ia64/linux-2.6.18-xen.hg

view fs/binfmt_elf.c @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 906b14e26f2f
children
line source
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 */
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/fs.h>
15 #include <linux/stat.h>
16 #include <linux/time.h>
17 #include <linux/mm.h>
18 #include <linux/mman.h>
19 #include <linux/a.out.h>
20 #include <linux/errno.h>
21 #include <linux/signal.h>
22 #include <linux/binfmts.h>
23 #include <linux/string.h>
24 #include <linux/file.h>
25 #include <linux/fcntl.h>
26 #include <linux/ptrace.h>
27 #include <linux/slab.h>
28 #include <linux/shm.h>
29 #include <linux/personality.h>
30 #include <linux/elfcore.h>
31 #include <linux/init.h>
32 #include <linux/highuid.h>
33 #include <linux/smp.h>
34 #include <linux/smp_lock.h>
35 #include <linux/compiler.h>
36 #include <linux/highmem.h>
37 #include <linux/pagemap.h>
38 #include <linux/security.h>
39 #include <linux/syscalls.h>
40 #include <linux/random.h>
41 #include <linux/elf.h>
42 #include <asm/uaccess.h>
43 #include <asm/param.h>
44 #include <asm/page.h>
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 extern int dump_fpu (struct pt_regs *, elf_fpregset_t *);
51 #ifndef elf_addr_t
52 #define elf_addr_t unsigned long
53 #endif
55 /*
56 * If we don't support core dumping, then supply a NULL so we
57 * don't even try.
58 */
59 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
60 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file);
61 #else
62 #define elf_core_dump NULL
63 #endif
65 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
66 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
67 #else
68 #define ELF_MIN_ALIGN PAGE_SIZE
69 #endif
71 #ifndef ELF_CORE_EFLAGS
72 #define ELF_CORE_EFLAGS 0
73 #endif
75 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
76 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
77 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
79 static struct linux_binfmt elf_format = {
80 .module = THIS_MODULE,
81 .load_binary = load_elf_binary,
82 .load_shlib = load_elf_library,
83 .core_dump = elf_core_dump,
84 .min_coredump = ELF_EXEC_PAGESIZE
85 };
87 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
89 static int set_brk(unsigned long start, unsigned long end)
90 {
91 start = ELF_PAGEALIGN(start);
92 end = ELF_PAGEALIGN(end);
93 if (end > start) {
94 unsigned long addr;
95 down_write(&current->mm->mmap_sem);
96 addr = do_brk(start, end - start);
97 up_write(&current->mm->mmap_sem);
98 if (BAD_ADDR(addr))
99 return addr;
100 }
101 current->mm->start_brk = current->mm->brk = end;
102 return 0;
103 }
105 /* We need to explicitly zero any fractional pages
106 after the data section (i.e. bss). This would
107 contain the junk from the file that should not
108 be in memory
109 */
110 static int padzero(unsigned long elf_bss)
111 {
112 unsigned long nbyte;
114 nbyte = ELF_PAGEOFFSET(elf_bss);
115 if (nbyte) {
116 nbyte = ELF_MIN_ALIGN - nbyte;
117 if (clear_user((void __user *) elf_bss, nbyte))
118 return -EFAULT;
119 }
120 return 0;
121 }
123 /* Let's use some macros to make this stack manipulation a litle clearer */
124 #ifdef CONFIG_STACK_GROWSUP
125 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
126 #define STACK_ROUND(sp, items) \
127 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
128 #define STACK_ALLOC(sp, len) ({ \
129 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
130 old_sp; })
131 #else
132 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
133 #define STACK_ROUND(sp, items) \
134 (((unsigned long) (sp - items)) &~ 15UL)
135 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
136 #endif
138 static int
139 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
140 int interp_aout, unsigned long load_addr,
141 unsigned long interp_load_addr)
142 {
143 unsigned long p = bprm->p;
144 int argc = bprm->argc;
145 int envc = bprm->envc;
146 elf_addr_t __user *argv;
147 elf_addr_t __user *envp;
148 elf_addr_t __user *sp;
149 elf_addr_t __user *u_platform;
150 const char *k_platform = ELF_PLATFORM;
151 int items;
152 elf_addr_t *elf_info;
153 int ei_index = 0;
154 struct task_struct *tsk = current;
156 /*
157 * If this architecture has a platform capability string, copy it
158 * to userspace. In some cases (Sparc), this info is impossible
159 * for userspace to get any other way, in others (i386) it is
160 * merely difficult.
161 */
162 u_platform = NULL;
163 if (k_platform) {
164 size_t len = strlen(k_platform) + 1;
166 /*
167 * In some cases (e.g. Hyper-Threading), we want to avoid L1
168 * evictions by the processes running on the same package. One
169 * thing we can do is to shuffle the initial stack for them.
170 */
172 p = arch_align_stack(p);
174 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
175 if (__copy_to_user(u_platform, k_platform, len))
176 return -EFAULT;
177 }
179 /* Create the ELF interpreter info */
180 elf_info = (elf_addr_t *)current->mm->saved_auxv;
181 #define NEW_AUX_ENT(id, val) \
182 do { \
183 elf_info[ei_index++] = id; \
184 elf_info[ei_index++] = val; \
185 } while (0)
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, tsk->uid);
204 NEW_AUX_ENT(AT_EUID, tsk->euid);
205 NEW_AUX_ENT(AT_GID, tsk->gid);
206 NEW_AUX_ENT(AT_EGID, tsk->egid);
207 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
208 if (k_platform) {
209 NEW_AUX_ENT(AT_PLATFORM,
210 (elf_addr_t)(unsigned long)u_platform);
211 }
212 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
213 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
214 }
215 #undef NEW_AUX_ENT
216 /* AT_NULL is zero; clear the rest too */
217 memset(&elf_info[ei_index], 0,
218 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
220 /* And advance past the AT_NULL entry. */
221 ei_index += 2;
223 sp = STACK_ADD(p, ei_index);
225 items = (argc + 1) + (envc + 1);
226 if (interp_aout) {
227 items += 3; /* a.out interpreters require argv & envp too */
228 } else {
229 items += 1; /* ELF interpreters only put argc on the stack */
230 }
231 bprm->p = STACK_ROUND(sp, items);
233 /* Point sp at the lowest address on the stack */
234 #ifdef CONFIG_STACK_GROWSUP
235 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
236 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
237 #else
238 sp = (elf_addr_t __user *)bprm->p;
239 #endif
241 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
242 if (__put_user(argc, sp++))
243 return -EFAULT;
244 if (interp_aout) {
245 argv = sp + 2;
246 envp = argv + argc + 1;
247 __put_user((elf_addr_t)(unsigned long)argv, sp++);
248 __put_user((elf_addr_t)(unsigned long)envp, sp++);
249 } else {
250 argv = sp;
251 envp = argv + argc + 1;
252 }
254 /* Populate argv and envp */
255 p = current->mm->arg_end = current->mm->arg_start;
256 while (argc-- > 0) {
257 size_t len;
258 __put_user((elf_addr_t)p, argv++);
259 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
260 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
261 return 0;
262 p += len;
263 }
264 if (__put_user(0, argv))
265 return -EFAULT;
266 current->mm->arg_end = current->mm->env_start = p;
267 while (envc-- > 0) {
268 size_t len;
269 __put_user((elf_addr_t)p, envp++);
270 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
271 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
272 return 0;
273 p += len;
274 }
275 if (__put_user(0, envp))
276 return -EFAULT;
277 current->mm->env_end = p;
279 /* Put the elf_info on the stack in the right place. */
280 sp = (elf_addr_t __user *)envp + 1;
281 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
282 return -EFAULT;
283 return 0;
284 }
286 #ifndef elf_map
288 static unsigned long elf_map(struct file *filep, unsigned long addr,
289 struct elf_phdr *eppnt, int prot, int type)
290 {
291 unsigned long map_addr;
292 unsigned long pageoffset = ELF_PAGEOFFSET(eppnt->p_vaddr);
294 down_write(&current->mm->mmap_sem);
295 /* mmap() will return -EINVAL if given a zero size, but a
296 * segment with zero filesize is perfectly valid */
297 if (eppnt->p_filesz + pageoffset)
298 map_addr = do_mmap(filep, ELF_PAGESTART(addr),
299 eppnt->p_filesz + pageoffset, prot, type,
300 eppnt->p_offset - pageoffset);
301 else
302 map_addr = ELF_PAGESTART(addr);
303 up_write(&current->mm->mmap_sem);
304 return(map_addr);
305 }
307 #endif /* !elf_map */
309 /* This is much more generalized than the library routine read function,
310 so we keep this separate. Technically the library read function
311 is only provided so that we can read a.out libraries that have
312 an ELF header */
314 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
315 struct file *interpreter, unsigned long *interp_load_addr)
316 {
317 struct elf_phdr *elf_phdata;
318 struct elf_phdr *eppnt;
319 unsigned long load_addr = 0;
320 int load_addr_set = 0;
321 unsigned long last_bss = 0, elf_bss = 0;
322 unsigned long error = ~0UL;
323 int retval, i, size;
325 /* First of all, some simple consistency checks */
326 if (interp_elf_ex->e_type != ET_EXEC &&
327 interp_elf_ex->e_type != ET_DYN)
328 goto out;
329 if (!elf_check_arch(interp_elf_ex))
330 goto out;
331 if (!interpreter->f_op || !interpreter->f_op->mmap)
332 goto out;
334 /*
335 * If the size of this structure has changed, then punt, since
336 * we will be doing the wrong thing.
337 */
338 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
339 goto out;
340 if (interp_elf_ex->e_phnum < 1 ||
341 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
342 goto out;
344 /* Now read in all of the header information */
345 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
346 if (size > ELF_MIN_ALIGN)
347 goto out;
348 elf_phdata = kmalloc(size, GFP_KERNEL);
349 if (!elf_phdata)
350 goto out;
352 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
353 (char *)elf_phdata,size);
354 error = -EIO;
355 if (retval != size) {
356 if (retval < 0)
357 error = retval;
358 goto out_close;
359 }
361 eppnt = elf_phdata;
362 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
363 if (eppnt->p_type == PT_LOAD) {
364 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
365 int elf_prot = 0;
366 unsigned long vaddr = 0;
367 unsigned long k, map_addr;
369 if (eppnt->p_flags & PF_R)
370 elf_prot = PROT_READ;
371 if (eppnt->p_flags & PF_W)
372 elf_prot |= PROT_WRITE;
373 if (eppnt->p_flags & PF_X)
374 elf_prot |= PROT_EXEC;
375 vaddr = eppnt->p_vaddr;
376 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
377 elf_type |= MAP_FIXED;
379 map_addr = elf_map(interpreter, load_addr + vaddr,
380 eppnt, elf_prot, elf_type);
381 error = map_addr;
382 if (BAD_ADDR(map_addr))
383 goto out_close;
385 if (!load_addr_set &&
386 interp_elf_ex->e_type == ET_DYN) {
387 load_addr = map_addr - ELF_PAGESTART(vaddr);
388 load_addr_set = 1;
389 }
391 /*
392 * Check to see if the section's size will overflow the
393 * allowed task size. Note that p_filesz must always be
394 * <= p_memsize so it's only necessary to check p_memsz.
395 */
396 k = load_addr + eppnt->p_vaddr;
397 if (BAD_ADDR(k) ||
398 eppnt->p_filesz > eppnt->p_memsz ||
399 eppnt->p_memsz > TASK_SIZE ||
400 TASK_SIZE - eppnt->p_memsz < k) {
401 error = -ENOMEM;
402 goto out_close;
403 }
405 /*
406 * Find the end of the file mapping for this phdr, and
407 * keep track of the largest address we see for this.
408 */
409 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
410 if (k > elf_bss)
411 elf_bss = k;
413 /*
414 * Do the same thing for the memory mapping - between
415 * elf_bss and last_bss is the bss section.
416 */
417 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
418 if (k > last_bss)
419 last_bss = k;
420 }
421 }
423 /*
424 * Now fill out the bss section. First pad the last page up
425 * to the page boundary, and then perform a mmap to make sure
426 * that there are zero-mapped pages up to and including the
427 * last bss page.
428 */
429 if (padzero(elf_bss)) {
430 error = -EFAULT;
431 goto out_close;
432 }
434 /* What we have mapped so far */
435 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
437 /* Map the last of the bss segment */
438 if (last_bss > elf_bss) {
439 down_write(&current->mm->mmap_sem);
440 error = do_brk(elf_bss, last_bss - elf_bss);
441 up_write(&current->mm->mmap_sem);
442 if (BAD_ADDR(error))
443 goto out_close;
444 }
446 *interp_load_addr = load_addr;
447 error = ((unsigned long)interp_elf_ex->e_entry) + load_addr;
449 out_close:
450 kfree(elf_phdata);
451 out:
452 return error;
453 }
455 static unsigned long load_aout_interp(struct exec *interp_ex,
456 struct file *interpreter)
457 {
458 unsigned long text_data, elf_entry = ~0UL;
459 char __user * addr;
460 loff_t offset;
462 current->mm->end_code = interp_ex->a_text;
463 text_data = interp_ex->a_text + interp_ex->a_data;
464 current->mm->end_data = text_data;
465 current->mm->brk = interp_ex->a_bss + text_data;
467 switch (N_MAGIC(*interp_ex)) {
468 case OMAGIC:
469 offset = 32;
470 addr = (char __user *)0;
471 break;
472 case ZMAGIC:
473 case QMAGIC:
474 offset = N_TXTOFF(*interp_ex);
475 addr = (char __user *)N_TXTADDR(*interp_ex);
476 break;
477 default:
478 goto out;
479 }
481 down_write(&current->mm->mmap_sem);
482 do_brk(0, text_data);
483 up_write(&current->mm->mmap_sem);
484 if (!interpreter->f_op || !interpreter->f_op->read)
485 goto out;
486 if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0)
487 goto out;
488 flush_icache_range((unsigned long)addr,
489 (unsigned long)addr + text_data);
491 down_write(&current->mm->mmap_sem);
492 do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
493 interp_ex->a_bss);
494 up_write(&current->mm->mmap_sem);
495 elf_entry = interp_ex->a_entry;
497 out:
498 return elf_entry;
499 }
501 /*
502 * These are the functions used to load ELF style executables and shared
503 * libraries. There is no binary dependent code anywhere else.
504 */
506 #define INTERPRETER_NONE 0
507 #define INTERPRETER_AOUT 1
508 #define INTERPRETER_ELF 2
510 #ifndef STACK_RND_MASK
511 #define STACK_RND_MASK 0x7ff /* with 4K pages 8MB of VA */
512 #endif
514 static unsigned long randomize_stack_top(unsigned long stack_top)
515 {
516 unsigned int random_variable = 0;
518 if (current->flags & PF_RANDOMIZE) {
519 random_variable = get_random_int() & STACK_RND_MASK;
520 random_variable <<= PAGE_SHIFT;
521 }
522 #ifdef CONFIG_STACK_GROWSUP
523 return PAGE_ALIGN(stack_top) + random_variable;
524 #else
525 return PAGE_ALIGN(stack_top) - random_variable;
526 #endif
527 }
529 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
530 {
531 struct file *interpreter = NULL; /* to shut gcc up */
532 unsigned long load_addr = 0, load_bias = 0;
533 int load_addr_set = 0;
534 char * elf_interpreter = NULL;
535 unsigned int interpreter_type = INTERPRETER_NONE;
536 unsigned char ibcs2_interpreter = 0;
537 unsigned long error;
538 struct elf_phdr *elf_ppnt, *elf_phdata;
539 unsigned long elf_bss, elf_brk;
540 int elf_exec_fileno;
541 int retval, i;
542 unsigned int size;
543 unsigned long elf_entry, interp_load_addr = 0;
544 unsigned long start_code, end_code, start_data, end_data;
545 unsigned long reloc_func_desc = 0;
546 char passed_fileno[6];
547 struct files_struct *files;
548 int have_pt_gnu_stack, executable_stack = EXSTACK_DEFAULT;
549 unsigned long def_flags = 0;
550 struct {
551 struct elfhdr elf_ex;
552 struct elfhdr interp_elf_ex;
553 struct exec interp_ex;
554 } *loc;
556 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
557 if (!loc) {
558 retval = -ENOMEM;
559 goto out_ret;
560 }
562 /* Get the exec-header */
563 loc->elf_ex = *((struct elfhdr *)bprm->buf);
565 retval = -ENOEXEC;
566 /* First of all, some simple consistency checks */
567 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
568 goto out;
570 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
571 goto out;
572 if (!elf_check_arch(&loc->elf_ex))
573 goto out;
574 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
575 goto out;
577 /* Now read in all of the header information */
578 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
579 goto out;
580 if (loc->elf_ex.e_phnum < 1 ||
581 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
582 goto out;
583 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
584 retval = -ENOMEM;
585 elf_phdata = kmalloc(size, GFP_KERNEL);
586 if (!elf_phdata)
587 goto out;
589 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
590 (char *)elf_phdata, size);
591 if (retval != size) {
592 if (retval >= 0)
593 retval = -EIO;
594 goto out_free_ph;
595 }
597 files = current->files; /* Refcounted so ok */
598 retval = unshare_files();
599 if (retval < 0)
600 goto out_free_ph;
601 if (files == current->files) {
602 put_files_struct(files);
603 files = NULL;
604 }
606 /* exec will make our files private anyway, but for the a.out
607 loader stuff we need to do it earlier */
608 retval = get_unused_fd();
609 if (retval < 0)
610 goto out_free_fh;
611 get_file(bprm->file);
612 fd_install(elf_exec_fileno = retval, bprm->file);
614 elf_ppnt = elf_phdata;
615 elf_bss = 0;
616 elf_brk = 0;
618 start_code = ~0UL;
619 end_code = 0;
620 start_data = 0;
621 end_data = 0;
623 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
624 if (elf_ppnt->p_type == PT_INTERP) {
625 /* This is the program interpreter used for
626 * shared libraries - for now assume that this
627 * is an a.out format binary
628 */
629 retval = -ENOEXEC;
630 if (elf_ppnt->p_filesz > PATH_MAX ||
631 elf_ppnt->p_filesz < 2)
632 goto out_free_file;
634 retval = -ENOMEM;
635 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
636 GFP_KERNEL);
637 if (!elf_interpreter)
638 goto out_free_file;
640 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
641 elf_interpreter,
642 elf_ppnt->p_filesz);
643 if (retval != elf_ppnt->p_filesz) {
644 if (retval >= 0)
645 retval = -EIO;
646 goto out_free_interp;
647 }
648 /* make sure path is NULL terminated */
649 retval = -ENOEXEC;
650 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
651 goto out_free_interp;
653 /* If the program interpreter is one of these two,
654 * then assume an iBCS2 image. Otherwise assume
655 * a native linux image.
656 */
657 if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
658 strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0)
659 ibcs2_interpreter = 1;
661 /*
662 * The early SET_PERSONALITY here is so that the lookup
663 * for the interpreter happens in the namespace of the
664 * to-be-execed image. SET_PERSONALITY can select an
665 * alternate root.
666 *
667 * However, SET_PERSONALITY is NOT allowed to switch
668 * this task into the new images's memory mapping
669 * policy - that is, TASK_SIZE must still evaluate to
670 * that which is appropriate to the execing application.
671 * This is because exit_mmap() needs to have TASK_SIZE
672 * evaluate to the size of the old image.
673 *
674 * So if (say) a 64-bit application is execing a 32-bit
675 * application it is the architecture's responsibility
676 * to defer changing the value of TASK_SIZE until the
677 * switch really is going to happen - do this in
678 * flush_thread(). - akpm
679 */
680 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
682 interpreter = open_exec(elf_interpreter);
683 retval = PTR_ERR(interpreter);
684 if (IS_ERR(interpreter))
685 goto out_free_interp;
686 retval = kernel_read(interpreter, 0, bprm->buf,
687 BINPRM_BUF_SIZE);
688 if (retval != BINPRM_BUF_SIZE) {
689 if (retval >= 0)
690 retval = -EIO;
691 goto out_free_dentry;
692 }
694 /* Get the exec headers */
695 loc->interp_ex = *((struct exec *)bprm->buf);
696 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
697 break;
698 }
699 elf_ppnt++;
700 }
702 elf_ppnt = elf_phdata;
703 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
704 if (elf_ppnt->p_type == PT_GNU_STACK) {
705 if (elf_ppnt->p_flags & PF_X)
706 executable_stack = EXSTACK_ENABLE_X;
707 else
708 executable_stack = EXSTACK_DISABLE_X;
709 break;
710 }
711 have_pt_gnu_stack = (i < loc->elf_ex.e_phnum);
713 /* Some simple consistency checks for the interpreter */
714 if (elf_interpreter) {
715 interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
717 /* Now figure out which format our binary is */
718 if ((N_MAGIC(loc->interp_ex) != OMAGIC) &&
719 (N_MAGIC(loc->interp_ex) != ZMAGIC) &&
720 (N_MAGIC(loc->interp_ex) != QMAGIC))
721 interpreter_type = INTERPRETER_ELF;
723 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
724 interpreter_type &= ~INTERPRETER_ELF;
726 retval = -ELIBBAD;
727 if (!interpreter_type)
728 goto out_free_dentry;
730 /* Make sure only one type was selected */
731 if ((interpreter_type & INTERPRETER_ELF) &&
732 interpreter_type != INTERPRETER_ELF) {
733 // FIXME - ratelimit this before re-enabling
734 // printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n");
735 interpreter_type = INTERPRETER_ELF;
736 }
737 /* Verify the interpreter has a valid arch */
738 if ((interpreter_type == INTERPRETER_ELF) &&
739 !elf_check_arch(&loc->interp_elf_ex))
740 goto out_free_dentry;
741 } else {
742 /* Executables without an interpreter also need a personality */
743 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
744 }
746 /* OK, we are done with that, now set up the arg stuff,
747 and then start this sucker up */
748 if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) {
749 char *passed_p = passed_fileno;
750 sprintf(passed_fileno, "%d", elf_exec_fileno);
752 if (elf_interpreter) {
753 retval = copy_strings_kernel(1, &passed_p, bprm);
754 if (retval)
755 goto out_free_dentry;
756 bprm->argc++;
757 }
758 }
760 /* Flush all traces of the currently running executable */
761 retval = flush_old_exec(bprm);
762 if (retval)
763 goto out_free_dentry;
765 /* Discard our unneeded old files struct */
766 if (files) {
767 put_files_struct(files);
768 files = NULL;
769 }
771 /* OK, This is the point of no return */
772 current->mm->start_data = 0;
773 current->mm->end_data = 0;
774 current->mm->end_code = 0;
775 current->mm->mmap = NULL;
776 current->flags &= ~PF_FORKNOEXEC;
777 current->mm->def_flags = def_flags;
779 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
780 may depend on the personality. */
781 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
782 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
783 current->personality |= READ_IMPLIES_EXEC;
785 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
786 current->flags |= PF_RANDOMIZE;
787 arch_pick_mmap_layout(current->mm);
789 /* Do this so that we can load the interpreter, if need be. We will
790 change some of these later */
791 current->mm->free_area_cache = current->mm->mmap_base;
792 current->mm->cached_hole_size = 0;
793 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
794 executable_stack);
795 if (retval < 0) {
796 send_sig(SIGKILL, current, 0);
797 goto out_free_dentry;
798 }
800 current->mm->start_stack = bprm->p;
802 /* Now we do a little grungy work by mmaping the ELF image into
803 the correct location in memory. At this point, we assume that
804 the image should be loaded at fixed address, not at a variable
805 address. */
806 for(i = 0, elf_ppnt = elf_phdata;
807 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
808 int elf_prot = 0, elf_flags;
809 unsigned long k, vaddr;
811 if (elf_ppnt->p_type != PT_LOAD)
812 continue;
814 if (unlikely (elf_brk > elf_bss)) {
815 unsigned long nbyte;
817 /* There was a PT_LOAD segment with p_memsz > p_filesz
818 before this one. Map anonymous pages, if needed,
819 and clear the area. */
820 retval = set_brk (elf_bss + load_bias,
821 elf_brk + load_bias);
822 if (retval) {
823 send_sig(SIGKILL, current, 0);
824 goto out_free_dentry;
825 }
826 nbyte = ELF_PAGEOFFSET(elf_bss);
827 if (nbyte) {
828 nbyte = ELF_MIN_ALIGN - nbyte;
829 if (nbyte > elf_brk - elf_bss)
830 nbyte = elf_brk - elf_bss;
831 if (clear_user((void __user *)elf_bss +
832 load_bias, nbyte)) {
833 /*
834 * This bss-zeroing can fail if the ELF
835 * file specifies odd protections. So
836 * we don't check the return value
837 */
838 }
839 }
840 }
842 if (elf_ppnt->p_flags & PF_R)
843 elf_prot |= PROT_READ;
844 if (elf_ppnt->p_flags & PF_W)
845 elf_prot |= PROT_WRITE;
846 if (elf_ppnt->p_flags & PF_X)
847 elf_prot |= PROT_EXEC;
849 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
851 vaddr = elf_ppnt->p_vaddr;
852 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
853 elf_flags |= MAP_FIXED;
854 } else if (loc->elf_ex.e_type == ET_DYN) {
855 /* Try and get dynamic programs out of the way of the
856 * default mmap base, as well as whatever program they
857 * might try to exec. This is because the brk will
858 * follow the loader, and is not movable. */
859 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
860 }
862 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
863 elf_prot, elf_flags);
864 if (BAD_ADDR(error)) {
865 send_sig(SIGKILL, current, 0);
866 goto out_free_dentry;
867 }
869 if (!load_addr_set) {
870 load_addr_set = 1;
871 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
872 if (loc->elf_ex.e_type == ET_DYN) {
873 load_bias += error -
874 ELF_PAGESTART(load_bias + vaddr);
875 load_addr += load_bias;
876 reloc_func_desc = load_bias;
877 }
878 }
879 k = elf_ppnt->p_vaddr;
880 if (k < start_code)
881 start_code = k;
882 if (start_data < k)
883 start_data = k;
885 /*
886 * Check to see if the section's size will overflow the
887 * allowed task size. Note that p_filesz must always be
888 * <= p_memsz so it is only necessary to check p_memsz.
889 */
890 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
891 elf_ppnt->p_memsz > TASK_SIZE ||
892 TASK_SIZE - elf_ppnt->p_memsz < k) {
893 /* set_brk can never work. Avoid overflows. */
894 send_sig(SIGKILL, current, 0);
895 goto out_free_dentry;
896 }
898 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
900 if (k > elf_bss)
901 elf_bss = k;
902 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
903 end_code = k;
904 if (end_data < k)
905 end_data = k;
906 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
907 if (k > elf_brk)
908 elf_brk = k;
909 }
911 loc->elf_ex.e_entry += load_bias;
912 elf_bss += load_bias;
913 elf_brk += load_bias;
914 start_code += load_bias;
915 end_code += load_bias;
916 start_data += load_bias;
917 end_data += load_bias;
919 /* Calling set_brk effectively mmaps the pages that we need
920 * for the bss and break sections. We must do this before
921 * mapping in the interpreter, to make sure it doesn't wind
922 * up getting placed where the bss needs to go.
923 */
924 retval = set_brk(elf_bss, elf_brk);
925 if (retval) {
926 send_sig(SIGKILL, current, 0);
927 goto out_free_dentry;
928 }
929 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
930 send_sig(SIGSEGV, current, 0);
931 retval = -EFAULT; /* Nobody gets to see this, but.. */
932 goto out_free_dentry;
933 }
935 if (elf_interpreter) {
936 if (interpreter_type == INTERPRETER_AOUT)
937 elf_entry = load_aout_interp(&loc->interp_ex,
938 interpreter);
939 else
940 elf_entry = load_elf_interp(&loc->interp_elf_ex,
941 interpreter,
942 &interp_load_addr);
943 if (BAD_ADDR(elf_entry)) {
944 force_sig(SIGSEGV, current);
945 retval = IS_ERR((void *)elf_entry) ?
946 (int)elf_entry : -EINVAL;
947 goto out_free_dentry;
948 }
949 reloc_func_desc = interp_load_addr;
951 allow_write_access(interpreter);
952 fput(interpreter);
953 kfree(elf_interpreter);
954 } else {
955 elf_entry = loc->elf_ex.e_entry;
956 if (BAD_ADDR(elf_entry)) {
957 force_sig(SIGSEGV, current);
958 retval = -EINVAL;
959 goto out_free_dentry;
960 }
961 }
963 kfree(elf_phdata);
965 if (interpreter_type != INTERPRETER_AOUT)
966 sys_close(elf_exec_fileno);
968 set_binfmt(&elf_format);
970 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
971 retval = arch_setup_additional_pages(bprm, executable_stack);
972 if (retval < 0) {
973 send_sig(SIGKILL, current, 0);
974 goto out;
975 }
976 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
978 compute_creds(bprm);
979 current->flags &= ~PF_FORKNOEXEC;
980 create_elf_tables(bprm, &loc->elf_ex,
981 (interpreter_type == INTERPRETER_AOUT),
982 load_addr, interp_load_addr);
983 /* N.B. passed_fileno might not be initialized? */
984 if (interpreter_type == INTERPRETER_AOUT)
985 current->mm->arg_start += strlen(passed_fileno) + 1;
986 current->mm->end_code = end_code;
987 current->mm->start_code = start_code;
988 current->mm->start_data = start_data;
989 current->mm->end_data = end_data;
990 current->mm->start_stack = bprm->p;
992 if (current->personality & MMAP_PAGE_ZERO) {
993 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
994 and some applications "depend" upon this behavior.
995 Since we do not have the power to recompile these, we
996 emulate the SVr4 behavior. Sigh. */
997 down_write(&current->mm->mmap_sem);
998 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
999 MAP_FIXED | MAP_PRIVATE, 0);
1000 up_write(&current->mm->mmap_sem);
1003 #ifdef ELF_PLAT_INIT
1004 /*
1005 * The ABI may specify that certain registers be set up in special
1006 * ways (on i386 %edx is the address of a DT_FINI function, for
1007 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1008 * that the e_entry field is the address of the function descriptor
1009 * for the startup routine, rather than the address of the startup
1010 * routine itself. This macro performs whatever initialization to
1011 * the regs structure is required as well as any relocations to the
1012 * function descriptor entries when executing dynamically links apps.
1013 */
1014 ELF_PLAT_INIT(regs, reloc_func_desc);
1015 #endif
1017 start_thread(regs, elf_entry, bprm->p);
1018 if (unlikely(current->ptrace & PT_PTRACED)) {
1019 if (current->ptrace & PT_TRACE_EXEC)
1020 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
1021 else
1022 send_sig(SIGTRAP, current, 0);
1024 retval = 0;
1025 out:
1026 kfree(loc);
1027 out_ret:
1028 return retval;
1030 /* error cleanup */
1031 out_free_dentry:
1032 allow_write_access(interpreter);
1033 if (interpreter)
1034 fput(interpreter);
1035 out_free_interp:
1036 kfree(elf_interpreter);
1037 out_free_file:
1038 sys_close(elf_exec_fileno);
1039 out_free_fh:
1040 if (files) {
1041 put_files_struct(current->files);
1042 current->files = files;
1044 out_free_ph:
1045 kfree(elf_phdata);
1046 goto out;
1049 /* This is really simpleminded and specialized - we are loading an
1050 a.out library that is given an ELF header. */
1051 static int load_elf_library(struct file *file)
1053 struct elf_phdr *elf_phdata;
1054 struct elf_phdr *eppnt;
1055 unsigned long elf_bss, bss, len;
1056 int retval, error, i, j;
1057 struct elfhdr elf_ex;
1059 error = -ENOEXEC;
1060 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1061 if (retval != sizeof(elf_ex))
1062 goto out;
1064 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1065 goto out;
1067 /* First of all, some simple consistency checks */
1068 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1069 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1070 goto out;
1072 /* Now read in all of the header information */
1074 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1075 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1077 error = -ENOMEM;
1078 elf_phdata = kmalloc(j, GFP_KERNEL);
1079 if (!elf_phdata)
1080 goto out;
1082 eppnt = elf_phdata;
1083 error = -ENOEXEC;
1084 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1085 if (retval != j)
1086 goto out_free_ph;
1088 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1089 if ((eppnt + i)->p_type == PT_LOAD)
1090 j++;
1091 if (j != 1)
1092 goto out_free_ph;
1094 while (eppnt->p_type != PT_LOAD)
1095 eppnt++;
1097 /* Now use mmap to map the library into memory. */
1098 down_write(&current->mm->mmap_sem);
1099 error = do_mmap(file,
1100 ELF_PAGESTART(eppnt->p_vaddr),
1101 (eppnt->p_filesz +
1102 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1103 PROT_READ | PROT_WRITE | PROT_EXEC,
1104 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1105 (eppnt->p_offset -
1106 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1107 up_write(&current->mm->mmap_sem);
1108 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1109 goto out_free_ph;
1111 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1112 if (padzero(elf_bss)) {
1113 error = -EFAULT;
1114 goto out_free_ph;
1117 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1118 ELF_MIN_ALIGN - 1);
1119 bss = eppnt->p_memsz + eppnt->p_vaddr;
1120 if (bss > len) {
1121 down_write(&current->mm->mmap_sem);
1122 do_brk(len, bss - len);
1123 up_write(&current->mm->mmap_sem);
1125 error = 0;
1127 out_free_ph:
1128 kfree(elf_phdata);
1129 out:
1130 return error;
1133 /*
1134 * Note that some platforms still use traditional core dumps and not
1135 * the ELF core dump. Each platform can select it as appropriate.
1136 */
1137 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1139 /*
1140 * ELF core dumper
1142 * Modelled on fs/exec.c:aout_core_dump()
1143 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1144 */
1145 /*
1146 * These are the only things you should do on a core-file: use only these
1147 * functions to write out all the necessary info.
1148 */
1149 static int dump_write(struct file *file, const void *addr, int nr)
1151 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1154 static int dump_seek(struct file *file, loff_t off)
1156 if (file->f_op->llseek) {
1157 if (file->f_op->llseek(file, off, 0) != off)
1158 return 0;
1159 } else
1160 file->f_pos = off;
1161 return 1;
1164 /*
1165 * Decide whether a segment is worth dumping; default is yes to be
1166 * sure (missing info is worse than too much; etc).
1167 * Personally I'd include everything, and use the coredump limit...
1169 * I think we should skip something. But I am not sure how. H.J.
1170 */
1171 static int maydump(struct vm_area_struct *vma)
1173 /* The vma can be set up to tell us the answer directly. */
1174 if (vma->vm_flags & VM_ALWAYSDUMP)
1175 return 1;
1177 /* Do not dump I/O mapped devices or special mappings */
1178 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1179 return 0;
1181 /* Dump shared memory only if mapped from an anonymous file. */
1182 if (vma->vm_flags & VM_SHARED)
1183 return vma->vm_file->f_dentry->d_inode->i_nlink == 0;
1185 /* If it hasn't been written to, don't write it out */
1186 if (!vma->anon_vma)
1187 return 0;
1189 return 1;
1192 /* An ELF note in memory */
1193 struct memelfnote
1195 const char *name;
1196 int type;
1197 unsigned int datasz;
1198 void *data;
1199 };
1201 static int notesize(struct memelfnote *en)
1203 int sz;
1205 sz = sizeof(struct elf_note);
1206 sz += roundup(strlen(en->name) + 1, 4);
1207 sz += roundup(en->datasz, 4);
1209 return sz;
1212 #define DUMP_WRITE(addr, nr) \
1213 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1214 #define DUMP_SEEK(off) \
1215 do { if (!dump_seek(file, (off))) return 0; } while(0)
1217 static int writenote(struct memelfnote *men, struct file *file)
1219 struct elf_note en;
1221 en.n_namesz = strlen(men->name) + 1;
1222 en.n_descsz = men->datasz;
1223 en.n_type = men->type;
1225 DUMP_WRITE(&en, sizeof(en));
1226 DUMP_WRITE(men->name, en.n_namesz);
1227 /* XXX - cast from long long to long to avoid need for libgcc.a */
1228 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1229 DUMP_WRITE(men->data, men->datasz);
1230 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1232 return 1;
1234 #undef DUMP_WRITE
1235 #undef DUMP_SEEK
1237 #define DUMP_WRITE(addr, nr) \
1238 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1239 goto end_coredump;
1240 #define DUMP_SEEK(off) \
1241 if (!dump_seek(file, (off))) \
1242 goto end_coredump;
1244 static void fill_elf_header(struct elfhdr *elf, int segs)
1246 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1247 elf->e_ident[EI_CLASS] = ELF_CLASS;
1248 elf->e_ident[EI_DATA] = ELF_DATA;
1249 elf->e_ident[EI_VERSION] = EV_CURRENT;
1250 elf->e_ident[EI_OSABI] = ELF_OSABI;
1251 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1253 elf->e_type = ET_CORE;
1254 elf->e_machine = ELF_ARCH;
1255 elf->e_version = EV_CURRENT;
1256 elf->e_entry = 0;
1257 elf->e_phoff = sizeof(struct elfhdr);
1258 elf->e_shoff = 0;
1259 elf->e_flags = ELF_CORE_EFLAGS;
1260 elf->e_ehsize = sizeof(struct elfhdr);
1261 elf->e_phentsize = sizeof(struct elf_phdr);
1262 elf->e_phnum = segs;
1263 elf->e_shentsize = 0;
1264 elf->e_shnum = 0;
1265 elf->e_shstrndx = 0;
1266 return;
1269 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, off_t offset)
1271 phdr->p_type = PT_NOTE;
1272 phdr->p_offset = offset;
1273 phdr->p_vaddr = 0;
1274 phdr->p_paddr = 0;
1275 phdr->p_filesz = sz;
1276 phdr->p_memsz = 0;
1277 phdr->p_flags = 0;
1278 phdr->p_align = 0;
1279 return;
1282 static void fill_note(struct memelfnote *note, const char *name, int type,
1283 unsigned int sz, void *data)
1285 note->name = name;
1286 note->type = type;
1287 note->datasz = sz;
1288 note->data = data;
1289 return;
1292 /*
1293 * fill up all the fields in prstatus from the given task struct, except
1294 * registers which need to be filled up separately.
1295 */
1296 static void fill_prstatus(struct elf_prstatus *prstatus,
1297 struct task_struct *p, long signr)
1299 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1300 prstatus->pr_sigpend = p->pending.signal.sig[0];
1301 prstatus->pr_sighold = p->blocked.sig[0];
1302 prstatus->pr_pid = p->pid;
1303 prstatus->pr_ppid = p->parent->pid;
1304 prstatus->pr_pgrp = process_group(p);
1305 prstatus->pr_sid = p->signal->session;
1306 if (thread_group_leader(p)) {
1307 /*
1308 * This is the record for the group leader. Add in the
1309 * cumulative times of previous dead threads. This total
1310 * won't include the time of each live thread whose state
1311 * is included in the core dump. The final total reported
1312 * to our parent process when it calls wait4 will include
1313 * those sums as well as the little bit more time it takes
1314 * this and each other thread to finish dying after the
1315 * core dump synchronization phase.
1316 */
1317 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1318 &prstatus->pr_utime);
1319 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1320 &prstatus->pr_stime);
1321 } else {
1322 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1323 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1325 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1326 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1329 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1330 struct mm_struct *mm)
1332 unsigned int i, len;
1334 /* first copy the parameters from user space */
1335 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1337 len = mm->arg_end - mm->arg_start;
1338 if (len >= ELF_PRARGSZ)
1339 len = ELF_PRARGSZ-1;
1340 if (copy_from_user(&psinfo->pr_psargs,
1341 (const char __user *)mm->arg_start, len))
1342 return -EFAULT;
1343 for(i = 0; i < len; i++)
1344 if (psinfo->pr_psargs[i] == 0)
1345 psinfo->pr_psargs[i] = ' ';
1346 psinfo->pr_psargs[len] = 0;
1348 psinfo->pr_pid = p->pid;
1349 psinfo->pr_ppid = p->parent->pid;
1350 psinfo->pr_pgrp = process_group(p);
1351 psinfo->pr_sid = p->signal->session;
1353 i = p->state ? ffz(~p->state) + 1 : 0;
1354 psinfo->pr_state = i;
1355 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1356 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1357 psinfo->pr_nice = task_nice(p);
1358 psinfo->pr_flag = p->flags;
1359 SET_UID(psinfo->pr_uid, p->uid);
1360 SET_GID(psinfo->pr_gid, p->gid);
1361 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1363 return 0;
1366 /* Here is the structure in which status of each thread is captured. */
1367 struct elf_thread_status
1369 struct list_head list;
1370 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1371 elf_fpregset_t fpu; /* NT_PRFPREG */
1372 struct task_struct *thread;
1373 #ifdef ELF_CORE_COPY_XFPREGS
1374 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1375 #endif
1376 struct memelfnote notes[3];
1377 int num_notes;
1378 };
1380 /*
1381 * In order to add the specific thread information for the elf file format,
1382 * we need to keep a linked list of every threads pr_status and then create
1383 * a single section for them in the final core file.
1384 */
1385 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1387 int sz = 0;
1388 struct task_struct *p = t->thread;
1389 t->num_notes = 0;
1391 fill_prstatus(&t->prstatus, p, signr);
1392 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1394 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1395 &(t->prstatus));
1396 t->num_notes++;
1397 sz += notesize(&t->notes[0]);
1399 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1400 &t->fpu))) {
1401 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1402 &(t->fpu));
1403 t->num_notes++;
1404 sz += notesize(&t->notes[1]);
1407 #ifdef ELF_CORE_COPY_XFPREGS
1408 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1409 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1410 &t->xfpu);
1411 t->num_notes++;
1412 sz += notesize(&t->notes[2]);
1414 #endif
1415 return sz;
1418 /*
1419 * Actual dumper
1421 * This is a two-pass process; first we find the offsets of the bits,
1422 * and then they are actually written out. If we run out of core limit
1423 * we just truncate.
1424 */
1425 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
1427 #define NUM_NOTES 6
1428 int has_dumped = 0;
1429 mm_segment_t fs;
1430 int segs;
1431 size_t size = 0;
1432 int i;
1433 struct vm_area_struct *vma;
1434 struct elfhdr *elf = NULL;
1435 off_t offset = 0, dataoff;
1436 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1437 int numnote;
1438 struct memelfnote *notes = NULL;
1439 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1440 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1441 struct task_struct *g, *p;
1442 LIST_HEAD(thread_list);
1443 struct list_head *t;
1444 elf_fpregset_t *fpu = NULL;
1445 #ifdef ELF_CORE_COPY_XFPREGS
1446 elf_fpxregset_t *xfpu = NULL;
1447 #endif
1448 int thread_status_size = 0;
1449 elf_addr_t *auxv;
1451 /*
1452 * We no longer stop all VM operations.
1454 * This is because those proceses that could possibly change map_count
1455 * or the mmap / vma pages are now blocked in do_exit on current
1456 * finishing this core dump.
1458 * Only ptrace can touch these memory addresses, but it doesn't change
1459 * the map_count or the pages allocated. So no possibility of crashing
1460 * exists while dumping the mm->vm_next areas to the core file.
1461 */
1463 /* alloc memory for large data structures: too large to be on stack */
1464 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1465 if (!elf)
1466 goto cleanup;
1467 prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
1468 if (!prstatus)
1469 goto cleanup;
1470 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1471 if (!psinfo)
1472 goto cleanup;
1473 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1474 if (!notes)
1475 goto cleanup;
1476 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1477 if (!fpu)
1478 goto cleanup;
1479 #ifdef ELF_CORE_COPY_XFPREGS
1480 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1481 if (!xfpu)
1482 goto cleanup;
1483 #endif
1485 if (signr) {
1486 struct elf_thread_status *tmp;
1487 read_lock(&tasklist_lock);
1488 do_each_thread(g,p)
1489 if (current->mm == p->mm && current != p) {
1490 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1491 if (!tmp) {
1492 read_unlock(&tasklist_lock);
1493 goto cleanup;
1495 INIT_LIST_HEAD(&tmp->list);
1496 tmp->thread = p;
1497 list_add(&tmp->list, &thread_list);
1499 while_each_thread(g,p);
1500 read_unlock(&tasklist_lock);
1501 list_for_each(t, &thread_list) {
1502 struct elf_thread_status *tmp;
1503 int sz;
1505 tmp = list_entry(t, struct elf_thread_status, list);
1506 sz = elf_dump_thread_status(signr, tmp);
1507 thread_status_size += sz;
1510 /* now collect the dump for the current */
1511 memset(prstatus, 0, sizeof(*prstatus));
1512 fill_prstatus(prstatus, current, signr);
1513 elf_core_copy_regs(&prstatus->pr_reg, regs);
1515 segs = current->mm->map_count;
1516 #ifdef ELF_CORE_EXTRA_PHDRS
1517 segs += ELF_CORE_EXTRA_PHDRS;
1518 #endif
1520 /* Set up header */
1521 fill_elf_header(elf, segs + 1); /* including notes section */
1523 has_dumped = 1;
1524 current->flags |= PF_DUMPCORE;
1526 /*
1527 * Set up the notes in similar form to SVR4 core dumps made
1528 * with info from their /proc.
1529 */
1531 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1532 fill_psinfo(psinfo, current->group_leader, current->mm);
1533 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1535 numnote = 2;
1537 auxv = (elf_addr_t *)current->mm->saved_auxv;
1539 i = 0;
1540 do
1541 i += 2;
1542 while (auxv[i - 2] != AT_NULL);
1543 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1544 i * sizeof(elf_addr_t), auxv);
1546 /* Try to dump the FPU. */
1547 if ((prstatus->pr_fpvalid =
1548 elf_core_copy_task_fpregs(current, regs, fpu)))
1549 fill_note(notes + numnote++,
1550 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1551 #ifdef ELF_CORE_COPY_XFPREGS
1552 if (elf_core_copy_task_xfpregs(current, xfpu))
1553 fill_note(notes + numnote++,
1554 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1555 #endif
1557 fs = get_fs();
1558 set_fs(KERNEL_DS);
1560 DUMP_WRITE(elf, sizeof(*elf));
1561 offset += sizeof(*elf); /* Elf header */
1562 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */
1564 /* Write notes phdr entry */
1566 struct elf_phdr phdr;
1567 int sz = 0;
1569 for (i = 0; i < numnote; i++)
1570 sz += notesize(notes + i);
1572 sz += thread_status_size;
1574 fill_elf_note_phdr(&phdr, sz, offset);
1575 offset += sz;
1576 DUMP_WRITE(&phdr, sizeof(phdr));
1579 /* Page-align dumped data */
1580 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1582 /* Write program headers for segments dump */
1583 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1584 struct elf_phdr phdr;
1585 size_t sz;
1587 sz = vma->vm_end - vma->vm_start;
1589 phdr.p_type = PT_LOAD;
1590 phdr.p_offset = offset;
1591 phdr.p_vaddr = vma->vm_start;
1592 phdr.p_paddr = 0;
1593 phdr.p_filesz = maydump(vma) ? sz : 0;
1594 phdr.p_memsz = sz;
1595 offset += phdr.p_filesz;
1596 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1597 if (vma->vm_flags & VM_WRITE)
1598 phdr.p_flags |= PF_W;
1599 if (vma->vm_flags & VM_EXEC)
1600 phdr.p_flags |= PF_X;
1601 phdr.p_align = ELF_EXEC_PAGESIZE;
1603 DUMP_WRITE(&phdr, sizeof(phdr));
1606 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1607 ELF_CORE_WRITE_EXTRA_PHDRS;
1608 #endif
1610 /* write out the notes section */
1611 for (i = 0; i < numnote; i++)
1612 if (!writenote(notes + i, file))
1613 goto end_coredump;
1615 /* write out the thread status notes section */
1616 list_for_each(t, &thread_list) {
1617 struct elf_thread_status *tmp =
1618 list_entry(t, struct elf_thread_status, list);
1620 for (i = 0; i < tmp->num_notes; i++)
1621 if (!writenote(&tmp->notes[i], file))
1622 goto end_coredump;
1625 DUMP_SEEK(dataoff);
1627 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1628 unsigned long addr;
1630 if (!maydump(vma))
1631 continue;
1633 for (addr = vma->vm_start;
1634 addr < vma->vm_end;
1635 addr += PAGE_SIZE) {
1636 struct page *page;
1637 struct vm_area_struct *vma;
1639 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1640 &page, &vma) <= 0) {
1641 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1642 } else {
1643 if (page == ZERO_PAGE(addr)) {
1644 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1645 } else {
1646 void *kaddr;
1647 flush_cache_page(vma, addr,
1648 page_to_pfn(page));
1649 kaddr = kmap(page);
1650 if ((size += PAGE_SIZE) > limit ||
1651 !dump_write(file, kaddr,
1652 PAGE_SIZE)) {
1653 kunmap(page);
1654 page_cache_release(page);
1655 goto end_coredump;
1657 kunmap(page);
1659 page_cache_release(page);
1664 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1665 ELF_CORE_WRITE_EXTRA_DATA;
1666 #endif
1668 if ((off_t)file->f_pos != offset) {
1669 /* Sanity check */
1670 printk(KERN_WARNING
1671 "elf_core_dump: file->f_pos (%ld) != offset (%ld)\n",
1672 (off_t)file->f_pos, offset);
1675 end_coredump:
1676 set_fs(fs);
1678 cleanup:
1679 while (!list_empty(&thread_list)) {
1680 struct list_head *tmp = thread_list.next;
1681 list_del(tmp);
1682 kfree(list_entry(tmp, struct elf_thread_status, list));
1685 kfree(elf);
1686 kfree(prstatus);
1687 kfree(psinfo);
1688 kfree(notes);
1689 kfree(fpu);
1690 #ifdef ELF_CORE_COPY_XFPREGS
1691 kfree(xfpu);
1692 #endif
1693 return has_dumped;
1694 #undef NUM_NOTES
1697 #endif /* USE_ELF_CORE_DUMP */
1699 static int __init init_elf_binfmt(void)
1701 return register_binfmt(&elf_format);
1704 static void __exit exit_elf_binfmt(void)
1706 /* Remove the COFF and ELF loaders. */
1707 unregister_binfmt(&elf_format);
1710 core_initcall(init_elf_binfmt);
1711 module_exit(exit_elf_binfmt);
1712 MODULE_LICENSE("GPL");