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sky2: Don't receive packets when the napi budget == 0
[linux-2.6/btrfs-unstable.git] / fs / binfmt_elf.c
blob67be2951b98a4e6b5d6b28508f9b37fad6b06607
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->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 #ifndef STACK_RND_MASK
547 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
548 #endif
549
550 static unsigned long randomize_stack_top(unsigned long stack_top)
551 {
552 unsigned int random_variable = 0;
553
554 if ((current->flags & PF_RANDOMIZE) &&
555 !(current->personality & ADDR_NO_RANDOMIZE)) {
556 random_variable = get_random_int() & STACK_RND_MASK;
557 random_variable <<= PAGE_SHIFT;
558 }
559 #ifdef CONFIG_STACK_GROWSUP
560 return PAGE_ALIGN(stack_top) + random_variable;
561 #else
562 return PAGE_ALIGN(stack_top) - random_variable;
563 #endif
564 }
565
566 static int load_elf_binary(struct linux_binprm *bprm)
567 {
568 struct file *interpreter = NULL; /* to shut gcc up */
569 unsigned long load_addr = 0, load_bias = 0;
570 int load_addr_set = 0;
571 char * elf_interpreter = NULL;
572 unsigned long error;
573 struct elf_phdr *elf_ppnt, *elf_phdata;
574 unsigned long elf_bss, elf_brk;
575 int retval, i;
576 unsigned int size;
577 unsigned long elf_entry;
578 unsigned long interp_load_addr = 0;
579 unsigned long start_code, end_code, start_data, end_data;
580 unsigned long reloc_func_desc __maybe_unused = 0;
581 int executable_stack = EXSTACK_DEFAULT;
582 unsigned long def_flags = 0;
583 struct pt_regs *regs = current_pt_regs();
584 struct {
585 struct elfhdr elf_ex;
586 struct elfhdr interp_elf_ex;
587 } *loc;
588
589 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
590 if (!loc) {
591 retval = -ENOMEM;
592 goto out_ret;
593 }
594
595 /* Get the exec-header */
596 loc->elf_ex = *((struct elfhdr *)bprm->buf);
597
598 retval = -ENOEXEC;
599 /* First of all, some simple consistency checks */
600 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
601 goto out;
602
603 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
604 goto out;
605 if (!elf_check_arch(&loc->elf_ex))
606 goto out;
607 if (!bprm->file->f_op->mmap)
608 goto out;
609
610 /* Now read in all of the header information */
611 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
612 goto out;
613 if (loc->elf_ex.e_phnum < 1 ||
614 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
615 goto out;
616 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
617 retval = -ENOMEM;
618 elf_phdata = kmalloc(size, GFP_KERNEL);
619 if (!elf_phdata)
620 goto out;
621
622 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
623 (char *)elf_phdata, size);
624 if (retval != size) {
625 if (retval >= 0)
626 retval = -EIO;
627 goto out_free_ph;
628 }
629
630 elf_ppnt = elf_phdata;
631 elf_bss = 0;
632 elf_brk = 0;
633
634 start_code = ~0UL;
635 end_code = 0;
636 start_data = 0;
637 end_data = 0;
638
639 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
640 if (elf_ppnt->p_type == PT_INTERP) {
641 /* This is the program interpreter used for
642 * shared libraries - for now assume that this
643 * is an a.out format binary
644 */
645 retval = -ENOEXEC;
646 if (elf_ppnt->p_filesz > PATH_MAX ||
647 elf_ppnt->p_filesz < 2)
648 goto out_free_ph;
649
650 retval = -ENOMEM;
651 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
652 GFP_KERNEL);
653 if (!elf_interpreter)
654 goto out_free_ph;
655
656 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
657 elf_interpreter,
658 elf_ppnt->p_filesz);
659 if (retval != elf_ppnt->p_filesz) {
660 if (retval >= 0)
661 retval = -EIO;
662 goto out_free_interp;
663 }
664 /* make sure path is NULL terminated */
665 retval = -ENOEXEC;
666 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
667 goto out_free_interp;
668
669 interpreter = open_exec(elf_interpreter);
670 retval = PTR_ERR(interpreter);
671 if (IS_ERR(interpreter))
672 goto out_free_interp;
673
674 /*
675 * If the binary is not readable then enforce
676 * mm->dumpable = 0 regardless of the interpreter's
677 * permissions.
678 */
679 would_dump(bprm, interpreter);
680
681 retval = kernel_read(interpreter, 0, bprm->buf,
682 BINPRM_BUF_SIZE);
683 if (retval != BINPRM_BUF_SIZE) {
684 if (retval >= 0)
685 retval = -EIO;
686 goto out_free_dentry;
687 }
688
689 /* Get the exec headers */
690 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
691 break;
692 }
693 elf_ppnt++;
694 }
695
696 elf_ppnt = elf_phdata;
697 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
698 if (elf_ppnt->p_type == PT_GNU_STACK) {
699 if (elf_ppnt->p_flags & PF_X)
700 executable_stack = EXSTACK_ENABLE_X;
701 else
702 executable_stack = EXSTACK_DISABLE_X;
703 break;
704 }
705
706 /* Some simple consistency checks for the interpreter */
707 if (elf_interpreter) {
708 retval = -ELIBBAD;
709 /* Not an ELF interpreter */
710 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
711 goto out_free_dentry;
712 /* Verify the interpreter has a valid arch */
713 if (!elf_check_arch(&loc->interp_elf_ex))
714 goto out_free_dentry;
715 }
716
717 /* Flush all traces of the currently running executable */
718 retval = flush_old_exec(bprm);
719 if (retval)
720 goto out_free_dentry;
721
722 /* OK, This is the point of no return */
723 current->mm->def_flags = def_flags;
724
725 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
726 may depend on the personality. */
727 SET_PERSONALITY(loc->elf_ex);
728 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
729 current->personality |= READ_IMPLIES_EXEC;
730
731 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
732 current->flags |= PF_RANDOMIZE;
733
734 setup_new_exec(bprm);
735
736 /* Do this so that we can load the interpreter, if need be. We will
737 change some of these later */
738 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
739 executable_stack);
740 if (retval < 0) {
741 send_sig(SIGKILL, current, 0);
742 goto out_free_dentry;
743 }
744
745 current->mm->start_stack = bprm->p;
746
747 /* Now we do a little grungy work by mmapping the ELF image into
748 the correct location in memory. */
749 for(i = 0, elf_ppnt = elf_phdata;
750 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
751 int elf_prot = 0, elf_flags;
752 unsigned long k, vaddr;
753
754 if (elf_ppnt->p_type != PT_LOAD)
755 continue;
756
757 if (unlikely (elf_brk > elf_bss)) {
758 unsigned long nbyte;
759
760 /* There was a PT_LOAD segment with p_memsz > p_filesz
761 before this one. Map anonymous pages, if needed,
762 and clear the area. */
763 retval = set_brk(elf_bss + load_bias,
764 elf_brk + load_bias);
765 if (retval) {
766 send_sig(SIGKILL, current, 0);
767 goto out_free_dentry;
768 }
769 nbyte = ELF_PAGEOFFSET(elf_bss);
770 if (nbyte) {
771 nbyte = ELF_MIN_ALIGN - nbyte;
772 if (nbyte > elf_brk - elf_bss)
773 nbyte = elf_brk - elf_bss;
774 if (clear_user((void __user *)elf_bss +
775 load_bias, nbyte)) {
776 /*
777 * This bss-zeroing can fail if the ELF
778 * file specifies odd protections. So
779 * we don't check the return value
780 */
781 }
782 }
783 }
784
785 if (elf_ppnt->p_flags & PF_R)
786 elf_prot |= PROT_READ;
787 if (elf_ppnt->p_flags & PF_W)
788 elf_prot |= PROT_WRITE;
789 if (elf_ppnt->p_flags & PF_X)
790 elf_prot |= PROT_EXEC;
791
792 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
793
794 vaddr = elf_ppnt->p_vaddr;
795 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
796 elf_flags |= MAP_FIXED;
797 } else if (loc->elf_ex.e_type == ET_DYN) {
798 /* Try and get dynamic programs out of the way of the
799 * default mmap base, as well as whatever program they
800 * might try to exec. This is because the brk will
801 * follow the loader, and is not movable. */
802 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
803 /* Memory randomization might have been switched off
804 * in runtime via sysctl or explicit setting of
805 * personality flags.
806 * If that is the case, retain the original non-zero
807 * load_bias value in order to establish proper
808 * non-randomized mappings.
809 */
810 if (current->flags & PF_RANDOMIZE)
811 load_bias = 0;
812 else
813 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
814 #else
815 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
816 #endif
817 }
818
819 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
820 elf_prot, elf_flags, 0);
821 if (BAD_ADDR(error)) {
822 send_sig(SIGKILL, current, 0);
823 retval = IS_ERR((void *)error) ?
824 PTR_ERR((void*)error) : -EINVAL;
825 goto out_free_dentry;
826 }
827
828 if (!load_addr_set) {
829 load_addr_set = 1;
830 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
831 if (loc->elf_ex.e_type == ET_DYN) {
832 load_bias += error -
833 ELF_PAGESTART(load_bias + vaddr);
834 load_addr += load_bias;
835 reloc_func_desc = load_bias;
836 }
837 }
838 k = elf_ppnt->p_vaddr;
839 if (k < start_code)
840 start_code = k;
841 if (start_data < k)
842 start_data = k;
843
844 /*
845 * Check to see if the section's size will overflow the
846 * allowed task size. Note that p_filesz must always be
847 * <= p_memsz so it is only necessary to check p_memsz.
848 */
849 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
850 elf_ppnt->p_memsz > TASK_SIZE ||
851 TASK_SIZE - elf_ppnt->p_memsz < k) {
852 /* set_brk can never work. Avoid overflows. */
853 send_sig(SIGKILL, current, 0);
854 retval = -EINVAL;
855 goto out_free_dentry;
856 }
857
858 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
859
860 if (k > elf_bss)
861 elf_bss = k;
862 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
863 end_code = k;
864 if (end_data < k)
865 end_data = k;
866 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
867 if (k > elf_brk)
868 elf_brk = k;
869 }
870
871 loc->elf_ex.e_entry += load_bias;
872 elf_bss += load_bias;
873 elf_brk += load_bias;
874 start_code += load_bias;
875 end_code += load_bias;
876 start_data += load_bias;
877 end_data += load_bias;
878
879 /* Calling set_brk effectively mmaps the pages that we need
880 * for the bss and break sections. We must do this before
881 * mapping in the interpreter, to make sure it doesn't wind
882 * up getting placed where the bss needs to go.
883 */
884 retval = set_brk(elf_bss, elf_brk);
885 if (retval) {
886 send_sig(SIGKILL, current, 0);
887 goto out_free_dentry;
888 }
889 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
890 send_sig(SIGSEGV, current, 0);
891 retval = -EFAULT; /* Nobody gets to see this, but.. */
892 goto out_free_dentry;
893 }
894
895 if (elf_interpreter) {
896 unsigned long interp_map_addr = 0;
897
898 elf_entry = load_elf_interp(&loc->interp_elf_ex,
899 interpreter,
900 &interp_map_addr,
901 load_bias);
902 if (!IS_ERR((void *)elf_entry)) {
903 /*
904 * load_elf_interp() returns relocation
905 * adjustment
906 */
907 interp_load_addr = elf_entry;
908 elf_entry += loc->interp_elf_ex.e_entry;
909 }
910 if (BAD_ADDR(elf_entry)) {
911 force_sig(SIGSEGV, current);
912 retval = IS_ERR((void *)elf_entry) ?
913 (int)elf_entry : -EINVAL;
914 goto out_free_dentry;
915 }
916 reloc_func_desc = interp_load_addr;
917
918 allow_write_access(interpreter);
919 fput(interpreter);
920 kfree(elf_interpreter);
921 } else {
922 elf_entry = loc->elf_ex.e_entry;
923 if (BAD_ADDR(elf_entry)) {
924 force_sig(SIGSEGV, current);
925 retval = -EINVAL;
926 goto out_free_dentry;
927 }
928 }
929
930 kfree(elf_phdata);
931
932 set_binfmt(&elf_format);
933
934 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
935 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
936 if (retval < 0) {
937 send_sig(SIGKILL, current, 0);
938 goto out;
939 }
940 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
941
942 install_exec_creds(bprm);
943 retval = create_elf_tables(bprm, &loc->elf_ex,
944 load_addr, interp_load_addr);
945 if (retval < 0) {
946 send_sig(SIGKILL, current, 0);
947 goto out;
948 }
949 /* N.B. passed_fileno might not be initialized? */
950 current->mm->end_code = end_code;
951 current->mm->start_code = start_code;
952 current->mm->start_data = start_data;
953 current->mm->end_data = end_data;
954 current->mm->start_stack = bprm->p;
955
956 #ifdef arch_randomize_brk
957 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
958 current->mm->brk = current->mm->start_brk =
959 arch_randomize_brk(current->mm);
960 #ifdef CONFIG_COMPAT_BRK
961 current->brk_randomized = 1;
962 #endif
963 }
964 #endif
965
966 if (current->personality & MMAP_PAGE_ZERO) {
967 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
968 and some applications "depend" upon this behavior.
969 Since we do not have the power to recompile these, we
970 emulate the SVr4 behavior. Sigh. */
971 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
972 MAP_FIXED | MAP_PRIVATE, 0);
973 }
974
975 #ifdef ELF_PLAT_INIT
976 /*
977 * The ABI may specify that certain registers be set up in special
978 * ways (on i386 %edx is the address of a DT_FINI function, for
979 * example. In addition, it may also specify (eg, PowerPC64 ELF)
980 * that the e_entry field is the address of the function descriptor
981 * for the startup routine, rather than the address of the startup
982 * routine itself. This macro performs whatever initialization to
983 * the regs structure is required as well as any relocations to the
984 * function descriptor entries when executing dynamically links apps.
985 */
986 ELF_PLAT_INIT(regs, reloc_func_desc);
987 #endif
988
989 start_thread(regs, elf_entry, bprm->p);
990 retval = 0;
991 out:
992 kfree(loc);
993 out_ret:
994 return retval;
995
996 /* error cleanup */
997 out_free_dentry:
998 allow_write_access(interpreter);
999 if (interpreter)
1000 fput(interpreter);
1001 out_free_interp:
1002 kfree(elf_interpreter);
1003 out_free_ph:
1004 kfree(elf_phdata);
1005 goto out;
1006 }
1007
1008 /* This is really simpleminded and specialized - we are loading an
1009 a.out library that is given an ELF header. */
1010 static int load_elf_library(struct file *file)
1011 {
1012 struct elf_phdr *elf_phdata;
1013 struct elf_phdr *eppnt;
1014 unsigned long elf_bss, bss, len;
1015 int retval, error, i, j;
1016 struct elfhdr elf_ex;
1017
1018 error = -ENOEXEC;
1019 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1020 if (retval != sizeof(elf_ex))
1021 goto out;
1022
1023 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1024 goto out;
1025
1026 /* First of all, some simple consistency checks */
1027 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1028 !elf_check_arch(&elf_ex) || !file->f_op->mmap)
1029 goto out;
1030
1031 /* Now read in all of the header information */
1032
1033 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1034 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1035
1036 error = -ENOMEM;
1037 elf_phdata = kmalloc(j, GFP_KERNEL);
1038 if (!elf_phdata)
1039 goto out;
1040
1041 eppnt = elf_phdata;
1042 error = -ENOEXEC;
1043 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1044 if (retval != j)
1045 goto out_free_ph;
1046
1047 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1048 if ((eppnt + i)->p_type == PT_LOAD)
1049 j++;
1050 if (j != 1)
1051 goto out_free_ph;
1052
1053 while (eppnt->p_type != PT_LOAD)
1054 eppnt++;
1055
1056 /* Now use mmap to map the library into memory. */
1057 error = vm_mmap(file,
1058 ELF_PAGESTART(eppnt->p_vaddr),
1059 (eppnt->p_filesz +
1060 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1061 PROT_READ | PROT_WRITE | PROT_EXEC,
1062 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1063 (eppnt->p_offset -
1064 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1065 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1066 goto out_free_ph;
1067
1068 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1069 if (padzero(elf_bss)) {
1070 error = -EFAULT;
1071 goto out_free_ph;
1072 }
1073
1074 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1075 ELF_MIN_ALIGN - 1);
1076 bss = eppnt->p_memsz + eppnt->p_vaddr;
1077 if (bss > len)
1078 vm_brk(len, bss - len);
1079 error = 0;
1080
1081 out_free_ph:
1082 kfree(elf_phdata);
1083 out:
1084 return error;
1085 }
1086
1087 #ifdef CONFIG_ELF_CORE
1088 /*
1089 * ELF core dumper
1090 *
1091 * Modelled on fs/exec.c:aout_core_dump()
1092 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1093 */
1094
1095 /*
1096 * The purpose of always_dump_vma() is to make sure that special kernel mappings
1097 * that are useful for post-mortem analysis are included in every core dump.
1098 * In that way we ensure that the core dump is fully interpretable later
1099 * without matching up the same kernel and hardware config to see what PC values
1100 * meant. These special mappings include - vDSO, vsyscall, and other
1101 * architecture specific mappings
1102 */
1103 static bool always_dump_vma(struct vm_area_struct *vma)
1104 {
1105 /* Any vsyscall mappings? */
1106 if (vma == get_gate_vma(vma->vm_mm))
1107 return true;
1108 /*
1109 * arch_vma_name() returns non-NULL for special architecture mappings,
1110 * such as vDSO sections.
1111 */
1112 if (arch_vma_name(vma))
1113 return true;
1114
1115 return false;
1116 }
1117
1118 /*
1119 * Decide what to dump of a segment, part, all or none.
1120 */
1121 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1122 unsigned long mm_flags)
1123 {
1124 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1125
1126 /* always dump the vdso and vsyscall sections */
1127 if (always_dump_vma(vma))
1128 goto whole;
1129
1130 if (vma->vm_flags & VM_DONTDUMP)
1131 return 0;
1132
1133 /* Hugetlb memory check */
1134 if (vma->vm_flags & VM_HUGETLB) {
1135 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1136 goto whole;
1137 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1138 goto whole;
1139 return 0;
1140 }
1141
1142 /* Do not dump I/O mapped devices or special mappings */
1143 if (vma->vm_flags & VM_IO)
1144 return 0;
1145
1146 /* By default, dump shared memory if mapped from an anonymous file. */
1147 if (vma->vm_flags & VM_SHARED) {
1148 if (file_inode(vma->vm_file)->i_nlink == 0 ?
1149 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1150 goto whole;
1151 return 0;
1152 }
1153
1154 /* Dump segments that have been written to. */
1155 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1156 goto whole;
1157 if (vma->vm_file == NULL)
1158 return 0;
1159
1160 if (FILTER(MAPPED_PRIVATE))
1161 goto whole;
1162
1163 /*
1164 * If this looks like the beginning of a DSO or executable mapping,
1165 * check for an ELF header. If we find one, dump the first page to
1166 * aid in determining what was mapped here.
1167 */
1168 if (FILTER(ELF_HEADERS) &&
1169 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1170 u32 __user *header = (u32 __user *) vma->vm_start;
1171 u32 word;
1172 mm_segment_t fs = get_fs();
1173 /*
1174 * Doing it this way gets the constant folded by GCC.
1175 */
1176 union {
1177 u32 cmp;
1178 char elfmag[SELFMAG];
1179 } magic;
1180 BUILD_BUG_ON(SELFMAG != sizeof word);
1181 magic.elfmag[EI_MAG0] = ELFMAG0;
1182 magic.elfmag[EI_MAG1] = ELFMAG1;
1183 magic.elfmag[EI_MAG2] = ELFMAG2;
1184 magic.elfmag[EI_MAG3] = ELFMAG3;
1185 /*
1186 * Switch to the user "segment" for get_user(),
1187 * then put back what elf_core_dump() had in place.
1188 */
1189 set_fs(USER_DS);
1190 if (unlikely(get_user(word, header)))
1191 word = 0;
1192 set_fs(fs);
1193 if (word == magic.cmp)
1194 return PAGE_SIZE;
1195 }
1196
1197 #undef FILTER
1198
1199 return 0;
1200
1201 whole:
1202 return vma->vm_end - vma->vm_start;
1203 }
1204
1205 /* An ELF note in memory */
1206 struct memelfnote
1207 {
1208 const char *name;
1209 int type;
1210 unsigned int datasz;
1211 void *data;
1212 };
1213
1214 static int notesize(struct memelfnote *en)
1215 {
1216 int sz;
1217
1218 sz = sizeof(struct elf_note);
1219 sz += roundup(strlen(en->name) + 1, 4);
1220 sz += roundup(en->datasz, 4);
1221
1222 return sz;
1223 }
1224
1225 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1226 {
1227 struct elf_note en;
1228 en.n_namesz = strlen(men->name) + 1;
1229 en.n_descsz = men->datasz;
1230 en.n_type = men->type;
1231
1232 return dump_emit(cprm, &en, sizeof(en)) &&
1233 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1234 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1235 }
1236
1237 static void fill_elf_header(struct elfhdr *elf, int segs,
1238 u16 machine, u32 flags)
1239 {
1240 memset(elf, 0, sizeof(*elf));
1241
1242 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1243 elf->e_ident[EI_CLASS] = ELF_CLASS;
1244 elf->e_ident[EI_DATA] = ELF_DATA;
1245 elf->e_ident[EI_VERSION] = EV_CURRENT;
1246 elf->e_ident[EI_OSABI] = ELF_OSABI;
1247
1248 elf->e_type = ET_CORE;
1249 elf->e_machine = machine;
1250 elf->e_version = EV_CURRENT;
1251 elf->e_phoff = sizeof(struct elfhdr);
1252 elf->e_flags = flags;
1253 elf->e_ehsize = sizeof(struct elfhdr);
1254 elf->e_phentsize = sizeof(struct elf_phdr);
1255 elf->e_phnum = segs;
1256
1257 return;
1258 }
1259
1260 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1261 {
1262 phdr->p_type = PT_NOTE;
1263 phdr->p_offset = offset;
1264 phdr->p_vaddr = 0;
1265 phdr->p_paddr = 0;
1266 phdr->p_filesz = sz;
1267 phdr->p_memsz = 0;
1268 phdr->p_flags = 0;
1269 phdr->p_align = 0;
1270 return;
1271 }
1272
1273 static void fill_note(struct memelfnote *note, const char *name, int type,
1274 unsigned int sz, void *data)
1275 {
1276 note->name = name;
1277 note->type = type;
1278 note->datasz = sz;
1279 note->data = data;
1280 return;
1281 }
1282
1283 /*
1284 * fill up all the fields in prstatus from the given task struct, except
1285 * registers which need to be filled up separately.
1286 */
1287 static void fill_prstatus(struct elf_prstatus *prstatus,
1288 struct task_struct *p, long signr)
1289 {
1290 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1291 prstatus->pr_sigpend = p->pending.signal.sig[0];
1292 prstatus->pr_sighold = p->blocked.sig[0];
1293 rcu_read_lock();
1294 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1295 rcu_read_unlock();
1296 prstatus->pr_pid = task_pid_vnr(p);
1297 prstatus->pr_pgrp = task_pgrp_vnr(p);
1298 prstatus->pr_sid = task_session_vnr(p);
1299 if (thread_group_leader(p)) {
1300 struct task_cputime cputime;
1301
1302 /*
1303 * This is the record for the group leader. It shows the
1304 * group-wide total, not its individual thread total.
1305 */
1306 thread_group_cputime(p, &cputime);
1307 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1308 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1309 } else {
1310 cputime_t utime, stime;
1311
1312 task_cputime(p, &utime, &stime);
1313 cputime_to_timeval(utime, &prstatus->pr_utime);
1314 cputime_to_timeval(stime, &prstatus->pr_stime);
1315 }
1316 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1317 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1318 }
1319
1320 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1321 struct mm_struct *mm)
1322 {
1323 const struct cred *cred;
1324 unsigned int i, len;
1325
1326 /* first copy the parameters from user space */
1327 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1328
1329 len = mm->arg_end - mm->arg_start;
1330 if (len >= ELF_PRARGSZ)
1331 len = ELF_PRARGSZ-1;
1332 if (copy_from_user(&psinfo->pr_psargs,
1333 (const char __user *)mm->arg_start, len))
1334 return -EFAULT;
1335 for(i = 0; i < len; i++)
1336 if (psinfo->pr_psargs[i] == 0)
1337 psinfo->pr_psargs[i] = ' ';
1338 psinfo->pr_psargs[len] = 0;
1339
1340 rcu_read_lock();
1341 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1342 rcu_read_unlock();
1343 psinfo->pr_pid = task_pid_vnr(p);
1344 psinfo->pr_pgrp = task_pgrp_vnr(p);
1345 psinfo->pr_sid = task_session_vnr(p);
1346
1347 i = p->state ? ffz(~p->state) + 1 : 0;
1348 psinfo->pr_state = i;
1349 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1350 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1351 psinfo->pr_nice = task_nice(p);
1352 psinfo->pr_flag = p->flags;
1353 rcu_read_lock();
1354 cred = __task_cred(p);
1355 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1356 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1357 rcu_read_unlock();
1358 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1359
1360 return 0;
1361 }
1362
1363 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1364 {
1365 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1366 int i = 0;
1367 do
1368 i += 2;
1369 while (auxv[i - 2] != AT_NULL);
1370 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1371 }
1372
1373 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1374 const siginfo_t *siginfo)
1375 {
1376 mm_segment_t old_fs = get_fs();
1377 set_fs(KERNEL_DS);
1378 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
1379 set_fs(old_fs);
1380 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1381 }
1382
1383 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1384 /*
1385 * Format of NT_FILE note:
1386 *
1387 * long count -- how many files are mapped
1388 * long page_size -- units for file_ofs
1389 * array of [COUNT] elements of
1390 * long start
1391 * long end
1392 * long file_ofs
1393 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1394 */
1395 static int fill_files_note(struct memelfnote *note)
1396 {
1397 struct vm_area_struct *vma;
1398 unsigned count, size, names_ofs, remaining, n;
1399 user_long_t *data;
1400 user_long_t *start_end_ofs;
1401 char *name_base, *name_curpos;
1402
1403 /* *Estimated* file count and total data size needed */
1404 count = current->mm->map_count;
1405 size = count * 64;
1406
1407 names_ofs = (2 + 3 * count) * sizeof(data[0]);
1408 alloc:
1409 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1410 return -EINVAL;
1411 size = round_up(size, PAGE_SIZE);
1412 data = vmalloc(size);
1413 if (!data)
1414 return -ENOMEM;
1415
1416 start_end_ofs = data + 2;
1417 name_base = name_curpos = ((char *)data) + names_ofs;
1418 remaining = size - names_ofs;
1419 count = 0;
1420 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1421 struct file *file;
1422 const char *filename;
1423
1424 file = vma->vm_file;
1425 if (!file)
1426 continue;
1427 filename = d_path(&file->f_path, name_curpos, remaining);
1428 if (IS_ERR(filename)) {
1429 if (PTR_ERR(filename) == -ENAMETOOLONG) {
1430 vfree(data);
1431 size = size * 5 / 4;
1432 goto alloc;
1433 }
1434 continue;
1435 }
1436
1437 /* d_path() fills at the end, move name down */
1438 /* n = strlen(filename) + 1: */
1439 n = (name_curpos + remaining) - filename;
1440 remaining = filename - name_curpos;
1441 memmove(name_curpos, filename, n);
1442 name_curpos += n;
1443
1444 *start_end_ofs++ = vma->vm_start;
1445 *start_end_ofs++ = vma->vm_end;
1446 *start_end_ofs++ = vma->vm_pgoff;
1447 count++;
1448 }
1449
1450 /* Now we know exact count of files, can store it */
1451 data[0] = count;
1452 data[1] = PAGE_SIZE;
1453 /*
1454 * Count usually is less than current->mm->map_count,
1455 * we need to move filenames down.
1456 */
1457 n = current->mm->map_count - count;
1458 if (n != 0) {
1459 unsigned shift_bytes = n * 3 * sizeof(data[0]);
1460 memmove(name_base - shift_bytes, name_base,
1461 name_curpos - name_base);
1462 name_curpos -= shift_bytes;
1463 }
1464
1465 size = name_curpos - (char *)data;
1466 fill_note(note, "CORE", NT_FILE, size, data);
1467 return 0;
1468 }
1469
1470 #ifdef CORE_DUMP_USE_REGSET
1471 #include <linux/regset.h>
1472
1473 struct elf_thread_core_info {
1474 struct elf_thread_core_info *next;
1475 struct task_struct *task;
1476 struct elf_prstatus prstatus;
1477 struct memelfnote notes[0];
1478 };
1479
1480 struct elf_note_info {
1481 struct elf_thread_core_info *thread;
1482 struct memelfnote psinfo;
1483 struct memelfnote signote;
1484 struct memelfnote auxv;
1485 struct memelfnote files;
1486 user_siginfo_t csigdata;
1487 size_t size;
1488 int thread_notes;
1489 };
1490
1491 /*
1492 * When a regset has a writeback hook, we call it on each thread before
1493 * dumping user memory. On register window machines, this makes sure the
1494 * user memory backing the register data is up to date before we read it.
1495 */
1496 static void do_thread_regset_writeback(struct task_struct *task,
1497 const struct user_regset *regset)
1498 {
1499 if (regset->writeback)
1500 regset->writeback(task, regset, 1);
1501 }
1502
1503 #ifndef PR_REG_SIZE
1504 #define PR_REG_SIZE(S) sizeof(S)
1505 #endif
1506
1507 #ifndef PRSTATUS_SIZE
1508 #define PRSTATUS_SIZE(S) sizeof(S)
1509 #endif
1510
1511 #ifndef PR_REG_PTR
1512 #define PR_REG_PTR(S) (&((S)->pr_reg))
1513 #endif
1514
1515 #ifndef SET_PR_FPVALID
1516 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V))
1517 #endif
1518
1519 static int fill_thread_core_info(struct elf_thread_core_info *t,
1520 const struct user_regset_view *view,
1521 long signr, size_t *total)
1522 {
1523 unsigned int i;
1524
1525 /*
1526 * NT_PRSTATUS is the one special case, because the regset data
1527 * goes into the pr_reg field inside the note contents, rather
1528 * than being the whole note contents. We fill the reset in here.
1529 * We assume that regset 0 is NT_PRSTATUS.
1530 */
1531 fill_prstatus(&t->prstatus, t->task, signr);
1532 (void) view->regsets[0].get(t->task, &view->regsets[0],
1533 0, PR_REG_SIZE(t->prstatus.pr_reg),
1534 PR_REG_PTR(&t->prstatus), NULL);
1535
1536 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1537 PRSTATUS_SIZE(t->prstatus), &t->prstatus);
1538 *total += notesize(&t->notes[0]);
1539
1540 do_thread_regset_writeback(t->task, &view->regsets[0]);
1541
1542 /*
1543 * Each other regset might generate a note too. For each regset
1544 * that has no core_note_type or is inactive, we leave t->notes[i]
1545 * all zero and we'll know to skip writing it later.
1546 */
1547 for (i = 1; i < view->n; ++i) {
1548 const struct user_regset *regset = &view->regsets[i];
1549 do_thread_regset_writeback(t->task, regset);
1550 if (regset->core_note_type && regset->get &&
1551 (!regset->active || regset->active(t->task, regset))) {
1552 int ret;
1553 size_t size = regset->n * regset->size;
1554 void *data = kmalloc(size, GFP_KERNEL);
1555 if (unlikely(!data))
1556 return 0;
1557 ret = regset->get(t->task, regset,
1558 0, size, data, NULL);
1559 if (unlikely(ret))
1560 kfree(data);
1561 else {
1562 if (regset->core_note_type != NT_PRFPREG)
1563 fill_note(&t->notes[i], "LINUX",
1564 regset->core_note_type,
1565 size, data);
1566 else {
1567 SET_PR_FPVALID(&t->prstatus, 1);
1568 fill_note(&t->notes[i], "CORE",
1569 NT_PRFPREG, size, data);
1570 }
1571 *total += notesize(&t->notes[i]);
1572 }
1573 }
1574 }
1575
1576 return 1;
1577 }
1578
1579 static int fill_note_info(struct elfhdr *elf, int phdrs,
1580 struct elf_note_info *info,
1581 const siginfo_t *siginfo, struct pt_regs *regs)
1582 {
1583 struct task_struct *dump_task = current;
1584 const struct user_regset_view *view = task_user_regset_view(dump_task);
1585 struct elf_thread_core_info *t;
1586 struct elf_prpsinfo *psinfo;
1587 struct core_thread *ct;
1588 unsigned int i;
1589
1590 info->size = 0;
1591 info->thread = NULL;
1592
1593 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1594 if (psinfo == NULL) {
1595 info->psinfo.data = NULL; /* So we don't free this wrongly */
1596 return 0;
1597 }
1598
1599 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1600
1601 /*
1602 * Figure out how many notes we're going to need for each thread.
1603 */
1604 info->thread_notes = 0;
1605 for (i = 0; i < view->n; ++i)
1606 if (view->regsets[i].core_note_type != 0)
1607 ++info->thread_notes;
1608
1609 /*
1610 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1611 * since it is our one special case.
1612 */
1613 if (unlikely(info->thread_notes == 0) ||
1614 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1615 WARN_ON(1);
1616 return 0;
1617 }
1618
1619 /*
1620 * Initialize the ELF file header.
1621 */
1622 fill_elf_header(elf, phdrs,
1623 view->e_machine, view->e_flags);
1624
1625 /*
1626 * Allocate a structure for each thread.
1627 */
1628 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1629 t = kzalloc(offsetof(struct elf_thread_core_info,
1630 notes[info->thread_notes]),
1631 GFP_KERNEL);
1632 if (unlikely(!t))
1633 return 0;
1634
1635 t->task = ct->task;
1636 if (ct->task == dump_task || !info->thread) {
1637 t->next = info->thread;
1638 info->thread = t;
1639 } else {
1640 /*
1641 * Make sure to keep the original task at
1642 * the head of the list.
1643 */
1644 t->next = info->thread->next;
1645 info->thread->next = t;
1646 }
1647 }
1648
1649 /*
1650 * Now fill in each thread's information.
1651 */
1652 for (t = info->thread; t != NULL; t = t->next)
1653 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1654 return 0;
1655
1656 /*
1657 * Fill in the two process-wide notes.
1658 */
1659 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1660 info->size += notesize(&info->psinfo);
1661
1662 fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1663 info->size += notesize(&info->signote);
1664
1665 fill_auxv_note(&info->auxv, current->mm);
1666 info->size += notesize(&info->auxv);
1667
1668 if (fill_files_note(&info->files) == 0)
1669 info->size += notesize(&info->files);
1670
1671 return 1;
1672 }
1673
1674 static size_t get_note_info_size(struct elf_note_info *info)
1675 {
1676 return info->size;
1677 }
1678
1679 /*
1680 * Write all the notes for each thread. When writing the first thread, the
1681 * process-wide notes are interleaved after the first thread-specific note.
1682 */
1683 static int write_note_info(struct elf_note_info *info,
1684 struct coredump_params *cprm)
1685 {
1686 bool first = 1;
1687 struct elf_thread_core_info *t = info->thread;
1688
1689 do {
1690 int i;
1691
1692 if (!writenote(&t->notes[0], cprm))
1693 return 0;
1694
1695 if (first && !writenote(&info->psinfo, cprm))
1696 return 0;
1697 if (first && !writenote(&info->signote, cprm))
1698 return 0;
1699 if (first && !writenote(&info->auxv, cprm))
1700 return 0;
1701 if (first && info->files.data &&
1702 !writenote(&info->files, cprm))
1703 return 0;
1704
1705 for (i = 1; i < info->thread_notes; ++i)
1706 if (t->notes[i].data &&
1707 !writenote(&t->notes[i], cprm))
1708 return 0;
1709
1710 first = 0;
1711 t = t->next;
1712 } while (t);
1713
1714 return 1;
1715 }
1716
1717 static void free_note_info(struct elf_note_info *info)
1718 {
1719 struct elf_thread_core_info *threads = info->thread;
1720 while (threads) {
1721 unsigned int i;
1722 struct elf_thread_core_info *t = threads;
1723 threads = t->next;
1724 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1725 for (i = 1; i < info->thread_notes; ++i)
1726 kfree(t->notes[i].data);
1727 kfree(t);
1728 }
1729 kfree(info->psinfo.data);
1730 vfree(info->files.data);
1731 }
1732
1733 #else
1734
1735 /* Here is the structure in which status of each thread is captured. */
1736 struct elf_thread_status
1737 {
1738 struct list_head list;
1739 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1740 elf_fpregset_t fpu; /* NT_PRFPREG */
1741 struct task_struct *thread;
1742 #ifdef ELF_CORE_COPY_XFPREGS
1743 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1744 #endif
1745 struct memelfnote notes[3];
1746 int num_notes;
1747 };
1748
1749 /*
1750 * In order to add the specific thread information for the elf file format,
1751 * we need to keep a linked list of every threads pr_status and then create
1752 * a single section for them in the final core file.
1753 */
1754 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1755 {
1756 int sz = 0;
1757 struct task_struct *p = t->thread;
1758 t->num_notes = 0;
1759
1760 fill_prstatus(&t->prstatus, p, signr);
1761 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1762
1763 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1764 &(t->prstatus));
1765 t->num_notes++;
1766 sz += notesize(&t->notes[0]);
1767
1768 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1769 &t->fpu))) {
1770 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1771 &(t->fpu));
1772 t->num_notes++;
1773 sz += notesize(&t->notes[1]);
1774 }
1775
1776 #ifdef ELF_CORE_COPY_XFPREGS
1777 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1778 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1779 sizeof(t->xfpu), &t->xfpu);
1780 t->num_notes++;
1781 sz += notesize(&t->notes[2]);
1782 }
1783 #endif
1784 return sz;
1785 }
1786
1787 struct elf_note_info {
1788 struct memelfnote *notes;
1789 struct memelfnote *notes_files;
1790 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1791 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1792 struct list_head thread_list;
1793 elf_fpregset_t *fpu;
1794 #ifdef ELF_CORE_COPY_XFPREGS
1795 elf_fpxregset_t *xfpu;
1796 #endif
1797 user_siginfo_t csigdata;
1798 int thread_status_size;
1799 int numnote;
1800 };
1801
1802 static int elf_note_info_init(struct elf_note_info *info)
1803 {
1804 memset(info, 0, sizeof(*info));
1805 INIT_LIST_HEAD(&info->thread_list);
1806
1807 /* Allocate space for ELF notes */
1808 info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL);
1809 if (!info->notes)
1810 return 0;
1811 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1812 if (!info->psinfo)
1813 return 0;
1814 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1815 if (!info->prstatus)
1816 return 0;
1817 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1818 if (!info->fpu)
1819 return 0;
1820 #ifdef ELF_CORE_COPY_XFPREGS
1821 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1822 if (!info->xfpu)
1823 return 0;
1824 #endif
1825 return 1;
1826 }
1827
1828 static int fill_note_info(struct elfhdr *elf, int phdrs,
1829 struct elf_note_info *info,
1830 const siginfo_t *siginfo, struct pt_regs *regs)
1831 {
1832 struct list_head *t;
1833 struct core_thread *ct;
1834 struct elf_thread_status *ets;
1835
1836 if (!elf_note_info_init(info))
1837 return 0;
1838
1839 for (ct = current->mm->core_state->dumper.next;
1840 ct; ct = ct->next) {
1841 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1842 if (!ets)
1843 return 0;
1844
1845 ets->thread = ct->task;
1846 list_add(&ets->list, &info->thread_list);
1847 }
1848
1849 list_for_each(t, &info->thread_list) {
1850 int sz;
1851
1852 ets = list_entry(t, struct elf_thread_status, list);
1853 sz = elf_dump_thread_status(siginfo->si_signo, ets);
1854 info->thread_status_size += sz;
1855 }
1856 /* now collect the dump for the current */
1857 memset(info->prstatus, 0, sizeof(*info->prstatus));
1858 fill_prstatus(info->prstatus, current, siginfo->si_signo);
1859 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1860
1861 /* Set up header */
1862 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
1863
1864 /*
1865 * Set up the notes in similar form to SVR4 core dumps made
1866 * with info from their /proc.
1867 */
1868
1869 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1870 sizeof(*info->prstatus), info->prstatus);
1871 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1872 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1873 sizeof(*info->psinfo), info->psinfo);
1874
1875 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
1876 fill_auxv_note(info->notes + 3, current->mm);
1877 info->numnote = 4;
1878
1879 if (fill_files_note(info->notes + info->numnote) == 0) {
1880 info->notes_files = info->notes + info->numnote;
1881 info->numnote++;
1882 }
1883
1884 /* Try to dump the FPU. */
1885 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1886 info->fpu);
1887 if (info->prstatus->pr_fpvalid)
1888 fill_note(info->notes + info->numnote++,
1889 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1890 #ifdef ELF_CORE_COPY_XFPREGS
1891 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1892 fill_note(info->notes + info->numnote++,
1893 "LINUX", ELF_CORE_XFPREG_TYPE,
1894 sizeof(*info->xfpu), info->xfpu);
1895 #endif
1896
1897 return 1;
1898 }
1899
1900 static size_t get_note_info_size(struct elf_note_info *info)
1901 {
1902 int sz = 0;
1903 int i;
1904
1905 for (i = 0; i < info->numnote; i++)
1906 sz += notesize(info->notes + i);
1907
1908 sz += info->thread_status_size;
1909
1910 return sz;
1911 }
1912
1913 static int write_note_info(struct elf_note_info *info,
1914 struct coredump_params *cprm)
1915 {
1916 int i;
1917 struct list_head *t;
1918
1919 for (i = 0; i < info->numnote; i++)
1920 if (!writenote(info->notes + i, cprm))
1921 return 0;
1922
1923 /* write out the thread status notes section */
1924 list_for_each(t, &info->thread_list) {
1925 struct elf_thread_status *tmp =
1926 list_entry(t, struct elf_thread_status, list);
1927
1928 for (i = 0; i < tmp->num_notes; i++)
1929 if (!writenote(&tmp->notes[i], cprm))
1930 return 0;
1931 }
1932
1933 return 1;
1934 }
1935
1936 static void free_note_info(struct elf_note_info *info)
1937 {
1938 while (!list_empty(&info->thread_list)) {
1939 struct list_head *tmp = info->thread_list.next;
1940 list_del(tmp);
1941 kfree(list_entry(tmp, struct elf_thread_status, list));
1942 }
1943
1944 /* Free data possibly allocated by fill_files_note(): */
1945 if (info->notes_files)
1946 vfree(info->notes_files->data);
1947
1948 kfree(info->prstatus);
1949 kfree(info->psinfo);
1950 kfree(info->notes);
1951 kfree(info->fpu);
1952 #ifdef ELF_CORE_COPY_XFPREGS
1953 kfree(info->xfpu);
1954 #endif
1955 }
1956
1957 #endif
1958
1959 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1960 struct vm_area_struct *gate_vma)
1961 {
1962 struct vm_area_struct *ret = tsk->mm->mmap;
1963
1964 if (ret)
1965 return ret;
1966 return gate_vma;
1967 }
1968 /*
1969 * Helper function for iterating across a vma list. It ensures that the caller
1970 * will visit `gate_vma' prior to terminating the search.
1971 */
1972 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1973 struct vm_area_struct *gate_vma)
1974 {
1975 struct vm_area_struct *ret;
1976
1977 ret = this_vma->vm_next;
1978 if (ret)
1979 return ret;
1980 if (this_vma == gate_vma)
1981 return NULL;
1982 return gate_vma;
1983 }
1984
1985 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1986 elf_addr_t e_shoff, int segs)
1987 {
1988 elf->e_shoff = e_shoff;
1989 elf->e_shentsize = sizeof(*shdr4extnum);
1990 elf->e_shnum = 1;
1991 elf->e_shstrndx = SHN_UNDEF;
1992
1993 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1994
1995 shdr4extnum->sh_type = SHT_NULL;
1996 shdr4extnum->sh_size = elf->e_shnum;
1997 shdr4extnum->sh_link = elf->e_shstrndx;
1998 shdr4extnum->sh_info = segs;
1999 }
2000
2001 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
2002 unsigned long mm_flags)
2003 {
2004 struct vm_area_struct *vma;
2005 size_t size = 0;
2006
2007 for (vma = first_vma(current, gate_vma); vma != NULL;
2008 vma = next_vma(vma, gate_vma))
2009 size += vma_dump_size(vma, mm_flags);
2010 return size;
2011 }
2012
2013 /*
2014 * Actual dumper
2015 *
2016 * This is a two-pass process; first we find the offsets of the bits,
2017 * and then they are actually written out. If we run out of core limit
2018 * we just truncate.
2019 */
2020 static int elf_core_dump(struct coredump_params *cprm)
2021 {
2022 int has_dumped = 0;
2023 mm_segment_t fs;
2024 int segs;
2025 struct vm_area_struct *vma, *gate_vma;
2026 struct elfhdr *elf = NULL;
2027 loff_t offset = 0, dataoff;
2028 struct elf_note_info info = { };
2029 struct elf_phdr *phdr4note = NULL;
2030 struct elf_shdr *shdr4extnum = NULL;
2031 Elf_Half e_phnum;
2032 elf_addr_t e_shoff;
2033
2034 /*
2035 * We no longer stop all VM operations.
2036 *
2037 * This is because those proceses that could possibly change map_count
2038 * or the mmap / vma pages are now blocked in do_exit on current
2039 * finishing this core dump.
2040 *
2041 * Only ptrace can touch these memory addresses, but it doesn't change
2042 * the map_count or the pages allocated. So no possibility of crashing
2043 * exists while dumping the mm->vm_next areas to the core file.
2044 */
2045
2046 /* alloc memory for large data structures: too large to be on stack */
2047 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
2048 if (!elf)
2049 goto out;
2050 /*
2051 * The number of segs are recored into ELF header as 16bit value.
2052 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2053 */
2054 segs = current->mm->map_count;
2055 segs += elf_core_extra_phdrs();
2056
2057 gate_vma = get_gate_vma(current->mm);
2058 if (gate_vma != NULL)
2059 segs++;
2060
2061 /* for notes section */
2062 segs++;
2063
2064 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2065 * this, kernel supports extended numbering. Have a look at
2066 * include/linux/elf.h for further information. */
2067 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2068
2069 /*
2070 * Collect all the non-memory information about the process for the
2071 * notes. This also sets up the file header.
2072 */
2073 if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2074 goto cleanup;
2075
2076 has_dumped = 1;
2077
2078 fs = get_fs();
2079 set_fs(KERNEL_DS);
2080
2081 offset += sizeof(*elf); /* Elf header */
2082 offset += segs * sizeof(struct elf_phdr); /* Program headers */
2083
2084 /* Write notes phdr entry */
2085 {
2086 size_t sz = get_note_info_size(&info);
2087
2088 sz += elf_coredump_extra_notes_size();
2089
2090 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2091 if (!phdr4note)
2092 goto end_coredump;
2093
2094 fill_elf_note_phdr(phdr4note, sz, offset);
2095 offset += sz;
2096 }
2097
2098 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2099
2100 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
2101 offset += elf_core_extra_data_size();
2102 e_shoff = offset;
2103
2104 if (e_phnum == PN_XNUM) {
2105 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2106 if (!shdr4extnum)
2107 goto end_coredump;
2108 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
2109 }
2110
2111 offset = dataoff;
2112
2113 if (!dump_emit(cprm, elf, sizeof(*elf)))
2114 goto end_coredump;
2115
2116 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
2117 goto end_coredump;
2118
2119 /* Write program headers for segments dump */
2120 for (vma = first_vma(current, gate_vma); vma != NULL;
2121 vma = next_vma(vma, gate_vma)) {
2122 struct elf_phdr phdr;
2123
2124 phdr.p_type = PT_LOAD;
2125 phdr.p_offset = offset;
2126 phdr.p_vaddr = vma->vm_start;
2127 phdr.p_paddr = 0;
2128 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
2129 phdr.p_memsz = vma->vm_end - vma->vm_start;
2130 offset += phdr.p_filesz;
2131 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2132 if (vma->vm_flags & VM_WRITE)
2133 phdr.p_flags |= PF_W;
2134 if (vma->vm_flags & VM_EXEC)
2135 phdr.p_flags |= PF_X;
2136 phdr.p_align = ELF_EXEC_PAGESIZE;
2137
2138 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
2139 goto end_coredump;
2140 }
2141
2142 if (!elf_core_write_extra_phdrs(cprm, offset))
2143 goto end_coredump;
2144
2145 /* write out the notes section */
2146 if (!write_note_info(&info, cprm))
2147 goto end_coredump;
2148
2149 if (elf_coredump_extra_notes_write(cprm))
2150 goto end_coredump;
2151
2152 /* Align to page */
2153 if (!dump_skip(cprm, dataoff - cprm->written))
2154 goto end_coredump;
2155
2156 for (vma = first_vma(current, gate_vma); vma != NULL;
2157 vma = next_vma(vma, gate_vma)) {
2158 unsigned long addr;
2159 unsigned long end;
2160
2161 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
2162
2163 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2164 struct page *page;
2165 int stop;
2166
2167 page = get_dump_page(addr);
2168 if (page) {
2169 void *kaddr = kmap(page);
2170 stop = !dump_emit(cprm, kaddr, PAGE_SIZE);
2171 kunmap(page);
2172 page_cache_release(page);
2173 } else
2174 stop = !dump_skip(cprm, PAGE_SIZE);
2175 if (stop)
2176 goto end_coredump;
2177 }
2178 }
2179
2180 if (!elf_core_write_extra_data(cprm))
2181 goto end_coredump;
2182
2183 if (e_phnum == PN_XNUM) {
2184 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
2185 goto end_coredump;
2186 }
2187
2188 end_coredump:
2189 set_fs(fs);
2190
2191 cleanup:
2192 free_note_info(&info);
2193 kfree(shdr4extnum);
2194 kfree(phdr4note);
2195 kfree(elf);
2196 out:
2197 return has_dumped;
2198 }
2199
2200 #endif /* CONFIG_ELF_CORE */
2201
2202 static int __init init_elf_binfmt(void)
2203 {
2204 register_binfmt(&elf_format);
2205 return 0;
2206 }
2207
2208 static void __exit exit_elf_binfmt(void)
2209 {
2210 /* Remove the COFF and ELF loaders. */
2211 unregister_binfmt(&elf_format);
2212 }
2213
2214 core_initcall(init_elf_binfmt);
2215 module_exit(exit_elf_binfmt);
2216 MODULE_LICENSE("GPL");
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