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[DCCP]: Fix build warning when debugging is disabled.
[linux-2.6.22.y-op.git] / fs / binfmt_elf.c
blobfa8ea33ab0be1ef56ff78b5908a691676d815e27
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/compiler.h>
35 #include <linux/highmem.h>
36 #include <linux/pagemap.h>
37 #include <linux/security.h>
38 #include <linux/syscalls.h>
39 #include <linux/random.h>
40 #include <linux/elf.h>
41 #include <linux/utsname.h>
42 #include <asm/uaccess.h>
43 #include <asm/param.h>
44 #include <asm/page.h>
45
46 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
47 static int load_elf_library(struct file *);
48 static unsigned long elf_map (struct file *, unsigned long, struct elf_phdr *, int, int);
49
50 /*
51 * If we don't support core dumping, then supply a NULL so we
52 * don't even try.
53 */
54 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
55 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file);
56 #else
57 #define elf_core_dump NULL
58 #endif
59
60 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
61 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
62 #else
63 #define ELF_MIN_ALIGN PAGE_SIZE
64 #endif
65
66 #ifndef ELF_CORE_EFLAGS
67 #define ELF_CORE_EFLAGS 0
68 #endif
69
70 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
71 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
72 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
73
74 static struct linux_binfmt elf_format = {
75 .module = THIS_MODULE,
76 .load_binary = load_elf_binary,
77 .load_shlib = load_elf_library,
78 .core_dump = elf_core_dump,
79 .min_coredump = ELF_EXEC_PAGESIZE,
80 .hasvdso = 1
81 };
82
83 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
84
85 static int set_brk(unsigned long start, unsigned long end)
86 {
87 start = ELF_PAGEALIGN(start);
88 end = ELF_PAGEALIGN(end);
89 if (end > start) {
90 unsigned long addr;
91 down_write(&current->mm->mmap_sem);
92 addr = do_brk(start, end - start);
93 up_write(&current->mm->mmap_sem);
94 if (BAD_ADDR(addr))
95 return addr;
96 }
97 current->mm->start_brk = current->mm->brk = end;
98 return 0;
99 }
100
101 /* We need to explicitly zero any fractional pages
102 after the data section (i.e. bss). This would
103 contain the junk from the file that should not
104 be in memory
105 */
106 static int padzero(unsigned long elf_bss)
107 {
108 unsigned long nbyte;
109
110 nbyte = ELF_PAGEOFFSET(elf_bss);
111 if (nbyte) {
112 nbyte = ELF_MIN_ALIGN - nbyte;
113 if (clear_user((void __user *) elf_bss, nbyte))
114 return -EFAULT;
115 }
116 return 0;
117 }
118
119 /* Let's use some macros to make this stack manipulation a litle clearer */
120 #ifdef CONFIG_STACK_GROWSUP
121 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
122 #define STACK_ROUND(sp, items) \
123 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
124 #define STACK_ALLOC(sp, len) ({ \
125 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
126 old_sp; })
127 #else
128 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
129 #define STACK_ROUND(sp, items) \
130 (((unsigned long) (sp - items)) &~ 15UL)
131 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
132 #endif
133
134 static int
135 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
136 int interp_aout, unsigned long load_addr,
137 unsigned long interp_load_addr)
138 {
139 unsigned long p = bprm->p;
140 int argc = bprm->argc;
141 int envc = bprm->envc;
142 elf_addr_t __user *argv;
143 elf_addr_t __user *envp;
144 elf_addr_t __user *sp;
145 elf_addr_t __user *u_platform;
146 const char *k_platform = ELF_PLATFORM;
147 int items;
148 elf_addr_t *elf_info;
149 int ei_index = 0;
150 struct task_struct *tsk = current;
151
152 /*
153 * If this architecture has a platform capability string, copy it
154 * to userspace. In some cases (Sparc), this info is impossible
155 * for userspace to get any other way, in others (i386) it is
156 * merely difficult.
157 */
158 u_platform = NULL;
159 if (k_platform) {
160 size_t len = strlen(k_platform) + 1;
161
162 /*
163 * In some cases (e.g. Hyper-Threading), we want to avoid L1
164 * evictions by the processes running on the same package. One
165 * thing we can do is to shuffle the initial stack for them.
166 */
167
168 p = arch_align_stack(p);
169
170 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
171 if (__copy_to_user(u_platform, k_platform, len))
172 return -EFAULT;
173 }
174
175 /* Create the ELF interpreter info */
176 elf_info = (elf_addr_t *)current->mm->saved_auxv;
177 #define NEW_AUX_ENT(id, val) \
178 do { \
179 elf_info[ei_index++] = id; \
180 elf_info[ei_index++] = val; \
181 } while (0)
182
183 #ifdef ARCH_DLINFO
184 /*
185 * ARCH_DLINFO must come first so PPC can do its special alignment of
186 * AUXV.
187 */
188 ARCH_DLINFO;
189 #endif
190 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
191 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
192 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
193 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
194 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
195 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
196 NEW_AUX_ENT(AT_BASE, interp_load_addr);
197 NEW_AUX_ENT(AT_FLAGS, 0);
198 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
199 NEW_AUX_ENT(AT_UID, tsk->uid);
200 NEW_AUX_ENT(AT_EUID, tsk->euid);
201 NEW_AUX_ENT(AT_GID, tsk->gid);
202 NEW_AUX_ENT(AT_EGID, tsk->egid);
203 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
204 if (k_platform) {
205 NEW_AUX_ENT(AT_PLATFORM,
206 (elf_addr_t)(unsigned long)u_platform);
207 }
208 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
209 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
210 }
211 #undef NEW_AUX_ENT
212 /* AT_NULL is zero; clear the rest too */
213 memset(&elf_info[ei_index], 0,
214 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
215
216 /* And advance past the AT_NULL entry. */
217 ei_index += 2;
218
219 sp = STACK_ADD(p, ei_index);
220
221 items = (argc + 1) + (envc + 1);
222 if (interp_aout) {
223 items += 3; /* a.out interpreters require argv & envp too */
224 } else {
225 items += 1; /* ELF interpreters only put argc on the stack */
226 }
227 bprm->p = STACK_ROUND(sp, items);
228
229 /* Point sp at the lowest address on the stack */
230 #ifdef CONFIG_STACK_GROWSUP
231 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
232 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
233 #else
234 sp = (elf_addr_t __user *)bprm->p;
235 #endif
236
237 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
238 if (__put_user(argc, sp++))
239 return -EFAULT;
240 if (interp_aout) {
241 argv = sp + 2;
242 envp = argv + argc + 1;
243 if (__put_user((elf_addr_t)(unsigned long)argv, sp++) ||
244 __put_user((elf_addr_t)(unsigned long)envp, sp++))
245 return -EFAULT;
246 } else {
247 argv = sp;
248 envp = argv + argc + 1;
249 }
250
251 /* Populate argv and envp */
252 p = current->mm->arg_end = current->mm->arg_start;
253 while (argc-- > 0) {
254 size_t len;
255 if (__put_user((elf_addr_t)p, argv++))
256 return -EFAULT;
257 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
258 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
259 return 0;
260 p += len;
261 }
262 if (__put_user(0, argv))
263 return -EFAULT;
264 current->mm->arg_end = current->mm->env_start = p;
265 while (envc-- > 0) {
266 size_t len;
267 if (__put_user((elf_addr_t)p, envp++))
268 return -EFAULT;
269 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
270 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
271 return 0;
272 p += len;
273 }
274 if (__put_user(0, envp))
275 return -EFAULT;
276 current->mm->env_end = p;
277
278 /* Put the elf_info on the stack in the right place. */
279 sp = (elf_addr_t __user *)envp + 1;
280 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
281 return -EFAULT;
282 return 0;
283 }
284
285 #ifndef elf_map
286
287 static unsigned long elf_map(struct file *filep, unsigned long addr,
288 struct elf_phdr *eppnt, int prot, int type)
289 {
290 unsigned long map_addr;
291 unsigned long pageoffset = ELF_PAGEOFFSET(eppnt->p_vaddr);
292
293 down_write(&current->mm->mmap_sem);
294 /* mmap() will return -EINVAL if given a zero size, but a
295 * segment with zero filesize is perfectly valid */
296 if (eppnt->p_filesz + pageoffset)
297 map_addr = do_mmap(filep, ELF_PAGESTART(addr),
298 eppnt->p_filesz + pageoffset, prot, type,
299 eppnt->p_offset - pageoffset);
300 else
301 map_addr = ELF_PAGESTART(addr);
302 up_write(&current->mm->mmap_sem);
303 return(map_addr);
304 }
305
306 #endif /* !elf_map */
307
308 /* This is much more generalized than the library routine read function,
309 so we keep this separate. Technically the library read function
310 is only provided so that we can read a.out libraries that have
311 an ELF header */
312
313 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
314 struct file *interpreter, unsigned long *interp_load_addr)
315 {
316 struct elf_phdr *elf_phdata;
317 struct elf_phdr *eppnt;
318 unsigned long load_addr = 0;
319 int load_addr_set = 0;
320 unsigned long last_bss = 0, elf_bss = 0;
321 unsigned long error = ~0UL;
322 int retval, i, size;
323
324 /* First of all, some simple consistency checks */
325 if (interp_elf_ex->e_type != ET_EXEC &&
326 interp_elf_ex->e_type != ET_DYN)
327 goto out;
328 if (!elf_check_arch(interp_elf_ex))
329 goto out;
330 if (!interpreter->f_op || !interpreter->f_op->mmap)
331 goto out;
332
333 /*
334 * If the size of this structure has changed, then punt, since
335 * we will be doing the wrong thing.
336 */
337 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
338 goto out;
339 if (interp_elf_ex->e_phnum < 1 ||
340 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
341 goto out;
342
343 /* Now read in all of the header information */
344 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
345 if (size > ELF_MIN_ALIGN)
346 goto out;
347 elf_phdata = kmalloc(size, GFP_KERNEL);
348 if (!elf_phdata)
349 goto out;
350
351 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
352 (char *)elf_phdata,size);
353 error = -EIO;
354 if (retval != size) {
355 if (retval < 0)
356 error = retval;
357 goto out_close;
358 }
359
360 eppnt = elf_phdata;
361 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
362 if (eppnt->p_type == PT_LOAD) {
363 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
364 int elf_prot = 0;
365 unsigned long vaddr = 0;
366 unsigned long k, map_addr;
367
368 if (eppnt->p_flags & PF_R)
369 elf_prot = PROT_READ;
370 if (eppnt->p_flags & PF_W)
371 elf_prot |= PROT_WRITE;
372 if (eppnt->p_flags & PF_X)
373 elf_prot |= PROT_EXEC;
374 vaddr = eppnt->p_vaddr;
375 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
376 elf_type |= MAP_FIXED;
377
378 map_addr = elf_map(interpreter, load_addr + vaddr,
379 eppnt, elf_prot, elf_type);
380 error = map_addr;
381 if (BAD_ADDR(map_addr))
382 goto out_close;
383
384 if (!load_addr_set &&
385 interp_elf_ex->e_type == ET_DYN) {
386 load_addr = map_addr - ELF_PAGESTART(vaddr);
387 load_addr_set = 1;
388 }
389
390 /*
391 * Check to see if the section's size will overflow the
392 * allowed task size. Note that p_filesz must always be
393 * <= p_memsize so it's only necessary to check p_memsz.
394 */
395 k = load_addr + eppnt->p_vaddr;
396 if (BAD_ADDR(k) ||
397 eppnt->p_filesz > eppnt->p_memsz ||
398 eppnt->p_memsz > TASK_SIZE ||
399 TASK_SIZE - eppnt->p_memsz < k) {
400 error = -ENOMEM;
401 goto out_close;
402 }
403
404 /*
405 * Find the end of the file mapping for this phdr, and
406 * keep track of the largest address we see for this.
407 */
408 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
409 if (k > elf_bss)
410 elf_bss = k;
411
412 /*
413 * Do the same thing for the memory mapping - between
414 * elf_bss and last_bss is the bss section.
415 */
416 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
417 if (k > last_bss)
418 last_bss = k;
419 }
420 }
421
422 /*
423 * Now fill out the bss section. First pad the last page up
424 * to the page boundary, and then perform a mmap to make sure
425 * that there are zero-mapped pages up to and including the
426 * last bss page.
427 */
428 if (padzero(elf_bss)) {
429 error = -EFAULT;
430 goto out_close;
431 }
432
433 /* What we have mapped so far */
434 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
435
436 /* Map the last of the bss segment */
437 if (last_bss > elf_bss) {
438 down_write(&current->mm->mmap_sem);
439 error = do_brk(elf_bss, last_bss - elf_bss);
440 up_write(&current->mm->mmap_sem);
441 if (BAD_ADDR(error))
442 goto out_close;
443 }
444
445 *interp_load_addr = load_addr;
446 error = ((unsigned long)interp_elf_ex->e_entry) + load_addr;
447
448 out_close:
449 kfree(elf_phdata);
450 out:
451 return error;
452 }
453
454 static unsigned long load_aout_interp(struct exec *interp_ex,
455 struct file *interpreter)
456 {
457 unsigned long text_data, elf_entry = ~0UL;
458 char __user * addr;
459 loff_t offset;
460
461 current->mm->end_code = interp_ex->a_text;
462 text_data = interp_ex->a_text + interp_ex->a_data;
463 current->mm->end_data = text_data;
464 current->mm->brk = interp_ex->a_bss + text_data;
465
466 switch (N_MAGIC(*interp_ex)) {
467 case OMAGIC:
468 offset = 32;
469 addr = (char __user *)0;
470 break;
471 case ZMAGIC:
472 case QMAGIC:
473 offset = N_TXTOFF(*interp_ex);
474 addr = (char __user *)N_TXTADDR(*interp_ex);
475 break;
476 default:
477 goto out;
478 }
479
480 down_write(&current->mm->mmap_sem);
481 do_brk(0, text_data);
482 up_write(&current->mm->mmap_sem);
483 if (!interpreter->f_op || !interpreter->f_op->read)
484 goto out;
485 if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0)
486 goto out;
487 flush_icache_range((unsigned long)addr,
488 (unsigned long)addr + text_data);
489
490 down_write(&current->mm->mmap_sem);
491 do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
492 interp_ex->a_bss);
493 up_write(&current->mm->mmap_sem);
494 elf_entry = interp_ex->a_entry;
495
496 out:
497 return elf_entry;
498 }
499
500 /*
501 * These are the functions used to load ELF style executables and shared
502 * libraries. There is no binary dependent code anywhere else.
503 */
504
505 #define INTERPRETER_NONE 0
506 #define INTERPRETER_AOUT 1
507 #define INTERPRETER_ELF 2
508
509 #ifndef STACK_RND_MASK
510 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
511 #endif
512
513 static unsigned long randomize_stack_top(unsigned long stack_top)
514 {
515 unsigned int random_variable = 0;
516
517 if ((current->flags & PF_RANDOMIZE) &&
518 !(current->personality & ADDR_NO_RANDOMIZE)) {
519 random_variable = get_random_int() & STACK_RND_MASK;
520 random_variable <<= PAGE_SHIFT;
521 }
522 #ifdef CONFIG_STACK_GROWSUP
523 return PAGE_ALIGN(stack_top) + random_variable;
524 #else
525 return PAGE_ALIGN(stack_top) - random_variable;
526 #endif
527 }
528
529 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
530 {
531 struct file *interpreter = NULL; /* to shut gcc up */
532 unsigned long load_addr = 0, load_bias = 0;
533 int load_addr_set = 0;
534 char * elf_interpreter = NULL;
535 unsigned int interpreter_type = INTERPRETER_NONE;
536 unsigned char ibcs2_interpreter = 0;
537 unsigned long error;
538 struct elf_phdr *elf_ppnt, *elf_phdata;
539 unsigned long elf_bss, elf_brk;
540 int elf_exec_fileno;
541 int retval, i;
542 unsigned int size;
543 unsigned long elf_entry, interp_load_addr = 0;
544 unsigned long start_code, end_code, start_data, end_data;
545 unsigned long reloc_func_desc = 0;
546 char passed_fileno[6];
547 struct files_struct *files;
548 int executable_stack = EXSTACK_DEFAULT;
549 unsigned long def_flags = 0;
550 struct {
551 struct elfhdr elf_ex;
552 struct elfhdr interp_elf_ex;
553 struct exec interp_ex;
554 } *loc;
555
556 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
557 if (!loc) {
558 retval = -ENOMEM;
559 goto out_ret;
560 }
561
562 /* Get the exec-header */
563 loc->elf_ex = *((struct elfhdr *)bprm->buf);
564
565 retval = -ENOEXEC;
566 /* First of all, some simple consistency checks */
567 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
568 goto out;
569
570 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
571 goto out;
572 if (!elf_check_arch(&loc->elf_ex))
573 goto out;
574 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
575 goto out;
576
577 /* Now read in all of the header information */
578 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
579 goto out;
580 if (loc->elf_ex.e_phnum < 1 ||
581 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
582 goto out;
583 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
584 retval = -ENOMEM;
585 elf_phdata = kmalloc(size, GFP_KERNEL);
586 if (!elf_phdata)
587 goto out;
588
589 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
590 (char *)elf_phdata, size);
591 if (retval != size) {
592 if (retval >= 0)
593 retval = -EIO;
594 goto out_free_ph;
595 }
596
597 files = current->files; /* Refcounted so ok */
598 retval = unshare_files();
599 if (retval < 0)
600 goto out_free_ph;
601 if (files == current->files) {
602 put_files_struct(files);
603 files = NULL;
604 }
605
606 /* exec will make our files private anyway, but for the a.out
607 loader stuff we need to do it earlier */
608 retval = get_unused_fd();
609 if (retval < 0)
610 goto out_free_fh;
611 get_file(bprm->file);
612 fd_install(elf_exec_fileno = retval, bprm->file);
613
614 elf_ppnt = elf_phdata;
615 elf_bss = 0;
616 elf_brk = 0;
617
618 start_code = ~0UL;
619 end_code = 0;
620 start_data = 0;
621 end_data = 0;
622
623 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
624 if (elf_ppnt->p_type == PT_INTERP) {
625 /* This is the program interpreter used for
626 * shared libraries - for now assume that this
627 * is an a.out format binary
628 */
629 retval = -ENOEXEC;
630 if (elf_ppnt->p_filesz > PATH_MAX ||
631 elf_ppnt->p_filesz < 2)
632 goto out_free_file;
633
634 retval = -ENOMEM;
635 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
636 GFP_KERNEL);
637 if (!elf_interpreter)
638 goto out_free_file;
639
640 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
641 elf_interpreter,
642 elf_ppnt->p_filesz);
643 if (retval != elf_ppnt->p_filesz) {
644 if (retval >= 0)
645 retval = -EIO;
646 goto out_free_interp;
647 }
648 /* make sure path is NULL terminated */
649 retval = -ENOEXEC;
650 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
651 goto out_free_interp;
652
653 /* If the program interpreter is one of these two,
654 * then assume an iBCS2 image. Otherwise assume
655 * a native linux image.
656 */
657 if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
658 strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0)
659 ibcs2_interpreter = 1;
660
661 /*
662 * The early SET_PERSONALITY here is so that the lookup
663 * for the interpreter happens in the namespace of the
664 * to-be-execed image. SET_PERSONALITY can select an
665 * alternate root.
666 *
667 * However, SET_PERSONALITY is NOT allowed to switch
668 * this task into the new images's memory mapping
669 * policy - that is, TASK_SIZE must still evaluate to
670 * that which is appropriate to the execing application.
671 * This is because exit_mmap() needs to have TASK_SIZE
672 * evaluate to the size of the old image.
673 *
674 * So if (say) a 64-bit application is execing a 32-bit
675 * application it is the architecture's responsibility
676 * to defer changing the value of TASK_SIZE until the
677 * switch really is going to happen - do this in
678 * flush_thread(). - akpm
679 */
680 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
681
682 interpreter = open_exec(elf_interpreter);
683 retval = PTR_ERR(interpreter);
684 if (IS_ERR(interpreter))
685 goto out_free_interp;
686
687 /*
688 * If the binary is not readable then enforce
689 * mm->dumpable = 0 regardless of the interpreter's
690 * permissions.
691 */
692 if (file_permission(interpreter, MAY_READ) < 0)
693 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
694
695 retval = kernel_read(interpreter, 0, bprm->buf,
696 BINPRM_BUF_SIZE);
697 if (retval != BINPRM_BUF_SIZE) {
698 if (retval >= 0)
699 retval = -EIO;
700 goto out_free_dentry;
701 }
702
703 /* Get the exec headers */
704 loc->interp_ex = *((struct exec *)bprm->buf);
705 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
706 break;
707 }
708 elf_ppnt++;
709 }
710
711 elf_ppnt = elf_phdata;
712 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
713 if (elf_ppnt->p_type == PT_GNU_STACK) {
714 if (elf_ppnt->p_flags & PF_X)
715 executable_stack = EXSTACK_ENABLE_X;
716 else
717 executable_stack = EXSTACK_DISABLE_X;
718 break;
719 }
720
721 /* Some simple consistency checks for the interpreter */
722 if (elf_interpreter) {
723 interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
724
725 /* Now figure out which format our binary is */
726 if ((N_MAGIC(loc->interp_ex) != OMAGIC) &&
727 (N_MAGIC(loc->interp_ex) != ZMAGIC) &&
728 (N_MAGIC(loc->interp_ex) != QMAGIC))
729 interpreter_type = INTERPRETER_ELF;
730
731 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
732 interpreter_type &= ~INTERPRETER_ELF;
733
734 retval = -ELIBBAD;
735 if (!interpreter_type)
736 goto out_free_dentry;
737
738 /* Make sure only one type was selected */
739 if ((interpreter_type & INTERPRETER_ELF) &&
740 interpreter_type != INTERPRETER_ELF) {
741 // FIXME - ratelimit this before re-enabling
742 // printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n");
743 interpreter_type = INTERPRETER_ELF;
744 }
745 /* Verify the interpreter has a valid arch */
746 if ((interpreter_type == INTERPRETER_ELF) &&
747 !elf_check_arch(&loc->interp_elf_ex))
748 goto out_free_dentry;
749 } else {
750 /* Executables without an interpreter also need a personality */
751 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
752 }
753
754 /* OK, we are done with that, now set up the arg stuff,
755 and then start this sucker up */
756 if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) {
757 char *passed_p = passed_fileno;
758 sprintf(passed_fileno, "%d", elf_exec_fileno);
759
760 if (elf_interpreter) {
761 retval = copy_strings_kernel(1, &passed_p, bprm);
762 if (retval)
763 goto out_free_dentry;
764 bprm->argc++;
765 }
766 }
767
768 /* Flush all traces of the currently running executable */
769 retval = flush_old_exec(bprm);
770 if (retval)
771 goto out_free_dentry;
772
773 /* Discard our unneeded old files struct */
774 if (files) {
775 put_files_struct(files);
776 files = NULL;
777 }
778
779 /* OK, This is the point of no return */
780 current->mm->start_data = 0;
781 current->mm->end_data = 0;
782 current->mm->end_code = 0;
783 current->mm->mmap = NULL;
784 current->flags &= ~PF_FORKNOEXEC;
785 current->mm->def_flags = def_flags;
786
787 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
788 may depend on the personality. */
789 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
790 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
791 current->personality |= READ_IMPLIES_EXEC;
792
793 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
794 current->flags |= PF_RANDOMIZE;
795 arch_pick_mmap_layout(current->mm);
796
797 /* Do this so that we can load the interpreter, if need be. We will
798 change some of these later */
799 current->mm->free_area_cache = current->mm->mmap_base;
800 current->mm->cached_hole_size = 0;
801 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
802 executable_stack);
803 if (retval < 0) {
804 send_sig(SIGKILL, current, 0);
805 goto out_free_dentry;
806 }
807
808 current->mm->start_stack = bprm->p;
809
810 /* Now we do a little grungy work by mmaping the ELF image into
811 the correct location in memory. At this point, we assume that
812 the image should be loaded at fixed address, not at a variable
813 address. */
814 for(i = 0, elf_ppnt = elf_phdata;
815 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
816 int elf_prot = 0, elf_flags;
817 unsigned long k, vaddr;
818
819 if (elf_ppnt->p_type != PT_LOAD)
820 continue;
821
822 if (unlikely (elf_brk > elf_bss)) {
823 unsigned long nbyte;
824
825 /* There was a PT_LOAD segment with p_memsz > p_filesz
826 before this one. Map anonymous pages, if needed,
827 and clear the area. */
828 retval = set_brk (elf_bss + load_bias,
829 elf_brk + load_bias);
830 if (retval) {
831 send_sig(SIGKILL, current, 0);
832 goto out_free_dentry;
833 }
834 nbyte = ELF_PAGEOFFSET(elf_bss);
835 if (nbyte) {
836 nbyte = ELF_MIN_ALIGN - nbyte;
837 if (nbyte > elf_brk - elf_bss)
838 nbyte = elf_brk - elf_bss;
839 if (clear_user((void __user *)elf_bss +
840 load_bias, nbyte)) {
841 /*
842 * This bss-zeroing can fail if the ELF
843 * file specifies odd protections. So
844 * we don't check the return value
845 */
846 }
847 }
848 }
849
850 if (elf_ppnt->p_flags & PF_R)
851 elf_prot |= PROT_READ;
852 if (elf_ppnt->p_flags & PF_W)
853 elf_prot |= PROT_WRITE;
854 if (elf_ppnt->p_flags & PF_X)
855 elf_prot |= PROT_EXEC;
856
857 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
858
859 vaddr = elf_ppnt->p_vaddr;
860 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
861 elf_flags |= MAP_FIXED;
862 } else if (loc->elf_ex.e_type == ET_DYN) {
863 /* Try and get dynamic programs out of the way of the
864 * default mmap base, as well as whatever program they
865 * might try to exec. This is because the brk will
866 * follow the loader, and is not movable. */
867 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
868 }
869
870 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
871 elf_prot, elf_flags);
872 if (BAD_ADDR(error)) {
873 send_sig(SIGKILL, current, 0);
874 retval = IS_ERR((void *)error) ?
875 PTR_ERR((void*)error) : -EINVAL;
876 goto out_free_dentry;
877 }
878
879 if (!load_addr_set) {
880 load_addr_set = 1;
881 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
882 if (loc->elf_ex.e_type == ET_DYN) {
883 load_bias += error -
884 ELF_PAGESTART(load_bias + vaddr);
885 load_addr += load_bias;
886 reloc_func_desc = load_bias;
887 }
888 }
889 k = elf_ppnt->p_vaddr;
890 if (k < start_code)
891 start_code = k;
892 if (start_data < k)
893 start_data = k;
894
895 /*
896 * Check to see if the section's size will overflow the
897 * allowed task size. Note that p_filesz must always be
898 * <= p_memsz so it is only necessary to check p_memsz.
899 */
900 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
901 elf_ppnt->p_memsz > TASK_SIZE ||
902 TASK_SIZE - elf_ppnt->p_memsz < k) {
903 /* set_brk can never work. Avoid overflows. */
904 send_sig(SIGKILL, current, 0);
905 retval = -EINVAL;
906 goto out_free_dentry;
907 }
908
909 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
910
911 if (k > elf_bss)
912 elf_bss = k;
913 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
914 end_code = k;
915 if (end_data < k)
916 end_data = k;
917 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
918 if (k > elf_brk)
919 elf_brk = k;
920 }
921
922 loc->elf_ex.e_entry += load_bias;
923 elf_bss += load_bias;
924 elf_brk += load_bias;
925 start_code += load_bias;
926 end_code += load_bias;
927 start_data += load_bias;
928 end_data += load_bias;
929
930 /* Calling set_brk effectively mmaps the pages that we need
931 * for the bss and break sections. We must do this before
932 * mapping in the interpreter, to make sure it doesn't wind
933 * up getting placed where the bss needs to go.
934 */
935 retval = set_brk(elf_bss, elf_brk);
936 if (retval) {
937 send_sig(SIGKILL, current, 0);
938 goto out_free_dentry;
939 }
940 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
941 send_sig(SIGSEGV, current, 0);
942 retval = -EFAULT; /* Nobody gets to see this, but.. */
943 goto out_free_dentry;
944 }
945
946 if (elf_interpreter) {
947 if (interpreter_type == INTERPRETER_AOUT)
948 elf_entry = load_aout_interp(&loc->interp_ex,
949 interpreter);
950 else
951 elf_entry = load_elf_interp(&loc->interp_elf_ex,
952 interpreter,
953 &interp_load_addr);
954 if (BAD_ADDR(elf_entry)) {
955 force_sig(SIGSEGV, current);
956 retval = IS_ERR((void *)elf_entry) ?
957 (int)elf_entry : -EINVAL;
958 goto out_free_dentry;
959 }
960 reloc_func_desc = interp_load_addr;
961
962 allow_write_access(interpreter);
963 fput(interpreter);
964 kfree(elf_interpreter);
965 } else {
966 elf_entry = loc->elf_ex.e_entry;
967 if (BAD_ADDR(elf_entry)) {
968 force_sig(SIGSEGV, current);
969 retval = -EINVAL;
970 goto out_free_dentry;
971 }
972 }
973
974 kfree(elf_phdata);
975
976 if (interpreter_type != INTERPRETER_AOUT)
977 sys_close(elf_exec_fileno);
978
979 set_binfmt(&elf_format);
980
981 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
982 retval = arch_setup_additional_pages(bprm, executable_stack);
983 if (retval < 0) {
984 send_sig(SIGKILL, current, 0);
985 goto out;
986 }
987 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
988
989 compute_creds(bprm);
990 current->flags &= ~PF_FORKNOEXEC;
991 create_elf_tables(bprm, &loc->elf_ex,
992 (interpreter_type == INTERPRETER_AOUT),
993 load_addr, interp_load_addr);
994 /* N.B. passed_fileno might not be initialized? */
995 if (interpreter_type == INTERPRETER_AOUT)
996 current->mm->arg_start += strlen(passed_fileno) + 1;
997 current->mm->end_code = end_code;
998 current->mm->start_code = start_code;
999 current->mm->start_data = start_data;
1000 current->mm->end_data = end_data;
1001 current->mm->start_stack = bprm->p;
1002
1003 if (current->personality & MMAP_PAGE_ZERO) {
1004 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
1005 and some applications "depend" upon this behavior.
1006 Since we do not have the power to recompile these, we
1007 emulate the SVr4 behavior. Sigh. */
1008 down_write(&current->mm->mmap_sem);
1009 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1010 MAP_FIXED | MAP_PRIVATE, 0);
1011 up_write(&current->mm->mmap_sem);
1012 }
1013
1014 #ifdef ELF_PLAT_INIT
1015 /*
1016 * The ABI may specify that certain registers be set up in special
1017 * ways (on i386 %edx is the address of a DT_FINI function, for
1018 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1019 * that the e_entry field is the address of the function descriptor
1020 * for the startup routine, rather than the address of the startup
1021 * routine itself. This macro performs whatever initialization to
1022 * the regs structure is required as well as any relocations to the
1023 * function descriptor entries when executing dynamically links apps.
1024 */
1025 ELF_PLAT_INIT(regs, reloc_func_desc);
1026 #endif
1027
1028 start_thread(regs, elf_entry, bprm->p);
1029 if (unlikely(current->ptrace & PT_PTRACED)) {
1030 if (current->ptrace & PT_TRACE_EXEC)
1031 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
1032 else
1033 send_sig(SIGTRAP, current, 0);
1034 }
1035 retval = 0;
1036 out:
1037 kfree(loc);
1038 out_ret:
1039 return retval;
1040
1041 /* error cleanup */
1042 out_free_dentry:
1043 allow_write_access(interpreter);
1044 if (interpreter)
1045 fput(interpreter);
1046 out_free_interp:
1047 kfree(elf_interpreter);
1048 out_free_file:
1049 sys_close(elf_exec_fileno);
1050 out_free_fh:
1051 if (files)
1052 reset_files_struct(current, files);
1053 out_free_ph:
1054 kfree(elf_phdata);
1055 goto out;
1056 }
1057
1058 /* This is really simpleminded and specialized - we are loading an
1059 a.out library that is given an ELF header. */
1060 static int load_elf_library(struct file *file)
1061 {
1062 struct elf_phdr *elf_phdata;
1063 struct elf_phdr *eppnt;
1064 unsigned long elf_bss, bss, len;
1065 int retval, error, i, j;
1066 struct elfhdr elf_ex;
1067
1068 error = -ENOEXEC;
1069 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1070 if (retval != sizeof(elf_ex))
1071 goto out;
1072
1073 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1074 goto out;
1075
1076 /* First of all, some simple consistency checks */
1077 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1078 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1079 goto out;
1080
1081 /* Now read in all of the header information */
1082
1083 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1084 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1085
1086 error = -ENOMEM;
1087 elf_phdata = kmalloc(j, GFP_KERNEL);
1088 if (!elf_phdata)
1089 goto out;
1090
1091 eppnt = elf_phdata;
1092 error = -ENOEXEC;
1093 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1094 if (retval != j)
1095 goto out_free_ph;
1096
1097 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1098 if ((eppnt + i)->p_type == PT_LOAD)
1099 j++;
1100 if (j != 1)
1101 goto out_free_ph;
1102
1103 while (eppnt->p_type != PT_LOAD)
1104 eppnt++;
1105
1106 /* Now use mmap to map the library into memory. */
1107 down_write(&current->mm->mmap_sem);
1108 error = do_mmap(file,
1109 ELF_PAGESTART(eppnt->p_vaddr),
1110 (eppnt->p_filesz +
1111 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1112 PROT_READ | PROT_WRITE | PROT_EXEC,
1113 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1114 (eppnt->p_offset -
1115 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1116 up_write(&current->mm->mmap_sem);
1117 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1118 goto out_free_ph;
1119
1120 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1121 if (padzero(elf_bss)) {
1122 error = -EFAULT;
1123 goto out_free_ph;
1124 }
1125
1126 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1127 ELF_MIN_ALIGN - 1);
1128 bss = eppnt->p_memsz + eppnt->p_vaddr;
1129 if (bss > len) {
1130 down_write(&current->mm->mmap_sem);
1131 do_brk(len, bss - len);
1132 up_write(&current->mm->mmap_sem);
1133 }
1134 error = 0;
1135
1136 out_free_ph:
1137 kfree(elf_phdata);
1138 out:
1139 return error;
1140 }
1141
1142 /*
1143 * Note that some platforms still use traditional core dumps and not
1144 * the ELF core dump. Each platform can select it as appropriate.
1145 */
1146 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1147
1148 /*
1149 * ELF core dumper
1150 *
1151 * Modelled on fs/exec.c:aout_core_dump()
1152 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1153 */
1154 /*
1155 * These are the only things you should do on a core-file: use only these
1156 * functions to write out all the necessary info.
1157 */
1158 static int dump_write(struct file *file, const void *addr, int nr)
1159 {
1160 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1161 }
1162
1163 static int dump_seek(struct file *file, loff_t off)
1164 {
1165 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1166 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1167 return 0;
1168 } else {
1169 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1170 if (!buf)
1171 return 0;
1172 while (off > 0) {
1173 unsigned long n = off;
1174 if (n > PAGE_SIZE)
1175 n = PAGE_SIZE;
1176 if (!dump_write(file, buf, n))
1177 return 0;
1178 off -= n;
1179 }
1180 free_page((unsigned long)buf);
1181 }
1182 return 1;
1183 }
1184
1185 /*
1186 * Decide whether a segment is worth dumping; default is yes to be
1187 * sure (missing info is worse than too much; etc).
1188 * Personally I'd include everything, and use the coredump limit...
1189 *
1190 * I think we should skip something. But I am not sure how. H.J.
1191 */
1192 static int maydump(struct vm_area_struct *vma)
1193 {
1194 /* The vma can be set up to tell us the answer directly. */
1195 if (vma->vm_flags & VM_ALWAYSDUMP)
1196 return 1;
1197
1198 /* Do not dump I/O mapped devices or special mappings */
1199 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1200 return 0;
1201
1202 /* Dump shared memory only if mapped from an anonymous file. */
1203 if (vma->vm_flags & VM_SHARED)
1204 return vma->vm_file->f_path.dentry->d_inode->i_nlink == 0;
1205
1206 /* If it hasn't been written to, don't write it out */
1207 if (!vma->anon_vma)
1208 return 0;
1209
1210 return 1;
1211 }
1212
1213 /* An ELF note in memory */
1214 struct memelfnote
1215 {
1216 const char *name;
1217 int type;
1218 unsigned int datasz;
1219 void *data;
1220 };
1221
1222 static int notesize(struct memelfnote *en)
1223 {
1224 int sz;
1225
1226 sz = sizeof(struct elf_note);
1227 sz += roundup(strlen(en->name) + 1, 4);
1228 sz += roundup(en->datasz, 4);
1229
1230 return sz;
1231 }
1232
1233 #define DUMP_WRITE(addr, nr, foffset) \
1234 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1235
1236 static int alignfile(struct file *file, loff_t *foffset)
1237 {
1238 static const char buf[4] = { 0, };
1239 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1240 return 1;
1241 }
1242
1243 static int writenote(struct memelfnote *men, struct file *file,
1244 loff_t *foffset)
1245 {
1246 struct elf_note en;
1247 en.n_namesz = strlen(men->name) + 1;
1248 en.n_descsz = men->datasz;
1249 en.n_type = men->type;
1250
1251 DUMP_WRITE(&en, sizeof(en), foffset);
1252 DUMP_WRITE(men->name, en.n_namesz, foffset);
1253 if (!alignfile(file, foffset))
1254 return 0;
1255 DUMP_WRITE(men->data, men->datasz, foffset);
1256 if (!alignfile(file, foffset))
1257 return 0;
1258
1259 return 1;
1260 }
1261 #undef DUMP_WRITE
1262
1263 #define DUMP_WRITE(addr, nr) \
1264 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1265 goto end_coredump;
1266 #define DUMP_SEEK(off) \
1267 if (!dump_seek(file, (off))) \
1268 goto end_coredump;
1269
1270 static void fill_elf_header(struct elfhdr *elf, int segs)
1271 {
1272 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1273 elf->e_ident[EI_CLASS] = ELF_CLASS;
1274 elf->e_ident[EI_DATA] = ELF_DATA;
1275 elf->e_ident[EI_VERSION] = EV_CURRENT;
1276 elf->e_ident[EI_OSABI] = ELF_OSABI;
1277 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1278
1279 elf->e_type = ET_CORE;
1280 elf->e_machine = ELF_ARCH;
1281 elf->e_version = EV_CURRENT;
1282 elf->e_entry = 0;
1283 elf->e_phoff = sizeof(struct elfhdr);
1284 elf->e_shoff = 0;
1285 elf->e_flags = ELF_CORE_EFLAGS;
1286 elf->e_ehsize = sizeof(struct elfhdr);
1287 elf->e_phentsize = sizeof(struct elf_phdr);
1288 elf->e_phnum = segs;
1289 elf->e_shentsize = 0;
1290 elf->e_shnum = 0;
1291 elf->e_shstrndx = 0;
1292 return;
1293 }
1294
1295 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1296 {
1297 phdr->p_type = PT_NOTE;
1298 phdr->p_offset = offset;
1299 phdr->p_vaddr = 0;
1300 phdr->p_paddr = 0;
1301 phdr->p_filesz = sz;
1302 phdr->p_memsz = 0;
1303 phdr->p_flags = 0;
1304 phdr->p_align = 0;
1305 return;
1306 }
1307
1308 static void fill_note(struct memelfnote *note, const char *name, int type,
1309 unsigned int sz, void *data)
1310 {
1311 note->name = name;
1312 note->type = type;
1313 note->datasz = sz;
1314 note->data = data;
1315 return;
1316 }
1317
1318 /*
1319 * fill up all the fields in prstatus from the given task struct, except
1320 * registers which need to be filled up separately.
1321 */
1322 static void fill_prstatus(struct elf_prstatus *prstatus,
1323 struct task_struct *p, long signr)
1324 {
1325 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1326 prstatus->pr_sigpend = p->pending.signal.sig[0];
1327 prstatus->pr_sighold = p->blocked.sig[0];
1328 prstatus->pr_pid = p->pid;
1329 prstatus->pr_ppid = p->parent->pid;
1330 prstatus->pr_pgrp = process_group(p);
1331 prstatus->pr_sid = process_session(p);
1332 if (thread_group_leader(p)) {
1333 /*
1334 * This is the record for the group leader. Add in the
1335 * cumulative times of previous dead threads. This total
1336 * won't include the time of each live thread whose state
1337 * is included in the core dump. The final total reported
1338 * to our parent process when it calls wait4 will include
1339 * those sums as well as the little bit more time it takes
1340 * this and each other thread to finish dying after the
1341 * core dump synchronization phase.
1342 */
1343 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1344 &prstatus->pr_utime);
1345 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1346 &prstatus->pr_stime);
1347 } else {
1348 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1349 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1350 }
1351 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1352 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1353 }
1354
1355 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1356 struct mm_struct *mm)
1357 {
1358 unsigned int i, len;
1359
1360 /* first copy the parameters from user space */
1361 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1362
1363 len = mm->arg_end - mm->arg_start;
1364 if (len >= ELF_PRARGSZ)
1365 len = ELF_PRARGSZ-1;
1366 if (copy_from_user(&psinfo->pr_psargs,
1367 (const char __user *)mm->arg_start, len))
1368 return -EFAULT;
1369 for(i = 0; i < len; i++)
1370 if (psinfo->pr_psargs[i] == 0)
1371 psinfo->pr_psargs[i] = ' ';
1372 psinfo->pr_psargs[len] = 0;
1373
1374 psinfo->pr_pid = p->pid;
1375 psinfo->pr_ppid = p->parent->pid;
1376 psinfo->pr_pgrp = process_group(p);
1377 psinfo->pr_sid = process_session(p);
1378
1379 i = p->state ? ffz(~p->state) + 1 : 0;
1380 psinfo->pr_state = i;
1381 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1382 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1383 psinfo->pr_nice = task_nice(p);
1384 psinfo->pr_flag = p->flags;
1385 SET_UID(psinfo->pr_uid, p->uid);
1386 SET_GID(psinfo->pr_gid, p->gid);
1387 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1388
1389 return 0;
1390 }
1391
1392 /* Here is the structure in which status of each thread is captured. */
1393 struct elf_thread_status
1394 {
1395 struct list_head list;
1396 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1397 elf_fpregset_t fpu; /* NT_PRFPREG */
1398 struct task_struct *thread;
1399 #ifdef ELF_CORE_COPY_XFPREGS
1400 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1401 #endif
1402 struct memelfnote notes[3];
1403 int num_notes;
1404 };
1405
1406 /*
1407 * In order to add the specific thread information for the elf file format,
1408 * we need to keep a linked list of every threads pr_status and then create
1409 * a single section for them in the final core file.
1410 */
1411 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1412 {
1413 int sz = 0;
1414 struct task_struct *p = t->thread;
1415 t->num_notes = 0;
1416
1417 fill_prstatus(&t->prstatus, p, signr);
1418 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1419
1420 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1421 &(t->prstatus));
1422 t->num_notes++;
1423 sz += notesize(&t->notes[0]);
1424
1425 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1426 &t->fpu))) {
1427 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1428 &(t->fpu));
1429 t->num_notes++;
1430 sz += notesize(&t->notes[1]);
1431 }
1432
1433 #ifdef ELF_CORE_COPY_XFPREGS
1434 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1435 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1436 &t->xfpu);
1437 t->num_notes++;
1438 sz += notesize(&t->notes[2]);
1439 }
1440 #endif
1441 return sz;
1442 }
1443
1444 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1445 struct vm_area_struct *gate_vma)
1446 {
1447 struct vm_area_struct *ret = tsk->mm->mmap;
1448
1449 if (ret)
1450 return ret;
1451 return gate_vma;
1452 }
1453 /*
1454 * Helper function for iterating across a vma list. It ensures that the caller
1455 * will visit `gate_vma' prior to terminating the search.
1456 */
1457 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1458 struct vm_area_struct *gate_vma)
1459 {
1460 struct vm_area_struct *ret;
1461
1462 ret = this_vma->vm_next;
1463 if (ret)
1464 return ret;
1465 if (this_vma == gate_vma)
1466 return NULL;
1467 return gate_vma;
1468 }
1469
1470 /*
1471 * Actual dumper
1472 *
1473 * This is a two-pass process; first we find the offsets of the bits,
1474 * and then they are actually written out. If we run out of core limit
1475 * we just truncate.
1476 */
1477 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
1478 {
1479 #define NUM_NOTES 6
1480 int has_dumped = 0;
1481 mm_segment_t fs;
1482 int segs;
1483 size_t size = 0;
1484 int i;
1485 struct vm_area_struct *vma, *gate_vma;
1486 struct elfhdr *elf = NULL;
1487 loff_t offset = 0, dataoff, foffset;
1488 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1489 int numnote;
1490 struct memelfnote *notes = NULL;
1491 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1492 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1493 struct task_struct *g, *p;
1494 LIST_HEAD(thread_list);
1495 struct list_head *t;
1496 elf_fpregset_t *fpu = NULL;
1497 #ifdef ELF_CORE_COPY_XFPREGS
1498 elf_fpxregset_t *xfpu = NULL;
1499 #endif
1500 int thread_status_size = 0;
1501 elf_addr_t *auxv;
1502
1503 /*
1504 * We no longer stop all VM operations.
1505 *
1506 * This is because those proceses that could possibly change map_count
1507 * or the mmap / vma pages are now blocked in do_exit on current
1508 * finishing this core dump.
1509 *
1510 * Only ptrace can touch these memory addresses, but it doesn't change
1511 * the map_count or the pages allocated. So no possibility of crashing
1512 * exists while dumping the mm->vm_next areas to the core file.
1513 */
1514
1515 /* alloc memory for large data structures: too large to be on stack */
1516 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1517 if (!elf)
1518 goto cleanup;
1519 prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
1520 if (!prstatus)
1521 goto cleanup;
1522 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1523 if (!psinfo)
1524 goto cleanup;
1525 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1526 if (!notes)
1527 goto cleanup;
1528 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1529 if (!fpu)
1530 goto cleanup;
1531 #ifdef ELF_CORE_COPY_XFPREGS
1532 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1533 if (!xfpu)
1534 goto cleanup;
1535 #endif
1536
1537 if (signr) {
1538 struct elf_thread_status *tmp;
1539 rcu_read_lock();
1540 do_each_thread(g,p)
1541 if (current->mm == p->mm && current != p) {
1542 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1543 if (!tmp) {
1544 rcu_read_unlock();
1545 goto cleanup;
1546 }
1547 tmp->thread = p;
1548 list_add(&tmp->list, &thread_list);
1549 }
1550 while_each_thread(g,p);
1551 rcu_read_unlock();
1552 list_for_each(t, &thread_list) {
1553 struct elf_thread_status *tmp;
1554 int sz;
1555
1556 tmp = list_entry(t, struct elf_thread_status, list);
1557 sz = elf_dump_thread_status(signr, tmp);
1558 thread_status_size += sz;
1559 }
1560 }
1561 /* now collect the dump for the current */
1562 memset(prstatus, 0, sizeof(*prstatus));
1563 fill_prstatus(prstatus, current, signr);
1564 elf_core_copy_regs(&prstatus->pr_reg, regs);
1565
1566 segs = current->mm->map_count;
1567 #ifdef ELF_CORE_EXTRA_PHDRS
1568 segs += ELF_CORE_EXTRA_PHDRS;
1569 #endif
1570
1571 gate_vma = get_gate_vma(current);
1572 if (gate_vma != NULL)
1573 segs++;
1574
1575 /* Set up header */
1576 fill_elf_header(elf, segs + 1); /* including notes section */
1577
1578 has_dumped = 1;
1579 current->flags |= PF_DUMPCORE;
1580
1581 /*
1582 * Set up the notes in similar form to SVR4 core dumps made
1583 * with info from their /proc.
1584 */
1585
1586 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1587 fill_psinfo(psinfo, current->group_leader, current->mm);
1588 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1589
1590 numnote = 2;
1591
1592 auxv = (elf_addr_t *)current->mm->saved_auxv;
1593
1594 i = 0;
1595 do
1596 i += 2;
1597 while (auxv[i - 2] != AT_NULL);
1598 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1599 i * sizeof(elf_addr_t), auxv);
1600
1601 /* Try to dump the FPU. */
1602 if ((prstatus->pr_fpvalid =
1603 elf_core_copy_task_fpregs(current, regs, fpu)))
1604 fill_note(notes + numnote++,
1605 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1606 #ifdef ELF_CORE_COPY_XFPREGS
1607 if (elf_core_copy_task_xfpregs(current, xfpu))
1608 fill_note(notes + numnote++,
1609 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1610 #endif
1611
1612 fs = get_fs();
1613 set_fs(KERNEL_DS);
1614
1615 DUMP_WRITE(elf, sizeof(*elf));
1616 offset += sizeof(*elf); /* Elf header */
1617 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1618 foffset = offset;
1619
1620 /* Write notes phdr entry */
1621 {
1622 struct elf_phdr phdr;
1623 int sz = 0;
1624
1625 for (i = 0; i < numnote; i++)
1626 sz += notesize(notes + i);
1627
1628 sz += thread_status_size;
1629
1630 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1631 sz += ELF_CORE_EXTRA_NOTES_SIZE;
1632 #endif
1633
1634 fill_elf_note_phdr(&phdr, sz, offset);
1635 offset += sz;
1636 DUMP_WRITE(&phdr, sizeof(phdr));
1637 }
1638
1639 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1640
1641 /* Write program headers for segments dump */
1642 for (vma = first_vma(current, gate_vma); vma != NULL;
1643 vma = next_vma(vma, gate_vma)) {
1644 struct elf_phdr phdr;
1645 size_t sz;
1646
1647 sz = vma->vm_end - vma->vm_start;
1648
1649 phdr.p_type = PT_LOAD;
1650 phdr.p_offset = offset;
1651 phdr.p_vaddr = vma->vm_start;
1652 phdr.p_paddr = 0;
1653 phdr.p_filesz = maydump(vma) ? sz : 0;
1654 phdr.p_memsz = sz;
1655 offset += phdr.p_filesz;
1656 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1657 if (vma->vm_flags & VM_WRITE)
1658 phdr.p_flags |= PF_W;
1659 if (vma->vm_flags & VM_EXEC)
1660 phdr.p_flags |= PF_X;
1661 phdr.p_align = ELF_EXEC_PAGESIZE;
1662
1663 DUMP_WRITE(&phdr, sizeof(phdr));
1664 }
1665
1666 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1667 ELF_CORE_WRITE_EXTRA_PHDRS;
1668 #endif
1669
1670 /* write out the notes section */
1671 for (i = 0; i < numnote; i++)
1672 if (!writenote(notes + i, file, &foffset))
1673 goto end_coredump;
1674
1675 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1676 ELF_CORE_WRITE_EXTRA_NOTES;
1677 #endif
1678
1679 /* write out the thread status notes section */
1680 list_for_each(t, &thread_list) {
1681 struct elf_thread_status *tmp =
1682 list_entry(t, struct elf_thread_status, list);
1683
1684 for (i = 0; i < tmp->num_notes; i++)
1685 if (!writenote(&tmp->notes[i], file, &foffset))
1686 goto end_coredump;
1687 }
1688
1689 /* Align to page */
1690 DUMP_SEEK(dataoff - foffset);
1691
1692 for (vma = first_vma(current, gate_vma); vma != NULL;
1693 vma = next_vma(vma, gate_vma)) {
1694 unsigned long addr;
1695
1696 if (!maydump(vma))
1697 continue;
1698
1699 for (addr = vma->vm_start;
1700 addr < vma->vm_end;
1701 addr += PAGE_SIZE) {
1702 struct page *page;
1703 struct vm_area_struct *vma;
1704
1705 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1706 &page, &vma) <= 0) {
1707 DUMP_SEEK(PAGE_SIZE);
1708 } else {
1709 if (page == ZERO_PAGE(addr)) {
1710 if (!dump_seek(file, PAGE_SIZE)) {
1711 page_cache_release(page);
1712 goto end_coredump;
1713 }
1714 } else {
1715 void *kaddr;
1716 flush_cache_page(vma, addr,
1717 page_to_pfn(page));
1718 kaddr = kmap(page);
1719 if ((size += PAGE_SIZE) > limit ||
1720 !dump_write(file, kaddr,
1721 PAGE_SIZE)) {
1722 kunmap(page);
1723 page_cache_release(page);
1724 goto end_coredump;
1725 }
1726 kunmap(page);
1727 }
1728 page_cache_release(page);
1729 }
1730 }
1731 }
1732
1733 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1734 ELF_CORE_WRITE_EXTRA_DATA;
1735 #endif
1736
1737 end_coredump:
1738 set_fs(fs);
1739
1740 cleanup:
1741 while (!list_empty(&thread_list)) {
1742 struct list_head *tmp = thread_list.next;
1743 list_del(tmp);
1744 kfree(list_entry(tmp, struct elf_thread_status, list));
1745 }
1746
1747 kfree(elf);
1748 kfree(prstatus);
1749 kfree(psinfo);
1750 kfree(notes);
1751 kfree(fpu);
1752 #ifdef ELF_CORE_COPY_XFPREGS
1753 kfree(xfpu);
1754 #endif
1755 return has_dumped;
1756 #undef NUM_NOTES
1757 }
1758
1759 #endif /* USE_ELF_CORE_DUMP */
1760
1761 static int __init init_elf_binfmt(void)
1762 {
1763 return register_binfmt(&elf_format);
1764 }
1765
1766 static void __exit exit_elf_binfmt(void)
1767 {
1768 /* Remove the COFF and ELF loaders. */
1769 unregister_binfmt(&elf_format);
1770 }
1771
1772 core_initcall(init_elf_binfmt);
1773 module_exit(exit_elf_binfmt);
1774 MODULE_LICENSE("GPL");
linux v2.6.22.y-op