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add-vmcore: use the existing ia64_tpa() instead of asm code
[linux-2.6/sactl.git] / fs / binfmt_elf.c
blob4263326ede0461a201d35ece02b28275ab3ac79a
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/a.out.h>
20 #include <linux/errno.h>
21 #include <linux/signal.h>
22 #include <linux/binfmts.h>
23 #include <linux/string.h>
24 #include <linux/file.h>
25 #include <linux/fcntl.h>
26 #include <linux/ptrace.h>
27 #include <linux/slab.h>
28 #include <linux/shm.h>
29 #include <linux/personality.h>
30 #include <linux/elfcore.h>
31 #include <linux/init.h>
32 #include <linux/highuid.h>
33 #include <linux/smp.h>
34 #include <linux/compiler.h>
35 #include <linux/highmem.h>
36 #include <linux/pagemap.h>
37 #include <linux/security.h>
38 #include <linux/syscalls.h>
39 #include <linux/random.h>
40 #include <linux/elf.h>
41 #include <linux/utsname.h>
42 #include <asm/uaccess.h>
43 #include <asm/param.h>
44 #include <asm/page.h>
45
46 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
47 static int load_elf_library(struct file *);
48 static unsigned long elf_map (struct file *, unsigned long, struct elf_phdr *, int, int);
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 litle 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 static int
135 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
136 int interp_aout, unsigned long load_addr,
137 unsigned long interp_load_addr)
138 {
139 unsigned long p = bprm->p;
140 int argc = bprm->argc;
141 int envc = bprm->envc;
142 elf_addr_t __user *argv;
143 elf_addr_t __user *envp;
144 elf_addr_t __user *sp;
145 elf_addr_t __user *u_platform;
146 const char *k_platform = ELF_PLATFORM;
147 int items;
148 elf_addr_t *elf_info;
149 int ei_index = 0;
150 struct task_struct *tsk = current;
151 struct vm_area_struct *vma;
152
153 /*
154 * If this architecture has a platform capability string, copy it
155 * to userspace. In some cases (Sparc), this info is impossible
156 * for userspace to get any other way, in others (i386) it is
157 * merely difficult.
158 */
159 u_platform = NULL;
160 if (k_platform) {
161 size_t len = strlen(k_platform) + 1;
162
163 /*
164 * In some cases (e.g. Hyper-Threading), we want to avoid L1
165 * evictions by the processes running on the same package. One
166 * thing we can do is to shuffle the initial stack for them.
167 */
168
169 p = arch_align_stack(p);
170
171 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
172 if (__copy_to_user(u_platform, k_platform, len))
173 return -EFAULT;
174 }
175
176 /* Create the ELF interpreter info */
177 elf_info = (elf_addr_t *)current->mm->saved_auxv;
178 #define NEW_AUX_ENT(id, val) \
179 do { \
180 elf_info[ei_index++] = id; \
181 elf_info[ei_index++] = val; \
182 } while (0)
183
184 #ifdef ARCH_DLINFO
185 /*
186 * ARCH_DLINFO must come first so PPC can do its special alignment of
187 * AUXV.
188 */
189 ARCH_DLINFO;
190 #endif
191 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
192 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
193 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
194 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
195 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
196 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
197 NEW_AUX_ENT(AT_BASE, interp_load_addr);
198 NEW_AUX_ENT(AT_FLAGS, 0);
199 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
200 NEW_AUX_ENT(AT_UID, tsk->uid);
201 NEW_AUX_ENT(AT_EUID, tsk->euid);
202 NEW_AUX_ENT(AT_GID, tsk->gid);
203 NEW_AUX_ENT(AT_EGID, tsk->egid);
204 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
205 if (k_platform) {
206 NEW_AUX_ENT(AT_PLATFORM,
207 (elf_addr_t)(unsigned long)u_platform);
208 }
209 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
210 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
211 }
212 #undef NEW_AUX_ENT
213 /* AT_NULL is zero; clear the rest too */
214 memset(&elf_info[ei_index], 0,
215 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
216
217 /* And advance past the AT_NULL entry. */
218 ei_index += 2;
219
220 sp = STACK_ADD(p, ei_index);
221
222 items = (argc + 1) + (envc + 1);
223 if (interp_aout) {
224 items += 3; /* a.out interpreters require argv & envp too */
225 } else {
226 items += 1; /* ELF interpreters only put argc on the stack */
227 }
228 bprm->p = STACK_ROUND(sp, items);
229
230 /* Point sp at the lowest address on the stack */
231 #ifdef CONFIG_STACK_GROWSUP
232 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
233 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
234 #else
235 sp = (elf_addr_t __user *)bprm->p;
236 #endif
237
238
239 /*
240 * Grow the stack manually; some architectures have a limit on how
241 * far ahead a user-space access may be in order to grow the stack.
242 */
243 vma = find_extend_vma(current->mm, bprm->p);
244 if (!vma)
245 return -EFAULT;
246
247 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
248 if (__put_user(argc, sp++))
249 return -EFAULT;
250 if (interp_aout) {
251 argv = sp + 2;
252 envp = argv + argc + 1;
253 if (__put_user((elf_addr_t)(unsigned long)argv, sp++) ||
254 __put_user((elf_addr_t)(unsigned long)envp, sp++))
255 return -EFAULT;
256 } else {
257 argv = sp;
258 envp = argv + argc + 1;
259 }
260
261 /* Populate argv and envp */
262 p = current->mm->arg_end = current->mm->arg_start;
263 while (argc-- > 0) {
264 size_t len;
265 if (__put_user((elf_addr_t)p, argv++))
266 return -EFAULT;
267 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
268 if (!len || len > MAX_ARG_STRLEN)
269 return 0;
270 p += len;
271 }
272 if (__put_user(0, argv))
273 return -EFAULT;
274 current->mm->arg_end = current->mm->env_start = p;
275 while (envc-- > 0) {
276 size_t len;
277 if (__put_user((elf_addr_t)p, envp++))
278 return -EFAULT;
279 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
280 if (!len || len > MAX_ARG_STRLEN)
281 return 0;
282 p += len;
283 }
284 if (__put_user(0, envp))
285 return -EFAULT;
286 current->mm->env_end = p;
287
288 /* Put the elf_info on the stack in the right place. */
289 sp = (elf_addr_t __user *)envp + 1;
290 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
291 return -EFAULT;
292 return 0;
293 }
294
295 #ifndef elf_map
296
297 static unsigned long elf_map(struct file *filep, unsigned long addr,
298 struct elf_phdr *eppnt, int prot, int type)
299 {
300 unsigned long map_addr;
301 unsigned long pageoffset = ELF_PAGEOFFSET(eppnt->p_vaddr);
302
303 down_write(&current->mm->mmap_sem);
304 /* mmap() will return -EINVAL if given a zero size, but a
305 * segment with zero filesize is perfectly valid */
306 if (eppnt->p_filesz + pageoffset)
307 map_addr = do_mmap(filep, ELF_PAGESTART(addr),
308 eppnt->p_filesz + pageoffset, prot, type,
309 eppnt->p_offset - pageoffset);
310 else
311 map_addr = ELF_PAGESTART(addr);
312 up_write(&current->mm->mmap_sem);
313 return(map_addr);
314 }
315
316 #endif /* !elf_map */
317
318 /* This is much more generalized than the library routine read function,
319 so we keep this separate. Technically the library read function
320 is only provided so that we can read a.out libraries that have
321 an ELF header */
322
323 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
324 struct file *interpreter, unsigned long *interp_load_addr)
325 {
326 struct elf_phdr *elf_phdata;
327 struct elf_phdr *eppnt;
328 unsigned long load_addr = 0;
329 int load_addr_set = 0;
330 unsigned long last_bss = 0, elf_bss = 0;
331 unsigned long error = ~0UL;
332 int retval, i, size;
333
334 /* First of all, some simple consistency checks */
335 if (interp_elf_ex->e_type != ET_EXEC &&
336 interp_elf_ex->e_type != ET_DYN)
337 goto out;
338 if (!elf_check_arch(interp_elf_ex))
339 goto out;
340 if (!interpreter->f_op || !interpreter->f_op->mmap)
341 goto out;
342
343 /*
344 * If the size of this structure has changed, then punt, since
345 * we will be doing the wrong thing.
346 */
347 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
348 goto out;
349 if (interp_elf_ex->e_phnum < 1 ||
350 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
351 goto out;
352
353 /* Now read in all of the header information */
354 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
355 if (size > ELF_MIN_ALIGN)
356 goto out;
357 elf_phdata = kmalloc(size, GFP_KERNEL);
358 if (!elf_phdata)
359 goto out;
360
361 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
362 (char *)elf_phdata,size);
363 error = -EIO;
364 if (retval != size) {
365 if (retval < 0)
366 error = retval;
367 goto out_close;
368 }
369
370 eppnt = elf_phdata;
371 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
372 if (eppnt->p_type == PT_LOAD) {
373 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
374 int elf_prot = 0;
375 unsigned long vaddr = 0;
376 unsigned long k, map_addr;
377
378 if (eppnt->p_flags & PF_R)
379 elf_prot = PROT_READ;
380 if (eppnt->p_flags & PF_W)
381 elf_prot |= PROT_WRITE;
382 if (eppnt->p_flags & PF_X)
383 elf_prot |= PROT_EXEC;
384 vaddr = eppnt->p_vaddr;
385 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
386 elf_type |= MAP_FIXED;
387
388 map_addr = elf_map(interpreter, load_addr + vaddr,
389 eppnt, elf_prot, elf_type);
390 error = map_addr;
391 if (BAD_ADDR(map_addr))
392 goto out_close;
393
394 if (!load_addr_set &&
395 interp_elf_ex->e_type == ET_DYN) {
396 load_addr = map_addr - ELF_PAGESTART(vaddr);
397 load_addr_set = 1;
398 }
399
400 /*
401 * Check to see if the section's size will overflow the
402 * allowed task size. Note that p_filesz must always be
403 * <= p_memsize so it's only necessary to check p_memsz.
404 */
405 k = load_addr + eppnt->p_vaddr;
406 if (BAD_ADDR(k) ||
407 eppnt->p_filesz > eppnt->p_memsz ||
408 eppnt->p_memsz > TASK_SIZE ||
409 TASK_SIZE - eppnt->p_memsz < k) {
410 error = -ENOMEM;
411 goto out_close;
412 }
413
414 /*
415 * Find the end of the file mapping for this phdr, and
416 * keep track of the largest address we see for this.
417 */
418 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
419 if (k > elf_bss)
420 elf_bss = k;
421
422 /*
423 * Do the same thing for the memory mapping - between
424 * elf_bss and last_bss is the bss section.
425 */
426 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
427 if (k > last_bss)
428 last_bss = k;
429 }
430 }
431
432 /*
433 * Now fill out the bss section. First pad the last page up
434 * to the page boundary, and then perform a mmap to make sure
435 * that there are zero-mapped pages up to and including the
436 * last bss page.
437 */
438 if (padzero(elf_bss)) {
439 error = -EFAULT;
440 goto out_close;
441 }
442
443 /* What we have mapped so far */
444 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
445
446 /* Map the last of the bss segment */
447 if (last_bss > elf_bss) {
448 down_write(&current->mm->mmap_sem);
449 error = do_brk(elf_bss, last_bss - elf_bss);
450 up_write(&current->mm->mmap_sem);
451 if (BAD_ADDR(error))
452 goto out_close;
453 }
454
455 *interp_load_addr = load_addr;
456 error = ((unsigned long)interp_elf_ex->e_entry) + load_addr;
457
458 out_close:
459 kfree(elf_phdata);
460 out:
461 return error;
462 }
463
464 static unsigned long load_aout_interp(struct exec *interp_ex,
465 struct file *interpreter)
466 {
467 unsigned long text_data, elf_entry = ~0UL;
468 char __user * addr;
469 loff_t offset;
470
471 current->mm->end_code = interp_ex->a_text;
472 text_data = interp_ex->a_text + interp_ex->a_data;
473 current->mm->end_data = text_data;
474 current->mm->brk = interp_ex->a_bss + text_data;
475
476 switch (N_MAGIC(*interp_ex)) {
477 case OMAGIC:
478 offset = 32;
479 addr = (char __user *)0;
480 break;
481 case ZMAGIC:
482 case QMAGIC:
483 offset = N_TXTOFF(*interp_ex);
484 addr = (char __user *)N_TXTADDR(*interp_ex);
485 break;
486 default:
487 goto out;
488 }
489
490 down_write(&current->mm->mmap_sem);
491 do_brk(0, text_data);
492 up_write(&current->mm->mmap_sem);
493 if (!interpreter->f_op || !interpreter->f_op->read)
494 goto out;
495 if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0)
496 goto out;
497 flush_icache_range((unsigned long)addr,
498 (unsigned long)addr + text_data);
499
500 down_write(&current->mm->mmap_sem);
501 do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
502 interp_ex->a_bss);
503 up_write(&current->mm->mmap_sem);
504 elf_entry = interp_ex->a_entry;
505
506 out:
507 return elf_entry;
508 }
509
510 /*
511 * These are the functions used to load ELF style executables and shared
512 * libraries. There is no binary dependent code anywhere else.
513 */
514
515 #define INTERPRETER_NONE 0
516 #define INTERPRETER_AOUT 1
517 #define INTERPRETER_ELF 2
518
519 #ifndef STACK_RND_MASK
520 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
521 #endif
522
523 static unsigned long randomize_stack_top(unsigned long stack_top)
524 {
525 unsigned int random_variable = 0;
526
527 if ((current->flags & PF_RANDOMIZE) &&
528 !(current->personality & ADDR_NO_RANDOMIZE)) {
529 random_variable = get_random_int() & STACK_RND_MASK;
530 random_variable <<= PAGE_SHIFT;
531 }
532 #ifdef CONFIG_STACK_GROWSUP
533 return PAGE_ALIGN(stack_top) + random_variable;
534 #else
535 return PAGE_ALIGN(stack_top) - random_variable;
536 #endif
537 }
538
539 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
540 {
541 struct file *interpreter = NULL; /* to shut gcc up */
542 unsigned long load_addr = 0, load_bias = 0;
543 int load_addr_set = 0;
544 char * elf_interpreter = NULL;
545 unsigned int interpreter_type = INTERPRETER_NONE;
546 unsigned char ibcs2_interpreter = 0;
547 unsigned long error;
548 struct elf_phdr *elf_ppnt, *elf_phdata;
549 unsigned long elf_bss, elf_brk;
550 int elf_exec_fileno;
551 int retval, i;
552 unsigned int size;
553 unsigned long elf_entry, interp_load_addr = 0;
554 unsigned long start_code, end_code, start_data, end_data;
555 unsigned long reloc_func_desc = 0;
556 char passed_fileno[6];
557 struct files_struct *files;
558 int executable_stack = EXSTACK_DEFAULT;
559 unsigned long def_flags = 0;
560 struct {
561 struct elfhdr elf_ex;
562 struct elfhdr interp_elf_ex;
563 struct exec interp_ex;
564 } *loc;
565
566 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
567 if (!loc) {
568 retval = -ENOMEM;
569 goto out_ret;
570 }
571
572 /* Get the exec-header */
573 loc->elf_ex = *((struct elfhdr *)bprm->buf);
574
575 retval = -ENOEXEC;
576 /* First of all, some simple consistency checks */
577 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
578 goto out;
579
580 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
581 goto out;
582 if (!elf_check_arch(&loc->elf_ex))
583 goto out;
584 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
585 goto out;
586
587 /* Now read in all of the header information */
588 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
589 goto out;
590 if (loc->elf_ex.e_phnum < 1 ||
591 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
592 goto out;
593 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
594 retval = -ENOMEM;
595 elf_phdata = kmalloc(size, GFP_KERNEL);
596 if (!elf_phdata)
597 goto out;
598
599 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
600 (char *)elf_phdata, size);
601 if (retval != size) {
602 if (retval >= 0)
603 retval = -EIO;
604 goto out_free_ph;
605 }
606
607 files = current->files; /* Refcounted so ok */
608 retval = unshare_files();
609 if (retval < 0)
610 goto out_free_ph;
611 if (files == current->files) {
612 put_files_struct(files);
613 files = NULL;
614 }
615
616 /* exec will make our files private anyway, but for the a.out
617 loader stuff we need to do it earlier */
618 retval = get_unused_fd();
619 if (retval < 0)
620 goto out_free_fh;
621 get_file(bprm->file);
622 fd_install(elf_exec_fileno = retval, bprm->file);
623
624 elf_ppnt = elf_phdata;
625 elf_bss = 0;
626 elf_brk = 0;
627
628 start_code = ~0UL;
629 end_code = 0;
630 start_data = 0;
631 end_data = 0;
632
633 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
634 if (elf_ppnt->p_type == PT_INTERP) {
635 /* This is the program interpreter used for
636 * shared libraries - for now assume that this
637 * is an a.out format binary
638 */
639 retval = -ENOEXEC;
640 if (elf_ppnt->p_filesz > PATH_MAX ||
641 elf_ppnt->p_filesz < 2)
642 goto out_free_file;
643
644 retval = -ENOMEM;
645 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
646 GFP_KERNEL);
647 if (!elf_interpreter)
648 goto out_free_file;
649
650 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
651 elf_interpreter,
652 elf_ppnt->p_filesz);
653 if (retval != elf_ppnt->p_filesz) {
654 if (retval >= 0)
655 retval = -EIO;
656 goto out_free_interp;
657 }
658 /* make sure path is NULL terminated */
659 retval = -ENOEXEC;
660 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
661 goto out_free_interp;
662
663 /* If the program interpreter is one of these two,
664 * then assume an iBCS2 image. Otherwise assume
665 * a native linux image.
666 */
667 if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
668 strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0)
669 ibcs2_interpreter = 1;
670
671 /*
672 * The early SET_PERSONALITY here is so that the lookup
673 * for the interpreter happens in the namespace of the
674 * to-be-execed image. SET_PERSONALITY can select an
675 * alternate root.
676 *
677 * However, SET_PERSONALITY is NOT allowed to switch
678 * this task into the new images's memory mapping
679 * policy - that is, TASK_SIZE must still evaluate to
680 * that which is appropriate to the execing application.
681 * This is because exit_mmap() needs to have TASK_SIZE
682 * evaluate to the size of the old image.
683 *
684 * So if (say) a 64-bit application is execing a 32-bit
685 * application it is the architecture's responsibility
686 * to defer changing the value of TASK_SIZE until the
687 * switch really is going to happen - do this in
688 * flush_thread(). - akpm
689 */
690 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
691
692 interpreter = open_exec(elf_interpreter);
693 retval = PTR_ERR(interpreter);
694 if (IS_ERR(interpreter))
695 goto out_free_interp;
696
697 /*
698 * If the binary is not readable then enforce
699 * mm->dumpable = 0 regardless of the interpreter's
700 * permissions.
701 */
702 if (file_permission(interpreter, MAY_READ) < 0)
703 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
704
705 retval = kernel_read(interpreter, 0, bprm->buf,
706 BINPRM_BUF_SIZE);
707 if (retval != BINPRM_BUF_SIZE) {
708 if (retval >= 0)
709 retval = -EIO;
710 goto out_free_dentry;
711 }
712
713 /* Get the exec headers */
714 loc->interp_ex = *((struct exec *)bprm->buf);
715 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
716 break;
717 }
718 elf_ppnt++;
719 }
720
721 elf_ppnt = elf_phdata;
722 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
723 if (elf_ppnt->p_type == PT_GNU_STACK) {
724 if (elf_ppnt->p_flags & PF_X)
725 executable_stack = EXSTACK_ENABLE_X;
726 else
727 executable_stack = EXSTACK_DISABLE_X;
728 break;
729 }
730
731 /* Some simple consistency checks for the interpreter */
732 if (elf_interpreter) {
733 static int warn;
734 interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
735
736 /* Now figure out which format our binary is */
737 if ((N_MAGIC(loc->interp_ex) != OMAGIC) &&
738 (N_MAGIC(loc->interp_ex) != ZMAGIC) &&
739 (N_MAGIC(loc->interp_ex) != QMAGIC))
740 interpreter_type = INTERPRETER_ELF;
741
742 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
743 interpreter_type &= ~INTERPRETER_ELF;
744
745 if (interpreter_type == INTERPRETER_AOUT && warn < 10) {
746 printk(KERN_WARNING "a.out ELF interpreter %s is "
747 "deprecated and will not be supported "
748 "after Linux 2.6.25\n", elf_interpreter);
749 warn++;
750 }
751
752 retval = -ELIBBAD;
753 if (!interpreter_type)
754 goto out_free_dentry;
755
756 /* Make sure only one type was selected */
757 if ((interpreter_type & INTERPRETER_ELF) &&
758 interpreter_type != INTERPRETER_ELF) {
759 // FIXME - ratelimit this before re-enabling
760 // printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n");
761 interpreter_type = INTERPRETER_ELF;
762 }
763 /* Verify the interpreter has a valid arch */
764 if ((interpreter_type == INTERPRETER_ELF) &&
765 !elf_check_arch(&loc->interp_elf_ex))
766 goto out_free_dentry;
767 } else {
768 /* Executables without an interpreter also need a personality */
769 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
770 }
771
772 /* OK, we are done with that, now set up the arg stuff,
773 and then start this sucker up */
774 if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) {
775 char *passed_p = passed_fileno;
776 sprintf(passed_fileno, "%d", elf_exec_fileno);
777
778 if (elf_interpreter) {
779 retval = copy_strings_kernel(1, &passed_p, bprm);
780 if (retval)
781 goto out_free_dentry;
782 bprm->argc++;
783 }
784 }
785
786 /* Flush all traces of the currently running executable */
787 retval = flush_old_exec(bprm);
788 if (retval)
789 goto out_free_dentry;
790
791 /* Discard our unneeded old files struct */
792 if (files) {
793 put_files_struct(files);
794 files = NULL;
795 }
796
797 /* OK, This is the point of no return */
798 current->flags &= ~PF_FORKNOEXEC;
799 current->mm->def_flags = def_flags;
800
801 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
802 may depend on the personality. */
803 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
804 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
805 current->personality |= READ_IMPLIES_EXEC;
806
807 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
808 current->flags |= PF_RANDOMIZE;
809 arch_pick_mmap_layout(current->mm);
810
811 /* Do this so that we can load the interpreter, if need be. We will
812 change some of these later */
813 current->mm->free_area_cache = current->mm->mmap_base;
814 current->mm->cached_hole_size = 0;
815 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
816 executable_stack);
817 if (retval < 0) {
818 send_sig(SIGKILL, current, 0);
819 goto out_free_dentry;
820 }
821
822 current->mm->start_stack = bprm->p;
823
824 /* Now we do a little grungy work by mmaping the ELF image into
825 the correct location in memory. At this point, we assume that
826 the image should be loaded at fixed address, not at a variable
827 address. */
828 for(i = 0, elf_ppnt = elf_phdata;
829 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
830 int elf_prot = 0, elf_flags;
831 unsigned long k, vaddr;
832
833 if (elf_ppnt->p_type != PT_LOAD)
834 continue;
835
836 if (unlikely (elf_brk > elf_bss)) {
837 unsigned long nbyte;
838
839 /* There was a PT_LOAD segment with p_memsz > p_filesz
840 before this one. Map anonymous pages, if needed,
841 and clear the area. */
842 retval = set_brk (elf_bss + load_bias,
843 elf_brk + load_bias);
844 if (retval) {
845 send_sig(SIGKILL, current, 0);
846 goto out_free_dentry;
847 }
848 nbyte = ELF_PAGEOFFSET(elf_bss);
849 if (nbyte) {
850 nbyte = ELF_MIN_ALIGN - nbyte;
851 if (nbyte > elf_brk - elf_bss)
852 nbyte = elf_brk - elf_bss;
853 if (clear_user((void __user *)elf_bss +
854 load_bias, nbyte)) {
855 /*
856 * This bss-zeroing can fail if the ELF
857 * file specifies odd protections. So
858 * we don't check the return value
859 */
860 }
861 }
862 }
863
864 if (elf_ppnt->p_flags & PF_R)
865 elf_prot |= PROT_READ;
866 if (elf_ppnt->p_flags & PF_W)
867 elf_prot |= PROT_WRITE;
868 if (elf_ppnt->p_flags & PF_X)
869 elf_prot |= PROT_EXEC;
870
871 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
872
873 vaddr = elf_ppnt->p_vaddr;
874 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
875 elf_flags |= MAP_FIXED;
876 } else if (loc->elf_ex.e_type == ET_DYN) {
877 /* Try and get dynamic programs out of the way of the
878 * default mmap base, as well as whatever program they
879 * might try to exec. This is because the brk will
880 * follow the loader, and is not movable. */
881 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
882 }
883
884 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
885 elf_prot, elf_flags);
886 if (BAD_ADDR(error)) {
887 send_sig(SIGKILL, current, 0);
888 retval = IS_ERR((void *)error) ?
889 PTR_ERR((void*)error) : -EINVAL;
890 goto out_free_dentry;
891 }
892
893 if (!load_addr_set) {
894 load_addr_set = 1;
895 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
896 if (loc->elf_ex.e_type == ET_DYN) {
897 load_bias += error -
898 ELF_PAGESTART(load_bias + vaddr);
899 load_addr += load_bias;
900 reloc_func_desc = load_bias;
901 }
902 }
903 k = elf_ppnt->p_vaddr;
904 if (k < start_code)
905 start_code = k;
906 if (start_data < k)
907 start_data = k;
908
909 /*
910 * Check to see if the section's size will overflow the
911 * allowed task size. Note that p_filesz must always be
912 * <= p_memsz so it is only necessary to check p_memsz.
913 */
914 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
915 elf_ppnt->p_memsz > TASK_SIZE ||
916 TASK_SIZE - elf_ppnt->p_memsz < k) {
917 /* set_brk can never work. Avoid overflows. */
918 send_sig(SIGKILL, current, 0);
919 retval = -EINVAL;
920 goto out_free_dentry;
921 }
922
923 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
924
925 if (k > elf_bss)
926 elf_bss = k;
927 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
928 end_code = k;
929 if (end_data < k)
930 end_data = k;
931 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
932 if (k > elf_brk)
933 elf_brk = k;
934 }
935
936 loc->elf_ex.e_entry += load_bias;
937 elf_bss += load_bias;
938 elf_brk += load_bias;
939 start_code += load_bias;
940 end_code += load_bias;
941 start_data += load_bias;
942 end_data += load_bias;
943
944 /* Calling set_brk effectively mmaps the pages that we need
945 * for the bss and break sections. We must do this before
946 * mapping in the interpreter, to make sure it doesn't wind
947 * up getting placed where the bss needs to go.
948 */
949 retval = set_brk(elf_bss, elf_brk);
950 if (retval) {
951 send_sig(SIGKILL, current, 0);
952 goto out_free_dentry;
953 }
954 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
955 send_sig(SIGSEGV, current, 0);
956 retval = -EFAULT; /* Nobody gets to see this, but.. */
957 goto out_free_dentry;
958 }
959
960 if (elf_interpreter) {
961 if (interpreter_type == INTERPRETER_AOUT)
962 elf_entry = load_aout_interp(&loc->interp_ex,
963 interpreter);
964 else
965 elf_entry = load_elf_interp(&loc->interp_elf_ex,
966 interpreter,
967 &interp_load_addr);
968 if (BAD_ADDR(elf_entry)) {
969 force_sig(SIGSEGV, current);
970 retval = IS_ERR((void *)elf_entry) ?
971 (int)elf_entry : -EINVAL;
972 goto out_free_dentry;
973 }
974 reloc_func_desc = interp_load_addr;
975
976 allow_write_access(interpreter);
977 fput(interpreter);
978 kfree(elf_interpreter);
979 } else {
980 elf_entry = loc->elf_ex.e_entry;
981 if (BAD_ADDR(elf_entry)) {
982 force_sig(SIGSEGV, current);
983 retval = -EINVAL;
984 goto out_free_dentry;
985 }
986 }
987
988 kfree(elf_phdata);
989
990 if (interpreter_type != INTERPRETER_AOUT)
991 sys_close(elf_exec_fileno);
992
993 set_binfmt(&elf_format);
994
995 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
996 retval = arch_setup_additional_pages(bprm, executable_stack);
997 if (retval < 0) {
998 send_sig(SIGKILL, current, 0);
999 goto out;
1000 }
1001 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
1002
1003 compute_creds(bprm);
1004 current->flags &= ~PF_FORKNOEXEC;
1005 retval = create_elf_tables(bprm, &loc->elf_ex,
1006 (interpreter_type == INTERPRETER_AOUT),
1007 load_addr, interp_load_addr);
1008 if (retval < 0) {
1009 send_sig(SIGKILL, current, 0);
1010 goto out;
1011 }
1012 /* N.B. passed_fileno might not be initialized? */
1013 if (interpreter_type == INTERPRETER_AOUT)
1014 current->mm->arg_start += strlen(passed_fileno) + 1;
1015 current->mm->end_code = end_code;
1016 current->mm->start_code = start_code;
1017 current->mm->start_data = start_data;
1018 current->mm->end_data = end_data;
1019 current->mm->start_stack = bprm->p;
1020
1021 if (current->personality & MMAP_PAGE_ZERO) {
1022 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
1023 and some applications "depend" upon this behavior.
1024 Since we do not have the power to recompile these, we
1025 emulate the SVr4 behavior. Sigh. */
1026 down_write(&current->mm->mmap_sem);
1027 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1028 MAP_FIXED | MAP_PRIVATE, 0);
1029 up_write(&current->mm->mmap_sem);
1030 }
1031
1032 #ifdef ELF_PLAT_INIT
1033 /*
1034 * The ABI may specify that certain registers be set up in special
1035 * ways (on i386 %edx is the address of a DT_FINI function, for
1036 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1037 * that the e_entry field is the address of the function descriptor
1038 * for the startup routine, rather than the address of the startup
1039 * routine itself. This macro performs whatever initialization to
1040 * the regs structure is required as well as any relocations to the
1041 * function descriptor entries when executing dynamically links apps.
1042 */
1043 ELF_PLAT_INIT(regs, reloc_func_desc);
1044 #endif
1045
1046 start_thread(regs, elf_entry, bprm->p);
1047 if (unlikely(current->ptrace & PT_PTRACED)) {
1048 if (current->ptrace & PT_TRACE_EXEC)
1049 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
1050 else
1051 send_sig(SIGTRAP, current, 0);
1052 }
1053 retval = 0;
1054 out:
1055 kfree(loc);
1056 out_ret:
1057 return retval;
1058
1059 /* error cleanup */
1060 out_free_dentry:
1061 allow_write_access(interpreter);
1062 if (interpreter)
1063 fput(interpreter);
1064 out_free_interp:
1065 kfree(elf_interpreter);
1066 out_free_file:
1067 sys_close(elf_exec_fileno);
1068 out_free_fh:
1069 if (files)
1070 reset_files_struct(current, files);
1071 out_free_ph:
1072 kfree(elf_phdata);
1073 goto out;
1074 }
1075
1076 /* This is really simpleminded and specialized - we are loading an
1077 a.out library that is given an ELF header. */
1078 static int load_elf_library(struct file *file)
1079 {
1080 struct elf_phdr *elf_phdata;
1081 struct elf_phdr *eppnt;
1082 unsigned long elf_bss, bss, len;
1083 int retval, error, i, j;
1084 struct elfhdr elf_ex;
1085
1086 error = -ENOEXEC;
1087 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1088 if (retval != sizeof(elf_ex))
1089 goto out;
1090
1091 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1092 goto out;
1093
1094 /* First of all, some simple consistency checks */
1095 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1096 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1097 goto out;
1098
1099 /* Now read in all of the header information */
1100
1101 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1102 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1103
1104 error = -ENOMEM;
1105 elf_phdata = kmalloc(j, GFP_KERNEL);
1106 if (!elf_phdata)
1107 goto out;
1108
1109 eppnt = elf_phdata;
1110 error = -ENOEXEC;
1111 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1112 if (retval != j)
1113 goto out_free_ph;
1114
1115 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1116 if ((eppnt + i)->p_type == PT_LOAD)
1117 j++;
1118 if (j != 1)
1119 goto out_free_ph;
1120
1121 while (eppnt->p_type != PT_LOAD)
1122 eppnt++;
1123
1124 /* Now use mmap to map the library into memory. */
1125 down_write(&current->mm->mmap_sem);
1126 error = do_mmap(file,
1127 ELF_PAGESTART(eppnt->p_vaddr),
1128 (eppnt->p_filesz +
1129 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1130 PROT_READ | PROT_WRITE | PROT_EXEC,
1131 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1132 (eppnt->p_offset -
1133 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1134 up_write(&current->mm->mmap_sem);
1135 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1136 goto out_free_ph;
1137
1138 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1139 if (padzero(elf_bss)) {
1140 error = -EFAULT;
1141 goto out_free_ph;
1142 }
1143
1144 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1145 ELF_MIN_ALIGN - 1);
1146 bss = eppnt->p_memsz + eppnt->p_vaddr;
1147 if (bss > len) {
1148 down_write(&current->mm->mmap_sem);
1149 do_brk(len, bss - len);
1150 up_write(&current->mm->mmap_sem);
1151 }
1152 error = 0;
1153
1154 out_free_ph:
1155 kfree(elf_phdata);
1156 out:
1157 return error;
1158 }
1159
1160 /*
1161 * Note that some platforms still use traditional core dumps and not
1162 * the ELF core dump. Each platform can select it as appropriate.
1163 */
1164 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1165
1166 /*
1167 * ELF core dumper
1168 *
1169 * Modelled on fs/exec.c:aout_core_dump()
1170 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1171 */
1172 /*
1173 * These are the only things you should do on a core-file: use only these
1174 * functions to write out all the necessary info.
1175 */
1176 static int dump_write(struct file *file, const void *addr, int nr)
1177 {
1178 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1179 }
1180
1181 static int dump_seek(struct file *file, loff_t off)
1182 {
1183 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1184 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1185 return 0;
1186 } else {
1187 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1188 if (!buf)
1189 return 0;
1190 while (off > 0) {
1191 unsigned long n = off;
1192 if (n > PAGE_SIZE)
1193 n = PAGE_SIZE;
1194 if (!dump_write(file, buf, n))
1195 return 0;
1196 off -= n;
1197 }
1198 free_page((unsigned long)buf);
1199 }
1200 return 1;
1201 }
1202
1203 /*
1204 * Decide what to dump of a segment, part, all or none.
1205 */
1206 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1207 unsigned long mm_flags)
1208 {
1209 /* The vma can be set up to tell us the answer directly. */
1210 if (vma->vm_flags & VM_ALWAYSDUMP)
1211 goto whole;
1212
1213 /* Do not dump I/O mapped devices or special mappings */
1214 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1215 return 0;
1216
1217 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1218
1219 /* By default, dump shared memory if mapped from an anonymous file. */
1220 if (vma->vm_flags & VM_SHARED) {
1221 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1222 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1223 goto whole;
1224 return 0;
1225 }
1226
1227 /* Dump segments that have been written to. */
1228 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1229 goto whole;
1230 if (vma->vm_file == NULL)
1231 return 0;
1232
1233 if (FILTER(MAPPED_PRIVATE))
1234 goto whole;
1235
1236 /*
1237 * If this looks like the beginning of a DSO or executable mapping,
1238 * check for an ELF header. If we find one, dump the first page to
1239 * aid in determining what was mapped here.
1240 */
1241 if (FILTER(ELF_HEADERS) && vma->vm_file != NULL && vma->vm_pgoff == 0) {
1242 u32 __user *header = (u32 __user *) vma->vm_start;
1243 u32 word;
1244 /*
1245 * Doing it this way gets the constant folded by GCC.
1246 */
1247 union {
1248 u32 cmp;
1249 char elfmag[SELFMAG];
1250 } magic;
1251 BUILD_BUG_ON(SELFMAG != sizeof word);
1252 magic.elfmag[EI_MAG0] = ELFMAG0;
1253 magic.elfmag[EI_MAG1] = ELFMAG1;
1254 magic.elfmag[EI_MAG2] = ELFMAG2;
1255 magic.elfmag[EI_MAG3] = ELFMAG3;
1256 if (get_user(word, header) == 0 && word == magic.cmp)
1257 return PAGE_SIZE;
1258 }
1259
1260 #undef FILTER
1261
1262 return 0;
1263
1264 whole:
1265 return vma->vm_end - vma->vm_start;
1266 }
1267
1268 /* An ELF note in memory */
1269 struct memelfnote
1270 {
1271 const char *name;
1272 int type;
1273 unsigned int datasz;
1274 void *data;
1275 };
1276
1277 static int notesize(struct memelfnote *en)
1278 {
1279 int sz;
1280
1281 sz = sizeof(struct elf_note);
1282 sz += roundup(strlen(en->name) + 1, 4);
1283 sz += roundup(en->datasz, 4);
1284
1285 return sz;
1286 }
1287
1288 #define DUMP_WRITE(addr, nr, foffset) \
1289 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1290
1291 static int alignfile(struct file *file, loff_t *foffset)
1292 {
1293 static const char buf[4] = { 0, };
1294 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1295 return 1;
1296 }
1297
1298 static int writenote(struct memelfnote *men, struct file *file,
1299 loff_t *foffset)
1300 {
1301 struct elf_note en;
1302 en.n_namesz = strlen(men->name) + 1;
1303 en.n_descsz = men->datasz;
1304 en.n_type = men->type;
1305
1306 DUMP_WRITE(&en, sizeof(en), foffset);
1307 DUMP_WRITE(men->name, en.n_namesz, foffset);
1308 if (!alignfile(file, foffset))
1309 return 0;
1310 DUMP_WRITE(men->data, men->datasz, foffset);
1311 if (!alignfile(file, foffset))
1312 return 0;
1313
1314 return 1;
1315 }
1316 #undef DUMP_WRITE
1317
1318 #define DUMP_WRITE(addr, nr) \
1319 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1320 goto end_coredump;
1321 #define DUMP_SEEK(off) \
1322 if (!dump_seek(file, (off))) \
1323 goto end_coredump;
1324
1325 static void fill_elf_header(struct elfhdr *elf, int segs)
1326 {
1327 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1328 elf->e_ident[EI_CLASS] = ELF_CLASS;
1329 elf->e_ident[EI_DATA] = ELF_DATA;
1330 elf->e_ident[EI_VERSION] = EV_CURRENT;
1331 elf->e_ident[EI_OSABI] = ELF_OSABI;
1332 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1333
1334 elf->e_type = ET_CORE;
1335 elf->e_machine = ELF_ARCH;
1336 elf->e_version = EV_CURRENT;
1337 elf->e_entry = 0;
1338 elf->e_phoff = sizeof(struct elfhdr);
1339 elf->e_shoff = 0;
1340 elf->e_flags = ELF_CORE_EFLAGS;
1341 elf->e_ehsize = sizeof(struct elfhdr);
1342 elf->e_phentsize = sizeof(struct elf_phdr);
1343 elf->e_phnum = segs;
1344 elf->e_shentsize = 0;
1345 elf->e_shnum = 0;
1346 elf->e_shstrndx = 0;
1347 return;
1348 }
1349
1350 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1351 {
1352 phdr->p_type = PT_NOTE;
1353 phdr->p_offset = offset;
1354 phdr->p_vaddr = 0;
1355 phdr->p_paddr = 0;
1356 phdr->p_filesz = sz;
1357 phdr->p_memsz = 0;
1358 phdr->p_flags = 0;
1359 phdr->p_align = 0;
1360 return;
1361 }
1362
1363 static void fill_note(struct memelfnote *note, const char *name, int type,
1364 unsigned int sz, void *data)
1365 {
1366 note->name = name;
1367 note->type = type;
1368 note->datasz = sz;
1369 note->data = data;
1370 return;
1371 }
1372
1373 /*
1374 * fill up all the fields in prstatus from the given task struct, except
1375 * registers which need to be filled up separately.
1376 */
1377 static void fill_prstatus(struct elf_prstatus *prstatus,
1378 struct task_struct *p, long signr)
1379 {
1380 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1381 prstatus->pr_sigpend = p->pending.signal.sig[0];
1382 prstatus->pr_sighold = p->blocked.sig[0];
1383 prstatus->pr_pid = p->pid;
1384 prstatus->pr_ppid = p->parent->pid;
1385 prstatus->pr_pgrp = process_group(p);
1386 prstatus->pr_sid = process_session(p);
1387 if (thread_group_leader(p)) {
1388 /*
1389 * This is the record for the group leader. Add in the
1390 * cumulative times of previous dead threads. This total
1391 * won't include the time of each live thread whose state
1392 * is included in the core dump. The final total reported
1393 * to our parent process when it calls wait4 will include
1394 * those sums as well as the little bit more time it takes
1395 * this and each other thread to finish dying after the
1396 * core dump synchronization phase.
1397 */
1398 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1399 &prstatus->pr_utime);
1400 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1401 &prstatus->pr_stime);
1402 } else {
1403 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1404 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1405 }
1406 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1407 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1408 }
1409
1410 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1411 struct mm_struct *mm)
1412 {
1413 unsigned int i, len;
1414
1415 /* first copy the parameters from user space */
1416 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1417
1418 len = mm->arg_end - mm->arg_start;
1419 if (len >= ELF_PRARGSZ)
1420 len = ELF_PRARGSZ-1;
1421 if (copy_from_user(&psinfo->pr_psargs,
1422 (const char __user *)mm->arg_start, len))
1423 return -EFAULT;
1424 for(i = 0; i < len; i++)
1425 if (psinfo->pr_psargs[i] == 0)
1426 psinfo->pr_psargs[i] = ' ';
1427 psinfo->pr_psargs[len] = 0;
1428
1429 psinfo->pr_pid = p->pid;
1430 psinfo->pr_ppid = p->parent->pid;
1431 psinfo->pr_pgrp = process_group(p);
1432 psinfo->pr_sid = process_session(p);
1433
1434 i = p->state ? ffz(~p->state) + 1 : 0;
1435 psinfo->pr_state = i;
1436 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1437 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1438 psinfo->pr_nice = task_nice(p);
1439 psinfo->pr_flag = p->flags;
1440 SET_UID(psinfo->pr_uid, p->uid);
1441 SET_GID(psinfo->pr_gid, p->gid);
1442 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1443
1444 return 0;
1445 }
1446
1447 /* Here is the structure in which status of each thread is captured. */
1448 struct elf_thread_status
1449 {
1450 struct list_head list;
1451 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1452 elf_fpregset_t fpu; /* NT_PRFPREG */
1453 struct task_struct *thread;
1454 #ifdef ELF_CORE_COPY_XFPREGS
1455 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1456 #endif
1457 struct memelfnote notes[3];
1458 int num_notes;
1459 };
1460
1461 /*
1462 * In order to add the specific thread information for the elf file format,
1463 * we need to keep a linked list of every threads pr_status and then create
1464 * a single section for them in the final core file.
1465 */
1466 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1467 {
1468 int sz = 0;
1469 struct task_struct *p = t->thread;
1470 t->num_notes = 0;
1471
1472 fill_prstatus(&t->prstatus, p, signr);
1473 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1474
1475 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1476 &(t->prstatus));
1477 t->num_notes++;
1478 sz += notesize(&t->notes[0]);
1479
1480 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1481 &t->fpu))) {
1482 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1483 &(t->fpu));
1484 t->num_notes++;
1485 sz += notesize(&t->notes[1]);
1486 }
1487
1488 #ifdef ELF_CORE_COPY_XFPREGS
1489 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1490 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1491 sizeof(t->xfpu), &t->xfpu);
1492 t->num_notes++;
1493 sz += notesize(&t->notes[2]);
1494 }
1495 #endif
1496 return sz;
1497 }
1498
1499 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1500 struct vm_area_struct *gate_vma)
1501 {
1502 struct vm_area_struct *ret = tsk->mm->mmap;
1503
1504 if (ret)
1505 return ret;
1506 return gate_vma;
1507 }
1508 /*
1509 * Helper function for iterating across a vma list. It ensures that the caller
1510 * will visit `gate_vma' prior to terminating the search.
1511 */
1512 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1513 struct vm_area_struct *gate_vma)
1514 {
1515 struct vm_area_struct *ret;
1516
1517 ret = this_vma->vm_next;
1518 if (ret)
1519 return ret;
1520 if (this_vma == gate_vma)
1521 return NULL;
1522 return gate_vma;
1523 }
1524
1525 /*
1526 * Actual dumper
1527 *
1528 * This is a two-pass process; first we find the offsets of the bits,
1529 * and then they are actually written out. If we run out of core limit
1530 * we just truncate.
1531 */
1532 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
1533 {
1534 #define NUM_NOTES 6
1535 int has_dumped = 0;
1536 mm_segment_t fs;
1537 int segs;
1538 size_t size = 0;
1539 int i;
1540 struct vm_area_struct *vma, *gate_vma;
1541 struct elfhdr *elf = NULL;
1542 loff_t offset = 0, dataoff, foffset;
1543 int numnote;
1544 struct memelfnote *notes = NULL;
1545 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1546 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1547 struct task_struct *g, *p;
1548 LIST_HEAD(thread_list);
1549 struct list_head *t;
1550 elf_fpregset_t *fpu = NULL;
1551 #ifdef ELF_CORE_COPY_XFPREGS
1552 elf_fpxregset_t *xfpu = NULL;
1553 #endif
1554 int thread_status_size = 0;
1555 elf_addr_t *auxv;
1556 unsigned long mm_flags;
1557
1558 /*
1559 * We no longer stop all VM operations.
1560 *
1561 * This is because those proceses that could possibly change map_count
1562 * or the mmap / vma pages are now blocked in do_exit on current
1563 * finishing this core dump.
1564 *
1565 * Only ptrace can touch these memory addresses, but it doesn't change
1566 * the map_count or the pages allocated. So no possibility of crashing
1567 * exists while dumping the mm->vm_next areas to the core file.
1568 */
1569
1570 /* alloc memory for large data structures: too large to be on stack */
1571 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1572 if (!elf)
1573 goto cleanup;
1574 prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
1575 if (!prstatus)
1576 goto cleanup;
1577 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1578 if (!psinfo)
1579 goto cleanup;
1580 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1581 if (!notes)
1582 goto cleanup;
1583 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1584 if (!fpu)
1585 goto cleanup;
1586 #ifdef ELF_CORE_COPY_XFPREGS
1587 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1588 if (!xfpu)
1589 goto cleanup;
1590 #endif
1591
1592 if (signr) {
1593 struct elf_thread_status *tmp;
1594 rcu_read_lock();
1595 do_each_thread(g,p)
1596 if (current->mm == p->mm && current != p) {
1597 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1598 if (!tmp) {
1599 rcu_read_unlock();
1600 goto cleanup;
1601 }
1602 tmp->thread = p;
1603 list_add(&tmp->list, &thread_list);
1604 }
1605 while_each_thread(g,p);
1606 rcu_read_unlock();
1607 list_for_each(t, &thread_list) {
1608 struct elf_thread_status *tmp;
1609 int sz;
1610
1611 tmp = list_entry(t, struct elf_thread_status, list);
1612 sz = elf_dump_thread_status(signr, tmp);
1613 thread_status_size += sz;
1614 }
1615 }
1616 /* now collect the dump for the current */
1617 memset(prstatus, 0, sizeof(*prstatus));
1618 fill_prstatus(prstatus, current, signr);
1619 elf_core_copy_regs(&prstatus->pr_reg, regs);
1620
1621 segs = current->mm->map_count;
1622 #ifdef ELF_CORE_EXTRA_PHDRS
1623 segs += ELF_CORE_EXTRA_PHDRS;
1624 #endif
1625
1626 gate_vma = get_gate_vma(current);
1627 if (gate_vma != NULL)
1628 segs++;
1629
1630 /* Set up header */
1631 fill_elf_header(elf, segs + 1); /* including notes section */
1632
1633 has_dumped = 1;
1634 current->flags |= PF_DUMPCORE;
1635
1636 /*
1637 * Set up the notes in similar form to SVR4 core dumps made
1638 * with info from their /proc.
1639 */
1640
1641 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1642 fill_psinfo(psinfo, current->group_leader, current->mm);
1643 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1644
1645 numnote = 2;
1646
1647 auxv = (elf_addr_t *)current->mm->saved_auxv;
1648
1649 i = 0;
1650 do
1651 i += 2;
1652 while (auxv[i - 2] != AT_NULL);
1653 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1654 i * sizeof(elf_addr_t), auxv);
1655
1656 /* Try to dump the FPU. */
1657 if ((prstatus->pr_fpvalid =
1658 elf_core_copy_task_fpregs(current, regs, fpu)))
1659 fill_note(notes + numnote++,
1660 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1661 #ifdef ELF_CORE_COPY_XFPREGS
1662 if (elf_core_copy_task_xfpregs(current, xfpu))
1663 fill_note(notes + numnote++,
1664 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1665 #endif
1666
1667 fs = get_fs();
1668 set_fs(KERNEL_DS);
1669
1670 DUMP_WRITE(elf, sizeof(*elf));
1671 offset += sizeof(*elf); /* Elf header */
1672 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1673 foffset = offset;
1674
1675 /* Write notes phdr entry */
1676 {
1677 struct elf_phdr phdr;
1678 int sz = 0;
1679
1680 for (i = 0; i < numnote; i++)
1681 sz += notesize(notes + i);
1682
1683 sz += thread_status_size;
1684
1685 sz += elf_coredump_extra_notes_size();
1686
1687 fill_elf_note_phdr(&phdr, sz, offset);
1688 offset += sz;
1689 DUMP_WRITE(&phdr, sizeof(phdr));
1690 }
1691
1692 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1693
1694 /*
1695 * We must use the same mm->flags while dumping core to avoid
1696 * inconsistency between the program headers and bodies, otherwise an
1697 * unusable core file can be generated.
1698 */
1699 mm_flags = current->mm->flags;
1700
1701 /* Write program headers for segments dump */
1702 for (vma = first_vma(current, gate_vma); vma != NULL;
1703 vma = next_vma(vma, gate_vma)) {
1704 struct elf_phdr phdr;
1705
1706 phdr.p_type = PT_LOAD;
1707 phdr.p_offset = offset;
1708 phdr.p_vaddr = vma->vm_start;
1709 phdr.p_paddr = 0;
1710 phdr.p_filesz = vma_dump_size(vma, mm_flags);
1711 phdr.p_memsz = vma->vm_end - vma->vm_start;
1712 offset += phdr.p_filesz;
1713 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1714 if (vma->vm_flags & VM_WRITE)
1715 phdr.p_flags |= PF_W;
1716 if (vma->vm_flags & VM_EXEC)
1717 phdr.p_flags |= PF_X;
1718 phdr.p_align = ELF_EXEC_PAGESIZE;
1719
1720 DUMP_WRITE(&phdr, sizeof(phdr));
1721 }
1722
1723 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1724 ELF_CORE_WRITE_EXTRA_PHDRS;
1725 #endif
1726
1727 /* write out the notes section */
1728 for (i = 0; i < numnote; i++)
1729 if (!writenote(notes + i, file, &foffset))
1730 goto end_coredump;
1731
1732 if (elf_coredump_extra_notes_write(file, &foffset))
1733 goto end_coredump;
1734
1735 /* write out the thread status notes section */
1736 list_for_each(t, &thread_list) {
1737 struct elf_thread_status *tmp =
1738 list_entry(t, struct elf_thread_status, list);
1739
1740 for (i = 0; i < tmp->num_notes; i++)
1741 if (!writenote(&tmp->notes[i], file, &foffset))
1742 goto end_coredump;
1743 }
1744
1745 /* Align to page */
1746 DUMP_SEEK(dataoff - foffset);
1747
1748 for (vma = first_vma(current, gate_vma); vma != NULL;
1749 vma = next_vma(vma, gate_vma)) {
1750 unsigned long addr;
1751 unsigned long end;
1752
1753 end = vma->vm_start + vma_dump_size(vma, mm_flags);
1754
1755 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
1756 struct page *page;
1757 struct vm_area_struct *vma;
1758
1759 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1760 &page, &vma) <= 0) {
1761 DUMP_SEEK(PAGE_SIZE);
1762 } else {
1763 if (page == ZERO_PAGE(0)) {
1764 if (!dump_seek(file, PAGE_SIZE)) {
1765 page_cache_release(page);
1766 goto end_coredump;
1767 }
1768 } else {
1769 void *kaddr;
1770 flush_cache_page(vma, addr,
1771 page_to_pfn(page));
1772 kaddr = kmap(page);
1773 if ((size += PAGE_SIZE) > limit ||
1774 !dump_write(file, kaddr,
1775 PAGE_SIZE)) {
1776 kunmap(page);
1777 page_cache_release(page);
1778 goto end_coredump;
1779 }
1780 kunmap(page);
1781 }
1782 page_cache_release(page);
1783 }
1784 }
1785 }
1786
1787 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1788 ELF_CORE_WRITE_EXTRA_DATA;
1789 #endif
1790
1791 end_coredump:
1792 set_fs(fs);
1793
1794 cleanup:
1795 while (!list_empty(&thread_list)) {
1796 struct list_head *tmp = thread_list.next;
1797 list_del(tmp);
1798 kfree(list_entry(tmp, struct elf_thread_status, list));
1799 }
1800
1801 kfree(elf);
1802 kfree(prstatus);
1803 kfree(psinfo);
1804 kfree(notes);
1805 kfree(fpu);
1806 #ifdef ELF_CORE_COPY_XFPREGS
1807 kfree(xfpu);
1808 #endif
1809 return has_dumped;
1810 #undef NUM_NOTES
1811 }
1812
1813 #endif /* USE_ELF_CORE_DUMP */
1814
1815 static int __init init_elf_binfmt(void)
1816 {
1817 return register_binfmt(&elf_format);
1818 }
1819
1820 static void __exit exit_elf_binfmt(void)
1821 {
1822 /* Remove the COFF and ELF loaders. */
1823 unregister_binfmt(&elf_format);
1824 }
1825
1826 core_initcall(init_elf_binfmt);
1827 module_exit(exit_elf_binfmt);
1828 MODULE_LICENSE("GPL");
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