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[XFS] Get rid of old 5.3/6.1 v1 log items. Cleanup patch sent in by Eric
[wrt350n-kernel.git] / fs / binfmt_elf.c
blob669dbe5b0317707f65e9ce374864cf789b9276f9
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 };
81
82 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
83
84 static int set_brk(unsigned long start, unsigned long end)
85 {
86 start = ELF_PAGEALIGN(start);
87 end = ELF_PAGEALIGN(end);
88 if (end > start) {
89 unsigned long addr;
90 down_write(&current->mm->mmap_sem);
91 addr = do_brk(start, end - start);
92 up_write(&current->mm->mmap_sem);
93 if (BAD_ADDR(addr))
94 return addr;
95 }
96 current->mm->start_brk = current->mm->brk = end;
97 return 0;
98 }
99
100 /* We need to explicitly zero any fractional pages
101 after the data section (i.e. bss). This would
102 contain the junk from the file that should not
103 be in memory
104 */
105 static int padzero(unsigned long elf_bss)
106 {
107 unsigned long nbyte;
108
109 nbyte = ELF_PAGEOFFSET(elf_bss);
110 if (nbyte) {
111 nbyte = ELF_MIN_ALIGN - nbyte;
112 if (clear_user((void __user *) elf_bss, nbyte))
113 return -EFAULT;
114 }
115 return 0;
116 }
117
118 /* Let's use some macros to make this stack manipulation a litle clearer */
119 #ifdef CONFIG_STACK_GROWSUP
120 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
121 #define STACK_ROUND(sp, items) \
122 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
123 #define STACK_ALLOC(sp, len) ({ \
124 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
125 old_sp; })
126 #else
127 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
128 #define STACK_ROUND(sp, items) \
129 (((unsigned long) (sp - items)) &~ 15UL)
130 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
131 #endif
132
133 static int
134 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
135 int interp_aout, unsigned long load_addr,
136 unsigned long interp_load_addr)
137 {
138 unsigned long p = bprm->p;
139 int argc = bprm->argc;
140 int envc = bprm->envc;
141 elf_addr_t __user *argv;
142 elf_addr_t __user *envp;
143 elf_addr_t __user *sp;
144 elf_addr_t __user *u_platform;
145 const char *k_platform = ELF_PLATFORM;
146 int items;
147 elf_addr_t *elf_info;
148 int ei_index = 0;
149 struct task_struct *tsk = current;
150
151 /*
152 * If this architecture has a platform capability string, copy it
153 * to userspace. In some cases (Sparc), this info is impossible
154 * for userspace to get any other way, in others (i386) it is
155 * merely difficult.
156 */
157 u_platform = NULL;
158 if (k_platform) {
159 size_t len = strlen(k_platform) + 1;
160
161 /*
162 * In some cases (e.g. Hyper-Threading), we want to avoid L1
163 * evictions by the processes running on the same package. One
164 * thing we can do is to shuffle the initial stack for them.
165 */
166
167 p = arch_align_stack(p);
168
169 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
170 if (__copy_to_user(u_platform, k_platform, len))
171 return -EFAULT;
172 }
173
174 /* Create the ELF interpreter info */
175 elf_info = (elf_addr_t *)current->mm->saved_auxv;
176 #define NEW_AUX_ENT(id, val) \
177 do { \
178 elf_info[ei_index++] = id; \
179 elf_info[ei_index++] = val; \
180 } while (0)
181
182 #ifdef ARCH_DLINFO
183 /*
184 * ARCH_DLINFO must come first so PPC can do its special alignment of
185 * AUXV.
186 */
187 ARCH_DLINFO;
188 #endif
189 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
190 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
191 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
192 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
193 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
194 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
195 NEW_AUX_ENT(AT_BASE, interp_load_addr);
196 NEW_AUX_ENT(AT_FLAGS, 0);
197 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
198 NEW_AUX_ENT(AT_UID, tsk->uid);
199 NEW_AUX_ENT(AT_EUID, tsk->euid);
200 NEW_AUX_ENT(AT_GID, tsk->gid);
201 NEW_AUX_ENT(AT_EGID, tsk->egid);
202 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
203 if (k_platform) {
204 NEW_AUX_ENT(AT_PLATFORM,
205 (elf_addr_t)(unsigned long)u_platform);
206 }
207 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
208 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
209 }
210 #undef NEW_AUX_ENT
211 /* AT_NULL is zero; clear the rest too */
212 memset(&elf_info[ei_index], 0,
213 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
214
215 /* And advance past the AT_NULL entry. */
216 ei_index += 2;
217
218 sp = STACK_ADD(p, ei_index);
219
220 items = (argc + 1) + (envc + 1);
221 if (interp_aout) {
222 items += 3; /* a.out interpreters require argv & envp too */
223 } else {
224 items += 1; /* ELF interpreters only put argc on the stack */
225 }
226 bprm->p = STACK_ROUND(sp, items);
227
228 /* Point sp at the lowest address on the stack */
229 #ifdef CONFIG_STACK_GROWSUP
230 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
231 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
232 #else
233 sp = (elf_addr_t __user *)bprm->p;
234 #endif
235
236 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
237 if (__put_user(argc, sp++))
238 return -EFAULT;
239 if (interp_aout) {
240 argv = sp + 2;
241 envp = argv + argc + 1;
242 if (__put_user((elf_addr_t)(unsigned long)argv, sp++) ||
243 __put_user((elf_addr_t)(unsigned long)envp, sp++))
244 return -EFAULT;
245 } else {
246 argv = sp;
247 envp = argv + argc + 1;
248 }
249
250 /* Populate argv and envp */
251 p = current->mm->arg_end = current->mm->arg_start;
252 while (argc-- > 0) {
253 size_t len;
254 if (__put_user((elf_addr_t)p, argv++))
255 return -EFAULT;
256 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
257 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
258 return 0;
259 p += len;
260 }
261 if (__put_user(0, argv))
262 return -EFAULT;
263 current->mm->arg_end = current->mm->env_start = p;
264 while (envc-- > 0) {
265 size_t len;
266 if (__put_user((elf_addr_t)p, envp++))
267 return -EFAULT;
268 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
269 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
270 return 0;
271 p += len;
272 }
273 if (__put_user(0, envp))
274 return -EFAULT;
275 current->mm->env_end = p;
276
277 /* Put the elf_info on the stack in the right place. */
278 sp = (elf_addr_t __user *)envp + 1;
279 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
280 return -EFAULT;
281 return 0;
282 }
283
284 #ifndef elf_map
285
286 static unsigned long elf_map(struct file *filep, unsigned long addr,
287 struct elf_phdr *eppnt, int prot, int type)
288 {
289 unsigned long map_addr;
290 unsigned long pageoffset = ELF_PAGEOFFSET(eppnt->p_vaddr);
291
292 down_write(&current->mm->mmap_sem);
293 /* mmap() will return -EINVAL if given a zero size, but a
294 * segment with zero filesize is perfectly valid */
295 if (eppnt->p_filesz + pageoffset)
296 map_addr = do_mmap(filep, ELF_PAGESTART(addr),
297 eppnt->p_filesz + pageoffset, prot, type,
298 eppnt->p_offset - pageoffset);
299 else
300 map_addr = ELF_PAGESTART(addr);
301 up_write(&current->mm->mmap_sem);
302 return(map_addr);
303 }
304
305 #endif /* !elf_map */
306
307 /* This is much more generalized than the library routine read function,
308 so we keep this separate. Technically the library read function
309 is only provided so that we can read a.out libraries that have
310 an ELF header */
311
312 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
313 struct file *interpreter, unsigned long *interp_load_addr)
314 {
315 struct elf_phdr *elf_phdata;
316 struct elf_phdr *eppnt;
317 unsigned long load_addr = 0;
318 int load_addr_set = 0;
319 unsigned long last_bss = 0, elf_bss = 0;
320 unsigned long error = ~0UL;
321 int retval, i, size;
322
323 /* First of all, some simple consistency checks */
324 if (interp_elf_ex->e_type != ET_EXEC &&
325 interp_elf_ex->e_type != ET_DYN)
326 goto out;
327 if (!elf_check_arch(interp_elf_ex))
328 goto out;
329 if (!interpreter->f_op || !interpreter->f_op->mmap)
330 goto out;
331
332 /*
333 * If the size of this structure has changed, then punt, since
334 * we will be doing the wrong thing.
335 */
336 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
337 goto out;
338 if (interp_elf_ex->e_phnum < 1 ||
339 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
340 goto out;
341
342 /* Now read in all of the header information */
343 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
344 if (size > ELF_MIN_ALIGN)
345 goto out;
346 elf_phdata = kmalloc(size, GFP_KERNEL);
347 if (!elf_phdata)
348 goto out;
349
350 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
351 (char *)elf_phdata,size);
352 error = -EIO;
353 if (retval != size) {
354 if (retval < 0)
355 error = retval;
356 goto out_close;
357 }
358
359 eppnt = elf_phdata;
360 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
361 if (eppnt->p_type == PT_LOAD) {
362 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
363 int elf_prot = 0;
364 unsigned long vaddr = 0;
365 unsigned long k, map_addr;
366
367 if (eppnt->p_flags & PF_R)
368 elf_prot = PROT_READ;
369 if (eppnt->p_flags & PF_W)
370 elf_prot |= PROT_WRITE;
371 if (eppnt->p_flags & PF_X)
372 elf_prot |= PROT_EXEC;
373 vaddr = eppnt->p_vaddr;
374 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
375 elf_type |= MAP_FIXED;
376
377 map_addr = elf_map(interpreter, load_addr + vaddr,
378 eppnt, elf_prot, elf_type);
379 error = map_addr;
380 if (BAD_ADDR(map_addr))
381 goto out_close;
382
383 if (!load_addr_set &&
384 interp_elf_ex->e_type == ET_DYN) {
385 load_addr = map_addr - ELF_PAGESTART(vaddr);
386 load_addr_set = 1;
387 }
388
389 /*
390 * Check to see if the section's size will overflow the
391 * allowed task size. Note that p_filesz must always be
392 * <= p_memsize so it's only necessary to check p_memsz.
393 */
394 k = load_addr + eppnt->p_vaddr;
395 if (BAD_ADDR(k) ||
396 eppnt->p_filesz > eppnt->p_memsz ||
397 eppnt->p_memsz > TASK_SIZE ||
398 TASK_SIZE - eppnt->p_memsz < k) {
399 error = -ENOMEM;
400 goto out_close;
401 }
402
403 /*
404 * Find the end of the file mapping for this phdr, and
405 * keep track of the largest address we see for this.
406 */
407 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
408 if (k > elf_bss)
409 elf_bss = k;
410
411 /*
412 * Do the same thing for the memory mapping - between
413 * elf_bss and last_bss is the bss section.
414 */
415 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
416 if (k > last_bss)
417 last_bss = k;
418 }
419 }
420
421 /*
422 * Now fill out the bss section. First pad the last page up
423 * to the page boundary, and then perform a mmap to make sure
424 * that there are zero-mapped pages up to and including the
425 * last bss page.
426 */
427 if (padzero(elf_bss)) {
428 error = -EFAULT;
429 goto out_close;
430 }
431
432 /* What we have mapped so far */
433 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
434
435 /* Map the last of the bss segment */
436 if (last_bss > elf_bss) {
437 down_write(&current->mm->mmap_sem);
438 error = do_brk(elf_bss, last_bss - elf_bss);
439 up_write(&current->mm->mmap_sem);
440 if (BAD_ADDR(error))
441 goto out_close;
442 }
443
444 *interp_load_addr = load_addr;
445 error = ((unsigned long)interp_elf_ex->e_entry) + load_addr;
446
447 out_close:
448 kfree(elf_phdata);
449 out:
450 return error;
451 }
452
453 static unsigned long load_aout_interp(struct exec *interp_ex,
454 struct file *interpreter)
455 {
456 unsigned long text_data, elf_entry = ~0UL;
457 char __user * addr;
458 loff_t offset;
459
460 current->mm->end_code = interp_ex->a_text;
461 text_data = interp_ex->a_text + interp_ex->a_data;
462 current->mm->end_data = text_data;
463 current->mm->brk = interp_ex->a_bss + text_data;
464
465 switch (N_MAGIC(*interp_ex)) {
466 case OMAGIC:
467 offset = 32;
468 addr = (char __user *)0;
469 break;
470 case ZMAGIC:
471 case QMAGIC:
472 offset = N_TXTOFF(*interp_ex);
473 addr = (char __user *)N_TXTADDR(*interp_ex);
474 break;
475 default:
476 goto out;
477 }
478
479 down_write(&current->mm->mmap_sem);
480 do_brk(0, text_data);
481 up_write(&current->mm->mmap_sem);
482 if (!interpreter->f_op || !interpreter->f_op->read)
483 goto out;
484 if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0)
485 goto out;
486 flush_icache_range((unsigned long)addr,
487 (unsigned long)addr + text_data);
488
489 down_write(&current->mm->mmap_sem);
490 do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
491 interp_ex->a_bss);
492 up_write(&current->mm->mmap_sem);
493 elf_entry = interp_ex->a_entry;
494
495 out:
496 return elf_entry;
497 }
498
499 /*
500 * These are the functions used to load ELF style executables and shared
501 * libraries. There is no binary dependent code anywhere else.
502 */
503
504 #define INTERPRETER_NONE 0
505 #define INTERPRETER_AOUT 1
506 #define INTERPRETER_ELF 2
507
508 #ifndef STACK_RND_MASK
509 #define STACK_RND_MASK 0x7ff /* with 4K pages 8MB of VA */
510 #endif
511
512 static unsigned long randomize_stack_top(unsigned long stack_top)
513 {
514 unsigned int random_variable = 0;
515
516 if ((current->flags & PF_RANDOMIZE) &&
517 !(current->personality & ADDR_NO_RANDOMIZE)) {
518 random_variable = get_random_int() & STACK_RND_MASK;
519 random_variable <<= PAGE_SHIFT;
520 }
521 #ifdef CONFIG_STACK_GROWSUP
522 return PAGE_ALIGN(stack_top) + random_variable;
523 #else
524 return PAGE_ALIGN(stack_top) - random_variable;
525 #endif
526 }
527
528 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
529 {
530 struct file *interpreter = NULL; /* to shut gcc up */
531 unsigned long load_addr = 0, load_bias = 0;
532 int load_addr_set = 0;
533 char * elf_interpreter = NULL;
534 unsigned int interpreter_type = INTERPRETER_NONE;
535 unsigned char ibcs2_interpreter = 0;
536 unsigned long error;
537 struct elf_phdr *elf_ppnt, *elf_phdata;
538 unsigned long elf_bss, elf_brk;
539 int elf_exec_fileno;
540 int retval, i;
541 unsigned int size;
542 unsigned long elf_entry, interp_load_addr = 0;
543 unsigned long start_code, end_code, start_data, end_data;
544 unsigned long reloc_func_desc = 0;
545 char passed_fileno[6];
546 struct files_struct *files;
547 int executable_stack = EXSTACK_DEFAULT;
548 unsigned long def_flags = 0;
549 struct {
550 struct elfhdr elf_ex;
551 struct elfhdr interp_elf_ex;
552 struct exec interp_ex;
553 } *loc;
554
555 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
556 if (!loc) {
557 retval = -ENOMEM;
558 goto out_ret;
559 }
560
561 /* Get the exec-header */
562 loc->elf_ex = *((struct elfhdr *)bprm->buf);
563
564 retval = -ENOEXEC;
565 /* First of all, some simple consistency checks */
566 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
567 goto out;
568
569 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
570 goto out;
571 if (!elf_check_arch(&loc->elf_ex))
572 goto out;
573 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
574 goto out;
575
576 /* Now read in all of the header information */
577 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
578 goto out;
579 if (loc->elf_ex.e_phnum < 1 ||
580 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
581 goto out;
582 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
583 retval = -ENOMEM;
584 elf_phdata = kmalloc(size, GFP_KERNEL);
585 if (!elf_phdata)
586 goto out;
587
588 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
589 (char *)elf_phdata, size);
590 if (retval != size) {
591 if (retval >= 0)
592 retval = -EIO;
593 goto out_free_ph;
594 }
595
596 files = current->files; /* Refcounted so ok */
597 retval = unshare_files();
598 if (retval < 0)
599 goto out_free_ph;
600 if (files == current->files) {
601 put_files_struct(files);
602 files = NULL;
603 }
604
605 /* exec will make our files private anyway, but for the a.out
606 loader stuff we need to do it earlier */
607 retval = get_unused_fd();
608 if (retval < 0)
609 goto out_free_fh;
610 get_file(bprm->file);
611 fd_install(elf_exec_fileno = retval, bprm->file);
612
613 elf_ppnt = elf_phdata;
614 elf_bss = 0;
615 elf_brk = 0;
616
617 start_code = ~0UL;
618 end_code = 0;
619 start_data = 0;
620 end_data = 0;
621
622 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
623 if (elf_ppnt->p_type == PT_INTERP) {
624 /* This is the program interpreter used for
625 * shared libraries - for now assume that this
626 * is an a.out format binary
627 */
628 retval = -ENOEXEC;
629 if (elf_ppnt->p_filesz > PATH_MAX ||
630 elf_ppnt->p_filesz < 2)
631 goto out_free_file;
632
633 retval = -ENOMEM;
634 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
635 GFP_KERNEL);
636 if (!elf_interpreter)
637 goto out_free_file;
638
639 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
640 elf_interpreter,
641 elf_ppnt->p_filesz);
642 if (retval != elf_ppnt->p_filesz) {
643 if (retval >= 0)
644 retval = -EIO;
645 goto out_free_interp;
646 }
647 /* make sure path is NULL terminated */
648 retval = -ENOEXEC;
649 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
650 goto out_free_interp;
651
652 /* If the program interpreter is one of these two,
653 * then assume an iBCS2 image. Otherwise assume
654 * a native linux image.
655 */
656 if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
657 strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0)
658 ibcs2_interpreter = 1;
659
660 /*
661 * The early SET_PERSONALITY here is so that the lookup
662 * for the interpreter happens in the namespace of the
663 * to-be-execed image. SET_PERSONALITY can select an
664 * alternate root.
665 *
666 * However, SET_PERSONALITY is NOT allowed to switch
667 * this task into the new images's memory mapping
668 * policy - that is, TASK_SIZE must still evaluate to
669 * that which is appropriate to the execing application.
670 * This is because exit_mmap() needs to have TASK_SIZE
671 * evaluate to the size of the old image.
672 *
673 * So if (say) a 64-bit application is execing a 32-bit
674 * application it is the architecture's responsibility
675 * to defer changing the value of TASK_SIZE until the
676 * switch really is going to happen - do this in
677 * flush_thread(). - akpm
678 */
679 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
680
681 interpreter = open_exec(elf_interpreter);
682 retval = PTR_ERR(interpreter);
683 if (IS_ERR(interpreter))
684 goto out_free_interp;
685
686 /*
687 * If the binary is not readable then enforce
688 * mm->dumpable = 0 regardless of the interpreter's
689 * permissions.
690 */
691 if (file_permission(interpreter, MAY_READ) < 0)
692 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
693
694 retval = kernel_read(interpreter, 0, bprm->buf,
695 BINPRM_BUF_SIZE);
696 if (retval != BINPRM_BUF_SIZE) {
697 if (retval >= 0)
698 retval = -EIO;
699 goto out_free_dentry;
700 }
701
702 /* Get the exec headers */
703 loc->interp_ex = *((struct exec *)bprm->buf);
704 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
705 break;
706 }
707 elf_ppnt++;
708 }
709
710 elf_ppnt = elf_phdata;
711 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
712 if (elf_ppnt->p_type == PT_GNU_STACK) {
713 if (elf_ppnt->p_flags & PF_X)
714 executable_stack = EXSTACK_ENABLE_X;
715 else
716 executable_stack = EXSTACK_DISABLE_X;
717 break;
718 }
719
720 /* Some simple consistency checks for the interpreter */
721 if (elf_interpreter) {
722 interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
723
724 /* Now figure out which format our binary is */
725 if ((N_MAGIC(loc->interp_ex) != OMAGIC) &&
726 (N_MAGIC(loc->interp_ex) != ZMAGIC) &&
727 (N_MAGIC(loc->interp_ex) != QMAGIC))
728 interpreter_type = INTERPRETER_ELF;
729
730 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
731 interpreter_type &= ~INTERPRETER_ELF;
732
733 retval = -ELIBBAD;
734 if (!interpreter_type)
735 goto out_free_dentry;
736
737 /* Make sure only one type was selected */
738 if ((interpreter_type & INTERPRETER_ELF) &&
739 interpreter_type != INTERPRETER_ELF) {
740 // FIXME - ratelimit this before re-enabling
741 // printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n");
742 interpreter_type = INTERPRETER_ELF;
743 }
744 /* Verify the interpreter has a valid arch */
745 if ((interpreter_type == INTERPRETER_ELF) &&
746 !elf_check_arch(&loc->interp_elf_ex))
747 goto out_free_dentry;
748 } else {
749 /* Executables without an interpreter also need a personality */
750 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
751 }
752
753 /* OK, we are done with that, now set up the arg stuff,
754 and then start this sucker up */
755 if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) {
756 char *passed_p = passed_fileno;
757 sprintf(passed_fileno, "%d", elf_exec_fileno);
758
759 if (elf_interpreter) {
760 retval = copy_strings_kernel(1, &passed_p, bprm);
761 if (retval)
762 goto out_free_dentry;
763 bprm->argc++;
764 }
765 }
766
767 /* Flush all traces of the currently running executable */
768 retval = flush_old_exec(bprm);
769 if (retval)
770 goto out_free_dentry;
771
772 /* Discard our unneeded old files struct */
773 if (files) {
774 put_files_struct(files);
775 files = NULL;
776 }
777
778 /* OK, This is the point of no return */
779 current->mm->start_data = 0;
780 current->mm->end_data = 0;
781 current->mm->end_code = 0;
782 current->mm->mmap = NULL;
783 current->flags &= ~PF_FORKNOEXEC;
784 current->mm->def_flags = def_flags;
785
786 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
787 may depend on the personality. */
788 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
789 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
790 current->personality |= READ_IMPLIES_EXEC;
791
792 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
793 current->flags |= PF_RANDOMIZE;
794 arch_pick_mmap_layout(current->mm);
795
796 /* Do this so that we can load the interpreter, if need be. We will
797 change some of these later */
798 current->mm->free_area_cache = current->mm->mmap_base;
799 current->mm->cached_hole_size = 0;
800 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
801 executable_stack);
802 if (retval < 0) {
803 send_sig(SIGKILL, current, 0);
804 goto out_free_dentry;
805 }
806
807 current->mm->start_stack = bprm->p;
808
809 /* Now we do a little grungy work by mmaping the ELF image into
810 the correct location in memory. At this point, we assume that
811 the image should be loaded at fixed address, not at a variable
812 address. */
813 for(i = 0, elf_ppnt = elf_phdata;
814 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
815 int elf_prot = 0, elf_flags;
816 unsigned long k, vaddr;
817
818 if (elf_ppnt->p_type != PT_LOAD)
819 continue;
820
821 if (unlikely (elf_brk > elf_bss)) {
822 unsigned long nbyte;
823
824 /* There was a PT_LOAD segment with p_memsz > p_filesz
825 before this one. Map anonymous pages, if needed,
826 and clear the area. */
827 retval = set_brk (elf_bss + load_bias,
828 elf_brk + load_bias);
829 if (retval) {
830 send_sig(SIGKILL, current, 0);
831 goto out_free_dentry;
832 }
833 nbyte = ELF_PAGEOFFSET(elf_bss);
834 if (nbyte) {
835 nbyte = ELF_MIN_ALIGN - nbyte;
836 if (nbyte > elf_brk - elf_bss)
837 nbyte = elf_brk - elf_bss;
838 if (clear_user((void __user *)elf_bss +
839 load_bias, nbyte)) {
840 /*
841 * This bss-zeroing can fail if the ELF
842 * file specifies odd protections. So
843 * we don't check the return value
844 */
845 }
846 }
847 }
848
849 if (elf_ppnt->p_flags & PF_R)
850 elf_prot |= PROT_READ;
851 if (elf_ppnt->p_flags & PF_W)
852 elf_prot |= PROT_WRITE;
853 if (elf_ppnt->p_flags & PF_X)
854 elf_prot |= PROT_EXEC;
855
856 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
857
858 vaddr = elf_ppnt->p_vaddr;
859 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
860 elf_flags |= MAP_FIXED;
861 } else if (loc->elf_ex.e_type == ET_DYN) {
862 /* Try and get dynamic programs out of the way of the
863 * default mmap base, as well as whatever program they
864 * might try to exec. This is because the brk will
865 * follow the loader, and is not movable. */
866 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
867 }
868
869 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
870 elf_prot, elf_flags);
871 if (BAD_ADDR(error)) {
872 send_sig(SIGKILL, current, 0);
873 goto out_free_dentry;
874 }
875
876 if (!load_addr_set) {
877 load_addr_set = 1;
878 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
879 if (loc->elf_ex.e_type == ET_DYN) {
880 load_bias += error -
881 ELF_PAGESTART(load_bias + vaddr);
882 load_addr += load_bias;
883 reloc_func_desc = load_bias;
884 }
885 }
886 k = elf_ppnt->p_vaddr;
887 if (k < start_code)
888 start_code = k;
889 if (start_data < k)
890 start_data = k;
891
892 /*
893 * Check to see if the section's size will overflow the
894 * allowed task size. Note that p_filesz must always be
895 * <= p_memsz so it is only necessary to check p_memsz.
896 */
897 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
898 elf_ppnt->p_memsz > TASK_SIZE ||
899 TASK_SIZE - elf_ppnt->p_memsz < k) {
900 /* set_brk can never work. Avoid overflows. */
901 send_sig(SIGKILL, current, 0);
902 goto out_free_dentry;
903 }
904
905 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
906
907 if (k > elf_bss)
908 elf_bss = k;
909 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
910 end_code = k;
911 if (end_data < k)
912 end_data = k;
913 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
914 if (k > elf_brk)
915 elf_brk = k;
916 }
917
918 loc->elf_ex.e_entry += load_bias;
919 elf_bss += load_bias;
920 elf_brk += load_bias;
921 start_code += load_bias;
922 end_code += load_bias;
923 start_data += load_bias;
924 end_data += load_bias;
925
926 /* Calling set_brk effectively mmaps the pages that we need
927 * for the bss and break sections. We must do this before
928 * mapping in the interpreter, to make sure it doesn't wind
929 * up getting placed where the bss needs to go.
930 */
931 retval = set_brk(elf_bss, elf_brk);
932 if (retval) {
933 send_sig(SIGKILL, current, 0);
934 goto out_free_dentry;
935 }
936 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
937 send_sig(SIGSEGV, current, 0);
938 retval = -EFAULT; /* Nobody gets to see this, but.. */
939 goto out_free_dentry;
940 }
941
942 if (elf_interpreter) {
943 if (interpreter_type == INTERPRETER_AOUT)
944 elf_entry = load_aout_interp(&loc->interp_ex,
945 interpreter);
946 else
947 elf_entry = load_elf_interp(&loc->interp_elf_ex,
948 interpreter,
949 &interp_load_addr);
950 if (BAD_ADDR(elf_entry)) {
951 force_sig(SIGSEGV, current);
952 retval = IS_ERR((void *)elf_entry) ?
953 (int)elf_entry : -EINVAL;
954 goto out_free_dentry;
955 }
956 reloc_func_desc = interp_load_addr;
957
958 allow_write_access(interpreter);
959 fput(interpreter);
960 kfree(elf_interpreter);
961 } else {
962 elf_entry = loc->elf_ex.e_entry;
963 if (BAD_ADDR(elf_entry)) {
964 force_sig(SIGSEGV, current);
965 retval = -EINVAL;
966 goto out_free_dentry;
967 }
968 }
969
970 kfree(elf_phdata);
971
972 if (interpreter_type != INTERPRETER_AOUT)
973 sys_close(elf_exec_fileno);
974
975 set_binfmt(&elf_format);
976
977 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
978 retval = arch_setup_additional_pages(bprm, executable_stack);
979 if (retval < 0) {
980 send_sig(SIGKILL, current, 0);
981 goto out;
982 }
983 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
984
985 compute_creds(bprm);
986 current->flags &= ~PF_FORKNOEXEC;
987 create_elf_tables(bprm, &loc->elf_ex,
988 (interpreter_type == INTERPRETER_AOUT),
989 load_addr, interp_load_addr);
990 /* N.B. passed_fileno might not be initialized? */
991 if (interpreter_type == INTERPRETER_AOUT)
992 current->mm->arg_start += strlen(passed_fileno) + 1;
993 current->mm->end_code = end_code;
994 current->mm->start_code = start_code;
995 current->mm->start_data = start_data;
996 current->mm->end_data = end_data;
997 current->mm->start_stack = bprm->p;
998
999 if (current->personality & MMAP_PAGE_ZERO) {
1000 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
1001 and some applications "depend" upon this behavior.
1002 Since we do not have the power to recompile these, we
1003 emulate the SVr4 behavior. Sigh. */
1004 down_write(&current->mm->mmap_sem);
1005 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1006 MAP_FIXED | MAP_PRIVATE, 0);
1007 up_write(&current->mm->mmap_sem);
1008 }
1009
1010 #ifdef ELF_PLAT_INIT
1011 /*
1012 * The ABI may specify that certain registers be set up in special
1013 * ways (on i386 %edx is the address of a DT_FINI function, for
1014 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1015 * that the e_entry field is the address of the function descriptor
1016 * for the startup routine, rather than the address of the startup
1017 * routine itself. This macro performs whatever initialization to
1018 * the regs structure is required as well as any relocations to the
1019 * function descriptor entries when executing dynamically links apps.
1020 */
1021 ELF_PLAT_INIT(regs, reloc_func_desc);
1022 #endif
1023
1024 start_thread(regs, elf_entry, bprm->p);
1025 if (unlikely(current->ptrace & PT_PTRACED)) {
1026 if (current->ptrace & PT_TRACE_EXEC)
1027 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
1028 else
1029 send_sig(SIGTRAP, current, 0);
1030 }
1031 retval = 0;
1032 out:
1033 kfree(loc);
1034 out_ret:
1035 return retval;
1036
1037 /* error cleanup */
1038 out_free_dentry:
1039 allow_write_access(interpreter);
1040 if (interpreter)
1041 fput(interpreter);
1042 out_free_interp:
1043 kfree(elf_interpreter);
1044 out_free_file:
1045 sys_close(elf_exec_fileno);
1046 out_free_fh:
1047 if (files)
1048 reset_files_struct(current, files);
1049 out_free_ph:
1050 kfree(elf_phdata);
1051 goto out;
1052 }
1053
1054 /* This is really simpleminded and specialized - we are loading an
1055 a.out library that is given an ELF header. */
1056 static int load_elf_library(struct file *file)
1057 {
1058 struct elf_phdr *elf_phdata;
1059 struct elf_phdr *eppnt;
1060 unsigned long elf_bss, bss, len;
1061 int retval, error, i, j;
1062 struct elfhdr elf_ex;
1063
1064 error = -ENOEXEC;
1065 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1066 if (retval != sizeof(elf_ex))
1067 goto out;
1068
1069 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1070 goto out;
1071
1072 /* First of all, some simple consistency checks */
1073 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1074 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1075 goto out;
1076
1077 /* Now read in all of the header information */
1078
1079 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1080 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1081
1082 error = -ENOMEM;
1083 elf_phdata = kmalloc(j, GFP_KERNEL);
1084 if (!elf_phdata)
1085 goto out;
1086
1087 eppnt = elf_phdata;
1088 error = -ENOEXEC;
1089 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1090 if (retval != j)
1091 goto out_free_ph;
1092
1093 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1094 if ((eppnt + i)->p_type == PT_LOAD)
1095 j++;
1096 if (j != 1)
1097 goto out_free_ph;
1098
1099 while (eppnt->p_type != PT_LOAD)
1100 eppnt++;
1101
1102 /* Now use mmap to map the library into memory. */
1103 down_write(&current->mm->mmap_sem);
1104 error = do_mmap(file,
1105 ELF_PAGESTART(eppnt->p_vaddr),
1106 (eppnt->p_filesz +
1107 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1108 PROT_READ | PROT_WRITE | PROT_EXEC,
1109 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1110 (eppnt->p_offset -
1111 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1112 up_write(&current->mm->mmap_sem);
1113 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1114 goto out_free_ph;
1115
1116 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1117 if (padzero(elf_bss)) {
1118 error = -EFAULT;
1119 goto out_free_ph;
1120 }
1121
1122 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1123 ELF_MIN_ALIGN - 1);
1124 bss = eppnt->p_memsz + eppnt->p_vaddr;
1125 if (bss > len) {
1126 down_write(&current->mm->mmap_sem);
1127 do_brk(len, bss - len);
1128 up_write(&current->mm->mmap_sem);
1129 }
1130 error = 0;
1131
1132 out_free_ph:
1133 kfree(elf_phdata);
1134 out:
1135 return error;
1136 }
1137
1138 /*
1139 * Note that some platforms still use traditional core dumps and not
1140 * the ELF core dump. Each platform can select it as appropriate.
1141 */
1142 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1143
1144 /*
1145 * ELF core dumper
1146 *
1147 * Modelled on fs/exec.c:aout_core_dump()
1148 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1149 */
1150 /*
1151 * These are the only things you should do on a core-file: use only these
1152 * functions to write out all the necessary info.
1153 */
1154 static int dump_write(struct file *file, const void *addr, int nr)
1155 {
1156 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1157 }
1158
1159 static int dump_seek(struct file *file, loff_t off)
1160 {
1161 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1162 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1163 return 0;
1164 } else {
1165 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1166 if (!buf)
1167 return 0;
1168 while (off > 0) {
1169 unsigned long n = off;
1170 if (n > PAGE_SIZE)
1171 n = PAGE_SIZE;
1172 if (!dump_write(file, buf, n))
1173 return 0;
1174 off -= n;
1175 }
1176 free_page((unsigned long)buf);
1177 }
1178 return 1;
1179 }
1180
1181 /*
1182 * Decide whether a segment is worth dumping; default is yes to be
1183 * sure (missing info is worse than too much; etc).
1184 * Personally I'd include everything, and use the coredump limit...
1185 *
1186 * I think we should skip something. But I am not sure how. H.J.
1187 */
1188 static int maydump(struct vm_area_struct *vma)
1189 {
1190 /* The vma can be set up to tell us the answer directly. */
1191 if (vma->vm_flags & VM_ALWAYSDUMP)
1192 return 1;
1193
1194 /* Do not dump I/O mapped devices or special mappings */
1195 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1196 return 0;
1197
1198 /* Dump shared memory only if mapped from an anonymous file. */
1199 if (vma->vm_flags & VM_SHARED)
1200 return vma->vm_file->f_path.dentry->d_inode->i_nlink == 0;
1201
1202 /* If it hasn't been written to, don't write it out */
1203 if (!vma->anon_vma)
1204 return 0;
1205
1206 return 1;
1207 }
1208
1209 /* An ELF note in memory */
1210 struct memelfnote
1211 {
1212 const char *name;
1213 int type;
1214 unsigned int datasz;
1215 void *data;
1216 };
1217
1218 static int notesize(struct memelfnote *en)
1219 {
1220 int sz;
1221
1222 sz = sizeof(struct elf_note);
1223 sz += roundup(strlen(en->name) + 1, 4);
1224 sz += roundup(en->datasz, 4);
1225
1226 return sz;
1227 }
1228
1229 #define DUMP_WRITE(addr, nr, foffset) \
1230 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1231
1232 static int alignfile(struct file *file, loff_t *foffset)
1233 {
1234 static const char buf[4] = { 0, };
1235 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1236 return 1;
1237 }
1238
1239 static int writenote(struct memelfnote *men, struct file *file,
1240 loff_t *foffset)
1241 {
1242 struct elf_note en;
1243 en.n_namesz = strlen(men->name) + 1;
1244 en.n_descsz = men->datasz;
1245 en.n_type = men->type;
1246
1247 DUMP_WRITE(&en, sizeof(en), foffset);
1248 DUMP_WRITE(men->name, en.n_namesz, foffset);
1249 if (!alignfile(file, foffset))
1250 return 0;
1251 DUMP_WRITE(men->data, men->datasz, foffset);
1252 if (!alignfile(file, foffset))
1253 return 0;
1254
1255 return 1;
1256 }
1257 #undef DUMP_WRITE
1258
1259 #define DUMP_WRITE(addr, nr) \
1260 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1261 goto end_coredump;
1262 #define DUMP_SEEK(off) \
1263 if (!dump_seek(file, (off))) \
1264 goto end_coredump;
1265
1266 static void fill_elf_header(struct elfhdr *elf, int segs)
1267 {
1268 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1269 elf->e_ident[EI_CLASS] = ELF_CLASS;
1270 elf->e_ident[EI_DATA] = ELF_DATA;
1271 elf->e_ident[EI_VERSION] = EV_CURRENT;
1272 elf->e_ident[EI_OSABI] = ELF_OSABI;
1273 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1274
1275 elf->e_type = ET_CORE;
1276 elf->e_machine = ELF_ARCH;
1277 elf->e_version = EV_CURRENT;
1278 elf->e_entry = 0;
1279 elf->e_phoff = sizeof(struct elfhdr);
1280 elf->e_shoff = 0;
1281 elf->e_flags = ELF_CORE_EFLAGS;
1282 elf->e_ehsize = sizeof(struct elfhdr);
1283 elf->e_phentsize = sizeof(struct elf_phdr);
1284 elf->e_phnum = segs;
1285 elf->e_shentsize = 0;
1286 elf->e_shnum = 0;
1287 elf->e_shstrndx = 0;
1288 return;
1289 }
1290
1291 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1292 {
1293 phdr->p_type = PT_NOTE;
1294 phdr->p_offset = offset;
1295 phdr->p_vaddr = 0;
1296 phdr->p_paddr = 0;
1297 phdr->p_filesz = sz;
1298 phdr->p_memsz = 0;
1299 phdr->p_flags = 0;
1300 phdr->p_align = 0;
1301 return;
1302 }
1303
1304 static void fill_note(struct memelfnote *note, const char *name, int type,
1305 unsigned int sz, void *data)
1306 {
1307 note->name = name;
1308 note->type = type;
1309 note->datasz = sz;
1310 note->data = data;
1311 return;
1312 }
1313
1314 /*
1315 * fill up all the fields in prstatus from the given task struct, except
1316 * registers which need to be filled up separately.
1317 */
1318 static void fill_prstatus(struct elf_prstatus *prstatus,
1319 struct task_struct *p, long signr)
1320 {
1321 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1322 prstatus->pr_sigpend = p->pending.signal.sig[0];
1323 prstatus->pr_sighold = p->blocked.sig[0];
1324 prstatus->pr_pid = p->pid;
1325 prstatus->pr_ppid = p->parent->pid;
1326 prstatus->pr_pgrp = process_group(p);
1327 prstatus->pr_sid = process_session(p);
1328 if (thread_group_leader(p)) {
1329 /*
1330 * This is the record for the group leader. Add in the
1331 * cumulative times of previous dead threads. This total
1332 * won't include the time of each live thread whose state
1333 * is included in the core dump. The final total reported
1334 * to our parent process when it calls wait4 will include
1335 * those sums as well as the little bit more time it takes
1336 * this and each other thread to finish dying after the
1337 * core dump synchronization phase.
1338 */
1339 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1340 &prstatus->pr_utime);
1341 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1342 &prstatus->pr_stime);
1343 } else {
1344 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1345 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1346 }
1347 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1348 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1349 }
1350
1351 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1352 struct mm_struct *mm)
1353 {
1354 unsigned int i, len;
1355
1356 /* first copy the parameters from user space */
1357 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1358
1359 len = mm->arg_end - mm->arg_start;
1360 if (len >= ELF_PRARGSZ)
1361 len = ELF_PRARGSZ-1;
1362 if (copy_from_user(&psinfo->pr_psargs,
1363 (const char __user *)mm->arg_start, len))
1364 return -EFAULT;
1365 for(i = 0; i < len; i++)
1366 if (psinfo->pr_psargs[i] == 0)
1367 psinfo->pr_psargs[i] = ' ';
1368 psinfo->pr_psargs[len] = 0;
1369
1370 psinfo->pr_pid = p->pid;
1371 psinfo->pr_ppid = p->parent->pid;
1372 psinfo->pr_pgrp = process_group(p);
1373 psinfo->pr_sid = process_session(p);
1374
1375 i = p->state ? ffz(~p->state) + 1 : 0;
1376 psinfo->pr_state = i;
1377 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1378 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1379 psinfo->pr_nice = task_nice(p);
1380 psinfo->pr_flag = p->flags;
1381 SET_UID(psinfo->pr_uid, p->uid);
1382 SET_GID(psinfo->pr_gid, p->gid);
1383 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1384
1385 return 0;
1386 }
1387
1388 /* Here is the structure in which status of each thread is captured. */
1389 struct elf_thread_status
1390 {
1391 struct list_head list;
1392 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1393 elf_fpregset_t fpu; /* NT_PRFPREG */
1394 struct task_struct *thread;
1395 #ifdef ELF_CORE_COPY_XFPREGS
1396 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1397 #endif
1398 struct memelfnote notes[3];
1399 int num_notes;
1400 };
1401
1402 /*
1403 * In order to add the specific thread information for the elf file format,
1404 * we need to keep a linked list of every threads pr_status and then create
1405 * a single section for them in the final core file.
1406 */
1407 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1408 {
1409 int sz = 0;
1410 struct task_struct *p = t->thread;
1411 t->num_notes = 0;
1412
1413 fill_prstatus(&t->prstatus, p, signr);
1414 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1415
1416 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1417 &(t->prstatus));
1418 t->num_notes++;
1419 sz += notesize(&t->notes[0]);
1420
1421 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1422 &t->fpu))) {
1423 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1424 &(t->fpu));
1425 t->num_notes++;
1426 sz += notesize(&t->notes[1]);
1427 }
1428
1429 #ifdef ELF_CORE_COPY_XFPREGS
1430 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1431 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1432 &t->xfpu);
1433 t->num_notes++;
1434 sz += notesize(&t->notes[2]);
1435 }
1436 #endif
1437 return sz;
1438 }
1439
1440 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1441 struct vm_area_struct *gate_vma)
1442 {
1443 struct vm_area_struct *ret = tsk->mm->mmap;
1444
1445 if (ret)
1446 return ret;
1447 return gate_vma;
1448 }
1449 /*
1450 * Helper function for iterating across a vma list. It ensures that the caller
1451 * will visit `gate_vma' prior to terminating the search.
1452 */
1453 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1454 struct vm_area_struct *gate_vma)
1455 {
1456 struct vm_area_struct *ret;
1457
1458 ret = this_vma->vm_next;
1459 if (ret)
1460 return ret;
1461 if (this_vma == gate_vma)
1462 return NULL;
1463 return gate_vma;
1464 }
1465
1466 /*
1467 * Actual dumper
1468 *
1469 * This is a two-pass process; first we find the offsets of the bits,
1470 * and then they are actually written out. If we run out of core limit
1471 * we just truncate.
1472 */
1473 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
1474 {
1475 #define NUM_NOTES 6
1476 int has_dumped = 0;
1477 mm_segment_t fs;
1478 int segs;
1479 size_t size = 0;
1480 int i;
1481 struct vm_area_struct *vma, *gate_vma;
1482 struct elfhdr *elf = NULL;
1483 loff_t offset = 0, dataoff, foffset;
1484 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1485 int numnote;
1486 struct memelfnote *notes = NULL;
1487 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1488 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1489 struct task_struct *g, *p;
1490 LIST_HEAD(thread_list);
1491 struct list_head *t;
1492 elf_fpregset_t *fpu = NULL;
1493 #ifdef ELF_CORE_COPY_XFPREGS
1494 elf_fpxregset_t *xfpu = NULL;
1495 #endif
1496 int thread_status_size = 0;
1497 elf_addr_t *auxv;
1498
1499 /*
1500 * We no longer stop all VM operations.
1501 *
1502 * This is because those proceses that could possibly change map_count
1503 * or the mmap / vma pages are now blocked in do_exit on current
1504 * finishing this core dump.
1505 *
1506 * Only ptrace can touch these memory addresses, but it doesn't change
1507 * the map_count or the pages allocated. So no possibility of crashing
1508 * exists while dumping the mm->vm_next areas to the core file.
1509 */
1510
1511 /* alloc memory for large data structures: too large to be on stack */
1512 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1513 if (!elf)
1514 goto cleanup;
1515 prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
1516 if (!prstatus)
1517 goto cleanup;
1518 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1519 if (!psinfo)
1520 goto cleanup;
1521 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1522 if (!notes)
1523 goto cleanup;
1524 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1525 if (!fpu)
1526 goto cleanup;
1527 #ifdef ELF_CORE_COPY_XFPREGS
1528 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1529 if (!xfpu)
1530 goto cleanup;
1531 #endif
1532
1533 if (signr) {
1534 struct elf_thread_status *tmp;
1535 rcu_read_lock();
1536 do_each_thread(g,p)
1537 if (current->mm == p->mm && current != p) {
1538 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1539 if (!tmp) {
1540 rcu_read_unlock();
1541 goto cleanup;
1542 }
1543 tmp->thread = p;
1544 list_add(&tmp->list, &thread_list);
1545 }
1546 while_each_thread(g,p);
1547 rcu_read_unlock();
1548 list_for_each(t, &thread_list) {
1549 struct elf_thread_status *tmp;
1550 int sz;
1551
1552 tmp = list_entry(t, struct elf_thread_status, list);
1553 sz = elf_dump_thread_status(signr, tmp);
1554 thread_status_size += sz;
1555 }
1556 }
1557 /* now collect the dump for the current */
1558 memset(prstatus, 0, sizeof(*prstatus));
1559 fill_prstatus(prstatus, current, signr);
1560 elf_core_copy_regs(&prstatus->pr_reg, regs);
1561
1562 segs = current->mm->map_count;
1563 #ifdef ELF_CORE_EXTRA_PHDRS
1564 segs += ELF_CORE_EXTRA_PHDRS;
1565 #endif
1566
1567 gate_vma = get_gate_vma(current);
1568 if (gate_vma != NULL)
1569 segs++;
1570
1571 /* Set up header */
1572 fill_elf_header(elf, segs + 1); /* including notes section */
1573
1574 has_dumped = 1;
1575 current->flags |= PF_DUMPCORE;
1576
1577 /*
1578 * Set up the notes in similar form to SVR4 core dumps made
1579 * with info from their /proc.
1580 */
1581
1582 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1583 fill_psinfo(psinfo, current->group_leader, current->mm);
1584 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1585
1586 numnote = 2;
1587
1588 auxv = (elf_addr_t *)current->mm->saved_auxv;
1589
1590 i = 0;
1591 do
1592 i += 2;
1593 while (auxv[i - 2] != AT_NULL);
1594 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1595 i * sizeof(elf_addr_t), auxv);
1596
1597 /* Try to dump the FPU. */
1598 if ((prstatus->pr_fpvalid =
1599 elf_core_copy_task_fpregs(current, regs, fpu)))
1600 fill_note(notes + numnote++,
1601 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1602 #ifdef ELF_CORE_COPY_XFPREGS
1603 if (elf_core_copy_task_xfpregs(current, xfpu))
1604 fill_note(notes + numnote++,
1605 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1606 #endif
1607
1608 fs = get_fs();
1609 set_fs(KERNEL_DS);
1610
1611 DUMP_WRITE(elf, sizeof(*elf));
1612 offset += sizeof(*elf); /* Elf header */
1613 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1614 foffset = offset;
1615
1616 /* Write notes phdr entry */
1617 {
1618 struct elf_phdr phdr;
1619 int sz = 0;
1620
1621 for (i = 0; i < numnote; i++)
1622 sz += notesize(notes + i);
1623
1624 sz += thread_status_size;
1625
1626 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1627 sz += ELF_CORE_EXTRA_NOTES_SIZE;
1628 #endif
1629
1630 fill_elf_note_phdr(&phdr, sz, offset);
1631 offset += sz;
1632 DUMP_WRITE(&phdr, sizeof(phdr));
1633 }
1634
1635 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1636
1637 /* Write program headers for segments dump */
1638 for (vma = first_vma(current, gate_vma); vma != NULL;
1639 vma = next_vma(vma, gate_vma)) {
1640 struct elf_phdr phdr;
1641 size_t sz;
1642
1643 sz = vma->vm_end - vma->vm_start;
1644
1645 phdr.p_type = PT_LOAD;
1646 phdr.p_offset = offset;
1647 phdr.p_vaddr = vma->vm_start;
1648 phdr.p_paddr = 0;
1649 phdr.p_filesz = maydump(vma) ? sz : 0;
1650 phdr.p_memsz = sz;
1651 offset += phdr.p_filesz;
1652 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1653 if (vma->vm_flags & VM_WRITE)
1654 phdr.p_flags |= PF_W;
1655 if (vma->vm_flags & VM_EXEC)
1656 phdr.p_flags |= PF_X;
1657 phdr.p_align = ELF_EXEC_PAGESIZE;
1658
1659 DUMP_WRITE(&phdr, sizeof(phdr));
1660 }
1661
1662 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1663 ELF_CORE_WRITE_EXTRA_PHDRS;
1664 #endif
1665
1666 /* write out the notes section */
1667 for (i = 0; i < numnote; i++)
1668 if (!writenote(notes + i, file, &foffset))
1669 goto end_coredump;
1670
1671 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1672 ELF_CORE_WRITE_EXTRA_NOTES;
1673 #endif
1674
1675 /* write out the thread status notes section */
1676 list_for_each(t, &thread_list) {
1677 struct elf_thread_status *tmp =
1678 list_entry(t, struct elf_thread_status, list);
1679
1680 for (i = 0; i < tmp->num_notes; i++)
1681 if (!writenote(&tmp->notes[i], file, &foffset))
1682 goto end_coredump;
1683 }
1684
1685 /* Align to page */
1686 DUMP_SEEK(dataoff - foffset);
1687
1688 for (vma = first_vma(current, gate_vma); vma != NULL;
1689 vma = next_vma(vma, gate_vma)) {
1690 unsigned long addr;
1691
1692 if (!maydump(vma))
1693 continue;
1694
1695 for (addr = vma->vm_start;
1696 addr < vma->vm_end;
1697 addr += PAGE_SIZE) {
1698 struct page *page;
1699 struct vm_area_struct *vma;
1700
1701 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1702 &page, &vma) <= 0) {
1703 DUMP_SEEK(PAGE_SIZE);
1704 } else {
1705 if (page == ZERO_PAGE(addr)) {
1706 DUMP_SEEK(PAGE_SIZE);
1707 } else {
1708 void *kaddr;
1709 flush_cache_page(vma, addr,
1710 page_to_pfn(page));
1711 kaddr = kmap(page);
1712 if ((size += PAGE_SIZE) > limit ||
1713 !dump_write(file, kaddr,
1714 PAGE_SIZE)) {
1715 kunmap(page);
1716 page_cache_release(page);
1717 goto end_coredump;
1718 }
1719 kunmap(page);
1720 }
1721 page_cache_release(page);
1722 }
1723 }
1724 }
1725
1726 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1727 ELF_CORE_WRITE_EXTRA_DATA;
1728 #endif
1729
1730 end_coredump:
1731 set_fs(fs);
1732
1733 cleanup:
1734 while (!list_empty(&thread_list)) {
1735 struct list_head *tmp = thread_list.next;
1736 list_del(tmp);
1737 kfree(list_entry(tmp, struct elf_thread_status, list));
1738 }
1739
1740 kfree(elf);
1741 kfree(prstatus);
1742 kfree(psinfo);
1743 kfree(notes);
1744 kfree(fpu);
1745 #ifdef ELF_CORE_COPY_XFPREGS
1746 kfree(xfpu);
1747 #endif
1748 return has_dumped;
1749 #undef NUM_NOTES
1750 }
1751
1752 #endif /* USE_ELF_CORE_DUMP */
1753
1754 static int __init init_elf_binfmt(void)
1755 {
1756 return register_binfmt(&elf_format);
1757 }
1758
1759 static void __exit exit_elf_binfmt(void)
1760 {
1761 /* Remove the COFF and ELF loaders. */
1762 unregister_binfmt(&elf_format);
1763 }
1764
1765 core_initcall(init_elf_binfmt);
1766 module_exit(exit_elf_binfmt);
1767 MODULE_LICENSE("GPL");
WRT350N Kernel Patches