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revert-mm-fix-blkdev-size-calculation-in-generic_write_checks
[linux-2.6/linux-trees-mm.git] / fs / binfmt_elf_fdpic.c
blob32649f2a16544502c8affe2d147ac89d1e02ae50
1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
2 *
3 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 * Derived from binfmt_elf.c
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
13 #include <linux/module.h>
14
15 #include <linux/fs.h>
16 #include <linux/stat.h>
17 #include <linux/sched.h>
18 #include <linux/mm.h>
19 #include <linux/mman.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/slab.h>
27 #include <linux/pagemap.h>
28 #include <linux/highmem.h>
29 #include <linux/highuid.h>
30 #include <linux/personality.h>
31 #include <linux/ptrace.h>
32 #include <linux/init.h>
33 #include <linux/elf.h>
34 #include <linux/elf-fdpic.h>
35 #include <linux/elfcore.h>
36
37 #include <asm/uaccess.h>
38 #include <asm/param.h>
39 #include <asm/pgalloc.h>
40
41 typedef char *elf_caddr_t;
42
43 #if 0
44 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
45 #else
46 #define kdebug(fmt, ...) do {} while(0)
47 #endif
48
49 #if 0
50 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
51 #else
52 #define kdcore(fmt, ...) do {} while(0)
53 #endif
54
55 MODULE_LICENSE("GPL");
56
57 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
58 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
59 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
60 struct mm_struct *, const char *);
61
62 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
63 struct elf_fdpic_params *,
64 struct elf_fdpic_params *);
65
66 #ifndef CONFIG_MMU
67 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
68 unsigned long *);
69 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
70 struct file *,
71 struct mm_struct *);
72 #endif
73
74 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
75 struct file *, struct mm_struct *);
76
77 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
78 static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *, unsigned long limit);
79 #endif
80
81 static struct linux_binfmt elf_fdpic_format = {
82 .module = THIS_MODULE,
83 .load_binary = load_elf_fdpic_binary,
84 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
85 .core_dump = elf_fdpic_core_dump,
86 #endif
87 .min_coredump = ELF_EXEC_PAGESIZE,
88 };
89
90 static int __init init_elf_fdpic_binfmt(void)
91 {
92 return register_binfmt(&elf_fdpic_format);
93 }
94
95 static void __exit exit_elf_fdpic_binfmt(void)
96 {
97 unregister_binfmt(&elf_fdpic_format);
98 }
99
100 core_initcall(init_elf_fdpic_binfmt);
101 module_exit(exit_elf_fdpic_binfmt);
102
103 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
104 {
105 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
106 return 0;
107 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
108 return 0;
109 if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
110 return 0;
111 if (!file->f_op || !file->f_op->mmap)
112 return 0;
113 return 1;
114 }
115
116 /*****************************************************************************/
117 /*
118 * read the program headers table into memory
119 */
120 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
121 struct file *file)
122 {
123 struct elf32_phdr *phdr;
124 unsigned long size;
125 int retval, loop;
126
127 if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
128 return -ENOMEM;
129 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
130 return -ENOMEM;
131
132 size = params->hdr.e_phnum * sizeof(struct elf_phdr);
133 params->phdrs = kmalloc(size, GFP_KERNEL);
134 if (!params->phdrs)
135 return -ENOMEM;
136
137 retval = kernel_read(file, params->hdr.e_phoff,
138 (char *) params->phdrs, size);
139 if (retval < 0)
140 return retval;
141
142 /* determine stack size for this binary */
143 phdr = params->phdrs;
144 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
145 if (phdr->p_type != PT_GNU_STACK)
146 continue;
147
148 if (phdr->p_flags & PF_X)
149 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
150 else
151 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
152
153 params->stack_size = phdr->p_memsz;
154 break;
155 }
156
157 return 0;
158 }
159
160 /*****************************************************************************/
161 /*
162 * load an fdpic binary into various bits of memory
163 */
164 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
165 struct pt_regs *regs)
166 {
167 struct elf_fdpic_params exec_params, interp_params;
168 struct elf_phdr *phdr;
169 unsigned long stack_size, entryaddr;
170 #ifndef CONFIG_MMU
171 unsigned long fullsize;
172 #endif
173 #ifdef ELF_FDPIC_PLAT_INIT
174 unsigned long dynaddr;
175 #endif
176 struct file *interpreter = NULL; /* to shut gcc up */
177 char *interpreter_name = NULL;
178 int executable_stack;
179 int retval, i;
180
181 kdebug("____ LOAD %d ____", current->pid);
182
183 memset(&exec_params, 0, sizeof(exec_params));
184 memset(&interp_params, 0, sizeof(interp_params));
185
186 exec_params.hdr = *(struct elfhdr *) bprm->buf;
187 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
188
189 /* check that this is a binary we know how to deal with */
190 retval = -ENOEXEC;
191 if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
192 goto error;
193
194 /* read the program header table */
195 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
196 if (retval < 0)
197 goto error;
198
199 /* scan for a program header that specifies an interpreter */
200 phdr = exec_params.phdrs;
201
202 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
203 switch (phdr->p_type) {
204 case PT_INTERP:
205 retval = -ENOMEM;
206 if (phdr->p_filesz > PATH_MAX)
207 goto error;
208 retval = -ENOENT;
209 if (phdr->p_filesz < 2)
210 goto error;
211
212 /* read the name of the interpreter into memory */
213 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
214 if (!interpreter_name)
215 goto error;
216
217 retval = kernel_read(bprm->file,
218 phdr->p_offset,
219 interpreter_name,
220 phdr->p_filesz);
221 if (retval < 0)
222 goto error;
223
224 retval = -ENOENT;
225 if (interpreter_name[phdr->p_filesz - 1] != '\0')
226 goto error;
227
228 kdebug("Using ELF interpreter %s", interpreter_name);
229
230 /* replace the program with the interpreter */
231 interpreter = open_exec(interpreter_name);
232 retval = PTR_ERR(interpreter);
233 if (IS_ERR(interpreter)) {
234 interpreter = NULL;
235 goto error;
236 }
237
238 /*
239 * If the binary is not readable then enforce
240 * mm->dumpable = 0 regardless of the interpreter's
241 * permissions.
242 */
243 if (file_permission(interpreter, MAY_READ) < 0)
244 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
245
246 retval = kernel_read(interpreter, 0, bprm->buf,
247 BINPRM_BUF_SIZE);
248 if (retval < 0)
249 goto error;
250
251 interp_params.hdr = *((struct elfhdr *) bprm->buf);
252 break;
253
254 case PT_LOAD:
255 #ifdef CONFIG_MMU
256 if (exec_params.load_addr == 0)
257 exec_params.load_addr = phdr->p_vaddr;
258 #endif
259 break;
260 }
261
262 }
263
264 if (elf_check_const_displacement(&exec_params.hdr))
265 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
266
267 /* perform insanity checks on the interpreter */
268 if (interpreter_name) {
269 retval = -ELIBBAD;
270 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
271 goto error;
272
273 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
274
275 /* read the interpreter's program header table */
276 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
277 if (retval < 0)
278 goto error;
279 }
280
281 stack_size = exec_params.stack_size;
282 if (stack_size < interp_params.stack_size)
283 stack_size = interp_params.stack_size;
284
285 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
286 executable_stack = EXSTACK_ENABLE_X;
287 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
288 executable_stack = EXSTACK_DISABLE_X;
289 else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
290 executable_stack = EXSTACK_ENABLE_X;
291 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
292 executable_stack = EXSTACK_DISABLE_X;
293 else
294 executable_stack = EXSTACK_DEFAULT;
295
296 retval = -ENOEXEC;
297 if (stack_size == 0)
298 goto error;
299
300 if (elf_check_const_displacement(&interp_params.hdr))
301 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
302
303 /* flush all traces of the currently running executable */
304 retval = flush_old_exec(bprm);
305 if (retval)
306 goto error;
307
308 /* there's now no turning back... the old userspace image is dead,
309 * defunct, deceased, etc. after this point we have to exit via
310 * error_kill */
311 set_personality(PER_LINUX_FDPIC);
312 set_binfmt(&elf_fdpic_format);
313
314 current->mm->start_code = 0;
315 current->mm->end_code = 0;
316 current->mm->start_stack = 0;
317 current->mm->start_data = 0;
318 current->mm->end_data = 0;
319 current->mm->context.exec_fdpic_loadmap = 0;
320 current->mm->context.interp_fdpic_loadmap = 0;
321
322 current->flags &= ~PF_FORKNOEXEC;
323
324 #ifdef CONFIG_MMU
325 elf_fdpic_arch_lay_out_mm(&exec_params,
326 &interp_params,
327 &current->mm->start_stack,
328 &current->mm->start_brk);
329
330 retval = setup_arg_pages(bprm, current->mm->start_stack,
331 executable_stack);
332 if (retval < 0) {
333 send_sig(SIGKILL, current, 0);
334 goto error_kill;
335 }
336 #endif
337
338 /* load the executable and interpreter into memory */
339 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
340 "executable");
341 if (retval < 0)
342 goto error_kill;
343
344 if (interpreter_name) {
345 retval = elf_fdpic_map_file(&interp_params, interpreter,
346 current->mm, "interpreter");
347 if (retval < 0) {
348 printk(KERN_ERR "Unable to load interpreter\n");
349 goto error_kill;
350 }
351
352 allow_write_access(interpreter);
353 fput(interpreter);
354 interpreter = NULL;
355 }
356
357 #ifdef CONFIG_MMU
358 if (!current->mm->start_brk)
359 current->mm->start_brk = current->mm->end_data;
360
361 current->mm->brk = current->mm->start_brk =
362 PAGE_ALIGN(current->mm->start_brk);
363
364 #else
365 /* create a stack and brk area big enough for everyone
366 * - the brk heap starts at the bottom and works up
367 * - the stack starts at the top and works down
368 */
369 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
370 if (stack_size < PAGE_SIZE * 2)
371 stack_size = PAGE_SIZE * 2;
372
373 down_write(&current->mm->mmap_sem);
374 current->mm->start_brk = do_mmap(NULL, 0, stack_size,
375 PROT_READ | PROT_WRITE | PROT_EXEC,
376 MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN,
377 0);
378
379 if (IS_ERR_VALUE(current->mm->start_brk)) {
380 up_write(&current->mm->mmap_sem);
381 retval = current->mm->start_brk;
382 current->mm->start_brk = 0;
383 goto error_kill;
384 }
385
386 /* expand the stack mapping to use up the entire allocation granule */
387 fullsize = ksize((char *) current->mm->start_brk);
388 if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
389 fullsize, 0, 0)))
390 stack_size = fullsize;
391 up_write(&current->mm->mmap_sem);
392
393 current->mm->brk = current->mm->start_brk;
394 current->mm->context.end_brk = current->mm->start_brk;
395 current->mm->context.end_brk +=
396 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
397 current->mm->start_stack = current->mm->start_brk + stack_size;
398 #endif
399
400 compute_creds(bprm);
401 current->flags &= ~PF_FORKNOEXEC;
402 if (create_elf_fdpic_tables(bprm, current->mm,
403 &exec_params, &interp_params) < 0)
404 goto error_kill;
405
406 kdebug("- start_code %lx", current->mm->start_code);
407 kdebug("- end_code %lx", current->mm->end_code);
408 kdebug("- start_data %lx", current->mm->start_data);
409 kdebug("- end_data %lx", current->mm->end_data);
410 kdebug("- start_brk %lx", current->mm->start_brk);
411 kdebug("- brk %lx", current->mm->brk);
412 kdebug("- start_stack %lx", current->mm->start_stack);
413
414 #ifdef ELF_FDPIC_PLAT_INIT
415 /*
416 * The ABI may specify that certain registers be set up in special
417 * ways (on i386 %edx is the address of a DT_FINI function, for
418 * example. This macro performs whatever initialization to
419 * the regs structure is required.
420 */
421 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
422 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
423 dynaddr);
424 #endif
425
426 /* everything is now ready... get the userspace context ready to roll */
427 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
428 start_thread(regs, entryaddr, current->mm->start_stack);
429
430 if (unlikely(current->ptrace & PT_PTRACED)) {
431 if (current->ptrace & PT_TRACE_EXEC)
432 ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
433 else
434 send_sig(SIGTRAP, current, 0);
435 }
436
437 retval = 0;
438
439 error:
440 if (interpreter) {
441 allow_write_access(interpreter);
442 fput(interpreter);
443 }
444 kfree(interpreter_name);
445 kfree(exec_params.phdrs);
446 kfree(exec_params.loadmap);
447 kfree(interp_params.phdrs);
448 kfree(interp_params.loadmap);
449 return retval;
450
451 /* unrecoverable error - kill the process */
452 error_kill:
453 send_sig(SIGSEGV, current, 0);
454 goto error;
455
456 }
457
458 /*****************************************************************************/
459 /*
460 * present useful information to the program
461 */
462 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
463 struct mm_struct *mm,
464 struct elf_fdpic_params *exec_params,
465 struct elf_fdpic_params *interp_params)
466 {
467 unsigned long sp, csp, nitems;
468 elf_caddr_t __user *argv, *envp;
469 size_t platform_len = 0, len;
470 char *k_platform;
471 char __user *u_platform, *p;
472 long hwcap;
473 int loop;
474
475 /* we're going to shovel a whole load of stuff onto the stack */
476 #ifdef CONFIG_MMU
477 sp = bprm->p;
478 #else
479 sp = mm->start_stack;
480
481 /* stack the program arguments and environment */
482 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
483 return -EFAULT;
484 #endif
485
486 /* get hold of platform and hardware capabilities masks for the machine
487 * we are running on. In some cases (Sparc), this info is impossible
488 * to get, in others (i386) it is merely difficult.
489 */
490 hwcap = ELF_HWCAP;
491 k_platform = ELF_PLATFORM;
492 u_platform = NULL;
493
494 if (k_platform) {
495 platform_len = strlen(k_platform) + 1;
496 sp -= platform_len;
497 u_platform = (char __user *) sp;
498 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
499 return -EFAULT;
500 }
501
502 #if defined(__i386__) && defined(CONFIG_SMP)
503 /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
504 * by the processes running on the same package. One thing we can do is
505 * to shuffle the initial stack for them.
506 *
507 * the conditionals here are unneeded, but kept in to make the code
508 * behaviour the same as pre change unless we have hyperthreaded
509 * processors. This keeps Mr Marcelo Person happier but should be
510 * removed for 2.5
511 */
512 if (smp_num_siblings > 1)
513 sp = sp - ((current->pid % 64) << 7);
514 #endif
515
516 sp &= ~7UL;
517
518 /* stack the load map(s) */
519 len = sizeof(struct elf32_fdpic_loadmap);
520 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
521 sp = (sp - len) & ~7UL;
522 exec_params->map_addr = sp;
523
524 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
525 return -EFAULT;
526
527 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
528
529 if (interp_params->loadmap) {
530 len = sizeof(struct elf32_fdpic_loadmap);
531 len += sizeof(struct elf32_fdpic_loadseg) *
532 interp_params->loadmap->nsegs;
533 sp = (sp - len) & ~7UL;
534 interp_params->map_addr = sp;
535
536 if (copy_to_user((void __user *) sp, interp_params->loadmap,
537 len) != 0)
538 return -EFAULT;
539
540 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
541 }
542
543 /* force 16 byte _final_ alignment here for generality */
544 #define DLINFO_ITEMS 13
545
546 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0);
547 #ifdef DLINFO_ARCH_ITEMS
548 nitems += DLINFO_ARCH_ITEMS;
549 #endif
550
551 csp = sp;
552 sp -= nitems * 2 * sizeof(unsigned long);
553 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
554 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
555 sp -= 1 * sizeof(unsigned long); /* argc */
556
557 csp -= sp & 15UL;
558 sp -= sp & 15UL;
559
560 /* put the ELF interpreter info on the stack */
561 #define NEW_AUX_ENT(nr, id, val) \
562 do { \
563 struct { unsigned long _id, _val; } __user *ent; \
564 \
565 ent = (void __user *) csp; \
566 __put_user((id), &ent[nr]._id); \
567 __put_user((val), &ent[nr]._val); \
568 } while (0)
569
570 csp -= 2 * sizeof(unsigned long);
571 NEW_AUX_ENT(0, AT_NULL, 0);
572 if (k_platform) {
573 csp -= 2 * sizeof(unsigned long);
574 NEW_AUX_ENT(0, AT_PLATFORM,
575 (elf_addr_t) (unsigned long) u_platform);
576 }
577
578 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
579 NEW_AUX_ENT( 0, AT_HWCAP, hwcap);
580 NEW_AUX_ENT( 1, AT_PAGESZ, PAGE_SIZE);
581 NEW_AUX_ENT( 2, AT_CLKTCK, CLOCKS_PER_SEC);
582 NEW_AUX_ENT( 3, AT_PHDR, exec_params->ph_addr);
583 NEW_AUX_ENT( 4, AT_PHENT, sizeof(struct elf_phdr));
584 NEW_AUX_ENT( 5, AT_PHNUM, exec_params->hdr.e_phnum);
585 NEW_AUX_ENT( 6, AT_BASE, interp_params->elfhdr_addr);
586 NEW_AUX_ENT( 7, AT_FLAGS, 0);
587 NEW_AUX_ENT( 8, AT_ENTRY, exec_params->entry_addr);
588 NEW_AUX_ENT( 9, AT_UID, (elf_addr_t) current->uid);
589 NEW_AUX_ENT(10, AT_EUID, (elf_addr_t) current->euid);
590 NEW_AUX_ENT(11, AT_GID, (elf_addr_t) current->gid);
591 NEW_AUX_ENT(12, AT_EGID, (elf_addr_t) current->egid);
592
593 #ifdef ARCH_DLINFO
594 /* ARCH_DLINFO must come last so platform specific code can enforce
595 * special alignment requirements on the AUXV if necessary (eg. PPC).
596 */
597 ARCH_DLINFO;
598 #endif
599 #undef NEW_AUX_ENT
600
601 /* allocate room for argv[] and envv[] */
602 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
603 envp = (elf_caddr_t __user *) csp;
604 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
605 argv = (elf_caddr_t __user *) csp;
606
607 /* stack argc */
608 csp -= sizeof(unsigned long);
609 __put_user(bprm->argc, (unsigned long __user *) csp);
610
611 BUG_ON(csp != sp);
612
613 /* fill in the argv[] array */
614 #ifdef CONFIG_MMU
615 current->mm->arg_start = bprm->p;
616 #else
617 current->mm->arg_start = current->mm->start_stack -
618 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
619 #endif
620
621 p = (char __user *) current->mm->arg_start;
622 for (loop = bprm->argc; loop > 0; loop--) {
623 __put_user((elf_caddr_t) p, argv++);
624 len = strnlen_user(p, MAX_ARG_STRLEN);
625 if (!len || len > MAX_ARG_STRLEN)
626 return -EINVAL;
627 p += len;
628 }
629 __put_user(NULL, argv);
630 current->mm->arg_end = (unsigned long) p;
631
632 /* fill in the envv[] array */
633 current->mm->env_start = (unsigned long) p;
634 for (loop = bprm->envc; loop > 0; loop--) {
635 __put_user((elf_caddr_t)(unsigned long) p, envp++);
636 len = strnlen_user(p, MAX_ARG_STRLEN);
637 if (!len || len > MAX_ARG_STRLEN)
638 return -EINVAL;
639 p += len;
640 }
641 __put_user(NULL, envp);
642 current->mm->env_end = (unsigned long) p;
643
644 mm->start_stack = (unsigned long) sp;
645 return 0;
646 }
647
648 /*****************************************************************************/
649 /*
650 * transfer the program arguments and environment from the holding pages onto
651 * the stack
652 */
653 #ifndef CONFIG_MMU
654 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
655 unsigned long *_sp)
656 {
657 unsigned long index, stop, sp;
658 char *src;
659 int ret = 0;
660
661 stop = bprm->p >> PAGE_SHIFT;
662 sp = *_sp;
663
664 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
665 src = kmap(bprm->page[index]);
666 sp -= PAGE_SIZE;
667 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
668 ret = -EFAULT;
669 kunmap(bprm->page[index]);
670 if (ret < 0)
671 goto out;
672 }
673
674 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
675
676 out:
677 return ret;
678 }
679 #endif
680
681 /*****************************************************************************/
682 /*
683 * load the appropriate binary image (executable or interpreter) into memory
684 * - we assume no MMU is available
685 * - if no other PIC bits are set in params->hdr->e_flags
686 * - we assume that the LOADable segments in the binary are independently relocatable
687 * - we assume R/O executable segments are shareable
688 * - else
689 * - we assume the loadable parts of the image to require fixed displacement
690 * - the image is not shareable
691 */
692 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
693 struct file *file,
694 struct mm_struct *mm,
695 const char *what)
696 {
697 struct elf32_fdpic_loadmap *loadmap;
698 #ifdef CONFIG_MMU
699 struct elf32_fdpic_loadseg *mseg;
700 #endif
701 struct elf32_fdpic_loadseg *seg;
702 struct elf32_phdr *phdr;
703 unsigned long load_addr, stop;
704 unsigned nloads, tmp;
705 size_t size;
706 int loop, ret;
707
708 /* allocate a load map table */
709 nloads = 0;
710 for (loop = 0; loop < params->hdr.e_phnum; loop++)
711 if (params->phdrs[loop].p_type == PT_LOAD)
712 nloads++;
713
714 if (nloads == 0)
715 return -ELIBBAD;
716
717 size = sizeof(*loadmap) + nloads * sizeof(*seg);
718 loadmap = kzalloc(size, GFP_KERNEL);
719 if (!loadmap)
720 return -ENOMEM;
721
722 params->loadmap = loadmap;
723
724 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
725 loadmap->nsegs = nloads;
726
727 load_addr = params->load_addr;
728 seg = loadmap->segs;
729
730 /* map the requested LOADs into the memory space */
731 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
732 case ELF_FDPIC_FLAG_CONSTDISP:
733 case ELF_FDPIC_FLAG_CONTIGUOUS:
734 #ifndef CONFIG_MMU
735 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
736 if (ret < 0)
737 return ret;
738 break;
739 #endif
740 default:
741 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
742 if (ret < 0)
743 return ret;
744 break;
745 }
746
747 /* map the entry point */
748 if (params->hdr.e_entry) {
749 seg = loadmap->segs;
750 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
751 if (params->hdr.e_entry >= seg->p_vaddr &&
752 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
753 params->entry_addr =
754 (params->hdr.e_entry - seg->p_vaddr) +
755 seg->addr;
756 break;
757 }
758 }
759 }
760
761 /* determine where the program header table has wound up if mapped */
762 stop = params->hdr.e_phoff;
763 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
764 phdr = params->phdrs;
765
766 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
767 if (phdr->p_type != PT_LOAD)
768 continue;
769
770 if (phdr->p_offset > params->hdr.e_phoff ||
771 phdr->p_offset + phdr->p_filesz < stop)
772 continue;
773
774 seg = loadmap->segs;
775 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
776 if (phdr->p_vaddr >= seg->p_vaddr &&
777 phdr->p_vaddr + phdr->p_filesz <=
778 seg->p_vaddr + seg->p_memsz) {
779 params->ph_addr =
780 (phdr->p_vaddr - seg->p_vaddr) +
781 seg->addr +
782 params->hdr.e_phoff - phdr->p_offset;
783 break;
784 }
785 }
786 break;
787 }
788
789 /* determine where the dynamic section has wound up if there is one */
790 phdr = params->phdrs;
791 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
792 if (phdr->p_type != PT_DYNAMIC)
793 continue;
794
795 seg = loadmap->segs;
796 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
797 if (phdr->p_vaddr >= seg->p_vaddr &&
798 phdr->p_vaddr + phdr->p_memsz <=
799 seg->p_vaddr + seg->p_memsz) {
800 params->dynamic_addr =
801 (phdr->p_vaddr - seg->p_vaddr) +
802 seg->addr;
803
804 /* check the dynamic section contains at least
805 * one item, and that the last item is a NULL
806 * entry */
807 if (phdr->p_memsz == 0 ||
808 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
809 goto dynamic_error;
810
811 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
812 if (((Elf32_Dyn *)
813 params->dynamic_addr)[tmp - 1].d_tag != 0)
814 goto dynamic_error;
815 break;
816 }
817 }
818 break;
819 }
820
821 /* now elide adjacent segments in the load map on MMU linux
822 * - on uClinux the holes between may actually be filled with system
823 * stuff or stuff from other processes
824 */
825 #ifdef CONFIG_MMU
826 nloads = loadmap->nsegs;
827 mseg = loadmap->segs;
828 seg = mseg + 1;
829 for (loop = 1; loop < nloads; loop++) {
830 /* see if we have a candidate for merging */
831 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
832 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
833 if (load_addr == (seg->addr & PAGE_MASK)) {
834 mseg->p_memsz +=
835 load_addr -
836 (mseg->addr + mseg->p_memsz);
837 mseg->p_memsz += seg->addr & ~PAGE_MASK;
838 mseg->p_memsz += seg->p_memsz;
839 loadmap->nsegs--;
840 continue;
841 }
842 }
843
844 mseg++;
845 if (mseg != seg)
846 *mseg = *seg;
847 }
848 #endif
849
850 kdebug("Mapped Object [%s]:", what);
851 kdebug("- elfhdr : %lx", params->elfhdr_addr);
852 kdebug("- entry : %lx", params->entry_addr);
853 kdebug("- PHDR[] : %lx", params->ph_addr);
854 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
855 seg = loadmap->segs;
856 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
857 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
858 loop,
859 seg->addr, seg->addr + seg->p_memsz - 1,
860 seg->p_vaddr, seg->p_memsz);
861
862 return 0;
863
864 dynamic_error:
865 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
866 what, file->f_path.dentry->d_inode->i_ino);
867 return -ELIBBAD;
868 }
869
870 /*****************************************************************************/
871 /*
872 * map a file with constant displacement under uClinux
873 */
874 #ifndef CONFIG_MMU
875 static int elf_fdpic_map_file_constdisp_on_uclinux(
876 struct elf_fdpic_params *params,
877 struct file *file,
878 struct mm_struct *mm)
879 {
880 struct elf32_fdpic_loadseg *seg;
881 struct elf32_phdr *phdr;
882 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
883 loff_t fpos;
884 int loop, ret;
885
886 load_addr = params->load_addr;
887 seg = params->loadmap->segs;
888
889 /* determine the bounds of the contiguous overall allocation we must
890 * make */
891 phdr = params->phdrs;
892 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
893 if (params->phdrs[loop].p_type != PT_LOAD)
894 continue;
895
896 if (base > phdr->p_vaddr)
897 base = phdr->p_vaddr;
898 if (top < phdr->p_vaddr + phdr->p_memsz)
899 top = phdr->p_vaddr + phdr->p_memsz;
900 }
901
902 /* allocate one big anon block for everything */
903 mflags = MAP_PRIVATE;
904 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
905 mflags |= MAP_EXECUTABLE;
906
907 down_write(&mm->mmap_sem);
908 maddr = do_mmap(NULL, load_addr, top - base,
909 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
910 up_write(&mm->mmap_sem);
911 if (IS_ERR_VALUE(maddr))
912 return (int) maddr;
913
914 if (load_addr != 0)
915 load_addr += PAGE_ALIGN(top - base);
916
917 /* and then load the file segments into it */
918 phdr = params->phdrs;
919 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
920 if (params->phdrs[loop].p_type != PT_LOAD)
921 continue;
922
923 fpos = phdr->p_offset;
924
925 seg->addr = maddr + (phdr->p_vaddr - base);
926 seg->p_vaddr = phdr->p_vaddr;
927 seg->p_memsz = phdr->p_memsz;
928
929 ret = file->f_op->read(file, (void *) seg->addr,
930 phdr->p_filesz, &fpos);
931 if (ret < 0)
932 return ret;
933
934 /* map the ELF header address if in this segment */
935 if (phdr->p_offset == 0)
936 params->elfhdr_addr = seg->addr;
937
938 /* clear any space allocated but not loaded */
939 if (phdr->p_filesz < phdr->p_memsz)
940 clear_user((void *) (seg->addr + phdr->p_filesz),
941 phdr->p_memsz - phdr->p_filesz);
942
943 if (mm) {
944 if (phdr->p_flags & PF_X) {
945 if (!mm->start_code) {
946 mm->start_code = seg->addr;
947 mm->end_code = seg->addr +
948 phdr->p_memsz;
949 }
950 } else if (!mm->start_data) {
951 mm->start_data = seg->addr;
952 #ifndef CONFIG_MMU
953 mm->end_data = seg->addr + phdr->p_memsz;
954 #endif
955 }
956
957 #ifdef CONFIG_MMU
958 if (seg->addr + phdr->p_memsz > mm->end_data)
959 mm->end_data = seg->addr + phdr->p_memsz;
960 #endif
961 }
962
963 seg++;
964 }
965
966 return 0;
967 }
968 #endif
969
970 /*****************************************************************************/
971 /*
972 * map a binary by direct mmap() of the individual PT_LOAD segments
973 */
974 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
975 struct file *file,
976 struct mm_struct *mm)
977 {
978 struct elf32_fdpic_loadseg *seg;
979 struct elf32_phdr *phdr;
980 unsigned long load_addr, delta_vaddr;
981 int loop, dvset;
982
983 load_addr = params->load_addr;
984 delta_vaddr = 0;
985 dvset = 0;
986
987 seg = params->loadmap->segs;
988
989 /* deal with each load segment separately */
990 phdr = params->phdrs;
991 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
992 unsigned long maddr, disp, excess, excess1;
993 int prot = 0, flags;
994
995 if (phdr->p_type != PT_LOAD)
996 continue;
997
998 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
999 (unsigned long) phdr->p_vaddr,
1000 (unsigned long) phdr->p_offset,
1001 (unsigned long) phdr->p_filesz,
1002 (unsigned long) phdr->p_memsz);
1003
1004 /* determine the mapping parameters */
1005 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1006 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1007 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1008
1009 flags = MAP_PRIVATE | MAP_DENYWRITE;
1010 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1011 flags |= MAP_EXECUTABLE;
1012
1013 maddr = 0;
1014
1015 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1016 case ELF_FDPIC_FLAG_INDEPENDENT:
1017 /* PT_LOADs are independently locatable */
1018 break;
1019
1020 case ELF_FDPIC_FLAG_HONOURVADDR:
1021 /* the specified virtual address must be honoured */
1022 maddr = phdr->p_vaddr;
1023 flags |= MAP_FIXED;
1024 break;
1025
1026 case ELF_FDPIC_FLAG_CONSTDISP:
1027 /* constant displacement
1028 * - can be mapped anywhere, but must be mapped as a
1029 * unit
1030 */
1031 if (!dvset) {
1032 maddr = load_addr;
1033 delta_vaddr = phdr->p_vaddr;
1034 dvset = 1;
1035 } else {
1036 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1037 flags |= MAP_FIXED;
1038 }
1039 break;
1040
1041 case ELF_FDPIC_FLAG_CONTIGUOUS:
1042 /* contiguity handled later */
1043 break;
1044
1045 default:
1046 BUG();
1047 }
1048
1049 maddr &= PAGE_MASK;
1050
1051 /* create the mapping */
1052 disp = phdr->p_vaddr & ~PAGE_MASK;
1053 down_write(&mm->mmap_sem);
1054 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1055 phdr->p_offset - disp);
1056 up_write(&mm->mmap_sem);
1057
1058 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1059 loop, phdr->p_memsz + disp, prot, flags,
1060 phdr->p_offset - disp, maddr);
1061
1062 if (IS_ERR_VALUE(maddr))
1063 return (int) maddr;
1064
1065 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1066 ELF_FDPIC_FLAG_CONTIGUOUS)
1067 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1068
1069 seg->addr = maddr + disp;
1070 seg->p_vaddr = phdr->p_vaddr;
1071 seg->p_memsz = phdr->p_memsz;
1072
1073 /* map the ELF header address if in this segment */
1074 if (phdr->p_offset == 0)
1075 params->elfhdr_addr = seg->addr;
1076
1077 /* clear the bit between beginning of mapping and beginning of
1078 * PT_LOAD */
1079 if (prot & PROT_WRITE && disp > 0) {
1080 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1081 clear_user((void __user *) maddr, disp);
1082 maddr += disp;
1083 }
1084
1085 /* clear any space allocated but not loaded
1086 * - on uClinux we can just clear the lot
1087 * - on MMU linux we'll get a SIGBUS beyond the last page
1088 * extant in the file
1089 */
1090 excess = phdr->p_memsz - phdr->p_filesz;
1091 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1092
1093 #ifdef CONFIG_MMU
1094 if (excess > excess1) {
1095 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1096 unsigned long xmaddr;
1097
1098 flags |= MAP_FIXED | MAP_ANONYMOUS;
1099 down_write(&mm->mmap_sem);
1100 xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1101 prot, flags, 0);
1102 up_write(&mm->mmap_sem);
1103
1104 kdebug("mmap[%d] <anon>"
1105 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1106 loop, xaddr, excess - excess1, prot, flags,
1107 xmaddr);
1108
1109 if (xmaddr != xaddr)
1110 return -ENOMEM;
1111 }
1112
1113 if (prot & PROT_WRITE && excess1 > 0) {
1114 kdebug("clear[%d] ad=%lx sz=%lx",
1115 loop, maddr + phdr->p_filesz, excess1);
1116 clear_user((void __user *) maddr + phdr->p_filesz,
1117 excess1);
1118 }
1119
1120 #else
1121 if (excess > 0) {
1122 kdebug("clear[%d] ad=%lx sz=%lx",
1123 loop, maddr + phdr->p_filesz, excess);
1124 clear_user((void *) maddr + phdr->p_filesz, excess);
1125 }
1126 #endif
1127
1128 if (mm) {
1129 if (phdr->p_flags & PF_X) {
1130 if (!mm->start_code) {
1131 mm->start_code = maddr;
1132 mm->end_code = maddr + phdr->p_memsz;
1133 }
1134 } else if (!mm->start_data) {
1135 mm->start_data = maddr;
1136 mm->end_data = maddr + phdr->p_memsz;
1137 }
1138 }
1139
1140 seg++;
1141 }
1142
1143 return 0;
1144 }
1145
1146 /*****************************************************************************/
1147 /*
1148 * ELF-FDPIC core dumper
1149 *
1150 * Modelled on fs/exec.c:aout_core_dump()
1151 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1152 *
1153 * Modelled on fs/binfmt_elf.c core dumper
1154 */
1155 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1156
1157 /*
1158 * These are the only things you should do on a core-file: use only these
1159 * functions to write out all the necessary info.
1160 */
1161 static int dump_write(struct file *file, const void *addr, int nr)
1162 {
1163 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1164 }
1165
1166 static int dump_seek(struct file *file, loff_t off)
1167 {
1168 if (file->f_op->llseek) {
1169 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1170 return 0;
1171 } else {
1172 file->f_pos = off;
1173 }
1174 return 1;
1175 }
1176
1177 /*
1178 * Decide whether a segment is worth dumping; default is yes to be
1179 * sure (missing info is worse than too much; etc).
1180 * Personally I'd include everything, and use the coredump limit...
1181 *
1182 * I think we should skip something. But I am not sure how. H.J.
1183 */
1184 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1185 {
1186 int dump_ok;
1187
1188 /* Do not dump I/O mapped devices or special mappings */
1189 if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1190 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1191 return 0;
1192 }
1193
1194 /* If we may not read the contents, don't allow us to dump
1195 * them either. "dump_write()" can't handle it anyway.
1196 */
1197 if (!(vma->vm_flags & VM_READ)) {
1198 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1199 return 0;
1200 }
1201
1202 /* By default, dump shared memory if mapped from an anonymous file. */
1203 if (vma->vm_flags & VM_SHARED) {
1204 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1205 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1206 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1207 vma->vm_flags, dump_ok ? "yes" : "no");
1208 return dump_ok;
1209 }
1210
1211 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1212 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1213 vma->vm_flags, dump_ok ? "yes" : "no");
1214 return dump_ok;
1215 }
1216
1217 #ifdef CONFIG_MMU
1218 /* By default, if it hasn't been written to, don't write it out */
1219 if (!vma->anon_vma) {
1220 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1221 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1222 vma->vm_flags, dump_ok ? "yes" : "no");
1223 return dump_ok;
1224 }
1225 #endif
1226
1227 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1228 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1229 dump_ok ? "yes" : "no");
1230 return dump_ok;
1231 }
1232
1233 /* An ELF note in memory */
1234 struct memelfnote
1235 {
1236 const char *name;
1237 int type;
1238 unsigned int datasz;
1239 void *data;
1240 };
1241
1242 static int notesize(struct memelfnote *en)
1243 {
1244 int sz;
1245
1246 sz = sizeof(struct elf_note);
1247 sz += roundup(strlen(en->name) + 1, 4);
1248 sz += roundup(en->datasz, 4);
1249
1250 return sz;
1251 }
1252
1253 /* #define DEBUG */
1254
1255 #define DUMP_WRITE(addr, nr) \
1256 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1257 #define DUMP_SEEK(off) \
1258 do { if (!dump_seek(file, (off))) return 0; } while(0)
1259
1260 static int writenote(struct memelfnote *men, struct file *file)
1261 {
1262 struct elf_note en;
1263
1264 en.n_namesz = strlen(men->name) + 1;
1265 en.n_descsz = men->datasz;
1266 en.n_type = men->type;
1267
1268 DUMP_WRITE(&en, sizeof(en));
1269 DUMP_WRITE(men->name, en.n_namesz);
1270 /* XXX - cast from long long to long to avoid need for libgcc.a */
1271 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1272 DUMP_WRITE(men->data, men->datasz);
1273 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1274
1275 return 1;
1276 }
1277 #undef DUMP_WRITE
1278 #undef DUMP_SEEK
1279
1280 #define DUMP_WRITE(addr, nr) \
1281 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1282 goto end_coredump;
1283 #define DUMP_SEEK(off) \
1284 if (!dump_seek(file, (off))) \
1285 goto end_coredump;
1286
1287 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1288 {
1289 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1290 elf->e_ident[EI_CLASS] = ELF_CLASS;
1291 elf->e_ident[EI_DATA] = ELF_DATA;
1292 elf->e_ident[EI_VERSION] = EV_CURRENT;
1293 elf->e_ident[EI_OSABI] = ELF_OSABI;
1294 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1295
1296 elf->e_type = ET_CORE;
1297 elf->e_machine = ELF_ARCH;
1298 elf->e_version = EV_CURRENT;
1299 elf->e_entry = 0;
1300 elf->e_phoff = sizeof(struct elfhdr);
1301 elf->e_shoff = 0;
1302 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1303 elf->e_ehsize = sizeof(struct elfhdr);
1304 elf->e_phentsize = sizeof(struct elf_phdr);
1305 elf->e_phnum = segs;
1306 elf->e_shentsize = 0;
1307 elf->e_shnum = 0;
1308 elf->e_shstrndx = 0;
1309 return;
1310 }
1311
1312 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1313 {
1314 phdr->p_type = PT_NOTE;
1315 phdr->p_offset = offset;
1316 phdr->p_vaddr = 0;
1317 phdr->p_paddr = 0;
1318 phdr->p_filesz = sz;
1319 phdr->p_memsz = 0;
1320 phdr->p_flags = 0;
1321 phdr->p_align = 0;
1322 return;
1323 }
1324
1325 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1326 unsigned int sz, void *data)
1327 {
1328 note->name = name;
1329 note->type = type;
1330 note->datasz = sz;
1331 note->data = data;
1332 return;
1333 }
1334
1335 /*
1336 * fill up all the fields in prstatus from the given task struct, except
1337 * registers which need to be filled up seperately.
1338 */
1339 static void fill_prstatus(struct elf_prstatus *prstatus,
1340 struct task_struct *p, long signr)
1341 {
1342 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1343 prstatus->pr_sigpend = p->pending.signal.sig[0];
1344 prstatus->pr_sighold = p->blocked.sig[0];
1345 prstatus->pr_pid = task_pid_vnr(p);
1346 prstatus->pr_ppid = task_pid_vnr(p->parent);
1347 prstatus->pr_pgrp = task_pgrp_vnr(p);
1348 prstatus->pr_sid = task_session_vnr(p);
1349 if (thread_group_leader(p)) {
1350 /*
1351 * This is the record for the group leader. Add in the
1352 * cumulative times of previous dead threads. This total
1353 * won't include the time of each live thread whose state
1354 * is included in the core dump. The final total reported
1355 * to our parent process when it calls wait4 will include
1356 * those sums as well as the little bit more time it takes
1357 * this and each other thread to finish dying after the
1358 * core dump synchronization phase.
1359 */
1360 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1361 &prstatus->pr_utime);
1362 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1363 &prstatus->pr_stime);
1364 } else {
1365 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1366 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1367 }
1368 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1369 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1370
1371 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1372 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1373 }
1374
1375 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1376 struct mm_struct *mm)
1377 {
1378 unsigned int i, len;
1379
1380 /* first copy the parameters from user space */
1381 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1382
1383 len = mm->arg_end - mm->arg_start;
1384 if (len >= ELF_PRARGSZ)
1385 len = ELF_PRARGSZ - 1;
1386 if (copy_from_user(&psinfo->pr_psargs,
1387 (const char __user *) mm->arg_start, len))
1388 return -EFAULT;
1389 for (i = 0; i < len; i++)
1390 if (psinfo->pr_psargs[i] == 0)
1391 psinfo->pr_psargs[i] = ' ';
1392 psinfo->pr_psargs[len] = 0;
1393
1394 psinfo->pr_pid = task_pid_vnr(p);
1395 psinfo->pr_ppid = task_pid_vnr(p->parent);
1396 psinfo->pr_pgrp = task_pgrp_vnr(p);
1397 psinfo->pr_sid = task_session_vnr(p);
1398
1399 i = p->state ? ffz(~p->state) + 1 : 0;
1400 psinfo->pr_state = i;
1401 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1402 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1403 psinfo->pr_nice = task_nice(p);
1404 psinfo->pr_flag = p->flags;
1405 SET_UID(psinfo->pr_uid, p->uid);
1406 SET_GID(psinfo->pr_gid, p->gid);
1407 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1408
1409 return 0;
1410 }
1411
1412 /* Here is the structure in which status of each thread is captured. */
1413 struct elf_thread_status
1414 {
1415 struct list_head list;
1416 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1417 elf_fpregset_t fpu; /* NT_PRFPREG */
1418 struct task_struct *thread;
1419 #ifdef ELF_CORE_COPY_XFPREGS
1420 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1421 #endif
1422 struct memelfnote notes[3];
1423 int num_notes;
1424 };
1425
1426 /*
1427 * In order to add the specific thread information for the elf file format,
1428 * we need to keep a linked list of every thread's pr_status and then create
1429 * a single section for them in the final core file.
1430 */
1431 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1432 {
1433 struct task_struct *p = t->thread;
1434 int sz = 0;
1435
1436 t->num_notes = 0;
1437
1438 fill_prstatus(&t->prstatus, p, signr);
1439 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1440
1441 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1442 &t->prstatus);
1443 t->num_notes++;
1444 sz += notesize(&t->notes[0]);
1445
1446 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1447 if (t->prstatus.pr_fpvalid) {
1448 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1449 &t->fpu);
1450 t->num_notes++;
1451 sz += notesize(&t->notes[1]);
1452 }
1453
1454 #ifdef ELF_CORE_COPY_XFPREGS
1455 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1456 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1457 sizeof(t->xfpu), &t->xfpu);
1458 t->num_notes++;
1459 sz += notesize(&t->notes[2]);
1460 }
1461 #endif
1462 return sz;
1463 }
1464
1465 /*
1466 * dump the segments for an MMU process
1467 */
1468 #ifdef CONFIG_MMU
1469 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1470 unsigned long *limit, unsigned long mm_flags)
1471 {
1472 struct vm_area_struct *vma;
1473
1474 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1475 unsigned long addr;
1476
1477 if (!maydump(vma, mm_flags))
1478 continue;
1479
1480 for (addr = vma->vm_start;
1481 addr < vma->vm_end;
1482 addr += PAGE_SIZE
1483 ) {
1484 struct vm_area_struct *vma;
1485 struct page *page;
1486
1487 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1488 &page, &vma) <= 0) {
1489 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1490 }
1491 else if (page == ZERO_PAGE(0)) {
1492 page_cache_release(page);
1493 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1494 }
1495 else {
1496 void *kaddr;
1497
1498 flush_cache_page(vma, addr, page_to_pfn(page));
1499 kaddr = kmap(page);
1500 if ((*size += PAGE_SIZE) > *limit ||
1501 !dump_write(file, kaddr, PAGE_SIZE)
1502 ) {
1503 kunmap(page);
1504 page_cache_release(page);
1505 return -EIO;
1506 }
1507 kunmap(page);
1508 page_cache_release(page);
1509 }
1510 }
1511 }
1512
1513 return 0;
1514
1515 end_coredump:
1516 return -EFBIG;
1517 }
1518 #endif
1519
1520 /*
1521 * dump the segments for a NOMMU process
1522 */
1523 #ifndef CONFIG_MMU
1524 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1525 unsigned long *limit, unsigned long mm_flags)
1526 {
1527 struct vm_list_struct *vml;
1528
1529 for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
1530 struct vm_area_struct *vma = vml->vma;
1531
1532 if (!maydump(vma, mm_flags))
1533 continue;
1534
1535 if ((*size += PAGE_SIZE) > *limit)
1536 return -EFBIG;
1537
1538 if (!dump_write(file, (void *) vma->vm_start,
1539 vma->vm_end - vma->vm_start))
1540 return -EIO;
1541 }
1542
1543 return 0;
1544 }
1545 #endif
1546
1547 /*
1548 * Actual dumper
1549 *
1550 * This is a two-pass process; first we find the offsets of the bits,
1551 * and then they are actually written out. If we run out of core limit
1552 * we just truncate.
1553 */
1554 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1555 struct file *file, unsigned long limit)
1556 {
1557 #define NUM_NOTES 6
1558 int has_dumped = 0;
1559 mm_segment_t fs;
1560 int segs;
1561 size_t size = 0;
1562 int i;
1563 struct vm_area_struct *vma;
1564 struct elfhdr *elf = NULL;
1565 loff_t offset = 0, dataoff;
1566 int numnote;
1567 struct memelfnote *notes = NULL;
1568 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1569 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1570 struct task_struct *g, *p;
1571 LIST_HEAD(thread_list);
1572 struct list_head *t;
1573 elf_fpregset_t *fpu = NULL;
1574 #ifdef ELF_CORE_COPY_XFPREGS
1575 elf_fpxregset_t *xfpu = NULL;
1576 #endif
1577 int thread_status_size = 0;
1578 #ifndef CONFIG_MMU
1579 struct vm_list_struct *vml;
1580 #endif
1581 elf_addr_t *auxv;
1582 unsigned long mm_flags;
1583
1584 /*
1585 * We no longer stop all VM operations.
1586 *
1587 * This is because those proceses that could possibly change map_count
1588 * or the mmap / vma pages are now blocked in do_exit on current
1589 * finishing this core dump.
1590 *
1591 * Only ptrace can touch these memory addresses, but it doesn't change
1592 * the map_count or the pages allocated. So no possibility of crashing
1593 * exists while dumping the mm->vm_next areas to the core file.
1594 */
1595
1596 /* alloc memory for large data structures: too large to be on stack */
1597 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1598 if (!elf)
1599 goto cleanup;
1600 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1601 if (!prstatus)
1602 goto cleanup;
1603 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1604 if (!psinfo)
1605 goto cleanup;
1606 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1607 if (!notes)
1608 goto cleanup;
1609 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1610 if (!fpu)
1611 goto cleanup;
1612 #ifdef ELF_CORE_COPY_XFPREGS
1613 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1614 if (!xfpu)
1615 goto cleanup;
1616 #endif
1617
1618 if (signr) {
1619 struct elf_thread_status *tmp;
1620 rcu_read_lock();
1621 do_each_thread(g,p)
1622 if (current->mm == p->mm && current != p) {
1623 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1624 if (!tmp) {
1625 rcu_read_unlock();
1626 goto cleanup;
1627 }
1628 tmp->thread = p;
1629 list_add(&tmp->list, &thread_list);
1630 }
1631 while_each_thread(g,p);
1632 rcu_read_unlock();
1633 list_for_each(t, &thread_list) {
1634 struct elf_thread_status *tmp;
1635 int sz;
1636
1637 tmp = list_entry(t, struct elf_thread_status, list);
1638 sz = elf_dump_thread_status(signr, tmp);
1639 thread_status_size += sz;
1640 }
1641 }
1642
1643 /* now collect the dump for the current */
1644 fill_prstatus(prstatus, current, signr);
1645 elf_core_copy_regs(&prstatus->pr_reg, regs);
1646
1647 #ifdef CONFIG_MMU
1648 segs = current->mm->map_count;
1649 #else
1650 segs = 0;
1651 for (vml = current->mm->context.vmlist; vml; vml = vml->next)
1652 segs++;
1653 #endif
1654 #ifdef ELF_CORE_EXTRA_PHDRS
1655 segs += ELF_CORE_EXTRA_PHDRS;
1656 #endif
1657
1658 /* Set up header */
1659 fill_elf_fdpic_header(elf, segs + 1); /* including notes section */
1660
1661 has_dumped = 1;
1662 current->flags |= PF_DUMPCORE;
1663
1664 /*
1665 * Set up the notes in similar form to SVR4 core dumps made
1666 * with info from their /proc.
1667 */
1668
1669 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1670 fill_psinfo(psinfo, current->group_leader, current->mm);
1671 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1672
1673 numnote = 2;
1674
1675 auxv = (elf_addr_t *) current->mm->saved_auxv;
1676
1677 i = 0;
1678 do
1679 i += 2;
1680 while (auxv[i - 2] != AT_NULL);
1681 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1682 i * sizeof(elf_addr_t), auxv);
1683
1684 /* Try to dump the FPU. */
1685 if ((prstatus->pr_fpvalid =
1686 elf_core_copy_task_fpregs(current, regs, fpu)))
1687 fill_note(notes + numnote++,
1688 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1689 #ifdef ELF_CORE_COPY_XFPREGS
1690 if (elf_core_copy_task_xfpregs(current, xfpu))
1691 fill_note(notes + numnote++,
1692 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1693 #endif
1694
1695 fs = get_fs();
1696 set_fs(KERNEL_DS);
1697
1698 DUMP_WRITE(elf, sizeof(*elf));
1699 offset += sizeof(*elf); /* Elf header */
1700 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */
1701
1702 /* Write notes phdr entry */
1703 {
1704 struct elf_phdr phdr;
1705 int sz = 0;
1706
1707 for (i = 0; i < numnote; i++)
1708 sz += notesize(notes + i);
1709
1710 sz += thread_status_size;
1711
1712 fill_elf_note_phdr(&phdr, sz, offset);
1713 offset += sz;
1714 DUMP_WRITE(&phdr, sizeof(phdr));
1715 }
1716
1717 /* Page-align dumped data */
1718 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1719
1720 /*
1721 * We must use the same mm->flags while dumping core to avoid
1722 * inconsistency between the program headers and bodies, otherwise an
1723 * unusable core file can be generated.
1724 */
1725 mm_flags = current->mm->flags;
1726
1727 /* write program headers for segments dump */
1728 for (
1729 #ifdef CONFIG_MMU
1730 vma = current->mm->mmap; vma; vma = vma->vm_next
1731 #else
1732 vml = current->mm->context.vmlist; vml; vml = vml->next
1733 #endif
1734 ) {
1735 struct elf_phdr phdr;
1736 size_t sz;
1737
1738 #ifndef CONFIG_MMU
1739 vma = vml->vma;
1740 #endif
1741
1742 sz = vma->vm_end - vma->vm_start;
1743
1744 phdr.p_type = PT_LOAD;
1745 phdr.p_offset = offset;
1746 phdr.p_vaddr = vma->vm_start;
1747 phdr.p_paddr = 0;
1748 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
1749 phdr.p_memsz = sz;
1750 offset += phdr.p_filesz;
1751 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1752 if (vma->vm_flags & VM_WRITE)
1753 phdr.p_flags |= PF_W;
1754 if (vma->vm_flags & VM_EXEC)
1755 phdr.p_flags |= PF_X;
1756 phdr.p_align = ELF_EXEC_PAGESIZE;
1757
1758 DUMP_WRITE(&phdr, sizeof(phdr));
1759 }
1760
1761 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1762 ELF_CORE_WRITE_EXTRA_PHDRS;
1763 #endif
1764
1765 /* write out the notes section */
1766 for (i = 0; i < numnote; i++)
1767 if (!writenote(notes + i, file))
1768 goto end_coredump;
1769
1770 /* write out the thread status notes section */
1771 list_for_each(t, &thread_list) {
1772 struct elf_thread_status *tmp =
1773 list_entry(t, struct elf_thread_status, list);
1774
1775 for (i = 0; i < tmp->num_notes; i++)
1776 if (!writenote(&tmp->notes[i], file))
1777 goto end_coredump;
1778 }
1779
1780 DUMP_SEEK(dataoff);
1781
1782 if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
1783 goto end_coredump;
1784
1785 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1786 ELF_CORE_WRITE_EXTRA_DATA;
1787 #endif
1788
1789 if (file->f_pos != offset) {
1790 /* Sanity check */
1791 printk(KERN_WARNING
1792 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1793 file->f_pos, offset);
1794 }
1795
1796 end_coredump:
1797 set_fs(fs);
1798
1799 cleanup:
1800 while (!list_empty(&thread_list)) {
1801 struct list_head *tmp = thread_list.next;
1802 list_del(tmp);
1803 kfree(list_entry(tmp, struct elf_thread_status, list));
1804 }
1805
1806 kfree(elf);
1807 kfree(prstatus);
1808 kfree(psinfo);
1809 kfree(notes);
1810 kfree(fpu);
1811 #ifdef ELF_CORE_COPY_XFPREGS
1812 kfree(xfpu);
1813 #endif
1814 return has_dumped;
1815 #undef NUM_NOTES
1816 }
1817
1818 #endif /* USE_ELF_CORE_DUMP */
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