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