > ELF_MIN_ALIGN) |
417 | goto out; |
418 | elf_phdata = kmalloc(size, GFP_KERNEL); |
419 | if (!elf_phdata) |
420 | goto out; |
421 | |
422 | retval = kernel_read(interpreter, interp_elf_ex->e_phoff, |
423 | (char *)elf_phdata,size); |
424 | error = -EIO; |
425 | if (retval != size) { |
426 | if (retval < 0) |
427 | error = retval; |
428 | goto out_close; |
429 | } |
430 | |
431 | total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum); |
432 | if (!total_size) { |
433 | error = -EINVAL; |
434 | goto out_close; |
435 | } |
436 | |
437 | eppnt = elf_phdata; |
438 | for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) { |
439 | if (eppnt->p_type == PT_LOAD) { |
440 | int elf_type = MAP_PRIVATE | MAP_DENYWRITE; |
441 | int elf_prot = 0; |
442 | unsigned long vaddr = 0; |
443 | unsigned long k, map_addr; |
444 | |
445 | if (eppnt->p_flags & PF_R) |
446 | elf_prot = PROT_READ; |
447 | if (eppnt->p_flags & PF_W) |
448 | elf_prot |= PROT_WRITE; |
449 | if (eppnt->p_flags & PF_X) |
450 | elf_prot |= PROT_EXEC; |
451 | vaddr = eppnt->p_vaddr; |
452 | if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) |
453 | elf_type |= MAP_FIXED; |
454 | else if (no_base && interp_elf_ex->e_type == ET_DYN) |
455 | load_addr = -vaddr; |
456 | |
457 | map_addr = elf_map(interpreter, load_addr + vaddr, |
458 | eppnt, elf_prot, elf_type, total_size); |
459 | total_size = 0; |
460 | if (!*interp_map_addr) |
461 | *interp_map_addr = map_addr; |
462 | error = map_addr; |
463 | if (BAD_ADDR(map_addr)) |
464 | goto out_close; |
465 | |
466 | if (!load_addr_set && |
467 | interp_elf_ex->e_type == ET_DYN) { |
468 | load_addr = map_addr - ELF_PAGESTART(vaddr); |
469 | load_addr_set = 1; |
470 | } |
471 | |
472 | /* |
473 | * Check to see if the section's size will overflow the |
474 | * allowed task size. Note that p_filesz must always be |
475 | * <= p_memsize so it's only necessary to check p_memsz. |
476 | */ |
477 | k = load_addr + eppnt->p_vaddr; |
478 | if (BAD_ADDR(k) || |
479 | eppnt->p_filesz > eppnt->p_memsz || |
480 | eppnt->p_memsz > TASK_SIZE || |
481 | TASK_SIZE - eppnt->p_memsz < k) { |
482 | error = -ENOMEM; |
483 | goto out_close; |
484 | } |
485 | |
486 | /* |
487 | * Find the end of the file mapping for this phdr, and |
488 | * keep track of the largest address we see for this. |
489 | */ |
490 | k = load_addr + eppnt->p_vaddr + eppnt->p_filesz; |
491 | if (k > elf_bss) |
492 | elf_bss = k; |
493 | |
494 | /* |
495 | * Do the same thing for the memory mapping - between |
496 | * elf_bss and last_bss is the bss section. |
497 | */ |
498 | k = load_addr + eppnt->p_memsz + eppnt->p_vaddr; |
499 | if (k > last_bss) |
500 | last_bss = k; |
501 | } |
502 | } |
503 | |
504 | /* |
505 | * Now fill out the bss section. First pad the last page up |
506 | * to the page boundary, and then perform a mmap to make sure |
507 | * that there are zero-mapped pages up to and including the |
508 | * last bss page. |
509 | */ |
510 | if (padzero(elf_bss)) { |
511 | error = -EFAULT; |
512 | goto out_close; |
513 | } |
514 | |
515 | /* What we have mapped so far */ |
516 | elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1); |
517 | |
518 | /* Map the last of the bss segment */ |
519 | if (last_bss > elf_bss) { |
520 | down_write(¤t->mm->mmap_sem); |
521 | error = do_brk(elf_bss, last_bss - elf_bss); |
522 | up_write(¤t->mm->mmap_sem); |
523 | if (BAD_ADDR(error)) |
524 | goto out_close; |
525 | } |
526 | |
527 | error = load_addr; |
528 | |
529 | out_close: |
530 | kfree(elf_phdata); |
531 | out: |
532 | return error; |
533 | } |
534 | |
535 | /* |
536 | * These are the functions used to load ELF style executables and shared |
537 | * libraries. There is no binary dependent code anywhere else. |
538 | */ |
539 | |
540 | #define INTERPRETER_NONE 0 |
541 | #define INTERPRETER_ELF 2 |
542 | |
543 | #ifndef STACK_RND_MASK |
544 | #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ |
545 | #endif |
546 | |
547 | static unsigned long randomize_stack_top(unsigned long stack_top) |
548 | { |
549 | unsigned int random_variable = 0; |
550 | |
551 | if ((current->flags & PF_RANDOMIZE) && |
552 | !(current->personality & ADDR_NO_RANDOMIZE)) { |
553 | random_variable = get_random_int() & STACK_RND_MASK; |
554 | random_variable <<= PAGE_SHIFT; |
555 | } |
556 | #ifdef CONFIG_STACK_GROWSUP |
557 | return PAGE_ALIGN(stack_top) + random_variable; |
558 | #else |
559 | return PAGE_ALIGN(stack_top) - random_variable; |
560 | #endif |
561 | } |
562 | |
563 | static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) |
564 | { |
565 | struct file *interpreter = NULL; /* to shut gcc up */ |
566 | unsigned long load_addr = 0, load_bias = 0; |
567 | int load_addr_set = 0; |
568 | char * elf_interpreter = NULL; |
569 | unsigned long error; |
570 | struct elf_phdr *elf_ppnt, *elf_phdata; |
571 | unsigned long elf_bss, elf_brk; |
572 | int retval, i; |
573 | unsigned int size; |
574 | unsigned long elf_entry; |
575 | unsigned long interp_load_addr = 0; |
576 | unsigned long start_code, end_code, start_data, end_data; |
577 | unsigned long reloc_func_desc = 0; |
578 | int executable_stack = EXSTACK_DEFAULT; |
579 | unsigned long def_flags = 0; |
580 | struct { |
581 | struct elfhdr elf_ex; |
582 | struct elfhdr interp_elf_ex; |
583 | } *loc; |
584 | |
585 | loc = kmalloc(sizeof(*loc), GFP_KERNEL); |
586 | if (!loc) { |
587 | retval = -ENOMEM; |
588 | goto out_ret; |
589 | } |
590 | |
591 | /* Get the exec-header */ |
592 | loc->elf_ex = *((struct elfhdr *)bprm->buf); |
593 | |
594 | retval = -ENOEXEC; |
595 | /* First of all, some simple consistency checks */ |
596 | if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0) |
597 | goto out; |
598 | |
599 | if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN) |
600 | goto out; |
601 | if (!elf_check_arch(&loc->elf_ex)) |
602 | goto out; |
603 | if (!bprm->file->f_op||!bprm->file->f_op->mmap) |
604 | goto out; |
605 | |
606 | /* Now read in all of the header information */ |
607 | if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr)) |
608 | goto out; |
609 | if (loc->elf_ex.e_phnum < 1 || |
610 | loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr)) |
611 | goto out; |
612 | size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr); |
613 | retval = -ENOMEM; |
614 | elf_phdata = kmalloc(size, GFP_KERNEL); |
615 | if (!elf_phdata) |
616 | goto out; |
617 | |
618 | retval = kernel_read(bprm->file, loc->elf_ex.e_phoff, |
619 | (char *)elf_phdata, size); |
620 | if (retval != size) { |
621 | if (retval >= 0) |
622 | retval = -EIO; |
623 | goto out_free_ph; |
624 | } |
625 | |
626 | elf_ppnt = elf_phdata; |
627 | elf_bss = 0; |
628 | elf_brk = 0; |
629 | |
630 | start_code = ~0UL; |
631 | end_code = 0; |
632 | start_data = 0; |
633 | end_data = 0; |
634 | |
635 | for (i = 0; i < loc->elf_ex.e_phnum; i++) { |
636 | if (elf_ppnt->p_type == PT_INTERP) { |
637 | /* This is the program interpreter used for |
638 | * shared libraries - for now assume that this |
639 | * is an a.out format binary |
640 | */ |
641 | retval = -ENOEXEC; |
642 | if (elf_ppnt->p_filesz > PATH_MAX || |
643 | elf_ppnt->p_filesz < 2) |
644 | goto out_free_ph; |
645 | |
646 | retval = -ENOMEM; |
647 | elf_interpreter = kmalloc(elf_ppnt->p_filesz, |
648 | GFP_KERNEL); |
649 | if (!elf_interpreter) |
650 | goto out_free_ph; |
651 | |
652 | retval = kernel_read(bprm->file, elf_ppnt->p_offset, |
653 | elf_interpreter, |
654 | elf_ppnt->p_filesz); |
655 | if (retval != elf_ppnt->p_filesz) { |
656 | if (retval >= 0) |
657 | retval = -EIO; |
658 | goto out_free_interp; |
659 | } |
660 | /* make sure path is NULL terminated */ |
661 | retval = -ENOEXEC; |
662 | if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0') |
663 | goto out_free_interp; |
664 | |
665 | /* |
666 | * The early SET_PERSONALITY here is so that the lookup |
667 | * for the interpreter happens in the namespace of the |
668 | * to-be-execed image. SET_PERSONALITY can select an |
669 | * alternate root. |
670 | * |
671 | * However, SET_PERSONALITY is NOT allowed to switch |
672 | * this task into the new images's memory mapping |
673 | * policy - that is, TASK_SIZE must still evaluate to |
674 | * that which is appropriate to the execing application. |
675 | * This is because exit_mmap() needs to have TASK_SIZE |
676 | * evaluate to the size of the old image. |
677 | * |
678 | * So if (say) a 64-bit application is execing a 32-bit |
679 | * application it is the architecture's responsibility |
680 | * to defer changing the value of TASK_SIZE until the |
681 | * switch really is going to happen - do this in |
682 | * flush_thread(). - akpm |
683 | */ |
684 | SET_PERSONALITY(loc->elf_ex); |
685 | |
686 | interpreter = open_exec(elf_interpreter); |
687 | retval = PTR_ERR(interpreter); |
688 | if (IS_ERR(interpreter)) |
689 | goto out_free_interp; |
690 | |
691 | /* |
692 | * If the binary is not readable then enforce |
693 | * mm->dumpable = 0 regardless of the interpreter's |
694 | * permissions. |
695 | */ |
696 | if (file_permission(interpreter, MAY_READ) < 0) |
697 | bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; |
698 | |
699 | retval = kernel_read(interpreter, 0, bprm->buf, |
700 | BINPRM_BUF_SIZE); |
701 | if (retval != BINPRM_BUF_SIZE) { |
702 | if (retval >= 0) |
703 | retval = -EIO; |
704 | goto out_free_dentry; |
705 | } |
706 | |
707 | /* Get the exec headers */ |
708 | loc->interp_elf_ex = *((struct elfhdr *)bprm->buf); |
709 | break; |
710 | } |
711 | elf_ppnt++; |
712 | } |
713 | |
714 | elf_ppnt = elf_phdata; |
715 | for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) |
716 | if (elf_ppnt->p_type == PT_GNU_STACK) { |
717 | if (elf_ppnt->p_flags & PF_X) |
718 | executable_stack = EXSTACK_ENABLE_X; |
719 | else |
720 | executable_stack = EXSTACK_DISABLE_X; |
721 | break; |
722 | } |
723 | |
724 | /* Some simple consistency checks for the interpreter */ |
725 | if (elf_interpreter) { |
726 | retval = -ELIBBAD; |
727 | /* Not an ELF interpreter */ |
728 | if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0) |
729 | goto out_free_dentry; |
730 | /* Verify the interpreter has a valid arch */ |
731 | if (!elf_check_arch(&loc->interp_elf_ex)) |
732 | goto out_free_dentry; |
733 | } else { |
734 | /* Executables without an interpreter also need a personality */ |
735 | SET_PERSONALITY(loc->elf_ex); |
736 | } |
737 | |
738 | /* Flush all traces of the currently running executable */ |
739 | retval = flush_old_exec(bprm); |
740 | if (retval) |
741 | goto out_free_dentry; |
742 | |
743 | /* OK, This is the point of no return */ |
744 | current->flags &= ~PF_FORKNOEXEC; |
745 | current->mm->def_flags = def_flags; |
746 | |
747 | /* Do this immediately, since STACK_TOP as used in setup_arg_pages |
748 | may depend on the personality. */ |
749 | SET_PERSONALITY(loc->elf_ex); |
750 | if (elf_read_implies_exec(loc->elf_ex, executable_stack)) |
751 | current->personality |= READ_IMPLIES_EXEC; |
752 | |
753 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) |
754 | current->flags |= PF_RANDOMIZE; |
755 | arch_pick_mmap_layout(current->mm); |
756 | |
757 | /* Do this so that we can load the interpreter, if need be. We will |
758 | change some of these later */ |
759 | current->mm->free_area_cache = current->mm->mmap_base; |
760 | current->mm->cached_hole_size = 0; |
761 | retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP), |
762 | executable_stack); |
763 | if (retval < 0) { |
764 | send_sig(SIGKILL, current, 0); |
765 | goto out_free_dentry; |
766 | } |
767 | |
768 | current->mm->start_stack = bprm->p; |
769 | |
770 | /* Now we do a little grungy work by mmaping the ELF image into |
771 | the correct location in memory. */ |
772 | for(i = 0, elf_ppnt = elf_phdata; |
773 | i < loc->elf_ex.e_phnum; i++, elf_ppnt++) { |
774 | int elf_prot = 0, elf_flags; |
775 | unsigned long k, vaddr; |
776 | |
777 | if (elf_ppnt->p_type != PT_LOAD) |
778 | continue; |
779 | |
780 | if (unlikely (elf_brk > elf_bss)) { |
781 | unsigned long nbyte; |
782 | |
783 | /* There was a PT_LOAD segment with p_memsz > p_filesz |
784 | before this one. Map anonymous pages, if needed, |
785 | and clear the area. */ |
786 | retval = set_brk (elf_bss + load_bias, |
787 | elf_brk + load_bias); |
788 | if (retval) { |
789 | send_sig(SIGKILL, current, 0); |
790 | goto out_free_dentry; |
791 | } |
792 | nbyte = ELF_PAGEOFFSET(elf_bss); |
793 | if (nbyte) { |
794 | nbyte = ELF_MIN_ALIGN - nbyte; |
795 | if (nbyte > elf_brk - elf_bss) |
796 | nbyte = elf_brk - elf_bss; |
797 | if (clear_user((void __user *)elf_bss + |
798 | load_bias, nbyte)) { |
799 | /* |
800 | * This bss-zeroing can fail if the ELF |
801 | * file specifies odd protections. So |
802 | * we don't check the return value |
803 | */ |
804 | } |
805 | } |
806 | } |
807 | |
808 | if (elf_ppnt->p_flags & PF_R) |
809 | elf_prot |= PROT_READ; |
810 | if (elf_ppnt->p_flags & PF_W) |
811 | elf_prot |= PROT_WRITE; |
812 | if (elf_ppnt->p_flags & PF_X) |
813 | elf_prot |= PROT_EXEC; |
814 | |
815 | elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE; |
816 | |
817 | vaddr = elf_ppnt->p_vaddr; |
818 | if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) { |
819 | elf_flags |= MAP_FIXED; |
820 | } else if (loc->elf_ex.e_type == ET_DYN) { |
821 | /* Try and get dynamic programs out of the way of the |
822 | * default mmap base, as well as whatever program they |
823 | * might try to exec. This is because the brk will |
824 | * follow the loader, and is not movable. */ |
825 | #ifdef CONFIG_X86 |
826 | load_bias = 0; |
827 | #else |
828 | load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); |
829 | #endif |
830 | } |
831 | |
832 | error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, |
833 | elf_prot, elf_flags, 0); |
834 | if (BAD_ADDR(error)) { |
835 | send_sig(SIGKILL, current, 0); |
836 | retval = IS_ERR((void *)error) ? |
837 | PTR_ERR((void*)error) : -EINVAL; |
838 | goto out_free_dentry; |
839 | } |
840 | |
841 | if (!load_addr_set) { |
842 | load_addr_set = 1; |
843 | load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset); |
844 | if (loc->elf_ex.e_type == ET_DYN) { |
845 | load_bias += error - |
846 | ELF_PAGESTART(load_bias + vaddr); |
847 | load_addr += load_bias; |
848 | reloc_func_desc = load_bias; |
849 | } |
850 | } |
851 | k = elf_ppnt->p_vaddr; |
852 | if (k < start_code) |
853 | start_code = k; |
854 | if (start_data < k) |
855 | start_data = k; |
856 | |
857 | /* |
858 | * Check to see if the section's size will overflow the |
859 | * allowed task size. Note that p_filesz must always be |
860 | * <= p_memsz so it is only necessary to check p_memsz. |
861 | */ |
862 | if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz || |
863 | elf_ppnt->p_memsz > TASK_SIZE || |
864 | TASK_SIZE - elf_ppnt->p_memsz < k) { |
865 | /* set_brk can never work. Avoid overflows. */ |
866 | send_sig(SIGKILL, current, 0); |
867 | retval = -EINVAL; |
868 | goto out_free_dentry; |
869 | } |
870 | |
871 | k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz; |
872 | |
873 | if (k > elf_bss) |
874 | elf_bss = k; |
875 | if ((elf_ppnt->p_flags & PF_X) && end_code < k) |
876 | end_code = k; |
877 | if (end_data < k) |
878 | end_data = k; |
879 | k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz; |
880 | if (k > elf_brk) |
881 | elf_brk = k; |
882 | } |
883 | |
884 | loc->elf_ex.e_entry += load_bias; |
885 | elf_bss += load_bias; |
886 | elf_brk += load_bias; |
887 | start_code += load_bias; |
888 | end_code += load_bias; |
889 | start_data += load_bias; |
890 | end_data += load_bias; |
891 | |
892 | /* Calling set_brk effectively mmaps the pages that we need |
893 | * for the bss and break sections. We must do this before |
894 | * mapping in the interpreter, to make sure it doesn't wind |
895 | * up getting placed where the bss needs to go. |
896 | */ |
897 | retval = set_brk(elf_bss, elf_brk); |
898 | if (retval) { |
899 | send_sig(SIGKILL, current, 0); |
900 | goto out_free_dentry; |
901 | } |
902 | if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) { |
903 | send_sig(SIGSEGV, current, 0); |
904 | retval = -EFAULT; /* Nobody gets to see this, but.. */ |
905 | goto out_free_dentry; |
906 | } |
907 | |
908 | if (elf_interpreter) { |
909 | unsigned long uninitialized_var(interp_map_addr); |
910 | |
911 | elf_entry = load_elf_interp(&loc->interp_elf_ex, |
912 | interpreter, |
913 | &interp_map_addr, |
914 | load_bias); |
915 | if (!IS_ERR((void *)elf_entry)) { |
916 | /* |
917 | * load_elf_interp() returns relocation |
918 | * adjustment |
919 | */ |
920 | interp_load_addr = elf_entry; |
921 | elf_entry += loc->interp_elf_ex.e_entry; |
922 | } |
923 | if (BAD_ADDR(elf_entry)) { |
924 | force_sig(SIGSEGV, current); |
925 | retval = IS_ERR((void *)elf_entry) ? |
926 | (int)elf_entry : -EINVAL; |
927 | goto out_free_dentry; |
928 | } |
929 | reloc_func_desc = interp_load_addr; |
930 | |
931 | allow_write_access(interpreter); |
932 | fput(interpreter); |
933 | kfree(elf_interpreter); |
934 | } else { |
935 | elf_entry = loc->elf_ex.e_entry; |
936 | if (BAD_ADDR(elf_entry)) { |
937 | force_sig(SIGSEGV, current); |
938 | retval = -EINVAL; |
939 | goto out_free_dentry; |
940 | } |
941 | } |
942 | |
943 | kfree(elf_phdata); |
944 | |
945 | set_binfmt(&elf_format); |
946 | |
947 | #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES |
948 | retval = arch_setup_additional_pages(bprm, !!elf_interpreter); |
949 | if (retval < 0) { |
950 | send_sig(SIGKILL, current, 0); |
951 | goto out; |
952 | } |
953 | #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ |
954 | |
955 | install_exec_creds(bprm); |
956 | current->flags &= ~PF_FORKNOEXEC; |
957 | retval = create_elf_tables(bprm, &loc->elf_ex, |
958 | load_addr, interp_load_addr); |
959 | if (retval < 0) { |
960 | send_sig(SIGKILL, current, 0); |
961 | goto out; |
962 | } |
963 | /* N.B. passed_fileno might not be initialized? */ |
964 | current->mm->end_code = end_code; |
965 | current->mm->start_code = start_code; |
966 | current->mm->start_data = start_data; |
967 | current->mm->end_data = end_data; |
968 | current->mm->start_stack = bprm->p; |
969 | |
970 | #ifdef arch_randomize_brk |
971 | if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) |
972 | current->mm->brk = current->mm->start_brk = |
973 | arch_randomize_brk(current->mm); |
974 | #endif |
975 | |
976 | if (current->personality & MMAP_PAGE_ZERO) { |
977 | /* Why this, you ask??? Well SVr4 maps page 0 as read-only, |
978 | and some applications "depend" upon this behavior. |
979 | Since we do not have the power to recompile these, we |
980 | emulate the SVr4 behavior. Sigh. */ |
981 | down_write(¤t->mm->mmap_sem); |
982 | error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC, |
983 | MAP_FIXED | MAP_PRIVATE, 0); |
984 | up_write(¤t->mm->mmap_sem); |
985 | } |
986 | |
987 | #ifdef ELF_PLAT_INIT |
988 | /* |
989 | * The ABI may specify that certain registers be set up in special |
990 | * ways (on i386 %edx is the address of a DT_FINI function, for |
991 | * example. In addition, it may also specify (eg, PowerPC64 ELF) |
992 | * that the e_entry field is the address of the function descriptor |
993 | * for the startup routine, rather than the address of the startup |
994 | * routine itself. This macro performs whatever initialization to |
995 | * the regs structure is required as well as any relocations to the |
996 | * function descriptor entries when executing dynamically links apps. |
997 | */ |
998 | ELF_PLAT_INIT(regs, reloc_func_desc); |
999 | #endif |
1000 | |
1001 | start_thread(regs, elf_entry, bprm->p); |
1002 | retval = 0; |
1003 | out: |
1004 | kfree(loc); |
1005 | out_ret: |
1006 | return retval; |
1007 | |
1008 | /* error cleanup */ |
1009 | out_free_dentry: |
1010 | allow_write_access(interpreter); |
1011 | if (interpreter) |
1012 | fput(interpreter); |
1013 | out_free_interp: |
1014 | kfree(elf_interpreter); |
1015 | out_free_ph: |
1016 | kfree(elf_phdata); |
1017 | goto out; |
1018 | } |
1019 | |
1020 | /* This is really simpleminded and specialized - we are loading an |
1021 | a.out library that is given an ELF header. */ |
1022 | static int load_elf_library(struct file *file) |
1023 | { |
1024 | struct elf_phdr *elf_phdata; |
1025 | struct elf_phdr *eppnt; |
1026 | unsigned long elf_bss, bss, len; |
1027 | int retval, error, i, j; |
1028 | struct elfhdr elf_ex; |
1029 | |
1030 | error = -ENOEXEC; |
1031 | retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex)); |
1032 | if (retval != sizeof(elf_ex)) |
1033 | goto out; |
1034 | |
1035 | if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) |
1036 | goto out; |
1037 | |
1038 | /* First of all, some simple consistency checks */ |
1039 | if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 || |
1040 | !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap) |
1041 | goto out; |
1042 | |
1043 | /* Now read in all of the header information */ |
1044 | |
1045 | j = sizeof(struct elf_phdr) * elf_ex.e_phnum; |
1046 | /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */ |
1047 | |
1048 | error = -ENOMEM; |
1049 | elf_phdata = kmalloc(j, GFP_KERNEL); |
1050 | if (!elf_phdata) |
1051 | goto out; |
1052 | |
1053 | eppnt = elf_phdata; |
1054 | error = -ENOEXEC; |
1055 | retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j); |
1056 | if (retval != j) |
1057 | goto out_free_ph; |
1058 | |
1059 | for (j = 0, i = 0; i<elf_ex.e_phnum; i++) |
1060 | if ((eppnt + i)->p_type == PT_LOAD) |
1061 | j++; |
1062 | if (j != 1) |
1063 | goto out_free_ph; |
1064 | |
1065 | while (eppnt->p_type != PT_LOAD) |
1066 | eppnt++; |
1067 | |
1068 | /* Now use mmap to map the library into memory. */ |
1069 | down_write(¤t->mm->mmap_sem); |
1070 | error = do_mmap(file, |
1071 | ELF_PAGESTART(eppnt->p_vaddr), |
1072 | (eppnt->p_filesz + |
1073 | ELF_PAGEOFFSET(eppnt->p_vaddr)), |
1074 | PROT_READ | PROT_WRITE | PROT_EXEC, |
1075 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, |
1076 | (eppnt->p_offset - |
1077 | ELF_PAGEOFFSET(eppnt->p_vaddr))); |
1078 | up_write(¤t->mm->mmap_sem); |
1079 | if (error != ELF_PAGESTART(eppnt->p_vaddr)) |
1080 | goto out_free_ph; |
1081 | |
1082 | elf_bss = eppnt->p_vaddr + eppnt->p_filesz; |
1083 | if (padzero(elf_bss)) { |
1084 | error = -EFAULT; |
1085 | goto out_free_ph; |
1086 | } |
1087 | |
1088 | len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + |
1089 | ELF_MIN_ALIGN - 1); |
1090 | bss = eppnt->p_memsz + eppnt->p_vaddr; |
1091 | if (bss > len) { |
1092 | down_write(¤t->mm->mmap_sem); |
1093 | do_brk(len, bss - len); |
1094 | up_write(¤t->mm->mmap_sem); |
1095 | } |
1096 | error = 0; |
1097 | |
1098 | out_free_ph: |
1099 | kfree(elf_phdata); |
1100 | out: |
1101 | return error; |
1102 | } |
1103 | |
1104 | /* |
1105 | * Note that some platforms still use traditional core dumps and not |
1106 | * the ELF core dump. Each platform can select it as appropriate. |
1107 | */ |
1108 | #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) |
1109 | |
1110 | /* |
1111 | * ELF core dumper |
1112 | * |
1113 | * Modelled on fs/exec.c:aout_core_dump() |
1114 | * Jeremy Fitzhardinge <jeremy@sw.oz.au> |
1115 | */ |
1116 | /* |
1117 | * These are the only things you should do on a core-file: use only these |
1118 | * functions to write out all the necessary info. |
1119 | */ |
1120 | static int dump_write(struct file *file, const void *addr, int nr) |
1121 | { |
1122 | return file->f_op->write(file, addr, nr, &file->f_pos) == nr; |
1123 | } |
1124 | |
1125 | static int dump_seek(struct file *file, loff_t off) |
1126 | { |
1127 | if (file->f_op->llseek && file->f_op->llseek != no_llseek) { |
1128 | if (file->f_op->llseek(file, off, SEEK_CUR) < 0) |
1129 | return 0; |
1130 | } else { |
1131 | char *buf = (char *)get_zeroed_page(GFP_KERNEL); |
1132 | if (!buf) |
1133 | return 0; |
1134 | while (off > 0) { |
1135 | unsigned long n = off; |
1136 | if (n > PAGE_SIZE) |
1137 | n = PAGE_SIZE; |
1138 | if (!dump_write(file, buf, n)) |
1139 | return 0; |
1140 | off -= n; |
1141 | } |
1142 | free_page((unsigned long)buf); |
1143 | } |
1144 | return 1; |
1145 | } |
1146 | |
1147 | /* |
1148 | * Decide what to dump of a segment, part, all or none. |
1149 | */ |
1150 | static unsigned long vma_dump_size(struct vm_area_struct *vma, |
1151 | unsigned long mm_flags) |
1152 | { |
1153 | #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type)) |
1154 | |
1155 | /* The vma can be set up to tell us the answer directly. */ |
1156 | if (vma->vm_flags & VM_ALWAYSDUMP) |
1157 | goto whole; |
1158 | |
1159 | /* Hugetlb memory check */ |
1160 | if (vma->vm_flags & VM_HUGETLB) { |
1161 | if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED)) |
1162 | goto whole; |
1163 | if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE)) |
1164 | goto whole; |
1165 | } |
1166 | |
1167 | /* Do not dump I/O mapped devices or special mappings */ |
1168 | if (vma->vm_flags & (VM_IO | VM_RESERVED)) |
1169 | return 0; |
1170 | |
1171 | /* By default, dump shared memory if mapped from an anonymous file. */ |
1172 | if (vma->vm_flags & VM_SHARED) { |
1173 | if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ? |
1174 | FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED)) |
1175 | goto whole; |
1176 | return 0; |
1177 | } |
1178 | |
1179 | /* Dump segments that have been written to. */ |
1180 | if (vma->anon_vma && FILTER(ANON_PRIVATE)) |
1181 | goto whole; |
1182 | if (vma->vm_file == NULL) |
1183 | return 0; |
1184 | |
1185 | if (FILTER(MAPPED_PRIVATE)) |
1186 | goto whole; |
1187 | |
1188 | /* |
1189 | * If this looks like the beginning of a DSO or executable mapping, |
1190 | * check for an ELF header. If we find one, dump the first page to |
1191 | * aid in determining what was mapped here. |
1192 | */ |
1193 | if (FILTER(ELF_HEADERS) && |
1194 | vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) { |
1195 | u32 __user *header = (u32 __user *) vma->vm_start; |
1196 | u32 word = 0; |
1197 | mm_segment_t fs = get_fs(); |
1198 | /* |
1199 | * Doing it this way gets the constant folded by GCC. |
1200 | */ |
1201 | union { |
1202 | u32 cmp; |
1203 | char elfmag[SELFMAG]; |
1204 | } magic; |
1205 | BUILD_BUG_ON(SELFMAG != sizeof word); |
1206 | magic.elfmag[EI_MAG0] = ELFMAG0; |
1207 | magic.elfmag[EI_MAG1] = ELFMAG1; |
1208 | magic.elfmag[EI_MAG2] = ELFMAG2; |
1209 | magic.elfmag[EI_MAG3] = ELFMAG3; |
1210 | /* |
1211 | * Switch to the user "segment" for get_user(), |
1212 | * then put back what elf_core_dump() had in place. |
1213 | */ |
1214 | set_fs(USER_DS); |
1215 | if (unlikely(get_user(word, header))) |
1216 | word = 0; |
1217 | set_fs(fs); |
1218 | if (word == magic.cmp) |
1219 | return PAGE_SIZE; |
1220 | } |
1221 | |
1222 | #undef FILTER |
1223 | |
1224 | return 0; |
1225 | |
1226 | whole: |
1227 | return vma->vm_end - vma->vm_start; |
1228 | } |
1229 | |
1230 | /* An ELF note in memory */ |
1231 | struct memelfnote |
1232 | { |
1233 | const char *name; |
1234 | int type; |
1235 | unsigned int datasz; |
1236 | void *data; |
1237 | }; |
1238 | |
1239 | static int notesize(struct memelfnote *en) |
1240 | { |
1241 | int sz; |
1242 | |
1243 | sz = sizeof(struct elf_note); |
1244 | sz += roundup(strlen(en->name) + 1, 4); |
1245 | sz += roundup(en->datasz, 4); |
1246 | |
1247 | return sz; |
1248 | } |
1249 | |
1250 | #define DUMP_WRITE(addr, nr, foffset) \ |
1251 | do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0) |
1252 | |
1253 | static int alignfile(struct file *file, loff_t *foffset) |
1254 | { |
1255 | static const char buf[4] = { 0, }; |
1256 | DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset); |
1257 | return 1; |
1258 | } |
1259 | |
1260 | static int writenote(struct memelfnote *men, struct file *file, |
1261 | loff_t *foffset) |
1262 | { |
1263 | struct elf_note en; |
1264 | en.n_namesz = strlen(men->name) + 1; |
1265 | en.n_descsz = men->datasz; |
1266 | en.n_type = men->type; |
1267 | |
1268 | DUMP_WRITE(&en, sizeof(en), foffset); |
1269 | DUMP_WRITE(men->name, en.n_namesz, foffset); |
1270 | if (!alignfile(file, foffset)) |
1271 | return 0; |
1272 | DUMP_WRITE(men->data, men->datasz, foffset); |
1273 | if (!alignfile(file, foffset)) |
1274 | return 0; |
1275 | |
1276 | return 1; |
1277 | } |
1278 | #undef DUMP_WRITE |
1279 | |
1280 | #define DUMP_WRITE(addr, nr) \ |
1281 | if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \ |
1282 | goto end_coredump; |
1283 | #define DUMP_SEEK(off) \ |
1284 | if (!dump_seek(file, (off))) \ |
1285 | goto end_coredump; |
1286 | |
1287 | static void fill_elf_header(struct elfhdr *elf, int segs, |
1288 | u16 machine, u32 flags, u8 osabi) |
1289 | { |
1290 | memset(elf, 0, sizeof(*elf)); |
1291 | |
1292 | memcpy(elf->e_ident, ELFMAG, SELFMAG); |
1293 | elf->e_ident[EI_CLASS] = ELF_CLASS; |
1294 | elf->e_ident[EI_DATA] = ELF_DATA; |
1295 | elf->e_ident[EI_VERSION] = EV_CURRENT; |
1296 | elf->e_ident[EI_OSABI] = ELF_OSABI; |
1297 | |
1298 | elf->e_type = ET_CORE; |
1299 | elf->e_machine = machine; |
1300 | elf->e_version = EV_CURRENT; |
1301 | elf->e_phoff = sizeof(struct elfhdr); |
1302 | elf->e_flags = flags; |
1303 | elf->e_ehsize = sizeof(struct elfhdr); |
1304 | elf->e_phentsize = sizeof(struct elf_phdr); |
1305 | elf->e_phnum = segs; |
1306 | |
1307 | return; |
1308 | } |
1309 | |
1310 | static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) |
1311 | { |
1312 | phdr->p_type = PT_NOTE; |
1313 | phdr->p_offset = offset; |
1314 | phdr->p_vaddr = 0; |
1315 | phdr->p_paddr = 0; |
1316 | phdr->p_filesz = sz; |
1317 | phdr->p_memsz = 0; |
1318 | phdr->p_flags = 0; |
1319 | phdr->p_align = 0; |
1320 | return; |
1321 | } |
1322 | |
1323 | static void fill_note(struct memelfnote *note, const char *name, int type, |
1324 | unsigned int sz, void *data) |
1325 | { |
1326 | note->name = name; |
1327 | note->type = type; |
1328 | note->datasz = sz; |
1329 | note->data = data; |
1330 | return; |
1331 | } |
1332 | |
1333 | /* |
1334 | * fill up all the fields in prstatus from the given task struct, except |
1335 | * registers which need to be filled up separately. |
1336 | */ |
1337 | static void fill_prstatus(struct elf_prstatus *prstatus, |
1338 | struct task_struct *p, long signr) |
1339 | { |
1340 | prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; |
1341 | prstatus->pr_sigpend = p->pending.signal.sig[0]; |
1342 | prstatus->pr_sighold = p->blocked.sig[0]; |
1343 | rcu_read_lock(); |
1344 | prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); |
1345 | rcu_read_unlock(); |
1346 | prstatus->pr_pid = task_pid_vnr(p); |
1347 | prstatus->pr_pgrp = task_pgrp_vnr(p); |
1348 | prstatus->pr_sid = task_session_vnr(p); |
1349 | if (thread_group_leader(p)) { |
1350 | struct task_cputime cputime; |
1351 | |
1352 | /* |
1353 | * This is the record for the group leader. It shows the |
1354 | * group-wide total, not its individual thread total. |
1355 | */ |
1356 | thread_group_cputime(p, &cputime); |
1357 | cputime_to_timeval(cputime.utime, &prstatus->pr_utime); |
1358 | cputime_to_timeval(cputime.stime, &prstatus->pr_stime); |
1359 | } else { |
1360 | cputime_to_timeval(p->utime, &prstatus->pr_utime); |
1361 | cputime_to_timeval(p->stime, &prstatus->pr_stime); |
1362 | } |
1363 | cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); |
1364 | cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); |
1365 | } |
1366 | |
1367 | static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, |
1368 | struct mm_struct *mm) |
1369 | { |
1370 | const struct cred *cred; |
1371 | unsigned int i, len; |
1372 | |
1373 | /* first copy the parameters from user space */ |
1374 | memset(psinfo, 0, sizeof(struct elf_prpsinfo)); |
1375 | |
1376 | len = mm->arg_end - mm->arg_start; |
1377 | if (len >= ELF_PRARGSZ) |
1378 | len = ELF_PRARGSZ-1; |
1379 | if (copy_from_user(&psinfo->pr_psargs, |
1380 | (const char __user *)mm->arg_start, len)) |
1381 | return -EFAULT; |
1382 | for(i = 0; i < len; i++) |
1383 | if (psinfo->pr_psargs[i] == 0) |
1384 | psinfo->pr_psargs[i] = ' '; |
1385 | psinfo->pr_psargs[len] = 0; |
1386 | |
1387 | rcu_read_lock(); |
1388 | psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); |
1389 | rcu_read_unlock(); |
1390 | psinfo->pr_pid = task_pid_vnr(p); |
1391 | psinfo->pr_pgrp = task_pgrp_vnr(p); |
1392 | psinfo->pr_sid = task_session_vnr(p); |
1393 | |
1394 | i = p->state ? ffz(~p->state) + 1 : 0; |
1395 | psinfo->pr_state = i; |
1396 | psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; |
1397 | psinfo->pr_zomb = psinfo->pr_sname == 'Z'; |
1398 | psinfo->pr_nice = task_nice(p); |
1399 | psinfo->pr_flag = p->flags; |
1400 | rcu_read_lock(); |
1401 | cred = __task_cred(p); |
1402 | SET_UID(psinfo->pr_uid, cred->uid); |
1403 | SET_GID(psinfo->pr_gid, cred->gid); |
1404 | rcu_read_unlock(); |
1405 | strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); |
1406 | |
1407 | return 0; |
1408 | } |
1409 | |
1410 | static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm) |
1411 | { |
1412 | elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv; |
1413 | int i = 0; |
1414 | do |
1415 | i += 2; |
1416 | while (auxv[i - 2] != AT_NULL); |
1417 | fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv); |
1418 | } |
1419 | |
1420 | #ifdef CORE_DUMP_USE_REGSET |
1421 | #include <linux/regset.h> |
1422 | |
1423 | struct elf_thread_core_info { |
1424 | struct elf_thread_core_info *next; |
1425 | struct task_struct *task; |
1426 | struct elf_prstatus prstatus; |
1427 | struct memelfnote notes[0]; |
1428 | }; |
1429 | |
1430 | struct elf_note_info { |
1431 | struct elf_thread_core_info *thread; |
1432 | struct memelfnote psinfo; |
1433 | struct memelfnote auxv; |
1434 | size_t size; |
1435 | int thread_notes; |
1436 | }; |
1437 | |
1438 | /* |
1439 | * When a regset has a writeback hook, we call it on each thread before |
1440 | * dumping user memory. On register window machines, this makes sure the |
1441 | * user memory backing the register data is up to date before we read it. |
1442 | */ |
1443 | static void do_thread_regset_writeback(struct task_struct *task, |
1444 | const struct user_regset *regset) |
1445 | { |
1446 | if (regset->writeback) |
1447 | regset->writeback(task, regset, 1); |
1448 | } |
1449 | |
1450 | static int fill_thread_core_info(struct elf_thread_core_info *t, |
1451 | const struct user_regset_view *view, |
1452 | long signr, size_t *total) |
1453 | { |
1454 | unsigned int i; |
1455 | |
1456 | /* |
1457 | * NT_PRSTATUS is the one special case, because the regset data |
1458 | * goes into the pr_reg field inside the note contents, rather |
1459 | * than being the whole note contents. We fill the reset in here. |
1460 | * We assume that regset 0 is NT_PRSTATUS. |
1461 | */ |
1462 | fill_prstatus(&t->prstatus, t->task, signr); |
1463 | (void) view->regsets[0].get(t->task, &view->regsets[0], |
1464 | 0, sizeof(t->prstatus.pr_reg), |
1465 | &t->prstatus.pr_reg, NULL); |
1466 | |
1467 | fill_note(&t->notes[0], "CORE", NT_PRSTATUS, |
1468 | sizeof(t->prstatus), &t->prstatus); |
1469 | *total += notesize(&t->notes[0]); |
1470 | |
1471 | do_thread_regset_writeback(t->task, &view->regsets[0]); |
1472 | |
1473 | /* |
1474 | * Each other regset might generate a note too. For each regset |
1475 | * that has no core_note_type or is inactive, we leave t->notes[i] |
1476 | * all zero and we'll know to skip writing it later. |
1477 | */ |
1478 | for (i = 1; i < view->n; ++i) { |
1479 | const struct user_regset *regset = &view->regsets[i]; |
1480 | do_thread_regset_writeback(t->task, regset); |
1481 | if (regset->core_note_type && |
1482 | (!regset->active || regset->active(t->task, regset))) { |
1483 | int ret; |
1484 | size_t size = regset->n * regset->size; |
1485 | void *data = kmalloc(size, GFP_KERNEL); |
1486 | if (unlikely(!data)) |
1487 | return 0; |
1488 | ret = regset->get(t->task, regset, |
1489 | 0, size, data, NULL); |
1490 | if (unlikely(ret)) |
1491 | kfree(data); |
1492 | else { |
1493 | if (regset->core_note_type != NT_PRFPREG) |
1494 | fill_note(&t->notes[i], "LINUX", |
1495 | regset->core_note_type, |
1496 | size, data); |
1497 | else { |
1498 | t->prstatus.pr_fpvalid = 1; |
1499 | fill_note(&t->notes[i], "CORE", |
1500 | NT_PRFPREG, size, data); |
1501 | } |
1502 | *total += notesize(&t->notes[i]); |
1503 | } |
1504 | } |
1505 | } |
1506 | |
1507 | return 1; |
1508 | } |
1509 | |
1510 | static int fill_note_info(struct elfhdr *elf, int phdrs, |
1511 | struct elf_note_info *info, |
1512 | long signr, struct pt_regs *regs) |
1513 | { |
1514 | struct task_struct *dump_task = current; |
1515 | const struct user_regset_view *view = task_user_regset_view(dump_task); |
1516 | struct elf_thread_core_info *t; |
1517 | struct elf_prpsinfo *psinfo; |
1518 | struct core_thread *ct; |
1519 | unsigned int i; |
1520 | |
1521 | info->size = 0; |
1522 | info->thread = NULL; |
1523 | |
1524 | psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); |
1525 | if (psinfo == NULL) |
1526 | return 0; |
1527 | |
1528 | fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); |
1529 | |
1530 | /* |
1531 | * Figure out how many notes we're going to need for each thread. |
1532 | */ |
1533 | info->thread_notes = 0; |
1534 | for (i = 0; i < view->n; ++i) |
1535 | if (view->regsets[i].core_note_type != 0) |
1536 | ++info->thread_notes; |
1537 | |
1538 | /* |
1539 | * Sanity check. We rely on regset 0 being in NT_PRSTATUS, |
1540 | * since it is our one special case. |
1541 | */ |
1542 | if (unlikely(info->thread_notes == 0) || |
1543 | unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) { |
1544 | WARN_ON(1); |
1545 | return 0; |
1546 | } |
1547 | |
1548 | /* |
1549 | * Initialize the ELF file header. |
1550 | */ |
1551 | fill_elf_header(elf, phdrs, |
1552 | view->e_machine, view->e_flags, view->ei_osabi); |
1553 | |
1554 | /* |
1555 | * Allocate a structure for each thread. |
1556 | */ |
1557 | for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) { |
1558 | t = kzalloc(offsetof(struct elf_thread_core_info, |
1559 | notes[info->thread_notes]), |
1560 | GFP_KERNEL); |
1561 | if (unlikely(!t)) |
1562 | return 0; |
1563 | |
1564 | t->task = ct->task; |
1565 | if (ct->task == dump_task || !info->thread) { |
1566 | t->next = info->thread; |
1567 | info->thread = t; |
1568 | } else { |
1569 | /* |
1570 | * Make sure to keep the original task at |
1571 | * the head of the list. |
1572 | */ |
1573 | t->next = info->thread->next; |
1574 | info->thread->next = t; |
1575 | } |
1576 | } |
1577 | |
1578 | /* |
1579 | * Now fill in each thread's information. |
1580 | */ |
1581 | for (t = info->thread; t != NULL; t = t->next) |
1582 | if (!fill_thread_core_info(t, view, signr, &info->size)) |
1583 | return 0; |
1584 | |
1585 | /* |
1586 | * Fill in the two process-wide notes. |
1587 | */ |
1588 | fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm); |
1589 | info->size += notesize(&info->psinfo); |
1590 | |
1591 | fill_auxv_note(&info->auxv, current->mm); |
1592 | info->size += notesize(&info->auxv); |
1593 | |
1594 | return 1; |
1595 | } |
1596 | |
1597 | static size_t get_note_info_size(struct elf_note_info *info) |
1598 | { |
1599 | return info->size; |
1600 | } |
1601 | |
1602 | /* |
1603 | * Write all the notes for each thread. When writing the first thread, the |
1604 | * process-wide notes are interleaved after the first thread-specific note. |
1605 | */ |
1606 | static int write_note_info(struct elf_note_info *info, |
1607 | struct file *file, loff_t *foffset) |
1608 | { |
1609 | bool first = 1; |
1610 | struct elf_thread_core_info *t = info->thread; |
1611 | |
1612 | do { |
1613 | int i; |
1614 | |
1615 | if (!writenote(&t->notes[0], file, foffset)) |
1616 | return 0; |
1617 | |
1618 | if (first && !writenote(&info->psinfo, file, foffset)) |
1619 | return 0; |
1620 | if (first && !writenote(&info->auxv, file, foffset)) |
1621 | return 0; |
1622 | |
1623 | for (i = 1; i < info->thread_notes; ++i) |
1624 | if (t->notes[i].data && |
1625 | !writenote(&t->notes[i], file, foffset)) |
1626 | return 0; |
1627 | |
1628 | first = 0; |
1629 | t = t->next; |
1630 | } while (t); |
1631 | |
1632 | return 1; |
1633 | } |
1634 | |
1635 | static void free_note_info(struct elf_note_info *info) |
1636 | { |
1637 | struct elf_thread_core_info *threads = info->thread; |
1638 | while (threads) { |
1639 | unsigned int i; |
1640 | struct elf_thread_core_info *t = threads; |
1641 | threads = t->next; |
1642 | WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus); |
1643 | for (i = 1; i < info->thread_notes; ++i) |
1644 | kfree(t->notes[i].data); |
1645 | kfree(t); |
1646 | } |
1647 | kfree(info->psinfo.data); |
1648 | } |
1649 | |
1650 | #else |
1651 | |
1652 | /* Here is the structure in which status of each thread is captured. */ |
1653 | struct elf_thread_status |
1654 | { |
1655 | struct list_head list; |
1656 | struct elf_prstatus prstatus; /* NT_PRSTATUS */ |
1657 | elf_fpregset_t fpu; /* NT_PRFPREG */ |
1658 | struct task_struct *thread; |
1659 | #ifdef ELF_CORE_COPY_XFPREGS |
1660 | elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ |
1661 | #endif |
1662 | struct memelfnote notes[3]; |
1663 | int num_notes; |
1664 | }; |
1665 | |
1666 | /* |
1667 | * In order to add the specific thread information for the elf file format, |
1668 | * we need to keep a linked list of every threads pr_status and then create |
1669 | * a single section for them in the final core file. |
1670 | */ |
1671 | static int elf_dump_thread_status(long signr, struct elf_thread_status *t) |
1672 | { |
1673 | int sz = 0; |
1674 | struct task_struct *p = t->thread; |
1675 | t->num_notes = 0; |
1676 | |
1677 | fill_prstatus(&t->prstatus, p, signr); |
1678 | elf_core_copy_task_regs(p, &t->prstatus.pr_reg); |
1679 | |
1680 | fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), |
1681 | &(t->prstatus)); |
1682 | t->num_notes++; |
1683 | sz += notesize(&t->notes[0]); |
1684 | |
1685 | if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, |
1686 | &t->fpu))) { |
1687 | fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), |
1688 | &(t->fpu)); |
1689 | t->num_notes++; |
1690 | sz += notesize(&t->notes[1]); |
1691 | } |
1692 | |
1693 | #ifdef ELF_CORE_COPY_XFPREGS |
1694 | if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { |
1695 | fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, |
1696 | sizeof(t->xfpu), &t->xfpu); |
1697 | t->num_notes++; |
1698 | sz += notesize(&t->notes[2]); |
1699 | } |
1700 | #endif |
1701 | return sz; |
1702 | } |
1703 | |
1704 | struct elf_note_info { |
1705 | struct memelfnote *notes; |
1706 | struct elf_prstatus *prstatus; /* NT_PRSTATUS */ |
1707 | struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */ |
1708 | struct list_head thread_list; |
1709 | elf_fpregset_t *fpu; |
1710 | #ifdef ELF_CORE_COPY_XFPREGS |
1711 | elf_fpxregset_t *xfpu; |
1712 | #endif |
1713 | int thread_status_size; |
1714 | int numnote; |
1715 | }; |
1716 | |
1717 | static int fill_note_info(struct elfhdr *elf, int phdrs, |
1718 | struct elf_note_info *info, |
1719 | long signr, struct pt_regs *regs) |
1720 | { |
1721 | #define NUM_NOTES 6 |
1722 | struct list_head *t; |
1723 | |
1724 | info->notes = NULL; |
1725 | info->prstatus = NULL; |
1726 | info->psinfo = NULL; |
1727 | info->fpu = NULL; |
1728 | #ifdef ELF_CORE_COPY_XFPREGS |
1729 | info->xfpu = NULL; |
1730 | #endif |
1731 | INIT_LIST_HEAD(&info->thread_list); |
1732 | |
1733 | info->notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), |
1734 | GFP_KERNEL); |
1735 | if (!info->notes) |
1736 | return 0; |
1737 | info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL); |
1738 | if (!info->psinfo) |
1739 | return 0; |
1740 | info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL); |
1741 | if (!info->prstatus) |
1742 | return 0; |
1743 | info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL); |
1744 | if (!info->fpu) |
1745 | return 0; |
1746 | #ifdef ELF_CORE_COPY_XFPREGS |
1747 | info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL); |
1748 | if (!info->xfpu) |
1749 | return 0; |
1750 | #endif |
1751 | |
1752 | info->thread_status_size = 0; |
1753 | if (signr) { |
1754 | struct core_thread *ct; |
1755 | struct elf_thread_status *ets; |
1756 | |
1757 | for (ct = current->mm->core_state->dumper.next; |
1758 | ct; ct = ct->next) { |
1759 | ets = kzalloc(sizeof(*ets), GFP_KERNEL); |
1760 | if (!ets) |
1761 | return 0; |
1762 | |
1763 | ets->thread = ct->task; |
1764 | list_add(&ets->list, &info->thread_list); |
1765 | } |
1766 | |
1767 | list_for_each(t, &info->thread_list) { |
1768 | int sz; |
1769 | |
1770 | ets = list_entry(t, struct elf_thread_status, list); |
1771 | sz = elf_dump_thread_status(signr, ets); |
1772 | info->thread_status_size += sz; |
1773 | } |
1774 | } |
1775 | /* now collect the dump for the current */ |
1776 | memset(info->prstatus, 0, sizeof(*info->prstatus)); |
1777 | fill_prstatus(info->prstatus, current, signr); |
1778 | elf_core_copy_regs(&info->prstatus->pr_reg, regs); |
1779 | |
1780 | /* Set up header */ |
1781 | fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI); |
1782 | |
1783 | /* |
1784 | * Set up the notes in similar form to SVR4 core dumps made |
1785 | * with info from their /proc. |
1786 | */ |
1787 | |
1788 | fill_note(info->notes + 0, "CORE", NT_PRSTATUS, |
1789 | sizeof(*info->prstatus), info->prstatus); |
1790 | fill_psinfo(info->psinfo, current->group_leader, current->mm); |
1791 | fill_note(info->notes + 1, "CORE", NT_PRPSINFO, |
1792 | sizeof(*info->psinfo), info->psinfo); |
1793 | |
1794 | info->numnote = 2; |
1795 | |
1796 | fill_auxv_note(&info->notes[info->numnote++], current->mm); |
1797 | |
1798 | /* Try to dump the FPU. */ |
1799 | info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs, |
1800 | info->fpu); |
1801 | if (info->prstatus->pr_fpvalid) |
1802 | fill_note(info->notes + info->numnote++, |
1803 | "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu); |
1804 | #ifdef ELF_CORE_COPY_XFPREGS |
1805 | if (elf_core_copy_task_xfpregs(current, info->xfpu)) |
1806 | fill_note(info->notes + info->numnote++, |
1807 | "LINUX", ELF_CORE_XFPREG_TYPE, |
1808 | sizeof(*info->xfpu), info->xfpu); |
1809 | #endif |
1810 | |
1811 | return 1; |
1812 | |
1813 | #undef NUM_NOTES |
1814 | } |
1815 | |
1816 | static size_t get_note_info_size(struct elf_note_info *info) |
1817 | { |
1818 | int sz = 0; |
1819 | int i; |
1820 | |
1821 | for (i = 0; i < info->numnote; i++) |
1822 | sz += notesize(info->notes + i); |
1823 | |
1824 | sz += info->thread_status_size; |
1825 | |
1826 | return sz; |
1827 | } |
1828 | |
1829 | static int write_note_info(struct elf_note_info *info, |
1830 | struct file *file, loff_t *foffset) |
1831 | { |
1832 | int i; |
1833 | struct list_head *t; |
1834 | |
1835 | for (i = 0; i < info->numnote; i++) |
1836 | if (!writenote(info->notes + i, file, foffset)) |
1837 | return 0; |
1838 | |
1839 | /* write out the thread status notes section */ |
1840 | list_for_each(t, &info->thread_list) { |
1841 | struct elf_thread_status *tmp = |
1842 | list_entry(t, struct elf_thread_status, list); |
1843 | |
1844 | for (i = 0; i < tmp->num_notes; i++) |
1845 | if (!writenote(&tmp->notes[i], file, foffset)) |
1846 | return 0; |
1847 | } |
1848 | |
1849 | return 1; |
1850 | } |
1851 | |
1852 | static void free_note_info(struct elf_note_info *info) |
1853 | { |
1854 | while (!list_empty(&info->thread_list)) { |
1855 | struct list_head *tmp = info->thread_list.next; |
1856 | list_del(tmp); |
1857 | kfree(list_entry(tmp, struct elf_thread_status, list)); |
1858 | } |
1859 | |
1860 | kfree(info->prstatus); |
1861 | kfree(info->psinfo); |
1862 | kfree(info->notes); |
1863 | kfree(info->fpu); |
1864 | #ifdef ELF_CORE_COPY_XFPREGS |
1865 | kfree(info->xfpu); |
1866 | #endif |
1867 | } |
1868 | |
1869 | #endif |
1870 | |
1871 | static struct vm_area_struct *first_vma(struct task_struct *tsk, |
1872 | struct vm_area_struct *gate_vma) |
1873 | { |
1874 | struct vm_area_struct *ret = tsk->mm->mmap; |
1875 | |
1876 | if (ret) |
1877 | return ret; |
1878 | return gate_vma; |
1879 | } |
1880 | /* |
1881 | * Helper function for iterating across a vma list. It ensures that the caller |
1882 | * will visit `gate_vma' prior to terminating the search. |
1883 | */ |
1884 | static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma, |
1885 | struct vm_area_struct *gate_vma) |
1886 | { |
1887 | struct vm_area_struct *ret; |
1888 | |
1889 | ret = this_vma->vm_next; |
1890 | if (ret) |
1891 | return ret; |
1892 | if (this_vma == gate_vma) |
1893 | return NULL; |
1894 | return gate_vma; |
1895 | } |
1896 | |
1897 | /* |
1898 | * Actual dumper |
1899 | * |
1900 | * This is a two-pass process; first we find the offsets of the bits, |
1901 | * and then they are actually written out. If we run out of core limit |
1902 | * we just truncate. |
1903 | */ |
1904 | static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit) |
1905 | { |
1906 | int has_dumped = 0; |
1907 | mm_segment_t fs; |
1908 | int segs; |
1909 | size_t size = 0; |
1910 | struct vm_area_struct *vma, *gate_vma; |
1911 | struct elfhdr *elf = NULL; |
1912 | loff_t offset = 0, dataoff, foffset; |
1913 | unsigned long mm_flags; |
1914 | struct elf_note_info info; |
1915 | |
1916 | /* |
1917 | * We no longer stop all VM operations. |
1918 | * |
1919 | * This is because those proceses that could possibly change map_count |
1920 | * or the mmap / vma pages are now blocked in do_exit on current |
1921 | * finishing this core dump. |
1922 | * |
1923 | * Only ptrace can touch these memory addresses, but it doesn't change |
1924 | * the map_count or the pages allocated. So no possibility of crashing |
1925 | * exists while dumping the mm->vm_next areas to the core file. |
1926 | */ |
1927 | |
1928 | /* alloc memory for large data structures: too large to be on stack */ |
1929 | elf = kmalloc(sizeof(*elf), GFP_KERNEL); |
1930 | if (!elf) |
1931 | goto out; |
1932 | /* |
1933 | * The number of segs are recored into ELF header as 16bit value. |
1934 | * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here. |
1935 | */ |
1936 | segs = current->mm->map_count; |
1937 | #ifdef ELF_CORE_EXTRA_PHDRS |
1938 | segs += ELF_CORE_EXTRA_PHDRS; |
1939 | #endif |
1940 | |
1941 | gate_vma = get_gate_vma(current); |
1942 | if (gate_vma != NULL) |
1943 | segs++; |
1944 | |
1945 | /* |
1946 | * Collect all the non-memory information about the process for the |
1947 | * notes. This also sets up the file header. |
1948 | */ |
1949 | if (!fill_note_info(elf, segs + 1, /* including notes section */ |
1950 | &info, signr, regs)) |
1951 | goto cleanup; |
1952 | |
1953 | has_dumped = 1; |
1954 | current->flags |= PF_DUMPCORE; |
1955 | |
1956 | fs = get_fs(); |
1957 | set_fs(KERNEL_DS); |
1958 | |
1959 | DUMP_WRITE(elf, sizeof(*elf)); |
1960 | offset += sizeof(*elf); /* Elf header */ |
1961 | offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */ |
1962 | foffset = offset; |
1963 | |
1964 | /* Write notes phdr entry */ |
1965 | { |
1966 | struct elf_phdr phdr; |
1967 | size_t sz = get_note_info_size(&info); |
1968 | |
1969 | sz += elf_coredump_extra_notes_size(); |
1970 | |
1971 | fill_elf_note_phdr(&phdr, sz, offset); |
1972 | offset += sz; |
1973 | DUMP_WRITE(&phdr, sizeof(phdr)); |
1974 | } |
1975 | |
1976 | dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); |
1977 | |
1978 | /* |
1979 | * We must use the same mm->flags while dumping core to avoid |
1980 | * inconsistency between the program headers and bodies, otherwise an |
1981 | * unusable core file can be generated. |
1982 | */ |
1983 | mm_flags = current->mm->flags; |
1984 | |
1985 | /* Write program headers for segments dump */ |
1986 | for (vma = first_vma(current, gate_vma); vma != NULL; |
1987 | vma = next_vma(vma, gate_vma)) { |
1988 | struct elf_phdr phdr; |
1989 | |
1990 | phdr.p_type = PT_LOAD; |
1991 | phdr.p_offset = offset; |
1992 | phdr.p_vaddr = vma->vm_start; |
1993 | phdr.p_paddr = 0; |
1994 | phdr.p_filesz = vma_dump_size(vma, mm_flags); |
1995 | phdr.p_memsz = vma->vm_end - vma->vm_start; |
1996 | offset += phdr.p_filesz; |
1997 | phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; |
1998 | if (vma->vm_flags & VM_WRITE) |
1999 | phdr.p_flags |= PF_W; |
2000 | if (vma->vm_flags & VM_EXEC) |
2001 | phdr.p_flags |= PF_X; |
2002 | phdr.p_align = ELF_EXEC_PAGESIZE; |
2003 | |
2004 | DUMP_WRITE(&phdr, sizeof(phdr)); |
2005 | } |
2006 | |
2007 | #ifdef ELF_CORE_WRITE_EXTRA_PHDRS |
2008 | ELF_CORE_WRITE_EXTRA_PHDRS; |
2009 | #endif |
2010 | |
2011 | /* write out the notes section */ |
2012 | if (!write_note_info(&info, file, &foffset)) |
2013 | goto end_coredump; |
2014 | |
2015 | if (elf_coredump_extra_notes_write(file, &foffset)) |
2016 | goto end_coredump; |
2017 | |
2018 | /* Align to page */ |
2019 | DUMP_SEEK(dataoff - foffset); |
2020 | |
2021 | for (vma = first_vma(current, gate_vma); vma != NULL; |
2022 | vma = next_vma(vma, gate_vma)) { |
2023 | unsigned long addr; |
2024 | unsigned long end; |
2025 | |
2026 | end = vma->vm_start + vma_dump_size(vma, mm_flags); |
2027 | |
2028 | for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) { |
2029 | struct page *page; |
2030 | struct vm_area_struct *tmp_vma; |
2031 | |
2032 | if (get_user_pages(current, current->mm, addr, 1, 0, 1, |
2033 | &page, &tmp_vma) <= 0) { |
2034 | DUMP_SEEK(PAGE_SIZE); |
2035 | } else { |
2036 | if (page == ZERO_PAGE(0)) { |
2037 | if (!dump_seek(file, PAGE_SIZE)) { |
2038 | page_cache_release(page); |
2039 | goto end_coredump; |
2040 | } |
2041 | } else { |
2042 | void *kaddr; |
2043 | flush_cache_page(tmp_vma, addr, |
2044 | page_to_pfn(page)); |
2045 | kaddr = kmap(page); |
2046 | if ((size += PAGE_SIZE) > limit || |
2047 | !dump_write(file, kaddr, |
2048 | PAGE_SIZE)) { |
2049 | kunmap(page); |
2050 | page_cache_release(page); |
2051 | goto end_coredump; |
2052 | } |
2053 | kunmap(page); |
2054 | } |
2055 | page_cache_release(page); |
2056 | } |
2057 | } |
2058 | } |
2059 | |
2060 | #ifdef ELF_CORE_WRITE_EXTRA_DATA |
2061 | ELF_CORE_WRITE_EXTRA_DATA; |
2062 | #endif |
2063 | |
2064 | end_coredump: |
2065 | set_fs(fs); |
2066 | |
2067 | cleanup: |
2068 | free_note_info(&info); |
2069 | kfree(elf); |
2070 | out: |
2071 | return has_dumped; |
2072 | } |
2073 | |
2074 | #endif /* USE_ELF_CORE_DUMP */ |
2075 | |
2076 | static int __init init_elf_binfmt(void) |
2077 | { |
2078 | return register_binfmt(&elf_format); |
2079 | } |
2080 | |
2081 | static void __exit exit_elf_binfmt(void) |
2082 | { |
2083 | /* Remove the COFF and ELF loaders. */ |
2084 | unregister_binfmt(&elf_format); |
2085 | } |
2086 | |
2087 | core_initcall(init_elf_binfmt); |
2088 | module_exit(exit_elf_binfmt); |
2089 | MODULE_LICENSE("GPL"); |
2090 |
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