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drivers/w1/slaves/w1_bq27000.c: fix the error handling in w1_bq27000_add_slave()
[deliverable/linux.git] / fs / binfmt_elf.c
1 /*
2 * linux/fs/binfmt_elf.c
3 *
4 * These are the functions used to load ELF format executables as used
5 * on SVr4 machines. Information on the format may be found in the book
6 * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
7 * Tools".
8 *
9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
10 */
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/fs.h>
15 #include <linux/mm.h>
16 #include <linux/mman.h>
17 #include <linux/errno.h>
18 #include <linux/signal.h>
19 #include <linux/binfmts.h>
20 #include <linux/string.h>
21 #include <linux/file.h>
22 #include <linux/slab.h>
23 #include <linux/personality.h>
24 #include <linux/elfcore.h>
25 #include <linux/init.h>
26 #include <linux/highuid.h>
27 #include <linux/compiler.h>
28 #include <linux/highmem.h>
29 #include <linux/pagemap.h>
30 #include <linux/vmalloc.h>
31 #include <linux/security.h>
32 #include <linux/random.h>
33 #include <linux/elf.h>
34 #include <linux/utsname.h>
35 #include <linux/coredump.h>
36 #include <linux/sched.h>
37 #include <asm/uaccess.h>
38 #include <asm/param.h>
39 #include <asm/page.h>
40
41 #ifndef user_long_t
42 #define user_long_t long
43 #endif
44 #ifndef user_siginfo_t
45 #define user_siginfo_t siginfo_t
46 #endif
47
48 static int load_elf_binary(struct linux_binprm *bprm);
49 static int load_elf_library(struct file *);
50 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
51 int, int, unsigned long);
52
53 /*
54 * If we don't support core dumping, then supply a NULL so we
55 * don't even try.
56 */
57 #ifdef CONFIG_ELF_CORE
58 static int elf_core_dump(struct coredump_params *cprm);
59 #else
60 #define elf_core_dump NULL
61 #endif
62
63 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
64 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
65 #else
66 #define ELF_MIN_ALIGN PAGE_SIZE
67 #endif
68
69 #ifndef ELF_CORE_EFLAGS
70 #define ELF_CORE_EFLAGS 0
71 #endif
72
73 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
74 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
75 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
76
77 static struct linux_binfmt elf_format = {
78 .module = THIS_MODULE,
79 .load_binary = load_elf_binary,
80 .load_shlib = load_elf_library,
81 .core_dump = elf_core_dump,
82 .min_coredump = ELF_EXEC_PAGESIZE,
83 };
84
85 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
86
87 static int set_brk(unsigned long start, unsigned long end)
88 {
89 start = ELF_PAGEALIGN(start);
90 end = ELF_PAGEALIGN(end);
91 if (end > start) {
92 unsigned long addr;
93 addr = vm_brk(start, end - start);
94 if (BAD_ADDR(addr))
95 return addr;
96 }
97 current->mm->start_brk = current->mm->brk = end;
98 return 0;
99 }
100
101 /* We need to explicitly zero any fractional pages
102 after the data section (i.e. bss). This would
103 contain the junk from the file that should not
104 be in memory
105 */
106 static int padzero(unsigned long elf_bss)
107 {
108 unsigned long nbyte;
109
110 nbyte = ELF_PAGEOFFSET(elf_bss);
111 if (nbyte) {
112 nbyte = ELF_MIN_ALIGN - nbyte;
113 if (clear_user((void __user *) elf_bss, nbyte))
114 return -EFAULT;
115 }
116 return 0;
117 }
118
119 /* Let's use some macros to make this stack manipulation a little clearer */
120 #ifdef CONFIG_STACK_GROWSUP
121 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
122 #define STACK_ROUND(sp, items) \
123 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
124 #define STACK_ALLOC(sp, len) ({ \
125 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
126 old_sp; })
127 #else
128 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
129 #define STACK_ROUND(sp, items) \
130 (((unsigned long) (sp - items)) &~ 15UL)
131 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
132 #endif
133
134 #ifndef ELF_BASE_PLATFORM
135 /*
136 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
137 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
138 * will be copied to the user stack in the same manner as AT_PLATFORM.
139 */
140 #define ELF_BASE_PLATFORM NULL
141 #endif
142
143 static int
144 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
145 unsigned long load_addr, unsigned long interp_load_addr)
146 {
147 unsigned long p = bprm->p;
148 int argc = bprm->argc;
149 int envc = bprm->envc;
150 elf_addr_t __user *argv;
151 elf_addr_t __user *envp;
152 elf_addr_t __user *sp;
153 elf_addr_t __user *u_platform;
154 elf_addr_t __user *u_base_platform;
155 elf_addr_t __user *u_rand_bytes;
156 const char *k_platform = ELF_PLATFORM;
157 const char *k_base_platform = ELF_BASE_PLATFORM;
158 unsigned char k_rand_bytes[16];
159 int items;
160 elf_addr_t *elf_info;
161 int ei_index = 0;
162 const struct cred *cred = current_cred();
163 struct vm_area_struct *vma;
164
165 /*
166 * In some cases (e.g. Hyper-Threading), we want to avoid L1
167 * evictions by the processes running on the same package. One
168 * thing we can do is to shuffle the initial stack for them.
169 */
170
171 p = arch_align_stack(p);
172
173 /*
174 * If this architecture has a platform capability string, copy it
175 * to userspace. In some cases (Sparc), this info is impossible
176 * for userspace to get any other way, in others (i386) it is
177 * merely difficult.
178 */
179 u_platform = NULL;
180 if (k_platform) {
181 size_t len = strlen(k_platform) + 1;
182
183 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
184 if (__copy_to_user(u_platform, k_platform, len))
185 return -EFAULT;
186 }
187
188 /*
189 * If this architecture has a "base" platform capability
190 * string, copy it to userspace.
191 */
192 u_base_platform = NULL;
193 if (k_base_platform) {
194 size_t len = strlen(k_base_platform) + 1;
195
196 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
197 if (__copy_to_user(u_base_platform, k_base_platform, len))
198 return -EFAULT;
199 }
200
201 /*
202 * Generate 16 random bytes for userspace PRNG seeding.
203 */
204 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
205 u_rand_bytes = (elf_addr_t __user *)
206 STACK_ALLOC(p, sizeof(k_rand_bytes));
207 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
208 return -EFAULT;
209
210 /* Create the ELF interpreter info */
211 elf_info = (elf_addr_t *)current->mm->saved_auxv;
212 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
213 #define NEW_AUX_ENT(id, val) \
214 do { \
215 elf_info[ei_index++] = id; \
216 elf_info[ei_index++] = val; \
217 } while (0)
218
219 #ifdef ARCH_DLINFO
220 /*
221 * ARCH_DLINFO must come first so PPC can do its special alignment of
222 * AUXV.
223 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
224 * ARCH_DLINFO changes
225 */
226 ARCH_DLINFO;
227 #endif
228 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
229 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
230 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
231 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
232 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
233 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
234 NEW_AUX_ENT(AT_BASE, interp_load_addr);
235 NEW_AUX_ENT(AT_FLAGS, 0);
236 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
237 NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
238 NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
239 NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
240 NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
241 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
242 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
243 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
244 if (k_platform) {
245 NEW_AUX_ENT(AT_PLATFORM,
246 (elf_addr_t)(unsigned long)u_platform);
247 }
248 if (k_base_platform) {
249 NEW_AUX_ENT(AT_BASE_PLATFORM,
250 (elf_addr_t)(unsigned long)u_base_platform);
251 }
252 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
253 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
254 }
255 #undef NEW_AUX_ENT
256 /* AT_NULL is zero; clear the rest too */
257 memset(&elf_info[ei_index], 0,
258 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
259
260 /* And advance past the AT_NULL entry. */
261 ei_index += 2;
262
263 sp = STACK_ADD(p, ei_index);
264
265 items = (argc + 1) + (envc + 1) + 1;
266 bprm->p = STACK_ROUND(sp, items);
267
268 /* Point sp at the lowest address on the stack */
269 #ifdef CONFIG_STACK_GROWSUP
270 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
271 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
272 #else
273 sp = (elf_addr_t __user *)bprm->p;
274 #endif
275
276
277 /*
278 * Grow the stack manually; some architectures have a limit on how
279 * far ahead a user-space access may be in order to grow the stack.
280 */
281 vma = find_extend_vma(current->mm, bprm->p);
282 if (!vma)
283 return -EFAULT;
284
285 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
286 if (__put_user(argc, sp++))
287 return -EFAULT;
288 argv = sp;
289 envp = argv + argc + 1;
290
291 /* Populate argv and envp */
292 p = current->mm->arg_end = current->mm->arg_start;
293 while (argc-- > 0) {
294 size_t len;
295 if (__put_user((elf_addr_t)p, argv++))
296 return -EFAULT;
297 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
298 if (!len || len > MAX_ARG_STRLEN)
299 return -EINVAL;
300 p += len;
301 }
302 if (__put_user(0, argv))
303 return -EFAULT;
304 current->mm->arg_end = current->mm->env_start = p;
305 while (envc-- > 0) {
306 size_t len;
307 if (__put_user((elf_addr_t)p, envp++))
308 return -EFAULT;
309 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
310 if (!len || len > MAX_ARG_STRLEN)
311 return -EINVAL;
312 p += len;
313 }
314 if (__put_user(0, envp))
315 return -EFAULT;
316 current->mm->env_end = p;
317
318 /* Put the elf_info on the stack in the right place. */
319 sp = (elf_addr_t __user *)envp + 1;
320 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
321 return -EFAULT;
322 return 0;
323 }
324
325 #ifndef elf_map
326
327 static unsigned long elf_map(struct file *filep, unsigned long addr,
328 struct elf_phdr *eppnt, int prot, int type,
329 unsigned long total_size)
330 {
331 unsigned long map_addr;
332 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
333 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
334 addr = ELF_PAGESTART(addr);
335 size = ELF_PAGEALIGN(size);
336
337 /* mmap() will return -EINVAL if given a zero size, but a
338 * segment with zero filesize is perfectly valid */
339 if (!size)
340 return addr;
341
342 /*
343 * total_size is the size of the ELF (interpreter) image.
344 * The _first_ mmap needs to know the full size, otherwise
345 * randomization might put this image into an overlapping
346 * position with the ELF binary image. (since size < total_size)
347 * So we first map the 'big' image - and unmap the remainder at
348 * the end. (which unmap is needed for ELF images with holes.)
349 */
350 if (total_size) {
351 total_size = ELF_PAGEALIGN(total_size);
352 map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
353 if (!BAD_ADDR(map_addr))
354 vm_munmap(map_addr+size, total_size-size);
355 } else
356 map_addr = vm_mmap(filep, addr, size, prot, type, off);
357
358 return(map_addr);
359 }
360
361 #endif /* !elf_map */
362
363 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
364 {
365 int i, first_idx = -1, last_idx = -1;
366
367 for (i = 0; i < nr; i++) {
368 if (cmds[i].p_type == PT_LOAD) {
369 last_idx = i;
370 if (first_idx == -1)
371 first_idx = i;
372 }
373 }
374 if (first_idx == -1)
375 return 0;
376
377 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
378 ELF_PAGESTART(cmds[first_idx].p_vaddr);
379 }
380
381
382 /* This is much more generalized than the library routine read function,
383 so we keep this separate. Technically the library read function
384 is only provided so that we can read a.out libraries that have
385 an ELF header */
386
387 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
388 struct file *interpreter, unsigned long *interp_map_addr,
389 unsigned long no_base)
390 {
391 struct elf_phdr *elf_phdata;
392 struct elf_phdr *eppnt;
393 unsigned long load_addr = 0;
394 int load_addr_set = 0;
395 unsigned long last_bss = 0, elf_bss = 0;
396 unsigned long error = ~0UL;
397 unsigned long total_size;
398 int retval, i, size;
399
400 /* First of all, some simple consistency checks */
401 if (interp_elf_ex->e_type != ET_EXEC &&
402 interp_elf_ex->e_type != ET_DYN)
403 goto out;
404 if (!elf_check_arch(interp_elf_ex))
405 goto out;
406 if (!interpreter->f_op || !interpreter->f_op->mmap)
407 goto out;
408
409 /*
410 * If the size of this structure has changed, then punt, since
411 * we will be doing the wrong thing.
412 */
413 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
414 goto out;
415 if (interp_elf_ex->e_phnum < 1 ||
416 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
417 goto out;
418
419 /* Now read in all of the header information */
420 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
421 if (size > ELF_MIN_ALIGN)
422 goto out;
423 elf_phdata = kmalloc(size, GFP_KERNEL);
424 if (!elf_phdata)
425 goto out;
426
427 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
428 (char *)elf_phdata, size);
429 error = -EIO;
430 if (retval != size) {
431 if (retval < 0)
432 error = retval;
433 goto out_close;
434 }
435
436 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
437 if (!total_size) {
438 error = -EINVAL;
439 goto out_close;
440 }
441
442 eppnt = elf_phdata;
443 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
444 if (eppnt->p_type == PT_LOAD) {
445 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
446 int elf_prot = 0;
447 unsigned long vaddr = 0;
448 unsigned long k, map_addr;
449
450 if (eppnt->p_flags & PF_R)
451 elf_prot = PROT_READ;
452 if (eppnt->p_flags & PF_W)
453 elf_prot |= PROT_WRITE;
454 if (eppnt->p_flags & PF_X)
455 elf_prot |= PROT_EXEC;
456 vaddr = eppnt->p_vaddr;
457 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
458 elf_type |= MAP_FIXED;
459 else if (no_base && interp_elf_ex->e_type == ET_DYN)
460 load_addr = -vaddr;
461
462 map_addr = elf_map(interpreter, load_addr + vaddr,
463 eppnt, elf_prot, elf_type, total_size);
464 total_size = 0;
465 if (!*interp_map_addr)
466 *interp_map_addr = map_addr;
467 error = map_addr;
468 if (BAD_ADDR(map_addr))
469 goto out_close;
470
471 if (!load_addr_set &&
472 interp_elf_ex->e_type == ET_DYN) {
473 load_addr = map_addr - ELF_PAGESTART(vaddr);
474 load_addr_set = 1;
475 }
476
477 /*
478 * Check to see if the section's size will overflow the
479 * allowed task size. Note that p_filesz must always be
480 * <= p_memsize so it's only necessary to check p_memsz.
481 */
482 k = load_addr + eppnt->p_vaddr;
483 if (BAD_ADDR(k) ||
484 eppnt->p_filesz > eppnt->p_memsz ||
485 eppnt->p_memsz > TASK_SIZE ||
486 TASK_SIZE - eppnt->p_memsz < k) {
487 error = -ENOMEM;
488 goto out_close;
489 }
490
491 /*
492 * Find the end of the file mapping for this phdr, and
493 * keep track of the largest address we see for this.
494 */
495 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
496 if (k > elf_bss)
497 elf_bss = k;
498
499 /*
500 * Do the same thing for the memory mapping - between
501 * elf_bss and last_bss is the bss section.
502 */
503 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
504 if (k > last_bss)
505 last_bss = k;
506 }
507 }
508
509 if (last_bss > elf_bss) {
510 /*
511 * Now fill out the bss section. First pad the last page up
512 * to the page boundary, and then perform a mmap to make sure
513 * that there are zero-mapped pages up to and including the
514 * last bss page.
515 */
516 if (padzero(elf_bss)) {
517 error = -EFAULT;
518 goto out_close;
519 }
520
521 /* What we have mapped so far */
522 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
523
524 /* Map the last of the bss segment */
525 error = vm_brk(elf_bss, last_bss - elf_bss);
526 if (BAD_ADDR(error))
527 goto out_close;
528 }
529
530 error = load_addr;
531
532 out_close:
533 kfree(elf_phdata);
534 out:
535 return error;
536 }
537
538 /*
539 * These are the functions used to load ELF style executables and shared
540 * libraries. There is no binary dependent code anywhere else.
541 */
542
543 #define INTERPRETER_NONE 0
544 #define INTERPRETER_ELF 2
545
546 #ifndef STACK_RND_MASK
547 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
548 #endif
549
550 static unsigned long randomize_stack_top(unsigned long stack_top)
551 {
552 unsigned int random_variable = 0;
553
554 if ((current->flags & PF_RANDOMIZE) &&
555 !(current->personality & ADDR_NO_RANDOMIZE)) {
556 random_variable = get_random_int() & STACK_RND_MASK;
557 random_variable <<= PAGE_SHIFT;
558 }
559 #ifdef CONFIG_STACK_GROWSUP
560 return PAGE_ALIGN(stack_top) + random_variable;
561 #else
562 return PAGE_ALIGN(stack_top) - random_variable;
563 #endif
564 }
565
566 static int load_elf_binary(struct linux_binprm *bprm)
567 {
568 struct file *interpreter = NULL; /* to shut gcc up */
569 unsigned long load_addr = 0, load_bias = 0;
570 int load_addr_set = 0;
571 char * elf_interpreter = NULL;
572 unsigned long error;
573 struct elf_phdr *elf_ppnt, *elf_phdata;
574 unsigned long elf_bss, elf_brk;
575 int retval, i;
576 unsigned int size;
577 unsigned long elf_entry;
578 unsigned long interp_load_addr = 0;
579 unsigned long start_code, end_code, start_data, end_data;
580 unsigned long reloc_func_desc __maybe_unused = 0;
581 int executable_stack = EXSTACK_DEFAULT;
582 unsigned long def_flags = 0;
583 struct pt_regs *regs = current_pt_regs();
584 struct {
585 struct elfhdr elf_ex;
586 struct elfhdr interp_elf_ex;
587 } *loc;
588
589 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
590 if (!loc) {
591 retval = -ENOMEM;
592 goto out_ret;
593 }
594
595 /* Get the exec-header */
596 loc->elf_ex = *((struct elfhdr *)bprm->buf);
597
598 retval = -ENOEXEC;
599 /* First of all, some simple consistency checks */
600 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
601 goto out;
602
603 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
604 goto out;
605 if (!elf_check_arch(&loc->elf_ex))
606 goto out;
607 if (!bprm->file->f_op || !bprm->file->f_op->mmap)
608 goto out;
609
610 /* Now read in all of the header information */
611 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
612 goto out;
613 if (loc->elf_ex.e_phnum < 1 ||
614 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
615 goto out;
616 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
617 retval = -ENOMEM;
618 elf_phdata = kmalloc(size, GFP_KERNEL);
619 if (!elf_phdata)
620 goto out;
621
622 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
623 (char *)elf_phdata, size);
624 if (retval != size) {
625 if (retval >= 0)
626 retval = -EIO;
627 goto out_free_ph;
628 }
629
630 elf_ppnt = elf_phdata;
631 elf_bss = 0;
632 elf_brk = 0;
633
634 start_code = ~0UL;
635 end_code = 0;
636 start_data = 0;
637 end_data = 0;
638
639 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
640 if (elf_ppnt->p_type == PT_INTERP) {
641 /* This is the program interpreter used for
642 * shared libraries - for now assume that this
643 * is an a.out format binary
644 */
645 retval = -ENOEXEC;
646 if (elf_ppnt->p_filesz > PATH_MAX ||
647 elf_ppnt->p_filesz < 2)
648 goto out_free_ph;
649
650 retval = -ENOMEM;
651 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
652 GFP_KERNEL);
653 if (!elf_interpreter)
654 goto out_free_ph;
655
656 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
657 elf_interpreter,
658 elf_ppnt->p_filesz);
659 if (retval != elf_ppnt->p_filesz) {
660 if (retval >= 0)
661 retval = -EIO;
662 goto out_free_interp;
663 }
664 /* make sure path is NULL terminated */
665 retval = -ENOEXEC;
666 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
667 goto out_free_interp;
668
669 interpreter = open_exec(elf_interpreter);
670 retval = PTR_ERR(interpreter);
671 if (IS_ERR(interpreter))
672 goto out_free_interp;
673
674 /*
675 * If the binary is not readable then enforce
676 * mm->dumpable = 0 regardless of the interpreter's
677 * permissions.
678 */
679 would_dump(bprm, interpreter);
680
681 retval = kernel_read(interpreter, 0, bprm->buf,
682 BINPRM_BUF_SIZE);
683 if (retval != BINPRM_BUF_SIZE) {
684 if (retval >= 0)
685 retval = -EIO;
686 goto out_free_dentry;
687 }
688
689 /* Get the exec headers */
690 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
691 break;
692 }
693 elf_ppnt++;
694 }
695
696 elf_ppnt = elf_phdata;
697 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
698 if (elf_ppnt->p_type == PT_GNU_STACK) {
699 if (elf_ppnt->p_flags & PF_X)
700 executable_stack = EXSTACK_ENABLE_X;
701 else
702 executable_stack = EXSTACK_DISABLE_X;
703 break;
704 }
705
706 /* Some simple consistency checks for the interpreter */
707 if (elf_interpreter) {
708 retval = -ELIBBAD;
709 /* Not an ELF interpreter */
710 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
711 goto out_free_dentry;
712 /* Verify the interpreter has a valid arch */
713 if (!elf_check_arch(&loc->interp_elf_ex))
714 goto out_free_dentry;
715 }
716
717 /* Flush all traces of the currently running executable */
718 retval = flush_old_exec(bprm);
719 if (retval)
720 goto out_free_dentry;
721
722 /* OK, This is the point of no return */
723 current->mm->def_flags = def_flags;
724
725 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
726 may depend on the personality. */
727 SET_PERSONALITY(loc->elf_ex);
728 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
729 current->personality |= READ_IMPLIES_EXEC;
730
731 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
732 current->flags |= PF_RANDOMIZE;
733
734 setup_new_exec(bprm);
735
736 /* Do this so that we can load the interpreter, if need be. We will
737 change some of these later */
738 current->mm->free_area_cache = current->mm->mmap_base;
739 current->mm->cached_hole_size = 0;
740 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
741 executable_stack);
742 if (retval < 0) {
743 send_sig(SIGKILL, current, 0);
744 goto out_free_dentry;
745 }
746
747 current->mm->start_stack = bprm->p;
748
749 /* Now we do a little grungy work by mmapping the ELF image into
750 the correct location in memory. */
751 for(i = 0, elf_ppnt = elf_phdata;
752 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
753 int elf_prot = 0, elf_flags;
754 unsigned long k, vaddr;
755
756 if (elf_ppnt->p_type != PT_LOAD)
757 continue;
758
759 if (unlikely (elf_brk > elf_bss)) {
760 unsigned long nbyte;
761
762 /* There was a PT_LOAD segment with p_memsz > p_filesz
763 before this one. Map anonymous pages, if needed,
764 and clear the area. */
765 retval = set_brk(elf_bss + load_bias,
766 elf_brk + load_bias);
767 if (retval) {
768 send_sig(SIGKILL, current, 0);
769 goto out_free_dentry;
770 }
771 nbyte = ELF_PAGEOFFSET(elf_bss);
772 if (nbyte) {
773 nbyte = ELF_MIN_ALIGN - nbyte;
774 if (nbyte > elf_brk - elf_bss)
775 nbyte = elf_brk - elf_bss;
776 if (clear_user((void __user *)elf_bss +
777 load_bias, nbyte)) {
778 /*
779 * This bss-zeroing can fail if the ELF
780 * file specifies odd protections. So
781 * we don't check the return value
782 */
783 }
784 }
785 }
786
787 if (elf_ppnt->p_flags & PF_R)
788 elf_prot |= PROT_READ;
789 if (elf_ppnt->p_flags & PF_W)
790 elf_prot |= PROT_WRITE;
791 if (elf_ppnt->p_flags & PF_X)
792 elf_prot |= PROT_EXEC;
793
794 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
795
796 vaddr = elf_ppnt->p_vaddr;
797 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
798 elf_flags |= MAP_FIXED;
799 } else if (loc->elf_ex.e_type == ET_DYN) {
800 /* Try and get dynamic programs out of the way of the
801 * default mmap base, as well as whatever program they
802 * might try to exec. This is because the brk will
803 * follow the loader, and is not movable. */
804 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
805 /* Memory randomization might have been switched off
806 * in runtime via sysctl or explicit setting of
807 * personality flags.
808 * If that is the case, retain the original non-zero
809 * load_bias value in order to establish proper
810 * non-randomized mappings.
811 */
812 if (current->flags & PF_RANDOMIZE)
813 load_bias = 0;
814 else
815 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
816 #else
817 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
818 #endif
819 }
820
821 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
822 elf_prot, elf_flags, 0);
823 if (BAD_ADDR(error)) {
824 send_sig(SIGKILL, current, 0);
825 retval = IS_ERR((void *)error) ?
826 PTR_ERR((void*)error) : -EINVAL;
827 goto out_free_dentry;
828 }
829
830 if (!load_addr_set) {
831 load_addr_set = 1;
832 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
833 if (loc->elf_ex.e_type == ET_DYN) {
834 load_bias += error -
835 ELF_PAGESTART(load_bias + vaddr);
836 load_addr += load_bias;
837 reloc_func_desc = load_bias;
838 }
839 }
840 k = elf_ppnt->p_vaddr;
841 if (k < start_code)
842 start_code = k;
843 if (start_data < k)
844 start_data = k;
845
846 /*
847 * Check to see if the section's size will overflow the
848 * allowed task size. Note that p_filesz must always be
849 * <= p_memsz so it is only necessary to check p_memsz.
850 */
851 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
852 elf_ppnt->p_memsz > TASK_SIZE ||
853 TASK_SIZE - elf_ppnt->p_memsz < k) {
854 /* set_brk can never work. Avoid overflows. */
855 send_sig(SIGKILL, current, 0);
856 retval = -EINVAL;
857 goto out_free_dentry;
858 }
859
860 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
861
862 if (k > elf_bss)
863 elf_bss = k;
864 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
865 end_code = k;
866 if (end_data < k)
867 end_data = k;
868 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
869 if (k > elf_brk)
870 elf_brk = k;
871 }
872
873 loc->elf_ex.e_entry += load_bias;
874 elf_bss += load_bias;
875 elf_brk += load_bias;
876 start_code += load_bias;
877 end_code += load_bias;
878 start_data += load_bias;
879 end_data += load_bias;
880
881 /* Calling set_brk effectively mmaps the pages that we need
882 * for the bss and break sections. We must do this before
883 * mapping in the interpreter, to make sure it doesn't wind
884 * up getting placed where the bss needs to go.
885 */
886 retval = set_brk(elf_bss, elf_brk);
887 if (retval) {
888 send_sig(SIGKILL, current, 0);
889 goto out_free_dentry;
890 }
891 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
892 send_sig(SIGSEGV, current, 0);
893 retval = -EFAULT; /* Nobody gets to see this, but.. */
894 goto out_free_dentry;
895 }
896
897 if (elf_interpreter) {
898 unsigned long interp_map_addr = 0;
899
900 elf_entry = load_elf_interp(&loc->interp_elf_ex,
901 interpreter,
902 &interp_map_addr,
903 load_bias);
904 if (!IS_ERR((void *)elf_entry)) {
905 /*
906 * load_elf_interp() returns relocation
907 * adjustment
908 */
909 interp_load_addr = elf_entry;
910 elf_entry += loc->interp_elf_ex.e_entry;
911 }
912 if (BAD_ADDR(elf_entry)) {
913 force_sig(SIGSEGV, current);
914 retval = IS_ERR((void *)elf_entry) ?
915 (int)elf_entry : -EINVAL;
916 goto out_free_dentry;
917 }
918 reloc_func_desc = interp_load_addr;
919
920 allow_write_access(interpreter);
921 fput(interpreter);
922 kfree(elf_interpreter);
923 } else {
924 elf_entry = loc->elf_ex.e_entry;
925 if (BAD_ADDR(elf_entry)) {
926 force_sig(SIGSEGV, current);
927 retval = -EINVAL;
928 goto out_free_dentry;
929 }
930 }
931
932 kfree(elf_phdata);
933
934 set_binfmt(&elf_format);
935
936 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
937 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
938 if (retval < 0) {
939 send_sig(SIGKILL, current, 0);
940 goto out;
941 }
942 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
943
944 install_exec_creds(bprm);
945 retval = create_elf_tables(bprm, &loc->elf_ex,
946 load_addr, interp_load_addr);
947 if (retval < 0) {
948 send_sig(SIGKILL, current, 0);
949 goto out;
950 }
951 /* N.B. passed_fileno might not be initialized? */
952 current->mm->end_code = end_code;
953 current->mm->start_code = start_code;
954 current->mm->start_data = start_data;
955 current->mm->end_data = end_data;
956 current->mm->start_stack = bprm->p;
957
958 #ifdef arch_randomize_brk
959 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
960 current->mm->brk = current->mm->start_brk =
961 arch_randomize_brk(current->mm);
962 #ifdef CONFIG_COMPAT_BRK
963 current->brk_randomized = 1;
964 #endif
965 }
966 #endif
967
968 if (current->personality & MMAP_PAGE_ZERO) {
969 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
970 and some applications "depend" upon this behavior.
971 Since we do not have the power to recompile these, we
972 emulate the SVr4 behavior. Sigh. */
973 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
974 MAP_FIXED | MAP_PRIVATE, 0);
975 }
976
977 #ifdef ELF_PLAT_INIT
978 /*
979 * The ABI may specify that certain registers be set up in special
980 * ways (on i386 %edx is the address of a DT_FINI function, for
981 * example. In addition, it may also specify (eg, PowerPC64 ELF)
982 * that the e_entry field is the address of the function descriptor
983 * for the startup routine, rather than the address of the startup
984 * routine itself. This macro performs whatever initialization to
985 * the regs structure is required as well as any relocations to the
986 * function descriptor entries when executing dynamically links apps.
987 */
988 ELF_PLAT_INIT(regs, reloc_func_desc);
989 #endif
990
991 start_thread(regs, elf_entry, bprm->p);
992 retval = 0;
993 out:
994 kfree(loc);
995 out_ret:
996 return retval;
997
998 /* error cleanup */
999 out_free_dentry:
1000 allow_write_access(interpreter);
1001 if (interpreter)
1002 fput(interpreter);
1003 out_free_interp:
1004 kfree(elf_interpreter);
1005 out_free_ph:
1006 kfree(elf_phdata);
1007 goto out;
1008 }
1009
1010 /* This is really simpleminded and specialized - we are loading an
1011 a.out library that is given an ELF header. */
1012 static int load_elf_library(struct file *file)
1013 {
1014 struct elf_phdr *elf_phdata;
1015 struct elf_phdr *eppnt;
1016 unsigned long elf_bss, bss, len;
1017 int retval, error, i, j;
1018 struct elfhdr elf_ex;
1019
1020 error = -ENOEXEC;
1021 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1022 if (retval != sizeof(elf_ex))
1023 goto out;
1024
1025 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1026 goto out;
1027
1028 /* First of all, some simple consistency checks */
1029 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1030 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1031 goto out;
1032
1033 /* Now read in all of the header information */
1034
1035 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1036 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1037
1038 error = -ENOMEM;
1039 elf_phdata = kmalloc(j, GFP_KERNEL);
1040 if (!elf_phdata)
1041 goto out;
1042
1043 eppnt = elf_phdata;
1044 error = -ENOEXEC;
1045 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1046 if (retval != j)
1047 goto out_free_ph;
1048
1049 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1050 if ((eppnt + i)->p_type == PT_LOAD)
1051 j++;
1052 if (j != 1)
1053 goto out_free_ph;
1054
1055 while (eppnt->p_type != PT_LOAD)
1056 eppnt++;
1057
1058 /* Now use mmap to map the library into memory. */
1059 error = vm_mmap(file,
1060 ELF_PAGESTART(eppnt->p_vaddr),
1061 (eppnt->p_filesz +
1062 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1063 PROT_READ | PROT_WRITE | PROT_EXEC,
1064 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1065 (eppnt->p_offset -
1066 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1067 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1068 goto out_free_ph;
1069
1070 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1071 if (padzero(elf_bss)) {
1072 error = -EFAULT;
1073 goto out_free_ph;
1074 }
1075
1076 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1077 ELF_MIN_ALIGN - 1);
1078 bss = eppnt->p_memsz + eppnt->p_vaddr;
1079 if (bss > len)
1080 vm_brk(len, bss - len);
1081 error = 0;
1082
1083 out_free_ph:
1084 kfree(elf_phdata);
1085 out:
1086 return error;
1087 }
1088
1089 #ifdef CONFIG_ELF_CORE
1090 /*
1091 * ELF core dumper
1092 *
1093 * Modelled on fs/exec.c:aout_core_dump()
1094 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1095 */
1096
1097 /*
1098 * The purpose of always_dump_vma() is to make sure that special kernel mappings
1099 * that are useful for post-mortem analysis are included in every core dump.
1100 * In that way we ensure that the core dump is fully interpretable later
1101 * without matching up the same kernel and hardware config to see what PC values
1102 * meant. These special mappings include - vDSO, vsyscall, and other
1103 * architecture specific mappings
1104 */
1105 static bool always_dump_vma(struct vm_area_struct *vma)
1106 {
1107 /* Any vsyscall mappings? */
1108 if (vma == get_gate_vma(vma->vm_mm))
1109 return true;
1110 /*
1111 * arch_vma_name() returns non-NULL for special architecture mappings,
1112 * such as vDSO sections.
1113 */
1114 if (arch_vma_name(vma))
1115 return true;
1116
1117 return false;
1118 }
1119
1120 /*
1121 * Decide what to dump of a segment, part, all or none.
1122 */
1123 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1124 unsigned long mm_flags)
1125 {
1126 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1127
1128 /* always dump the vdso and vsyscall sections */
1129 if (always_dump_vma(vma))
1130 goto whole;
1131
1132 if (vma->vm_flags & VM_DONTDUMP)
1133 return 0;
1134
1135 /* Hugetlb memory check */
1136 if (vma->vm_flags & VM_HUGETLB) {
1137 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1138 goto whole;
1139 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1140 goto whole;
1141 return 0;
1142 }
1143
1144 /* Do not dump I/O mapped devices or special mappings */
1145 if (vma->vm_flags & VM_IO)
1146 return 0;
1147
1148 /* By default, dump shared memory if mapped from an anonymous file. */
1149 if (vma->vm_flags & VM_SHARED) {
1150 if (file_inode(vma->vm_file)->i_nlink == 0 ?
1151 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1152 goto whole;
1153 return 0;
1154 }
1155
1156 /* Dump segments that have been written to. */
1157 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1158 goto whole;
1159 if (vma->vm_file == NULL)
1160 return 0;
1161
1162 if (FILTER(MAPPED_PRIVATE))
1163 goto whole;
1164
1165 /*
1166 * If this looks like the beginning of a DSO or executable mapping,
1167 * check for an ELF header. If we find one, dump the first page to
1168 * aid in determining what was mapped here.
1169 */
1170 if (FILTER(ELF_HEADERS) &&
1171 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1172 u32 __user *header = (u32 __user *) vma->vm_start;
1173 u32 word;
1174 mm_segment_t fs = get_fs();
1175 /*
1176 * Doing it this way gets the constant folded by GCC.
1177 */
1178 union {
1179 u32 cmp;
1180 char elfmag[SELFMAG];
1181 } magic;
1182 BUILD_BUG_ON(SELFMAG != sizeof word);
1183 magic.elfmag[EI_MAG0] = ELFMAG0;
1184 magic.elfmag[EI_MAG1] = ELFMAG1;
1185 magic.elfmag[EI_MAG2] = ELFMAG2;
1186 magic.elfmag[EI_MAG3] = ELFMAG3;
1187 /*
1188 * Switch to the user "segment" for get_user(),
1189 * then put back what elf_core_dump() had in place.
1190 */
1191 set_fs(USER_DS);
1192 if (unlikely(get_user(word, header)))
1193 word = 0;
1194 set_fs(fs);
1195 if (word == magic.cmp)
1196 return PAGE_SIZE;
1197 }
1198
1199 #undef FILTER
1200
1201 return 0;
1202
1203 whole:
1204 return vma->vm_end - vma->vm_start;
1205 }
1206
1207 /* An ELF note in memory */
1208 struct memelfnote
1209 {
1210 const char *name;
1211 int type;
1212 unsigned int datasz;
1213 void *data;
1214 };
1215
1216 static int notesize(struct memelfnote *en)
1217 {
1218 int sz;
1219
1220 sz = sizeof(struct elf_note);
1221 sz += roundup(strlen(en->name) + 1, 4);
1222 sz += roundup(en->datasz, 4);
1223
1224 return sz;
1225 }
1226
1227 #define DUMP_WRITE(addr, nr, foffset) \
1228 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1229
1230 static int alignfile(struct file *file, loff_t *foffset)
1231 {
1232 static const char buf[4] = { 0, };
1233 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1234 return 1;
1235 }
1236
1237 static int writenote(struct memelfnote *men, struct file *file,
1238 loff_t *foffset)
1239 {
1240 struct elf_note en;
1241 en.n_namesz = strlen(men->name) + 1;
1242 en.n_descsz = men->datasz;
1243 en.n_type = men->type;
1244
1245 DUMP_WRITE(&en, sizeof(en), foffset);
1246 DUMP_WRITE(men->name, en.n_namesz, foffset);
1247 if (!alignfile(file, foffset))
1248 return 0;
1249 DUMP_WRITE(men->data, men->datasz, foffset);
1250 if (!alignfile(file, foffset))
1251 return 0;
1252
1253 return 1;
1254 }
1255 #undef DUMP_WRITE
1256
1257 static void fill_elf_header(struct elfhdr *elf, int segs,
1258 u16 machine, u32 flags)
1259 {
1260 memset(elf, 0, sizeof(*elf));
1261
1262 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1263 elf->e_ident[EI_CLASS] = ELF_CLASS;
1264 elf->e_ident[EI_DATA] = ELF_DATA;
1265 elf->e_ident[EI_VERSION] = EV_CURRENT;
1266 elf->e_ident[EI_OSABI] = ELF_OSABI;
1267
1268 elf->e_type = ET_CORE;
1269 elf->e_machine = machine;
1270 elf->e_version = EV_CURRENT;
1271 elf->e_phoff = sizeof(struct elfhdr);
1272 elf->e_flags = flags;
1273 elf->e_ehsize = sizeof(struct elfhdr);
1274 elf->e_phentsize = sizeof(struct elf_phdr);
1275 elf->e_phnum = segs;
1276
1277 return;
1278 }
1279
1280 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1281 {
1282 phdr->p_type = PT_NOTE;
1283 phdr->p_offset = offset;
1284 phdr->p_vaddr = 0;
1285 phdr->p_paddr = 0;
1286 phdr->p_filesz = sz;
1287 phdr->p_memsz = 0;
1288 phdr->p_flags = 0;
1289 phdr->p_align = 0;
1290 return;
1291 }
1292
1293 static void fill_note(struct memelfnote *note, const char *name, int type,
1294 unsigned int sz, void *data)
1295 {
1296 note->name = name;
1297 note->type = type;
1298 note->datasz = sz;
1299 note->data = data;
1300 return;
1301 }
1302
1303 /*
1304 * fill up all the fields in prstatus from the given task struct, except
1305 * registers which need to be filled up separately.
1306 */
1307 static void fill_prstatus(struct elf_prstatus *prstatus,
1308 struct task_struct *p, long signr)
1309 {
1310 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1311 prstatus->pr_sigpend = p->pending.signal.sig[0];
1312 prstatus->pr_sighold = p->blocked.sig[0];
1313 rcu_read_lock();
1314 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1315 rcu_read_unlock();
1316 prstatus->pr_pid = task_pid_vnr(p);
1317 prstatus->pr_pgrp = task_pgrp_vnr(p);
1318 prstatus->pr_sid = task_session_vnr(p);
1319 if (thread_group_leader(p)) {
1320 struct task_cputime cputime;
1321
1322 /*
1323 * This is the record for the group leader. It shows the
1324 * group-wide total, not its individual thread total.
1325 */
1326 thread_group_cputime(p, &cputime);
1327 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1328 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1329 } else {
1330 cputime_t utime, stime;
1331
1332 task_cputime(p, &utime, &stime);
1333 cputime_to_timeval(utime, &prstatus->pr_utime);
1334 cputime_to_timeval(stime, &prstatus->pr_stime);
1335 }
1336 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1337 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1338 }
1339
1340 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1341 struct mm_struct *mm)
1342 {
1343 const struct cred *cred;
1344 unsigned int i, len;
1345
1346 /* first copy the parameters from user space */
1347 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1348
1349 len = mm->arg_end - mm->arg_start;
1350 if (len >= ELF_PRARGSZ)
1351 len = ELF_PRARGSZ-1;
1352 if (copy_from_user(&psinfo->pr_psargs,
1353 (const char __user *)mm->arg_start, len))
1354 return -EFAULT;
1355 for(i = 0; i < len; i++)
1356 if (psinfo->pr_psargs[i] == 0)
1357 psinfo->pr_psargs[i] = ' ';
1358 psinfo->pr_psargs[len] = 0;
1359
1360 rcu_read_lock();
1361 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1362 rcu_read_unlock();
1363 psinfo->pr_pid = task_pid_vnr(p);
1364 psinfo->pr_pgrp = task_pgrp_vnr(p);
1365 psinfo->pr_sid = task_session_vnr(p);
1366
1367 i = p->state ? ffz(~p->state) + 1 : 0;
1368 psinfo->pr_state = i;
1369 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1370 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1371 psinfo->pr_nice = task_nice(p);
1372 psinfo->pr_flag = p->flags;
1373 rcu_read_lock();
1374 cred = __task_cred(p);
1375 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1376 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1377 rcu_read_unlock();
1378 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1379
1380 return 0;
1381 }
1382
1383 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1384 {
1385 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1386 int i = 0;
1387 do
1388 i += 2;
1389 while (auxv[i - 2] != AT_NULL);
1390 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1391 }
1392
1393 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1394 siginfo_t *siginfo)
1395 {
1396 mm_segment_t old_fs = get_fs();
1397 set_fs(KERNEL_DS);
1398 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
1399 set_fs(old_fs);
1400 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1401 }
1402
1403 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1404 /*
1405 * Format of NT_FILE note:
1406 *
1407 * long count -- how many files are mapped
1408 * long page_size -- units for file_ofs
1409 * array of [COUNT] elements of
1410 * long start
1411 * long end
1412 * long file_ofs
1413 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1414 */
1415 static void fill_files_note(struct memelfnote *note)
1416 {
1417 struct vm_area_struct *vma;
1418 unsigned count, size, names_ofs, remaining, n;
1419 user_long_t *data;
1420 user_long_t *start_end_ofs;
1421 char *name_base, *name_curpos;
1422
1423 /* *Estimated* file count and total data size needed */
1424 count = current->mm->map_count;
1425 size = count * 64;
1426
1427 names_ofs = (2 + 3 * count) * sizeof(data[0]);
1428 alloc:
1429 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1430 goto err;
1431 size = round_up(size, PAGE_SIZE);
1432 data = vmalloc(size);
1433 if (!data)
1434 goto err;
1435
1436 start_end_ofs = data + 2;
1437 name_base = name_curpos = ((char *)data) + names_ofs;
1438 remaining = size - names_ofs;
1439 count = 0;
1440 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1441 struct file *file;
1442 const char *filename;
1443
1444 file = vma->vm_file;
1445 if (!file)
1446 continue;
1447 filename = d_path(&file->f_path, name_curpos, remaining);
1448 if (IS_ERR(filename)) {
1449 if (PTR_ERR(filename) == -ENAMETOOLONG) {
1450 vfree(data);
1451 size = size * 5 / 4;
1452 goto alloc;
1453 }
1454 continue;
1455 }
1456
1457 /* d_path() fills at the end, move name down */
1458 /* n = strlen(filename) + 1: */
1459 n = (name_curpos + remaining) - filename;
1460 remaining = filename - name_curpos;
1461 memmove(name_curpos, filename, n);
1462 name_curpos += n;
1463
1464 *start_end_ofs++ = vma->vm_start;
1465 *start_end_ofs++ = vma->vm_end;
1466 *start_end_ofs++ = vma->vm_pgoff;
1467 count++;
1468 }
1469
1470 /* Now we know exact count of files, can store it */
1471 data[0] = count;
1472 data[1] = PAGE_SIZE;
1473 /*
1474 * Count usually is less than current->mm->map_count,
1475 * we need to move filenames down.
1476 */
1477 n = current->mm->map_count - count;
1478 if (n != 0) {
1479 unsigned shift_bytes = n * 3 * sizeof(data[0]);
1480 memmove(name_base - shift_bytes, name_base,
1481 name_curpos - name_base);
1482 name_curpos -= shift_bytes;
1483 }
1484
1485 size = name_curpos - (char *)data;
1486 fill_note(note, "CORE", NT_FILE, size, data);
1487 err: ;
1488 }
1489
1490 #ifdef CORE_DUMP_USE_REGSET
1491 #include <linux/regset.h>
1492
1493 struct elf_thread_core_info {
1494 struct elf_thread_core_info *next;
1495 struct task_struct *task;
1496 struct elf_prstatus prstatus;
1497 struct memelfnote notes[0];
1498 };
1499
1500 struct elf_note_info {
1501 struct elf_thread_core_info *thread;
1502 struct memelfnote psinfo;
1503 struct memelfnote signote;
1504 struct memelfnote auxv;
1505 struct memelfnote files;
1506 user_siginfo_t csigdata;
1507 size_t size;
1508 int thread_notes;
1509 };
1510
1511 /*
1512 * When a regset has a writeback hook, we call it on each thread before
1513 * dumping user memory. On register window machines, this makes sure the
1514 * user memory backing the register data is up to date before we read it.
1515 */
1516 static void do_thread_regset_writeback(struct task_struct *task,
1517 const struct user_regset *regset)
1518 {
1519 if (regset->writeback)
1520 regset->writeback(task, regset, 1);
1521 }
1522
1523 #ifndef PR_REG_SIZE
1524 #define PR_REG_SIZE(S) sizeof(S)
1525 #endif
1526
1527 #ifndef PRSTATUS_SIZE
1528 #define PRSTATUS_SIZE(S) sizeof(S)
1529 #endif
1530
1531 #ifndef PR_REG_PTR
1532 #define PR_REG_PTR(S) (&((S)->pr_reg))
1533 #endif
1534
1535 #ifndef SET_PR_FPVALID
1536 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V))
1537 #endif
1538
1539 static int fill_thread_core_info(struct elf_thread_core_info *t,
1540 const struct user_regset_view *view,
1541 long signr, size_t *total)
1542 {
1543 unsigned int i;
1544
1545 /*
1546 * NT_PRSTATUS is the one special case, because the regset data
1547 * goes into the pr_reg field inside the note contents, rather
1548 * than being the whole note contents. We fill the reset in here.
1549 * We assume that regset 0 is NT_PRSTATUS.
1550 */
1551 fill_prstatus(&t->prstatus, t->task, signr);
1552 (void) view->regsets[0].get(t->task, &view->regsets[0],
1553 0, PR_REG_SIZE(t->prstatus.pr_reg),
1554 PR_REG_PTR(&t->prstatus), NULL);
1555
1556 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1557 PRSTATUS_SIZE(t->prstatus), &t->prstatus);
1558 *total += notesize(&t->notes[0]);
1559
1560 do_thread_regset_writeback(t->task, &view->regsets[0]);
1561
1562 /*
1563 * Each other regset might generate a note too. For each regset
1564 * that has no core_note_type or is inactive, we leave t->notes[i]
1565 * all zero and we'll know to skip writing it later.
1566 */
1567 for (i = 1; i < view->n; ++i) {
1568 const struct user_regset *regset = &view->regsets[i];
1569 do_thread_regset_writeback(t->task, regset);
1570 if (regset->core_note_type && regset->get &&
1571 (!regset->active || regset->active(t->task, regset))) {
1572 int ret;
1573 size_t size = regset->n * regset->size;
1574 void *data = kmalloc(size, GFP_KERNEL);
1575 if (unlikely(!data))
1576 return 0;
1577 ret = regset->get(t->task, regset,
1578 0, size, data, NULL);
1579 if (unlikely(ret))
1580 kfree(data);
1581 else {
1582 if (regset->core_note_type != NT_PRFPREG)
1583 fill_note(&t->notes[i], "LINUX",
1584 regset->core_note_type,
1585 size, data);
1586 else {
1587 SET_PR_FPVALID(&t->prstatus, 1);
1588 fill_note(&t->notes[i], "CORE",
1589 NT_PRFPREG, size, data);
1590 }
1591 *total += notesize(&t->notes[i]);
1592 }
1593 }
1594 }
1595
1596 return 1;
1597 }
1598
1599 static int fill_note_info(struct elfhdr *elf, int phdrs,
1600 struct elf_note_info *info,
1601 siginfo_t *siginfo, struct pt_regs *regs)
1602 {
1603 struct task_struct *dump_task = current;
1604 const struct user_regset_view *view = task_user_regset_view(dump_task);
1605 struct elf_thread_core_info *t;
1606 struct elf_prpsinfo *psinfo;
1607 struct core_thread *ct;
1608 unsigned int i;
1609
1610 info->size = 0;
1611 info->thread = NULL;
1612
1613 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1614 if (psinfo == NULL) {
1615 info->psinfo.data = NULL; /* So we don't free this wrongly */
1616 return 0;
1617 }
1618
1619 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1620
1621 /*
1622 * Figure out how many notes we're going to need for each thread.
1623 */
1624 info->thread_notes = 0;
1625 for (i = 0; i < view->n; ++i)
1626 if (view->regsets[i].core_note_type != 0)
1627 ++info->thread_notes;
1628
1629 /*
1630 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1631 * since it is our one special case.
1632 */
1633 if (unlikely(info->thread_notes == 0) ||
1634 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1635 WARN_ON(1);
1636 return 0;
1637 }
1638
1639 /*
1640 * Initialize the ELF file header.
1641 */
1642 fill_elf_header(elf, phdrs,
1643 view->e_machine, view->e_flags);
1644
1645 /*
1646 * Allocate a structure for each thread.
1647 */
1648 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1649 t = kzalloc(offsetof(struct elf_thread_core_info,
1650 notes[info->thread_notes]),
1651 GFP_KERNEL);
1652 if (unlikely(!t))
1653 return 0;
1654
1655 t->task = ct->task;
1656 if (ct->task == dump_task || !info->thread) {
1657 t->next = info->thread;
1658 info->thread = t;
1659 } else {
1660 /*
1661 * Make sure to keep the original task at
1662 * the head of the list.
1663 */
1664 t->next = info->thread->next;
1665 info->thread->next = t;
1666 }
1667 }
1668
1669 /*
1670 * Now fill in each thread's information.
1671 */
1672 for (t = info->thread; t != NULL; t = t->next)
1673 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1674 return 0;
1675
1676 /*
1677 * Fill in the two process-wide notes.
1678 */
1679 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1680 info->size += notesize(&info->psinfo);
1681
1682 fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1683 info->size += notesize(&info->signote);
1684
1685 fill_auxv_note(&info->auxv, current->mm);
1686 info->size += notesize(&info->auxv);
1687
1688 fill_files_note(&info->files);
1689 info->size += notesize(&info->files);
1690
1691 return 1;
1692 }
1693
1694 static size_t get_note_info_size(struct elf_note_info *info)
1695 {
1696 return info->size;
1697 }
1698
1699 /*
1700 * Write all the notes for each thread. When writing the first thread, the
1701 * process-wide notes are interleaved after the first thread-specific note.
1702 */
1703 static int write_note_info(struct elf_note_info *info,
1704 struct file *file, loff_t *foffset)
1705 {
1706 bool first = 1;
1707 struct elf_thread_core_info *t = info->thread;
1708
1709 do {
1710 int i;
1711
1712 if (!writenote(&t->notes[0], file, foffset))
1713 return 0;
1714
1715 if (first && !writenote(&info->psinfo, file, foffset))
1716 return 0;
1717 if (first && !writenote(&info->signote, file, foffset))
1718 return 0;
1719 if (first && !writenote(&info->auxv, file, foffset))
1720 return 0;
1721 if (first && !writenote(&info->files, file, foffset))
1722 return 0;
1723
1724 for (i = 1; i < info->thread_notes; ++i)
1725 if (t->notes[i].data &&
1726 !writenote(&t->notes[i], file, foffset))
1727 return 0;
1728
1729 first = 0;
1730 t = t->next;
1731 } while (t);
1732
1733 return 1;
1734 }
1735
1736 static void free_note_info(struct elf_note_info *info)
1737 {
1738 struct elf_thread_core_info *threads = info->thread;
1739 while (threads) {
1740 unsigned int i;
1741 struct elf_thread_core_info *t = threads;
1742 threads = t->next;
1743 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1744 for (i = 1; i < info->thread_notes; ++i)
1745 kfree(t->notes[i].data);
1746 kfree(t);
1747 }
1748 kfree(info->psinfo.data);
1749 vfree(info->files.data);
1750 }
1751
1752 #else
1753
1754 /* Here is the structure in which status of each thread is captured. */
1755 struct elf_thread_status
1756 {
1757 struct list_head list;
1758 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1759 elf_fpregset_t fpu; /* NT_PRFPREG */
1760 struct task_struct *thread;
1761 #ifdef ELF_CORE_COPY_XFPREGS
1762 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1763 #endif
1764 struct memelfnote notes[3];
1765 int num_notes;
1766 };
1767
1768 /*
1769 * In order to add the specific thread information for the elf file format,
1770 * we need to keep a linked list of every threads pr_status and then create
1771 * a single section for them in the final core file.
1772 */
1773 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1774 {
1775 int sz = 0;
1776 struct task_struct *p = t->thread;
1777 t->num_notes = 0;
1778
1779 fill_prstatus(&t->prstatus, p, signr);
1780 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1781
1782 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1783 &(t->prstatus));
1784 t->num_notes++;
1785 sz += notesize(&t->notes[0]);
1786
1787 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1788 &t->fpu))) {
1789 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1790 &(t->fpu));
1791 t->num_notes++;
1792 sz += notesize(&t->notes[1]);
1793 }
1794
1795 #ifdef ELF_CORE_COPY_XFPREGS
1796 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1797 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1798 sizeof(t->xfpu), &t->xfpu);
1799 t->num_notes++;
1800 sz += notesize(&t->notes[2]);
1801 }
1802 #endif
1803 return sz;
1804 }
1805
1806 struct elf_note_info {
1807 struct memelfnote *notes;
1808 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1809 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1810 struct list_head thread_list;
1811 elf_fpregset_t *fpu;
1812 #ifdef ELF_CORE_COPY_XFPREGS
1813 elf_fpxregset_t *xfpu;
1814 #endif
1815 user_siginfo_t csigdata;
1816 int thread_status_size;
1817 int numnote;
1818 };
1819
1820 static int elf_note_info_init(struct elf_note_info *info)
1821 {
1822 memset(info, 0, sizeof(*info));
1823 INIT_LIST_HEAD(&info->thread_list);
1824
1825 /* Allocate space for ELF notes */
1826 info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL);
1827 if (!info->notes)
1828 return 0;
1829 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1830 if (!info->psinfo)
1831 return 0;
1832 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1833 if (!info->prstatus)
1834 return 0;
1835 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1836 if (!info->fpu)
1837 return 0;
1838 #ifdef ELF_CORE_COPY_XFPREGS
1839 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1840 if (!info->xfpu)
1841 return 0;
1842 #endif
1843 return 1;
1844 }
1845
1846 static int fill_note_info(struct elfhdr *elf, int phdrs,
1847 struct elf_note_info *info,
1848 siginfo_t *siginfo, struct pt_regs *regs)
1849 {
1850 struct list_head *t;
1851
1852 if (!elf_note_info_init(info))
1853 return 0;
1854
1855 if (siginfo->si_signo) {
1856 struct core_thread *ct;
1857 struct elf_thread_status *ets;
1858
1859 for (ct = current->mm->core_state->dumper.next;
1860 ct; ct = ct->next) {
1861 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1862 if (!ets)
1863 return 0;
1864
1865 ets->thread = ct->task;
1866 list_add(&ets->list, &info->thread_list);
1867 }
1868
1869 list_for_each(t, &info->thread_list) {
1870 int sz;
1871
1872 ets = list_entry(t, struct elf_thread_status, list);
1873 sz = elf_dump_thread_status(siginfo->si_signo, ets);
1874 info->thread_status_size += sz;
1875 }
1876 }
1877 /* now collect the dump for the current */
1878 memset(info->prstatus, 0, sizeof(*info->prstatus));
1879 fill_prstatus(info->prstatus, current, siginfo->si_signo);
1880 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1881
1882 /* Set up header */
1883 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
1884
1885 /*
1886 * Set up the notes in similar form to SVR4 core dumps made
1887 * with info from their /proc.
1888 */
1889
1890 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1891 sizeof(*info->prstatus), info->prstatus);
1892 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1893 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1894 sizeof(*info->psinfo), info->psinfo);
1895
1896 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
1897 fill_auxv_note(info->notes + 3, current->mm);
1898 fill_files_note(info->notes + 4);
1899
1900 info->numnote = 5;
1901
1902 /* Try to dump the FPU. */
1903 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1904 info->fpu);
1905 if (info->prstatus->pr_fpvalid)
1906 fill_note(info->notes + info->numnote++,
1907 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1908 #ifdef ELF_CORE_COPY_XFPREGS
1909 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1910 fill_note(info->notes + info->numnote++,
1911 "LINUX", ELF_CORE_XFPREG_TYPE,
1912 sizeof(*info->xfpu), info->xfpu);
1913 #endif
1914
1915 return 1;
1916 }
1917
1918 static size_t get_note_info_size(struct elf_note_info *info)
1919 {
1920 int sz = 0;
1921 int i;
1922
1923 for (i = 0; i < info->numnote; i++)
1924 sz += notesize(info->notes + i);
1925
1926 sz += info->thread_status_size;
1927
1928 return sz;
1929 }
1930
1931 static int write_note_info(struct elf_note_info *info,
1932 struct file *file, loff_t *foffset)
1933 {
1934 int i;
1935 struct list_head *t;
1936
1937 for (i = 0; i < info->numnote; i++)
1938 if (!writenote(info->notes + i, file, foffset))
1939 return 0;
1940
1941 /* write out the thread status notes section */
1942 list_for_each(t, &info->thread_list) {
1943 struct elf_thread_status *tmp =
1944 list_entry(t, struct elf_thread_status, list);
1945
1946 for (i = 0; i < tmp->num_notes; i++)
1947 if (!writenote(&tmp->notes[i], file, foffset))
1948 return 0;
1949 }
1950
1951 return 1;
1952 }
1953
1954 static void free_note_info(struct elf_note_info *info)
1955 {
1956 while (!list_empty(&info->thread_list)) {
1957 struct list_head *tmp = info->thread_list.next;
1958 list_del(tmp);
1959 kfree(list_entry(tmp, struct elf_thread_status, list));
1960 }
1961
1962 /* Free data allocated by fill_files_note(): */
1963 vfree(info->notes[4].data);
1964
1965 kfree(info->prstatus);
1966 kfree(info->psinfo);
1967 kfree(info->notes);
1968 kfree(info->fpu);
1969 #ifdef ELF_CORE_COPY_XFPREGS
1970 kfree(info->xfpu);
1971 #endif
1972 }
1973
1974 #endif
1975
1976 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1977 struct vm_area_struct *gate_vma)
1978 {
1979 struct vm_area_struct *ret = tsk->mm->mmap;
1980
1981 if (ret)
1982 return ret;
1983 return gate_vma;
1984 }
1985 /*
1986 * Helper function for iterating across a vma list. It ensures that the caller
1987 * will visit `gate_vma' prior to terminating the search.
1988 */
1989 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1990 struct vm_area_struct *gate_vma)
1991 {
1992 struct vm_area_struct *ret;
1993
1994 ret = this_vma->vm_next;
1995 if (ret)
1996 return ret;
1997 if (this_vma == gate_vma)
1998 return NULL;
1999 return gate_vma;
2000 }
2001
2002 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
2003 elf_addr_t e_shoff, int segs)
2004 {
2005 elf->e_shoff = e_shoff;
2006 elf->e_shentsize = sizeof(*shdr4extnum);
2007 elf->e_shnum = 1;
2008 elf->e_shstrndx = SHN_UNDEF;
2009
2010 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
2011
2012 shdr4extnum->sh_type = SHT_NULL;
2013 shdr4extnum->sh_size = elf->e_shnum;
2014 shdr4extnum->sh_link = elf->e_shstrndx;
2015 shdr4extnum->sh_info = segs;
2016 }
2017
2018 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
2019 unsigned long mm_flags)
2020 {
2021 struct vm_area_struct *vma;
2022 size_t size = 0;
2023
2024 for (vma = first_vma(current, gate_vma); vma != NULL;
2025 vma = next_vma(vma, gate_vma))
2026 size += vma_dump_size(vma, mm_flags);
2027 return size;
2028 }
2029
2030 /*
2031 * Actual dumper
2032 *
2033 * This is a two-pass process; first we find the offsets of the bits,
2034 * and then they are actually written out. If we run out of core limit
2035 * we just truncate.
2036 */
2037 static int elf_core_dump(struct coredump_params *cprm)
2038 {
2039 int has_dumped = 0;
2040 mm_segment_t fs;
2041 int segs;
2042 size_t size = 0;
2043 struct vm_area_struct *vma, *gate_vma;
2044 struct elfhdr *elf = NULL;
2045 loff_t offset = 0, dataoff, foffset;
2046 struct elf_note_info info;
2047 struct elf_phdr *phdr4note = NULL;
2048 struct elf_shdr *shdr4extnum = NULL;
2049 Elf_Half e_phnum;
2050 elf_addr_t e_shoff;
2051
2052 /*
2053 * We no longer stop all VM operations.
2054 *
2055 * This is because those proceses that could possibly change map_count
2056 * or the mmap / vma pages are now blocked in do_exit on current
2057 * finishing this core dump.
2058 *
2059 * Only ptrace can touch these memory addresses, but it doesn't change
2060 * the map_count or the pages allocated. So no possibility of crashing
2061 * exists while dumping the mm->vm_next areas to the core file.
2062 */
2063
2064 /* alloc memory for large data structures: too large to be on stack */
2065 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
2066 if (!elf)
2067 goto out;
2068 /*
2069 * The number of segs are recored into ELF header as 16bit value.
2070 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2071 */
2072 segs = current->mm->map_count;
2073 segs += elf_core_extra_phdrs();
2074
2075 gate_vma = get_gate_vma(current->mm);
2076 if (gate_vma != NULL)
2077 segs++;
2078
2079 /* for notes section */
2080 segs++;
2081
2082 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2083 * this, kernel supports extended numbering. Have a look at
2084 * include/linux/elf.h for further information. */
2085 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2086
2087 /*
2088 * Collect all the non-memory information about the process for the
2089 * notes. This also sets up the file header.
2090 */
2091 if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2092 goto cleanup;
2093
2094 has_dumped = 1;
2095
2096 fs = get_fs();
2097 set_fs(KERNEL_DS);
2098
2099 offset += sizeof(*elf); /* Elf header */
2100 offset += segs * sizeof(struct elf_phdr); /* Program headers */
2101 foffset = offset;
2102
2103 /* Write notes phdr entry */
2104 {
2105 size_t sz = get_note_info_size(&info);
2106
2107 sz += elf_coredump_extra_notes_size();
2108
2109 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2110 if (!phdr4note)
2111 goto end_coredump;
2112
2113 fill_elf_note_phdr(phdr4note, sz, offset);
2114 offset += sz;
2115 }
2116
2117 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2118
2119 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
2120 offset += elf_core_extra_data_size();
2121 e_shoff = offset;
2122
2123 if (e_phnum == PN_XNUM) {
2124 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2125 if (!shdr4extnum)
2126 goto end_coredump;
2127 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
2128 }
2129
2130 offset = dataoff;
2131
2132 size += sizeof(*elf);
2133 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
2134 goto end_coredump;
2135
2136 size += sizeof(*phdr4note);
2137 if (size > cprm->limit
2138 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
2139 goto end_coredump;
2140
2141 /* Write program headers for segments dump */
2142 for (vma = first_vma(current, gate_vma); vma != NULL;
2143 vma = next_vma(vma, gate_vma)) {
2144 struct elf_phdr phdr;
2145
2146 phdr.p_type = PT_LOAD;
2147 phdr.p_offset = offset;
2148 phdr.p_vaddr = vma->vm_start;
2149 phdr.p_paddr = 0;
2150 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
2151 phdr.p_memsz = vma->vm_end - vma->vm_start;
2152 offset += phdr.p_filesz;
2153 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2154 if (vma->vm_flags & VM_WRITE)
2155 phdr.p_flags |= PF_W;
2156 if (vma->vm_flags & VM_EXEC)
2157 phdr.p_flags |= PF_X;
2158 phdr.p_align = ELF_EXEC_PAGESIZE;
2159
2160 size += sizeof(phdr);
2161 if (size > cprm->limit
2162 || !dump_write(cprm->file, &phdr, sizeof(phdr)))
2163 goto end_coredump;
2164 }
2165
2166 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
2167 goto end_coredump;
2168
2169 /* write out the notes section */
2170 if (!write_note_info(&info, cprm->file, &foffset))
2171 goto end_coredump;
2172
2173 if (elf_coredump_extra_notes_write(cprm->file, &foffset))
2174 goto end_coredump;
2175
2176 /* Align to page */
2177 if (!dump_seek(cprm->file, dataoff - foffset))
2178 goto end_coredump;
2179
2180 for (vma = first_vma(current, gate_vma); vma != NULL;
2181 vma = next_vma(vma, gate_vma)) {
2182 unsigned long addr;
2183 unsigned long end;
2184
2185 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
2186
2187 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2188 struct page *page;
2189 int stop;
2190
2191 page = get_dump_page(addr);
2192 if (page) {
2193 void *kaddr = kmap(page);
2194 stop = ((size += PAGE_SIZE) > cprm->limit) ||
2195 !dump_write(cprm->file, kaddr,
2196 PAGE_SIZE);
2197 kunmap(page);
2198 page_cache_release(page);
2199 } else
2200 stop = !dump_seek(cprm->file, PAGE_SIZE);
2201 if (stop)
2202 goto end_coredump;
2203 }
2204 }
2205
2206 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
2207 goto end_coredump;
2208
2209 if (e_phnum == PN_XNUM) {
2210 size += sizeof(*shdr4extnum);
2211 if (size > cprm->limit
2212 || !dump_write(cprm->file, shdr4extnum,
2213 sizeof(*shdr4extnum)))
2214 goto end_coredump;
2215 }
2216
2217 end_coredump:
2218 set_fs(fs);
2219
2220 cleanup:
2221 free_note_info(&info);
2222 kfree(shdr4extnum);
2223 kfree(phdr4note);
2224 kfree(elf);
2225 out:
2226 return has_dumped;
2227 }
2228
2229 #endif /* CONFIG_ELF_CORE */
2230
2231 static int __init init_elf_binfmt(void)
2232 {
2233 register_binfmt(&elf_format);
2234 return 0;
2235 }
2236
2237 static void __exit exit_elf_binfmt(void)
2238 {
2239 /* Remove the COFF and ELF loaders. */
2240 unregister_binfmt(&elf_format);
2241 }
2242
2243 core_initcall(init_elf_binfmt);
2244 module_exit(exit_elf_binfmt);
2245 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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