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block: Do not clamp max_hw_sectors for stacking devices
[linux-2.6/next.git] / fs / binfmt_elf.c
blobb9b3bb51b1e485ff0caa0b7555d468804b552b9a
1 /*
2 * linux/fs/binfmt_elf.c
3 *
4 * These are the functions used to load ELF format executables as used
5 * on SVr4 machines. Information on the format may be found in the book
6 * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
7 * Tools".
8 *
9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
10 */
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/fs.h>
15 #include <linux/mm.h>
16 #include <linux/mman.h>
17 #include <linux/errno.h>
18 #include <linux/signal.h>
19 #include <linux/binfmts.h>
20 #include <linux/string.h>
21 #include <linux/file.h>
22 #include <linux/slab.h>
23 #include <linux/personality.h>
24 #include <linux/elfcore.h>
25 #include <linux/init.h>
26 #include <linux/highuid.h>
27 #include <linux/compiler.h>
28 #include <linux/highmem.h>
29 #include <linux/pagemap.h>
30 #include <linux/security.h>
31 #include <linux/random.h>
32 #include <linux/elf.h>
33 #include <linux/utsname.h>
34 #include <asm/uaccess.h>
35 #include <asm/param.h>
36 #include <asm/page.h>
37
38 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
39 static int load_elf_library(struct file *);
40 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
41 int, int, unsigned long);
42
43 /*
44 * If we don't support core dumping, then supply a NULL so we
45 * don't even try.
46 */
47 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
48 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
49 #else
50 #define elf_core_dump NULL
51 #endif
52
53 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
54 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
55 #else
56 #define ELF_MIN_ALIGN PAGE_SIZE
57 #endif
58
59 #ifndef ELF_CORE_EFLAGS
60 #define ELF_CORE_EFLAGS 0
61 #endif
62
63 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
64 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
65 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
66
67 static struct linux_binfmt elf_format = {
68 .module = THIS_MODULE,
69 .load_binary = load_elf_binary,
70 .load_shlib = load_elf_library,
71 .core_dump = elf_core_dump,
72 .min_coredump = ELF_EXEC_PAGESIZE,
73 .hasvdso = 1
74 };
75
76 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
77
78 static int set_brk(unsigned long start, unsigned long end)
79 {
80 start = ELF_PAGEALIGN(start);
81 end = ELF_PAGEALIGN(end);
82 if (end > start) {
83 unsigned long addr;
84 down_write(&current->mm->mmap_sem);
85 addr = do_brk(start, end - start);
86 up_write(&current->mm->mmap_sem);
87 if (BAD_ADDR(addr))
88 return addr;
89 }
90 current->mm->start_brk = current->mm->brk = end;
91 return 0;
92 }
93
94 /* We need to explicitly zero any fractional pages
95 after the data section (i.e. bss). This would
96 contain the junk from the file that should not
97 be in memory
98 */
99 static int padzero(unsigned long elf_bss)
100 {
101 unsigned long nbyte;
102
103 nbyte = ELF_PAGEOFFSET(elf_bss);
104 if (nbyte) {
105 nbyte = ELF_MIN_ALIGN - nbyte;
106 if (clear_user((void __user *) elf_bss, nbyte))
107 return -EFAULT;
108 }
109 return 0;
110 }
111
112 /* Let's use some macros to make this stack manipulation a little clearer */
113 #ifdef CONFIG_STACK_GROWSUP
114 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
115 #define STACK_ROUND(sp, items) \
116 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
117 #define STACK_ALLOC(sp, len) ({ \
118 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
119 old_sp; })
120 #else
121 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
122 #define STACK_ROUND(sp, items) \
123 (((unsigned long) (sp - items)) &~ 15UL)
124 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
125 #endif
126
127 #ifndef ELF_BASE_PLATFORM
128 /*
129 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
130 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
131 * will be copied to the user stack in the same manner as AT_PLATFORM.
132 */
133 #define ELF_BASE_PLATFORM NULL
134 #endif
135
136 static int
137 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
138 unsigned long load_addr, unsigned long interp_load_addr)
139 {
140 unsigned long p = bprm->p;
141 int argc = bprm->argc;
142 int envc = bprm->envc;
143 elf_addr_t __user *argv;
144 elf_addr_t __user *envp;
145 elf_addr_t __user *sp;
146 elf_addr_t __user *u_platform;
147 elf_addr_t __user *u_base_platform;
148 elf_addr_t __user *u_rand_bytes;
149 const char *k_platform = ELF_PLATFORM;
150 const char *k_base_platform = ELF_BASE_PLATFORM;
151 unsigned char k_rand_bytes[16];
152 int items;
153 elf_addr_t *elf_info;
154 int ei_index = 0;
155 const struct cred *cred = current_cred();
156 struct vm_area_struct *vma;
157
158 /*
159 * In some cases (e.g. Hyper-Threading), we want to avoid L1
160 * evictions by the processes running on the same package. One
161 * thing we can do is to shuffle the initial stack for them.
162 */
163
164 p = arch_align_stack(p);
165
166 /*
167 * If this architecture has a platform capability string, copy it
168 * to userspace. In some cases (Sparc), this info is impossible
169 * for userspace to get any other way, in others (i386) it is
170 * merely difficult.
171 */
172 u_platform = NULL;
173 if (k_platform) {
174 size_t len = strlen(k_platform) + 1;
175
176 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
177 if (__copy_to_user(u_platform, k_platform, len))
178 return -EFAULT;
179 }
180
181 /*
182 * If this architecture has a "base" platform capability
183 * string, copy it to userspace.
184 */
185 u_base_platform = NULL;
186 if (k_base_platform) {
187 size_t len = strlen(k_base_platform) + 1;
188
189 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
190 if (__copy_to_user(u_base_platform, k_base_platform, len))
191 return -EFAULT;
192 }
193
194 /*
195 * Generate 16 random bytes for userspace PRNG seeding.
196 */
197 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
198 u_rand_bytes = (elf_addr_t __user *)
199 STACK_ALLOC(p, sizeof(k_rand_bytes));
200 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
201 return -EFAULT;
202
203 /* Create the ELF interpreter info */
204 elf_info = (elf_addr_t *)current->mm->saved_auxv;
205 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
206 #define NEW_AUX_ENT(id, val) \
207 do { \
208 elf_info[ei_index++] = id; \
209 elf_info[ei_index++] = val; \
210 } while (0)
211
212 #ifdef ARCH_DLINFO
213 /*
214 * ARCH_DLINFO must come first so PPC can do its special alignment of
215 * AUXV.
216 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
217 * ARCH_DLINFO changes
218 */
219 ARCH_DLINFO;
220 #endif
221 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
222 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
223 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
224 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
225 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
226 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
227 NEW_AUX_ENT(AT_BASE, interp_load_addr);
228 NEW_AUX_ENT(AT_FLAGS, 0);
229 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
230 NEW_AUX_ENT(AT_UID, cred->uid);
231 NEW_AUX_ENT(AT_EUID, cred->euid);
232 NEW_AUX_ENT(AT_GID, cred->gid);
233 NEW_AUX_ENT(AT_EGID, cred->egid);
234 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
235 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
236 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
237 if (k_platform) {
238 NEW_AUX_ENT(AT_PLATFORM,
239 (elf_addr_t)(unsigned long)u_platform);
240 }
241 if (k_base_platform) {
242 NEW_AUX_ENT(AT_BASE_PLATFORM,
243 (elf_addr_t)(unsigned long)u_base_platform);
244 }
245 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
246 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
247 }
248 #undef NEW_AUX_ENT
249 /* AT_NULL is zero; clear the rest too */
250 memset(&elf_info[ei_index], 0,
251 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
252
253 /* And advance past the AT_NULL entry. */
254 ei_index += 2;
255
256 sp = STACK_ADD(p, ei_index);
257
258 items = (argc + 1) + (envc + 1) + 1;
259 bprm->p = STACK_ROUND(sp, items);
260
261 /* Point sp at the lowest address on the stack */
262 #ifdef CONFIG_STACK_GROWSUP
263 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
264 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
265 #else
266 sp = (elf_addr_t __user *)bprm->p;
267 #endif
268
269
270 /*
271 * Grow the stack manually; some architectures have a limit on how
272 * far ahead a user-space access may be in order to grow the stack.
273 */
274 vma = find_extend_vma(current->mm, bprm->p);
275 if (!vma)
276 return -EFAULT;
277
278 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
279 if (__put_user(argc, sp++))
280 return -EFAULT;
281 argv = sp;
282 envp = argv + argc + 1;
283
284 /* Populate argv and envp */
285 p = current->mm->arg_end = current->mm->arg_start;
286 while (argc-- > 0) {
287 size_t len;
288 if (__put_user((elf_addr_t)p, argv++))
289 return -EFAULT;
290 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
291 if (!len || len > MAX_ARG_STRLEN)
292 return -EINVAL;
293 p += len;
294 }
295 if (__put_user(0, argv))
296 return -EFAULT;
297 current->mm->arg_end = current->mm->env_start = p;
298 while (envc-- > 0) {
299 size_t len;
300 if (__put_user((elf_addr_t)p, envp++))
301 return -EFAULT;
302 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
303 if (!len || len > MAX_ARG_STRLEN)
304 return -EINVAL;
305 p += len;
306 }
307 if (__put_user(0, envp))
308 return -EFAULT;
309 current->mm->env_end = p;
310
311 /* Put the elf_info on the stack in the right place. */
312 sp = (elf_addr_t __user *)envp + 1;
313 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
314 return -EFAULT;
315 return 0;
316 }
317
318 #ifndef elf_map
319
320 static unsigned long elf_map(struct file *filep, unsigned long addr,
321 struct elf_phdr *eppnt, int prot, int type,
322 unsigned long total_size)
323 {
324 unsigned long map_addr;
325 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
326 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
327 addr = ELF_PAGESTART(addr);
328 size = ELF_PAGEALIGN(size);
329
330 /* mmap() will return -EINVAL if given a zero size, but a
331 * segment with zero filesize is perfectly valid */
332 if (!size)
333 return addr;
334
335 down_write(&current->mm->mmap_sem);
336 /*
337 * total_size is the size of the ELF (interpreter) image.
338 * The _first_ mmap needs to know the full size, otherwise
339 * randomization might put this image into an overlapping
340 * position with the ELF binary image. (since size < total_size)
341 * So we first map the 'big' image - and unmap the remainder at
342 * the end. (which unmap is needed for ELF images with holes.)
343 */
344 if (total_size) {
345 total_size = ELF_PAGEALIGN(total_size);
346 map_addr = do_mmap(filep, addr, total_size, prot, type, off);
347 if (!BAD_ADDR(map_addr))
348 do_munmap(current->mm, map_addr+size, total_size-size);
349 } else
350 map_addr = do_mmap(filep, addr, size, prot, type, off);
351
352 up_write(&current->mm->mmap_sem);
353 return(map_addr);
354 }
355
356 #endif /* !elf_map */
357
358 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
359 {
360 int i, first_idx = -1, last_idx = -1;
361
362 for (i = 0; i < nr; i++) {
363 if (cmds[i].p_type == PT_LOAD) {
364 last_idx = i;
365 if (first_idx == -1)
366 first_idx = i;
367 }
368 }
369 if (first_idx == -1)
370 return 0;
371
372 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
373 ELF_PAGESTART(cmds[first_idx].p_vaddr);
374 }
375
376
377 /* This is much more generalized than the library routine read function,
378 so we keep this separate. Technically the library read function
379 is only provided so that we can read a.out libraries that have
380 an ELF header */
381
382 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
383 struct file *interpreter, unsigned long *interp_map_addr,
384 unsigned long no_base)
385 {
386 struct elf_phdr *elf_phdata;
387 struct elf_phdr *eppnt;
388 unsigned long load_addr = 0;
389 int load_addr_set = 0;
390 unsigned long last_bss = 0, elf_bss = 0;
391 unsigned long error = ~0UL;
392 unsigned long total_size;
393 int retval, i, size;
394
395 /* First of all, some simple consistency checks */
396 if (interp_elf_ex->e_type != ET_EXEC &&
397 interp_elf_ex->e_type != ET_DYN)
398 goto out;
399 if (!elf_check_arch(interp_elf_ex))
400 goto out;
401 if (!interpreter->f_op || !interpreter->f_op->mmap)
402 goto out;
403
404 /*
405 * If the size of this structure has changed, then punt, since
406 * we will be doing the wrong thing.
407 */
408 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
409 goto out;
410 if (interp_elf_ex->e_phnum < 1 ||
411 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
412 goto out;
413
414 /* Now read in all of the header information */
415 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
416 if (size > ELF_MIN_ALIGN)
417 goto out;
418 elf_phdata = kmalloc(size, GFP_KERNEL);
419 if (!elf_phdata)
420 goto out;
421
422 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
423 (char *)elf_phdata,size);
424 error = -EIO;
425 if (retval != size) {
426 if (retval < 0)
427 error = retval;
428 goto out_close;
429 }
430
431 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
432 if (!total_size) {
433 error = -EINVAL;
434 goto out_close;
435 }
436
437 eppnt = elf_phdata;
438 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
439 if (eppnt->p_type == PT_LOAD) {
440 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
441 int elf_prot = 0;
442 unsigned long vaddr = 0;
443 unsigned long k, map_addr;
444
445 if (eppnt->p_flags & PF_R)
446 elf_prot = PROT_READ;
447 if (eppnt->p_flags & PF_W)
448 elf_prot |= PROT_WRITE;
449 if (eppnt->p_flags & PF_X)
450 elf_prot |= PROT_EXEC;
451 vaddr = eppnt->p_vaddr;
452 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
453 elf_type |= MAP_FIXED;
454 else if (no_base && interp_elf_ex->e_type == ET_DYN)
455 load_addr = -vaddr;
456
457 map_addr = elf_map(interpreter, load_addr + vaddr,
458 eppnt, elf_prot, elf_type, total_size);
459 total_size = 0;
460 if (!*interp_map_addr)
461 *interp_map_addr = map_addr;
462 error = map_addr;
463 if (BAD_ADDR(map_addr))
464 goto out_close;
465
466 if (!load_addr_set &&
467 interp_elf_ex->e_type == ET_DYN) {
468 load_addr = map_addr - ELF_PAGESTART(vaddr);
469 load_addr_set = 1;
470 }
471
472 /*
473 * Check to see if the section's size will overflow the
474 * allowed task size. Note that p_filesz must always be
475 * <= p_memsize so it's only necessary to check p_memsz.
476 */
477 k = load_addr + eppnt->p_vaddr;
478 if (BAD_ADDR(k) ||
479 eppnt->p_filesz > eppnt->p_memsz ||
480 eppnt->p_memsz > TASK_SIZE ||
481 TASK_SIZE - eppnt->p_memsz < k) {
482 error = -ENOMEM;
483 goto out_close;
484 }
485
486 /*
487 * Find the end of the file mapping for this phdr, and
488 * keep track of the largest address we see for this.
489 */
490 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
491 if (k > elf_bss)
492 elf_bss = k;
493
494 /*
495 * Do the same thing for the memory mapping - between
496 * elf_bss and last_bss is the bss section.
497 */
498 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
499 if (k > last_bss)
500 last_bss = k;
501 }
502 }
503
504 if (last_bss > elf_bss) {
505 /*
506 * Now fill out the bss section. First pad the last page up
507 * to the page boundary, and then perform a mmap to make sure
508 * that there are zero-mapped pages up to and including the
509 * last bss page.
510 */
511 if (padzero(elf_bss)) {
512 error = -EFAULT;
513 goto out_close;
514 }
515
516 /* What we have mapped so far */
517 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
518
519 /* Map the last of the bss segment */
520 down_write(&current->mm->mmap_sem);
521 error = do_brk(elf_bss, last_bss - elf_bss);
522 up_write(&current->mm->mmap_sem);
523 if (BAD_ADDR(error))
524 goto out_close;
525 }
526
527 error = load_addr;
528
529 out_close:
530 kfree(elf_phdata);
531 out:
532 return error;
533 }
534
535 /*
536 * These are the functions used to load ELF style executables and shared
537 * libraries. There is no binary dependent code anywhere else.
538 */
539
540 #define INTERPRETER_NONE 0
541 #define INTERPRETER_ELF 2
542
543 #ifndef STACK_RND_MASK
544 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
545 #endif
546
547 static unsigned long randomize_stack_top(unsigned long stack_top)
548 {
549 unsigned int random_variable = 0;
550
551 if ((current->flags & PF_RANDOMIZE) &&
552 !(current->personality & ADDR_NO_RANDOMIZE)) {
553 random_variable = get_random_int() & STACK_RND_MASK;
554 random_variable <<= PAGE_SHIFT;
555 }
556 #ifdef CONFIG_STACK_GROWSUP
557 return PAGE_ALIGN(stack_top) + random_variable;
558 #else
559 return PAGE_ALIGN(stack_top) - random_variable;
560 #endif
561 }
562
563 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
564 {
565 struct file *interpreter = NULL; /* to shut gcc up */
566 unsigned long load_addr = 0, load_bias = 0;
567 int load_addr_set = 0;
568 char * elf_interpreter = NULL;
569 unsigned long error;
570 struct elf_phdr *elf_ppnt, *elf_phdata;
571 unsigned long elf_bss, elf_brk;
572 int retval, i;
573 unsigned int size;
574 unsigned long elf_entry;
575 unsigned long interp_load_addr = 0;
576 unsigned long start_code, end_code, start_data, end_data;
577 unsigned long reloc_func_desc = 0;
578 int executable_stack = EXSTACK_DEFAULT;
579 unsigned long def_flags = 0;
580 struct {
581 struct elfhdr elf_ex;
582 struct elfhdr interp_elf_ex;
583 } *loc;
584
585 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
586 if (!loc) {
587 retval = -ENOMEM;
588 goto out_ret;
589 }
590
591 /* Get the exec-header */
592 loc->elf_ex = *((struct elfhdr *)bprm->buf);
593
594 retval = -ENOEXEC;
595 /* First of all, some simple consistency checks */
596 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
597 goto out;
598
599 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
600 goto out;
601 if (!elf_check_arch(&loc->elf_ex))
602 goto out;
603 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
604 goto out;
605
606 /* Now read in all of the header information */
607 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
608 goto out;
609 if (loc->elf_ex.e_phnum < 1 ||
610 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
611 goto out;
612 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
613 retval = -ENOMEM;
614 elf_phdata = kmalloc(size, GFP_KERNEL);
615 if (!elf_phdata)
616 goto out;
617
618 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
619 (char *)elf_phdata, size);
620 if (retval != size) {
621 if (retval >= 0)
622 retval = -EIO;
623 goto out_free_ph;
624 }
625
626 elf_ppnt = elf_phdata;
627 elf_bss = 0;
628 elf_brk = 0;
629
630 start_code = ~0UL;
631 end_code = 0;
632 start_data = 0;
633 end_data = 0;
634
635 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
636 if (elf_ppnt->p_type == PT_INTERP) {
637 /* This is the program interpreter used for
638 * shared libraries - for now assume that this
639 * is an a.out format binary
640 */
641 retval = -ENOEXEC;
642 if (elf_ppnt->p_filesz > PATH_MAX ||
643 elf_ppnt->p_filesz < 2)
644 goto out_free_ph;
645
646 retval = -ENOMEM;
647 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
648 GFP_KERNEL);
649 if (!elf_interpreter)
650 goto out_free_ph;
651
652 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
653 elf_interpreter,
654 elf_ppnt->p_filesz);
655 if (retval != elf_ppnt->p_filesz) {
656 if (retval >= 0)
657 retval = -EIO;
658 goto out_free_interp;
659 }
660 /* make sure path is NULL terminated */
661 retval = -ENOEXEC;
662 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
663 goto out_free_interp;
664
665 /*
666 * The early SET_PERSONALITY here is so that the lookup
667 * for the interpreter happens in the namespace of the
668 * to-be-execed image. SET_PERSONALITY can select an
669 * alternate root.
670 *
671 * However, SET_PERSONALITY is NOT allowed to switch
672 * this task into the new images's memory mapping
673 * policy - that is, TASK_SIZE must still evaluate to
674 * that which is appropriate to the execing application.
675 * This is because exit_mmap() needs to have TASK_SIZE
676 * evaluate to the size of the old image.
677 *
678 * So if (say) a 64-bit application is execing a 32-bit
679 * application it is the architecture's responsibility
680 * to defer changing the value of TASK_SIZE until the
681 * switch really is going to happen - do this in
682 * flush_thread(). - akpm
683 */
684 SET_PERSONALITY(loc->elf_ex);
685
686 interpreter = open_exec(elf_interpreter);
687 retval = PTR_ERR(interpreter);
688 if (IS_ERR(interpreter))
689 goto out_free_interp;
690
691 /*
692 * If the binary is not readable then enforce
693 * mm->dumpable = 0 regardless of the interpreter's
694 * permissions.
695 */
696 if (file_permission(interpreter, MAY_READ) < 0)
697 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
698
699 retval = kernel_read(interpreter, 0, bprm->buf,
700 BINPRM_BUF_SIZE);
701 if (retval != BINPRM_BUF_SIZE) {
702 if (retval >= 0)
703 retval = -EIO;
704 goto out_free_dentry;
705 }
706
707 /* Get the exec headers */
708 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
709 break;
710 }
711 elf_ppnt++;
712 }
713
714 elf_ppnt = elf_phdata;
715 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
716 if (elf_ppnt->p_type == PT_GNU_STACK) {
717 if (elf_ppnt->p_flags & PF_X)
718 executable_stack = EXSTACK_ENABLE_X;
719 else
720 executable_stack = EXSTACK_DISABLE_X;
721 break;
722 }
723
724 /* Some simple consistency checks for the interpreter */
725 if (elf_interpreter) {
726 retval = -ELIBBAD;
727 /* Not an ELF interpreter */
728 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
729 goto out_free_dentry;
730 /* Verify the interpreter has a valid arch */
731 if (!elf_check_arch(&loc->interp_elf_ex))
732 goto out_free_dentry;
733 } else {
734 /* Executables without an interpreter also need a personality */
735 SET_PERSONALITY(loc->elf_ex);
736 }
737
738 /* Flush all traces of the currently running executable */
739 retval = flush_old_exec(bprm);
740 if (retval)
741 goto out_free_dentry;
742
743 /* OK, This is the point of no return */
744 current->flags &= ~PF_FORKNOEXEC;
745 current->mm->def_flags = def_flags;
746
747 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
748 may depend on the personality. */
749 SET_PERSONALITY(loc->elf_ex);
750 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
751 current->personality |= READ_IMPLIES_EXEC;
752
753 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
754 current->flags |= PF_RANDOMIZE;
755 arch_pick_mmap_layout(current->mm);
756
757 /* Do this so that we can load the interpreter, if need be. We will
758 change some of these later */
759 current->mm->free_area_cache = current->mm->mmap_base;
760 current->mm->cached_hole_size = 0;
761 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
762 executable_stack);
763 if (retval < 0) {
764 send_sig(SIGKILL, current, 0);
765 goto out_free_dentry;
766 }
767
768 current->mm->start_stack = bprm->p;
769
770 /* Now we do a little grungy work by mmaping the ELF image into
771 the correct location in memory. */
772 for(i = 0, elf_ppnt = elf_phdata;
773 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
774 int elf_prot = 0, elf_flags;
775 unsigned long k, vaddr;
776
777 if (elf_ppnt->p_type != PT_LOAD)
778 continue;
779
780 if (unlikely (elf_brk > elf_bss)) {
781 unsigned long nbyte;
782
783 /* There was a PT_LOAD segment with p_memsz > p_filesz
784 before this one. Map anonymous pages, if needed,
785 and clear the area. */
786 retval = set_brk (elf_bss + load_bias,
787 elf_brk + load_bias);
788 if (retval) {
789 send_sig(SIGKILL, current, 0);
790 goto out_free_dentry;
791 }
792 nbyte = ELF_PAGEOFFSET(elf_bss);
793 if (nbyte) {
794 nbyte = ELF_MIN_ALIGN - nbyte;
795 if (nbyte > elf_brk - elf_bss)
796 nbyte = elf_brk - elf_bss;
797 if (clear_user((void __user *)elf_bss +
798 load_bias, nbyte)) {
799 /*
800 * This bss-zeroing can fail if the ELF
801 * file specifies odd protections. So
802 * we don't check the return value
803 */
804 }
805 }
806 }
807
808 if (elf_ppnt->p_flags & PF_R)
809 elf_prot |= PROT_READ;
810 if (elf_ppnt->p_flags & PF_W)
811 elf_prot |= PROT_WRITE;
812 if (elf_ppnt->p_flags & PF_X)
813 elf_prot |= PROT_EXEC;
814
815 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
816
817 vaddr = elf_ppnt->p_vaddr;
818 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
819 elf_flags |= MAP_FIXED;
820 } else if (loc->elf_ex.e_type == ET_DYN) {
821 /* Try and get dynamic programs out of the way of the
822 * default mmap base, as well as whatever program they
823 * might try to exec. This is because the brk will
824 * follow the loader, and is not movable. */
825 #ifdef CONFIG_X86
826 load_bias = 0;
827 #else
828 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
829 #endif
830 }
831
832 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
833 elf_prot, elf_flags, 0);
834 if (BAD_ADDR(error)) {
835 send_sig(SIGKILL, current, 0);
836 retval = IS_ERR((void *)error) ?
837 PTR_ERR((void*)error) : -EINVAL;
838 goto out_free_dentry;
839 }
840
841 if (!load_addr_set) {
842 load_addr_set = 1;
843 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
844 if (loc->elf_ex.e_type == ET_DYN) {
845 load_bias += error -
846 ELF_PAGESTART(load_bias + vaddr);
847 load_addr += load_bias;
848 reloc_func_desc = load_bias;
849 }
850 }
851 k = elf_ppnt->p_vaddr;
852 if (k < start_code)
853 start_code = k;
854 if (start_data < k)
855 start_data = k;
856
857 /*
858 * Check to see if the section's size will overflow the
859 * allowed task size. Note that p_filesz must always be
860 * <= p_memsz so it is only necessary to check p_memsz.
861 */
862 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
863 elf_ppnt->p_memsz > TASK_SIZE ||
864 TASK_SIZE - elf_ppnt->p_memsz < k) {
865 /* set_brk can never work. Avoid overflows. */
866 send_sig(SIGKILL, current, 0);
867 retval = -EINVAL;
868 goto out_free_dentry;
869 }
870
871 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
872
873 if (k > elf_bss)
874 elf_bss = k;
875 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
876 end_code = k;
877 if (end_data < k)
878 end_data = k;
879 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
880 if (k > elf_brk)
881 elf_brk = k;
882 }
883
884 loc->elf_ex.e_entry += load_bias;
885 elf_bss += load_bias;
886 elf_brk += load_bias;
887 start_code += load_bias;
888 end_code += load_bias;
889 start_data += load_bias;
890 end_data += load_bias;
891
892 /* Calling set_brk effectively mmaps the pages that we need
893 * for the bss and break sections. We must do this before
894 * mapping in the interpreter, to make sure it doesn't wind
895 * up getting placed where the bss needs to go.
896 */
897 retval = set_brk(elf_bss, elf_brk);
898 if (retval) {
899 send_sig(SIGKILL, current, 0);
900 goto out_free_dentry;
901 }
902 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
903 send_sig(SIGSEGV, current, 0);
904 retval = -EFAULT; /* Nobody gets to see this, but.. */
905 goto out_free_dentry;
906 }
907
908 if (elf_interpreter) {
909 unsigned long uninitialized_var(interp_map_addr);
910
911 elf_entry = load_elf_interp(&loc->interp_elf_ex,
912 interpreter,
913 &interp_map_addr,
914 load_bias);
915 if (!IS_ERR((void *)elf_entry)) {
916 /*
917 * load_elf_interp() returns relocation
918 * adjustment
919 */
920 interp_load_addr = elf_entry;
921 elf_entry += loc->interp_elf_ex.e_entry;
922 }
923 if (BAD_ADDR(elf_entry)) {
924 force_sig(SIGSEGV, current);
925 retval = IS_ERR((void *)elf_entry) ?
926 (int)elf_entry : -EINVAL;
927 goto out_free_dentry;
928 }
929 reloc_func_desc = interp_load_addr;
930
931 allow_write_access(interpreter);
932 fput(interpreter);
933 kfree(elf_interpreter);
934 } else {
935 elf_entry = loc->elf_ex.e_entry;
936 if (BAD_ADDR(elf_entry)) {
937 force_sig(SIGSEGV, current);
938 retval = -EINVAL;
939 goto out_free_dentry;
940 }
941 }
942
943 kfree(elf_phdata);
944
945 set_binfmt(&elf_format);
946
947 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
948 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
949 if (retval < 0) {
950 send_sig(SIGKILL, current, 0);
951 goto out;
952 }
953 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
954
955 install_exec_creds(bprm);
956 current->flags &= ~PF_FORKNOEXEC;
957 retval = create_elf_tables(bprm, &loc->elf_ex,
958 load_addr, interp_load_addr);
959 if (retval < 0) {
960 send_sig(SIGKILL, current, 0);
961 goto out;
962 }
963 /* N.B. passed_fileno might not be initialized? */
964 current->mm->end_code = end_code;
965 current->mm->start_code = start_code;
966 current->mm->start_data = start_data;
967 current->mm->end_data = end_data;
968 current->mm->start_stack = bprm->p;
969
970 #ifdef arch_randomize_brk
971 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1))
972 current->mm->brk = current->mm->start_brk =
973 arch_randomize_brk(current->mm);
974 #endif
975
976 if (current->personality & MMAP_PAGE_ZERO) {
977 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
978 and some applications "depend" upon this behavior.
979 Since we do not have the power to recompile these, we
980 emulate the SVr4 behavior. Sigh. */
981 down_write(&current->mm->mmap_sem);
982 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
983 MAP_FIXED | MAP_PRIVATE, 0);
984 up_write(&current->mm->mmap_sem);
985 }
986
987 #ifdef ELF_PLAT_INIT
988 /*
989 * The ABI may specify that certain registers be set up in special
990 * ways (on i386 %edx is the address of a DT_FINI function, for
991 * example. In addition, it may also specify (eg, PowerPC64 ELF)
992 * that the e_entry field is the address of the function descriptor
993 * for the startup routine, rather than the address of the startup
994 * routine itself. This macro performs whatever initialization to
995 * the regs structure is required as well as any relocations to the
996 * function descriptor entries when executing dynamically links apps.
997 */
998 ELF_PLAT_INIT(regs, reloc_func_desc);
999 #endif
1000
1001 start_thread(regs, elf_entry, bprm->p);
1002 retval = 0;
1003 out:
1004 kfree(loc);
1005 out_ret:
1006 return retval;
1007
1008 /* error cleanup */
1009 out_free_dentry:
1010 allow_write_access(interpreter);
1011 if (interpreter)
1012 fput(interpreter);
1013 out_free_interp:
1014 kfree(elf_interpreter);
1015 out_free_ph:
1016 kfree(elf_phdata);
1017 goto out;
1018 }
1019
1020 /* This is really simpleminded and specialized - we are loading an
1021 a.out library that is given an ELF header. */
1022 static int load_elf_library(struct file *file)
1023 {
1024 struct elf_phdr *elf_phdata;
1025 struct elf_phdr *eppnt;
1026 unsigned long elf_bss, bss, len;
1027 int retval, error, i, j;
1028 struct elfhdr elf_ex;
1029
1030 error = -ENOEXEC;
1031 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1032 if (retval != sizeof(elf_ex))
1033 goto out;
1034
1035 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1036 goto out;
1037
1038 /* First of all, some simple consistency checks */
1039 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1040 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1041 goto out;
1042
1043 /* Now read in all of the header information */
1044
1045 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1046 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1047
1048 error = -ENOMEM;
1049 elf_phdata = kmalloc(j, GFP_KERNEL);
1050 if (!elf_phdata)
1051 goto out;
1052
1053 eppnt = elf_phdata;
1054 error = -ENOEXEC;
1055 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1056 if (retval != j)
1057 goto out_free_ph;
1058
1059 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1060 if ((eppnt + i)->p_type == PT_LOAD)
1061 j++;
1062 if (j != 1)
1063 goto out_free_ph;
1064
1065 while (eppnt->p_type != PT_LOAD)
1066 eppnt++;
1067
1068 /* Now use mmap to map the library into memory. */
1069 down_write(&current->mm->mmap_sem);
1070 error = do_mmap(file,
1071 ELF_PAGESTART(eppnt->p_vaddr),
1072 (eppnt->p_filesz +
1073 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1074 PROT_READ | PROT_WRITE | PROT_EXEC,
1075 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1076 (eppnt->p_offset -
1077 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1078 up_write(&current->mm->mmap_sem);
1079 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1080 goto out_free_ph;
1081
1082 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1083 if (padzero(elf_bss)) {
1084 error = -EFAULT;
1085 goto out_free_ph;
1086 }
1087
1088 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1089 ELF_MIN_ALIGN - 1);
1090 bss = eppnt->p_memsz + eppnt->p_vaddr;
1091 if (bss > len) {
1092 down_write(&current->mm->mmap_sem);
1093 do_brk(len, bss - len);
1094 up_write(&current->mm->mmap_sem);
1095 }
1096 error = 0;
1097
1098 out_free_ph:
1099 kfree(elf_phdata);
1100 out:
1101 return error;
1102 }
1103
1104 /*
1105 * Note that some platforms still use traditional core dumps and not
1106 * the ELF core dump. Each platform can select it as appropriate.
1107 */
1108 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1109
1110 /*
1111 * ELF core dumper
1112 *
1113 * Modelled on fs/exec.c:aout_core_dump()
1114 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1115 */
1116 /*
1117 * These are the only things you should do on a core-file: use only these
1118 * functions to write out all the necessary info.
1119 */
1120 static int dump_write(struct file *file, const void *addr, int nr)
1121 {
1122 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1123 }
1124
1125 static int dump_seek(struct file *file, loff_t off)
1126 {
1127 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1128 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1129 return 0;
1130 } else {
1131 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1132 if (!buf)
1133 return 0;
1134 while (off > 0) {
1135 unsigned long n = off;
1136 if (n > PAGE_SIZE)
1137 n = PAGE_SIZE;
1138 if (!dump_write(file, buf, n))
1139 return 0;
1140 off -= n;
1141 }
1142 free_page((unsigned long)buf);
1143 }
1144 return 1;
1145 }
1146
1147 /*
1148 * Decide what to dump of a segment, part, all or none.
1149 */
1150 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1151 unsigned long mm_flags)
1152 {
1153 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1154
1155 /* The vma can be set up to tell us the answer directly. */
1156 if (vma->vm_flags & VM_ALWAYSDUMP)
1157 goto whole;
1158
1159 /* Hugetlb memory check */
1160 if (vma->vm_flags & VM_HUGETLB) {
1161 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1162 goto whole;
1163 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1164 goto whole;
1165 }
1166
1167 /* Do not dump I/O mapped devices or special mappings */
1168 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1169 return 0;
1170
1171 /* By default, dump shared memory if mapped from an anonymous file. */
1172 if (vma->vm_flags & VM_SHARED) {
1173 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1174 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1175 goto whole;
1176 return 0;
1177 }
1178
1179 /* Dump segments that have been written to. */
1180 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1181 goto whole;
1182 if (vma->vm_file == NULL)
1183 return 0;
1184
1185 if (FILTER(MAPPED_PRIVATE))
1186 goto whole;
1187
1188 /*
1189 * If this looks like the beginning of a DSO or executable mapping,
1190 * check for an ELF header. If we find one, dump the first page to
1191 * aid in determining what was mapped here.
1192 */
1193 if (FILTER(ELF_HEADERS) &&
1194 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1195 u32 __user *header = (u32 __user *) vma->vm_start;
1196 u32 word;
1197 mm_segment_t fs = get_fs();
1198 /*
1199 * Doing it this way gets the constant folded by GCC.
1200 */
1201 union {
1202 u32 cmp;
1203 char elfmag[SELFMAG];
1204 } magic;
1205 BUILD_BUG_ON(SELFMAG != sizeof word);
1206 magic.elfmag[EI_MAG0] = ELFMAG0;
1207 magic.elfmag[EI_MAG1] = ELFMAG1;
1208 magic.elfmag[EI_MAG2] = ELFMAG2;
1209 magic.elfmag[EI_MAG3] = ELFMAG3;
1210 /*
1211 * Switch to the user "segment" for get_user(),
1212 * then put back what elf_core_dump() had in place.
1213 */
1214 set_fs(USER_DS);
1215 if (unlikely(get_user(word, header)))
1216 word = 0;
1217 set_fs(fs);
1218 if (word == magic.cmp)
1219 return PAGE_SIZE;
1220 }
1221
1222 #undef FILTER
1223
1224 return 0;
1225
1226 whole:
1227 return vma->vm_end - vma->vm_start;
1228 }
1229
1230 /* An ELF note in memory */
1231 struct memelfnote
1232 {
1233 const char *name;
1234 int type;
1235 unsigned int datasz;
1236 void *data;
1237 };
1238
1239 static int notesize(struct memelfnote *en)
1240 {
1241 int sz;
1242
1243 sz = sizeof(struct elf_note);
1244 sz += roundup(strlen(en->name) + 1, 4);
1245 sz += roundup(en->datasz, 4);
1246
1247 return sz;
1248 }
1249
1250 #define DUMP_WRITE(addr, nr, foffset) \
1251 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1252
1253 static int alignfile(struct file *file, loff_t *foffset)
1254 {
1255 static const char buf[4] = { 0, };
1256 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1257 return 1;
1258 }
1259
1260 static int writenote(struct memelfnote *men, struct file *file,
1261 loff_t *foffset)
1262 {
1263 struct elf_note en;
1264 en.n_namesz = strlen(men->name) + 1;
1265 en.n_descsz = men->datasz;
1266 en.n_type = men->type;
1267
1268 DUMP_WRITE(&en, sizeof(en), foffset);
1269 DUMP_WRITE(men->name, en.n_namesz, foffset);
1270 if (!alignfile(file, foffset))
1271 return 0;
1272 DUMP_WRITE(men->data, men->datasz, foffset);
1273 if (!alignfile(file, foffset))
1274 return 0;
1275
1276 return 1;
1277 }
1278 #undef DUMP_WRITE
1279
1280 #define DUMP_WRITE(addr, nr) \
1281 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1282 goto end_coredump;
1283
1284 static void fill_elf_header(struct elfhdr *elf, int segs,
1285 u16 machine, u32 flags, u8 osabi)
1286 {
1287 memset(elf, 0, sizeof(*elf));
1288
1289 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1290 elf->e_ident[EI_CLASS] = ELF_CLASS;
1291 elf->e_ident[EI_DATA] = ELF_DATA;
1292 elf->e_ident[EI_VERSION] = EV_CURRENT;
1293 elf->e_ident[EI_OSABI] = ELF_OSABI;
1294
1295 elf->e_type = ET_CORE;
1296 elf->e_machine = machine;
1297 elf->e_version = EV_CURRENT;
1298 elf->e_phoff = sizeof(struct elfhdr);
1299 elf->e_flags = flags;
1300 elf->e_ehsize = sizeof(struct elfhdr);
1301 elf->e_phentsize = sizeof(struct elf_phdr);
1302 elf->e_phnum = segs;
1303
1304 return;
1305 }
1306
1307 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1308 {
1309 phdr->p_type = PT_NOTE;
1310 phdr->p_offset = offset;
1311 phdr->p_vaddr = 0;
1312 phdr->p_paddr = 0;
1313 phdr->p_filesz = sz;
1314 phdr->p_memsz = 0;
1315 phdr->p_flags = 0;
1316 phdr->p_align = 0;
1317 return;
1318 }
1319
1320 static void fill_note(struct memelfnote *note, const char *name, int type,
1321 unsigned int sz, void *data)
1322 {
1323 note->name = name;
1324 note->type = type;
1325 note->datasz = sz;
1326 note->data = data;
1327 return;
1328 }
1329
1330 /*
1331 * fill up all the fields in prstatus from the given task struct, except
1332 * registers which need to be filled up separately.
1333 */
1334 static void fill_prstatus(struct elf_prstatus *prstatus,
1335 struct task_struct *p, long signr)
1336 {
1337 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1338 prstatus->pr_sigpend = p->pending.signal.sig[0];
1339 prstatus->pr_sighold = p->blocked.sig[0];
1340 rcu_read_lock();
1341 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1342 rcu_read_unlock();
1343 prstatus->pr_pid = task_pid_vnr(p);
1344 prstatus->pr_pgrp = task_pgrp_vnr(p);
1345 prstatus->pr_sid = task_session_vnr(p);
1346 if (thread_group_leader(p)) {
1347 struct task_cputime cputime;
1348
1349 /*
1350 * This is the record for the group leader. It shows the
1351 * group-wide total, not its individual thread total.
1352 */
1353 thread_group_cputime(p, &cputime);
1354 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1355 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1356 } else {
1357 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1358 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1359 }
1360 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1361 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1362 }
1363
1364 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1365 struct mm_struct *mm)
1366 {
1367 const struct cred *cred;
1368 unsigned int i, len;
1369
1370 /* first copy the parameters from user space */
1371 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1372
1373 len = mm->arg_end - mm->arg_start;
1374 if (len >= ELF_PRARGSZ)
1375 len = ELF_PRARGSZ-1;
1376 if (copy_from_user(&psinfo->pr_psargs,
1377 (const char __user *)mm->arg_start, len))
1378 return -EFAULT;
1379 for(i = 0; i < len; i++)
1380 if (psinfo->pr_psargs[i] == 0)
1381 psinfo->pr_psargs[i] = ' ';
1382 psinfo->pr_psargs[len] = 0;
1383
1384 rcu_read_lock();
1385 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1386 rcu_read_unlock();
1387 psinfo->pr_pid = task_pid_vnr(p);
1388 psinfo->pr_pgrp = task_pgrp_vnr(p);
1389 psinfo->pr_sid = task_session_vnr(p);
1390
1391 i = p->state ? ffz(~p->state) + 1 : 0;
1392 psinfo->pr_state = i;
1393 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1394 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1395 psinfo->pr_nice = task_nice(p);
1396 psinfo->pr_flag = p->flags;
1397 rcu_read_lock();
1398 cred = __task_cred(p);
1399 SET_UID(psinfo->pr_uid, cred->uid);
1400 SET_GID(psinfo->pr_gid, cred->gid);
1401 rcu_read_unlock();
1402 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1403
1404 return 0;
1405 }
1406
1407 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1408 {
1409 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1410 int i = 0;
1411 do
1412 i += 2;
1413 while (auxv[i - 2] != AT_NULL);
1414 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1415 }
1416
1417 #ifdef CORE_DUMP_USE_REGSET
1418 #include <linux/regset.h>
1419
1420 struct elf_thread_core_info {
1421 struct elf_thread_core_info *next;
1422 struct task_struct *task;
1423 struct elf_prstatus prstatus;
1424 struct memelfnote notes[0];
1425 };
1426
1427 struct elf_note_info {
1428 struct elf_thread_core_info *thread;
1429 struct memelfnote psinfo;
1430 struct memelfnote auxv;
1431 size_t size;
1432 int thread_notes;
1433 };
1434
1435 /*
1436 * When a regset has a writeback hook, we call it on each thread before
1437 * dumping user memory. On register window machines, this makes sure the
1438 * user memory backing the register data is up to date before we read it.
1439 */
1440 static void do_thread_regset_writeback(struct task_struct *task,
1441 const struct user_regset *regset)
1442 {
1443 if (regset->writeback)
1444 regset->writeback(task, regset, 1);
1445 }
1446
1447 static int fill_thread_core_info(struct elf_thread_core_info *t,
1448 const struct user_regset_view *view,
1449 long signr, size_t *total)
1450 {
1451 unsigned int i;
1452
1453 /*
1454 * NT_PRSTATUS is the one special case, because the regset data
1455 * goes into the pr_reg field inside the note contents, rather
1456 * than being the whole note contents. We fill the reset in here.
1457 * We assume that regset 0 is NT_PRSTATUS.
1458 */
1459 fill_prstatus(&t->prstatus, t->task, signr);
1460 (void) view->regsets[0].get(t->task, &view->regsets[0],
1461 0, sizeof(t->prstatus.pr_reg),
1462 &t->prstatus.pr_reg, NULL);
1463
1464 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1465 sizeof(t->prstatus), &t->prstatus);
1466 *total += notesize(&t->notes[0]);
1467
1468 do_thread_regset_writeback(t->task, &view->regsets[0]);
1469
1470 /*
1471 * Each other regset might generate a note too. For each regset
1472 * that has no core_note_type or is inactive, we leave t->notes[i]
1473 * all zero and we'll know to skip writing it later.
1474 */
1475 for (i = 1; i < view->n; ++i) {
1476 const struct user_regset *regset = &view->regsets[i];
1477 do_thread_regset_writeback(t->task, regset);
1478 if (regset->core_note_type &&
1479 (!regset->active || regset->active(t->task, regset))) {
1480 int ret;
1481 size_t size = regset->n * regset->size;
1482 void *data = kmalloc(size, GFP_KERNEL);
1483 if (unlikely(!data))
1484 return 0;
1485 ret = regset->get(t->task, regset,
1486 0, size, data, NULL);
1487 if (unlikely(ret))
1488 kfree(data);
1489 else {
1490 if (regset->core_note_type != NT_PRFPREG)
1491 fill_note(&t->notes[i], "LINUX",
1492 regset->core_note_type,
1493 size, data);
1494 else {
1495 t->prstatus.pr_fpvalid = 1;
1496 fill_note(&t->notes[i], "CORE",
1497 NT_PRFPREG, size, data);
1498 }
1499 *total += notesize(&t->notes[i]);
1500 }
1501 }
1502 }
1503
1504 return 1;
1505 }
1506
1507 static int fill_note_info(struct elfhdr *elf, int phdrs,
1508 struct elf_note_info *info,
1509 long signr, struct pt_regs *regs)
1510 {
1511 struct task_struct *dump_task = current;
1512 const struct user_regset_view *view = task_user_regset_view(dump_task);
1513 struct elf_thread_core_info *t;
1514 struct elf_prpsinfo *psinfo;
1515 struct core_thread *ct;
1516 unsigned int i;
1517
1518 info->size = 0;
1519 info->thread = NULL;
1520
1521 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1522 if (psinfo == NULL)
1523 return 0;
1524
1525 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1526
1527 /*
1528 * Figure out how many notes we're going to need for each thread.
1529 */
1530 info->thread_notes = 0;
1531 for (i = 0; i < view->n; ++i)
1532 if (view->regsets[i].core_note_type != 0)
1533 ++info->thread_notes;
1534
1535 /*
1536 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1537 * since it is our one special case.
1538 */
1539 if (unlikely(info->thread_notes == 0) ||
1540 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1541 WARN_ON(1);
1542 return 0;
1543 }
1544
1545 /*
1546 * Initialize the ELF file header.
1547 */
1548 fill_elf_header(elf, phdrs,
1549 view->e_machine, view->e_flags, view->ei_osabi);
1550
1551 /*
1552 * Allocate a structure for each thread.
1553 */
1554 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1555 t = kzalloc(offsetof(struct elf_thread_core_info,
1556 notes[info->thread_notes]),
1557 GFP_KERNEL);
1558 if (unlikely(!t))
1559 return 0;
1560
1561 t->task = ct->task;
1562 if (ct->task == dump_task || !info->thread) {
1563 t->next = info->thread;
1564 info->thread = t;
1565 } else {
1566 /*
1567 * Make sure to keep the original task at
1568 * the head of the list.
1569 */
1570 t->next = info->thread->next;
1571 info->thread->next = t;
1572 }
1573 }
1574
1575 /*
1576 * Now fill in each thread's information.
1577 */
1578 for (t = info->thread; t != NULL; t = t->next)
1579 if (!fill_thread_core_info(t, view, signr, &info->size))
1580 return 0;
1581
1582 /*
1583 * Fill in the two process-wide notes.
1584 */
1585 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1586 info->size += notesize(&info->psinfo);
1587
1588 fill_auxv_note(&info->auxv, current->mm);
1589 info->size += notesize(&info->auxv);
1590
1591 return 1;
1592 }
1593
1594 static size_t get_note_info_size(struct elf_note_info *info)
1595 {
1596 return info->size;
1597 }
1598
1599 /*
1600 * Write all the notes for each thread. When writing the first thread, the
1601 * process-wide notes are interleaved after the first thread-specific note.
1602 */
1603 static int write_note_info(struct elf_note_info *info,
1604 struct file *file, loff_t *foffset)
1605 {
1606 bool first = 1;
1607 struct elf_thread_core_info *t = info->thread;
1608
1609 do {
1610 int i;
1611
1612 if (!writenote(&t->notes[0], file, foffset))
1613 return 0;
1614
1615 if (first && !writenote(&info->psinfo, file, foffset))
1616 return 0;
1617 if (first && !writenote(&info->auxv, file, foffset))
1618 return 0;
1619
1620 for (i = 1; i < info->thread_notes; ++i)
1621 if (t->notes[i].data &&
1622 !writenote(&t->notes[i], file, foffset))
1623 return 0;
1624
1625 first = 0;
1626 t = t->next;
1627 } while (t);
1628
1629 return 1;
1630 }
1631
1632 static void free_note_info(struct elf_note_info *info)
1633 {
1634 struct elf_thread_core_info *threads = info->thread;
1635 while (threads) {
1636 unsigned int i;
1637 struct elf_thread_core_info *t = threads;
1638 threads = t->next;
1639 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1640 for (i = 1; i < info->thread_notes; ++i)
1641 kfree(t->notes[i].data);
1642 kfree(t);
1643 }
1644 kfree(info->psinfo.data);
1645 }
1646
1647 #else
1648
1649 /* Here is the structure in which status of each thread is captured. */
1650 struct elf_thread_status
1651 {
1652 struct list_head list;
1653 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1654 elf_fpregset_t fpu; /* NT_PRFPREG */
1655 struct task_struct *thread;
1656 #ifdef ELF_CORE_COPY_XFPREGS
1657 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1658 #endif
1659 struct memelfnote notes[3];
1660 int num_notes;
1661 };
1662
1663 /*
1664 * In order to add the specific thread information for the elf file format,
1665 * we need to keep a linked list of every threads pr_status and then create
1666 * a single section for them in the final core file.
1667 */
1668 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1669 {
1670 int sz = 0;
1671 struct task_struct *p = t->thread;
1672 t->num_notes = 0;
1673
1674 fill_prstatus(&t->prstatus, p, signr);
1675 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1676
1677 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1678 &(t->prstatus));
1679 t->num_notes++;
1680 sz += notesize(&t->notes[0]);
1681
1682 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1683 &t->fpu))) {
1684 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1685 &(t->fpu));
1686 t->num_notes++;
1687 sz += notesize(&t->notes[1]);
1688 }
1689
1690 #ifdef ELF_CORE_COPY_XFPREGS
1691 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1692 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1693 sizeof(t->xfpu), &t->xfpu);
1694 t->num_notes++;
1695 sz += notesize(&t->notes[2]);
1696 }
1697 #endif
1698 return sz;
1699 }
1700
1701 struct elf_note_info {
1702 struct memelfnote *notes;
1703 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1704 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1705 struct list_head thread_list;
1706 elf_fpregset_t *fpu;
1707 #ifdef ELF_CORE_COPY_XFPREGS
1708 elf_fpxregset_t *xfpu;
1709 #endif
1710 int thread_status_size;
1711 int numnote;
1712 };
1713
1714 static int elf_note_info_init(struct elf_note_info *info)
1715 {
1716 memset(info, 0, sizeof(*info));
1717 INIT_LIST_HEAD(&info->thread_list);
1718
1719 /* Allocate space for six ELF notes */
1720 info->notes = kmalloc(6 * sizeof(struct memelfnote), GFP_KERNEL);
1721 if (!info->notes)
1722 return 0;
1723 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1724 if (!info->psinfo)
1725 goto notes_free;
1726 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1727 if (!info->prstatus)
1728 goto psinfo_free;
1729 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1730 if (!info->fpu)
1731 goto prstatus_free;
1732 #ifdef ELF_CORE_COPY_XFPREGS
1733 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1734 if (!info->xfpu)
1735 goto fpu_free;
1736 #endif
1737 return 1;
1738 #ifdef ELF_CORE_COPY_XFPREGS
1739 fpu_free:
1740 kfree(info->fpu);
1741 #endif
1742 prstatus_free:
1743 kfree(info->prstatus);
1744 psinfo_free:
1745 kfree(info->psinfo);
1746 notes_free:
1747 kfree(info->notes);
1748 return 0;
1749 }
1750
1751 static int fill_note_info(struct elfhdr *elf, int phdrs,
1752 struct elf_note_info *info,
1753 long signr, struct pt_regs *regs)
1754 {
1755 struct list_head *t;
1756
1757 if (!elf_note_info_init(info))
1758 return 0;
1759
1760 if (signr) {
1761 struct core_thread *ct;
1762 struct elf_thread_status *ets;
1763
1764 for (ct = current->mm->core_state->dumper.next;
1765 ct; ct = ct->next) {
1766 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1767 if (!ets)
1768 return 0;
1769
1770 ets->thread = ct->task;
1771 list_add(&ets->list, &info->thread_list);
1772 }
1773
1774 list_for_each(t, &info->thread_list) {
1775 int sz;
1776
1777 ets = list_entry(t, struct elf_thread_status, list);
1778 sz = elf_dump_thread_status(signr, ets);
1779 info->thread_status_size += sz;
1780 }
1781 }
1782 /* now collect the dump for the current */
1783 memset(info->prstatus, 0, sizeof(*info->prstatus));
1784 fill_prstatus(info->prstatus, current, signr);
1785 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1786
1787 /* Set up header */
1788 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);
1789
1790 /*
1791 * Set up the notes in similar form to SVR4 core dumps made
1792 * with info from their /proc.
1793 */
1794
1795 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1796 sizeof(*info->prstatus), info->prstatus);
1797 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1798 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1799 sizeof(*info->psinfo), info->psinfo);
1800
1801 info->numnote = 2;
1802
1803 fill_auxv_note(&info->notes[info->numnote++], current->mm);
1804
1805 /* Try to dump the FPU. */
1806 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1807 info->fpu);
1808 if (info->prstatus->pr_fpvalid)
1809 fill_note(info->notes + info->numnote++,
1810 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1811 #ifdef ELF_CORE_COPY_XFPREGS
1812 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1813 fill_note(info->notes + info->numnote++,
1814 "LINUX", ELF_CORE_XFPREG_TYPE,
1815 sizeof(*info->xfpu), info->xfpu);
1816 #endif
1817
1818 return 1;
1819 }
1820
1821 static size_t get_note_info_size(struct elf_note_info *info)
1822 {
1823 int sz = 0;
1824 int i;
1825
1826 for (i = 0; i < info->numnote; i++)
1827 sz += notesize(info->notes + i);
1828
1829 sz += info->thread_status_size;
1830
1831 return sz;
1832 }
1833
1834 static int write_note_info(struct elf_note_info *info,
1835 struct file *file, loff_t *foffset)
1836 {
1837 int i;
1838 struct list_head *t;
1839
1840 for (i = 0; i < info->numnote; i++)
1841 if (!writenote(info->notes + i, file, foffset))
1842 return 0;
1843
1844 /* write out the thread status notes section */
1845 list_for_each(t, &info->thread_list) {
1846 struct elf_thread_status *tmp =
1847 list_entry(t, struct elf_thread_status, list);
1848
1849 for (i = 0; i < tmp->num_notes; i++)
1850 if (!writenote(&tmp->notes[i], file, foffset))
1851 return 0;
1852 }
1853
1854 return 1;
1855 }
1856
1857 static void free_note_info(struct elf_note_info *info)
1858 {
1859 while (!list_empty(&info->thread_list)) {
1860 struct list_head *tmp = info->thread_list.next;
1861 list_del(tmp);
1862 kfree(list_entry(tmp, struct elf_thread_status, list));
1863 }
1864
1865 kfree(info->prstatus);
1866 kfree(info->psinfo);
1867 kfree(info->notes);
1868 kfree(info->fpu);
1869 #ifdef ELF_CORE_COPY_XFPREGS
1870 kfree(info->xfpu);
1871 #endif
1872 }
1873
1874 #endif
1875
1876 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1877 struct vm_area_struct *gate_vma)
1878 {
1879 struct vm_area_struct *ret = tsk->mm->mmap;
1880
1881 if (ret)
1882 return ret;
1883 return gate_vma;
1884 }
1885 /*
1886 * Helper function for iterating across a vma list. It ensures that the caller
1887 * will visit `gate_vma' prior to terminating the search.
1888 */
1889 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1890 struct vm_area_struct *gate_vma)
1891 {
1892 struct vm_area_struct *ret;
1893
1894 ret = this_vma->vm_next;
1895 if (ret)
1896 return ret;
1897 if (this_vma == gate_vma)
1898 return NULL;
1899 return gate_vma;
1900 }
1901
1902 /*
1903 * Actual dumper
1904 *
1905 * This is a two-pass process; first we find the offsets of the bits,
1906 * and then they are actually written out. If we run out of core limit
1907 * we just truncate.
1908 */
1909 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
1910 {
1911 int has_dumped = 0;
1912 mm_segment_t fs;
1913 int segs;
1914 size_t size = 0;
1915 struct vm_area_struct *vma, *gate_vma;
1916 struct elfhdr *elf = NULL;
1917 loff_t offset = 0, dataoff, foffset;
1918 unsigned long mm_flags;
1919 struct elf_note_info info;
1920
1921 /*
1922 * We no longer stop all VM operations.
1923 *
1924 * This is because those proceses that could possibly change map_count
1925 * or the mmap / vma pages are now blocked in do_exit on current
1926 * finishing this core dump.
1927 *
1928 * Only ptrace can touch these memory addresses, but it doesn't change
1929 * the map_count or the pages allocated. So no possibility of crashing
1930 * exists while dumping the mm->vm_next areas to the core file.
1931 */
1932
1933 /* alloc memory for large data structures: too large to be on stack */
1934 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1935 if (!elf)
1936 goto out;
1937 /*
1938 * The number of segs are recored into ELF header as 16bit value.
1939 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
1940 */
1941 segs = current->mm->map_count;
1942 #ifdef ELF_CORE_EXTRA_PHDRS
1943 segs += ELF_CORE_EXTRA_PHDRS;
1944 #endif
1945
1946 gate_vma = get_gate_vma(current);
1947 if (gate_vma != NULL)
1948 segs++;
1949
1950 /*
1951 * Collect all the non-memory information about the process for the
1952 * notes. This also sets up the file header.
1953 */
1954 if (!fill_note_info(elf, segs + 1, /* including notes section */
1955 &info, signr, regs))
1956 goto cleanup;
1957
1958 has_dumped = 1;
1959 current->flags |= PF_DUMPCORE;
1960
1961 fs = get_fs();
1962 set_fs(KERNEL_DS);
1963
1964 DUMP_WRITE(elf, sizeof(*elf));
1965 offset += sizeof(*elf); /* Elf header */
1966 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1967 foffset = offset;
1968
1969 /* Write notes phdr entry */
1970 {
1971 struct elf_phdr phdr;
1972 size_t sz = get_note_info_size(&info);
1973
1974 sz += elf_coredump_extra_notes_size();
1975
1976 fill_elf_note_phdr(&phdr, sz, offset);
1977 offset += sz;
1978 DUMP_WRITE(&phdr, sizeof(phdr));
1979 }
1980
1981 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1982
1983 /*
1984 * We must use the same mm->flags while dumping core to avoid
1985 * inconsistency between the program headers and bodies, otherwise an
1986 * unusable core file can be generated.
1987 */
1988 mm_flags = current->mm->flags;
1989
1990 /* Write program headers for segments dump */
1991 for (vma = first_vma(current, gate_vma); vma != NULL;
1992 vma = next_vma(vma, gate_vma)) {
1993 struct elf_phdr phdr;
1994
1995 phdr.p_type = PT_LOAD;
1996 phdr.p_offset = offset;
1997 phdr.p_vaddr = vma->vm_start;
1998 phdr.p_paddr = 0;
1999 phdr.p_filesz = vma_dump_size(vma, mm_flags);
2000 phdr.p_memsz = vma->vm_end - vma->vm_start;
2001 offset += phdr.p_filesz;
2002 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2003 if (vma->vm_flags & VM_WRITE)
2004 phdr.p_flags |= PF_W;
2005 if (vma->vm_flags & VM_EXEC)
2006 phdr.p_flags |= PF_X;
2007 phdr.p_align = ELF_EXEC_PAGESIZE;
2008
2009 DUMP_WRITE(&phdr, sizeof(phdr));
2010 }
2011
2012 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
2013 ELF_CORE_WRITE_EXTRA_PHDRS;
2014 #endif
2015
2016 /* write out the notes section */
2017 if (!write_note_info(&info, file, &foffset))
2018 goto end_coredump;
2019
2020 if (elf_coredump_extra_notes_write(file, &foffset))
2021 goto end_coredump;
2022
2023 /* Align to page */
2024 if (!dump_seek(file, dataoff - foffset))
2025 goto end_coredump;
2026
2027 for (vma = first_vma(current, gate_vma); vma != NULL;
2028 vma = next_vma(vma, gate_vma)) {
2029 unsigned long addr;
2030 unsigned long end;
2031
2032 end = vma->vm_start + vma_dump_size(vma, mm_flags);
2033
2034 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2035 struct page *page;
2036 int stop;
2037
2038 page = get_dump_page(addr);
2039 if (page) {
2040 void *kaddr = kmap(page);
2041 stop = ((size += PAGE_SIZE) > limit) ||
2042 !dump_write(file, kaddr, PAGE_SIZE);
2043 kunmap(page);
2044 page_cache_release(page);
2045 } else
2046 stop = !dump_seek(file, PAGE_SIZE);
2047 if (stop)
2048 goto end_coredump;
2049 }
2050 }
2051
2052 #ifdef ELF_CORE_WRITE_EXTRA_DATA
2053 ELF_CORE_WRITE_EXTRA_DATA;
2054 #endif
2055
2056 end_coredump:
2057 set_fs(fs);
2058
2059 cleanup:
2060 free_note_info(&info);
2061 kfree(elf);
2062 out:
2063 return has_dumped;
2064 }
2065
2066 #endif /* USE_ELF_CORE_DUMP */
2067
2068 static int __init init_elf_binfmt(void)
2069 {
2070 return register_binfmt(&elf_format);
2071 }
2072
2073 static void __exit exit_elf_binfmt(void)
2074 {
2075 /* Remove the COFF and ELF loaders. */
2076 unregister_binfmt(&elf_format);
2077 }
2078
2079 core_initcall(init_elf_binfmt);
2080 module_exit(exit_elf_binfmt);
2081 MODULE_LICENSE("GPL");
linux-next