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[PATCH] ext4 balloc: say rb_entry not list_entry
[firewire-audio.git] / fs / binfmt_elf.c
blob14ea630a857c62779e6b0b42df96c6f66f6fcc3f
1 /*
2 * linux/fs/binfmt_elf.c
3 *
4 * These are the functions used to load ELF format executables as used
5 * on SVr4 machines. Information on the format may be found in the book
6 * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
7 * Tools".
8 *
9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
10 */
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/fs.h>
15 #include <linux/stat.h>
16 #include <linux/time.h>
17 #include <linux/mm.h>
18 #include <linux/mman.h>
19 #include <linux/a.out.h>
20 #include <linux/errno.h>
21 #include <linux/signal.h>
22 #include <linux/binfmts.h>
23 #include <linux/string.h>
24 #include <linux/file.h>
25 #include <linux/fcntl.h>
26 #include <linux/ptrace.h>
27 #include <linux/slab.h>
28 #include <linux/shm.h>
29 #include <linux/personality.h>
30 #include <linux/elfcore.h>
31 #include <linux/init.h>
32 #include <linux/highuid.h>
33 #include <linux/smp.h>
34 #include <linux/smp_lock.h>
35 #include <linux/compiler.h>
36 #include <linux/highmem.h>
37 #include <linux/pagemap.h>
38 #include <linux/security.h>
39 #include <linux/syscalls.h>
40 #include <linux/random.h>
41 #include <linux/elf.h>
42 #include <asm/uaccess.h>
43 #include <asm/param.h>
44 #include <asm/page.h>
45
46 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
47 static int load_elf_library(struct file *);
48 static unsigned long elf_map (struct file *, unsigned long, struct elf_phdr *, int, int);
49
50 /*
51 * If we don't support core dumping, then supply a NULL so we
52 * don't even try.
53 */
54 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
55 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file);
56 #else
57 #define elf_core_dump NULL
58 #endif
59
60 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
61 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
62 #else
63 #define ELF_MIN_ALIGN PAGE_SIZE
64 #endif
65
66 #ifndef ELF_CORE_EFLAGS
67 #define ELF_CORE_EFLAGS 0
68 #endif
69
70 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
71 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
72 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
73
74 static struct linux_binfmt elf_format = {
75 .module = THIS_MODULE,
76 .load_binary = load_elf_binary,
77 .load_shlib = load_elf_library,
78 .core_dump = elf_core_dump,
79 .min_coredump = ELF_EXEC_PAGESIZE
80 };
81
82 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
83
84 static int set_brk(unsigned long start, unsigned long end)
85 {
86 start = ELF_PAGEALIGN(start);
87 end = ELF_PAGEALIGN(end);
88 if (end > start) {
89 unsigned long addr;
90 down_write(&current->mm->mmap_sem);
91 addr = do_brk(start, end - start);
92 up_write(&current->mm->mmap_sem);
93 if (BAD_ADDR(addr))
94 return addr;
95 }
96 current->mm->start_brk = current->mm->brk = end;
97 return 0;
98 }
99
100 /* We need to explicitly zero any fractional pages
101 after the data section (i.e. bss). This would
102 contain the junk from the file that should not
103 be in memory
104 */
105 static int padzero(unsigned long elf_bss)
106 {
107 unsigned long nbyte;
108
109 nbyte = ELF_PAGEOFFSET(elf_bss);
110 if (nbyte) {
111 nbyte = ELF_MIN_ALIGN - nbyte;
112 if (clear_user((void __user *) elf_bss, nbyte))
113 return -EFAULT;
114 }
115 return 0;
116 }
117
118 /* Let's use some macros to make this stack manipulation a litle clearer */
119 #ifdef CONFIG_STACK_GROWSUP
120 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
121 #define STACK_ROUND(sp, items) \
122 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
123 #define STACK_ALLOC(sp, len) ({ \
124 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
125 old_sp; })
126 #else
127 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
128 #define STACK_ROUND(sp, items) \
129 (((unsigned long) (sp - items)) &~ 15UL)
130 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
131 #endif
132
133 static int
134 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
135 int interp_aout, unsigned long load_addr,
136 unsigned long interp_load_addr)
137 {
138 unsigned long p = bprm->p;
139 int argc = bprm->argc;
140 int envc = bprm->envc;
141 elf_addr_t __user *argv;
142 elf_addr_t __user *envp;
143 elf_addr_t __user *sp;
144 elf_addr_t __user *u_platform;
145 const char *k_platform = ELF_PLATFORM;
146 int items;
147 elf_addr_t *elf_info;
148 int ei_index = 0;
149 struct task_struct *tsk = current;
150
151 /*
152 * If this architecture has a platform capability string, copy it
153 * to userspace. In some cases (Sparc), this info is impossible
154 * for userspace to get any other way, in others (i386) it is
155 * merely difficult.
156 */
157 u_platform = NULL;
158 if (k_platform) {
159 size_t len = strlen(k_platform) + 1;
160
161 /*
162 * In some cases (e.g. Hyper-Threading), we want to avoid L1
163 * evictions by the processes running on the same package. One
164 * thing we can do is to shuffle the initial stack for them.
165 */
166
167 p = arch_align_stack(p);
168
169 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
170 if (__copy_to_user(u_platform, k_platform, len))
171 return -EFAULT;
172 }
173
174 /* Create the ELF interpreter info */
175 elf_info = (elf_addr_t *)current->mm->saved_auxv;
176 #define NEW_AUX_ENT(id, val) \
177 do { \
178 elf_info[ei_index++] = id; \
179 elf_info[ei_index++] = val; \
180 } while (0)
181
182 #ifdef ARCH_DLINFO
183 /*
184 * ARCH_DLINFO must come first so PPC can do its special alignment of
185 * AUXV.
186 */
187 ARCH_DLINFO;
188 #endif
189 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
190 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
191 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
192 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
193 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
194 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
195 NEW_AUX_ENT(AT_BASE, interp_load_addr);
196 NEW_AUX_ENT(AT_FLAGS, 0);
197 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
198 NEW_AUX_ENT(AT_UID, tsk->uid);
199 NEW_AUX_ENT(AT_EUID, tsk->euid);
200 NEW_AUX_ENT(AT_GID, tsk->gid);
201 NEW_AUX_ENT(AT_EGID, tsk->egid);
202 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
203 if (k_platform) {
204 NEW_AUX_ENT(AT_PLATFORM,
205 (elf_addr_t)(unsigned long)u_platform);
206 }
207 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
208 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
209 }
210 #undef NEW_AUX_ENT
211 /* AT_NULL is zero; clear the rest too */
212 memset(&elf_info[ei_index], 0,
213 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
214
215 /* And advance past the AT_NULL entry. */
216 ei_index += 2;
217
218 sp = STACK_ADD(p, ei_index);
219
220 items = (argc + 1) + (envc + 1);
221 if (interp_aout) {
222 items += 3; /* a.out interpreters require argv & envp too */
223 } else {
224 items += 1; /* ELF interpreters only put argc on the stack */
225 }
226 bprm->p = STACK_ROUND(sp, items);
227
228 /* Point sp at the lowest address on the stack */
229 #ifdef CONFIG_STACK_GROWSUP
230 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
231 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
232 #else
233 sp = (elf_addr_t __user *)bprm->p;
234 #endif
235
236 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
237 if (__put_user(argc, sp++))
238 return -EFAULT;
239 if (interp_aout) {
240 argv = sp + 2;
241 envp = argv + argc + 1;
242 if (__put_user((elf_addr_t)(unsigned long)argv, sp++) ||
243 __put_user((elf_addr_t)(unsigned long)envp, sp++))
244 return -EFAULT;
245 } else {
246 argv = sp;
247 envp = argv + argc + 1;
248 }
249
250 /* Populate argv and envp */
251 p = current->mm->arg_end = current->mm->arg_start;
252 while (argc-- > 0) {
253 size_t len;
254 if (__put_user((elf_addr_t)p, argv++))
255 return -EFAULT;
256 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
257 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
258 return 0;
259 p += len;
260 }
261 if (__put_user(0, argv))
262 return -EFAULT;
263 current->mm->arg_end = current->mm->env_start = p;
264 while (envc-- > 0) {
265 size_t len;
266 if (__put_user((elf_addr_t)p, envp++))
267 return -EFAULT;
268 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
269 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
270 return 0;
271 p += len;
272 }
273 if (__put_user(0, envp))
274 return -EFAULT;
275 current->mm->env_end = p;
276
277 /* Put the elf_info on the stack in the right place. */
278 sp = (elf_addr_t __user *)envp + 1;
279 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
280 return -EFAULT;
281 return 0;
282 }
283
284 #ifndef elf_map
285
286 static unsigned long elf_map(struct file *filep, unsigned long addr,
287 struct elf_phdr *eppnt, int prot, int type)
288 {
289 unsigned long map_addr;
290 unsigned long pageoffset = ELF_PAGEOFFSET(eppnt->p_vaddr);
291
292 down_write(&current->mm->mmap_sem);
293 /* mmap() will return -EINVAL if given a zero size, but a
294 * segment with zero filesize is perfectly valid */
295 if (eppnt->p_filesz + pageoffset)
296 map_addr = do_mmap(filep, ELF_PAGESTART(addr),
297 eppnt->p_filesz + pageoffset, prot, type,
298 eppnt->p_offset - pageoffset);
299 else
300 map_addr = ELF_PAGESTART(addr);
301 up_write(&current->mm->mmap_sem);
302 return(map_addr);
303 }
304
305 #endif /* !elf_map */
306
307 /* This is much more generalized than the library routine read function,
308 so we keep this separate. Technically the library read function
309 is only provided so that we can read a.out libraries that have
310 an ELF header */
311
312 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
313 struct file *interpreter, unsigned long *interp_load_addr)
314 {
315 struct elf_phdr *elf_phdata;
316 struct elf_phdr *eppnt;
317 unsigned long load_addr = 0;
318 int load_addr_set = 0;
319 unsigned long last_bss = 0, elf_bss = 0;
320 unsigned long error = ~0UL;
321 int retval, i, size;
322
323 /* First of all, some simple consistency checks */
324 if (interp_elf_ex->e_type != ET_EXEC &&
325 interp_elf_ex->e_type != ET_DYN)
326 goto out;
327 if (!elf_check_arch(interp_elf_ex))
328 goto out;
329 if (!interpreter->f_op || !interpreter->f_op->mmap)
330 goto out;
331
332 /*
333 * If the size of this structure has changed, then punt, since
334 * we will be doing the wrong thing.
335 */
336 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
337 goto out;
338 if (interp_elf_ex->e_phnum < 1 ||
339 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
340 goto out;
341
342 /* Now read in all of the header information */
343 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
344 if (size > ELF_MIN_ALIGN)
345 goto out;
346 elf_phdata = kmalloc(size, GFP_KERNEL);
347 if (!elf_phdata)
348 goto out;
349
350 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
351 (char *)elf_phdata,size);
352 error = -EIO;
353 if (retval != size) {
354 if (retval < 0)
355 error = retval;
356 goto out_close;
357 }
358
359 eppnt = elf_phdata;
360 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
361 if (eppnt->p_type == PT_LOAD) {
362 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
363 int elf_prot = 0;
364 unsigned long vaddr = 0;
365 unsigned long k, map_addr;
366
367 if (eppnt->p_flags & PF_R)
368 elf_prot = PROT_READ;
369 if (eppnt->p_flags & PF_W)
370 elf_prot |= PROT_WRITE;
371 if (eppnt->p_flags & PF_X)
372 elf_prot |= PROT_EXEC;
373 vaddr = eppnt->p_vaddr;
374 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
375 elf_type |= MAP_FIXED;
376
377 map_addr = elf_map(interpreter, load_addr + vaddr,
378 eppnt, elf_prot, elf_type);
379 error = map_addr;
380 if (BAD_ADDR(map_addr))
381 goto out_close;
382
383 if (!load_addr_set &&
384 interp_elf_ex->e_type == ET_DYN) {
385 load_addr = map_addr - ELF_PAGESTART(vaddr);
386 load_addr_set = 1;
387 }
388
389 /*
390 * Check to see if the section's size will overflow the
391 * allowed task size. Note that p_filesz must always be
392 * <= p_memsize so it's only necessary to check p_memsz.
393 */
394 k = load_addr + eppnt->p_vaddr;
395 if (BAD_ADDR(k) ||
396 eppnt->p_filesz > eppnt->p_memsz ||
397 eppnt->p_memsz > TASK_SIZE ||
398 TASK_SIZE - eppnt->p_memsz < k) {
399 error = -ENOMEM;
400 goto out_close;
401 }
402
403 /*
404 * Find the end of the file mapping for this phdr, and
405 * keep track of the largest address we see for this.
406 */
407 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
408 if (k > elf_bss)
409 elf_bss = k;
410
411 /*
412 * Do the same thing for the memory mapping - between
413 * elf_bss and last_bss is the bss section.
414 */
415 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
416 if (k > last_bss)
417 last_bss = k;
418 }
419 }
420
421 /*
422 * Now fill out the bss section. First pad the last page up
423 * to the page boundary, and then perform a mmap to make sure
424 * that there are zero-mapped pages up to and including the
425 * last bss page.
426 */
427 if (padzero(elf_bss)) {
428 error = -EFAULT;
429 goto out_close;
430 }
431
432 /* What we have mapped so far */
433 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
434
435 /* Map the last of the bss segment */
436 if (last_bss > elf_bss) {
437 down_write(&current->mm->mmap_sem);
438 error = do_brk(elf_bss, last_bss - elf_bss);
439 up_write(&current->mm->mmap_sem);
440 if (BAD_ADDR(error))
441 goto out_close;
442 }
443
444 *interp_load_addr = load_addr;
445 error = ((unsigned long)interp_elf_ex->e_entry) + load_addr;
446
447 out_close:
448 kfree(elf_phdata);
449 out:
450 return error;
451 }
452
453 static unsigned long load_aout_interp(struct exec *interp_ex,
454 struct file *interpreter)
455 {
456 unsigned long text_data, elf_entry = ~0UL;
457 char __user * addr;
458 loff_t offset;
459
460 current->mm->end_code = interp_ex->a_text;
461 text_data = interp_ex->a_text + interp_ex->a_data;
462 current->mm->end_data = text_data;
463 current->mm->brk = interp_ex->a_bss + text_data;
464
465 switch (N_MAGIC(*interp_ex)) {
466 case OMAGIC:
467 offset = 32;
468 addr = (char __user *)0;
469 break;
470 case ZMAGIC:
471 case QMAGIC:
472 offset = N_TXTOFF(*interp_ex);
473 addr = (char __user *)N_TXTADDR(*interp_ex);
474 break;
475 default:
476 goto out;
477 }
478
479 down_write(&current->mm->mmap_sem);
480 do_brk(0, text_data);
481 up_write(&current->mm->mmap_sem);
482 if (!interpreter->f_op || !interpreter->f_op->read)
483 goto out;
484 if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0)
485 goto out;
486 flush_icache_range((unsigned long)addr,
487 (unsigned long)addr + text_data);
488
489 down_write(&current->mm->mmap_sem);
490 do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
491 interp_ex->a_bss);
492 up_write(&current->mm->mmap_sem);
493 elf_entry = interp_ex->a_entry;
494
495 out:
496 return elf_entry;
497 }
498
499 /*
500 * These are the functions used to load ELF style executables and shared
501 * libraries. There is no binary dependent code anywhere else.
502 */
503
504 #define INTERPRETER_NONE 0
505 #define INTERPRETER_AOUT 1
506 #define INTERPRETER_ELF 2
507
508 #ifndef STACK_RND_MASK
509 #define STACK_RND_MASK 0x7ff /* with 4K pages 8MB of VA */
510 #endif
511
512 static unsigned long randomize_stack_top(unsigned long stack_top)
513 {
514 unsigned int random_variable = 0;
515
516 if ((current->flags & PF_RANDOMIZE) &&
517 !(current->personality & ADDR_NO_RANDOMIZE)) {
518 random_variable = get_random_int() & STACK_RND_MASK;
519 random_variable <<= PAGE_SHIFT;
520 }
521 #ifdef CONFIG_STACK_GROWSUP
522 return PAGE_ALIGN(stack_top) + random_variable;
523 #else
524 return PAGE_ALIGN(stack_top) - random_variable;
525 #endif
526 }
527
528 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
529 {
530 struct file *interpreter = NULL; /* to shut gcc up */
531 unsigned long load_addr = 0, load_bias = 0;
532 int load_addr_set = 0;
533 char * elf_interpreter = NULL;
534 unsigned int interpreter_type = INTERPRETER_NONE;
535 unsigned char ibcs2_interpreter = 0;
536 unsigned long error;
537 struct elf_phdr *elf_ppnt, *elf_phdata;
538 unsigned long elf_bss, elf_brk;
539 int elf_exec_fileno;
540 int retval, i;
541 unsigned int size;
542 unsigned long elf_entry, interp_load_addr = 0;
543 unsigned long start_code, end_code, start_data, end_data;
544 unsigned long reloc_func_desc = 0;
545 char passed_fileno[6];
546 struct files_struct *files;
547 int have_pt_gnu_stack, executable_stack = EXSTACK_DEFAULT;
548 unsigned long def_flags = 0;
549 struct {
550 struct elfhdr elf_ex;
551 struct elfhdr interp_elf_ex;
552 struct exec interp_ex;
553 } *loc;
554
555 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
556 if (!loc) {
557 retval = -ENOMEM;
558 goto out_ret;
559 }
560
561 /* Get the exec-header */
562 loc->elf_ex = *((struct elfhdr *)bprm->buf);
563
564 retval = -ENOEXEC;
565 /* First of all, some simple consistency checks */
566 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
567 goto out;
568
569 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
570 goto out;
571 if (!elf_check_arch(&loc->elf_ex))
572 goto out;
573 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
574 goto out;
575
576 /* Now read in all of the header information */
577 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
578 goto out;
579 if (loc->elf_ex.e_phnum < 1 ||
580 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
581 goto out;
582 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
583 retval = -ENOMEM;
584 elf_phdata = kmalloc(size, GFP_KERNEL);
585 if (!elf_phdata)
586 goto out;
587
588 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
589 (char *)elf_phdata, size);
590 if (retval != size) {
591 if (retval >= 0)
592 retval = -EIO;
593 goto out_free_ph;
594 }
595
596 files = current->files; /* Refcounted so ok */
597 retval = unshare_files();
598 if (retval < 0)
599 goto out_free_ph;
600 if (files == current->files) {
601 put_files_struct(files);
602 files = NULL;
603 }
604
605 /* exec will make our files private anyway, but for the a.out
606 loader stuff we need to do it earlier */
607 retval = get_unused_fd();
608 if (retval < 0)
609 goto out_free_fh;
610 get_file(bprm->file);
611 fd_install(elf_exec_fileno = retval, bprm->file);
612
613 elf_ppnt = elf_phdata;
614 elf_bss = 0;
615 elf_brk = 0;
616
617 start_code = ~0UL;
618 end_code = 0;
619 start_data = 0;
620 end_data = 0;
621
622 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
623 if (elf_ppnt->p_type == PT_INTERP) {
624 /* This is the program interpreter used for
625 * shared libraries - for now assume that this
626 * is an a.out format binary
627 */
628 retval = -ENOEXEC;
629 if (elf_ppnt->p_filesz > PATH_MAX ||
630 elf_ppnt->p_filesz < 2)
631 goto out_free_file;
632
633 retval = -ENOMEM;
634 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
635 GFP_KERNEL);
636 if (!elf_interpreter)
637 goto out_free_file;
638
639 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
640 elf_interpreter,
641 elf_ppnt->p_filesz);
642 if (retval != elf_ppnt->p_filesz) {
643 if (retval >= 0)
644 retval = -EIO;
645 goto out_free_interp;
646 }
647 /* make sure path is NULL terminated */
648 retval = -ENOEXEC;
649 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
650 goto out_free_interp;
651
652 /* If the program interpreter is one of these two,
653 * then assume an iBCS2 image. Otherwise assume
654 * a native linux image.
655 */
656 if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
657 strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0)
658 ibcs2_interpreter = 1;
659
660 /*
661 * The early SET_PERSONALITY here is so that the lookup
662 * for the interpreter happens in the namespace of the
663 * to-be-execed image. SET_PERSONALITY can select an
664 * alternate root.
665 *
666 * However, SET_PERSONALITY is NOT allowed to switch
667 * this task into the new images's memory mapping
668 * policy - that is, TASK_SIZE must still evaluate to
669 * that which is appropriate to the execing application.
670 * This is because exit_mmap() needs to have TASK_SIZE
671 * evaluate to the size of the old image.
672 *
673 * So if (say) a 64-bit application is execing a 32-bit
674 * application it is the architecture's responsibility
675 * to defer changing the value of TASK_SIZE until the
676 * switch really is going to happen - do this in
677 * flush_thread(). - akpm
678 */
679 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
680
681 interpreter = open_exec(elf_interpreter);
682 retval = PTR_ERR(interpreter);
683 if (IS_ERR(interpreter))
684 goto out_free_interp;
685 retval = kernel_read(interpreter, 0, bprm->buf,
686 BINPRM_BUF_SIZE);
687 if (retval != BINPRM_BUF_SIZE) {
688 if (retval >= 0)
689 retval = -EIO;
690 goto out_free_dentry;
691 }
692
693 /* Get the exec headers */
694 loc->interp_ex = *((struct exec *)bprm->buf);
695 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
696 break;
697 }
698 elf_ppnt++;
699 }
700
701 elf_ppnt = elf_phdata;
702 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
703 if (elf_ppnt->p_type == PT_GNU_STACK) {
704 if (elf_ppnt->p_flags & PF_X)
705 executable_stack = EXSTACK_ENABLE_X;
706 else
707 executable_stack = EXSTACK_DISABLE_X;
708 break;
709 }
710 have_pt_gnu_stack = (i < loc->elf_ex.e_phnum);
711
712 /* Some simple consistency checks for the interpreter */
713 if (elf_interpreter) {
714 interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
715
716 /* Now figure out which format our binary is */
717 if ((N_MAGIC(loc->interp_ex) != OMAGIC) &&
718 (N_MAGIC(loc->interp_ex) != ZMAGIC) &&
719 (N_MAGIC(loc->interp_ex) != QMAGIC))
720 interpreter_type = INTERPRETER_ELF;
721
722 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
723 interpreter_type &= ~INTERPRETER_ELF;
724
725 retval = -ELIBBAD;
726 if (!interpreter_type)
727 goto out_free_dentry;
728
729 /* Make sure only one type was selected */
730 if ((interpreter_type & INTERPRETER_ELF) &&
731 interpreter_type != INTERPRETER_ELF) {
732 // FIXME - ratelimit this before re-enabling
733 // printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n");
734 interpreter_type = INTERPRETER_ELF;
735 }
736 /* Verify the interpreter has a valid arch */
737 if ((interpreter_type == INTERPRETER_ELF) &&
738 !elf_check_arch(&loc->interp_elf_ex))
739 goto out_free_dentry;
740 } else {
741 /* Executables without an interpreter also need a personality */
742 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
743 }
744
745 /* OK, we are done with that, now set up the arg stuff,
746 and then start this sucker up */
747 if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) {
748 char *passed_p = passed_fileno;
749 sprintf(passed_fileno, "%d", elf_exec_fileno);
750
751 if (elf_interpreter) {
752 retval = copy_strings_kernel(1, &passed_p, bprm);
753 if (retval)
754 goto out_free_dentry;
755 bprm->argc++;
756 }
757 }
758
759 /* Flush all traces of the currently running executable */
760 retval = flush_old_exec(bprm);
761 if (retval)
762 goto out_free_dentry;
763
764 /* Discard our unneeded old files struct */
765 if (files) {
766 put_files_struct(files);
767 files = NULL;
768 }
769
770 /* OK, This is the point of no return */
771 current->mm->start_data = 0;
772 current->mm->end_data = 0;
773 current->mm->end_code = 0;
774 current->mm->mmap = NULL;
775 current->flags &= ~PF_FORKNOEXEC;
776 current->mm->def_flags = def_flags;
777
778 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
779 may depend on the personality. */
780 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
781 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
782 current->personality |= READ_IMPLIES_EXEC;
783
784 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
785 current->flags |= PF_RANDOMIZE;
786 arch_pick_mmap_layout(current->mm);
787
788 /* Do this so that we can load the interpreter, if need be. We will
789 change some of these later */
790 current->mm->free_area_cache = current->mm->mmap_base;
791 current->mm->cached_hole_size = 0;
792 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
793 executable_stack);
794 if (retval < 0) {
795 send_sig(SIGKILL, current, 0);
796 goto out_free_dentry;
797 }
798
799 current->mm->start_stack = bprm->p;
800
801 /* Now we do a little grungy work by mmaping the ELF image into
802 the correct location in memory. At this point, we assume that
803 the image should be loaded at fixed address, not at a variable
804 address. */
805 for(i = 0, elf_ppnt = elf_phdata;
806 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
807 int elf_prot = 0, elf_flags;
808 unsigned long k, vaddr;
809
810 if (elf_ppnt->p_type != PT_LOAD)
811 continue;
812
813 if (unlikely (elf_brk > elf_bss)) {
814 unsigned long nbyte;
815
816 /* There was a PT_LOAD segment with p_memsz > p_filesz
817 before this one. Map anonymous pages, if needed,
818 and clear the area. */
819 retval = set_brk (elf_bss + load_bias,
820 elf_brk + load_bias);
821 if (retval) {
822 send_sig(SIGKILL, current, 0);
823 goto out_free_dentry;
824 }
825 nbyte = ELF_PAGEOFFSET(elf_bss);
826 if (nbyte) {
827 nbyte = ELF_MIN_ALIGN - nbyte;
828 if (nbyte > elf_brk - elf_bss)
829 nbyte = elf_brk - elf_bss;
830 if (clear_user((void __user *)elf_bss +
831 load_bias, nbyte)) {
832 /*
833 * This bss-zeroing can fail if the ELF
834 * file specifies odd protections. So
835 * we don't check the return value
836 */
837 }
838 }
839 }
840
841 if (elf_ppnt->p_flags & PF_R)
842 elf_prot |= PROT_READ;
843 if (elf_ppnt->p_flags & PF_W)
844 elf_prot |= PROT_WRITE;
845 if (elf_ppnt->p_flags & PF_X)
846 elf_prot |= PROT_EXEC;
847
848 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
849
850 vaddr = elf_ppnt->p_vaddr;
851 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
852 elf_flags |= MAP_FIXED;
853 } else if (loc->elf_ex.e_type == ET_DYN) {
854 /* Try and get dynamic programs out of the way of the
855 * default mmap base, as well as whatever program they
856 * might try to exec. This is because the brk will
857 * follow the loader, and is not movable. */
858 if (current->flags & PF_RANDOMIZE)
859 load_bias = randomize_range(0x10000,
860 ELF_ET_DYN_BASE,
861 0);
862 else
863 load_bias = ELF_ET_DYN_BASE;
864 load_bias = ELF_PAGESTART(load_bias - vaddr);
865 }
866
867 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
868 elf_prot, elf_flags);
869 if (BAD_ADDR(error)) {
870 send_sig(SIGKILL, current, 0);
871 goto out_free_dentry;
872 }
873
874 if (!load_addr_set) {
875 load_addr_set = 1;
876 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
877 if (loc->elf_ex.e_type == ET_DYN) {
878 load_bias += error -
879 ELF_PAGESTART(load_bias + vaddr);
880 load_addr += load_bias;
881 reloc_func_desc = load_bias;
882 }
883 }
884 k = elf_ppnt->p_vaddr;
885 if (k < start_code)
886 start_code = k;
887 if (start_data < k)
888 start_data = k;
889
890 /*
891 * Check to see if the section's size will overflow the
892 * allowed task size. Note that p_filesz must always be
893 * <= p_memsz so it is only necessary to check p_memsz.
894 */
895 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
896 elf_ppnt->p_memsz > TASK_SIZE ||
897 TASK_SIZE - elf_ppnt->p_memsz < k) {
898 /* set_brk can never work. Avoid overflows. */
899 send_sig(SIGKILL, current, 0);
900 goto out_free_dentry;
901 }
902
903 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
904
905 if (k > elf_bss)
906 elf_bss = k;
907 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
908 end_code = k;
909 if (end_data < k)
910 end_data = k;
911 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
912 if (k > elf_brk)
913 elf_brk = k;
914 }
915
916 loc->elf_ex.e_entry += load_bias;
917 elf_bss += load_bias;
918 elf_brk += load_bias;
919 start_code += load_bias;
920 end_code += load_bias;
921 start_data += load_bias;
922 end_data += load_bias;
923
924 /* Calling set_brk effectively mmaps the pages that we need
925 * for the bss and break sections. We must do this before
926 * mapping in the interpreter, to make sure it doesn't wind
927 * up getting placed where the bss needs to go.
928 */
929 retval = set_brk(elf_bss, elf_brk);
930 if (retval) {
931 send_sig(SIGKILL, current, 0);
932 goto out_free_dentry;
933 }
934 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
935 send_sig(SIGSEGV, current, 0);
936 retval = -EFAULT; /* Nobody gets to see this, but.. */
937 goto out_free_dentry;
938 }
939
940 if (elf_interpreter) {
941 if (interpreter_type == INTERPRETER_AOUT)
942 elf_entry = load_aout_interp(&loc->interp_ex,
943 interpreter);
944 else
945 elf_entry = load_elf_interp(&loc->interp_elf_ex,
946 interpreter,
947 &interp_load_addr);
948 if (BAD_ADDR(elf_entry)) {
949 force_sig(SIGSEGV, current);
950 retval = IS_ERR((void *)elf_entry) ?
951 (int)elf_entry : -EINVAL;
952 goto out_free_dentry;
953 }
954 reloc_func_desc = interp_load_addr;
955
956 allow_write_access(interpreter);
957 fput(interpreter);
958 kfree(elf_interpreter);
959 } else {
960 elf_entry = loc->elf_ex.e_entry;
961 if (BAD_ADDR(elf_entry)) {
962 force_sig(SIGSEGV, current);
963 retval = -EINVAL;
964 goto out_free_dentry;
965 }
966 }
967
968 kfree(elf_phdata);
969
970 if (interpreter_type != INTERPRETER_AOUT)
971 sys_close(elf_exec_fileno);
972
973 set_binfmt(&elf_format);
974
975 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
976 retval = arch_setup_additional_pages(bprm, executable_stack);
977 if (retval < 0) {
978 send_sig(SIGKILL, current, 0);
979 goto out;
980 }
981 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
982
983 compute_creds(bprm);
984 current->flags &= ~PF_FORKNOEXEC;
985 create_elf_tables(bprm, &loc->elf_ex,
986 (interpreter_type == INTERPRETER_AOUT),
987 load_addr, interp_load_addr);
988 /* N.B. passed_fileno might not be initialized? */
989 if (interpreter_type == INTERPRETER_AOUT)
990 current->mm->arg_start += strlen(passed_fileno) + 1;
991 current->mm->end_code = end_code;
992 current->mm->start_code = start_code;
993 current->mm->start_data = start_data;
994 current->mm->end_data = end_data;
995 current->mm->start_stack = bprm->p;
996
997 if (current->personality & MMAP_PAGE_ZERO) {
998 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
999 and some applications "depend" upon this behavior.
1000 Since we do not have the power to recompile these, we
1001 emulate the SVr4 behavior. Sigh. */
1002 down_write(&current->mm->mmap_sem);
1003 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1004 MAP_FIXED | MAP_PRIVATE, 0);
1005 up_write(&current->mm->mmap_sem);
1006 }
1007
1008 #ifdef ELF_PLAT_INIT
1009 /*
1010 * The ABI may specify that certain registers be set up in special
1011 * ways (on i386 %edx is the address of a DT_FINI function, for
1012 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1013 * that the e_entry field is the address of the function descriptor
1014 * for the startup routine, rather than the address of the startup
1015 * routine itself. This macro performs whatever initialization to
1016 * the regs structure is required as well as any relocations to the
1017 * function descriptor entries when executing dynamically links apps.
1018 */
1019 ELF_PLAT_INIT(regs, reloc_func_desc);
1020 #endif
1021
1022 start_thread(regs, elf_entry, bprm->p);
1023 if (unlikely(current->ptrace & PT_PTRACED)) {
1024 if (current->ptrace & PT_TRACE_EXEC)
1025 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
1026 else
1027 send_sig(SIGTRAP, current, 0);
1028 }
1029 retval = 0;
1030 out:
1031 kfree(loc);
1032 out_ret:
1033 return retval;
1034
1035 /* error cleanup */
1036 out_free_dentry:
1037 allow_write_access(interpreter);
1038 if (interpreter)
1039 fput(interpreter);
1040 out_free_interp:
1041 kfree(elf_interpreter);
1042 out_free_file:
1043 sys_close(elf_exec_fileno);
1044 out_free_fh:
1045 if (files)
1046 reset_files_struct(current, files);
1047 out_free_ph:
1048 kfree(elf_phdata);
1049 goto out;
1050 }
1051
1052 /* This is really simpleminded and specialized - we are loading an
1053 a.out library that is given an ELF header. */
1054 static int load_elf_library(struct file *file)
1055 {
1056 struct elf_phdr *elf_phdata;
1057 struct elf_phdr *eppnt;
1058 unsigned long elf_bss, bss, len;
1059 int retval, error, i, j;
1060 struct elfhdr elf_ex;
1061
1062 error = -ENOEXEC;
1063 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1064 if (retval != sizeof(elf_ex))
1065 goto out;
1066
1067 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1068 goto out;
1069
1070 /* First of all, some simple consistency checks */
1071 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1072 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1073 goto out;
1074
1075 /* Now read in all of the header information */
1076
1077 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1078 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1079
1080 error = -ENOMEM;
1081 elf_phdata = kmalloc(j, GFP_KERNEL);
1082 if (!elf_phdata)
1083 goto out;
1084
1085 eppnt = elf_phdata;
1086 error = -ENOEXEC;
1087 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1088 if (retval != j)
1089 goto out_free_ph;
1090
1091 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1092 if ((eppnt + i)->p_type == PT_LOAD)
1093 j++;
1094 if (j != 1)
1095 goto out_free_ph;
1096
1097 while (eppnt->p_type != PT_LOAD)
1098 eppnt++;
1099
1100 /* Now use mmap to map the library into memory. */
1101 down_write(&current->mm->mmap_sem);
1102 error = do_mmap(file,
1103 ELF_PAGESTART(eppnt->p_vaddr),
1104 (eppnt->p_filesz +
1105 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1106 PROT_READ | PROT_WRITE | PROT_EXEC,
1107 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1108 (eppnt->p_offset -
1109 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1110 up_write(&current->mm->mmap_sem);
1111 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1112 goto out_free_ph;
1113
1114 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1115 if (padzero(elf_bss)) {
1116 error = -EFAULT;
1117 goto out_free_ph;
1118 }
1119
1120 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1121 ELF_MIN_ALIGN - 1);
1122 bss = eppnt->p_memsz + eppnt->p_vaddr;
1123 if (bss > len) {
1124 down_write(&current->mm->mmap_sem);
1125 do_brk(len, bss - len);
1126 up_write(&current->mm->mmap_sem);
1127 }
1128 error = 0;
1129
1130 out_free_ph:
1131 kfree(elf_phdata);
1132 out:
1133 return error;
1134 }
1135
1136 /*
1137 * Note that some platforms still use traditional core dumps and not
1138 * the ELF core dump. Each platform can select it as appropriate.
1139 */
1140 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1141
1142 /*
1143 * ELF core dumper
1144 *
1145 * Modelled on fs/exec.c:aout_core_dump()
1146 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1147 */
1148 /*
1149 * These are the only things you should do on a core-file: use only these
1150 * functions to write out all the necessary info.
1151 */
1152 static int dump_write(struct file *file, const void *addr, int nr)
1153 {
1154 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1155 }
1156
1157 static int dump_seek(struct file *file, loff_t off)
1158 {
1159 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1160 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1161 return 0;
1162 } else {
1163 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1164 if (!buf)
1165 return 0;
1166 while (off > 0) {
1167 unsigned long n = off;
1168 if (n > PAGE_SIZE)
1169 n = PAGE_SIZE;
1170 if (!dump_write(file, buf, n))
1171 return 0;
1172 off -= n;
1173 }
1174 free_page((unsigned long)buf);
1175 }
1176 return 1;
1177 }
1178
1179 /*
1180 * Decide whether a segment is worth dumping; default is yes to be
1181 * sure (missing info is worse than too much; etc).
1182 * Personally I'd include everything, and use the coredump limit...
1183 *
1184 * I think we should skip something. But I am not sure how. H.J.
1185 */
1186 static int maydump(struct vm_area_struct *vma)
1187 {
1188 /* Do not dump I/O mapped devices or special mappings */
1189 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1190 return 0;
1191
1192 /* Dump shared memory only if mapped from an anonymous file. */
1193 if (vma->vm_flags & VM_SHARED)
1194 return vma->vm_file->f_dentry->d_inode->i_nlink == 0;
1195
1196 /* If it hasn't been written to, don't write it out */
1197 if (!vma->anon_vma)
1198 return 0;
1199
1200 return 1;
1201 }
1202
1203 /* An ELF note in memory */
1204 struct memelfnote
1205 {
1206 const char *name;
1207 int type;
1208 unsigned int datasz;
1209 void *data;
1210 };
1211
1212 static int notesize(struct memelfnote *en)
1213 {
1214 int sz;
1215
1216 sz = sizeof(struct elf_note);
1217 sz += roundup(strlen(en->name) + 1, 4);
1218 sz += roundup(en->datasz, 4);
1219
1220 return sz;
1221 }
1222
1223 #define DUMP_WRITE(addr, nr, foffset) \
1224 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1225
1226 static int alignfile(struct file *file, loff_t *foffset)
1227 {
1228 static const char buf[4] = { 0, };
1229 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1230 return 1;
1231 }
1232
1233 static int writenote(struct memelfnote *men, struct file *file,
1234 loff_t *foffset)
1235 {
1236 struct elf_note en;
1237 en.n_namesz = strlen(men->name) + 1;
1238 en.n_descsz = men->datasz;
1239 en.n_type = men->type;
1240
1241 DUMP_WRITE(&en, sizeof(en), foffset);
1242 DUMP_WRITE(men->name, en.n_namesz, foffset);
1243 if (!alignfile(file, foffset))
1244 return 0;
1245 DUMP_WRITE(men->data, men->datasz, foffset);
1246 if (!alignfile(file, foffset))
1247 return 0;
1248
1249 return 1;
1250 }
1251 #undef DUMP_WRITE
1252
1253 #define DUMP_WRITE(addr, nr) \
1254 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1255 goto end_coredump;
1256 #define DUMP_SEEK(off) \
1257 if (!dump_seek(file, (off))) \
1258 goto end_coredump;
1259
1260 static void fill_elf_header(struct elfhdr *elf, int segs)
1261 {
1262 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1263 elf->e_ident[EI_CLASS] = ELF_CLASS;
1264 elf->e_ident[EI_DATA] = ELF_DATA;
1265 elf->e_ident[EI_VERSION] = EV_CURRENT;
1266 elf->e_ident[EI_OSABI] = ELF_OSABI;
1267 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1268
1269 elf->e_type = ET_CORE;
1270 elf->e_machine = ELF_ARCH;
1271 elf->e_version = EV_CURRENT;
1272 elf->e_entry = 0;
1273 elf->e_phoff = sizeof(struct elfhdr);
1274 elf->e_shoff = 0;
1275 elf->e_flags = ELF_CORE_EFLAGS;
1276 elf->e_ehsize = sizeof(struct elfhdr);
1277 elf->e_phentsize = sizeof(struct elf_phdr);
1278 elf->e_phnum = segs;
1279 elf->e_shentsize = 0;
1280 elf->e_shnum = 0;
1281 elf->e_shstrndx = 0;
1282 return;
1283 }
1284
1285 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1286 {
1287 phdr->p_type = PT_NOTE;
1288 phdr->p_offset = offset;
1289 phdr->p_vaddr = 0;
1290 phdr->p_paddr = 0;
1291 phdr->p_filesz = sz;
1292 phdr->p_memsz = 0;
1293 phdr->p_flags = 0;
1294 phdr->p_align = 0;
1295 return;
1296 }
1297
1298 static void fill_note(struct memelfnote *note, const char *name, int type,
1299 unsigned int sz, void *data)
1300 {
1301 note->name = name;
1302 note->type = type;
1303 note->datasz = sz;
1304 note->data = data;
1305 return;
1306 }
1307
1308 /*
1309 * fill up all the fields in prstatus from the given task struct, except
1310 * registers which need to be filled up separately.
1311 */
1312 static void fill_prstatus(struct elf_prstatus *prstatus,
1313 struct task_struct *p, long signr)
1314 {
1315 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1316 prstatus->pr_sigpend = p->pending.signal.sig[0];
1317 prstatus->pr_sighold = p->blocked.sig[0];
1318 prstatus->pr_pid = p->pid;
1319 prstatus->pr_ppid = p->parent->pid;
1320 prstatus->pr_pgrp = process_group(p);
1321 prstatus->pr_sid = p->signal->session;
1322 if (thread_group_leader(p)) {
1323 /*
1324 * This is the record for the group leader. Add in the
1325 * cumulative times of previous dead threads. This total
1326 * won't include the time of each live thread whose state
1327 * is included in the core dump. The final total reported
1328 * to our parent process when it calls wait4 will include
1329 * those sums as well as the little bit more time it takes
1330 * this and each other thread to finish dying after the
1331 * core dump synchronization phase.
1332 */
1333 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1334 &prstatus->pr_utime);
1335 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1336 &prstatus->pr_stime);
1337 } else {
1338 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1339 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1340 }
1341 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1342 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1343 }
1344
1345 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1346 struct mm_struct *mm)
1347 {
1348 unsigned int i, len;
1349
1350 /* first copy the parameters from user space */
1351 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1352
1353 len = mm->arg_end - mm->arg_start;
1354 if (len >= ELF_PRARGSZ)
1355 len = ELF_PRARGSZ-1;
1356 if (copy_from_user(&psinfo->pr_psargs,
1357 (const char __user *)mm->arg_start, len))
1358 return -EFAULT;
1359 for(i = 0; i < len; i++)
1360 if (psinfo->pr_psargs[i] == 0)
1361 psinfo->pr_psargs[i] = ' ';
1362 psinfo->pr_psargs[len] = 0;
1363
1364 psinfo->pr_pid = p->pid;
1365 psinfo->pr_ppid = p->parent->pid;
1366 psinfo->pr_pgrp = process_group(p);
1367 psinfo->pr_sid = p->signal->session;
1368
1369 i = p->state ? ffz(~p->state) + 1 : 0;
1370 psinfo->pr_state = i;
1371 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1372 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1373 psinfo->pr_nice = task_nice(p);
1374 psinfo->pr_flag = p->flags;
1375 SET_UID(psinfo->pr_uid, p->uid);
1376 SET_GID(psinfo->pr_gid, p->gid);
1377 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1378
1379 return 0;
1380 }
1381
1382 /* Here is the structure in which status of each thread is captured. */
1383 struct elf_thread_status
1384 {
1385 struct list_head list;
1386 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1387 elf_fpregset_t fpu; /* NT_PRFPREG */
1388 struct task_struct *thread;
1389 #ifdef ELF_CORE_COPY_XFPREGS
1390 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1391 #endif
1392 struct memelfnote notes[3];
1393 int num_notes;
1394 };
1395
1396 /*
1397 * In order to add the specific thread information for the elf file format,
1398 * we need to keep a linked list of every threads pr_status and then create
1399 * a single section for them in the final core file.
1400 */
1401 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1402 {
1403 int sz = 0;
1404 struct task_struct *p = t->thread;
1405 t->num_notes = 0;
1406
1407 fill_prstatus(&t->prstatus, p, signr);
1408 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1409
1410 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1411 &(t->prstatus));
1412 t->num_notes++;
1413 sz += notesize(&t->notes[0]);
1414
1415 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1416 &t->fpu))) {
1417 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1418 &(t->fpu));
1419 t->num_notes++;
1420 sz += notesize(&t->notes[1]);
1421 }
1422
1423 #ifdef ELF_CORE_COPY_XFPREGS
1424 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1425 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1426 &t->xfpu);
1427 t->num_notes++;
1428 sz += notesize(&t->notes[2]);
1429 }
1430 #endif
1431 return sz;
1432 }
1433
1434 /*
1435 * Actual dumper
1436 *
1437 * This is a two-pass process; first we find the offsets of the bits,
1438 * and then they are actually written out. If we run out of core limit
1439 * we just truncate.
1440 */
1441 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
1442 {
1443 #define NUM_NOTES 6
1444 int has_dumped = 0;
1445 mm_segment_t fs;
1446 int segs;
1447 size_t size = 0;
1448 int i;
1449 struct vm_area_struct *vma;
1450 struct elfhdr *elf = NULL;
1451 loff_t offset = 0, dataoff, foffset;
1452 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1453 int numnote;
1454 struct memelfnote *notes = NULL;
1455 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1456 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1457 struct task_struct *g, *p;
1458 LIST_HEAD(thread_list);
1459 struct list_head *t;
1460 elf_fpregset_t *fpu = NULL;
1461 #ifdef ELF_CORE_COPY_XFPREGS
1462 elf_fpxregset_t *xfpu = NULL;
1463 #endif
1464 int thread_status_size = 0;
1465 elf_addr_t *auxv;
1466
1467 /*
1468 * We no longer stop all VM operations.
1469 *
1470 * This is because those proceses that could possibly change map_count
1471 * or the mmap / vma pages are now blocked in do_exit on current
1472 * finishing this core dump.
1473 *
1474 * Only ptrace can touch these memory addresses, but it doesn't change
1475 * the map_count or the pages allocated. So no possibility of crashing
1476 * exists while dumping the mm->vm_next areas to the core file.
1477 */
1478
1479 /* alloc memory for large data structures: too large to be on stack */
1480 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1481 if (!elf)
1482 goto cleanup;
1483 prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
1484 if (!prstatus)
1485 goto cleanup;
1486 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1487 if (!psinfo)
1488 goto cleanup;
1489 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1490 if (!notes)
1491 goto cleanup;
1492 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1493 if (!fpu)
1494 goto cleanup;
1495 #ifdef ELF_CORE_COPY_XFPREGS
1496 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1497 if (!xfpu)
1498 goto cleanup;
1499 #endif
1500
1501 if (signr) {
1502 struct elf_thread_status *tmp;
1503 rcu_read_lock();
1504 do_each_thread(g,p)
1505 if (current->mm == p->mm && current != p) {
1506 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1507 if (!tmp) {
1508 rcu_read_unlock();
1509 goto cleanup;
1510 }
1511 tmp->thread = p;
1512 list_add(&tmp->list, &thread_list);
1513 }
1514 while_each_thread(g,p);
1515 rcu_read_unlock();
1516 list_for_each(t, &thread_list) {
1517 struct elf_thread_status *tmp;
1518 int sz;
1519
1520 tmp = list_entry(t, struct elf_thread_status, list);
1521 sz = elf_dump_thread_status(signr, tmp);
1522 thread_status_size += sz;
1523 }
1524 }
1525 /* now collect the dump for the current */
1526 memset(prstatus, 0, sizeof(*prstatus));
1527 fill_prstatus(prstatus, current, signr);
1528 elf_core_copy_regs(&prstatus->pr_reg, regs);
1529
1530 segs = current->mm->map_count;
1531 #ifdef ELF_CORE_EXTRA_PHDRS
1532 segs += ELF_CORE_EXTRA_PHDRS;
1533 #endif
1534
1535 /* Set up header */
1536 fill_elf_header(elf, segs + 1); /* including notes section */
1537
1538 has_dumped = 1;
1539 current->flags |= PF_DUMPCORE;
1540
1541 /*
1542 * Set up the notes in similar form to SVR4 core dumps made
1543 * with info from their /proc.
1544 */
1545
1546 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1547 fill_psinfo(psinfo, current->group_leader, current->mm);
1548 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1549
1550 numnote = 2;
1551
1552 auxv = (elf_addr_t *)current->mm->saved_auxv;
1553
1554 i = 0;
1555 do
1556 i += 2;
1557 while (auxv[i - 2] != AT_NULL);
1558 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1559 i * sizeof(elf_addr_t), auxv);
1560
1561 /* Try to dump the FPU. */
1562 if ((prstatus->pr_fpvalid =
1563 elf_core_copy_task_fpregs(current, regs, fpu)))
1564 fill_note(notes + numnote++,
1565 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1566 #ifdef ELF_CORE_COPY_XFPREGS
1567 if (elf_core_copy_task_xfpregs(current, xfpu))
1568 fill_note(notes + numnote++,
1569 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1570 #endif
1571
1572 fs = get_fs();
1573 set_fs(KERNEL_DS);
1574
1575 DUMP_WRITE(elf, sizeof(*elf));
1576 offset += sizeof(*elf); /* Elf header */
1577 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1578 foffset = offset;
1579
1580 /* Write notes phdr entry */
1581 {
1582 struct elf_phdr phdr;
1583 int sz = 0;
1584
1585 for (i = 0; i < numnote; i++)
1586 sz += notesize(notes + i);
1587
1588 sz += thread_status_size;
1589
1590 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1591 sz += ELF_CORE_EXTRA_NOTES_SIZE;
1592 #endif
1593
1594 fill_elf_note_phdr(&phdr, sz, offset);
1595 offset += sz;
1596 DUMP_WRITE(&phdr, sizeof(phdr));
1597 }
1598
1599 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1600
1601 /* Write program headers for segments dump */
1602 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1603 struct elf_phdr phdr;
1604 size_t sz;
1605
1606 sz = vma->vm_end - vma->vm_start;
1607
1608 phdr.p_type = PT_LOAD;
1609 phdr.p_offset = offset;
1610 phdr.p_vaddr = vma->vm_start;
1611 phdr.p_paddr = 0;
1612 phdr.p_filesz = maydump(vma) ? sz : 0;
1613 phdr.p_memsz = sz;
1614 offset += phdr.p_filesz;
1615 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1616 if (vma->vm_flags & VM_WRITE)
1617 phdr.p_flags |= PF_W;
1618 if (vma->vm_flags & VM_EXEC)
1619 phdr.p_flags |= PF_X;
1620 phdr.p_align = ELF_EXEC_PAGESIZE;
1621
1622 DUMP_WRITE(&phdr, sizeof(phdr));
1623 }
1624
1625 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1626 ELF_CORE_WRITE_EXTRA_PHDRS;
1627 #endif
1628
1629 /* write out the notes section */
1630 for (i = 0; i < numnote; i++)
1631 if (!writenote(notes + i, file, &foffset))
1632 goto end_coredump;
1633
1634 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1635 ELF_CORE_WRITE_EXTRA_NOTES;
1636 #endif
1637
1638 /* write out the thread status notes section */
1639 list_for_each(t, &thread_list) {
1640 struct elf_thread_status *tmp =
1641 list_entry(t, struct elf_thread_status, list);
1642
1643 for (i = 0; i < tmp->num_notes; i++)
1644 if (!writenote(&tmp->notes[i], file, &foffset))
1645 goto end_coredump;
1646 }
1647
1648 /* Align to page */
1649 DUMP_SEEK(dataoff - foffset);
1650
1651 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1652 unsigned long addr;
1653
1654 if (!maydump(vma))
1655 continue;
1656
1657 for (addr = vma->vm_start;
1658 addr < vma->vm_end;
1659 addr += PAGE_SIZE) {
1660 struct page *page;
1661 struct vm_area_struct *vma;
1662
1663 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1664 &page, &vma) <= 0) {
1665 DUMP_SEEK(PAGE_SIZE);
1666 } else {
1667 if (page == ZERO_PAGE(addr)) {
1668 DUMP_SEEK(PAGE_SIZE);
1669 } else {
1670 void *kaddr;
1671 flush_cache_page(vma, addr,
1672 page_to_pfn(page));
1673 kaddr = kmap(page);
1674 if ((size += PAGE_SIZE) > limit ||
1675 !dump_write(file, kaddr,
1676 PAGE_SIZE)) {
1677 kunmap(page);
1678 page_cache_release(page);
1679 goto end_coredump;
1680 }
1681 kunmap(page);
1682 }
1683 page_cache_release(page);
1684 }
1685 }
1686 }
1687
1688 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1689 ELF_CORE_WRITE_EXTRA_DATA;
1690 #endif
1691
1692 end_coredump:
1693 set_fs(fs);
1694
1695 cleanup:
1696 while (!list_empty(&thread_list)) {
1697 struct list_head *tmp = thread_list.next;
1698 list_del(tmp);
1699 kfree(list_entry(tmp, struct elf_thread_status, list));
1700 }
1701
1702 kfree(elf);
1703 kfree(prstatus);
1704 kfree(psinfo);
1705 kfree(notes);
1706 kfree(fpu);
1707 #ifdef ELF_CORE_COPY_XFPREGS
1708 kfree(xfpu);
1709 #endif
1710 return has_dumped;
1711 #undef NUM_NOTES
1712 }
1713
1714 #endif /* USE_ELF_CORE_DUMP */
1715
1716 static int __init init_elf_binfmt(void)
1717 {
1718 return register_binfmt(&elf_format);
1719 }
1720
1721 static void __exit exit_elf_binfmt(void)
1722 {
1723 /* Remove the COFF and ELF loaders. */
1724 unregister_binfmt(&elf_format);
1725 }
1726
1727 core_initcall(init_elf_binfmt);
1728 module_exit(exit_elf_binfmt);
1729 MODULE_LICENSE("GPL");
AMDTP streaming driver for the Linux FireWire stack (Juju)