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Merge tag 'gpio-for-v3.11-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw...
[linux-2.6.git] / fs / binfmt_elf.c
blob100edcc5e3122323eb8f4087305e623c666eceb0
1 /*
2 * linux/fs/binfmt_elf.c
3 *
4 * These are the functions used to load ELF format executables as used
5 * on SVr4 machines. Information on the format may be found in the book
6 * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
7 * Tools".
8 *
9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
10 */
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/fs.h>
15 #include <linux/mm.h>
16 #include <linux/mman.h>
17 #include <linux/errno.h>
18 #include <linux/signal.h>
19 #include <linux/binfmts.h>
20 #include <linux/string.h>
21 #include <linux/file.h>
22 #include <linux/slab.h>
23 #include <linux/personality.h>
24 #include <linux/elfcore.h>
25 #include <linux/init.h>
26 #include <linux/highuid.h>
27 #include <linux/compiler.h>
28 #include <linux/highmem.h>
29 #include <linux/pagemap.h>
30 #include <linux/vmalloc.h>
31 #include <linux/security.h>
32 #include <linux/random.h>
33 #include <linux/elf.h>
34 #include <linux/utsname.h>
35 #include <linux/coredump.h>
36 #include <linux/sched.h>
37 #include <asm/uaccess.h>
38 #include <asm/param.h>
39 #include <asm/page.h>
40
41 #ifndef user_long_t
42 #define user_long_t long
43 #endif
44 #ifndef user_siginfo_t
45 #define user_siginfo_t siginfo_t
46 #endif
47
48 static int load_elf_binary(struct linux_binprm *bprm);
49 static int load_elf_library(struct file *);
50 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
51 int, int, unsigned long);
52
53 /*
54 * If we don't support core dumping, then supply a NULL so we
55 * don't even try.
56 */
57 #ifdef CONFIG_ELF_CORE
58 static int elf_core_dump(struct coredump_params *cprm);
59 #else
60 #define elf_core_dump NULL
61 #endif
62
63 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
64 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
65 #else
66 #define ELF_MIN_ALIGN PAGE_SIZE
67 #endif
68
69 #ifndef ELF_CORE_EFLAGS
70 #define ELF_CORE_EFLAGS 0
71 #endif
72
73 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
74 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
75 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
76
77 static struct linux_binfmt elf_format = {
78 .module = THIS_MODULE,
79 .load_binary = load_elf_binary,
80 .load_shlib = load_elf_library,
81 .core_dump = elf_core_dump,
82 .min_coredump = ELF_EXEC_PAGESIZE,
83 };
84
85 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
86
87 static int set_brk(unsigned long start, unsigned long end)
88 {
89 start = ELF_PAGEALIGN(start);
90 end = ELF_PAGEALIGN(end);
91 if (end > start) {
92 unsigned long addr;
93 addr = vm_brk(start, end - start);
94 if (BAD_ADDR(addr))
95 return addr;
96 }
97 current->mm->start_brk = current->mm->brk = end;
98 return 0;
99 }
100
101 /* We need to explicitly zero any fractional pages
102 after the data section (i.e. bss). This would
103 contain the junk from the file that should not
104 be in memory
105 */
106 static int padzero(unsigned long elf_bss)
107 {
108 unsigned long nbyte;
109
110 nbyte = ELF_PAGEOFFSET(elf_bss);
111 if (nbyte) {
112 nbyte = ELF_MIN_ALIGN - nbyte;
113 if (clear_user((void __user *) elf_bss, nbyte))
114 return -EFAULT;
115 }
116 return 0;
117 }
118
119 /* Let's use some macros to make this stack manipulation a little clearer */
120 #ifdef CONFIG_STACK_GROWSUP
121 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
122 #define STACK_ROUND(sp, items) \
123 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
124 #define STACK_ALLOC(sp, len) ({ \
125 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
126 old_sp; })
127 #else
128 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
129 #define STACK_ROUND(sp, items) \
130 (((unsigned long) (sp - items)) &~ 15UL)
131 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
132 #endif
133
134 #ifndef ELF_BASE_PLATFORM
135 /*
136 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
137 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
138 * will be copied to the user stack in the same manner as AT_PLATFORM.
139 */
140 #define ELF_BASE_PLATFORM NULL
141 #endif
142
143 static int
144 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
145 unsigned long load_addr, unsigned long interp_load_addr)
146 {
147 unsigned long p = bprm->p;
148 int argc = bprm->argc;
149 int envc = bprm->envc;
150 elf_addr_t __user *argv;
151 elf_addr_t __user *envp;
152 elf_addr_t __user *sp;
153 elf_addr_t __user *u_platform;
154 elf_addr_t __user *u_base_platform;
155 elf_addr_t __user *u_rand_bytes;
156 const char *k_platform = ELF_PLATFORM;
157 const char *k_base_platform = ELF_BASE_PLATFORM;
158 unsigned char k_rand_bytes[16];
159 int items;
160 elf_addr_t *elf_info;
161 int ei_index = 0;
162 const struct cred *cred = current_cred();
163 struct vm_area_struct *vma;
164
165 /*
166 * In some cases (e.g. Hyper-Threading), we want to avoid L1
167 * evictions by the processes running on the same package. One
168 * thing we can do is to shuffle the initial stack for them.
169 */
170
171 p = arch_align_stack(p);
172
173 /*
174 * If this architecture has a platform capability string, copy it
175 * to userspace. In some cases (Sparc), this info is impossible
176 * for userspace to get any other way, in others (i386) it is
177 * merely difficult.
178 */
179 u_platform = NULL;
180 if (k_platform) {
181 size_t len = strlen(k_platform) + 1;
182
183 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
184 if (__copy_to_user(u_platform, k_platform, len))
185 return -EFAULT;
186 }
187
188 /*
189 * If this architecture has a "base" platform capability
190 * string, copy it to userspace.
191 */
192 u_base_platform = NULL;
193 if (k_base_platform) {
194 size_t len = strlen(k_base_platform) + 1;
195
196 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
197 if (__copy_to_user(u_base_platform, k_base_platform, len))
198 return -EFAULT;
199 }
200
201 /*
202 * Generate 16 random bytes for userspace PRNG seeding.
203 */
204 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
205 u_rand_bytes = (elf_addr_t __user *)
206 STACK_ALLOC(p, sizeof(k_rand_bytes));
207 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
208 return -EFAULT;
209
210 /* Create the ELF interpreter info */
211 elf_info = (elf_addr_t *)current->mm->saved_auxv;
212 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
213 #define NEW_AUX_ENT(id, val) \
214 do { \
215 elf_info[ei_index++] = id; \
216 elf_info[ei_index++] = val; \
217 } while (0)
218
219 #ifdef ARCH_DLINFO
220 /*
221 * ARCH_DLINFO must come first so PPC can do its special alignment of
222 * AUXV.
223 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
224 * ARCH_DLINFO changes
225 */
226 ARCH_DLINFO;
227 #endif
228 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
229 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
230 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
231 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
232 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
233 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
234 NEW_AUX_ENT(AT_BASE, interp_load_addr);
235 NEW_AUX_ENT(AT_FLAGS, 0);
236 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
237 NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
238 NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
239 NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
240 NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
241 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
242 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
243 #ifdef ELF_HWCAP2
244 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
245 #endif
246 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
247 if (k_platform) {
248 NEW_AUX_ENT(AT_PLATFORM,
249 (elf_addr_t)(unsigned long)u_platform);
250 }
251 if (k_base_platform) {
252 NEW_AUX_ENT(AT_BASE_PLATFORM,
253 (elf_addr_t)(unsigned long)u_base_platform);
254 }
255 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
256 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
257 }
258 #undef NEW_AUX_ENT
259 /* AT_NULL is zero; clear the rest too */
260 memset(&elf_info[ei_index], 0,
261 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
262
263 /* And advance past the AT_NULL entry. */
264 ei_index += 2;
265
266 sp = STACK_ADD(p, ei_index);
267
268 items = (argc + 1) + (envc + 1) + 1;
269 bprm->p = STACK_ROUND(sp, items);
270
271 /* Point sp at the lowest address on the stack */
272 #ifdef CONFIG_STACK_GROWSUP
273 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
274 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
275 #else
276 sp = (elf_addr_t __user *)bprm->p;
277 #endif
278
279
280 /*
281 * Grow the stack manually; some architectures have a limit on how
282 * far ahead a user-space access may be in order to grow the stack.
283 */
284 vma = find_extend_vma(current->mm, bprm->p);
285 if (!vma)
286 return -EFAULT;
287
288 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
289 if (__put_user(argc, sp++))
290 return -EFAULT;
291 argv = sp;
292 envp = argv + argc + 1;
293
294 /* Populate argv and envp */
295 p = current->mm->arg_end = current->mm->arg_start;
296 while (argc-- > 0) {
297 size_t len;
298 if (__put_user((elf_addr_t)p, argv++))
299 return -EFAULT;
300 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
301 if (!len || len > MAX_ARG_STRLEN)
302 return -EINVAL;
303 p += len;
304 }
305 if (__put_user(0, argv))
306 return -EFAULT;
307 current->mm->arg_end = current->mm->env_start = p;
308 while (envc-- > 0) {
309 size_t len;
310 if (__put_user((elf_addr_t)p, envp++))
311 return -EFAULT;
312 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
313 if (!len || len > MAX_ARG_STRLEN)
314 return -EINVAL;
315 p += len;
316 }
317 if (__put_user(0, envp))
318 return -EFAULT;
319 current->mm->env_end = p;
320
321 /* Put the elf_info on the stack in the right place. */
322 sp = (elf_addr_t __user *)envp + 1;
323 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
324 return -EFAULT;
325 return 0;
326 }
327
328 #ifndef elf_map
329
330 static unsigned long elf_map(struct file *filep, unsigned long addr,
331 struct elf_phdr *eppnt, int prot, int type,
332 unsigned long total_size)
333 {
334 unsigned long map_addr;
335 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
336 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
337 addr = ELF_PAGESTART(addr);
338 size = ELF_PAGEALIGN(size);
339
340 /* mmap() will return -EINVAL if given a zero size, but a
341 * segment with zero filesize is perfectly valid */
342 if (!size)
343 return addr;
344
345 /*
346 * total_size is the size of the ELF (interpreter) image.
347 * The _first_ mmap needs to know the full size, otherwise
348 * randomization might put this image into an overlapping
349 * position with the ELF binary image. (since size < total_size)
350 * So we first map the 'big' image - and unmap the remainder at
351 * the end. (which unmap is needed for ELF images with holes.)
352 */
353 if (total_size) {
354 total_size = ELF_PAGEALIGN(total_size);
355 map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
356 if (!BAD_ADDR(map_addr))
357 vm_munmap(map_addr+size, total_size-size);
358 } else
359 map_addr = vm_mmap(filep, addr, size, prot, type, off);
360
361 return(map_addr);
362 }
363
364 #endif /* !elf_map */
365
366 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
367 {
368 int i, first_idx = -1, last_idx = -1;
369
370 for (i = 0; i < nr; i++) {
371 if (cmds[i].p_type == PT_LOAD) {
372 last_idx = i;
373 if (first_idx == -1)
374 first_idx = i;
375 }
376 }
377 if (first_idx == -1)
378 return 0;
379
380 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
381 ELF_PAGESTART(cmds[first_idx].p_vaddr);
382 }
383
384
385 /* This is much more generalized than the library routine read function,
386 so we keep this separate. Technically the library read function
387 is only provided so that we can read a.out libraries that have
388 an ELF header */
389
390 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
391 struct file *interpreter, unsigned long *interp_map_addr,
392 unsigned long no_base)
393 {
394 struct elf_phdr *elf_phdata;
395 struct elf_phdr *eppnt;
396 unsigned long load_addr = 0;
397 int load_addr_set = 0;
398 unsigned long last_bss = 0, elf_bss = 0;
399 unsigned long error = ~0UL;
400 unsigned long total_size;
401 int retval, i, size;
402
403 /* First of all, some simple consistency checks */
404 if (interp_elf_ex->e_type != ET_EXEC &&
405 interp_elf_ex->e_type != ET_DYN)
406 goto out;
407 if (!elf_check_arch(interp_elf_ex))
408 goto out;
409 if (!interpreter->f_op || !interpreter->f_op->mmap)
410 goto out;
411
412 /*
413 * If the size of this structure has changed, then punt, since
414 * we will be doing the wrong thing.
415 */
416 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
417 goto out;
418 if (interp_elf_ex->e_phnum < 1 ||
419 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
420 goto out;
421
422 /* Now read in all of the header information */
423 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
424 if (size > ELF_MIN_ALIGN)
425 goto out;
426 elf_phdata = kmalloc(size, GFP_KERNEL);
427 if (!elf_phdata)
428 goto out;
429
430 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
431 (char *)elf_phdata, size);
432 error = -EIO;
433 if (retval != size) {
434 if (retval < 0)
435 error = retval;
436 goto out_close;
437 }
438
439 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
440 if (!total_size) {
441 error = -EINVAL;
442 goto out_close;
443 }
444
445 eppnt = elf_phdata;
446 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
447 if (eppnt->p_type == PT_LOAD) {
448 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
449 int elf_prot = 0;
450 unsigned long vaddr = 0;
451 unsigned long k, map_addr;
452
453 if (eppnt->p_flags & PF_R)
454 elf_prot = PROT_READ;
455 if (eppnt->p_flags & PF_W)
456 elf_prot |= PROT_WRITE;
457 if (eppnt->p_flags & PF_X)
458 elf_prot |= PROT_EXEC;
459 vaddr = eppnt->p_vaddr;
460 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
461 elf_type |= MAP_FIXED;
462 else if (no_base && interp_elf_ex->e_type == ET_DYN)
463 load_addr = -vaddr;
464
465 map_addr = elf_map(interpreter, load_addr + vaddr,
466 eppnt, elf_prot, elf_type, total_size);
467 total_size = 0;
468 if (!*interp_map_addr)
469 *interp_map_addr = map_addr;
470 error = map_addr;
471 if (BAD_ADDR(map_addr))
472 goto out_close;
473
474 if (!load_addr_set &&
475 interp_elf_ex->e_type == ET_DYN) {
476 load_addr = map_addr - ELF_PAGESTART(vaddr);
477 load_addr_set = 1;
478 }
479
480 /*
481 * Check to see if the section's size will overflow the
482 * allowed task size. Note that p_filesz must always be
483 * <= p_memsize so it's only necessary to check p_memsz.
484 */
485 k = load_addr + eppnt->p_vaddr;
486 if (BAD_ADDR(k) ||
487 eppnt->p_filesz > eppnt->p_memsz ||
488 eppnt->p_memsz > TASK_SIZE ||
489 TASK_SIZE - eppnt->p_memsz < k) {
490 error = -ENOMEM;
491 goto out_close;
492 }
493
494 /*
495 * Find the end of the file mapping for this phdr, and
496 * keep track of the largest address we see for this.
497 */
498 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
499 if (k > elf_bss)
500 elf_bss = k;
501
502 /*
503 * Do the same thing for the memory mapping - between
504 * elf_bss and last_bss is the bss section.
505 */
506 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
507 if (k > last_bss)
508 last_bss = k;
509 }
510 }
511
512 if (last_bss > elf_bss) {
513 /*
514 * Now fill out the bss section. First pad the last page up
515 * to the page boundary, and then perform a mmap to make sure
516 * that there are zero-mapped pages up to and including the
517 * last bss page.
518 */
519 if (padzero(elf_bss)) {
520 error = -EFAULT;
521 goto out_close;
522 }
523
524 /* What we have mapped so far */
525 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
526
527 /* Map the last of the bss segment */
528 error = vm_brk(elf_bss, last_bss - elf_bss);
529 if (BAD_ADDR(error))
530 goto out_close;
531 }
532
533 error = load_addr;
534
535 out_close:
536 kfree(elf_phdata);
537 out:
538 return error;
539 }
540
541 /*
542 * These are the functions used to load ELF style executables and shared
543 * libraries. There is no binary dependent code anywhere else.
544 */
545
546 #define INTERPRETER_NONE 0
547 #define INTERPRETER_ELF 2
548
549 #ifndef STACK_RND_MASK
550 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
551 #endif
552
553 static unsigned long randomize_stack_top(unsigned long stack_top)
554 {
555 unsigned int random_variable = 0;
556
557 if ((current->flags & PF_RANDOMIZE) &&
558 !(current->personality & ADDR_NO_RANDOMIZE)) {
559 random_variable = get_random_int() & STACK_RND_MASK;
560 random_variable <<= PAGE_SHIFT;
561 }
562 #ifdef CONFIG_STACK_GROWSUP
563 return PAGE_ALIGN(stack_top) + random_variable;
564 #else
565 return PAGE_ALIGN(stack_top) - random_variable;
566 #endif
567 }
568
569 static int load_elf_binary(struct linux_binprm *bprm)
570 {
571 struct file *interpreter = NULL; /* to shut gcc up */
572 unsigned long load_addr = 0, load_bias = 0;
573 int load_addr_set = 0;
574 char * elf_interpreter = NULL;
575 unsigned long error;
576 struct elf_phdr *elf_ppnt, *elf_phdata;
577 unsigned long elf_bss, elf_brk;
578 int retval, i;
579 unsigned int size;
580 unsigned long elf_entry;
581 unsigned long interp_load_addr = 0;
582 unsigned long start_code, end_code, start_data, end_data;
583 unsigned long reloc_func_desc __maybe_unused = 0;
584 int executable_stack = EXSTACK_DEFAULT;
585 unsigned long def_flags = 0;
586 struct pt_regs *regs = current_pt_regs();
587 struct {
588 struct elfhdr elf_ex;
589 struct elfhdr interp_elf_ex;
590 } *loc;
591
592 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
593 if (!loc) {
594 retval = -ENOMEM;
595 goto out_ret;
596 }
597
598 /* Get the exec-header */
599 loc->elf_ex = *((struct elfhdr *)bprm->buf);
600
601 retval = -ENOEXEC;
602 /* First of all, some simple consistency checks */
603 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
604 goto out;
605
606 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
607 goto out;
608 if (!elf_check_arch(&loc->elf_ex))
609 goto out;
610 if (!bprm->file->f_op || !bprm->file->f_op->mmap)
611 goto out;
612
613 /* Now read in all of the header information */
614 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
615 goto out;
616 if (loc->elf_ex.e_phnum < 1 ||
617 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
618 goto out;
619 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
620 retval = -ENOMEM;
621 elf_phdata = kmalloc(size, GFP_KERNEL);
622 if (!elf_phdata)
623 goto out;
624
625 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
626 (char *)elf_phdata, size);
627 if (retval != size) {
628 if (retval >= 0)
629 retval = -EIO;
630 goto out_free_ph;
631 }
632
633 elf_ppnt = elf_phdata;
634 elf_bss = 0;
635 elf_brk = 0;
636
637 start_code = ~0UL;
638 end_code = 0;
639 start_data = 0;
640 end_data = 0;
641
642 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
643 if (elf_ppnt->p_type == PT_INTERP) {
644 /* This is the program interpreter used for
645 * shared libraries - for now assume that this
646 * is an a.out format binary
647 */
648 retval = -ENOEXEC;
649 if (elf_ppnt->p_filesz > PATH_MAX ||
650 elf_ppnt->p_filesz < 2)
651 goto out_free_ph;
652
653 retval = -ENOMEM;
654 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
655 GFP_KERNEL);
656 if (!elf_interpreter)
657 goto out_free_ph;
658
659 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
660 elf_interpreter,
661 elf_ppnt->p_filesz);
662 if (retval != elf_ppnt->p_filesz) {
663 if (retval >= 0)
664 retval = -EIO;
665 goto out_free_interp;
666 }
667 /* make sure path is NULL terminated */
668 retval = -ENOEXEC;
669 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
670 goto out_free_interp;
671
672 interpreter = open_exec(elf_interpreter);
673 retval = PTR_ERR(interpreter);
674 if (IS_ERR(interpreter))
675 goto out_free_interp;
676
677 /*
678 * If the binary is not readable then enforce
679 * mm->dumpable = 0 regardless of the interpreter's
680 * permissions.
681 */
682 would_dump(bprm, interpreter);
683
684 retval = kernel_read(interpreter, 0, bprm->buf,
685 BINPRM_BUF_SIZE);
686 if (retval != BINPRM_BUF_SIZE) {
687 if (retval >= 0)
688 retval = -EIO;
689 goto out_free_dentry;
690 }
691
692 /* Get the exec headers */
693 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
694 break;
695 }
696 elf_ppnt++;
697 }
698
699 elf_ppnt = elf_phdata;
700 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
701 if (elf_ppnt->p_type == PT_GNU_STACK) {
702 if (elf_ppnt->p_flags & PF_X)
703 executable_stack = EXSTACK_ENABLE_X;
704 else
705 executable_stack = EXSTACK_DISABLE_X;
706 break;
707 }
708
709 /* Some simple consistency checks for the interpreter */
710 if (elf_interpreter) {
711 retval = -ELIBBAD;
712 /* Not an ELF interpreter */
713 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
714 goto out_free_dentry;
715 /* Verify the interpreter has a valid arch */
716 if (!elf_check_arch(&loc->interp_elf_ex))
717 goto out_free_dentry;
718 }
719
720 /* Flush all traces of the currently running executable */
721 retval = flush_old_exec(bprm);
722 if (retval)
723 goto out_free_dentry;
724
725 /* OK, This is the point of no return */
726 current->mm->def_flags = def_flags;
727
728 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
729 may depend on the personality. */
730 SET_PERSONALITY(loc->elf_ex);
731 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
732 current->personality |= READ_IMPLIES_EXEC;
733
734 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
735 current->flags |= PF_RANDOMIZE;
736
737 setup_new_exec(bprm);
738
739 /* Do this so that we can load the interpreter, if need be. We will
740 change some of these later */
741 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
742 executable_stack);
743 if (retval < 0) {
744 send_sig(SIGKILL, current, 0);
745 goto out_free_dentry;
746 }
747
748 current->mm->start_stack = bprm->p;
749
750 /* Now we do a little grungy work by mmapping the ELF image into
751 the correct location in memory. */
752 for(i = 0, elf_ppnt = elf_phdata;
753 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
754 int elf_prot = 0, elf_flags;
755 unsigned long k, vaddr;
756
757 if (elf_ppnt->p_type != PT_LOAD)
758 continue;
759
760 if (unlikely (elf_brk > elf_bss)) {
761 unsigned long nbyte;
762
763 /* There was a PT_LOAD segment with p_memsz > p_filesz
764 before this one. Map anonymous pages, if needed,
765 and clear the area. */
766 retval = set_brk(elf_bss + load_bias,
767 elf_brk + load_bias);
768 if (retval) {
769 send_sig(SIGKILL, current, 0);
770 goto out_free_dentry;
771 }
772 nbyte = ELF_PAGEOFFSET(elf_bss);
773 if (nbyte) {
774 nbyte = ELF_MIN_ALIGN - nbyte;
775 if (nbyte > elf_brk - elf_bss)
776 nbyte = elf_brk - elf_bss;
777 if (clear_user((void __user *)elf_bss +
778 load_bias, nbyte)) {
779 /*
780 * This bss-zeroing can fail if the ELF
781 * file specifies odd protections. So
782 * we don't check the return value
783 */
784 }
785 }
786 }
787
788 if (elf_ppnt->p_flags & PF_R)
789 elf_prot |= PROT_READ;
790 if (elf_ppnt->p_flags & PF_W)
791 elf_prot |= PROT_WRITE;
792 if (elf_ppnt->p_flags & PF_X)
793 elf_prot |= PROT_EXEC;
794
795 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
796
797 vaddr = elf_ppnt->p_vaddr;
798 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
799 elf_flags |= MAP_FIXED;
800 } else if (loc->elf_ex.e_type == ET_DYN) {
801 /* Try and get dynamic programs out of the way of the
802 * default mmap base, as well as whatever program they
803 * might try to exec. This is because the brk will
804 * follow the loader, and is not movable. */
805 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
806 /* Memory randomization might have been switched off
807 * in runtime via sysctl or explicit setting of
808 * personality flags.
809 * If that is the case, retain the original non-zero
810 * load_bias value in order to establish proper
811 * non-randomized mappings.
812 */
813 if (current->flags & PF_RANDOMIZE)
814 load_bias = 0;
815 else
816 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
817 #else
818 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
819 #endif
820 }
821
822 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
823 elf_prot, elf_flags, 0);
824 if (BAD_ADDR(error)) {
825 send_sig(SIGKILL, current, 0);
826 retval = IS_ERR((void *)error) ?
827 PTR_ERR((void*)error) : -EINVAL;
828 goto out_free_dentry;
829 }
830
831 if (!load_addr_set) {
832 load_addr_set = 1;
833 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
834 if (loc->elf_ex.e_type == ET_DYN) {
835 load_bias += error -
836 ELF_PAGESTART(load_bias + vaddr);
837 load_addr += load_bias;
838 reloc_func_desc = load_bias;
839 }
840 }
841 k = elf_ppnt->p_vaddr;
842 if (k < start_code)
843 start_code = k;
844 if (start_data < k)
845 start_data = k;
846
847 /*
848 * Check to see if the section's size will overflow the
849 * allowed task size. Note that p_filesz must always be
850 * <= p_memsz so it is only necessary to check p_memsz.
851 */
852 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
853 elf_ppnt->p_memsz > TASK_SIZE ||
854 TASK_SIZE - elf_ppnt->p_memsz < k) {
855 /* set_brk can never work. Avoid overflows. */
856 send_sig(SIGKILL, current, 0);
857 retval = -EINVAL;
858 goto out_free_dentry;
859 }
860
861 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
862
863 if (k > elf_bss)
864 elf_bss = k;
865 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
866 end_code = k;
867 if (end_data < k)
868 end_data = k;
869 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
870 if (k > elf_brk)
871 elf_brk = k;
872 }
873
874 loc->elf_ex.e_entry += load_bias;
875 elf_bss += load_bias;
876 elf_brk += load_bias;
877 start_code += load_bias;
878 end_code += load_bias;
879 start_data += load_bias;
880 end_data += load_bias;
881
882 /* Calling set_brk effectively mmaps the pages that we need
883 * for the bss and break sections. We must do this before
884 * mapping in the interpreter, to make sure it doesn't wind
885 * up getting placed where the bss needs to go.
886 */
887 retval = set_brk(elf_bss, elf_brk);
888 if (retval) {
889 send_sig(SIGKILL, current, 0);
890 goto out_free_dentry;
891 }
892 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
893 send_sig(SIGSEGV, current, 0);
894 retval = -EFAULT; /* Nobody gets to see this, but.. */
895 goto out_free_dentry;
896 }
897
898 if (elf_interpreter) {
899 unsigned long interp_map_addr = 0;
900
901 elf_entry = load_elf_interp(&loc->interp_elf_ex,
902 interpreter,
903 &interp_map_addr,
904 load_bias);
905 if (!IS_ERR((void *)elf_entry)) {
906 /*
907 * load_elf_interp() returns relocation
908 * adjustment
909 */
910 interp_load_addr = elf_entry;
911 elf_entry += loc->interp_elf_ex.e_entry;
912 }
913 if (BAD_ADDR(elf_entry)) {
914 force_sig(SIGSEGV, current);
915 retval = IS_ERR((void *)elf_entry) ?
916 (int)elf_entry : -EINVAL;
917 goto out_free_dentry;
918 }
919 reloc_func_desc = interp_load_addr;
920
921 allow_write_access(interpreter);
922 fput(interpreter);
923 kfree(elf_interpreter);
924 } else {
925 elf_entry = loc->elf_ex.e_entry;
926 if (BAD_ADDR(elf_entry)) {
927 force_sig(SIGSEGV, current);
928 retval = -EINVAL;
929 goto out_free_dentry;
930 }
931 }
932
933 kfree(elf_phdata);
934
935 set_binfmt(&elf_format);
936
937 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
938 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
939 if (retval < 0) {
940 send_sig(SIGKILL, current, 0);
941 goto out;
942 }
943 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
944
945 install_exec_creds(bprm);
946 retval = create_elf_tables(bprm, &loc->elf_ex,
947 load_addr, interp_load_addr);
948 if (retval < 0) {
949 send_sig(SIGKILL, current, 0);
950 goto out;
951 }
952 /* N.B. passed_fileno might not be initialized? */
953 current->mm->end_code = end_code;
954 current->mm->start_code = start_code;
955 current->mm->start_data = start_data;
956 current->mm->end_data = end_data;
957 current->mm->start_stack = bprm->p;
958
959 #ifdef arch_randomize_brk
960 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
961 current->mm->brk = current->mm->start_brk =
962 arch_randomize_brk(current->mm);
963 #ifdef CONFIG_COMPAT_BRK
964 current->brk_randomized = 1;
965 #endif
966 }
967 #endif
968
969 if (current->personality & MMAP_PAGE_ZERO) {
970 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
971 and some applications "depend" upon this behavior.
972 Since we do not have the power to recompile these, we
973 emulate the SVr4 behavior. Sigh. */
974 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
975 MAP_FIXED | MAP_PRIVATE, 0);
976 }
977
978 #ifdef ELF_PLAT_INIT
979 /*
980 * The ABI may specify that certain registers be set up in special
981 * ways (on i386 %edx is the address of a DT_FINI function, for
982 * example. In addition, it may also specify (eg, PowerPC64 ELF)
983 * that the e_entry field is the address of the function descriptor
984 * for the startup routine, rather than the address of the startup
985 * routine itself. This macro performs whatever initialization to
986 * the regs structure is required as well as any relocations to the
987 * function descriptor entries when executing dynamically links apps.
988 */
989 ELF_PLAT_INIT(regs, reloc_func_desc);
990 #endif
991
992 start_thread(regs, elf_entry, bprm->p);
993 retval = 0;
994 out:
995 kfree(loc);
996 out_ret:
997 return retval;
998
999 /* error cleanup */
1000 out_free_dentry:
1001 allow_write_access(interpreter);
1002 if (interpreter)
1003 fput(interpreter);
1004 out_free_interp:
1005 kfree(elf_interpreter);
1006 out_free_ph:
1007 kfree(elf_phdata);
1008 goto out;
1009 }
1010
1011 /* This is really simpleminded and specialized - we are loading an
1012 a.out library that is given an ELF header. */
1013 static int load_elf_library(struct file *file)
1014 {
1015 struct elf_phdr *elf_phdata;
1016 struct elf_phdr *eppnt;
1017 unsigned long elf_bss, bss, len;
1018 int retval, error, i, j;
1019 struct elfhdr elf_ex;
1020
1021 error = -ENOEXEC;
1022 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1023 if (retval != sizeof(elf_ex))
1024 goto out;
1025
1026 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1027 goto out;
1028
1029 /* First of all, some simple consistency checks */
1030 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1031 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1032 goto out;
1033
1034 /* Now read in all of the header information */
1035
1036 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1037 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1038
1039 error = -ENOMEM;
1040 elf_phdata = kmalloc(j, GFP_KERNEL);
1041 if (!elf_phdata)
1042 goto out;
1043
1044 eppnt = elf_phdata;
1045 error = -ENOEXEC;
1046 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1047 if (retval != j)
1048 goto out_free_ph;
1049
1050 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1051 if ((eppnt + i)->p_type == PT_LOAD)
1052 j++;
1053 if (j != 1)
1054 goto out_free_ph;
1055
1056 while (eppnt->p_type != PT_LOAD)
1057 eppnt++;
1058
1059 /* Now use mmap to map the library into memory. */
1060 error = vm_mmap(file,
1061 ELF_PAGESTART(eppnt->p_vaddr),
1062 (eppnt->p_filesz +
1063 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1064 PROT_READ | PROT_WRITE | PROT_EXEC,
1065 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1066 (eppnt->p_offset -
1067 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1068 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1069 goto out_free_ph;
1070
1071 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1072 if (padzero(elf_bss)) {
1073 error = -EFAULT;
1074 goto out_free_ph;
1075 }
1076
1077 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1078 ELF_MIN_ALIGN - 1);
1079 bss = eppnt->p_memsz + eppnt->p_vaddr;
1080 if (bss > len)
1081 vm_brk(len, bss - len);
1082 error = 0;
1083
1084 out_free_ph:
1085 kfree(elf_phdata);
1086 out:
1087 return error;
1088 }
1089
1090 #ifdef CONFIG_ELF_CORE
1091 /*
1092 * ELF core dumper
1093 *
1094 * Modelled on fs/exec.c:aout_core_dump()
1095 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1096 */
1097
1098 /*
1099 * The purpose of always_dump_vma() is to make sure that special kernel mappings
1100 * that are useful for post-mortem analysis are included in every core dump.
1101 * In that way we ensure that the core dump is fully interpretable later
1102 * without matching up the same kernel and hardware config to see what PC values
1103 * meant. These special mappings include - vDSO, vsyscall, and other
1104 * architecture specific mappings
1105 */
1106 static bool always_dump_vma(struct vm_area_struct *vma)
1107 {
1108 /* Any vsyscall mappings? */
1109 if (vma == get_gate_vma(vma->vm_mm))
1110 return true;
1111 /*
1112 * arch_vma_name() returns non-NULL for special architecture mappings,
1113 * such as vDSO sections.
1114 */
1115 if (arch_vma_name(vma))
1116 return true;
1117
1118 return false;
1119 }
1120
1121 /*
1122 * Decide what to dump of a segment, part, all or none.
1123 */
1124 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1125 unsigned long mm_flags)
1126 {
1127 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1128
1129 /* always dump the vdso and vsyscall sections */
1130 if (always_dump_vma(vma))
1131 goto whole;
1132
1133 if (vma->vm_flags & VM_DONTDUMP)
1134 return 0;
1135
1136 /* Hugetlb memory check */
1137 if (vma->vm_flags & VM_HUGETLB) {
1138 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1139 goto whole;
1140 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1141 goto whole;
1142 return 0;
1143 }
1144
1145 /* Do not dump I/O mapped devices or special mappings */
1146 if (vma->vm_flags & VM_IO)
1147 return 0;
1148
1149 /* By default, dump shared memory if mapped from an anonymous file. */
1150 if (vma->vm_flags & VM_SHARED) {
1151 if (file_inode(vma->vm_file)->i_nlink == 0 ?
1152 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1153 goto whole;
1154 return 0;
1155 }
1156
1157 /* Dump segments that have been written to. */
1158 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1159 goto whole;
1160 if (vma->vm_file == NULL)
1161 return 0;
1162
1163 if (FILTER(MAPPED_PRIVATE))
1164 goto whole;
1165
1166 /*
1167 * If this looks like the beginning of a DSO or executable mapping,
1168 * check for an ELF header. If we find one, dump the first page to
1169 * aid in determining what was mapped here.
1170 */
1171 if (FILTER(ELF_HEADERS) &&
1172 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1173 u32 __user *header = (u32 __user *) vma->vm_start;
1174 u32 word;
1175 mm_segment_t fs = get_fs();
1176 /*
1177 * Doing it this way gets the constant folded by GCC.
1178 */
1179 union {
1180 u32 cmp;
1181 char elfmag[SELFMAG];
1182 } magic;
1183 BUILD_BUG_ON(SELFMAG != sizeof word);
1184 magic.elfmag[EI_MAG0] = ELFMAG0;
1185 magic.elfmag[EI_MAG1] = ELFMAG1;
1186 magic.elfmag[EI_MAG2] = ELFMAG2;
1187 magic.elfmag[EI_MAG3] = ELFMAG3;
1188 /*
1189 * Switch to the user "segment" for get_user(),
1190 * then put back what elf_core_dump() had in place.
1191 */
1192 set_fs(USER_DS);
1193 if (unlikely(get_user(word, header)))
1194 word = 0;
1195 set_fs(fs);
1196 if (word == magic.cmp)
1197 return PAGE_SIZE;
1198 }
1199
1200 #undef FILTER
1201
1202 return 0;
1203
1204 whole:
1205 return vma->vm_end - vma->vm_start;
1206 }
1207
1208 /* An ELF note in memory */
1209 struct memelfnote
1210 {
1211 const char *name;
1212 int type;
1213 unsigned int datasz;
1214 void *data;
1215 };
1216
1217 static int notesize(struct memelfnote *en)
1218 {
1219 int sz;
1220
1221 sz = sizeof(struct elf_note);
1222 sz += roundup(strlen(en->name) + 1, 4);
1223 sz += roundup(en->datasz, 4);
1224
1225 return sz;
1226 }
1227
1228 #define DUMP_WRITE(addr, nr, foffset) \
1229 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1230
1231 static int alignfile(struct file *file, loff_t *foffset)
1232 {
1233 static const char buf[4] = { 0, };
1234 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1235 return 1;
1236 }
1237
1238 static int writenote(struct memelfnote *men, struct file *file,
1239 loff_t *foffset)
1240 {
1241 struct elf_note en;
1242 en.n_namesz = strlen(men->name) + 1;
1243 en.n_descsz = men->datasz;
1244 en.n_type = men->type;
1245
1246 DUMP_WRITE(&en, sizeof(en), foffset);
1247 DUMP_WRITE(men->name, en.n_namesz, foffset);
1248 if (!alignfile(file, foffset))
1249 return 0;
1250 DUMP_WRITE(men->data, men->datasz, foffset);
1251 if (!alignfile(file, foffset))
1252 return 0;
1253
1254 return 1;
1255 }
1256 #undef DUMP_WRITE
1257
1258 static void fill_elf_header(struct elfhdr *elf, int segs,
1259 u16 machine, u32 flags)
1260 {
1261 memset(elf, 0, sizeof(*elf));
1262
1263 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1264 elf->e_ident[EI_CLASS] = ELF_CLASS;
1265 elf->e_ident[EI_DATA] = ELF_DATA;
1266 elf->e_ident[EI_VERSION] = EV_CURRENT;
1267 elf->e_ident[EI_OSABI] = ELF_OSABI;
1268
1269 elf->e_type = ET_CORE;
1270 elf->e_machine = machine;
1271 elf->e_version = EV_CURRENT;
1272 elf->e_phoff = sizeof(struct elfhdr);
1273 elf->e_flags = flags;
1274 elf->e_ehsize = sizeof(struct elfhdr);
1275 elf->e_phentsize = sizeof(struct elf_phdr);
1276 elf->e_phnum = segs;
1277
1278 return;
1279 }
1280
1281 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1282 {
1283 phdr->p_type = PT_NOTE;
1284 phdr->p_offset = offset;
1285 phdr->p_vaddr = 0;
1286 phdr->p_paddr = 0;
1287 phdr->p_filesz = sz;
1288 phdr->p_memsz = 0;
1289 phdr->p_flags = 0;
1290 phdr->p_align = 0;
1291 return;
1292 }
1293
1294 static void fill_note(struct memelfnote *note, const char *name, int type,
1295 unsigned int sz, void *data)
1296 {
1297 note->name = name;
1298 note->type = type;
1299 note->datasz = sz;
1300 note->data = data;
1301 return;
1302 }
1303
1304 /*
1305 * fill up all the fields in prstatus from the given task struct, except
1306 * registers which need to be filled up separately.
1307 */
1308 static void fill_prstatus(struct elf_prstatus *prstatus,
1309 struct task_struct *p, long signr)
1310 {
1311 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1312 prstatus->pr_sigpend = p->pending.signal.sig[0];
1313 prstatus->pr_sighold = p->blocked.sig[0];
1314 rcu_read_lock();
1315 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1316 rcu_read_unlock();
1317 prstatus->pr_pid = task_pid_vnr(p);
1318 prstatus->pr_pgrp = task_pgrp_vnr(p);
1319 prstatus->pr_sid = task_session_vnr(p);
1320 if (thread_group_leader(p)) {
1321 struct task_cputime cputime;
1322
1323 /*
1324 * This is the record for the group leader. It shows the
1325 * group-wide total, not its individual thread total.
1326 */
1327 thread_group_cputime(p, &cputime);
1328 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1329 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1330 } else {
1331 cputime_t utime, stime;
1332
1333 task_cputime(p, &utime, &stime);
1334 cputime_to_timeval(utime, &prstatus->pr_utime);
1335 cputime_to_timeval(stime, &prstatus->pr_stime);
1336 }
1337 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1338 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1339 }
1340
1341 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1342 struct mm_struct *mm)
1343 {
1344 const struct cred *cred;
1345 unsigned int i, len;
1346
1347 /* first copy the parameters from user space */
1348 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1349
1350 len = mm->arg_end - mm->arg_start;
1351 if (len >= ELF_PRARGSZ)
1352 len = ELF_PRARGSZ-1;
1353 if (copy_from_user(&psinfo->pr_psargs,
1354 (const char __user *)mm->arg_start, len))
1355 return -EFAULT;
1356 for(i = 0; i < len; i++)
1357 if (psinfo->pr_psargs[i] == 0)
1358 psinfo->pr_psargs[i] = ' ';
1359 psinfo->pr_psargs[len] = 0;
1360
1361 rcu_read_lock();
1362 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1363 rcu_read_unlock();
1364 psinfo->pr_pid = task_pid_vnr(p);
1365 psinfo->pr_pgrp = task_pgrp_vnr(p);
1366 psinfo->pr_sid = task_session_vnr(p);
1367
1368 i = p->state ? ffz(~p->state) + 1 : 0;
1369 psinfo->pr_state = i;
1370 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1371 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1372 psinfo->pr_nice = task_nice(p);
1373 psinfo->pr_flag = p->flags;
1374 rcu_read_lock();
1375 cred = __task_cred(p);
1376 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1377 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1378 rcu_read_unlock();
1379 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1380
1381 return 0;
1382 }
1383
1384 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1385 {
1386 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1387 int i = 0;
1388 do
1389 i += 2;
1390 while (auxv[i - 2] != AT_NULL);
1391 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1392 }
1393
1394 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1395 siginfo_t *siginfo)
1396 {
1397 mm_segment_t old_fs = get_fs();
1398 set_fs(KERNEL_DS);
1399 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
1400 set_fs(old_fs);
1401 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1402 }
1403
1404 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1405 /*
1406 * Format of NT_FILE note:
1407 *
1408 * long count -- how many files are mapped
1409 * long page_size -- units for file_ofs
1410 * array of [COUNT] elements of
1411 * long start
1412 * long end
1413 * long file_ofs
1414 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1415 */
1416 static void fill_files_note(struct memelfnote *note)
1417 {
1418 struct vm_area_struct *vma;
1419 unsigned count, size, names_ofs, remaining, n;
1420 user_long_t *data;
1421 user_long_t *start_end_ofs;
1422 char *name_base, *name_curpos;
1423
1424 /* *Estimated* file count and total data size needed */
1425 count = current->mm->map_count;
1426 size = count * 64;
1427
1428 names_ofs = (2 + 3 * count) * sizeof(data[0]);
1429 alloc:
1430 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1431 goto err;
1432 size = round_up(size, PAGE_SIZE);
1433 data = vmalloc(size);
1434 if (!data)
1435 goto err;
1436
1437 start_end_ofs = data + 2;
1438 name_base = name_curpos = ((char *)data) + names_ofs;
1439 remaining = size - names_ofs;
1440 count = 0;
1441 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1442 struct file *file;
1443 const char *filename;
1444
1445 file = vma->vm_file;
1446 if (!file)
1447 continue;
1448 filename = d_path(&file->f_path, name_curpos, remaining);
1449 if (IS_ERR(filename)) {
1450 if (PTR_ERR(filename) == -ENAMETOOLONG) {
1451 vfree(data);
1452 size = size * 5 / 4;
1453 goto alloc;
1454 }
1455 continue;
1456 }
1457
1458 /* d_path() fills at the end, move name down */
1459 /* n = strlen(filename) + 1: */
1460 n = (name_curpos + remaining) - filename;
1461 remaining = filename - name_curpos;
1462 memmove(name_curpos, filename, n);
1463 name_curpos += n;
1464
1465 *start_end_ofs++ = vma->vm_start;
1466 *start_end_ofs++ = vma->vm_end;
1467 *start_end_ofs++ = vma->vm_pgoff;
1468 count++;
1469 }
1470
1471 /* Now we know exact count of files, can store it */
1472 data[0] = count;
1473 data[1] = PAGE_SIZE;
1474 /*
1475 * Count usually is less than current->mm->map_count,
1476 * we need to move filenames down.
1477 */
1478 n = current->mm->map_count - count;
1479 if (n != 0) {
1480 unsigned shift_bytes = n * 3 * sizeof(data[0]);
1481 memmove(name_base - shift_bytes, name_base,
1482 name_curpos - name_base);
1483 name_curpos -= shift_bytes;
1484 }
1485
1486 size = name_curpos - (char *)data;
1487 fill_note(note, "CORE", NT_FILE, size, data);
1488 err: ;
1489 }
1490
1491 #ifdef CORE_DUMP_USE_REGSET
1492 #include <linux/regset.h>
1493
1494 struct elf_thread_core_info {
1495 struct elf_thread_core_info *next;
1496 struct task_struct *task;
1497 struct elf_prstatus prstatus;
1498 struct memelfnote notes[0];
1499 };
1500
1501 struct elf_note_info {
1502 struct elf_thread_core_info *thread;
1503 struct memelfnote psinfo;
1504 struct memelfnote signote;
1505 struct memelfnote auxv;
1506 struct memelfnote files;
1507 user_siginfo_t csigdata;
1508 size_t size;
1509 int thread_notes;
1510 };
1511
1512 /*
1513 * When a regset has a writeback hook, we call it on each thread before
1514 * dumping user memory. On register window machines, this makes sure the
1515 * user memory backing the register data is up to date before we read it.
1516 */
1517 static void do_thread_regset_writeback(struct task_struct *task,
1518 const struct user_regset *regset)
1519 {
1520 if (regset->writeback)
1521 regset->writeback(task, regset, 1);
1522 }
1523
1524 #ifndef PR_REG_SIZE
1525 #define PR_REG_SIZE(S) sizeof(S)
1526 #endif
1527
1528 #ifndef PRSTATUS_SIZE
1529 #define PRSTATUS_SIZE(S) sizeof(S)
1530 #endif
1531
1532 #ifndef PR_REG_PTR
1533 #define PR_REG_PTR(S) (&((S)->pr_reg))
1534 #endif
1535
1536 #ifndef SET_PR_FPVALID
1537 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V))
1538 #endif
1539
1540 static int fill_thread_core_info(struct elf_thread_core_info *t,
1541 const struct user_regset_view *view,
1542 long signr, size_t *total)
1543 {
1544 unsigned int i;
1545
1546 /*
1547 * NT_PRSTATUS is the one special case, because the regset data
1548 * goes into the pr_reg field inside the note contents, rather
1549 * than being the whole note contents. We fill the reset in here.
1550 * We assume that regset 0 is NT_PRSTATUS.
1551 */
1552 fill_prstatus(&t->prstatus, t->task, signr);
1553 (void) view->regsets[0].get(t->task, &view->regsets[0],
1554 0, PR_REG_SIZE(t->prstatus.pr_reg),
1555 PR_REG_PTR(&t->prstatus), NULL);
1556
1557 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1558 PRSTATUS_SIZE(t->prstatus), &t->prstatus);
1559 *total += notesize(&t->notes[0]);
1560
1561 do_thread_regset_writeback(t->task, &view->regsets[0]);
1562
1563 /*
1564 * Each other regset might generate a note too. For each regset
1565 * that has no core_note_type or is inactive, we leave t->notes[i]
1566 * all zero and we'll know to skip writing it later.
1567 */
1568 for (i = 1; i < view->n; ++i) {
1569 const struct user_regset *regset = &view->regsets[i];
1570 do_thread_regset_writeback(t->task, regset);
1571 if (regset->core_note_type && regset->get &&
1572 (!regset->active || regset->active(t->task, regset))) {
1573 int ret;
1574 size_t size = regset->n * regset->size;
1575 void *data = kmalloc(size, GFP_KERNEL);
1576 if (unlikely(!data))
1577 return 0;
1578 ret = regset->get(t->task, regset,
1579 0, size, data, NULL);
1580 if (unlikely(ret))
1581 kfree(data);
1582 else {
1583 if (regset->core_note_type != NT_PRFPREG)
1584 fill_note(&t->notes[i], "LINUX",
1585 regset->core_note_type,
1586 size, data);
1587 else {
1588 SET_PR_FPVALID(&t->prstatus, 1);
1589 fill_note(&t->notes[i], "CORE",
1590 NT_PRFPREG, size, data);
1591 }
1592 *total += notesize(&t->notes[i]);
1593 }
1594 }
1595 }
1596
1597 return 1;
1598 }
1599
1600 static int fill_note_info(struct elfhdr *elf, int phdrs,
1601 struct elf_note_info *info,
1602 siginfo_t *siginfo, struct pt_regs *regs)
1603 {
1604 struct task_struct *dump_task = current;
1605 const struct user_regset_view *view = task_user_regset_view(dump_task);
1606 struct elf_thread_core_info *t;
1607 struct elf_prpsinfo *psinfo;
1608 struct core_thread *ct;
1609 unsigned int i;
1610
1611 info->size = 0;
1612 info->thread = NULL;
1613
1614 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1615 if (psinfo == NULL) {
1616 info->psinfo.data = NULL; /* So we don't free this wrongly */
1617 return 0;
1618 }
1619
1620 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1621
1622 /*
1623 * Figure out how many notes we're going to need for each thread.
1624 */
1625 info->thread_notes = 0;
1626 for (i = 0; i < view->n; ++i)
1627 if (view->regsets[i].core_note_type != 0)
1628 ++info->thread_notes;
1629
1630 /*
1631 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1632 * since it is our one special case.
1633 */
1634 if (unlikely(info->thread_notes == 0) ||
1635 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1636 WARN_ON(1);
1637 return 0;
1638 }
1639
1640 /*
1641 * Initialize the ELF file header.
1642 */
1643 fill_elf_header(elf, phdrs,
1644 view->e_machine, view->e_flags);
1645
1646 /*
1647 * Allocate a structure for each thread.
1648 */
1649 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1650 t = kzalloc(offsetof(struct elf_thread_core_info,
1651 notes[info->thread_notes]),
1652 GFP_KERNEL);
1653 if (unlikely(!t))
1654 return 0;
1655
1656 t->task = ct->task;
1657 if (ct->task == dump_task || !info->thread) {
1658 t->next = info->thread;
1659 info->thread = t;
1660 } else {
1661 /*
1662 * Make sure to keep the original task at
1663 * the head of the list.
1664 */
1665 t->next = info->thread->next;
1666 info->thread->next = t;
1667 }
1668 }
1669
1670 /*
1671 * Now fill in each thread's information.
1672 */
1673 for (t = info->thread; t != NULL; t = t->next)
1674 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1675 return 0;
1676
1677 /*
1678 * Fill in the two process-wide notes.
1679 */
1680 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1681 info->size += notesize(&info->psinfo);
1682
1683 fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1684 info->size += notesize(&info->signote);
1685
1686 fill_auxv_note(&info->auxv, current->mm);
1687 info->size += notesize(&info->auxv);
1688
1689 fill_files_note(&info->files);
1690 info->size += notesize(&info->files);
1691
1692 return 1;
1693 }
1694
1695 static size_t get_note_info_size(struct elf_note_info *info)
1696 {
1697 return info->size;
1698 }
1699
1700 /*
1701 * Write all the notes for each thread. When writing the first thread, the
1702 * process-wide notes are interleaved after the first thread-specific note.
1703 */
1704 static int write_note_info(struct elf_note_info *info,
1705 struct file *file, loff_t *foffset)
1706 {
1707 bool first = 1;
1708 struct elf_thread_core_info *t = info->thread;
1709
1710 do {
1711 int i;
1712
1713 if (!writenote(&t->notes[0], file, foffset))
1714 return 0;
1715
1716 if (first && !writenote(&info->psinfo, file, foffset))
1717 return 0;
1718 if (first && !writenote(&info->signote, file, foffset))
1719 return 0;
1720 if (first && !writenote(&info->auxv, file, foffset))
1721 return 0;
1722 if (first && !writenote(&info->files, file, foffset))
1723 return 0;
1724
1725 for (i = 1; i < info->thread_notes; ++i)
1726 if (t->notes[i].data &&
1727 !writenote(&t->notes[i], file, foffset))
1728 return 0;
1729
1730 first = 0;
1731 t = t->next;
1732 } while (t);
1733
1734 return 1;
1735 }
1736
1737 static void free_note_info(struct elf_note_info *info)
1738 {
1739 struct elf_thread_core_info *threads = info->thread;
1740 while (threads) {
1741 unsigned int i;
1742 struct elf_thread_core_info *t = threads;
1743 threads = t->next;
1744 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1745 for (i = 1; i < info->thread_notes; ++i)
1746 kfree(t->notes[i].data);
1747 kfree(t);
1748 }
1749 kfree(info->psinfo.data);
1750 vfree(info->files.data);
1751 }
1752
1753 #else
1754
1755 /* Here is the structure in which status of each thread is captured. */
1756 struct elf_thread_status
1757 {
1758 struct list_head list;
1759 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1760 elf_fpregset_t fpu; /* NT_PRFPREG */
1761 struct task_struct *thread;
1762 #ifdef ELF_CORE_COPY_XFPREGS
1763 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1764 #endif
1765 struct memelfnote notes[3];
1766 int num_notes;
1767 };
1768
1769 /*
1770 * In order to add the specific thread information for the elf file format,
1771 * we need to keep a linked list of every threads pr_status and then create
1772 * a single section for them in the final core file.
1773 */
1774 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1775 {
1776 int sz = 0;
1777 struct task_struct *p = t->thread;
1778 t->num_notes = 0;
1779
1780 fill_prstatus(&t->prstatus, p, signr);
1781 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1782
1783 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1784 &(t->prstatus));
1785 t->num_notes++;
1786 sz += notesize(&t->notes[0]);
1787
1788 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1789 &t->fpu))) {
1790 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1791 &(t->fpu));
1792 t->num_notes++;
1793 sz += notesize(&t->notes[1]);
1794 }
1795
1796 #ifdef ELF_CORE_COPY_XFPREGS
1797 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1798 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1799 sizeof(t->xfpu), &t->xfpu);
1800 t->num_notes++;
1801 sz += notesize(&t->notes[2]);
1802 }
1803 #endif
1804 return sz;
1805 }
1806
1807 struct elf_note_info {
1808 struct memelfnote *notes;
1809 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1810 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1811 struct list_head thread_list;
1812 elf_fpregset_t *fpu;
1813 #ifdef ELF_CORE_COPY_XFPREGS
1814 elf_fpxregset_t *xfpu;
1815 #endif
1816 user_siginfo_t csigdata;
1817 int thread_status_size;
1818 int numnote;
1819 };
1820
1821 static int elf_note_info_init(struct elf_note_info *info)
1822 {
1823 memset(info, 0, sizeof(*info));
1824 INIT_LIST_HEAD(&info->thread_list);
1825
1826 /* Allocate space for ELF notes */
1827 info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL);
1828 if (!info->notes)
1829 return 0;
1830 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1831 if (!info->psinfo)
1832 return 0;
1833 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1834 if (!info->prstatus)
1835 return 0;
1836 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1837 if (!info->fpu)
1838 return 0;
1839 #ifdef ELF_CORE_COPY_XFPREGS
1840 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1841 if (!info->xfpu)
1842 return 0;
1843 #endif
1844 return 1;
1845 }
1846
1847 static int fill_note_info(struct elfhdr *elf, int phdrs,
1848 struct elf_note_info *info,
1849 siginfo_t *siginfo, struct pt_regs *regs)
1850 {
1851 struct list_head *t;
1852
1853 if (!elf_note_info_init(info))
1854 return 0;
1855
1856 if (siginfo->si_signo) {
1857 struct core_thread *ct;
1858 struct elf_thread_status *ets;
1859
1860 for (ct = current->mm->core_state->dumper.next;
1861 ct; ct = ct->next) {
1862 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1863 if (!ets)
1864 return 0;
1865
1866 ets->thread = ct->task;
1867 list_add(&ets->list, &info->thread_list);
1868 }
1869
1870 list_for_each(t, &info->thread_list) {
1871 int sz;
1872
1873 ets = list_entry(t, struct elf_thread_status, list);
1874 sz = elf_dump_thread_status(siginfo->si_signo, ets);
1875 info->thread_status_size += sz;
1876 }
1877 }
1878 /* now collect the dump for the current */
1879 memset(info->prstatus, 0, sizeof(*info->prstatus));
1880 fill_prstatus(info->prstatus, current, siginfo->si_signo);
1881 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1882
1883 /* Set up header */
1884 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
1885
1886 /*
1887 * Set up the notes in similar form to SVR4 core dumps made
1888 * with info from their /proc.
1889 */
1890
1891 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1892 sizeof(*info->prstatus), info->prstatus);
1893 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1894 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1895 sizeof(*info->psinfo), info->psinfo);
1896
1897 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
1898 fill_auxv_note(info->notes + 3, current->mm);
1899 fill_files_note(info->notes + 4);
1900
1901 info->numnote = 5;
1902
1903 /* Try to dump the FPU. */
1904 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1905 info->fpu);
1906 if (info->prstatus->pr_fpvalid)
1907 fill_note(info->notes + info->numnote++,
1908 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1909 #ifdef ELF_CORE_COPY_XFPREGS
1910 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1911 fill_note(info->notes + info->numnote++,
1912 "LINUX", ELF_CORE_XFPREG_TYPE,
1913 sizeof(*info->xfpu), info->xfpu);
1914 #endif
1915
1916 return 1;
1917 }
1918
1919 static size_t get_note_info_size(struct elf_note_info *info)
1920 {
1921 int sz = 0;
1922 int i;
1923
1924 for (i = 0; i < info->numnote; i++)
1925 sz += notesize(info->notes + i);
1926
1927 sz += info->thread_status_size;
1928
1929 return sz;
1930 }
1931
1932 static int write_note_info(struct elf_note_info *info,
1933 struct file *file, loff_t *foffset)
1934 {
1935 int i;
1936 struct list_head *t;
1937
1938 for (i = 0; i < info->numnote; i++)
1939 if (!writenote(info->notes + i, file, foffset))
1940 return 0;
1941
1942 /* write out the thread status notes section */
1943 list_for_each(t, &info->thread_list) {
1944 struct elf_thread_status *tmp =
1945 list_entry(t, struct elf_thread_status, list);
1946
1947 for (i = 0; i < tmp->num_notes; i++)
1948 if (!writenote(&tmp->notes[i], file, foffset))
1949 return 0;
1950 }
1951
1952 return 1;
1953 }
1954
1955 static void free_note_info(struct elf_note_info *info)
1956 {
1957 while (!list_empty(&info->thread_list)) {
1958 struct list_head *tmp = info->thread_list.next;
1959 list_del(tmp);
1960 kfree(list_entry(tmp, struct elf_thread_status, list));
1961 }
1962
1963 /* Free data allocated by fill_files_note(): */
1964 vfree(info->notes[4].data);
1965
1966 kfree(info->prstatus);
1967 kfree(info->psinfo);
1968 kfree(info->notes);
1969 kfree(info->fpu);
1970 #ifdef ELF_CORE_COPY_XFPREGS
1971 kfree(info->xfpu);
1972 #endif
1973 }
1974
1975 #endif
1976
1977 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1978 struct vm_area_struct *gate_vma)
1979 {
1980 struct vm_area_struct *ret = tsk->mm->mmap;
1981
1982 if (ret)
1983 return ret;
1984 return gate_vma;
1985 }
1986 /*
1987 * Helper function for iterating across a vma list. It ensures that the caller
1988 * will visit `gate_vma' prior to terminating the search.
1989 */
1990 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1991 struct vm_area_struct *gate_vma)
1992 {
1993 struct vm_area_struct *ret;
1994
1995 ret = this_vma->vm_next;
1996 if (ret)
1997 return ret;
1998 if (this_vma == gate_vma)
1999 return NULL;
2000 return gate_vma;
2001 }
2002
2003 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
2004 elf_addr_t e_shoff, int segs)
2005 {
2006 elf->e_shoff = e_shoff;
2007 elf->e_shentsize = sizeof(*shdr4extnum);
2008 elf->e_shnum = 1;
2009 elf->e_shstrndx = SHN_UNDEF;
2010
2011 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
2012
2013 shdr4extnum->sh_type = SHT_NULL;
2014 shdr4extnum->sh_size = elf->e_shnum;
2015 shdr4extnum->sh_link = elf->e_shstrndx;
2016 shdr4extnum->sh_info = segs;
2017 }
2018
2019 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
2020 unsigned long mm_flags)
2021 {
2022 struct vm_area_struct *vma;
2023 size_t size = 0;
2024
2025 for (vma = first_vma(current, gate_vma); vma != NULL;
2026 vma = next_vma(vma, gate_vma))
2027 size += vma_dump_size(vma, mm_flags);
2028 return size;
2029 }
2030
2031 /*
2032 * Actual dumper
2033 *
2034 * This is a two-pass process; first we find the offsets of the bits,
2035 * and then they are actually written out. If we run out of core limit
2036 * we just truncate.
2037 */
2038 static int elf_core_dump(struct coredump_params *cprm)
2039 {
2040 int has_dumped = 0;
2041 mm_segment_t fs;
2042 int segs;
2043 size_t size = 0;
2044 struct vm_area_struct *vma, *gate_vma;
2045 struct elfhdr *elf = NULL;
2046 loff_t offset = 0, dataoff, foffset;
2047 struct elf_note_info info;
2048 struct elf_phdr *phdr4note = NULL;
2049 struct elf_shdr *shdr4extnum = NULL;
2050 Elf_Half e_phnum;
2051 elf_addr_t e_shoff;
2052
2053 /*
2054 * We no longer stop all VM operations.
2055 *
2056 * This is because those proceses that could possibly change map_count
2057 * or the mmap / vma pages are now blocked in do_exit on current
2058 * finishing this core dump.
2059 *
2060 * Only ptrace can touch these memory addresses, but it doesn't change
2061 * the map_count or the pages allocated. So no possibility of crashing
2062 * exists while dumping the mm->vm_next areas to the core file.
2063 */
2064
2065 /* alloc memory for large data structures: too large to be on stack */
2066 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
2067 if (!elf)
2068 goto out;
2069 /*
2070 * The number of segs are recored into ELF header as 16bit value.
2071 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2072 */
2073 segs = current->mm->map_count;
2074 segs += elf_core_extra_phdrs();
2075
2076 gate_vma = get_gate_vma(current->mm);
2077 if (gate_vma != NULL)
2078 segs++;
2079
2080 /* for notes section */
2081 segs++;
2082
2083 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2084 * this, kernel supports extended numbering. Have a look at
2085 * include/linux/elf.h for further information. */
2086 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2087
2088 /*
2089 * Collect all the non-memory information about the process for the
2090 * notes. This also sets up the file header.
2091 */
2092 if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2093 goto cleanup;
2094
2095 has_dumped = 1;
2096
2097 fs = get_fs();
2098 set_fs(KERNEL_DS);
2099
2100 offset += sizeof(*elf); /* Elf header */
2101 offset += segs * sizeof(struct elf_phdr); /* Program headers */
2102 foffset = offset;
2103
2104 /* Write notes phdr entry */
2105 {
2106 size_t sz = get_note_info_size(&info);
2107
2108 sz += elf_coredump_extra_notes_size();
2109
2110 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2111 if (!phdr4note)
2112 goto end_coredump;
2113
2114 fill_elf_note_phdr(phdr4note, sz, offset);
2115 offset += sz;
2116 }
2117
2118 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2119
2120 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
2121 offset += elf_core_extra_data_size();
2122 e_shoff = offset;
2123
2124 if (e_phnum == PN_XNUM) {
2125 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2126 if (!shdr4extnum)
2127 goto end_coredump;
2128 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
2129 }
2130
2131 offset = dataoff;
2132
2133 size += sizeof(*elf);
2134 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
2135 goto end_coredump;
2136
2137 size += sizeof(*phdr4note);
2138 if (size > cprm->limit
2139 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
2140 goto end_coredump;
2141
2142 /* Write program headers for segments dump */
2143 for (vma = first_vma(current, gate_vma); vma != NULL;
2144 vma = next_vma(vma, gate_vma)) {
2145 struct elf_phdr phdr;
2146
2147 phdr.p_type = PT_LOAD;
2148 phdr.p_offset = offset;
2149 phdr.p_vaddr = vma->vm_start;
2150 phdr.p_paddr = 0;
2151 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
2152 phdr.p_memsz = vma->vm_end - vma->vm_start;
2153 offset += phdr.p_filesz;
2154 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2155 if (vma->vm_flags & VM_WRITE)
2156 phdr.p_flags |= PF_W;
2157 if (vma->vm_flags & VM_EXEC)
2158 phdr.p_flags |= PF_X;
2159 phdr.p_align = ELF_EXEC_PAGESIZE;
2160
2161 size += sizeof(phdr);
2162 if (size > cprm->limit
2163 || !dump_write(cprm->file, &phdr, sizeof(phdr)))
2164 goto end_coredump;
2165 }
2166
2167 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
2168 goto end_coredump;
2169
2170 /* write out the notes section */
2171 if (!write_note_info(&info, cprm->file, &foffset))
2172 goto end_coredump;
2173
2174 if (elf_coredump_extra_notes_write(cprm->file, &foffset))
2175 goto end_coredump;
2176
2177 /* Align to page */
2178 if (!dump_seek(cprm->file, dataoff - foffset))
2179 goto end_coredump;
2180
2181 for (vma = first_vma(current, gate_vma); vma != NULL;
2182 vma = next_vma(vma, gate_vma)) {
2183 unsigned long addr;
2184 unsigned long end;
2185
2186 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
2187
2188 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2189 struct page *page;
2190 int stop;
2191
2192 page = get_dump_page(addr);
2193 if (page) {
2194 void *kaddr = kmap(page);
2195 stop = ((size += PAGE_SIZE) > cprm->limit) ||
2196 !dump_write(cprm->file, kaddr,
2197 PAGE_SIZE);
2198 kunmap(page);
2199 page_cache_release(page);
2200 } else
2201 stop = !dump_seek(cprm->file, PAGE_SIZE);
2202 if (stop)
2203 goto end_coredump;
2204 }
2205 }
2206
2207 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
2208 goto end_coredump;
2209
2210 if (e_phnum == PN_XNUM) {
2211 size += sizeof(*shdr4extnum);
2212 if (size > cprm->limit
2213 || !dump_write(cprm->file, shdr4extnum,
2214 sizeof(*shdr4extnum)))
2215 goto end_coredump;
2216 }
2217
2218 end_coredump:
2219 set_fs(fs);
2220
2221 cleanup:
2222 free_note_info(&info);
2223 kfree(shdr4extnum);
2224 kfree(phdr4note);
2225 kfree(elf);
2226 out:
2227 return has_dumped;
2228 }
2229
2230 #endif /* CONFIG_ELF_CORE */
2231
2232 static int __init init_elf_binfmt(void)
2233 {
2234 register_binfmt(&elf_format);
2235 return 0;
2236 }
2237
2238 static void __exit exit_elf_binfmt(void)
2239 {
2240 /* Remove the COFF and ELF loaders. */
2241 unregister_binfmt(&elf_format);
2242 }
2243
2244 core_initcall(init_elf_binfmt);
2245 module_exit(exit_elf_binfmt);
2246 MODULE_LICENSE("GPL");
Linus' kernel tree