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Linux v2.6.15-rc7
[pohmelfs.git] / fs / binfmt_elf.c
blobf36f2210204f524b2922fa69ea704295bfbe5a59
1 /*
2 * linux/fs/binfmt_elf.c
3 *
4 * These are the functions used to load ELF format executables as used
5 * on SVr4 machines. Information on the format may be found in the book
6 * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
7 * Tools".
8 *
9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
10 */
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/fs.h>
15 #include <linux/stat.h>
16 #include <linux/time.h>
17 #include <linux/mm.h>
18 #include <linux/mman.h>
19 #include <linux/a.out.h>
20 #include <linux/errno.h>
21 #include <linux/signal.h>
22 #include <linux/binfmts.h>
23 #include <linux/string.h>
24 #include <linux/file.h>
25 #include <linux/fcntl.h>
26 #include <linux/ptrace.h>
27 #include <linux/slab.h>
28 #include <linux/shm.h>
29 #include <linux/personality.h>
30 #include <linux/elfcore.h>
31 #include <linux/init.h>
32 #include <linux/highuid.h>
33 #include <linux/smp.h>
34 #include <linux/smp_lock.h>
35 #include <linux/compiler.h>
36 #include <linux/highmem.h>
37 #include <linux/pagemap.h>
38 #include <linux/security.h>
39 #include <linux/syscalls.h>
40 #include <linux/random.h>
41
42 #include <asm/uaccess.h>
43 #include <asm/param.h>
44 #include <asm/page.h>
45
46 #include <linux/elf.h>
47
48 static int load_elf_binary(struct linux_binprm * bprm, struct pt_regs * regs);
49 static int load_elf_library(struct file*);
50 static unsigned long elf_map (struct file *, unsigned long, struct elf_phdr *, int, int);
51 extern int dump_fpu (struct pt_regs *, elf_fpregset_t *);
52
53 #ifndef elf_addr_t
54 #define elf_addr_t unsigned long
55 #endif
56
57 /*
58 * If we don't support core dumping, then supply a NULL so we
59 * don't even try.
60 */
61 #ifdef USE_ELF_CORE_DUMP
62 static int elf_core_dump(long signr, struct pt_regs * regs, struct file * file);
63 #else
64 #define elf_core_dump NULL
65 #endif
66
67 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
68 # define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
69 #else
70 # define ELF_MIN_ALIGN PAGE_SIZE
71 #endif
72
73 #ifndef ELF_CORE_EFLAGS
74 #define ELF_CORE_EFLAGS 0
75 #endif
76
77 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
78 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
79 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
80
81 static struct linux_binfmt elf_format = {
82 .module = THIS_MODULE,
83 .load_binary = load_elf_binary,
84 .load_shlib = load_elf_library,
85 .core_dump = elf_core_dump,
86 .min_coredump = ELF_EXEC_PAGESIZE
87 };
88
89 #define BAD_ADDR(x) ((unsigned long)(x) > TASK_SIZE)
90
91 static int set_brk(unsigned long start, unsigned long end)
92 {
93 start = ELF_PAGEALIGN(start);
94 end = ELF_PAGEALIGN(end);
95 if (end > start) {
96 unsigned long addr;
97 down_write(&current->mm->mmap_sem);
98 addr = do_brk(start, end - start);
99 up_write(&current->mm->mmap_sem);
100 if (BAD_ADDR(addr))
101 return addr;
102 }
103 current->mm->start_brk = current->mm->brk = end;
104 return 0;
105 }
106
107
108 /* We need to explicitly zero any fractional pages
109 after the data section (i.e. bss). This would
110 contain the junk from the file that should not
111 be in memory */
112
113
114 static int padzero(unsigned long elf_bss)
115 {
116 unsigned long nbyte;
117
118 nbyte = ELF_PAGEOFFSET(elf_bss);
119 if (nbyte) {
120 nbyte = ELF_MIN_ALIGN - nbyte;
121 if (clear_user((void __user *) elf_bss, nbyte))
122 return -EFAULT;
123 }
124 return 0;
125 }
126
127 /* Let's use some macros to make this stack manipulation a litle clearer */
128 #ifdef CONFIG_STACK_GROWSUP
129 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
130 #define STACK_ROUND(sp, items) \
131 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
132 #define STACK_ALLOC(sp, len) ({ elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; old_sp; })
133 #else
134 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
135 #define STACK_ROUND(sp, items) \
136 (((unsigned long) (sp - items)) &~ 15UL)
137 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
138 #endif
139
140 static int
141 create_elf_tables(struct linux_binprm *bprm, struct elfhdr * exec,
142 int interp_aout, unsigned long load_addr,
143 unsigned long interp_load_addr)
144 {
145 unsigned long p = bprm->p;
146 int argc = bprm->argc;
147 int envc = bprm->envc;
148 elf_addr_t __user *argv;
149 elf_addr_t __user *envp;
150 elf_addr_t __user *sp;
151 elf_addr_t __user *u_platform;
152 const char *k_platform = ELF_PLATFORM;
153 int items;
154 elf_addr_t *elf_info;
155 int ei_index = 0;
156 struct task_struct *tsk = current;
157
158 /*
159 * If this architecture has a platform capability string, copy it
160 * to userspace. In some cases (Sparc), this info is impossible
161 * for userspace to get any other way, in others (i386) it is
162 * merely difficult.
163 */
164
165 u_platform = NULL;
166 if (k_platform) {
167 size_t len = strlen(k_platform) + 1;
168
169 /*
170 * In some cases (e.g. Hyper-Threading), we want to avoid L1
171 * evictions by the processes running on the same package. One
172 * thing we can do is to shuffle the initial stack for them.
173 */
174
175 p = arch_align_stack(p);
176
177 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
178 if (__copy_to_user(u_platform, k_platform, len))
179 return -EFAULT;
180 }
181
182 /* Create the ELF interpreter info */
183 elf_info = (elf_addr_t *) current->mm->saved_auxv;
184 #define NEW_AUX_ENT(id, val) \
185 do { elf_info[ei_index++] = id; elf_info[ei_index++] = val; } while (0)
186
187 #ifdef ARCH_DLINFO
188 /*
189 * ARCH_DLINFO must come first so PPC can do its special alignment of
190 * AUXV.
191 */
192 ARCH_DLINFO;
193 #endif
194 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
195 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
196 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
197 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
198 NEW_AUX_ENT(AT_PHENT, sizeof (struct elf_phdr));
199 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
200 NEW_AUX_ENT(AT_BASE, interp_load_addr);
201 NEW_AUX_ENT(AT_FLAGS, 0);
202 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
203 NEW_AUX_ENT(AT_UID, (elf_addr_t) tsk->uid);
204 NEW_AUX_ENT(AT_EUID, (elf_addr_t) tsk->euid);
205 NEW_AUX_ENT(AT_GID, (elf_addr_t) tsk->gid);
206 NEW_AUX_ENT(AT_EGID, (elf_addr_t) tsk->egid);
207 NEW_AUX_ENT(AT_SECURE, (elf_addr_t) security_bprm_secureexec(bprm));
208 if (k_platform) {
209 NEW_AUX_ENT(AT_PLATFORM, (elf_addr_t)(unsigned long)u_platform);
210 }
211 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
212 NEW_AUX_ENT(AT_EXECFD, (elf_addr_t) bprm->interp_data);
213 }
214 #undef NEW_AUX_ENT
215 /* AT_NULL is zero; clear the rest too */
216 memset(&elf_info[ei_index], 0,
217 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
218
219 /* And advance past the AT_NULL entry. */
220 ei_index += 2;
221
222 sp = STACK_ADD(p, ei_index);
223
224 items = (argc + 1) + (envc + 1);
225 if (interp_aout) {
226 items += 3; /* a.out interpreters require argv & envp too */
227 } else {
228 items += 1; /* ELF interpreters only put argc on the stack */
229 }
230 bprm->p = STACK_ROUND(sp, items);
231
232 /* Point sp at the lowest address on the stack */
233 #ifdef CONFIG_STACK_GROWSUP
234 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
235 bprm->exec = (unsigned long) sp; /* XXX: PARISC HACK */
236 #else
237 sp = (elf_addr_t __user *)bprm->p;
238 #endif
239
240 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
241 if (__put_user(argc, sp++))
242 return -EFAULT;
243 if (interp_aout) {
244 argv = sp + 2;
245 envp = argv + argc + 1;
246 __put_user((elf_addr_t)(unsigned long)argv, sp++);
247 __put_user((elf_addr_t)(unsigned long)envp, sp++);
248 } else {
249 argv = sp;
250 envp = argv + argc + 1;
251 }
252
253 /* Populate argv and envp */
254 p = current->mm->arg_end = current->mm->arg_start;
255 while (argc-- > 0) {
256 size_t len;
257 __put_user((elf_addr_t)p, argv++);
258 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
259 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
260 return 0;
261 p += len;
262 }
263 if (__put_user(0, argv))
264 return -EFAULT;
265 current->mm->arg_end = current->mm->env_start = p;
266 while (envc-- > 0) {
267 size_t len;
268 __put_user((elf_addr_t)p, envp++);
269 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
270 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
271 return 0;
272 p += len;
273 }
274 if (__put_user(0, envp))
275 return -EFAULT;
276 current->mm->env_end = p;
277
278 /* Put the elf_info on the stack in the right place. */
279 sp = (elf_addr_t __user *)envp + 1;
280 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
281 return -EFAULT;
282 return 0;
283 }
284
285 #ifndef elf_map
286
287 static unsigned long elf_map(struct file *filep, unsigned long addr,
288 struct elf_phdr *eppnt, int prot, int type)
289 {
290 unsigned long map_addr;
291
292 down_write(&current->mm->mmap_sem);
293 map_addr = do_mmap(filep, ELF_PAGESTART(addr),
294 eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr), prot, type,
295 eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr));
296 up_write(&current->mm->mmap_sem);
297 return(map_addr);
298 }
299
300 #endif /* !elf_map */
301
302 /* This is much more generalized than the library routine read function,
303 so we keep this separate. Technically the library read function
304 is only provided so that we can read a.out libraries that have
305 an ELF header */
306
307 static unsigned long load_elf_interp(struct elfhdr * interp_elf_ex,
308 struct file * interpreter,
309 unsigned long *interp_load_addr)
310 {
311 struct elf_phdr *elf_phdata;
312 struct elf_phdr *eppnt;
313 unsigned long load_addr = 0;
314 int load_addr_set = 0;
315 unsigned long last_bss = 0, elf_bss = 0;
316 unsigned long error = ~0UL;
317 int retval, i, size;
318
319 /* First of all, some simple consistency checks */
320 if (interp_elf_ex->e_type != ET_EXEC &&
321 interp_elf_ex->e_type != ET_DYN)
322 goto out;
323 if (!elf_check_arch(interp_elf_ex))
324 goto out;
325 if (!interpreter->f_op || !interpreter->f_op->mmap)
326 goto out;
327
328 /*
329 * If the size of this structure has changed, then punt, since
330 * we will be doing the wrong thing.
331 */
332 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
333 goto out;
334 if (interp_elf_ex->e_phnum < 1 ||
335 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
336 goto out;
337
338 /* Now read in all of the header information */
339
340 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
341 if (size > ELF_MIN_ALIGN)
342 goto out;
343 elf_phdata = (struct elf_phdr *) kmalloc(size, GFP_KERNEL);
344 if (!elf_phdata)
345 goto out;
346
347 retval = kernel_read(interpreter,interp_elf_ex->e_phoff,(char *)elf_phdata,size);
348 error = -EIO;
349 if (retval != size) {
350 if (retval < 0)
351 error = retval;
352 goto out_close;
353 }
354
355 eppnt = elf_phdata;
356 for (i=0; i<interp_elf_ex->e_phnum; i++, eppnt++) {
357 if (eppnt->p_type == PT_LOAD) {
358 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
359 int elf_prot = 0;
360 unsigned long vaddr = 0;
361 unsigned long k, map_addr;
362
363 if (eppnt->p_flags & PF_R) elf_prot = PROT_READ;
364 if (eppnt->p_flags & PF_W) elf_prot |= PROT_WRITE;
365 if (eppnt->p_flags & PF_X) elf_prot |= PROT_EXEC;
366 vaddr = eppnt->p_vaddr;
367 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
368 elf_type |= MAP_FIXED;
369
370 map_addr = elf_map(interpreter, load_addr + vaddr, eppnt, elf_prot, elf_type);
371 error = map_addr;
372 if (BAD_ADDR(map_addr))
373 goto out_close;
374
375 if (!load_addr_set && interp_elf_ex->e_type == ET_DYN) {
376 load_addr = map_addr - ELF_PAGESTART(vaddr);
377 load_addr_set = 1;
378 }
379
380 /*
381 * Check to see if the section's size will overflow the
382 * allowed task size. Note that p_filesz must always be
383 * <= p_memsize so it is only necessary to check p_memsz.
384 */
385 k = load_addr + eppnt->p_vaddr;
386 if (k > TASK_SIZE || eppnt->p_filesz > eppnt->p_memsz ||
387 eppnt->p_memsz > TASK_SIZE || TASK_SIZE - eppnt->p_memsz < k) {
388 error = -ENOMEM;
389 goto out_close;
390 }
391
392 /*
393 * Find the end of the file mapping for this phdr, and keep
394 * track of the largest address we see for this.
395 */
396 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
397 if (k > elf_bss)
398 elf_bss = k;
399
400 /*
401 * Do the same thing for the memory mapping - between
402 * elf_bss and last_bss is the bss section.
403 */
404 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
405 if (k > last_bss)
406 last_bss = k;
407 }
408 }
409
410 /*
411 * Now fill out the bss section. First pad the last page up
412 * to the page boundary, and then perform a mmap to make sure
413 * that there are zero-mapped pages up to and including the
414 * last bss page.
415 */
416 if (padzero(elf_bss)) {
417 error = -EFAULT;
418 goto out_close;
419 }
420
421 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1); /* What we have mapped so far */
422
423 /* Map the last of the bss segment */
424 if (last_bss > elf_bss) {
425 down_write(&current->mm->mmap_sem);
426 error = do_brk(elf_bss, last_bss - elf_bss);
427 up_write(&current->mm->mmap_sem);
428 if (BAD_ADDR(error))
429 goto out_close;
430 }
431
432 *interp_load_addr = load_addr;
433 error = ((unsigned long) interp_elf_ex->e_entry) + load_addr;
434
435 out_close:
436 kfree(elf_phdata);
437 out:
438 return error;
439 }
440
441 static unsigned long load_aout_interp(struct exec * interp_ex,
442 struct file * interpreter)
443 {
444 unsigned long text_data, elf_entry = ~0UL;
445 char __user * addr;
446 loff_t offset;
447
448 current->mm->end_code = interp_ex->a_text;
449 text_data = interp_ex->a_text + interp_ex->a_data;
450 current->mm->end_data = text_data;
451 current->mm->brk = interp_ex->a_bss + text_data;
452
453 switch (N_MAGIC(*interp_ex)) {
454 case OMAGIC:
455 offset = 32;
456 addr = (char __user *)0;
457 break;
458 case ZMAGIC:
459 case QMAGIC:
460 offset = N_TXTOFF(*interp_ex);
461 addr = (char __user *) N_TXTADDR(*interp_ex);
462 break;
463 default:
464 goto out;
465 }
466
467 down_write(&current->mm->mmap_sem);
468 do_brk(0, text_data);
469 up_write(&current->mm->mmap_sem);
470 if (!interpreter->f_op || !interpreter->f_op->read)
471 goto out;
472 if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0)
473 goto out;
474 flush_icache_range((unsigned long)addr,
475 (unsigned long)addr + text_data);
476
477
478 down_write(&current->mm->mmap_sem);
479 do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
480 interp_ex->a_bss);
481 up_write(&current->mm->mmap_sem);
482 elf_entry = interp_ex->a_entry;
483
484 out:
485 return elf_entry;
486 }
487
488 /*
489 * These are the functions used to load ELF style executables and shared
490 * libraries. There is no binary dependent code anywhere else.
491 */
492
493 #define INTERPRETER_NONE 0
494 #define INTERPRETER_AOUT 1
495 #define INTERPRETER_ELF 2
496
497
498 static unsigned long randomize_stack_top(unsigned long stack_top)
499 {
500 unsigned int random_variable = 0;
501
502 if (current->flags & PF_RANDOMIZE)
503 random_variable = get_random_int() % (8*1024*1024);
504 #ifdef CONFIG_STACK_GROWSUP
505 return PAGE_ALIGN(stack_top + random_variable);
506 #else
507 return PAGE_ALIGN(stack_top - random_variable);
508 #endif
509 }
510
511 static int load_elf_binary(struct linux_binprm * bprm, struct pt_regs * regs)
512 {
513 struct file *interpreter = NULL; /* to shut gcc up */
514 unsigned long load_addr = 0, load_bias = 0;
515 int load_addr_set = 0;
516 char * elf_interpreter = NULL;
517 unsigned int interpreter_type = INTERPRETER_NONE;
518 unsigned char ibcs2_interpreter = 0;
519 unsigned long error;
520 struct elf_phdr * elf_ppnt, *elf_phdata;
521 unsigned long elf_bss, elf_brk;
522 int elf_exec_fileno;
523 int retval, i;
524 unsigned int size;
525 unsigned long elf_entry, interp_load_addr = 0;
526 unsigned long start_code, end_code, start_data, end_data;
527 unsigned long reloc_func_desc = 0;
528 char passed_fileno[6];
529 struct files_struct *files;
530 int have_pt_gnu_stack, executable_stack = EXSTACK_DEFAULT;
531 unsigned long def_flags = 0;
532 struct {
533 struct elfhdr elf_ex;
534 struct elfhdr interp_elf_ex;
535 struct exec interp_ex;
536 } *loc;
537
538 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
539 if (!loc) {
540 retval = -ENOMEM;
541 goto out_ret;
542 }
543
544 /* Get the exec-header */
545 loc->elf_ex = *((struct elfhdr *) bprm->buf);
546
547 retval = -ENOEXEC;
548 /* First of all, some simple consistency checks */
549 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
550 goto out;
551
552 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
553 goto out;
554 if (!elf_check_arch(&loc->elf_ex))
555 goto out;
556 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
557 goto out;
558
559 /* Now read in all of the header information */
560
561 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
562 goto out;
563 if (loc->elf_ex.e_phnum < 1 ||
564 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
565 goto out;
566 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
567 retval = -ENOMEM;
568 elf_phdata = (struct elf_phdr *) kmalloc(size, GFP_KERNEL);
569 if (!elf_phdata)
570 goto out;
571
572 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff, (char *) elf_phdata, size);
573 if (retval != size) {
574 if (retval >= 0)
575 retval = -EIO;
576 goto out_free_ph;
577 }
578
579 files = current->files; /* Refcounted so ok */
580 retval = unshare_files();
581 if (retval < 0)
582 goto out_free_ph;
583 if (files == current->files) {
584 put_files_struct(files);
585 files = NULL;
586 }
587
588 /* exec will make our files private anyway, but for the a.out
589 loader stuff we need to do it earlier */
590
591 retval = get_unused_fd();
592 if (retval < 0)
593 goto out_free_fh;
594 get_file(bprm->file);
595 fd_install(elf_exec_fileno = retval, bprm->file);
596
597 elf_ppnt = elf_phdata;
598 elf_bss = 0;
599 elf_brk = 0;
600
601 start_code = ~0UL;
602 end_code = 0;
603 start_data = 0;
604 end_data = 0;
605
606 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
607 if (elf_ppnt->p_type == PT_INTERP) {
608 /* This is the program interpreter used for
609 * shared libraries - for now assume that this
610 * is an a.out format binary
611 */
612
613 retval = -ENOEXEC;
614 if (elf_ppnt->p_filesz > PATH_MAX ||
615 elf_ppnt->p_filesz < 2)
616 goto out_free_file;
617
618 retval = -ENOMEM;
619 elf_interpreter = (char *) kmalloc(elf_ppnt->p_filesz,
620 GFP_KERNEL);
621 if (!elf_interpreter)
622 goto out_free_file;
623
624 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
625 elf_interpreter,
626 elf_ppnt->p_filesz);
627 if (retval != elf_ppnt->p_filesz) {
628 if (retval >= 0)
629 retval = -EIO;
630 goto out_free_interp;
631 }
632 /* make sure path is NULL terminated */
633 retval = -ENOEXEC;
634 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
635 goto out_free_interp;
636
637 /* If the program interpreter is one of these two,
638 * then assume an iBCS2 image. Otherwise assume
639 * a native linux image.
640 */
641 if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
642 strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0)
643 ibcs2_interpreter = 1;
644
645 /*
646 * The early SET_PERSONALITY here is so that the lookup
647 * for the interpreter happens in the namespace of the
648 * to-be-execed image. SET_PERSONALITY can select an
649 * alternate root.
650 *
651 * However, SET_PERSONALITY is NOT allowed to switch
652 * this task into the new images's memory mapping
653 * policy - that is, TASK_SIZE must still evaluate to
654 * that which is appropriate to the execing application.
655 * This is because exit_mmap() needs to have TASK_SIZE
656 * evaluate to the size of the old image.
657 *
658 * So if (say) a 64-bit application is execing a 32-bit
659 * application it is the architecture's responsibility
660 * to defer changing the value of TASK_SIZE until the
661 * switch really is going to happen - do this in
662 * flush_thread(). - akpm
663 */
664 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
665
666 interpreter = open_exec(elf_interpreter);
667 retval = PTR_ERR(interpreter);
668 if (IS_ERR(interpreter))
669 goto out_free_interp;
670 retval = kernel_read(interpreter, 0, bprm->buf, BINPRM_BUF_SIZE);
671 if (retval != BINPRM_BUF_SIZE) {
672 if (retval >= 0)
673 retval = -EIO;
674 goto out_free_dentry;
675 }
676
677 /* Get the exec headers */
678 loc->interp_ex = *((struct exec *) bprm->buf);
679 loc->interp_elf_ex = *((struct elfhdr *) bprm->buf);
680 break;
681 }
682 elf_ppnt++;
683 }
684
685 elf_ppnt = elf_phdata;
686 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
687 if (elf_ppnt->p_type == PT_GNU_STACK) {
688 if (elf_ppnt->p_flags & PF_X)
689 executable_stack = EXSTACK_ENABLE_X;
690 else
691 executable_stack = EXSTACK_DISABLE_X;
692 break;
693 }
694 have_pt_gnu_stack = (i < loc->elf_ex.e_phnum);
695
696 /* Some simple consistency checks for the interpreter */
697 if (elf_interpreter) {
698 interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
699
700 /* Now figure out which format our binary is */
701 if ((N_MAGIC(loc->interp_ex) != OMAGIC) &&
702 (N_MAGIC(loc->interp_ex) != ZMAGIC) &&
703 (N_MAGIC(loc->interp_ex) != QMAGIC))
704 interpreter_type = INTERPRETER_ELF;
705
706 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
707 interpreter_type &= ~INTERPRETER_ELF;
708
709 retval = -ELIBBAD;
710 if (!interpreter_type)
711 goto out_free_dentry;
712
713 /* Make sure only one type was selected */
714 if ((interpreter_type & INTERPRETER_ELF) &&
715 interpreter_type != INTERPRETER_ELF) {
716 // FIXME - ratelimit this before re-enabling
717 // printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n");
718 interpreter_type = INTERPRETER_ELF;
719 }
720 /* Verify the interpreter has a valid arch */
721 if ((interpreter_type == INTERPRETER_ELF) &&
722 !elf_check_arch(&loc->interp_elf_ex))
723 goto out_free_dentry;
724 } else {
725 /* Executables without an interpreter also need a personality */
726 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
727 }
728
729 /* OK, we are done with that, now set up the arg stuff,
730 and then start this sucker up */
731
732 if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) {
733 char *passed_p = passed_fileno;
734 sprintf(passed_fileno, "%d", elf_exec_fileno);
735
736 if (elf_interpreter) {
737 retval = copy_strings_kernel(1, &passed_p, bprm);
738 if (retval)
739 goto out_free_dentry;
740 bprm->argc++;
741 }
742 }
743
744 /* Flush all traces of the currently running executable */
745 retval = flush_old_exec(bprm);
746 if (retval)
747 goto out_free_dentry;
748
749 /* Discard our unneeded old files struct */
750 if (files) {
751 steal_locks(files);
752 put_files_struct(files);
753 files = NULL;
754 }
755
756 /* OK, This is the point of no return */
757 current->mm->start_data = 0;
758 current->mm->end_data = 0;
759 current->mm->end_code = 0;
760 current->mm->mmap = NULL;
761 current->flags &= ~PF_FORKNOEXEC;
762 current->mm->def_flags = def_flags;
763
764 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
765 may depend on the personality. */
766 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
767 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
768 current->personality |= READ_IMPLIES_EXEC;
769
770 if ( !(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
771 current->flags |= PF_RANDOMIZE;
772 arch_pick_mmap_layout(current->mm);
773
774 /* Do this so that we can load the interpreter, if need be. We will
775 change some of these later */
776 current->mm->free_area_cache = current->mm->mmap_base;
777 current->mm->cached_hole_size = 0;
778 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
779 executable_stack);
780 if (retval < 0) {
781 send_sig(SIGKILL, current, 0);
782 goto out_free_dentry;
783 }
784
785 current->mm->start_stack = bprm->p;
786
787 /* Now we do a little grungy work by mmaping the ELF image into
788 the correct location in memory. At this point, we assume that
789 the image should be loaded at fixed address, not at a variable
790 address. */
791
792 for(i = 0, elf_ppnt = elf_phdata; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
793 int elf_prot = 0, elf_flags;
794 unsigned long k, vaddr;
795
796 if (elf_ppnt->p_type != PT_LOAD)
797 continue;
798
799 if (unlikely (elf_brk > elf_bss)) {
800 unsigned long nbyte;
801
802 /* There was a PT_LOAD segment with p_memsz > p_filesz
803 before this one. Map anonymous pages, if needed,
804 and clear the area. */
805 retval = set_brk (elf_bss + load_bias,
806 elf_brk + load_bias);
807 if (retval) {
808 send_sig(SIGKILL, current, 0);
809 goto out_free_dentry;
810 }
811 nbyte = ELF_PAGEOFFSET(elf_bss);
812 if (nbyte) {
813 nbyte = ELF_MIN_ALIGN - nbyte;
814 if (nbyte > elf_brk - elf_bss)
815 nbyte = elf_brk - elf_bss;
816 if (clear_user((void __user *)elf_bss +
817 load_bias, nbyte)) {
818 /*
819 * This bss-zeroing can fail if the ELF
820 * file specifies odd protections. So
821 * we don't check the return value
822 */
823 }
824 }
825 }
826
827 if (elf_ppnt->p_flags & PF_R) elf_prot |= PROT_READ;
828 if (elf_ppnt->p_flags & PF_W) elf_prot |= PROT_WRITE;
829 if (elf_ppnt->p_flags & PF_X) elf_prot |= PROT_EXEC;
830
831 elf_flags = MAP_PRIVATE|MAP_DENYWRITE|MAP_EXECUTABLE;
832
833 vaddr = elf_ppnt->p_vaddr;
834 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
835 elf_flags |= MAP_FIXED;
836 } else if (loc->elf_ex.e_type == ET_DYN) {
837 /* Try and get dynamic programs out of the way of the default mmap
838 base, as well as whatever program they might try to exec. This
839 is because the brk will follow the loader, and is not movable. */
840 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
841 }
842
843 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, elf_prot, elf_flags);
844 if (BAD_ADDR(error)) {
845 send_sig(SIGKILL, current, 0);
846 goto out_free_dentry;
847 }
848
849 if (!load_addr_set) {
850 load_addr_set = 1;
851 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
852 if (loc->elf_ex.e_type == ET_DYN) {
853 load_bias += error -
854 ELF_PAGESTART(load_bias + vaddr);
855 load_addr += load_bias;
856 reloc_func_desc = load_bias;
857 }
858 }
859 k = elf_ppnt->p_vaddr;
860 if (k < start_code) start_code = k;
861 if (start_data < k) start_data = k;
862
863 /*
864 * Check to see if the section's size will overflow the
865 * allowed task size. Note that p_filesz must always be
866 * <= p_memsz so it is only necessary to check p_memsz.
867 */
868 if (k > TASK_SIZE || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
869 elf_ppnt->p_memsz > TASK_SIZE ||
870 TASK_SIZE - elf_ppnt->p_memsz < k) {
871 /* set_brk can never work. Avoid overflows. */
872 send_sig(SIGKILL, current, 0);
873 goto out_free_dentry;
874 }
875
876 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
877
878 if (k > elf_bss)
879 elf_bss = k;
880 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
881 end_code = k;
882 if (end_data < k)
883 end_data = k;
884 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
885 if (k > elf_brk)
886 elf_brk = k;
887 }
888
889 loc->elf_ex.e_entry += load_bias;
890 elf_bss += load_bias;
891 elf_brk += load_bias;
892 start_code += load_bias;
893 end_code += load_bias;
894 start_data += load_bias;
895 end_data += load_bias;
896
897 /* Calling set_brk effectively mmaps the pages that we need
898 * for the bss and break sections. We must do this before
899 * mapping in the interpreter, to make sure it doesn't wind
900 * up getting placed where the bss needs to go.
901 */
902 retval = set_brk(elf_bss, elf_brk);
903 if (retval) {
904 send_sig(SIGKILL, current, 0);
905 goto out_free_dentry;
906 }
907 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
908 send_sig(SIGSEGV, current, 0);
909 retval = -EFAULT; /* Nobody gets to see this, but.. */
910 goto out_free_dentry;
911 }
912
913 if (elf_interpreter) {
914 if (interpreter_type == INTERPRETER_AOUT)
915 elf_entry = load_aout_interp(&loc->interp_ex,
916 interpreter);
917 else
918 elf_entry = load_elf_interp(&loc->interp_elf_ex,
919 interpreter,
920 &interp_load_addr);
921 if (BAD_ADDR(elf_entry)) {
922 printk(KERN_ERR "Unable to load interpreter %.128s\n",
923 elf_interpreter);
924 force_sig(SIGSEGV, current);
925 retval = -ENOEXEC; /* Nobody gets to see this, but.. */
926 goto out_free_dentry;
927 }
928 reloc_func_desc = interp_load_addr;
929
930 allow_write_access(interpreter);
931 fput(interpreter);
932 kfree(elf_interpreter);
933 } else {
934 elf_entry = loc->elf_ex.e_entry;
935 }
936
937 kfree(elf_phdata);
938
939 if (interpreter_type != INTERPRETER_AOUT)
940 sys_close(elf_exec_fileno);
941
942 set_binfmt(&elf_format);
943
944 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
945 retval = arch_setup_additional_pages(bprm, executable_stack);
946 if (retval < 0) {
947 send_sig(SIGKILL, current, 0);
948 goto out;
949 }
950 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
951
952 compute_creds(bprm);
953 current->flags &= ~PF_FORKNOEXEC;
954 create_elf_tables(bprm, &loc->elf_ex, (interpreter_type == INTERPRETER_AOUT),
955 load_addr, interp_load_addr);
956 /* N.B. passed_fileno might not be initialized? */
957 if (interpreter_type == INTERPRETER_AOUT)
958 current->mm->arg_start += strlen(passed_fileno) + 1;
959 current->mm->end_code = end_code;
960 current->mm->start_code = start_code;
961 current->mm->start_data = start_data;
962 current->mm->end_data = end_data;
963 current->mm->start_stack = bprm->p;
964
965 if (current->personality & MMAP_PAGE_ZERO) {
966 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
967 and some applications "depend" upon this behavior.
968 Since we do not have the power to recompile these, we
969 emulate the SVr4 behavior. Sigh. */
970 down_write(&current->mm->mmap_sem);
971 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
972 MAP_FIXED | MAP_PRIVATE, 0);
973 up_write(&current->mm->mmap_sem);
974 }
975
976 #ifdef ELF_PLAT_INIT
977 /*
978 * The ABI may specify that certain registers be set up in special
979 * ways (on i386 %edx is the address of a DT_FINI function, for
980 * example. In addition, it may also specify (eg, PowerPC64 ELF)
981 * that the e_entry field is the address of the function descriptor
982 * for the startup routine, rather than the address of the startup
983 * routine itself. This macro performs whatever initialization to
984 * the regs structure is required as well as any relocations to the
985 * function descriptor entries when executing dynamically links apps.
986 */
987 ELF_PLAT_INIT(regs, reloc_func_desc);
988 #endif
989
990 start_thread(regs, elf_entry, bprm->p);
991 if (unlikely(current->ptrace & PT_PTRACED)) {
992 if (current->ptrace & PT_TRACE_EXEC)
993 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
994 else
995 send_sig(SIGTRAP, current, 0);
996 }
997 retval = 0;
998 out:
999 kfree(loc);
1000 out_ret:
1001 return retval;
1002
1003 /* error cleanup */
1004 out_free_dentry:
1005 allow_write_access(interpreter);
1006 if (interpreter)
1007 fput(interpreter);
1008 out_free_interp:
1009 kfree(elf_interpreter);
1010 out_free_file:
1011 sys_close(elf_exec_fileno);
1012 out_free_fh:
1013 if (files) {
1014 put_files_struct(current->files);
1015 current->files = files;
1016 }
1017 out_free_ph:
1018 kfree(elf_phdata);
1019 goto out;
1020 }
1021
1022 /* This is really simpleminded and specialized - we are loading an
1023 a.out library that is given an ELF header. */
1024
1025 static int load_elf_library(struct file *file)
1026 {
1027 struct elf_phdr *elf_phdata;
1028 struct elf_phdr *eppnt;
1029 unsigned long elf_bss, bss, len;
1030 int retval, error, i, j;
1031 struct elfhdr elf_ex;
1032
1033 error = -ENOEXEC;
1034 retval = kernel_read(file, 0, (char *) &elf_ex, sizeof(elf_ex));
1035 if (retval != sizeof(elf_ex))
1036 goto out;
1037
1038 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1039 goto out;
1040
1041 /* First of all, some simple consistency checks */
1042 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1043 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1044 goto out;
1045
1046 /* Now read in all of the header information */
1047
1048 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1049 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1050
1051 error = -ENOMEM;
1052 elf_phdata = kmalloc(j, GFP_KERNEL);
1053 if (!elf_phdata)
1054 goto out;
1055
1056 eppnt = elf_phdata;
1057 error = -ENOEXEC;
1058 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1059 if (retval != j)
1060 goto out_free_ph;
1061
1062 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1063 if ((eppnt + i)->p_type == PT_LOAD)
1064 j++;
1065 if (j != 1)
1066 goto out_free_ph;
1067
1068 while (eppnt->p_type != PT_LOAD)
1069 eppnt++;
1070
1071 /* Now use mmap to map the library into memory. */
1072 down_write(&current->mm->mmap_sem);
1073 error = do_mmap(file,
1074 ELF_PAGESTART(eppnt->p_vaddr),
1075 (eppnt->p_filesz +
1076 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1077 PROT_READ | PROT_WRITE | PROT_EXEC,
1078 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1079 (eppnt->p_offset -
1080 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1081 up_write(&current->mm->mmap_sem);
1082 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1083 goto out_free_ph;
1084
1085 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1086 if (padzero(elf_bss)) {
1087 error = -EFAULT;
1088 goto out_free_ph;
1089 }
1090
1091 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + ELF_MIN_ALIGN - 1);
1092 bss = eppnt->p_memsz + eppnt->p_vaddr;
1093 if (bss > len) {
1094 down_write(&current->mm->mmap_sem);
1095 do_brk(len, bss - len);
1096 up_write(&current->mm->mmap_sem);
1097 }
1098 error = 0;
1099
1100 out_free_ph:
1101 kfree(elf_phdata);
1102 out:
1103 return error;
1104 }
1105
1106 /*
1107 * Note that some platforms still use traditional core dumps and not
1108 * the ELF core dump. Each platform can select it as appropriate.
1109 */
1110 #ifdef USE_ELF_CORE_DUMP
1111
1112 /*
1113 * ELF core dumper
1114 *
1115 * Modelled on fs/exec.c:aout_core_dump()
1116 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1117 */
1118 /*
1119 * These are the only things you should do on a core-file: use only these
1120 * functions to write out all the necessary info.
1121 */
1122 static int dump_write(struct file *file, const void *addr, int nr)
1123 {
1124 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1125 }
1126
1127 static int dump_seek(struct file *file, loff_t off)
1128 {
1129 if (file->f_op->llseek) {
1130 if (file->f_op->llseek(file, off, 0) != off)
1131 return 0;
1132 } else
1133 file->f_pos = off;
1134 return 1;
1135 }
1136
1137 /*
1138 * Decide whether a segment is worth dumping; default is yes to be
1139 * sure (missing info is worse than too much; etc).
1140 * Personally I'd include everything, and use the coredump limit...
1141 *
1142 * I think we should skip something. But I am not sure how. H.J.
1143 */
1144 static int maydump(struct vm_area_struct *vma)
1145 {
1146 /* Do not dump I/O mapped devices or special mappings */
1147 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1148 return 0;
1149
1150 /* Dump shared memory only if mapped from an anonymous file. */
1151 if (vma->vm_flags & VM_SHARED)
1152 return vma->vm_file->f_dentry->d_inode->i_nlink == 0;
1153
1154 /* If it hasn't been written to, don't write it out */
1155 if (!vma->anon_vma)
1156 return 0;
1157
1158 return 1;
1159 }
1160
1161 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y))
1162
1163 /* An ELF note in memory */
1164 struct memelfnote
1165 {
1166 const char *name;
1167 int type;
1168 unsigned int datasz;
1169 void *data;
1170 };
1171
1172 static int notesize(struct memelfnote *en)
1173 {
1174 int sz;
1175
1176 sz = sizeof(struct elf_note);
1177 sz += roundup(strlen(en->name) + 1, 4);
1178 sz += roundup(en->datasz, 4);
1179
1180 return sz;
1181 }
1182
1183 #define DUMP_WRITE(addr, nr) \
1184 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1185 #define DUMP_SEEK(off) \
1186 do { if (!dump_seek(file, (off))) return 0; } while(0)
1187
1188 static int writenote(struct memelfnote *men, struct file *file)
1189 {
1190 struct elf_note en;
1191
1192 en.n_namesz = strlen(men->name) + 1;
1193 en.n_descsz = men->datasz;
1194 en.n_type = men->type;
1195
1196 DUMP_WRITE(&en, sizeof(en));
1197 DUMP_WRITE(men->name, en.n_namesz);
1198 /* XXX - cast from long long to long to avoid need for libgcc.a */
1199 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1200 DUMP_WRITE(men->data, men->datasz);
1201 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1202
1203 return 1;
1204 }
1205 #undef DUMP_WRITE
1206 #undef DUMP_SEEK
1207
1208 #define DUMP_WRITE(addr, nr) \
1209 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1210 goto end_coredump;
1211 #define DUMP_SEEK(off) \
1212 if (!dump_seek(file, (off))) \
1213 goto end_coredump;
1214
1215 static inline void fill_elf_header(struct elfhdr *elf, int segs)
1216 {
1217 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1218 elf->e_ident[EI_CLASS] = ELF_CLASS;
1219 elf->e_ident[EI_DATA] = ELF_DATA;
1220 elf->e_ident[EI_VERSION] = EV_CURRENT;
1221 elf->e_ident[EI_OSABI] = ELF_OSABI;
1222 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1223
1224 elf->e_type = ET_CORE;
1225 elf->e_machine = ELF_ARCH;
1226 elf->e_version = EV_CURRENT;
1227 elf->e_entry = 0;
1228 elf->e_phoff = sizeof(struct elfhdr);
1229 elf->e_shoff = 0;
1230 elf->e_flags = ELF_CORE_EFLAGS;
1231 elf->e_ehsize = sizeof(struct elfhdr);
1232 elf->e_phentsize = sizeof(struct elf_phdr);
1233 elf->e_phnum = segs;
1234 elf->e_shentsize = 0;
1235 elf->e_shnum = 0;
1236 elf->e_shstrndx = 0;
1237 return;
1238 }
1239
1240 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, off_t offset)
1241 {
1242 phdr->p_type = PT_NOTE;
1243 phdr->p_offset = offset;
1244 phdr->p_vaddr = 0;
1245 phdr->p_paddr = 0;
1246 phdr->p_filesz = sz;
1247 phdr->p_memsz = 0;
1248 phdr->p_flags = 0;
1249 phdr->p_align = 0;
1250 return;
1251 }
1252
1253 static void fill_note(struct memelfnote *note, const char *name, int type,
1254 unsigned int sz, void *data)
1255 {
1256 note->name = name;
1257 note->type = type;
1258 note->datasz = sz;
1259 note->data = data;
1260 return;
1261 }
1262
1263 /*
1264 * fill up all the fields in prstatus from the given task struct, except registers
1265 * which need to be filled up separately.
1266 */
1267 static void fill_prstatus(struct elf_prstatus *prstatus,
1268 struct task_struct *p, long signr)
1269 {
1270 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1271 prstatus->pr_sigpend = p->pending.signal.sig[0];
1272 prstatus->pr_sighold = p->blocked.sig[0];
1273 prstatus->pr_pid = p->pid;
1274 prstatus->pr_ppid = p->parent->pid;
1275 prstatus->pr_pgrp = process_group(p);
1276 prstatus->pr_sid = p->signal->session;
1277 if (thread_group_leader(p)) {
1278 /*
1279 * This is the record for the group leader. Add in the
1280 * cumulative times of previous dead threads. This total
1281 * won't include the time of each live thread whose state
1282 * is included in the core dump. The final total reported
1283 * to our parent process when it calls wait4 will include
1284 * those sums as well as the little bit more time it takes
1285 * this and each other thread to finish dying after the
1286 * core dump synchronization phase.
1287 */
1288 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1289 &prstatus->pr_utime);
1290 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1291 &prstatus->pr_stime);
1292 } else {
1293 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1294 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1295 }
1296 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1297 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1298 }
1299
1300 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1301 struct mm_struct *mm)
1302 {
1303 unsigned int i, len;
1304
1305 /* first copy the parameters from user space */
1306 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1307
1308 len = mm->arg_end - mm->arg_start;
1309 if (len >= ELF_PRARGSZ)
1310 len = ELF_PRARGSZ-1;
1311 if (copy_from_user(&psinfo->pr_psargs,
1312 (const char __user *)mm->arg_start, len))
1313 return -EFAULT;
1314 for(i = 0; i < len; i++)
1315 if (psinfo->pr_psargs[i] == 0)
1316 psinfo->pr_psargs[i] = ' ';
1317 psinfo->pr_psargs[len] = 0;
1318
1319 psinfo->pr_pid = p->pid;
1320 psinfo->pr_ppid = p->parent->pid;
1321 psinfo->pr_pgrp = process_group(p);
1322 psinfo->pr_sid = p->signal->session;
1323
1324 i = p->state ? ffz(~p->state) + 1 : 0;
1325 psinfo->pr_state = i;
1326 psinfo->pr_sname = (i < 0 || i > 5) ? '.' : "RSDTZW"[i];
1327 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1328 psinfo->pr_nice = task_nice(p);
1329 psinfo->pr_flag = p->flags;
1330 SET_UID(psinfo->pr_uid, p->uid);
1331 SET_GID(psinfo->pr_gid, p->gid);
1332 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1333
1334 return 0;
1335 }
1336
1337 /* Here is the structure in which status of each thread is captured. */
1338 struct elf_thread_status
1339 {
1340 struct list_head list;
1341 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1342 elf_fpregset_t fpu; /* NT_PRFPREG */
1343 struct task_struct *thread;
1344 #ifdef ELF_CORE_COPY_XFPREGS
1345 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1346 #endif
1347 struct memelfnote notes[3];
1348 int num_notes;
1349 };
1350
1351 /*
1352 * In order to add the specific thread information for the elf file format,
1353 * we need to keep a linked list of every threads pr_status and then
1354 * create a single section for them in the final core file.
1355 */
1356 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1357 {
1358 int sz = 0;
1359 struct task_struct *p = t->thread;
1360 t->num_notes = 0;
1361
1362 fill_prstatus(&t->prstatus, p, signr);
1363 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1364
1365 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), &(t->prstatus));
1366 t->num_notes++;
1367 sz += notesize(&t->notes[0]);
1368
1369 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu))) {
1370 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), &(t->fpu));
1371 t->num_notes++;
1372 sz += notesize(&t->notes[1]);
1373 }
1374
1375 #ifdef ELF_CORE_COPY_XFPREGS
1376 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1377 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu), &t->xfpu);
1378 t->num_notes++;
1379 sz += notesize(&t->notes[2]);
1380 }
1381 #endif
1382 return sz;
1383 }
1384
1385 /*
1386 * Actual dumper
1387 *
1388 * This is a two-pass process; first we find the offsets of the bits,
1389 * and then they are actually written out. If we run out of core limit
1390 * we just truncate.
1391 */
1392 static int elf_core_dump(long signr, struct pt_regs * regs, struct file * file)
1393 {
1394 #define NUM_NOTES 6
1395 int has_dumped = 0;
1396 mm_segment_t fs;
1397 int segs;
1398 size_t size = 0;
1399 int i;
1400 struct vm_area_struct *vma;
1401 struct elfhdr *elf = NULL;
1402 off_t offset = 0, dataoff;
1403 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1404 int numnote;
1405 struct memelfnote *notes = NULL;
1406 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1407 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1408 struct task_struct *g, *p;
1409 LIST_HEAD(thread_list);
1410 struct list_head *t;
1411 elf_fpregset_t *fpu = NULL;
1412 #ifdef ELF_CORE_COPY_XFPREGS
1413 elf_fpxregset_t *xfpu = NULL;
1414 #endif
1415 int thread_status_size = 0;
1416 elf_addr_t *auxv;
1417
1418 /*
1419 * We no longer stop all VM operations.
1420 *
1421 * This is because those proceses that could possibly change map_count or
1422 * the mmap / vma pages are now blocked in do_exit on current finishing
1423 * this core dump.
1424 *
1425 * Only ptrace can touch these memory addresses, but it doesn't change
1426 * the map_count or the pages allocated. So no possibility of crashing
1427 * exists while dumping the mm->vm_next areas to the core file.
1428 */
1429
1430 /* alloc memory for large data structures: too large to be on stack */
1431 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1432 if (!elf)
1433 goto cleanup;
1434 prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
1435 if (!prstatus)
1436 goto cleanup;
1437 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1438 if (!psinfo)
1439 goto cleanup;
1440 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1441 if (!notes)
1442 goto cleanup;
1443 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1444 if (!fpu)
1445 goto cleanup;
1446 #ifdef ELF_CORE_COPY_XFPREGS
1447 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1448 if (!xfpu)
1449 goto cleanup;
1450 #endif
1451
1452 if (signr) {
1453 struct elf_thread_status *tmp;
1454 read_lock(&tasklist_lock);
1455 do_each_thread(g,p)
1456 if (current->mm == p->mm && current != p) {
1457 tmp = kmalloc(sizeof(*tmp), GFP_ATOMIC);
1458 if (!tmp) {
1459 read_unlock(&tasklist_lock);
1460 goto cleanup;
1461 }
1462 memset(tmp, 0, sizeof(*tmp));
1463 INIT_LIST_HEAD(&tmp->list);
1464 tmp->thread = p;
1465 list_add(&tmp->list, &thread_list);
1466 }
1467 while_each_thread(g,p);
1468 read_unlock(&tasklist_lock);
1469 list_for_each(t, &thread_list) {
1470 struct elf_thread_status *tmp;
1471 int sz;
1472
1473 tmp = list_entry(t, struct elf_thread_status, list);
1474 sz = elf_dump_thread_status(signr, tmp);
1475 thread_status_size += sz;
1476 }
1477 }
1478 /* now collect the dump for the current */
1479 memset(prstatus, 0, sizeof(*prstatus));
1480 fill_prstatus(prstatus, current, signr);
1481 elf_core_copy_regs(&prstatus->pr_reg, regs);
1482
1483 segs = current->mm->map_count;
1484 #ifdef ELF_CORE_EXTRA_PHDRS
1485 segs += ELF_CORE_EXTRA_PHDRS;
1486 #endif
1487
1488 /* Set up header */
1489 fill_elf_header(elf, segs+1); /* including notes section */
1490
1491 has_dumped = 1;
1492 current->flags |= PF_DUMPCORE;
1493
1494 /*
1495 * Set up the notes in similar form to SVR4 core dumps made
1496 * with info from their /proc.
1497 */
1498
1499 fill_note(notes +0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1500
1501 fill_psinfo(psinfo, current->group_leader, current->mm);
1502 fill_note(notes +1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1503
1504 numnote = 2;
1505
1506 auxv = (elf_addr_t *) current->mm->saved_auxv;
1507
1508 i = 0;
1509 do
1510 i += 2;
1511 while (auxv[i - 2] != AT_NULL);
1512 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1513 i * sizeof (elf_addr_t), auxv);
1514
1515 /* Try to dump the FPU. */
1516 if ((prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs, fpu)))
1517 fill_note(notes + numnote++,
1518 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1519 #ifdef ELF_CORE_COPY_XFPREGS
1520 if (elf_core_copy_task_xfpregs(current, xfpu))
1521 fill_note(notes + numnote++,
1522 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1523 #endif
1524
1525 fs = get_fs();
1526 set_fs(KERNEL_DS);
1527
1528 DUMP_WRITE(elf, sizeof(*elf));
1529 offset += sizeof(*elf); /* Elf header */
1530 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */
1531
1532 /* Write notes phdr entry */
1533 {
1534 struct elf_phdr phdr;
1535 int sz = 0;
1536
1537 for (i = 0; i < numnote; i++)
1538 sz += notesize(notes + i);
1539
1540 sz += thread_status_size;
1541
1542 fill_elf_note_phdr(&phdr, sz, offset);
1543 offset += sz;
1544 DUMP_WRITE(&phdr, sizeof(phdr));
1545 }
1546
1547 /* Page-align dumped data */
1548 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1549
1550 /* Write program headers for segments dump */
1551 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1552 struct elf_phdr phdr;
1553 size_t sz;
1554
1555 sz = vma->vm_end - vma->vm_start;
1556
1557 phdr.p_type = PT_LOAD;
1558 phdr.p_offset = offset;
1559 phdr.p_vaddr = vma->vm_start;
1560 phdr.p_paddr = 0;
1561 phdr.p_filesz = maydump(vma) ? sz : 0;
1562 phdr.p_memsz = sz;
1563 offset += phdr.p_filesz;
1564 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1565 if (vma->vm_flags & VM_WRITE) phdr.p_flags |= PF_W;
1566 if (vma->vm_flags & VM_EXEC) phdr.p_flags |= PF_X;
1567 phdr.p_align = ELF_EXEC_PAGESIZE;
1568
1569 DUMP_WRITE(&phdr, sizeof(phdr));
1570 }
1571
1572 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1573 ELF_CORE_WRITE_EXTRA_PHDRS;
1574 #endif
1575
1576 /* write out the notes section */
1577 for (i = 0; i < numnote; i++)
1578 if (!writenote(notes + i, file))
1579 goto end_coredump;
1580
1581 /* write out the thread status notes section */
1582 list_for_each(t, &thread_list) {
1583 struct elf_thread_status *tmp = list_entry(t, struct elf_thread_status, list);
1584 for (i = 0; i < tmp->num_notes; i++)
1585 if (!writenote(&tmp->notes[i], file))
1586 goto end_coredump;
1587 }
1588
1589 DUMP_SEEK(dataoff);
1590
1591 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1592 unsigned long addr;
1593
1594 if (!maydump(vma))
1595 continue;
1596
1597 for (addr = vma->vm_start;
1598 addr < vma->vm_end;
1599 addr += PAGE_SIZE) {
1600 struct page* page;
1601 struct vm_area_struct *vma;
1602
1603 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1604 &page, &vma) <= 0) {
1605 DUMP_SEEK (file->f_pos + PAGE_SIZE);
1606 } else {
1607 if (page == ZERO_PAGE(addr)) {
1608 DUMP_SEEK (file->f_pos + PAGE_SIZE);
1609 } else {
1610 void *kaddr;
1611 flush_cache_page(vma, addr, page_to_pfn(page));
1612 kaddr = kmap(page);
1613 if ((size += PAGE_SIZE) > limit ||
1614 !dump_write(file, kaddr,
1615 PAGE_SIZE)) {
1616 kunmap(page);
1617 page_cache_release(page);
1618 goto end_coredump;
1619 }
1620 kunmap(page);
1621 }
1622 page_cache_release(page);
1623 }
1624 }
1625 }
1626
1627 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1628 ELF_CORE_WRITE_EXTRA_DATA;
1629 #endif
1630
1631 if ((off_t) file->f_pos != offset) {
1632 /* Sanity check */
1633 printk("elf_core_dump: file->f_pos (%ld) != offset (%ld)\n",
1634 (off_t) file->f_pos, offset);
1635 }
1636
1637 end_coredump:
1638 set_fs(fs);
1639
1640 cleanup:
1641 while(!list_empty(&thread_list)) {
1642 struct list_head *tmp = thread_list.next;
1643 list_del(tmp);
1644 kfree(list_entry(tmp, struct elf_thread_status, list));
1645 }
1646
1647 kfree(elf);
1648 kfree(prstatus);
1649 kfree(psinfo);
1650 kfree(notes);
1651 kfree(fpu);
1652 #ifdef ELF_CORE_COPY_XFPREGS
1653 kfree(xfpu);
1654 #endif
1655 return has_dumped;
1656 #undef NUM_NOTES
1657 }
1658
1659 #endif /* USE_ELF_CORE_DUMP */
1660
1661 static int __init init_elf_binfmt(void)
1662 {
1663 return register_binfmt(&elf_format);
1664 }
1665
1666 static void __exit exit_elf_binfmt(void)
1667 {
1668 /* Remove the COFF and ELF loaders. */
1669 unregister_binfmt(&elf_format);
1670 }
1671
1672 core_initcall(init_elf_binfmt);
1673 module_exit(exit_elf_binfmt);
1674 MODULE_LICENSE("GPL");