?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
sched: batch sleeper bonus
[usb.git] / fs / binfmt_elf.c
blob4482a0673b1591869c63358a1db6a21582848252
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 struct vm_area_struct *vma;
152
153 /*
154 * If this architecture has a platform capability string, copy it
155 * to userspace. In some cases (Sparc), this info is impossible
156 * for userspace to get any other way, in others (i386) it is
157 * merely difficult.
158 */
159 u_platform = NULL;
160 if (k_platform) {
161 size_t len = strlen(k_platform) + 1;
162
163 /*
164 * In some cases (e.g. Hyper-Threading), we want to avoid L1
165 * evictions by the processes running on the same package. One
166 * thing we can do is to shuffle the initial stack for them.
167 */
168
169 p = arch_align_stack(p);
170
171 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
172 if (__copy_to_user(u_platform, k_platform, len))
173 return -EFAULT;
174 }
175
176 /* Create the ELF interpreter info */
177 elf_info = (elf_addr_t *)current->mm->saved_auxv;
178 #define NEW_AUX_ENT(id, val) \
179 do { \
180 elf_info[ei_index++] = id; \
181 elf_info[ei_index++] = val; \
182 } while (0)
183
184 #ifdef ARCH_DLINFO
185 /*
186 * ARCH_DLINFO must come first so PPC can do its special alignment of
187 * AUXV.
188 */
189 ARCH_DLINFO;
190 #endif
191 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
192 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
193 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
194 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
195 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
196 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
197 NEW_AUX_ENT(AT_BASE, interp_load_addr);
198 NEW_AUX_ENT(AT_FLAGS, 0);
199 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
200 NEW_AUX_ENT(AT_UID, tsk->uid);
201 NEW_AUX_ENT(AT_EUID, tsk->euid);
202 NEW_AUX_ENT(AT_GID, tsk->gid);
203 NEW_AUX_ENT(AT_EGID, tsk->egid);
204 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
205 if (k_platform) {
206 NEW_AUX_ENT(AT_PLATFORM,
207 (elf_addr_t)(unsigned long)u_platform);
208 }
209 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
210 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
211 }
212 #undef NEW_AUX_ENT
213 /* AT_NULL is zero; clear the rest too */
214 memset(&elf_info[ei_index], 0,
215 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
216
217 /* And advance past the AT_NULL entry. */
218 ei_index += 2;
219
220 sp = STACK_ADD(p, ei_index);
221
222 items = (argc + 1) + (envc + 1);
223 if (interp_aout) {
224 items += 3; /* a.out interpreters require argv & envp too */
225 } else {
226 items += 1; /* ELF interpreters only put argc on the stack */
227 }
228 bprm->p = STACK_ROUND(sp, items);
229
230 /* Point sp at the lowest address on the stack */
231 #ifdef CONFIG_STACK_GROWSUP
232 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
233 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
234 #else
235 sp = (elf_addr_t __user *)bprm->p;
236 #endif
237
238
239 /*
240 * Grow the stack manually; some architectures have a limit on how
241 * far ahead a user-space access may be in order to grow the stack.
242 */
243 vma = find_extend_vma(current->mm, bprm->p);
244 if (!vma)
245 return -EFAULT;
246
247 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
248 if (__put_user(argc, sp++))
249 return -EFAULT;
250 if (interp_aout) {
251 argv = sp + 2;
252 envp = argv + argc + 1;
253 if (__put_user((elf_addr_t)(unsigned long)argv, sp++) ||
254 __put_user((elf_addr_t)(unsigned long)envp, sp++))
255 return -EFAULT;
256 } else {
257 argv = sp;
258 envp = argv + argc + 1;
259 }
260
261 /* Populate argv and envp */
262 p = current->mm->arg_end = current->mm->arg_start;
263 while (argc-- > 0) {
264 size_t len;
265 if (__put_user((elf_addr_t)p, argv++))
266 return -EFAULT;
267 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
268 if (!len || len > MAX_ARG_STRLEN)
269 return 0;
270 p += len;
271 }
272 if (__put_user(0, argv))
273 return -EFAULT;
274 current->mm->arg_end = current->mm->env_start = p;
275 while (envc-- > 0) {
276 size_t len;
277 if (__put_user((elf_addr_t)p, envp++))
278 return -EFAULT;
279 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
280 if (!len || len > MAX_ARG_STRLEN)
281 return 0;
282 p += len;
283 }
284 if (__put_user(0, envp))
285 return -EFAULT;
286 current->mm->env_end = p;
287
288 /* Put the elf_info on the stack in the right place. */
289 sp = (elf_addr_t __user *)envp + 1;
290 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
291 return -EFAULT;
292 return 0;
293 }
294
295 #ifndef elf_map
296
297 static unsigned long elf_map(struct file *filep, unsigned long addr,
298 struct elf_phdr *eppnt, int prot, int type)
299 {
300 unsigned long map_addr;
301 unsigned long pageoffset = ELF_PAGEOFFSET(eppnt->p_vaddr);
302
303 down_write(&current->mm->mmap_sem);
304 /* mmap() will return -EINVAL if given a zero size, but a
305 * segment with zero filesize is perfectly valid */
306 if (eppnt->p_filesz + pageoffset)
307 map_addr = do_mmap(filep, ELF_PAGESTART(addr),
308 eppnt->p_filesz + pageoffset, prot, type,
309 eppnt->p_offset - pageoffset);
310 else
311 map_addr = ELF_PAGESTART(addr);
312 up_write(&current->mm->mmap_sem);
313 return(map_addr);
314 }
315
316 #endif /* !elf_map */
317
318 /* This is much more generalized than the library routine read function,
319 so we keep this separate. Technically the library read function
320 is only provided so that we can read a.out libraries that have
321 an ELF header */
322
323 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
324 struct file *interpreter, unsigned long *interp_load_addr)
325 {
326 struct elf_phdr *elf_phdata;
327 struct elf_phdr *eppnt;
328 unsigned long load_addr = 0;
329 int load_addr_set = 0;
330 unsigned long last_bss = 0, elf_bss = 0;
331 unsigned long error = ~0UL;
332 int retval, i, size;
333
334 /* First of all, some simple consistency checks */
335 if (interp_elf_ex->e_type != ET_EXEC &&
336 interp_elf_ex->e_type != ET_DYN)
337 goto out;
338 if (!elf_check_arch(interp_elf_ex))
339 goto out;
340 if (!interpreter->f_op || !interpreter->f_op->mmap)
341 goto out;
342
343 /*
344 * If the size of this structure has changed, then punt, since
345 * we will be doing the wrong thing.
346 */
347 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
348 goto out;
349 if (interp_elf_ex->e_phnum < 1 ||
350 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
351 goto out;
352
353 /* Now read in all of the header information */
354 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
355 if (size > ELF_MIN_ALIGN)
356 goto out;
357 elf_phdata = kmalloc(size, GFP_KERNEL);
358 if (!elf_phdata)
359 goto out;
360
361 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
362 (char *)elf_phdata,size);
363 error = -EIO;
364 if (retval != size) {
365 if (retval < 0)
366 error = retval;
367 goto out_close;
368 }
369
370 eppnt = elf_phdata;
371 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
372 if (eppnt->p_type == PT_LOAD) {
373 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
374 int elf_prot = 0;
375 unsigned long vaddr = 0;
376 unsigned long k, map_addr;
377
378 if (eppnt->p_flags & PF_R)
379 elf_prot = PROT_READ;
380 if (eppnt->p_flags & PF_W)
381 elf_prot |= PROT_WRITE;
382 if (eppnt->p_flags & PF_X)
383 elf_prot |= PROT_EXEC;
384 vaddr = eppnt->p_vaddr;
385 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
386 elf_type |= MAP_FIXED;
387
388 map_addr = elf_map(interpreter, load_addr + vaddr,
389 eppnt, elf_prot, elf_type);
390 error = map_addr;
391 if (BAD_ADDR(map_addr))
392 goto out_close;
393
394 if (!load_addr_set &&
395 interp_elf_ex->e_type == ET_DYN) {
396 load_addr = map_addr - ELF_PAGESTART(vaddr);
397 load_addr_set = 1;
398 }
399
400 /*
401 * Check to see if the section's size will overflow the
402 * allowed task size. Note that p_filesz must always be
403 * <= p_memsize so it's only necessary to check p_memsz.
404 */
405 k = load_addr + eppnt->p_vaddr;
406 if (BAD_ADDR(k) ||
407 eppnt->p_filesz > eppnt->p_memsz ||
408 eppnt->p_memsz > TASK_SIZE ||
409 TASK_SIZE - eppnt->p_memsz < k) {
410 error = -ENOMEM;
411 goto out_close;
412 }
413
414 /*
415 * Find the end of the file mapping for this phdr, and
416 * keep track of the largest address we see for this.
417 */
418 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
419 if (k > elf_bss)
420 elf_bss = k;
421
422 /*
423 * Do the same thing for the memory mapping - between
424 * elf_bss and last_bss is the bss section.
425 */
426 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
427 if (k > last_bss)
428 last_bss = k;
429 }
430 }
431
432 /*
433 * Now fill out the bss section. First pad the last page up
434 * to the page boundary, and then perform a mmap to make sure
435 * that there are zero-mapped pages up to and including the
436 * last bss page.
437 */
438 if (padzero(elf_bss)) {
439 error = -EFAULT;
440 goto out_close;
441 }
442
443 /* What we have mapped so far */
444 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
445
446 /* Map the last of the bss segment */
447 if (last_bss > elf_bss) {
448 down_write(&current->mm->mmap_sem);
449 error = do_brk(elf_bss, last_bss - elf_bss);
450 up_write(&current->mm->mmap_sem);
451 if (BAD_ADDR(error))
452 goto out_close;
453 }
454
455 *interp_load_addr = load_addr;
456 error = ((unsigned long)interp_elf_ex->e_entry) + load_addr;
457
458 out_close:
459 kfree(elf_phdata);
460 out:
461 return error;
462 }
463
464 static unsigned long load_aout_interp(struct exec *interp_ex,
465 struct file *interpreter)
466 {
467 unsigned long text_data, elf_entry = ~0UL;
468 char __user * addr;
469 loff_t offset;
470
471 current->mm->end_code = interp_ex->a_text;
472 text_data = interp_ex->a_text + interp_ex->a_data;
473 current->mm->end_data = text_data;
474 current->mm->brk = interp_ex->a_bss + text_data;
475
476 switch (N_MAGIC(*interp_ex)) {
477 case OMAGIC:
478 offset = 32;
479 addr = (char __user *)0;
480 break;
481 case ZMAGIC:
482 case QMAGIC:
483 offset = N_TXTOFF(*interp_ex);
484 addr = (char __user *)N_TXTADDR(*interp_ex);
485 break;
486 default:
487 goto out;
488 }
489
490 down_write(&current->mm->mmap_sem);
491 do_brk(0, text_data);
492 up_write(&current->mm->mmap_sem);
493 if (!interpreter->f_op || !interpreter->f_op->read)
494 goto out;
495 if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0)
496 goto out;
497 flush_icache_range((unsigned long)addr,
498 (unsigned long)addr + text_data);
499
500 down_write(&current->mm->mmap_sem);
501 do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
502 interp_ex->a_bss);
503 up_write(&current->mm->mmap_sem);
504 elf_entry = interp_ex->a_entry;
505
506 out:
507 return elf_entry;
508 }
509
510 /*
511 * These are the functions used to load ELF style executables and shared
512 * libraries. There is no binary dependent code anywhere else.
513 */
514
515 #define INTERPRETER_NONE 0
516 #define INTERPRETER_AOUT 1
517 #define INTERPRETER_ELF 2
518
519 #ifndef STACK_RND_MASK
520 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
521 #endif
522
523 static unsigned long randomize_stack_top(unsigned long stack_top)
524 {
525 unsigned int random_variable = 0;
526
527 if ((current->flags & PF_RANDOMIZE) &&
528 !(current->personality & ADDR_NO_RANDOMIZE)) {
529 random_variable = get_random_int() & STACK_RND_MASK;
530 random_variable <<= PAGE_SHIFT;
531 }
532 #ifdef CONFIG_STACK_GROWSUP
533 return PAGE_ALIGN(stack_top) + random_variable;
534 #else
535 return PAGE_ALIGN(stack_top) - random_variable;
536 #endif
537 }
538
539 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
540 {
541 struct file *interpreter = NULL; /* to shut gcc up */
542 unsigned long load_addr = 0, load_bias = 0;
543 int load_addr_set = 0;
544 char * elf_interpreter = NULL;
545 unsigned int interpreter_type = INTERPRETER_NONE;
546 unsigned char ibcs2_interpreter = 0;
547 unsigned long error;
548 struct elf_phdr *elf_ppnt, *elf_phdata;
549 unsigned long elf_bss, elf_brk;
550 int elf_exec_fileno;
551 int retval, i;
552 unsigned int size;
553 unsigned long elf_entry, interp_load_addr = 0;
554 unsigned long start_code, end_code, start_data, end_data;
555 unsigned long reloc_func_desc = 0;
556 char passed_fileno[6];
557 struct files_struct *files;
558 int executable_stack = EXSTACK_DEFAULT;
559 unsigned long def_flags = 0;
560 struct {
561 struct elfhdr elf_ex;
562 struct elfhdr interp_elf_ex;
563 struct exec interp_ex;
564 } *loc;
565
566 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
567 if (!loc) {
568 retval = -ENOMEM;
569 goto out_ret;
570 }
571
572 /* Get the exec-header */
573 loc->elf_ex = *((struct elfhdr *)bprm->buf);
574
575 retval = -ENOEXEC;
576 /* First of all, some simple consistency checks */
577 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
578 goto out;
579
580 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
581 goto out;
582 if (!elf_check_arch(&loc->elf_ex))
583 goto out;
584 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
585 goto out;
586
587 /* Now read in all of the header information */
588 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
589 goto out;
590 if (loc->elf_ex.e_phnum < 1 ||
591 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
592 goto out;
593 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
594 retval = -ENOMEM;
595 elf_phdata = kmalloc(size, GFP_KERNEL);
596 if (!elf_phdata)
597 goto out;
598
599 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
600 (char *)elf_phdata, size);
601 if (retval != size) {
602 if (retval >= 0)
603 retval = -EIO;
604 goto out_free_ph;
605 }
606
607 files = current->files; /* Refcounted so ok */
608 retval = unshare_files();
609 if (retval < 0)
610 goto out_free_ph;
611 if (files == current->files) {
612 put_files_struct(files);
613 files = NULL;
614 }
615
616 /* exec will make our files private anyway, but for the a.out
617 loader stuff we need to do it earlier */
618 retval = get_unused_fd();
619 if (retval < 0)
620 goto out_free_fh;
621 get_file(bprm->file);
622 fd_install(elf_exec_fileno = retval, bprm->file);
623
624 elf_ppnt = elf_phdata;
625 elf_bss = 0;
626 elf_brk = 0;
627
628 start_code = ~0UL;
629 end_code = 0;
630 start_data = 0;
631 end_data = 0;
632
633 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
634 if (elf_ppnt->p_type == PT_INTERP) {
635 /* This is the program interpreter used for
636 * shared libraries - for now assume that this
637 * is an a.out format binary
638 */
639 retval = -ENOEXEC;
640 if (elf_ppnt->p_filesz > PATH_MAX ||
641 elf_ppnt->p_filesz < 2)
642 goto out_free_file;
643
644 retval = -ENOMEM;
645 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
646 GFP_KERNEL);
647 if (!elf_interpreter)
648 goto out_free_file;
649
650 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
651 elf_interpreter,
652 elf_ppnt->p_filesz);
653 if (retval != elf_ppnt->p_filesz) {
654 if (retval >= 0)
655 retval = -EIO;
656 goto out_free_interp;
657 }
658 /* make sure path is NULL terminated */
659 retval = -ENOEXEC;
660 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
661 goto out_free_interp;
662
663 /* If the program interpreter is one of these two,
664 * then assume an iBCS2 image. Otherwise assume
665 * a native linux image.
666 */
667 if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
668 strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0)
669 ibcs2_interpreter = 1;
670
671 /*
672 * The early SET_PERSONALITY here is so that the lookup
673 * for the interpreter happens in the namespace of the
674 * to-be-execed image. SET_PERSONALITY can select an
675 * alternate root.
676 *
677 * However, SET_PERSONALITY is NOT allowed to switch
678 * this task into the new images's memory mapping
679 * policy - that is, TASK_SIZE must still evaluate to
680 * that which is appropriate to the execing application.
681 * This is because exit_mmap() needs to have TASK_SIZE
682 * evaluate to the size of the old image.
683 *
684 * So if (say) a 64-bit application is execing a 32-bit
685 * application it is the architecture's responsibility
686 * to defer changing the value of TASK_SIZE until the
687 * switch really is going to happen - do this in
688 * flush_thread(). - akpm
689 */
690 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
691
692 interpreter = open_exec(elf_interpreter);
693 retval = PTR_ERR(interpreter);
694 if (IS_ERR(interpreter))
695 goto out_free_interp;
696
697 /*
698 * If the binary is not readable then enforce
699 * mm->dumpable = 0 regardless of the interpreter's
700 * permissions.
701 */
702 if (file_permission(interpreter, MAY_READ) < 0)
703 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
704
705 retval = kernel_read(interpreter, 0, bprm->buf,
706 BINPRM_BUF_SIZE);
707 if (retval != BINPRM_BUF_SIZE) {
708 if (retval >= 0)
709 retval = -EIO;
710 goto out_free_dentry;
711 }
712
713 /* Get the exec headers */
714 loc->interp_ex = *((struct exec *)bprm->buf);
715 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
716 break;
717 }
718 elf_ppnt++;
719 }
720
721 elf_ppnt = elf_phdata;
722 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
723 if (elf_ppnt->p_type == PT_GNU_STACK) {
724 if (elf_ppnt->p_flags & PF_X)
725 executable_stack = EXSTACK_ENABLE_X;
726 else
727 executable_stack = EXSTACK_DISABLE_X;
728 break;
729 }
730
731 /* Some simple consistency checks for the interpreter */
732 if (elf_interpreter) {
733 interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
734
735 /* Now figure out which format our binary is */
736 if ((N_MAGIC(loc->interp_ex) != OMAGIC) &&
737 (N_MAGIC(loc->interp_ex) != ZMAGIC) &&
738 (N_MAGIC(loc->interp_ex) != QMAGIC))
739 interpreter_type = INTERPRETER_ELF;
740
741 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
742 interpreter_type &= ~INTERPRETER_ELF;
743
744 retval = -ELIBBAD;
745 if (!interpreter_type)
746 goto out_free_dentry;
747
748 /* Make sure only one type was selected */
749 if ((interpreter_type & INTERPRETER_ELF) &&
750 interpreter_type != INTERPRETER_ELF) {
751 // FIXME - ratelimit this before re-enabling
752 // printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n");
753 interpreter_type = INTERPRETER_ELF;
754 }
755 /* Verify the interpreter has a valid arch */
756 if ((interpreter_type == INTERPRETER_ELF) &&
757 !elf_check_arch(&loc->interp_elf_ex))
758 goto out_free_dentry;
759 } else {
760 /* Executables without an interpreter also need a personality */
761 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
762 }
763
764 /* OK, we are done with that, now set up the arg stuff,
765 and then start this sucker up */
766 if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) {
767 char *passed_p = passed_fileno;
768 sprintf(passed_fileno, "%d", elf_exec_fileno);
769
770 if (elf_interpreter) {
771 retval = copy_strings_kernel(1, &passed_p, bprm);
772 if (retval)
773 goto out_free_dentry;
774 bprm->argc++;
775 }
776 }
777
778 /* Flush all traces of the currently running executable */
779 retval = flush_old_exec(bprm);
780 if (retval)
781 goto out_free_dentry;
782
783 /* Discard our unneeded old files struct */
784 if (files) {
785 put_files_struct(files);
786 files = NULL;
787 }
788
789 /* OK, This is the point of no return */
790 current->flags &= ~PF_FORKNOEXEC;
791 current->mm->def_flags = def_flags;
792
793 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
794 may depend on the personality. */
795 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
796 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
797 current->personality |= READ_IMPLIES_EXEC;
798
799 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
800 current->flags |= PF_RANDOMIZE;
801 arch_pick_mmap_layout(current->mm);
802
803 /* Do this so that we can load the interpreter, if need be. We will
804 change some of these later */
805 current->mm->free_area_cache = current->mm->mmap_base;
806 current->mm->cached_hole_size = 0;
807 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
808 executable_stack);
809 if (retval < 0) {
810 send_sig(SIGKILL, current, 0);
811 goto out_free_dentry;
812 }
813
814 current->mm->start_stack = bprm->p;
815
816 /* Now we do a little grungy work by mmaping the ELF image into
817 the correct location in memory. At this point, we assume that
818 the image should be loaded at fixed address, not at a variable
819 address. */
820 for(i = 0, elf_ppnt = elf_phdata;
821 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
822 int elf_prot = 0, elf_flags;
823 unsigned long k, vaddr;
824
825 if (elf_ppnt->p_type != PT_LOAD)
826 continue;
827
828 if (unlikely (elf_brk > elf_bss)) {
829 unsigned long nbyte;
830
831 /* There was a PT_LOAD segment with p_memsz > p_filesz
832 before this one. Map anonymous pages, if needed,
833 and clear the area. */
834 retval = set_brk (elf_bss + load_bias,
835 elf_brk + load_bias);
836 if (retval) {
837 send_sig(SIGKILL, current, 0);
838 goto out_free_dentry;
839 }
840 nbyte = ELF_PAGEOFFSET(elf_bss);
841 if (nbyte) {
842 nbyte = ELF_MIN_ALIGN - nbyte;
843 if (nbyte > elf_brk - elf_bss)
844 nbyte = elf_brk - elf_bss;
845 if (clear_user((void __user *)elf_bss +
846 load_bias, nbyte)) {
847 /*
848 * This bss-zeroing can fail if the ELF
849 * file specifies odd protections. So
850 * we don't check the return value
851 */
852 }
853 }
854 }
855
856 if (elf_ppnt->p_flags & PF_R)
857 elf_prot |= PROT_READ;
858 if (elf_ppnt->p_flags & PF_W)
859 elf_prot |= PROT_WRITE;
860 if (elf_ppnt->p_flags & PF_X)
861 elf_prot |= PROT_EXEC;
862
863 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
864
865 vaddr = elf_ppnt->p_vaddr;
866 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
867 elf_flags |= MAP_FIXED;
868 } else if (loc->elf_ex.e_type == ET_DYN) {
869 /* Try and get dynamic programs out of the way of the
870 * default mmap base, as well as whatever program they
871 * might try to exec. This is because the brk will
872 * follow the loader, and is not movable. */
873 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
874 }
875
876 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
877 elf_prot, elf_flags);
878 if (BAD_ADDR(error)) {
879 send_sig(SIGKILL, current, 0);
880 retval = IS_ERR((void *)error) ?
881 PTR_ERR((void*)error) : -EINVAL;
882 goto out_free_dentry;
883 }
884
885 if (!load_addr_set) {
886 load_addr_set = 1;
887 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
888 if (loc->elf_ex.e_type == ET_DYN) {
889 load_bias += error -
890 ELF_PAGESTART(load_bias + vaddr);
891 load_addr += load_bias;
892 reloc_func_desc = load_bias;
893 }
894 }
895 k = elf_ppnt->p_vaddr;
896 if (k < start_code)
897 start_code = k;
898 if (start_data < k)
899 start_data = k;
900
901 /*
902 * Check to see if the section's size will overflow the
903 * allowed task size. Note that p_filesz must always be
904 * <= p_memsz so it is only necessary to check p_memsz.
905 */
906 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
907 elf_ppnt->p_memsz > TASK_SIZE ||
908 TASK_SIZE - elf_ppnt->p_memsz < k) {
909 /* set_brk can never work. Avoid overflows. */
910 send_sig(SIGKILL, current, 0);
911 retval = -EINVAL;
912 goto out_free_dentry;
913 }
914
915 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
916
917 if (k > elf_bss)
918 elf_bss = k;
919 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
920 end_code = k;
921 if (end_data < k)
922 end_data = k;
923 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
924 if (k > elf_brk)
925 elf_brk = k;
926 }
927
928 loc->elf_ex.e_entry += load_bias;
929 elf_bss += load_bias;
930 elf_brk += load_bias;
931 start_code += load_bias;
932 end_code += load_bias;
933 start_data += load_bias;
934 end_data += load_bias;
935
936 /* Calling set_brk effectively mmaps the pages that we need
937 * for the bss and break sections. We must do this before
938 * mapping in the interpreter, to make sure it doesn't wind
939 * up getting placed where the bss needs to go.
940 */
941 retval = set_brk(elf_bss, elf_brk);
942 if (retval) {
943 send_sig(SIGKILL, current, 0);
944 goto out_free_dentry;
945 }
946 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
947 send_sig(SIGSEGV, current, 0);
948 retval = -EFAULT; /* Nobody gets to see this, but.. */
949 goto out_free_dentry;
950 }
951
952 if (elf_interpreter) {
953 if (interpreter_type == INTERPRETER_AOUT)
954 elf_entry = load_aout_interp(&loc->interp_ex,
955 interpreter);
956 else
957 elf_entry = load_elf_interp(&loc->interp_elf_ex,
958 interpreter,
959 &interp_load_addr);
960 if (BAD_ADDR(elf_entry)) {
961 force_sig(SIGSEGV, current);
962 retval = IS_ERR((void *)elf_entry) ?
963 (int)elf_entry : -EINVAL;
964 goto out_free_dentry;
965 }
966 reloc_func_desc = interp_load_addr;
967
968 allow_write_access(interpreter);
969 fput(interpreter);
970 kfree(elf_interpreter);
971 } else {
972 elf_entry = loc->elf_ex.e_entry;
973 if (BAD_ADDR(elf_entry)) {
974 force_sig(SIGSEGV, current);
975 retval = -EINVAL;
976 goto out_free_dentry;
977 }
978 }
979
980 kfree(elf_phdata);
981
982 if (interpreter_type != INTERPRETER_AOUT)
983 sys_close(elf_exec_fileno);
984
985 set_binfmt(&elf_format);
986
987 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
988 retval = arch_setup_additional_pages(bprm, executable_stack);
989 if (retval < 0) {
990 send_sig(SIGKILL, current, 0);
991 goto out;
992 }
993 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
994
995 compute_creds(bprm);
996 current->flags &= ~PF_FORKNOEXEC;
997 retval = create_elf_tables(bprm, &loc->elf_ex,
998 (interpreter_type == INTERPRETER_AOUT),
999 load_addr, interp_load_addr);
1000 if (retval < 0) {
1001 send_sig(SIGKILL, current, 0);
1002 goto out;
1003 }
1004 /* N.B. passed_fileno might not be initialized? */
1005 if (interpreter_type == INTERPRETER_AOUT)
1006 current->mm->arg_start += strlen(passed_fileno) + 1;
1007 current->mm->end_code = end_code;
1008 current->mm->start_code = start_code;
1009 current->mm->start_data = start_data;
1010 current->mm->end_data = end_data;
1011 current->mm->start_stack = bprm->p;
1012
1013 if (current->personality & MMAP_PAGE_ZERO) {
1014 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
1015 and some applications "depend" upon this behavior.
1016 Since we do not have the power to recompile these, we
1017 emulate the SVr4 behavior. Sigh. */
1018 down_write(&current->mm->mmap_sem);
1019 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1020 MAP_FIXED | MAP_PRIVATE, 0);
1021 up_write(&current->mm->mmap_sem);
1022 }
1023
1024 #ifdef ELF_PLAT_INIT
1025 /*
1026 * The ABI may specify that certain registers be set up in special
1027 * ways (on i386 %edx is the address of a DT_FINI function, for
1028 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1029 * that the e_entry field is the address of the function descriptor
1030 * for the startup routine, rather than the address of the startup
1031 * routine itself. This macro performs whatever initialization to
1032 * the regs structure is required as well as any relocations to the
1033 * function descriptor entries when executing dynamically links apps.
1034 */
1035 ELF_PLAT_INIT(regs, reloc_func_desc);
1036 #endif
1037
1038 start_thread(regs, elf_entry, bprm->p);
1039 if (unlikely(current->ptrace & PT_PTRACED)) {
1040 if (current->ptrace & PT_TRACE_EXEC)
1041 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
1042 else
1043 send_sig(SIGTRAP, current, 0);
1044 }
1045 retval = 0;
1046 out:
1047 kfree(loc);
1048 out_ret:
1049 return retval;
1050
1051 /* error cleanup */
1052 out_free_dentry:
1053 allow_write_access(interpreter);
1054 if (interpreter)
1055 fput(interpreter);
1056 out_free_interp:
1057 kfree(elf_interpreter);
1058 out_free_file:
1059 sys_close(elf_exec_fileno);
1060 out_free_fh:
1061 if (files)
1062 reset_files_struct(current, files);
1063 out_free_ph:
1064 kfree(elf_phdata);
1065 goto out;
1066 }
1067
1068 /* This is really simpleminded and specialized - we are loading an
1069 a.out library that is given an ELF header. */
1070 static int load_elf_library(struct file *file)
1071 {
1072 struct elf_phdr *elf_phdata;
1073 struct elf_phdr *eppnt;
1074 unsigned long elf_bss, bss, len;
1075 int retval, error, i, j;
1076 struct elfhdr elf_ex;
1077
1078 error = -ENOEXEC;
1079 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1080 if (retval != sizeof(elf_ex))
1081 goto out;
1082
1083 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1084 goto out;
1085
1086 /* First of all, some simple consistency checks */
1087 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1088 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1089 goto out;
1090
1091 /* Now read in all of the header information */
1092
1093 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1094 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1095
1096 error = -ENOMEM;
1097 elf_phdata = kmalloc(j, GFP_KERNEL);
1098 if (!elf_phdata)
1099 goto out;
1100
1101 eppnt = elf_phdata;
1102 error = -ENOEXEC;
1103 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1104 if (retval != j)
1105 goto out_free_ph;
1106
1107 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1108 if ((eppnt + i)->p_type == PT_LOAD)
1109 j++;
1110 if (j != 1)
1111 goto out_free_ph;
1112
1113 while (eppnt->p_type != PT_LOAD)
1114 eppnt++;
1115
1116 /* Now use mmap to map the library into memory. */
1117 down_write(&current->mm->mmap_sem);
1118 error = do_mmap(file,
1119 ELF_PAGESTART(eppnt->p_vaddr),
1120 (eppnt->p_filesz +
1121 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1122 PROT_READ | PROT_WRITE | PROT_EXEC,
1123 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1124 (eppnt->p_offset -
1125 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1126 up_write(&current->mm->mmap_sem);
1127 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1128 goto out_free_ph;
1129
1130 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1131 if (padzero(elf_bss)) {
1132 error = -EFAULT;
1133 goto out_free_ph;
1134 }
1135
1136 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1137 ELF_MIN_ALIGN - 1);
1138 bss = eppnt->p_memsz + eppnt->p_vaddr;
1139 if (bss > len) {
1140 down_write(&current->mm->mmap_sem);
1141 do_brk(len, bss - len);
1142 up_write(&current->mm->mmap_sem);
1143 }
1144 error = 0;
1145
1146 out_free_ph:
1147 kfree(elf_phdata);
1148 out:
1149 return error;
1150 }
1151
1152 /*
1153 * Note that some platforms still use traditional core dumps and not
1154 * the ELF core dump. Each platform can select it as appropriate.
1155 */
1156 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1157
1158 /*
1159 * ELF core dumper
1160 *
1161 * Modelled on fs/exec.c:aout_core_dump()
1162 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1163 */
1164 /*
1165 * These are the only things you should do on a core-file: use only these
1166 * functions to write out all the necessary info.
1167 */
1168 static int dump_write(struct file *file, const void *addr, int nr)
1169 {
1170 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1171 }
1172
1173 static int dump_seek(struct file *file, loff_t off)
1174 {
1175 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1176 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1177 return 0;
1178 } else {
1179 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1180 if (!buf)
1181 return 0;
1182 while (off > 0) {
1183 unsigned long n = off;
1184 if (n > PAGE_SIZE)
1185 n = PAGE_SIZE;
1186 if (!dump_write(file, buf, n))
1187 return 0;
1188 off -= n;
1189 }
1190 free_page((unsigned long)buf);
1191 }
1192 return 1;
1193 }
1194
1195 /*
1196 * Decide whether a segment is worth dumping; default is yes to be
1197 * sure (missing info is worse than too much; etc).
1198 * Personally I'd include everything, and use the coredump limit...
1199 *
1200 * I think we should skip something. But I am not sure how. H.J.
1201 */
1202 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1203 {
1204 /* The vma can be set up to tell us the answer directly. */
1205 if (vma->vm_flags & VM_ALWAYSDUMP)
1206 return 1;
1207
1208 /* Do not dump I/O mapped devices or special mappings */
1209 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1210 return 0;
1211
1212 /* By default, dump shared memory if mapped from an anonymous file. */
1213 if (vma->vm_flags & VM_SHARED) {
1214 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0)
1215 return test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1216 else
1217 return test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1218 }
1219
1220 /* By default, if it hasn't been written to, don't write it out. */
1221 if (!vma->anon_vma)
1222 return test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1223
1224 return test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1225 }
1226
1227 /* An ELF note in memory */
1228 struct memelfnote
1229 {
1230 const char *name;
1231 int type;
1232 unsigned int datasz;
1233 void *data;
1234 };
1235
1236 static int notesize(struct memelfnote *en)
1237 {
1238 int sz;
1239
1240 sz = sizeof(struct elf_note);
1241 sz += roundup(strlen(en->name) + 1, 4);
1242 sz += roundup(en->datasz, 4);
1243
1244 return sz;
1245 }
1246
1247 #define DUMP_WRITE(addr, nr, foffset) \
1248 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1249
1250 static int alignfile(struct file *file, loff_t *foffset)
1251 {
1252 static const char buf[4] = { 0, };
1253 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1254 return 1;
1255 }
1256
1257 static int writenote(struct memelfnote *men, struct file *file,
1258 loff_t *foffset)
1259 {
1260 struct elf_note en;
1261 en.n_namesz = strlen(men->name) + 1;
1262 en.n_descsz = men->datasz;
1263 en.n_type = men->type;
1264
1265 DUMP_WRITE(&en, sizeof(en), foffset);
1266 DUMP_WRITE(men->name, en.n_namesz, foffset);
1267 if (!alignfile(file, foffset))
1268 return 0;
1269 DUMP_WRITE(men->data, men->datasz, foffset);
1270 if (!alignfile(file, foffset))
1271 return 0;
1272
1273 return 1;
1274 }
1275 #undef DUMP_WRITE
1276
1277 #define DUMP_WRITE(addr, nr) \
1278 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1279 goto end_coredump;
1280 #define DUMP_SEEK(off) \
1281 if (!dump_seek(file, (off))) \
1282 goto end_coredump;
1283
1284 static void fill_elf_header(struct elfhdr *elf, int segs)
1285 {
1286 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1287 elf->e_ident[EI_CLASS] = ELF_CLASS;
1288 elf->e_ident[EI_DATA] = ELF_DATA;
1289 elf->e_ident[EI_VERSION] = EV_CURRENT;
1290 elf->e_ident[EI_OSABI] = ELF_OSABI;
1291 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1292
1293 elf->e_type = ET_CORE;
1294 elf->e_machine = ELF_ARCH;
1295 elf->e_version = EV_CURRENT;
1296 elf->e_entry = 0;
1297 elf->e_phoff = sizeof(struct elfhdr);
1298 elf->e_shoff = 0;
1299 elf->e_flags = ELF_CORE_EFLAGS;
1300 elf->e_ehsize = sizeof(struct elfhdr);
1301 elf->e_phentsize = sizeof(struct elf_phdr);
1302 elf->e_phnum = segs;
1303 elf->e_shentsize = 0;
1304 elf->e_shnum = 0;
1305 elf->e_shstrndx = 0;
1306 return;
1307 }
1308
1309 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1310 {
1311 phdr->p_type = PT_NOTE;
1312 phdr->p_offset = offset;
1313 phdr->p_vaddr = 0;
1314 phdr->p_paddr = 0;
1315 phdr->p_filesz = sz;
1316 phdr->p_memsz = 0;
1317 phdr->p_flags = 0;
1318 phdr->p_align = 0;
1319 return;
1320 }
1321
1322 static void fill_note(struct memelfnote *note, const char *name, int type,
1323 unsigned int sz, void *data)
1324 {
1325 note->name = name;
1326 note->type = type;
1327 note->datasz = sz;
1328 note->data = data;
1329 return;
1330 }
1331
1332 /*
1333 * fill up all the fields in prstatus from the given task struct, except
1334 * registers which need to be filled up separately.
1335 */
1336 static void fill_prstatus(struct elf_prstatus *prstatus,
1337 struct task_struct *p, long signr)
1338 {
1339 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1340 prstatus->pr_sigpend = p->pending.signal.sig[0];
1341 prstatus->pr_sighold = p->blocked.sig[0];
1342 prstatus->pr_pid = p->pid;
1343 prstatus->pr_ppid = p->parent->pid;
1344 prstatus->pr_pgrp = process_group(p);
1345 prstatus->pr_sid = process_session(p);
1346 if (thread_group_leader(p)) {
1347 /*
1348 * This is the record for the group leader. Add in the
1349 * cumulative times of previous dead threads. This total
1350 * won't include the time of each live thread whose state
1351 * is included in the core dump. The final total reported
1352 * to our parent process when it calls wait4 will include
1353 * those sums as well as the little bit more time it takes
1354 * this and each other thread to finish dying after the
1355 * core dump synchronization phase.
1356 */
1357 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1358 &prstatus->pr_utime);
1359 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1360 &prstatus->pr_stime);
1361 } else {
1362 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1363 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1364 }
1365 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1366 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1367 }
1368
1369 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1370 struct mm_struct *mm)
1371 {
1372 unsigned int i, len;
1373
1374 /* first copy the parameters from user space */
1375 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1376
1377 len = mm->arg_end - mm->arg_start;
1378 if (len >= ELF_PRARGSZ)
1379 len = ELF_PRARGSZ-1;
1380 if (copy_from_user(&psinfo->pr_psargs,
1381 (const char __user *)mm->arg_start, len))
1382 return -EFAULT;
1383 for(i = 0; i < len; i++)
1384 if (psinfo->pr_psargs[i] == 0)
1385 psinfo->pr_psargs[i] = ' ';
1386 psinfo->pr_psargs[len] = 0;
1387
1388 psinfo->pr_pid = p->pid;
1389 psinfo->pr_ppid = p->parent->pid;
1390 psinfo->pr_pgrp = process_group(p);
1391 psinfo->pr_sid = process_session(p);
1392
1393 i = p->state ? ffz(~p->state) + 1 : 0;
1394 psinfo->pr_state = i;
1395 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1396 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1397 psinfo->pr_nice = task_nice(p);
1398 psinfo->pr_flag = p->flags;
1399 SET_UID(psinfo->pr_uid, p->uid);
1400 SET_GID(psinfo->pr_gid, p->gid);
1401 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1402
1403 return 0;
1404 }
1405
1406 /* Here is the structure in which status of each thread is captured. */
1407 struct elf_thread_status
1408 {
1409 struct list_head list;
1410 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1411 elf_fpregset_t fpu; /* NT_PRFPREG */
1412 struct task_struct *thread;
1413 #ifdef ELF_CORE_COPY_XFPREGS
1414 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1415 #endif
1416 struct memelfnote notes[3];
1417 int num_notes;
1418 };
1419
1420 /*
1421 * In order to add the specific thread information for the elf file format,
1422 * we need to keep a linked list of every threads pr_status and then create
1423 * a single section for them in the final core file.
1424 */
1425 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1426 {
1427 int sz = 0;
1428 struct task_struct *p = t->thread;
1429 t->num_notes = 0;
1430
1431 fill_prstatus(&t->prstatus, p, signr);
1432 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1433
1434 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1435 &(t->prstatus));
1436 t->num_notes++;
1437 sz += notesize(&t->notes[0]);
1438
1439 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1440 &t->fpu))) {
1441 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1442 &(t->fpu));
1443 t->num_notes++;
1444 sz += notesize(&t->notes[1]);
1445 }
1446
1447 #ifdef ELF_CORE_COPY_XFPREGS
1448 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1449 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1450 &t->xfpu);
1451 t->num_notes++;
1452 sz += notesize(&t->notes[2]);
1453 }
1454 #endif
1455 return sz;
1456 }
1457
1458 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1459 struct vm_area_struct *gate_vma)
1460 {
1461 struct vm_area_struct *ret = tsk->mm->mmap;
1462
1463 if (ret)
1464 return ret;
1465 return gate_vma;
1466 }
1467 /*
1468 * Helper function for iterating across a vma list. It ensures that the caller
1469 * will visit `gate_vma' prior to terminating the search.
1470 */
1471 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1472 struct vm_area_struct *gate_vma)
1473 {
1474 struct vm_area_struct *ret;
1475
1476 ret = this_vma->vm_next;
1477 if (ret)
1478 return ret;
1479 if (this_vma == gate_vma)
1480 return NULL;
1481 return gate_vma;
1482 }
1483
1484 /*
1485 * Actual dumper
1486 *
1487 * This is a two-pass process; first we find the offsets of the bits,
1488 * and then they are actually written out. If we run out of core limit
1489 * we just truncate.
1490 */
1491 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
1492 {
1493 #define NUM_NOTES 6
1494 int has_dumped = 0;
1495 mm_segment_t fs;
1496 int segs;
1497 size_t size = 0;
1498 int i;
1499 struct vm_area_struct *vma, *gate_vma;
1500 struct elfhdr *elf = NULL;
1501 loff_t offset = 0, dataoff, foffset;
1502 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1503 int numnote;
1504 struct memelfnote *notes = NULL;
1505 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1506 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1507 struct task_struct *g, *p;
1508 LIST_HEAD(thread_list);
1509 struct list_head *t;
1510 elf_fpregset_t *fpu = NULL;
1511 #ifdef ELF_CORE_COPY_XFPREGS
1512 elf_fpxregset_t *xfpu = NULL;
1513 #endif
1514 int thread_status_size = 0;
1515 elf_addr_t *auxv;
1516 unsigned long mm_flags;
1517 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1518 int extra_notes_size;
1519 #endif
1520
1521 /*
1522 * We no longer stop all VM operations.
1523 *
1524 * This is because those proceses that could possibly change map_count
1525 * or the mmap / vma pages are now blocked in do_exit on current
1526 * finishing this core dump.
1527 *
1528 * Only ptrace can touch these memory addresses, but it doesn't change
1529 * the map_count or the pages allocated. So no possibility of crashing
1530 * exists while dumping the mm->vm_next areas to the core file.
1531 */
1532
1533 /* alloc memory for large data structures: too large to be on stack */
1534 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1535 if (!elf)
1536 goto cleanup;
1537 prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
1538 if (!prstatus)
1539 goto cleanup;
1540 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1541 if (!psinfo)
1542 goto cleanup;
1543 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1544 if (!notes)
1545 goto cleanup;
1546 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1547 if (!fpu)
1548 goto cleanup;
1549 #ifdef ELF_CORE_COPY_XFPREGS
1550 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1551 if (!xfpu)
1552 goto cleanup;
1553 #endif
1554
1555 if (signr) {
1556 struct elf_thread_status *tmp;
1557 rcu_read_lock();
1558 do_each_thread(g,p)
1559 if (current->mm == p->mm && current != p) {
1560 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1561 if (!tmp) {
1562 rcu_read_unlock();
1563 goto cleanup;
1564 }
1565 tmp->thread = p;
1566 list_add(&tmp->list, &thread_list);
1567 }
1568 while_each_thread(g,p);
1569 rcu_read_unlock();
1570 list_for_each(t, &thread_list) {
1571 struct elf_thread_status *tmp;
1572 int sz;
1573
1574 tmp = list_entry(t, struct elf_thread_status, list);
1575 sz = elf_dump_thread_status(signr, tmp);
1576 thread_status_size += sz;
1577 }
1578 }
1579 /* now collect the dump for the current */
1580 memset(prstatus, 0, sizeof(*prstatus));
1581 fill_prstatus(prstatus, current, signr);
1582 elf_core_copy_regs(&prstatus->pr_reg, regs);
1583
1584 segs = current->mm->map_count;
1585 #ifdef ELF_CORE_EXTRA_PHDRS
1586 segs += ELF_CORE_EXTRA_PHDRS;
1587 #endif
1588
1589 gate_vma = get_gate_vma(current);
1590 if (gate_vma != NULL)
1591 segs++;
1592
1593 /* Set up header */
1594 fill_elf_header(elf, segs + 1); /* including notes section */
1595
1596 has_dumped = 1;
1597 current->flags |= PF_DUMPCORE;
1598
1599 /*
1600 * Set up the notes in similar form to SVR4 core dumps made
1601 * with info from their /proc.
1602 */
1603
1604 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1605 fill_psinfo(psinfo, current->group_leader, current->mm);
1606 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1607
1608 numnote = 2;
1609
1610 auxv = (elf_addr_t *)current->mm->saved_auxv;
1611
1612 i = 0;
1613 do
1614 i += 2;
1615 while (auxv[i - 2] != AT_NULL);
1616 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1617 i * sizeof(elf_addr_t), auxv);
1618
1619 /* Try to dump the FPU. */
1620 if ((prstatus->pr_fpvalid =
1621 elf_core_copy_task_fpregs(current, regs, fpu)))
1622 fill_note(notes + numnote++,
1623 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1624 #ifdef ELF_CORE_COPY_XFPREGS
1625 if (elf_core_copy_task_xfpregs(current, xfpu))
1626 fill_note(notes + numnote++,
1627 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1628 #endif
1629
1630 fs = get_fs();
1631 set_fs(KERNEL_DS);
1632
1633 DUMP_WRITE(elf, sizeof(*elf));
1634 offset += sizeof(*elf); /* Elf header */
1635 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1636 foffset = offset;
1637
1638 /* Write notes phdr entry */
1639 {
1640 struct elf_phdr phdr;
1641 int sz = 0;
1642
1643 for (i = 0; i < numnote; i++)
1644 sz += notesize(notes + i);
1645
1646 sz += thread_status_size;
1647
1648 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1649 extra_notes_size = ELF_CORE_EXTRA_NOTES_SIZE;
1650 sz += extra_notes_size;
1651 #endif
1652
1653 fill_elf_note_phdr(&phdr, sz, offset);
1654 offset += sz;
1655 DUMP_WRITE(&phdr, sizeof(phdr));
1656 }
1657
1658 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1659
1660 /*
1661 * We must use the same mm->flags while dumping core to avoid
1662 * inconsistency between the program headers and bodies, otherwise an
1663 * unusable core file can be generated.
1664 */
1665 mm_flags = current->mm->flags;
1666
1667 /* Write program headers for segments dump */
1668 for (vma = first_vma(current, gate_vma); vma != NULL;
1669 vma = next_vma(vma, gate_vma)) {
1670 struct elf_phdr phdr;
1671 size_t sz;
1672
1673 sz = vma->vm_end - vma->vm_start;
1674
1675 phdr.p_type = PT_LOAD;
1676 phdr.p_offset = offset;
1677 phdr.p_vaddr = vma->vm_start;
1678 phdr.p_paddr = 0;
1679 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
1680 phdr.p_memsz = sz;
1681 offset += phdr.p_filesz;
1682 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1683 if (vma->vm_flags & VM_WRITE)
1684 phdr.p_flags |= PF_W;
1685 if (vma->vm_flags & VM_EXEC)
1686 phdr.p_flags |= PF_X;
1687 phdr.p_align = ELF_EXEC_PAGESIZE;
1688
1689 DUMP_WRITE(&phdr, sizeof(phdr));
1690 }
1691
1692 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1693 ELF_CORE_WRITE_EXTRA_PHDRS;
1694 #endif
1695
1696 /* write out the notes section */
1697 for (i = 0; i < numnote; i++)
1698 if (!writenote(notes + i, file, &foffset))
1699 goto end_coredump;
1700
1701 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1702 ELF_CORE_WRITE_EXTRA_NOTES;
1703 foffset += extra_notes_size;
1704 #endif
1705
1706 /* write out the thread status notes section */
1707 list_for_each(t, &thread_list) {
1708 struct elf_thread_status *tmp =
1709 list_entry(t, struct elf_thread_status, list);
1710
1711 for (i = 0; i < tmp->num_notes; i++)
1712 if (!writenote(&tmp->notes[i], file, &foffset))
1713 goto end_coredump;
1714 }
1715
1716 /* Align to page */
1717 DUMP_SEEK(dataoff - foffset);
1718
1719 for (vma = first_vma(current, gate_vma); vma != NULL;
1720 vma = next_vma(vma, gate_vma)) {
1721 unsigned long addr;
1722
1723 if (!maydump(vma, mm_flags))
1724 continue;
1725
1726 for (addr = vma->vm_start;
1727 addr < vma->vm_end;
1728 addr += PAGE_SIZE) {
1729 struct page *page;
1730 struct vm_area_struct *vma;
1731
1732 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1733 &page, &vma) <= 0) {
1734 DUMP_SEEK(PAGE_SIZE);
1735 } else {
1736 if (page == ZERO_PAGE(addr)) {
1737 if (!dump_seek(file, PAGE_SIZE)) {
1738 page_cache_release(page);
1739 goto end_coredump;
1740 }
1741 } else {
1742 void *kaddr;
1743 flush_cache_page(vma, addr,
1744 page_to_pfn(page));
1745 kaddr = kmap(page);
1746 if ((size += PAGE_SIZE) > limit ||
1747 !dump_write(file, kaddr,
1748 PAGE_SIZE)) {
1749 kunmap(page);
1750 page_cache_release(page);
1751 goto end_coredump;
1752 }
1753 kunmap(page);
1754 }
1755 page_cache_release(page);
1756 }
1757 }
1758 }
1759
1760 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1761 ELF_CORE_WRITE_EXTRA_DATA;
1762 #endif
1763
1764 end_coredump:
1765 set_fs(fs);
1766
1767 cleanup:
1768 while (!list_empty(&thread_list)) {
1769 struct list_head *tmp = thread_list.next;
1770 list_del(tmp);
1771 kfree(list_entry(tmp, struct elf_thread_status, list));
1772 }
1773
1774 kfree(elf);
1775 kfree(prstatus);
1776 kfree(psinfo);
1777 kfree(notes);
1778 kfree(fpu);
1779 #ifdef ELF_CORE_COPY_XFPREGS
1780 kfree(xfpu);
1781 #endif
1782 return has_dumped;
1783 #undef NUM_NOTES
1784 }
1785
1786 #endif /* USE_ELF_CORE_DUMP */
1787
1788 static int __init init_elf_binfmt(void)
1789 {
1790 return register_binfmt(&elf_format);
1791 }
1792
1793 static void __exit exit_elf_binfmt(void)
1794 {
1795 /* Remove the COFF and ELF loaders. */
1796 unregister_binfmt(&elf_format);
1797 }
1798
1799 core_initcall(init_elf_binfmt);
1800 module_exit(exit_elf_binfmt);
1801 MODULE_LICENSE("GPL");
USB Experimental Work