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Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git...
[GitHub/mt8127/android_kernel_alcatel_ttab.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 #ifdef ELF_HWCAP2
244 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
245 #endif
246 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
247 if (k_platform) {
248 NEW_AUX_ENT(AT_PLATFORM,
249 (elf_addr_t)(unsigned long)u_platform);
250 }
251 if (k_base_platform) {
252 NEW_AUX_ENT(AT_BASE_PLATFORM,
253 (elf_addr_t)(unsigned long)u_base_platform);
254 }
255 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
256 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
257 }
258 #undef NEW_AUX_ENT
259 /* AT_NULL is zero; clear the rest too */
260 memset(&elf_info[ei_index], 0,
261 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
262
263 /* And advance past the AT_NULL entry. */
264 ei_index += 2;
265
266 sp = STACK_ADD(p, ei_index);
267
268 items = (argc + 1) + (envc + 1) + 1;
269 bprm->p = STACK_ROUND(sp, items);
270
271 /* Point sp at the lowest address on the stack */
272 #ifdef CONFIG_STACK_GROWSUP
273 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
274 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
275 #else
276 sp = (elf_addr_t __user *)bprm->p;
277 #endif
278
279
280 /*
281 * Grow the stack manually; some architectures have a limit on how
282 * far ahead a user-space access may be in order to grow the stack.
283 */
284 vma = find_extend_vma(current->mm, bprm->p);
285 if (!vma)
286 return -EFAULT;
287
288 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
289 if (__put_user(argc, sp++))
290 return -EFAULT;
291 argv = sp;
292 envp = argv + argc + 1;
293
294 /* Populate argv and envp */
295 p = current->mm->arg_end = current->mm->arg_start;
296 while (argc-- > 0) {
297 size_t len;
298 if (__put_user((elf_addr_t)p, argv++))
299 return -EFAULT;
300 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
301 if (!len || len > MAX_ARG_STRLEN)
302 return -EINVAL;
303 p += len;
304 }
305 if (__put_user(0, argv))
306 return -EFAULT;
307 current->mm->arg_end = current->mm->env_start = p;
308 while (envc-- > 0) {
309 size_t len;
310 if (__put_user((elf_addr_t)p, envp++))
311 return -EFAULT;
312 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
313 if (!len || len > MAX_ARG_STRLEN)
314 return -EINVAL;
315 p += len;
316 }
317 if (__put_user(0, envp))
318 return -EFAULT;
319 current->mm->env_end = p;
320
321 /* Put the elf_info on the stack in the right place. */
322 sp = (elf_addr_t __user *)envp + 1;
323 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
324 return -EFAULT;
325 return 0;
326 }
327
328 #ifndef elf_map
329
330 static unsigned long elf_map(struct file *filep, unsigned long addr,
331 struct elf_phdr *eppnt, int prot, int type,
332 unsigned long total_size)
333 {
334 unsigned long map_addr;
335 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
336 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
337 addr = ELF_PAGESTART(addr);
338 size = ELF_PAGEALIGN(size);
339
340 /* mmap() will return -EINVAL if given a zero size, but a
341 * segment with zero filesize is perfectly valid */
342 if (!size)
343 return addr;
344
345 /*
346 * total_size is the size of the ELF (interpreter) image.
347 * The _first_ mmap needs to know the full size, otherwise
348 * randomization might put this image into an overlapping
349 * position with the ELF binary image. (since size < total_size)
350 * So we first map the 'big' image - and unmap the remainder at
351 * the end. (which unmap is needed for ELF images with holes.)
352 */
353 if (total_size) {
354 total_size = ELF_PAGEALIGN(total_size);
355 map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
356 if (!BAD_ADDR(map_addr))
357 vm_munmap(map_addr+size, total_size-size);
358 } else
359 map_addr = vm_mmap(filep, addr, size, prot, type, off);
360
361 return(map_addr);
362 }
363
364 #endif /* !elf_map */
365
366 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
367 {
368 int i, first_idx = -1, last_idx = -1;
369
370 for (i = 0; i < nr; i++) {
371 if (cmds[i].p_type == PT_LOAD) {
372 last_idx = i;
373 if (first_idx == -1)
374 first_idx = i;
375 }
376 }
377 if (first_idx == -1)
378 return 0;
379
380 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
381 ELF_PAGESTART(cmds[first_idx].p_vaddr);
382 }
383
384
385 /* This is much more generalized than the library routine read function,
386 so we keep this separate. Technically the library read function
387 is only provided so that we can read a.out libraries that have
388 an ELF header */
389
390 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
391 struct file *interpreter, unsigned long *interp_map_addr,
392 unsigned long no_base)
393 {
394 struct elf_phdr *elf_phdata;
395 struct elf_phdr *eppnt;
396 unsigned long load_addr = 0;
397 int load_addr_set = 0;
398 unsigned long last_bss = 0, elf_bss = 0;
399 unsigned long error = ~0UL;
400 unsigned long total_size;
401 int retval, i, size;
402
403 /* First of all, some simple consistency checks */
404 if (interp_elf_ex->e_type != ET_EXEC &&
405 interp_elf_ex->e_type != ET_DYN)
406 goto out;
407 if (!elf_check_arch(interp_elf_ex))
408 goto out;
409 if (!interpreter->f_op || !interpreter->f_op->mmap)
410 goto out;
411
412 /*
413 * If the size of this structure has changed, then punt, since
414 * we will be doing the wrong thing.
415 */
416 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
417 goto out;
418 if (interp_elf_ex->e_phnum < 1 ||
419 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
420 goto out;
421
422 /* Now read in all of the header information */
423 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
424 if (size > ELF_MIN_ALIGN)
425 goto out;
426 elf_phdata = kmalloc(size, GFP_KERNEL);
427 if (!elf_phdata)
428 goto out;
429
430 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
431 (char *)elf_phdata, size);
432 error = -EIO;
433 if (retval != size) {
434 if (retval < 0)
435 error = retval;
436 goto out_close;
437 }
438
439 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
440 if (!total_size) {
441 error = -EINVAL;
442 goto out_close;
443 }
444
445 eppnt = elf_phdata;
446 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
447 if (eppnt->p_type == PT_LOAD) {
448 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
449 int elf_prot = 0;
450 unsigned long vaddr = 0;
451 unsigned long k, map_addr;
452
453 if (eppnt->p_flags & PF_R)
454 elf_prot = PROT_READ;
455 if (eppnt->p_flags & PF_W)
456 elf_prot |= PROT_WRITE;
457 if (eppnt->p_flags & PF_X)
458 elf_prot |= PROT_EXEC;
459 vaddr = eppnt->p_vaddr;
460 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
461 elf_type |= MAP_FIXED;
462 else if (no_base && interp_elf_ex->e_type == ET_DYN)
463 load_addr = -vaddr;
464
465 map_addr = elf_map(interpreter, load_addr + vaddr,
466 eppnt, elf_prot, elf_type, total_size);
467 total_size = 0;
468 if (!*interp_map_addr)
469 *interp_map_addr = map_addr;
470 error = map_addr;
471 if (BAD_ADDR(map_addr))
472 goto out_close;
473
474 if (!load_addr_set &&
475 interp_elf_ex->e_type == ET_DYN) {
476 load_addr = map_addr - ELF_PAGESTART(vaddr);
477 load_addr_set = 1;
478 }
479
480 /*
481 * Check to see if the section's size will overflow the
482 * allowed task size. Note that p_filesz must always be
483 * <= p_memsize so it's only necessary to check p_memsz.
484 */
485 k = load_addr + eppnt->p_vaddr;
486 if (BAD_ADDR(k) ||
487 eppnt->p_filesz > eppnt->p_memsz ||
488 eppnt->p_memsz > TASK_SIZE ||
489 TASK_SIZE - eppnt->p_memsz < k) {
490 error = -ENOMEM;
491 goto out_close;
492 }
493
494 /*
495 * Find the end of the file mapping for this phdr, and
496 * keep track of the largest address we see for this.
497 */
498 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
499 if (k > elf_bss)
500 elf_bss = k;
501
502 /*
503 * Do the same thing for the memory mapping - between
504 * elf_bss and last_bss is the bss section.
505 */
506 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
507 if (k > last_bss)
508 last_bss = k;
509 }
510 }
511
512 if (last_bss > elf_bss) {
513 /*
514 * Now fill out the bss section. First pad the last page up
515 * to the page boundary, and then perform a mmap to make sure
516 * that there are zero-mapped pages up to and including the
517 * last bss page.
518 */
519 if (padzero(elf_bss)) {
520 error = -EFAULT;
521 goto out_close;
522 }
523
524 /* What we have mapped so far */
525 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
526
527 /* Map the last of the bss segment */
528 error = vm_brk(elf_bss, last_bss - elf_bss);
529 if (BAD_ADDR(error))
530 goto out_close;
531 }
532
533 error = load_addr;
534
535 out_close:
536 kfree(elf_phdata);
537 out:
538 return error;
539 }
540
541 /*
542 * These are the functions used to load ELF style executables and shared
543 * libraries. There is no binary dependent code anywhere else.
544 */
545
546 #define INTERPRETER_NONE 0
547 #define INTERPRETER_ELF 2
548
549 #ifndef STACK_RND_MASK
550 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
551 #endif
552
553 static unsigned long randomize_stack_top(unsigned long stack_top)
554 {
555 unsigned int random_variable = 0;
556
557 if ((current->flags & PF_RANDOMIZE) &&
558 !(current->personality & ADDR_NO_RANDOMIZE)) {
559 random_variable = get_random_int() & STACK_RND_MASK;
560 random_variable <<= PAGE_SHIFT;
561 }
562 #ifdef CONFIG_STACK_GROWSUP
563 return PAGE_ALIGN(stack_top) + random_variable;
564 #else
565 return PAGE_ALIGN(stack_top) - random_variable;
566 #endif
567 }
568
569 static int load_elf_binary(struct linux_binprm *bprm)
570 {
571 struct file *interpreter = NULL; /* to shut gcc up */
572 unsigned long load_addr = 0, load_bias = 0;
573 int load_addr_set = 0;
574 char * elf_interpreter = NULL;
575 unsigned long error;
576 struct elf_phdr *elf_ppnt, *elf_phdata;
577 unsigned long elf_bss, elf_brk;
578 int retval, i;
579 unsigned int size;
580 unsigned long elf_entry;
581 unsigned long interp_load_addr = 0;
582 unsigned long start_code, end_code, start_data, end_data;
583 unsigned long reloc_func_desc __maybe_unused = 0;
584 int executable_stack = EXSTACK_DEFAULT;
585 unsigned long def_flags = 0;
586 struct pt_regs *regs = current_pt_regs();
587 struct {
588 struct elfhdr elf_ex;
589 struct elfhdr interp_elf_ex;
590 } *loc;
591
592 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
593 if (!loc) {
594 retval = -ENOMEM;
595 goto out_ret;
596 }
597
598 /* Get the exec-header */
599 loc->elf_ex = *((struct elfhdr *)bprm->buf);
600
601 retval = -ENOEXEC;
602 /* First of all, some simple consistency checks */
603 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
604 goto out;
605
606 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
607 goto out;
608 if (!elf_check_arch(&loc->elf_ex))
609 goto out;
610 if (!bprm->file->f_op || !bprm->file->f_op->mmap)
611 goto out;
612
613 /* Now read in all of the header information */
614 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
615 goto out;
616 if (loc->elf_ex.e_phnum < 1 ||
617 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
618 goto out;
619 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
620 retval = -ENOMEM;
621 elf_phdata = kmalloc(size, GFP_KERNEL);
622 if (!elf_phdata)
623 goto out;
624
625 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
626 (char *)elf_phdata, size);
627 if (retval != size) {
628 if (retval >= 0)
629 retval = -EIO;
630 goto out_free_ph;
631 }
632
633 elf_ppnt = elf_phdata;
634 elf_bss = 0;
635 elf_brk = 0;
636
637 start_code = ~0UL;
638 end_code = 0;
639 start_data = 0;
640 end_data = 0;
641
642 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
643 if (elf_ppnt->p_type == PT_INTERP) {
644 /* This is the program interpreter used for
645 * shared libraries - for now assume that this
646 * is an a.out format binary
647 */
648 retval = -ENOEXEC;
649 if (elf_ppnt->p_filesz > PATH_MAX ||
650 elf_ppnt->p_filesz < 2)
651 goto out_free_ph;
652
653 retval = -ENOMEM;
654 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
655 GFP_KERNEL);
656 if (!elf_interpreter)
657 goto out_free_ph;
658
659 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
660 elf_interpreter,
661 elf_ppnt->p_filesz);
662 if (retval != elf_ppnt->p_filesz) {
663 if (retval >= 0)
664 retval = -EIO;
665 goto out_free_interp;
666 }
667 /* make sure path is NULL terminated */
668 retval = -ENOEXEC;
669 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
670 goto out_free_interp;
671
672 interpreter = open_exec(elf_interpreter);
673 retval = PTR_ERR(interpreter);
674 if (IS_ERR(interpreter))
675 goto out_free_interp;
676
677 /*
678 * If the binary is not readable then enforce
679 * mm->dumpable = 0 regardless of the interpreter's
680 * permissions.
681 */
682 would_dump(bprm, interpreter);
683
684 retval = kernel_read(interpreter, 0, bprm->buf,
685 BINPRM_BUF_SIZE);
686 if (retval != BINPRM_BUF_SIZE) {
687 if (retval >= 0)
688 retval = -EIO;
689 goto out_free_dentry;
690 }
691
692 /* Get the exec headers */
693 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
694 break;
695 }
696 elf_ppnt++;
697 }
698
699 elf_ppnt = elf_phdata;
700 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
701 if (elf_ppnt->p_type == PT_GNU_STACK) {
702 if (elf_ppnt->p_flags & PF_X)
703 executable_stack = EXSTACK_ENABLE_X;
704 else
705 executable_stack = EXSTACK_DISABLE_X;
706 break;
707 }
708
709 /* Some simple consistency checks for the interpreter */
710 if (elf_interpreter) {
711 retval = -ELIBBAD;
712 /* Not an ELF interpreter */
713 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
714 goto out_free_dentry;
715 /* Verify the interpreter has a valid arch */
716 if (!elf_check_arch(&loc->interp_elf_ex))
717 goto out_free_dentry;
718 }
719
720 /* Flush all traces of the currently running executable */
721 retval = flush_old_exec(bprm);
722 if (retval)
723 goto out_free_dentry;
724
725 /* OK, This is the point of no return */
726 current->mm->def_flags = def_flags;
727
728 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
729 may depend on the personality. */
730 SET_PERSONALITY(loc->elf_ex);
731 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
732 current->personality |= READ_IMPLIES_EXEC;
733
734 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
735 current->flags |= PF_RANDOMIZE;
736
737 setup_new_exec(bprm);
738
739 /* Do this so that we can load the interpreter, if need be. We will
740 change some of these later */
741 current->mm->free_area_cache = current->mm->mmap_base;
742 current->mm->cached_hole_size = 0;
743 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
744 executable_stack);
745 if (retval < 0) {
746 send_sig(SIGKILL, current, 0);
747 goto out_free_dentry;
748 }
749
750 current->mm->start_stack = bprm->p;
751
752 /* Now we do a little grungy work by mmapping the ELF image into
753 the correct location in memory. */
754 for(i = 0, elf_ppnt = elf_phdata;
755 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
756 int elf_prot = 0, elf_flags;
757 unsigned long k, vaddr;
758
759 if (elf_ppnt->p_type != PT_LOAD)
760 continue;
761
762 if (unlikely (elf_brk > elf_bss)) {
763 unsigned long nbyte;
764
765 /* There was a PT_LOAD segment with p_memsz > p_filesz
766 before this one. Map anonymous pages, if needed,
767 and clear the area. */
768 retval = set_brk(elf_bss + load_bias,
769 elf_brk + load_bias);
770 if (retval) {
771 send_sig(SIGKILL, current, 0);
772 goto out_free_dentry;
773 }
774 nbyte = ELF_PAGEOFFSET(elf_bss);
775 if (nbyte) {
776 nbyte = ELF_MIN_ALIGN - nbyte;
777 if (nbyte > elf_brk - elf_bss)
778 nbyte = elf_brk - elf_bss;
779 if (clear_user((void __user *)elf_bss +
780 load_bias, nbyte)) {
781 /*
782 * This bss-zeroing can fail if the ELF
783 * file specifies odd protections. So
784 * we don't check the return value
785 */
786 }
787 }
788 }
789
790 if (elf_ppnt->p_flags & PF_R)
791 elf_prot |= PROT_READ;
792 if (elf_ppnt->p_flags & PF_W)
793 elf_prot |= PROT_WRITE;
794 if (elf_ppnt->p_flags & PF_X)
795 elf_prot |= PROT_EXEC;
796
797 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
798
799 vaddr = elf_ppnt->p_vaddr;
800 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
801 elf_flags |= MAP_FIXED;
802 } else if (loc->elf_ex.e_type == ET_DYN) {
803 /* Try and get dynamic programs out of the way of the
804 * default mmap base, as well as whatever program they
805 * might try to exec. This is because the brk will
806 * follow the loader, and is not movable. */
807 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
808 /* Memory randomization might have been switched off
809 * in runtime via sysctl or explicit setting of
810 * personality flags.
811 * If that is the case, retain the original non-zero
812 * load_bias value in order to establish proper
813 * non-randomized mappings.
814 */
815 if (current->flags & PF_RANDOMIZE)
816 load_bias = 0;
817 else
818 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
819 #else
820 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
821 #endif
822 }
823
824 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
825 elf_prot, elf_flags, 0);
826 if (BAD_ADDR(error)) {
827 send_sig(SIGKILL, current, 0);
828 retval = IS_ERR((void *)error) ?
829 PTR_ERR((void*)error) : -EINVAL;
830 goto out_free_dentry;
831 }
832
833 if (!load_addr_set) {
834 load_addr_set = 1;
835 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
836 if (loc->elf_ex.e_type == ET_DYN) {
837 load_bias += error -
838 ELF_PAGESTART(load_bias + vaddr);
839 load_addr += load_bias;
840 reloc_func_desc = load_bias;
841 }
842 }
843 k = elf_ppnt->p_vaddr;
844 if (k < start_code)
845 start_code = k;
846 if (start_data < k)
847 start_data = k;
848
849 /*
850 * Check to see if the section's size will overflow the
851 * allowed task size. Note that p_filesz must always be
852 * <= p_memsz so it is only necessary to check p_memsz.
853 */
854 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
855 elf_ppnt->p_memsz > TASK_SIZE ||
856 TASK_SIZE - elf_ppnt->p_memsz < k) {
857 /* set_brk can never work. Avoid overflows. */
858 send_sig(SIGKILL, current, 0);
859 retval = -EINVAL;
860 goto out_free_dentry;
861 }
862
863 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
864
865 if (k > elf_bss)
866 elf_bss = k;
867 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
868 end_code = k;
869 if (end_data < k)
870 end_data = k;
871 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
872 if (k > elf_brk)
873 elf_brk = k;
874 }
875
876 loc->elf_ex.e_entry += load_bias;
877 elf_bss += load_bias;
878 elf_brk += load_bias;
879 start_code += load_bias;
880 end_code += load_bias;
881 start_data += load_bias;
882 end_data += load_bias;
883
884 /* Calling set_brk effectively mmaps the pages that we need
885 * for the bss and break sections. We must do this before
886 * mapping in the interpreter, to make sure it doesn't wind
887 * up getting placed where the bss needs to go.
888 */
889 retval = set_brk(elf_bss, elf_brk);
890 if (retval) {
891 send_sig(SIGKILL, current, 0);
892 goto out_free_dentry;
893 }
894 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
895 send_sig(SIGSEGV, current, 0);
896 retval = -EFAULT; /* Nobody gets to see this, but.. */
897 goto out_free_dentry;
898 }
899
900 if (elf_interpreter) {
901 unsigned long interp_map_addr = 0;
902
903 elf_entry = load_elf_interp(&loc->interp_elf_ex,
904 interpreter,
905 &interp_map_addr,
906 load_bias);
907 if (!IS_ERR((void *)elf_entry)) {
908 /*
909 * load_elf_interp() returns relocation
910 * adjustment
911 */
912 interp_load_addr = elf_entry;
913 elf_entry += loc->interp_elf_ex.e_entry;
914 }
915 if (BAD_ADDR(elf_entry)) {
916 force_sig(SIGSEGV, current);
917 retval = IS_ERR((void *)elf_entry) ?
918 (int)elf_entry : -EINVAL;
919 goto out_free_dentry;
920 }
921 reloc_func_desc = interp_load_addr;
922
923 allow_write_access(interpreter);
924 fput(interpreter);
925 kfree(elf_interpreter);
926 } else {
927 elf_entry = loc->elf_ex.e_entry;
928 if (BAD_ADDR(elf_entry)) {
929 force_sig(SIGSEGV, current);
930 retval = -EINVAL;
931 goto out_free_dentry;
932 }
933 }
934
935 kfree(elf_phdata);
936
937 set_binfmt(&elf_format);
938
939 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
940 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
941 if (retval < 0) {
942 send_sig(SIGKILL, current, 0);
943 goto out;
944 }
945 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
946
947 install_exec_creds(bprm);
948 retval = create_elf_tables(bprm, &loc->elf_ex,
949 load_addr, interp_load_addr);
950 if (retval < 0) {
951 send_sig(SIGKILL, current, 0);
952 goto out;
953 }
954 /* N.B. passed_fileno might not be initialized? */
955 current->mm->end_code = end_code;
956 current->mm->start_code = start_code;
957 current->mm->start_data = start_data;
958 current->mm->end_data = end_data;
959 current->mm->start_stack = bprm->p;
960
961 #ifdef arch_randomize_brk
962 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
963 current->mm->brk = current->mm->start_brk =
964 arch_randomize_brk(current->mm);
965 #ifdef CONFIG_COMPAT_BRK
966 current->brk_randomized = 1;
967 #endif
968 }
969 #endif
970
971 if (current->personality & MMAP_PAGE_ZERO) {
972 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
973 and some applications "depend" upon this behavior.
974 Since we do not have the power to recompile these, we
975 emulate the SVr4 behavior. Sigh. */
976 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
977 MAP_FIXED | MAP_PRIVATE, 0);
978 }
979
980 #ifdef ELF_PLAT_INIT
981 /*
982 * The ABI may specify that certain registers be set up in special
983 * ways (on i386 %edx is the address of a DT_FINI function, for
984 * example. In addition, it may also specify (eg, PowerPC64 ELF)
985 * that the e_entry field is the address of the function descriptor
986 * for the startup routine, rather than the address of the startup
987 * routine itself. This macro performs whatever initialization to
988 * the regs structure is required as well as any relocations to the
989 * function descriptor entries when executing dynamically links apps.
990 */
991 ELF_PLAT_INIT(regs, reloc_func_desc);
992 #endif
993
994 start_thread(regs, elf_entry, bprm->p);
995 retval = 0;
996 out:
997 kfree(loc);
998 out_ret:
999 return retval;
1000
1001 /* error cleanup */
1002 out_free_dentry:
1003 allow_write_access(interpreter);
1004 if (interpreter)
1005 fput(interpreter);
1006 out_free_interp:
1007 kfree(elf_interpreter);
1008 out_free_ph:
1009 kfree(elf_phdata);
1010 goto out;
1011 }
1012
1013 /* This is really simpleminded and specialized - we are loading an
1014 a.out library that is given an ELF header. */
1015 static int load_elf_library(struct file *file)
1016 {
1017 struct elf_phdr *elf_phdata;
1018 struct elf_phdr *eppnt;
1019 unsigned long elf_bss, bss, len;
1020 int retval, error, i, j;
1021 struct elfhdr elf_ex;
1022
1023 error = -ENOEXEC;
1024 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1025 if (retval != sizeof(elf_ex))
1026 goto out;
1027
1028 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1029 goto out;
1030
1031 /* First of all, some simple consistency checks */
1032 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1033 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1034 goto out;
1035
1036 /* Now read in all of the header information */
1037
1038 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1039 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1040
1041 error = -ENOMEM;
1042 elf_phdata = kmalloc(j, GFP_KERNEL);
1043 if (!elf_phdata)
1044 goto out;
1045
1046 eppnt = elf_phdata;
1047 error = -ENOEXEC;
1048 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1049 if (retval != j)
1050 goto out_free_ph;
1051
1052 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1053 if ((eppnt + i)->p_type == PT_LOAD)
1054 j++;
1055 if (j != 1)
1056 goto out_free_ph;
1057
1058 while (eppnt->p_type != PT_LOAD)
1059 eppnt++;
1060
1061 /* Now use mmap to map the library into memory. */
1062 error = vm_mmap(file,
1063 ELF_PAGESTART(eppnt->p_vaddr),
1064 (eppnt->p_filesz +
1065 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1066 PROT_READ | PROT_WRITE | PROT_EXEC,
1067 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1068 (eppnt->p_offset -
1069 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1070 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1071 goto out_free_ph;
1072
1073 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1074 if (padzero(elf_bss)) {
1075 error = -EFAULT;
1076 goto out_free_ph;
1077 }
1078
1079 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1080 ELF_MIN_ALIGN - 1);
1081 bss = eppnt->p_memsz + eppnt->p_vaddr;
1082 if (bss > len)
1083 vm_brk(len, bss - len);
1084 error = 0;
1085
1086 out_free_ph:
1087 kfree(elf_phdata);
1088 out:
1089 return error;
1090 }
1091
1092 #ifdef CONFIG_ELF_CORE
1093 /*
1094 * ELF core dumper
1095 *
1096 * Modelled on fs/exec.c:aout_core_dump()
1097 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1098 */
1099
1100 /*
1101 * The purpose of always_dump_vma() is to make sure that special kernel mappings
1102 * that are useful for post-mortem analysis are included in every core dump.
1103 * In that way we ensure that the core dump is fully interpretable later
1104 * without matching up the same kernel and hardware config to see what PC values
1105 * meant. These special mappings include - vDSO, vsyscall, and other
1106 * architecture specific mappings
1107 */
1108 static bool always_dump_vma(struct vm_area_struct *vma)
1109 {
1110 /* Any vsyscall mappings? */
1111 if (vma == get_gate_vma(vma->vm_mm))
1112 return true;
1113 /*
1114 * arch_vma_name() returns non-NULL for special architecture mappings,
1115 * such as vDSO sections.
1116 */
1117 if (arch_vma_name(vma))
1118 return true;
1119
1120 return false;
1121 }
1122
1123 /*
1124 * Decide what to dump of a segment, part, all or none.
1125 */
1126 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1127 unsigned long mm_flags)
1128 {
1129 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1130
1131 /* always dump the vdso and vsyscall sections */
1132 if (always_dump_vma(vma))
1133 goto whole;
1134
1135 if (vma->vm_flags & VM_DONTDUMP)
1136 return 0;
1137
1138 /* Hugetlb memory check */
1139 if (vma->vm_flags & VM_HUGETLB) {
1140 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1141 goto whole;
1142 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1143 goto whole;
1144 return 0;
1145 }
1146
1147 /* Do not dump I/O mapped devices or special mappings */
1148 if (vma->vm_flags & VM_IO)
1149 return 0;
1150
1151 /* By default, dump shared memory if mapped from an anonymous file. */
1152 if (vma->vm_flags & VM_SHARED) {
1153 if (file_inode(vma->vm_file)->i_nlink == 0 ?
1154 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1155 goto whole;
1156 return 0;
1157 }
1158
1159 /* Dump segments that have been written to. */
1160 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1161 goto whole;
1162 if (vma->vm_file == NULL)
1163 return 0;
1164
1165 if (FILTER(MAPPED_PRIVATE))
1166 goto whole;
1167
1168 /*
1169 * If this looks like the beginning of a DSO or executable mapping,
1170 * check for an ELF header. If we find one, dump the first page to
1171 * aid in determining what was mapped here.
1172 */
1173 if (FILTER(ELF_HEADERS) &&
1174 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1175 u32 __user *header = (u32 __user *) vma->vm_start;
1176 u32 word;
1177 mm_segment_t fs = get_fs();
1178 /*
1179 * Doing it this way gets the constant folded by GCC.
1180 */
1181 union {
1182 u32 cmp;
1183 char elfmag[SELFMAG];
1184 } magic;
1185 BUILD_BUG_ON(SELFMAG != sizeof word);
1186 magic.elfmag[EI_MAG0] = ELFMAG0;
1187 magic.elfmag[EI_MAG1] = ELFMAG1;
1188 magic.elfmag[EI_MAG2] = ELFMAG2;
1189 magic.elfmag[EI_MAG3] = ELFMAG3;
1190 /*
1191 * Switch to the user "segment" for get_user(),
1192 * then put back what elf_core_dump() had in place.
1193 */
1194 set_fs(USER_DS);
1195 if (unlikely(get_user(word, header)))
1196 word = 0;
1197 set_fs(fs);
1198 if (word == magic.cmp)
1199 return PAGE_SIZE;
1200 }
1201
1202 #undef FILTER
1203
1204 return 0;
1205
1206 whole:
1207 return vma->vm_end - vma->vm_start;
1208 }
1209
1210 /* An ELF note in memory */
1211 struct memelfnote
1212 {
1213 const char *name;
1214 int type;
1215 unsigned int datasz;
1216 void *data;
1217 };
1218
1219 static int notesize(struct memelfnote *en)
1220 {
1221 int sz;
1222
1223 sz = sizeof(struct elf_note);
1224 sz += roundup(strlen(en->name) + 1, 4);
1225 sz += roundup(en->datasz, 4);
1226
1227 return sz;
1228 }
1229
1230 #define DUMP_WRITE(addr, nr, foffset) \
1231 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1232
1233 static int alignfile(struct file *file, loff_t *foffset)
1234 {
1235 static const char buf[4] = { 0, };
1236 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1237 return 1;
1238 }
1239
1240 static int writenote(struct memelfnote *men, struct file *file,
1241 loff_t *foffset)
1242 {
1243 struct elf_note en;
1244 en.n_namesz = strlen(men->name) + 1;
1245 en.n_descsz = men->datasz;
1246 en.n_type = men->type;
1247
1248 DUMP_WRITE(&en, sizeof(en), foffset);
1249 DUMP_WRITE(men->name, en.n_namesz, foffset);
1250 if (!alignfile(file, foffset))
1251 return 0;
1252 DUMP_WRITE(men->data, men->datasz, foffset);
1253 if (!alignfile(file, foffset))
1254 return 0;
1255
1256 return 1;
1257 }
1258 #undef DUMP_WRITE
1259
1260 static void fill_elf_header(struct elfhdr *elf, int segs,
1261 u16 machine, u32 flags)
1262 {
1263 memset(elf, 0, sizeof(*elf));
1264
1265 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1266 elf->e_ident[EI_CLASS] = ELF_CLASS;
1267 elf->e_ident[EI_DATA] = ELF_DATA;
1268 elf->e_ident[EI_VERSION] = EV_CURRENT;
1269 elf->e_ident[EI_OSABI] = ELF_OSABI;
1270
1271 elf->e_type = ET_CORE;
1272 elf->e_machine = machine;
1273 elf->e_version = EV_CURRENT;
1274 elf->e_phoff = sizeof(struct elfhdr);
1275 elf->e_flags = flags;
1276 elf->e_ehsize = sizeof(struct elfhdr);
1277 elf->e_phentsize = sizeof(struct elf_phdr);
1278 elf->e_phnum = segs;
1279
1280 return;
1281 }
1282
1283 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1284 {
1285 phdr->p_type = PT_NOTE;
1286 phdr->p_offset = offset;
1287 phdr->p_vaddr = 0;
1288 phdr->p_paddr = 0;
1289 phdr->p_filesz = sz;
1290 phdr->p_memsz = 0;
1291 phdr->p_flags = 0;
1292 phdr->p_align = 0;
1293 return;
1294 }
1295
1296 static void fill_note(struct memelfnote *note, const char *name, int type,
1297 unsigned int sz, void *data)
1298 {
1299 note->name = name;
1300 note->type = type;
1301 note->datasz = sz;
1302 note->data = data;
1303 return;
1304 }
1305
1306 /*
1307 * fill up all the fields in prstatus from the given task struct, except
1308 * registers which need to be filled up separately.
1309 */
1310 static void fill_prstatus(struct elf_prstatus *prstatus,
1311 struct task_struct *p, long signr)
1312 {
1313 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1314 prstatus->pr_sigpend = p->pending.signal.sig[0];
1315 prstatus->pr_sighold = p->blocked.sig[0];
1316 rcu_read_lock();
1317 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1318 rcu_read_unlock();
1319 prstatus->pr_pid = task_pid_vnr(p);
1320 prstatus->pr_pgrp = task_pgrp_vnr(p);
1321 prstatus->pr_sid = task_session_vnr(p);
1322 if (thread_group_leader(p)) {
1323 struct task_cputime cputime;
1324
1325 /*
1326 * This is the record for the group leader. It shows the
1327 * group-wide total, not its individual thread total.
1328 */
1329 thread_group_cputime(p, &cputime);
1330 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1331 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1332 } else {
1333 cputime_t utime, stime;
1334
1335 task_cputime(p, &utime, &stime);
1336 cputime_to_timeval(utime, &prstatus->pr_utime);
1337 cputime_to_timeval(stime, &prstatus->pr_stime);
1338 }
1339 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1340 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1341 }
1342
1343 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1344 struct mm_struct *mm)
1345 {
1346 const struct cred *cred;
1347 unsigned int i, len;
1348
1349 /* first copy the parameters from user space */
1350 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1351
1352 len = mm->arg_end - mm->arg_start;
1353 if (len >= ELF_PRARGSZ)
1354 len = ELF_PRARGSZ-1;
1355 if (copy_from_user(&psinfo->pr_psargs,
1356 (const char __user *)mm->arg_start, len))
1357 return -EFAULT;
1358 for(i = 0; i < len; i++)
1359 if (psinfo->pr_psargs[i] == 0)
1360 psinfo->pr_psargs[i] = ' ';
1361 psinfo->pr_psargs[len] = 0;
1362
1363 rcu_read_lock();
1364 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1365 rcu_read_unlock();
1366 psinfo->pr_pid = task_pid_vnr(p);
1367 psinfo->pr_pgrp = task_pgrp_vnr(p);
1368 psinfo->pr_sid = task_session_vnr(p);
1369
1370 i = p->state ? ffz(~p->state) + 1 : 0;
1371 psinfo->pr_state = i;
1372 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1373 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1374 psinfo->pr_nice = task_nice(p);
1375 psinfo->pr_flag = p->flags;
1376 rcu_read_lock();
1377 cred = __task_cred(p);
1378 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1379 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1380 rcu_read_unlock();
1381 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1382
1383 return 0;
1384 }
1385
1386 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1387 {
1388 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1389 int i = 0;
1390 do
1391 i += 2;
1392 while (auxv[i - 2] != AT_NULL);
1393 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1394 }
1395
1396 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1397 siginfo_t *siginfo)
1398 {
1399 mm_segment_t old_fs = get_fs();
1400 set_fs(KERNEL_DS);
1401 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
1402 set_fs(old_fs);
1403 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1404 }
1405
1406 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1407 /*
1408 * Format of NT_FILE note:
1409 *
1410 * long count -- how many files are mapped
1411 * long page_size -- units for file_ofs
1412 * array of [COUNT] elements of
1413 * long start
1414 * long end
1415 * long file_ofs
1416 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1417 */
1418 static void fill_files_note(struct memelfnote *note)
1419 {
1420 struct vm_area_struct *vma;
1421 unsigned count, size, names_ofs, remaining, n;
1422 user_long_t *data;
1423 user_long_t *start_end_ofs;
1424 char *name_base, *name_curpos;
1425
1426 /* *Estimated* file count and total data size needed */
1427 count = current->mm->map_count;
1428 size = count * 64;
1429
1430 names_ofs = (2 + 3 * count) * sizeof(data[0]);
1431 alloc:
1432 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1433 goto err;
1434 size = round_up(size, PAGE_SIZE);
1435 data = vmalloc(size);
1436 if (!data)
1437 goto err;
1438
1439 start_end_ofs = data + 2;
1440 name_base = name_curpos = ((char *)data) + names_ofs;
1441 remaining = size - names_ofs;
1442 count = 0;
1443 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1444 struct file *file;
1445 const char *filename;
1446
1447 file = vma->vm_file;
1448 if (!file)
1449 continue;
1450 filename = d_path(&file->f_path, name_curpos, remaining);
1451 if (IS_ERR(filename)) {
1452 if (PTR_ERR(filename) == -ENAMETOOLONG) {
1453 vfree(data);
1454 size = size * 5 / 4;
1455 goto alloc;
1456 }
1457 continue;
1458 }
1459
1460 /* d_path() fills at the end, move name down */
1461 /* n = strlen(filename) + 1: */
1462 n = (name_curpos + remaining) - filename;
1463 remaining = filename - name_curpos;
1464 memmove(name_curpos, filename, n);
1465 name_curpos += n;
1466
1467 *start_end_ofs++ = vma->vm_start;
1468 *start_end_ofs++ = vma->vm_end;
1469 *start_end_ofs++ = vma->vm_pgoff;
1470 count++;
1471 }
1472
1473 /* Now we know exact count of files, can store it */
1474 data[0] = count;
1475 data[1] = PAGE_SIZE;
1476 /*
1477 * Count usually is less than current->mm->map_count,
1478 * we need to move filenames down.
1479 */
1480 n = current->mm->map_count - count;
1481 if (n != 0) {
1482 unsigned shift_bytes = n * 3 * sizeof(data[0]);
1483 memmove(name_base - shift_bytes, name_base,
1484 name_curpos - name_base);
1485 name_curpos -= shift_bytes;
1486 }
1487
1488 size = name_curpos - (char *)data;
1489 fill_note(note, "CORE", NT_FILE, size, data);
1490 err: ;
1491 }
1492
1493 #ifdef CORE_DUMP_USE_REGSET
1494 #include <linux/regset.h>
1495
1496 struct elf_thread_core_info {
1497 struct elf_thread_core_info *next;
1498 struct task_struct *task;
1499 struct elf_prstatus prstatus;
1500 struct memelfnote notes[0];
1501 };
1502
1503 struct elf_note_info {
1504 struct elf_thread_core_info *thread;
1505 struct memelfnote psinfo;
1506 struct memelfnote signote;
1507 struct memelfnote auxv;
1508 struct memelfnote files;
1509 user_siginfo_t csigdata;
1510 size_t size;
1511 int thread_notes;
1512 };
1513
1514 /*
1515 * When a regset has a writeback hook, we call it on each thread before
1516 * dumping user memory. On register window machines, this makes sure the
1517 * user memory backing the register data is up to date before we read it.
1518 */
1519 static void do_thread_regset_writeback(struct task_struct *task,
1520 const struct user_regset *regset)
1521 {
1522 if (regset->writeback)
1523 regset->writeback(task, regset, 1);
1524 }
1525
1526 #ifndef PR_REG_SIZE
1527 #define PR_REG_SIZE(S) sizeof(S)
1528 #endif
1529
1530 #ifndef PRSTATUS_SIZE
1531 #define PRSTATUS_SIZE(S) sizeof(S)
1532 #endif
1533
1534 #ifndef PR_REG_PTR
1535 #define PR_REG_PTR(S) (&((S)->pr_reg))
1536 #endif
1537
1538 #ifndef SET_PR_FPVALID
1539 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V))
1540 #endif
1541
1542 static int fill_thread_core_info(struct elf_thread_core_info *t,
1543 const struct user_regset_view *view,
1544 long signr, size_t *total)
1545 {
1546 unsigned int i;
1547
1548 /*
1549 * NT_PRSTATUS is the one special case, because the regset data
1550 * goes into the pr_reg field inside the note contents, rather
1551 * than being the whole note contents. We fill the reset in here.
1552 * We assume that regset 0 is NT_PRSTATUS.
1553 */
1554 fill_prstatus(&t->prstatus, t->task, signr);
1555 (void) view->regsets[0].get(t->task, &view->regsets[0],
1556 0, PR_REG_SIZE(t->prstatus.pr_reg),
1557 PR_REG_PTR(&t->prstatus), NULL);
1558
1559 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1560 PRSTATUS_SIZE(t->prstatus), &t->prstatus);
1561 *total += notesize(&t->notes[0]);
1562
1563 do_thread_regset_writeback(t->task, &view->regsets[0]);
1564
1565 /*
1566 * Each other regset might generate a note too. For each regset
1567 * that has no core_note_type or is inactive, we leave t->notes[i]
1568 * all zero and we'll know to skip writing it later.
1569 */
1570 for (i = 1; i < view->n; ++i) {
1571 const struct user_regset *regset = &view->regsets[i];
1572 do_thread_regset_writeback(t->task, regset);
1573 if (regset->core_note_type && regset->get &&
1574 (!regset->active || regset->active(t->task, regset))) {
1575 int ret;
1576 size_t size = regset->n * regset->size;
1577 void *data = kmalloc(size, GFP_KERNEL);
1578 if (unlikely(!data))
1579 return 0;
1580 ret = regset->get(t->task, regset,
1581 0, size, data, NULL);
1582 if (unlikely(ret))
1583 kfree(data);
1584 else {
1585 if (regset->core_note_type != NT_PRFPREG)
1586 fill_note(&t->notes[i], "LINUX",
1587 regset->core_note_type,
1588 size, data);
1589 else {
1590 SET_PR_FPVALID(&t->prstatus, 1);
1591 fill_note(&t->notes[i], "CORE",
1592 NT_PRFPREG, size, data);
1593 }
1594 *total += notesize(&t->notes[i]);
1595 }
1596 }
1597 }
1598
1599 return 1;
1600 }
1601
1602 static int fill_note_info(struct elfhdr *elf, int phdrs,
1603 struct elf_note_info *info,
1604 siginfo_t *siginfo, struct pt_regs *regs)
1605 {
1606 struct task_struct *dump_task = current;
1607 const struct user_regset_view *view = task_user_regset_view(dump_task);
1608 struct elf_thread_core_info *t;
1609 struct elf_prpsinfo *psinfo;
1610 struct core_thread *ct;
1611 unsigned int i;
1612
1613 info->size = 0;
1614 info->thread = NULL;
1615
1616 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1617 if (psinfo == NULL) {
1618 info->psinfo.data = NULL; /* So we don't free this wrongly */
1619 return 0;
1620 }
1621
1622 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1623
1624 /*
1625 * Figure out how many notes we're going to need for each thread.
1626 */
1627 info->thread_notes = 0;
1628 for (i = 0; i < view->n; ++i)
1629 if (view->regsets[i].core_note_type != 0)
1630 ++info->thread_notes;
1631
1632 /*
1633 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1634 * since it is our one special case.
1635 */
1636 if (unlikely(info->thread_notes == 0) ||
1637 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1638 WARN_ON(1);
1639 return 0;
1640 }
1641
1642 /*
1643 * Initialize the ELF file header.
1644 */
1645 fill_elf_header(elf, phdrs,
1646 view->e_machine, view->e_flags);
1647
1648 /*
1649 * Allocate a structure for each thread.
1650 */
1651 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1652 t = kzalloc(offsetof(struct elf_thread_core_info,
1653 notes[info->thread_notes]),
1654 GFP_KERNEL);
1655 if (unlikely(!t))
1656 return 0;
1657
1658 t->task = ct->task;
1659 if (ct->task == dump_task || !info->thread) {
1660 t->next = info->thread;
1661 info->thread = t;
1662 } else {
1663 /*
1664 * Make sure to keep the original task at
1665 * the head of the list.
1666 */
1667 t->next = info->thread->next;
1668 info->thread->next = t;
1669 }
1670 }
1671
1672 /*
1673 * Now fill in each thread's information.
1674 */
1675 for (t = info->thread; t != NULL; t = t->next)
1676 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1677 return 0;
1678
1679 /*
1680 * Fill in the two process-wide notes.
1681 */
1682 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1683 info->size += notesize(&info->psinfo);
1684
1685 fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1686 info->size += notesize(&info->signote);
1687
1688 fill_auxv_note(&info->auxv, current->mm);
1689 info->size += notesize(&info->auxv);
1690
1691 fill_files_note(&info->files);
1692 info->size += notesize(&info->files);
1693
1694 return 1;
1695 }
1696
1697 static size_t get_note_info_size(struct elf_note_info *info)
1698 {
1699 return info->size;
1700 }
1701
1702 /*
1703 * Write all the notes for each thread. When writing the first thread, the
1704 * process-wide notes are interleaved after the first thread-specific note.
1705 */
1706 static int write_note_info(struct elf_note_info *info,
1707 struct file *file, loff_t *foffset)
1708 {
1709 bool first = 1;
1710 struct elf_thread_core_info *t = info->thread;
1711
1712 do {
1713 int i;
1714
1715 if (!writenote(&t->notes[0], file, foffset))
1716 return 0;
1717
1718 if (first && !writenote(&info->psinfo, file, foffset))
1719 return 0;
1720 if (first && !writenote(&info->signote, file, foffset))
1721 return 0;
1722 if (first && !writenote(&info->auxv, file, foffset))
1723 return 0;
1724 if (first && !writenote(&info->files, file, foffset))
1725 return 0;
1726
1727 for (i = 1; i < info->thread_notes; ++i)
1728 if (t->notes[i].data &&
1729 !writenote(&t->notes[i], file, foffset))
1730 return 0;
1731
1732 first = 0;
1733 t = t->next;
1734 } while (t);
1735
1736 return 1;
1737 }
1738
1739 static void free_note_info(struct elf_note_info *info)
1740 {
1741 struct elf_thread_core_info *threads = info->thread;
1742 while (threads) {
1743 unsigned int i;
1744 struct elf_thread_core_info *t = threads;
1745 threads = t->next;
1746 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1747 for (i = 1; i < info->thread_notes; ++i)
1748 kfree(t->notes[i].data);
1749 kfree(t);
1750 }
1751 kfree(info->psinfo.data);
1752 vfree(info->files.data);
1753 }
1754
1755 #else
1756
1757 /* Here is the structure in which status of each thread is captured. */
1758 struct elf_thread_status
1759 {
1760 struct list_head list;
1761 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1762 elf_fpregset_t fpu; /* NT_PRFPREG */
1763 struct task_struct *thread;
1764 #ifdef ELF_CORE_COPY_XFPREGS
1765 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1766 #endif
1767 struct memelfnote notes[3];
1768 int num_notes;
1769 };
1770
1771 /*
1772 * In order to add the specific thread information for the elf file format,
1773 * we need to keep a linked list of every threads pr_status and then create
1774 * a single section for them in the final core file.
1775 */
1776 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1777 {
1778 int sz = 0;
1779 struct task_struct *p = t->thread;
1780 t->num_notes = 0;
1781
1782 fill_prstatus(&t->prstatus, p, signr);
1783 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1784
1785 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1786 &(t->prstatus));
1787 t->num_notes++;
1788 sz += notesize(&t->notes[0]);
1789
1790 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1791 &t->fpu))) {
1792 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1793 &(t->fpu));
1794 t->num_notes++;
1795 sz += notesize(&t->notes[1]);
1796 }
1797
1798 #ifdef ELF_CORE_COPY_XFPREGS
1799 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1800 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1801 sizeof(t->xfpu), &t->xfpu);
1802 t->num_notes++;
1803 sz += notesize(&t->notes[2]);
1804 }
1805 #endif
1806 return sz;
1807 }
1808
1809 struct elf_note_info {
1810 struct memelfnote *notes;
1811 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1812 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1813 struct list_head thread_list;
1814 elf_fpregset_t *fpu;
1815 #ifdef ELF_CORE_COPY_XFPREGS
1816 elf_fpxregset_t *xfpu;
1817 #endif
1818 user_siginfo_t csigdata;
1819 int thread_status_size;
1820 int numnote;
1821 };
1822
1823 static int elf_note_info_init(struct elf_note_info *info)
1824 {
1825 memset(info, 0, sizeof(*info));
1826 INIT_LIST_HEAD(&info->thread_list);
1827
1828 /* Allocate space for ELF notes */
1829 info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL);
1830 if (!info->notes)
1831 return 0;
1832 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1833 if (!info->psinfo)
1834 return 0;
1835 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1836 if (!info->prstatus)
1837 return 0;
1838 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1839 if (!info->fpu)
1840 return 0;
1841 #ifdef ELF_CORE_COPY_XFPREGS
1842 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1843 if (!info->xfpu)
1844 return 0;
1845 #endif
1846 return 1;
1847 }
1848
1849 static int fill_note_info(struct elfhdr *elf, int phdrs,
1850 struct elf_note_info *info,
1851 siginfo_t *siginfo, struct pt_regs *regs)
1852 {
1853 struct list_head *t;
1854
1855 if (!elf_note_info_init(info))
1856 return 0;
1857
1858 if (siginfo->si_signo) {
1859 struct core_thread *ct;
1860 struct elf_thread_status *ets;
1861
1862 for (ct = current->mm->core_state->dumper.next;
1863 ct; ct = ct->next) {
1864 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1865 if (!ets)
1866 return 0;
1867
1868 ets->thread = ct->task;
1869 list_add(&ets->list, &info->thread_list);
1870 }
1871
1872 list_for_each(t, &info->thread_list) {
1873 int sz;
1874
1875 ets = list_entry(t, struct elf_thread_status, list);
1876 sz = elf_dump_thread_status(siginfo->si_signo, ets);
1877 info->thread_status_size += sz;
1878 }
1879 }
1880 /* now collect the dump for the current */
1881 memset(info->prstatus, 0, sizeof(*info->prstatus));
1882 fill_prstatus(info->prstatus, current, siginfo->si_signo);
1883 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1884
1885 /* Set up header */
1886 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
1887
1888 /*
1889 * Set up the notes in similar form to SVR4 core dumps made
1890 * with info from their /proc.
1891 */
1892
1893 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1894 sizeof(*info->prstatus), info->prstatus);
1895 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1896 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1897 sizeof(*info->psinfo), info->psinfo);
1898
1899 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
1900 fill_auxv_note(info->notes + 3, current->mm);
1901 fill_files_note(info->notes + 4);
1902
1903 info->numnote = 5;
1904
1905 /* Try to dump the FPU. */
1906 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1907 info->fpu);
1908 if (info->prstatus->pr_fpvalid)
1909 fill_note(info->notes + info->numnote++,
1910 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1911 #ifdef ELF_CORE_COPY_XFPREGS
1912 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1913 fill_note(info->notes + info->numnote++,
1914 "LINUX", ELF_CORE_XFPREG_TYPE,
1915 sizeof(*info->xfpu), info->xfpu);
1916 #endif
1917
1918 return 1;
1919 }
1920
1921 static size_t get_note_info_size(struct elf_note_info *info)
1922 {
1923 int sz = 0;
1924 int i;
1925
1926 for (i = 0; i < info->numnote; i++)
1927 sz += notesize(info->notes + i);
1928
1929 sz += info->thread_status_size;
1930
1931 return sz;
1932 }
1933
1934 static int write_note_info(struct elf_note_info *info,
1935 struct file *file, loff_t *foffset)
1936 {
1937 int i;
1938 struct list_head *t;
1939
1940 for (i = 0; i < info->numnote; i++)
1941 if (!writenote(info->notes + i, file, foffset))
1942 return 0;
1943
1944 /* write out the thread status notes section */
1945 list_for_each(t, &info->thread_list) {
1946 struct elf_thread_status *tmp =
1947 list_entry(t, struct elf_thread_status, list);
1948
1949 for (i = 0; i < tmp->num_notes; i++)
1950 if (!writenote(&tmp->notes[i], file, foffset))
1951 return 0;
1952 }
1953
1954 return 1;
1955 }
1956
1957 static void free_note_info(struct elf_note_info *info)
1958 {
1959 while (!list_empty(&info->thread_list)) {
1960 struct list_head *tmp = info->thread_list.next;
1961 list_del(tmp);
1962 kfree(list_entry(tmp, struct elf_thread_status, list));
1963 }
1964
1965 /* Free data allocated by fill_files_note(): */
1966 vfree(info->notes[4].data);
1967
1968 kfree(info->prstatus);
1969 kfree(info->psinfo);
1970 kfree(info->notes);
1971 kfree(info->fpu);
1972 #ifdef ELF_CORE_COPY_XFPREGS
1973 kfree(info->xfpu);
1974 #endif
1975 }
1976
1977 #endif
1978
1979 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1980 struct vm_area_struct *gate_vma)
1981 {
1982 struct vm_area_struct *ret = tsk->mm->mmap;
1983
1984 if (ret)
1985 return ret;
1986 return gate_vma;
1987 }
1988 /*
1989 * Helper function for iterating across a vma list. It ensures that the caller
1990 * will visit `gate_vma' prior to terminating the search.
1991 */
1992 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1993 struct vm_area_struct *gate_vma)
1994 {
1995 struct vm_area_struct *ret;
1996
1997 ret = this_vma->vm_next;
1998 if (ret)
1999 return ret;
2000 if (this_vma == gate_vma)
2001 return NULL;
2002 return gate_vma;
2003 }
2004
2005 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
2006 elf_addr_t e_shoff, int segs)
2007 {
2008 elf->e_shoff = e_shoff;
2009 elf->e_shentsize = sizeof(*shdr4extnum);
2010 elf->e_shnum = 1;
2011 elf->e_shstrndx = SHN_UNDEF;
2012
2013 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
2014
2015 shdr4extnum->sh_type = SHT_NULL;
2016 shdr4extnum->sh_size = elf->e_shnum;
2017 shdr4extnum->sh_link = elf->e_shstrndx;
2018 shdr4extnum->sh_info = segs;
2019 }
2020
2021 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
2022 unsigned long mm_flags)
2023 {
2024 struct vm_area_struct *vma;
2025 size_t size = 0;
2026
2027 for (vma = first_vma(current, gate_vma); vma != NULL;
2028 vma = next_vma(vma, gate_vma))
2029 size += vma_dump_size(vma, mm_flags);
2030 return size;
2031 }
2032
2033 /*
2034 * Actual dumper
2035 *
2036 * This is a two-pass process; first we find the offsets of the bits,
2037 * and then they are actually written out. If we run out of core limit
2038 * we just truncate.
2039 */
2040 static int elf_core_dump(struct coredump_params *cprm)
2041 {
2042 int has_dumped = 0;
2043 mm_segment_t fs;
2044 int segs;
2045 size_t size = 0;
2046 struct vm_area_struct *vma, *gate_vma;
2047 struct elfhdr *elf = NULL;
2048 loff_t offset = 0, dataoff, foffset;
2049 struct elf_note_info info;
2050 struct elf_phdr *phdr4note = NULL;
2051 struct elf_shdr *shdr4extnum = NULL;
2052 Elf_Half e_phnum;
2053 elf_addr_t e_shoff;
2054
2055 /*
2056 * We no longer stop all VM operations.
2057 *
2058 * This is because those proceses that could possibly change map_count
2059 * or the mmap / vma pages are now blocked in do_exit on current
2060 * finishing this core dump.
2061 *
2062 * Only ptrace can touch these memory addresses, but it doesn't change
2063 * the map_count or the pages allocated. So no possibility of crashing
2064 * exists while dumping the mm->vm_next areas to the core file.
2065 */
2066
2067 /* alloc memory for large data structures: too large to be on stack */
2068 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
2069 if (!elf)
2070 goto out;
2071 /*
2072 * The number of segs are recored into ELF header as 16bit value.
2073 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2074 */
2075 segs = current->mm->map_count;
2076 segs += elf_core_extra_phdrs();
2077
2078 gate_vma = get_gate_vma(current->mm);
2079 if (gate_vma != NULL)
2080 segs++;
2081
2082 /* for notes section */
2083 segs++;
2084
2085 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2086 * this, kernel supports extended numbering. Have a look at
2087 * include/linux/elf.h for further information. */
2088 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2089
2090 /*
2091 * Collect all the non-memory information about the process for the
2092 * notes. This also sets up the file header.
2093 */
2094 if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2095 goto cleanup;
2096
2097 has_dumped = 1;
2098
2099 fs = get_fs();
2100 set_fs(KERNEL_DS);
2101
2102 offset += sizeof(*elf); /* Elf header */
2103 offset += segs * sizeof(struct elf_phdr); /* Program headers */
2104 foffset = offset;
2105
2106 /* Write notes phdr entry */
2107 {
2108 size_t sz = get_note_info_size(&info);
2109
2110 sz += elf_coredump_extra_notes_size();
2111
2112 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2113 if (!phdr4note)
2114 goto end_coredump;
2115
2116 fill_elf_note_phdr(phdr4note, sz, offset);
2117 offset += sz;
2118 }
2119
2120 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2121
2122 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
2123 offset += elf_core_extra_data_size();
2124 e_shoff = offset;
2125
2126 if (e_phnum == PN_XNUM) {
2127 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2128 if (!shdr4extnum)
2129 goto end_coredump;
2130 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
2131 }
2132
2133 offset = dataoff;
2134
2135 size += sizeof(*elf);
2136 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
2137 goto end_coredump;
2138
2139 size += sizeof(*phdr4note);
2140 if (size > cprm->limit
2141 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
2142 goto end_coredump;
2143
2144 /* Write program headers for segments dump */
2145 for (vma = first_vma(current, gate_vma); vma != NULL;
2146 vma = next_vma(vma, gate_vma)) {
2147 struct elf_phdr phdr;
2148
2149 phdr.p_type = PT_LOAD;
2150 phdr.p_offset = offset;
2151 phdr.p_vaddr = vma->vm_start;
2152 phdr.p_paddr = 0;
2153 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
2154 phdr.p_memsz = vma->vm_end - vma->vm_start;
2155 offset += phdr.p_filesz;
2156 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2157 if (vma->vm_flags & VM_WRITE)
2158 phdr.p_flags |= PF_W;
2159 if (vma->vm_flags & VM_EXEC)
2160 phdr.p_flags |= PF_X;
2161 phdr.p_align = ELF_EXEC_PAGESIZE;
2162
2163 size += sizeof(phdr);
2164 if (size > cprm->limit
2165 || !dump_write(cprm->file, &phdr, sizeof(phdr)))
2166 goto end_coredump;
2167 }
2168
2169 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
2170 goto end_coredump;
2171
2172 /* write out the notes section */
2173 if (!write_note_info(&info, cprm->file, &foffset))
2174 goto end_coredump;
2175
2176 if (elf_coredump_extra_notes_write(cprm->file, &foffset))
2177 goto end_coredump;
2178
2179 /* Align to page */
2180 if (!dump_seek(cprm->file, dataoff - foffset))
2181 goto end_coredump;
2182
2183 for (vma = first_vma(current, gate_vma); vma != NULL;
2184 vma = next_vma(vma, gate_vma)) {
2185 unsigned long addr;
2186 unsigned long end;
2187
2188 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
2189
2190 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2191 struct page *page;
2192 int stop;
2193
2194 page = get_dump_page(addr);
2195 if (page) {
2196 void *kaddr = kmap(page);
2197 stop = ((size += PAGE_SIZE) > cprm->limit) ||
2198 !dump_write(cprm->file, kaddr,
2199 PAGE_SIZE);
2200 kunmap(page);
2201 page_cache_release(page);
2202 } else
2203 stop = !dump_seek(cprm->file, PAGE_SIZE);
2204 if (stop)
2205 goto end_coredump;
2206 }
2207 }
2208
2209 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
2210 goto end_coredump;
2211
2212 if (e_phnum == PN_XNUM) {
2213 size += sizeof(*shdr4extnum);
2214 if (size > cprm->limit
2215 || !dump_write(cprm->file, shdr4extnum,
2216 sizeof(*shdr4extnum)))
2217 goto end_coredump;
2218 }
2219
2220 end_coredump:
2221 set_fs(fs);
2222
2223 cleanup:
2224 free_note_info(&info);
2225 kfree(shdr4extnum);
2226 kfree(phdr4note);
2227 kfree(elf);
2228 out:
2229 return has_dumped;
2230 }
2231
2232 #endif /* CONFIG_ELF_CORE */
2233
2234 static int __init init_elf_binfmt(void)
2235 {
2236 register_binfmt(&elf_format);
2237 return 0;
2238 }
2239
2240 static void __exit exit_elf_binfmt(void)
2241 {
2242 /* Remove the COFF and ELF loaders. */
2243 unregister_binfmt(&elf_format);
2244 }
2245
2246 core_initcall(init_elf_binfmt);
2247 module_exit(exit_elf_binfmt);
2248 MODULE_LICENSE("GPL");
kernel source for telekom puls (alcatel/mediatek)