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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 <linux/coredump.h> |
35 | #include <asm/uaccess.h> |
36 | #include <asm/param.h> |
37 | #include <asm/page.h> |
38 | |
39 | static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs); |
40 | static int load_elf_library(struct file *); |
41 | static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *, |
42 | int, int, unsigned long); |
43 | |
44 | /* |
45 | * If we don't support core dumping, then supply a NULL so we |
46 | * don't even try. |
47 | */ |
48 | #ifdef CONFIG_ELF_CORE |
49 | static int elf_core_dump(struct coredump_params *cprm); |
50 | #else |
51 | #define elf_core_dump NULL |
52 | #endif |
53 | |
54 | #if ELF_EXEC_PAGESIZE > PAGE_SIZE |
55 | #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE |
56 | #else |
57 | #define ELF_MIN_ALIGN PAGE_SIZE |
58 | #endif |
59 | |
60 | #ifndef ELF_CORE_EFLAGS |
61 | #define ELF_CORE_EFLAGS 0 |
62 | #endif |
63 | |
64 | #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1)) |
65 | #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1)) |
66 | #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1)) |
67 | |
68 | static struct linux_binfmt elf_format = { |
69 | .module = THIS_MODULE, |
70 | .load_binary = load_elf_binary, |
71 | .load_shlib = load_elf_library, |
72 | .core_dump = elf_core_dump, |
73 | .min_coredump = ELF_EXEC_PAGESIZE, |
74 | .hasvdso = 1 |
75 | }; |
76 | |
77 | #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) |
78 | |
79 | static int set_brk(unsigned long start, unsigned long end) |
80 | { |
81 | start = ELF_PAGEALIGN(start); |
82 | end = ELF_PAGEALIGN(end); |
83 | if (end > start) { |
84 | unsigned long addr; |
85 | down_write(¤t->mm->mmap_sem); |
86 | addr = do_brk(start, end - start); |
87 | up_write(¤t->mm->mmap_sem); |
88 | if (BAD_ADDR(addr)) |
89 | return addr; |
90 | } |
91 | current->mm->start_brk = current->mm->brk = end; |
92 | return 0; |
93 | } |
94 | |
95 | /* We need to explicitly zero any fractional pages |
96 | after the data section (i.e. bss). This would |
97 | contain the junk from the file that should not |
98 | be in memory |
99 | */ |
100 | static int padzero(unsigned long elf_bss) |
101 | { |
102 | unsigned long nbyte; |
103 | |
104 | nbyte = ELF_PAGEOFFSET(elf_bss); |
105 | if (nbyte) { |
106 | nbyte = ELF_MIN_ALIGN - nbyte; |
107 | if (clear_user((void __user *) elf_bss, nbyte)) |
108 | return -EFAULT; |
109 | } |
110 | return 0; |
111 | } |
112 | |
113 | /* Let's use some macros to make this stack manipulation a little clearer */ |
114 | #ifdef CONFIG_STACK_GROWSUP |
115 | #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items)) |
116 | #define STACK_ROUND(sp, items) \ |
117 | ((15 + (unsigned long) ((sp) + (items))) &~ 15UL) |
118 | #define STACK_ALLOC(sp, len) ({ \ |
119 | elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \ |
120 | old_sp; }) |
121 | #else |
122 | #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items)) |
123 | #define STACK_ROUND(sp, items) \ |
124 | (((unsigned long) (sp - items)) &~ 15UL) |
125 | #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; }) |
126 | #endif |
127 | |
128 | #ifndef ELF_BASE_PLATFORM |
129 | /* |
130 | * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. |
131 | * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value |
132 | * will be copied to the user stack in the same manner as AT_PLATFORM. |
133 | */ |
134 | #define ELF_BASE_PLATFORM NULL |
135 | #endif |
136 | |
137 | static int |
138 | create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, |
139 | unsigned long load_addr, unsigned long interp_load_addr) |
140 | { |
141 | unsigned long p = bprm->p; |
142 | int argc = bprm->argc; |
143 | int envc = bprm->envc; |
144 | elf_addr_t __user *argv; |
145 | elf_addr_t __user *envp; |
146 | elf_addr_t __user *sp; |
147 | elf_addr_t __user *u_platform; |
148 | elf_addr_t __user *u_base_platform; |
149 | elf_addr_t __user *u_rand_bytes; |
150 | const char *k_platform = ELF_PLATFORM; |
151 | const char *k_base_platform = ELF_BASE_PLATFORM; |
152 | unsigned char k_rand_bytes[16]; |
153 | int items; |
154 | elf_addr_t *elf_info; |
155 | int ei_index = 0; |
156 | const struct cred *cred = current_cred(); |
157 | struct vm_area_struct *vma; |
158 | |
159 | /* |
160 | * In some cases (e.g. Hyper-Threading), we want to avoid L1 |
161 | * evictions by the processes running on the same package. One |
162 | * thing we can do is to shuffle the initial stack for them. |
163 | */ |
164 | |
165 | p = arch_align_stack(p); |
166 | |
167 | /* |
168 | * If this architecture has a platform capability string, copy it |
169 | * to userspace. In some cases (Sparc), this info is impossible |
170 | * for userspace to get any other way, in others (i386) it is |
171 | * merely difficult. |
172 | */ |
173 | u_platform = NULL; |
174 | if (k_platform) { |
175 | size_t len = strlen(k_platform) + 1; |
176 | |
177 | u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); |
178 | if (__copy_to_user(u_platform, k_platform, len)) |
179 | return -EFAULT; |
180 | } |
181 | |
182 | /* |
183 | * If this architecture has a "base" platform capability |
184 | * string, copy it to userspace. |
185 | */ |
186 | u_base_platform = NULL; |
187 | if (k_base_platform) { |
188 | size_t len = strlen(k_base_platform) + 1; |
189 | |
190 | u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); |
191 | if (__copy_to_user(u_base_platform, k_base_platform, len)) |
192 | return -EFAULT; |
193 | } |
194 | |
195 | /* |
196 | * Generate 16 random bytes for userspace PRNG seeding. |
197 | */ |
198 | get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes)); |
199 | u_rand_bytes = (elf_addr_t __user *) |
200 | STACK_ALLOC(p, sizeof(k_rand_bytes)); |
201 | if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes))) |
202 | return -EFAULT; |
203 | |
204 | /* Create the ELF interpreter info */ |
205 | elf_info = (elf_addr_t *)current->mm->saved_auxv; |
206 | /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */ |
207 | #define NEW_AUX_ENT(id, val) \ |
208 | do { \ |
209 | elf_info[ei_index++] = id; \ |
210 | elf_info[ei_index++] = val; \ |
211 | } while (0) |
212 | |
213 | #ifdef ARCH_DLINFO |
214 | /* |
215 | * ARCH_DLINFO must come first so PPC can do its special alignment of |
216 | * AUXV. |
217 | * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in |
218 | * ARCH_DLINFO changes |
219 | */ |
220 | ARCH_DLINFO; |
221 | #endif |
222 | NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); |
223 | NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE); |
224 | NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); |
225 | NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff); |
226 | NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); |
227 | NEW_AUX_ENT(AT_PHNUM, exec->e_phnum); |
228 | NEW_AUX_ENT(AT_BASE, interp_load_addr); |
229 | NEW_AUX_ENT(AT_FLAGS, 0); |
230 | NEW_AUX_ENT(AT_ENTRY, exec->e_entry); |
231 | NEW_AUX_ENT(AT_UID, cred->uid); |
232 | NEW_AUX_ENT(AT_EUID, cred->euid); |
233 | NEW_AUX_ENT(AT_GID, cred->gid); |
234 | NEW_AUX_ENT(AT_EGID, cred->egid); |
235 | NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); |
236 | NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes); |
237 | NEW_AUX_ENT(AT_EXECFN, bprm->exec); |
238 | if (k_platform) { |
239 | NEW_AUX_ENT(AT_PLATFORM, |
240 | (elf_addr_t)(unsigned long)u_platform); |
241 | } |
242 | if (k_base_platform) { |
243 | NEW_AUX_ENT(AT_BASE_PLATFORM, |
244 | (elf_addr_t)(unsigned long)u_base_platform); |
245 | } |
246 | if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { |
247 | NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); |
248 | } |
249 | #undef NEW_AUX_ENT |
250 | /* AT_NULL is zero; clear the rest too */ |
251 | memset(&elf_info[ei_index], 0, |
252 | sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]); |
253 | |
254 | /* And advance past the AT_NULL entry. */ |
255 | ei_index += 2; |
256 | |
257 | sp = STACK_ADD(p, ei_index); |
258 | |
259 | items = (argc + 1) + (envc + 1) + 1; |
260 | bprm->p = STACK_ROUND(sp, items); |
261 | |
262 | /* Point sp at the lowest address on the stack */ |
263 | #ifdef CONFIG_STACK_GROWSUP |
264 | sp = (elf_addr_t __user *)bprm->p - items - ei_index; |
265 | bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */ |
266 | #else |
267 | sp = (elf_addr_t __user *)bprm->p; |
268 | #endif |
269 | |
270 | |
271 | /* |
272 | * Grow the stack manually; some architectures have a limit on how |
273 | * far ahead a user-space access may be in order to grow the stack. |
274 | */ |
275 | vma = find_extend_vma(current->mm, bprm->p); |
276 | if (!vma) |
277 | return -EFAULT; |
278 | |
279 | /* Now, let's put argc (and argv, envp if appropriate) on the stack */ |
280 | if (__put_user(argc, sp++)) |
281 | return -EFAULT; |
282 | argv = sp; |
283 | envp = argv + argc + 1; |
284 | |
285 | /* Populate argv and envp */ |
286 | p = current->mm->arg_end = current->mm->arg_start; |
287 | while (argc-- > 0) { |
288 | size_t len; |
289 | if (__put_user((elf_addr_t)p, argv++)) |
290 | return -EFAULT; |
291 | len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); |
292 | if (!len || len > MAX_ARG_STRLEN) |
293 | return -EINVAL; |
294 | p += len; |
295 | } |
296 | if (__put_user(0, argv)) |
297 | return -EFAULT; |
298 | current->mm->arg_end = current->mm->env_start = p; |
299 | while (envc-- > 0) { |
300 | size_t len; |
301 | if (__put_user((elf_addr_t)p, envp++)) |
302 | return -EFAULT; |
303 | len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); |
304 | if (!len || len > MAX_ARG_STRLEN) |
305 | return -EINVAL; |
306 | p += len; |
307 | } |
308 | if (__put_user(0, envp)) |
309 | return -EFAULT; |
310 | current->mm->env_end = p; |
311 | |
312 | /* Put the elf_info on the stack in the right place. */ |
313 | sp = (elf_addr_t __user *)envp + 1; |
314 | if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t))) |
315 | return -EFAULT; |
316 | return 0; |
317 | } |
318 | |
319 | #ifndef elf_map |
320 | |
321 | static unsigned long elf_map(struct file *filep, unsigned long addr, |
322 | struct elf_phdr *eppnt, int prot, int type, |
323 | unsigned long total_size) |
324 | { |
325 | unsigned long map_addr; |
326 | unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr); |
327 | unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr); |
328 | addr = ELF_PAGESTART(addr); |
329 | size = ELF_PAGEALIGN(size); |
330 | |
331 | /* mmap() will return -EINVAL if given a zero size, but a |
332 | * segment with zero filesize is perfectly valid */ |
333 | if (!size) |
334 | return addr; |
335 | |
336 | down_write(¤t->mm->mmap_sem); |
337 | /* |
338 | * total_size is the size of the ELF (interpreter) image. |
339 | * The _first_ mmap needs to know the full size, otherwise |
340 | * randomization might put this image into an overlapping |
341 | * position with the ELF binary image. (since size < total_size) |
342 | * So we first map the 'big' image - and unmap the remainder at |
343 | * the end. (which unmap is needed for ELF images with holes.) |
344 | */ |
345 | if (total_size) { |
346 | total_size = ELF_PAGEALIGN(total_size); |
347 | map_addr = do_mmap(filep, addr, total_size, prot, type, off); |
348 | if (!BAD_ADDR(map_addr)) |
349 | do_munmap(current->mm, map_addr+size, total_size-size); |
350 | } else |
351 | map_addr = do_mmap(filep, addr, size, prot, type, off); |
352 | |
353 | up_write(¤t->mm->mmap_sem); |
354 | return(map_addr); |
355 | } |
356 | |
357 | #endif /* !elf_map */ |
358 | |
359 | static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr) |
360 | { |
361 | int i, first_idx = -1, last_idx = -1; |
362 | |
363 | for (i = 0; i < nr; i++) { |
364 | if (cmds[i].p_type == PT_LOAD) { |
365 | last_idx = i; |
366 | if (first_idx == -1) |
367 | first_idx = i; |
368 | } |
369 | } |
370 | if (first_idx == -1) |
371 | return 0; |
372 | |
373 | return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz - |
374 | ELF_PAGESTART(cmds[first_idx].p_vaddr); |
375 | } |
376 | |
377 | |
378 | /* This is much more generalized than the library routine read function, |
379 | so we keep this separate. Technically the library read function |
380 | is only provided so that we can read a.out libraries that have |
381 | an ELF header */ |
382 | |
383 | static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex, |
384 | struct file *interpreter, unsigned long *interp_map_addr, |
385 | unsigned long no_base) |
386 | { |
387 | struct elf_phdr *elf_phdata; |
388 | struct elf_phdr *eppnt; |
389 | unsigned long load_addr = 0; |
390 | int load_addr_set = 0; |
391 | unsigned long last_bss = 0, elf_bss = 0; |
392 | unsigned long error = ~0UL; |
393 | unsigned long total_size; |
394 | int retval, i, size; |
395 | |
396 | /* First of all, some simple consistency checks */ |
397 | if (interp_elf_ex->e_type != ET_EXEC && |
398 | interp_elf_ex->e_type != ET_DYN) |
399 | goto out; |
400 | if (!elf_check_arch(interp_elf_ex)) |
401 | goto out; |
402 | if (!interpreter->f_op || !interpreter->f_op->mmap) |
403 | goto out; |
404 | |
405 | /* |
406 | * If the size of this structure has changed, then punt, since |
407 | * we will be doing the wrong thing. |
408 | */ |
409 | if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr)) |
410 | goto out; |
411 | if (interp_elf_ex->e_phnum < 1 || |
412 | interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr)) |
413 | goto out; |
414 | |
415 | /* Now read in all of the header information */ |
416 | size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum; |
417 | if (size > ELF_MIN_ALIGN) |
418 | goto out; |
419 | elf_phdata = kmalloc(size, GFP_KERNEL); |
420 | if (!elf_phdata) |
421 | goto out; |
422 | |
423 | retval = kernel_read(interpreter, interp_elf_ex->e_phoff, |
424 | (char *)elf_phdata,size); |
425 | error = -EIO; |
426 | if (retval != size) { |
427 | if (retval < 0) |
428 | error = retval; |
429 | goto out_close; |
430 | } |
431 | |
432 | total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum); |
433 | if (!total_size) { |
434 | error = -EINVAL; |
435 | goto out_close; |
436 | } |
437 | |
438 | eppnt = elf_phdata; |
439 | for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) { |
440 | if (eppnt->p_type == PT_LOAD) { |
441 | int elf_type = MAP_PRIVATE | MAP_DENYWRITE; |
442 | int elf_prot = 0; |
443 | unsigned long vaddr = 0; |
444 | unsigned long k, map_addr; |
445 | |
446 | if (eppnt->p_flags & PF_R) |
447 | elf_prot = PROT_READ; |
448 | if (eppnt->p_flags & PF_W) |
449 | elf_prot |= PROT_WRITE; |
450 | if (eppnt->p_flags & PF_X) |
451 | elf_prot |= PROT_EXEC; |
452 | vaddr = eppnt->p_vaddr; |
453 | if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) |
454 | elf_type |= MAP_FIXED; |
455 | else if (no_base && interp_elf_ex->e_type == ET_DYN) |
456 | load_addr = -vaddr; |
457 | |
458 | map_addr = elf_map(interpreter, load_addr + vaddr, |
459 | eppnt, elf_prot, elf_type, total_size); |
460 | total_size = 0; |
461 | if (!*interp_map_addr) |
462 | *interp_map_addr = map_addr; |
463 | error = map_addr; |
464 | if (BAD_ADDR(map_addr)) |
465 | goto out_close; |
466 | |
467 | if (!load_addr_set && |
468 | interp_elf_ex->e_type == ET_DYN) { |
469 | load_addr = map_addr - ELF_PAGESTART(vaddr); |
470 | load_addr_set = 1; |
471 | } |
472 | |
473 | /* |
474 | * Check to see if the section's size will overflow the |
475 | * allowed task size. Note that p_filesz must always be |
476 | * <= p_memsize so it's only necessary to check p_memsz. |
477 | */ |
478 | k = load_addr + eppnt->p_vaddr; |
479 | if (BAD_ADDR(k) || |
480 | eppnt->p_filesz > eppnt->p_memsz || |
481 | eppnt->p_memsz > TASK_SIZE || |
482 | TASK_SIZE - eppnt->p_memsz < k) { |
483 | error = -ENOMEM; |
484 | goto out_close; |
485 | } |
486 | |
487 | /* |
488 | * Find the end of the file mapping for this phdr, and |
489 | * keep track of the largest address we see for this. |
490 | */ |
491 | k = load_addr + eppnt->p_vaddr + eppnt->p_filesz; |
492 | if (k > elf_bss) |
493 | elf_bss = k; |
494 | |
495 | /* |
496 | * Do the same thing for the memory mapping - between |
497 | * elf_bss and last_bss is the bss section. |
498 | */ |
499 | k = load_addr + eppnt->p_memsz + eppnt->p_vaddr; |
500 | if (k > last_bss) |
501 | last_bss = k; |
502 | } |
503 | } |
504 | |
505 | if (last_bss > elf_bss) { |
506 | /* |
507 | * Now fill out the bss section. First pad the last page up |
508 | * to the page boundary, and then perform a mmap to make sure |
509 | * that there are zero-mapped pages up to and including the |
510 | * last bss page. |
511 | */ |
512 | if (padzero(elf_bss)) { |
513 | error = -EFAULT; |
514 | goto out_close; |
515 | } |
516 | |
517 | /* What we have mapped so far */ |
518 | elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1); |
519 | |
520 | /* Map the last of the bss segment */ |
521 | down_write(¤t->mm->mmap_sem); |
522 | error = do_brk(elf_bss, last_bss - elf_bss); |
523 | up_write(¤t->mm->mmap_sem); |
524 | if (BAD_ADDR(error)) |
525 | goto out_close; |
526 | } |
527 | |
528 | error = load_addr; |
529 | |
530 | out_close: |
531 | kfree(elf_phdata); |
532 | out: |
533 | return error; |
534 | } |
535 | |
536 | /* |
537 | * These are the functions used to load ELF style executables and shared |
538 | * libraries. There is no binary dependent code anywhere else. |
539 | */ |
540 | |
541 | #define INTERPRETER_NONE 0 |
542 | #define INTERPRETER_ELF 2 |
543 | |
544 | #ifndef STACK_RND_MASK |
545 | #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ |
546 | #endif |
547 | |
548 | static unsigned long randomize_stack_top(unsigned long stack_top) |
549 | { |
550 | unsigned int random_variable = 0; |
551 | |
552 | if ((current->flags & PF_RANDOMIZE) && |
553 | !(current->personality & ADDR_NO_RANDOMIZE)) { |
554 | random_variable = get_random_int() & STACK_RND_MASK; |
555 | random_variable <<= PAGE_SHIFT; |
556 | } |
557 | #ifdef CONFIG_STACK_GROWSUP |
558 | return PAGE_ALIGN(stack_top) + random_variable; |
559 | #else |
560 | return PAGE_ALIGN(stack_top) - random_variable; |
561 | #endif |
562 | } |
563 | |
564 | static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) |
565 | { |
566 | struct file *interpreter = NULL; /* to shut gcc up */ |
567 | unsigned long load_addr = 0, load_bias = 0; |
568 | int load_addr_set = 0; |
569 | char * elf_interpreter = NULL; |
570 | unsigned long error; |
571 | struct elf_phdr *elf_ppnt, *elf_phdata; |
572 | unsigned long elf_bss, elf_brk; |
573 | int retval, i; |
574 | unsigned int size; |
575 | unsigned long elf_entry; |
576 | unsigned long interp_load_addr = 0; |
577 | unsigned long start_code, end_code, start_data, end_data; |
578 | unsigned long reloc_func_desc = 0; |
579 | int executable_stack = EXSTACK_DEFAULT; |
580 | unsigned long def_flags = 0; |
581 | struct { |
582 | struct elfhdr elf_ex; |
583 | struct elfhdr interp_elf_ex; |
584 | } *loc; |
585 | |
586 | loc = kmalloc(sizeof(*loc), GFP_KERNEL); |
587 | if (!loc) { |
588 | retval = -ENOMEM; |
589 | goto out_ret; |
590 | } |
591 | |
592 | /* Get the exec-header */ |
593 | loc->elf_ex = *((struct elfhdr *)bprm->buf); |
594 | |
595 | retval = -ENOEXEC; |
596 | /* First of all, some simple consistency checks */ |
597 | if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0) |
598 | goto out; |
599 | |
600 | if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN) |
601 | goto out; |
602 | if (!elf_check_arch(&loc->elf_ex)) |
603 | goto out; |
604 | if (!bprm->file->f_op||!bprm->file->f_op->mmap) |
605 | goto out; |
606 | |
607 | /* Now read in all of the header information */ |
608 | if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr)) |
609 | goto out; |
610 | if (loc->elf_ex.e_phnum < 1 || |
611 | loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr)) |
612 | goto out; |
613 | size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr); |
614 | retval = -ENOMEM; |
615 | elf_phdata = kmalloc(size, GFP_KERNEL); |
616 | if (!elf_phdata) |
617 | goto out; |
618 | |
619 | retval = kernel_read(bprm->file, loc->elf_ex.e_phoff, |
620 | (char *)elf_phdata, size); |
621 | if (retval != size) { |
622 | if (retval >= 0) |
623 | retval = -EIO; |
624 | goto out_free_ph; |
625 | } |
626 | |
627 | elf_ppnt = elf_phdata; |
628 | elf_bss = 0; |
629 | elf_brk = 0; |
630 | |
631 | start_code = ~0UL; |
632 | end_code = 0; |
633 | start_data = 0; |
634 | end_data = 0; |
635 | |
636 | for (i = 0; i < loc->elf_ex.e_phnum; i++) { |
637 | if (elf_ppnt->p_type == PT_INTERP) { |
638 | /* This is the program interpreter used for |
639 | * shared libraries - for now assume that this |
640 | * is an a.out format binary |
641 | */ |
642 | retval = -ENOEXEC; |
643 | if (elf_ppnt->p_filesz > PATH_MAX || |
644 | elf_ppnt->p_filesz < 2) |
645 | goto out_free_ph; |
646 | |
647 | retval = -ENOMEM; |
648 | elf_interpreter = kmalloc(elf_ppnt->p_filesz, |
649 | GFP_KERNEL); |
650 | if (!elf_interpreter) |
651 | goto out_free_ph; |
652 | |
653 | retval = kernel_read(bprm->file, elf_ppnt->p_offset, |
654 | elf_interpreter, |
655 | elf_ppnt->p_filesz); |
656 | if (retval != elf_ppnt->p_filesz) { |
657 | if (retval >= 0) |
658 | retval = -EIO; |
659 | goto out_free_interp; |
660 | } |
661 | /* make sure path is NULL terminated */ |
662 | retval = -ENOEXEC; |
663 | if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0') |
664 | goto out_free_interp; |
665 | |
666 | interpreter = open_exec(elf_interpreter); |
667 | retval = PTR_ERR(interpreter); |
668 | if (IS_ERR(interpreter)) |
669 | goto out_free_interp; |
670 | |
671 | /* |
672 | * If the binary is not readable then enforce |
673 | * mm->dumpable = 0 regardless of the interpreter's |
674 | * permissions. |
675 | */ |
676 | if (file_permission(interpreter, MAY_READ) < 0) |
677 | bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; |
678 | |
679 | retval = kernel_read(interpreter, 0, bprm->buf, |
680 | BINPRM_BUF_SIZE); |
681 | if (retval != BINPRM_BUF_SIZE) { |
682 | if (retval >= 0) |
683 | retval = -EIO; |
684 | goto out_free_dentry; |
685 | } |
686 | |
687 | /* Get the exec headers */ |
688 | loc->interp_elf_ex = *((struct elfhdr *)bprm->buf); |
689 | break; |
690 | } |
691 | elf_ppnt++; |
692 | } |
693 | |
694 | elf_ppnt = elf_phdata; |
695 | for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) |
696 | if (elf_ppnt->p_type == PT_GNU_STACK) { |
697 | if (elf_ppnt->p_flags & PF_X) |
698 | executable_stack = EXSTACK_ENABLE_X; |
699 | else |
700 | executable_stack = EXSTACK_DISABLE_X; |
701 | break; |
702 | } |
703 | |
704 | /* Some simple consistency checks for the interpreter */ |
705 | if (elf_interpreter) { |
706 | retval = -ELIBBAD; |
707 | /* Not an ELF interpreter */ |
708 | if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0) |
709 | goto out_free_dentry; |
710 | /* Verify the interpreter has a valid arch */ |
711 | if (!elf_check_arch(&loc->interp_elf_ex)) |
712 | goto out_free_dentry; |
713 | } |
714 | |
715 | /* Flush all traces of the currently running executable */ |
716 | retval = flush_old_exec(bprm); |
717 | if (retval) |
718 | goto out_free_dentry; |
719 | |
720 | /* OK, This is the point of no return */ |
721 | current->flags &= ~PF_FORKNOEXEC; |
722 | current->mm->def_flags = def_flags; |
723 | |
724 | /* Do this immediately, since STACK_TOP as used in setup_arg_pages |
725 | may depend on the personality. */ |
726 | SET_PERSONALITY(loc->elf_ex); |
727 | if (elf_read_implies_exec(loc->elf_ex, executable_stack)) |
728 | current->personality |= READ_IMPLIES_EXEC; |
729 | |
730 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) |
731 | current->flags |= PF_RANDOMIZE; |
732 | |
733 | setup_new_exec(bprm); |
734 | |
735 | /* Do this so that we can load the interpreter, if need be. We will |
736 | change some of these later */ |
737 | current->mm->free_area_cache = current->mm->mmap_base; |
738 | current->mm->cached_hole_size = 0; |
739 | retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP), |
740 | executable_stack); |
741 | if (retval < 0) { |
742 | send_sig(SIGKILL, current, 0); |
743 | goto out_free_dentry; |
744 | } |
745 | |
746 | current->mm->start_stack = bprm->p; |
747 | |
748 | /* Now we do a little grungy work by mmapping the ELF image into |
749 | the correct location in memory. */ |
750 | for(i = 0, elf_ppnt = elf_phdata; |
751 | i < loc->elf_ex.e_phnum; i++, elf_ppnt++) { |
752 | int elf_prot = 0, elf_flags; |
753 | unsigned long k, vaddr; |
754 | |
755 | if (elf_ppnt->p_type != PT_LOAD) |
756 | continue; |
757 | |
758 | if (unlikely (elf_brk > elf_bss)) { |
759 | unsigned long nbyte; |
760 | |
761 | /* There was a PT_LOAD segment with p_memsz > p_filesz |
762 | before this one. Map anonymous pages, if needed, |
763 | and clear the area. */ |
764 | retval = set_brk (elf_bss + load_bias, |
765 | elf_brk + load_bias); |
766 | if (retval) { |
767 | send_sig(SIGKILL, current, 0); |
768 | goto out_free_dentry; |
769 | } |
770 | nbyte = ELF_PAGEOFFSET(elf_bss); |
771 | if (nbyte) { |
772 | nbyte = ELF_MIN_ALIGN - nbyte; |
773 | if (nbyte > elf_brk - elf_bss) |
774 | nbyte = elf_brk - elf_bss; |
775 | if (clear_user((void __user *)elf_bss + |
776 | load_bias, nbyte)) { |
777 | /* |
778 | * This bss-zeroing can fail if the ELF |
779 | * file specifies odd protections. So |
780 | * we don't check the return value |
781 | */ |
782 | } |
783 | } |
784 | } |
785 | |
786 | if (elf_ppnt->p_flags & PF_R) |
787 | elf_prot |= PROT_READ; |
788 | if (elf_ppnt->p_flags & PF_W) |
789 | elf_prot |= PROT_WRITE; |
790 | if (elf_ppnt->p_flags & PF_X) |
791 | elf_prot |= PROT_EXEC; |
792 | |
793 | elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE; |
794 | |
795 | vaddr = elf_ppnt->p_vaddr; |
796 | if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) { |
797 | elf_flags |= MAP_FIXED; |
798 | } else if (loc->elf_ex.e_type == ET_DYN) { |
799 | /* Try and get dynamic programs out of the way of the |
800 | * default mmap base, as well as whatever program they |
801 | * might try to exec. This is because the brk will |
802 | * follow the loader, and is not movable. */ |
803 | #ifdef CONFIG_X86 |
804 | load_bias = 0; |
805 | #else |
806 | load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); |
807 | #endif |
808 | } |
809 | |
810 | error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, |
811 | elf_prot, elf_flags, 0); |
812 | if (BAD_ADDR(error)) { |
813 | send_sig(SIGKILL, current, 0); |
814 | retval = IS_ERR((void *)error) ? |
815 | PTR_ERR((void*)error) : -EINVAL; |
816 | goto out_free_dentry; |
817 | } |
818 | |
819 | if (!load_addr_set) { |
820 | load_addr_set = 1; |
821 | load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset); |
822 | if (loc->elf_ex.e_type == ET_DYN) { |
823 | load_bias += error - |
824 | ELF_PAGESTART(load_bias + vaddr); |
825 | load_addr += load_bias; |
826 | reloc_func_desc = load_bias; |
827 | } |
828 | } |
829 | k = elf_ppnt->p_vaddr; |
830 | if (k < start_code) |
831 | start_code = k; |
832 | if (start_data < k) |
833 | start_data = k; |
834 | |
835 | /* |
836 | * Check to see if the section's size will overflow the |
837 | * allowed task size. Note that p_filesz must always be |
838 | * <= p_memsz so it is only necessary to check p_memsz. |
839 | */ |
840 | if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz || |
841 | elf_ppnt->p_memsz > TASK_SIZE || |
842 | TASK_SIZE - elf_ppnt->p_memsz < k) { |
843 | /* set_brk can never work. Avoid overflows. */ |
844 | send_sig(SIGKILL, current, 0); |
845 | retval = -EINVAL; |
846 | goto out_free_dentry; |
847 | } |
848 | |
849 | k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz; |
850 | |
851 | if (k > elf_bss) |
852 | elf_bss = k; |
853 | if ((elf_ppnt->p_flags & PF_X) && end_code < k) |
854 | end_code = k; |
855 | if (end_data < k) |
856 | end_data = k; |
857 | k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz; |
858 | if (k > elf_brk) |
859 | elf_brk = k; |
860 | } |
861 | |
862 | loc->elf_ex.e_entry += load_bias; |
863 | elf_bss += load_bias; |
864 | elf_brk += load_bias; |
865 | start_code += load_bias; |
866 | end_code += load_bias; |
867 | start_data += load_bias; |
868 | end_data += load_bias; |
869 | |
870 | /* Calling set_brk effectively mmaps the pages that we need |
871 | * for the bss and break sections. We must do this before |
872 | * mapping in the interpreter, to make sure it doesn't wind |
873 | * up getting placed where the bss needs to go. |
874 | */ |
875 | retval = set_brk(elf_bss, elf_brk); |
876 | if (retval) { |
877 | send_sig(SIGKILL, current, 0); |
878 | goto out_free_dentry; |
879 | } |
880 | if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) { |
881 | send_sig(SIGSEGV, current, 0); |
882 | retval = -EFAULT; /* Nobody gets to see this, but.. */ |
883 | goto out_free_dentry; |
884 | } |
885 | |
886 | if (elf_interpreter) { |
887 | unsigned long uninitialized_var(interp_map_addr); |
888 | |
889 | elf_entry = load_elf_interp(&loc->interp_elf_ex, |
890 | interpreter, |
891 | &interp_map_addr, |
892 | load_bias); |
893 | if (!IS_ERR((void *)elf_entry)) { |
894 | /* |
895 | * load_elf_interp() returns relocation |
896 | * adjustment |
897 | */ |
898 | interp_load_addr = elf_entry; |
899 | elf_entry += loc->interp_elf_ex.e_entry; |
900 | } |
901 | if (BAD_ADDR(elf_entry)) { |
902 | force_sig(SIGSEGV, current); |
903 | retval = IS_ERR((void *)elf_entry) ? |
904 | (int)elf_entry : -EINVAL; |
905 | goto out_free_dentry; |
906 | } |
907 | reloc_func_desc = interp_load_addr; |
908 | |
909 | allow_write_access(interpreter); |
910 | fput(interpreter); |
911 | kfree(elf_interpreter); |
912 | } else { |
913 | elf_entry = loc->elf_ex.e_entry; |
914 | if (BAD_ADDR(elf_entry)) { |
915 | force_sig(SIGSEGV, current); |
916 | retval = -EINVAL; |
917 | goto out_free_dentry; |
918 | } |
919 | } |
920 | |
921 | kfree(elf_phdata); |
922 | |
923 | set_binfmt(&elf_format); |
924 | |
925 | #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES |
926 | retval = arch_setup_additional_pages(bprm, !!elf_interpreter); |
927 | if (retval < 0) { |
928 | send_sig(SIGKILL, current, 0); |
929 | goto out; |
930 | } |
931 | #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ |
932 | |
933 | install_exec_creds(bprm); |
934 | current->flags &= ~PF_FORKNOEXEC; |
935 | retval = create_elf_tables(bprm, &loc->elf_ex, |
936 | load_addr, interp_load_addr); |
937 | if (retval < 0) { |
938 | send_sig(SIGKILL, current, 0); |
939 | goto out; |
940 | } |
941 | /* N.B. passed_fileno might not be initialized? */ |
942 | current->mm->end_code = end_code; |
943 | current->mm->start_code = start_code; |
944 | current->mm->start_data = start_data; |
945 | current->mm->end_data = end_data; |
946 | current->mm->start_stack = bprm->p; |
947 | |
948 | #ifdef arch_randomize_brk |
949 | if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) |
950 | current->mm->brk = current->mm->start_brk = |
951 | arch_randomize_brk(current->mm); |
952 | #endif |
953 | |
954 | if (current->personality & MMAP_PAGE_ZERO) { |
955 | /* Why this, you ask??? Well SVr4 maps page 0 as read-only, |
956 | and some applications "depend" upon this behavior. |
957 | Since we do not have the power to recompile these, we |
958 | emulate the SVr4 behavior. Sigh. */ |
959 | down_write(¤t->mm->mmap_sem); |
960 | error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC, |
961 | MAP_FIXED | MAP_PRIVATE, 0); |
962 | up_write(¤t->mm->mmap_sem); |
963 | } |
964 | |
965 | #ifdef ELF_PLAT_INIT |
966 | /* |
967 | * The ABI may specify that certain registers be set up in special |
968 | * ways (on i386 %edx is the address of a DT_FINI function, for |
969 | * example. In addition, it may also specify (eg, PowerPC64 ELF) |
970 | * that the e_entry field is the address of the function descriptor |
971 | * for the startup routine, rather than the address of the startup |
972 | * routine itself. This macro performs whatever initialization to |
973 | * the regs structure is required as well as any relocations to the |
974 | * function descriptor entries when executing dynamically links apps. |
975 | */ |
976 | ELF_PLAT_INIT(regs, reloc_func_desc); |
977 | #endif |
978 | |
979 | start_thread(regs, elf_entry, bprm->p); |
980 | retval = 0; |
981 | out: |
982 | kfree(loc); |
983 | out_ret: |
984 | return retval; |
985 | |
986 | /* error cleanup */ |
987 | out_free_dentry: |
988 | allow_write_access(interpreter); |
989 | if (interpreter) |
990 | fput(interpreter); |
991 | out_free_interp: |
992 | kfree(elf_interpreter); |
993 | out_free_ph: |
994 | kfree(elf_phdata); |
995 | goto out; |
996 | } |
997 | |
998 | /* This is really simpleminded and specialized - we are loading an |
999 | a.out library that is given an ELF header. */ |
1000 | static int load_elf_library(struct file *file) |
1001 | { |
1002 | struct elf_phdr *elf_phdata; |
1003 | struct elf_phdr *eppnt; |
1004 | unsigned long elf_bss, bss, len; |
1005 | int retval, error, i, j; |
1006 | struct elfhdr elf_ex; |
1007 | |
1008 | error = -ENOEXEC; |
1009 | retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex)); |
1010 | if (retval != sizeof(elf_ex)) |
1011 | goto out; |
1012 | |
1013 | if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) |
1014 | goto out; |
1015 | |
1016 | /* First of all, some simple consistency checks */ |
1017 | if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 || |
1018 | !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap) |
1019 | goto out; |
1020 | |
1021 | /* Now read in all of the header information */ |
1022 | |
1023 | j = sizeof(struct elf_phdr) * elf_ex.e_phnum; |
1024 | /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */ |
1025 | |
1026 | error = -ENOMEM; |
1027 | elf_phdata = kmalloc(j, GFP_KERNEL); |
1028 | if (!elf_phdata) |
1029 | goto out; |
1030 | |
1031 | eppnt = elf_phdata; |
1032 | error = -ENOEXEC; |
1033 | retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j); |
1034 | if (retval != j) |
1035 | goto out_free_ph; |
1036 | |
1037 | for (j = 0, i = 0; i<elf_ex.e_phnum; i++) |
1038 | if ((eppnt + i)->p_type == PT_LOAD) |
1039 | j++; |
1040 | if (j != 1) |
1041 | goto out_free_ph; |
1042 | |
1043 | while (eppnt->p_type != PT_LOAD) |
1044 | eppnt++; |
1045 | |
1046 | /* Now use mmap to map the library into memory. */ |
1047 | down_write(¤t->mm->mmap_sem); |
1048 | error = do_mmap(file, |
1049 | ELF_PAGESTART(eppnt->p_vaddr), |
1050 | (eppnt->p_filesz + |
1051 | ELF_PAGEOFFSET(eppnt->p_vaddr)), |
1052 | PROT_READ | PROT_WRITE | PROT_EXEC, |
1053 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, |
1054 | (eppnt->p_offset - |
1055 | ELF_PAGEOFFSET(eppnt->p_vaddr))); |
1056 | up_write(¤t->mm->mmap_sem); |
1057 | if (error != ELF_PAGESTART(eppnt->p_vaddr)) |
1058 | goto out_free_ph; |
1059 | |
1060 | elf_bss = eppnt->p_vaddr + eppnt->p_filesz; |
1061 | if (padzero(elf_bss)) { |
1062 | error = -EFAULT; |
1063 | goto out_free_ph; |
1064 | } |
1065 | |
1066 | len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + |
1067 | ELF_MIN_ALIGN - 1); |
1068 | bss = eppnt->p_memsz + eppnt->p_vaddr; |
1069 | if (bss > len) { |
1070 | down_write(¤t->mm->mmap_sem); |
1071 | do_brk(len, bss - len); |
1072 | up_write(¤t->mm->mmap_sem); |
1073 | } |
1074 | error = 0; |
1075 | |
1076 | out_free_ph: |
1077 | kfree(elf_phdata); |
1078 | out: |
1079 | return error; |
1080 | } |
1081 | |
1082 | #ifdef CONFIG_ELF_CORE |
1083 | /* |
1084 | * ELF core dumper |
1085 | * |
1086 | * Modelled on fs/exec.c:aout_core_dump() |
1087 | * Jeremy Fitzhardinge <jeremy@sw.oz.au> |
1088 | */ |
1089 | |
1090 | /* |
1091 | * Decide what to dump of a segment, part, all or none. |
1092 | */ |
1093 | static unsigned long vma_dump_size(struct vm_area_struct *vma, |
1094 | unsigned long mm_flags) |
1095 | { |
1096 | #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type)) |
1097 | |
1098 | /* The vma can be set up to tell us the answer directly. */ |
1099 | if (vma->vm_flags & VM_ALWAYSDUMP) |
1100 | goto whole; |
1101 | |
1102 | /* Hugetlb memory check */ |
1103 | if (vma->vm_flags & VM_HUGETLB) { |
1104 | if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED)) |
1105 | goto whole; |
1106 | if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE)) |
1107 | goto whole; |
1108 | } |
1109 | |
1110 | /* Do not dump I/O mapped devices or special mappings */ |
1111 | if (vma->vm_flags & (VM_IO | VM_RESERVED)) |
1112 | return 0; |
1113 | |
1114 | /* By default, dump shared memory if mapped from an anonymous file. */ |
1115 | if (vma->vm_flags & VM_SHARED) { |
1116 | if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ? |
1117 | FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED)) |
1118 | goto whole; |
1119 | return 0; |
1120 | } |
1121 | |
1122 | /* Dump segments that have been written to. */ |
1123 | if (vma->anon_vma && FILTER(ANON_PRIVATE)) |
1124 | goto whole; |
1125 | if (vma->vm_file == NULL) |
1126 | return 0; |
1127 | |
1128 | if (FILTER(MAPPED_PRIVATE)) |
1129 | goto whole; |
1130 | |
1131 | /* |
1132 | * If this looks like the beginning of a DSO or executable mapping, |
1133 | * check for an ELF header. If we find one, dump the first page to |
1134 | * aid in determining what was mapped here. |
1135 | */ |
1136 | if (FILTER(ELF_HEADERS) && |
1137 | vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) { |
1138 | u32 __user *header = (u32 __user *) vma->vm_start; |
1139 | u32 word; |
1140 | mm_segment_t fs = get_fs(); |
1141 | /* |
1142 | * Doing it this way gets the constant folded by GCC. |
1143 | */ |
1144 | union { |
1145 | u32 cmp; |
1146 | char elfmag[SELFMAG]; |
1147 | } magic; |
1148 | BUILD_BUG_ON(SELFMAG != sizeof word); |
1149 | magic.elfmag[EI_MAG0] = ELFMAG0; |
1150 | magic.elfmag[EI_MAG1] = ELFMAG1; |
1151 | magic.elfmag[EI_MAG2] = ELFMAG2; |
1152 | magic.elfmag[EI_MAG3] = ELFMAG3; |
1153 | /* |
1154 | * Switch to the user "segment" for get_user(), |
1155 | * then put back what elf_core_dump() had in place. |
1156 | */ |
1157 | set_fs(USER_DS); |
1158 | if (unlikely(get_user(word, header))) |
1159 | word = 0; |
1160 | set_fs(fs); |
1161 | if (word == magic.cmp) |
1162 | return PAGE_SIZE; |
1163 | } |
1164 | |
1165 | #undef FILTER |
1166 | |
1167 | return 0; |
1168 | |
1169 | whole: |
1170 | return vma->vm_end - vma->vm_start; |
1171 | } |
1172 | |
1173 | /* An ELF note in memory */ |
1174 | struct memelfnote |
1175 | { |
1176 | const char *name; |
1177 | int type; |
1178 | unsigned int datasz; |
1179 | void *data; |
1180 | }; |
1181 | |
1182 | static int notesize(struct memelfnote *en) |
1183 | { |
1184 | int sz; |
1185 | |
1186 | sz = sizeof(struct elf_note); |
1187 | sz += roundup(strlen(en->name) + 1, 4); |
1188 | sz += roundup(en->datasz, 4); |
1189 | |
1190 | return sz; |
1191 | } |
1192 | |
1193 | #define DUMP_WRITE(addr, nr, foffset) \ |
1194 | do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0) |
1195 | |
1196 | static int alignfile(struct file *file, loff_t *foffset) |
1197 | { |
1198 | static const char buf[4] = { 0, }; |
1199 | DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset); |
1200 | return 1; |
1201 | } |
1202 | |
1203 | static int writenote(struct memelfnote *men, struct file *file, |
1204 | loff_t *foffset) |
1205 | { |
1206 | struct elf_note en; |
1207 | en.n_namesz = strlen(men->name) + 1; |
1208 | en.n_descsz = men->datasz; |
1209 | en.n_type = men->type; |
1210 | |
1211 | DUMP_WRITE(&en, sizeof(en), foffset); |
1212 | DUMP_WRITE(men->name, en.n_namesz, foffset); |
1213 | if (!alignfile(file, foffset)) |
1214 | return 0; |
1215 | DUMP_WRITE(men->data, men->datasz, foffset); |
1216 | if (!alignfile(file, foffset)) |
1217 | return 0; |
1218 | |
1219 | return 1; |
1220 | } |
1221 | #undef DUMP_WRITE |
1222 | |
1223 | static void fill_elf_header(struct elfhdr *elf, int segs, |
1224 | u16 machine, u32 flags, u8 osabi) |
1225 | { |
1226 | memset(elf, 0, sizeof(*elf)); |
1227 | |
1228 | memcpy(elf->e_ident, ELFMAG, SELFMAG); |
1229 | elf->e_ident[EI_CLASS] = ELF_CLASS; |
1230 | elf->e_ident[EI_DATA] = ELF_DATA; |
1231 | elf->e_ident[EI_VERSION] = EV_CURRENT; |
1232 | elf->e_ident[EI_OSABI] = ELF_OSABI; |
1233 | |
1234 | elf->e_type = ET_CORE; |
1235 | elf->e_machine = machine; |
1236 | elf->e_version = EV_CURRENT; |
1237 | elf->e_phoff = sizeof(struct elfhdr); |
1238 | elf->e_flags = flags; |
1239 | elf->e_ehsize = sizeof(struct elfhdr); |
1240 | elf->e_phentsize = sizeof(struct elf_phdr); |
1241 | elf->e_phnum = segs; |
1242 | |
1243 | return; |
1244 | } |
1245 | |
1246 | static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) |
1247 | { |
1248 | phdr->p_type = PT_NOTE; |
1249 | phdr->p_offset = offset; |
1250 | phdr->p_vaddr = 0; |
1251 | phdr->p_paddr = 0; |
1252 | phdr->p_filesz = sz; |
1253 | phdr->p_memsz = 0; |
1254 | phdr->p_flags = 0; |
1255 | phdr->p_align = 0; |
1256 | return; |
1257 | } |
1258 | |
1259 | static void fill_note(struct memelfnote *note, const char *name, int type, |
1260 | unsigned int sz, void *data) |
1261 | { |
1262 | note->name = name; |
1263 | note->type = type; |
1264 | note->datasz = sz; |
1265 | note->data = data; |
1266 | return; |
1267 | } |
1268 | |
1269 | /* |
1270 | * fill up all the fields in prstatus from the given task struct, except |
1271 | * registers which need to be filled up separately. |
1272 | */ |
1273 | static void fill_prstatus(struct elf_prstatus *prstatus, |
1274 | struct task_struct *p, long signr) |
1275 | { |
1276 | prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; |
1277 | prstatus->pr_sigpend = p->pending.signal.sig[0]; |
1278 | prstatus->pr_sighold = p->blocked.sig[0]; |
1279 | rcu_read_lock(); |
1280 | prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); |
1281 | rcu_read_unlock(); |
1282 | prstatus->pr_pid = task_pid_vnr(p); |
1283 | prstatus->pr_pgrp = task_pgrp_vnr(p); |
1284 | prstatus->pr_sid = task_session_vnr(p); |
1285 | if (thread_group_leader(p)) { |
1286 | struct task_cputime cputime; |
1287 | |
1288 | /* |
1289 | * This is the record for the group leader. It shows the |
1290 | * group-wide total, not its individual thread total. |
1291 | */ |
1292 | thread_group_cputime(p, &cputime); |
1293 | cputime_to_timeval(cputime.utime, &prstatus->pr_utime); |
1294 | cputime_to_timeval(cputime.stime, &prstatus->pr_stime); |
1295 | } else { |
1296 | cputime_to_timeval(p->utime, &prstatus->pr_utime); |
1297 | cputime_to_timeval(p->stime, &prstatus->pr_stime); |
1298 | } |
1299 | cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); |
1300 | cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); |
1301 | } |
1302 | |
1303 | static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, |
1304 | struct mm_struct *mm) |
1305 | { |
1306 | const struct cred *cred; |
1307 | unsigned int i, len; |
1308 | |
1309 | /* first copy the parameters from user space */ |
1310 | memset(psinfo, 0, sizeof(struct elf_prpsinfo)); |
1311 | |
1312 | len = mm->arg_end - mm->arg_start; |
1313 | if (len >= ELF_PRARGSZ) |
1314 | len = ELF_PRARGSZ-1; |
1315 | if (copy_from_user(&psinfo->pr_psargs, |
1316 | (const char __user *)mm->arg_start, len)) |
1317 | return -EFAULT; |
1318 | for(i = 0; i < len; i++) |
1319 | if (psinfo->pr_psargs[i] == 0) |
1320 | psinfo->pr_psargs[i] = ' '; |
1321 | psinfo->pr_psargs[len] = 0; |
1322 | |
1323 | rcu_read_lock(); |
1324 | psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); |
1325 | rcu_read_unlock(); |
1326 | psinfo->pr_pid = task_pid_vnr(p); |
1327 | psinfo->pr_pgrp = task_pgrp_vnr(p); |
1328 | psinfo->pr_sid = task_session_vnr(p); |
1329 | |
1330 | i = p->state ? ffz(~p->state) + 1 : 0; |
1331 | psinfo->pr_state = i; |
1332 | psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; |
1333 | psinfo->pr_zomb = psinfo->pr_sname == 'Z'; |
1334 | psinfo->pr_nice = task_nice(p); |
1335 | psinfo->pr_flag = p->flags; |
1336 | rcu_read_lock(); |
1337 | cred = __task_cred(p); |
1338 | SET_UID(psinfo->pr_uid, cred->uid); |
1339 | SET_GID(psinfo->pr_gid, cred->gid); |
1340 | rcu_read_unlock(); |
1341 | strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); |
1342 | |
1343 | return 0; |
1344 | } |
1345 | |
1346 | static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm) |
1347 | { |
1348 | elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv; |
1349 | int i = 0; |
1350 | do |
1351 | i += 2; |
1352 | while (auxv[i - 2] != AT_NULL); |
1353 | fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv); |
1354 | } |
1355 | |
1356 | #ifdef CORE_DUMP_USE_REGSET |
1357 | #include <linux/regset.h> |
1358 | |
1359 | struct elf_thread_core_info { |
1360 | struct elf_thread_core_info *next; |
1361 | struct task_struct *task; |
1362 | struct elf_prstatus prstatus; |
1363 | struct memelfnote notes[0]; |
1364 | }; |
1365 | |
1366 | struct elf_note_info { |
1367 | struct elf_thread_core_info *thread; |
1368 | struct memelfnote psinfo; |
1369 | struct memelfnote auxv; |
1370 | size_t size; |
1371 | int thread_notes; |
1372 | }; |
1373 | |
1374 | /* |
1375 | * When a regset has a writeback hook, we call it on each thread before |
1376 | * dumping user memory. On register window machines, this makes sure the |
1377 | * user memory backing the register data is up to date before we read it. |
1378 | */ |
1379 | static void do_thread_regset_writeback(struct task_struct *task, |
1380 | const struct user_regset *regset) |
1381 | { |
1382 | if (regset->writeback) |
1383 | regset->writeback(task, regset, 1); |
1384 | } |
1385 | |
1386 | static int fill_thread_core_info(struct elf_thread_core_info *t, |
1387 | const struct user_regset_view *view, |
1388 | long signr, size_t *total) |
1389 | { |
1390 | unsigned int i; |
1391 | |
1392 | /* |
1393 | * NT_PRSTATUS is the one special case, because the regset data |
1394 | * goes into the pr_reg field inside the note contents, rather |
1395 | * than being the whole note contents. We fill the reset in here. |
1396 | * We assume that regset 0 is NT_PRSTATUS. |
1397 | */ |
1398 | fill_prstatus(&t->prstatus, t->task, signr); |
1399 | (void) view->regsets[0].get(t->task, &view->regsets[0], |
1400 | 0, sizeof(t->prstatus.pr_reg), |
1401 | &t->prstatus.pr_reg, NULL); |
1402 | |
1403 | fill_note(&t->notes[0], "CORE", NT_PRSTATUS, |
1404 | sizeof(t->prstatus), &t->prstatus); |
1405 | *total += notesize(&t->notes[0]); |
1406 | |
1407 | do_thread_regset_writeback(t->task, &view->regsets[0]); |
1408 | |
1409 | /* |
1410 | * Each other regset might generate a note too. For each regset |
1411 | * that has no core_note_type or is inactive, we leave t->notes[i] |
1412 | * all zero and we'll know to skip writing it later. |
1413 | */ |
1414 | for (i = 1; i < view->n; ++i) { |
1415 | const struct user_regset *regset = &view->regsets[i]; |
1416 | do_thread_regset_writeback(t->task, regset); |
1417 | if (regset->core_note_type && |
1418 | (!regset->active || regset->active(t->task, regset))) { |
1419 | int ret; |
1420 | size_t size = regset->n * regset->size; |
1421 | void *data = kmalloc(size, GFP_KERNEL); |
1422 | if (unlikely(!data)) |
1423 | return 0; |
1424 | ret = regset->get(t->task, regset, |
1425 | 0, size, data, NULL); |
1426 | if (unlikely(ret)) |
1427 | kfree(data); |
1428 | else { |
1429 | if (regset->core_note_type != NT_PRFPREG) |
1430 | fill_note(&t->notes[i], "LINUX", |
1431 | regset->core_note_type, |
1432 | size, data); |
1433 | else { |
1434 | t->prstatus.pr_fpvalid = 1; |
1435 | fill_note(&t->notes[i], "CORE", |
1436 | NT_PRFPREG, size, data); |
1437 | } |
1438 | *total += notesize(&t->notes[i]); |
1439 | } |
1440 | } |
1441 | } |
1442 | |
1443 | return 1; |
1444 | } |
1445 | |
1446 | static int fill_note_info(struct elfhdr *elf, int phdrs, |
1447 | struct elf_note_info *info, |
1448 | long signr, struct pt_regs *regs) |
1449 | { |
1450 | struct task_struct *dump_task = current; |
1451 | const struct user_regset_view *view = task_user_regset_view(dump_task); |
1452 | struct elf_thread_core_info *t; |
1453 | struct elf_prpsinfo *psinfo; |
1454 | struct core_thread *ct; |
1455 | unsigned int i; |
1456 | |
1457 | info->size = 0; |
1458 | info->thread = NULL; |
1459 | |
1460 | psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); |
1461 | if (psinfo == NULL) |
1462 | return 0; |
1463 | |
1464 | fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); |
1465 | |
1466 | /* |
1467 | * Figure out how many notes we're going to need for each thread. |
1468 | */ |
1469 | info->thread_notes = 0; |
1470 | for (i = 0; i < view->n; ++i) |
1471 | if (view->regsets[i].core_note_type != 0) |
1472 | ++info->thread_notes; |
1473 | |
1474 | /* |
1475 | * Sanity check. We rely on regset 0 being in NT_PRSTATUS, |
1476 | * since it is our one special case. |
1477 | */ |
1478 | if (unlikely(info->thread_notes == 0) || |
1479 | unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) { |
1480 | WARN_ON(1); |
1481 | return 0; |
1482 | } |
1483 | |
1484 | /* |
1485 | * Initialize the ELF file header. |
1486 | */ |
1487 | fill_elf_header(elf, phdrs, |
1488 | view->e_machine, view->e_flags, view->ei_osabi); |
1489 | |
1490 | /* |
1491 | * Allocate a structure for each thread. |
1492 | */ |
1493 | for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) { |
1494 | t = kzalloc(offsetof(struct elf_thread_core_info, |
1495 | notes[info->thread_notes]), |
1496 | GFP_KERNEL); |
1497 | if (unlikely(!t)) |
1498 | return 0; |
1499 | |
1500 | t->task = ct->task; |
1501 | if (ct->task == dump_task || !info->thread) { |
1502 | t->next = info->thread; |
1503 | info->thread = t; |
1504 | } else { |
1505 | /* |
1506 | * Make sure to keep the original task at |
1507 | * the head of the list. |
1508 | */ |
1509 | t->next = info->thread->next; |
1510 | info->thread->next = t; |
1511 | } |
1512 | } |
1513 | |
1514 | /* |
1515 | * Now fill in each thread's information. |
1516 | */ |
1517 | for (t = info->thread; t != NULL; t = t->next) |
1518 | if (!fill_thread_core_info(t, view, signr, &info->size)) |
1519 | return 0; |
1520 | |
1521 | /* |
1522 | * Fill in the two process-wide notes. |
1523 | */ |
1524 | fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm); |
1525 | info->size += notesize(&info->psinfo); |
1526 | |
1527 | fill_auxv_note(&info->auxv, current->mm); |
1528 | info->size += notesize(&info->auxv); |
1529 | |
1530 | return 1; |
1531 | } |
1532 | |
1533 | static size_t get_note_info_size(struct elf_note_info *info) |
1534 | { |
1535 | return info->size; |
1536 | } |
1537 | |
1538 | /* |
1539 | * Write all the notes for each thread. When writing the first thread, the |
1540 | * process-wide notes are interleaved after the first thread-specific note. |
1541 | */ |
1542 | static int write_note_info(struct elf_note_info *info, |
1543 | struct file *file, loff_t *foffset) |
1544 | { |
1545 | bool first = 1; |
1546 | struct elf_thread_core_info *t = info->thread; |
1547 | |
1548 | do { |
1549 | int i; |
1550 | |
1551 | if (!writenote(&t->notes[0], file, foffset)) |
1552 | return 0; |
1553 | |
1554 | if (first && !writenote(&info->psinfo, file, foffset)) |
1555 | return 0; |
1556 | if (first && !writenote(&info->auxv, file, foffset)) |
1557 | return 0; |
1558 | |
1559 | for (i = 1; i < info->thread_notes; ++i) |
1560 | if (t->notes[i].data && |
1561 | !writenote(&t->notes[i], file, foffset)) |
1562 | return 0; |
1563 | |
1564 | first = 0; |
1565 | t = t->next; |
1566 | } while (t); |
1567 | |
1568 | return 1; |
1569 | } |
1570 | |
1571 | static void free_note_info(struct elf_note_info *info) |
1572 | { |
1573 | struct elf_thread_core_info *threads = info->thread; |
1574 | while (threads) { |
1575 | unsigned int i; |
1576 | struct elf_thread_core_info *t = threads; |
1577 | threads = t->next; |
1578 | WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus); |
1579 | for (i = 1; i < info->thread_notes; ++i) |
1580 | kfree(t->notes[i].data); |
1581 | kfree(t); |
1582 | } |
1583 | kfree(info->psinfo.data); |
1584 | } |
1585 | |
1586 | #else |
1587 | |
1588 | /* Here is the structure in which status of each thread is captured. */ |
1589 | struct elf_thread_status |
1590 | { |
1591 | struct list_head list; |
1592 | struct elf_prstatus prstatus; /* NT_PRSTATUS */ |
1593 | elf_fpregset_t fpu; /* NT_PRFPREG */ |
1594 | struct task_struct *thread; |
1595 | #ifdef ELF_CORE_COPY_XFPREGS |
1596 | elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ |
1597 | #endif |
1598 | struct memelfnote notes[3]; |
1599 | int num_notes; |
1600 | }; |
1601 | |
1602 | /* |
1603 | * In order to add the specific thread information for the elf file format, |
1604 | * we need to keep a linked list of every threads pr_status and then create |
1605 | * a single section for them in the final core file. |
1606 | */ |
1607 | static int elf_dump_thread_status(long signr, struct elf_thread_status *t) |
1608 | { |
1609 | int sz = 0; |
1610 | struct task_struct *p = t->thread; |
1611 | t->num_notes = 0; |
1612 | |
1613 | fill_prstatus(&t->prstatus, p, signr); |
1614 | elf_core_copy_task_regs(p, &t->prstatus.pr_reg); |
1615 | |
1616 | fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), |
1617 | &(t->prstatus)); |
1618 | t->num_notes++; |
1619 | sz += notesize(&t->notes[0]); |
1620 | |
1621 | if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, |
1622 | &t->fpu))) { |
1623 | fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), |
1624 | &(t->fpu)); |
1625 | t->num_notes++; |
1626 | sz += notesize(&t->notes[1]); |
1627 | } |
1628 | |
1629 | #ifdef ELF_CORE_COPY_XFPREGS |
1630 | if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { |
1631 | fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, |
1632 | sizeof(t->xfpu), &t->xfpu); |
1633 | t->num_notes++; |
1634 | sz += notesize(&t->notes[2]); |
1635 | } |
1636 | #endif |
1637 | return sz; |
1638 | } |
1639 | |
1640 | struct elf_note_info { |
1641 | struct memelfnote *notes; |
1642 | struct elf_prstatus *prstatus; /* NT_PRSTATUS */ |
1643 | struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */ |
1644 | struct list_head thread_list; |
1645 | elf_fpregset_t *fpu; |
1646 | #ifdef ELF_CORE_COPY_XFPREGS |
1647 | elf_fpxregset_t *xfpu; |
1648 | #endif |
1649 | int thread_status_size; |
1650 | int numnote; |
1651 | }; |
1652 | |
1653 | static int elf_note_info_init(struct elf_note_info *info) |
1654 | { |
1655 | memset(info, 0, sizeof(*info)); |
1656 | INIT_LIST_HEAD(&info->thread_list); |
1657 | |
1658 | /* Allocate space for six ELF notes */ |
1659 | info->notes = kmalloc(6 * sizeof(struct memelfnote), GFP_KERNEL); |
1660 | if (!info->notes) |
1661 | return 0; |
1662 | info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL); |
1663 | if (!info->psinfo) |
1664 | goto notes_free; |
1665 | info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL); |
1666 | if (!info->prstatus) |
1667 | goto psinfo_free; |
1668 | info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL); |
1669 | if (!info->fpu) |
1670 | goto prstatus_free; |
1671 | #ifdef ELF_CORE_COPY_XFPREGS |
1672 | info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL); |
1673 | if (!info->xfpu) |
1674 | goto fpu_free; |
1675 | #endif |
1676 | return 1; |
1677 | #ifdef ELF_CORE_COPY_XFPREGS |
1678 | fpu_free: |
1679 | kfree(info->fpu); |
1680 | #endif |
1681 | prstatus_free: |
1682 | kfree(info->prstatus); |
1683 | psinfo_free: |
1684 | kfree(info->psinfo); |
1685 | notes_free: |
1686 | kfree(info->notes); |
1687 | return 0; |
1688 | } |
1689 | |
1690 | static int fill_note_info(struct elfhdr *elf, int phdrs, |
1691 | struct elf_note_info *info, |
1692 | long signr, struct pt_regs *regs) |
1693 | { |
1694 | struct list_head *t; |
1695 | |
1696 | if (!elf_note_info_init(info)) |
1697 | return 0; |
1698 | |
1699 | if (signr) { |
1700 | struct core_thread *ct; |
1701 | struct elf_thread_status *ets; |
1702 | |
1703 | for (ct = current->mm->core_state->dumper.next; |
1704 | ct; ct = ct->next) { |
1705 | ets = kzalloc(sizeof(*ets), GFP_KERNEL); |
1706 | if (!ets) |
1707 | return 0; |
1708 | |
1709 | ets->thread = ct->task; |
1710 | list_add(&ets->list, &info->thread_list); |
1711 | } |
1712 | |
1713 | list_for_each(t, &info->thread_list) { |
1714 | int sz; |
1715 | |
1716 | ets = list_entry(t, struct elf_thread_status, list); |
1717 | sz = elf_dump_thread_status(signr, ets); |
1718 | info->thread_status_size += sz; |
1719 | } |
1720 | } |
1721 | /* now collect the dump for the current */ |
1722 | memset(info->prstatus, 0, sizeof(*info->prstatus)); |
1723 | fill_prstatus(info->prstatus, current, signr); |
1724 | elf_core_copy_regs(&info->prstatus->pr_reg, regs); |
1725 | |
1726 | /* Set up header */ |
1727 | fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI); |
1728 | |
1729 | /* |
1730 | * Set up the notes in similar form to SVR4 core dumps made |
1731 | * with info from their /proc. |
1732 | */ |
1733 | |
1734 | fill_note(info->notes + 0, "CORE", NT_PRSTATUS, |
1735 | sizeof(*info->prstatus), info->prstatus); |
1736 | fill_psinfo(info->psinfo, current->group_leader, current->mm); |
1737 | fill_note(info->notes + 1, "CORE", NT_PRPSINFO, |
1738 | sizeof(*info->psinfo), info->psinfo); |
1739 | |
1740 | info->numnote = 2; |
1741 | |
1742 | fill_auxv_note(&info->notes[info->numnote++], current->mm); |
1743 | |
1744 | /* Try to dump the FPU. */ |
1745 | info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs, |
1746 | info->fpu); |
1747 | if (info->prstatus->pr_fpvalid) |
1748 | fill_note(info->notes + info->numnote++, |
1749 | "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu); |
1750 | #ifdef ELF_CORE_COPY_XFPREGS |
1751 | if (elf_core_copy_task_xfpregs(current, info->xfpu)) |
1752 | fill_note(info->notes + info->numnote++, |
1753 | "LINUX", ELF_CORE_XFPREG_TYPE, |
1754 | sizeof(*info->xfpu), info->xfpu); |
1755 | #endif |
1756 | |
1757 | return 1; |
1758 | } |
1759 | |
1760 | static size_t get_note_info_size(struct elf_note_info *info) |
1761 | { |
1762 | int sz = 0; |
1763 | int i; |
1764 | |
1765 | for (i = 0; i < info->numnote; i++) |
1766 | sz += notesize(info->notes + i); |
1767 | |
1768 | sz += info->thread_status_size; |
1769 | |
1770 | return sz; |
1771 | } |
1772 | |
1773 | static int write_note_info(struct elf_note_info *info, |
1774 | struct file *file, loff_t *foffset) |
1775 | { |
1776 | int i; |
1777 | struct list_head *t; |
1778 | |
1779 | for (i = 0; i < info->numnote; i++) |
1780 | if (!writenote(info->notes + i, file, foffset)) |
1781 | return 0; |
1782 | |
1783 | /* write out the thread status notes section */ |
1784 | list_for_each(t, &info->thread_list) { |
1785 | struct elf_thread_status *tmp = |
1786 | list_entry(t, struct elf_thread_status, list); |
1787 | |
1788 | for (i = 0; i < tmp->num_notes; i++) |
1789 | if (!writenote(&tmp->notes[i], file, foffset)) |
1790 | return 0; |
1791 | } |
1792 | |
1793 | return 1; |
1794 | } |
1795 | |
1796 | static void free_note_info(struct elf_note_info *info) |
1797 | { |
1798 | while (!list_empty(&info->thread_list)) { |
1799 | struct list_head *tmp = info->thread_list.next; |
1800 | list_del(tmp); |
1801 | kfree(list_entry(tmp, struct elf_thread_status, list)); |
1802 | } |
1803 | |
1804 | kfree(info->prstatus); |
1805 | kfree(info->psinfo); |
1806 | kfree(info->notes); |
1807 | kfree(info->fpu); |
1808 | #ifdef ELF_CORE_COPY_XFPREGS |
1809 | kfree(info->xfpu); |
1810 | #endif |
1811 | } |
1812 | |
1813 | #endif |
1814 | |
1815 | static struct vm_area_struct *first_vma(struct task_struct *tsk, |
1816 | struct vm_area_struct *gate_vma) |
1817 | { |
1818 | struct vm_area_struct *ret = tsk->mm->mmap; |
1819 | |
1820 | if (ret) |
1821 | return ret; |
1822 | return gate_vma; |
1823 | } |
1824 | /* |
1825 | * Helper function for iterating across a vma list. It ensures that the caller |
1826 | * will visit `gate_vma' prior to terminating the search. |
1827 | */ |
1828 | static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma, |
1829 | struct vm_area_struct *gate_vma) |
1830 | { |
1831 | struct vm_area_struct *ret; |
1832 | |
1833 | ret = this_vma->vm_next; |
1834 | if (ret) |
1835 | return ret; |
1836 | if (this_vma == gate_vma) |
1837 | return NULL; |
1838 | return gate_vma; |
1839 | } |
1840 | |
1841 | static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, |
1842 | elf_addr_t e_shoff, int segs) |
1843 | { |
1844 | elf->e_shoff = e_shoff; |
1845 | elf->e_shentsize = sizeof(*shdr4extnum); |
1846 | elf->e_shnum = 1; |
1847 | elf->e_shstrndx = SHN_UNDEF; |
1848 | |
1849 | memset(shdr4extnum, 0, sizeof(*shdr4extnum)); |
1850 | |
1851 | shdr4extnum->sh_type = SHT_NULL; |
1852 | shdr4extnum->sh_size = elf->e_shnum; |
1853 | shdr4extnum->sh_link = elf->e_shstrndx; |
1854 | shdr4extnum->sh_info = segs; |
1855 | } |
1856 | |
1857 | static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma, |
1858 | unsigned long mm_flags) |
1859 | { |
1860 | struct vm_area_struct *vma; |
1861 | size_t size = 0; |
1862 | |
1863 | for (vma = first_vma(current, gate_vma); vma != NULL; |
1864 | vma = next_vma(vma, gate_vma)) |
1865 | size += vma_dump_size(vma, mm_flags); |
1866 | return size; |
1867 | } |
1868 | |
1869 | /* |
1870 | * Actual dumper |
1871 | * |
1872 | * This is a two-pass process; first we find the offsets of the bits, |
1873 | * and then they are actually written out. If we run out of core limit |
1874 | * we just truncate. |
1875 | */ |
1876 | static int elf_core_dump(struct coredump_params *cprm) |
1877 | { |
1878 | int has_dumped = 0; |
1879 | mm_segment_t fs; |
1880 | int segs; |
1881 | size_t size = 0; |
1882 | struct vm_area_struct *vma, *gate_vma; |
1883 | struct elfhdr *elf = NULL; |
1884 | loff_t offset = 0, dataoff, foffset; |
1885 | struct elf_note_info info; |
1886 | struct elf_phdr *phdr4note = NULL; |
1887 | struct elf_shdr *shdr4extnum = NULL; |
1888 | Elf_Half e_phnum; |
1889 | elf_addr_t e_shoff; |
1890 | |
1891 | /* |
1892 | * We no longer stop all VM operations. |
1893 | * |
1894 | * This is because those proceses that could possibly change map_count |
1895 | * or the mmap / vma pages are now blocked in do_exit on current |
1896 | * finishing this core dump. |
1897 | * |
1898 | * Only ptrace can touch these memory addresses, but it doesn't change |
1899 | * the map_count or the pages allocated. So no possibility of crashing |
1900 | * exists while dumping the mm->vm_next areas to the core file. |
1901 | */ |
1902 | |
1903 | /* alloc memory for large data structures: too large to be on stack */ |
1904 | elf = kmalloc(sizeof(*elf), GFP_KERNEL); |
1905 | if (!elf) |
1906 | goto out; |
1907 | /* |
1908 | * The number of segs are recored into ELF header as 16bit value. |
1909 | * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here. |
1910 | */ |
1911 | segs = current->mm->map_count; |
1912 | segs += elf_core_extra_phdrs(); |
1913 | |
1914 | gate_vma = get_gate_vma(current); |
1915 | if (gate_vma != NULL) |
1916 | segs++; |
1917 | |
1918 | /* for notes section */ |
1919 | segs++; |
1920 | |
1921 | /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid |
1922 | * this, kernel supports extended numbering. Have a look at |
1923 | * include/linux/elf.h for further information. */ |
1924 | e_phnum = segs > PN_XNUM ? PN_XNUM : segs; |
1925 | |
1926 | /* |
1927 | * Collect all the non-memory information about the process for the |
1928 | * notes. This also sets up the file header. |
1929 | */ |
1930 | if (!fill_note_info(elf, e_phnum, &info, cprm->signr, cprm->regs)) |
1931 | goto cleanup; |
1932 | |
1933 | has_dumped = 1; |
1934 | current->flags |= PF_DUMPCORE; |
1935 | |
1936 | fs = get_fs(); |
1937 | set_fs(KERNEL_DS); |
1938 | |
1939 | offset += sizeof(*elf); /* Elf header */ |
1940 | offset += segs * sizeof(struct elf_phdr); /* Program headers */ |
1941 | foffset = offset; |
1942 | |
1943 | /* Write notes phdr entry */ |
1944 | { |
1945 | size_t sz = get_note_info_size(&info); |
1946 | |
1947 | sz += elf_coredump_extra_notes_size(); |
1948 | |
1949 | phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); |
1950 | if (!phdr4note) |
1951 | goto end_coredump; |
1952 | |
1953 | fill_elf_note_phdr(phdr4note, sz, offset); |
1954 | offset += sz; |
1955 | } |
1956 | |
1957 | dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); |
1958 | |
1959 | offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags); |
1960 | offset += elf_core_extra_data_size(); |
1961 | e_shoff = offset; |
1962 | |
1963 | if (e_phnum == PN_XNUM) { |
1964 | shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); |
1965 | if (!shdr4extnum) |
1966 | goto end_coredump; |
1967 | fill_extnum_info(elf, shdr4extnum, e_shoff, segs); |
1968 | } |
1969 | |
1970 | offset = dataoff; |
1971 | |
1972 | size += sizeof(*elf); |
1973 | if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf))) |
1974 | goto end_coredump; |
1975 | |
1976 | size += sizeof(*phdr4note); |
1977 | if (size > cprm->limit |
1978 | || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note))) |
1979 | goto end_coredump; |
1980 | |
1981 | /* Write program headers for segments dump */ |
1982 | for (vma = first_vma(current, gate_vma); vma != NULL; |
1983 | vma = next_vma(vma, gate_vma)) { |
1984 | struct elf_phdr phdr; |
1985 | |
1986 | phdr.p_type = PT_LOAD; |
1987 | phdr.p_offset = offset; |
1988 | phdr.p_vaddr = vma->vm_start; |
1989 | phdr.p_paddr = 0; |
1990 | phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags); |
1991 | phdr.p_memsz = vma->vm_end - vma->vm_start; |
1992 | offset += phdr.p_filesz; |
1993 | phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; |
1994 | if (vma->vm_flags & VM_WRITE) |
1995 | phdr.p_flags |= PF_W; |
1996 | if (vma->vm_flags & VM_EXEC) |
1997 | phdr.p_flags |= PF_X; |
1998 | phdr.p_align = ELF_EXEC_PAGESIZE; |
1999 | |
2000 | size += sizeof(phdr); |
2001 | if (size > cprm->limit |
2002 | || !dump_write(cprm->file, &phdr, sizeof(phdr))) |
2003 | goto end_coredump; |
2004 | } |
2005 | |
2006 | if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit)) |
2007 | goto end_coredump; |
2008 | |
2009 | /* write out the notes section */ |
2010 | if (!write_note_info(&info, cprm->file, &foffset)) |
2011 | goto end_coredump; |
2012 | |
2013 | if (elf_coredump_extra_notes_write(cprm->file, &foffset)) |
2014 | goto end_coredump; |
2015 | |
2016 | /* Align to page */ |
2017 | if (!dump_seek(cprm->file, dataoff - foffset)) |
2018 | goto end_coredump; |
2019 | |
2020 | for (vma = first_vma(current, gate_vma); vma != NULL; |
2021 | vma = next_vma(vma, gate_vma)) { |
2022 | unsigned long addr; |
2023 | unsigned long end; |
2024 | |
2025 | end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags); |
2026 | |
2027 | for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) { |
2028 | struct page *page; |
2029 | int stop; |
2030 | |
2031 | page = get_dump_page(addr); |
2032 | if (page) { |
2033 | void *kaddr = kmap(page); |
2034 | stop = ((size += PAGE_SIZE) > cprm->limit) || |
2035 | !dump_write(cprm->file, kaddr, |
2036 | PAGE_SIZE); |
2037 | kunmap(page); |
2038 | page_cache_release(page); |
2039 | } else |
2040 | stop = !dump_seek(cprm->file, PAGE_SIZE); |
2041 | if (stop) |
2042 | goto end_coredump; |
2043 | } |
2044 | } |
2045 | |
2046 | if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit)) |
2047 | goto end_coredump; |
2048 | |
2049 | if (e_phnum == PN_XNUM) { |
2050 | size += sizeof(*shdr4extnum); |
2051 | if (size > cprm->limit |
2052 | || !dump_write(cprm->file, shdr4extnum, |
2053 | sizeof(*shdr4extnum))) |
2054 | goto end_coredump; |
2055 | } |
2056 | |
2057 | end_coredump: |
2058 | set_fs(fs); |
2059 | |
2060 | cleanup: |
2061 | free_note_info(&info); |
2062 | kfree(shdr4extnum); |
2063 | kfree(phdr4note); |
2064 | kfree(elf); |
2065 | out: |
2066 | return has_dumped; |
2067 | } |
2068 | |
2069 | #endif /* CONFIG_ELF_CORE */ |
2070 | |
2071 | static int __init init_elf_binfmt(void) |
2072 | { |
2073 | return register_binfmt(&elf_format); |
2074 | } |
2075 | |
2076 | static void __exit exit_elf_binfmt(void) |
2077 | { |
2078 | /* Remove the COFF and ELF loaders. */ |
2079 | unregister_binfmt(&elf_format); |
2080 | } |
2081 | |
2082 | core_initcall(init_elf_binfmt); |
2083 | module_exit(exit_elf_binfmt); |
2084 | MODULE_LICENSE("GPL"); |
2085 |
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