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Merge branch 'akpm' (fixes from Andrew)
[linux-2.6/cjktty.git] / fs / binfmt_elf.c
blob3939829f6c5cc67e7d0ca1e9518f1df834be5088
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.
807 * If that is the case, retain the original non-zero
808 * load_bias value in order to establish proper
809 * non-randomized mappings.
810 */
811 if (current->flags & PF_RANDOMIZE)
812 load_bias = 0;
813 else
814 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
815 #else
816 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
817 #endif
818 }
819
820 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
821 elf_prot, elf_flags, 0);
822 if (BAD_ADDR(error)) {
823 send_sig(SIGKILL, current, 0);
824 retval = IS_ERR((void *)error) ?
825 PTR_ERR((void*)error) : -EINVAL;
826 goto out_free_dentry;
827 }
828
829 if (!load_addr_set) {
830 load_addr_set = 1;
831 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
832 if (loc->elf_ex.e_type == ET_DYN) {
833 load_bias += error -
834 ELF_PAGESTART(load_bias + vaddr);
835 load_addr += load_bias;
836 reloc_func_desc = load_bias;
837 }
838 }
839 k = elf_ppnt->p_vaddr;
840 if (k < start_code)
841 start_code = k;
842 if (start_data < k)
843 start_data = k;
844
845 /*
846 * Check to see if the section's size will overflow the
847 * allowed task size. Note that p_filesz must always be
848 * <= p_memsz so it is only necessary to check p_memsz.
849 */
850 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
851 elf_ppnt->p_memsz > TASK_SIZE ||
852 TASK_SIZE - elf_ppnt->p_memsz < k) {
853 /* set_brk can never work. Avoid overflows. */
854 send_sig(SIGKILL, current, 0);
855 retval = -EINVAL;
856 goto out_free_dentry;
857 }
858
859 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
860
861 if (k > elf_bss)
862 elf_bss = k;
863 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
864 end_code = k;
865 if (end_data < k)
866 end_data = k;
867 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
868 if (k > elf_brk)
869 elf_brk = k;
870 }
871
872 loc->elf_ex.e_entry += load_bias;
873 elf_bss += load_bias;
874 elf_brk += load_bias;
875 start_code += load_bias;
876 end_code += load_bias;
877 start_data += load_bias;
878 end_data += load_bias;
879
880 /* Calling set_brk effectively mmaps the pages that we need
881 * for the bss and break sections. We must do this before
882 * mapping in the interpreter, to make sure it doesn't wind
883 * up getting placed where the bss needs to go.
884 */
885 retval = set_brk(elf_bss, elf_brk);
886 if (retval) {
887 send_sig(SIGKILL, current, 0);
888 goto out_free_dentry;
889 }
890 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
891 send_sig(SIGSEGV, current, 0);
892 retval = -EFAULT; /* Nobody gets to see this, but.. */
893 goto out_free_dentry;
894 }
895
896 if (elf_interpreter) {
897 unsigned long interp_map_addr = 0;
898
899 elf_entry = load_elf_interp(&loc->interp_elf_ex,
900 interpreter,
901 &interp_map_addr,
902 load_bias);
903 if (!IS_ERR((void *)elf_entry)) {
904 /*
905 * load_elf_interp() returns relocation
906 * adjustment
907 */
908 interp_load_addr = elf_entry;
909 elf_entry += loc->interp_elf_ex.e_entry;
910 }
911 if (BAD_ADDR(elf_entry)) {
912 force_sig(SIGSEGV, current);
913 retval = IS_ERR((void *)elf_entry) ?
914 (int)elf_entry : -EINVAL;
915 goto out_free_dentry;
916 }
917 reloc_func_desc = interp_load_addr;
918
919 allow_write_access(interpreter);
920 fput(interpreter);
921 kfree(elf_interpreter);
922 } else {
923 elf_entry = loc->elf_ex.e_entry;
924 if (BAD_ADDR(elf_entry)) {
925 force_sig(SIGSEGV, current);
926 retval = -EINVAL;
927 goto out_free_dentry;
928 }
929 }
930
931 kfree(elf_phdata);
932
933 set_binfmt(&elf_format);
934
935 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
936 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
937 if (retval < 0) {
938 send_sig(SIGKILL, current, 0);
939 goto out;
940 }
941 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
942
943 install_exec_creds(bprm);
944 retval = create_elf_tables(bprm, &loc->elf_ex,
945 load_addr, interp_load_addr);
946 if (retval < 0) {
947 send_sig(SIGKILL, current, 0);
948 goto out;
949 }
950 /* N.B. passed_fileno might not be initialized? */
951 current->mm->end_code = end_code;
952 current->mm->start_code = start_code;
953 current->mm->start_data = start_data;
954 current->mm->end_data = end_data;
955 current->mm->start_stack = bprm->p;
956
957 #ifdef arch_randomize_brk
958 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
959 current->mm->brk = current->mm->start_brk =
960 arch_randomize_brk(current->mm);
961 #ifdef CONFIG_COMPAT_BRK
962 current->brk_randomized = 1;
963 #endif
964 }
965 #endif
966
967 if (current->personality & MMAP_PAGE_ZERO) {
968 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
969 and some applications "depend" upon this behavior.
970 Since we do not have the power to recompile these, we
971 emulate the SVr4 behavior. Sigh. */
972 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
973 MAP_FIXED | MAP_PRIVATE, 0);
974 }
975
976 #ifdef ELF_PLAT_INIT
977 /*
978 * The ABI may specify that certain registers be set up in special
979 * ways (on i386 %edx is the address of a DT_FINI function, for
980 * example. In addition, it may also specify (eg, PowerPC64 ELF)
981 * that the e_entry field is the address of the function descriptor
982 * for the startup routine, rather than the address of the startup
983 * routine itself. This macro performs whatever initialization to
984 * the regs structure is required as well as any relocations to the
985 * function descriptor entries when executing dynamically links apps.
986 */
987 ELF_PLAT_INIT(regs, reloc_func_desc);
988 #endif
989
990 start_thread(regs, elf_entry, bprm->p);
991 retval = 0;
992 out:
993 kfree(loc);
994 out_ret:
995 return retval;
996
997 /* error cleanup */
998 out_free_dentry:
999 allow_write_access(interpreter);
1000 if (interpreter)
1001 fput(interpreter);
1002 out_free_interp:
1003 kfree(elf_interpreter);
1004 out_free_ph:
1005 kfree(elf_phdata);
1006 goto out;
1007 }
1008
1009 /* This is really simpleminded and specialized - we are loading an
1010 a.out library that is given an ELF header. */
1011 static int load_elf_library(struct file *file)
1012 {
1013 struct elf_phdr *elf_phdata;
1014 struct elf_phdr *eppnt;
1015 unsigned long elf_bss, bss, len;
1016 int retval, error, i, j;
1017 struct elfhdr elf_ex;
1018
1019 error = -ENOEXEC;
1020 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1021 if (retval != sizeof(elf_ex))
1022 goto out;
1023
1024 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1025 goto out;
1026
1027 /* First of all, some simple consistency checks */
1028 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1029 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1030 goto out;
1031
1032 /* Now read in all of the header information */
1033
1034 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1035 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1036
1037 error = -ENOMEM;
1038 elf_phdata = kmalloc(j, GFP_KERNEL);
1039 if (!elf_phdata)
1040 goto out;
1041
1042 eppnt = elf_phdata;
1043 error = -ENOEXEC;
1044 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1045 if (retval != j)
1046 goto out_free_ph;
1047
1048 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1049 if ((eppnt + i)->p_type == PT_LOAD)
1050 j++;
1051 if (j != 1)
1052 goto out_free_ph;
1053
1054 while (eppnt->p_type != PT_LOAD)
1055 eppnt++;
1056
1057 /* Now use mmap to map the library into memory. */
1058 error = vm_mmap(file,
1059 ELF_PAGESTART(eppnt->p_vaddr),
1060 (eppnt->p_filesz +
1061 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1062 PROT_READ | PROT_WRITE | PROT_EXEC,
1063 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1064 (eppnt->p_offset -
1065 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1066 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1067 goto out_free_ph;
1068
1069 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1070 if (padzero(elf_bss)) {
1071 error = -EFAULT;
1072 goto out_free_ph;
1073 }
1074
1075 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1076 ELF_MIN_ALIGN - 1);
1077 bss = eppnt->p_memsz + eppnt->p_vaddr;
1078 if (bss > len)
1079 vm_brk(len, bss - len);
1080 error = 0;
1081
1082 out_free_ph:
1083 kfree(elf_phdata);
1084 out:
1085 return error;
1086 }
1087
1088 #ifdef CONFIG_ELF_CORE
1089 /*
1090 * ELF core dumper
1091 *
1092 * Modelled on fs/exec.c:aout_core_dump()
1093 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1094 */
1095
1096 /*
1097 * The purpose of always_dump_vma() is to make sure that special kernel mappings
1098 * that are useful for post-mortem analysis are included in every core dump.
1099 * In that way we ensure that the core dump is fully interpretable later
1100 * without matching up the same kernel and hardware config to see what PC values
1101 * meant. These special mappings include - vDSO, vsyscall, and other
1102 * architecture specific mappings
1103 */
1104 static bool always_dump_vma(struct vm_area_struct *vma)
1105 {
1106 /* Any vsyscall mappings? */
1107 if (vma == get_gate_vma(vma->vm_mm))
1108 return true;
1109 /*
1110 * arch_vma_name() returns non-NULL for special architecture mappings,
1111 * such as vDSO sections.
1112 */
1113 if (arch_vma_name(vma))
1114 return true;
1115
1116 return false;
1117 }
1118
1119 /*
1120 * Decide what to dump of a segment, part, all or none.
1121 */
1122 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1123 unsigned long mm_flags)
1124 {
1125 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1126
1127 /* always dump the vdso and vsyscall sections */
1128 if (always_dump_vma(vma))
1129 goto whole;
1130
1131 if (vma->vm_flags & VM_DONTDUMP)
1132 return 0;
1133
1134 /* Hugetlb memory check */
1135 if (vma->vm_flags & VM_HUGETLB) {
1136 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1137 goto whole;
1138 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1139 goto whole;
1140 }
1141
1142 /* Do not dump I/O mapped devices or special mappings */
1143 if (vma->vm_flags & VM_IO)
1144 return 0;
1145
1146 /* By default, dump shared memory if mapped from an anonymous file. */
1147 if (vma->vm_flags & VM_SHARED) {
1148 if (file_inode(vma->vm_file)->i_nlink == 0 ?
1149 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1150 goto whole;
1151 return 0;
1152 }
1153
1154 /* Dump segments that have been written to. */
1155 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1156 goto whole;
1157 if (vma->vm_file == NULL)
1158 return 0;
1159
1160 if (FILTER(MAPPED_PRIVATE))
1161 goto whole;
1162
1163 /*
1164 * If this looks like the beginning of a DSO or executable mapping,
1165 * check for an ELF header. If we find one, dump the first page to
1166 * aid in determining what was mapped here.
1167 */
1168 if (FILTER(ELF_HEADERS) &&
1169 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1170 u32 __user *header = (u32 __user *) vma->vm_start;
1171 u32 word;
1172 mm_segment_t fs = get_fs();
1173 /*
1174 * Doing it this way gets the constant folded by GCC.
1175 */
1176 union {
1177 u32 cmp;
1178 char elfmag[SELFMAG];
1179 } magic;
1180 BUILD_BUG_ON(SELFMAG != sizeof word);
1181 magic.elfmag[EI_MAG0] = ELFMAG0;
1182 magic.elfmag[EI_MAG1] = ELFMAG1;
1183 magic.elfmag[EI_MAG2] = ELFMAG2;
1184 magic.elfmag[EI_MAG3] = ELFMAG3;
1185 /*
1186 * Switch to the user "segment" for get_user(),
1187 * then put back what elf_core_dump() had in place.
1188 */
1189 set_fs(USER_DS);
1190 if (unlikely(get_user(word, header)))
1191 word = 0;
1192 set_fs(fs);
1193 if (word == magic.cmp)
1194 return PAGE_SIZE;
1195 }
1196
1197 #undef FILTER
1198
1199 return 0;
1200
1201 whole:
1202 return vma->vm_end - vma->vm_start;
1203 }
1204
1205 /* An ELF note in memory */
1206 struct memelfnote
1207 {
1208 const char *name;
1209 int type;
1210 unsigned int datasz;
1211 void *data;
1212 };
1213
1214 static int notesize(struct memelfnote *en)
1215 {
1216 int sz;
1217
1218 sz = sizeof(struct elf_note);
1219 sz += roundup(strlen(en->name) + 1, 4);
1220 sz += roundup(en->datasz, 4);
1221
1222 return sz;
1223 }
1224
1225 #define DUMP_WRITE(addr, nr, foffset) \
1226 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1227
1228 static int alignfile(struct file *file, loff_t *foffset)
1229 {
1230 static const char buf[4] = { 0, };
1231 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1232 return 1;
1233 }
1234
1235 static int writenote(struct memelfnote *men, struct file *file,
1236 loff_t *foffset)
1237 {
1238 struct elf_note en;
1239 en.n_namesz = strlen(men->name) + 1;
1240 en.n_descsz = men->datasz;
1241 en.n_type = men->type;
1242
1243 DUMP_WRITE(&en, sizeof(en), foffset);
1244 DUMP_WRITE(men->name, en.n_namesz, foffset);
1245 if (!alignfile(file, foffset))
1246 return 0;
1247 DUMP_WRITE(men->data, men->datasz, foffset);
1248 if (!alignfile(file, foffset))
1249 return 0;
1250
1251 return 1;
1252 }
1253 #undef DUMP_WRITE
1254
1255 static void fill_elf_header(struct elfhdr *elf, int segs,
1256 u16 machine, u32 flags)
1257 {
1258 memset(elf, 0, sizeof(*elf));
1259
1260 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1261 elf->e_ident[EI_CLASS] = ELF_CLASS;
1262 elf->e_ident[EI_DATA] = ELF_DATA;
1263 elf->e_ident[EI_VERSION] = EV_CURRENT;
1264 elf->e_ident[EI_OSABI] = ELF_OSABI;
1265
1266 elf->e_type = ET_CORE;
1267 elf->e_machine = machine;
1268 elf->e_version = EV_CURRENT;
1269 elf->e_phoff = sizeof(struct elfhdr);
1270 elf->e_flags = flags;
1271 elf->e_ehsize = sizeof(struct elfhdr);
1272 elf->e_phentsize = sizeof(struct elf_phdr);
1273 elf->e_phnum = segs;
1274
1275 return;
1276 }
1277
1278 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1279 {
1280 phdr->p_type = PT_NOTE;
1281 phdr->p_offset = offset;
1282 phdr->p_vaddr = 0;
1283 phdr->p_paddr = 0;
1284 phdr->p_filesz = sz;
1285 phdr->p_memsz = 0;
1286 phdr->p_flags = 0;
1287 phdr->p_align = 0;
1288 return;
1289 }
1290
1291 static void fill_note(struct memelfnote *note, const char *name, int type,
1292 unsigned int sz, void *data)
1293 {
1294 note->name = name;
1295 note->type = type;
1296 note->datasz = sz;
1297 note->data = data;
1298 return;
1299 }
1300
1301 /*
1302 * fill up all the fields in prstatus from the given task struct, except
1303 * registers which need to be filled up separately.
1304 */
1305 static void fill_prstatus(struct elf_prstatus *prstatus,
1306 struct task_struct *p, long signr)
1307 {
1308 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1309 prstatus->pr_sigpend = p->pending.signal.sig[0];
1310 prstatus->pr_sighold = p->blocked.sig[0];
1311 rcu_read_lock();
1312 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1313 rcu_read_unlock();
1314 prstatus->pr_pid = task_pid_vnr(p);
1315 prstatus->pr_pgrp = task_pgrp_vnr(p);
1316 prstatus->pr_sid = task_session_vnr(p);
1317 if (thread_group_leader(p)) {
1318 struct task_cputime cputime;
1319
1320 /*
1321 * This is the record for the group leader. It shows the
1322 * group-wide total, not its individual thread total.
1323 */
1324 thread_group_cputime(p, &cputime);
1325 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1326 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1327 } else {
1328 cputime_t utime, stime;
1329
1330 task_cputime(p, &utime, &stime);
1331 cputime_to_timeval(utime, &prstatus->pr_utime);
1332 cputime_to_timeval(stime, &prstatus->pr_stime);
1333 }
1334 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1335 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1336 }
1337
1338 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1339 struct mm_struct *mm)
1340 {
1341 const struct cred *cred;
1342 unsigned int i, len;
1343
1344 /* first copy the parameters from user space */
1345 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1346
1347 len = mm->arg_end - mm->arg_start;
1348 if (len >= ELF_PRARGSZ)
1349 len = ELF_PRARGSZ-1;
1350 if (copy_from_user(&psinfo->pr_psargs,
1351 (const char __user *)mm->arg_start, len))
1352 return -EFAULT;
1353 for(i = 0; i < len; i++)
1354 if (psinfo->pr_psargs[i] == 0)
1355 psinfo->pr_psargs[i] = ' ';
1356 psinfo->pr_psargs[len] = 0;
1357
1358 rcu_read_lock();
1359 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1360 rcu_read_unlock();
1361 psinfo->pr_pid = task_pid_vnr(p);
1362 psinfo->pr_pgrp = task_pgrp_vnr(p);
1363 psinfo->pr_sid = task_session_vnr(p);
1364
1365 i = p->state ? ffz(~p->state) + 1 : 0;
1366 psinfo->pr_state = i;
1367 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1368 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1369 psinfo->pr_nice = task_nice(p);
1370 psinfo->pr_flag = p->flags;
1371 rcu_read_lock();
1372 cred = __task_cred(p);
1373 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1374 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1375 rcu_read_unlock();
1376 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1377
1378 return 0;
1379 }
1380
1381 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1382 {
1383 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1384 int i = 0;
1385 do
1386 i += 2;
1387 while (auxv[i - 2] != AT_NULL);
1388 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1389 }
1390
1391 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1392 siginfo_t *siginfo)
1393 {
1394 mm_segment_t old_fs = get_fs();
1395 set_fs(KERNEL_DS);
1396 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
1397 set_fs(old_fs);
1398 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1399 }
1400
1401 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1402 /*
1403 * Format of NT_FILE note:
1404 *
1405 * long count -- how many files are mapped
1406 * long page_size -- units for file_ofs
1407 * array of [COUNT] elements of
1408 * long start
1409 * long end
1410 * long file_ofs
1411 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1412 */
1413 static void fill_files_note(struct memelfnote *note)
1414 {
1415 struct vm_area_struct *vma;
1416 unsigned count, size, names_ofs, remaining, n;
1417 user_long_t *data;
1418 user_long_t *start_end_ofs;
1419 char *name_base, *name_curpos;
1420
1421 /* *Estimated* file count and total data size needed */
1422 count = current->mm->map_count;
1423 size = count * 64;
1424
1425 names_ofs = (2 + 3 * count) * sizeof(data[0]);
1426 alloc:
1427 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1428 goto err;
1429 size = round_up(size, PAGE_SIZE);
1430 data = vmalloc(size);
1431 if (!data)
1432 goto err;
1433
1434 start_end_ofs = data + 2;
1435 name_base = name_curpos = ((char *)data) + names_ofs;
1436 remaining = size - names_ofs;
1437 count = 0;
1438 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1439 struct file *file;
1440 const char *filename;
1441
1442 file = vma->vm_file;
1443 if (!file)
1444 continue;
1445 filename = d_path(&file->f_path, name_curpos, remaining);
1446 if (IS_ERR(filename)) {
1447 if (PTR_ERR(filename) == -ENAMETOOLONG) {
1448 vfree(data);
1449 size = size * 5 / 4;
1450 goto alloc;
1451 }
1452 continue;
1453 }
1454
1455 /* d_path() fills at the end, move name down */
1456 /* n = strlen(filename) + 1: */
1457 n = (name_curpos + remaining) - filename;
1458 remaining = filename - name_curpos;
1459 memmove(name_curpos, filename, n);
1460 name_curpos += n;
1461
1462 *start_end_ofs++ = vma->vm_start;
1463 *start_end_ofs++ = vma->vm_end;
1464 *start_end_ofs++ = vma->vm_pgoff;
1465 count++;
1466 }
1467
1468 /* Now we know exact count of files, can store it */
1469 data[0] = count;
1470 data[1] = PAGE_SIZE;
1471 /*
1472 * Count usually is less than current->mm->map_count,
1473 * we need to move filenames down.
1474 */
1475 n = current->mm->map_count - count;
1476 if (n != 0) {
1477 unsigned shift_bytes = n * 3 * sizeof(data[0]);
1478 memmove(name_base - shift_bytes, name_base,
1479 name_curpos - name_base);
1480 name_curpos -= shift_bytes;
1481 }
1482
1483 size = name_curpos - (char *)data;
1484 fill_note(note, "CORE", NT_FILE, size, data);
1485 err: ;
1486 }
1487
1488 #ifdef CORE_DUMP_USE_REGSET
1489 #include <linux/regset.h>
1490
1491 struct elf_thread_core_info {
1492 struct elf_thread_core_info *next;
1493 struct task_struct *task;
1494 struct elf_prstatus prstatus;
1495 struct memelfnote notes[0];
1496 };
1497
1498 struct elf_note_info {
1499 struct elf_thread_core_info *thread;
1500 struct memelfnote psinfo;
1501 struct memelfnote signote;
1502 struct memelfnote auxv;
1503 struct memelfnote files;
1504 user_siginfo_t csigdata;
1505 size_t size;
1506 int thread_notes;
1507 };
1508
1509 /*
1510 * When a regset has a writeback hook, we call it on each thread before
1511 * dumping user memory. On register window machines, this makes sure the
1512 * user memory backing the register data is up to date before we read it.
1513 */
1514 static void do_thread_regset_writeback(struct task_struct *task,
1515 const struct user_regset *regset)
1516 {
1517 if (regset->writeback)
1518 regset->writeback(task, regset, 1);
1519 }
1520
1521 #ifndef PR_REG_SIZE
1522 #define PR_REG_SIZE(S) sizeof(S)
1523 #endif
1524
1525 #ifndef PRSTATUS_SIZE
1526 #define PRSTATUS_SIZE(S) sizeof(S)
1527 #endif
1528
1529 #ifndef PR_REG_PTR
1530 #define PR_REG_PTR(S) (&((S)->pr_reg))
1531 #endif
1532
1533 #ifndef SET_PR_FPVALID
1534 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V))
1535 #endif
1536
1537 static int fill_thread_core_info(struct elf_thread_core_info *t,
1538 const struct user_regset_view *view,
1539 long signr, size_t *total)
1540 {
1541 unsigned int i;
1542
1543 /*
1544 * NT_PRSTATUS is the one special case, because the regset data
1545 * goes into the pr_reg field inside the note contents, rather
1546 * than being the whole note contents. We fill the reset in here.
1547 * We assume that regset 0 is NT_PRSTATUS.
1548 */
1549 fill_prstatus(&t->prstatus, t->task, signr);
1550 (void) view->regsets[0].get(t->task, &view->regsets[0],
1551 0, PR_REG_SIZE(t->prstatus.pr_reg),
1552 PR_REG_PTR(&t->prstatus), NULL);
1553
1554 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1555 PRSTATUS_SIZE(t->prstatus), &t->prstatus);
1556 *total += notesize(&t->notes[0]);
1557
1558 do_thread_regset_writeback(t->task, &view->regsets[0]);
1559
1560 /*
1561 * Each other regset might generate a note too. For each regset
1562 * that has no core_note_type or is inactive, we leave t->notes[i]
1563 * all zero and we'll know to skip writing it later.
1564 */
1565 for (i = 1; i < view->n; ++i) {
1566 const struct user_regset *regset = &view->regsets[i];
1567 do_thread_regset_writeback(t->task, regset);
1568 if (regset->core_note_type && regset->get &&
1569 (!regset->active || regset->active(t->task, regset))) {
1570 int ret;
1571 size_t size = regset->n * regset->size;
1572 void *data = kmalloc(size, GFP_KERNEL);
1573 if (unlikely(!data))
1574 return 0;
1575 ret = regset->get(t->task, regset,
1576 0, size, data, NULL);
1577 if (unlikely(ret))
1578 kfree(data);
1579 else {
1580 if (regset->core_note_type != NT_PRFPREG)
1581 fill_note(&t->notes[i], "LINUX",
1582 regset->core_note_type,
1583 size, data);
1584 else {
1585 SET_PR_FPVALID(&t->prstatus, 1);
1586 fill_note(&t->notes[i], "CORE",
1587 NT_PRFPREG, size, data);
1588 }
1589 *total += notesize(&t->notes[i]);
1590 }
1591 }
1592 }
1593
1594 return 1;
1595 }
1596
1597 static int fill_note_info(struct elfhdr *elf, int phdrs,
1598 struct elf_note_info *info,
1599 siginfo_t *siginfo, struct pt_regs *regs)
1600 {
1601 struct task_struct *dump_task = current;
1602 const struct user_regset_view *view = task_user_regset_view(dump_task);
1603 struct elf_thread_core_info *t;
1604 struct elf_prpsinfo *psinfo;
1605 struct core_thread *ct;
1606 unsigned int i;
1607
1608 info->size = 0;
1609 info->thread = NULL;
1610
1611 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1612 if (psinfo == NULL) {
1613 info->psinfo.data = NULL; /* So we don't free this wrongly */
1614 return 0;
1615 }
1616
1617 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1618
1619 /*
1620 * Figure out how many notes we're going to need for each thread.
1621 */
1622 info->thread_notes = 0;
1623 for (i = 0; i < view->n; ++i)
1624 if (view->regsets[i].core_note_type != 0)
1625 ++info->thread_notes;
1626
1627 /*
1628 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1629 * since it is our one special case.
1630 */
1631 if (unlikely(info->thread_notes == 0) ||
1632 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1633 WARN_ON(1);
1634 return 0;
1635 }
1636
1637 /*
1638 * Initialize the ELF file header.
1639 */
1640 fill_elf_header(elf, phdrs,
1641 view->e_machine, view->e_flags);
1642
1643 /*
1644 * Allocate a structure for each thread.
1645 */
1646 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1647 t = kzalloc(offsetof(struct elf_thread_core_info,
1648 notes[info->thread_notes]),
1649 GFP_KERNEL);
1650 if (unlikely(!t))
1651 return 0;
1652
1653 t->task = ct->task;
1654 if (ct->task == dump_task || !info->thread) {
1655 t->next = info->thread;
1656 info->thread = t;
1657 } else {
1658 /*
1659 * Make sure to keep the original task at
1660 * the head of the list.
1661 */
1662 t->next = info->thread->next;
1663 info->thread->next = t;
1664 }
1665 }
1666
1667 /*
1668 * Now fill in each thread's information.
1669 */
1670 for (t = info->thread; t != NULL; t = t->next)
1671 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1672 return 0;
1673
1674 /*
1675 * Fill in the two process-wide notes.
1676 */
1677 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1678 info->size += notesize(&info->psinfo);
1679
1680 fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1681 info->size += notesize(&info->signote);
1682
1683 fill_auxv_note(&info->auxv, current->mm);
1684 info->size += notesize(&info->auxv);
1685
1686 fill_files_note(&info->files);
1687 info->size += notesize(&info->files);
1688
1689 return 1;
1690 }
1691
1692 static size_t get_note_info_size(struct elf_note_info *info)
1693 {
1694 return info->size;
1695 }
1696
1697 /*
1698 * Write all the notes for each thread. When writing the first thread, the
1699 * process-wide notes are interleaved after the first thread-specific note.
1700 */
1701 static int write_note_info(struct elf_note_info *info,
1702 struct file *file, loff_t *foffset)
1703 {
1704 bool first = 1;
1705 struct elf_thread_core_info *t = info->thread;
1706
1707 do {
1708 int i;
1709
1710 if (!writenote(&t->notes[0], file, foffset))
1711 return 0;
1712
1713 if (first && !writenote(&info->psinfo, file, foffset))
1714 return 0;
1715 if (first && !writenote(&info->signote, file, foffset))
1716 return 0;
1717 if (first && !writenote(&info->auxv, file, foffset))
1718 return 0;
1719 if (first && !writenote(&info->files, file, foffset))
1720 return 0;
1721
1722 for (i = 1; i < info->thread_notes; ++i)
1723 if (t->notes[i].data &&
1724 !writenote(&t->notes[i], file, foffset))
1725 return 0;
1726
1727 first = 0;
1728 t = t->next;
1729 } while (t);
1730
1731 return 1;
1732 }
1733
1734 static void free_note_info(struct elf_note_info *info)
1735 {
1736 struct elf_thread_core_info *threads = info->thread;
1737 while (threads) {
1738 unsigned int i;
1739 struct elf_thread_core_info *t = threads;
1740 threads = t->next;
1741 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1742 for (i = 1; i < info->thread_notes; ++i)
1743 kfree(t->notes[i].data);
1744 kfree(t);
1745 }
1746 kfree(info->psinfo.data);
1747 vfree(info->files.data);
1748 }
1749
1750 #else
1751
1752 /* Here is the structure in which status of each thread is captured. */
1753 struct elf_thread_status
1754 {
1755 struct list_head list;
1756 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1757 elf_fpregset_t fpu; /* NT_PRFPREG */
1758 struct task_struct *thread;
1759 #ifdef ELF_CORE_COPY_XFPREGS
1760 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1761 #endif
1762 struct memelfnote notes[3];
1763 int num_notes;
1764 };
1765
1766 /*
1767 * In order to add the specific thread information for the elf file format,
1768 * we need to keep a linked list of every threads pr_status and then create
1769 * a single section for them in the final core file.
1770 */
1771 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1772 {
1773 int sz = 0;
1774 struct task_struct *p = t->thread;
1775 t->num_notes = 0;
1776
1777 fill_prstatus(&t->prstatus, p, signr);
1778 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1779
1780 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1781 &(t->prstatus));
1782 t->num_notes++;
1783 sz += notesize(&t->notes[0]);
1784
1785 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1786 &t->fpu))) {
1787 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1788 &(t->fpu));
1789 t->num_notes++;
1790 sz += notesize(&t->notes[1]);
1791 }
1792
1793 #ifdef ELF_CORE_COPY_XFPREGS
1794 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1795 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1796 sizeof(t->xfpu), &t->xfpu);
1797 t->num_notes++;
1798 sz += notesize(&t->notes[2]);
1799 }
1800 #endif
1801 return sz;
1802 }
1803
1804 struct elf_note_info {
1805 struct memelfnote *notes;
1806 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1807 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1808 struct list_head thread_list;
1809 elf_fpregset_t *fpu;
1810 #ifdef ELF_CORE_COPY_XFPREGS
1811 elf_fpxregset_t *xfpu;
1812 #endif
1813 user_siginfo_t csigdata;
1814 int thread_status_size;
1815 int numnote;
1816 };
1817
1818 static int elf_note_info_init(struct elf_note_info *info)
1819 {
1820 memset(info, 0, sizeof(*info));
1821 INIT_LIST_HEAD(&info->thread_list);
1822
1823 /* Allocate space for ELF notes */
1824 info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL);
1825 if (!info->notes)
1826 return 0;
1827 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1828 if (!info->psinfo)
1829 return 0;
1830 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1831 if (!info->prstatus)
1832 return 0;
1833 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1834 if (!info->fpu)
1835 return 0;
1836 #ifdef ELF_CORE_COPY_XFPREGS
1837 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1838 if (!info->xfpu)
1839 return 0;
1840 #endif
1841 return 1;
1842 }
1843
1844 static int fill_note_info(struct elfhdr *elf, int phdrs,
1845 struct elf_note_info *info,
1846 siginfo_t *siginfo, struct pt_regs *regs)
1847 {
1848 struct list_head *t;
1849
1850 if (!elf_note_info_init(info))
1851 return 0;
1852
1853 if (siginfo->si_signo) {
1854 struct core_thread *ct;
1855 struct elf_thread_status *ets;
1856
1857 for (ct = current->mm->core_state->dumper.next;
1858 ct; ct = ct->next) {
1859 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1860 if (!ets)
1861 return 0;
1862
1863 ets->thread = ct->task;
1864 list_add(&ets->list, &info->thread_list);
1865 }
1866
1867 list_for_each(t, &info->thread_list) {
1868 int sz;
1869
1870 ets = list_entry(t, struct elf_thread_status, list);
1871 sz = elf_dump_thread_status(siginfo->si_signo, ets);
1872 info->thread_status_size += sz;
1873 }
1874 }
1875 /* now collect the dump for the current */
1876 memset(info->prstatus, 0, sizeof(*info->prstatus));
1877 fill_prstatus(info->prstatus, current, siginfo->si_signo);
1878 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1879
1880 /* Set up header */
1881 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
1882
1883 /*
1884 * Set up the notes in similar form to SVR4 core dumps made
1885 * with info from their /proc.
1886 */
1887
1888 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1889 sizeof(*info->prstatus), info->prstatus);
1890 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1891 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1892 sizeof(*info->psinfo), info->psinfo);
1893
1894 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
1895 fill_auxv_note(info->notes + 3, current->mm);
1896 fill_files_note(info->notes + 4);
1897
1898 info->numnote = 5;
1899
1900 /* Try to dump the FPU. */
1901 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1902 info->fpu);
1903 if (info->prstatus->pr_fpvalid)
1904 fill_note(info->notes + info->numnote++,
1905 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1906 #ifdef ELF_CORE_COPY_XFPREGS
1907 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1908 fill_note(info->notes + info->numnote++,
1909 "LINUX", ELF_CORE_XFPREG_TYPE,
1910 sizeof(*info->xfpu), info->xfpu);
1911 #endif
1912
1913 return 1;
1914 }
1915
1916 static size_t get_note_info_size(struct elf_note_info *info)
1917 {
1918 int sz = 0;
1919 int i;
1920
1921 for (i = 0; i < info->numnote; i++)
1922 sz += notesize(info->notes + i);
1923
1924 sz += info->thread_status_size;
1925
1926 return sz;
1927 }
1928
1929 static int write_note_info(struct elf_note_info *info,
1930 struct file *file, loff_t *foffset)
1931 {
1932 int i;
1933 struct list_head *t;
1934
1935 for (i = 0; i < info->numnote; i++)
1936 if (!writenote(info->notes + i, file, foffset))
1937 return 0;
1938
1939 /* write out the thread status notes section */
1940 list_for_each(t, &info->thread_list) {
1941 struct elf_thread_status *tmp =
1942 list_entry(t, struct elf_thread_status, list);
1943
1944 for (i = 0; i < tmp->num_notes; i++)
1945 if (!writenote(&tmp->notes[i], file, foffset))
1946 return 0;
1947 }
1948
1949 return 1;
1950 }
1951
1952 static void free_note_info(struct elf_note_info *info)
1953 {
1954 while (!list_empty(&info->thread_list)) {
1955 struct list_head *tmp = info->thread_list.next;
1956 list_del(tmp);
1957 kfree(list_entry(tmp, struct elf_thread_status, list));
1958 }
1959
1960 /* Free data allocated by fill_files_note(): */
1961 vfree(info->notes[4].data);
1962
1963 kfree(info->prstatus);
1964 kfree(info->psinfo);
1965 kfree(info->notes);
1966 kfree(info->fpu);
1967 #ifdef ELF_CORE_COPY_XFPREGS
1968 kfree(info->xfpu);
1969 #endif
1970 }
1971
1972 #endif
1973
1974 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1975 struct vm_area_struct *gate_vma)
1976 {
1977 struct vm_area_struct *ret = tsk->mm->mmap;
1978
1979 if (ret)
1980 return ret;
1981 return gate_vma;
1982 }
1983 /*
1984 * Helper function for iterating across a vma list. It ensures that the caller
1985 * will visit `gate_vma' prior to terminating the search.
1986 */
1987 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1988 struct vm_area_struct *gate_vma)
1989 {
1990 struct vm_area_struct *ret;
1991
1992 ret = this_vma->vm_next;
1993 if (ret)
1994 return ret;
1995 if (this_vma == gate_vma)
1996 return NULL;
1997 return gate_vma;
1998 }
1999
2000 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
2001 elf_addr_t e_shoff, int segs)
2002 {
2003 elf->e_shoff = e_shoff;
2004 elf->e_shentsize = sizeof(*shdr4extnum);
2005 elf->e_shnum = 1;
2006 elf->e_shstrndx = SHN_UNDEF;
2007
2008 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
2009
2010 shdr4extnum->sh_type = SHT_NULL;
2011 shdr4extnum->sh_size = elf->e_shnum;
2012 shdr4extnum->sh_link = elf->e_shstrndx;
2013 shdr4extnum->sh_info = segs;
2014 }
2015
2016 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
2017 unsigned long mm_flags)
2018 {
2019 struct vm_area_struct *vma;
2020 size_t size = 0;
2021
2022 for (vma = first_vma(current, gate_vma); vma != NULL;
2023 vma = next_vma(vma, gate_vma))
2024 size += vma_dump_size(vma, mm_flags);
2025 return size;
2026 }
2027
2028 /*
2029 * Actual dumper
2030 *
2031 * This is a two-pass process; first we find the offsets of the bits,
2032 * and then they are actually written out. If we run out of core limit
2033 * we just truncate.
2034 */
2035 static int elf_core_dump(struct coredump_params *cprm)
2036 {
2037 int has_dumped = 0;
2038 mm_segment_t fs;
2039 int segs;
2040 size_t size = 0;
2041 struct vm_area_struct *vma, *gate_vma;
2042 struct elfhdr *elf = NULL;
2043 loff_t offset = 0, dataoff, foffset;
2044 struct elf_note_info info;
2045 struct elf_phdr *phdr4note = NULL;
2046 struct elf_shdr *shdr4extnum = NULL;
2047 Elf_Half e_phnum;
2048 elf_addr_t e_shoff;
2049
2050 /*
2051 * We no longer stop all VM operations.
2052 *
2053 * This is because those proceses that could possibly change map_count
2054 * or the mmap / vma pages are now blocked in do_exit on current
2055 * finishing this core dump.
2056 *
2057 * Only ptrace can touch these memory addresses, but it doesn't change
2058 * the map_count or the pages allocated. So no possibility of crashing
2059 * exists while dumping the mm->vm_next areas to the core file.
2060 */
2061
2062 /* alloc memory for large data structures: too large to be on stack */
2063 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
2064 if (!elf)
2065 goto out;
2066 /*
2067 * The number of segs are recored into ELF header as 16bit value.
2068 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2069 */
2070 segs = current->mm->map_count;
2071 segs += elf_core_extra_phdrs();
2072
2073 gate_vma = get_gate_vma(current->mm);
2074 if (gate_vma != NULL)
2075 segs++;
2076
2077 /* for notes section */
2078 segs++;
2079
2080 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2081 * this, kernel supports extended numbering. Have a look at
2082 * include/linux/elf.h for further information. */
2083 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2084
2085 /*
2086 * Collect all the non-memory information about the process for the
2087 * notes. This also sets up the file header.
2088 */
2089 if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2090 goto cleanup;
2091
2092 has_dumped = 1;
2093 current->flags |= PF_DUMPCORE;
2094
2095 fs = get_fs();
2096 set_fs(KERNEL_DS);
2097
2098 offset += sizeof(*elf); /* Elf header */
2099 offset += segs * sizeof(struct elf_phdr); /* Program headers */
2100 foffset = offset;
2101
2102 /* Write notes phdr entry */
2103 {
2104 size_t sz = get_note_info_size(&info);
2105
2106 sz += elf_coredump_extra_notes_size();
2107
2108 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2109 if (!phdr4note)
2110 goto end_coredump;
2111
2112 fill_elf_note_phdr(phdr4note, sz, offset);
2113 offset += sz;
2114 }
2115
2116 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2117
2118 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
2119 offset += elf_core_extra_data_size();
2120 e_shoff = offset;
2121
2122 if (e_phnum == PN_XNUM) {
2123 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2124 if (!shdr4extnum)
2125 goto end_coredump;
2126 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
2127 }
2128
2129 offset = dataoff;
2130
2131 size += sizeof(*elf);
2132 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
2133 goto end_coredump;
2134
2135 size += sizeof(*phdr4note);
2136 if (size > cprm->limit
2137 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
2138 goto end_coredump;
2139
2140 /* Write program headers for segments dump */
2141 for (vma = first_vma(current, gate_vma); vma != NULL;
2142 vma = next_vma(vma, gate_vma)) {
2143 struct elf_phdr phdr;
2144
2145 phdr.p_type = PT_LOAD;
2146 phdr.p_offset = offset;
2147 phdr.p_vaddr = vma->vm_start;
2148 phdr.p_paddr = 0;
2149 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
2150 phdr.p_memsz = vma->vm_end - vma->vm_start;
2151 offset += phdr.p_filesz;
2152 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2153 if (vma->vm_flags & VM_WRITE)
2154 phdr.p_flags |= PF_W;
2155 if (vma->vm_flags & VM_EXEC)
2156 phdr.p_flags |= PF_X;
2157 phdr.p_align = ELF_EXEC_PAGESIZE;
2158
2159 size += sizeof(phdr);
2160 if (size > cprm->limit
2161 || !dump_write(cprm->file, &phdr, sizeof(phdr)))
2162 goto end_coredump;
2163 }
2164
2165 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
2166 goto end_coredump;
2167
2168 /* write out the notes section */
2169 if (!write_note_info(&info, cprm->file, &foffset))
2170 goto end_coredump;
2171
2172 if (elf_coredump_extra_notes_write(cprm->file, &foffset))
2173 goto end_coredump;
2174
2175 /* Align to page */
2176 if (!dump_seek(cprm->file, dataoff - foffset))
2177 goto end_coredump;
2178
2179 for (vma = first_vma(current, gate_vma); vma != NULL;
2180 vma = next_vma(vma, gate_vma)) {
2181 unsigned long addr;
2182 unsigned long end;
2183
2184 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
2185
2186 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2187 struct page *page;
2188 int stop;
2189
2190 page = get_dump_page(addr);
2191 if (page) {
2192 void *kaddr = kmap(page);
2193 stop = ((size += PAGE_SIZE) > cprm->limit) ||
2194 !dump_write(cprm->file, kaddr,
2195 PAGE_SIZE);
2196 kunmap(page);
2197 page_cache_release(page);
2198 } else
2199 stop = !dump_seek(cprm->file, PAGE_SIZE);
2200 if (stop)
2201 goto end_coredump;
2202 }
2203 }
2204
2205 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
2206 goto end_coredump;
2207
2208 if (e_phnum == PN_XNUM) {
2209 size += sizeof(*shdr4extnum);
2210 if (size > cprm->limit
2211 || !dump_write(cprm->file, shdr4extnum,
2212 sizeof(*shdr4extnum)))
2213 goto end_coredump;
2214 }
2215
2216 end_coredump:
2217 set_fs(fs);
2218
2219 cleanup:
2220 free_note_info(&info);
2221 kfree(shdr4extnum);
2222 kfree(phdr4note);
2223 kfree(elf);
2224 out:
2225 return has_dumped;
2226 }
2227
2228 #endif /* CONFIG_ELF_CORE */
2229
2230 static int __init init_elf_binfmt(void)
2231 {
2232 register_binfmt(&elf_format);
2233 return 0;
2234 }
2235
2236 static void __exit exit_elf_binfmt(void)
2237 {
2238 /* Remove the COFF and ELF loaders. */
2239 unregister_binfmt(&elf_format);
2240 }
2241
2242 core_initcall(init_elf_binfmt);
2243 module_exit(exit_elf_binfmt);
2244 MODULE_LICENSE("GPL");
CJK support for tty framebuffer vt