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Linux 3.18.55
[linux/fpc-iii.git] / fs / binfmt_elf.c
blobe39fe28f1ea007b0ce4421d7b905f0155c1cccfb
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 unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
50 int, int, unsigned long);
51
52 #ifdef CONFIG_USELIB
53 static int load_elf_library(struct file *);
54 #else
55 #define load_elf_library NULL
56 #endif
57
58 /*
59 * If we don't support core dumping, then supply a NULL so we
60 * don't even try.
61 */
62 #ifdef CONFIG_ELF_CORE
63 static int elf_core_dump(struct coredump_params *cprm);
64 #else
65 #define elf_core_dump NULL
66 #endif
67
68 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
69 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
70 #else
71 #define ELF_MIN_ALIGN PAGE_SIZE
72 #endif
73
74 #ifndef ELF_CORE_EFLAGS
75 #define ELF_CORE_EFLAGS 0
76 #endif
77
78 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
79 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
80 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
81
82 static struct linux_binfmt elf_format = {
83 .module = THIS_MODULE,
84 .load_binary = load_elf_binary,
85 .load_shlib = load_elf_library,
86 .core_dump = elf_core_dump,
87 .min_coredump = ELF_EXEC_PAGESIZE,
88 };
89
90 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
91
92 static int set_brk(unsigned long start, unsigned long end)
93 {
94 start = ELF_PAGEALIGN(start);
95 end = ELF_PAGEALIGN(end);
96 if (end > start) {
97 unsigned long addr;
98 addr = vm_brk(start, end - start);
99 if (BAD_ADDR(addr))
100 return addr;
101 }
102 current->mm->start_brk = current->mm->brk = end;
103 return 0;
104 }
105
106 /* We need to explicitly zero any fractional pages
107 after the data section (i.e. bss). This would
108 contain the junk from the file that should not
109 be in memory
110 */
111 static int padzero(unsigned long elf_bss)
112 {
113 unsigned long nbyte;
114
115 nbyte = ELF_PAGEOFFSET(elf_bss);
116 if (nbyte) {
117 nbyte = ELF_MIN_ALIGN - nbyte;
118 if (clear_user((void __user *) elf_bss, nbyte))
119 return -EFAULT;
120 }
121 return 0;
122 }
123
124 /* Let's use some macros to make this stack manipulation a little clearer */
125 #ifdef CONFIG_STACK_GROWSUP
126 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
127 #define STACK_ROUND(sp, items) \
128 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
129 #define STACK_ALLOC(sp, len) ({ \
130 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
131 old_sp; })
132 #else
133 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
134 #define STACK_ROUND(sp, items) \
135 (((unsigned long) (sp - items)) &~ 15UL)
136 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
137 #endif
138
139 #ifndef ELF_BASE_PLATFORM
140 /*
141 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
142 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
143 * will be copied to the user stack in the same manner as AT_PLATFORM.
144 */
145 #define ELF_BASE_PLATFORM NULL
146 #endif
147
148 static int
149 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
150 unsigned long load_addr, unsigned long interp_load_addr)
151 {
152 unsigned long p = bprm->p;
153 int argc = bprm->argc;
154 int envc = bprm->envc;
155 elf_addr_t __user *argv;
156 elf_addr_t __user *envp;
157 elf_addr_t __user *sp;
158 elf_addr_t __user *u_platform;
159 elf_addr_t __user *u_base_platform;
160 elf_addr_t __user *u_rand_bytes;
161 const char *k_platform = ELF_PLATFORM;
162 const char *k_base_platform = ELF_BASE_PLATFORM;
163 unsigned char k_rand_bytes[16];
164 int items;
165 elf_addr_t *elf_info;
166 int ei_index = 0;
167 const struct cred *cred = current_cred();
168 struct vm_area_struct *vma;
169
170 /*
171 * In some cases (e.g. Hyper-Threading), we want to avoid L1
172 * evictions by the processes running on the same package. One
173 * thing we can do is to shuffle the initial stack for them.
174 */
175
176 p = arch_align_stack(p);
177
178 /*
179 * If this architecture has a platform capability string, copy it
180 * to userspace. In some cases (Sparc), this info is impossible
181 * for userspace to get any other way, in others (i386) it is
182 * merely difficult.
183 */
184 u_platform = NULL;
185 if (k_platform) {
186 size_t len = strlen(k_platform) + 1;
187
188 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
189 if (__copy_to_user(u_platform, k_platform, len))
190 return -EFAULT;
191 }
192
193 /*
194 * If this architecture has a "base" platform capability
195 * string, copy it to userspace.
196 */
197 u_base_platform = NULL;
198 if (k_base_platform) {
199 size_t len = strlen(k_base_platform) + 1;
200
201 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
202 if (__copy_to_user(u_base_platform, k_base_platform, len))
203 return -EFAULT;
204 }
205
206 /*
207 * Generate 16 random bytes for userspace PRNG seeding.
208 */
209 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
210 u_rand_bytes = (elf_addr_t __user *)
211 STACK_ALLOC(p, sizeof(k_rand_bytes));
212 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
213 return -EFAULT;
214
215 /* Create the ELF interpreter info */
216 elf_info = (elf_addr_t *)current->mm->saved_auxv;
217 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
218 #define NEW_AUX_ENT(id, val) \
219 do { \
220 elf_info[ei_index++] = id; \
221 elf_info[ei_index++] = val; \
222 } while (0)
223
224 #ifdef ARCH_DLINFO
225 /*
226 * ARCH_DLINFO must come first so PPC can do its special alignment of
227 * AUXV.
228 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
229 * ARCH_DLINFO changes
230 */
231 ARCH_DLINFO;
232 #endif
233 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
234 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
235 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
236 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
237 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
238 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
239 NEW_AUX_ENT(AT_BASE, interp_load_addr);
240 NEW_AUX_ENT(AT_FLAGS, 0);
241 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
242 NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
243 NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
244 NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
245 NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
246 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
247 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
248 #ifdef ELF_HWCAP2
249 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
250 #endif
251 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
252 if (k_platform) {
253 NEW_AUX_ENT(AT_PLATFORM,
254 (elf_addr_t)(unsigned long)u_platform);
255 }
256 if (k_base_platform) {
257 NEW_AUX_ENT(AT_BASE_PLATFORM,
258 (elf_addr_t)(unsigned long)u_base_platform);
259 }
260 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
261 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
262 }
263 #undef NEW_AUX_ENT
264 /* AT_NULL is zero; clear the rest too */
265 memset(&elf_info[ei_index], 0,
266 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
267
268 /* And advance past the AT_NULL entry. */
269 ei_index += 2;
270
271 sp = STACK_ADD(p, ei_index);
272
273 items = (argc + 1) + (envc + 1) + 1;
274 bprm->p = STACK_ROUND(sp, items);
275
276 /* Point sp at the lowest address on the stack */
277 #ifdef CONFIG_STACK_GROWSUP
278 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
279 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
280 #else
281 sp = (elf_addr_t __user *)bprm->p;
282 #endif
283
284
285 /*
286 * Grow the stack manually; some architectures have a limit on how
287 * far ahead a user-space access may be in order to grow the stack.
288 */
289 vma = find_extend_vma(current->mm, bprm->p);
290 if (!vma)
291 return -EFAULT;
292
293 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
294 if (__put_user(argc, sp++))
295 return -EFAULT;
296 argv = sp;
297 envp = argv + argc + 1;
298
299 /* Populate argv and envp */
300 p = current->mm->arg_end = current->mm->arg_start;
301 while (argc-- > 0) {
302 size_t len;
303 if (__put_user((elf_addr_t)p, argv++))
304 return -EFAULT;
305 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
306 if (!len || len > MAX_ARG_STRLEN)
307 return -EINVAL;
308 p += len;
309 }
310 if (__put_user(0, argv))
311 return -EFAULT;
312 current->mm->arg_end = current->mm->env_start = p;
313 while (envc-- > 0) {
314 size_t len;
315 if (__put_user((elf_addr_t)p, envp++))
316 return -EFAULT;
317 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
318 if (!len || len > MAX_ARG_STRLEN)
319 return -EINVAL;
320 p += len;
321 }
322 if (__put_user(0, envp))
323 return -EFAULT;
324 current->mm->env_end = p;
325
326 /* Put the elf_info on the stack in the right place. */
327 sp = (elf_addr_t __user *)envp + 1;
328 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
329 return -EFAULT;
330 return 0;
331 }
332
333 #ifndef elf_map
334
335 static unsigned long elf_map(struct file *filep, unsigned long addr,
336 struct elf_phdr *eppnt, int prot, int type,
337 unsigned long total_size)
338 {
339 unsigned long map_addr;
340 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
341 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
342 addr = ELF_PAGESTART(addr);
343 size = ELF_PAGEALIGN(size);
344
345 /* mmap() will return -EINVAL if given a zero size, but a
346 * segment with zero filesize is perfectly valid */
347 if (!size)
348 return addr;
349
350 /*
351 * total_size is the size of the ELF (interpreter) image.
352 * The _first_ mmap needs to know the full size, otherwise
353 * randomization might put this image into an overlapping
354 * position with the ELF binary image. (since size < total_size)
355 * So we first map the 'big' image - and unmap the remainder at
356 * the end. (which unmap is needed for ELF images with holes.)
357 */
358 if (total_size) {
359 total_size = ELF_PAGEALIGN(total_size);
360 map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
361 if (!BAD_ADDR(map_addr))
362 vm_munmap(map_addr+size, total_size-size);
363 } else
364 map_addr = vm_mmap(filep, addr, size, prot, type, off);
365
366 return(map_addr);
367 }
368
369 #endif /* !elf_map */
370
371 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
372 {
373 int i, first_idx = -1, last_idx = -1;
374
375 for (i = 0; i < nr; i++) {
376 if (cmds[i].p_type == PT_LOAD) {
377 last_idx = i;
378 if (first_idx == -1)
379 first_idx = i;
380 }
381 }
382 if (first_idx == -1)
383 return 0;
384
385 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
386 ELF_PAGESTART(cmds[first_idx].p_vaddr);
387 }
388
389
390 /* This is much more generalized than the library routine read function,
391 so we keep this separate. Technically the library read function
392 is only provided so that we can read a.out libraries that have
393 an ELF header */
394
395 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
396 struct file *interpreter, unsigned long *interp_map_addr,
397 unsigned long no_base)
398 {
399 struct elf_phdr *elf_phdata;
400 struct elf_phdr *eppnt;
401 unsigned long load_addr = 0;
402 int load_addr_set = 0;
403 unsigned long last_bss = 0, elf_bss = 0;
404 unsigned long error = ~0UL;
405 unsigned long total_size;
406 int retval, i, size;
407
408 /* First of all, some simple consistency checks */
409 if (interp_elf_ex->e_type != ET_EXEC &&
410 interp_elf_ex->e_type != ET_DYN)
411 goto out;
412 if (!elf_check_arch(interp_elf_ex))
413 goto out;
414 if (!interpreter->f_op->mmap)
415 goto out;
416
417 /*
418 * If the size of this structure has changed, then punt, since
419 * we will be doing the wrong thing.
420 */
421 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
422 goto out;
423 if (interp_elf_ex->e_phnum < 1 ||
424 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
425 goto out;
426
427 /* Now read in all of the header information */
428 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
429 if (size > ELF_MIN_ALIGN)
430 goto out;
431 elf_phdata = kmalloc(size, GFP_KERNEL);
432 if (!elf_phdata)
433 goto out;
434
435 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
436 (char *)elf_phdata, size);
437 error = -EIO;
438 if (retval != size) {
439 if (retval < 0)
440 error = retval;
441 goto out_close;
442 }
443
444 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
445 if (!total_size) {
446 error = -EINVAL;
447 goto out_close;
448 }
449
450 eppnt = elf_phdata;
451 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
452 if (eppnt->p_type == PT_LOAD) {
453 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
454 int elf_prot = 0;
455 unsigned long vaddr = 0;
456 unsigned long k, map_addr;
457
458 if (eppnt->p_flags & PF_R)
459 elf_prot = PROT_READ;
460 if (eppnt->p_flags & PF_W)
461 elf_prot |= PROT_WRITE;
462 if (eppnt->p_flags & PF_X)
463 elf_prot |= PROT_EXEC;
464 vaddr = eppnt->p_vaddr;
465 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
466 elf_type |= MAP_FIXED;
467 else if (no_base && interp_elf_ex->e_type == ET_DYN)
468 load_addr = -vaddr;
469
470 map_addr = elf_map(interpreter, load_addr + vaddr,
471 eppnt, elf_prot, elf_type, total_size);
472 total_size = 0;
473 if (!*interp_map_addr)
474 *interp_map_addr = map_addr;
475 error = map_addr;
476 if (BAD_ADDR(map_addr))
477 goto out_close;
478
479 if (!load_addr_set &&
480 interp_elf_ex->e_type == ET_DYN) {
481 load_addr = map_addr - ELF_PAGESTART(vaddr);
482 load_addr_set = 1;
483 }
484
485 /*
486 * Check to see if the section's size will overflow the
487 * allowed task size. Note that p_filesz must always be
488 * <= p_memsize so it's only necessary to check p_memsz.
489 */
490 k = load_addr + eppnt->p_vaddr;
491 if (BAD_ADDR(k) ||
492 eppnt->p_filesz > eppnt->p_memsz ||
493 eppnt->p_memsz > TASK_SIZE ||
494 TASK_SIZE - eppnt->p_memsz < k) {
495 error = -ENOMEM;
496 goto out_close;
497 }
498
499 /*
500 * Find the end of the file mapping for this phdr, and
501 * keep track of the largest address we see for this.
502 */
503 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
504 if (k > elf_bss)
505 elf_bss = k;
506
507 /*
508 * Do the same thing for the memory mapping - between
509 * elf_bss and last_bss is the bss section.
510 */
511 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
512 if (k > last_bss)
513 last_bss = k;
514 }
515 }
516
517 if (last_bss > elf_bss) {
518 /*
519 * Now fill out the bss section. First pad the last page up
520 * to the page boundary, and then perform a mmap to make sure
521 * that there are zero-mapped pages up to and including the
522 * last bss page.
523 */
524 if (padzero(elf_bss)) {
525 error = -EFAULT;
526 goto out_close;
527 }
528
529 /* What we have mapped so far */
530 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
531
532 /* Map the last of the bss segment */
533 error = vm_brk(elf_bss, last_bss - elf_bss);
534 if (BAD_ADDR(error))
535 goto out_close;
536 }
537
538 error = load_addr;
539
540 out_close:
541 kfree(elf_phdata);
542 out:
543 return error;
544 }
545
546 /*
547 * These are the functions used to load ELF style executables and shared
548 * libraries. There is no binary dependent code anywhere else.
549 */
550
551 #ifndef STACK_RND_MASK
552 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
553 #endif
554
555 static unsigned long randomize_stack_top(unsigned long stack_top)
556 {
557 unsigned long random_variable = 0;
558
559 if ((current->flags & PF_RANDOMIZE) &&
560 !(current->personality & ADDR_NO_RANDOMIZE)) {
561 random_variable = (unsigned long) get_random_int();
562 random_variable &= STACK_RND_MASK;
563 random_variable <<= PAGE_SHIFT;
564 }
565 #ifdef CONFIG_STACK_GROWSUP
566 return PAGE_ALIGN(stack_top) + random_variable;
567 #else
568 return PAGE_ALIGN(stack_top) - random_variable;
569 #endif
570 }
571
572 static int load_elf_binary(struct linux_binprm *bprm)
573 {
574 struct file *interpreter = NULL; /* to shut gcc up */
575 unsigned long load_addr = 0, load_bias = 0;
576 int load_addr_set = 0;
577 char * elf_interpreter = NULL;
578 unsigned long error;
579 struct elf_phdr *elf_ppnt, *elf_phdata;
580 unsigned long elf_bss, elf_brk;
581 int retval, i;
582 unsigned int size;
583 unsigned long elf_entry;
584 unsigned long interp_load_addr = 0;
585 unsigned long start_code, end_code, start_data, end_data;
586 unsigned long reloc_func_desc __maybe_unused = 0;
587 int executable_stack = EXSTACK_DEFAULT;
588 struct pt_regs *regs = current_pt_regs();
589 struct {
590 struct elfhdr elf_ex;
591 struct elfhdr interp_elf_ex;
592 } *loc;
593
594 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
595 if (!loc) {
596 retval = -ENOMEM;
597 goto out_ret;
598 }
599
600 /* Get the exec-header */
601 loc->elf_ex = *((struct elfhdr *)bprm->buf);
602
603 retval = -ENOEXEC;
604 /* First of all, some simple consistency checks */
605 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
606 goto out;
607
608 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
609 goto out;
610 if (!elf_check_arch(&loc->elf_ex))
611 goto out;
612 if (!bprm->file->f_op->mmap)
613 goto out;
614
615 /* Now read in all of the header information */
616 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
617 goto out;
618 if (loc->elf_ex.e_phnum < 1 ||
619 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
620 goto out;
621 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
622 retval = -ENOMEM;
623 elf_phdata = kmalloc(size, GFP_KERNEL);
624 if (!elf_phdata)
625 goto out;
626
627 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
628 (char *)elf_phdata, size);
629 if (retval != size) {
630 if (retval >= 0)
631 retval = -EIO;
632 goto out_free_ph;
633 }
634
635 elf_ppnt = elf_phdata;
636 elf_bss = 0;
637 elf_brk = 0;
638
639 start_code = ~0UL;
640 end_code = 0;
641 start_data = 0;
642 end_data = 0;
643
644 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
645 if (elf_ppnt->p_type == PT_INTERP) {
646 /* This is the program interpreter used for
647 * shared libraries - for now assume that this
648 * is an a.out format binary
649 */
650 retval = -ENOEXEC;
651 if (elf_ppnt->p_filesz > PATH_MAX ||
652 elf_ppnt->p_filesz < 2)
653 goto out_free_ph;
654
655 retval = -ENOMEM;
656 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
657 GFP_KERNEL);
658 if (!elf_interpreter)
659 goto out_free_ph;
660
661 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
662 elf_interpreter,
663 elf_ppnt->p_filesz);
664 if (retval != elf_ppnt->p_filesz) {
665 if (retval >= 0)
666 retval = -EIO;
667 goto out_free_interp;
668 }
669 /* make sure path is NULL terminated */
670 retval = -ENOEXEC;
671 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
672 goto out_free_interp;
673
674 interpreter = open_exec(elf_interpreter);
675 retval = PTR_ERR(interpreter);
676 if (IS_ERR(interpreter))
677 goto out_free_interp;
678
679 /*
680 * If the binary is not readable then enforce
681 * mm->dumpable = 0 regardless of the interpreter's
682 * permissions.
683 */
684 would_dump(bprm, interpreter);
685
686 retval = kernel_read(interpreter, 0, bprm->buf,
687 BINPRM_BUF_SIZE);
688 if (retval != BINPRM_BUF_SIZE) {
689 if (retval >= 0)
690 retval = -EIO;
691 goto out_free_dentry;
692 }
693
694 /* Get the exec headers */
695 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
696 break;
697 }
698 elf_ppnt++;
699 }
700
701 elf_ppnt = elf_phdata;
702 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
703 if (elf_ppnt->p_type == PT_GNU_STACK) {
704 if (elf_ppnt->p_flags & PF_X)
705 executable_stack = EXSTACK_ENABLE_X;
706 else
707 executable_stack = EXSTACK_DISABLE_X;
708 break;
709 }
710
711 /* Some simple consistency checks for the interpreter */
712 if (elf_interpreter) {
713 retval = -ELIBBAD;
714 /* Not an ELF interpreter */
715 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
716 goto out_free_dentry;
717 /* Verify the interpreter has a valid arch */
718 if (!elf_check_arch(&loc->interp_elf_ex))
719 goto out_free_dentry;
720 }
721
722 /* Flush all traces of the currently running executable */
723 retval = flush_old_exec(bprm);
724 if (retval)
725 goto out_free_dentry;
726
727 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
728 may depend on the personality. */
729 SET_PERSONALITY(loc->elf_ex);
730 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
731 current->personality |= READ_IMPLIES_EXEC;
732
733 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
734 current->flags |= PF_RANDOMIZE;
735
736 setup_new_exec(bprm);
737
738 /* Do this so that we can load the interpreter, if need be. We will
739 change some of these later */
740 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
741 executable_stack);
742 if (retval < 0)
743 goto out_free_dentry;
744
745 current->mm->start_stack = bprm->p;
746
747 /* Now we do a little grungy work by mmapping the ELF image into
748 the correct location in memory. */
749 for(i = 0, elf_ppnt = elf_phdata;
750 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
751 int elf_prot = 0, elf_flags;
752 unsigned long k, vaddr;
753 unsigned long total_size = 0;
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 goto out_free_dentry;
768 nbyte = ELF_PAGEOFFSET(elf_bss);
769 if (nbyte) {
770 nbyte = ELF_MIN_ALIGN - nbyte;
771 if (nbyte > elf_brk - elf_bss)
772 nbyte = elf_brk - elf_bss;
773 if (clear_user((void __user *)elf_bss +
774 load_bias, nbyte)) {
775 /*
776 * This bss-zeroing can fail if the ELF
777 * file specifies odd protections. So
778 * we don't check the return value
779 */
780 }
781 }
782 }
783
784 if (elf_ppnt->p_flags & PF_R)
785 elf_prot |= PROT_READ;
786 if (elf_ppnt->p_flags & PF_W)
787 elf_prot |= PROT_WRITE;
788 if (elf_ppnt->p_flags & PF_X)
789 elf_prot |= PROT_EXEC;
790
791 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
792
793 vaddr = elf_ppnt->p_vaddr;
794 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
795 elf_flags |= MAP_FIXED;
796 } else if (loc->elf_ex.e_type == ET_DYN) {
797 /* Try and get dynamic programs out of the way of the
798 * default mmap base, as well as whatever program they
799 * might try to exec. This is because the brk will
800 * follow the loader, and is not movable. */
801 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
802 /* Memory randomization might have been switched off
803 * in runtime via sysctl or explicit setting of
804 * personality flags.
805 * If that is the case, retain the original non-zero
806 * load_bias value in order to establish proper
807 * non-randomized mappings.
808 */
809 if (current->flags & PF_RANDOMIZE)
810 load_bias = 0;
811 else
812 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
813 #else
814 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
815 #endif
816 total_size = total_mapping_size(elf_phdata,
817 loc->elf_ex.e_phnum);
818 if (!total_size) {
819 retval = -EINVAL;
820 goto out_free_dentry;
821 }
822 }
823
824 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
825 elf_prot, elf_flags, total_size);
826 if (BAD_ADDR(error)) {
827 retval = IS_ERR((void *)error) ?
828 PTR_ERR((void*)error) : -EINVAL;
829 goto out_free_dentry;
830 }
831
832 if (!load_addr_set) {
833 load_addr_set = 1;
834 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
835 if (loc->elf_ex.e_type == ET_DYN) {
836 load_bias += error -
837 ELF_PAGESTART(load_bias + vaddr);
838 load_addr += load_bias;
839 reloc_func_desc = load_bias;
840 }
841 }
842 k = elf_ppnt->p_vaddr;
843 if (k < start_code)
844 start_code = k;
845 if (start_data < k)
846 start_data = k;
847
848 /*
849 * Check to see if the section's size will overflow the
850 * allowed task size. Note that p_filesz must always be
851 * <= p_memsz so it is only necessary to check p_memsz.
852 */
853 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
854 elf_ppnt->p_memsz > TASK_SIZE ||
855 TASK_SIZE - elf_ppnt->p_memsz < k) {
856 /* set_brk can never work. Avoid overflows. */
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 goto out_free_dentry;
890 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
891 retval = -EFAULT; /* Nobody gets to see this, but.. */
892 goto out_free_dentry;
893 }
894
895 if (elf_interpreter) {
896 unsigned long interp_map_addr = 0;
897
898 elf_entry = load_elf_interp(&loc->interp_elf_ex,
899 interpreter,
900 &interp_map_addr,
901 load_bias);
902 if (!IS_ERR((void *)elf_entry)) {
903 /*
904 * load_elf_interp() returns relocation
905 * adjustment
906 */
907 interp_load_addr = elf_entry;
908 elf_entry += loc->interp_elf_ex.e_entry;
909 }
910 if (BAD_ADDR(elf_entry)) {
911 retval = IS_ERR((void *)elf_entry) ?
912 (int)elf_entry : -EINVAL;
913 goto out_free_dentry;
914 }
915 reloc_func_desc = interp_load_addr;
916
917 allow_write_access(interpreter);
918 fput(interpreter);
919 kfree(elf_interpreter);
920 } else {
921 elf_entry = loc->elf_ex.e_entry;
922 if (BAD_ADDR(elf_entry)) {
923 retval = -EINVAL;
924 goto out_free_dentry;
925 }
926 }
927
928 kfree(elf_phdata);
929
930 set_binfmt(&elf_format);
931
932 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
933 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
934 if (retval < 0)
935 goto out;
936 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
937
938 install_exec_creds(bprm);
939 retval = create_elf_tables(bprm, &loc->elf_ex,
940 load_addr, interp_load_addr);
941 if (retval < 0)
942 goto out;
943 /* N.B. passed_fileno might not be initialized? */
944 current->mm->end_code = end_code;
945 current->mm->start_code = start_code;
946 current->mm->start_data = start_data;
947 current->mm->end_data = end_data;
948 current->mm->start_stack = bprm->p;
949
950 #ifdef arch_randomize_brk
951 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
952 current->mm->brk = current->mm->start_brk =
953 arch_randomize_brk(current->mm);
954 #ifdef CONFIG_COMPAT_BRK
955 current->brk_randomized = 1;
956 #endif
957 }
958 #endif
959
960 if (current->personality & MMAP_PAGE_ZERO) {
961 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
962 and some applications "depend" upon this behavior.
963 Since we do not have the power to recompile these, we
964 emulate the SVr4 behavior. Sigh. */
965 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
966 MAP_FIXED | MAP_PRIVATE, 0);
967 }
968
969 #ifdef ELF_PLAT_INIT
970 /*
971 * The ABI may specify that certain registers be set up in special
972 * ways (on i386 %edx is the address of a DT_FINI function, for
973 * example. In addition, it may also specify (eg, PowerPC64 ELF)
974 * that the e_entry field is the address of the function descriptor
975 * for the startup routine, rather than the address of the startup
976 * routine itself. This macro performs whatever initialization to
977 * the regs structure is required as well as any relocations to the
978 * function descriptor entries when executing dynamically links apps.
979 */
980 ELF_PLAT_INIT(regs, reloc_func_desc);
981 #endif
982
983 start_thread(regs, elf_entry, bprm->p);
984 retval = 0;
985 out:
986 kfree(loc);
987 out_ret:
988 return retval;
989
990 /* error cleanup */
991 out_free_dentry:
992 allow_write_access(interpreter);
993 if (interpreter)
994 fput(interpreter);
995 out_free_interp:
996 kfree(elf_interpreter);
997 out_free_ph:
998 kfree(elf_phdata);
999 goto out;
1000 }
1001
1002 #ifdef CONFIG_USELIB
1003 /* This is really simpleminded and specialized - we are loading an
1004 a.out library that is given an ELF header. */
1005 static int load_elf_library(struct file *file)
1006 {
1007 struct elf_phdr *elf_phdata;
1008 struct elf_phdr *eppnt;
1009 unsigned long elf_bss, bss, len;
1010 int retval, error, i, j;
1011 struct elfhdr elf_ex;
1012
1013 error = -ENOEXEC;
1014 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1015 if (retval != sizeof(elf_ex))
1016 goto out;
1017
1018 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1019 goto out;
1020
1021 /* First of all, some simple consistency checks */
1022 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1023 !elf_check_arch(&elf_ex) || !file->f_op->mmap)
1024 goto out;
1025
1026 /* Now read in all of the header information */
1027
1028 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1029 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1030
1031 error = -ENOMEM;
1032 elf_phdata = kmalloc(j, GFP_KERNEL);
1033 if (!elf_phdata)
1034 goto out;
1035
1036 eppnt = elf_phdata;
1037 error = -ENOEXEC;
1038 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1039 if (retval != j)
1040 goto out_free_ph;
1041
1042 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1043 if ((eppnt + i)->p_type == PT_LOAD)
1044 j++;
1045 if (j != 1)
1046 goto out_free_ph;
1047
1048 while (eppnt->p_type != PT_LOAD)
1049 eppnt++;
1050
1051 /* Now use mmap to map the library into memory. */
1052 error = vm_mmap(file,
1053 ELF_PAGESTART(eppnt->p_vaddr),
1054 (eppnt->p_filesz +
1055 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1056 PROT_READ | PROT_WRITE | PROT_EXEC,
1057 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1058 (eppnt->p_offset -
1059 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1060 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1061 goto out_free_ph;
1062
1063 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1064 if (padzero(elf_bss)) {
1065 error = -EFAULT;
1066 goto out_free_ph;
1067 }
1068
1069 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1070 ELF_MIN_ALIGN - 1);
1071 bss = eppnt->p_memsz + eppnt->p_vaddr;
1072 if (bss > len)
1073 vm_brk(len, bss - len);
1074 error = 0;
1075
1076 out_free_ph:
1077 kfree(elf_phdata);
1078 out:
1079 return error;
1080 }
1081 #endif /* #ifdef CONFIG_USELIB */
1082
1083 #ifdef CONFIG_ELF_CORE
1084 /*
1085 * ELF core dumper
1086 *
1087 * Modelled on fs/exec.c:aout_core_dump()
1088 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1089 */
1090
1091 /*
1092 * The purpose of always_dump_vma() is to make sure that special kernel mappings
1093 * that are useful for post-mortem analysis are included in every core dump.
1094 * In that way we ensure that the core dump is fully interpretable later
1095 * without matching up the same kernel and hardware config to see what PC values
1096 * meant. These special mappings include - vDSO, vsyscall, and other
1097 * architecture specific mappings
1098 */
1099 static bool always_dump_vma(struct vm_area_struct *vma)
1100 {
1101 /* Any vsyscall mappings? */
1102 if (vma == get_gate_vma(vma->vm_mm))
1103 return true;
1104
1105 /*
1106 * Assume that all vmas with a .name op should always be dumped.
1107 * If this changes, a new vm_ops field can easily be added.
1108 */
1109 if (vma->vm_ops && vma->vm_ops->name && vma->vm_ops->name(vma))
1110 return true;
1111
1112 /*
1113 * arch_vma_name() returns non-NULL for special architecture mappings,
1114 * such as vDSO sections.
1115 */
1116 if (arch_vma_name(vma))
1117 return true;
1118
1119 return false;
1120 }
1121
1122 /*
1123 * Decide what to dump of a segment, part, all or none.
1124 */
1125 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1126 unsigned long mm_flags)
1127 {
1128 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1129
1130 /* always dump the vdso and vsyscall sections */
1131 if (always_dump_vma(vma))
1132 goto whole;
1133
1134 if (vma->vm_flags & VM_DONTDUMP)
1135 return 0;
1136
1137 /* Hugetlb memory check */
1138 if (vma->vm_flags & VM_HUGETLB) {
1139 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1140 goto whole;
1141 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1142 goto whole;
1143 return 0;
1144 }
1145
1146 /* Do not dump I/O mapped devices or special mappings */
1147 if (vma->vm_flags & VM_IO)
1148 return 0;
1149
1150 /* By default, dump shared memory if mapped from an anonymous file. */
1151 if (vma->vm_flags & VM_SHARED) {
1152 if (file_inode(vma->vm_file)->i_nlink == 0 ?
1153 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1154 goto whole;
1155 return 0;
1156 }
1157
1158 /* Dump segments that have been written to. */
1159 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1160 goto whole;
1161 if (vma->vm_file == NULL)
1162 return 0;
1163
1164 if (FILTER(MAPPED_PRIVATE))
1165 goto whole;
1166
1167 /*
1168 * If this looks like the beginning of a DSO or executable mapping,
1169 * check for an ELF header. If we find one, dump the first page to
1170 * aid in determining what was mapped here.
1171 */
1172 if (FILTER(ELF_HEADERS) &&
1173 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1174 u32 __user *header = (u32 __user *) vma->vm_start;
1175 u32 word;
1176 mm_segment_t fs = get_fs();
1177 /*
1178 * Doing it this way gets the constant folded by GCC.
1179 */
1180 union {
1181 u32 cmp;
1182 char elfmag[SELFMAG];
1183 } magic;
1184 BUILD_BUG_ON(SELFMAG != sizeof word);
1185 magic.elfmag[EI_MAG0] = ELFMAG0;
1186 magic.elfmag[EI_MAG1] = ELFMAG1;
1187 magic.elfmag[EI_MAG2] = ELFMAG2;
1188 magic.elfmag[EI_MAG3] = ELFMAG3;
1189 /*
1190 * Switch to the user "segment" for get_user(),
1191 * then put back what elf_core_dump() had in place.
1192 */
1193 set_fs(USER_DS);
1194 if (unlikely(get_user(word, header)))
1195 word = 0;
1196 set_fs(fs);
1197 if (word == magic.cmp)
1198 return PAGE_SIZE;
1199 }
1200
1201 #undef FILTER
1202
1203 return 0;
1204
1205 whole:
1206 return vma->vm_end - vma->vm_start;
1207 }
1208
1209 /* An ELF note in memory */
1210 struct memelfnote
1211 {
1212 const char *name;
1213 int type;
1214 unsigned int datasz;
1215 void *data;
1216 };
1217
1218 static int notesize(struct memelfnote *en)
1219 {
1220 int sz;
1221
1222 sz = sizeof(struct elf_note);
1223 sz += roundup(strlen(en->name) + 1, 4);
1224 sz += roundup(en->datasz, 4);
1225
1226 return sz;
1227 }
1228
1229 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1230 {
1231 struct elf_note en;
1232 en.n_namesz = strlen(men->name) + 1;
1233 en.n_descsz = men->datasz;
1234 en.n_type = men->type;
1235
1236 return dump_emit(cprm, &en, sizeof(en)) &&
1237 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1238 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1239 }
1240
1241 static void fill_elf_header(struct elfhdr *elf, int segs,
1242 u16 machine, u32 flags)
1243 {
1244 memset(elf, 0, sizeof(*elf));
1245
1246 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1247 elf->e_ident[EI_CLASS] = ELF_CLASS;
1248 elf->e_ident[EI_DATA] = ELF_DATA;
1249 elf->e_ident[EI_VERSION] = EV_CURRENT;
1250 elf->e_ident[EI_OSABI] = ELF_OSABI;
1251
1252 elf->e_type = ET_CORE;
1253 elf->e_machine = machine;
1254 elf->e_version = EV_CURRENT;
1255 elf->e_phoff = sizeof(struct elfhdr);
1256 elf->e_flags = flags;
1257 elf->e_ehsize = sizeof(struct elfhdr);
1258 elf->e_phentsize = sizeof(struct elf_phdr);
1259 elf->e_phnum = segs;
1260
1261 return;
1262 }
1263
1264 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1265 {
1266 phdr->p_type = PT_NOTE;
1267 phdr->p_offset = offset;
1268 phdr->p_vaddr = 0;
1269 phdr->p_paddr = 0;
1270 phdr->p_filesz = sz;
1271 phdr->p_memsz = 0;
1272 phdr->p_flags = 0;
1273 phdr->p_align = 0;
1274 return;
1275 }
1276
1277 static void fill_note(struct memelfnote *note, const char *name, int type,
1278 unsigned int sz, void *data)
1279 {
1280 note->name = name;
1281 note->type = type;
1282 note->datasz = sz;
1283 note->data = data;
1284 return;
1285 }
1286
1287 /*
1288 * fill up all the fields in prstatus from the given task struct, except
1289 * registers which need to be filled up separately.
1290 */
1291 static void fill_prstatus(struct elf_prstatus *prstatus,
1292 struct task_struct *p, long signr)
1293 {
1294 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1295 prstatus->pr_sigpend = p->pending.signal.sig[0];
1296 prstatus->pr_sighold = p->blocked.sig[0];
1297 rcu_read_lock();
1298 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1299 rcu_read_unlock();
1300 prstatus->pr_pid = task_pid_vnr(p);
1301 prstatus->pr_pgrp = task_pgrp_vnr(p);
1302 prstatus->pr_sid = task_session_vnr(p);
1303 if (thread_group_leader(p)) {
1304 struct task_cputime cputime;
1305
1306 /*
1307 * This is the record for the group leader. It shows the
1308 * group-wide total, not its individual thread total.
1309 */
1310 thread_group_cputime(p, &cputime);
1311 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1312 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1313 } else {
1314 cputime_t utime, stime;
1315
1316 task_cputime(p, &utime, &stime);
1317 cputime_to_timeval(utime, &prstatus->pr_utime);
1318 cputime_to_timeval(stime, &prstatus->pr_stime);
1319 }
1320 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1321 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1322 }
1323
1324 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1325 struct mm_struct *mm)
1326 {
1327 const struct cred *cred;
1328 unsigned int i, len;
1329
1330 /* first copy the parameters from user space */
1331 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1332
1333 len = mm->arg_end - mm->arg_start;
1334 if (len >= ELF_PRARGSZ)
1335 len = ELF_PRARGSZ-1;
1336 if (copy_from_user(&psinfo->pr_psargs,
1337 (const char __user *)mm->arg_start, len))
1338 return -EFAULT;
1339 for(i = 0; i < len; i++)
1340 if (psinfo->pr_psargs[i] == 0)
1341 psinfo->pr_psargs[i] = ' ';
1342 psinfo->pr_psargs[len] = 0;
1343
1344 rcu_read_lock();
1345 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1346 rcu_read_unlock();
1347 psinfo->pr_pid = task_pid_vnr(p);
1348 psinfo->pr_pgrp = task_pgrp_vnr(p);
1349 psinfo->pr_sid = task_session_vnr(p);
1350
1351 i = p->state ? ffz(~p->state) + 1 : 0;
1352 psinfo->pr_state = i;
1353 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1354 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1355 psinfo->pr_nice = task_nice(p);
1356 psinfo->pr_flag = p->flags;
1357 rcu_read_lock();
1358 cred = __task_cred(p);
1359 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1360 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1361 rcu_read_unlock();
1362 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1363
1364 return 0;
1365 }
1366
1367 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1368 {
1369 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1370 int i = 0;
1371 do
1372 i += 2;
1373 while (auxv[i - 2] != AT_NULL);
1374 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1375 }
1376
1377 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1378 const siginfo_t *siginfo)
1379 {
1380 mm_segment_t old_fs = get_fs();
1381 set_fs(KERNEL_DS);
1382 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
1383 set_fs(old_fs);
1384 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1385 }
1386
1387 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1388 /*
1389 * Format of NT_FILE note:
1390 *
1391 * long count -- how many files are mapped
1392 * long page_size -- units for file_ofs
1393 * array of [COUNT] elements of
1394 * long start
1395 * long end
1396 * long file_ofs
1397 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1398 */
1399 static int fill_files_note(struct memelfnote *note)
1400 {
1401 struct vm_area_struct *vma;
1402 unsigned count, size, names_ofs, remaining, n;
1403 user_long_t *data;
1404 user_long_t *start_end_ofs;
1405 char *name_base, *name_curpos;
1406
1407 /* *Estimated* file count and total data size needed */
1408 count = current->mm->map_count;
1409 size = count * 64;
1410
1411 names_ofs = (2 + 3 * count) * sizeof(data[0]);
1412 alloc:
1413 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1414 return -EINVAL;
1415 size = round_up(size, PAGE_SIZE);
1416 data = vmalloc(size);
1417 if (!data)
1418 return -ENOMEM;
1419
1420 start_end_ofs = data + 2;
1421 name_base = name_curpos = ((char *)data) + names_ofs;
1422 remaining = size - names_ofs;
1423 count = 0;
1424 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1425 struct file *file;
1426 const char *filename;
1427
1428 file = vma->vm_file;
1429 if (!file)
1430 continue;
1431 filename = d_path(&file->f_path, name_curpos, remaining);
1432 if (IS_ERR(filename)) {
1433 if (PTR_ERR(filename) == -ENAMETOOLONG) {
1434 vfree(data);
1435 size = size * 5 / 4;
1436 goto alloc;
1437 }
1438 continue;
1439 }
1440
1441 /* d_path() fills at the end, move name down */
1442 /* n = strlen(filename) + 1: */
1443 n = (name_curpos + remaining) - filename;
1444 remaining = filename - name_curpos;
1445 memmove(name_curpos, filename, n);
1446 name_curpos += n;
1447
1448 *start_end_ofs++ = vma->vm_start;
1449 *start_end_ofs++ = vma->vm_end;
1450 *start_end_ofs++ = vma->vm_pgoff;
1451 count++;
1452 }
1453
1454 /* Now we know exact count of files, can store it */
1455 data[0] = count;
1456 data[1] = PAGE_SIZE;
1457 /*
1458 * Count usually is less than current->mm->map_count,
1459 * we need to move filenames down.
1460 */
1461 n = current->mm->map_count - count;
1462 if (n != 0) {
1463 unsigned shift_bytes = n * 3 * sizeof(data[0]);
1464 memmove(name_base - shift_bytes, name_base,
1465 name_curpos - name_base);
1466 name_curpos -= shift_bytes;
1467 }
1468
1469 size = name_curpos - (char *)data;
1470 fill_note(note, "CORE", NT_FILE, size, data);
1471 return 0;
1472 }
1473
1474 #ifdef CORE_DUMP_USE_REGSET
1475 #include <linux/regset.h>
1476
1477 struct elf_thread_core_info {
1478 struct elf_thread_core_info *next;
1479 struct task_struct *task;
1480 struct elf_prstatus prstatus;
1481 struct memelfnote notes[0];
1482 };
1483
1484 struct elf_note_info {
1485 struct elf_thread_core_info *thread;
1486 struct memelfnote psinfo;
1487 struct memelfnote signote;
1488 struct memelfnote auxv;
1489 struct memelfnote files;
1490 user_siginfo_t csigdata;
1491 size_t size;
1492 int thread_notes;
1493 };
1494
1495 /*
1496 * When a regset has a writeback hook, we call it on each thread before
1497 * dumping user memory. On register window machines, this makes sure the
1498 * user memory backing the register data is up to date before we read it.
1499 */
1500 static void do_thread_regset_writeback(struct task_struct *task,
1501 const struct user_regset *regset)
1502 {
1503 if (regset->writeback)
1504 regset->writeback(task, regset, 1);
1505 }
1506
1507 #ifndef PR_REG_SIZE
1508 #define PR_REG_SIZE(S) sizeof(S)
1509 #endif
1510
1511 #ifndef PRSTATUS_SIZE
1512 #define PRSTATUS_SIZE(S) sizeof(S)
1513 #endif
1514
1515 #ifndef PR_REG_PTR
1516 #define PR_REG_PTR(S) (&((S)->pr_reg))
1517 #endif
1518
1519 #ifndef SET_PR_FPVALID
1520 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V))
1521 #endif
1522
1523 static int fill_thread_core_info(struct elf_thread_core_info *t,
1524 const struct user_regset_view *view,
1525 long signr, size_t *total)
1526 {
1527 unsigned int i;
1528
1529 /*
1530 * NT_PRSTATUS is the one special case, because the regset data
1531 * goes into the pr_reg field inside the note contents, rather
1532 * than being the whole note contents. We fill the reset in here.
1533 * We assume that regset 0 is NT_PRSTATUS.
1534 */
1535 fill_prstatus(&t->prstatus, t->task, signr);
1536 (void) view->regsets[0].get(t->task, &view->regsets[0],
1537 0, PR_REG_SIZE(t->prstatus.pr_reg),
1538 PR_REG_PTR(&t->prstatus), NULL);
1539
1540 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1541 PRSTATUS_SIZE(t->prstatus), &t->prstatus);
1542 *total += notesize(&t->notes[0]);
1543
1544 do_thread_regset_writeback(t->task, &view->regsets[0]);
1545
1546 /*
1547 * Each other regset might generate a note too. For each regset
1548 * that has no core_note_type or is inactive, we leave t->notes[i]
1549 * all zero and we'll know to skip writing it later.
1550 */
1551 for (i = 1; i < view->n; ++i) {
1552 const struct user_regset *regset = &view->regsets[i];
1553 do_thread_regset_writeback(t->task, regset);
1554 if (regset->core_note_type && regset->get &&
1555 (!regset->active || regset->active(t->task, regset))) {
1556 int ret;
1557 size_t size = regset->n * regset->size;
1558 void *data = kmalloc(size, GFP_KERNEL);
1559 if (unlikely(!data))
1560 return 0;
1561 ret = regset->get(t->task, regset,
1562 0, size, data, NULL);
1563 if (unlikely(ret))
1564 kfree(data);
1565 else {
1566 if (regset->core_note_type != NT_PRFPREG)
1567 fill_note(&t->notes[i], "LINUX",
1568 regset->core_note_type,
1569 size, data);
1570 else {
1571 SET_PR_FPVALID(&t->prstatus, 1);
1572 fill_note(&t->notes[i], "CORE",
1573 NT_PRFPREG, size, data);
1574 }
1575 *total += notesize(&t->notes[i]);
1576 }
1577 }
1578 }
1579
1580 return 1;
1581 }
1582
1583 static int fill_note_info(struct elfhdr *elf, int phdrs,
1584 struct elf_note_info *info,
1585 const siginfo_t *siginfo, struct pt_regs *regs)
1586 {
1587 struct task_struct *dump_task = current;
1588 const struct user_regset_view *view = task_user_regset_view(dump_task);
1589 struct elf_thread_core_info *t;
1590 struct elf_prpsinfo *psinfo;
1591 struct core_thread *ct;
1592 unsigned int i;
1593
1594 info->size = 0;
1595 info->thread = NULL;
1596
1597 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1598 if (psinfo == NULL) {
1599 info->psinfo.data = NULL; /* So we don't free this wrongly */
1600 return 0;
1601 }
1602
1603 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1604
1605 /*
1606 * Figure out how many notes we're going to need for each thread.
1607 */
1608 info->thread_notes = 0;
1609 for (i = 0; i < view->n; ++i)
1610 if (view->regsets[i].core_note_type != 0)
1611 ++info->thread_notes;
1612
1613 /*
1614 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1615 * since it is our one special case.
1616 */
1617 if (unlikely(info->thread_notes == 0) ||
1618 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1619 WARN_ON(1);
1620 return 0;
1621 }
1622
1623 /*
1624 * Initialize the ELF file header.
1625 */
1626 fill_elf_header(elf, phdrs,
1627 view->e_machine, view->e_flags);
1628
1629 /*
1630 * Allocate a structure for each thread.
1631 */
1632 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1633 t = kzalloc(offsetof(struct elf_thread_core_info,
1634 notes[info->thread_notes]),
1635 GFP_KERNEL);
1636 if (unlikely(!t))
1637 return 0;
1638
1639 t->task = ct->task;
1640 if (ct->task == dump_task || !info->thread) {
1641 t->next = info->thread;
1642 info->thread = t;
1643 } else {
1644 /*
1645 * Make sure to keep the original task at
1646 * the head of the list.
1647 */
1648 t->next = info->thread->next;
1649 info->thread->next = t;
1650 }
1651 }
1652
1653 /*
1654 * Now fill in each thread's information.
1655 */
1656 for (t = info->thread; t != NULL; t = t->next)
1657 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1658 return 0;
1659
1660 /*
1661 * Fill in the two process-wide notes.
1662 */
1663 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1664 info->size += notesize(&info->psinfo);
1665
1666 fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1667 info->size += notesize(&info->signote);
1668
1669 fill_auxv_note(&info->auxv, current->mm);
1670 info->size += notesize(&info->auxv);
1671
1672 if (fill_files_note(&info->files) == 0)
1673 info->size += notesize(&info->files);
1674
1675 return 1;
1676 }
1677
1678 static size_t get_note_info_size(struct elf_note_info *info)
1679 {
1680 return info->size;
1681 }
1682
1683 /*
1684 * Write all the notes for each thread. When writing the first thread, the
1685 * process-wide notes are interleaved after the first thread-specific note.
1686 */
1687 static int write_note_info(struct elf_note_info *info,
1688 struct coredump_params *cprm)
1689 {
1690 bool first = true;
1691 struct elf_thread_core_info *t = info->thread;
1692
1693 do {
1694 int i;
1695
1696 if (!writenote(&t->notes[0], cprm))
1697 return 0;
1698
1699 if (first && !writenote(&info->psinfo, cprm))
1700 return 0;
1701 if (first && !writenote(&info->signote, cprm))
1702 return 0;
1703 if (first && !writenote(&info->auxv, cprm))
1704 return 0;
1705 if (first && info->files.data &&
1706 !writenote(&info->files, cprm))
1707 return 0;
1708
1709 for (i = 1; i < info->thread_notes; ++i)
1710 if (t->notes[i].data &&
1711 !writenote(&t->notes[i], cprm))
1712 return 0;
1713
1714 first = false;
1715 t = t->next;
1716 } while (t);
1717
1718 return 1;
1719 }
1720
1721 static void free_note_info(struct elf_note_info *info)
1722 {
1723 struct elf_thread_core_info *threads = info->thread;
1724 while (threads) {
1725 unsigned int i;
1726 struct elf_thread_core_info *t = threads;
1727 threads = t->next;
1728 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1729 for (i = 1; i < info->thread_notes; ++i)
1730 kfree(t->notes[i].data);
1731 kfree(t);
1732 }
1733 kfree(info->psinfo.data);
1734 vfree(info->files.data);
1735 }
1736
1737 #else
1738
1739 /* Here is the structure in which status of each thread is captured. */
1740 struct elf_thread_status
1741 {
1742 struct list_head list;
1743 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1744 elf_fpregset_t fpu; /* NT_PRFPREG */
1745 struct task_struct *thread;
1746 #ifdef ELF_CORE_COPY_XFPREGS
1747 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1748 #endif
1749 struct memelfnote notes[3];
1750 int num_notes;
1751 };
1752
1753 /*
1754 * In order to add the specific thread information for the elf file format,
1755 * we need to keep a linked list of every threads pr_status and then create
1756 * a single section for them in the final core file.
1757 */
1758 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1759 {
1760 int sz = 0;
1761 struct task_struct *p = t->thread;
1762 t->num_notes = 0;
1763
1764 fill_prstatus(&t->prstatus, p, signr);
1765 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1766
1767 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1768 &(t->prstatus));
1769 t->num_notes++;
1770 sz += notesize(&t->notes[0]);
1771
1772 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1773 &t->fpu))) {
1774 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1775 &(t->fpu));
1776 t->num_notes++;
1777 sz += notesize(&t->notes[1]);
1778 }
1779
1780 #ifdef ELF_CORE_COPY_XFPREGS
1781 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1782 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1783 sizeof(t->xfpu), &t->xfpu);
1784 t->num_notes++;
1785 sz += notesize(&t->notes[2]);
1786 }
1787 #endif
1788 return sz;
1789 }
1790
1791 struct elf_note_info {
1792 struct memelfnote *notes;
1793 struct memelfnote *notes_files;
1794 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1795 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1796 struct list_head thread_list;
1797 elf_fpregset_t *fpu;
1798 #ifdef ELF_CORE_COPY_XFPREGS
1799 elf_fpxregset_t *xfpu;
1800 #endif
1801 user_siginfo_t csigdata;
1802 int thread_status_size;
1803 int numnote;
1804 };
1805
1806 static int elf_note_info_init(struct elf_note_info *info)
1807 {
1808 memset(info, 0, sizeof(*info));
1809 INIT_LIST_HEAD(&info->thread_list);
1810
1811 /* Allocate space for ELF notes */
1812 info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL);
1813 if (!info->notes)
1814 return 0;
1815 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1816 if (!info->psinfo)
1817 return 0;
1818 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1819 if (!info->prstatus)
1820 return 0;
1821 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1822 if (!info->fpu)
1823 return 0;
1824 #ifdef ELF_CORE_COPY_XFPREGS
1825 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1826 if (!info->xfpu)
1827 return 0;
1828 #endif
1829 return 1;
1830 }
1831
1832 static int fill_note_info(struct elfhdr *elf, int phdrs,
1833 struct elf_note_info *info,
1834 const siginfo_t *siginfo, struct pt_regs *regs)
1835 {
1836 struct list_head *t;
1837 struct core_thread *ct;
1838 struct elf_thread_status *ets;
1839
1840 if (!elf_note_info_init(info))
1841 return 0;
1842
1843 for (ct = current->mm->core_state->dumper.next;
1844 ct; ct = ct->next) {
1845 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1846 if (!ets)
1847 return 0;
1848
1849 ets->thread = ct->task;
1850 list_add(&ets->list, &info->thread_list);
1851 }
1852
1853 list_for_each(t, &info->thread_list) {
1854 int sz;
1855
1856 ets = list_entry(t, struct elf_thread_status, list);
1857 sz = elf_dump_thread_status(siginfo->si_signo, ets);
1858 info->thread_status_size += sz;
1859 }
1860 /* now collect the dump for the current */
1861 memset(info->prstatus, 0, sizeof(*info->prstatus));
1862 fill_prstatus(info->prstatus, current, siginfo->si_signo);
1863 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1864
1865 /* Set up header */
1866 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
1867
1868 /*
1869 * Set up the notes in similar form to SVR4 core dumps made
1870 * with info from their /proc.
1871 */
1872
1873 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1874 sizeof(*info->prstatus), info->prstatus);
1875 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1876 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1877 sizeof(*info->psinfo), info->psinfo);
1878
1879 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
1880 fill_auxv_note(info->notes + 3, current->mm);
1881 info->numnote = 4;
1882
1883 if (fill_files_note(info->notes + info->numnote) == 0) {
1884 info->notes_files = info->notes + info->numnote;
1885 info->numnote++;
1886 }
1887
1888 /* Try to dump the FPU. */
1889 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1890 info->fpu);
1891 if (info->prstatus->pr_fpvalid)
1892 fill_note(info->notes + info->numnote++,
1893 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1894 #ifdef ELF_CORE_COPY_XFPREGS
1895 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1896 fill_note(info->notes + info->numnote++,
1897 "LINUX", ELF_CORE_XFPREG_TYPE,
1898 sizeof(*info->xfpu), info->xfpu);
1899 #endif
1900
1901 return 1;
1902 }
1903
1904 static size_t get_note_info_size(struct elf_note_info *info)
1905 {
1906 int sz = 0;
1907 int i;
1908
1909 for (i = 0; i < info->numnote; i++)
1910 sz += notesize(info->notes + i);
1911
1912 sz += info->thread_status_size;
1913
1914 return sz;
1915 }
1916
1917 static int write_note_info(struct elf_note_info *info,
1918 struct coredump_params *cprm)
1919 {
1920 int i;
1921 struct list_head *t;
1922
1923 for (i = 0; i < info->numnote; i++)
1924 if (!writenote(info->notes + i, cprm))
1925 return 0;
1926
1927 /* write out the thread status notes section */
1928 list_for_each(t, &info->thread_list) {
1929 struct elf_thread_status *tmp =
1930 list_entry(t, struct elf_thread_status, list);
1931
1932 for (i = 0; i < tmp->num_notes; i++)
1933 if (!writenote(&tmp->notes[i], cprm))
1934 return 0;
1935 }
1936
1937 return 1;
1938 }
1939
1940 static void free_note_info(struct elf_note_info *info)
1941 {
1942 while (!list_empty(&info->thread_list)) {
1943 struct list_head *tmp = info->thread_list.next;
1944 list_del(tmp);
1945 kfree(list_entry(tmp, struct elf_thread_status, list));
1946 }
1947
1948 /* Free data possibly allocated by fill_files_note(): */
1949 if (info->notes_files)
1950 vfree(info->notes_files->data);
1951
1952 kfree(info->prstatus);
1953 kfree(info->psinfo);
1954 kfree(info->notes);
1955 kfree(info->fpu);
1956 #ifdef ELF_CORE_COPY_XFPREGS
1957 kfree(info->xfpu);
1958 #endif
1959 }
1960
1961 #endif
1962
1963 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1964 struct vm_area_struct *gate_vma)
1965 {
1966 struct vm_area_struct *ret = tsk->mm->mmap;
1967
1968 if (ret)
1969 return ret;
1970 return gate_vma;
1971 }
1972 /*
1973 * Helper function for iterating across a vma list. It ensures that the caller
1974 * will visit `gate_vma' prior to terminating the search.
1975 */
1976 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1977 struct vm_area_struct *gate_vma)
1978 {
1979 struct vm_area_struct *ret;
1980
1981 ret = this_vma->vm_next;
1982 if (ret)
1983 return ret;
1984 if (this_vma == gate_vma)
1985 return NULL;
1986 return gate_vma;
1987 }
1988
1989 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1990 elf_addr_t e_shoff, int segs)
1991 {
1992 elf->e_shoff = e_shoff;
1993 elf->e_shentsize = sizeof(*shdr4extnum);
1994 elf->e_shnum = 1;
1995 elf->e_shstrndx = SHN_UNDEF;
1996
1997 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1998
1999 shdr4extnum->sh_type = SHT_NULL;
2000 shdr4extnum->sh_size = elf->e_shnum;
2001 shdr4extnum->sh_link = elf->e_shstrndx;
2002 shdr4extnum->sh_info = segs;
2003 }
2004
2005 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
2006 unsigned long mm_flags)
2007 {
2008 struct vm_area_struct *vma;
2009 size_t size = 0;
2010
2011 for (vma = first_vma(current, gate_vma); vma != NULL;
2012 vma = next_vma(vma, gate_vma))
2013 size += vma_dump_size(vma, mm_flags);
2014 return size;
2015 }
2016
2017 /*
2018 * Actual dumper
2019 *
2020 * This is a two-pass process; first we find the offsets of the bits,
2021 * and then they are actually written out. If we run out of core limit
2022 * we just truncate.
2023 */
2024 static int elf_core_dump(struct coredump_params *cprm)
2025 {
2026 int has_dumped = 0;
2027 mm_segment_t fs;
2028 int segs;
2029 struct vm_area_struct *vma, *gate_vma;
2030 struct elfhdr *elf = NULL;
2031 loff_t offset = 0, dataoff;
2032 struct elf_note_info info = { };
2033 struct elf_phdr *phdr4note = NULL;
2034 struct elf_shdr *shdr4extnum = NULL;
2035 Elf_Half e_phnum;
2036 elf_addr_t e_shoff;
2037
2038 /*
2039 * We no longer stop all VM operations.
2040 *
2041 * This is because those proceses that could possibly change map_count
2042 * or the mmap / vma pages are now blocked in do_exit on current
2043 * finishing this core dump.
2044 *
2045 * Only ptrace can touch these memory addresses, but it doesn't change
2046 * the map_count or the pages allocated. So no possibility of crashing
2047 * exists while dumping the mm->vm_next areas to the core file.
2048 */
2049
2050 /* alloc memory for large data structures: too large to be on stack */
2051 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
2052 if (!elf)
2053 goto out;
2054 /*
2055 * The number of segs are recored into ELF header as 16bit value.
2056 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2057 */
2058 segs = current->mm->map_count;
2059 segs += elf_core_extra_phdrs();
2060
2061 gate_vma = get_gate_vma(current->mm);
2062 if (gate_vma != NULL)
2063 segs++;
2064
2065 /* for notes section */
2066 segs++;
2067
2068 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2069 * this, kernel supports extended numbering. Have a look at
2070 * include/linux/elf.h for further information. */
2071 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2072
2073 /*
2074 * Collect all the non-memory information about the process for the
2075 * notes. This also sets up the file header.
2076 */
2077 if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2078 goto cleanup;
2079
2080 has_dumped = 1;
2081
2082 fs = get_fs();
2083 set_fs(KERNEL_DS);
2084
2085 offset += sizeof(*elf); /* Elf header */
2086 offset += segs * sizeof(struct elf_phdr); /* Program headers */
2087
2088 /* Write notes phdr entry */
2089 {
2090 size_t sz = get_note_info_size(&info);
2091
2092 sz += elf_coredump_extra_notes_size();
2093
2094 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2095 if (!phdr4note)
2096 goto end_coredump;
2097
2098 fill_elf_note_phdr(phdr4note, sz, offset);
2099 offset += sz;
2100 }
2101
2102 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2103
2104 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
2105 offset += elf_core_extra_data_size();
2106 e_shoff = offset;
2107
2108 if (e_phnum == PN_XNUM) {
2109 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2110 if (!shdr4extnum)
2111 goto end_coredump;
2112 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
2113 }
2114
2115 offset = dataoff;
2116
2117 if (!dump_emit(cprm, elf, sizeof(*elf)))
2118 goto end_coredump;
2119
2120 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
2121 goto end_coredump;
2122
2123 /* Write program headers for segments dump */
2124 for (vma = first_vma(current, gate_vma); vma != NULL;
2125 vma = next_vma(vma, gate_vma)) {
2126 struct elf_phdr phdr;
2127
2128 phdr.p_type = PT_LOAD;
2129 phdr.p_offset = offset;
2130 phdr.p_vaddr = vma->vm_start;
2131 phdr.p_paddr = 0;
2132 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
2133 phdr.p_memsz = vma->vm_end - vma->vm_start;
2134 offset += phdr.p_filesz;
2135 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2136 if (vma->vm_flags & VM_WRITE)
2137 phdr.p_flags |= PF_W;
2138 if (vma->vm_flags & VM_EXEC)
2139 phdr.p_flags |= PF_X;
2140 phdr.p_align = ELF_EXEC_PAGESIZE;
2141
2142 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
2143 goto end_coredump;
2144 }
2145
2146 if (!elf_core_write_extra_phdrs(cprm, offset))
2147 goto end_coredump;
2148
2149 /* write out the notes section */
2150 if (!write_note_info(&info, cprm))
2151 goto end_coredump;
2152
2153 if (elf_coredump_extra_notes_write(cprm))
2154 goto end_coredump;
2155
2156 /* Align to page */
2157 if (!dump_skip(cprm, dataoff - cprm->written))
2158 goto end_coredump;
2159
2160 for (vma = first_vma(current, gate_vma); vma != NULL;
2161 vma = next_vma(vma, gate_vma)) {
2162 unsigned long addr;
2163 unsigned long end;
2164
2165 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
2166
2167 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2168 struct page *page;
2169 int stop;
2170
2171 page = get_dump_page(addr);
2172 if (page) {
2173 void *kaddr = kmap(page);
2174 stop = !dump_emit(cprm, kaddr, PAGE_SIZE);
2175 kunmap(page);
2176 page_cache_release(page);
2177 } else
2178 stop = !dump_skip(cprm, PAGE_SIZE);
2179 if (stop)
2180 goto end_coredump;
2181 }
2182 }
2183
2184 if (!elf_core_write_extra_data(cprm))
2185 goto end_coredump;
2186
2187 if (e_phnum == PN_XNUM) {
2188 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
2189 goto end_coredump;
2190 }
2191
2192 end_coredump:
2193 set_fs(fs);
2194
2195 cleanup:
2196 free_note_info(&info);
2197 kfree(shdr4extnum);
2198 kfree(phdr4note);
2199 kfree(elf);
2200 out:
2201 return has_dumped;
2202 }
2203
2204 #endif /* CONFIG_ELF_CORE */
2205
2206 static int __init init_elf_binfmt(void)
2207 {
2208 register_binfmt(&elf_format);
2209 return 0;
2210 }
2211
2212 static void __exit exit_elf_binfmt(void)
2213 {
2214 /* Remove the COFF and ELF loaders. */
2215 unregister_binfmt(&elf_format);
2216 }
2217
2218 core_initcall(init_elf_binfmt);
2219 module_exit(exit_elf_binfmt);
2220 MODULE_LICENSE("GPL");
Linux with added FPC-III support