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Revert some of "binfmt_elf: cleanups"
[deliverable/linux.git] / fs / binfmt_elf.c
1 /*
2 * linux/fs/binfmt_elf.c
3 *
4 * These are the functions used to load ELF format executables as used
5 * on SVr4 machines. Information on the format may be found in the book
6 * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
7 * Tools".
8 *
9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
10 */
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/fs.h>
15 #include <linux/mm.h>
16 #include <linux/mman.h>
17 #include <linux/errno.h>
18 #include <linux/signal.h>
19 #include <linux/binfmts.h>
20 #include <linux/string.h>
21 #include <linux/file.h>
22 #include <linux/slab.h>
23 #include <linux/personality.h>
24 #include <linux/elfcore.h>
25 #include <linux/init.h>
26 #include <linux/highuid.h>
27 #include <linux/compiler.h>
28 #include <linux/highmem.h>
29 #include <linux/pagemap.h>
30 #include <linux/vmalloc.h>
31 #include <linux/security.h>
32 #include <linux/random.h>
33 #include <linux/elf.h>
34 #include <linux/utsname.h>
35 #include <linux/coredump.h>
36 #include <asm/uaccess.h>
37 #include <asm/param.h>
38 #include <asm/page.h>
39
40 #ifndef user_long_t
41 #define user_long_t long
42 #endif
43 #ifndef user_siginfo_t
44 #define user_siginfo_t siginfo_t
45 #endif
46
47 static int load_elf_binary(struct linux_binprm *bprm);
48 static int load_elf_library(struct file *);
49 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
50 int, int, unsigned long);
51
52 /*
53 * If we don't support core dumping, then supply a NULL so we
54 * don't even try.
55 */
56 #ifdef CONFIG_ELF_CORE
57 static int elf_core_dump(struct coredump_params *cprm);
58 #else
59 #define elf_core_dump NULL
60 #endif
61
62 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
63 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
64 #else
65 #define ELF_MIN_ALIGN PAGE_SIZE
66 #endif
67
68 #ifndef ELF_CORE_EFLAGS
69 #define ELF_CORE_EFLAGS 0
70 #endif
71
72 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
73 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
74 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
75
76 static struct linux_binfmt elf_format = {
77 .module = THIS_MODULE,
78 .load_binary = load_elf_binary,
79 .load_shlib = load_elf_library,
80 .core_dump = elf_core_dump,
81 .min_coredump = ELF_EXEC_PAGESIZE,
82 };
83
84 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
85
86 static int set_brk(unsigned long start, unsigned long end)
87 {
88 start = ELF_PAGEALIGN(start);
89 end = ELF_PAGEALIGN(end);
90 if (end > start) {
91 unsigned long addr;
92 addr = vm_brk(start, end - start);
93 if (BAD_ADDR(addr))
94 return addr;
95 }
96 current->mm->start_brk = current->mm->brk = end;
97 return 0;
98 }
99
100 /* We need to explicitly zero any fractional pages
101 after the data section (i.e. bss). This would
102 contain the junk from the file that should not
103 be in memory
104 */
105 static int padzero(unsigned long elf_bss)
106 {
107 unsigned long nbyte;
108
109 nbyte = ELF_PAGEOFFSET(elf_bss);
110 if (nbyte) {
111 nbyte = ELF_MIN_ALIGN - nbyte;
112 if (clear_user((void __user *) elf_bss, nbyte))
113 return -EFAULT;
114 }
115 return 0;
116 }
117
118 /* Let's use some macros to make this stack manipulation a little clearer */
119 #ifdef CONFIG_STACK_GROWSUP
120 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
121 #define STACK_ROUND(sp, items) \
122 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
123 #define STACK_ALLOC(sp, len) ({ \
124 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
125 old_sp; })
126 #else
127 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
128 #define STACK_ROUND(sp, items) \
129 (((unsigned long) (sp - items)) &~ 15UL)
130 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
131 #endif
132
133 #ifndef ELF_BASE_PLATFORM
134 /*
135 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
136 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
137 * will be copied to the user stack in the same manner as AT_PLATFORM.
138 */
139 #define ELF_BASE_PLATFORM NULL
140 #endif
141
142 static int
143 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
144 unsigned long load_addr, unsigned long interp_load_addr)
145 {
146 unsigned long p = bprm->p;
147 int argc = bprm->argc;
148 int envc = bprm->envc;
149 elf_addr_t __user *argv;
150 elf_addr_t __user *envp;
151 elf_addr_t __user *sp;
152 elf_addr_t __user *u_platform;
153 elf_addr_t __user *u_base_platform;
154 elf_addr_t __user *u_rand_bytes;
155 const char *k_platform = ELF_PLATFORM;
156 const char *k_base_platform = ELF_BASE_PLATFORM;
157 unsigned char k_rand_bytes[16];
158 int items;
159 elf_addr_t *elf_info;
160 int ei_index = 0;
161 const struct cred *cred = current_cred();
162 struct vm_area_struct *vma;
163
164 /*
165 * In some cases (e.g. Hyper-Threading), we want to avoid L1
166 * evictions by the processes running on the same package. One
167 * thing we can do is to shuffle the initial stack for them.
168 */
169
170 p = arch_align_stack(p);
171
172 /*
173 * If this architecture has a platform capability string, copy it
174 * to userspace. In some cases (Sparc), this info is impossible
175 * for userspace to get any other way, in others (i386) it is
176 * merely difficult.
177 */
178 u_platform = NULL;
179 if (k_platform) {
180 size_t len = strlen(k_platform) + 1;
181
182 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
183 if (__copy_to_user(u_platform, k_platform, len))
184 return -EFAULT;
185 }
186
187 /*
188 * If this architecture has a "base" platform capability
189 * string, copy it to userspace.
190 */
191 u_base_platform = NULL;
192 if (k_base_platform) {
193 size_t len = strlen(k_base_platform) + 1;
194
195 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
196 if (__copy_to_user(u_base_platform, k_base_platform, len))
197 return -EFAULT;
198 }
199
200 /*
201 * Generate 16 random bytes for userspace PRNG seeding.
202 */
203 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
204 u_rand_bytes = (elf_addr_t __user *)
205 STACK_ALLOC(p, sizeof(k_rand_bytes));
206 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
207 return -EFAULT;
208
209 /* Create the ELF interpreter info */
210 elf_info = (elf_addr_t *)current->mm->saved_auxv;
211 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
212 #define NEW_AUX_ENT(id, val) \
213 do { \
214 elf_info[ei_index++] = id; \
215 elf_info[ei_index++] = val; \
216 } while (0)
217
218 #ifdef ARCH_DLINFO
219 /*
220 * ARCH_DLINFO must come first so PPC can do its special alignment of
221 * AUXV.
222 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
223 * ARCH_DLINFO changes
224 */
225 ARCH_DLINFO;
226 #endif
227 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
228 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
229 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
230 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
231 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
232 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
233 NEW_AUX_ENT(AT_BASE, interp_load_addr);
234 NEW_AUX_ENT(AT_FLAGS, 0);
235 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
236 NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
237 NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
238 NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
239 NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
240 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
241 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
242 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
243 if (k_platform) {
244 NEW_AUX_ENT(AT_PLATFORM,
245 (elf_addr_t)(unsigned long)u_platform);
246 }
247 if (k_base_platform) {
248 NEW_AUX_ENT(AT_BASE_PLATFORM,
249 (elf_addr_t)(unsigned long)u_base_platform);
250 }
251 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
252 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
253 }
254 #undef NEW_AUX_ENT
255 /* AT_NULL is zero; clear the rest too */
256 memset(&elf_info[ei_index], 0,
257 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
258
259 /* And advance past the AT_NULL entry. */
260 ei_index += 2;
261
262 sp = STACK_ADD(p, ei_index);
263
264 items = (argc + 1) + (envc + 1) + 1;
265 bprm->p = STACK_ROUND(sp, items);
266
267 /* Point sp at the lowest address on the stack */
268 #ifdef CONFIG_STACK_GROWSUP
269 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
270 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
271 #else
272 sp = (elf_addr_t __user *)bprm->p;
273 #endif
274
275
276 /*
277 * Grow the stack manually; some architectures have a limit on how
278 * far ahead a user-space access may be in order to grow the stack.
279 */
280 vma = find_extend_vma(current->mm, bprm->p);
281 if (!vma)
282 return -EFAULT;
283
284 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
285 if (__put_user(argc, sp++))
286 return -EFAULT;
287 argv = sp;
288 envp = argv + argc + 1;
289
290 /* Populate argv and envp */
291 p = current->mm->arg_end = current->mm->arg_start;
292 while (argc-- > 0) {
293 size_t len;
294 if (__put_user((elf_addr_t)p, argv++))
295 return -EFAULT;
296 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
297 if (!len || len > MAX_ARG_STRLEN)
298 return -EINVAL;
299 p += len;
300 }
301 if (__put_user(0, argv))
302 return -EFAULT;
303 current->mm->arg_end = current->mm->env_start = p;
304 while (envc-- > 0) {
305 size_t len;
306 if (__put_user((elf_addr_t)p, envp++))
307 return -EFAULT;
308 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
309 if (!len || len > MAX_ARG_STRLEN)
310 return -EINVAL;
311 p += len;
312 }
313 if (__put_user(0, envp))
314 return -EFAULT;
315 current->mm->env_end = p;
316
317 /* Put the elf_info on the stack in the right place. */
318 sp = (elf_addr_t __user *)envp + 1;
319 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
320 return -EFAULT;
321 return 0;
322 }
323
324 #ifndef elf_map
325
326 static unsigned long elf_map(struct file *filep, unsigned long addr,
327 struct elf_phdr *eppnt, int prot, int type,
328 unsigned long total_size)
329 {
330 unsigned long map_addr;
331 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
332 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
333 addr = ELF_PAGESTART(addr);
334 size = ELF_PAGEALIGN(size);
335
336 /* mmap() will return -EINVAL if given a zero size, but a
337 * segment with zero filesize is perfectly valid */
338 if (!size)
339 return addr;
340
341 /*
342 * total_size is the size of the ELF (interpreter) image.
343 * The _first_ mmap needs to know the full size, otherwise
344 * randomization might put this image into an overlapping
345 * position with the ELF binary image. (since size < total_size)
346 * So we first map the 'big' image - and unmap the remainder at
347 * the end. (which unmap is needed for ELF images with holes.)
348 */
349 if (total_size) {
350 total_size = ELF_PAGEALIGN(total_size);
351 map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
352 if (!BAD_ADDR(map_addr))
353 vm_munmap(map_addr+size, total_size-size);
354 } else
355 map_addr = vm_mmap(filep, addr, size, prot, type, off);
356
357 return(map_addr);
358 }
359
360 #endif /* !elf_map */
361
362 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
363 {
364 int i, first_idx = -1, last_idx = -1;
365
366 for (i = 0; i < nr; i++) {
367 if (cmds[i].p_type == PT_LOAD) {
368 last_idx = i;
369 if (first_idx == -1)
370 first_idx = i;
371 }
372 }
373 if (first_idx == -1)
374 return 0;
375
376 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
377 ELF_PAGESTART(cmds[first_idx].p_vaddr);
378 }
379
380
381 /* This is much more generalized than the library routine read function,
382 so we keep this separate. Technically the library read function
383 is only provided so that we can read a.out libraries that have
384 an ELF header */
385
386 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
387 struct file *interpreter, unsigned long *interp_map_addr,
388 unsigned long no_base)
389 {
390 struct elf_phdr *elf_phdata;
391 struct elf_phdr *eppnt;
392 unsigned long load_addr = 0;
393 int load_addr_set = 0;
394 unsigned long last_bss = 0, elf_bss = 0;
395 unsigned long error = ~0UL;
396 unsigned long total_size;
397 int retval, i, size;
398
399 /* First of all, some simple consistency checks */
400 if (interp_elf_ex->e_type != ET_EXEC &&
401 interp_elf_ex->e_type != ET_DYN)
402 goto out;
403 if (!elf_check_arch(interp_elf_ex))
404 goto out;
405 if (!interpreter->f_op || !interpreter->f_op->mmap)
406 goto out;
407
408 /*
409 * If the size of this structure has changed, then punt, since
410 * we will be doing the wrong thing.
411 */
412 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
413 goto out;
414 if (interp_elf_ex->e_phnum < 1 ||
415 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
416 goto out;
417
418 /* Now read in all of the header information */
419 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
420 if (size > ELF_MIN_ALIGN)
421 goto out;
422 elf_phdata = kmalloc(size, GFP_KERNEL);
423 if (!elf_phdata)
424 goto out;
425
426 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
427 (char *)elf_phdata, size);
428 error = -EIO;
429 if (retval != size) {
430 if (retval < 0)
431 error = retval;
432 goto out_close;
433 }
434
435 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
436 if (!total_size) {
437 error = -EINVAL;
438 goto out_close;
439 }
440
441 eppnt = elf_phdata;
442 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
443 if (eppnt->p_type == PT_LOAD) {
444 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
445 int elf_prot = 0;
446 unsigned long vaddr = 0;
447 unsigned long k, map_addr;
448
449 if (eppnt->p_flags & PF_R)
450 elf_prot = PROT_READ;
451 if (eppnt->p_flags & PF_W)
452 elf_prot |= PROT_WRITE;
453 if (eppnt->p_flags & PF_X)
454 elf_prot |= PROT_EXEC;
455 vaddr = eppnt->p_vaddr;
456 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
457 elf_type |= MAP_FIXED;
458 else if (no_base && interp_elf_ex->e_type == ET_DYN)
459 load_addr = -vaddr;
460
461 map_addr = elf_map(interpreter, load_addr + vaddr,
462 eppnt, elf_prot, elf_type, total_size);
463 total_size = 0;
464 if (!*interp_map_addr)
465 *interp_map_addr = map_addr;
466 error = map_addr;
467 if (BAD_ADDR(map_addr))
468 goto out_close;
469
470 if (!load_addr_set &&
471 interp_elf_ex->e_type == ET_DYN) {
472 load_addr = map_addr - ELF_PAGESTART(vaddr);
473 load_addr_set = 1;
474 }
475
476 /*
477 * Check to see if the section's size will overflow the
478 * allowed task size. Note that p_filesz must always be
479 * <= p_memsize so it's only necessary to check p_memsz.
480 */
481 k = load_addr + eppnt->p_vaddr;
482 if (BAD_ADDR(k) ||
483 eppnt->p_filesz > eppnt->p_memsz ||
484 eppnt->p_memsz > TASK_SIZE ||
485 TASK_SIZE - eppnt->p_memsz < k) {
486 error = -ENOMEM;
487 goto out_close;
488 }
489
490 /*
491 * Find the end of the file mapping for this phdr, and
492 * keep track of the largest address we see for this.
493 */
494 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
495 if (k > elf_bss)
496 elf_bss = k;
497
498 /*
499 * Do the same thing for the memory mapping - between
500 * elf_bss and last_bss is the bss section.
501 */
502 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
503 if (k > last_bss)
504 last_bss = k;
505 }
506 }
507
508 if (last_bss > elf_bss) {
509 /*
510 * Now fill out the bss section. First pad the last page up
511 * to the page boundary, and then perform a mmap to make sure
512 * that there are zero-mapped pages up to and including the
513 * last bss page.
514 */
515 if (padzero(elf_bss)) {
516 error = -EFAULT;
517 goto out_close;
518 }
519
520 /* What we have mapped so far */
521 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
522
523 /* Map the last of the bss segment */
524 error = vm_brk(elf_bss, last_bss - elf_bss);
525 if (BAD_ADDR(error))
526 goto out_close;
527 }
528
529 error = load_addr;
530
531 out_close:
532 kfree(elf_phdata);
533 out:
534 return error;
535 }
536
537 /*
538 * These are the functions used to load ELF style executables and shared
539 * libraries. There is no binary dependent code anywhere else.
540 */
541
542 #define INTERPRETER_NONE 0
543 #define INTERPRETER_ELF 2
544
545 #ifndef STACK_RND_MASK
546 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
547 #endif
548
549 static unsigned long randomize_stack_top(unsigned long stack_top)
550 {
551 unsigned int random_variable = 0;
552
553 if ((current->flags & PF_RANDOMIZE) &&
554 !(current->personality & ADDR_NO_RANDOMIZE)) {
555 random_variable = get_random_int() & STACK_RND_MASK;
556 random_variable <<= PAGE_SHIFT;
557 }
558 #ifdef CONFIG_STACK_GROWSUP
559 return PAGE_ALIGN(stack_top) + random_variable;
560 #else
561 return PAGE_ALIGN(stack_top) - random_variable;
562 #endif
563 }
564
565 static int load_elf_binary(struct linux_binprm *bprm)
566 {
567 struct file *interpreter = NULL; /* to shut gcc up */
568 unsigned long load_addr = 0, load_bias = 0;
569 int load_addr_set = 0;
570 char * elf_interpreter = NULL;
571 unsigned long error;
572 struct elf_phdr *elf_ppnt, *elf_phdata;
573 unsigned long elf_bss, elf_brk;
574 int retval, i;
575 unsigned int size;
576 unsigned long elf_entry;
577 unsigned long interp_load_addr = 0;
578 unsigned long start_code, end_code, start_data, end_data;
579 unsigned long reloc_func_desc __maybe_unused = 0;
580 int executable_stack = EXSTACK_DEFAULT;
581 unsigned long def_flags = 0;
582 struct pt_regs *regs = current_pt_regs();
583 struct {
584 struct elfhdr elf_ex;
585 struct elfhdr interp_elf_ex;
586 } *loc;
587
588 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
589 if (!loc) {
590 retval = -ENOMEM;
591 goto out_ret;
592 }
593
594 /* Get the exec-header */
595 loc->elf_ex = *((struct elfhdr *)bprm->buf);
596
597 retval = -ENOEXEC;
598 /* First of all, some simple consistency checks */
599 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
600 goto out;
601
602 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
603 goto out;
604 if (!elf_check_arch(&loc->elf_ex))
605 goto out;
606 if (!bprm->file->f_op || !bprm->file->f_op->mmap)
607 goto out;
608
609 /* Now read in all of the header information */
610 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
611 goto out;
612 if (loc->elf_ex.e_phnum < 1 ||
613 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
614 goto out;
615 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
616 retval = -ENOMEM;
617 elf_phdata = kmalloc(size, GFP_KERNEL);
618 if (!elf_phdata)
619 goto out;
620
621 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
622 (char *)elf_phdata, size);
623 if (retval != size) {
624 if (retval >= 0)
625 retval = -EIO;
626 goto out_free_ph;
627 }
628
629 elf_ppnt = elf_phdata;
630 elf_bss = 0;
631 elf_brk = 0;
632
633 start_code = ~0UL;
634 end_code = 0;
635 start_data = 0;
636 end_data = 0;
637
638 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
639 if (elf_ppnt->p_type == PT_INTERP) {
640 /* This is the program interpreter used for
641 * shared libraries - for now assume that this
642 * is an a.out format binary
643 */
644 retval = -ENOEXEC;
645 if (elf_ppnt->p_filesz > PATH_MAX ||
646 elf_ppnt->p_filesz < 2)
647 goto out_free_ph;
648
649 retval = -ENOMEM;
650 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
651 GFP_KERNEL);
652 if (!elf_interpreter)
653 goto out_free_ph;
654
655 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
656 elf_interpreter,
657 elf_ppnt->p_filesz);
658 if (retval != elf_ppnt->p_filesz) {
659 if (retval >= 0)
660 retval = -EIO;
661 goto out_free_interp;
662 }
663 /* make sure path is NULL terminated */
664 retval = -ENOEXEC;
665 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
666 goto out_free_interp;
667
668 interpreter = open_exec(elf_interpreter);
669 retval = PTR_ERR(interpreter);
670 if (IS_ERR(interpreter))
671 goto out_free_interp;
672
673 /*
674 * If the binary is not readable then enforce
675 * mm->dumpable = 0 regardless of the interpreter's
676 * permissions.
677 */
678 would_dump(bprm, interpreter);
679
680 retval = kernel_read(interpreter, 0, bprm->buf,
681 BINPRM_BUF_SIZE);
682 if (retval != BINPRM_BUF_SIZE) {
683 if (retval >= 0)
684 retval = -EIO;
685 goto out_free_dentry;
686 }
687
688 /* Get the exec headers */
689 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
690 break;
691 }
692 elf_ppnt++;
693 }
694
695 elf_ppnt = elf_phdata;
696 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
697 if (elf_ppnt->p_type == PT_GNU_STACK) {
698 if (elf_ppnt->p_flags & PF_X)
699 executable_stack = EXSTACK_ENABLE_X;
700 else
701 executable_stack = EXSTACK_DISABLE_X;
702 break;
703 }
704
705 /* Some simple consistency checks for the interpreter */
706 if (elf_interpreter) {
707 retval = -ELIBBAD;
708 /* Not an ELF interpreter */
709 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
710 goto out_free_dentry;
711 /* Verify the interpreter has a valid arch */
712 if (!elf_check_arch(&loc->interp_elf_ex))
713 goto out_free_dentry;
714 }
715
716 /* Flush all traces of the currently running executable */
717 retval = flush_old_exec(bprm);
718 if (retval)
719 goto out_free_dentry;
720
721 /* OK, This is the point of no return */
722 current->mm->def_flags = def_flags;
723
724 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
725 may depend on the personality. */
726 SET_PERSONALITY(loc->elf_ex);
727 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
728 current->personality |= READ_IMPLIES_EXEC;
729
730 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
731 current->flags |= PF_RANDOMIZE;
732
733 setup_new_exec(bprm);
734
735 /* Do this so that we can load the interpreter, if need be. We will
736 change some of these later */
737 current->mm->free_area_cache = current->mm->mmap_base;
738 current->mm->cached_hole_size = 0;
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.
806 * If that is the case, retain the original non-zero
807 * load_bias value in order to establish proper
808 * non-randomized mappings.
809 */
810 if (current->flags & PF_RANDOMIZE)
811 load_bias = 0;
812 else
813 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
814 #else
815 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
816 #endif
817 }
818
819 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
820 elf_prot, elf_flags, 0);
821 if (BAD_ADDR(error)) {
822 send_sig(SIGKILL, current, 0);
823 retval = IS_ERR((void *)error) ?
824 PTR_ERR((void*)error) : -EINVAL;
825 goto out_free_dentry;
826 }
827
828 if (!load_addr_set) {
829 load_addr_set = 1;
830 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
831 if (loc->elf_ex.e_type == ET_DYN) {
832 load_bias += error -
833 ELF_PAGESTART(load_bias + vaddr);
834 load_addr += load_bias;
835 reloc_func_desc = load_bias;
836 }
837 }
838 k = elf_ppnt->p_vaddr;
839 if (k < start_code)
840 start_code = k;
841 if (start_data < k)
842 start_data = k;
843
844 /*
845 * Check to see if the section's size will overflow the
846 * allowed task size. Note that p_filesz must always be
847 * <= p_memsz so it is only necessary to check p_memsz.
848 */
849 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
850 elf_ppnt->p_memsz > TASK_SIZE ||
851 TASK_SIZE - elf_ppnt->p_memsz < k) {
852 /* set_brk can never work. Avoid overflows. */
853 send_sig(SIGKILL, current, 0);
854 retval = -EINVAL;
855 goto out_free_dentry;
856 }
857
858 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
859
860 if (k > elf_bss)
861 elf_bss = k;
862 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
863 end_code = k;
864 if (end_data < k)
865 end_data = k;
866 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
867 if (k > elf_brk)
868 elf_brk = k;
869 }
870
871 loc->elf_ex.e_entry += load_bias;
872 elf_bss += load_bias;
873 elf_brk += load_bias;
874 start_code += load_bias;
875 end_code += load_bias;
876 start_data += load_bias;
877 end_data += load_bias;
878
879 /* Calling set_brk effectively mmaps the pages that we need
880 * for the bss and break sections. We must do this before
881 * mapping in the interpreter, to make sure it doesn't wind
882 * up getting placed where the bss needs to go.
883 */
884 retval = set_brk(elf_bss, elf_brk);
885 if (retval) {
886 send_sig(SIGKILL, current, 0);
887 goto out_free_dentry;
888 }
889 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
890 send_sig(SIGSEGV, current, 0);
891 retval = -EFAULT; /* Nobody gets to see this, but.. */
892 goto out_free_dentry;
893 }
894
895 if (elf_interpreter) {
896 unsigned long interp_map_addr = 0;
897
898 elf_entry = load_elf_interp(&loc->interp_elf_ex,
899 interpreter,
900 &interp_map_addr,
901 load_bias);
902 if (!IS_ERR((void *)elf_entry)) {
903 /*
904 * load_elf_interp() returns relocation
905 * adjustment
906 */
907 interp_load_addr = elf_entry;
908 elf_entry += loc->interp_elf_ex.e_entry;
909 }
910 if (BAD_ADDR(elf_entry)) {
911 force_sig(SIGSEGV, current);
912 retval = IS_ERR((void *)elf_entry) ?
913 (int)elf_entry : -EINVAL;
914 goto out_free_dentry;
915 }
916 reloc_func_desc = interp_load_addr;
917
918 allow_write_access(interpreter);
919 fput(interpreter);
920 kfree(elf_interpreter);
921 } else {
922 elf_entry = loc->elf_ex.e_entry;
923 if (BAD_ADDR(elf_entry)) {
924 force_sig(SIGSEGV, current);
925 retval = -EINVAL;
926 goto out_free_dentry;
927 }
928 }
929
930 kfree(elf_phdata);
931
932 set_binfmt(&elf_format);
933
934 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
935 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
936 if (retval < 0) {
937 send_sig(SIGKILL, current, 0);
938 goto out;
939 }
940 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
941
942 install_exec_creds(bprm);
943 retval = create_elf_tables(bprm, &loc->elf_ex,
944 load_addr, interp_load_addr);
945 if (retval < 0) {
946 send_sig(SIGKILL, current, 0);
947 goto out;
948 }
949 /* N.B. passed_fileno might not be initialized? */
950 current->mm->end_code = end_code;
951 current->mm->start_code = start_code;
952 current->mm->start_data = start_data;
953 current->mm->end_data = end_data;
954 current->mm->start_stack = bprm->p;
955
956 #ifdef arch_randomize_brk
957 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
958 current->mm->brk = current->mm->start_brk =
959 arch_randomize_brk(current->mm);
960 #ifdef CONFIG_COMPAT_BRK
961 current->brk_randomized = 1;
962 #endif
963 }
964 #endif
965
966 if (current->personality & MMAP_PAGE_ZERO) {
967 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
968 and some applications "depend" upon this behavior.
969 Since we do not have the power to recompile these, we
970 emulate the SVr4 behavior. Sigh. */
971 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
972 MAP_FIXED | MAP_PRIVATE, 0);
973 }
974
975 #ifdef ELF_PLAT_INIT
976 /*
977 * The ABI may specify that certain registers be set up in special
978 * ways (on i386 %edx is the address of a DT_FINI function, for
979 * example. In addition, it may also specify (eg, PowerPC64 ELF)
980 * that the e_entry field is the address of the function descriptor
981 * for the startup routine, rather than the address of the startup
982 * routine itself. This macro performs whatever initialization to
983 * the regs structure is required as well as any relocations to the
984 * function descriptor entries when executing dynamically links apps.
985 */
986 ELF_PLAT_INIT(regs, reloc_func_desc);
987 #endif
988
989 start_thread(regs, elf_entry, bprm->p);
990 retval = 0;
991 out:
992 kfree(loc);
993 out_ret:
994 return retval;
995
996 /* error cleanup */
997 out_free_dentry:
998 allow_write_access(interpreter);
999 if (interpreter)
1000 fput(interpreter);
1001 out_free_interp:
1002 kfree(elf_interpreter);
1003 out_free_ph:
1004 kfree(elf_phdata);
1005 goto out;
1006 }
1007
1008 /* This is really simpleminded and specialized - we are loading an
1009 a.out library that is given an ELF header. */
1010 static int load_elf_library(struct file *file)
1011 {
1012 struct elf_phdr *elf_phdata;
1013 struct elf_phdr *eppnt;
1014 unsigned long elf_bss, bss, len;
1015 int retval, error, i, j;
1016 struct elfhdr elf_ex;
1017
1018 error = -ENOEXEC;
1019 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1020 if (retval != sizeof(elf_ex))
1021 goto out;
1022
1023 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1024 goto out;
1025
1026 /* First of all, some simple consistency checks */
1027 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1028 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1029 goto out;
1030
1031 /* Now read in all of the header information */
1032
1033 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1034 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1035
1036 error = -ENOMEM;
1037 elf_phdata = kmalloc(j, GFP_KERNEL);
1038 if (!elf_phdata)
1039 goto out;
1040
1041 eppnt = elf_phdata;
1042 error = -ENOEXEC;
1043 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1044 if (retval != j)
1045 goto out_free_ph;
1046
1047 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1048 if ((eppnt + i)->p_type == PT_LOAD)
1049 j++;
1050 if (j != 1)
1051 goto out_free_ph;
1052
1053 while (eppnt->p_type != PT_LOAD)
1054 eppnt++;
1055
1056 /* Now use mmap to map the library into memory. */
1057 error = vm_mmap(file,
1058 ELF_PAGESTART(eppnt->p_vaddr),
1059 (eppnt->p_filesz +
1060 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1061 PROT_READ | PROT_WRITE | PROT_EXEC,
1062 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1063 (eppnt->p_offset -
1064 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1065 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1066 goto out_free_ph;
1067
1068 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1069 if (padzero(elf_bss)) {
1070 error = -EFAULT;
1071 goto out_free_ph;
1072 }
1073
1074 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1075 ELF_MIN_ALIGN - 1);
1076 bss = eppnt->p_memsz + eppnt->p_vaddr;
1077 if (bss > len)
1078 vm_brk(len, bss - len);
1079 error = 0;
1080
1081 out_free_ph:
1082 kfree(elf_phdata);
1083 out:
1084 return error;
1085 }
1086
1087 #ifdef CONFIG_ELF_CORE
1088 /*
1089 * ELF core dumper
1090 *
1091 * Modelled on fs/exec.c:aout_core_dump()
1092 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1093 */
1094
1095 /*
1096 * The purpose of always_dump_vma() is to make sure that special kernel mappings
1097 * that are useful for post-mortem analysis are included in every core dump.
1098 * In that way we ensure that the core dump is fully interpretable later
1099 * without matching up the same kernel and hardware config to see what PC values
1100 * meant. These special mappings include - vDSO, vsyscall, and other
1101 * architecture specific mappings
1102 */
1103 static bool always_dump_vma(struct vm_area_struct *vma)
1104 {
1105 /* Any vsyscall mappings? */
1106 if (vma == get_gate_vma(vma->vm_mm))
1107 return true;
1108 /*
1109 * arch_vma_name() returns non-NULL for special architecture mappings,
1110 * such as vDSO sections.
1111 */
1112 if (arch_vma_name(vma))
1113 return true;
1114
1115 return false;
1116 }
1117
1118 /*
1119 * Decide what to dump of a segment, part, all or none.
1120 */
1121 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1122 unsigned long mm_flags)
1123 {
1124 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1125
1126 /* always dump the vdso and vsyscall sections */
1127 if (always_dump_vma(vma))
1128 goto whole;
1129
1130 if (vma->vm_flags & VM_DONTDUMP)
1131 return 0;
1132
1133 /* Hugetlb memory check */
1134 if (vma->vm_flags & VM_HUGETLB) {
1135 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1136 goto whole;
1137 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1138 goto whole;
1139 }
1140
1141 /* Do not dump I/O mapped devices or special mappings */
1142 if (vma->vm_flags & VM_IO)
1143 return 0;
1144
1145 /* By default, dump shared memory if mapped from an anonymous file. */
1146 if (vma->vm_flags & VM_SHARED) {
1147 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1148 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1149 goto whole;
1150 return 0;
1151 }
1152
1153 /* Dump segments that have been written to. */
1154 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1155 goto whole;
1156 if (vma->vm_file == NULL)
1157 return 0;
1158
1159 if (FILTER(MAPPED_PRIVATE))
1160 goto whole;
1161
1162 /*
1163 * If this looks like the beginning of a DSO or executable mapping,
1164 * check for an ELF header. If we find one, dump the first page to
1165 * aid in determining what was mapped here.
1166 */
1167 if (FILTER(ELF_HEADERS) &&
1168 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1169 u32 __user *header = (u32 __user *) vma->vm_start;
1170 u32 word;
1171 mm_segment_t fs = get_fs();
1172 /*
1173 * Doing it this way gets the constant folded by GCC.
1174 */
1175 union {
1176 u32 cmp;
1177 char elfmag[SELFMAG];
1178 } magic;
1179 BUILD_BUG_ON(SELFMAG != sizeof word);
1180 magic.elfmag[EI_MAG0] = ELFMAG0;
1181 magic.elfmag[EI_MAG1] = ELFMAG1;
1182 magic.elfmag[EI_MAG2] = ELFMAG2;
1183 magic.elfmag[EI_MAG3] = ELFMAG3;
1184 /*
1185 * Switch to the user "segment" for get_user(),
1186 * then put back what elf_core_dump() had in place.
1187 */
1188 set_fs(USER_DS);
1189 if (unlikely(get_user(word, header)))
1190 word = 0;
1191 set_fs(fs);
1192 if (word == magic.cmp)
1193 return PAGE_SIZE;
1194 }
1195
1196 #undef FILTER
1197
1198 return 0;
1199
1200 whole:
1201 return vma->vm_end - vma->vm_start;
1202 }
1203
1204 /* An ELF note in memory */
1205 struct memelfnote
1206 {
1207 const char *name;
1208 int type;
1209 unsigned int datasz;
1210 void *data;
1211 };
1212
1213 static int notesize(struct memelfnote *en)
1214 {
1215 int sz;
1216
1217 sz = sizeof(struct elf_note);
1218 sz += roundup(strlen(en->name) + 1, 4);
1219 sz += roundup(en->datasz, 4);
1220
1221 return sz;
1222 }
1223
1224 #define DUMP_WRITE(addr, nr, foffset) \
1225 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1226
1227 static int alignfile(struct file *file, loff_t *foffset)
1228 {
1229 static const char buf[4] = { 0, };
1230 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1231 return 1;
1232 }
1233
1234 static int writenote(struct memelfnote *men, struct file *file,
1235 loff_t *foffset)
1236 {
1237 struct elf_note en;
1238 en.n_namesz = strlen(men->name) + 1;
1239 en.n_descsz = men->datasz;
1240 en.n_type = men->type;
1241
1242 DUMP_WRITE(&en, sizeof(en), foffset);
1243 DUMP_WRITE(men->name, en.n_namesz, foffset);
1244 if (!alignfile(file, foffset))
1245 return 0;
1246 DUMP_WRITE(men->data, men->datasz, foffset);
1247 if (!alignfile(file, foffset))
1248 return 0;
1249
1250 return 1;
1251 }
1252 #undef DUMP_WRITE
1253
1254 static void fill_elf_header(struct elfhdr *elf, int segs,
1255 u16 machine, u32 flags, u8 osabi)
1256 {
1257 memset(elf, 0, sizeof(*elf));
1258
1259 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1260 elf->e_ident[EI_CLASS] = ELF_CLASS;
1261 elf->e_ident[EI_DATA] = ELF_DATA;
1262 elf->e_ident[EI_VERSION] = EV_CURRENT;
1263 elf->e_ident[EI_OSABI] = ELF_OSABI;
1264
1265 elf->e_type = ET_CORE;
1266 elf->e_machine = machine;
1267 elf->e_version = EV_CURRENT;
1268 elf->e_phoff = sizeof(struct elfhdr);
1269 elf->e_flags = flags;
1270 elf->e_ehsize = sizeof(struct elfhdr);
1271 elf->e_phentsize = sizeof(struct elf_phdr);
1272 elf->e_phnum = segs;
1273
1274 return;
1275 }
1276
1277 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1278 {
1279 phdr->p_type = PT_NOTE;
1280 phdr->p_offset = offset;
1281 phdr->p_vaddr = 0;
1282 phdr->p_paddr = 0;
1283 phdr->p_filesz = sz;
1284 phdr->p_memsz = 0;
1285 phdr->p_flags = 0;
1286 phdr->p_align = 0;
1287 return;
1288 }
1289
1290 static void fill_note(struct memelfnote *note, const char *name, int type,
1291 unsigned int sz, void *data)
1292 {
1293 note->name = name;
1294 note->type = type;
1295 note->datasz = sz;
1296 note->data = data;
1297 return;
1298 }
1299
1300 /*
1301 * fill up all the fields in prstatus from the given task struct, except
1302 * registers which need to be filled up separately.
1303 */
1304 static void fill_prstatus(struct elf_prstatus *prstatus,
1305 struct task_struct *p, long signr)
1306 {
1307 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1308 prstatus->pr_sigpend = p->pending.signal.sig[0];
1309 prstatus->pr_sighold = p->blocked.sig[0];
1310 rcu_read_lock();
1311 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1312 rcu_read_unlock();
1313 prstatus->pr_pid = task_pid_vnr(p);
1314 prstatus->pr_pgrp = task_pgrp_vnr(p);
1315 prstatus->pr_sid = task_session_vnr(p);
1316 if (thread_group_leader(p)) {
1317 struct task_cputime cputime;
1318
1319 /*
1320 * This is the record for the group leader. It shows the
1321 * group-wide total, not its individual thread total.
1322 */
1323 thread_group_cputime(p, &cputime);
1324 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1325 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1326 } else {
1327 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1328 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1329 }
1330 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1331 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1332 }
1333
1334 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1335 struct mm_struct *mm)
1336 {
1337 const struct cred *cred;
1338 unsigned int i, len;
1339
1340 /* first copy the parameters from user space */
1341 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1342
1343 len = mm->arg_end - mm->arg_start;
1344 if (len >= ELF_PRARGSZ)
1345 len = ELF_PRARGSZ-1;
1346 if (copy_from_user(&psinfo->pr_psargs,
1347 (const char __user *)mm->arg_start, len))
1348 return -EFAULT;
1349 for(i = 0; i < len; i++)
1350 if (psinfo->pr_psargs[i] == 0)
1351 psinfo->pr_psargs[i] = ' ';
1352 psinfo->pr_psargs[len] = 0;
1353
1354 rcu_read_lock();
1355 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1356 rcu_read_unlock();
1357 psinfo->pr_pid = task_pid_vnr(p);
1358 psinfo->pr_pgrp = task_pgrp_vnr(p);
1359 psinfo->pr_sid = task_session_vnr(p);
1360
1361 i = p->state ? ffz(~p->state) + 1 : 0;
1362 psinfo->pr_state = i;
1363 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1364 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1365 psinfo->pr_nice = task_nice(p);
1366 psinfo->pr_flag = p->flags;
1367 rcu_read_lock();
1368 cred = __task_cred(p);
1369 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1370 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1371 rcu_read_unlock();
1372 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1373
1374 return 0;
1375 }
1376
1377 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1378 {
1379 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1380 int i = 0;
1381 do
1382 i += 2;
1383 while (auxv[i - 2] != AT_NULL);
1384 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1385 }
1386
1387 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1388 siginfo_t *siginfo)
1389 {
1390 mm_segment_t old_fs = get_fs();
1391 set_fs(KERNEL_DS);
1392 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
1393 set_fs(old_fs);
1394 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1395 }
1396
1397 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1398 /*
1399 * Format of NT_FILE note:
1400 *
1401 * long count -- how many files are mapped
1402 * long page_size -- units for file_ofs
1403 * array of [COUNT] elements of
1404 * long start
1405 * long end
1406 * long file_ofs
1407 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1408 */
1409 static void fill_files_note(struct memelfnote *note)
1410 {
1411 struct vm_area_struct *vma;
1412 unsigned count, size, names_ofs, remaining, n;
1413 user_long_t *data;
1414 user_long_t *start_end_ofs;
1415 char *name_base, *name_curpos;
1416
1417 /* *Estimated* file count and total data size needed */
1418 count = current->mm->map_count;
1419 size = count * 64;
1420
1421 names_ofs = (2 + 3 * count) * sizeof(data[0]);
1422 alloc:
1423 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1424 goto err;
1425 size = round_up(size, PAGE_SIZE);
1426 data = vmalloc(size);
1427 if (!data)
1428 goto err;
1429
1430 start_end_ofs = data + 2;
1431 name_base = name_curpos = ((char *)data) + names_ofs;
1432 remaining = size - names_ofs;
1433 count = 0;
1434 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1435 struct file *file;
1436 const char *filename;
1437
1438 file = vma->vm_file;
1439 if (!file)
1440 continue;
1441 filename = d_path(&file->f_path, name_curpos, remaining);
1442 if (IS_ERR(filename)) {
1443 if (PTR_ERR(filename) == -ENAMETOOLONG) {
1444 vfree(data);
1445 size = size * 5 / 4;
1446 goto alloc;
1447 }
1448 continue;
1449 }
1450
1451 /* d_path() fills at the end, move name down */
1452 /* n = strlen(filename) + 1: */
1453 n = (name_curpos + remaining) - filename;
1454 remaining = filename - name_curpos;
1455 memmove(name_curpos, filename, n);
1456 name_curpos += n;
1457
1458 *start_end_ofs++ = vma->vm_start;
1459 *start_end_ofs++ = vma->vm_end;
1460 *start_end_ofs++ = vma->vm_pgoff;
1461 count++;
1462 }
1463
1464 /* Now we know exact count of files, can store it */
1465 data[0] = count;
1466 data[1] = PAGE_SIZE;
1467 /*
1468 * Count usually is less than current->mm->map_count,
1469 * we need to move filenames down.
1470 */
1471 n = current->mm->map_count - count;
1472 if (n != 0) {
1473 unsigned shift_bytes = n * 3 * sizeof(data[0]);
1474 memmove(name_base - shift_bytes, name_base,
1475 name_curpos - name_base);
1476 name_curpos -= shift_bytes;
1477 }
1478
1479 size = name_curpos - (char *)data;
1480 fill_note(note, "CORE", NT_FILE, size, data);
1481 err: ;
1482 }
1483
1484 #ifdef CORE_DUMP_USE_REGSET
1485 #include <linux/regset.h>
1486
1487 struct elf_thread_core_info {
1488 struct elf_thread_core_info *next;
1489 struct task_struct *task;
1490 struct elf_prstatus prstatus;
1491 struct memelfnote notes[0];
1492 };
1493
1494 struct elf_note_info {
1495 struct elf_thread_core_info *thread;
1496 struct memelfnote psinfo;
1497 struct memelfnote signote;
1498 struct memelfnote auxv;
1499 struct memelfnote files;
1500 user_siginfo_t csigdata;
1501 size_t size;
1502 int thread_notes;
1503 };
1504
1505 /*
1506 * When a regset has a writeback hook, we call it on each thread before
1507 * dumping user memory. On register window machines, this makes sure the
1508 * user memory backing the register data is up to date before we read it.
1509 */
1510 static void do_thread_regset_writeback(struct task_struct *task,
1511 const struct user_regset *regset)
1512 {
1513 if (regset->writeback)
1514 regset->writeback(task, regset, 1);
1515 }
1516
1517 #ifndef PR_REG_SIZE
1518 #define PR_REG_SIZE(S) sizeof(S)
1519 #endif
1520
1521 #ifndef PRSTATUS_SIZE
1522 #define PRSTATUS_SIZE(S) sizeof(S)
1523 #endif
1524
1525 #ifndef PR_REG_PTR
1526 #define PR_REG_PTR(S) (&((S)->pr_reg))
1527 #endif
1528
1529 #ifndef SET_PR_FPVALID
1530 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V))
1531 #endif
1532
1533 static int fill_thread_core_info(struct elf_thread_core_info *t,
1534 const struct user_regset_view *view,
1535 long signr, size_t *total)
1536 {
1537 unsigned int i;
1538
1539 /*
1540 * NT_PRSTATUS is the one special case, because the regset data
1541 * goes into the pr_reg field inside the note contents, rather
1542 * than being the whole note contents. We fill the reset in here.
1543 * We assume that regset 0 is NT_PRSTATUS.
1544 */
1545 fill_prstatus(&t->prstatus, t->task, signr);
1546 (void) view->regsets[0].get(t->task, &view->regsets[0],
1547 0, PR_REG_SIZE(t->prstatus.pr_reg),
1548 PR_REG_PTR(&t->prstatus), NULL);
1549
1550 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1551 PRSTATUS_SIZE(t->prstatus), &t->prstatus);
1552 *total += notesize(&t->notes[0]);
1553
1554 do_thread_regset_writeback(t->task, &view->regsets[0]);
1555
1556 /*
1557 * Each other regset might generate a note too. For each regset
1558 * that has no core_note_type or is inactive, we leave t->notes[i]
1559 * all zero and we'll know to skip writing it later.
1560 */
1561 for (i = 1; i < view->n; ++i) {
1562 const struct user_regset *regset = &view->regsets[i];
1563 do_thread_regset_writeback(t->task, regset);
1564 if (regset->core_note_type && regset->get &&
1565 (!regset->active || regset->active(t->task, regset))) {
1566 int ret;
1567 size_t size = regset->n * regset->size;
1568 void *data = kmalloc(size, GFP_KERNEL);
1569 if (unlikely(!data))
1570 return 0;
1571 ret = regset->get(t->task, regset,
1572 0, size, data, NULL);
1573 if (unlikely(ret))
1574 kfree(data);
1575 else {
1576 if (regset->core_note_type != NT_PRFPREG)
1577 fill_note(&t->notes[i], "LINUX",
1578 regset->core_note_type,
1579 size, data);
1580 else {
1581 SET_PR_FPVALID(&t->prstatus, 1);
1582 fill_note(&t->notes[i], "CORE",
1583 NT_PRFPREG, size, data);
1584 }
1585 *total += notesize(&t->notes[i]);
1586 }
1587 }
1588 }
1589
1590 return 1;
1591 }
1592
1593 static int fill_note_info(struct elfhdr *elf, int phdrs,
1594 struct elf_note_info *info,
1595 siginfo_t *siginfo, struct pt_regs *regs)
1596 {
1597 struct task_struct *dump_task = current;
1598 const struct user_regset_view *view = task_user_regset_view(dump_task);
1599 struct elf_thread_core_info *t;
1600 struct elf_prpsinfo *psinfo;
1601 struct core_thread *ct;
1602 unsigned int i;
1603
1604 info->size = 0;
1605 info->thread = NULL;
1606
1607 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1608 if (psinfo == NULL) {
1609 info->psinfo.data = NULL; /* So we don't free this wrongly */
1610 return 0;
1611 }
1612
1613 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1614
1615 /*
1616 * Figure out how many notes we're going to need for each thread.
1617 */
1618 info->thread_notes = 0;
1619 for (i = 0; i < view->n; ++i)
1620 if (view->regsets[i].core_note_type != 0)
1621 ++info->thread_notes;
1622
1623 /*
1624 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1625 * since it is our one special case.
1626 */
1627 if (unlikely(info->thread_notes == 0) ||
1628 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1629 WARN_ON(1);
1630 return 0;
1631 }
1632
1633 /*
1634 * Initialize the ELF file header.
1635 */
1636 fill_elf_header(elf, phdrs,
1637 view->e_machine, view->e_flags, view->ei_osabi);
1638
1639 /*
1640 * Allocate a structure for each thread.
1641 */
1642 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1643 t = kzalloc(offsetof(struct elf_thread_core_info,
1644 notes[info->thread_notes]),
1645 GFP_KERNEL);
1646 if (unlikely(!t))
1647 return 0;
1648
1649 t->task = ct->task;
1650 if (ct->task == dump_task || !info->thread) {
1651 t->next = info->thread;
1652 info->thread = t;
1653 } else {
1654 /*
1655 * Make sure to keep the original task at
1656 * the head of the list.
1657 */
1658 t->next = info->thread->next;
1659 info->thread->next = t;
1660 }
1661 }
1662
1663 /*
1664 * Now fill in each thread's information.
1665 */
1666 for (t = info->thread; t != NULL; t = t->next)
1667 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1668 return 0;
1669
1670 /*
1671 * Fill in the two process-wide notes.
1672 */
1673 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1674 info->size += notesize(&info->psinfo);
1675
1676 fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1677 info->size += notesize(&info->signote);
1678
1679 fill_auxv_note(&info->auxv, current->mm);
1680 info->size += notesize(&info->auxv);
1681
1682 fill_files_note(&info->files);
1683 info->size += notesize(&info->files);
1684
1685 return 1;
1686 }
1687
1688 static size_t get_note_info_size(struct elf_note_info *info)
1689 {
1690 return info->size;
1691 }
1692
1693 /*
1694 * Write all the notes for each thread. When writing the first thread, the
1695 * process-wide notes are interleaved after the first thread-specific note.
1696 */
1697 static int write_note_info(struct elf_note_info *info,
1698 struct file *file, loff_t *foffset)
1699 {
1700 bool first = 1;
1701 struct elf_thread_core_info *t = info->thread;
1702
1703 do {
1704 int i;
1705
1706 if (!writenote(&t->notes[0], file, foffset))
1707 return 0;
1708
1709 if (first && !writenote(&info->psinfo, file, foffset))
1710 return 0;
1711 if (first && !writenote(&info->signote, file, foffset))
1712 return 0;
1713 if (first && !writenote(&info->auxv, file, foffset))
1714 return 0;
1715 if (first && !writenote(&info->files, file, foffset))
1716 return 0;
1717
1718 for (i = 1; i < info->thread_notes; ++i)
1719 if (t->notes[i].data &&
1720 !writenote(&t->notes[i], file, foffset))
1721 return 0;
1722
1723 first = 0;
1724 t = t->next;
1725 } while (t);
1726
1727 return 1;
1728 }
1729
1730 static void free_note_info(struct elf_note_info *info)
1731 {
1732 struct elf_thread_core_info *threads = info->thread;
1733 while (threads) {
1734 unsigned int i;
1735 struct elf_thread_core_info *t = threads;
1736 threads = t->next;
1737 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1738 for (i = 1; i < info->thread_notes; ++i)
1739 kfree(t->notes[i].data);
1740 kfree(t);
1741 }
1742 kfree(info->psinfo.data);
1743 vfree(info->files.data);
1744 }
1745
1746 #else
1747
1748 /* Here is the structure in which status of each thread is captured. */
1749 struct elf_thread_status
1750 {
1751 struct list_head list;
1752 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1753 elf_fpregset_t fpu; /* NT_PRFPREG */
1754 struct task_struct *thread;
1755 #ifdef ELF_CORE_COPY_XFPREGS
1756 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1757 #endif
1758 struct memelfnote notes[3];
1759 int num_notes;
1760 };
1761
1762 /*
1763 * In order to add the specific thread information for the elf file format,
1764 * we need to keep a linked list of every threads pr_status and then create
1765 * a single section for them in the final core file.
1766 */
1767 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1768 {
1769 int sz = 0;
1770 struct task_struct *p = t->thread;
1771 t->num_notes = 0;
1772
1773 fill_prstatus(&t->prstatus, p, signr);
1774 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1775
1776 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1777 &(t->prstatus));
1778 t->num_notes++;
1779 sz += notesize(&t->notes[0]);
1780
1781 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1782 &t->fpu))) {
1783 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1784 &(t->fpu));
1785 t->num_notes++;
1786 sz += notesize(&t->notes[1]);
1787 }
1788
1789 #ifdef ELF_CORE_COPY_XFPREGS
1790 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1791 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1792 sizeof(t->xfpu), &t->xfpu);
1793 t->num_notes++;
1794 sz += notesize(&t->notes[2]);
1795 }
1796 #endif
1797 return sz;
1798 }
1799
1800 struct elf_note_info {
1801 struct memelfnote *notes;
1802 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1803 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1804 struct list_head thread_list;
1805 elf_fpregset_t *fpu;
1806 #ifdef ELF_CORE_COPY_XFPREGS
1807 elf_fpxregset_t *xfpu;
1808 #endif
1809 user_siginfo_t csigdata;
1810 int thread_status_size;
1811 int numnote;
1812 };
1813
1814 static int elf_note_info_init(struct elf_note_info *info)
1815 {
1816 memset(info, 0, sizeof(*info));
1817 INIT_LIST_HEAD(&info->thread_list);
1818
1819 /* Allocate space for ELF notes */
1820 info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL);
1821 if (!info->notes)
1822 return 0;
1823 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1824 if (!info->psinfo)
1825 return 0;
1826 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1827 if (!info->prstatus)
1828 return 0;
1829 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1830 if (!info->fpu)
1831 return 0;
1832 #ifdef ELF_CORE_COPY_XFPREGS
1833 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1834 if (!info->xfpu)
1835 return 0;
1836 #endif
1837 return 1;
1838 }
1839
1840 static int fill_note_info(struct elfhdr *elf, int phdrs,
1841 struct elf_note_info *info,
1842 siginfo_t *siginfo, struct pt_regs *regs)
1843 {
1844 struct list_head *t;
1845
1846 if (!elf_note_info_init(info))
1847 return 0;
1848
1849 if (siginfo->si_signo) {
1850 struct core_thread *ct;
1851 struct elf_thread_status *ets;
1852
1853 for (ct = current->mm->core_state->dumper.next;
1854 ct; ct = ct->next) {
1855 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1856 if (!ets)
1857 return 0;
1858
1859 ets->thread = ct->task;
1860 list_add(&ets->list, &info->thread_list);
1861 }
1862
1863 list_for_each(t, &info->thread_list) {
1864 int sz;
1865
1866 ets = list_entry(t, struct elf_thread_status, list);
1867 sz = elf_dump_thread_status(siginfo->si_signo, ets);
1868 info->thread_status_size += sz;
1869 }
1870 }
1871 /* now collect the dump for the current */
1872 memset(info->prstatus, 0, sizeof(*info->prstatus));
1873 fill_prstatus(info->prstatus, current, siginfo->si_signo);
1874 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1875
1876 /* Set up header */
1877 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);
1878
1879 /*
1880 * Set up the notes in similar form to SVR4 core dumps made
1881 * with info from their /proc.
1882 */
1883
1884 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1885 sizeof(*info->prstatus), info->prstatus);
1886 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1887 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1888 sizeof(*info->psinfo), info->psinfo);
1889
1890 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
1891 fill_auxv_note(info->notes + 3, current->mm);
1892 fill_files_note(info->notes + 4);
1893
1894 info->numnote = 5;
1895
1896 /* Try to dump the FPU. */
1897 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1898 info->fpu);
1899 if (info->prstatus->pr_fpvalid)
1900 fill_note(info->notes + info->numnote++,
1901 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1902 #ifdef ELF_CORE_COPY_XFPREGS
1903 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1904 fill_note(info->notes + info->numnote++,
1905 "LINUX", ELF_CORE_XFPREG_TYPE,
1906 sizeof(*info->xfpu), info->xfpu);
1907 #endif
1908
1909 return 1;
1910 }
1911
1912 static size_t get_note_info_size(struct elf_note_info *info)
1913 {
1914 int sz = 0;
1915 int i;
1916
1917 for (i = 0; i < info->numnote; i++)
1918 sz += notesize(info->notes + i);
1919
1920 sz += info->thread_status_size;
1921
1922 return sz;
1923 }
1924
1925 static int write_note_info(struct elf_note_info *info,
1926 struct file *file, loff_t *foffset)
1927 {
1928 int i;
1929 struct list_head *t;
1930
1931 for (i = 0; i < info->numnote; i++)
1932 if (!writenote(info->notes + i, file, foffset))
1933 return 0;
1934
1935 /* write out the thread status notes section */
1936 list_for_each(t, &info->thread_list) {
1937 struct elf_thread_status *tmp =
1938 list_entry(t, struct elf_thread_status, list);
1939
1940 for (i = 0; i < tmp->num_notes; i++)
1941 if (!writenote(&tmp->notes[i], file, foffset))
1942 return 0;
1943 }
1944
1945 return 1;
1946 }
1947
1948 static void free_note_info(struct elf_note_info *info)
1949 {
1950 while (!list_empty(&info->thread_list)) {
1951 struct list_head *tmp = info->thread_list.next;
1952 list_del(tmp);
1953 kfree(list_entry(tmp, struct elf_thread_status, list));
1954 }
1955
1956 /* Free data allocated by fill_files_note(): */
1957 vfree(info->notes[4].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 size_t size = 0;
2037 struct vm_area_struct *vma, *gate_vma;
2038 struct elfhdr *elf = NULL;
2039 loff_t offset = 0, dataoff, foffset;
2040 struct elf_note_info info;
2041 struct elf_phdr *phdr4note = NULL;
2042 struct elf_shdr *shdr4extnum = NULL;
2043 Elf_Half e_phnum;
2044 elf_addr_t e_shoff;
2045
2046 /*
2047 * We no longer stop all VM operations.
2048 *
2049 * This is because those proceses that could possibly change map_count
2050 * or the mmap / vma pages are now blocked in do_exit on current
2051 * finishing this core dump.
2052 *
2053 * Only ptrace can touch these memory addresses, but it doesn't change
2054 * the map_count or the pages allocated. So no possibility of crashing
2055 * exists while dumping the mm->vm_next areas to the core file.
2056 */
2057
2058 /* alloc memory for large data structures: too large to be on stack */
2059 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
2060 if (!elf)
2061 goto out;
2062 /*
2063 * The number of segs are recored into ELF header as 16bit value.
2064 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2065 */
2066 segs = current->mm->map_count;
2067 segs += elf_core_extra_phdrs();
2068
2069 gate_vma = get_gate_vma(current->mm);
2070 if (gate_vma != NULL)
2071 segs++;
2072
2073 /* for notes section */
2074 segs++;
2075
2076 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2077 * this, kernel supports extended numbering. Have a look at
2078 * include/linux/elf.h for further information. */
2079 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2080
2081 /*
2082 * Collect all the non-memory information about the process for the
2083 * notes. This also sets up the file header.
2084 */
2085 if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2086 goto cleanup;
2087
2088 has_dumped = 1;
2089 current->flags |= PF_DUMPCORE;
2090
2091 fs = get_fs();
2092 set_fs(KERNEL_DS);
2093
2094 offset += sizeof(*elf); /* Elf header */
2095 offset += segs * sizeof(struct elf_phdr); /* Program headers */
2096 foffset = offset;
2097
2098 /* Write notes phdr entry */
2099 {
2100 size_t sz = get_note_info_size(&info);
2101
2102 sz += elf_coredump_extra_notes_size();
2103
2104 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2105 if (!phdr4note)
2106 goto end_coredump;
2107
2108 fill_elf_note_phdr(phdr4note, sz, offset);
2109 offset += sz;
2110 }
2111
2112 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2113
2114 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
2115 offset += elf_core_extra_data_size();
2116 e_shoff = offset;
2117
2118 if (e_phnum == PN_XNUM) {
2119 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2120 if (!shdr4extnum)
2121 goto end_coredump;
2122 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
2123 }
2124
2125 offset = dataoff;
2126
2127 size += sizeof(*elf);
2128 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
2129 goto end_coredump;
2130
2131 size += sizeof(*phdr4note);
2132 if (size > cprm->limit
2133 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
2134 goto end_coredump;
2135
2136 /* Write program headers for segments dump */
2137 for (vma = first_vma(current, gate_vma); vma != NULL;
2138 vma = next_vma(vma, gate_vma)) {
2139 struct elf_phdr phdr;
2140
2141 phdr.p_type = PT_LOAD;
2142 phdr.p_offset = offset;
2143 phdr.p_vaddr = vma->vm_start;
2144 phdr.p_paddr = 0;
2145 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
2146 phdr.p_memsz = vma->vm_end - vma->vm_start;
2147 offset += phdr.p_filesz;
2148 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2149 if (vma->vm_flags & VM_WRITE)
2150 phdr.p_flags |= PF_W;
2151 if (vma->vm_flags & VM_EXEC)
2152 phdr.p_flags |= PF_X;
2153 phdr.p_align = ELF_EXEC_PAGESIZE;
2154
2155 size += sizeof(phdr);
2156 if (size > cprm->limit
2157 || !dump_write(cprm->file, &phdr, sizeof(phdr)))
2158 goto end_coredump;
2159 }
2160
2161 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
2162 goto end_coredump;
2163
2164 /* write out the notes section */
2165 if (!write_note_info(&info, cprm->file, &foffset))
2166 goto end_coredump;
2167
2168 if (elf_coredump_extra_notes_write(cprm->file, &foffset))
2169 goto end_coredump;
2170
2171 /* Align to page */
2172 if (!dump_seek(cprm->file, dataoff - foffset))
2173 goto end_coredump;
2174
2175 for (vma = first_vma(current, gate_vma); vma != NULL;
2176 vma = next_vma(vma, gate_vma)) {
2177 unsigned long addr;
2178 unsigned long end;
2179
2180 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
2181
2182 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2183 struct page *page;
2184 int stop;
2185
2186 page = get_dump_page(addr);
2187 if (page) {
2188 void *kaddr = kmap(page);
2189 stop = ((size += PAGE_SIZE) > cprm->limit) ||
2190 !dump_write(cprm->file, kaddr,
2191 PAGE_SIZE);
2192 kunmap(page);
2193 page_cache_release(page);
2194 } else
2195 stop = !dump_seek(cprm->file, PAGE_SIZE);
2196 if (stop)
2197 goto end_coredump;
2198 }
2199 }
2200
2201 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
2202 goto end_coredump;
2203
2204 if (e_phnum == PN_XNUM) {
2205 size += sizeof(*shdr4extnum);
2206 if (size > cprm->limit
2207 || !dump_write(cprm->file, shdr4extnum,
2208 sizeof(*shdr4extnum)))
2209 goto end_coredump;
2210 }
2211
2212 end_coredump:
2213 set_fs(fs);
2214
2215 cleanup:
2216 free_note_info(&info);
2217 kfree(shdr4extnum);
2218 kfree(phdr4note);
2219 kfree(elf);
2220 out:
2221 return has_dumped;
2222 }
2223
2224 #endif /* CONFIG_ELF_CORE */
2225
2226 static int __init init_elf_binfmt(void)
2227 {
2228 register_binfmt(&elf_format);
2229 return 0;
2230 }
2231
2232 static void __exit exit_elf_binfmt(void)
2233 {
2234 /* Remove the COFF and ELF loaders. */
2235 unregister_binfmt(&elf_format);
2236 }
2237
2238 core_initcall(init_elf_binfmt);
2239 module_exit(exit_elf_binfmt);
2240 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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