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scripts: kernel-doc whitespace cleanup
[pv_ops_mirror.git] / fs / binfmt_elf.c
blob9cc4f0a8aaaec1ffba2b8a5f66389f2503fab2f3
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/smp_lock.h>
35 #include <linux/compiler.h>
36 #include <linux/highmem.h>
37 #include <linux/pagemap.h>
38 #include <linux/security.h>
39 #include <linux/syscalls.h>
40 #include <linux/random.h>
41 #include <linux/elf.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);
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
152 /*
153 * If this architecture has a platform capability string, copy it
154 * to userspace. In some cases (Sparc), this info is impossible
155 * for userspace to get any other way, in others (i386) it is
156 * merely difficult.
157 */
158 u_platform = NULL;
159 if (k_platform) {
160 size_t len = strlen(k_platform) + 1;
161
162 /*
163 * In some cases (e.g. Hyper-Threading), we want to avoid L1
164 * evictions by the processes running on the same package. One
165 * thing we can do is to shuffle the initial stack for them.
166 */
167
168 p = arch_align_stack(p);
169
170 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
171 if (__copy_to_user(u_platform, k_platform, len))
172 return -EFAULT;
173 }
174
175 /* Create the ELF interpreter info */
176 elf_info = (elf_addr_t *)current->mm->saved_auxv;
177 #define NEW_AUX_ENT(id, val) \
178 do { \
179 elf_info[ei_index++] = id; \
180 elf_info[ei_index++] = val; \
181 } while (0)
182
183 #ifdef ARCH_DLINFO
184 /*
185 * ARCH_DLINFO must come first so PPC can do its special alignment of
186 * AUXV.
187 */
188 ARCH_DLINFO;
189 #endif
190 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
191 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
192 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
193 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
194 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
195 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
196 NEW_AUX_ENT(AT_BASE, interp_load_addr);
197 NEW_AUX_ENT(AT_FLAGS, 0);
198 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
199 NEW_AUX_ENT(AT_UID, tsk->uid);
200 NEW_AUX_ENT(AT_EUID, tsk->euid);
201 NEW_AUX_ENT(AT_GID, tsk->gid);
202 NEW_AUX_ENT(AT_EGID, tsk->egid);
203 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
204 if (k_platform) {
205 NEW_AUX_ENT(AT_PLATFORM,
206 (elf_addr_t)(unsigned long)u_platform);
207 }
208 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
209 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
210 }
211 #undef NEW_AUX_ENT
212 /* AT_NULL is zero; clear the rest too */
213 memset(&elf_info[ei_index], 0,
214 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
215
216 /* And advance past the AT_NULL entry. */
217 ei_index += 2;
218
219 sp = STACK_ADD(p, ei_index);
220
221 items = (argc + 1) + (envc + 1);
222 if (interp_aout) {
223 items += 3; /* a.out interpreters require argv & envp too */
224 } else {
225 items += 1; /* ELF interpreters only put argc on the stack */
226 }
227 bprm->p = STACK_ROUND(sp, items);
228
229 /* Point sp at the lowest address on the stack */
230 #ifdef CONFIG_STACK_GROWSUP
231 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
232 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
233 #else
234 sp = (elf_addr_t __user *)bprm->p;
235 #endif
236
237 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
238 if (__put_user(argc, sp++))
239 return -EFAULT;
240 if (interp_aout) {
241 argv = sp + 2;
242 envp = argv + argc + 1;
243 if (__put_user((elf_addr_t)(unsigned long)argv, sp++) ||
244 __put_user((elf_addr_t)(unsigned long)envp, sp++))
245 return -EFAULT;
246 } else {
247 argv = sp;
248 envp = argv + argc + 1;
249 }
250
251 /* Populate argv and envp */
252 p = current->mm->arg_end = current->mm->arg_start;
253 while (argc-- > 0) {
254 size_t len;
255 if (__put_user((elf_addr_t)p, argv++))
256 return -EFAULT;
257 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
258 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
259 return 0;
260 p += len;
261 }
262 if (__put_user(0, argv))
263 return -EFAULT;
264 current->mm->arg_end = current->mm->env_start = p;
265 while (envc-- > 0) {
266 size_t len;
267 if (__put_user((elf_addr_t)p, envp++))
268 return -EFAULT;
269 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
270 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
271 return 0;
272 p += len;
273 }
274 if (__put_user(0, envp))
275 return -EFAULT;
276 current->mm->env_end = p;
277
278 /* Put the elf_info on the stack in the right place. */
279 sp = (elf_addr_t __user *)envp + 1;
280 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
281 return -EFAULT;
282 return 0;
283 }
284
285 #ifndef elf_map
286
287 static unsigned long elf_map(struct file *filep, unsigned long addr,
288 struct elf_phdr *eppnt, int prot, int type)
289 {
290 unsigned long map_addr;
291 unsigned long pageoffset = ELF_PAGEOFFSET(eppnt->p_vaddr);
292
293 down_write(&current->mm->mmap_sem);
294 /* mmap() will return -EINVAL if given a zero size, but a
295 * segment with zero filesize is perfectly valid */
296 if (eppnt->p_filesz + pageoffset)
297 map_addr = do_mmap(filep, ELF_PAGESTART(addr),
298 eppnt->p_filesz + pageoffset, prot, type,
299 eppnt->p_offset - pageoffset);
300 else
301 map_addr = ELF_PAGESTART(addr);
302 up_write(&current->mm->mmap_sem);
303 return(map_addr);
304 }
305
306 #endif /* !elf_map */
307
308 /* This is much more generalized than the library routine read function,
309 so we keep this separate. Technically the library read function
310 is only provided so that we can read a.out libraries that have
311 an ELF header */
312
313 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
314 struct file *interpreter, unsigned long *interp_load_addr)
315 {
316 struct elf_phdr *elf_phdata;
317 struct elf_phdr *eppnt;
318 unsigned long load_addr = 0;
319 int load_addr_set = 0;
320 unsigned long last_bss = 0, elf_bss = 0;
321 unsigned long error = ~0UL;
322 int retval, i, size;
323
324 /* First of all, some simple consistency checks */
325 if (interp_elf_ex->e_type != ET_EXEC &&
326 interp_elf_ex->e_type != ET_DYN)
327 goto out;
328 if (!elf_check_arch(interp_elf_ex))
329 goto out;
330 if (!interpreter->f_op || !interpreter->f_op->mmap)
331 goto out;
332
333 /*
334 * If the size of this structure has changed, then punt, since
335 * we will be doing the wrong thing.
336 */
337 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
338 goto out;
339 if (interp_elf_ex->e_phnum < 1 ||
340 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
341 goto out;
342
343 /* Now read in all of the header information */
344 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
345 if (size > ELF_MIN_ALIGN)
346 goto out;
347 elf_phdata = kmalloc(size, GFP_KERNEL);
348 if (!elf_phdata)
349 goto out;
350
351 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
352 (char *)elf_phdata,size);
353 error = -EIO;
354 if (retval != size) {
355 if (retval < 0)
356 error = retval;
357 goto out_close;
358 }
359
360 eppnt = elf_phdata;
361 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
362 if (eppnt->p_type == PT_LOAD) {
363 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
364 int elf_prot = 0;
365 unsigned long vaddr = 0;
366 unsigned long k, map_addr;
367
368 if (eppnt->p_flags & PF_R)
369 elf_prot = PROT_READ;
370 if (eppnt->p_flags & PF_W)
371 elf_prot |= PROT_WRITE;
372 if (eppnt->p_flags & PF_X)
373 elf_prot |= PROT_EXEC;
374 vaddr = eppnt->p_vaddr;
375 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
376 elf_type |= MAP_FIXED;
377
378 map_addr = elf_map(interpreter, load_addr + vaddr,
379 eppnt, elf_prot, elf_type);
380 error = map_addr;
381 if (BAD_ADDR(map_addr))
382 goto out_close;
383
384 if (!load_addr_set &&
385 interp_elf_ex->e_type == ET_DYN) {
386 load_addr = map_addr - ELF_PAGESTART(vaddr);
387 load_addr_set = 1;
388 }
389
390 /*
391 * Check to see if the section's size will overflow the
392 * allowed task size. Note that p_filesz must always be
393 * <= p_memsize so it's only necessary to check p_memsz.
394 */
395 k = load_addr + eppnt->p_vaddr;
396 if (BAD_ADDR(k) ||
397 eppnt->p_filesz > eppnt->p_memsz ||
398 eppnt->p_memsz > TASK_SIZE ||
399 TASK_SIZE - eppnt->p_memsz < k) {
400 error = -ENOMEM;
401 goto out_close;
402 }
403
404 /*
405 * Find the end of the file mapping for this phdr, and
406 * keep track of the largest address we see for this.
407 */
408 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
409 if (k > elf_bss)
410 elf_bss = k;
411
412 /*
413 * Do the same thing for the memory mapping - between
414 * elf_bss and last_bss is the bss section.
415 */
416 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
417 if (k > last_bss)
418 last_bss = k;
419 }
420 }
421
422 /*
423 * Now fill out the bss section. First pad the last page up
424 * to the page boundary, and then perform a mmap to make sure
425 * that there are zero-mapped pages up to and including the
426 * last bss page.
427 */
428 if (padzero(elf_bss)) {
429 error = -EFAULT;
430 goto out_close;
431 }
432
433 /* What we have mapped so far */
434 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
435
436 /* Map the last of the bss segment */
437 if (last_bss > elf_bss) {
438 down_write(&current->mm->mmap_sem);
439 error = do_brk(elf_bss, last_bss - elf_bss);
440 up_write(&current->mm->mmap_sem);
441 if (BAD_ADDR(error))
442 goto out_close;
443 }
444
445 *interp_load_addr = load_addr;
446 error = ((unsigned long)interp_elf_ex->e_entry) + load_addr;
447
448 out_close:
449 kfree(elf_phdata);
450 out:
451 return error;
452 }
453
454 static unsigned long load_aout_interp(struct exec *interp_ex,
455 struct file *interpreter)
456 {
457 unsigned long text_data, elf_entry = ~0UL;
458 char __user * addr;
459 loff_t offset;
460
461 current->mm->end_code = interp_ex->a_text;
462 text_data = interp_ex->a_text + interp_ex->a_data;
463 current->mm->end_data = text_data;
464 current->mm->brk = interp_ex->a_bss + text_data;
465
466 switch (N_MAGIC(*interp_ex)) {
467 case OMAGIC:
468 offset = 32;
469 addr = (char __user *)0;
470 break;
471 case ZMAGIC:
472 case QMAGIC:
473 offset = N_TXTOFF(*interp_ex);
474 addr = (char __user *)N_TXTADDR(*interp_ex);
475 break;
476 default:
477 goto out;
478 }
479
480 down_write(&current->mm->mmap_sem);
481 do_brk(0, text_data);
482 up_write(&current->mm->mmap_sem);
483 if (!interpreter->f_op || !interpreter->f_op->read)
484 goto out;
485 if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0)
486 goto out;
487 flush_icache_range((unsigned long)addr,
488 (unsigned long)addr + text_data);
489
490 down_write(&current->mm->mmap_sem);
491 do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
492 interp_ex->a_bss);
493 up_write(&current->mm->mmap_sem);
494 elf_entry = interp_ex->a_entry;
495
496 out:
497 return elf_entry;
498 }
499
500 /*
501 * These are the functions used to load ELF style executables and shared
502 * libraries. There is no binary dependent code anywhere else.
503 */
504
505 #define INTERPRETER_NONE 0
506 #define INTERPRETER_AOUT 1
507 #define INTERPRETER_ELF 2
508
509 #ifndef STACK_RND_MASK
510 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
511 #endif
512
513 static unsigned long randomize_stack_top(unsigned long stack_top)
514 {
515 unsigned int random_variable = 0;
516
517 if ((current->flags & PF_RANDOMIZE) &&
518 !(current->personality & ADDR_NO_RANDOMIZE)) {
519 random_variable = get_random_int() & STACK_RND_MASK;
520 random_variable <<= PAGE_SHIFT;
521 }
522 #ifdef CONFIG_STACK_GROWSUP
523 return PAGE_ALIGN(stack_top) + random_variable;
524 #else
525 return PAGE_ALIGN(stack_top) - random_variable;
526 #endif
527 }
528
529 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
530 {
531 struct file *interpreter = NULL; /* to shut gcc up */
532 unsigned long load_addr = 0, load_bias = 0;
533 int load_addr_set = 0;
534 char * elf_interpreter = NULL;
535 unsigned int interpreter_type = INTERPRETER_NONE;
536 unsigned char ibcs2_interpreter = 0;
537 unsigned long error;
538 struct elf_phdr *elf_ppnt, *elf_phdata;
539 unsigned long elf_bss, elf_brk;
540 int elf_exec_fileno;
541 int retval, i;
542 unsigned int size;
543 unsigned long elf_entry, interp_load_addr = 0;
544 unsigned long start_code, end_code, start_data, end_data;
545 unsigned long reloc_func_desc = 0;
546 char passed_fileno[6];
547 struct files_struct *files;
548 int executable_stack = EXSTACK_DEFAULT;
549 unsigned long def_flags = 0;
550 struct {
551 struct elfhdr elf_ex;
552 struct elfhdr interp_elf_ex;
553 struct exec interp_ex;
554 } *loc;
555
556 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
557 if (!loc) {
558 retval = -ENOMEM;
559 goto out_ret;
560 }
561
562 /* Get the exec-header */
563 loc->elf_ex = *((struct elfhdr *)bprm->buf);
564
565 retval = -ENOEXEC;
566 /* First of all, some simple consistency checks */
567 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
568 goto out;
569
570 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
571 goto out;
572 if (!elf_check_arch(&loc->elf_ex))
573 goto out;
574 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
575 goto out;
576
577 /* Now read in all of the header information */
578 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
579 goto out;
580 if (loc->elf_ex.e_phnum < 1 ||
581 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
582 goto out;
583 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
584 retval = -ENOMEM;
585 elf_phdata = kmalloc(size, GFP_KERNEL);
586 if (!elf_phdata)
587 goto out;
588
589 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
590 (char *)elf_phdata, size);
591 if (retval != size) {
592 if (retval >= 0)
593 retval = -EIO;
594 goto out_free_ph;
595 }
596
597 files = current->files; /* Refcounted so ok */
598 retval = unshare_files();
599 if (retval < 0)
600 goto out_free_ph;
601 if (files == current->files) {
602 put_files_struct(files);
603 files = NULL;
604 }
605
606 /* exec will make our files private anyway, but for the a.out
607 loader stuff we need to do it earlier */
608 retval = get_unused_fd();
609 if (retval < 0)
610 goto out_free_fh;
611 get_file(bprm->file);
612 fd_install(elf_exec_fileno = retval, bprm->file);
613
614 elf_ppnt = elf_phdata;
615 elf_bss = 0;
616 elf_brk = 0;
617
618 start_code = ~0UL;
619 end_code = 0;
620 start_data = 0;
621 end_data = 0;
622
623 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
624 if (elf_ppnt->p_type == PT_INTERP) {
625 /* This is the program interpreter used for
626 * shared libraries - for now assume that this
627 * is an a.out format binary
628 */
629 retval = -ENOEXEC;
630 if (elf_ppnt->p_filesz > PATH_MAX ||
631 elf_ppnt->p_filesz < 2)
632 goto out_free_file;
633
634 retval = -ENOMEM;
635 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
636 GFP_KERNEL);
637 if (!elf_interpreter)
638 goto out_free_file;
639
640 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
641 elf_interpreter,
642 elf_ppnt->p_filesz);
643 if (retval != elf_ppnt->p_filesz) {
644 if (retval >= 0)
645 retval = -EIO;
646 goto out_free_interp;
647 }
648 /* make sure path is NULL terminated */
649 retval = -ENOEXEC;
650 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
651 goto out_free_interp;
652
653 /* If the program interpreter is one of these two,
654 * then assume an iBCS2 image. Otherwise assume
655 * a native linux image.
656 */
657 if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
658 strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0)
659 ibcs2_interpreter = 1;
660
661 /*
662 * The early SET_PERSONALITY here is so that the lookup
663 * for the interpreter happens in the namespace of the
664 * to-be-execed image. SET_PERSONALITY can select an
665 * alternate root.
666 *
667 * However, SET_PERSONALITY is NOT allowed to switch
668 * this task into the new images's memory mapping
669 * policy - that is, TASK_SIZE must still evaluate to
670 * that which is appropriate to the execing application.
671 * This is because exit_mmap() needs to have TASK_SIZE
672 * evaluate to the size of the old image.
673 *
674 * So if (say) a 64-bit application is execing a 32-bit
675 * application it is the architecture's responsibility
676 * to defer changing the value of TASK_SIZE until the
677 * switch really is going to happen - do this in
678 * flush_thread(). - akpm
679 */
680 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
681
682 interpreter = open_exec(elf_interpreter);
683 retval = PTR_ERR(interpreter);
684 if (IS_ERR(interpreter))
685 goto out_free_interp;
686
687 /*
688 * If the binary is not readable then enforce
689 * mm->dumpable = 0 regardless of the interpreter's
690 * permissions.
691 */
692 if (file_permission(interpreter, MAY_READ) < 0)
693 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
694
695 retval = kernel_read(interpreter, 0, bprm->buf,
696 BINPRM_BUF_SIZE);
697 if (retval != BINPRM_BUF_SIZE) {
698 if (retval >= 0)
699 retval = -EIO;
700 goto out_free_dentry;
701 }
702
703 /* Get the exec headers */
704 loc->interp_ex = *((struct exec *)bprm->buf);
705 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
706 break;
707 }
708 elf_ppnt++;
709 }
710
711 elf_ppnt = elf_phdata;
712 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
713 if (elf_ppnt->p_type == PT_GNU_STACK) {
714 if (elf_ppnt->p_flags & PF_X)
715 executable_stack = EXSTACK_ENABLE_X;
716 else
717 executable_stack = EXSTACK_DISABLE_X;
718 break;
719 }
720
721 /* Some simple consistency checks for the interpreter */
722 if (elf_interpreter) {
723 interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
724
725 /* Now figure out which format our binary is */
726 if ((N_MAGIC(loc->interp_ex) != OMAGIC) &&
727 (N_MAGIC(loc->interp_ex) != ZMAGIC) &&
728 (N_MAGIC(loc->interp_ex) != QMAGIC))
729 interpreter_type = INTERPRETER_ELF;
730
731 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
732 interpreter_type &= ~INTERPRETER_ELF;
733
734 retval = -ELIBBAD;
735 if (!interpreter_type)
736 goto out_free_dentry;
737
738 /* Make sure only one type was selected */
739 if ((interpreter_type & INTERPRETER_ELF) &&
740 interpreter_type != INTERPRETER_ELF) {
741 // FIXME - ratelimit this before re-enabling
742 // printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n");
743 interpreter_type = INTERPRETER_ELF;
744 }
745 /* Verify the interpreter has a valid arch */
746 if ((interpreter_type == INTERPRETER_ELF) &&
747 !elf_check_arch(&loc->interp_elf_ex))
748 goto out_free_dentry;
749 } else {
750 /* Executables without an interpreter also need a personality */
751 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
752 }
753
754 /* OK, we are done with that, now set up the arg stuff,
755 and then start this sucker up */
756 if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) {
757 char *passed_p = passed_fileno;
758 sprintf(passed_fileno, "%d", elf_exec_fileno);
759
760 if (elf_interpreter) {
761 retval = copy_strings_kernel(1, &passed_p, bprm);
762 if (retval)
763 goto out_free_dentry;
764 bprm->argc++;
765 }
766 }
767
768 /* Flush all traces of the currently running executable */
769 retval = flush_old_exec(bprm);
770 if (retval)
771 goto out_free_dentry;
772
773 /* Discard our unneeded old files struct */
774 if (files) {
775 put_files_struct(files);
776 files = NULL;
777 }
778
779 /* OK, This is the point of no return */
780 current->mm->start_data = 0;
781 current->mm->end_data = 0;
782 current->mm->end_code = 0;
783 current->mm->mmap = NULL;
784 current->flags &= ~PF_FORKNOEXEC;
785 current->mm->def_flags = def_flags;
786
787 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
788 may depend on the personality. */
789 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
790 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
791 current->personality |= READ_IMPLIES_EXEC;
792
793 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
794 current->flags |= PF_RANDOMIZE;
795 arch_pick_mmap_layout(current->mm);
796
797 /* Do this so that we can load the interpreter, if need be. We will
798 change some of these later */
799 current->mm->free_area_cache = current->mm->mmap_base;
800 current->mm->cached_hole_size = 0;
801 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
802 executable_stack);
803 if (retval < 0) {
804 send_sig(SIGKILL, current, 0);
805 goto out_free_dentry;
806 }
807
808 current->mm->start_stack = bprm->p;
809
810 /* Now we do a little grungy work by mmaping the ELF image into
811 the correct location in memory. At this point, we assume that
812 the image should be loaded at fixed address, not at a variable
813 address. */
814 for(i = 0, elf_ppnt = elf_phdata;
815 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
816 int elf_prot = 0, elf_flags;
817 unsigned long k, vaddr;
818
819 if (elf_ppnt->p_type != PT_LOAD)
820 continue;
821
822 if (unlikely (elf_brk > elf_bss)) {
823 unsigned long nbyte;
824
825 /* There was a PT_LOAD segment with p_memsz > p_filesz
826 before this one. Map anonymous pages, if needed,
827 and clear the area. */
828 retval = set_brk (elf_bss + load_bias,
829 elf_brk + load_bias);
830 if (retval) {
831 send_sig(SIGKILL, current, 0);
832 goto out_free_dentry;
833 }
834 nbyte = ELF_PAGEOFFSET(elf_bss);
835 if (nbyte) {
836 nbyte = ELF_MIN_ALIGN - nbyte;
837 if (nbyte > elf_brk - elf_bss)
838 nbyte = elf_brk - elf_bss;
839 if (clear_user((void __user *)elf_bss +
840 load_bias, nbyte)) {
841 /*
842 * This bss-zeroing can fail if the ELF
843 * file specifies odd protections. So
844 * we don't check the return value
845 */
846 }
847 }
848 }
849
850 if (elf_ppnt->p_flags & PF_R)
851 elf_prot |= PROT_READ;
852 if (elf_ppnt->p_flags & PF_W)
853 elf_prot |= PROT_WRITE;
854 if (elf_ppnt->p_flags & PF_X)
855 elf_prot |= PROT_EXEC;
856
857 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
858
859 vaddr = elf_ppnt->p_vaddr;
860 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
861 elf_flags |= MAP_FIXED;
862 } else if (loc->elf_ex.e_type == ET_DYN) {
863 /* Try and get dynamic programs out of the way of the
864 * default mmap base, as well as whatever program they
865 * might try to exec. This is because the brk will
866 * follow the loader, and is not movable. */
867 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
868 }
869
870 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
871 elf_prot, elf_flags);
872 if (BAD_ADDR(error)) {
873 send_sig(SIGKILL, current, 0);
874 goto out_free_dentry;
875 }
876
877 if (!load_addr_set) {
878 load_addr_set = 1;
879 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
880 if (loc->elf_ex.e_type == ET_DYN) {
881 load_bias += error -
882 ELF_PAGESTART(load_bias + vaddr);
883 load_addr += load_bias;
884 reloc_func_desc = load_bias;
885 }
886 }
887 k = elf_ppnt->p_vaddr;
888 if (k < start_code)
889 start_code = k;
890 if (start_data < k)
891 start_data = k;
892
893 /*
894 * Check to see if the section's size will overflow the
895 * allowed task size. Note that p_filesz must always be
896 * <= p_memsz so it is only necessary to check p_memsz.
897 */
898 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
899 elf_ppnt->p_memsz > TASK_SIZE ||
900 TASK_SIZE - elf_ppnt->p_memsz < k) {
901 /* set_brk can never work. Avoid overflows. */
902 send_sig(SIGKILL, current, 0);
903 goto out_free_dentry;
904 }
905
906 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
907
908 if (k > elf_bss)
909 elf_bss = k;
910 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
911 end_code = k;
912 if (end_data < k)
913 end_data = k;
914 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
915 if (k > elf_brk)
916 elf_brk = k;
917 }
918
919 loc->elf_ex.e_entry += load_bias;
920 elf_bss += load_bias;
921 elf_brk += load_bias;
922 start_code += load_bias;
923 end_code += load_bias;
924 start_data += load_bias;
925 end_data += load_bias;
926
927 /* Calling set_brk effectively mmaps the pages that we need
928 * for the bss and break sections. We must do this before
929 * mapping in the interpreter, to make sure it doesn't wind
930 * up getting placed where the bss needs to go.
931 */
932 retval = set_brk(elf_bss, elf_brk);
933 if (retval) {
934 send_sig(SIGKILL, current, 0);
935 goto out_free_dentry;
936 }
937 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
938 send_sig(SIGSEGV, current, 0);
939 retval = -EFAULT; /* Nobody gets to see this, but.. */
940 goto out_free_dentry;
941 }
942
943 if (elf_interpreter) {
944 if (interpreter_type == INTERPRETER_AOUT)
945 elf_entry = load_aout_interp(&loc->interp_ex,
946 interpreter);
947 else
948 elf_entry = load_elf_interp(&loc->interp_elf_ex,
949 interpreter,
950 &interp_load_addr);
951 if (BAD_ADDR(elf_entry)) {
952 force_sig(SIGSEGV, current);
953 retval = IS_ERR((void *)elf_entry) ?
954 (int)elf_entry : -EINVAL;
955 goto out_free_dentry;
956 }
957 reloc_func_desc = interp_load_addr;
958
959 allow_write_access(interpreter);
960 fput(interpreter);
961 kfree(elf_interpreter);
962 } else {
963 elf_entry = loc->elf_ex.e_entry;
964 if (BAD_ADDR(elf_entry)) {
965 force_sig(SIGSEGV, current);
966 retval = -EINVAL;
967 goto out_free_dentry;
968 }
969 }
970
971 kfree(elf_phdata);
972
973 if (interpreter_type != INTERPRETER_AOUT)
974 sys_close(elf_exec_fileno);
975
976 set_binfmt(&elf_format);
977
978 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
979 retval = arch_setup_additional_pages(bprm, executable_stack);
980 if (retval < 0) {
981 send_sig(SIGKILL, current, 0);
982 goto out;
983 }
984 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
985
986 compute_creds(bprm);
987 current->flags &= ~PF_FORKNOEXEC;
988 create_elf_tables(bprm, &loc->elf_ex,
989 (interpreter_type == INTERPRETER_AOUT),
990 load_addr, interp_load_addr);
991 /* N.B. passed_fileno might not be initialized? */
992 if (interpreter_type == INTERPRETER_AOUT)
993 current->mm->arg_start += strlen(passed_fileno) + 1;
994 current->mm->end_code = end_code;
995 current->mm->start_code = start_code;
996 current->mm->start_data = start_data;
997 current->mm->end_data = end_data;
998 current->mm->start_stack = bprm->p;
999
1000 if (current->personality & MMAP_PAGE_ZERO) {
1001 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
1002 and some applications "depend" upon this behavior.
1003 Since we do not have the power to recompile these, we
1004 emulate the SVr4 behavior. Sigh. */
1005 down_write(&current->mm->mmap_sem);
1006 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1007 MAP_FIXED | MAP_PRIVATE, 0);
1008 up_write(&current->mm->mmap_sem);
1009 }
1010
1011 #ifdef ELF_PLAT_INIT
1012 /*
1013 * The ABI may specify that certain registers be set up in special
1014 * ways (on i386 %edx is the address of a DT_FINI function, for
1015 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1016 * that the e_entry field is the address of the function descriptor
1017 * for the startup routine, rather than the address of the startup
1018 * routine itself. This macro performs whatever initialization to
1019 * the regs structure is required as well as any relocations to the
1020 * function descriptor entries when executing dynamically links apps.
1021 */
1022 ELF_PLAT_INIT(regs, reloc_func_desc);
1023 #endif
1024
1025 start_thread(regs, elf_entry, bprm->p);
1026 if (unlikely(current->ptrace & PT_PTRACED)) {
1027 if (current->ptrace & PT_TRACE_EXEC)
1028 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
1029 else
1030 send_sig(SIGTRAP, current, 0);
1031 }
1032 retval = 0;
1033 out:
1034 kfree(loc);
1035 out_ret:
1036 return retval;
1037
1038 /* error cleanup */
1039 out_free_dentry:
1040 allow_write_access(interpreter);
1041 if (interpreter)
1042 fput(interpreter);
1043 out_free_interp:
1044 kfree(elf_interpreter);
1045 out_free_file:
1046 sys_close(elf_exec_fileno);
1047 out_free_fh:
1048 if (files)
1049 reset_files_struct(current, files);
1050 out_free_ph:
1051 kfree(elf_phdata);
1052 goto out;
1053 }
1054
1055 /* This is really simpleminded and specialized - we are loading an
1056 a.out library that is given an ELF header. */
1057 static int load_elf_library(struct file *file)
1058 {
1059 struct elf_phdr *elf_phdata;
1060 struct elf_phdr *eppnt;
1061 unsigned long elf_bss, bss, len;
1062 int retval, error, i, j;
1063 struct elfhdr elf_ex;
1064
1065 error = -ENOEXEC;
1066 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1067 if (retval != sizeof(elf_ex))
1068 goto out;
1069
1070 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1071 goto out;
1072
1073 /* First of all, some simple consistency checks */
1074 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1075 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1076 goto out;
1077
1078 /* Now read in all of the header information */
1079
1080 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1081 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1082
1083 error = -ENOMEM;
1084 elf_phdata = kmalloc(j, GFP_KERNEL);
1085 if (!elf_phdata)
1086 goto out;
1087
1088 eppnt = elf_phdata;
1089 error = -ENOEXEC;
1090 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1091 if (retval != j)
1092 goto out_free_ph;
1093
1094 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1095 if ((eppnt + i)->p_type == PT_LOAD)
1096 j++;
1097 if (j != 1)
1098 goto out_free_ph;
1099
1100 while (eppnt->p_type != PT_LOAD)
1101 eppnt++;
1102
1103 /* Now use mmap to map the library into memory. */
1104 down_write(&current->mm->mmap_sem);
1105 error = do_mmap(file,
1106 ELF_PAGESTART(eppnt->p_vaddr),
1107 (eppnt->p_filesz +
1108 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1109 PROT_READ | PROT_WRITE | PROT_EXEC,
1110 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1111 (eppnt->p_offset -
1112 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1113 up_write(&current->mm->mmap_sem);
1114 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1115 goto out_free_ph;
1116
1117 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1118 if (padzero(elf_bss)) {
1119 error = -EFAULT;
1120 goto out_free_ph;
1121 }
1122
1123 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1124 ELF_MIN_ALIGN - 1);
1125 bss = eppnt->p_memsz + eppnt->p_vaddr;
1126 if (bss > len) {
1127 down_write(&current->mm->mmap_sem);
1128 do_brk(len, bss - len);
1129 up_write(&current->mm->mmap_sem);
1130 }
1131 error = 0;
1132
1133 out_free_ph:
1134 kfree(elf_phdata);
1135 out:
1136 return error;
1137 }
1138
1139 /*
1140 * Note that some platforms still use traditional core dumps and not
1141 * the ELF core dump. Each platform can select it as appropriate.
1142 */
1143 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1144
1145 /*
1146 * ELF core dumper
1147 *
1148 * Modelled on fs/exec.c:aout_core_dump()
1149 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1150 */
1151 /*
1152 * These are the only things you should do on a core-file: use only these
1153 * functions to write out all the necessary info.
1154 */
1155 static int dump_write(struct file *file, const void *addr, int nr)
1156 {
1157 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1158 }
1159
1160 static int dump_seek(struct file *file, loff_t off)
1161 {
1162 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1163 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1164 return 0;
1165 } else {
1166 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1167 if (!buf)
1168 return 0;
1169 while (off > 0) {
1170 unsigned long n = off;
1171 if (n > PAGE_SIZE)
1172 n = PAGE_SIZE;
1173 if (!dump_write(file, buf, n))
1174 return 0;
1175 off -= n;
1176 }
1177 free_page((unsigned long)buf);
1178 }
1179 return 1;
1180 }
1181
1182 /*
1183 * Decide whether a segment is worth dumping; default is yes to be
1184 * sure (missing info is worse than too much; etc).
1185 * Personally I'd include everything, and use the coredump limit...
1186 *
1187 * I think we should skip something. But I am not sure how. H.J.
1188 */
1189 static int maydump(struct vm_area_struct *vma)
1190 {
1191 /* The vma can be set up to tell us the answer directly. */
1192 if (vma->vm_flags & VM_ALWAYSDUMP)
1193 return 1;
1194
1195 /* Do not dump I/O mapped devices or special mappings */
1196 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1197 return 0;
1198
1199 /* Dump shared memory only if mapped from an anonymous file. */
1200 if (vma->vm_flags & VM_SHARED)
1201 return vma->vm_file->f_path.dentry->d_inode->i_nlink == 0;
1202
1203 /* If it hasn't been written to, don't write it out */
1204 if (!vma->anon_vma)
1205 return 0;
1206
1207 return 1;
1208 }
1209
1210 /* An ELF note in memory */
1211 struct memelfnote
1212 {
1213 const char *name;
1214 int type;
1215 unsigned int datasz;
1216 void *data;
1217 };
1218
1219 static int notesize(struct memelfnote *en)
1220 {
1221 int sz;
1222
1223 sz = sizeof(struct elf_note);
1224 sz += roundup(strlen(en->name) + 1, 4);
1225 sz += roundup(en->datasz, 4);
1226
1227 return sz;
1228 }
1229
1230 #define DUMP_WRITE(addr, nr, foffset) \
1231 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1232
1233 static int alignfile(struct file *file, loff_t *foffset)
1234 {
1235 static const char buf[4] = { 0, };
1236 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1237 return 1;
1238 }
1239
1240 static int writenote(struct memelfnote *men, struct file *file,
1241 loff_t *foffset)
1242 {
1243 struct elf_note en;
1244 en.n_namesz = strlen(men->name) + 1;
1245 en.n_descsz = men->datasz;
1246 en.n_type = men->type;
1247
1248 DUMP_WRITE(&en, sizeof(en), foffset);
1249 DUMP_WRITE(men->name, en.n_namesz, foffset);
1250 if (!alignfile(file, foffset))
1251 return 0;
1252 DUMP_WRITE(men->data, men->datasz, foffset);
1253 if (!alignfile(file, foffset))
1254 return 0;
1255
1256 return 1;
1257 }
1258 #undef DUMP_WRITE
1259
1260 #define DUMP_WRITE(addr, nr) \
1261 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1262 goto end_coredump;
1263 #define DUMP_SEEK(off) \
1264 if (!dump_seek(file, (off))) \
1265 goto end_coredump;
1266
1267 static void fill_elf_header(struct elfhdr *elf, int segs)
1268 {
1269 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1270 elf->e_ident[EI_CLASS] = ELF_CLASS;
1271 elf->e_ident[EI_DATA] = ELF_DATA;
1272 elf->e_ident[EI_VERSION] = EV_CURRENT;
1273 elf->e_ident[EI_OSABI] = ELF_OSABI;
1274 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1275
1276 elf->e_type = ET_CORE;
1277 elf->e_machine = ELF_ARCH;
1278 elf->e_version = EV_CURRENT;
1279 elf->e_entry = 0;
1280 elf->e_phoff = sizeof(struct elfhdr);
1281 elf->e_shoff = 0;
1282 elf->e_flags = ELF_CORE_EFLAGS;
1283 elf->e_ehsize = sizeof(struct elfhdr);
1284 elf->e_phentsize = sizeof(struct elf_phdr);
1285 elf->e_phnum = segs;
1286 elf->e_shentsize = 0;
1287 elf->e_shnum = 0;
1288 elf->e_shstrndx = 0;
1289 return;
1290 }
1291
1292 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1293 {
1294 phdr->p_type = PT_NOTE;
1295 phdr->p_offset = offset;
1296 phdr->p_vaddr = 0;
1297 phdr->p_paddr = 0;
1298 phdr->p_filesz = sz;
1299 phdr->p_memsz = 0;
1300 phdr->p_flags = 0;
1301 phdr->p_align = 0;
1302 return;
1303 }
1304
1305 static void fill_note(struct memelfnote *note, const char *name, int type,
1306 unsigned int sz, void *data)
1307 {
1308 note->name = name;
1309 note->type = type;
1310 note->datasz = sz;
1311 note->data = data;
1312 return;
1313 }
1314
1315 /*
1316 * fill up all the fields in prstatus from the given task struct, except
1317 * registers which need to be filled up separately.
1318 */
1319 static void fill_prstatus(struct elf_prstatus *prstatus,
1320 struct task_struct *p, long signr)
1321 {
1322 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1323 prstatus->pr_sigpend = p->pending.signal.sig[0];
1324 prstatus->pr_sighold = p->blocked.sig[0];
1325 prstatus->pr_pid = p->pid;
1326 prstatus->pr_ppid = p->parent->pid;
1327 prstatus->pr_pgrp = process_group(p);
1328 prstatus->pr_sid = process_session(p);
1329 if (thread_group_leader(p)) {
1330 /*
1331 * This is the record for the group leader. Add in the
1332 * cumulative times of previous dead threads. This total
1333 * won't include the time of each live thread whose state
1334 * is included in the core dump. The final total reported
1335 * to our parent process when it calls wait4 will include
1336 * those sums as well as the little bit more time it takes
1337 * this and each other thread to finish dying after the
1338 * core dump synchronization phase.
1339 */
1340 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1341 &prstatus->pr_utime);
1342 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1343 &prstatus->pr_stime);
1344 } else {
1345 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1346 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1347 }
1348 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1349 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1350 }
1351
1352 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1353 struct mm_struct *mm)
1354 {
1355 unsigned int i, len;
1356
1357 /* first copy the parameters from user space */
1358 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1359
1360 len = mm->arg_end - mm->arg_start;
1361 if (len >= ELF_PRARGSZ)
1362 len = ELF_PRARGSZ-1;
1363 if (copy_from_user(&psinfo->pr_psargs,
1364 (const char __user *)mm->arg_start, len))
1365 return -EFAULT;
1366 for(i = 0; i < len; i++)
1367 if (psinfo->pr_psargs[i] == 0)
1368 psinfo->pr_psargs[i] = ' ';
1369 psinfo->pr_psargs[len] = 0;
1370
1371 psinfo->pr_pid = p->pid;
1372 psinfo->pr_ppid = p->parent->pid;
1373 psinfo->pr_pgrp = process_group(p);
1374 psinfo->pr_sid = process_session(p);
1375
1376 i = p->state ? ffz(~p->state) + 1 : 0;
1377 psinfo->pr_state = i;
1378 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1379 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1380 psinfo->pr_nice = task_nice(p);
1381 psinfo->pr_flag = p->flags;
1382 SET_UID(psinfo->pr_uid, p->uid);
1383 SET_GID(psinfo->pr_gid, p->gid);
1384 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1385
1386 return 0;
1387 }
1388
1389 /* Here is the structure in which status of each thread is captured. */
1390 struct elf_thread_status
1391 {
1392 struct list_head list;
1393 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1394 elf_fpregset_t fpu; /* NT_PRFPREG */
1395 struct task_struct *thread;
1396 #ifdef ELF_CORE_COPY_XFPREGS
1397 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1398 #endif
1399 struct memelfnote notes[3];
1400 int num_notes;
1401 };
1402
1403 /*
1404 * In order to add the specific thread information for the elf file format,
1405 * we need to keep a linked list of every threads pr_status and then create
1406 * a single section for them in the final core file.
1407 */
1408 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1409 {
1410 int sz = 0;
1411 struct task_struct *p = t->thread;
1412 t->num_notes = 0;
1413
1414 fill_prstatus(&t->prstatus, p, signr);
1415 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1416
1417 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1418 &(t->prstatus));
1419 t->num_notes++;
1420 sz += notesize(&t->notes[0]);
1421
1422 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1423 &t->fpu))) {
1424 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1425 &(t->fpu));
1426 t->num_notes++;
1427 sz += notesize(&t->notes[1]);
1428 }
1429
1430 #ifdef ELF_CORE_COPY_XFPREGS
1431 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1432 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1433 &t->xfpu);
1434 t->num_notes++;
1435 sz += notesize(&t->notes[2]);
1436 }
1437 #endif
1438 return sz;
1439 }
1440
1441 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1442 struct vm_area_struct *gate_vma)
1443 {
1444 struct vm_area_struct *ret = tsk->mm->mmap;
1445
1446 if (ret)
1447 return ret;
1448 return gate_vma;
1449 }
1450 /*
1451 * Helper function for iterating across a vma list. It ensures that the caller
1452 * will visit `gate_vma' prior to terminating the search.
1453 */
1454 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1455 struct vm_area_struct *gate_vma)
1456 {
1457 struct vm_area_struct *ret;
1458
1459 ret = this_vma->vm_next;
1460 if (ret)
1461 return ret;
1462 if (this_vma == gate_vma)
1463 return NULL;
1464 return gate_vma;
1465 }
1466
1467 /*
1468 * Actual dumper
1469 *
1470 * This is a two-pass process; first we find the offsets of the bits,
1471 * and then they are actually written out. If we run out of core limit
1472 * we just truncate.
1473 */
1474 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
1475 {
1476 #define NUM_NOTES 6
1477 int has_dumped = 0;
1478 mm_segment_t fs;
1479 int segs;
1480 size_t size = 0;
1481 int i;
1482 struct vm_area_struct *vma, *gate_vma;
1483 struct elfhdr *elf = NULL;
1484 loff_t offset = 0, dataoff, foffset;
1485 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1486 int numnote;
1487 struct memelfnote *notes = NULL;
1488 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1489 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1490 struct task_struct *g, *p;
1491 LIST_HEAD(thread_list);
1492 struct list_head *t;
1493 elf_fpregset_t *fpu = NULL;
1494 #ifdef ELF_CORE_COPY_XFPREGS
1495 elf_fpxregset_t *xfpu = NULL;
1496 #endif
1497 int thread_status_size = 0;
1498 elf_addr_t *auxv;
1499
1500 /*
1501 * We no longer stop all VM operations.
1502 *
1503 * This is because those proceses that could possibly change map_count
1504 * or the mmap / vma pages are now blocked in do_exit on current
1505 * finishing this core dump.
1506 *
1507 * Only ptrace can touch these memory addresses, but it doesn't change
1508 * the map_count or the pages allocated. So no possibility of crashing
1509 * exists while dumping the mm->vm_next areas to the core file.
1510 */
1511
1512 /* alloc memory for large data structures: too large to be on stack */
1513 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1514 if (!elf)
1515 goto cleanup;
1516 prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
1517 if (!prstatus)
1518 goto cleanup;
1519 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1520 if (!psinfo)
1521 goto cleanup;
1522 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1523 if (!notes)
1524 goto cleanup;
1525 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1526 if (!fpu)
1527 goto cleanup;
1528 #ifdef ELF_CORE_COPY_XFPREGS
1529 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1530 if (!xfpu)
1531 goto cleanup;
1532 #endif
1533
1534 if (signr) {
1535 struct elf_thread_status *tmp;
1536 rcu_read_lock();
1537 do_each_thread(g,p)
1538 if (current->mm == p->mm && current != p) {
1539 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1540 if (!tmp) {
1541 rcu_read_unlock();
1542 goto cleanup;
1543 }
1544 tmp->thread = p;
1545 list_add(&tmp->list, &thread_list);
1546 }
1547 while_each_thread(g,p);
1548 rcu_read_unlock();
1549 list_for_each(t, &thread_list) {
1550 struct elf_thread_status *tmp;
1551 int sz;
1552
1553 tmp = list_entry(t, struct elf_thread_status, list);
1554 sz = elf_dump_thread_status(signr, tmp);
1555 thread_status_size += sz;
1556 }
1557 }
1558 /* now collect the dump for the current */
1559 memset(prstatus, 0, sizeof(*prstatus));
1560 fill_prstatus(prstatus, current, signr);
1561 elf_core_copy_regs(&prstatus->pr_reg, regs);
1562
1563 segs = current->mm->map_count;
1564 #ifdef ELF_CORE_EXTRA_PHDRS
1565 segs += ELF_CORE_EXTRA_PHDRS;
1566 #endif
1567
1568 gate_vma = get_gate_vma(current);
1569 if (gate_vma != NULL)
1570 segs++;
1571
1572 /* Set up header */
1573 fill_elf_header(elf, segs + 1); /* including notes section */
1574
1575 has_dumped = 1;
1576 current->flags |= PF_DUMPCORE;
1577
1578 /*
1579 * Set up the notes in similar form to SVR4 core dumps made
1580 * with info from their /proc.
1581 */
1582
1583 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1584 fill_psinfo(psinfo, current->group_leader, current->mm);
1585 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1586
1587 numnote = 2;
1588
1589 auxv = (elf_addr_t *)current->mm->saved_auxv;
1590
1591 i = 0;
1592 do
1593 i += 2;
1594 while (auxv[i - 2] != AT_NULL);
1595 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1596 i * sizeof(elf_addr_t), auxv);
1597
1598 /* Try to dump the FPU. */
1599 if ((prstatus->pr_fpvalid =
1600 elf_core_copy_task_fpregs(current, regs, fpu)))
1601 fill_note(notes + numnote++,
1602 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1603 #ifdef ELF_CORE_COPY_XFPREGS
1604 if (elf_core_copy_task_xfpregs(current, xfpu))
1605 fill_note(notes + numnote++,
1606 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1607 #endif
1608
1609 fs = get_fs();
1610 set_fs(KERNEL_DS);
1611
1612 DUMP_WRITE(elf, sizeof(*elf));
1613 offset += sizeof(*elf); /* Elf header */
1614 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1615 foffset = offset;
1616
1617 /* Write notes phdr entry */
1618 {
1619 struct elf_phdr phdr;
1620 int sz = 0;
1621
1622 for (i = 0; i < numnote; i++)
1623 sz += notesize(notes + i);
1624
1625 sz += thread_status_size;
1626
1627 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1628 sz += ELF_CORE_EXTRA_NOTES_SIZE;
1629 #endif
1630
1631 fill_elf_note_phdr(&phdr, sz, offset);
1632 offset += sz;
1633 DUMP_WRITE(&phdr, sizeof(phdr));
1634 }
1635
1636 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1637
1638 /* Write program headers for segments dump */
1639 for (vma = first_vma(current, gate_vma); vma != NULL;
1640 vma = next_vma(vma, gate_vma)) {
1641 struct elf_phdr phdr;
1642 size_t sz;
1643
1644 sz = vma->vm_end - vma->vm_start;
1645
1646 phdr.p_type = PT_LOAD;
1647 phdr.p_offset = offset;
1648 phdr.p_vaddr = vma->vm_start;
1649 phdr.p_paddr = 0;
1650 phdr.p_filesz = maydump(vma) ? sz : 0;
1651 phdr.p_memsz = sz;
1652 offset += phdr.p_filesz;
1653 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1654 if (vma->vm_flags & VM_WRITE)
1655 phdr.p_flags |= PF_W;
1656 if (vma->vm_flags & VM_EXEC)
1657 phdr.p_flags |= PF_X;
1658 phdr.p_align = ELF_EXEC_PAGESIZE;
1659
1660 DUMP_WRITE(&phdr, sizeof(phdr));
1661 }
1662
1663 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1664 ELF_CORE_WRITE_EXTRA_PHDRS;
1665 #endif
1666
1667 /* write out the notes section */
1668 for (i = 0; i < numnote; i++)
1669 if (!writenote(notes + i, file, &foffset))
1670 goto end_coredump;
1671
1672 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1673 ELF_CORE_WRITE_EXTRA_NOTES;
1674 #endif
1675
1676 /* write out the thread status notes section */
1677 list_for_each(t, &thread_list) {
1678 struct elf_thread_status *tmp =
1679 list_entry(t, struct elf_thread_status, list);
1680
1681 for (i = 0; i < tmp->num_notes; i++)
1682 if (!writenote(&tmp->notes[i], file, &foffset))
1683 goto end_coredump;
1684 }
1685
1686 /* Align to page */
1687 DUMP_SEEK(dataoff - foffset);
1688
1689 for (vma = first_vma(current, gate_vma); vma != NULL;
1690 vma = next_vma(vma, gate_vma)) {
1691 unsigned long addr;
1692
1693 if (!maydump(vma))
1694 continue;
1695
1696 for (addr = vma->vm_start;
1697 addr < vma->vm_end;
1698 addr += PAGE_SIZE) {
1699 struct page *page;
1700 struct vm_area_struct *vma;
1701
1702 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1703 &page, &vma) <= 0) {
1704 DUMP_SEEK(PAGE_SIZE);
1705 } else {
1706 if (page == ZERO_PAGE(addr)) {
1707 if (!dump_seek(file, PAGE_SIZE)) {
1708 page_cache_release(page);
1709 goto end_coredump;
1710 }
1711 } else {
1712 void *kaddr;
1713 flush_cache_page(vma, addr,
1714 page_to_pfn(page));
1715 kaddr = kmap(page);
1716 if ((size += PAGE_SIZE) > limit ||
1717 !dump_write(file, kaddr,
1718 PAGE_SIZE)) {
1719 kunmap(page);
1720 page_cache_release(page);
1721 goto end_coredump;
1722 }
1723 kunmap(page);
1724 }
1725 page_cache_release(page);
1726 }
1727 }
1728 }
1729
1730 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1731 ELF_CORE_WRITE_EXTRA_DATA;
1732 #endif
1733
1734 end_coredump:
1735 set_fs(fs);
1736
1737 cleanup:
1738 while (!list_empty(&thread_list)) {
1739 struct list_head *tmp = thread_list.next;
1740 list_del(tmp);
1741 kfree(list_entry(tmp, struct elf_thread_status, list));
1742 }
1743
1744 kfree(elf);
1745 kfree(prstatus);
1746 kfree(psinfo);
1747 kfree(notes);
1748 kfree(fpu);
1749 #ifdef ELF_CORE_COPY_XFPREGS
1750 kfree(xfpu);
1751 #endif
1752 return has_dumped;
1753 #undef NUM_NOTES
1754 }
1755
1756 #endif /* USE_ELF_CORE_DUMP */
1757
1758 static int __init init_elf_binfmt(void)
1759 {
1760 return register_binfmt(&elf_format);
1761 }
1762
1763 static void __exit exit_elf_binfmt(void)
1764 {
1765 /* Remove the COFF and ELF loaders. */
1766 unregister_binfmt(&elf_format);
1767 }
1768
1769 core_initcall(init_elf_binfmt);
1770 module_exit(exit_elf_binfmt);
1771 MODULE_LICENSE("GPL");
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