?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
[NETFILTER]: nf_conntrack: add helper function for expectation initialization
[hh.org.git] / fs / binfmt_elf.c
blob79b05a1a436582ebfd2415a682cce4a322be00d5
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 #ifndef elf_addr_t
51 #define elf_addr_t unsigned long
52 #endif
53
54 /*
55 * If we don't support core dumping, then supply a NULL so we
56 * don't even try.
57 */
58 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
59 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file);
60 #else
61 #define elf_core_dump NULL
62 #endif
63
64 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
65 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
66 #else
67 #define ELF_MIN_ALIGN PAGE_SIZE
68 #endif
69
70 #ifndef ELF_CORE_EFLAGS
71 #define ELF_CORE_EFLAGS 0
72 #endif
73
74 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
75 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
76 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
77
78 static struct linux_binfmt elf_format = {
79 .module = THIS_MODULE,
80 .load_binary = load_elf_binary,
81 .load_shlib = load_elf_library,
82 .core_dump = elf_core_dump,
83 .min_coredump = ELF_EXEC_PAGESIZE
84 };
85
86 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
87
88 static int set_brk(unsigned long start, unsigned long end)
89 {
90 start = ELF_PAGEALIGN(start);
91 end = ELF_PAGEALIGN(end);
92 if (end > start) {
93 unsigned long addr;
94 down_write(&current->mm->mmap_sem);
95 addr = do_brk(start, end - start);
96 up_write(&current->mm->mmap_sem);
97 if (BAD_ADDR(addr))
98 return addr;
99 }
100 current->mm->start_brk = current->mm->brk = end;
101 return 0;
102 }
103
104 /* We need to explicitly zero any fractional pages
105 after the data section (i.e. bss). This would
106 contain the junk from the file that should not
107 be in memory
108 */
109 static int padzero(unsigned long elf_bss)
110 {
111 unsigned long nbyte;
112
113 nbyte = ELF_PAGEOFFSET(elf_bss);
114 if (nbyte) {
115 nbyte = ELF_MIN_ALIGN - nbyte;
116 if (clear_user((void __user *) elf_bss, nbyte))
117 return -EFAULT;
118 }
119 return 0;
120 }
121
122 /* Let's use some macros to make this stack manipulation a litle clearer */
123 #ifdef CONFIG_STACK_GROWSUP
124 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
125 #define STACK_ROUND(sp, items) \
126 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
127 #define STACK_ALLOC(sp, len) ({ \
128 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
129 old_sp; })
130 #else
131 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
132 #define STACK_ROUND(sp, items) \
133 (((unsigned long) (sp - items)) &~ 15UL)
134 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
135 #endif
136
137 static int
138 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
139 int interp_aout, unsigned long load_addr,
140 unsigned long interp_load_addr)
141 {
142 unsigned long p = bprm->p;
143 int argc = bprm->argc;
144 int envc = bprm->envc;
145 elf_addr_t __user *argv;
146 elf_addr_t __user *envp;
147 elf_addr_t __user *sp;
148 elf_addr_t __user *u_platform;
149 const char *k_platform = ELF_PLATFORM;
150 int items;
151 elf_addr_t *elf_info;
152 int ei_index = 0;
153 struct task_struct *tsk = current;
154
155 /*
156 * If this architecture has a platform capability string, copy it
157 * to userspace. In some cases (Sparc), this info is impossible
158 * for userspace to get any other way, in others (i386) it is
159 * merely difficult.
160 */
161 u_platform = NULL;
162 if (k_platform) {
163 size_t len = strlen(k_platform) + 1;
164
165 /*
166 * In some cases (e.g. Hyper-Threading), we want to avoid L1
167 * evictions by the processes running on the same package. One
168 * thing we can do is to shuffle the initial stack for them.
169 */
170
171 p = arch_align_stack(p);
172
173 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
174 if (__copy_to_user(u_platform, k_platform, len))
175 return -EFAULT;
176 }
177
178 /* Create the ELF interpreter info */
179 elf_info = (elf_addr_t *)current->mm->saved_auxv;
180 #define NEW_AUX_ENT(id, val) \
181 do { \
182 elf_info[ei_index++] = id; \
183 elf_info[ei_index++] = val; \
184 } while (0)
185
186 #ifdef ARCH_DLINFO
187 /*
188 * ARCH_DLINFO must come first so PPC can do its special alignment of
189 * AUXV.
190 */
191 ARCH_DLINFO;
192 #endif
193 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
194 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
195 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
196 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
197 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
198 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
199 NEW_AUX_ENT(AT_BASE, interp_load_addr);
200 NEW_AUX_ENT(AT_FLAGS, 0);
201 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
202 NEW_AUX_ENT(AT_UID, tsk->uid);
203 NEW_AUX_ENT(AT_EUID, tsk->euid);
204 NEW_AUX_ENT(AT_GID, tsk->gid);
205 NEW_AUX_ENT(AT_EGID, tsk->egid);
206 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
207 if (k_platform) {
208 NEW_AUX_ENT(AT_PLATFORM,
209 (elf_addr_t)(unsigned long)u_platform);
210 }
211 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
212 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
213 }
214 #undef NEW_AUX_ENT
215 /* AT_NULL is zero; clear the rest too */
216 memset(&elf_info[ei_index], 0,
217 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
218
219 /* And advance past the AT_NULL entry. */
220 ei_index += 2;
221
222 sp = STACK_ADD(p, ei_index);
223
224 items = (argc + 1) + (envc + 1);
225 if (interp_aout) {
226 items += 3; /* a.out interpreters require argv & envp too */
227 } else {
228 items += 1; /* ELF interpreters only put argc on the stack */
229 }
230 bprm->p = STACK_ROUND(sp, items);
231
232 /* Point sp at the lowest address on the stack */
233 #ifdef CONFIG_STACK_GROWSUP
234 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
235 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
236 #else
237 sp = (elf_addr_t __user *)bprm->p;
238 #endif
239
240 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
241 if (__put_user(argc, sp++))
242 return -EFAULT;
243 if (interp_aout) {
244 argv = sp + 2;
245 envp = argv + argc + 1;
246 __put_user((elf_addr_t)(unsigned long)argv, sp++);
247 __put_user((elf_addr_t)(unsigned long)envp, sp++);
248 } else {
249 argv = sp;
250 envp = argv + argc + 1;
251 }
252
253 /* Populate argv and envp */
254 p = current->mm->arg_end = current->mm->arg_start;
255 while (argc-- > 0) {
256 size_t len;
257 __put_user((elf_addr_t)p, argv++);
258 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
259 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
260 return 0;
261 p += len;
262 }
263 if (__put_user(0, argv))
264 return -EFAULT;
265 current->mm->arg_end = current->mm->env_start = p;
266 while (envc-- > 0) {
267 size_t len;
268 __put_user((elf_addr_t)p, envp++);
269 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
270 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
271 return 0;
272 p += len;
273 }
274 if (__put_user(0, envp))
275 return -EFAULT;
276 current->mm->env_end = p;
277
278 /* Put the elf_info on the stack in the right place. */
279 sp = (elf_addr_t __user *)envp + 1;
280 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
281 return -EFAULT;
282 return 0;
283 }
284
285 #ifndef elf_map
286
287 static unsigned long elf_map(struct file *filep, unsigned long addr,
288 struct elf_phdr *eppnt, int prot, int type)
289 {
290 unsigned long map_addr;
291 unsigned long pageoffset = ELF_PAGEOFFSET(eppnt->p_vaddr);
292
293 down_write(&current->mm->mmap_sem);
294 /* mmap() will return -EINVAL if given a zero size, but a
295 * segment with zero filesize is perfectly valid */
296 if (eppnt->p_filesz + pageoffset)
297 map_addr = do_mmap(filep, ELF_PAGESTART(addr),
298 eppnt->p_filesz + pageoffset, prot, type,
299 eppnt->p_offset - pageoffset);
300 else
301 map_addr = ELF_PAGESTART(addr);
302 up_write(&current->mm->mmap_sem);
303 return(map_addr);
304 }
305
306 #endif /* !elf_map */
307
308 /* This is much more generalized than the library routine read function,
309 so we keep this separate. Technically the library read function
310 is only provided so that we can read a.out libraries that have
311 an ELF header */
312
313 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
314 struct file *interpreter, unsigned long *interp_load_addr)
315 {
316 struct elf_phdr *elf_phdata;
317 struct elf_phdr *eppnt;
318 unsigned long load_addr = 0;
319 int load_addr_set = 0;
320 unsigned long last_bss = 0, elf_bss = 0;
321 unsigned long error = ~0UL;
322 int retval, i, size;
323
324 /* First of all, some simple consistency checks */
325 if (interp_elf_ex->e_type != ET_EXEC &&
326 interp_elf_ex->e_type != ET_DYN)
327 goto out;
328 if (!elf_check_arch(interp_elf_ex))
329 goto out;
330 if (!interpreter->f_op || !interpreter->f_op->mmap)
331 goto out;
332
333 /*
334 * If the size of this structure has changed, then punt, since
335 * we will be doing the wrong thing.
336 */
337 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
338 goto out;
339 if (interp_elf_ex->e_phnum < 1 ||
340 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
341 goto out;
342
343 /* Now read in all of the header information */
344 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
345 if (size > ELF_MIN_ALIGN)
346 goto out;
347 elf_phdata = kmalloc(size, GFP_KERNEL);
348 if (!elf_phdata)
349 goto out;
350
351 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
352 (char *)elf_phdata,size);
353 error = -EIO;
354 if (retval != size) {
355 if (retval < 0)
356 error = retval;
357 goto out_close;
358 }
359
360 eppnt = elf_phdata;
361 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
362 if (eppnt->p_type == PT_LOAD) {
363 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
364 int elf_prot = 0;
365 unsigned long vaddr = 0;
366 unsigned long k, map_addr;
367
368 if (eppnt->p_flags & PF_R)
369 elf_prot = PROT_READ;
370 if (eppnt->p_flags & PF_W)
371 elf_prot |= PROT_WRITE;
372 if (eppnt->p_flags & PF_X)
373 elf_prot |= PROT_EXEC;
374 vaddr = eppnt->p_vaddr;
375 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
376 elf_type |= MAP_FIXED;
377
378 map_addr = elf_map(interpreter, load_addr + vaddr,
379 eppnt, elf_prot, elf_type);
380 error = map_addr;
381 if (BAD_ADDR(map_addr))
382 goto out_close;
383
384 if (!load_addr_set &&
385 interp_elf_ex->e_type == ET_DYN) {
386 load_addr = map_addr - ELF_PAGESTART(vaddr);
387 load_addr_set = 1;
388 }
389
390 /*
391 * Check to see if the section's size will overflow the
392 * allowed task size. Note that p_filesz must always be
393 * <= p_memsize so it's only necessary to check p_memsz.
394 */
395 k = load_addr + eppnt->p_vaddr;
396 if (BAD_ADDR(k) ||
397 eppnt->p_filesz > eppnt->p_memsz ||
398 eppnt->p_memsz > TASK_SIZE ||
399 TASK_SIZE - eppnt->p_memsz < k) {
400 error = -ENOMEM;
401 goto out_close;
402 }
403
404 /*
405 * Find the end of the file mapping for this phdr, and
406 * keep track of the largest address we see for this.
407 */
408 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
409 if (k > elf_bss)
410 elf_bss = k;
411
412 /*
413 * Do the same thing for the memory mapping - between
414 * elf_bss and last_bss is the bss section.
415 */
416 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
417 if (k > last_bss)
418 last_bss = k;
419 }
420 }
421
422 /*
423 * Now fill out the bss section. First pad the last page up
424 * to the page boundary, and then perform a mmap to make sure
425 * that there are zero-mapped pages up to and including the
426 * last bss page.
427 */
428 if (padzero(elf_bss)) {
429 error = -EFAULT;
430 goto out_close;
431 }
432
433 /* What we have mapped so far */
434 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
435
436 /* Map the last of the bss segment */
437 if (last_bss > elf_bss) {
438 down_write(&current->mm->mmap_sem);
439 error = do_brk(elf_bss, last_bss - elf_bss);
440 up_write(&current->mm->mmap_sem);
441 if (BAD_ADDR(error))
442 goto out_close;
443 }
444
445 *interp_load_addr = load_addr;
446 error = ((unsigned long)interp_elf_ex->e_entry) + load_addr;
447
448 out_close:
449 kfree(elf_phdata);
450 out:
451 return error;
452 }
453
454 static unsigned long load_aout_interp(struct exec *interp_ex,
455 struct file *interpreter)
456 {
457 unsigned long text_data, elf_entry = ~0UL;
458 char __user * addr;
459 loff_t offset;
460
461 current->mm->end_code = interp_ex->a_text;
462 text_data = interp_ex->a_text + interp_ex->a_data;
463 current->mm->end_data = text_data;
464 current->mm->brk = interp_ex->a_bss + text_data;
465
466 switch (N_MAGIC(*interp_ex)) {
467 case OMAGIC:
468 offset = 32;
469 addr = (char __user *)0;
470 break;
471 case ZMAGIC:
472 case QMAGIC:
473 offset = N_TXTOFF(*interp_ex);
474 addr = (char __user *)N_TXTADDR(*interp_ex);
475 break;
476 default:
477 goto out;
478 }
479
480 down_write(&current->mm->mmap_sem);
481 do_brk(0, text_data);
482 up_write(&current->mm->mmap_sem);
483 if (!interpreter->f_op || !interpreter->f_op->read)
484 goto out;
485 if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0)
486 goto out;
487 flush_icache_range((unsigned long)addr,
488 (unsigned long)addr + text_data);
489
490 down_write(&current->mm->mmap_sem);
491 do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
492 interp_ex->a_bss);
493 up_write(&current->mm->mmap_sem);
494 elf_entry = interp_ex->a_entry;
495
496 out:
497 return elf_entry;
498 }
499
500 /*
501 * These are the functions used to load ELF style executables and shared
502 * libraries. There is no binary dependent code anywhere else.
503 */
504
505 #define INTERPRETER_NONE 0
506 #define INTERPRETER_AOUT 1
507 #define INTERPRETER_ELF 2
508
509 #ifndef STACK_RND_MASK
510 #define STACK_RND_MASK 0x7ff /* with 4K pages 8MB of VA */
511 #endif
512
513 static unsigned long randomize_stack_top(unsigned long stack_top)
514 {
515 unsigned int random_variable = 0;
516
517 if ((current->flags & PF_RANDOMIZE) &&
518 !(current->personality & ADDR_NO_RANDOMIZE)) {
519 random_variable = get_random_int() & STACK_RND_MASK;
520 random_variable <<= PAGE_SHIFT;
521 }
522 #ifdef CONFIG_STACK_GROWSUP
523 return PAGE_ALIGN(stack_top) + random_variable;
524 #else
525 return PAGE_ALIGN(stack_top) - random_variable;
526 #endif
527 }
528
529 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
530 {
531 struct file *interpreter = NULL; /* to shut gcc up */
532 unsigned long load_addr = 0, load_bias = 0;
533 int load_addr_set = 0;
534 char * elf_interpreter = NULL;
535 unsigned int interpreter_type = INTERPRETER_NONE;
536 unsigned char ibcs2_interpreter = 0;
537 unsigned long error;
538 struct elf_phdr *elf_ppnt, *elf_phdata;
539 unsigned long elf_bss, elf_brk;
540 int elf_exec_fileno;
541 int retval, i;
542 unsigned int size;
543 unsigned long elf_entry, interp_load_addr = 0;
544 unsigned long start_code, end_code, start_data, end_data;
545 unsigned long reloc_func_desc = 0;
546 char passed_fileno[6];
547 struct files_struct *files;
548 int have_pt_gnu_stack, executable_stack = EXSTACK_DEFAULT;
549 unsigned long def_flags = 0;
550 struct {
551 struct elfhdr elf_ex;
552 struct elfhdr interp_elf_ex;
553 struct exec interp_ex;
554 } *loc;
555
556 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
557 if (!loc) {
558 retval = -ENOMEM;
559 goto out_ret;
560 }
561
562 /* Get the exec-header */
563 loc->elf_ex = *((struct elfhdr *)bprm->buf);
564
565 retval = -ENOEXEC;
566 /* First of all, some simple consistency checks */
567 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
568 goto out;
569
570 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
571 goto out;
572 if (!elf_check_arch(&loc->elf_ex))
573 goto out;
574 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
575 goto out;
576
577 /* Now read in all of the header information */
578 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
579 goto out;
580 if (loc->elf_ex.e_phnum < 1 ||
581 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
582 goto out;
583 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
584 retval = -ENOMEM;
585 elf_phdata = kmalloc(size, GFP_KERNEL);
586 if (!elf_phdata)
587 goto out;
588
589 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
590 (char *)elf_phdata, size);
591 if (retval != size) {
592 if (retval >= 0)
593 retval = -EIO;
594 goto out_free_ph;
595 }
596
597 files = current->files; /* Refcounted so ok */
598 retval = unshare_files();
599 if (retval < 0)
600 goto out_free_ph;
601 if (files == current->files) {
602 put_files_struct(files);
603 files = NULL;
604 }
605
606 /* exec will make our files private anyway, but for the a.out
607 loader stuff we need to do it earlier */
608 retval = get_unused_fd();
609 if (retval < 0)
610 goto out_free_fh;
611 get_file(bprm->file);
612 fd_install(elf_exec_fileno = retval, bprm->file);
613
614 elf_ppnt = elf_phdata;
615 elf_bss = 0;
616 elf_brk = 0;
617
618 start_code = ~0UL;
619 end_code = 0;
620 start_data = 0;
621 end_data = 0;
622
623 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
624 if (elf_ppnt->p_type == PT_INTERP) {
625 /* This is the program interpreter used for
626 * shared libraries - for now assume that this
627 * is an a.out format binary
628 */
629 retval = -ENOEXEC;
630 if (elf_ppnt->p_filesz > PATH_MAX ||
631 elf_ppnt->p_filesz < 2)
632 goto out_free_file;
633
634 retval = -ENOMEM;
635 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
636 GFP_KERNEL);
637 if (!elf_interpreter)
638 goto out_free_file;
639
640 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
641 elf_interpreter,
642 elf_ppnt->p_filesz);
643 if (retval != elf_ppnt->p_filesz) {
644 if (retval >= 0)
645 retval = -EIO;
646 goto out_free_interp;
647 }
648 /* make sure path is NULL terminated */
649 retval = -ENOEXEC;
650 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
651 goto out_free_interp;
652
653 /* If the program interpreter is one of these two,
654 * then assume an iBCS2 image. Otherwise assume
655 * a native linux image.
656 */
657 if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
658 strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0)
659 ibcs2_interpreter = 1;
660
661 /*
662 * The early SET_PERSONALITY here is so that the lookup
663 * for the interpreter happens in the namespace of the
664 * to-be-execed image. SET_PERSONALITY can select an
665 * alternate root.
666 *
667 * However, SET_PERSONALITY is NOT allowed to switch
668 * this task into the new images's memory mapping
669 * policy - that is, TASK_SIZE must still evaluate to
670 * that which is appropriate to the execing application.
671 * This is because exit_mmap() needs to have TASK_SIZE
672 * evaluate to the size of the old image.
673 *
674 * So if (say) a 64-bit application is execing a 32-bit
675 * application it is the architecture's responsibility
676 * to defer changing the value of TASK_SIZE until the
677 * switch really is going to happen - do this in
678 * flush_thread(). - akpm
679 */
680 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
681
682 interpreter = open_exec(elf_interpreter);
683 retval = PTR_ERR(interpreter);
684 if (IS_ERR(interpreter))
685 goto out_free_interp;
686 retval = kernel_read(interpreter, 0, bprm->buf,
687 BINPRM_BUF_SIZE);
688 if (retval != BINPRM_BUF_SIZE) {
689 if (retval >= 0)
690 retval = -EIO;
691 goto out_free_dentry;
692 }
693
694 /* Get the exec headers */
695 loc->interp_ex = *((struct exec *)bprm->buf);
696 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
697 break;
698 }
699 elf_ppnt++;
700 }
701
702 elf_ppnt = elf_phdata;
703 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
704 if (elf_ppnt->p_type == PT_GNU_STACK) {
705 if (elf_ppnt->p_flags & PF_X)
706 executable_stack = EXSTACK_ENABLE_X;
707 else
708 executable_stack = EXSTACK_DISABLE_X;
709 break;
710 }
711 have_pt_gnu_stack = (i < loc->elf_ex.e_phnum);
712
713 /* Some simple consistency checks for the interpreter */
714 if (elf_interpreter) {
715 interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
716
717 /* Now figure out which format our binary is */
718 if ((N_MAGIC(loc->interp_ex) != OMAGIC) &&
719 (N_MAGIC(loc->interp_ex) != ZMAGIC) &&
720 (N_MAGIC(loc->interp_ex) != QMAGIC))
721 interpreter_type = INTERPRETER_ELF;
722
723 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
724 interpreter_type &= ~INTERPRETER_ELF;
725
726 retval = -ELIBBAD;
727 if (!interpreter_type)
728 goto out_free_dentry;
729
730 /* Make sure only one type was selected */
731 if ((interpreter_type & INTERPRETER_ELF) &&
732 interpreter_type != INTERPRETER_ELF) {
733 // FIXME - ratelimit this before re-enabling
734 // printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n");
735 interpreter_type = INTERPRETER_ELF;
736 }
737 /* Verify the interpreter has a valid arch */
738 if ((interpreter_type == INTERPRETER_ELF) &&
739 !elf_check_arch(&loc->interp_elf_ex))
740 goto out_free_dentry;
741 } else {
742 /* Executables without an interpreter also need a personality */
743 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
744 }
745
746 /* OK, we are done with that, now set up the arg stuff,
747 and then start this sucker up */
748 if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) {
749 char *passed_p = passed_fileno;
750 sprintf(passed_fileno, "%d", elf_exec_fileno);
751
752 if (elf_interpreter) {
753 retval = copy_strings_kernel(1, &passed_p, bprm);
754 if (retval)
755 goto out_free_dentry;
756 bprm->argc++;
757 }
758 }
759
760 /* Flush all traces of the currently running executable */
761 retval = flush_old_exec(bprm);
762 if (retval)
763 goto out_free_dentry;
764
765 /* Discard our unneeded old files struct */
766 if (files) {
767 put_files_struct(files);
768 files = NULL;
769 }
770
771 /* OK, This is the point of no return */
772 current->mm->start_data = 0;
773 current->mm->end_data = 0;
774 current->mm->end_code = 0;
775 current->mm->mmap = NULL;
776 current->flags &= ~PF_FORKNOEXEC;
777 current->mm->def_flags = def_flags;
778
779 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
780 may depend on the personality. */
781 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
782 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
783 current->personality |= READ_IMPLIES_EXEC;
784
785 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
786 current->flags |= PF_RANDOMIZE;
787 arch_pick_mmap_layout(current->mm);
788
789 /* Do this so that we can load the interpreter, if need be. We will
790 change some of these later */
791 current->mm->free_area_cache = current->mm->mmap_base;
792 current->mm->cached_hole_size = 0;
793 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
794 executable_stack);
795 if (retval < 0) {
796 send_sig(SIGKILL, current, 0);
797 goto out_free_dentry;
798 }
799
800 current->mm->start_stack = bprm->p;
801
802 /* Now we do a little grungy work by mmaping the ELF image into
803 the correct location in memory. At this point, we assume that
804 the image should be loaded at fixed address, not at a variable
805 address. */
806 for(i = 0, elf_ppnt = elf_phdata;
807 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
808 int elf_prot = 0, elf_flags;
809 unsigned long k, vaddr;
810
811 if (elf_ppnt->p_type != PT_LOAD)
812 continue;
813
814 if (unlikely (elf_brk > elf_bss)) {
815 unsigned long nbyte;
816
817 /* There was a PT_LOAD segment with p_memsz > p_filesz
818 before this one. Map anonymous pages, if needed,
819 and clear the area. */
820 retval = set_brk (elf_bss + load_bias,
821 elf_brk + load_bias);
822 if (retval) {
823 send_sig(SIGKILL, current, 0);
824 goto out_free_dentry;
825 }
826 nbyte = ELF_PAGEOFFSET(elf_bss);
827 if (nbyte) {
828 nbyte = ELF_MIN_ALIGN - nbyte;
829 if (nbyte > elf_brk - elf_bss)
830 nbyte = elf_brk - elf_bss;
831 if (clear_user((void __user *)elf_bss +
832 load_bias, nbyte)) {
833 /*
834 * This bss-zeroing can fail if the ELF
835 * file specifies odd protections. So
836 * we don't check the return value
837 */
838 }
839 }
840 }
841
842 if (elf_ppnt->p_flags & PF_R)
843 elf_prot |= PROT_READ;
844 if (elf_ppnt->p_flags & PF_W)
845 elf_prot |= PROT_WRITE;
846 if (elf_ppnt->p_flags & PF_X)
847 elf_prot |= PROT_EXEC;
848
849 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
850
851 vaddr = elf_ppnt->p_vaddr;
852 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
853 elf_flags |= MAP_FIXED;
854 } else if (loc->elf_ex.e_type == ET_DYN) {
855 /* Try and get dynamic programs out of the way of the
856 * default mmap base, as well as whatever program they
857 * might try to exec. This is because the brk will
858 * follow the loader, and is not movable. */
859 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
860 }
861
862 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
863 elf_prot, elf_flags);
864 if (BAD_ADDR(error)) {
865 send_sig(SIGKILL, current, 0);
866 goto out_free_dentry;
867 }
868
869 if (!load_addr_set) {
870 load_addr_set = 1;
871 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
872 if (loc->elf_ex.e_type == ET_DYN) {
873 load_bias += error -
874 ELF_PAGESTART(load_bias + vaddr);
875 load_addr += load_bias;
876 reloc_func_desc = load_bias;
877 }
878 }
879 k = elf_ppnt->p_vaddr;
880 if (k < start_code)
881 start_code = k;
882 if (start_data < k)
883 start_data = k;
884
885 /*
886 * Check to see if the section's size will overflow the
887 * allowed task size. Note that p_filesz must always be
888 * <= p_memsz so it is only necessary to check p_memsz.
889 */
890 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
891 elf_ppnt->p_memsz > TASK_SIZE ||
892 TASK_SIZE - elf_ppnt->p_memsz < k) {
893 /* set_brk can never work. Avoid overflows. */
894 send_sig(SIGKILL, current, 0);
895 goto out_free_dentry;
896 }
897
898 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
899
900 if (k > elf_bss)
901 elf_bss = k;
902 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
903 end_code = k;
904 if (end_data < k)
905 end_data = k;
906 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
907 if (k > elf_brk)
908 elf_brk = k;
909 }
910
911 loc->elf_ex.e_entry += load_bias;
912 elf_bss += load_bias;
913 elf_brk += load_bias;
914 start_code += load_bias;
915 end_code += load_bias;
916 start_data += load_bias;
917 end_data += load_bias;
918
919 /* Calling set_brk effectively mmaps the pages that we need
920 * for the bss and break sections. We must do this before
921 * mapping in the interpreter, to make sure it doesn't wind
922 * up getting placed where the bss needs to go.
923 */
924 retval = set_brk(elf_bss, elf_brk);
925 if (retval) {
926 send_sig(SIGKILL, current, 0);
927 goto out_free_dentry;
928 }
929 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
930 send_sig(SIGSEGV, current, 0);
931 retval = -EFAULT; /* Nobody gets to see this, but.. */
932 goto out_free_dentry;
933 }
934
935 if (elf_interpreter) {
936 if (interpreter_type == INTERPRETER_AOUT)
937 elf_entry = load_aout_interp(&loc->interp_ex,
938 interpreter);
939 else
940 elf_entry = load_elf_interp(&loc->interp_elf_ex,
941 interpreter,
942 &interp_load_addr);
943 if (BAD_ADDR(elf_entry)) {
944 force_sig(SIGSEGV, current);
945 retval = IS_ERR((void *)elf_entry) ?
946 (int)elf_entry : -EINVAL;
947 goto out_free_dentry;
948 }
949 reloc_func_desc = interp_load_addr;
950
951 allow_write_access(interpreter);
952 fput(interpreter);
953 kfree(elf_interpreter);
954 } else {
955 elf_entry = loc->elf_ex.e_entry;
956 if (BAD_ADDR(elf_entry)) {
957 force_sig(SIGSEGV, current);
958 retval = -EINVAL;
959 goto out_free_dentry;
960 }
961 }
962
963 kfree(elf_phdata);
964
965 if (interpreter_type != INTERPRETER_AOUT)
966 sys_close(elf_exec_fileno);
967
968 set_binfmt(&elf_format);
969
970 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
971 retval = arch_setup_additional_pages(bprm, executable_stack);
972 if (retval < 0) {
973 send_sig(SIGKILL, current, 0);
974 goto out;
975 }
976 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
977
978 compute_creds(bprm);
979 current->flags &= ~PF_FORKNOEXEC;
980 create_elf_tables(bprm, &loc->elf_ex,
981 (interpreter_type == INTERPRETER_AOUT),
982 load_addr, interp_load_addr);
983 /* N.B. passed_fileno might not be initialized? */
984 if (interpreter_type == INTERPRETER_AOUT)
985 current->mm->arg_start += strlen(passed_fileno) + 1;
986 current->mm->end_code = end_code;
987 current->mm->start_code = start_code;
988 current->mm->start_data = start_data;
989 current->mm->end_data = end_data;
990 current->mm->start_stack = bprm->p;
991
992 if (current->personality & MMAP_PAGE_ZERO) {
993 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
994 and some applications "depend" upon this behavior.
995 Since we do not have the power to recompile these, we
996 emulate the SVr4 behavior. Sigh. */
997 down_write(&current->mm->mmap_sem);
998 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
999 MAP_FIXED | MAP_PRIVATE, 0);
1000 up_write(&current->mm->mmap_sem);
1001 }
1002
1003 #ifdef ELF_PLAT_INIT
1004 /*
1005 * The ABI may specify that certain registers be set up in special
1006 * ways (on i386 %edx is the address of a DT_FINI function, for
1007 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1008 * that the e_entry field is the address of the function descriptor
1009 * for the startup routine, rather than the address of the startup
1010 * routine itself. This macro performs whatever initialization to
1011 * the regs structure is required as well as any relocations to the
1012 * function descriptor entries when executing dynamically links apps.
1013 */
1014 ELF_PLAT_INIT(regs, reloc_func_desc);
1015 #endif
1016
1017 start_thread(regs, elf_entry, bprm->p);
1018 if (unlikely(current->ptrace & PT_PTRACED)) {
1019 if (current->ptrace & PT_TRACE_EXEC)
1020 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
1021 else
1022 send_sig(SIGTRAP, current, 0);
1023 }
1024 retval = 0;
1025 out:
1026 kfree(loc);
1027 out_ret:
1028 return retval;
1029
1030 /* error cleanup */
1031 out_free_dentry:
1032 allow_write_access(interpreter);
1033 if (interpreter)
1034 fput(interpreter);
1035 out_free_interp:
1036 kfree(elf_interpreter);
1037 out_free_file:
1038 sys_close(elf_exec_fileno);
1039 out_free_fh:
1040 if (files)
1041 reset_files_struct(current, files);
1042 out_free_ph:
1043 kfree(elf_phdata);
1044 goto out;
1045 }
1046
1047 /* This is really simpleminded and specialized - we are loading an
1048 a.out library that is given an ELF header. */
1049 static int load_elf_library(struct file *file)
1050 {
1051 struct elf_phdr *elf_phdata;
1052 struct elf_phdr *eppnt;
1053 unsigned long elf_bss, bss, len;
1054 int retval, error, i, j;
1055 struct elfhdr elf_ex;
1056
1057 error = -ENOEXEC;
1058 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1059 if (retval != sizeof(elf_ex))
1060 goto out;
1061
1062 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1063 goto out;
1064
1065 /* First of all, some simple consistency checks */
1066 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1067 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1068 goto out;
1069
1070 /* Now read in all of the header information */
1071
1072 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1073 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1074
1075 error = -ENOMEM;
1076 elf_phdata = kmalloc(j, GFP_KERNEL);
1077 if (!elf_phdata)
1078 goto out;
1079
1080 eppnt = elf_phdata;
1081 error = -ENOEXEC;
1082 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1083 if (retval != j)
1084 goto out_free_ph;
1085
1086 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1087 if ((eppnt + i)->p_type == PT_LOAD)
1088 j++;
1089 if (j != 1)
1090 goto out_free_ph;
1091
1092 while (eppnt->p_type != PT_LOAD)
1093 eppnt++;
1094
1095 /* Now use mmap to map the library into memory. */
1096 down_write(&current->mm->mmap_sem);
1097 error = do_mmap(file,
1098 ELF_PAGESTART(eppnt->p_vaddr),
1099 (eppnt->p_filesz +
1100 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1101 PROT_READ | PROT_WRITE | PROT_EXEC,
1102 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1103 (eppnt->p_offset -
1104 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1105 up_write(&current->mm->mmap_sem);
1106 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1107 goto out_free_ph;
1108
1109 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1110 if (padzero(elf_bss)) {
1111 error = -EFAULT;
1112 goto out_free_ph;
1113 }
1114
1115 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1116 ELF_MIN_ALIGN - 1);
1117 bss = eppnt->p_memsz + eppnt->p_vaddr;
1118 if (bss > len) {
1119 down_write(&current->mm->mmap_sem);
1120 do_brk(len, bss - len);
1121 up_write(&current->mm->mmap_sem);
1122 }
1123 error = 0;
1124
1125 out_free_ph:
1126 kfree(elf_phdata);
1127 out:
1128 return error;
1129 }
1130
1131 /*
1132 * Note that some platforms still use traditional core dumps and not
1133 * the ELF core dump. Each platform can select it as appropriate.
1134 */
1135 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1136
1137 /*
1138 * ELF core dumper
1139 *
1140 * Modelled on fs/exec.c:aout_core_dump()
1141 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1142 */
1143 /*
1144 * These are the only things you should do on a core-file: use only these
1145 * functions to write out all the necessary info.
1146 */
1147 static int dump_write(struct file *file, const void *addr, int nr)
1148 {
1149 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1150 }
1151
1152 static int dump_seek(struct file *file, loff_t off)
1153 {
1154 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1155 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1156 return 0;
1157 } else {
1158 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1159 if (!buf)
1160 return 0;
1161 while (off > 0) {
1162 unsigned long n = off;
1163 if (n > PAGE_SIZE)
1164 n = PAGE_SIZE;
1165 if (!dump_write(file, buf, n))
1166 return 0;
1167 off -= n;
1168 }
1169 free_page((unsigned long)buf);
1170 }
1171 return 1;
1172 }
1173
1174 /*
1175 * Decide whether a segment is worth dumping; default is yes to be
1176 * sure (missing info is worse than too much; etc).
1177 * Personally I'd include everything, and use the coredump limit...
1178 *
1179 * I think we should skip something. But I am not sure how. H.J.
1180 */
1181 static int maydump(struct vm_area_struct *vma)
1182 {
1183 /* Do not dump I/O mapped devices or special mappings */
1184 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1185 return 0;
1186
1187 /* Dump shared memory only if mapped from an anonymous file. */
1188 if (vma->vm_flags & VM_SHARED)
1189 return vma->vm_file->f_dentry->d_inode->i_nlink == 0;
1190
1191 /* If it hasn't been written to, don't write it out */
1192 if (!vma->anon_vma)
1193 return 0;
1194
1195 return 1;
1196 }
1197
1198 /* An ELF note in memory */
1199 struct memelfnote
1200 {
1201 const char *name;
1202 int type;
1203 unsigned int datasz;
1204 void *data;
1205 };
1206
1207 static int notesize(struct memelfnote *en)
1208 {
1209 int sz;
1210
1211 sz = sizeof(struct elf_note);
1212 sz += roundup(strlen(en->name) + 1, 4);
1213 sz += roundup(en->datasz, 4);
1214
1215 return sz;
1216 }
1217
1218 #define DUMP_WRITE(addr, nr, foffset) \
1219 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1220
1221 static int alignfile(struct file *file, loff_t *foffset)
1222 {
1223 static const char buf[4] = { 0, };
1224 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1225 return 1;
1226 }
1227
1228 static int writenote(struct memelfnote *men, struct file *file,
1229 loff_t *foffset)
1230 {
1231 struct elf_note en;
1232 en.n_namesz = strlen(men->name) + 1;
1233 en.n_descsz = men->datasz;
1234 en.n_type = men->type;
1235
1236 DUMP_WRITE(&en, sizeof(en), foffset);
1237 DUMP_WRITE(men->name, en.n_namesz, foffset);
1238 if (!alignfile(file, foffset))
1239 return 0;
1240 DUMP_WRITE(men->data, men->datasz, foffset);
1241 if (!alignfile(file, foffset))
1242 return 0;
1243
1244 return 1;
1245 }
1246 #undef DUMP_WRITE
1247
1248 #define DUMP_WRITE(addr, nr) \
1249 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1250 goto end_coredump;
1251 #define DUMP_SEEK(off) \
1252 if (!dump_seek(file, (off))) \
1253 goto end_coredump;
1254
1255 static void fill_elf_header(struct elfhdr *elf, int segs)
1256 {
1257 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1258 elf->e_ident[EI_CLASS] = ELF_CLASS;
1259 elf->e_ident[EI_DATA] = ELF_DATA;
1260 elf->e_ident[EI_VERSION] = EV_CURRENT;
1261 elf->e_ident[EI_OSABI] = ELF_OSABI;
1262 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1263
1264 elf->e_type = ET_CORE;
1265 elf->e_machine = ELF_ARCH;
1266 elf->e_version = EV_CURRENT;
1267 elf->e_entry = 0;
1268 elf->e_phoff = sizeof(struct elfhdr);
1269 elf->e_shoff = 0;
1270 elf->e_flags = ELF_CORE_EFLAGS;
1271 elf->e_ehsize = sizeof(struct elfhdr);
1272 elf->e_phentsize = sizeof(struct elf_phdr);
1273 elf->e_phnum = segs;
1274 elf->e_shentsize = 0;
1275 elf->e_shnum = 0;
1276 elf->e_shstrndx = 0;
1277 return;
1278 }
1279
1280 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1281 {
1282 phdr->p_type = PT_NOTE;
1283 phdr->p_offset = offset;
1284 phdr->p_vaddr = 0;
1285 phdr->p_paddr = 0;
1286 phdr->p_filesz = sz;
1287 phdr->p_memsz = 0;
1288 phdr->p_flags = 0;
1289 phdr->p_align = 0;
1290 return;
1291 }
1292
1293 static void fill_note(struct memelfnote *note, const char *name, int type,
1294 unsigned int sz, void *data)
1295 {
1296 note->name = name;
1297 note->type = type;
1298 note->datasz = sz;
1299 note->data = data;
1300 return;
1301 }
1302
1303 /*
1304 * fill up all the fields in prstatus from the given task struct, except
1305 * registers which need to be filled up separately.
1306 */
1307 static void fill_prstatus(struct elf_prstatus *prstatus,
1308 struct task_struct *p, long signr)
1309 {
1310 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1311 prstatus->pr_sigpend = p->pending.signal.sig[0];
1312 prstatus->pr_sighold = p->blocked.sig[0];
1313 prstatus->pr_pid = p->pid;
1314 prstatus->pr_ppid = p->parent->pid;
1315 prstatus->pr_pgrp = process_group(p);
1316 prstatus->pr_sid = p->signal->session;
1317 if (thread_group_leader(p)) {
1318 /*
1319 * This is the record for the group leader. Add in the
1320 * cumulative times of previous dead threads. This total
1321 * won't include the time of each live thread whose state
1322 * is included in the core dump. The final total reported
1323 * to our parent process when it calls wait4 will include
1324 * those sums as well as the little bit more time it takes
1325 * this and each other thread to finish dying after the
1326 * core dump synchronization phase.
1327 */
1328 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1329 &prstatus->pr_utime);
1330 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1331 &prstatus->pr_stime);
1332 } else {
1333 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1334 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1335 }
1336 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1337 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1338 }
1339
1340 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1341 struct mm_struct *mm)
1342 {
1343 unsigned int i, len;
1344
1345 /* first copy the parameters from user space */
1346 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1347
1348 len = mm->arg_end - mm->arg_start;
1349 if (len >= ELF_PRARGSZ)
1350 len = ELF_PRARGSZ-1;
1351 if (copy_from_user(&psinfo->pr_psargs,
1352 (const char __user *)mm->arg_start, len))
1353 return -EFAULT;
1354 for(i = 0; i < len; i++)
1355 if (psinfo->pr_psargs[i] == 0)
1356 psinfo->pr_psargs[i] = ' ';
1357 psinfo->pr_psargs[len] = 0;
1358
1359 psinfo->pr_pid = p->pid;
1360 psinfo->pr_ppid = p->parent->pid;
1361 psinfo->pr_pgrp = process_group(p);
1362 psinfo->pr_sid = p->signal->session;
1363
1364 i = p->state ? ffz(~p->state) + 1 : 0;
1365 psinfo->pr_state = i;
1366 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1367 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1368 psinfo->pr_nice = task_nice(p);
1369 psinfo->pr_flag = p->flags;
1370 SET_UID(psinfo->pr_uid, p->uid);
1371 SET_GID(psinfo->pr_gid, p->gid);
1372 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1373
1374 return 0;
1375 }
1376
1377 /* Here is the structure in which status of each thread is captured. */
1378 struct elf_thread_status
1379 {
1380 struct list_head list;
1381 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1382 elf_fpregset_t fpu; /* NT_PRFPREG */
1383 struct task_struct *thread;
1384 #ifdef ELF_CORE_COPY_XFPREGS
1385 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1386 #endif
1387 struct memelfnote notes[3];
1388 int num_notes;
1389 };
1390
1391 /*
1392 * In order to add the specific thread information for the elf file format,
1393 * we need to keep a linked list of every threads pr_status and then create
1394 * a single section for them in the final core file.
1395 */
1396 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1397 {
1398 int sz = 0;
1399 struct task_struct *p = t->thread;
1400 t->num_notes = 0;
1401
1402 fill_prstatus(&t->prstatus, p, signr);
1403 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1404
1405 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1406 &(t->prstatus));
1407 t->num_notes++;
1408 sz += notesize(&t->notes[0]);
1409
1410 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1411 &t->fpu))) {
1412 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1413 &(t->fpu));
1414 t->num_notes++;
1415 sz += notesize(&t->notes[1]);
1416 }
1417
1418 #ifdef ELF_CORE_COPY_XFPREGS
1419 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1420 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1421 &t->xfpu);
1422 t->num_notes++;
1423 sz += notesize(&t->notes[2]);
1424 }
1425 #endif
1426 return sz;
1427 }
1428
1429 /*
1430 * Actual dumper
1431 *
1432 * This is a two-pass process; first we find the offsets of the bits,
1433 * and then they are actually written out. If we run out of core limit
1434 * we just truncate.
1435 */
1436 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
1437 {
1438 #define NUM_NOTES 6
1439 int has_dumped = 0;
1440 mm_segment_t fs;
1441 int segs;
1442 size_t size = 0;
1443 int i;
1444 struct vm_area_struct *vma;
1445 struct elfhdr *elf = NULL;
1446 loff_t offset = 0, dataoff, foffset;
1447 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1448 int numnote;
1449 struct memelfnote *notes = NULL;
1450 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1451 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1452 struct task_struct *g, *p;
1453 LIST_HEAD(thread_list);
1454 struct list_head *t;
1455 elf_fpregset_t *fpu = NULL;
1456 #ifdef ELF_CORE_COPY_XFPREGS
1457 elf_fpxregset_t *xfpu = NULL;
1458 #endif
1459 int thread_status_size = 0;
1460 elf_addr_t *auxv;
1461
1462 /*
1463 * We no longer stop all VM operations.
1464 *
1465 * This is because those proceses that could possibly change map_count
1466 * or the mmap / vma pages are now blocked in do_exit on current
1467 * finishing this core dump.
1468 *
1469 * Only ptrace can touch these memory addresses, but it doesn't change
1470 * the map_count or the pages allocated. So no possibility of crashing
1471 * exists while dumping the mm->vm_next areas to the core file.
1472 */
1473
1474 /* alloc memory for large data structures: too large to be on stack */
1475 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1476 if (!elf)
1477 goto cleanup;
1478 prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
1479 if (!prstatus)
1480 goto cleanup;
1481 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1482 if (!psinfo)
1483 goto cleanup;
1484 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1485 if (!notes)
1486 goto cleanup;
1487 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1488 if (!fpu)
1489 goto cleanup;
1490 #ifdef ELF_CORE_COPY_XFPREGS
1491 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1492 if (!xfpu)
1493 goto cleanup;
1494 #endif
1495
1496 if (signr) {
1497 struct elf_thread_status *tmp;
1498 rcu_read_lock();
1499 do_each_thread(g,p)
1500 if (current->mm == p->mm && current != p) {
1501 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1502 if (!tmp) {
1503 rcu_read_unlock();
1504 goto cleanup;
1505 }
1506 tmp->thread = p;
1507 list_add(&tmp->list, &thread_list);
1508 }
1509 while_each_thread(g,p);
1510 rcu_read_unlock();
1511 list_for_each(t, &thread_list) {
1512 struct elf_thread_status *tmp;
1513 int sz;
1514
1515 tmp = list_entry(t, struct elf_thread_status, list);
1516 sz = elf_dump_thread_status(signr, tmp);
1517 thread_status_size += sz;
1518 }
1519 }
1520 /* now collect the dump for the current */
1521 memset(prstatus, 0, sizeof(*prstatus));
1522 fill_prstatus(prstatus, current, signr);
1523 elf_core_copy_regs(&prstatus->pr_reg, regs);
1524
1525 segs = current->mm->map_count;
1526 #ifdef ELF_CORE_EXTRA_PHDRS
1527 segs += ELF_CORE_EXTRA_PHDRS;
1528 #endif
1529
1530 /* Set up header */
1531 fill_elf_header(elf, segs + 1); /* including notes section */
1532
1533 has_dumped = 1;
1534 current->flags |= PF_DUMPCORE;
1535
1536 /*
1537 * Set up the notes in similar form to SVR4 core dumps made
1538 * with info from their /proc.
1539 */
1540
1541 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1542 fill_psinfo(psinfo, current->group_leader, current->mm);
1543 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1544
1545 numnote = 2;
1546
1547 auxv = (elf_addr_t *)current->mm->saved_auxv;
1548
1549 i = 0;
1550 do
1551 i += 2;
1552 while (auxv[i - 2] != AT_NULL);
1553 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1554 i * sizeof(elf_addr_t), auxv);
1555
1556 /* Try to dump the FPU. */
1557 if ((prstatus->pr_fpvalid =
1558 elf_core_copy_task_fpregs(current, regs, fpu)))
1559 fill_note(notes + numnote++,
1560 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1561 #ifdef ELF_CORE_COPY_XFPREGS
1562 if (elf_core_copy_task_xfpregs(current, xfpu))
1563 fill_note(notes + numnote++,
1564 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1565 #endif
1566
1567 fs = get_fs();
1568 set_fs(KERNEL_DS);
1569
1570 DUMP_WRITE(elf, sizeof(*elf));
1571 offset += sizeof(*elf); /* Elf header */
1572 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1573 foffset = offset;
1574
1575 /* Write notes phdr entry */
1576 {
1577 struct elf_phdr phdr;
1578 int sz = 0;
1579
1580 for (i = 0; i < numnote; i++)
1581 sz += notesize(notes + i);
1582
1583 sz += thread_status_size;
1584
1585 fill_elf_note_phdr(&phdr, sz, offset);
1586 offset += sz;
1587 DUMP_WRITE(&phdr, sizeof(phdr));
1588 }
1589
1590 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1591
1592 /* Write program headers for segments dump */
1593 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1594 struct elf_phdr phdr;
1595 size_t sz;
1596
1597 sz = vma->vm_end - vma->vm_start;
1598
1599 phdr.p_type = PT_LOAD;
1600 phdr.p_offset = offset;
1601 phdr.p_vaddr = vma->vm_start;
1602 phdr.p_paddr = 0;
1603 phdr.p_filesz = maydump(vma) ? sz : 0;
1604 phdr.p_memsz = sz;
1605 offset += phdr.p_filesz;
1606 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1607 if (vma->vm_flags & VM_WRITE)
1608 phdr.p_flags |= PF_W;
1609 if (vma->vm_flags & VM_EXEC)
1610 phdr.p_flags |= PF_X;
1611 phdr.p_align = ELF_EXEC_PAGESIZE;
1612
1613 DUMP_WRITE(&phdr, sizeof(phdr));
1614 }
1615
1616 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1617 ELF_CORE_WRITE_EXTRA_PHDRS;
1618 #endif
1619
1620 /* write out the notes section */
1621 for (i = 0; i < numnote; i++)
1622 if (!writenote(notes + i, file, &foffset))
1623 goto end_coredump;
1624
1625 /* write out the thread status notes section */
1626 list_for_each(t, &thread_list) {
1627 struct elf_thread_status *tmp =
1628 list_entry(t, struct elf_thread_status, list);
1629
1630 for (i = 0; i < tmp->num_notes; i++)
1631 if (!writenote(&tmp->notes[i], file, &foffset))
1632 goto end_coredump;
1633 }
1634
1635 /* Align to page */
1636 DUMP_SEEK(dataoff - foffset);
1637
1638 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1639 unsigned long addr;
1640
1641 if (!maydump(vma))
1642 continue;
1643
1644 for (addr = vma->vm_start;
1645 addr < vma->vm_end;
1646 addr += PAGE_SIZE) {
1647 struct page *page;
1648 struct vm_area_struct *vma;
1649
1650 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1651 &page, &vma) <= 0) {
1652 DUMP_SEEK(PAGE_SIZE);
1653 } else {
1654 if (page == ZERO_PAGE(addr)) {
1655 DUMP_SEEK(PAGE_SIZE);
1656 } else {
1657 void *kaddr;
1658 flush_cache_page(vma, addr,
1659 page_to_pfn(page));
1660 kaddr = kmap(page);
1661 if ((size += PAGE_SIZE) > limit ||
1662 !dump_write(file, kaddr,
1663 PAGE_SIZE)) {
1664 kunmap(page);
1665 page_cache_release(page);
1666 goto end_coredump;
1667 }
1668 kunmap(page);
1669 }
1670 page_cache_release(page);
1671 }
1672 }
1673 }
1674
1675 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1676 ELF_CORE_WRITE_EXTRA_DATA;
1677 #endif
1678
1679 end_coredump:
1680 set_fs(fs);
1681
1682 cleanup:
1683 while (!list_empty(&thread_list)) {
1684 struct list_head *tmp = thread_list.next;
1685 list_del(tmp);
1686 kfree(list_entry(tmp, struct elf_thread_status, list));
1687 }
1688
1689 kfree(elf);
1690 kfree(prstatus);
1691 kfree(psinfo);
1692 kfree(notes);
1693 kfree(fpu);
1694 #ifdef ELF_CORE_COPY_XFPREGS
1695 kfree(xfpu);
1696 #endif
1697 return has_dumped;
1698 #undef NUM_NOTES
1699 }
1700
1701 #endif /* USE_ELF_CORE_DUMP */
1702
1703 static int __init init_elf_binfmt(void)
1704 {
1705 return register_binfmt(&elf_format);
1706 }
1707
1708 static void __exit exit_elf_binfmt(void)
1709 {
1710 /* Remove the COFF and ELF loaders. */
1711 unregister_binfmt(&elf_format);
1712 }
1713
1714 core_initcall(init_elf_binfmt);
1715 module_exit(exit_elf_binfmt);
1716 MODULE_LICENSE("GPL");
hh.org GIT migration