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Pull ec into test branch
[linux-2.6/kmemtrace.git] / fs / binfmt_elf.c
blobd3adfd353ff99eec4277b672088024eee9da22ac
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 retval = kernel_read(interpreter, 0, bprm->buf,
686 BINPRM_BUF_SIZE);
687 if (retval != BINPRM_BUF_SIZE) {
688 if (retval >= 0)
689 retval = -EIO;
690 goto out_free_dentry;
691 }
692
693 /* Get the exec headers */
694 loc->interp_ex = *((struct exec *)bprm->buf);
695 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
696 break;
697 }
698 elf_ppnt++;
699 }
700
701 elf_ppnt = elf_phdata;
702 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
703 if (elf_ppnt->p_type == PT_GNU_STACK) {
704 if (elf_ppnt->p_flags & PF_X)
705 executable_stack = EXSTACK_ENABLE_X;
706 else
707 executable_stack = EXSTACK_DISABLE_X;
708 break;
709 }
710
711 /* Some simple consistency checks for the interpreter */
712 if (elf_interpreter) {
713 interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
714
715 /* Now figure out which format our binary is */
716 if ((N_MAGIC(loc->interp_ex) != OMAGIC) &&
717 (N_MAGIC(loc->interp_ex) != ZMAGIC) &&
718 (N_MAGIC(loc->interp_ex) != QMAGIC))
719 interpreter_type = INTERPRETER_ELF;
720
721 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
722 interpreter_type &= ~INTERPRETER_ELF;
723
724 retval = -ELIBBAD;
725 if (!interpreter_type)
726 goto out_free_dentry;
727
728 /* Make sure only one type was selected */
729 if ((interpreter_type & INTERPRETER_ELF) &&
730 interpreter_type != INTERPRETER_ELF) {
731 // FIXME - ratelimit this before re-enabling
732 // printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n");
733 interpreter_type = INTERPRETER_ELF;
734 }
735 /* Verify the interpreter has a valid arch */
736 if ((interpreter_type == INTERPRETER_ELF) &&
737 !elf_check_arch(&loc->interp_elf_ex))
738 goto out_free_dentry;
739 } else {
740 /* Executables without an interpreter also need a personality */
741 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
742 }
743
744 /* OK, we are done with that, now set up the arg stuff,
745 and then start this sucker up */
746 if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) {
747 char *passed_p = passed_fileno;
748 sprintf(passed_fileno, "%d", elf_exec_fileno);
749
750 if (elf_interpreter) {
751 retval = copy_strings_kernel(1, &passed_p, bprm);
752 if (retval)
753 goto out_free_dentry;
754 bprm->argc++;
755 }
756 }
757
758 /* Flush all traces of the currently running executable */
759 retval = flush_old_exec(bprm);
760 if (retval)
761 goto out_free_dentry;
762
763 /* Discard our unneeded old files struct */
764 if (files) {
765 put_files_struct(files);
766 files = NULL;
767 }
768
769 /* OK, This is the point of no return */
770 current->mm->start_data = 0;
771 current->mm->end_data = 0;
772 current->mm->end_code = 0;
773 current->mm->mmap = NULL;
774 current->flags &= ~PF_FORKNOEXEC;
775 current->mm->def_flags = def_flags;
776
777 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
778 may depend on the personality. */
779 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
780 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
781 current->personality |= READ_IMPLIES_EXEC;
782
783 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
784 current->flags |= PF_RANDOMIZE;
785 arch_pick_mmap_layout(current->mm);
786
787 /* Do this so that we can load the interpreter, if need be. We will
788 change some of these later */
789 current->mm->free_area_cache = current->mm->mmap_base;
790 current->mm->cached_hole_size = 0;
791 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
792 executable_stack);
793 if (retval < 0) {
794 send_sig(SIGKILL, current, 0);
795 goto out_free_dentry;
796 }
797
798 current->mm->start_stack = bprm->p;
799
800 /* Now we do a little grungy work by mmaping the ELF image into
801 the correct location in memory. At this point, we assume that
802 the image should be loaded at fixed address, not at a variable
803 address. */
804 for(i = 0, elf_ppnt = elf_phdata;
805 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
806 int elf_prot = 0, elf_flags;
807 unsigned long k, vaddr;
808
809 if (elf_ppnt->p_type != PT_LOAD)
810 continue;
811
812 if (unlikely (elf_brk > elf_bss)) {
813 unsigned long nbyte;
814
815 /* There was a PT_LOAD segment with p_memsz > p_filesz
816 before this one. Map anonymous pages, if needed,
817 and clear the area. */
818 retval = set_brk (elf_bss + load_bias,
819 elf_brk + load_bias);
820 if (retval) {
821 send_sig(SIGKILL, current, 0);
822 goto out_free_dentry;
823 }
824 nbyte = ELF_PAGEOFFSET(elf_bss);
825 if (nbyte) {
826 nbyte = ELF_MIN_ALIGN - nbyte;
827 if (nbyte > elf_brk - elf_bss)
828 nbyte = elf_brk - elf_bss;
829 if (clear_user((void __user *)elf_bss +
830 load_bias, nbyte)) {
831 /*
832 * This bss-zeroing can fail if the ELF
833 * file specifies odd protections. So
834 * we don't check the return value
835 */
836 }
837 }
838 }
839
840 if (elf_ppnt->p_flags & PF_R)
841 elf_prot |= PROT_READ;
842 if (elf_ppnt->p_flags & PF_W)
843 elf_prot |= PROT_WRITE;
844 if (elf_ppnt->p_flags & PF_X)
845 elf_prot |= PROT_EXEC;
846
847 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
848
849 vaddr = elf_ppnt->p_vaddr;
850 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
851 elf_flags |= MAP_FIXED;
852 } else if (loc->elf_ex.e_type == ET_DYN) {
853 /* Try and get dynamic programs out of the way of the
854 * default mmap base, as well as whatever program they
855 * might try to exec. This is because the brk will
856 * follow the loader, and is not movable. */
857 if (current->flags & PF_RANDOMIZE)
858 load_bias = randomize_range(0x10000,
859 ELF_ET_DYN_BASE,
860 0);
861 else
862 load_bias = ELF_ET_DYN_BASE;
863 load_bias = ELF_PAGESTART(load_bias - vaddr);
864 }
865
866 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
867 elf_prot, elf_flags);
868 if (BAD_ADDR(error)) {
869 send_sig(SIGKILL, current, 0);
870 goto out_free_dentry;
871 }
872
873 if (!load_addr_set) {
874 load_addr_set = 1;
875 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
876 if (loc->elf_ex.e_type == ET_DYN) {
877 load_bias += error -
878 ELF_PAGESTART(load_bias + vaddr);
879 load_addr += load_bias;
880 reloc_func_desc = load_bias;
881 }
882 }
883 k = elf_ppnt->p_vaddr;
884 if (k < start_code)
885 start_code = k;
886 if (start_data < k)
887 start_data = k;
888
889 /*
890 * Check to see if the section's size will overflow the
891 * allowed task size. Note that p_filesz must always be
892 * <= p_memsz so it is only necessary to check p_memsz.
893 */
894 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
895 elf_ppnt->p_memsz > TASK_SIZE ||
896 TASK_SIZE - elf_ppnt->p_memsz < k) {
897 /* set_brk can never work. Avoid overflows. */
898 send_sig(SIGKILL, current, 0);
899 goto out_free_dentry;
900 }
901
902 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
903
904 if (k > elf_bss)
905 elf_bss = k;
906 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
907 end_code = k;
908 if (end_data < k)
909 end_data = k;
910 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
911 if (k > elf_brk)
912 elf_brk = k;
913 }
914
915 loc->elf_ex.e_entry += load_bias;
916 elf_bss += load_bias;
917 elf_brk += load_bias;
918 start_code += load_bias;
919 end_code += load_bias;
920 start_data += load_bias;
921 end_data += load_bias;
922
923 /* Calling set_brk effectively mmaps the pages that we need
924 * for the bss and break sections. We must do this before
925 * mapping in the interpreter, to make sure it doesn't wind
926 * up getting placed where the bss needs to go.
927 */
928 retval = set_brk(elf_bss, elf_brk);
929 if (retval) {
930 send_sig(SIGKILL, current, 0);
931 goto out_free_dentry;
932 }
933 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
934 send_sig(SIGSEGV, current, 0);
935 retval = -EFAULT; /* Nobody gets to see this, but.. */
936 goto out_free_dentry;
937 }
938
939 if (elf_interpreter) {
940 if (interpreter_type == INTERPRETER_AOUT)
941 elf_entry = load_aout_interp(&loc->interp_ex,
942 interpreter);
943 else
944 elf_entry = load_elf_interp(&loc->interp_elf_ex,
945 interpreter,
946 &interp_load_addr);
947 if (BAD_ADDR(elf_entry)) {
948 force_sig(SIGSEGV, current);
949 retval = IS_ERR((void *)elf_entry) ?
950 (int)elf_entry : -EINVAL;
951 goto out_free_dentry;
952 }
953 reloc_func_desc = interp_load_addr;
954
955 allow_write_access(interpreter);
956 fput(interpreter);
957 kfree(elf_interpreter);
958 } else {
959 elf_entry = loc->elf_ex.e_entry;
960 if (BAD_ADDR(elf_entry)) {
961 force_sig(SIGSEGV, current);
962 retval = -EINVAL;
963 goto out_free_dentry;
964 }
965 }
966
967 kfree(elf_phdata);
968
969 if (interpreter_type != INTERPRETER_AOUT)
970 sys_close(elf_exec_fileno);
971
972 set_binfmt(&elf_format);
973
974 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
975 retval = arch_setup_additional_pages(bprm, executable_stack);
976 if (retval < 0) {
977 send_sig(SIGKILL, current, 0);
978 goto out;
979 }
980 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
981
982 compute_creds(bprm);
983 current->flags &= ~PF_FORKNOEXEC;
984 create_elf_tables(bprm, &loc->elf_ex,
985 (interpreter_type == INTERPRETER_AOUT),
986 load_addr, interp_load_addr);
987 /* N.B. passed_fileno might not be initialized? */
988 if (interpreter_type == INTERPRETER_AOUT)
989 current->mm->arg_start += strlen(passed_fileno) + 1;
990 current->mm->end_code = end_code;
991 current->mm->start_code = start_code;
992 current->mm->start_data = start_data;
993 current->mm->end_data = end_data;
994 current->mm->start_stack = bprm->p;
995
996 if (current->personality & MMAP_PAGE_ZERO) {
997 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
998 and some applications "depend" upon this behavior.
999 Since we do not have the power to recompile these, we
1000 emulate the SVr4 behavior. Sigh. */
1001 down_write(&current->mm->mmap_sem);
1002 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1003 MAP_FIXED | MAP_PRIVATE, 0);
1004 up_write(&current->mm->mmap_sem);
1005 }
1006
1007 #ifdef ELF_PLAT_INIT
1008 /*
1009 * The ABI may specify that certain registers be set up in special
1010 * ways (on i386 %edx is the address of a DT_FINI function, for
1011 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1012 * that the e_entry field is the address of the function descriptor
1013 * for the startup routine, rather than the address of the startup
1014 * routine itself. This macro performs whatever initialization to
1015 * the regs structure is required as well as any relocations to the
1016 * function descriptor entries when executing dynamically links apps.
1017 */
1018 ELF_PLAT_INIT(regs, reloc_func_desc);
1019 #endif
1020
1021 start_thread(regs, elf_entry, bprm->p);
1022 if (unlikely(current->ptrace & PT_PTRACED)) {
1023 if (current->ptrace & PT_TRACE_EXEC)
1024 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
1025 else
1026 send_sig(SIGTRAP, current, 0);
1027 }
1028 retval = 0;
1029 out:
1030 kfree(loc);
1031 out_ret:
1032 return retval;
1033
1034 /* error cleanup */
1035 out_free_dentry:
1036 allow_write_access(interpreter);
1037 if (interpreter)
1038 fput(interpreter);
1039 out_free_interp:
1040 kfree(elf_interpreter);
1041 out_free_file:
1042 sys_close(elf_exec_fileno);
1043 out_free_fh:
1044 if (files)
1045 reset_files_struct(current, files);
1046 out_free_ph:
1047 kfree(elf_phdata);
1048 goto out;
1049 }
1050
1051 /* This is really simpleminded and specialized - we are loading an
1052 a.out library that is given an ELF header. */
1053 static int load_elf_library(struct file *file)
1054 {
1055 struct elf_phdr *elf_phdata;
1056 struct elf_phdr *eppnt;
1057 unsigned long elf_bss, bss, len;
1058 int retval, error, i, j;
1059 struct elfhdr elf_ex;
1060
1061 error = -ENOEXEC;
1062 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1063 if (retval != sizeof(elf_ex))
1064 goto out;
1065
1066 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1067 goto out;
1068
1069 /* First of all, some simple consistency checks */
1070 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1071 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1072 goto out;
1073
1074 /* Now read in all of the header information */
1075
1076 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1077 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1078
1079 error = -ENOMEM;
1080 elf_phdata = kmalloc(j, GFP_KERNEL);
1081 if (!elf_phdata)
1082 goto out;
1083
1084 eppnt = elf_phdata;
1085 error = -ENOEXEC;
1086 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1087 if (retval != j)
1088 goto out_free_ph;
1089
1090 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1091 if ((eppnt + i)->p_type == PT_LOAD)
1092 j++;
1093 if (j != 1)
1094 goto out_free_ph;
1095
1096 while (eppnt->p_type != PT_LOAD)
1097 eppnt++;
1098
1099 /* Now use mmap to map the library into memory. */
1100 down_write(&current->mm->mmap_sem);
1101 error = do_mmap(file,
1102 ELF_PAGESTART(eppnt->p_vaddr),
1103 (eppnt->p_filesz +
1104 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1105 PROT_READ | PROT_WRITE | PROT_EXEC,
1106 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1107 (eppnt->p_offset -
1108 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1109 up_write(&current->mm->mmap_sem);
1110 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1111 goto out_free_ph;
1112
1113 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1114 if (padzero(elf_bss)) {
1115 error = -EFAULT;
1116 goto out_free_ph;
1117 }
1118
1119 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1120 ELF_MIN_ALIGN - 1);
1121 bss = eppnt->p_memsz + eppnt->p_vaddr;
1122 if (bss > len) {
1123 down_write(&current->mm->mmap_sem);
1124 do_brk(len, bss - len);
1125 up_write(&current->mm->mmap_sem);
1126 }
1127 error = 0;
1128
1129 out_free_ph:
1130 kfree(elf_phdata);
1131 out:
1132 return error;
1133 }
1134
1135 /*
1136 * Note that some platforms still use traditional core dumps and not
1137 * the ELF core dump. Each platform can select it as appropriate.
1138 */
1139 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1140
1141 /*
1142 * ELF core dumper
1143 *
1144 * Modelled on fs/exec.c:aout_core_dump()
1145 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1146 */
1147 /*
1148 * These are the only things you should do on a core-file: use only these
1149 * functions to write out all the necessary info.
1150 */
1151 static int dump_write(struct file *file, const void *addr, int nr)
1152 {
1153 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1154 }
1155
1156 static int dump_seek(struct file *file, loff_t off)
1157 {
1158 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1159 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1160 return 0;
1161 } else {
1162 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1163 if (!buf)
1164 return 0;
1165 while (off > 0) {
1166 unsigned long n = off;
1167 if (n > PAGE_SIZE)
1168 n = PAGE_SIZE;
1169 if (!dump_write(file, buf, n))
1170 return 0;
1171 off -= n;
1172 }
1173 free_page((unsigned long)buf);
1174 }
1175 return 1;
1176 }
1177
1178 /*
1179 * Decide whether a segment is worth dumping; default is yes to be
1180 * sure (missing info is worse than too much; etc).
1181 * Personally I'd include everything, and use the coredump limit...
1182 *
1183 * I think we should skip something. But I am not sure how. H.J.
1184 */
1185 static int maydump(struct vm_area_struct *vma)
1186 {
1187 /* Do not dump I/O mapped devices or special mappings */
1188 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1189 return 0;
1190
1191 /* Dump shared memory only if mapped from an anonymous file. */
1192 if (vma->vm_flags & VM_SHARED)
1193 return vma->vm_file->f_path.dentry->d_inode->i_nlink == 0;
1194
1195 /* If it hasn't been written to, don't write it out */
1196 if (!vma->anon_vma)
1197 return 0;
1198
1199 return 1;
1200 }
1201
1202 /* An ELF note in memory */
1203 struct memelfnote
1204 {
1205 const char *name;
1206 int type;
1207 unsigned int datasz;
1208 void *data;
1209 };
1210
1211 static int notesize(struct memelfnote *en)
1212 {
1213 int sz;
1214
1215 sz = sizeof(struct elf_note);
1216 sz += roundup(strlen(en->name) + 1, 4);
1217 sz += roundup(en->datasz, 4);
1218
1219 return sz;
1220 }
1221
1222 #define DUMP_WRITE(addr, nr, foffset) \
1223 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1224
1225 static int alignfile(struct file *file, loff_t *foffset)
1226 {
1227 static const char buf[4] = { 0, };
1228 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1229 return 1;
1230 }
1231
1232 static int writenote(struct memelfnote *men, struct file *file,
1233 loff_t *foffset)
1234 {
1235 struct elf_note en;
1236 en.n_namesz = strlen(men->name) + 1;
1237 en.n_descsz = men->datasz;
1238 en.n_type = men->type;
1239
1240 DUMP_WRITE(&en, sizeof(en), foffset);
1241 DUMP_WRITE(men->name, en.n_namesz, foffset);
1242 if (!alignfile(file, foffset))
1243 return 0;
1244 DUMP_WRITE(men->data, men->datasz, foffset);
1245 if (!alignfile(file, foffset))
1246 return 0;
1247
1248 return 1;
1249 }
1250 #undef DUMP_WRITE
1251
1252 #define DUMP_WRITE(addr, nr) \
1253 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1254 goto end_coredump;
1255 #define DUMP_SEEK(off) \
1256 if (!dump_seek(file, (off))) \
1257 goto end_coredump;
1258
1259 static void fill_elf_header(struct elfhdr *elf, int segs)
1260 {
1261 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1262 elf->e_ident[EI_CLASS] = ELF_CLASS;
1263 elf->e_ident[EI_DATA] = ELF_DATA;
1264 elf->e_ident[EI_VERSION] = EV_CURRENT;
1265 elf->e_ident[EI_OSABI] = ELF_OSABI;
1266 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1267
1268 elf->e_type = ET_CORE;
1269 elf->e_machine = ELF_ARCH;
1270 elf->e_version = EV_CURRENT;
1271 elf->e_entry = 0;
1272 elf->e_phoff = sizeof(struct elfhdr);
1273 elf->e_shoff = 0;
1274 elf->e_flags = ELF_CORE_EFLAGS;
1275 elf->e_ehsize = sizeof(struct elfhdr);
1276 elf->e_phentsize = sizeof(struct elf_phdr);
1277 elf->e_phnum = segs;
1278 elf->e_shentsize = 0;
1279 elf->e_shnum = 0;
1280 elf->e_shstrndx = 0;
1281 return;
1282 }
1283
1284 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1285 {
1286 phdr->p_type = PT_NOTE;
1287 phdr->p_offset = offset;
1288 phdr->p_vaddr = 0;
1289 phdr->p_paddr = 0;
1290 phdr->p_filesz = sz;
1291 phdr->p_memsz = 0;
1292 phdr->p_flags = 0;
1293 phdr->p_align = 0;
1294 return;
1295 }
1296
1297 static void fill_note(struct memelfnote *note, const char *name, int type,
1298 unsigned int sz, void *data)
1299 {
1300 note->name = name;
1301 note->type = type;
1302 note->datasz = sz;
1303 note->data = data;
1304 return;
1305 }
1306
1307 /*
1308 * fill up all the fields in prstatus from the given task struct, except
1309 * registers which need to be filled up separately.
1310 */
1311 static void fill_prstatus(struct elf_prstatus *prstatus,
1312 struct task_struct *p, long signr)
1313 {
1314 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1315 prstatus->pr_sigpend = p->pending.signal.sig[0];
1316 prstatus->pr_sighold = p->blocked.sig[0];
1317 prstatus->pr_pid = p->pid;
1318 prstatus->pr_ppid = p->parent->pid;
1319 prstatus->pr_pgrp = process_group(p);
1320 prstatus->pr_sid = process_session(p);
1321 if (thread_group_leader(p)) {
1322 /*
1323 * This is the record for the group leader. Add in the
1324 * cumulative times of previous dead threads. This total
1325 * won't include the time of each live thread whose state
1326 * is included in the core dump. The final total reported
1327 * to our parent process when it calls wait4 will include
1328 * those sums as well as the little bit more time it takes
1329 * this and each other thread to finish dying after the
1330 * core dump synchronization phase.
1331 */
1332 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1333 &prstatus->pr_utime);
1334 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1335 &prstatus->pr_stime);
1336 } else {
1337 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1338 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1339 }
1340 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1341 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1342 }
1343
1344 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1345 struct mm_struct *mm)
1346 {
1347 unsigned int i, len;
1348
1349 /* first copy the parameters from user space */
1350 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1351
1352 len = mm->arg_end - mm->arg_start;
1353 if (len >= ELF_PRARGSZ)
1354 len = ELF_PRARGSZ-1;
1355 if (copy_from_user(&psinfo->pr_psargs,
1356 (const char __user *)mm->arg_start, len))
1357 return -EFAULT;
1358 for(i = 0; i < len; i++)
1359 if (psinfo->pr_psargs[i] == 0)
1360 psinfo->pr_psargs[i] = ' ';
1361 psinfo->pr_psargs[len] = 0;
1362
1363 psinfo->pr_pid = p->pid;
1364 psinfo->pr_ppid = p->parent->pid;
1365 psinfo->pr_pgrp = process_group(p);
1366 psinfo->pr_sid = process_session(p);
1367
1368 i = p->state ? ffz(~p->state) + 1 : 0;
1369 psinfo->pr_state = i;
1370 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1371 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1372 psinfo->pr_nice = task_nice(p);
1373 psinfo->pr_flag = p->flags;
1374 SET_UID(psinfo->pr_uid, p->uid);
1375 SET_GID(psinfo->pr_gid, p->gid);
1376 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1377
1378 return 0;
1379 }
1380
1381 /* Here is the structure in which status of each thread is captured. */
1382 struct elf_thread_status
1383 {
1384 struct list_head list;
1385 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1386 elf_fpregset_t fpu; /* NT_PRFPREG */
1387 struct task_struct *thread;
1388 #ifdef ELF_CORE_COPY_XFPREGS
1389 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1390 #endif
1391 struct memelfnote notes[3];
1392 int num_notes;
1393 };
1394
1395 /*
1396 * In order to add the specific thread information for the elf file format,
1397 * we need to keep a linked list of every threads pr_status and then create
1398 * a single section for them in the final core file.
1399 */
1400 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1401 {
1402 int sz = 0;
1403 struct task_struct *p = t->thread;
1404 t->num_notes = 0;
1405
1406 fill_prstatus(&t->prstatus, p, signr);
1407 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1408
1409 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1410 &(t->prstatus));
1411 t->num_notes++;
1412 sz += notesize(&t->notes[0]);
1413
1414 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1415 &t->fpu))) {
1416 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1417 &(t->fpu));
1418 t->num_notes++;
1419 sz += notesize(&t->notes[1]);
1420 }
1421
1422 #ifdef ELF_CORE_COPY_XFPREGS
1423 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1424 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1425 &t->xfpu);
1426 t->num_notes++;
1427 sz += notesize(&t->notes[2]);
1428 }
1429 #endif
1430 return sz;
1431 }
1432
1433 /*
1434 * Actual dumper
1435 *
1436 * This is a two-pass process; first we find the offsets of the bits,
1437 * and then they are actually written out. If we run out of core limit
1438 * we just truncate.
1439 */
1440 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
1441 {
1442 #define NUM_NOTES 6
1443 int has_dumped = 0;
1444 mm_segment_t fs;
1445 int segs;
1446 size_t size = 0;
1447 int i;
1448 struct vm_area_struct *vma;
1449 struct elfhdr *elf = NULL;
1450 loff_t offset = 0, dataoff, foffset;
1451 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1452 int numnote;
1453 struct memelfnote *notes = NULL;
1454 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1455 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1456 struct task_struct *g, *p;
1457 LIST_HEAD(thread_list);
1458 struct list_head *t;
1459 elf_fpregset_t *fpu = NULL;
1460 #ifdef ELF_CORE_COPY_XFPREGS
1461 elf_fpxregset_t *xfpu = NULL;
1462 #endif
1463 int thread_status_size = 0;
1464 elf_addr_t *auxv;
1465
1466 /*
1467 * We no longer stop all VM operations.
1468 *
1469 * This is because those proceses that could possibly change map_count
1470 * or the mmap / vma pages are now blocked in do_exit on current
1471 * finishing this core dump.
1472 *
1473 * Only ptrace can touch these memory addresses, but it doesn't change
1474 * the map_count or the pages allocated. So no possibility of crashing
1475 * exists while dumping the mm->vm_next areas to the core file.
1476 */
1477
1478 /* alloc memory for large data structures: too large to be on stack */
1479 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1480 if (!elf)
1481 goto cleanup;
1482 prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
1483 if (!prstatus)
1484 goto cleanup;
1485 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1486 if (!psinfo)
1487 goto cleanup;
1488 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1489 if (!notes)
1490 goto cleanup;
1491 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1492 if (!fpu)
1493 goto cleanup;
1494 #ifdef ELF_CORE_COPY_XFPREGS
1495 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1496 if (!xfpu)
1497 goto cleanup;
1498 #endif
1499
1500 if (signr) {
1501 struct elf_thread_status *tmp;
1502 rcu_read_lock();
1503 do_each_thread(g,p)
1504 if (current->mm == p->mm && current != p) {
1505 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1506 if (!tmp) {
1507 rcu_read_unlock();
1508 goto cleanup;
1509 }
1510 tmp->thread = p;
1511 list_add(&tmp->list, &thread_list);
1512 }
1513 while_each_thread(g,p);
1514 rcu_read_unlock();
1515 list_for_each(t, &thread_list) {
1516 struct elf_thread_status *tmp;
1517 int sz;
1518
1519 tmp = list_entry(t, struct elf_thread_status, list);
1520 sz = elf_dump_thread_status(signr, tmp);
1521 thread_status_size += sz;
1522 }
1523 }
1524 /* now collect the dump for the current */
1525 memset(prstatus, 0, sizeof(*prstatus));
1526 fill_prstatus(prstatus, current, signr);
1527 elf_core_copy_regs(&prstatus->pr_reg, regs);
1528
1529 segs = current->mm->map_count;
1530 #ifdef ELF_CORE_EXTRA_PHDRS
1531 segs += ELF_CORE_EXTRA_PHDRS;
1532 #endif
1533
1534 /* Set up header */
1535 fill_elf_header(elf, segs + 1); /* including notes section */
1536
1537 has_dumped = 1;
1538 current->flags |= PF_DUMPCORE;
1539
1540 /*
1541 * Set up the notes in similar form to SVR4 core dumps made
1542 * with info from their /proc.
1543 */
1544
1545 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1546 fill_psinfo(psinfo, current->group_leader, current->mm);
1547 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1548
1549 numnote = 2;
1550
1551 auxv = (elf_addr_t *)current->mm->saved_auxv;
1552
1553 i = 0;
1554 do
1555 i += 2;
1556 while (auxv[i - 2] != AT_NULL);
1557 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1558 i * sizeof(elf_addr_t), auxv);
1559
1560 /* Try to dump the FPU. */
1561 if ((prstatus->pr_fpvalid =
1562 elf_core_copy_task_fpregs(current, regs, fpu)))
1563 fill_note(notes + numnote++,
1564 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1565 #ifdef ELF_CORE_COPY_XFPREGS
1566 if (elf_core_copy_task_xfpregs(current, xfpu))
1567 fill_note(notes + numnote++,
1568 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1569 #endif
1570
1571 fs = get_fs();
1572 set_fs(KERNEL_DS);
1573
1574 DUMP_WRITE(elf, sizeof(*elf));
1575 offset += sizeof(*elf); /* Elf header */
1576 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1577 foffset = offset;
1578
1579 /* Write notes phdr entry */
1580 {
1581 struct elf_phdr phdr;
1582 int sz = 0;
1583
1584 for (i = 0; i < numnote; i++)
1585 sz += notesize(notes + i);
1586
1587 sz += thread_status_size;
1588
1589 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1590 sz += ELF_CORE_EXTRA_NOTES_SIZE;
1591 #endif
1592
1593 fill_elf_note_phdr(&phdr, sz, offset);
1594 offset += sz;
1595 DUMP_WRITE(&phdr, sizeof(phdr));
1596 }
1597
1598 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1599
1600 /* Write program headers for segments dump */
1601 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1602 struct elf_phdr phdr;
1603 size_t sz;
1604
1605 sz = vma->vm_end - vma->vm_start;
1606
1607 phdr.p_type = PT_LOAD;
1608 phdr.p_offset = offset;
1609 phdr.p_vaddr = vma->vm_start;
1610 phdr.p_paddr = 0;
1611 phdr.p_filesz = maydump(vma) ? sz : 0;
1612 phdr.p_memsz = sz;
1613 offset += phdr.p_filesz;
1614 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1615 if (vma->vm_flags & VM_WRITE)
1616 phdr.p_flags |= PF_W;
1617 if (vma->vm_flags & VM_EXEC)
1618 phdr.p_flags |= PF_X;
1619 phdr.p_align = ELF_EXEC_PAGESIZE;
1620
1621 DUMP_WRITE(&phdr, sizeof(phdr));
1622 }
1623
1624 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1625 ELF_CORE_WRITE_EXTRA_PHDRS;
1626 #endif
1627
1628 /* write out the notes section */
1629 for (i = 0; i < numnote; i++)
1630 if (!writenote(notes + i, file, &foffset))
1631 goto end_coredump;
1632
1633 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1634 ELF_CORE_WRITE_EXTRA_NOTES;
1635 #endif
1636
1637 /* write out the thread status notes section */
1638 list_for_each(t, &thread_list) {
1639 struct elf_thread_status *tmp =
1640 list_entry(t, struct elf_thread_status, list);
1641
1642 for (i = 0; i < tmp->num_notes; i++)
1643 if (!writenote(&tmp->notes[i], file, &foffset))
1644 goto end_coredump;
1645 }
1646
1647 /* Align to page */
1648 DUMP_SEEK(dataoff - foffset);
1649
1650 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1651 unsigned long addr;
1652
1653 if (!maydump(vma))
1654 continue;
1655
1656 for (addr = vma->vm_start;
1657 addr < vma->vm_end;
1658 addr += PAGE_SIZE) {
1659 struct page *page;
1660 struct vm_area_struct *vma;
1661
1662 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1663 &page, &vma) <= 0) {
1664 DUMP_SEEK(PAGE_SIZE);
1665 } else {
1666 if (page == ZERO_PAGE(addr)) {
1667 DUMP_SEEK(PAGE_SIZE);
1668 } else {
1669 void *kaddr;
1670 flush_cache_page(vma, addr,
1671 page_to_pfn(page));
1672 kaddr = kmap(page);
1673 if ((size += PAGE_SIZE) > limit ||
1674 !dump_write(file, kaddr,
1675 PAGE_SIZE)) {
1676 kunmap(page);
1677 page_cache_release(page);
1678 goto end_coredump;
1679 }
1680 kunmap(page);
1681 }
1682 page_cache_release(page);
1683 }
1684 }
1685 }
1686
1687 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1688 ELF_CORE_WRITE_EXTRA_DATA;
1689 #endif
1690
1691 end_coredump:
1692 set_fs(fs);
1693
1694 cleanup:
1695 while (!list_empty(&thread_list)) {
1696 struct list_head *tmp = thread_list.next;
1697 list_del(tmp);
1698 kfree(list_entry(tmp, struct elf_thread_status, list));
1699 }
1700
1701 kfree(elf);
1702 kfree(prstatus);
1703 kfree(psinfo);
1704 kfree(notes);
1705 kfree(fpu);
1706 #ifdef ELF_CORE_COPY_XFPREGS
1707 kfree(xfpu);
1708 #endif
1709 return has_dumped;
1710 #undef NUM_NOTES
1711 }
1712
1713 #endif /* USE_ELF_CORE_DUMP */
1714
1715 static int __init init_elf_binfmt(void)
1716 {
1717 return register_binfmt(&elf_format);
1718 }
1719
1720 static void __exit exit_elf_binfmt(void)
1721 {
1722 /* Remove the COFF and ELF loaders. */
1723 unregister_binfmt(&elf_format);
1724 }
1725
1726 core_initcall(init_elf_binfmt);
1727 module_exit(exit_elf_binfmt);
1728 MODULE_LICENSE("GPL");
kmemtrace - Kernel memory tracer