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xen-pciback: notify hypervisor about devices intended to be assigned to guests
[deliverable/linux.git] / fs / binfmt_elf.c
1 /*
2 * linux/fs/binfmt_elf.c
3 *
4 * These are the functions used to load ELF format executables as used
5 * on SVr4 machines. Information on the format may be found in the book
6 * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
7 * Tools".
8 *
9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
10 */
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/fs.h>
15 #include <linux/mm.h>
16 #include <linux/mman.h>
17 #include <linux/errno.h>
18 #include <linux/signal.h>
19 #include <linux/binfmts.h>
20 #include <linux/string.h>
21 #include <linux/file.h>
22 #include <linux/slab.h>
23 #include <linux/personality.h>
24 #include <linux/elfcore.h>
25 #include <linux/init.h>
26 #include <linux/highuid.h>
27 #include <linux/compiler.h>
28 #include <linux/highmem.h>
29 #include <linux/pagemap.h>
30 #include <linux/vmalloc.h>
31 #include <linux/security.h>
32 #include <linux/random.h>
33 #include <linux/elf.h>
34 #include <linux/utsname.h>
35 #include <linux/coredump.h>
36 #include <linux/sched.h>
37 #include <asm/uaccess.h>
38 #include <asm/param.h>
39 #include <asm/page.h>
40
41 #ifndef user_long_t
42 #define user_long_t long
43 #endif
44 #ifndef user_siginfo_t
45 #define user_siginfo_t siginfo_t
46 #endif
47
48 static int load_elf_binary(struct linux_binprm *bprm);
49 static int load_elf_library(struct file *);
50 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
51 int, int, unsigned long);
52
53 /*
54 * If we don't support core dumping, then supply a NULL so we
55 * don't even try.
56 */
57 #ifdef CONFIG_ELF_CORE
58 static int elf_core_dump(struct coredump_params *cprm);
59 #else
60 #define elf_core_dump NULL
61 #endif
62
63 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
64 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
65 #else
66 #define ELF_MIN_ALIGN PAGE_SIZE
67 #endif
68
69 #ifndef ELF_CORE_EFLAGS
70 #define ELF_CORE_EFLAGS 0
71 #endif
72
73 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
74 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
75 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
76
77 static struct linux_binfmt elf_format = {
78 .module = THIS_MODULE,
79 .load_binary = load_elf_binary,
80 .load_shlib = load_elf_library,
81 .core_dump = elf_core_dump,
82 .min_coredump = ELF_EXEC_PAGESIZE,
83 };
84
85 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
86
87 static int set_brk(unsigned long start, unsigned long end)
88 {
89 start = ELF_PAGEALIGN(start);
90 end = ELF_PAGEALIGN(end);
91 if (end > start) {
92 unsigned long addr;
93 addr = vm_brk(start, end - start);
94 if (BAD_ADDR(addr))
95 return addr;
96 }
97 current->mm->start_brk = current->mm->brk = end;
98 return 0;
99 }
100
101 /* We need to explicitly zero any fractional pages
102 after the data section (i.e. bss). This would
103 contain the junk from the file that should not
104 be in memory
105 */
106 static int padzero(unsigned long elf_bss)
107 {
108 unsigned long nbyte;
109
110 nbyte = ELF_PAGEOFFSET(elf_bss);
111 if (nbyte) {
112 nbyte = ELF_MIN_ALIGN - nbyte;
113 if (clear_user((void __user *) elf_bss, nbyte))
114 return -EFAULT;
115 }
116 return 0;
117 }
118
119 /* Let's use some macros to make this stack manipulation a little clearer */
120 #ifdef CONFIG_STACK_GROWSUP
121 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
122 #define STACK_ROUND(sp, items) \
123 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
124 #define STACK_ALLOC(sp, len) ({ \
125 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
126 old_sp; })
127 #else
128 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
129 #define STACK_ROUND(sp, items) \
130 (((unsigned long) (sp - items)) &~ 15UL)
131 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
132 #endif
133
134 #ifndef ELF_BASE_PLATFORM
135 /*
136 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
137 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
138 * will be copied to the user stack in the same manner as AT_PLATFORM.
139 */
140 #define ELF_BASE_PLATFORM NULL
141 #endif
142
143 static int
144 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
145 unsigned long load_addr, unsigned long interp_load_addr)
146 {
147 unsigned long p = bprm->p;
148 int argc = bprm->argc;
149 int envc = bprm->envc;
150 elf_addr_t __user *argv;
151 elf_addr_t __user *envp;
152 elf_addr_t __user *sp;
153 elf_addr_t __user *u_platform;
154 elf_addr_t __user *u_base_platform;
155 elf_addr_t __user *u_rand_bytes;
156 const char *k_platform = ELF_PLATFORM;
157 const char *k_base_platform = ELF_BASE_PLATFORM;
158 unsigned char k_rand_bytes[16];
159 int items;
160 elf_addr_t *elf_info;
161 int ei_index = 0;
162 const struct cred *cred = current_cred();
163 struct vm_area_struct *vma;
164
165 /*
166 * In some cases (e.g. Hyper-Threading), we want to avoid L1
167 * evictions by the processes running on the same package. One
168 * thing we can do is to shuffle the initial stack for them.
169 */
170
171 p = arch_align_stack(p);
172
173 /*
174 * If this architecture has a platform capability string, copy it
175 * to userspace. In some cases (Sparc), this info is impossible
176 * for userspace to get any other way, in others (i386) it is
177 * merely difficult.
178 */
179 u_platform = NULL;
180 if (k_platform) {
181 size_t len = strlen(k_platform) + 1;
182
183 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
184 if (__copy_to_user(u_platform, k_platform, len))
185 return -EFAULT;
186 }
187
188 /*
189 * If this architecture has a "base" platform capability
190 * string, copy it to userspace.
191 */
192 u_base_platform = NULL;
193 if (k_base_platform) {
194 size_t len = strlen(k_base_platform) + 1;
195
196 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
197 if (__copy_to_user(u_base_platform, k_base_platform, len))
198 return -EFAULT;
199 }
200
201 /*
202 * Generate 16 random bytes for userspace PRNG seeding.
203 */
204 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
205 u_rand_bytes = (elf_addr_t __user *)
206 STACK_ALLOC(p, sizeof(k_rand_bytes));
207 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
208 return -EFAULT;
209
210 /* Create the ELF interpreter info */
211 elf_info = (elf_addr_t *)current->mm->saved_auxv;
212 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
213 #define NEW_AUX_ENT(id, val) \
214 do { \
215 elf_info[ei_index++] = id; \
216 elf_info[ei_index++] = val; \
217 } while (0)
218
219 #ifdef ARCH_DLINFO
220 /*
221 * ARCH_DLINFO must come first so PPC can do its special alignment of
222 * AUXV.
223 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
224 * ARCH_DLINFO changes
225 */
226 ARCH_DLINFO;
227 #endif
228 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
229 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
230 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
231 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
232 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
233 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
234 NEW_AUX_ENT(AT_BASE, interp_load_addr);
235 NEW_AUX_ENT(AT_FLAGS, 0);
236 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
237 NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
238 NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
239 NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
240 NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
241 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
242 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
243 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
244 if (k_platform) {
245 NEW_AUX_ENT(AT_PLATFORM,
246 (elf_addr_t)(unsigned long)u_platform);
247 }
248 if (k_base_platform) {
249 NEW_AUX_ENT(AT_BASE_PLATFORM,
250 (elf_addr_t)(unsigned long)u_base_platform);
251 }
252 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
253 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
254 }
255 #undef NEW_AUX_ENT
256 /* AT_NULL is zero; clear the rest too */
257 memset(&elf_info[ei_index], 0,
258 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
259
260 /* And advance past the AT_NULL entry. */
261 ei_index += 2;
262
263 sp = STACK_ADD(p, ei_index);
264
265 items = (argc + 1) + (envc + 1) + 1;
266 bprm->p = STACK_ROUND(sp, items);
267
268 /* Point sp at the lowest address on the stack */
269 #ifdef CONFIG_STACK_GROWSUP
270 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
271 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
272 #else
273 sp = (elf_addr_t __user *)bprm->p;
274 #endif
275
276
277 /*
278 * Grow the stack manually; some architectures have a limit on how
279 * far ahead a user-space access may be in order to grow the stack.
280 */
281 vma = find_extend_vma(current->mm, bprm->p);
282 if (!vma)
283 return -EFAULT;
284
285 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
286 if (__put_user(argc, sp++))
287 return -EFAULT;
288 argv = sp;
289 envp = argv + argc + 1;
290
291 /* Populate argv and envp */
292 p = current->mm->arg_end = current->mm->arg_start;
293 while (argc-- > 0) {
294 size_t len;
295 if (__put_user((elf_addr_t)p, argv++))
296 return -EFAULT;
297 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
298 if (!len || len > MAX_ARG_STRLEN)
299 return -EINVAL;
300 p += len;
301 }
302 if (__put_user(0, argv))
303 return -EFAULT;
304 current->mm->arg_end = current->mm->env_start = p;
305 while (envc-- > 0) {
306 size_t len;
307 if (__put_user((elf_addr_t)p, envp++))
308 return -EFAULT;
309 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
310 if (!len || len > MAX_ARG_STRLEN)
311 return -EINVAL;
312 p += len;
313 }
314 if (__put_user(0, envp))
315 return -EFAULT;
316 current->mm->env_end = p;
317
318 /* Put the elf_info on the stack in the right place. */
319 sp = (elf_addr_t __user *)envp + 1;
320 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
321 return -EFAULT;
322 return 0;
323 }
324
325 static unsigned long elf_map(struct file *filep, unsigned long addr,
326 struct elf_phdr *eppnt, int prot, int type,
327 unsigned long total_size)
328 {
329 unsigned long map_addr;
330 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
331 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
332 addr = ELF_PAGESTART(addr);
333 size = ELF_PAGEALIGN(size);
334
335 /* mmap() will return -EINVAL if given a zero size, but a
336 * segment with zero filesize is perfectly valid */
337 if (!size)
338 return addr;
339
340 /*
341 * total_size is the size of the ELF (interpreter) image.
342 * The _first_ mmap needs to know the full size, otherwise
343 * randomization might put this image into an overlapping
344 * position with the ELF binary image. (since size < total_size)
345 * So we first map the 'big' image - and unmap the remainder at
346 * the end. (which unmap is needed for ELF images with holes.)
347 */
348 if (total_size) {
349 total_size = ELF_PAGEALIGN(total_size);
350 map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
351 if (!BAD_ADDR(map_addr))
352 vm_munmap(map_addr+size, total_size-size);
353 } else
354 map_addr = vm_mmap(filep, addr, size, prot, type, off);
355
356 return(map_addr);
357 }
358
359 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
360 {
361 int i, first_idx = -1, last_idx = -1;
362
363 for (i = 0; i < nr; i++) {
364 if (cmds[i].p_type == PT_LOAD) {
365 last_idx = i;
366 if (first_idx == -1)
367 first_idx = i;
368 }
369 }
370 if (first_idx == -1)
371 return 0;
372
373 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
374 ELF_PAGESTART(cmds[first_idx].p_vaddr);
375 }
376
377
378 /* This is much more generalized than the library routine read function,
379 so we keep this separate. Technically the library read function
380 is only provided so that we can read a.out libraries that have
381 an ELF header */
382
383 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
384 struct file *interpreter, unsigned long *interp_map_addr,
385 unsigned long no_base)
386 {
387 struct elf_phdr *elf_phdata;
388 struct elf_phdr *eppnt;
389 unsigned long load_addr = 0;
390 int load_addr_set = 0;
391 unsigned long last_bss = 0, elf_bss = 0;
392 unsigned long error = ~0UL;
393 unsigned long total_size;
394 int retval, i, size;
395
396 /* First of all, some simple consistency checks */
397 if (interp_elf_ex->e_type != ET_EXEC &&
398 interp_elf_ex->e_type != ET_DYN)
399 goto out;
400 if (!elf_check_arch(interp_elf_ex))
401 goto out;
402 if (!interpreter->f_op || !interpreter->f_op->mmap)
403 goto out;
404
405 /*
406 * If the size of this structure has changed, then punt, since
407 * we will be doing the wrong thing.
408 */
409 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
410 goto out;
411 if (interp_elf_ex->e_phnum < 1 ||
412 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
413 goto out;
414
415 /* Now read in all of the header information */
416 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
417 if (size > ELF_MIN_ALIGN)
418 goto out;
419 elf_phdata = kmalloc(size, GFP_KERNEL);
420 if (!elf_phdata)
421 goto out;
422
423 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
424 (char *)elf_phdata, size);
425 error = -EIO;
426 if (retval != size) {
427 if (retval < 0)
428 error = retval;
429 goto out_close;
430 }
431
432 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
433 if (!total_size) {
434 error = -EINVAL;
435 goto out_close;
436 }
437
438 eppnt = elf_phdata;
439 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
440 if (eppnt->p_type == PT_LOAD) {
441 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
442 int elf_prot = 0;
443 unsigned long vaddr = 0;
444 unsigned long k, map_addr;
445
446 if (eppnt->p_flags & PF_R)
447 elf_prot = PROT_READ;
448 if (eppnt->p_flags & PF_W)
449 elf_prot |= PROT_WRITE;
450 if (eppnt->p_flags & PF_X)
451 elf_prot |= PROT_EXEC;
452 vaddr = eppnt->p_vaddr;
453 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
454 elf_type |= MAP_FIXED;
455 else if (no_base && interp_elf_ex->e_type == ET_DYN)
456 load_addr = -vaddr;
457
458 map_addr = elf_map(interpreter, load_addr + vaddr,
459 eppnt, elf_prot, elf_type, total_size);
460 total_size = 0;
461 if (!*interp_map_addr)
462 *interp_map_addr = map_addr;
463 error = map_addr;
464 if (BAD_ADDR(map_addr))
465 goto out_close;
466
467 if (!load_addr_set &&
468 interp_elf_ex->e_type == ET_DYN) {
469 load_addr = map_addr - ELF_PAGESTART(vaddr);
470 load_addr_set = 1;
471 }
472
473 /*
474 * Check to see if the section's size will overflow the
475 * allowed task size. Note that p_filesz must always be
476 * <= p_memsize so it's only necessary to check p_memsz.
477 */
478 k = load_addr + eppnt->p_vaddr;
479 if (BAD_ADDR(k) ||
480 eppnt->p_filesz > eppnt->p_memsz ||
481 eppnt->p_memsz > TASK_SIZE ||
482 TASK_SIZE - eppnt->p_memsz < k) {
483 error = -ENOMEM;
484 goto out_close;
485 }
486
487 /*
488 * Find the end of the file mapping for this phdr, and
489 * keep track of the largest address we see for this.
490 */
491 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
492 if (k > elf_bss)
493 elf_bss = k;
494
495 /*
496 * Do the same thing for the memory mapping - between
497 * elf_bss and last_bss is the bss section.
498 */
499 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
500 if (k > last_bss)
501 last_bss = k;
502 }
503 }
504
505 if (last_bss > elf_bss) {
506 /*
507 * Now fill out the bss section. First pad the last page up
508 * to the page boundary, and then perform a mmap to make sure
509 * that there are zero-mapped pages up to and including the
510 * last bss page.
511 */
512 if (padzero(elf_bss)) {
513 error = -EFAULT;
514 goto out_close;
515 }
516
517 /* What we have mapped so far */
518 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
519
520 /* Map the last of the bss segment */
521 error = vm_brk(elf_bss, last_bss - elf_bss);
522 if (BAD_ADDR(error))
523 goto out_close;
524 }
525
526 error = load_addr;
527
528 out_close:
529 kfree(elf_phdata);
530 out:
531 return error;
532 }
533
534 /*
535 * These are the functions used to load ELF style executables and shared
536 * libraries. There is no binary dependent code anywhere else.
537 */
538
539 #define INTERPRETER_NONE 0
540 #define INTERPRETER_ELF 2
541
542 #ifndef STACK_RND_MASK
543 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
544 #endif
545
546 static unsigned long randomize_stack_top(unsigned long stack_top)
547 {
548 unsigned int random_variable = 0;
549
550 if ((current->flags & PF_RANDOMIZE) &&
551 !(current->personality & ADDR_NO_RANDOMIZE)) {
552 random_variable = get_random_int() & STACK_RND_MASK;
553 random_variable <<= PAGE_SHIFT;
554 }
555 #ifdef CONFIG_STACK_GROWSUP
556 return PAGE_ALIGN(stack_top) + random_variable;
557 #else
558 return PAGE_ALIGN(stack_top) - random_variable;
559 #endif
560 }
561
562 static int load_elf_binary(struct linux_binprm *bprm)
563 {
564 struct file *interpreter = NULL; /* to shut gcc up */
565 unsigned long load_addr = 0, load_bias = 0;
566 int load_addr_set = 0;
567 char * elf_interpreter = NULL;
568 unsigned long error;
569 struct elf_phdr *elf_ppnt, *elf_phdata;
570 unsigned long elf_bss, elf_brk;
571 int retval, i;
572 unsigned int size;
573 unsigned long elf_entry;
574 unsigned long interp_load_addr = 0;
575 unsigned long start_code, end_code, start_data, end_data;
576 unsigned long reloc_func_desc __maybe_unused = 0;
577 int executable_stack = EXSTACK_DEFAULT;
578 unsigned long def_flags = 0;
579 struct pt_regs *regs = current_pt_regs();
580 struct {
581 struct elfhdr elf_ex;
582 struct elfhdr interp_elf_ex;
583 } *loc;
584
585 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
586 if (!loc) {
587 retval = -ENOMEM;
588 goto out_ret;
589 }
590
591 /* Get the exec-header */
592 loc->elf_ex = *((struct elfhdr *)bprm->buf);
593
594 retval = -ENOEXEC;
595 /* First of all, some simple consistency checks */
596 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
597 goto out;
598
599 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
600 goto out;
601 if (!elf_check_arch(&loc->elf_ex))
602 goto out;
603 if (!bprm->file->f_op || !bprm->file->f_op->mmap)
604 goto out;
605
606 /* Now read in all of the header information */
607 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
608 goto out;
609 if (loc->elf_ex.e_phnum < 1 ||
610 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
611 goto out;
612 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
613 retval = -ENOMEM;
614 elf_phdata = kmalloc(size, GFP_KERNEL);
615 if (!elf_phdata)
616 goto out;
617
618 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
619 (char *)elf_phdata, size);
620 if (retval != size) {
621 if (retval >= 0)
622 retval = -EIO;
623 goto out_free_ph;
624 }
625
626 elf_ppnt = elf_phdata;
627 elf_bss = 0;
628 elf_brk = 0;
629
630 start_code = ~0UL;
631 end_code = 0;
632 start_data = 0;
633 end_data = 0;
634
635 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
636 if (elf_ppnt->p_type == PT_INTERP) {
637 /* This is the program interpreter used for
638 * shared libraries - for now assume that this
639 * is an a.out format binary
640 */
641 retval = -ENOEXEC;
642 if (elf_ppnt->p_filesz > PATH_MAX ||
643 elf_ppnt->p_filesz < 2)
644 goto out_free_ph;
645
646 retval = -ENOMEM;
647 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
648 GFP_KERNEL);
649 if (!elf_interpreter)
650 goto out_free_ph;
651
652 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
653 elf_interpreter,
654 elf_ppnt->p_filesz);
655 if (retval != elf_ppnt->p_filesz) {
656 if (retval >= 0)
657 retval = -EIO;
658 goto out_free_interp;
659 }
660 /* make sure path is NULL terminated */
661 retval = -ENOEXEC;
662 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
663 goto out_free_interp;
664
665 interpreter = open_exec(elf_interpreter);
666 retval = PTR_ERR(interpreter);
667 if (IS_ERR(interpreter))
668 goto out_free_interp;
669
670 /*
671 * If the binary is not readable then enforce
672 * mm->dumpable = 0 regardless of the interpreter's
673 * permissions.
674 */
675 would_dump(bprm, interpreter);
676
677 retval = kernel_read(interpreter, 0, bprm->buf,
678 BINPRM_BUF_SIZE);
679 if (retval != BINPRM_BUF_SIZE) {
680 if (retval >= 0)
681 retval = -EIO;
682 goto out_free_dentry;
683 }
684
685 /* Get the exec headers */
686 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
687 break;
688 }
689 elf_ppnt++;
690 }
691
692 elf_ppnt = elf_phdata;
693 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
694 if (elf_ppnt->p_type == PT_GNU_STACK) {
695 if (elf_ppnt->p_flags & PF_X)
696 executable_stack = EXSTACK_ENABLE_X;
697 else
698 executable_stack = EXSTACK_DISABLE_X;
699 break;
700 }
701
702 /* Some simple consistency checks for the interpreter */
703 if (elf_interpreter) {
704 retval = -ELIBBAD;
705 /* Not an ELF interpreter */
706 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
707 goto out_free_dentry;
708 /* Verify the interpreter has a valid arch */
709 if (!elf_check_arch(&loc->interp_elf_ex))
710 goto out_free_dentry;
711 }
712
713 /* Flush all traces of the currently running executable */
714 retval = flush_old_exec(bprm);
715 if (retval)
716 goto out_free_dentry;
717
718 /* OK, This is the point of no return */
719 current->mm->def_flags = def_flags;
720
721 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
722 may depend on the personality. */
723 SET_PERSONALITY(loc->elf_ex);
724 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
725 current->personality |= READ_IMPLIES_EXEC;
726
727 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
728 current->flags |= PF_RANDOMIZE;
729
730 setup_new_exec(bprm);
731
732 /* Do this so that we can load the interpreter, if need be. We will
733 change some of these later */
734 current->mm->free_area_cache = current->mm->mmap_base;
735 current->mm->cached_hole_size = 0;
736 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
737 executable_stack);
738 if (retval < 0) {
739 send_sig(SIGKILL, current, 0);
740 goto out_free_dentry;
741 }
742
743 current->mm->start_stack = bprm->p;
744
745 /* Now we do a little grungy work by mmapping the ELF image into
746 the correct location in memory. */
747 for(i = 0, elf_ppnt = elf_phdata;
748 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
749 int elf_prot = 0, elf_flags;
750 unsigned long k, vaddr;
751
752 if (elf_ppnt->p_type != PT_LOAD)
753 continue;
754
755 if (unlikely (elf_brk > elf_bss)) {
756 unsigned long nbyte;
757
758 /* There was a PT_LOAD segment with p_memsz > p_filesz
759 before this one. Map anonymous pages, if needed,
760 and clear the area. */
761 retval = set_brk(elf_bss + load_bias,
762 elf_brk + load_bias);
763 if (retval) {
764 send_sig(SIGKILL, current, 0);
765 goto out_free_dentry;
766 }
767 nbyte = ELF_PAGEOFFSET(elf_bss);
768 if (nbyte) {
769 nbyte = ELF_MIN_ALIGN - nbyte;
770 if (nbyte > elf_brk - elf_bss)
771 nbyte = elf_brk - elf_bss;
772 if (clear_user((void __user *)elf_bss +
773 load_bias, nbyte)) {
774 /*
775 * This bss-zeroing can fail if the ELF
776 * file specifies odd protections. So
777 * we don't check the return value
778 */
779 }
780 }
781 }
782
783 if (elf_ppnt->p_flags & PF_R)
784 elf_prot |= PROT_READ;
785 if (elf_ppnt->p_flags & PF_W)
786 elf_prot |= PROT_WRITE;
787 if (elf_ppnt->p_flags & PF_X)
788 elf_prot |= PROT_EXEC;
789
790 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
791
792 vaddr = elf_ppnt->p_vaddr;
793 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
794 elf_flags |= MAP_FIXED;
795 } else if (loc->elf_ex.e_type == ET_DYN) {
796 /* Try and get dynamic programs out of the way of the
797 * default mmap base, as well as whatever program they
798 * might try to exec. This is because the brk will
799 * follow the loader, and is not movable. */
800 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
801 /* Memory randomization might have been switched off
802 * in runtime via sysctl.
803 * If that is the case, retain the original non-zero
804 * load_bias value in order to establish proper
805 * non-randomized mappings.
806 */
807 if (current->flags & PF_RANDOMIZE)
808 load_bias = 0;
809 else
810 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
811 #else
812 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
813 #endif
814 }
815
816 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
817 elf_prot, elf_flags, 0);
818 if (BAD_ADDR(error)) {
819 send_sig(SIGKILL, current, 0);
820 retval = IS_ERR((void *)error) ?
821 PTR_ERR((void*)error) : -EINVAL;
822 goto out_free_dentry;
823 }
824
825 if (!load_addr_set) {
826 load_addr_set = 1;
827 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
828 if (loc->elf_ex.e_type == ET_DYN) {
829 load_bias += error -
830 ELF_PAGESTART(load_bias + vaddr);
831 load_addr += load_bias;
832 reloc_func_desc = load_bias;
833 }
834 }
835 k = elf_ppnt->p_vaddr;
836 if (k < start_code)
837 start_code = k;
838 if (start_data < k)
839 start_data = k;
840
841 /*
842 * Check to see if the section's size will overflow the
843 * allowed task size. Note that p_filesz must always be
844 * <= p_memsz so it is only necessary to check p_memsz.
845 */
846 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
847 elf_ppnt->p_memsz > TASK_SIZE ||
848 TASK_SIZE - elf_ppnt->p_memsz < k) {
849 /* set_brk can never work. Avoid overflows. */
850 send_sig(SIGKILL, current, 0);
851 retval = -EINVAL;
852 goto out_free_dentry;
853 }
854
855 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
856
857 if (k > elf_bss)
858 elf_bss = k;
859 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
860 end_code = k;
861 if (end_data < k)
862 end_data = k;
863 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
864 if (k > elf_brk)
865 elf_brk = k;
866 }
867
868 loc->elf_ex.e_entry += load_bias;
869 elf_bss += load_bias;
870 elf_brk += load_bias;
871 start_code += load_bias;
872 end_code += load_bias;
873 start_data += load_bias;
874 end_data += load_bias;
875
876 /* Calling set_brk effectively mmaps the pages that we need
877 * for the bss and break sections. We must do this before
878 * mapping in the interpreter, to make sure it doesn't wind
879 * up getting placed where the bss needs to go.
880 */
881 retval = set_brk(elf_bss, elf_brk);
882 if (retval) {
883 send_sig(SIGKILL, current, 0);
884 goto out_free_dentry;
885 }
886 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
887 send_sig(SIGSEGV, current, 0);
888 retval = -EFAULT; /* Nobody gets to see this, but.. */
889 goto out_free_dentry;
890 }
891
892 if (elf_interpreter) {
893 unsigned long interp_map_addr = 0;
894
895 elf_entry = load_elf_interp(&loc->interp_elf_ex,
896 interpreter,
897 &interp_map_addr,
898 load_bias);
899 if (!IS_ERR((void *)elf_entry)) {
900 /*
901 * load_elf_interp() returns relocation
902 * adjustment
903 */
904 interp_load_addr = elf_entry;
905 elf_entry += loc->interp_elf_ex.e_entry;
906 }
907 if (BAD_ADDR(elf_entry)) {
908 force_sig(SIGSEGV, current);
909 retval = IS_ERR((void *)elf_entry) ?
910 (int)elf_entry : -EINVAL;
911 goto out_free_dentry;
912 }
913 reloc_func_desc = interp_load_addr;
914
915 allow_write_access(interpreter);
916 fput(interpreter);
917 kfree(elf_interpreter);
918 } else {
919 elf_entry = loc->elf_ex.e_entry;
920 if (BAD_ADDR(elf_entry)) {
921 force_sig(SIGSEGV, current);
922 retval = -EINVAL;
923 goto out_free_dentry;
924 }
925 }
926
927 kfree(elf_phdata);
928
929 set_binfmt(&elf_format);
930
931 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
932 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
933 if (retval < 0) {
934 send_sig(SIGKILL, current, 0);
935 goto out;
936 }
937 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
938
939 install_exec_creds(bprm);
940 retval = create_elf_tables(bprm, &loc->elf_ex,
941 load_addr, interp_load_addr);
942 if (retval < 0) {
943 send_sig(SIGKILL, current, 0);
944 goto out;
945 }
946 /* N.B. passed_fileno might not be initialized? */
947 current->mm->end_code = end_code;
948 current->mm->start_code = start_code;
949 current->mm->start_data = start_data;
950 current->mm->end_data = end_data;
951 current->mm->start_stack = bprm->p;
952
953 #ifdef arch_randomize_brk
954 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
955 current->mm->brk = current->mm->start_brk =
956 arch_randomize_brk(current->mm);
957 #ifdef CONFIG_COMPAT_BRK
958 current->brk_randomized = 1;
959 #endif
960 }
961 #endif
962
963 if (current->personality & MMAP_PAGE_ZERO) {
964 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
965 and some applications "depend" upon this behavior.
966 Since we do not have the power to recompile these, we
967 emulate the SVr4 behavior. Sigh. */
968 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
969 MAP_FIXED | MAP_PRIVATE, 0);
970 }
971
972 #ifdef ELF_PLAT_INIT
973 /*
974 * The ABI may specify that certain registers be set up in special
975 * ways (on i386 %edx is the address of a DT_FINI function, for
976 * example. In addition, it may also specify (eg, PowerPC64 ELF)
977 * that the e_entry field is the address of the function descriptor
978 * for the startup routine, rather than the address of the startup
979 * routine itself. This macro performs whatever initialization to
980 * the regs structure is required as well as any relocations to the
981 * function descriptor entries when executing dynamically links apps.
982 */
983 ELF_PLAT_INIT(regs, reloc_func_desc);
984 #endif
985
986 start_thread(regs, elf_entry, bprm->p);
987 retval = 0;
988 out:
989 kfree(loc);
990 out_ret:
991 return retval;
992
993 /* error cleanup */
994 out_free_dentry:
995 allow_write_access(interpreter);
996 if (interpreter)
997 fput(interpreter);
998 out_free_interp:
999 kfree(elf_interpreter);
1000 out_free_ph:
1001 kfree(elf_phdata);
1002 goto out;
1003 }
1004
1005 /* This is really simpleminded and specialized - we are loading an
1006 a.out library that is given an ELF header. */
1007 static int load_elf_library(struct file *file)
1008 {
1009 struct elf_phdr *elf_phdata;
1010 struct elf_phdr *eppnt;
1011 unsigned long elf_bss, bss, len;
1012 int retval, error, i, j;
1013 struct elfhdr elf_ex;
1014
1015 error = -ENOEXEC;
1016 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1017 if (retval != sizeof(elf_ex))
1018 goto out;
1019
1020 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1021 goto out;
1022
1023 /* First of all, some simple consistency checks */
1024 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1025 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1026 goto out;
1027
1028 /* Now read in all of the header information */
1029
1030 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1031 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1032
1033 error = -ENOMEM;
1034 elf_phdata = kmalloc(j, GFP_KERNEL);
1035 if (!elf_phdata)
1036 goto out;
1037
1038 eppnt = elf_phdata;
1039 error = -ENOEXEC;
1040 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1041 if (retval != j)
1042 goto out_free_ph;
1043
1044 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1045 if ((eppnt + i)->p_type == PT_LOAD)
1046 j++;
1047 if (j != 1)
1048 goto out_free_ph;
1049
1050 while (eppnt->p_type != PT_LOAD)
1051 eppnt++;
1052
1053 /* Now use mmap to map the library into memory. */
1054 error = vm_mmap(file,
1055 ELF_PAGESTART(eppnt->p_vaddr),
1056 (eppnt->p_filesz +
1057 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1058 PROT_READ | PROT_WRITE | PROT_EXEC,
1059 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1060 (eppnt->p_offset -
1061 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1062 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1063 goto out_free_ph;
1064
1065 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1066 if (padzero(elf_bss)) {
1067 error = -EFAULT;
1068 goto out_free_ph;
1069 }
1070
1071 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1072 ELF_MIN_ALIGN - 1);
1073 bss = eppnt->p_memsz + eppnt->p_vaddr;
1074 if (bss > len)
1075 vm_brk(len, bss - len);
1076 error = 0;
1077
1078 out_free_ph:
1079 kfree(elf_phdata);
1080 out:
1081 return error;
1082 }
1083
1084 #ifdef CONFIG_ELF_CORE
1085 /*
1086 * ELF core dumper
1087 *
1088 * Modelled on fs/exec.c:aout_core_dump()
1089 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1090 */
1091
1092 /*
1093 * The purpose of always_dump_vma() is to make sure that special kernel mappings
1094 * that are useful for post-mortem analysis are included in every core dump.
1095 * In that way we ensure that the core dump is fully interpretable later
1096 * without matching up the same kernel and hardware config to see what PC values
1097 * meant. These special mappings include - vDSO, vsyscall, and other
1098 * architecture specific mappings
1099 */
1100 static bool always_dump_vma(struct vm_area_struct *vma)
1101 {
1102 /* Any vsyscall mappings? */
1103 if (vma == get_gate_vma(vma->vm_mm))
1104 return true;
1105 /*
1106 * arch_vma_name() returns non-NULL for special architecture mappings,
1107 * such as vDSO sections.
1108 */
1109 if (arch_vma_name(vma))
1110 return true;
1111
1112 return false;
1113 }
1114
1115 /*
1116 * Decide what to dump of a segment, part, all or none.
1117 */
1118 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1119 unsigned long mm_flags)
1120 {
1121 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1122
1123 /* always dump the vdso and vsyscall sections */
1124 if (always_dump_vma(vma))
1125 goto whole;
1126
1127 if (vma->vm_flags & VM_DONTDUMP)
1128 return 0;
1129
1130 /* Hugetlb memory check */
1131 if (vma->vm_flags & VM_HUGETLB) {
1132 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1133 goto whole;
1134 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1135 goto whole;
1136 }
1137
1138 /* Do not dump I/O mapped devices or special mappings */
1139 if (vma->vm_flags & VM_IO)
1140 return 0;
1141
1142 /* By default, dump shared memory if mapped from an anonymous file. */
1143 if (vma->vm_flags & VM_SHARED) {
1144 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1145 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1146 goto whole;
1147 return 0;
1148 }
1149
1150 /* Dump segments that have been written to. */
1151 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1152 goto whole;
1153 if (vma->vm_file == NULL)
1154 return 0;
1155
1156 if (FILTER(MAPPED_PRIVATE))
1157 goto whole;
1158
1159 /*
1160 * If this looks like the beginning of a DSO or executable mapping,
1161 * check for an ELF header. If we find one, dump the first page to
1162 * aid in determining what was mapped here.
1163 */
1164 if (FILTER(ELF_HEADERS) &&
1165 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1166 u32 __user *header = (u32 __user *) vma->vm_start;
1167 u32 word;
1168 mm_segment_t fs = get_fs();
1169 /*
1170 * Doing it this way gets the constant folded by GCC.
1171 */
1172 union {
1173 u32 cmp;
1174 char elfmag[SELFMAG];
1175 } magic;
1176 BUILD_BUG_ON(SELFMAG != sizeof word);
1177 magic.elfmag[EI_MAG0] = ELFMAG0;
1178 magic.elfmag[EI_MAG1] = ELFMAG1;
1179 magic.elfmag[EI_MAG2] = ELFMAG2;
1180 magic.elfmag[EI_MAG3] = ELFMAG3;
1181 /*
1182 * Switch to the user "segment" for get_user(),
1183 * then put back what elf_core_dump() had in place.
1184 */
1185 set_fs(USER_DS);
1186 if (unlikely(get_user(word, header)))
1187 word = 0;
1188 set_fs(fs);
1189 if (word == magic.cmp)
1190 return PAGE_SIZE;
1191 }
1192
1193 #undef FILTER
1194
1195 return 0;
1196
1197 whole:
1198 return vma->vm_end - vma->vm_start;
1199 }
1200
1201 /* An ELF note in memory */
1202 struct memelfnote
1203 {
1204 const char *name;
1205 int type;
1206 unsigned int datasz;
1207 void *data;
1208 };
1209
1210 static int notesize(struct memelfnote *en)
1211 {
1212 int sz;
1213
1214 sz = sizeof(struct elf_note);
1215 sz += roundup(strlen(en->name) + 1, 4);
1216 sz += roundup(en->datasz, 4);
1217
1218 return sz;
1219 }
1220
1221 #define DUMP_WRITE(addr, nr, foffset) \
1222 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1223
1224 static int alignfile(struct file *file, loff_t *foffset)
1225 {
1226 static const char buf[4] = { 0, };
1227 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1228 return 1;
1229 }
1230
1231 static int writenote(struct memelfnote *men, struct file *file,
1232 loff_t *foffset)
1233 {
1234 struct elf_note en;
1235 en.n_namesz = strlen(men->name) + 1;
1236 en.n_descsz = men->datasz;
1237 en.n_type = men->type;
1238
1239 DUMP_WRITE(&en, sizeof(en), foffset);
1240 DUMP_WRITE(men->name, en.n_namesz, foffset);
1241 if (!alignfile(file, foffset))
1242 return 0;
1243 DUMP_WRITE(men->data, men->datasz, foffset);
1244 if (!alignfile(file, foffset))
1245 return 0;
1246
1247 return 1;
1248 }
1249 #undef DUMP_WRITE
1250
1251 static void fill_elf_header(struct elfhdr *elf, int segs,
1252 u16 machine, u32 flags)
1253 {
1254 memset(elf, 0, sizeof(*elf));
1255
1256 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1257 elf->e_ident[EI_CLASS] = ELF_CLASS;
1258 elf->e_ident[EI_DATA] = ELF_DATA;
1259 elf->e_ident[EI_VERSION] = EV_CURRENT;
1260 elf->e_ident[EI_OSABI] = ELF_OSABI;
1261
1262 elf->e_type = ET_CORE;
1263 elf->e_machine = machine;
1264 elf->e_version = EV_CURRENT;
1265 elf->e_phoff = sizeof(struct elfhdr);
1266 elf->e_flags = flags;
1267 elf->e_ehsize = sizeof(struct elfhdr);
1268 elf->e_phentsize = sizeof(struct elf_phdr);
1269 elf->e_phnum = segs;
1270
1271 return;
1272 }
1273
1274 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1275 {
1276 phdr->p_type = PT_NOTE;
1277 phdr->p_offset = offset;
1278 phdr->p_vaddr = 0;
1279 phdr->p_paddr = 0;
1280 phdr->p_filesz = sz;
1281 phdr->p_memsz = 0;
1282 phdr->p_flags = 0;
1283 phdr->p_align = 0;
1284 return;
1285 }
1286
1287 static void fill_note(struct memelfnote *note, const char *name, int type,
1288 unsigned int sz, void *data)
1289 {
1290 note->name = name;
1291 note->type = type;
1292 note->datasz = sz;
1293 note->data = data;
1294 return;
1295 }
1296
1297 /*
1298 * fill up all the fields in prstatus from the given task struct, except
1299 * registers which need to be filled up separately.
1300 */
1301 static void fill_prstatus(struct elf_prstatus *prstatus,
1302 struct task_struct *p, long signr)
1303 {
1304 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1305 prstatus->pr_sigpend = p->pending.signal.sig[0];
1306 prstatus->pr_sighold = p->blocked.sig[0];
1307 rcu_read_lock();
1308 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1309 rcu_read_unlock();
1310 prstatus->pr_pid = task_pid_vnr(p);
1311 prstatus->pr_pgrp = task_pgrp_vnr(p);
1312 prstatus->pr_sid = task_session_vnr(p);
1313 if (thread_group_leader(p)) {
1314 struct task_cputime cputime;
1315
1316 /*
1317 * This is the record for the group leader. It shows the
1318 * group-wide total, not its individual thread total.
1319 */
1320 thread_group_cputime(p, &cputime);
1321 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1322 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1323 } else {
1324 cputime_t utime, stime;
1325
1326 task_cputime(p, &utime, &stime);
1327 cputime_to_timeval(utime, &prstatus->pr_utime);
1328 cputime_to_timeval(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);
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);
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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