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[S390] Fix comments in lowcore structure
[zen-stable.git] / fs / binfmt_elf.c
blob33b7235f853b2d46a7a685d805163d57ee0ef505
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/stat.h>
16 #include <linux/time.h>
17 #include <linux/mm.h>
18 #include <linux/mman.h>
19 #include <linux/errno.h>
20 #include <linux/signal.h>
21 #include <linux/binfmts.h>
22 #include <linux/string.h>
23 #include <linux/file.h>
24 #include <linux/fcntl.h>
25 #include <linux/ptrace.h>
26 #include <linux/slab.h>
27 #include <linux/shm.h>
28 #include <linux/personality.h>
29 #include <linux/elfcore.h>
30 #include <linux/init.h>
31 #include <linux/highuid.h>
32 #include <linux/smp.h>
33 #include <linux/compiler.h>
34 #include <linux/highmem.h>
35 #include <linux/pagemap.h>
36 #include <linux/security.h>
37 #include <linux/syscalls.h>
38 #include <linux/random.h>
39 #include <linux/elf.h>
40 #include <linux/utsname.h>
41 #include <asm/uaccess.h>
42 #include <asm/param.h>
43 #include <asm/page.h>
44
45 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
46 static int load_elf_library(struct file *);
47 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
48 int, int, unsigned long);
49
50 /*
51 * If we don't support core dumping, then supply a NULL so we
52 * don't even try.
53 */
54 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
55 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
56 #else
57 #define elf_core_dump NULL
58 #endif
59
60 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
61 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
62 #else
63 #define ELF_MIN_ALIGN PAGE_SIZE
64 #endif
65
66 #ifndef ELF_CORE_EFLAGS
67 #define ELF_CORE_EFLAGS 0
68 #endif
69
70 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
71 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
72 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
73
74 static struct linux_binfmt elf_format = {
75 .module = THIS_MODULE,
76 .load_binary = load_elf_binary,
77 .load_shlib = load_elf_library,
78 .core_dump = elf_core_dump,
79 .min_coredump = ELF_EXEC_PAGESIZE,
80 .hasvdso = 1
81 };
82
83 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
84
85 static int set_brk(unsigned long start, unsigned long end)
86 {
87 start = ELF_PAGEALIGN(start);
88 end = ELF_PAGEALIGN(end);
89 if (end > start) {
90 unsigned long addr;
91 down_write(&current->mm->mmap_sem);
92 addr = do_brk(start, end - start);
93 up_write(&current->mm->mmap_sem);
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, cred->uid);
238 NEW_AUX_ENT(AT_EUID, cred->euid);
239 NEW_AUX_ENT(AT_GID, cred->gid);
240 NEW_AUX_ENT(AT_EGID, 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 down_write(&current->mm->mmap_sem);
343 /*
344 * total_size is the size of the ELF (interpreter) image.
345 * The _first_ mmap needs to know the full size, otherwise
346 * randomization might put this image into an overlapping
347 * position with the ELF binary image. (since size < total_size)
348 * So we first map the 'big' image - and unmap the remainder at
349 * the end. (which unmap is needed for ELF images with holes.)
350 */
351 if (total_size) {
352 total_size = ELF_PAGEALIGN(total_size);
353 map_addr = do_mmap(filep, addr, total_size, prot, type, off);
354 if (!BAD_ADDR(map_addr))
355 do_munmap(current->mm, map_addr+size, total_size-size);
356 } else
357 map_addr = do_mmap(filep, addr, size, prot, type, off);
358
359 up_write(&current->mm->mmap_sem);
360 return(map_addr);
361 }
362
363 #endif /* !elf_map */
364
365 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
366 {
367 int i, first_idx = -1, last_idx = -1;
368
369 for (i = 0; i < nr; i++) {
370 if (cmds[i].p_type == PT_LOAD) {
371 last_idx = i;
372 if (first_idx == -1)
373 first_idx = i;
374 }
375 }
376 if (first_idx == -1)
377 return 0;
378
379 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
380 ELF_PAGESTART(cmds[first_idx].p_vaddr);
381 }
382
383
384 /* This is much more generalized than the library routine read function,
385 so we keep this separate. Technically the library read function
386 is only provided so that we can read a.out libraries that have
387 an ELF header */
388
389 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
390 struct file *interpreter, unsigned long *interp_map_addr,
391 unsigned long no_base)
392 {
393 struct elf_phdr *elf_phdata;
394 struct elf_phdr *eppnt;
395 unsigned long load_addr = 0;
396 int load_addr_set = 0;
397 unsigned long last_bss = 0, elf_bss = 0;
398 unsigned long error = ~0UL;
399 unsigned long total_size;
400 int retval, i, size;
401
402 /* First of all, some simple consistency checks */
403 if (interp_elf_ex->e_type != ET_EXEC &&
404 interp_elf_ex->e_type != ET_DYN)
405 goto out;
406 if (!elf_check_arch(interp_elf_ex))
407 goto out;
408 if (!interpreter->f_op || !interpreter->f_op->mmap)
409 goto out;
410
411 /*
412 * If the size of this structure has changed, then punt, since
413 * we will be doing the wrong thing.
414 */
415 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
416 goto out;
417 if (interp_elf_ex->e_phnum < 1 ||
418 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
419 goto out;
420
421 /* Now read in all of the header information */
422 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
423 if (size > ELF_MIN_ALIGN)
424 goto out;
425 elf_phdata = kmalloc(size, GFP_KERNEL);
426 if (!elf_phdata)
427 goto out;
428
429 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
430 (char *)elf_phdata,size);
431 error = -EIO;
432 if (retval != size) {
433 if (retval < 0)
434 error = retval;
435 goto out_close;
436 }
437
438 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
439 if (!total_size) {
440 error = -EINVAL;
441 goto out_close;
442 }
443
444 eppnt = elf_phdata;
445 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
446 if (eppnt->p_type == PT_LOAD) {
447 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
448 int elf_prot = 0;
449 unsigned long vaddr = 0;
450 unsigned long k, map_addr;
451
452 if (eppnt->p_flags & PF_R)
453 elf_prot = PROT_READ;
454 if (eppnt->p_flags & PF_W)
455 elf_prot |= PROT_WRITE;
456 if (eppnt->p_flags & PF_X)
457 elf_prot |= PROT_EXEC;
458 vaddr = eppnt->p_vaddr;
459 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
460 elf_type |= MAP_FIXED;
461 else if (no_base && interp_elf_ex->e_type == ET_DYN)
462 load_addr = -vaddr;
463
464 map_addr = elf_map(interpreter, load_addr + vaddr,
465 eppnt, elf_prot, elf_type, total_size);
466 total_size = 0;
467 if (!*interp_map_addr)
468 *interp_map_addr = map_addr;
469 error = map_addr;
470 if (BAD_ADDR(map_addr))
471 goto out_close;
472
473 if (!load_addr_set &&
474 interp_elf_ex->e_type == ET_DYN) {
475 load_addr = map_addr - ELF_PAGESTART(vaddr);
476 load_addr_set = 1;
477 }
478
479 /*
480 * Check to see if the section's size will overflow the
481 * allowed task size. Note that p_filesz must always be
482 * <= p_memsize so it's only necessary to check p_memsz.
483 */
484 k = load_addr + eppnt->p_vaddr;
485 if (BAD_ADDR(k) ||
486 eppnt->p_filesz > eppnt->p_memsz ||
487 eppnt->p_memsz > TASK_SIZE ||
488 TASK_SIZE - eppnt->p_memsz < k) {
489 error = -ENOMEM;
490 goto out_close;
491 }
492
493 /*
494 * Find the end of the file mapping for this phdr, and
495 * keep track of the largest address we see for this.
496 */
497 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
498 if (k > elf_bss)
499 elf_bss = k;
500
501 /*
502 * Do the same thing for the memory mapping - between
503 * elf_bss and last_bss is the bss section.
504 */
505 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
506 if (k > last_bss)
507 last_bss = k;
508 }
509 }
510
511 /*
512 * Now fill out the bss section. First pad the last page up
513 * to the page boundary, and then perform a mmap to make sure
514 * that there are zero-mapped pages up to and including the
515 * last bss page.
516 */
517 if (padzero(elf_bss)) {
518 error = -EFAULT;
519 goto out_close;
520 }
521
522 /* What we have mapped so far */
523 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
524
525 /* Map the last of the bss segment */
526 if (last_bss > elf_bss) {
527 down_write(&current->mm->mmap_sem);
528 error = do_brk(elf_bss, last_bss - elf_bss);
529 up_write(&current->mm->mmap_sem);
530 if (BAD_ADDR(error))
531 goto out_close;
532 }
533
534 error = load_addr;
535
536 out_close:
537 kfree(elf_phdata);
538 out:
539 return error;
540 }
541
542 /*
543 * These are the functions used to load ELF style executables and shared
544 * libraries. There is no binary dependent code anywhere else.
545 */
546
547 #define INTERPRETER_NONE 0
548 #define INTERPRETER_ELF 2
549
550 #ifndef STACK_RND_MASK
551 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
552 #endif
553
554 static unsigned long randomize_stack_top(unsigned long stack_top)
555 {
556 unsigned int random_variable = 0;
557
558 if ((current->flags & PF_RANDOMIZE) &&
559 !(current->personality & ADDR_NO_RANDOMIZE)) {
560 random_variable = get_random_int() & STACK_RND_MASK;
561 random_variable <<= PAGE_SHIFT;
562 }
563 #ifdef CONFIG_STACK_GROWSUP
564 return PAGE_ALIGN(stack_top) + random_variable;
565 #else
566 return PAGE_ALIGN(stack_top) - random_variable;
567 #endif
568 }
569
570 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
571 {
572 struct file *interpreter = NULL; /* to shut gcc up */
573 unsigned long load_addr = 0, load_bias = 0;
574 int load_addr_set = 0;
575 char * elf_interpreter = NULL;
576 unsigned long error;
577 struct elf_phdr *elf_ppnt, *elf_phdata;
578 unsigned long elf_bss, elf_brk;
579 int elf_exec_fileno;
580 int retval, i;
581 unsigned int size;
582 unsigned long elf_entry;
583 unsigned long interp_load_addr = 0;
584 unsigned long start_code, end_code, start_data, end_data;
585 unsigned long reloc_func_desc = 0;
586 int executable_stack = EXSTACK_DEFAULT;
587 unsigned long def_flags = 0;
588 struct {
589 struct elfhdr elf_ex;
590 struct elfhdr interp_elf_ex;
591 } *loc;
592
593 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
594 if (!loc) {
595 retval = -ENOMEM;
596 goto out_ret;
597 }
598
599 /* Get the exec-header */
600 loc->elf_ex = *((struct elfhdr *)bprm->buf);
601
602 retval = -ENOEXEC;
603 /* First of all, some simple consistency checks */
604 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
605 goto out;
606
607 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
608 goto out;
609 if (!elf_check_arch(&loc->elf_ex))
610 goto out;
611 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
612 goto out;
613
614 /* Now read in all of the header information */
615 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
616 goto out;
617 if (loc->elf_ex.e_phnum < 1 ||
618 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
619 goto out;
620 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
621 retval = -ENOMEM;
622 elf_phdata = kmalloc(size, GFP_KERNEL);
623 if (!elf_phdata)
624 goto out;
625
626 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
627 (char *)elf_phdata, size);
628 if (retval != size) {
629 if (retval >= 0)
630 retval = -EIO;
631 goto out_free_ph;
632 }
633
634 retval = get_unused_fd();
635 if (retval < 0)
636 goto out_free_ph;
637 get_file(bprm->file);
638 fd_install(elf_exec_fileno = retval, bprm->file);
639
640 elf_ppnt = elf_phdata;
641 elf_bss = 0;
642 elf_brk = 0;
643
644 start_code = ~0UL;
645 end_code = 0;
646 start_data = 0;
647 end_data = 0;
648
649 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
650 if (elf_ppnt->p_type == PT_INTERP) {
651 /* This is the program interpreter used for
652 * shared libraries - for now assume that this
653 * is an a.out format binary
654 */
655 retval = -ENOEXEC;
656 if (elf_ppnt->p_filesz > PATH_MAX ||
657 elf_ppnt->p_filesz < 2)
658 goto out_free_file;
659
660 retval = -ENOMEM;
661 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
662 GFP_KERNEL);
663 if (!elf_interpreter)
664 goto out_free_file;
665
666 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
667 elf_interpreter,
668 elf_ppnt->p_filesz);
669 if (retval != elf_ppnt->p_filesz) {
670 if (retval >= 0)
671 retval = -EIO;
672 goto out_free_interp;
673 }
674 /* make sure path is NULL terminated */
675 retval = -ENOEXEC;
676 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
677 goto out_free_interp;
678
679 /*
680 * The early SET_PERSONALITY here is so that the lookup
681 * for the interpreter happens in the namespace of the
682 * to-be-execed image. SET_PERSONALITY can select an
683 * alternate root.
684 *
685 * However, SET_PERSONALITY is NOT allowed to switch
686 * this task into the new images's memory mapping
687 * policy - that is, TASK_SIZE must still evaluate to
688 * that which is appropriate to the execing application.
689 * This is because exit_mmap() needs to have TASK_SIZE
690 * evaluate to the size of the old image.
691 *
692 * So if (say) a 64-bit application is execing a 32-bit
693 * application it is the architecture's responsibility
694 * to defer changing the value of TASK_SIZE until the
695 * switch really is going to happen - do this in
696 * flush_thread(). - akpm
697 */
698 SET_PERSONALITY(loc->elf_ex);
699
700 interpreter = open_exec(elf_interpreter);
701 retval = PTR_ERR(interpreter);
702 if (IS_ERR(interpreter))
703 goto out_free_interp;
704
705 /*
706 * If the binary is not readable then enforce
707 * mm->dumpable = 0 regardless of the interpreter's
708 * permissions.
709 */
710 if (file_permission(interpreter, MAY_READ) < 0)
711 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
712
713 retval = kernel_read(interpreter, 0, bprm->buf,
714 BINPRM_BUF_SIZE);
715 if (retval != BINPRM_BUF_SIZE) {
716 if (retval >= 0)
717 retval = -EIO;
718 goto out_free_dentry;
719 }
720
721 /* Get the exec headers */
722 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
723 break;
724 }
725 elf_ppnt++;
726 }
727
728 elf_ppnt = elf_phdata;
729 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
730 if (elf_ppnt->p_type == PT_GNU_STACK) {
731 if (elf_ppnt->p_flags & PF_X)
732 executable_stack = EXSTACK_ENABLE_X;
733 else
734 executable_stack = EXSTACK_DISABLE_X;
735 break;
736 }
737
738 /* Some simple consistency checks for the interpreter */
739 if (elf_interpreter) {
740 retval = -ELIBBAD;
741 /* Not an ELF interpreter */
742 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
743 goto out_free_dentry;
744 /* Verify the interpreter has a valid arch */
745 if (!elf_check_arch(&loc->interp_elf_ex))
746 goto out_free_dentry;
747 } else {
748 /* Executables without an interpreter also need a personality */
749 SET_PERSONALITY(loc->elf_ex);
750 }
751
752 /* Flush all traces of the currently running executable */
753 retval = flush_old_exec(bprm);
754 if (retval)
755 goto out_free_dentry;
756
757 /* OK, This is the point of no return */
758 current->flags &= ~PF_FORKNOEXEC;
759 current->mm->def_flags = def_flags;
760
761 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
762 may depend on the personality. */
763 SET_PERSONALITY(loc->elf_ex);
764 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
765 current->personality |= READ_IMPLIES_EXEC;
766
767 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
768 current->flags |= PF_RANDOMIZE;
769 arch_pick_mmap_layout(current->mm);
770
771 /* Do this so that we can load the interpreter, if need be. We will
772 change some of these later */
773 current->mm->free_area_cache = current->mm->mmap_base;
774 current->mm->cached_hole_size = 0;
775 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
776 executable_stack);
777 if (retval < 0) {
778 send_sig(SIGKILL, current, 0);
779 goto out_free_dentry;
780 }
781
782 current->mm->start_stack = bprm->p;
783
784 /* Now we do a little grungy work by mmaping the ELF image into
785 the correct location in memory. */
786 for(i = 0, elf_ppnt = elf_phdata;
787 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
788 int elf_prot = 0, elf_flags;
789 unsigned long k, vaddr;
790
791 if (elf_ppnt->p_type != PT_LOAD)
792 continue;
793
794 if (unlikely (elf_brk > elf_bss)) {
795 unsigned long nbyte;
796
797 /* There was a PT_LOAD segment with p_memsz > p_filesz
798 before this one. Map anonymous pages, if needed,
799 and clear the area. */
800 retval = set_brk (elf_bss + load_bias,
801 elf_brk + load_bias);
802 if (retval) {
803 send_sig(SIGKILL, current, 0);
804 goto out_free_dentry;
805 }
806 nbyte = ELF_PAGEOFFSET(elf_bss);
807 if (nbyte) {
808 nbyte = ELF_MIN_ALIGN - nbyte;
809 if (nbyte > elf_brk - elf_bss)
810 nbyte = elf_brk - elf_bss;
811 if (clear_user((void __user *)elf_bss +
812 load_bias, nbyte)) {
813 /*
814 * This bss-zeroing can fail if the ELF
815 * file specifies odd protections. So
816 * we don't check the return value
817 */
818 }
819 }
820 }
821
822 if (elf_ppnt->p_flags & PF_R)
823 elf_prot |= PROT_READ;
824 if (elf_ppnt->p_flags & PF_W)
825 elf_prot |= PROT_WRITE;
826 if (elf_ppnt->p_flags & PF_X)
827 elf_prot |= PROT_EXEC;
828
829 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
830
831 vaddr = elf_ppnt->p_vaddr;
832 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
833 elf_flags |= MAP_FIXED;
834 } else if (loc->elf_ex.e_type == ET_DYN) {
835 /* Try and get dynamic programs out of the way of the
836 * default mmap base, as well as whatever program they
837 * might try to exec. This is because the brk will
838 * follow the loader, and is not movable. */
839 #ifdef CONFIG_X86
840 load_bias = 0;
841 #else
842 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
843 #endif
844 }
845
846 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
847 elf_prot, elf_flags, 0);
848 if (BAD_ADDR(error)) {
849 send_sig(SIGKILL, current, 0);
850 retval = IS_ERR((void *)error) ?
851 PTR_ERR((void*)error) : -EINVAL;
852 goto out_free_dentry;
853 }
854
855 if (!load_addr_set) {
856 load_addr_set = 1;
857 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
858 if (loc->elf_ex.e_type == ET_DYN) {
859 load_bias += error -
860 ELF_PAGESTART(load_bias + vaddr);
861 load_addr += load_bias;
862 reloc_func_desc = load_bias;
863 }
864 }
865 k = elf_ppnt->p_vaddr;
866 if (k < start_code)
867 start_code = k;
868 if (start_data < k)
869 start_data = k;
870
871 /*
872 * Check to see if the section's size will overflow the
873 * allowed task size. Note that p_filesz must always be
874 * <= p_memsz so it is only necessary to check p_memsz.
875 */
876 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
877 elf_ppnt->p_memsz > TASK_SIZE ||
878 TASK_SIZE - elf_ppnt->p_memsz < k) {
879 /* set_brk can never work. Avoid overflows. */
880 send_sig(SIGKILL, current, 0);
881 retval = -EINVAL;
882 goto out_free_dentry;
883 }
884
885 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
886
887 if (k > elf_bss)
888 elf_bss = k;
889 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
890 end_code = k;
891 if (end_data < k)
892 end_data = k;
893 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
894 if (k > elf_brk)
895 elf_brk = k;
896 }
897
898 loc->elf_ex.e_entry += load_bias;
899 elf_bss += load_bias;
900 elf_brk += load_bias;
901 start_code += load_bias;
902 end_code += load_bias;
903 start_data += load_bias;
904 end_data += load_bias;
905
906 /* Calling set_brk effectively mmaps the pages that we need
907 * for the bss and break sections. We must do this before
908 * mapping in the interpreter, to make sure it doesn't wind
909 * up getting placed where the bss needs to go.
910 */
911 retval = set_brk(elf_bss, elf_brk);
912 if (retval) {
913 send_sig(SIGKILL, current, 0);
914 goto out_free_dentry;
915 }
916 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
917 send_sig(SIGSEGV, current, 0);
918 retval = -EFAULT; /* Nobody gets to see this, but.. */
919 goto out_free_dentry;
920 }
921
922 if (elf_interpreter) {
923 unsigned long uninitialized_var(interp_map_addr);
924
925 elf_entry = load_elf_interp(&loc->interp_elf_ex,
926 interpreter,
927 &interp_map_addr,
928 load_bias);
929 if (!IS_ERR((void *)elf_entry)) {
930 /*
931 * load_elf_interp() returns relocation
932 * adjustment
933 */
934 interp_load_addr = elf_entry;
935 elf_entry += loc->interp_elf_ex.e_entry;
936 }
937 if (BAD_ADDR(elf_entry)) {
938 force_sig(SIGSEGV, current);
939 retval = IS_ERR((void *)elf_entry) ?
940 (int)elf_entry : -EINVAL;
941 goto out_free_dentry;
942 }
943 reloc_func_desc = interp_load_addr;
944
945 allow_write_access(interpreter);
946 fput(interpreter);
947 kfree(elf_interpreter);
948 } else {
949 elf_entry = loc->elf_ex.e_entry;
950 if (BAD_ADDR(elf_entry)) {
951 force_sig(SIGSEGV, current);
952 retval = -EINVAL;
953 goto out_free_dentry;
954 }
955 }
956
957 kfree(elf_phdata);
958
959 sys_close(elf_exec_fileno);
960
961 set_binfmt(&elf_format);
962
963 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
964 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
965 if (retval < 0) {
966 send_sig(SIGKILL, current, 0);
967 goto out;
968 }
969 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
970
971 install_exec_creds(bprm);
972 current->flags &= ~PF_FORKNOEXEC;
973 retval = create_elf_tables(bprm, &loc->elf_ex,
974 load_addr, interp_load_addr);
975 if (retval < 0) {
976 send_sig(SIGKILL, current, 0);
977 goto out;
978 }
979 /* N.B. passed_fileno might not be initialized? */
980 current->mm->end_code = end_code;
981 current->mm->start_code = start_code;
982 current->mm->start_data = start_data;
983 current->mm->end_data = end_data;
984 current->mm->start_stack = bprm->p;
985
986 #ifdef arch_randomize_brk
987 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1))
988 current->mm->brk = current->mm->start_brk =
989 arch_randomize_brk(current->mm);
990 #endif
991
992 if (current->personality & MMAP_PAGE_ZERO) {
993 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
994 and some applications "depend" upon this behavior.
995 Since we do not have the power to recompile these, we
996 emulate the SVr4 behavior. Sigh. */
997 down_write(&current->mm->mmap_sem);
998 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
999 MAP_FIXED | MAP_PRIVATE, 0);
1000 up_write(&current->mm->mmap_sem);
1001 }
1002
1003 #ifdef ELF_PLAT_INIT
1004 /*
1005 * The ABI may specify that certain registers be set up in special
1006 * ways (on i386 %edx is the address of a DT_FINI function, for
1007 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1008 * that the e_entry field is the address of the function descriptor
1009 * for the startup routine, rather than the address of the startup
1010 * routine itself. This macro performs whatever initialization to
1011 * the regs structure is required as well as any relocations to the
1012 * function descriptor entries when executing dynamically links apps.
1013 */
1014 ELF_PLAT_INIT(regs, reloc_func_desc);
1015 #endif
1016
1017 start_thread(regs, elf_entry, bprm->p);
1018 retval = 0;
1019 out:
1020 kfree(loc);
1021 out_ret:
1022 return retval;
1023
1024 /* error cleanup */
1025 out_free_dentry:
1026 allow_write_access(interpreter);
1027 if (interpreter)
1028 fput(interpreter);
1029 out_free_interp:
1030 kfree(elf_interpreter);
1031 out_free_file:
1032 sys_close(elf_exec_fileno);
1033 out_free_ph:
1034 kfree(elf_phdata);
1035 goto out;
1036 }
1037
1038 /* This is really simpleminded and specialized - we are loading an
1039 a.out library that is given an ELF header. */
1040 static int load_elf_library(struct file *file)
1041 {
1042 struct elf_phdr *elf_phdata;
1043 struct elf_phdr *eppnt;
1044 unsigned long elf_bss, bss, len;
1045 int retval, error, i, j;
1046 struct elfhdr elf_ex;
1047
1048 error = -ENOEXEC;
1049 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1050 if (retval != sizeof(elf_ex))
1051 goto out;
1052
1053 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1054 goto out;
1055
1056 /* First of all, some simple consistency checks */
1057 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1058 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1059 goto out;
1060
1061 /* Now read in all of the header information */
1062
1063 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1064 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1065
1066 error = -ENOMEM;
1067 elf_phdata = kmalloc(j, GFP_KERNEL);
1068 if (!elf_phdata)
1069 goto out;
1070
1071 eppnt = elf_phdata;
1072 error = -ENOEXEC;
1073 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1074 if (retval != j)
1075 goto out_free_ph;
1076
1077 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1078 if ((eppnt + i)->p_type == PT_LOAD)
1079 j++;
1080 if (j != 1)
1081 goto out_free_ph;
1082
1083 while (eppnt->p_type != PT_LOAD)
1084 eppnt++;
1085
1086 /* Now use mmap to map the library into memory. */
1087 down_write(&current->mm->mmap_sem);
1088 error = do_mmap(file,
1089 ELF_PAGESTART(eppnt->p_vaddr),
1090 (eppnt->p_filesz +
1091 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1092 PROT_READ | PROT_WRITE | PROT_EXEC,
1093 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1094 (eppnt->p_offset -
1095 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1096 up_write(&current->mm->mmap_sem);
1097 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1098 goto out_free_ph;
1099
1100 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1101 if (padzero(elf_bss)) {
1102 error = -EFAULT;
1103 goto out_free_ph;
1104 }
1105
1106 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1107 ELF_MIN_ALIGN - 1);
1108 bss = eppnt->p_memsz + eppnt->p_vaddr;
1109 if (bss > len) {
1110 down_write(&current->mm->mmap_sem);
1111 do_brk(len, bss - len);
1112 up_write(&current->mm->mmap_sem);
1113 }
1114 error = 0;
1115
1116 out_free_ph:
1117 kfree(elf_phdata);
1118 out:
1119 return error;
1120 }
1121
1122 /*
1123 * Note that some platforms still use traditional core dumps and not
1124 * the ELF core dump. Each platform can select it as appropriate.
1125 */
1126 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1127
1128 /*
1129 * ELF core dumper
1130 *
1131 * Modelled on fs/exec.c:aout_core_dump()
1132 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1133 */
1134 /*
1135 * These are the only things you should do on a core-file: use only these
1136 * functions to write out all the necessary info.
1137 */
1138 static int dump_write(struct file *file, const void *addr, int nr)
1139 {
1140 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1141 }
1142
1143 static int dump_seek(struct file *file, loff_t off)
1144 {
1145 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1146 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1147 return 0;
1148 } else {
1149 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1150 if (!buf)
1151 return 0;
1152 while (off > 0) {
1153 unsigned long n = off;
1154 if (n > PAGE_SIZE)
1155 n = PAGE_SIZE;
1156 if (!dump_write(file, buf, n))
1157 return 0;
1158 off -= n;
1159 }
1160 free_page((unsigned long)buf);
1161 }
1162 return 1;
1163 }
1164
1165 /*
1166 * Decide what to dump of a segment, part, all or none.
1167 */
1168 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1169 unsigned long mm_flags)
1170 {
1171 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1172
1173 /* The vma can be set up to tell us the answer directly. */
1174 if (vma->vm_flags & VM_ALWAYSDUMP)
1175 goto whole;
1176
1177 /* Hugetlb memory check */
1178 if (vma->vm_flags & VM_HUGETLB) {
1179 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1180 goto whole;
1181 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1182 goto whole;
1183 }
1184
1185 /* Do not dump I/O mapped devices or special mappings */
1186 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1187 return 0;
1188
1189 /* By default, dump shared memory if mapped from an anonymous file. */
1190 if (vma->vm_flags & VM_SHARED) {
1191 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1192 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1193 goto whole;
1194 return 0;
1195 }
1196
1197 /* Dump segments that have been written to. */
1198 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1199 goto whole;
1200 if (vma->vm_file == NULL)
1201 return 0;
1202
1203 if (FILTER(MAPPED_PRIVATE))
1204 goto whole;
1205
1206 /*
1207 * If this looks like the beginning of a DSO or executable mapping,
1208 * check for an ELF header. If we find one, dump the first page to
1209 * aid in determining what was mapped here.
1210 */
1211 if (FILTER(ELF_HEADERS) &&
1212 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1213 u32 __user *header = (u32 __user *) vma->vm_start;
1214 u32 word;
1215 mm_segment_t fs = get_fs();
1216 /*
1217 * Doing it this way gets the constant folded by GCC.
1218 */
1219 union {
1220 u32 cmp;
1221 char elfmag[SELFMAG];
1222 } magic;
1223 BUILD_BUG_ON(SELFMAG != sizeof word);
1224 magic.elfmag[EI_MAG0] = ELFMAG0;
1225 magic.elfmag[EI_MAG1] = ELFMAG1;
1226 magic.elfmag[EI_MAG2] = ELFMAG2;
1227 magic.elfmag[EI_MAG3] = ELFMAG3;
1228 /*
1229 * Switch to the user "segment" for get_user(),
1230 * then put back what elf_core_dump() had in place.
1231 */
1232 set_fs(USER_DS);
1233 if (unlikely(get_user(word, header)))
1234 word = 0;
1235 set_fs(fs);
1236 if (word == magic.cmp)
1237 return PAGE_SIZE;
1238 }
1239
1240 #undef FILTER
1241
1242 return 0;
1243
1244 whole:
1245 return vma->vm_end - vma->vm_start;
1246 }
1247
1248 /* An ELF note in memory */
1249 struct memelfnote
1250 {
1251 const char *name;
1252 int type;
1253 unsigned int datasz;
1254 void *data;
1255 };
1256
1257 static int notesize(struct memelfnote *en)
1258 {
1259 int sz;
1260
1261 sz = sizeof(struct elf_note);
1262 sz += roundup(strlen(en->name) + 1, 4);
1263 sz += roundup(en->datasz, 4);
1264
1265 return sz;
1266 }
1267
1268 #define DUMP_WRITE(addr, nr, foffset) \
1269 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1270
1271 static int alignfile(struct file *file, loff_t *foffset)
1272 {
1273 static const char buf[4] = { 0, };
1274 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1275 return 1;
1276 }
1277
1278 static int writenote(struct memelfnote *men, struct file *file,
1279 loff_t *foffset)
1280 {
1281 struct elf_note en;
1282 en.n_namesz = strlen(men->name) + 1;
1283 en.n_descsz = men->datasz;
1284 en.n_type = men->type;
1285
1286 DUMP_WRITE(&en, sizeof(en), foffset);
1287 DUMP_WRITE(men->name, en.n_namesz, foffset);
1288 if (!alignfile(file, foffset))
1289 return 0;
1290 DUMP_WRITE(men->data, men->datasz, foffset);
1291 if (!alignfile(file, foffset))
1292 return 0;
1293
1294 return 1;
1295 }
1296 #undef DUMP_WRITE
1297
1298 #define DUMP_WRITE(addr, nr) \
1299 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1300 goto end_coredump;
1301 #define DUMP_SEEK(off) \
1302 if (!dump_seek(file, (off))) \
1303 goto end_coredump;
1304
1305 static void fill_elf_header(struct elfhdr *elf, int segs,
1306 u16 machine, u32 flags, u8 osabi)
1307 {
1308 memset(elf, 0, sizeof(*elf));
1309
1310 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1311 elf->e_ident[EI_CLASS] = ELF_CLASS;
1312 elf->e_ident[EI_DATA] = ELF_DATA;
1313 elf->e_ident[EI_VERSION] = EV_CURRENT;
1314 elf->e_ident[EI_OSABI] = ELF_OSABI;
1315
1316 elf->e_type = ET_CORE;
1317 elf->e_machine = machine;
1318 elf->e_version = EV_CURRENT;
1319 elf->e_phoff = sizeof(struct elfhdr);
1320 elf->e_flags = flags;
1321 elf->e_ehsize = sizeof(struct elfhdr);
1322 elf->e_phentsize = sizeof(struct elf_phdr);
1323 elf->e_phnum = segs;
1324
1325 return;
1326 }
1327
1328 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1329 {
1330 phdr->p_type = PT_NOTE;
1331 phdr->p_offset = offset;
1332 phdr->p_vaddr = 0;
1333 phdr->p_paddr = 0;
1334 phdr->p_filesz = sz;
1335 phdr->p_memsz = 0;
1336 phdr->p_flags = 0;
1337 phdr->p_align = 0;
1338 return;
1339 }
1340
1341 static void fill_note(struct memelfnote *note, const char *name, int type,
1342 unsigned int sz, void *data)
1343 {
1344 note->name = name;
1345 note->type = type;
1346 note->datasz = sz;
1347 note->data = data;
1348 return;
1349 }
1350
1351 /*
1352 * fill up all the fields in prstatus from the given task struct, except
1353 * registers which need to be filled up separately.
1354 */
1355 static void fill_prstatus(struct elf_prstatus *prstatus,
1356 struct task_struct *p, long signr)
1357 {
1358 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1359 prstatus->pr_sigpend = p->pending.signal.sig[0];
1360 prstatus->pr_sighold = p->blocked.sig[0];
1361 prstatus->pr_pid = task_pid_vnr(p);
1362 prstatus->pr_ppid = task_pid_vnr(p->real_parent);
1363 prstatus->pr_pgrp = task_pgrp_vnr(p);
1364 prstatus->pr_sid = task_session_vnr(p);
1365 if (thread_group_leader(p)) {
1366 struct task_cputime cputime;
1367
1368 /*
1369 * This is the record for the group leader. It shows the
1370 * group-wide total, not its individual thread total.
1371 */
1372 thread_group_cputime(p, &cputime);
1373 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1374 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1375 } else {
1376 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1377 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1378 }
1379 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1380 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1381 }
1382
1383 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1384 struct mm_struct *mm)
1385 {
1386 const struct cred *cred;
1387 unsigned int i, len;
1388
1389 /* first copy the parameters from user space */
1390 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1391
1392 len = mm->arg_end - mm->arg_start;
1393 if (len >= ELF_PRARGSZ)
1394 len = ELF_PRARGSZ-1;
1395 if (copy_from_user(&psinfo->pr_psargs,
1396 (const char __user *)mm->arg_start, len))
1397 return -EFAULT;
1398 for(i = 0; i < len; i++)
1399 if (psinfo->pr_psargs[i] == 0)
1400 psinfo->pr_psargs[i] = ' ';
1401 psinfo->pr_psargs[len] = 0;
1402
1403 psinfo->pr_pid = task_pid_vnr(p);
1404 psinfo->pr_ppid = task_pid_vnr(p->real_parent);
1405 psinfo->pr_pgrp = task_pgrp_vnr(p);
1406 psinfo->pr_sid = task_session_vnr(p);
1407
1408 i = p->state ? ffz(~p->state) + 1 : 0;
1409 psinfo->pr_state = i;
1410 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1411 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1412 psinfo->pr_nice = task_nice(p);
1413 psinfo->pr_flag = p->flags;
1414 rcu_read_lock();
1415 cred = __task_cred(p);
1416 SET_UID(psinfo->pr_uid, cred->uid);
1417 SET_GID(psinfo->pr_gid, cred->gid);
1418 rcu_read_unlock();
1419 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1420
1421 return 0;
1422 }
1423
1424 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1425 {
1426 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1427 int i = 0;
1428 do
1429 i += 2;
1430 while (auxv[i - 2] != AT_NULL);
1431 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1432 }
1433
1434 #ifdef CORE_DUMP_USE_REGSET
1435 #include <linux/regset.h>
1436
1437 struct elf_thread_core_info {
1438 struct elf_thread_core_info *next;
1439 struct task_struct *task;
1440 struct elf_prstatus prstatus;
1441 struct memelfnote notes[0];
1442 };
1443
1444 struct elf_note_info {
1445 struct elf_thread_core_info *thread;
1446 struct memelfnote psinfo;
1447 struct memelfnote auxv;
1448 size_t size;
1449 int thread_notes;
1450 };
1451
1452 /*
1453 * When a regset has a writeback hook, we call it on each thread before
1454 * dumping user memory. On register window machines, this makes sure the
1455 * user memory backing the register data is up to date before we read it.
1456 */
1457 static void do_thread_regset_writeback(struct task_struct *task,
1458 const struct user_regset *regset)
1459 {
1460 if (regset->writeback)
1461 regset->writeback(task, regset, 1);
1462 }
1463
1464 static int fill_thread_core_info(struct elf_thread_core_info *t,
1465 const struct user_regset_view *view,
1466 long signr, size_t *total)
1467 {
1468 unsigned int i;
1469
1470 /*
1471 * NT_PRSTATUS is the one special case, because the regset data
1472 * goes into the pr_reg field inside the note contents, rather
1473 * than being the whole note contents. We fill the reset in here.
1474 * We assume that regset 0 is NT_PRSTATUS.
1475 */
1476 fill_prstatus(&t->prstatus, t->task, signr);
1477 (void) view->regsets[0].get(t->task, &view->regsets[0],
1478 0, sizeof(t->prstatus.pr_reg),
1479 &t->prstatus.pr_reg, NULL);
1480
1481 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1482 sizeof(t->prstatus), &t->prstatus);
1483 *total += notesize(&t->notes[0]);
1484
1485 do_thread_regset_writeback(t->task, &view->regsets[0]);
1486
1487 /*
1488 * Each other regset might generate a note too. For each regset
1489 * that has no core_note_type or is inactive, we leave t->notes[i]
1490 * all zero and we'll know to skip writing it later.
1491 */
1492 for (i = 1; i < view->n; ++i) {
1493 const struct user_regset *regset = &view->regsets[i];
1494 do_thread_regset_writeback(t->task, regset);
1495 if (regset->core_note_type &&
1496 (!regset->active || regset->active(t->task, regset))) {
1497 int ret;
1498 size_t size = regset->n * regset->size;
1499 void *data = kmalloc(size, GFP_KERNEL);
1500 if (unlikely(!data))
1501 return 0;
1502 ret = regset->get(t->task, regset,
1503 0, size, data, NULL);
1504 if (unlikely(ret))
1505 kfree(data);
1506 else {
1507 if (regset->core_note_type != NT_PRFPREG)
1508 fill_note(&t->notes[i], "LINUX",
1509 regset->core_note_type,
1510 size, data);
1511 else {
1512 t->prstatus.pr_fpvalid = 1;
1513 fill_note(&t->notes[i], "CORE",
1514 NT_PRFPREG, size, data);
1515 }
1516 *total += notesize(&t->notes[i]);
1517 }
1518 }
1519 }
1520
1521 return 1;
1522 }
1523
1524 static int fill_note_info(struct elfhdr *elf, int phdrs,
1525 struct elf_note_info *info,
1526 long signr, struct pt_regs *regs)
1527 {
1528 struct task_struct *dump_task = current;
1529 const struct user_regset_view *view = task_user_regset_view(dump_task);
1530 struct elf_thread_core_info *t;
1531 struct elf_prpsinfo *psinfo;
1532 struct core_thread *ct;
1533 unsigned int i;
1534
1535 info->size = 0;
1536 info->thread = NULL;
1537
1538 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1539 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1540
1541 if (psinfo == NULL)
1542 return 0;
1543
1544 /*
1545 * Figure out how many notes we're going to need for each thread.
1546 */
1547 info->thread_notes = 0;
1548 for (i = 0; i < view->n; ++i)
1549 if (view->regsets[i].core_note_type != 0)
1550 ++info->thread_notes;
1551
1552 /*
1553 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1554 * since it is our one special case.
1555 */
1556 if (unlikely(info->thread_notes == 0) ||
1557 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1558 WARN_ON(1);
1559 return 0;
1560 }
1561
1562 /*
1563 * Initialize the ELF file header.
1564 */
1565 fill_elf_header(elf, phdrs,
1566 view->e_machine, view->e_flags, view->ei_osabi);
1567
1568 /*
1569 * Allocate a structure for each thread.
1570 */
1571 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1572 t = kzalloc(offsetof(struct elf_thread_core_info,
1573 notes[info->thread_notes]),
1574 GFP_KERNEL);
1575 if (unlikely(!t))
1576 return 0;
1577
1578 t->task = ct->task;
1579 if (ct->task == dump_task || !info->thread) {
1580 t->next = info->thread;
1581 info->thread = t;
1582 } else {
1583 /*
1584 * Make sure to keep the original task at
1585 * the head of the list.
1586 */
1587 t->next = info->thread->next;
1588 info->thread->next = t;
1589 }
1590 }
1591
1592 /*
1593 * Now fill in each thread's information.
1594 */
1595 for (t = info->thread; t != NULL; t = t->next)
1596 if (!fill_thread_core_info(t, view, signr, &info->size))
1597 return 0;
1598
1599 /*
1600 * Fill in the two process-wide notes.
1601 */
1602 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1603 info->size += notesize(&info->psinfo);
1604
1605 fill_auxv_note(&info->auxv, current->mm);
1606 info->size += notesize(&info->auxv);
1607
1608 return 1;
1609 }
1610
1611 static size_t get_note_info_size(struct elf_note_info *info)
1612 {
1613 return info->size;
1614 }
1615
1616 /*
1617 * Write all the notes for each thread. When writing the first thread, the
1618 * process-wide notes are interleaved after the first thread-specific note.
1619 */
1620 static int write_note_info(struct elf_note_info *info,
1621 struct file *file, loff_t *foffset)
1622 {
1623 bool first = 1;
1624 struct elf_thread_core_info *t = info->thread;
1625
1626 do {
1627 int i;
1628
1629 if (!writenote(&t->notes[0], file, foffset))
1630 return 0;
1631
1632 if (first && !writenote(&info->psinfo, file, foffset))
1633 return 0;
1634 if (first && !writenote(&info->auxv, file, foffset))
1635 return 0;
1636
1637 for (i = 1; i < info->thread_notes; ++i)
1638 if (t->notes[i].data &&
1639 !writenote(&t->notes[i], file, foffset))
1640 return 0;
1641
1642 first = 0;
1643 t = t->next;
1644 } while (t);
1645
1646 return 1;
1647 }
1648
1649 static void free_note_info(struct elf_note_info *info)
1650 {
1651 struct elf_thread_core_info *threads = info->thread;
1652 while (threads) {
1653 unsigned int i;
1654 struct elf_thread_core_info *t = threads;
1655 threads = t->next;
1656 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1657 for (i = 1; i < info->thread_notes; ++i)
1658 kfree(t->notes[i].data);
1659 kfree(t);
1660 }
1661 kfree(info->psinfo.data);
1662 }
1663
1664 #else
1665
1666 /* Here is the structure in which status of each thread is captured. */
1667 struct elf_thread_status
1668 {
1669 struct list_head list;
1670 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1671 elf_fpregset_t fpu; /* NT_PRFPREG */
1672 struct task_struct *thread;
1673 #ifdef ELF_CORE_COPY_XFPREGS
1674 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1675 #endif
1676 struct memelfnote notes[3];
1677 int num_notes;
1678 };
1679
1680 /*
1681 * In order to add the specific thread information for the elf file format,
1682 * we need to keep a linked list of every threads pr_status and then create
1683 * a single section for them in the final core file.
1684 */
1685 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1686 {
1687 int sz = 0;
1688 struct task_struct *p = t->thread;
1689 t->num_notes = 0;
1690
1691 fill_prstatus(&t->prstatus, p, signr);
1692 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1693
1694 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1695 &(t->prstatus));
1696 t->num_notes++;
1697 sz += notesize(&t->notes[0]);
1698
1699 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1700 &t->fpu))) {
1701 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1702 &(t->fpu));
1703 t->num_notes++;
1704 sz += notesize(&t->notes[1]);
1705 }
1706
1707 #ifdef ELF_CORE_COPY_XFPREGS
1708 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1709 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1710 sizeof(t->xfpu), &t->xfpu);
1711 t->num_notes++;
1712 sz += notesize(&t->notes[2]);
1713 }
1714 #endif
1715 return sz;
1716 }
1717
1718 struct elf_note_info {
1719 struct memelfnote *notes;
1720 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1721 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1722 struct list_head thread_list;
1723 elf_fpregset_t *fpu;
1724 #ifdef ELF_CORE_COPY_XFPREGS
1725 elf_fpxregset_t *xfpu;
1726 #endif
1727 int thread_status_size;
1728 int numnote;
1729 };
1730
1731 static int fill_note_info(struct elfhdr *elf, int phdrs,
1732 struct elf_note_info *info,
1733 long signr, struct pt_regs *regs)
1734 {
1735 #define NUM_NOTES 6
1736 struct list_head *t;
1737
1738 info->notes = NULL;
1739 info->prstatus = NULL;
1740 info->psinfo = NULL;
1741 info->fpu = NULL;
1742 #ifdef ELF_CORE_COPY_XFPREGS
1743 info->xfpu = NULL;
1744 #endif
1745 INIT_LIST_HEAD(&info->thread_list);
1746
1747 info->notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote),
1748 GFP_KERNEL);
1749 if (!info->notes)
1750 return 0;
1751 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1752 if (!info->psinfo)
1753 return 0;
1754 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1755 if (!info->prstatus)
1756 return 0;
1757 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1758 if (!info->fpu)
1759 return 0;
1760 #ifdef ELF_CORE_COPY_XFPREGS
1761 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1762 if (!info->xfpu)
1763 return 0;
1764 #endif
1765
1766 info->thread_status_size = 0;
1767 if (signr) {
1768 struct core_thread *ct;
1769 struct elf_thread_status *ets;
1770
1771 for (ct = current->mm->core_state->dumper.next;
1772 ct; ct = ct->next) {
1773 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1774 if (!ets)
1775 return 0;
1776
1777 ets->thread = ct->task;
1778 list_add(&ets->list, &info->thread_list);
1779 }
1780
1781 list_for_each(t, &info->thread_list) {
1782 int sz;
1783
1784 ets = list_entry(t, struct elf_thread_status, list);
1785 sz = elf_dump_thread_status(signr, ets);
1786 info->thread_status_size += sz;
1787 }
1788 }
1789 /* now collect the dump for the current */
1790 memset(info->prstatus, 0, sizeof(*info->prstatus));
1791 fill_prstatus(info->prstatus, current, signr);
1792 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1793
1794 /* Set up header */
1795 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);
1796
1797 /*
1798 * Set up the notes in similar form to SVR4 core dumps made
1799 * with info from their /proc.
1800 */
1801
1802 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1803 sizeof(*info->prstatus), info->prstatus);
1804 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1805 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1806 sizeof(*info->psinfo), info->psinfo);
1807
1808 info->numnote = 2;
1809
1810 fill_auxv_note(&info->notes[info->numnote++], current->mm);
1811
1812 /* Try to dump the FPU. */
1813 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1814 info->fpu);
1815 if (info->prstatus->pr_fpvalid)
1816 fill_note(info->notes + info->numnote++,
1817 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1818 #ifdef ELF_CORE_COPY_XFPREGS
1819 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1820 fill_note(info->notes + info->numnote++,
1821 "LINUX", ELF_CORE_XFPREG_TYPE,
1822 sizeof(*info->xfpu), info->xfpu);
1823 #endif
1824
1825 return 1;
1826
1827 #undef NUM_NOTES
1828 }
1829
1830 static size_t get_note_info_size(struct elf_note_info *info)
1831 {
1832 int sz = 0;
1833 int i;
1834
1835 for (i = 0; i < info->numnote; i++)
1836 sz += notesize(info->notes + i);
1837
1838 sz += info->thread_status_size;
1839
1840 return sz;
1841 }
1842
1843 static int write_note_info(struct elf_note_info *info,
1844 struct file *file, loff_t *foffset)
1845 {
1846 int i;
1847 struct list_head *t;
1848
1849 for (i = 0; i < info->numnote; i++)
1850 if (!writenote(info->notes + i, file, foffset))
1851 return 0;
1852
1853 /* write out the thread status notes section */
1854 list_for_each(t, &info->thread_list) {
1855 struct elf_thread_status *tmp =
1856 list_entry(t, struct elf_thread_status, list);
1857
1858 for (i = 0; i < tmp->num_notes; i++)
1859 if (!writenote(&tmp->notes[i], file, foffset))
1860 return 0;
1861 }
1862
1863 return 1;
1864 }
1865
1866 static void free_note_info(struct elf_note_info *info)
1867 {
1868 while (!list_empty(&info->thread_list)) {
1869 struct list_head *tmp = info->thread_list.next;
1870 list_del(tmp);
1871 kfree(list_entry(tmp, struct elf_thread_status, list));
1872 }
1873
1874 kfree(info->prstatus);
1875 kfree(info->psinfo);
1876 kfree(info->notes);
1877 kfree(info->fpu);
1878 #ifdef ELF_CORE_COPY_XFPREGS
1879 kfree(info->xfpu);
1880 #endif
1881 }
1882
1883 #endif
1884
1885 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1886 struct vm_area_struct *gate_vma)
1887 {
1888 struct vm_area_struct *ret = tsk->mm->mmap;
1889
1890 if (ret)
1891 return ret;
1892 return gate_vma;
1893 }
1894 /*
1895 * Helper function for iterating across a vma list. It ensures that the caller
1896 * will visit `gate_vma' prior to terminating the search.
1897 */
1898 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1899 struct vm_area_struct *gate_vma)
1900 {
1901 struct vm_area_struct *ret;
1902
1903 ret = this_vma->vm_next;
1904 if (ret)
1905 return ret;
1906 if (this_vma == gate_vma)
1907 return NULL;
1908 return gate_vma;
1909 }
1910
1911 /*
1912 * Actual dumper
1913 *
1914 * This is a two-pass process; first we find the offsets of the bits,
1915 * and then they are actually written out. If we run out of core limit
1916 * we just truncate.
1917 */
1918 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
1919 {
1920 int has_dumped = 0;
1921 mm_segment_t fs;
1922 int segs;
1923 size_t size = 0;
1924 struct vm_area_struct *vma, *gate_vma;
1925 struct elfhdr *elf = NULL;
1926 loff_t offset = 0, dataoff, foffset;
1927 unsigned long mm_flags;
1928 struct elf_note_info info;
1929
1930 /*
1931 * We no longer stop all VM operations.
1932 *
1933 * This is because those proceses that could possibly change map_count
1934 * or the mmap / vma pages are now blocked in do_exit on current
1935 * finishing this core dump.
1936 *
1937 * Only ptrace can touch these memory addresses, but it doesn't change
1938 * the map_count or the pages allocated. So no possibility of crashing
1939 * exists while dumping the mm->vm_next areas to the core file.
1940 */
1941
1942 /* alloc memory for large data structures: too large to be on stack */
1943 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1944 if (!elf)
1945 goto out;
1946
1947 segs = current->mm->map_count;
1948 #ifdef ELF_CORE_EXTRA_PHDRS
1949 segs += ELF_CORE_EXTRA_PHDRS;
1950 #endif
1951
1952 gate_vma = get_gate_vma(current);
1953 if (gate_vma != NULL)
1954 segs++;
1955
1956 /*
1957 * Collect all the non-memory information about the process for the
1958 * notes. This also sets up the file header.
1959 */
1960 if (!fill_note_info(elf, segs + 1, /* including notes section */
1961 &info, signr, regs))
1962 goto cleanup;
1963
1964 has_dumped = 1;
1965 current->flags |= PF_DUMPCORE;
1966
1967 fs = get_fs();
1968 set_fs(KERNEL_DS);
1969
1970 DUMP_WRITE(elf, sizeof(*elf));
1971 offset += sizeof(*elf); /* Elf header */
1972 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1973 foffset = offset;
1974
1975 /* Write notes phdr entry */
1976 {
1977 struct elf_phdr phdr;
1978 size_t sz = get_note_info_size(&info);
1979
1980 sz += elf_coredump_extra_notes_size();
1981
1982 fill_elf_note_phdr(&phdr, sz, offset);
1983 offset += sz;
1984 DUMP_WRITE(&phdr, sizeof(phdr));
1985 }
1986
1987 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1988
1989 /*
1990 * We must use the same mm->flags while dumping core to avoid
1991 * inconsistency between the program headers and bodies, otherwise an
1992 * unusable core file can be generated.
1993 */
1994 mm_flags = current->mm->flags;
1995
1996 /* Write program headers for segments dump */
1997 for (vma = first_vma(current, gate_vma); vma != NULL;
1998 vma = next_vma(vma, gate_vma)) {
1999 struct elf_phdr phdr;
2000
2001 phdr.p_type = PT_LOAD;
2002 phdr.p_offset = offset;
2003 phdr.p_vaddr = vma->vm_start;
2004 phdr.p_paddr = 0;
2005 phdr.p_filesz = vma_dump_size(vma, mm_flags);
2006 phdr.p_memsz = vma->vm_end - vma->vm_start;
2007 offset += phdr.p_filesz;
2008 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2009 if (vma->vm_flags & VM_WRITE)
2010 phdr.p_flags |= PF_W;
2011 if (vma->vm_flags & VM_EXEC)
2012 phdr.p_flags |= PF_X;
2013 phdr.p_align = ELF_EXEC_PAGESIZE;
2014
2015 DUMP_WRITE(&phdr, sizeof(phdr));
2016 }
2017
2018 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
2019 ELF_CORE_WRITE_EXTRA_PHDRS;
2020 #endif
2021
2022 /* write out the notes section */
2023 if (!write_note_info(&info, file, &foffset))
2024 goto end_coredump;
2025
2026 if (elf_coredump_extra_notes_write(file, &foffset))
2027 goto end_coredump;
2028
2029 /* Align to page */
2030 DUMP_SEEK(dataoff - foffset);
2031
2032 for (vma = first_vma(current, gate_vma); vma != NULL;
2033 vma = next_vma(vma, gate_vma)) {
2034 unsigned long addr;
2035 unsigned long end;
2036
2037 end = vma->vm_start + vma_dump_size(vma, mm_flags);
2038
2039 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2040 struct page *page;
2041 struct vm_area_struct *tmp_vma;
2042
2043 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
2044 &page, &tmp_vma) <= 0) {
2045 DUMP_SEEK(PAGE_SIZE);
2046 } else {
2047 if (page == ZERO_PAGE(0)) {
2048 if (!dump_seek(file, PAGE_SIZE)) {
2049 page_cache_release(page);
2050 goto end_coredump;
2051 }
2052 } else {
2053 void *kaddr;
2054 flush_cache_page(tmp_vma, addr,
2055 page_to_pfn(page));
2056 kaddr = kmap(page);
2057 if ((size += PAGE_SIZE) > limit ||
2058 !dump_write(file, kaddr,
2059 PAGE_SIZE)) {
2060 kunmap(page);
2061 page_cache_release(page);
2062 goto end_coredump;
2063 }
2064 kunmap(page);
2065 }
2066 page_cache_release(page);
2067 }
2068 }
2069 }
2070
2071 #ifdef ELF_CORE_WRITE_EXTRA_DATA
2072 ELF_CORE_WRITE_EXTRA_DATA;
2073 #endif
2074
2075 end_coredump:
2076 set_fs(fs);
2077
2078 cleanup:
2079 free_note_info(&info);
2080 kfree(elf);
2081 out:
2082 return has_dumped;
2083 }
2084
2085 #endif /* USE_ELF_CORE_DUMP */
2086
2087 static int __init init_elf_binfmt(void)
2088 {
2089 return register_binfmt(&elf_format);
2090 }
2091
2092 static void __exit exit_elf_binfmt(void)
2093 {
2094 /* Remove the COFF and ELF loaders. */
2095 unregister_binfmt(&elf_format);
2096 }
2097
2098 core_initcall(init_elf_binfmt);
2099 module_exit(exit_elf_binfmt);
2100 MODULE_LICENSE("GPL");