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arm: Add devicetree fixup machine function
[linux/fpc-iii.git] / fs / binfmt_elf.c
blob3892c1a2324143498f3e62fc171a0f5cdc6c44c9
1 /*
2 * linux/fs/binfmt_elf.c
3 *
4 * These are the functions used to load ELF format executables as used
5 * on SVr4 machines. Information on the format may be found in the book
6 * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
7 * Tools".
8 *
9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
10 */
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/fs.h>
15 #include <linux/mm.h>
16 #include <linux/mman.h>
17 #include <linux/errno.h>
18 #include <linux/signal.h>
19 #include <linux/binfmts.h>
20 #include <linux/string.h>
21 #include <linux/file.h>
22 #include <linux/slab.h>
23 #include <linux/personality.h>
24 #include <linux/elfcore.h>
25 #include <linux/init.h>
26 #include <linux/highuid.h>
27 #include <linux/compiler.h>
28 #include <linux/highmem.h>
29 #include <linux/pagemap.h>
30 #include <linux/vmalloc.h>
31 #include <linux/security.h>
32 #include <linux/random.h>
33 #include <linux/elf.h>
34 #include <linux/utsname.h>
35 #include <linux/coredump.h>
36 #include <linux/sched.h>
37 #include <asm/uaccess.h>
38 #include <asm/param.h>
39 #include <asm/page.h>
40
41 #ifndef user_long_t
42 #define user_long_t long
43 #endif
44 #ifndef user_siginfo_t
45 #define user_siginfo_t siginfo_t
46 #endif
47
48 static int load_elf_binary(struct linux_binprm *bprm);
49 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
50 int, int, unsigned long);
51
52 #ifdef CONFIG_USELIB
53 static int load_elf_library(struct file *);
54 #else
55 #define load_elf_library NULL
56 #endif
57
58 /*
59 * If we don't support core dumping, then supply a NULL so we
60 * don't even try.
61 */
62 #ifdef CONFIG_ELF_CORE
63 static int elf_core_dump(struct coredump_params *cprm);
64 #else
65 #define elf_core_dump NULL
66 #endif
67
68 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
69 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
70 #else
71 #define ELF_MIN_ALIGN PAGE_SIZE
72 #endif
73
74 #ifndef ELF_CORE_EFLAGS
75 #define ELF_CORE_EFLAGS 0
76 #endif
77
78 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
79 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
80 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
81
82 static struct linux_binfmt elf_format = {
83 .module = THIS_MODULE,
84 .load_binary = load_elf_binary,
85 .load_shlib = load_elf_library,
86 .core_dump = elf_core_dump,
87 .min_coredump = ELF_EXEC_PAGESIZE,
88 };
89
90 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
91
92 static int set_brk(unsigned long start, unsigned long end)
93 {
94 start = ELF_PAGEALIGN(start);
95 end = ELF_PAGEALIGN(end);
96 if (end > start) {
97 unsigned long addr;
98 addr = vm_brk(start, end - start);
99 if (BAD_ADDR(addr))
100 return addr;
101 }
102 current->mm->start_brk = current->mm->brk = end;
103 return 0;
104 }
105
106 /* We need to explicitly zero any fractional pages
107 after the data section (i.e. bss). This would
108 contain the junk from the file that should not
109 be in memory
110 */
111 static int padzero(unsigned long elf_bss)
112 {
113 unsigned long nbyte;
114
115 nbyte = ELF_PAGEOFFSET(elf_bss);
116 if (nbyte) {
117 nbyte = ELF_MIN_ALIGN - nbyte;
118 if (clear_user((void __user *) elf_bss, nbyte))
119 return -EFAULT;
120 }
121 return 0;
122 }
123
124 /* Let's use some macros to make this stack manipulation a little clearer */
125 #ifdef CONFIG_STACK_GROWSUP
126 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
127 #define STACK_ROUND(sp, items) \
128 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
129 #define STACK_ALLOC(sp, len) ({ \
130 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
131 old_sp; })
132 #else
133 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
134 #define STACK_ROUND(sp, items) \
135 (((unsigned long) (sp - items)) &~ 15UL)
136 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
137 #endif
138
139 #ifndef ELF_BASE_PLATFORM
140 /*
141 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
142 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
143 * will be copied to the user stack in the same manner as AT_PLATFORM.
144 */
145 #define ELF_BASE_PLATFORM NULL
146 #endif
147
148 static int
149 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
150 unsigned long load_addr, unsigned long interp_load_addr)
151 {
152 unsigned long p = bprm->p;
153 int argc = bprm->argc;
154 int envc = bprm->envc;
155 elf_addr_t __user *argv;
156 elf_addr_t __user *envp;
157 elf_addr_t __user *sp;
158 elf_addr_t __user *u_platform;
159 elf_addr_t __user *u_base_platform;
160 elf_addr_t __user *u_rand_bytes;
161 const char *k_platform = ELF_PLATFORM;
162 const char *k_base_platform = ELF_BASE_PLATFORM;
163 unsigned char k_rand_bytes[16];
164 int items;
165 elf_addr_t *elf_info;
166 int ei_index = 0;
167 const struct cred *cred = current_cred();
168 struct vm_area_struct *vma;
169
170 /*
171 * In some cases (e.g. Hyper-Threading), we want to avoid L1
172 * evictions by the processes running on the same package. One
173 * thing we can do is to shuffle the initial stack for them.
174 */
175
176 p = arch_align_stack(p);
177
178 /*
179 * If this architecture has a platform capability string, copy it
180 * to userspace. In some cases (Sparc), this info is impossible
181 * for userspace to get any other way, in others (i386) it is
182 * merely difficult.
183 */
184 u_platform = NULL;
185 if (k_platform) {
186 size_t len = strlen(k_platform) + 1;
187
188 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
189 if (__copy_to_user(u_platform, k_platform, len))
190 return -EFAULT;
191 }
192
193 /*
194 * If this architecture has a "base" platform capability
195 * string, copy it to userspace.
196 */
197 u_base_platform = NULL;
198 if (k_base_platform) {
199 size_t len = strlen(k_base_platform) + 1;
200
201 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
202 if (__copy_to_user(u_base_platform, k_base_platform, len))
203 return -EFAULT;
204 }
205
206 /*
207 * Generate 16 random bytes for userspace PRNG seeding.
208 */
209 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
210 u_rand_bytes = (elf_addr_t __user *)
211 STACK_ALLOC(p, sizeof(k_rand_bytes));
212 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
213 return -EFAULT;
214
215 /* Create the ELF interpreter info */
216 elf_info = (elf_addr_t *)current->mm->saved_auxv;
217 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
218 #define NEW_AUX_ENT(id, val) \
219 do { \
220 elf_info[ei_index++] = id; \
221 elf_info[ei_index++] = val; \
222 } while (0)
223
224 #ifdef ARCH_DLINFO
225 /*
226 * ARCH_DLINFO must come first so PPC can do its special alignment of
227 * AUXV.
228 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
229 * ARCH_DLINFO changes
230 */
231 ARCH_DLINFO;
232 #endif
233 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
234 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
235 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
236 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
237 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
238 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
239 NEW_AUX_ENT(AT_BASE, interp_load_addr);
240 NEW_AUX_ENT(AT_FLAGS, 0);
241 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
242 NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
243 NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
244 NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
245 NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
246 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
247 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
248 #ifdef ELF_HWCAP2
249 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
250 #endif
251 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
252 if (k_platform) {
253 NEW_AUX_ENT(AT_PLATFORM,
254 (elf_addr_t)(unsigned long)u_platform);
255 }
256 if (k_base_platform) {
257 NEW_AUX_ENT(AT_BASE_PLATFORM,
258 (elf_addr_t)(unsigned long)u_base_platform);
259 }
260 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
261 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
262 }
263 #undef NEW_AUX_ENT
264 /* AT_NULL is zero; clear the rest too */
265 memset(&elf_info[ei_index], 0,
266 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
267
268 /* And advance past the AT_NULL entry. */
269 ei_index += 2;
270
271 sp = STACK_ADD(p, ei_index);
272
273 items = (argc + 1) + (envc + 1) + 1;
274 bprm->p = STACK_ROUND(sp, items);
275
276 /* Point sp at the lowest address on the stack */
277 #ifdef CONFIG_STACK_GROWSUP
278 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
279 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
280 #else
281 sp = (elf_addr_t __user *)bprm->p;
282 #endif
283
284
285 /*
286 * Grow the stack manually; some architectures have a limit on how
287 * far ahead a user-space access may be in order to grow the stack.
288 */
289 vma = find_extend_vma(current->mm, bprm->p);
290 if (!vma)
291 return -EFAULT;
292
293 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
294 if (__put_user(argc, sp++))
295 return -EFAULT;
296 argv = sp;
297 envp = argv + argc + 1;
298
299 /* Populate argv and envp */
300 p = current->mm->arg_end = current->mm->arg_start;
301 while (argc-- > 0) {
302 size_t len;
303 if (__put_user((elf_addr_t)p, argv++))
304 return -EFAULT;
305 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
306 if (!len || len > MAX_ARG_STRLEN)
307 return -EINVAL;
308 p += len;
309 }
310 if (__put_user(0, argv))
311 return -EFAULT;
312 current->mm->arg_end = current->mm->env_start = p;
313 while (envc-- > 0) {
314 size_t len;
315 if (__put_user((elf_addr_t)p, envp++))
316 return -EFAULT;
317 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
318 if (!len || len > MAX_ARG_STRLEN)
319 return -EINVAL;
320 p += len;
321 }
322 if (__put_user(0, envp))
323 return -EFAULT;
324 current->mm->env_end = p;
325
326 /* Put the elf_info on the stack in the right place. */
327 sp = (elf_addr_t __user *)envp + 1;
328 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
329 return -EFAULT;
330 return 0;
331 }
332
333 #ifndef elf_map
334
335 static unsigned long elf_map(struct file *filep, unsigned long addr,
336 struct elf_phdr *eppnt, int prot, int type,
337 unsigned long total_size)
338 {
339 unsigned long map_addr;
340 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
341 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
342 addr = ELF_PAGESTART(addr);
343 size = ELF_PAGEALIGN(size);
344
345 /* mmap() will return -EINVAL if given a zero size, but a
346 * segment with zero filesize is perfectly valid */
347 if (!size)
348 return addr;
349
350 /*
351 * total_size is the size of the ELF (interpreter) image.
352 * The _first_ mmap needs to know the full size, otherwise
353 * randomization might put this image into an overlapping
354 * position with the ELF binary image. (since size < total_size)
355 * So we first map the 'big' image - and unmap the remainder at
356 * the end. (which unmap is needed for ELF images with holes.)
357 */
358 if (total_size) {
359 total_size = ELF_PAGEALIGN(total_size);
360 map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
361 if (!BAD_ADDR(map_addr))
362 vm_munmap(map_addr+size, total_size-size);
363 } else
364 map_addr = vm_mmap(filep, addr, size, prot, type, off);
365
366 return(map_addr);
367 }
368
369 #endif /* !elf_map */
370
371 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
372 {
373 int i, first_idx = -1, last_idx = -1;
374
375 for (i = 0; i < nr; i++) {
376 if (cmds[i].p_type == PT_LOAD) {
377 last_idx = i;
378 if (first_idx == -1)
379 first_idx = i;
380 }
381 }
382 if (first_idx == -1)
383 return 0;
384
385 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
386 ELF_PAGESTART(cmds[first_idx].p_vaddr);
387 }
388
389
390 /* This is much more generalized than the library routine read function,
391 so we keep this separate. Technically the library read function
392 is only provided so that we can read a.out libraries that have
393 an ELF header */
394
395 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
396 struct file *interpreter, unsigned long *interp_map_addr,
397 unsigned long no_base)
398 {
399 struct elf_phdr *elf_phdata;
400 struct elf_phdr *eppnt;
401 unsigned long load_addr = 0;
402 int load_addr_set = 0;
403 unsigned long last_bss = 0, elf_bss = 0;
404 unsigned long error = ~0UL;
405 unsigned long total_size;
406 int retval, i, size;
407
408 /* First of all, some simple consistency checks */
409 if (interp_elf_ex->e_type != ET_EXEC &&
410 interp_elf_ex->e_type != ET_DYN)
411 goto out;
412 if (!elf_check_arch(interp_elf_ex))
413 goto out;
414 if (!interpreter->f_op->mmap)
415 goto out;
416
417 /*
418 * If the size of this structure has changed, then punt, since
419 * we will be doing the wrong thing.
420 */
421 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
422 goto out;
423 if (interp_elf_ex->e_phnum < 1 ||
424 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
425 goto out;
426
427 /* Now read in all of the header information */
428 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
429 if (size > ELF_MIN_ALIGN)
430 goto out;
431 elf_phdata = kmalloc(size, GFP_KERNEL);
432 if (!elf_phdata)
433 goto out;
434
435 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
436 (char *)elf_phdata, size);
437 error = -EIO;
438 if (retval != size) {
439 if (retval < 0)
440 error = retval;
441 goto out_close;
442 }
443
444 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
445 if (!total_size) {
446 error = -EINVAL;
447 goto out_close;
448 }
449
450 eppnt = elf_phdata;
451 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
452 if (eppnt->p_type == PT_LOAD) {
453 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
454 int elf_prot = 0;
455 unsigned long vaddr = 0;
456 unsigned long k, map_addr;
457
458 if (eppnt->p_flags & PF_R)
459 elf_prot = PROT_READ;
460 if (eppnt->p_flags & PF_W)
461 elf_prot |= PROT_WRITE;
462 if (eppnt->p_flags & PF_X)
463 elf_prot |= PROT_EXEC;
464 vaddr = eppnt->p_vaddr;
465 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
466 elf_type |= MAP_FIXED;
467 else if (no_base && interp_elf_ex->e_type == ET_DYN)
468 load_addr = -vaddr;
469
470 map_addr = elf_map(interpreter, load_addr + vaddr,
471 eppnt, elf_prot, elf_type, total_size);
472 total_size = 0;
473 if (!*interp_map_addr)
474 *interp_map_addr = map_addr;
475 error = map_addr;
476 if (BAD_ADDR(map_addr))
477 goto out_close;
478
479 if (!load_addr_set &&
480 interp_elf_ex->e_type == ET_DYN) {
481 load_addr = map_addr - ELF_PAGESTART(vaddr);
482 load_addr_set = 1;
483 }
484
485 /*
486 * Check to see if the section's size will overflow the
487 * allowed task size. Note that p_filesz must always be
488 * <= p_memsize so it's only necessary to check p_memsz.
489 */
490 k = load_addr + eppnt->p_vaddr;
491 if (BAD_ADDR(k) ||
492 eppnt->p_filesz > eppnt->p_memsz ||
493 eppnt->p_memsz > TASK_SIZE ||
494 TASK_SIZE - eppnt->p_memsz < k) {
495 error = -ENOMEM;
496 goto out_close;
497 }
498
499 /*
500 * Find the end of the file mapping for this phdr, and
501 * keep track of the largest address we see for this.
502 */
503 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
504 if (k > elf_bss)
505 elf_bss = k;
506
507 /*
508 * Do the same thing for the memory mapping - between
509 * elf_bss and last_bss is the bss section.
510 */
511 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
512 if (k > last_bss)
513 last_bss = k;
514 }
515 }
516
517 if (last_bss > elf_bss) {
518 /*
519 * Now fill out the bss section. First pad the last page up
520 * to the page boundary, and then perform a mmap to make sure
521 * that there are zero-mapped pages up to and including the
522 * last bss page.
523 */
524 if (padzero(elf_bss)) {
525 error = -EFAULT;
526 goto out_close;
527 }
528
529 /* What we have mapped so far */
530 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
531
532 /* Map the last of the bss segment */
533 error = vm_brk(elf_bss, last_bss - elf_bss);
534 if (BAD_ADDR(error))
535 goto out_close;
536 }
537
538 error = load_addr;
539
540 out_close:
541 kfree(elf_phdata);
542 out:
543 return error;
544 }
545
546 /*
547 * These are the functions used to load ELF style executables and shared
548 * libraries. There is no binary dependent code anywhere else.
549 */
550
551 #ifndef STACK_RND_MASK
552 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
553 #endif
554
555 static unsigned long randomize_stack_top(unsigned long stack_top)
556 {
557 unsigned int random_variable = 0;
558
559 if ((current->flags & PF_RANDOMIZE) &&
560 !(current->personality & ADDR_NO_RANDOMIZE)) {
561 random_variable = get_random_int() & STACK_RND_MASK;
562 random_variable <<= PAGE_SHIFT;
563 }
564 #ifdef CONFIG_STACK_GROWSUP
565 return PAGE_ALIGN(stack_top) + random_variable;
566 #else
567 return PAGE_ALIGN(stack_top) - random_variable;
568 #endif
569 }
570
571 static int load_elf_binary(struct linux_binprm *bprm)
572 {
573 struct file *interpreter = NULL; /* to shut gcc up */
574 unsigned long load_addr = 0, load_bias = 0;
575 int load_addr_set = 0;
576 char * elf_interpreter = NULL;
577 unsigned long error;
578 struct elf_phdr *elf_ppnt, *elf_phdata;
579 unsigned long elf_bss, elf_brk;
580 int retval, i;
581 unsigned int size;
582 unsigned long elf_entry;
583 unsigned long interp_load_addr = 0;
584 unsigned long start_code, end_code, start_data, end_data;
585 unsigned long reloc_func_desc __maybe_unused = 0;
586 int executable_stack = EXSTACK_DEFAULT;
587 struct pt_regs *regs = current_pt_regs();
588 struct {
589 struct elfhdr elf_ex;
590 struct elfhdr interp_elf_ex;
591 } *loc;
592
593 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
594 if (!loc) {
595 retval = -ENOMEM;
596 goto out_ret;
597 }
598
599 /* Get the exec-header */
600 loc->elf_ex = *((struct elfhdr *)bprm->buf);
601
602 retval = -ENOEXEC;
603 /* First of all, some simple consistency checks */
604 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
605 goto out;
606
607 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
608 goto out;
609 if (!elf_check_arch(&loc->elf_ex))
610 goto out;
611 if (!bprm->file->f_op->mmap)
612 goto out;
613
614 /* Now read in all of the header information */
615 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
616 goto out;
617 if (loc->elf_ex.e_phnum < 1 ||
618 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
619 goto out;
620 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
621 retval = -ENOMEM;
622 elf_phdata = kmalloc(size, GFP_KERNEL);
623 if (!elf_phdata)
624 goto out;
625
626 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
627 (char *)elf_phdata, size);
628 if (retval != size) {
629 if (retval >= 0)
630 retval = -EIO;
631 goto out_free_ph;
632 }
633
634 elf_ppnt = elf_phdata;
635 elf_bss = 0;
636 elf_brk = 0;
637
638 start_code = ~0UL;
639 end_code = 0;
640 start_data = 0;
641 end_data = 0;
642
643 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
644 if (elf_ppnt->p_type == PT_INTERP) {
645 /* This is the program interpreter used for
646 * shared libraries - for now assume that this
647 * is an a.out format binary
648 */
649 retval = -ENOEXEC;
650 if (elf_ppnt->p_filesz > PATH_MAX ||
651 elf_ppnt->p_filesz < 2)
652 goto out_free_ph;
653
654 retval = -ENOMEM;
655 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
656 GFP_KERNEL);
657 if (!elf_interpreter)
658 goto out_free_ph;
659
660 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
661 elf_interpreter,
662 elf_ppnt->p_filesz);
663 if (retval != elf_ppnt->p_filesz) {
664 if (retval >= 0)
665 retval = -EIO;
666 goto out_free_interp;
667 }
668 /* make sure path is NULL terminated */
669 retval = -ENOEXEC;
670 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
671 goto out_free_interp;
672
673 interpreter = open_exec(elf_interpreter);
674 retval = PTR_ERR(interpreter);
675 if (IS_ERR(interpreter))
676 goto out_free_interp;
677
678 /*
679 * If the binary is not readable then enforce
680 * mm->dumpable = 0 regardless of the interpreter's
681 * permissions.
682 */
683 would_dump(bprm, interpreter);
684
685 retval = kernel_read(interpreter, 0, bprm->buf,
686 BINPRM_BUF_SIZE);
687 if (retval != BINPRM_BUF_SIZE) {
688 if (retval >= 0)
689 retval = -EIO;
690 goto out_free_dentry;
691 }
692
693 /* Get the exec headers */
694 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
695 break;
696 }
697 elf_ppnt++;
698 }
699
700 elf_ppnt = elf_phdata;
701 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
702 if (elf_ppnt->p_type == PT_GNU_STACK) {
703 if (elf_ppnt->p_flags & PF_X)
704 executable_stack = EXSTACK_ENABLE_X;
705 else
706 executable_stack = EXSTACK_DISABLE_X;
707 break;
708 }
709
710 /* Some simple consistency checks for the interpreter */
711 if (elf_interpreter) {
712 retval = -ELIBBAD;
713 /* Not an ELF interpreter */
714 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
715 goto out_free_dentry;
716 /* Verify the interpreter has a valid arch */
717 if (!elf_check_arch(&loc->interp_elf_ex))
718 goto out_free_dentry;
719 }
720
721 /* Flush all traces of the currently running executable */
722 retval = flush_old_exec(bprm);
723 if (retval)
724 goto out_free_dentry;
725
726 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
727 may depend on the personality. */
728 SET_PERSONALITY(loc->elf_ex);
729 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
730 current->personality |= READ_IMPLIES_EXEC;
731
732 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
733 current->flags |= PF_RANDOMIZE;
734
735 setup_new_exec(bprm);
736
737 /* Do this so that we can load the interpreter, if need be. We will
738 change some of these later */
739 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
740 executable_stack);
741 if (retval < 0) {
742 send_sig(SIGKILL, current, 0);
743 goto out_free_dentry;
744 }
745
746 current->mm->start_stack = bprm->p;
747
748 /* Now we do a little grungy work by mmapping the ELF image into
749 the correct location in memory. */
750 for(i = 0, elf_ppnt = elf_phdata;
751 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
752 int elf_prot = 0, elf_flags;
753 unsigned long k, vaddr;
754
755 if (elf_ppnt->p_type != PT_LOAD)
756 continue;
757
758 if (unlikely (elf_brk > elf_bss)) {
759 unsigned long nbyte;
760
761 /* There was a PT_LOAD segment with p_memsz > p_filesz
762 before this one. Map anonymous pages, if needed,
763 and clear the area. */
764 retval = set_brk(elf_bss + load_bias,
765 elf_brk + load_bias);
766 if (retval) {
767 send_sig(SIGKILL, current, 0);
768 goto out_free_dentry;
769 }
770 nbyte = ELF_PAGEOFFSET(elf_bss);
771 if (nbyte) {
772 nbyte = ELF_MIN_ALIGN - nbyte;
773 if (nbyte > elf_brk - elf_bss)
774 nbyte = elf_brk - elf_bss;
775 if (clear_user((void __user *)elf_bss +
776 load_bias, nbyte)) {
777 /*
778 * This bss-zeroing can fail if the ELF
779 * file specifies odd protections. So
780 * we don't check the return value
781 */
782 }
783 }
784 }
785
786 if (elf_ppnt->p_flags & PF_R)
787 elf_prot |= PROT_READ;
788 if (elf_ppnt->p_flags & PF_W)
789 elf_prot |= PROT_WRITE;
790 if (elf_ppnt->p_flags & PF_X)
791 elf_prot |= PROT_EXEC;
792
793 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
794
795 vaddr = elf_ppnt->p_vaddr;
796 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
797 elf_flags |= MAP_FIXED;
798 } else if (loc->elf_ex.e_type == ET_DYN) {
799 /* Try and get dynamic programs out of the way of the
800 * default mmap base, as well as whatever program they
801 * might try to exec. This is because the brk will
802 * follow the loader, and is not movable. */
803 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
804 /* Memory randomization might have been switched off
805 * in runtime via sysctl or explicit setting of
806 * personality flags.
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 #ifdef CONFIG_USELIB
1010 /* This is really simpleminded and specialized - we are loading an
1011 a.out library that is given an ELF header. */
1012 static int load_elf_library(struct file *file)
1013 {
1014 struct elf_phdr *elf_phdata;
1015 struct elf_phdr *eppnt;
1016 unsigned long elf_bss, bss, len;
1017 int retval, error, i, j;
1018 struct elfhdr elf_ex;
1019
1020 error = -ENOEXEC;
1021 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1022 if (retval != sizeof(elf_ex))
1023 goto out;
1024
1025 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1026 goto out;
1027
1028 /* First of all, some simple consistency checks */
1029 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1030 !elf_check_arch(&elf_ex) || !file->f_op->mmap)
1031 goto out;
1032
1033 /* Now read in all of the header information */
1034
1035 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1036 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1037
1038 error = -ENOMEM;
1039 elf_phdata = kmalloc(j, GFP_KERNEL);
1040 if (!elf_phdata)
1041 goto out;
1042
1043 eppnt = elf_phdata;
1044 error = -ENOEXEC;
1045 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1046 if (retval != j)
1047 goto out_free_ph;
1048
1049 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1050 if ((eppnt + i)->p_type == PT_LOAD)
1051 j++;
1052 if (j != 1)
1053 goto out_free_ph;
1054
1055 while (eppnt->p_type != PT_LOAD)
1056 eppnt++;
1057
1058 /* Now use mmap to map the library into memory. */
1059 error = vm_mmap(file,
1060 ELF_PAGESTART(eppnt->p_vaddr),
1061 (eppnt->p_filesz +
1062 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1063 PROT_READ | PROT_WRITE | PROT_EXEC,
1064 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1065 (eppnt->p_offset -
1066 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1067 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1068 goto out_free_ph;
1069
1070 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1071 if (padzero(elf_bss)) {
1072 error = -EFAULT;
1073 goto out_free_ph;
1074 }
1075
1076 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1077 ELF_MIN_ALIGN - 1);
1078 bss = eppnt->p_memsz + eppnt->p_vaddr;
1079 if (bss > len)
1080 vm_brk(len, bss - len);
1081 error = 0;
1082
1083 out_free_ph:
1084 kfree(elf_phdata);
1085 out:
1086 return error;
1087 }
1088 #endif /* #ifdef CONFIG_USELIB */
1089
1090 #ifdef CONFIG_ELF_CORE
1091 /*
1092 * ELF core dumper
1093 *
1094 * Modelled on fs/exec.c:aout_core_dump()
1095 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1096 */
1097
1098 /*
1099 * The purpose of always_dump_vma() is to make sure that special kernel mappings
1100 * that are useful for post-mortem analysis are included in every core dump.
1101 * In that way we ensure that the core dump is fully interpretable later
1102 * without matching up the same kernel and hardware config to see what PC values
1103 * meant. These special mappings include - vDSO, vsyscall, and other
1104 * architecture specific mappings
1105 */
1106 static bool always_dump_vma(struct vm_area_struct *vma)
1107 {
1108 /* Any vsyscall mappings? */
1109 if (vma == get_gate_vma(vma->vm_mm))
1110 return true;
1111
1112 /*
1113 * Assume that all vmas with a .name op should always be dumped.
1114 * If this changes, a new vm_ops field can easily be added.
1115 */
1116 if (vma->vm_ops && vma->vm_ops->name && vma->vm_ops->name(vma))
1117 return true;
1118
1119 /*
1120 * arch_vma_name() returns non-NULL for special architecture mappings,
1121 * such as vDSO sections.
1122 */
1123 if (arch_vma_name(vma))
1124 return true;
1125
1126 return false;
1127 }
1128
1129 /*
1130 * Decide what to dump of a segment, part, all or none.
1131 */
1132 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1133 unsigned long mm_flags)
1134 {
1135 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1136
1137 /* always dump the vdso and vsyscall sections */
1138 if (always_dump_vma(vma))
1139 goto whole;
1140
1141 if (vma->vm_flags & VM_DONTDUMP)
1142 return 0;
1143
1144 /* Hugetlb memory check */
1145 if (vma->vm_flags & VM_HUGETLB) {
1146 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1147 goto whole;
1148 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1149 goto whole;
1150 return 0;
1151 }
1152
1153 /* Do not dump I/O mapped devices or special mappings */
1154 if (vma->vm_flags & VM_IO)
1155 return 0;
1156
1157 /* By default, dump shared memory if mapped from an anonymous file. */
1158 if (vma->vm_flags & VM_SHARED) {
1159 if (file_inode(vma->vm_file)->i_nlink == 0 ?
1160 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1161 goto whole;
1162 return 0;
1163 }
1164
1165 /* Dump segments that have been written to. */
1166 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1167 goto whole;
1168 if (vma->vm_file == NULL)
1169 return 0;
1170
1171 if (FILTER(MAPPED_PRIVATE))
1172 goto whole;
1173
1174 /*
1175 * If this looks like the beginning of a DSO or executable mapping,
1176 * check for an ELF header. If we find one, dump the first page to
1177 * aid in determining what was mapped here.
1178 */
1179 if (FILTER(ELF_HEADERS) &&
1180 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1181 u32 __user *header = (u32 __user *) vma->vm_start;
1182 u32 word;
1183 mm_segment_t fs = get_fs();
1184 /*
1185 * Doing it this way gets the constant folded by GCC.
1186 */
1187 union {
1188 u32 cmp;
1189 char elfmag[SELFMAG];
1190 } magic;
1191 BUILD_BUG_ON(SELFMAG != sizeof word);
1192 magic.elfmag[EI_MAG0] = ELFMAG0;
1193 magic.elfmag[EI_MAG1] = ELFMAG1;
1194 magic.elfmag[EI_MAG2] = ELFMAG2;
1195 magic.elfmag[EI_MAG3] = ELFMAG3;
1196 /*
1197 * Switch to the user "segment" for get_user(),
1198 * then put back what elf_core_dump() had in place.
1199 */
1200 set_fs(USER_DS);
1201 if (unlikely(get_user(word, header)))
1202 word = 0;
1203 set_fs(fs);
1204 if (word == magic.cmp)
1205 return PAGE_SIZE;
1206 }
1207
1208 #undef FILTER
1209
1210 return 0;
1211
1212 whole:
1213 return vma->vm_end - vma->vm_start;
1214 }
1215
1216 /* An ELF note in memory */
1217 struct memelfnote
1218 {
1219 const char *name;
1220 int type;
1221 unsigned int datasz;
1222 void *data;
1223 };
1224
1225 static int notesize(struct memelfnote *en)
1226 {
1227 int sz;
1228
1229 sz = sizeof(struct elf_note);
1230 sz += roundup(strlen(en->name) + 1, 4);
1231 sz += roundup(en->datasz, 4);
1232
1233 return sz;
1234 }
1235
1236 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1237 {
1238 struct elf_note en;
1239 en.n_namesz = strlen(men->name) + 1;
1240 en.n_descsz = men->datasz;
1241 en.n_type = men->type;
1242
1243 return dump_emit(cprm, &en, sizeof(en)) &&
1244 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1245 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1246 }
1247
1248 static void fill_elf_header(struct elfhdr *elf, int segs,
1249 u16 machine, u32 flags)
1250 {
1251 memset(elf, 0, sizeof(*elf));
1252
1253 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1254 elf->e_ident[EI_CLASS] = ELF_CLASS;
1255 elf->e_ident[EI_DATA] = ELF_DATA;
1256 elf->e_ident[EI_VERSION] = EV_CURRENT;
1257 elf->e_ident[EI_OSABI] = ELF_OSABI;
1258
1259 elf->e_type = ET_CORE;
1260 elf->e_machine = machine;
1261 elf->e_version = EV_CURRENT;
1262 elf->e_phoff = sizeof(struct elfhdr);
1263 elf->e_flags = flags;
1264 elf->e_ehsize = sizeof(struct elfhdr);
1265 elf->e_phentsize = sizeof(struct elf_phdr);
1266 elf->e_phnum = segs;
1267
1268 return;
1269 }
1270
1271 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1272 {
1273 phdr->p_type = PT_NOTE;
1274 phdr->p_offset = offset;
1275 phdr->p_vaddr = 0;
1276 phdr->p_paddr = 0;
1277 phdr->p_filesz = sz;
1278 phdr->p_memsz = 0;
1279 phdr->p_flags = 0;
1280 phdr->p_align = 0;
1281 return;
1282 }
1283
1284 static void fill_note(struct memelfnote *note, const char *name, int type,
1285 unsigned int sz, void *data)
1286 {
1287 note->name = name;
1288 note->type = type;
1289 note->datasz = sz;
1290 note->data = data;
1291 return;
1292 }
1293
1294 /*
1295 * fill up all the fields in prstatus from the given task struct, except
1296 * registers which need to be filled up separately.
1297 */
1298 static void fill_prstatus(struct elf_prstatus *prstatus,
1299 struct task_struct *p, long signr)
1300 {
1301 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1302 prstatus->pr_sigpend = p->pending.signal.sig[0];
1303 prstatus->pr_sighold = p->blocked.sig[0];
1304 rcu_read_lock();
1305 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1306 rcu_read_unlock();
1307 prstatus->pr_pid = task_pid_vnr(p);
1308 prstatus->pr_pgrp = task_pgrp_vnr(p);
1309 prstatus->pr_sid = task_session_vnr(p);
1310 if (thread_group_leader(p)) {
1311 struct task_cputime cputime;
1312
1313 /*
1314 * This is the record for the group leader. It shows the
1315 * group-wide total, not its individual thread total.
1316 */
1317 thread_group_cputime(p, &cputime);
1318 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1319 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1320 } else {
1321 cputime_t utime, stime;
1322
1323 task_cputime(p, &utime, &stime);
1324 cputime_to_timeval(utime, &prstatus->pr_utime);
1325 cputime_to_timeval(stime, &prstatus->pr_stime);
1326 }
1327 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1328 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1329 }
1330
1331 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1332 struct mm_struct *mm)
1333 {
1334 const struct cred *cred;
1335 unsigned int i, len;
1336
1337 /* first copy the parameters from user space */
1338 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1339
1340 len = mm->arg_end - mm->arg_start;
1341 if (len >= ELF_PRARGSZ)
1342 len = ELF_PRARGSZ-1;
1343 if (copy_from_user(&psinfo->pr_psargs,
1344 (const char __user *)mm->arg_start, len))
1345 return -EFAULT;
1346 for(i = 0; i < len; i++)
1347 if (psinfo->pr_psargs[i] == 0)
1348 psinfo->pr_psargs[i] = ' ';
1349 psinfo->pr_psargs[len] = 0;
1350
1351 rcu_read_lock();
1352 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1353 rcu_read_unlock();
1354 psinfo->pr_pid = task_pid_vnr(p);
1355 psinfo->pr_pgrp = task_pgrp_vnr(p);
1356 psinfo->pr_sid = task_session_vnr(p);
1357
1358 i = p->state ? ffz(~p->state) + 1 : 0;
1359 psinfo->pr_state = i;
1360 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1361 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1362 psinfo->pr_nice = task_nice(p);
1363 psinfo->pr_flag = p->flags;
1364 rcu_read_lock();
1365 cred = __task_cred(p);
1366 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1367 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1368 rcu_read_unlock();
1369 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1370
1371 return 0;
1372 }
1373
1374 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1375 {
1376 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1377 int i = 0;
1378 do
1379 i += 2;
1380 while (auxv[i - 2] != AT_NULL);
1381 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1382 }
1383
1384 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1385 const siginfo_t *siginfo)
1386 {
1387 mm_segment_t old_fs = get_fs();
1388 set_fs(KERNEL_DS);
1389 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
1390 set_fs(old_fs);
1391 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1392 }
1393
1394 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1395 /*
1396 * Format of NT_FILE note:
1397 *
1398 * long count -- how many files are mapped
1399 * long page_size -- units for file_ofs
1400 * array of [COUNT] elements of
1401 * long start
1402 * long end
1403 * long file_ofs
1404 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1405 */
1406 static int fill_files_note(struct memelfnote *note)
1407 {
1408 struct vm_area_struct *vma;
1409 unsigned count, size, names_ofs, remaining, n;
1410 user_long_t *data;
1411 user_long_t *start_end_ofs;
1412 char *name_base, *name_curpos;
1413
1414 /* *Estimated* file count and total data size needed */
1415 count = current->mm->map_count;
1416 size = count * 64;
1417
1418 names_ofs = (2 + 3 * count) * sizeof(data[0]);
1419 alloc:
1420 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1421 return -EINVAL;
1422 size = round_up(size, PAGE_SIZE);
1423 data = vmalloc(size);
1424 if (!data)
1425 return -ENOMEM;
1426
1427 start_end_ofs = data + 2;
1428 name_base = name_curpos = ((char *)data) + names_ofs;
1429 remaining = size - names_ofs;
1430 count = 0;
1431 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1432 struct file *file;
1433 const char *filename;
1434
1435 file = vma->vm_file;
1436 if (!file)
1437 continue;
1438 filename = d_path(&file->f_path, name_curpos, remaining);
1439 if (IS_ERR(filename)) {
1440 if (PTR_ERR(filename) == -ENAMETOOLONG) {
1441 vfree(data);
1442 size = size * 5 / 4;
1443 goto alloc;
1444 }
1445 continue;
1446 }
1447
1448 /* d_path() fills at the end, move name down */
1449 /* n = strlen(filename) + 1: */
1450 n = (name_curpos + remaining) - filename;
1451 remaining = filename - name_curpos;
1452 memmove(name_curpos, filename, n);
1453 name_curpos += n;
1454
1455 *start_end_ofs++ = vma->vm_start;
1456 *start_end_ofs++ = vma->vm_end;
1457 *start_end_ofs++ = vma->vm_pgoff;
1458 count++;
1459 }
1460
1461 /* Now we know exact count of files, can store it */
1462 data[0] = count;
1463 data[1] = PAGE_SIZE;
1464 /*
1465 * Count usually is less than current->mm->map_count,
1466 * we need to move filenames down.
1467 */
1468 n = current->mm->map_count - count;
1469 if (n != 0) {
1470 unsigned shift_bytes = n * 3 * sizeof(data[0]);
1471 memmove(name_base - shift_bytes, name_base,
1472 name_curpos - name_base);
1473 name_curpos -= shift_bytes;
1474 }
1475
1476 size = name_curpos - (char *)data;
1477 fill_note(note, "CORE", NT_FILE, size, data);
1478 return 0;
1479 }
1480
1481 #ifdef CORE_DUMP_USE_REGSET
1482 #include <linux/regset.h>
1483
1484 struct elf_thread_core_info {
1485 struct elf_thread_core_info *next;
1486 struct task_struct *task;
1487 struct elf_prstatus prstatus;
1488 struct memelfnote notes[0];
1489 };
1490
1491 struct elf_note_info {
1492 struct elf_thread_core_info *thread;
1493 struct memelfnote psinfo;
1494 struct memelfnote signote;
1495 struct memelfnote auxv;
1496 struct memelfnote files;
1497 user_siginfo_t csigdata;
1498 size_t size;
1499 int thread_notes;
1500 };
1501
1502 /*
1503 * When a regset has a writeback hook, we call it on each thread before
1504 * dumping user memory. On register window machines, this makes sure the
1505 * user memory backing the register data is up to date before we read it.
1506 */
1507 static void do_thread_regset_writeback(struct task_struct *task,
1508 const struct user_regset *regset)
1509 {
1510 if (regset->writeback)
1511 regset->writeback(task, regset, 1);
1512 }
1513
1514 #ifndef PR_REG_SIZE
1515 #define PR_REG_SIZE(S) sizeof(S)
1516 #endif
1517
1518 #ifndef PRSTATUS_SIZE
1519 #define PRSTATUS_SIZE(S) sizeof(S)
1520 #endif
1521
1522 #ifndef PR_REG_PTR
1523 #define PR_REG_PTR(S) (&((S)->pr_reg))
1524 #endif
1525
1526 #ifndef SET_PR_FPVALID
1527 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V))
1528 #endif
1529
1530 static int fill_thread_core_info(struct elf_thread_core_info *t,
1531 const struct user_regset_view *view,
1532 long signr, size_t *total)
1533 {
1534 unsigned int i;
1535
1536 /*
1537 * NT_PRSTATUS is the one special case, because the regset data
1538 * goes into the pr_reg field inside the note contents, rather
1539 * than being the whole note contents. We fill the reset in here.
1540 * We assume that regset 0 is NT_PRSTATUS.
1541 */
1542 fill_prstatus(&t->prstatus, t->task, signr);
1543 (void) view->regsets[0].get(t->task, &view->regsets[0],
1544 0, PR_REG_SIZE(t->prstatus.pr_reg),
1545 PR_REG_PTR(&t->prstatus), NULL);
1546
1547 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1548 PRSTATUS_SIZE(t->prstatus), &t->prstatus);
1549 *total += notesize(&t->notes[0]);
1550
1551 do_thread_regset_writeback(t->task, &view->regsets[0]);
1552
1553 /*
1554 * Each other regset might generate a note too. For each regset
1555 * that has no core_note_type or is inactive, we leave t->notes[i]
1556 * all zero and we'll know to skip writing it later.
1557 */
1558 for (i = 1; i < view->n; ++i) {
1559 const struct user_regset *regset = &view->regsets[i];
1560 do_thread_regset_writeback(t->task, regset);
1561 if (regset->core_note_type && regset->get &&
1562 (!regset->active || regset->active(t->task, regset))) {
1563 int ret;
1564 size_t size = regset->n * regset->size;
1565 void *data = kmalloc(size, GFP_KERNEL);
1566 if (unlikely(!data))
1567 return 0;
1568 ret = regset->get(t->task, regset,
1569 0, size, data, NULL);
1570 if (unlikely(ret))
1571 kfree(data);
1572 else {
1573 if (regset->core_note_type != NT_PRFPREG)
1574 fill_note(&t->notes[i], "LINUX",
1575 regset->core_note_type,
1576 size, data);
1577 else {
1578 SET_PR_FPVALID(&t->prstatus, 1);
1579 fill_note(&t->notes[i], "CORE",
1580 NT_PRFPREG, size, data);
1581 }
1582 *total += notesize(&t->notes[i]);
1583 }
1584 }
1585 }
1586
1587 return 1;
1588 }
1589
1590 static int fill_note_info(struct elfhdr *elf, int phdrs,
1591 struct elf_note_info *info,
1592 const siginfo_t *siginfo, struct pt_regs *regs)
1593 {
1594 struct task_struct *dump_task = current;
1595 const struct user_regset_view *view = task_user_regset_view(dump_task);
1596 struct elf_thread_core_info *t;
1597 struct elf_prpsinfo *psinfo;
1598 struct core_thread *ct;
1599 unsigned int i;
1600
1601 info->size = 0;
1602 info->thread = NULL;
1603
1604 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1605 if (psinfo == NULL) {
1606 info->psinfo.data = NULL; /* So we don't free this wrongly */
1607 return 0;
1608 }
1609
1610 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1611
1612 /*
1613 * Figure out how many notes we're going to need for each thread.
1614 */
1615 info->thread_notes = 0;
1616 for (i = 0; i < view->n; ++i)
1617 if (view->regsets[i].core_note_type != 0)
1618 ++info->thread_notes;
1619
1620 /*
1621 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1622 * since it is our one special case.
1623 */
1624 if (unlikely(info->thread_notes == 0) ||
1625 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1626 WARN_ON(1);
1627 return 0;
1628 }
1629
1630 /*
1631 * Initialize the ELF file header.
1632 */
1633 fill_elf_header(elf, phdrs,
1634 view->e_machine, view->e_flags);
1635
1636 /*
1637 * Allocate a structure for each thread.
1638 */
1639 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1640 t = kzalloc(offsetof(struct elf_thread_core_info,
1641 notes[info->thread_notes]),
1642 GFP_KERNEL);
1643 if (unlikely(!t))
1644 return 0;
1645
1646 t->task = ct->task;
1647 if (ct->task == dump_task || !info->thread) {
1648 t->next = info->thread;
1649 info->thread = t;
1650 } else {
1651 /*
1652 * Make sure to keep the original task at
1653 * the head of the list.
1654 */
1655 t->next = info->thread->next;
1656 info->thread->next = t;
1657 }
1658 }
1659
1660 /*
1661 * Now fill in each thread's information.
1662 */
1663 for (t = info->thread; t != NULL; t = t->next)
1664 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1665 return 0;
1666
1667 /*
1668 * Fill in the two process-wide notes.
1669 */
1670 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1671 info->size += notesize(&info->psinfo);
1672
1673 fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1674 info->size += notesize(&info->signote);
1675
1676 fill_auxv_note(&info->auxv, current->mm);
1677 info->size += notesize(&info->auxv);
1678
1679 if (fill_files_note(&info->files) == 0)
1680 info->size += notesize(&info->files);
1681
1682 return 1;
1683 }
1684
1685 static size_t get_note_info_size(struct elf_note_info *info)
1686 {
1687 return info->size;
1688 }
1689
1690 /*
1691 * Write all the notes for each thread. When writing the first thread, the
1692 * process-wide notes are interleaved after the first thread-specific note.
1693 */
1694 static int write_note_info(struct elf_note_info *info,
1695 struct coredump_params *cprm)
1696 {
1697 bool first = true;
1698 struct elf_thread_core_info *t = info->thread;
1699
1700 do {
1701 int i;
1702
1703 if (!writenote(&t->notes[0], cprm))
1704 return 0;
1705
1706 if (first && !writenote(&info->psinfo, cprm))
1707 return 0;
1708 if (first && !writenote(&info->signote, cprm))
1709 return 0;
1710 if (first && !writenote(&info->auxv, cprm))
1711 return 0;
1712 if (first && info->files.data &&
1713 !writenote(&info->files, cprm))
1714 return 0;
1715
1716 for (i = 1; i < info->thread_notes; ++i)
1717 if (t->notes[i].data &&
1718 !writenote(&t->notes[i], cprm))
1719 return 0;
1720
1721 first = false;
1722 t = t->next;
1723 } while (t);
1724
1725 return 1;
1726 }
1727
1728 static void free_note_info(struct elf_note_info *info)
1729 {
1730 struct elf_thread_core_info *threads = info->thread;
1731 while (threads) {
1732 unsigned int i;
1733 struct elf_thread_core_info *t = threads;
1734 threads = t->next;
1735 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1736 for (i = 1; i < info->thread_notes; ++i)
1737 kfree(t->notes[i].data);
1738 kfree(t);
1739 }
1740 kfree(info->psinfo.data);
1741 vfree(info->files.data);
1742 }
1743
1744 #else
1745
1746 /* Here is the structure in which status of each thread is captured. */
1747 struct elf_thread_status
1748 {
1749 struct list_head list;
1750 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1751 elf_fpregset_t fpu; /* NT_PRFPREG */
1752 struct task_struct *thread;
1753 #ifdef ELF_CORE_COPY_XFPREGS
1754 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1755 #endif
1756 struct memelfnote notes[3];
1757 int num_notes;
1758 };
1759
1760 /*
1761 * In order to add the specific thread information for the elf file format,
1762 * we need to keep a linked list of every threads pr_status and then create
1763 * a single section for them in the final core file.
1764 */
1765 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1766 {
1767 int sz = 0;
1768 struct task_struct *p = t->thread;
1769 t->num_notes = 0;
1770
1771 fill_prstatus(&t->prstatus, p, signr);
1772 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1773
1774 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1775 &(t->prstatus));
1776 t->num_notes++;
1777 sz += notesize(&t->notes[0]);
1778
1779 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1780 &t->fpu))) {
1781 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1782 &(t->fpu));
1783 t->num_notes++;
1784 sz += notesize(&t->notes[1]);
1785 }
1786
1787 #ifdef ELF_CORE_COPY_XFPREGS
1788 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1789 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1790 sizeof(t->xfpu), &t->xfpu);
1791 t->num_notes++;
1792 sz += notesize(&t->notes[2]);
1793 }
1794 #endif
1795 return sz;
1796 }
1797
1798 struct elf_note_info {
1799 struct memelfnote *notes;
1800 struct memelfnote *notes_files;
1801 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1802 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1803 struct list_head thread_list;
1804 elf_fpregset_t *fpu;
1805 #ifdef ELF_CORE_COPY_XFPREGS
1806 elf_fpxregset_t *xfpu;
1807 #endif
1808 user_siginfo_t csigdata;
1809 int thread_status_size;
1810 int numnote;
1811 };
1812
1813 static int elf_note_info_init(struct elf_note_info *info)
1814 {
1815 memset(info, 0, sizeof(*info));
1816 INIT_LIST_HEAD(&info->thread_list);
1817
1818 /* Allocate space for ELF notes */
1819 info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL);
1820 if (!info->notes)
1821 return 0;
1822 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1823 if (!info->psinfo)
1824 return 0;
1825 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1826 if (!info->prstatus)
1827 return 0;
1828 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1829 if (!info->fpu)
1830 return 0;
1831 #ifdef ELF_CORE_COPY_XFPREGS
1832 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1833 if (!info->xfpu)
1834 return 0;
1835 #endif
1836 return 1;
1837 }
1838
1839 static int fill_note_info(struct elfhdr *elf, int phdrs,
1840 struct elf_note_info *info,
1841 const siginfo_t *siginfo, struct pt_regs *regs)
1842 {
1843 struct list_head *t;
1844 struct core_thread *ct;
1845 struct elf_thread_status *ets;
1846
1847 if (!elf_note_info_init(info))
1848 return 0;
1849
1850 for (ct = current->mm->core_state->dumper.next;
1851 ct; ct = ct->next) {
1852 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1853 if (!ets)
1854 return 0;
1855
1856 ets->thread = ct->task;
1857 list_add(&ets->list, &info->thread_list);
1858 }
1859
1860 list_for_each(t, &info->thread_list) {
1861 int sz;
1862
1863 ets = list_entry(t, struct elf_thread_status, list);
1864 sz = elf_dump_thread_status(siginfo->si_signo, ets);
1865 info->thread_status_size += sz;
1866 }
1867 /* now collect the dump for the current */
1868 memset(info->prstatus, 0, sizeof(*info->prstatus));
1869 fill_prstatus(info->prstatus, current, siginfo->si_signo);
1870 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1871
1872 /* Set up header */
1873 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
1874
1875 /*
1876 * Set up the notes in similar form to SVR4 core dumps made
1877 * with info from their /proc.
1878 */
1879
1880 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1881 sizeof(*info->prstatus), info->prstatus);
1882 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1883 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1884 sizeof(*info->psinfo), info->psinfo);
1885
1886 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
1887 fill_auxv_note(info->notes + 3, current->mm);
1888 info->numnote = 4;
1889
1890 if (fill_files_note(info->notes + info->numnote) == 0) {
1891 info->notes_files = info->notes + info->numnote;
1892 info->numnote++;
1893 }
1894
1895 /* Try to dump the FPU. */
1896 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1897 info->fpu);
1898 if (info->prstatus->pr_fpvalid)
1899 fill_note(info->notes + info->numnote++,
1900 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1901 #ifdef ELF_CORE_COPY_XFPREGS
1902 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1903 fill_note(info->notes + info->numnote++,
1904 "LINUX", ELF_CORE_XFPREG_TYPE,
1905 sizeof(*info->xfpu), info->xfpu);
1906 #endif
1907
1908 return 1;
1909 }
1910
1911 static size_t get_note_info_size(struct elf_note_info *info)
1912 {
1913 int sz = 0;
1914 int i;
1915
1916 for (i = 0; i < info->numnote; i++)
1917 sz += notesize(info->notes + i);
1918
1919 sz += info->thread_status_size;
1920
1921 return sz;
1922 }
1923
1924 static int write_note_info(struct elf_note_info *info,
1925 struct coredump_params *cprm)
1926 {
1927 int i;
1928 struct list_head *t;
1929
1930 for (i = 0; i < info->numnote; i++)
1931 if (!writenote(info->notes + i, cprm))
1932 return 0;
1933
1934 /* write out the thread status notes section */
1935 list_for_each(t, &info->thread_list) {
1936 struct elf_thread_status *tmp =
1937 list_entry(t, struct elf_thread_status, list);
1938
1939 for (i = 0; i < tmp->num_notes; i++)
1940 if (!writenote(&tmp->notes[i], cprm))
1941 return 0;
1942 }
1943
1944 return 1;
1945 }
1946
1947 static void free_note_info(struct elf_note_info *info)
1948 {
1949 while (!list_empty(&info->thread_list)) {
1950 struct list_head *tmp = info->thread_list.next;
1951 list_del(tmp);
1952 kfree(list_entry(tmp, struct elf_thread_status, list));
1953 }
1954
1955 /* Free data possibly allocated by fill_files_note(): */
1956 if (info->notes_files)
1957 vfree(info->notes_files->data);
1958
1959 kfree(info->prstatus);
1960 kfree(info->psinfo);
1961 kfree(info->notes);
1962 kfree(info->fpu);
1963 #ifdef ELF_CORE_COPY_XFPREGS
1964 kfree(info->xfpu);
1965 #endif
1966 }
1967
1968 #endif
1969
1970 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1971 struct vm_area_struct *gate_vma)
1972 {
1973 struct vm_area_struct *ret = tsk->mm->mmap;
1974
1975 if (ret)
1976 return ret;
1977 return gate_vma;
1978 }
1979 /*
1980 * Helper function for iterating across a vma list. It ensures that the caller
1981 * will visit `gate_vma' prior to terminating the search.
1982 */
1983 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1984 struct vm_area_struct *gate_vma)
1985 {
1986 struct vm_area_struct *ret;
1987
1988 ret = this_vma->vm_next;
1989 if (ret)
1990 return ret;
1991 if (this_vma == gate_vma)
1992 return NULL;
1993 return gate_vma;
1994 }
1995
1996 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1997 elf_addr_t e_shoff, int segs)
1998 {
1999 elf->e_shoff = e_shoff;
2000 elf->e_shentsize = sizeof(*shdr4extnum);
2001 elf->e_shnum = 1;
2002 elf->e_shstrndx = SHN_UNDEF;
2003
2004 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
2005
2006 shdr4extnum->sh_type = SHT_NULL;
2007 shdr4extnum->sh_size = elf->e_shnum;
2008 shdr4extnum->sh_link = elf->e_shstrndx;
2009 shdr4extnum->sh_info = segs;
2010 }
2011
2012 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
2013 unsigned long mm_flags)
2014 {
2015 struct vm_area_struct *vma;
2016 size_t size = 0;
2017
2018 for (vma = first_vma(current, gate_vma); vma != NULL;
2019 vma = next_vma(vma, gate_vma))
2020 size += vma_dump_size(vma, mm_flags);
2021 return size;
2022 }
2023
2024 /*
2025 * Actual dumper
2026 *
2027 * This is a two-pass process; first we find the offsets of the bits,
2028 * and then they are actually written out. If we run out of core limit
2029 * we just truncate.
2030 */
2031 static int elf_core_dump(struct coredump_params *cprm)
2032 {
2033 int has_dumped = 0;
2034 mm_segment_t fs;
2035 int segs;
2036 struct vm_area_struct *vma, *gate_vma;
2037 struct elfhdr *elf = NULL;
2038 loff_t offset = 0, dataoff;
2039 struct elf_note_info info = { };
2040 struct elf_phdr *phdr4note = NULL;
2041 struct elf_shdr *shdr4extnum = NULL;
2042 Elf_Half e_phnum;
2043 elf_addr_t e_shoff;
2044
2045 /*
2046 * We no longer stop all VM operations.
2047 *
2048 * This is because those proceses that could possibly change map_count
2049 * or the mmap / vma pages are now blocked in do_exit on current
2050 * finishing this core dump.
2051 *
2052 * Only ptrace can touch these memory addresses, but it doesn't change
2053 * the map_count or the pages allocated. So no possibility of crashing
2054 * exists while dumping the mm->vm_next areas to the core file.
2055 */
2056
2057 /* alloc memory for large data structures: too large to be on stack */
2058 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
2059 if (!elf)
2060 goto out;
2061 /*
2062 * The number of segs are recored into ELF header as 16bit value.
2063 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2064 */
2065 segs = current->mm->map_count;
2066 segs += elf_core_extra_phdrs();
2067
2068 gate_vma = get_gate_vma(current->mm);
2069 if (gate_vma != NULL)
2070 segs++;
2071
2072 /* for notes section */
2073 segs++;
2074
2075 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2076 * this, kernel supports extended numbering. Have a look at
2077 * include/linux/elf.h for further information. */
2078 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2079
2080 /*
2081 * Collect all the non-memory information about the process for the
2082 * notes. This also sets up the file header.
2083 */
2084 if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2085 goto cleanup;
2086
2087 has_dumped = 1;
2088
2089 fs = get_fs();
2090 set_fs(KERNEL_DS);
2091
2092 offset += sizeof(*elf); /* Elf header */
2093 offset += segs * sizeof(struct elf_phdr); /* Program headers */
2094
2095 /* Write notes phdr entry */
2096 {
2097 size_t sz = get_note_info_size(&info);
2098
2099 sz += elf_coredump_extra_notes_size();
2100
2101 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2102 if (!phdr4note)
2103 goto end_coredump;
2104
2105 fill_elf_note_phdr(phdr4note, sz, offset);
2106 offset += sz;
2107 }
2108
2109 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2110
2111 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
2112 offset += elf_core_extra_data_size();
2113 e_shoff = offset;
2114
2115 if (e_phnum == PN_XNUM) {
2116 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2117 if (!shdr4extnum)
2118 goto end_coredump;
2119 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
2120 }
2121
2122 offset = dataoff;
2123
2124 if (!dump_emit(cprm, elf, sizeof(*elf)))
2125 goto end_coredump;
2126
2127 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
2128 goto end_coredump;
2129
2130 /* Write program headers for segments dump */
2131 for (vma = first_vma(current, gate_vma); vma != NULL;
2132 vma = next_vma(vma, gate_vma)) {
2133 struct elf_phdr phdr;
2134
2135 phdr.p_type = PT_LOAD;
2136 phdr.p_offset = offset;
2137 phdr.p_vaddr = vma->vm_start;
2138 phdr.p_paddr = 0;
2139 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
2140 phdr.p_memsz = vma->vm_end - vma->vm_start;
2141 offset += phdr.p_filesz;
2142 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2143 if (vma->vm_flags & VM_WRITE)
2144 phdr.p_flags |= PF_W;
2145 if (vma->vm_flags & VM_EXEC)
2146 phdr.p_flags |= PF_X;
2147 phdr.p_align = ELF_EXEC_PAGESIZE;
2148
2149 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
2150 goto end_coredump;
2151 }
2152
2153 if (!elf_core_write_extra_phdrs(cprm, offset))
2154 goto end_coredump;
2155
2156 /* write out the notes section */
2157 if (!write_note_info(&info, cprm))
2158 goto end_coredump;
2159
2160 if (elf_coredump_extra_notes_write(cprm))
2161 goto end_coredump;
2162
2163 /* Align to page */
2164 if (!dump_skip(cprm, dataoff - cprm->written))
2165 goto end_coredump;
2166
2167 for (vma = first_vma(current, gate_vma); vma != NULL;
2168 vma = next_vma(vma, gate_vma)) {
2169 unsigned long addr;
2170 unsigned long end;
2171
2172 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
2173
2174 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2175 struct page *page;
2176 int stop;
2177
2178 page = get_dump_page(addr);
2179 if (page) {
2180 void *kaddr = kmap(page);
2181 stop = !dump_emit(cprm, kaddr, PAGE_SIZE);
2182 kunmap(page);
2183 page_cache_release(page);
2184 } else
2185 stop = !dump_skip(cprm, PAGE_SIZE);
2186 if (stop)
2187 goto end_coredump;
2188 }
2189 }
2190
2191 if (!elf_core_write_extra_data(cprm))
2192 goto end_coredump;
2193
2194 if (e_phnum == PN_XNUM) {
2195 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
2196 goto end_coredump;
2197 }
2198
2199 end_coredump:
2200 set_fs(fs);
2201
2202 cleanup:
2203 free_note_info(&info);
2204 kfree(shdr4extnum);
2205 kfree(phdr4note);
2206 kfree(elf);
2207 out:
2208 return has_dumped;
2209 }
2210
2211 #endif /* CONFIG_ELF_CORE */
2212
2213 static int __init init_elf_binfmt(void)
2214 {
2215 register_binfmt(&elf_format);
2216 return 0;
2217 }
2218
2219 static void __exit exit_elf_binfmt(void)
2220 {
2221 /* Remove the COFF and ELF loaders. */
2222 unregister_binfmt(&elf_format);
2223 }
2224
2225 core_initcall(init_elf_binfmt);
2226 module_exit(exit_elf_binfmt);
2227 MODULE_LICENSE("GPL");
Linux with added FPC-III support