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[PATCH] Add VM_ALWAYSDUMP
[linux-2.6/mini2440.git] / fs / binfmt_elf.c
blob6fec8bfa6bac165d260e7bcbcb0a18c27fbfb573
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 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
858 }
859
860 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
861 elf_prot, elf_flags);
862 if (BAD_ADDR(error)) {
863 send_sig(SIGKILL, current, 0);
864 goto out_free_dentry;
865 }
866
867 if (!load_addr_set) {
868 load_addr_set = 1;
869 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
870 if (loc->elf_ex.e_type == ET_DYN) {
871 load_bias += error -
872 ELF_PAGESTART(load_bias + vaddr);
873 load_addr += load_bias;
874 reloc_func_desc = load_bias;
875 }
876 }
877 k = elf_ppnt->p_vaddr;
878 if (k < start_code)
879 start_code = k;
880 if (start_data < k)
881 start_data = k;
882
883 /*
884 * Check to see if the section's size will overflow the
885 * allowed task size. Note that p_filesz must always be
886 * <= p_memsz so it is only necessary to check p_memsz.
887 */
888 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
889 elf_ppnt->p_memsz > TASK_SIZE ||
890 TASK_SIZE - elf_ppnt->p_memsz < k) {
891 /* set_brk can never work. Avoid overflows. */
892 send_sig(SIGKILL, current, 0);
893 goto out_free_dentry;
894 }
895
896 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
897
898 if (k > elf_bss)
899 elf_bss = k;
900 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
901 end_code = k;
902 if (end_data < k)
903 end_data = k;
904 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
905 if (k > elf_brk)
906 elf_brk = k;
907 }
908
909 loc->elf_ex.e_entry += load_bias;
910 elf_bss += load_bias;
911 elf_brk += load_bias;
912 start_code += load_bias;
913 end_code += load_bias;
914 start_data += load_bias;
915 end_data += load_bias;
916
917 /* Calling set_brk effectively mmaps the pages that we need
918 * for the bss and break sections. We must do this before
919 * mapping in the interpreter, to make sure it doesn't wind
920 * up getting placed where the bss needs to go.
921 */
922 retval = set_brk(elf_bss, elf_brk);
923 if (retval) {
924 send_sig(SIGKILL, current, 0);
925 goto out_free_dentry;
926 }
927 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
928 send_sig(SIGSEGV, current, 0);
929 retval = -EFAULT; /* Nobody gets to see this, but.. */
930 goto out_free_dentry;
931 }
932
933 if (elf_interpreter) {
934 if (interpreter_type == INTERPRETER_AOUT)
935 elf_entry = load_aout_interp(&loc->interp_ex,
936 interpreter);
937 else
938 elf_entry = load_elf_interp(&loc->interp_elf_ex,
939 interpreter,
940 &interp_load_addr);
941 if (BAD_ADDR(elf_entry)) {
942 force_sig(SIGSEGV, current);
943 retval = IS_ERR((void *)elf_entry) ?
944 (int)elf_entry : -EINVAL;
945 goto out_free_dentry;
946 }
947 reloc_func_desc = interp_load_addr;
948
949 allow_write_access(interpreter);
950 fput(interpreter);
951 kfree(elf_interpreter);
952 } else {
953 elf_entry = loc->elf_ex.e_entry;
954 if (BAD_ADDR(elf_entry)) {
955 force_sig(SIGSEGV, current);
956 retval = -EINVAL;
957 goto out_free_dentry;
958 }
959 }
960
961 kfree(elf_phdata);
962
963 if (interpreter_type != INTERPRETER_AOUT)
964 sys_close(elf_exec_fileno);
965
966 set_binfmt(&elf_format);
967
968 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
969 retval = arch_setup_additional_pages(bprm, executable_stack);
970 if (retval < 0) {
971 send_sig(SIGKILL, current, 0);
972 goto out;
973 }
974 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
975
976 compute_creds(bprm);
977 current->flags &= ~PF_FORKNOEXEC;
978 create_elf_tables(bprm, &loc->elf_ex,
979 (interpreter_type == INTERPRETER_AOUT),
980 load_addr, interp_load_addr);
981 /* N.B. passed_fileno might not be initialized? */
982 if (interpreter_type == INTERPRETER_AOUT)
983 current->mm->arg_start += strlen(passed_fileno) + 1;
984 current->mm->end_code = end_code;
985 current->mm->start_code = start_code;
986 current->mm->start_data = start_data;
987 current->mm->end_data = end_data;
988 current->mm->start_stack = bprm->p;
989
990 if (current->personality & MMAP_PAGE_ZERO) {
991 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
992 and some applications "depend" upon this behavior.
993 Since we do not have the power to recompile these, we
994 emulate the SVr4 behavior. Sigh. */
995 down_write(&current->mm->mmap_sem);
996 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
997 MAP_FIXED | MAP_PRIVATE, 0);
998 up_write(&current->mm->mmap_sem);
999 }
1000
1001 #ifdef ELF_PLAT_INIT
1002 /*
1003 * The ABI may specify that certain registers be set up in special
1004 * ways (on i386 %edx is the address of a DT_FINI function, for
1005 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1006 * that the e_entry field is the address of the function descriptor
1007 * for the startup routine, rather than the address of the startup
1008 * routine itself. This macro performs whatever initialization to
1009 * the regs structure is required as well as any relocations to the
1010 * function descriptor entries when executing dynamically links apps.
1011 */
1012 ELF_PLAT_INIT(regs, reloc_func_desc);
1013 #endif
1014
1015 start_thread(regs, elf_entry, bprm->p);
1016 if (unlikely(current->ptrace & PT_PTRACED)) {
1017 if (current->ptrace & PT_TRACE_EXEC)
1018 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
1019 else
1020 send_sig(SIGTRAP, current, 0);
1021 }
1022 retval = 0;
1023 out:
1024 kfree(loc);
1025 out_ret:
1026 return retval;
1027
1028 /* error cleanup */
1029 out_free_dentry:
1030 allow_write_access(interpreter);
1031 if (interpreter)
1032 fput(interpreter);
1033 out_free_interp:
1034 kfree(elf_interpreter);
1035 out_free_file:
1036 sys_close(elf_exec_fileno);
1037 out_free_fh:
1038 if (files)
1039 reset_files_struct(current, files);
1040 out_free_ph:
1041 kfree(elf_phdata);
1042 goto out;
1043 }
1044
1045 /* This is really simpleminded and specialized - we are loading an
1046 a.out library that is given an ELF header. */
1047 static int load_elf_library(struct file *file)
1048 {
1049 struct elf_phdr *elf_phdata;
1050 struct elf_phdr *eppnt;
1051 unsigned long elf_bss, bss, len;
1052 int retval, error, i, j;
1053 struct elfhdr elf_ex;
1054
1055 error = -ENOEXEC;
1056 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1057 if (retval != sizeof(elf_ex))
1058 goto out;
1059
1060 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1061 goto out;
1062
1063 /* First of all, some simple consistency checks */
1064 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1065 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1066 goto out;
1067
1068 /* Now read in all of the header information */
1069
1070 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1071 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1072
1073 error = -ENOMEM;
1074 elf_phdata = kmalloc(j, GFP_KERNEL);
1075 if (!elf_phdata)
1076 goto out;
1077
1078 eppnt = elf_phdata;
1079 error = -ENOEXEC;
1080 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1081 if (retval != j)
1082 goto out_free_ph;
1083
1084 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1085 if ((eppnt + i)->p_type == PT_LOAD)
1086 j++;
1087 if (j != 1)
1088 goto out_free_ph;
1089
1090 while (eppnt->p_type != PT_LOAD)
1091 eppnt++;
1092
1093 /* Now use mmap to map the library into memory. */
1094 down_write(&current->mm->mmap_sem);
1095 error = do_mmap(file,
1096 ELF_PAGESTART(eppnt->p_vaddr),
1097 (eppnt->p_filesz +
1098 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1099 PROT_READ | PROT_WRITE | PROT_EXEC,
1100 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1101 (eppnt->p_offset -
1102 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1103 up_write(&current->mm->mmap_sem);
1104 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1105 goto out_free_ph;
1106
1107 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1108 if (padzero(elf_bss)) {
1109 error = -EFAULT;
1110 goto out_free_ph;
1111 }
1112
1113 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1114 ELF_MIN_ALIGN - 1);
1115 bss = eppnt->p_memsz + eppnt->p_vaddr;
1116 if (bss > len) {
1117 down_write(&current->mm->mmap_sem);
1118 do_brk(len, bss - len);
1119 up_write(&current->mm->mmap_sem);
1120 }
1121 error = 0;
1122
1123 out_free_ph:
1124 kfree(elf_phdata);
1125 out:
1126 return error;
1127 }
1128
1129 /*
1130 * Note that some platforms still use traditional core dumps and not
1131 * the ELF core dump. Each platform can select it as appropriate.
1132 */
1133 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1134
1135 /*
1136 * ELF core dumper
1137 *
1138 * Modelled on fs/exec.c:aout_core_dump()
1139 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1140 */
1141 /*
1142 * These are the only things you should do on a core-file: use only these
1143 * functions to write out all the necessary info.
1144 */
1145 static int dump_write(struct file *file, const void *addr, int nr)
1146 {
1147 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1148 }
1149
1150 static int dump_seek(struct file *file, loff_t off)
1151 {
1152 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1153 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1154 return 0;
1155 } else {
1156 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1157 if (!buf)
1158 return 0;
1159 while (off > 0) {
1160 unsigned long n = off;
1161 if (n > PAGE_SIZE)
1162 n = PAGE_SIZE;
1163 if (!dump_write(file, buf, n))
1164 return 0;
1165 off -= n;
1166 }
1167 free_page((unsigned long)buf);
1168 }
1169 return 1;
1170 }
1171
1172 /*
1173 * Decide whether a segment is worth dumping; default is yes to be
1174 * sure (missing info is worse than too much; etc).
1175 * Personally I'd include everything, and use the coredump limit...
1176 *
1177 * I think we should skip something. But I am not sure how. H.J.
1178 */
1179 static int maydump(struct vm_area_struct *vma)
1180 {
1181 /* The vma can be set up to tell us the answer directly. */
1182 if (vma->vm_flags & VM_ALWAYSDUMP)
1183 return 1;
1184
1185 /* Do not dump I/O mapped devices or special mappings */
1186 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1187 return 0;
1188
1189 /* Dump shared memory only if mapped from an anonymous file. */
1190 if (vma->vm_flags & VM_SHARED)
1191 return vma->vm_file->f_path.dentry->d_inode->i_nlink == 0;
1192
1193 /* If it hasn't been written to, don't write it out */
1194 if (!vma->anon_vma)
1195 return 0;
1196
1197 return 1;
1198 }
1199
1200 /* An ELF note in memory */
1201 struct memelfnote
1202 {
1203 const char *name;
1204 int type;
1205 unsigned int datasz;
1206 void *data;
1207 };
1208
1209 static int notesize(struct memelfnote *en)
1210 {
1211 int sz;
1212
1213 sz = sizeof(struct elf_note);
1214 sz += roundup(strlen(en->name) + 1, 4);
1215 sz += roundup(en->datasz, 4);
1216
1217 return sz;
1218 }
1219
1220 #define DUMP_WRITE(addr, nr, foffset) \
1221 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1222
1223 static int alignfile(struct file *file, loff_t *foffset)
1224 {
1225 static const char buf[4] = { 0, };
1226 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1227 return 1;
1228 }
1229
1230 static int writenote(struct memelfnote *men, struct file *file,
1231 loff_t *foffset)
1232 {
1233 struct elf_note en;
1234 en.n_namesz = strlen(men->name) + 1;
1235 en.n_descsz = men->datasz;
1236 en.n_type = men->type;
1237
1238 DUMP_WRITE(&en, sizeof(en), foffset);
1239 DUMP_WRITE(men->name, en.n_namesz, foffset);
1240 if (!alignfile(file, foffset))
1241 return 0;
1242 DUMP_WRITE(men->data, men->datasz, foffset);
1243 if (!alignfile(file, foffset))
1244 return 0;
1245
1246 return 1;
1247 }
1248 #undef DUMP_WRITE
1249
1250 #define DUMP_WRITE(addr, nr) \
1251 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1252 goto end_coredump;
1253 #define DUMP_SEEK(off) \
1254 if (!dump_seek(file, (off))) \
1255 goto end_coredump;
1256
1257 static void fill_elf_header(struct elfhdr *elf, int segs)
1258 {
1259 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1260 elf->e_ident[EI_CLASS] = ELF_CLASS;
1261 elf->e_ident[EI_DATA] = ELF_DATA;
1262 elf->e_ident[EI_VERSION] = EV_CURRENT;
1263 elf->e_ident[EI_OSABI] = ELF_OSABI;
1264 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1265
1266 elf->e_type = ET_CORE;
1267 elf->e_machine = ELF_ARCH;
1268 elf->e_version = EV_CURRENT;
1269 elf->e_entry = 0;
1270 elf->e_phoff = sizeof(struct elfhdr);
1271 elf->e_shoff = 0;
1272 elf->e_flags = ELF_CORE_EFLAGS;
1273 elf->e_ehsize = sizeof(struct elfhdr);
1274 elf->e_phentsize = sizeof(struct elf_phdr);
1275 elf->e_phnum = segs;
1276 elf->e_shentsize = 0;
1277 elf->e_shnum = 0;
1278 elf->e_shstrndx = 0;
1279 return;
1280 }
1281
1282 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1283 {
1284 phdr->p_type = PT_NOTE;
1285 phdr->p_offset = offset;
1286 phdr->p_vaddr = 0;
1287 phdr->p_paddr = 0;
1288 phdr->p_filesz = sz;
1289 phdr->p_memsz = 0;
1290 phdr->p_flags = 0;
1291 phdr->p_align = 0;
1292 return;
1293 }
1294
1295 static void fill_note(struct memelfnote *note, const char *name, int type,
1296 unsigned int sz, void *data)
1297 {
1298 note->name = name;
1299 note->type = type;
1300 note->datasz = sz;
1301 note->data = data;
1302 return;
1303 }
1304
1305 /*
1306 * fill up all the fields in prstatus from the given task struct, except
1307 * registers which need to be filled up separately.
1308 */
1309 static void fill_prstatus(struct elf_prstatus *prstatus,
1310 struct task_struct *p, long signr)
1311 {
1312 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1313 prstatus->pr_sigpend = p->pending.signal.sig[0];
1314 prstatus->pr_sighold = p->blocked.sig[0];
1315 prstatus->pr_pid = p->pid;
1316 prstatus->pr_ppid = p->parent->pid;
1317 prstatus->pr_pgrp = process_group(p);
1318 prstatus->pr_sid = process_session(p);
1319 if (thread_group_leader(p)) {
1320 /*
1321 * This is the record for the group leader. Add in the
1322 * cumulative times of previous dead threads. This total
1323 * won't include the time of each live thread whose state
1324 * is included in the core dump. The final total reported
1325 * to our parent process when it calls wait4 will include
1326 * those sums as well as the little bit more time it takes
1327 * this and each other thread to finish dying after the
1328 * core dump synchronization phase.
1329 */
1330 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1331 &prstatus->pr_utime);
1332 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1333 &prstatus->pr_stime);
1334 } else {
1335 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1336 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1337 }
1338 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1339 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1340 }
1341
1342 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1343 struct mm_struct *mm)
1344 {
1345 unsigned int i, len;
1346
1347 /* first copy the parameters from user space */
1348 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1349
1350 len = mm->arg_end - mm->arg_start;
1351 if (len >= ELF_PRARGSZ)
1352 len = ELF_PRARGSZ-1;
1353 if (copy_from_user(&psinfo->pr_psargs,
1354 (const char __user *)mm->arg_start, len))
1355 return -EFAULT;
1356 for(i = 0; i < len; i++)
1357 if (psinfo->pr_psargs[i] == 0)
1358 psinfo->pr_psargs[i] = ' ';
1359 psinfo->pr_psargs[len] = 0;
1360
1361 psinfo->pr_pid = p->pid;
1362 psinfo->pr_ppid = p->parent->pid;
1363 psinfo->pr_pgrp = process_group(p);
1364 psinfo->pr_sid = process_session(p);
1365
1366 i = p->state ? ffz(~p->state) + 1 : 0;
1367 psinfo->pr_state = i;
1368 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1369 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1370 psinfo->pr_nice = task_nice(p);
1371 psinfo->pr_flag = p->flags;
1372 SET_UID(psinfo->pr_uid, p->uid);
1373 SET_GID(psinfo->pr_gid, p->gid);
1374 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1375
1376 return 0;
1377 }
1378
1379 /* Here is the structure in which status of each thread is captured. */
1380 struct elf_thread_status
1381 {
1382 struct list_head list;
1383 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1384 elf_fpregset_t fpu; /* NT_PRFPREG */
1385 struct task_struct *thread;
1386 #ifdef ELF_CORE_COPY_XFPREGS
1387 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1388 #endif
1389 struct memelfnote notes[3];
1390 int num_notes;
1391 };
1392
1393 /*
1394 * In order to add the specific thread information for the elf file format,
1395 * we need to keep a linked list of every threads pr_status and then create
1396 * a single section for them in the final core file.
1397 */
1398 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1399 {
1400 int sz = 0;
1401 struct task_struct *p = t->thread;
1402 t->num_notes = 0;
1403
1404 fill_prstatus(&t->prstatus, p, signr);
1405 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1406
1407 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1408 &(t->prstatus));
1409 t->num_notes++;
1410 sz += notesize(&t->notes[0]);
1411
1412 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1413 &t->fpu))) {
1414 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1415 &(t->fpu));
1416 t->num_notes++;
1417 sz += notesize(&t->notes[1]);
1418 }
1419
1420 #ifdef ELF_CORE_COPY_XFPREGS
1421 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1422 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1423 &t->xfpu);
1424 t->num_notes++;
1425 sz += notesize(&t->notes[2]);
1426 }
1427 #endif
1428 return sz;
1429 }
1430
1431 /*
1432 * Actual dumper
1433 *
1434 * This is a two-pass process; first we find the offsets of the bits,
1435 * and then they are actually written out. If we run out of core limit
1436 * we just truncate.
1437 */
1438 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
1439 {
1440 #define NUM_NOTES 6
1441 int has_dumped = 0;
1442 mm_segment_t fs;
1443 int segs;
1444 size_t size = 0;
1445 int i;
1446 struct vm_area_struct *vma;
1447 struct elfhdr *elf = NULL;
1448 loff_t offset = 0, dataoff, foffset;
1449 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1450 int numnote;
1451 struct memelfnote *notes = NULL;
1452 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1453 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1454 struct task_struct *g, *p;
1455 LIST_HEAD(thread_list);
1456 struct list_head *t;
1457 elf_fpregset_t *fpu = NULL;
1458 #ifdef ELF_CORE_COPY_XFPREGS
1459 elf_fpxregset_t *xfpu = NULL;
1460 #endif
1461 int thread_status_size = 0;
1462 elf_addr_t *auxv;
1463
1464 /*
1465 * We no longer stop all VM operations.
1466 *
1467 * This is because those proceses that could possibly change map_count
1468 * or the mmap / vma pages are now blocked in do_exit on current
1469 * finishing this core dump.
1470 *
1471 * Only ptrace can touch these memory addresses, but it doesn't change
1472 * the map_count or the pages allocated. So no possibility of crashing
1473 * exists while dumping the mm->vm_next areas to the core file.
1474 */
1475
1476 /* alloc memory for large data structures: too large to be on stack */
1477 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1478 if (!elf)
1479 goto cleanup;
1480 prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
1481 if (!prstatus)
1482 goto cleanup;
1483 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1484 if (!psinfo)
1485 goto cleanup;
1486 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1487 if (!notes)
1488 goto cleanup;
1489 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1490 if (!fpu)
1491 goto cleanup;
1492 #ifdef ELF_CORE_COPY_XFPREGS
1493 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1494 if (!xfpu)
1495 goto cleanup;
1496 #endif
1497
1498 if (signr) {
1499 struct elf_thread_status *tmp;
1500 rcu_read_lock();
1501 do_each_thread(g,p)
1502 if (current->mm == p->mm && current != p) {
1503 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1504 if (!tmp) {
1505 rcu_read_unlock();
1506 goto cleanup;
1507 }
1508 tmp->thread = p;
1509 list_add(&tmp->list, &thread_list);
1510 }
1511 while_each_thread(g,p);
1512 rcu_read_unlock();
1513 list_for_each(t, &thread_list) {
1514 struct elf_thread_status *tmp;
1515 int sz;
1516
1517 tmp = list_entry(t, struct elf_thread_status, list);
1518 sz = elf_dump_thread_status(signr, tmp);
1519 thread_status_size += sz;
1520 }
1521 }
1522 /* now collect the dump for the current */
1523 memset(prstatus, 0, sizeof(*prstatus));
1524 fill_prstatus(prstatus, current, signr);
1525 elf_core_copy_regs(&prstatus->pr_reg, regs);
1526
1527 segs = current->mm->map_count;
1528 #ifdef ELF_CORE_EXTRA_PHDRS
1529 segs += ELF_CORE_EXTRA_PHDRS;
1530 #endif
1531
1532 /* Set up header */
1533 fill_elf_header(elf, segs + 1); /* including notes section */
1534
1535 has_dumped = 1;
1536 current->flags |= PF_DUMPCORE;
1537
1538 /*
1539 * Set up the notes in similar form to SVR4 core dumps made
1540 * with info from their /proc.
1541 */
1542
1543 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1544 fill_psinfo(psinfo, current->group_leader, current->mm);
1545 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1546
1547 numnote = 2;
1548
1549 auxv = (elf_addr_t *)current->mm->saved_auxv;
1550
1551 i = 0;
1552 do
1553 i += 2;
1554 while (auxv[i - 2] != AT_NULL);
1555 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1556 i * sizeof(elf_addr_t), auxv);
1557
1558 /* Try to dump the FPU. */
1559 if ((prstatus->pr_fpvalid =
1560 elf_core_copy_task_fpregs(current, regs, fpu)))
1561 fill_note(notes + numnote++,
1562 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1563 #ifdef ELF_CORE_COPY_XFPREGS
1564 if (elf_core_copy_task_xfpregs(current, xfpu))
1565 fill_note(notes + numnote++,
1566 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1567 #endif
1568
1569 fs = get_fs();
1570 set_fs(KERNEL_DS);
1571
1572 DUMP_WRITE(elf, sizeof(*elf));
1573 offset += sizeof(*elf); /* Elf header */
1574 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1575 foffset = offset;
1576
1577 /* Write notes phdr entry */
1578 {
1579 struct elf_phdr phdr;
1580 int sz = 0;
1581
1582 for (i = 0; i < numnote; i++)
1583 sz += notesize(notes + i);
1584
1585 sz += thread_status_size;
1586
1587 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1588 sz += ELF_CORE_EXTRA_NOTES_SIZE;
1589 #endif
1590
1591 fill_elf_note_phdr(&phdr, sz, offset);
1592 offset += sz;
1593 DUMP_WRITE(&phdr, sizeof(phdr));
1594 }
1595
1596 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1597
1598 /* Write program headers for segments dump */
1599 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1600 struct elf_phdr phdr;
1601 size_t sz;
1602
1603 sz = vma->vm_end - vma->vm_start;
1604
1605 phdr.p_type = PT_LOAD;
1606 phdr.p_offset = offset;
1607 phdr.p_vaddr = vma->vm_start;
1608 phdr.p_paddr = 0;
1609 phdr.p_filesz = maydump(vma) ? sz : 0;
1610 phdr.p_memsz = sz;
1611 offset += phdr.p_filesz;
1612 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1613 if (vma->vm_flags & VM_WRITE)
1614 phdr.p_flags |= PF_W;
1615 if (vma->vm_flags & VM_EXEC)
1616 phdr.p_flags |= PF_X;
1617 phdr.p_align = ELF_EXEC_PAGESIZE;
1618
1619 DUMP_WRITE(&phdr, sizeof(phdr));
1620 }
1621
1622 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1623 ELF_CORE_WRITE_EXTRA_PHDRS;
1624 #endif
1625
1626 /* write out the notes section */
1627 for (i = 0; i < numnote; i++)
1628 if (!writenote(notes + i, file, &foffset))
1629 goto end_coredump;
1630
1631 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1632 ELF_CORE_WRITE_EXTRA_NOTES;
1633 #endif
1634
1635 /* write out the thread status notes section */
1636 list_for_each(t, &thread_list) {
1637 struct elf_thread_status *tmp =
1638 list_entry(t, struct elf_thread_status, list);
1639
1640 for (i = 0; i < tmp->num_notes; i++)
1641 if (!writenote(&tmp->notes[i], file, &foffset))
1642 goto end_coredump;
1643 }
1644
1645 /* Align to page */
1646 DUMP_SEEK(dataoff - foffset);
1647
1648 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1649 unsigned long addr;
1650
1651 if (!maydump(vma))
1652 continue;
1653
1654 for (addr = vma->vm_start;
1655 addr < vma->vm_end;
1656 addr += PAGE_SIZE) {
1657 struct page *page;
1658 struct vm_area_struct *vma;
1659
1660 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1661 &page, &vma) <= 0) {
1662 DUMP_SEEK(PAGE_SIZE);
1663 } else {
1664 if (page == ZERO_PAGE(addr)) {
1665 DUMP_SEEK(PAGE_SIZE);
1666 } else {
1667 void *kaddr;
1668 flush_cache_page(vma, addr,
1669 page_to_pfn(page));
1670 kaddr = kmap(page);
1671 if ((size += PAGE_SIZE) > limit ||
1672 !dump_write(file, kaddr,
1673 PAGE_SIZE)) {
1674 kunmap(page);
1675 page_cache_release(page);
1676 goto end_coredump;
1677 }
1678 kunmap(page);
1679 }
1680 page_cache_release(page);
1681 }
1682 }
1683 }
1684
1685 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1686 ELF_CORE_WRITE_EXTRA_DATA;
1687 #endif
1688
1689 end_coredump:
1690 set_fs(fs);
1691
1692 cleanup:
1693 while (!list_empty(&thread_list)) {
1694 struct list_head *tmp = thread_list.next;
1695 list_del(tmp);
1696 kfree(list_entry(tmp, struct elf_thread_status, list));
1697 }
1698
1699 kfree(elf);
1700 kfree(prstatus);
1701 kfree(psinfo);
1702 kfree(notes);
1703 kfree(fpu);
1704 #ifdef ELF_CORE_COPY_XFPREGS
1705 kfree(xfpu);
1706 #endif
1707 return has_dumped;
1708 #undef NUM_NOTES
1709 }
1710
1711 #endif /* USE_ELF_CORE_DUMP */
1712
1713 static int __init init_elf_binfmt(void)
1714 {
1715 return register_binfmt(&elf_format);
1716 }
1717
1718 static void __exit exit_elf_binfmt(void)
1719 {
1720 /* Remove the COFF and ELF loaders. */
1721 unregister_binfmt(&elf_format);
1722 }
1723
1724 core_initcall(init_elf_binfmt);
1725 module_exit(exit_elf_binfmt);
1726 MODULE_LICENSE("GPL");
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