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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/vmalloc.h> |
31 | #include <linux/security.h> |
32 | #include <linux/random.h> |
33 | #include <linux/elf.h> |
34 | #include <linux/utsname.h> |
35 | #include <linux/coredump.h> |
36 | #include <linux/sched.h> |
37 | #include <asm/uaccess.h> |
38 | #include <asm/param.h> |
39 | #include <asm/page.h> |
40 | |
41 | #ifndef user_long_t |
42 | #define user_long_t long |
43 | #endif |
44 | #ifndef user_siginfo_t |
45 | #define user_siginfo_t siginfo_t |
46 | #endif |
47 | |
48 | static int load_elf_binary(struct linux_binprm *bprm); |
49 | static int load_elf_library(struct file *); |
50 | static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *, |
51 | int, int, unsigned long); |
52 | |
53 | /* |
54 | * If we don't support core dumping, then supply a NULL so we |
55 | * don't even try. |
56 | */ |
57 | #ifdef CONFIG_ELF_CORE |
58 | static int elf_core_dump(struct coredump_params *cprm); |
59 | #else |
60 | #define elf_core_dump NULL |
61 | #endif |
62 | |
63 | #if ELF_EXEC_PAGESIZE > PAGE_SIZE |
64 | #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE |
65 | #else |
66 | #define ELF_MIN_ALIGN PAGE_SIZE |
67 | #endif |
68 | |
69 | #ifndef ELF_CORE_EFLAGS |
70 | #define ELF_CORE_EFLAGS 0 |
71 | #endif |
72 | |
73 | #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1)) |
74 | #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1)) |
75 | #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1)) |
76 | |
77 | static struct linux_binfmt elf_format = { |
78 | .module = THIS_MODULE, |
79 | .load_binary = load_elf_binary, |
80 | .load_shlib = load_elf_library, |
81 | .core_dump = elf_core_dump, |
82 | .min_coredump = ELF_EXEC_PAGESIZE, |
83 | }; |
84 | |
85 | #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) |
86 | |
87 | static int set_brk(unsigned long start, unsigned long end) |
88 | { |
89 | start = ELF_PAGEALIGN(start); |
90 | end = ELF_PAGEALIGN(end); |
91 | if (end > start) { |
92 | unsigned long addr; |
93 | addr = vm_brk(start, end - start); |
94 | if (BAD_ADDR(addr)) |
95 | return addr; |
96 | } |
97 | current->mm->start_brk = current->mm->brk = end; |
98 | return 0; |
99 | } |
100 | |
101 | /* We need to explicitly zero any fractional pages |
102 | after the data section (i.e. bss). This would |
103 | contain the junk from the file that should not |
104 | be in memory |
105 | */ |
106 | static int padzero(unsigned long elf_bss) |
107 | { |
108 | unsigned long nbyte; |
109 | |
110 | nbyte = ELF_PAGEOFFSET(elf_bss); |
111 | if (nbyte) { |
112 | nbyte = ELF_MIN_ALIGN - nbyte; |
113 | if (clear_user((void __user *) elf_bss, nbyte)) |
114 | return -EFAULT; |
115 | } |
116 | return 0; |
117 | } |
118 | |
119 | /* Let's use some macros to make this stack manipulation a little clearer */ |
120 | #ifdef CONFIG_STACK_GROWSUP |
121 | #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items)) |
122 | #define STACK_ROUND(sp, items) \ |
123 | ((15 + (unsigned long) ((sp) + (items))) &~ 15UL) |
124 | #define STACK_ALLOC(sp, len) ({ \ |
125 | elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \ |
126 | old_sp; }) |
127 | #else |
128 | #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items)) |
129 | #define STACK_ROUND(sp, items) \ |
130 | (((unsigned long) (sp - items)) &~ 15UL) |
131 | #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; }) |
132 | #endif |
133 | |
134 | #ifndef ELF_BASE_PLATFORM |
135 | /* |
136 | * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. |
137 | * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value |
138 | * will be copied to the user stack in the same manner as AT_PLATFORM. |
139 | */ |
140 | #define ELF_BASE_PLATFORM NULL |
141 | #endif |
142 | |
143 | static int |
144 | create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, |
145 | unsigned long load_addr, unsigned long interp_load_addr) |
146 | { |
147 | unsigned long p = bprm->p; |
148 | int argc = bprm->argc; |
149 | int envc = bprm->envc; |
150 | elf_addr_t __user *argv; |
151 | elf_addr_t __user *envp; |
152 | elf_addr_t __user *sp; |
153 | elf_addr_t __user *u_platform; |
154 | elf_addr_t __user *u_base_platform; |
155 | elf_addr_t __user *u_rand_bytes; |
156 | const char *k_platform = ELF_PLATFORM; |
157 | const char *k_base_platform = ELF_BASE_PLATFORM; |
158 | unsigned char k_rand_bytes[16]; |
159 | int items; |
160 | elf_addr_t *elf_info; |
161 | int ei_index = 0; |
162 | const struct cred *cred = current_cred(); |
163 | struct vm_area_struct *vma; |
164 | |
165 | /* |
166 | * In some cases (e.g. Hyper-Threading), we want to avoid L1 |
167 | * evictions by the processes running on the same package. One |
168 | * thing we can do is to shuffle the initial stack for them. |
169 | */ |
170 | |
171 | p = arch_align_stack(p); |
172 | |
173 | /* |
174 | * If this architecture has a platform capability string, copy it |
175 | * to userspace. In some cases (Sparc), this info is impossible |
176 | * for userspace to get any other way, in others (i386) it is |
177 | * merely difficult. |
178 | */ |
179 | u_platform = NULL; |
180 | if (k_platform) { |
181 | size_t len = strlen(k_platform) + 1; |
182 | |
183 | u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); |
184 | if (__copy_to_user(u_platform, k_platform, len)) |
185 | return -EFAULT; |
186 | } |
187 | |
188 | /* |
189 | * If this architecture has a "base" platform capability |
190 | * string, copy it to userspace. |
191 | */ |
192 | u_base_platform = NULL; |
193 | if (k_base_platform) { |
194 | size_t len = strlen(k_base_platform) + 1; |
195 | |
196 | u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); |
197 | if (__copy_to_user(u_base_platform, k_base_platform, len)) |
198 | return -EFAULT; |
199 | } |
200 | |
201 | /* |
202 | * Generate 16 random bytes for userspace PRNG seeding. |
203 | */ |
204 | get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes)); |
205 | u_rand_bytes = (elf_addr_t __user *) |
206 | STACK_ALLOC(p, sizeof(k_rand_bytes)); |
207 | if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes))) |
208 | return -EFAULT; |
209 | |
210 | /* Create the ELF interpreter info */ |
211 | elf_info = (elf_addr_t *)current->mm->saved_auxv; |
212 | /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */ |
213 | #define NEW_AUX_ENT(id, val) \ |
214 | do { \ |
215 | elf_info[ei_index++] = id; \ |
216 | elf_info[ei_index++] = val; \ |
217 | } while (0) |
218 | |
219 | #ifdef ARCH_DLINFO |
220 | /* |
221 | * ARCH_DLINFO must come first so PPC can do its special alignment of |
222 | * AUXV. |
223 | * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in |
224 | * ARCH_DLINFO changes |
225 | */ |
226 | ARCH_DLINFO; |
227 | #endif |
228 | NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); |
229 | NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE); |
230 | NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); |
231 | NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff); |
232 | NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); |
233 | NEW_AUX_ENT(AT_PHNUM, exec->e_phnum); |
234 | NEW_AUX_ENT(AT_BASE, interp_load_addr); |
235 | NEW_AUX_ENT(AT_FLAGS, 0); |
236 | NEW_AUX_ENT(AT_ENTRY, exec->e_entry); |
237 | NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid)); |
238 | NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid)); |
239 | NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid)); |
240 | NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid)); |
241 | NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); |
242 | NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes); |
243 | #ifdef ELF_HWCAP2 |
244 | NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); |
245 | #endif |
246 | NEW_AUX_ENT(AT_EXECFN, bprm->exec); |
247 | if (k_platform) { |
248 | NEW_AUX_ENT(AT_PLATFORM, |
249 | (elf_addr_t)(unsigned long)u_platform); |
250 | } |
251 | if (k_base_platform) { |
252 | NEW_AUX_ENT(AT_BASE_PLATFORM, |
253 | (elf_addr_t)(unsigned long)u_base_platform); |
254 | } |
255 | if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { |
256 | NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); |
257 | } |
258 | #undef NEW_AUX_ENT |
259 | /* AT_NULL is zero; clear the rest too */ |
260 | memset(&elf_info[ei_index], 0, |
261 | sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]); |
262 | |
263 | /* And advance past the AT_NULL entry. */ |
264 | ei_index += 2; |
265 | |
266 | sp = STACK_ADD(p, ei_index); |
267 | |
268 | items = (argc + 1) + (envc + 1) + 1; |
269 | bprm->p = STACK_ROUND(sp, items); |
270 | |
271 | /* Point sp at the lowest address on the stack */ |
272 | #ifdef CONFIG_STACK_GROWSUP |
273 | sp = (elf_addr_t __user *)bprm->p - items - ei_index; |
274 | bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */ |
275 | #else |
276 | sp = (elf_addr_t __user *)bprm->p; |
277 | #endif |
278 | |
279 | |
280 | /* |
281 | * Grow the stack manually; some architectures have a limit on how |
282 | * far ahead a user-space access may be in order to grow the stack. |
283 | */ |
284 | vma = find_extend_vma(current->mm, bprm->p); |
285 | if (!vma) |
286 | return -EFAULT; |
287 | |
288 | /* Now, let's put argc (and argv, envp if appropriate) on the stack */ |
289 | if (__put_user(argc, sp++)) |
290 | return -EFAULT; |
291 | argv = sp; |
292 | envp = argv + argc + 1; |
293 | |
294 | /* Populate argv and envp */ |
295 | p = current->mm->arg_end = current->mm->arg_start; |
296 | while (argc-- > 0) { |
297 | size_t len; |
298 | if (__put_user((elf_addr_t)p, argv++)) |
299 | return -EFAULT; |
300 | len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); |
301 | if (!len || len > MAX_ARG_STRLEN) |
302 | return -EINVAL; |
303 | p += len; |
304 | } |
305 | if (__put_user(0, argv)) |
306 | return -EFAULT; |
307 | current->mm->arg_end = current->mm->env_start = p; |
308 | while (envc-- > 0) { |
309 | size_t len; |
310 | if (__put_user((elf_addr_t)p, envp++)) |
311 | return -EFAULT; |
312 | len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); |
313 | if (!len || len > MAX_ARG_STRLEN) |
314 | return -EINVAL; |
315 | p += len; |
316 | } |
317 | if (__put_user(0, envp)) |
318 | return -EFAULT; |
319 | current->mm->env_end = p; |
320 | |
321 | /* Put the elf_info on the stack in the right place. */ |
322 | sp = (elf_addr_t __user *)envp + 1; |
323 | if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t))) |
324 | return -EFAULT; |
325 | return 0; |
326 | } |
327 | |
328 | #ifndef elf_map |
329 | |
330 | static unsigned long elf_map(struct file *filep, unsigned long addr, |
331 | struct elf_phdr *eppnt, int prot, int type, |
332 | unsigned long total_size) |
333 | { |
334 | unsigned long map_addr; |
335 | unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr); |
336 | unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr); |
337 | addr = ELF_PAGESTART(addr); |
338 | size = ELF_PAGEALIGN(size); |
339 | |
340 | /* mmap() will return -EINVAL if given a zero size, but a |
341 | * segment with zero filesize is perfectly valid */ |
342 | if (!size) |
343 | return addr; |
344 | |
345 | /* |
346 | * total_size is the size of the ELF (interpreter) image. |
347 | * The _first_ mmap needs to know the full size, otherwise |
348 | * randomization might put this image into an overlapping |
349 | * position with the ELF binary image. (since size < total_size) |
350 | * So we first map the 'big' image - and unmap the remainder at |
351 | * the end. (which unmap is needed for ELF images with holes.) |
352 | */ |
353 | if (total_size) { |
354 | total_size = ELF_PAGEALIGN(total_size); |
355 | map_addr = vm_mmap(filep, addr, total_size, prot, type, off); |
356 | if (!BAD_ADDR(map_addr)) |
357 | vm_munmap(map_addr+size, total_size-size); |
358 | } else |
359 | map_addr = vm_mmap(filep, addr, size, prot, type, off); |
360 | |
361 | return(map_addr); |
362 | } |
363 | |
364 | #endif /* !elf_map */ |
365 | |
366 | static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr) |
367 | { |
368 | int i, first_idx = -1, last_idx = -1; |
369 | |
370 | for (i = 0; i < nr; i++) { |
371 | if (cmds[i].p_type == PT_LOAD) { |
372 | last_idx = i; |
373 | if (first_idx == -1) |
374 | first_idx = i; |
375 | } |
376 | } |
377 | if (first_idx == -1) |
378 | return 0; |
379 | |
380 | return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz - |
381 | ELF_PAGESTART(cmds[first_idx].p_vaddr); |
382 | } |
383 | |
384 | |
385 | /* This is much more generalized than the library routine read function, |
386 | so we keep this separate. Technically the library read function |
387 | is only provided so that we can read a.out libraries that have |
388 | an ELF header */ |
389 | |
390 | static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex, |
391 | struct file *interpreter, unsigned long *interp_map_addr, |
392 | unsigned long no_base) |
393 | { |
394 | struct elf_phdr *elf_phdata; |
395 | struct elf_phdr *eppnt; |
396 | unsigned long load_addr = 0; |
397 | int load_addr_set = 0; |
398 | unsigned long last_bss = 0, elf_bss = 0; |
399 | unsigned long error = ~0UL; |
400 | unsigned long total_size; |
401 | int retval, i, size; |
402 | |
403 | /* First of all, some simple consistency checks */ |
404 | if (interp_elf_ex->e_type != ET_EXEC && |
405 | interp_elf_ex->e_type != ET_DYN) |
406 | goto out; |
407 | if (!elf_check_arch(interp_elf_ex)) |
408 | goto out; |
409 | if (!interpreter->f_op || !interpreter->f_op->mmap) |
410 | goto out; |
411 | |
412 | /* |
413 | * If the size of this structure has changed, then punt, since |
414 | * we will be doing the wrong thing. |
415 | */ |
416 | if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr)) |
417 | goto out; |
418 | if (interp_elf_ex->e_phnum < 1 || |
419 | interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr)) |
420 | goto out; |
421 | |
422 | /* Now read in all of the header information */ |
423 | size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum; |
424 | if (size > ELF_MIN_ALIGN) |
425 | goto out; |
426 | elf_phdata = kmalloc(size, GFP_KERNEL); |
427 | if (!elf_phdata) |
428 | goto out; |
429 | |
430 | retval = kernel_read(interpreter, interp_elf_ex->e_phoff, |
431 | (char *)elf_phdata, size); |
432 | error = -EIO; |
433 | if (retval != size) { |
434 | if (retval < 0) |
435 | error = retval; |
436 | goto out_close; |
437 | } |
438 | |
439 | total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum); |
440 | if (!total_size) { |
441 | error = -EINVAL; |
442 | goto out_close; |
443 | } |
444 | |
445 | eppnt = elf_phdata; |
446 | for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) { |
447 | if (eppnt->p_type == PT_LOAD) { |
448 | int elf_type = MAP_PRIVATE | MAP_DENYWRITE; |
449 | int elf_prot = 0; |
450 | unsigned long vaddr = 0; |
451 | unsigned long k, map_addr; |
452 | |
453 | if (eppnt->p_flags & PF_R) |
454 | elf_prot = PROT_READ; |
455 | if (eppnt->p_flags & PF_W) |
456 | elf_prot |= PROT_WRITE; |
457 | if (eppnt->p_flags & PF_X) |
458 | elf_prot |= PROT_EXEC; |
459 | vaddr = eppnt->p_vaddr; |
460 | if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) |
461 | elf_type |= MAP_FIXED; |
462 | else if (no_base && interp_elf_ex->e_type == ET_DYN) |
463 | load_addr = -vaddr; |
464 | |
465 | map_addr = elf_map(interpreter, load_addr + vaddr, |
466 | eppnt, elf_prot, elf_type, total_size); |
467 | total_size = 0; |
468 | if (!*interp_map_addr) |
469 | *interp_map_addr = map_addr; |
470 | error = map_addr; |
471 | if (BAD_ADDR(map_addr)) |
472 | goto out_close; |
473 | |
474 | if (!load_addr_set && |
475 | interp_elf_ex->e_type == ET_DYN) { |
476 | load_addr = map_addr - ELF_PAGESTART(vaddr); |
477 | load_addr_set = 1; |
478 | } |
479 | |
480 | /* |
481 | * Check to see if the section's size will overflow the |
482 | * allowed task size. Note that p_filesz must always be |
483 | * <= p_memsize so it's only necessary to check p_memsz. |
484 | */ |
485 | k = load_addr + eppnt->p_vaddr; |
486 | if (BAD_ADDR(k) || |
487 | eppnt->p_filesz > eppnt->p_memsz || |
488 | eppnt->p_memsz > TASK_SIZE || |
489 | TASK_SIZE - eppnt->p_memsz < k) { |
490 | error = -ENOMEM; |
491 | goto out_close; |
492 | } |
493 | |
494 | /* |
495 | * Find the end of the file mapping for this phdr, and |
496 | * keep track of the largest address we see for this. |
497 | */ |
498 | k = load_addr + eppnt->p_vaddr + eppnt->p_filesz; |
499 | if (k > elf_bss) |
500 | elf_bss = k; |
501 | |
502 | /* |
503 | * Do the same thing for the memory mapping - between |
504 | * elf_bss and last_bss is the bss section. |
505 | */ |
506 | k = load_addr + eppnt->p_memsz + eppnt->p_vaddr; |
507 | if (k > last_bss) |
508 | last_bss = k; |
509 | } |
510 | } |
511 | |
512 | if (last_bss > elf_bss) { |
513 | /* |
514 | * Now fill out the bss section. First pad the last page up |
515 | * to the page boundary, and then perform a mmap to make sure |
516 | * that there are zero-mapped pages up to and including the |
517 | * last bss page. |
518 | */ |
519 | if (padzero(elf_bss)) { |
520 | error = -EFAULT; |
521 | goto out_close; |
522 | } |
523 | |
524 | /* What we have mapped so far */ |
525 | elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1); |
526 | |
527 | /* Map the last of the bss segment */ |
528 | error = vm_brk(elf_bss, last_bss - elf_bss); |
529 | if (BAD_ADDR(error)) |
530 | goto out_close; |
531 | } |
532 | |
533 | error = load_addr; |
534 | |
535 | out_close: |
536 | kfree(elf_phdata); |
537 | out: |
538 | return error; |
539 | } |
540 | |
541 | /* |
542 | * These are the functions used to load ELF style executables and shared |
543 | * libraries. There is no binary dependent code anywhere else. |
544 | */ |
545 | |
546 | #define INTERPRETER_NONE 0 |
547 | #define INTERPRETER_ELF 2 |
548 | |
549 | #ifndef STACK_RND_MASK |
550 | #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ |
551 | #endif |
552 | |
553 | static unsigned long randomize_stack_top(unsigned long stack_top) |
554 | { |
555 | unsigned int random_variable = 0; |
556 | |
557 | if ((current->flags & PF_RANDOMIZE) && |
558 | !(current->personality & ADDR_NO_RANDOMIZE)) { |
559 | random_variable = get_random_int() & STACK_RND_MASK; |
560 | random_variable <<= PAGE_SHIFT; |
561 | } |
562 | #ifdef CONFIG_STACK_GROWSUP |
563 | return PAGE_ALIGN(stack_top) + random_variable; |
564 | #else |
565 | return PAGE_ALIGN(stack_top) - random_variable; |
566 | #endif |
567 | } |
568 | |
569 | static int load_elf_binary(struct linux_binprm *bprm) |
570 | { |
571 | struct file *interpreter = NULL; /* to shut gcc up */ |
572 | unsigned long load_addr = 0, load_bias = 0; |
573 | int load_addr_set = 0; |
574 | char * elf_interpreter = NULL; |
575 | unsigned long error; |
576 | struct elf_phdr *elf_ppnt, *elf_phdata; |
577 | unsigned long elf_bss, elf_brk; |
578 | int retval, i; |
579 | unsigned int size; |
580 | unsigned long elf_entry; |
581 | unsigned long interp_load_addr = 0; |
582 | unsigned long start_code, end_code, start_data, end_data; |
583 | unsigned long reloc_func_desc __maybe_unused = 0; |
584 | int executable_stack = EXSTACK_DEFAULT; |
585 | unsigned long def_flags = 0; |
586 | struct pt_regs *regs = current_pt_regs(); |
587 | struct { |
588 | struct elfhdr elf_ex; |
589 | struct elfhdr interp_elf_ex; |
590 | } *loc; |
591 | |
592 | loc = kmalloc(sizeof(*loc), GFP_KERNEL); |
593 | if (!loc) { |
594 | retval = -ENOMEM; |
595 | goto out_ret; |
596 | } |
597 | |
598 | /* Get the exec-header */ |
599 | loc->elf_ex = *((struct elfhdr *)bprm->buf); |
600 | |
601 | retval = -ENOEXEC; |
602 | /* First of all, some simple consistency checks */ |
603 | if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0) |
604 | goto out; |
605 | |
606 | if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN) |
607 | goto out; |
608 | if (!elf_check_arch(&loc->elf_ex)) |
609 | goto out; |
610 | if (!bprm->file->f_op || !bprm->file->f_op->mmap) |
611 | goto out; |
612 | |
613 | /* Now read in all of the header information */ |
614 | if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr)) |
615 | goto out; |
616 | if (loc->elf_ex.e_phnum < 1 || |
617 | loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr)) |
618 | goto out; |
619 | size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr); |
620 | retval = -ENOMEM; |
621 | elf_phdata = kmalloc(size, GFP_KERNEL); |
622 | if (!elf_phdata) |
623 | goto out; |
624 | |
625 | retval = kernel_read(bprm->file, loc->elf_ex.e_phoff, |
626 | (char *)elf_phdata, size); |
627 | if (retval != size) { |
628 | if (retval >= 0) |
629 | retval = -EIO; |
630 | goto out_free_ph; |
631 | } |
632 | |
633 | elf_ppnt = elf_phdata; |
634 | elf_bss = 0; |
635 | elf_brk = 0; |
636 | |
637 | start_code = ~0UL; |
638 | end_code = 0; |
639 | start_data = 0; |
640 | end_data = 0; |
641 | |
642 | for (i = 0; i < loc->elf_ex.e_phnum; i++) { |
643 | if (elf_ppnt->p_type == PT_INTERP) { |
644 | /* This is the program interpreter used for |
645 | * shared libraries - for now assume that this |
646 | * is an a.out format binary |
647 | */ |
648 | retval = -ENOEXEC; |
649 | if (elf_ppnt->p_filesz > PATH_MAX || |
650 | elf_ppnt->p_filesz < 2) |
651 | goto out_free_ph; |
652 | |
653 | retval = -ENOMEM; |
654 | elf_interpreter = kmalloc(elf_ppnt->p_filesz, |
655 | GFP_KERNEL); |
656 | if (!elf_interpreter) |
657 | goto out_free_ph; |
658 | |
659 | retval = kernel_read(bprm->file, elf_ppnt->p_offset, |
660 | elf_interpreter, |
661 | elf_ppnt->p_filesz); |
662 | if (retval != elf_ppnt->p_filesz) { |
663 | if (retval >= 0) |
664 | retval = -EIO; |
665 | goto out_free_interp; |
666 | } |
667 | /* make sure path is NULL terminated */ |
668 | retval = -ENOEXEC; |
669 | if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0') |
670 | goto out_free_interp; |
671 | |
672 | interpreter = open_exec(elf_interpreter); |
673 | retval = PTR_ERR(interpreter); |
674 | if (IS_ERR(interpreter)) |
675 | goto out_free_interp; |
676 | |
677 | /* |
678 | * If the binary is not readable then enforce |
679 | * mm->dumpable = 0 regardless of the interpreter's |
680 | * permissions. |
681 | */ |
682 | would_dump(bprm, interpreter); |
683 | |
684 | retval = kernel_read(interpreter, 0, bprm->buf, |
685 | BINPRM_BUF_SIZE); |
686 | if (retval != BINPRM_BUF_SIZE) { |
687 | if (retval >= 0) |
688 | retval = -EIO; |
689 | goto out_free_dentry; |
690 | } |
691 | |
692 | /* Get the exec headers */ |
693 | loc->interp_elf_ex = *((struct elfhdr *)bprm->buf); |
694 | break; |
695 | } |
696 | elf_ppnt++; |
697 | } |
698 | |
699 | elf_ppnt = elf_phdata; |
700 | for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) |
701 | if (elf_ppnt->p_type == PT_GNU_STACK) { |
702 | if (elf_ppnt->p_flags & PF_X) |
703 | executable_stack = EXSTACK_ENABLE_X; |
704 | else |
705 | executable_stack = EXSTACK_DISABLE_X; |
706 | break; |
707 | } |
708 | |
709 | /* Some simple consistency checks for the interpreter */ |
710 | if (elf_interpreter) { |
711 | retval = -ELIBBAD; |
712 | /* Not an ELF interpreter */ |
713 | if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0) |
714 | goto out_free_dentry; |
715 | /* Verify the interpreter has a valid arch */ |
716 | if (!elf_check_arch(&loc->interp_elf_ex)) |
717 | goto out_free_dentry; |
718 | } |
719 | |
720 | /* Flush all traces of the currently running executable */ |
721 | retval = flush_old_exec(bprm); |
722 | if (retval) |
723 | goto out_free_dentry; |
724 | |
725 | /* OK, This is the point of no return */ |
726 | current->mm->def_flags = def_flags; |
727 | |
728 | /* Do this immediately, since STACK_TOP as used in setup_arg_pages |
729 | may depend on the personality. */ |
730 | SET_PERSONALITY(loc->elf_ex); |
731 | if (elf_read_implies_exec(loc->elf_ex, executable_stack)) |
732 | current->personality |= READ_IMPLIES_EXEC; |
733 | |
734 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) |
735 | current->flags |= PF_RANDOMIZE; |
736 | |
737 | setup_new_exec(bprm); |
738 | |
739 | /* Do this so that we can load the interpreter, if need be. We will |
740 | change some of these later */ |
741 | retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP), |
742 | executable_stack); |
743 | if (retval < 0) { |
744 | send_sig(SIGKILL, current, 0); |
745 | goto out_free_dentry; |
746 | } |
747 | |
748 | current->mm->start_stack = bprm->p; |
749 | |
750 | /* Now we do a little grungy work by mmapping the ELF image into |
751 | the correct location in memory. */ |
752 | for(i = 0, elf_ppnt = elf_phdata; |
753 | i < loc->elf_ex.e_phnum; i++, elf_ppnt++) { |
754 | int elf_prot = 0, elf_flags; |
755 | unsigned long k, vaddr; |
756 | |
757 | if (elf_ppnt->p_type != PT_LOAD) |
758 | continue; |
759 | |
760 | if (unlikely (elf_brk > elf_bss)) { |
761 | unsigned long nbyte; |
762 | |
763 | /* There was a PT_LOAD segment with p_memsz > p_filesz |
764 | before this one. Map anonymous pages, if needed, |
765 | and clear the area. */ |
766 | retval = set_brk(elf_bss + load_bias, |
767 | elf_brk + load_bias); |
768 | if (retval) { |
769 | send_sig(SIGKILL, current, 0); |
770 | goto out_free_dentry; |
771 | } |
772 | nbyte = ELF_PAGEOFFSET(elf_bss); |
773 | if (nbyte) { |
774 | nbyte = ELF_MIN_ALIGN - nbyte; |
775 | if (nbyte > elf_brk - elf_bss) |
776 | nbyte = elf_brk - elf_bss; |
777 | if (clear_user((void __user *)elf_bss + |
778 | load_bias, nbyte)) { |
779 | /* |
780 | * This bss-zeroing can fail if the ELF |
781 | * file specifies odd protections. So |
782 | * we don't check the return value |
783 | */ |
784 | } |
785 | } |
786 | } |
787 | |
788 | if (elf_ppnt->p_flags & PF_R) |
789 | elf_prot |= PROT_READ; |
790 | if (elf_ppnt->p_flags & PF_W) |
791 | elf_prot |= PROT_WRITE; |
792 | if (elf_ppnt->p_flags & PF_X) |
793 | elf_prot |= PROT_EXEC; |
794 | |
795 | elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE; |
796 | |
797 | vaddr = elf_ppnt->p_vaddr; |
798 | if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) { |
799 | elf_flags |= MAP_FIXED; |
800 | } else if (loc->elf_ex.e_type == ET_DYN) { |
801 | /* Try and get dynamic programs out of the way of the |
802 | * default mmap base, as well as whatever program they |
803 | * might try to exec. This is because the brk will |
804 | * follow the loader, and is not movable. */ |
805 | #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE |
806 | /* Memory randomization might have been switched off |
807 | * in runtime via sysctl or explicit setting of |
808 | * personality flags. |
809 | * If that is the case, retain the original non-zero |
810 | * load_bias value in order to establish proper |
811 | * non-randomized mappings. |
812 | */ |
813 | if (current->flags & PF_RANDOMIZE) |
814 | load_bias = 0; |
815 | else |
816 | load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); |
817 | #else |
818 | load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); |
819 | #endif |
820 | } |
821 | |
822 | error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, |
823 | elf_prot, elf_flags, 0); |
824 | if (BAD_ADDR(error)) { |
825 | send_sig(SIGKILL, current, 0); |
826 | retval = IS_ERR((void *)error) ? |
827 | PTR_ERR((void*)error) : -EINVAL; |
828 | goto out_free_dentry; |
829 | } |
830 | |
831 | if (!load_addr_set) { |
832 | load_addr_set = 1; |
833 | load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset); |
834 | if (loc->elf_ex.e_type == ET_DYN) { |
835 | load_bias += error - |
836 | ELF_PAGESTART(load_bias + vaddr); |
837 | load_addr += load_bias; |
838 | reloc_func_desc = load_bias; |
839 | } |
840 | } |
841 | k = elf_ppnt->p_vaddr; |
842 | if (k < start_code) |
843 | start_code = k; |
844 | if (start_data < k) |
845 | start_data = k; |
846 | |
847 | /* |
848 | * Check to see if the section's size will overflow the |
849 | * allowed task size. Note that p_filesz must always be |
850 | * <= p_memsz so it is only necessary to check p_memsz. |
851 | */ |
852 | if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz || |
853 | elf_ppnt->p_memsz > TASK_SIZE || |
854 | TASK_SIZE - elf_ppnt->p_memsz < k) { |
855 | /* set_brk can never work. Avoid overflows. */ |
856 | send_sig(SIGKILL, current, 0); |
857 | retval = -EINVAL; |
858 | goto out_free_dentry; |
859 | } |
860 | |
861 | k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz; |
862 | |
863 | if (k > elf_bss) |
864 | elf_bss = k; |
865 | if ((elf_ppnt->p_flags & PF_X) && end_code < k) |
866 | end_code = k; |
867 | if (end_data < k) |
868 | end_data = k; |
869 | k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz; |
870 | if (k > elf_brk) |
871 | elf_brk = k; |
872 | } |
873 | |
874 | loc->elf_ex.e_entry += load_bias; |
875 | elf_bss += load_bias; |
876 | elf_brk += load_bias; |
877 | start_code += load_bias; |
878 | end_code += load_bias; |
879 | start_data += load_bias; |
880 | end_data += load_bias; |
881 | |
882 | /* Calling set_brk effectively mmaps the pages that we need |
883 | * for the bss and break sections. We must do this before |
884 | * mapping in the interpreter, to make sure it doesn't wind |
885 | * up getting placed where the bss needs to go. |
886 | */ |
887 | retval = set_brk(elf_bss, elf_brk); |
888 | if (retval) { |
889 | send_sig(SIGKILL, current, 0); |
890 | goto out_free_dentry; |
891 | } |
892 | if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) { |
893 | send_sig(SIGSEGV, current, 0); |
894 | retval = -EFAULT; /* Nobody gets to see this, but.. */ |
895 | goto out_free_dentry; |
896 | } |
897 | |
898 | if (elf_interpreter) { |
899 | unsigned long interp_map_addr = 0; |
900 | |
901 | elf_entry = load_elf_interp(&loc->interp_elf_ex, |
902 | interpreter, |
903 | &interp_map_addr, |
904 | load_bias); |
905 | if (!IS_ERR((void *)elf_entry)) { |
906 | /* |
907 | * load_elf_interp() returns relocation |
908 | * adjustment |
909 | */ |
910 | interp_load_addr = elf_entry; |
911 | elf_entry += loc->interp_elf_ex.e_entry; |
912 | } |
913 | if (BAD_ADDR(elf_entry)) { |
914 | force_sig(SIGSEGV, current); |
915 | retval = IS_ERR((void *)elf_entry) ? |
916 | (int)elf_entry : -EINVAL; |
917 | goto out_free_dentry; |
918 | } |
919 | reloc_func_desc = interp_load_addr; |
920 | |
921 | allow_write_access(interpreter); |
922 | fput(interpreter); |
923 | kfree(elf_interpreter); |
924 | } else { |
925 | elf_entry = loc->elf_ex.e_entry; |
926 | if (BAD_ADDR(elf_entry)) { |
927 | force_sig(SIGSEGV, current); |
928 | retval = -EINVAL; |
929 | goto out_free_dentry; |
930 | } |
931 | } |
932 | |
933 | kfree(elf_phdata); |
934 | |
935 | set_binfmt(&elf_format); |
936 | |
937 | #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES |
938 | retval = arch_setup_additional_pages(bprm, !!elf_interpreter); |
939 | if (retval < 0) { |
940 | send_sig(SIGKILL, current, 0); |
941 | goto out; |
942 | } |
943 | #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ |
944 | |
945 | install_exec_creds(bprm); |
946 | retval = create_elf_tables(bprm, &loc->elf_ex, |
947 | load_addr, interp_load_addr); |
948 | if (retval < 0) { |
949 | send_sig(SIGKILL, current, 0); |
950 | goto out; |
951 | } |
952 | /* N.B. passed_fileno might not be initialized? */ |
953 | current->mm->end_code = end_code; |
954 | current->mm->start_code = start_code; |
955 | current->mm->start_data = start_data; |
956 | current->mm->end_data = end_data; |
957 | current->mm->start_stack = bprm->p; |
958 | |
959 | #ifdef arch_randomize_brk |
960 | if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) { |
961 | current->mm->brk = current->mm->start_brk = |
962 | arch_randomize_brk(current->mm); |
963 | #ifdef CONFIG_COMPAT_BRK |
964 | current->brk_randomized = 1; |
965 | #endif |
966 | } |
967 | #endif |
968 | |
969 | if (current->personality & MMAP_PAGE_ZERO) { |
970 | /* Why this, you ask??? Well SVr4 maps page 0 as read-only, |
971 | and some applications "depend" upon this behavior. |
972 | Since we do not have the power to recompile these, we |
973 | emulate the SVr4 behavior. Sigh. */ |
974 | error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC, |
975 | MAP_FIXED | MAP_PRIVATE, 0); |
976 | } |
977 | |
978 | #ifdef ELF_PLAT_INIT |
979 | /* |
980 | * The ABI may specify that certain registers be set up in special |
981 | * ways (on i386 %edx is the address of a DT_FINI function, for |
982 | * example. In addition, it may also specify (eg, PowerPC64 ELF) |
983 | * that the e_entry field is the address of the function descriptor |
984 | * for the startup routine, rather than the address of the startup |
985 | * routine itself. This macro performs whatever initialization to |
986 | * the regs structure is required as well as any relocations to the |
987 | * function descriptor entries when executing dynamically links apps. |
988 | */ |
989 | ELF_PLAT_INIT(regs, reloc_func_desc); |
990 | #endif |
991 | |
992 | start_thread(regs, elf_entry, bprm->p); |
993 | retval = 0; |
994 | out: |
995 | kfree(loc); |
996 | out_ret: |
997 | return retval; |
998 | |
999 | /* error cleanup */ |
1000 | out_free_dentry: |
1001 | allow_write_access(interpreter); |
1002 | if (interpreter) |
1003 | fput(interpreter); |
1004 | out_free_interp: |
1005 | kfree(elf_interpreter); |
1006 | out_free_ph: |
1007 | kfree(elf_phdata); |
1008 | goto out; |
1009 | } |
1010 | |
1011 | /* This is really simpleminded and specialized - we are loading an |
1012 | a.out library that is given an ELF header. */ |
1013 | static int load_elf_library(struct file *file) |
1014 | { |
1015 | struct elf_phdr *elf_phdata; |
1016 | struct elf_phdr *eppnt; |
1017 | unsigned long elf_bss, bss, len; |
1018 | int retval, error, i, j; |
1019 | struct elfhdr elf_ex; |
1020 | |
1021 | error = -ENOEXEC; |
1022 | retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex)); |
1023 | if (retval != sizeof(elf_ex)) |
1024 | goto out; |
1025 | |
1026 | if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) |
1027 | goto out; |
1028 | |
1029 | /* First of all, some simple consistency checks */ |
1030 | if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 || |
1031 | !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap) |
1032 | goto out; |
1033 | |
1034 | /* Now read in all of the header information */ |
1035 | |
1036 | j = sizeof(struct elf_phdr) * elf_ex.e_phnum; |
1037 | /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */ |
1038 | |
1039 | error = -ENOMEM; |
1040 | elf_phdata = kmalloc(j, GFP_KERNEL); |
1041 | if (!elf_phdata) |
1042 | goto out; |
1043 | |
1044 | eppnt = elf_phdata; |
1045 | error = -ENOEXEC; |
1046 | retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j); |
1047 | if (retval != j) |
1048 | goto out_free_ph; |
1049 | |
1050 | for (j = 0, i = 0; i<elf_ex.e_phnum; i++) |
1051 | if ((eppnt + i)->p_type == PT_LOAD) |
1052 | j++; |
1053 | if (j != 1) |
1054 | goto out_free_ph; |
1055 | |
1056 | while (eppnt->p_type != PT_LOAD) |
1057 | eppnt++; |
1058 | |
1059 | /* Now use mmap to map the library into memory. */ |
1060 | error = vm_mmap(file, |
1061 | ELF_PAGESTART(eppnt->p_vaddr), |
1062 | (eppnt->p_filesz + |
1063 | ELF_PAGEOFFSET(eppnt->p_vaddr)), |
1064 | PROT_READ | PROT_WRITE | PROT_EXEC, |
1065 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, |
1066 | (eppnt->p_offset - |
1067 | ELF_PAGEOFFSET(eppnt->p_vaddr))); |
1068 | if (error != ELF_PAGESTART(eppnt->p_vaddr)) |
1069 | goto out_free_ph; |
1070 | |
1071 | elf_bss = eppnt->p_vaddr + eppnt->p_filesz; |
1072 | if (padzero(elf_bss)) { |
1073 | error = -EFAULT; |
1074 | goto out_free_ph; |
1075 | } |
1076 | |
1077 | len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + |
1078 | ELF_MIN_ALIGN - 1); |
1079 | bss = eppnt->p_memsz + eppnt->p_vaddr; |
1080 | if (bss > len) |
1081 | vm_brk(len, bss - len); |
1082 | error = 0; |
1083 | |
1084 | out_free_ph: |
1085 | kfree(elf_phdata); |
1086 | out: |
1087 | return error; |
1088 | } |
1089 | |
1090 | #ifdef CONFIG_ELF_CORE |
1091 | /* |
1092 | * ELF core dumper |
1093 | * |
1094 | * Modelled on fs/exec.c:aout_core_dump() |
1095 | * Jeremy Fitzhardinge <jeremy@sw.oz.au> |
1096 | */ |
1097 | |
1098 | /* |
1099 | * The purpose of always_dump_vma() is to make sure that special kernel mappings |
1100 | * that are useful for post-mortem analysis are included in every core dump. |
1101 | * In that way we ensure that the core dump is fully interpretable later |
1102 | * without matching up the same kernel and hardware config to see what PC values |
1103 | * meant. These special mappings include - vDSO, vsyscall, and other |
1104 | * architecture specific mappings |
1105 | */ |
1106 | static bool always_dump_vma(struct vm_area_struct *vma) |
1107 | { |
1108 | /* Any vsyscall mappings? */ |
1109 | if (vma == get_gate_vma(vma->vm_mm)) |
1110 | return true; |
1111 | /* |
1112 | * arch_vma_name() returns non-NULL for special architecture mappings, |
1113 | * such as vDSO sections. |
1114 | */ |
1115 | if (arch_vma_name(vma)) |
1116 | return true; |
1117 | |
1118 | return false; |
1119 | } |
1120 | |
1121 | /* |
1122 | * Decide what to dump of a segment, part, all or none. |
1123 | */ |
1124 | static unsigned long vma_dump_size(struct vm_area_struct *vma, |
1125 | unsigned long mm_flags) |
1126 | { |
1127 | #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type)) |
1128 | |
1129 | /* always dump the vdso and vsyscall sections */ |
1130 | if (always_dump_vma(vma)) |
1131 | goto whole; |
1132 | |
1133 | if (vma->vm_flags & VM_DONTDUMP) |
1134 | return 0; |
1135 | |
1136 | /* Hugetlb memory check */ |
1137 | if (vma->vm_flags & VM_HUGETLB) { |
1138 | if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED)) |
1139 | goto whole; |
1140 | if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE)) |
1141 | goto whole; |
1142 | return 0; |
1143 | } |
1144 | |
1145 | /* Do not dump I/O mapped devices or special mappings */ |
1146 | if (vma->vm_flags & VM_IO) |
1147 | return 0; |
1148 | |
1149 | /* By default, dump shared memory if mapped from an anonymous file. */ |
1150 | if (vma->vm_flags & VM_SHARED) { |
1151 | if (file_inode(vma->vm_file)->i_nlink == 0 ? |
1152 | FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED)) |
1153 | goto whole; |
1154 | return 0; |
1155 | } |
1156 | |
1157 | /* Dump segments that have been written to. */ |
1158 | if (vma->anon_vma && FILTER(ANON_PRIVATE)) |
1159 | goto whole; |
1160 | if (vma->vm_file == NULL) |
1161 | return 0; |
1162 | |
1163 | if (FILTER(MAPPED_PRIVATE)) |
1164 | goto whole; |
1165 | |
1166 | /* |
1167 | * If this looks like the beginning of a DSO or executable mapping, |
1168 | * check for an ELF header. If we find one, dump the first page to |
1169 | * aid in determining what was mapped here. |
1170 | */ |
1171 | if (FILTER(ELF_HEADERS) && |
1172 | vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) { |
1173 | u32 __user *header = (u32 __user *) vma->vm_start; |
1174 | u32 word; |
1175 | mm_segment_t fs = get_fs(); |
1176 | /* |
1177 | * Doing it this way gets the constant folded by GCC. |
1178 | */ |
1179 | union { |
1180 | u32 cmp; |
1181 | char elfmag[SELFMAG]; |
1182 | } magic; |
1183 | BUILD_BUG_ON(SELFMAG != sizeof word); |
1184 | magic.elfmag[EI_MAG0] = ELFMAG0; |
1185 | magic.elfmag[EI_MAG1] = ELFMAG1; |
1186 | magic.elfmag[EI_MAG2] = ELFMAG2; |
1187 | magic.elfmag[EI_MAG3] = ELFMAG3; |
1188 | /* |
1189 | * Switch to the user "segment" for get_user(), |
1190 | * then put back what elf_core_dump() had in place. |
1191 | */ |
1192 | set_fs(USER_DS); |
1193 | if (unlikely(get_user(word, header))) |
1194 | word = 0; |
1195 | set_fs(fs); |
1196 | if (word == magic.cmp) |
1197 | return PAGE_SIZE; |
1198 | } |
1199 | |
1200 | #undef FILTER |
1201 | |
1202 | return 0; |
1203 | |
1204 | whole: |
1205 | return vma->vm_end - vma->vm_start; |
1206 | } |
1207 | |
1208 | /* An ELF note in memory */ |
1209 | struct memelfnote |
1210 | { |
1211 | const char *name; |
1212 | int type; |
1213 | unsigned int datasz; |
1214 | void *data; |
1215 | }; |
1216 | |
1217 | static int notesize(struct memelfnote *en) |
1218 | { |
1219 | int sz; |
1220 | |
1221 | sz = sizeof(struct elf_note); |
1222 | sz += roundup(strlen(en->name) + 1, 4); |
1223 | sz += roundup(en->datasz, 4); |
1224 | |
1225 | return sz; |
1226 | } |
1227 | |
1228 | #define DUMP_WRITE(addr, nr, foffset) \ |
1229 | do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0) |
1230 | |
1231 | static int alignfile(struct file *file, loff_t *foffset) |
1232 | { |
1233 | static const char buf[4] = { 0, }; |
1234 | DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset); |
1235 | return 1; |
1236 | } |
1237 | |
1238 | static int writenote(struct memelfnote *men, struct file *file, |
1239 | loff_t *foffset) |
1240 | { |
1241 | struct elf_note en; |
1242 | en.n_namesz = strlen(men->name) + 1; |
1243 | en.n_descsz = men->datasz; |
1244 | en.n_type = men->type; |
1245 | |
1246 | DUMP_WRITE(&en, sizeof(en), foffset); |
1247 | DUMP_WRITE(men->name, en.n_namesz, foffset); |
1248 | if (!alignfile(file, foffset)) |
1249 | return 0; |
1250 | DUMP_WRITE(men->data, men->datasz, foffset); |
1251 | if (!alignfile(file, foffset)) |
1252 | return 0; |
1253 | |
1254 | return 1; |
1255 | } |
1256 | #undef DUMP_WRITE |
1257 | |
1258 | static void fill_elf_header(struct elfhdr *elf, int segs, |
1259 | u16 machine, u32 flags) |
1260 | { |
1261 | memset(elf, 0, sizeof(*elf)); |
1262 | |
1263 | memcpy(elf->e_ident, ELFMAG, SELFMAG); |
1264 | elf->e_ident[EI_CLASS] = ELF_CLASS; |
1265 | elf->e_ident[EI_DATA] = ELF_DATA; |
1266 | elf->e_ident[EI_VERSION] = EV_CURRENT; |
1267 | elf->e_ident[EI_OSABI] = ELF_OSABI; |
1268 | |
1269 | elf->e_type = ET_CORE; |
1270 | elf->e_machine = machine; |
1271 | elf->e_version = EV_CURRENT; |
1272 | elf->e_phoff = sizeof(struct elfhdr); |
1273 | elf->e_flags = flags; |
1274 | elf->e_ehsize = sizeof(struct elfhdr); |
1275 | elf->e_phentsize = sizeof(struct elf_phdr); |
1276 | elf->e_phnum = segs; |
1277 | |
1278 | return; |
1279 | } |
1280 | |
1281 | static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) |
1282 | { |
1283 | phdr->p_type = PT_NOTE; |
1284 | phdr->p_offset = offset; |
1285 | phdr->p_vaddr = 0; |
1286 | phdr->p_paddr = 0; |
1287 | phdr->p_filesz = sz; |
1288 | phdr->p_memsz = 0; |
1289 | phdr->p_flags = 0; |
1290 | phdr->p_align = 0; |
1291 | return; |
1292 | } |
1293 | |
1294 | static void fill_note(struct memelfnote *note, const char *name, int type, |
1295 | unsigned int sz, void *data) |
1296 | { |
1297 | note->name = name; |
1298 | note->type = type; |
1299 | note->datasz = sz; |
1300 | note->data = data; |
1301 | return; |
1302 | } |
1303 | |
1304 | /* |
1305 | * fill up all the fields in prstatus from the given task struct, except |
1306 | * registers which need to be filled up separately. |
1307 | */ |
1308 | static void fill_prstatus(struct elf_prstatus *prstatus, |
1309 | struct task_struct *p, long signr) |
1310 | { |
1311 | prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; |
1312 | prstatus->pr_sigpend = p->pending.signal.sig[0]; |
1313 | prstatus->pr_sighold = p->blocked.sig[0]; |
1314 | rcu_read_lock(); |
1315 | prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); |
1316 | rcu_read_unlock(); |
1317 | prstatus->pr_pid = task_pid_vnr(p); |
1318 | prstatus->pr_pgrp = task_pgrp_vnr(p); |
1319 | prstatus->pr_sid = task_session_vnr(p); |
1320 | if (thread_group_leader(p)) { |
1321 | struct task_cputime cputime; |
1322 | |
1323 | /* |
1324 | * This is the record for the group leader. It shows the |
1325 | * group-wide total, not its individual thread total. |
1326 | */ |
1327 | thread_group_cputime(p, &cputime); |
1328 | cputime_to_timeval(cputime.utime, &prstatus->pr_utime); |
1329 | cputime_to_timeval(cputime.stime, &prstatus->pr_stime); |
1330 | } else { |
1331 | cputime_t utime, stime; |
1332 | |
1333 | task_cputime(p, &utime, &stime); |
1334 | cputime_to_timeval(utime, &prstatus->pr_utime); |
1335 | cputime_to_timeval(stime, &prstatus->pr_stime); |
1336 | } |
1337 | cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); |
1338 | cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); |
1339 | } |
1340 | |
1341 | static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, |
1342 | struct mm_struct *mm) |
1343 | { |
1344 | const struct cred *cred; |
1345 | unsigned int i, len; |
1346 | |
1347 | /* first copy the parameters from user space */ |
1348 | memset(psinfo, 0, sizeof(struct elf_prpsinfo)); |
1349 | |
1350 | len = mm->arg_end - mm->arg_start; |
1351 | if (len >= ELF_PRARGSZ) |
1352 | len = ELF_PRARGSZ-1; |
1353 | if (copy_from_user(&psinfo->pr_psargs, |
1354 | (const char __user *)mm->arg_start, len)) |
1355 | return -EFAULT; |
1356 | for(i = 0; i < len; i++) |
1357 | if (psinfo->pr_psargs[i] == 0) |
1358 | psinfo->pr_psargs[i] = ' '; |
1359 | psinfo->pr_psargs[len] = 0; |
1360 | |
1361 | rcu_read_lock(); |
1362 | psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); |
1363 | rcu_read_unlock(); |
1364 | psinfo->pr_pid = task_pid_vnr(p); |
1365 | psinfo->pr_pgrp = task_pgrp_vnr(p); |
1366 | psinfo->pr_sid = task_session_vnr(p); |
1367 | |
1368 | i = p->state ? ffz(~p->state) + 1 : 0; |
1369 | psinfo->pr_state = i; |
1370 | psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; |
1371 | psinfo->pr_zomb = psinfo->pr_sname == 'Z'; |
1372 | psinfo->pr_nice = task_nice(p); |
1373 | psinfo->pr_flag = p->flags; |
1374 | rcu_read_lock(); |
1375 | cred = __task_cred(p); |
1376 | SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); |
1377 | SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); |
1378 | rcu_read_unlock(); |
1379 | strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); |
1380 | |
1381 | return 0; |
1382 | } |
1383 | |
1384 | static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm) |
1385 | { |
1386 | elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv; |
1387 | int i = 0; |
1388 | do |
1389 | i += 2; |
1390 | while (auxv[i - 2] != AT_NULL); |
1391 | fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv); |
1392 | } |
1393 | |
1394 | static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata, |
1395 | siginfo_t *siginfo) |
1396 | { |
1397 | mm_segment_t old_fs = get_fs(); |
1398 | set_fs(KERNEL_DS); |
1399 | copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo); |
1400 | set_fs(old_fs); |
1401 | fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata); |
1402 | } |
1403 | |
1404 | #define MAX_FILE_NOTE_SIZE (4*1024*1024) |
1405 | /* |
1406 | * Format of NT_FILE note: |
1407 | * |
1408 | * long count -- how many files are mapped |
1409 | * long page_size -- units for file_ofs |
1410 | * array of [COUNT] elements of |
1411 | * long start |
1412 | * long end |
1413 | * long file_ofs |
1414 | * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL... |
1415 | */ |
1416 | static void fill_files_note(struct memelfnote *note) |
1417 | { |
1418 | struct vm_area_struct *vma; |
1419 | unsigned count, size, names_ofs, remaining, n; |
1420 | user_long_t *data; |
1421 | user_long_t *start_end_ofs; |
1422 | char *name_base, *name_curpos; |
1423 | |
1424 | /* *Estimated* file count and total data size needed */ |
1425 | count = current->mm->map_count; |
1426 | size = count * 64; |
1427 | |
1428 | names_ofs = (2 + 3 * count) * sizeof(data[0]); |
1429 | alloc: |
1430 | if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */ |
1431 | goto err; |
1432 | size = round_up(size, PAGE_SIZE); |
1433 | data = vmalloc(size); |
1434 | if (!data) |
1435 | goto err; |
1436 | |
1437 | start_end_ofs = data + 2; |
1438 | name_base = name_curpos = ((char *)data) + names_ofs; |
1439 | remaining = size - names_ofs; |
1440 | count = 0; |
1441 | for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) { |
1442 | struct file *file; |
1443 | const char *filename; |
1444 | |
1445 | file = vma->vm_file; |
1446 | if (!file) |
1447 | continue; |
1448 | filename = d_path(&file->f_path, name_curpos, remaining); |
1449 | if (IS_ERR(filename)) { |
1450 | if (PTR_ERR(filename) == -ENAMETOOLONG) { |
1451 | vfree(data); |
1452 | size = size * 5 / 4; |
1453 | goto alloc; |
1454 | } |
1455 | continue; |
1456 | } |
1457 | |
1458 | /* d_path() fills at the end, move name down */ |
1459 | /* n = strlen(filename) + 1: */ |
1460 | n = (name_curpos + remaining) - filename; |
1461 | remaining = filename - name_curpos; |
1462 | memmove(name_curpos, filename, n); |
1463 | name_curpos += n; |
1464 | |
1465 | *start_end_ofs++ = vma->vm_start; |
1466 | *start_end_ofs++ = vma->vm_end; |
1467 | *start_end_ofs++ = vma->vm_pgoff; |
1468 | count++; |
1469 | } |
1470 | |
1471 | /* Now we know exact count of files, can store it */ |
1472 | data[0] = count; |
1473 | data[1] = PAGE_SIZE; |
1474 | /* |
1475 | * Count usually is less than current->mm->map_count, |
1476 | * we need to move filenames down. |
1477 | */ |
1478 | n = current->mm->map_count - count; |
1479 | if (n != 0) { |
1480 | unsigned shift_bytes = n * 3 * sizeof(data[0]); |
1481 | memmove(name_base - shift_bytes, name_base, |
1482 | name_curpos - name_base); |
1483 | name_curpos -= shift_bytes; |
1484 | } |
1485 | |
1486 | size = name_curpos - (char *)data; |
1487 | fill_note(note, "CORE", NT_FILE, size, data); |
1488 | err: ; |
1489 | } |
1490 | |
1491 | #ifdef CORE_DUMP_USE_REGSET |
1492 | #include <linux/regset.h> |
1493 | |
1494 | struct elf_thread_core_info { |
1495 | struct elf_thread_core_info *next; |
1496 | struct task_struct *task; |
1497 | struct elf_prstatus prstatus; |
1498 | struct memelfnote notes[0]; |
1499 | }; |
1500 | |
1501 | struct elf_note_info { |
1502 | struct elf_thread_core_info *thread; |
1503 | struct memelfnote psinfo; |
1504 | struct memelfnote signote; |
1505 | struct memelfnote auxv; |
1506 | struct memelfnote files; |
1507 | user_siginfo_t csigdata; |
1508 | size_t size; |
1509 | int thread_notes; |
1510 | }; |
1511 | |
1512 | /* |
1513 | * When a regset has a writeback hook, we call it on each thread before |
1514 | * dumping user memory. On register window machines, this makes sure the |
1515 | * user memory backing the register data is up to date before we read it. |
1516 | */ |
1517 | static void do_thread_regset_writeback(struct task_struct *task, |
1518 | const struct user_regset *regset) |
1519 | { |
1520 | if (regset->writeback) |
1521 | regset->writeback(task, regset, 1); |
1522 | } |
1523 | |
1524 | #ifndef PR_REG_SIZE |
1525 | #define PR_REG_SIZE(S) sizeof(S) |
1526 | #endif |
1527 | |
1528 | #ifndef PRSTATUS_SIZE |
1529 | #define PRSTATUS_SIZE(S) sizeof(S) |
1530 | #endif |
1531 | |
1532 | #ifndef PR_REG_PTR |
1533 | #define PR_REG_PTR(S) (&((S)->pr_reg)) |
1534 | #endif |
1535 | |
1536 | #ifndef SET_PR_FPVALID |
1537 | #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V)) |
1538 | #endif |
1539 | |
1540 | static int fill_thread_core_info(struct elf_thread_core_info *t, |
1541 | const struct user_regset_view *view, |
1542 | long signr, size_t *total) |
1543 | { |
1544 | unsigned int i; |
1545 | |
1546 | /* |
1547 | * NT_PRSTATUS is the one special case, because the regset data |
1548 | * goes into the pr_reg field inside the note contents, rather |
1549 | * than being the whole note contents. We fill the reset in here. |
1550 | * We assume that regset 0 is NT_PRSTATUS. |
1551 | */ |
1552 | fill_prstatus(&t->prstatus, t->task, signr); |
1553 | (void) view->regsets[0].get(t->task, &view->regsets[0], |
1554 | 0, PR_REG_SIZE(t->prstatus.pr_reg), |
1555 | PR_REG_PTR(&t->prstatus), NULL); |
1556 | |
1557 | fill_note(&t->notes[0], "CORE", NT_PRSTATUS, |
1558 | PRSTATUS_SIZE(t->prstatus), &t->prstatus); |
1559 | *total += notesize(&t->notes[0]); |
1560 | |
1561 | do_thread_regset_writeback(t->task, &view->regsets[0]); |
1562 | |
1563 | /* |
1564 | * Each other regset might generate a note too. For each regset |
1565 | * that has no core_note_type or is inactive, we leave t->notes[i] |
1566 | * all zero and we'll know to skip writing it later. |
1567 | */ |
1568 | for (i = 1; i < view->n; ++i) { |
1569 | const struct user_regset *regset = &view->regsets[i]; |
1570 | do_thread_regset_writeback(t->task, regset); |
1571 | if (regset->core_note_type && regset->get && |
1572 | (!regset->active || regset->active(t->task, regset))) { |
1573 | int ret; |
1574 | size_t size = regset->n * regset->size; |
1575 | void *data = kmalloc(size, GFP_KERNEL); |
1576 | if (unlikely(!data)) |
1577 | return 0; |
1578 | ret = regset->get(t->task, regset, |
1579 | 0, size, data, NULL); |
1580 | if (unlikely(ret)) |
1581 | kfree(data); |
1582 | else { |
1583 | if (regset->core_note_type != NT_PRFPREG) |
1584 | fill_note(&t->notes[i], "LINUX", |
1585 | regset->core_note_type, |
1586 | size, data); |
1587 | else { |
1588 | SET_PR_FPVALID(&t->prstatus, 1); |
1589 | fill_note(&t->notes[i], "CORE", |
1590 | NT_PRFPREG, size, data); |
1591 | } |
1592 | *total += notesize(&t->notes[i]); |
1593 | } |
1594 | } |
1595 | } |
1596 | |
1597 | return 1; |
1598 | } |
1599 | |
1600 | static int fill_note_info(struct elfhdr *elf, int phdrs, |
1601 | struct elf_note_info *info, |
1602 | siginfo_t *siginfo, struct pt_regs *regs) |
1603 | { |
1604 | struct task_struct *dump_task = current; |
1605 | const struct user_regset_view *view = task_user_regset_view(dump_task); |
1606 | struct elf_thread_core_info *t; |
1607 | struct elf_prpsinfo *psinfo; |
1608 | struct core_thread *ct; |
1609 | unsigned int i; |
1610 | |
1611 | info->size = 0; |
1612 | info->thread = NULL; |
1613 | |
1614 | psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); |
1615 | if (psinfo == NULL) { |
1616 | info->psinfo.data = NULL; /* So we don't free this wrongly */ |
1617 | return 0; |
1618 | } |
1619 | |
1620 | fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); |
1621 | |
1622 | /* |
1623 | * Figure out how many notes we're going to need for each thread. |
1624 | */ |
1625 | info->thread_notes = 0; |
1626 | for (i = 0; i < view->n; ++i) |
1627 | if (view->regsets[i].core_note_type != 0) |
1628 | ++info->thread_notes; |
1629 | |
1630 | /* |
1631 | * Sanity check. We rely on regset 0 being in NT_PRSTATUS, |
1632 | * since it is our one special case. |
1633 | */ |
1634 | if (unlikely(info->thread_notes == 0) || |
1635 | unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) { |
1636 | WARN_ON(1); |
1637 | return 0; |
1638 | } |
1639 | |
1640 | /* |
1641 | * Initialize the ELF file header. |
1642 | */ |
1643 | fill_elf_header(elf, phdrs, |
1644 | view->e_machine, view->e_flags); |
1645 | |
1646 | /* |
1647 | * Allocate a structure for each thread. |
1648 | */ |
1649 | for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) { |
1650 | t = kzalloc(offsetof(struct elf_thread_core_info, |
1651 | notes[info->thread_notes]), |
1652 | GFP_KERNEL); |
1653 | if (unlikely(!t)) |
1654 | return 0; |
1655 | |
1656 | t->task = ct->task; |
1657 | if (ct->task == dump_task || !info->thread) { |
1658 | t->next = info->thread; |
1659 | info->thread = t; |
1660 | } else { |
1661 | /* |
1662 | * Make sure to keep the original task at |
1663 | * the head of the list. |
1664 | */ |
1665 | t->next = info->thread->next; |
1666 | info->thread->next = t; |
1667 | } |
1668 | } |
1669 | |
1670 | /* |
1671 | * Now fill in each thread's information. |
1672 | */ |
1673 | for (t = info->thread; t != NULL; t = t->next) |
1674 | if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size)) |
1675 | return 0; |
1676 | |
1677 | /* |
1678 | * Fill in the two process-wide notes. |
1679 | */ |
1680 | fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm); |
1681 | info->size += notesize(&info->psinfo); |
1682 | |
1683 | fill_siginfo_note(&info->signote, &info->csigdata, siginfo); |
1684 | info->size += notesize(&info->signote); |
1685 | |
1686 | fill_auxv_note(&info->auxv, current->mm); |
1687 | info->size += notesize(&info->auxv); |
1688 | |
1689 | fill_files_note(&info->files); |
1690 | info->size += notesize(&info->files); |
1691 | |
1692 | return 1; |
1693 | } |
1694 | |
1695 | static size_t get_note_info_size(struct elf_note_info *info) |
1696 | { |
1697 | return info->size; |
1698 | } |
1699 | |
1700 | /* |
1701 | * Write all the notes for each thread. When writing the first thread, the |
1702 | * process-wide notes are interleaved after the first thread-specific note. |
1703 | */ |
1704 | static int write_note_info(struct elf_note_info *info, |
1705 | struct file *file, loff_t *foffset) |
1706 | { |
1707 | bool first = 1; |
1708 | struct elf_thread_core_info *t = info->thread; |
1709 | |
1710 | do { |
1711 | int i; |
1712 | |
1713 | if (!writenote(&t->notes[0], file, foffset)) |
1714 | return 0; |
1715 | |
1716 | if (first && !writenote(&info->psinfo, file, foffset)) |
1717 | return 0; |
1718 | if (first && !writenote(&info->signote, file, foffset)) |
1719 | return 0; |
1720 | if (first && !writenote(&info->auxv, file, foffset)) |
1721 | return 0; |
1722 | if (first && !writenote(&info->files, file, foffset)) |
1723 | return 0; |
1724 | |
1725 | for (i = 1; i < info->thread_notes; ++i) |
1726 | if (t->notes[i].data && |
1727 | !writenote(&t->notes[i], file, foffset)) |
1728 | return 0; |
1729 | |
1730 | first = 0; |
1731 | t = t->next; |
1732 | } while (t); |
1733 | |
1734 | return 1; |
1735 | } |
1736 | |
1737 | static void free_note_info(struct elf_note_info *info) |
1738 | { |
1739 | struct elf_thread_core_info *threads = info->thread; |
1740 | while (threads) { |
1741 | unsigned int i; |
1742 | struct elf_thread_core_info *t = threads; |
1743 | threads = t->next; |
1744 | WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus); |
1745 | for (i = 1; i < info->thread_notes; ++i) |
1746 | kfree(t->notes[i].data); |
1747 | kfree(t); |
1748 | } |
1749 | kfree(info->psinfo.data); |
1750 | vfree(info->files.data); |
1751 | } |
1752 | |
1753 | #else |
1754 | |
1755 | /* Here is the structure in which status of each thread is captured. */ |
1756 | struct elf_thread_status |
1757 | { |
1758 | struct list_head list; |
1759 | struct elf_prstatus prstatus; /* NT_PRSTATUS */ |
1760 | elf_fpregset_t fpu; /* NT_PRFPREG */ |
1761 | struct task_struct *thread; |
1762 | #ifdef ELF_CORE_COPY_XFPREGS |
1763 | elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ |
1764 | #endif |
1765 | struct memelfnote notes[3]; |
1766 | int num_notes; |
1767 | }; |
1768 | |
1769 | /* |
1770 | * In order to add the specific thread information for the elf file format, |
1771 | * we need to keep a linked list of every threads pr_status and then create |
1772 | * a single section for them in the final core file. |
1773 | */ |
1774 | static int elf_dump_thread_status(long signr, struct elf_thread_status *t) |
1775 | { |
1776 | int sz = 0; |
1777 | struct task_struct *p = t->thread; |
1778 | t->num_notes = 0; |
1779 | |
1780 | fill_prstatus(&t->prstatus, p, signr); |
1781 | elf_core_copy_task_regs(p, &t->prstatus.pr_reg); |
1782 | |
1783 | fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), |
1784 | &(t->prstatus)); |
1785 | t->num_notes++; |
1786 | sz += notesize(&t->notes[0]); |
1787 | |
1788 | if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, |
1789 | &t->fpu))) { |
1790 | fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), |
1791 | &(t->fpu)); |
1792 | t->num_notes++; |
1793 | sz += notesize(&t->notes[1]); |
1794 | } |
1795 | |
1796 | #ifdef ELF_CORE_COPY_XFPREGS |
1797 | if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { |
1798 | fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, |
1799 | sizeof(t->xfpu), &t->xfpu); |
1800 | t->num_notes++; |
1801 | sz += notesize(&t->notes[2]); |
1802 | } |
1803 | #endif |
1804 | return sz; |
1805 | } |
1806 | |
1807 | struct elf_note_info { |
1808 | struct memelfnote *notes; |
1809 | struct elf_prstatus *prstatus; /* NT_PRSTATUS */ |
1810 | struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */ |
1811 | struct list_head thread_list; |
1812 | elf_fpregset_t *fpu; |
1813 | #ifdef ELF_CORE_COPY_XFPREGS |
1814 | elf_fpxregset_t *xfpu; |
1815 | #endif |
1816 | user_siginfo_t csigdata; |
1817 | int thread_status_size; |
1818 | int numnote; |
1819 | }; |
1820 | |
1821 | static int elf_note_info_init(struct elf_note_info *info) |
1822 | { |
1823 | memset(info, 0, sizeof(*info)); |
1824 | INIT_LIST_HEAD(&info->thread_list); |
1825 | |
1826 | /* Allocate space for ELF notes */ |
1827 | info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL); |
1828 | if (!info->notes) |
1829 | return 0; |
1830 | info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL); |
1831 | if (!info->psinfo) |
1832 | return 0; |
1833 | info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL); |
1834 | if (!info->prstatus) |
1835 | return 0; |
1836 | info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL); |
1837 | if (!info->fpu) |
1838 | return 0; |
1839 | #ifdef ELF_CORE_COPY_XFPREGS |
1840 | info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL); |
1841 | if (!info->xfpu) |
1842 | return 0; |
1843 | #endif |
1844 | return 1; |
1845 | } |
1846 | |
1847 | static int fill_note_info(struct elfhdr *elf, int phdrs, |
1848 | struct elf_note_info *info, |
1849 | siginfo_t *siginfo, struct pt_regs *regs) |
1850 | { |
1851 | struct list_head *t; |
1852 | |
1853 | if (!elf_note_info_init(info)) |
1854 | return 0; |
1855 | |
1856 | if (siginfo->si_signo) { |
1857 | struct core_thread *ct; |
1858 | struct elf_thread_status *ets; |
1859 | |
1860 | for (ct = current->mm->core_state->dumper.next; |
1861 | ct; ct = ct->next) { |
1862 | ets = kzalloc(sizeof(*ets), GFP_KERNEL); |
1863 | if (!ets) |
1864 | return 0; |
1865 | |
1866 | ets->thread = ct->task; |
1867 | list_add(&ets->list, &info->thread_list); |
1868 | } |
1869 | |
1870 | list_for_each(t, &info->thread_list) { |
1871 | int sz; |
1872 | |
1873 | ets = list_entry(t, struct elf_thread_status, list); |
1874 | sz = elf_dump_thread_status(siginfo->si_signo, ets); |
1875 | info->thread_status_size += sz; |
1876 | } |
1877 | } |
1878 | /* now collect the dump for the current */ |
1879 | memset(info->prstatus, 0, sizeof(*info->prstatus)); |
1880 | fill_prstatus(info->prstatus, current, siginfo->si_signo); |
1881 | elf_core_copy_regs(&info->prstatus->pr_reg, regs); |
1882 | |
1883 | /* Set up header */ |
1884 | fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS); |
1885 | |
1886 | /* |
1887 | * Set up the notes in similar form to SVR4 core dumps made |
1888 | * with info from their /proc. |
1889 | */ |
1890 | |
1891 | fill_note(info->notes + 0, "CORE", NT_PRSTATUS, |
1892 | sizeof(*info->prstatus), info->prstatus); |
1893 | fill_psinfo(info->psinfo, current->group_leader, current->mm); |
1894 | fill_note(info->notes + 1, "CORE", NT_PRPSINFO, |
1895 | sizeof(*info->psinfo), info->psinfo); |
1896 | |
1897 | fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo); |
1898 | fill_auxv_note(info->notes + 3, current->mm); |
1899 | fill_files_note(info->notes + 4); |
1900 | |
1901 | info->numnote = 5; |
1902 | |
1903 | /* Try to dump the FPU. */ |
1904 | info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs, |
1905 | info->fpu); |
1906 | if (info->prstatus->pr_fpvalid) |
1907 | fill_note(info->notes + info->numnote++, |
1908 | "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu); |
1909 | #ifdef ELF_CORE_COPY_XFPREGS |
1910 | if (elf_core_copy_task_xfpregs(current, info->xfpu)) |
1911 | fill_note(info->notes + info->numnote++, |
1912 | "LINUX", ELF_CORE_XFPREG_TYPE, |
1913 | sizeof(*info->xfpu), info->xfpu); |
1914 | #endif |
1915 | |
1916 | return 1; |
1917 | } |
1918 | |
1919 | static size_t get_note_info_size(struct elf_note_info *info) |
1920 | { |
1921 | int sz = 0; |
1922 | int i; |
1923 | |
1924 | for (i = 0; i < info->numnote; i++) |
1925 | sz += notesize(info->notes + i); |
1926 | |
1927 | sz += info->thread_status_size; |
1928 | |
1929 | return sz; |
1930 | } |
1931 | |
1932 | static int write_note_info(struct elf_note_info *info, |
1933 | struct file *file, loff_t *foffset) |
1934 | { |
1935 | int i; |
1936 | struct list_head *t; |
1937 | |
1938 | for (i = 0; i < info->numnote; i++) |
1939 | if (!writenote(info->notes + i, file, foffset)) |
1940 | return 0; |
1941 | |
1942 | /* write out the thread status notes section */ |
1943 | list_for_each(t, &info->thread_list) { |
1944 | struct elf_thread_status *tmp = |
1945 | list_entry(t, struct elf_thread_status, list); |
1946 | |
1947 | for (i = 0; i < tmp->num_notes; i++) |
1948 | if (!writenote(&tmp->notes[i], file, foffset)) |
1949 | return 0; |
1950 | } |
1951 | |
1952 | return 1; |
1953 | } |
1954 | |
1955 | static void free_note_info(struct elf_note_info *info) |
1956 | { |
1957 | while (!list_empty(&info->thread_list)) { |
1958 | struct list_head *tmp = info->thread_list.next; |
1959 | list_del(tmp); |
1960 | kfree(list_entry(tmp, struct elf_thread_status, list)); |
1961 | } |
1962 | |
1963 | /* Free data allocated by fill_files_note(): */ |
1964 | vfree(info->notes[4].data); |
1965 | |
1966 | kfree(info->prstatus); |
1967 | kfree(info->psinfo); |
1968 | kfree(info->notes); |
1969 | kfree(info->fpu); |
1970 | #ifdef ELF_CORE_COPY_XFPREGS |
1971 | kfree(info->xfpu); |
1972 | #endif |
1973 | } |
1974 | |
1975 | #endif |
1976 | |
1977 | static struct vm_area_struct *first_vma(struct task_struct *tsk, |
1978 | struct vm_area_struct *gate_vma) |
1979 | { |
1980 | struct vm_area_struct *ret = tsk->mm->mmap; |
1981 | |
1982 | if (ret) |
1983 | return ret; |
1984 | return gate_vma; |
1985 | } |
1986 | /* |
1987 | * Helper function for iterating across a vma list. It ensures that the caller |
1988 | * will visit `gate_vma' prior to terminating the search. |
1989 | */ |
1990 | static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma, |
1991 | struct vm_area_struct *gate_vma) |
1992 | { |
1993 | struct vm_area_struct *ret; |
1994 | |
1995 | ret = this_vma->vm_next; |
1996 | if (ret) |
1997 | return ret; |
1998 | if (this_vma == gate_vma) |
1999 | return NULL; |
2000 | return gate_vma; |
2001 | } |
2002 | |
2003 | static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, |
2004 | elf_addr_t e_shoff, int segs) |
2005 | { |
2006 | elf->e_shoff = e_shoff; |
2007 | elf->e_shentsize = sizeof(*shdr4extnum); |
2008 | elf->e_shnum = 1; |
2009 | elf->e_shstrndx = SHN_UNDEF; |
2010 | |
2011 | memset(shdr4extnum, 0, sizeof(*shdr4extnum)); |
2012 | |
2013 | shdr4extnum->sh_type = SHT_NULL; |
2014 | shdr4extnum->sh_size = elf->e_shnum; |
2015 | shdr4extnum->sh_link = elf->e_shstrndx; |
2016 | shdr4extnum->sh_info = segs; |
2017 | } |
2018 | |
2019 | static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma, |
2020 | unsigned long mm_flags) |
2021 | { |
2022 | struct vm_area_struct *vma; |
2023 | size_t size = 0; |
2024 | |
2025 | for (vma = first_vma(current, gate_vma); vma != NULL; |
2026 | vma = next_vma(vma, gate_vma)) |
2027 | size += vma_dump_size(vma, mm_flags); |
2028 | return size; |
2029 | } |
2030 | |
2031 | /* |
2032 | * Actual dumper |
2033 | * |
2034 | * This is a two-pass process; first we find the offsets of the bits, |
2035 | * and then they are actually written out. If we run out of core limit |
2036 | * we just truncate. |
2037 | */ |
2038 | static int elf_core_dump(struct coredump_params *cprm) |
2039 | { |
2040 | int has_dumped = 0; |
2041 | mm_segment_t fs; |
2042 | int segs; |
2043 | size_t size = 0; |
2044 | struct vm_area_struct *vma, *gate_vma; |
2045 | struct elfhdr *elf = NULL; |
2046 | loff_t offset = 0, dataoff, foffset; |
2047 | struct elf_note_info info; |
2048 | struct elf_phdr *phdr4note = NULL; |
2049 | struct elf_shdr *shdr4extnum = NULL; |
2050 | Elf_Half e_phnum; |
2051 | elf_addr_t e_shoff; |
2052 | |
2053 | /* |
2054 | * We no longer stop all VM operations. |
2055 | * |
2056 | * This is because those proceses that could possibly change map_count |
2057 | * or the mmap / vma pages are now blocked in do_exit on current |
2058 | * finishing this core dump. |
2059 | * |
2060 | * Only ptrace can touch these memory addresses, but it doesn't change |
2061 | * the map_count or the pages allocated. So no possibility of crashing |
2062 | * exists while dumping the mm->vm_next areas to the core file. |
2063 | */ |
2064 | |
2065 | /* alloc memory for large data structures: too large to be on stack */ |
2066 | elf = kmalloc(sizeof(*elf), GFP_KERNEL); |
2067 | if (!elf) |
2068 | goto out; |
2069 | /* |
2070 | * The number of segs are recored into ELF header as 16bit value. |
2071 | * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here. |
2072 | */ |
2073 | segs = current->mm->map_count; |
2074 | segs += elf_core_extra_phdrs(); |
2075 | |
2076 | gate_vma = get_gate_vma(current->mm); |
2077 | if (gate_vma != NULL) |
2078 | segs++; |
2079 | |
2080 | /* for notes section */ |
2081 | segs++; |
2082 | |
2083 | /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid |
2084 | * this, kernel supports extended numbering. Have a look at |
2085 | * include/linux/elf.h for further information. */ |
2086 | e_phnum = segs > PN_XNUM ? PN_XNUM : segs; |
2087 | |
2088 | /* |
2089 | * Collect all the non-memory information about the process for the |
2090 | * notes. This also sets up the file header. |
2091 | */ |
2092 | if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs)) |
2093 | goto cleanup; |
2094 | |
2095 | has_dumped = 1; |
2096 | |
2097 | fs = get_fs(); |
2098 | set_fs(KERNEL_DS); |
2099 | |
2100 | offset += sizeof(*elf); /* Elf header */ |
2101 | offset += segs * sizeof(struct elf_phdr); /* Program headers */ |
2102 | foffset = offset; |
2103 | |
2104 | /* Write notes phdr entry */ |
2105 | { |
2106 | size_t sz = get_note_info_size(&info); |
2107 | |
2108 | sz += elf_coredump_extra_notes_size(); |
2109 | |
2110 | phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); |
2111 | if (!phdr4note) |
2112 | goto end_coredump; |
2113 | |
2114 | fill_elf_note_phdr(phdr4note, sz, offset); |
2115 | offset += sz; |
2116 | } |
2117 | |
2118 | dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); |
2119 | |
2120 | offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags); |
2121 | offset += elf_core_extra_data_size(); |
2122 | e_shoff = offset; |
2123 | |
2124 | if (e_phnum == PN_XNUM) { |
2125 | shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); |
2126 | if (!shdr4extnum) |
2127 | goto end_coredump; |
2128 | fill_extnum_info(elf, shdr4extnum, e_shoff, segs); |
2129 | } |
2130 | |
2131 | offset = dataoff; |
2132 | |
2133 | size += sizeof(*elf); |
2134 | if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf))) |
2135 | goto end_coredump; |
2136 | |
2137 | size += sizeof(*phdr4note); |
2138 | if (size > cprm->limit |
2139 | || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note))) |
2140 | goto end_coredump; |
2141 | |
2142 | /* Write program headers for segments dump */ |
2143 | for (vma = first_vma(current, gate_vma); vma != NULL; |
2144 | vma = next_vma(vma, gate_vma)) { |
2145 | struct elf_phdr phdr; |
2146 | |
2147 | phdr.p_type = PT_LOAD; |
2148 | phdr.p_offset = offset; |
2149 | phdr.p_vaddr = vma->vm_start; |
2150 | phdr.p_paddr = 0; |
2151 | phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags); |
2152 | phdr.p_memsz = vma->vm_end - vma->vm_start; |
2153 | offset += phdr.p_filesz; |
2154 | phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; |
2155 | if (vma->vm_flags & VM_WRITE) |
2156 | phdr.p_flags |= PF_W; |
2157 | if (vma->vm_flags & VM_EXEC) |
2158 | phdr.p_flags |= PF_X; |
2159 | phdr.p_align = ELF_EXEC_PAGESIZE; |
2160 | |
2161 | size += sizeof(phdr); |
2162 | if (size > cprm->limit |
2163 | || !dump_write(cprm->file, &phdr, sizeof(phdr))) |
2164 | goto end_coredump; |
2165 | } |
2166 | |
2167 | if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit)) |
2168 | goto end_coredump; |
2169 | |
2170 | /* write out the notes section */ |
2171 | if (!write_note_info(&info, cprm->file, &foffset)) |
2172 | goto end_coredump; |
2173 | |
2174 | if (elf_coredump_extra_notes_write(cprm->file, &foffset)) |
2175 | goto end_coredump; |
2176 | |
2177 | /* Align to page */ |
2178 | if (!dump_seek(cprm->file, dataoff - foffset)) |
2179 | goto end_coredump; |
2180 | |
2181 | for (vma = first_vma(current, gate_vma); vma != NULL; |
2182 | vma = next_vma(vma, gate_vma)) { |
2183 | unsigned long addr; |
2184 | unsigned long end; |
2185 | |
2186 | end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags); |
2187 | |
2188 | for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) { |
2189 | struct page *page; |
2190 | int stop; |
2191 | |
2192 | page = get_dump_page(addr); |
2193 | if (page) { |
2194 | void *kaddr = kmap(page); |
2195 | stop = ((size += PAGE_SIZE) > cprm->limit) || |
2196 | !dump_write(cprm->file, kaddr, |
2197 | PAGE_SIZE); |
2198 | kunmap(page); |
2199 | page_cache_release(page); |
2200 | } else |
2201 | stop = !dump_seek(cprm->file, PAGE_SIZE); |
2202 | if (stop) |
2203 | goto end_coredump; |
2204 | } |
2205 | } |
2206 | |
2207 | if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit)) |
2208 | goto end_coredump; |
2209 | |
2210 | if (e_phnum == PN_XNUM) { |
2211 | size += sizeof(*shdr4extnum); |
2212 | if (size > cprm->limit |
2213 | || !dump_write(cprm->file, shdr4extnum, |
2214 | sizeof(*shdr4extnum))) |
2215 | goto end_coredump; |
2216 | } |
2217 | |
2218 | end_coredump: |
2219 | set_fs(fs); |
2220 | |
2221 | cleanup: |
2222 | free_note_info(&info); |
2223 | kfree(shdr4extnum); |
2224 | kfree(phdr4note); |
2225 | kfree(elf); |
2226 | out: |
2227 | return has_dumped; |
2228 | } |
2229 | |
2230 | #endif /* CONFIG_ELF_CORE */ |
2231 | |
2232 | static int __init init_elf_binfmt(void) |
2233 | { |
2234 | register_binfmt(&elf_format); |
2235 | return 0; |
2236 | } |
2237 | |
2238 | static void __exit exit_elf_binfmt(void) |
2239 | { |
2240 | /* Remove the COFF and ELF loaders. */ |
2241 | unregister_binfmt(&elf_format); |
2242 | } |
2243 | |
2244 | core_initcall(init_elf_binfmt); |
2245 | module_exit(exit_elf_binfmt); |
2246 | MODULE_LICENSE("GPL"); |
2247 |
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