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tcp: add helper for lost bit toggling
[linux-2.6/mini2440.git] / fs / binfmt_elf_fdpic.c
blob80c1f952ef7814fc36b099457c6ab11c670c1884
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 (unlikely(retval != size))
140 return retval < 0 ? retval : -ENOEXEC;
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 (unlikely(retval != phdr->p_filesz)) {
222 if (retval >= 0)
223 retval = -ENOEXEC;
224 goto error;
225 }
226
227 retval = -ENOENT;
228 if (interpreter_name[phdr->p_filesz - 1] != '\0')
229 goto error;
230
231 kdebug("Using ELF interpreter %s", interpreter_name);
232
233 /* replace the program with the interpreter */
234 interpreter = open_exec(interpreter_name);
235 retval = PTR_ERR(interpreter);
236 if (IS_ERR(interpreter)) {
237 interpreter = NULL;
238 goto error;
239 }
240
241 /*
242 * If the binary is not readable then enforce
243 * mm->dumpable = 0 regardless of the interpreter's
244 * permissions.
245 */
246 if (file_permission(interpreter, MAY_READ) < 0)
247 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
248
249 retval = kernel_read(interpreter, 0, bprm->buf,
250 BINPRM_BUF_SIZE);
251 if (unlikely(retval != BINPRM_BUF_SIZE)) {
252 if (retval >= 0)
253 retval = -ENOEXEC;
254 goto error;
255 }
256
257 interp_params.hdr = *((struct elfhdr *) bprm->buf);
258 break;
259
260 case PT_LOAD:
261 #ifdef CONFIG_MMU
262 if (exec_params.load_addr == 0)
263 exec_params.load_addr = phdr->p_vaddr;
264 #endif
265 break;
266 }
267
268 }
269
270 if (elf_check_const_displacement(&exec_params.hdr))
271 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
272
273 /* perform insanity checks on the interpreter */
274 if (interpreter_name) {
275 retval = -ELIBBAD;
276 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
277 goto error;
278
279 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
280
281 /* read the interpreter's program header table */
282 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
283 if (retval < 0)
284 goto error;
285 }
286
287 stack_size = exec_params.stack_size;
288 if (stack_size < interp_params.stack_size)
289 stack_size = interp_params.stack_size;
290
291 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
292 executable_stack = EXSTACK_ENABLE_X;
293 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
294 executable_stack = EXSTACK_DISABLE_X;
295 else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
296 executable_stack = EXSTACK_ENABLE_X;
297 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
298 executable_stack = EXSTACK_DISABLE_X;
299 else
300 executable_stack = EXSTACK_DEFAULT;
301
302 retval = -ENOEXEC;
303 if (stack_size == 0)
304 goto error;
305
306 if (elf_check_const_displacement(&interp_params.hdr))
307 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
308
309 /* flush all traces of the currently running executable */
310 retval = flush_old_exec(bprm);
311 if (retval)
312 goto error;
313
314 /* there's now no turning back... the old userspace image is dead,
315 * defunct, deceased, etc. after this point we have to exit via
316 * error_kill */
317 set_personality(PER_LINUX_FDPIC);
318 set_binfmt(&elf_fdpic_format);
319
320 current->mm->start_code = 0;
321 current->mm->end_code = 0;
322 current->mm->start_stack = 0;
323 current->mm->start_data = 0;
324 current->mm->end_data = 0;
325 current->mm->context.exec_fdpic_loadmap = 0;
326 current->mm->context.interp_fdpic_loadmap = 0;
327
328 current->flags &= ~PF_FORKNOEXEC;
329
330 #ifdef CONFIG_MMU
331 elf_fdpic_arch_lay_out_mm(&exec_params,
332 &interp_params,
333 &current->mm->start_stack,
334 &current->mm->start_brk);
335
336 retval = setup_arg_pages(bprm, current->mm->start_stack,
337 executable_stack);
338 if (retval < 0) {
339 send_sig(SIGKILL, current, 0);
340 goto error_kill;
341 }
342 #endif
343
344 /* load the executable and interpreter into memory */
345 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
346 "executable");
347 if (retval < 0)
348 goto error_kill;
349
350 if (interpreter_name) {
351 retval = elf_fdpic_map_file(&interp_params, interpreter,
352 current->mm, "interpreter");
353 if (retval < 0) {
354 printk(KERN_ERR "Unable to load interpreter\n");
355 goto error_kill;
356 }
357
358 allow_write_access(interpreter);
359 fput(interpreter);
360 interpreter = NULL;
361 }
362
363 #ifdef CONFIG_MMU
364 if (!current->mm->start_brk)
365 current->mm->start_brk = current->mm->end_data;
366
367 current->mm->brk = current->mm->start_brk =
368 PAGE_ALIGN(current->mm->start_brk);
369
370 #else
371 /* create a stack and brk area big enough for everyone
372 * - the brk heap starts at the bottom and works up
373 * - the stack starts at the top and works down
374 */
375 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
376 if (stack_size < PAGE_SIZE * 2)
377 stack_size = PAGE_SIZE * 2;
378
379 down_write(&current->mm->mmap_sem);
380 current->mm->start_brk = do_mmap(NULL, 0, stack_size,
381 PROT_READ | PROT_WRITE | PROT_EXEC,
382 MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN,
383 0);
384
385 if (IS_ERR_VALUE(current->mm->start_brk)) {
386 up_write(&current->mm->mmap_sem);
387 retval = current->mm->start_brk;
388 current->mm->start_brk = 0;
389 goto error_kill;
390 }
391
392 /* expand the stack mapping to use up the entire allocation granule */
393 fullsize = kobjsize((char *) current->mm->start_brk);
394 if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
395 fullsize, 0, 0)))
396 stack_size = fullsize;
397 up_write(&current->mm->mmap_sem);
398
399 current->mm->brk = current->mm->start_brk;
400 current->mm->context.end_brk = current->mm->start_brk;
401 current->mm->context.end_brk +=
402 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
403 current->mm->start_stack = current->mm->start_brk + stack_size;
404 #endif
405
406 compute_creds(bprm);
407 current->flags &= ~PF_FORKNOEXEC;
408 if (create_elf_fdpic_tables(bprm, current->mm,
409 &exec_params, &interp_params) < 0)
410 goto error_kill;
411
412 kdebug("- start_code %lx", current->mm->start_code);
413 kdebug("- end_code %lx", current->mm->end_code);
414 kdebug("- start_data %lx", current->mm->start_data);
415 kdebug("- end_data %lx", current->mm->end_data);
416 kdebug("- start_brk %lx", current->mm->start_brk);
417 kdebug("- brk %lx", current->mm->brk);
418 kdebug("- start_stack %lx", current->mm->start_stack);
419
420 #ifdef ELF_FDPIC_PLAT_INIT
421 /*
422 * The ABI may specify that certain registers be set up in special
423 * ways (on i386 %edx is the address of a DT_FINI function, for
424 * example. This macro performs whatever initialization to
425 * the regs structure is required.
426 */
427 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
428 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
429 dynaddr);
430 #endif
431
432 /* everything is now ready... get the userspace context ready to roll */
433 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
434 start_thread(regs, entryaddr, current->mm->start_stack);
435
436 retval = 0;
437
438 error:
439 if (interpreter) {
440 allow_write_access(interpreter);
441 fput(interpreter);
442 }
443 kfree(interpreter_name);
444 kfree(exec_params.phdrs);
445 kfree(exec_params.loadmap);
446 kfree(interp_params.phdrs);
447 kfree(interp_params.loadmap);
448 return retval;
449
450 /* unrecoverable error - kill the process */
451 error_kill:
452 send_sig(SIGSEGV, current, 0);
453 goto error;
454
455 }
456
457 /*****************************************************************************/
458 /*
459 * present useful information to the program
460 */
461 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
462 struct mm_struct *mm,
463 struct elf_fdpic_params *exec_params,
464 struct elf_fdpic_params *interp_params)
465 {
466 unsigned long sp, csp, nitems;
467 elf_caddr_t __user *argv, *envp;
468 size_t platform_len = 0, len;
469 char *k_platform;
470 char __user *u_platform, *p;
471 long hwcap;
472 int loop;
473 int nr; /* reset for each csp adjustment */
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) + AT_VECTOR_SIZE_ARCH;
547
548 csp = sp;
549 sp -= nitems * 2 * sizeof(unsigned long);
550 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
551 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
552 sp -= 1 * sizeof(unsigned long); /* argc */
553
554 csp -= sp & 15UL;
555 sp -= sp & 15UL;
556
557 /* put the ELF interpreter info on the stack */
558 #define NEW_AUX_ENT(id, val) \
559 do { \
560 struct { unsigned long _id, _val; } __user *ent; \
561 \
562 ent = (void __user *) csp; \
563 __put_user((id), &ent[nr]._id); \
564 __put_user((val), &ent[nr]._val); \
565 nr++; \
566 } while (0)
567
568 nr = 0;
569 csp -= 2 * sizeof(unsigned long);
570 NEW_AUX_ENT(AT_NULL, 0);
571 if (k_platform) {
572 nr = 0;
573 csp -= 2 * sizeof(unsigned long);
574 NEW_AUX_ENT(AT_PLATFORM,
575 (elf_addr_t) (unsigned long) u_platform);
576 }
577
578 nr = 0;
579 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
580 NEW_AUX_ENT(AT_HWCAP, hwcap);
581 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
582 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
583 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
584 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
585 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
586 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
587 NEW_AUX_ENT(AT_FLAGS, 0);
588 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
589 NEW_AUX_ENT(AT_UID, (elf_addr_t) current->uid);
590 NEW_AUX_ENT(AT_EUID, (elf_addr_t) current->euid);
591 NEW_AUX_ENT(AT_GID, (elf_addr_t) current->gid);
592 NEW_AUX_ENT(AT_EGID, (elf_addr_t) current->egid);
593
594 #ifdef ARCH_DLINFO
595 nr = 0;
596 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
597
598 /* ARCH_DLINFO must come last so platform specific code can enforce
599 * special alignment requirements on the AUXV if necessary (eg. PPC).
600 */
601 ARCH_DLINFO;
602 #endif
603 #undef NEW_AUX_ENT
604
605 /* allocate room for argv[] and envv[] */
606 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
607 envp = (elf_caddr_t __user *) csp;
608 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
609 argv = (elf_caddr_t __user *) csp;
610
611 /* stack argc */
612 csp -= sizeof(unsigned long);
613 __put_user(bprm->argc, (unsigned long __user *) csp);
614
615 BUG_ON(csp != sp);
616
617 /* fill in the argv[] array */
618 #ifdef CONFIG_MMU
619 current->mm->arg_start = bprm->p;
620 #else
621 current->mm->arg_start = current->mm->start_stack -
622 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
623 #endif
624
625 p = (char __user *) current->mm->arg_start;
626 for (loop = bprm->argc; loop > 0; loop--) {
627 __put_user((elf_caddr_t) p, argv++);
628 len = strnlen_user(p, MAX_ARG_STRLEN);
629 if (!len || len > MAX_ARG_STRLEN)
630 return -EINVAL;
631 p += len;
632 }
633 __put_user(NULL, argv);
634 current->mm->arg_end = (unsigned long) p;
635
636 /* fill in the envv[] array */
637 current->mm->env_start = (unsigned long) p;
638 for (loop = bprm->envc; loop > 0; loop--) {
639 __put_user((elf_caddr_t)(unsigned long) p, envp++);
640 len = strnlen_user(p, MAX_ARG_STRLEN);
641 if (!len || len > MAX_ARG_STRLEN)
642 return -EINVAL;
643 p += len;
644 }
645 __put_user(NULL, envp);
646 current->mm->env_end = (unsigned long) p;
647
648 mm->start_stack = (unsigned long) sp;
649 return 0;
650 }
651
652 /*****************************************************************************/
653 /*
654 * transfer the program arguments and environment from the holding pages onto
655 * the stack
656 */
657 #ifndef CONFIG_MMU
658 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
659 unsigned long *_sp)
660 {
661 unsigned long index, stop, sp;
662 char *src;
663 int ret = 0;
664
665 stop = bprm->p >> PAGE_SHIFT;
666 sp = *_sp;
667
668 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
669 src = kmap(bprm->page[index]);
670 sp -= PAGE_SIZE;
671 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
672 ret = -EFAULT;
673 kunmap(bprm->page[index]);
674 if (ret < 0)
675 goto out;
676 }
677
678 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
679
680 out:
681 return ret;
682 }
683 #endif
684
685 /*****************************************************************************/
686 /*
687 * load the appropriate binary image (executable or interpreter) into memory
688 * - we assume no MMU is available
689 * - if no other PIC bits are set in params->hdr->e_flags
690 * - we assume that the LOADable segments in the binary are independently relocatable
691 * - we assume R/O executable segments are shareable
692 * - else
693 * - we assume the loadable parts of the image to require fixed displacement
694 * - the image is not shareable
695 */
696 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
697 struct file *file,
698 struct mm_struct *mm,
699 const char *what)
700 {
701 struct elf32_fdpic_loadmap *loadmap;
702 #ifdef CONFIG_MMU
703 struct elf32_fdpic_loadseg *mseg;
704 #endif
705 struct elf32_fdpic_loadseg *seg;
706 struct elf32_phdr *phdr;
707 unsigned long load_addr, stop;
708 unsigned nloads, tmp;
709 size_t size;
710 int loop, ret;
711
712 /* allocate a load map table */
713 nloads = 0;
714 for (loop = 0; loop < params->hdr.e_phnum; loop++)
715 if (params->phdrs[loop].p_type == PT_LOAD)
716 nloads++;
717
718 if (nloads == 0)
719 return -ELIBBAD;
720
721 size = sizeof(*loadmap) + nloads * sizeof(*seg);
722 loadmap = kzalloc(size, GFP_KERNEL);
723 if (!loadmap)
724 return -ENOMEM;
725
726 params->loadmap = loadmap;
727
728 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
729 loadmap->nsegs = nloads;
730
731 load_addr = params->load_addr;
732 seg = loadmap->segs;
733
734 /* map the requested LOADs into the memory space */
735 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
736 case ELF_FDPIC_FLAG_CONSTDISP:
737 case ELF_FDPIC_FLAG_CONTIGUOUS:
738 #ifndef CONFIG_MMU
739 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
740 if (ret < 0)
741 return ret;
742 break;
743 #endif
744 default:
745 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
746 if (ret < 0)
747 return ret;
748 break;
749 }
750
751 /* map the entry point */
752 if (params->hdr.e_entry) {
753 seg = loadmap->segs;
754 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
755 if (params->hdr.e_entry >= seg->p_vaddr &&
756 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
757 params->entry_addr =
758 (params->hdr.e_entry - seg->p_vaddr) +
759 seg->addr;
760 break;
761 }
762 }
763 }
764
765 /* determine where the program header table has wound up if mapped */
766 stop = params->hdr.e_phoff;
767 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
768 phdr = params->phdrs;
769
770 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
771 if (phdr->p_type != PT_LOAD)
772 continue;
773
774 if (phdr->p_offset > params->hdr.e_phoff ||
775 phdr->p_offset + phdr->p_filesz < stop)
776 continue;
777
778 seg = loadmap->segs;
779 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
780 if (phdr->p_vaddr >= seg->p_vaddr &&
781 phdr->p_vaddr + phdr->p_filesz <=
782 seg->p_vaddr + seg->p_memsz) {
783 params->ph_addr =
784 (phdr->p_vaddr - seg->p_vaddr) +
785 seg->addr +
786 params->hdr.e_phoff - phdr->p_offset;
787 break;
788 }
789 }
790 break;
791 }
792
793 /* determine where the dynamic section has wound up if there is one */
794 phdr = params->phdrs;
795 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
796 if (phdr->p_type != PT_DYNAMIC)
797 continue;
798
799 seg = loadmap->segs;
800 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
801 if (phdr->p_vaddr >= seg->p_vaddr &&
802 phdr->p_vaddr + phdr->p_memsz <=
803 seg->p_vaddr + seg->p_memsz) {
804 params->dynamic_addr =
805 (phdr->p_vaddr - seg->p_vaddr) +
806 seg->addr;
807
808 /* check the dynamic section contains at least
809 * one item, and that the last item is a NULL
810 * entry */
811 if (phdr->p_memsz == 0 ||
812 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
813 goto dynamic_error;
814
815 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
816 if (((Elf32_Dyn *)
817 params->dynamic_addr)[tmp - 1].d_tag != 0)
818 goto dynamic_error;
819 break;
820 }
821 }
822 break;
823 }
824
825 /* now elide adjacent segments in the load map on MMU linux
826 * - on uClinux the holes between may actually be filled with system
827 * stuff or stuff from other processes
828 */
829 #ifdef CONFIG_MMU
830 nloads = loadmap->nsegs;
831 mseg = loadmap->segs;
832 seg = mseg + 1;
833 for (loop = 1; loop < nloads; loop++) {
834 /* see if we have a candidate for merging */
835 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
836 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
837 if (load_addr == (seg->addr & PAGE_MASK)) {
838 mseg->p_memsz +=
839 load_addr -
840 (mseg->addr + mseg->p_memsz);
841 mseg->p_memsz += seg->addr & ~PAGE_MASK;
842 mseg->p_memsz += seg->p_memsz;
843 loadmap->nsegs--;
844 continue;
845 }
846 }
847
848 mseg++;
849 if (mseg != seg)
850 *mseg = *seg;
851 }
852 #endif
853
854 kdebug("Mapped Object [%s]:", what);
855 kdebug("- elfhdr : %lx", params->elfhdr_addr);
856 kdebug("- entry : %lx", params->entry_addr);
857 kdebug("- PHDR[] : %lx", params->ph_addr);
858 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
859 seg = loadmap->segs;
860 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
861 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
862 loop,
863 seg->addr, seg->addr + seg->p_memsz - 1,
864 seg->p_vaddr, seg->p_memsz);
865
866 return 0;
867
868 dynamic_error:
869 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
870 what, file->f_path.dentry->d_inode->i_ino);
871 return -ELIBBAD;
872 }
873
874 /*****************************************************************************/
875 /*
876 * map a file with constant displacement under uClinux
877 */
878 #ifndef CONFIG_MMU
879 static int elf_fdpic_map_file_constdisp_on_uclinux(
880 struct elf_fdpic_params *params,
881 struct file *file,
882 struct mm_struct *mm)
883 {
884 struct elf32_fdpic_loadseg *seg;
885 struct elf32_phdr *phdr;
886 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
887 loff_t fpos;
888 int loop, ret;
889
890 load_addr = params->load_addr;
891 seg = params->loadmap->segs;
892
893 /* determine the bounds of the contiguous overall allocation we must
894 * make */
895 phdr = params->phdrs;
896 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
897 if (params->phdrs[loop].p_type != PT_LOAD)
898 continue;
899
900 if (base > phdr->p_vaddr)
901 base = phdr->p_vaddr;
902 if (top < phdr->p_vaddr + phdr->p_memsz)
903 top = phdr->p_vaddr + phdr->p_memsz;
904 }
905
906 /* allocate one big anon block for everything */
907 mflags = MAP_PRIVATE;
908 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
909 mflags |= MAP_EXECUTABLE;
910
911 down_write(&mm->mmap_sem);
912 maddr = do_mmap(NULL, load_addr, top - base,
913 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
914 up_write(&mm->mmap_sem);
915 if (IS_ERR_VALUE(maddr))
916 return (int) maddr;
917
918 if (load_addr != 0)
919 load_addr += PAGE_ALIGN(top - base);
920
921 /* and then load the file segments into it */
922 phdr = params->phdrs;
923 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
924 if (params->phdrs[loop].p_type != PT_LOAD)
925 continue;
926
927 fpos = phdr->p_offset;
928
929 seg->addr = maddr + (phdr->p_vaddr - base);
930 seg->p_vaddr = phdr->p_vaddr;
931 seg->p_memsz = phdr->p_memsz;
932
933 ret = file->f_op->read(file, (void *) seg->addr,
934 phdr->p_filesz, &fpos);
935 if (ret < 0)
936 return ret;
937
938 /* map the ELF header address if in this segment */
939 if (phdr->p_offset == 0)
940 params->elfhdr_addr = seg->addr;
941
942 /* clear any space allocated but not loaded */
943 if (phdr->p_filesz < phdr->p_memsz)
944 clear_user((void *) (seg->addr + phdr->p_filesz),
945 phdr->p_memsz - phdr->p_filesz);
946
947 if (mm) {
948 if (phdr->p_flags & PF_X) {
949 if (!mm->start_code) {
950 mm->start_code = seg->addr;
951 mm->end_code = seg->addr +
952 phdr->p_memsz;
953 }
954 } else if (!mm->start_data) {
955 mm->start_data = seg->addr;
956 #ifndef CONFIG_MMU
957 mm->end_data = seg->addr + phdr->p_memsz;
958 #endif
959 }
960
961 #ifdef CONFIG_MMU
962 if (seg->addr + phdr->p_memsz > mm->end_data)
963 mm->end_data = seg->addr + phdr->p_memsz;
964 #endif
965 }
966
967 seg++;
968 }
969
970 return 0;
971 }
972 #endif
973
974 /*****************************************************************************/
975 /*
976 * map a binary by direct mmap() of the individual PT_LOAD segments
977 */
978 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
979 struct file *file,
980 struct mm_struct *mm)
981 {
982 struct elf32_fdpic_loadseg *seg;
983 struct elf32_phdr *phdr;
984 unsigned long load_addr, delta_vaddr;
985 int loop, dvset;
986
987 load_addr = params->load_addr;
988 delta_vaddr = 0;
989 dvset = 0;
990
991 seg = params->loadmap->segs;
992
993 /* deal with each load segment separately */
994 phdr = params->phdrs;
995 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
996 unsigned long maddr, disp, excess, excess1;
997 int prot = 0, flags;
998
999 if (phdr->p_type != PT_LOAD)
1000 continue;
1001
1002 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1003 (unsigned long) phdr->p_vaddr,
1004 (unsigned long) phdr->p_offset,
1005 (unsigned long) phdr->p_filesz,
1006 (unsigned long) phdr->p_memsz);
1007
1008 /* determine the mapping parameters */
1009 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1010 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1011 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1012
1013 flags = MAP_PRIVATE | MAP_DENYWRITE;
1014 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1015 flags |= MAP_EXECUTABLE;
1016
1017 maddr = 0;
1018
1019 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1020 case ELF_FDPIC_FLAG_INDEPENDENT:
1021 /* PT_LOADs are independently locatable */
1022 break;
1023
1024 case ELF_FDPIC_FLAG_HONOURVADDR:
1025 /* the specified virtual address must be honoured */
1026 maddr = phdr->p_vaddr;
1027 flags |= MAP_FIXED;
1028 break;
1029
1030 case ELF_FDPIC_FLAG_CONSTDISP:
1031 /* constant displacement
1032 * - can be mapped anywhere, but must be mapped as a
1033 * unit
1034 */
1035 if (!dvset) {
1036 maddr = load_addr;
1037 delta_vaddr = phdr->p_vaddr;
1038 dvset = 1;
1039 } else {
1040 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1041 flags |= MAP_FIXED;
1042 }
1043 break;
1044
1045 case ELF_FDPIC_FLAG_CONTIGUOUS:
1046 /* contiguity handled later */
1047 break;
1048
1049 default:
1050 BUG();
1051 }
1052
1053 maddr &= PAGE_MASK;
1054
1055 /* create the mapping */
1056 disp = phdr->p_vaddr & ~PAGE_MASK;
1057 down_write(&mm->mmap_sem);
1058 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1059 phdr->p_offset - disp);
1060 up_write(&mm->mmap_sem);
1061
1062 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1063 loop, phdr->p_memsz + disp, prot, flags,
1064 phdr->p_offset - disp, maddr);
1065
1066 if (IS_ERR_VALUE(maddr))
1067 return (int) maddr;
1068
1069 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1070 ELF_FDPIC_FLAG_CONTIGUOUS)
1071 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1072
1073 seg->addr = maddr + disp;
1074 seg->p_vaddr = phdr->p_vaddr;
1075 seg->p_memsz = phdr->p_memsz;
1076
1077 /* map the ELF header address if in this segment */
1078 if (phdr->p_offset == 0)
1079 params->elfhdr_addr = seg->addr;
1080
1081 /* clear the bit between beginning of mapping and beginning of
1082 * PT_LOAD */
1083 if (prot & PROT_WRITE && disp > 0) {
1084 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1085 clear_user((void __user *) maddr, disp);
1086 maddr += disp;
1087 }
1088
1089 /* clear any space allocated but not loaded
1090 * - on uClinux we can just clear the lot
1091 * - on MMU linux we'll get a SIGBUS beyond the last page
1092 * extant in the file
1093 */
1094 excess = phdr->p_memsz - phdr->p_filesz;
1095 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1096
1097 #ifdef CONFIG_MMU
1098 if (excess > excess1) {
1099 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1100 unsigned long xmaddr;
1101
1102 flags |= MAP_FIXED | MAP_ANONYMOUS;
1103 down_write(&mm->mmap_sem);
1104 xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1105 prot, flags, 0);
1106 up_write(&mm->mmap_sem);
1107
1108 kdebug("mmap[%d] <anon>"
1109 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1110 loop, xaddr, excess - excess1, prot, flags,
1111 xmaddr);
1112
1113 if (xmaddr != xaddr)
1114 return -ENOMEM;
1115 }
1116
1117 if (prot & PROT_WRITE && excess1 > 0) {
1118 kdebug("clear[%d] ad=%lx sz=%lx",
1119 loop, maddr + phdr->p_filesz, excess1);
1120 clear_user((void __user *) maddr + phdr->p_filesz,
1121 excess1);
1122 }
1123
1124 #else
1125 if (excess > 0) {
1126 kdebug("clear[%d] ad=%lx sz=%lx",
1127 loop, maddr + phdr->p_filesz, excess);
1128 clear_user((void *) maddr + phdr->p_filesz, excess);
1129 }
1130 #endif
1131
1132 if (mm) {
1133 if (phdr->p_flags & PF_X) {
1134 if (!mm->start_code) {
1135 mm->start_code = maddr;
1136 mm->end_code = maddr + phdr->p_memsz;
1137 }
1138 } else if (!mm->start_data) {
1139 mm->start_data = maddr;
1140 mm->end_data = maddr + phdr->p_memsz;
1141 }
1142 }
1143
1144 seg++;
1145 }
1146
1147 return 0;
1148 }
1149
1150 /*****************************************************************************/
1151 /*
1152 * ELF-FDPIC core dumper
1153 *
1154 * Modelled on fs/exec.c:aout_core_dump()
1155 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1156 *
1157 * Modelled on fs/binfmt_elf.c core dumper
1158 */
1159 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1160
1161 /*
1162 * These are the only things you should do on a core-file: use only these
1163 * functions to write out all the necessary info.
1164 */
1165 static int dump_write(struct file *file, const void *addr, int nr)
1166 {
1167 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1168 }
1169
1170 static int dump_seek(struct file *file, loff_t off)
1171 {
1172 if (file->f_op->llseek) {
1173 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1174 return 0;
1175 } else {
1176 file->f_pos = off;
1177 }
1178 return 1;
1179 }
1180
1181 /*
1182 * Decide whether a segment is worth dumping; default is yes to be
1183 * sure (missing info is worse than too much; etc).
1184 * Personally I'd include everything, and use the coredump limit...
1185 *
1186 * I think we should skip something. But I am not sure how. H.J.
1187 */
1188 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1189 {
1190 int dump_ok;
1191
1192 /* Do not dump I/O mapped devices or special mappings */
1193 if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1194 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1195 return 0;
1196 }
1197
1198 /* If we may not read the contents, don't allow us to dump
1199 * them either. "dump_write()" can't handle it anyway.
1200 */
1201 if (!(vma->vm_flags & VM_READ)) {
1202 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1203 return 0;
1204 }
1205
1206 /* By default, dump shared memory if mapped from an anonymous file. */
1207 if (vma->vm_flags & VM_SHARED) {
1208 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1209 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1210 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1211 vma->vm_flags, dump_ok ? "yes" : "no");
1212 return dump_ok;
1213 }
1214
1215 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1216 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1217 vma->vm_flags, dump_ok ? "yes" : "no");
1218 return dump_ok;
1219 }
1220
1221 #ifdef CONFIG_MMU
1222 /* By default, if it hasn't been written to, don't write it out */
1223 if (!vma->anon_vma) {
1224 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1225 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1226 vma->vm_flags, dump_ok ? "yes" : "no");
1227 return dump_ok;
1228 }
1229 #endif
1230
1231 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1232 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1233 dump_ok ? "yes" : "no");
1234 return dump_ok;
1235 }
1236
1237 /* An ELF note in memory */
1238 struct memelfnote
1239 {
1240 const char *name;
1241 int type;
1242 unsigned int datasz;
1243 void *data;
1244 };
1245
1246 static int notesize(struct memelfnote *en)
1247 {
1248 int sz;
1249
1250 sz = sizeof(struct elf_note);
1251 sz += roundup(strlen(en->name) + 1, 4);
1252 sz += roundup(en->datasz, 4);
1253
1254 return sz;
1255 }
1256
1257 /* #define DEBUG */
1258
1259 #define DUMP_WRITE(addr, nr) \
1260 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1261 #define DUMP_SEEK(off) \
1262 do { if (!dump_seek(file, (off))) return 0; } while(0)
1263
1264 static int writenote(struct memelfnote *men, struct file *file)
1265 {
1266 struct elf_note en;
1267
1268 en.n_namesz = strlen(men->name) + 1;
1269 en.n_descsz = men->datasz;
1270 en.n_type = men->type;
1271
1272 DUMP_WRITE(&en, sizeof(en));
1273 DUMP_WRITE(men->name, en.n_namesz);
1274 /* XXX - cast from long long to long to avoid need for libgcc.a */
1275 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1276 DUMP_WRITE(men->data, men->datasz);
1277 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1278
1279 return 1;
1280 }
1281 #undef DUMP_WRITE
1282 #undef DUMP_SEEK
1283
1284 #define DUMP_WRITE(addr, nr) \
1285 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1286 goto end_coredump;
1287 #define DUMP_SEEK(off) \
1288 if (!dump_seek(file, (off))) \
1289 goto end_coredump;
1290
1291 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1292 {
1293 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1294 elf->e_ident[EI_CLASS] = ELF_CLASS;
1295 elf->e_ident[EI_DATA] = ELF_DATA;
1296 elf->e_ident[EI_VERSION] = EV_CURRENT;
1297 elf->e_ident[EI_OSABI] = ELF_OSABI;
1298 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1299
1300 elf->e_type = ET_CORE;
1301 elf->e_machine = ELF_ARCH;
1302 elf->e_version = EV_CURRENT;
1303 elf->e_entry = 0;
1304 elf->e_phoff = sizeof(struct elfhdr);
1305 elf->e_shoff = 0;
1306 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1307 elf->e_ehsize = sizeof(struct elfhdr);
1308 elf->e_phentsize = sizeof(struct elf_phdr);
1309 elf->e_phnum = segs;
1310 elf->e_shentsize = 0;
1311 elf->e_shnum = 0;
1312 elf->e_shstrndx = 0;
1313 return;
1314 }
1315
1316 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1317 {
1318 phdr->p_type = PT_NOTE;
1319 phdr->p_offset = offset;
1320 phdr->p_vaddr = 0;
1321 phdr->p_paddr = 0;
1322 phdr->p_filesz = sz;
1323 phdr->p_memsz = 0;
1324 phdr->p_flags = 0;
1325 phdr->p_align = 0;
1326 return;
1327 }
1328
1329 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1330 unsigned int sz, void *data)
1331 {
1332 note->name = name;
1333 note->type = type;
1334 note->datasz = sz;
1335 note->data = data;
1336 return;
1337 }
1338
1339 /*
1340 * fill up all the fields in prstatus from the given task struct, except
1341 * registers which need to be filled up seperately.
1342 */
1343 static void fill_prstatus(struct elf_prstatus *prstatus,
1344 struct task_struct *p, long signr)
1345 {
1346 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1347 prstatus->pr_sigpend = p->pending.signal.sig[0];
1348 prstatus->pr_sighold = p->blocked.sig[0];
1349 prstatus->pr_pid = task_pid_vnr(p);
1350 prstatus->pr_ppid = task_pid_vnr(p->parent);
1351 prstatus->pr_pgrp = task_pgrp_vnr(p);
1352 prstatus->pr_sid = task_session_vnr(p);
1353 if (thread_group_leader(p)) {
1354 /*
1355 * This is the record for the group leader. Add in the
1356 * cumulative times of previous dead threads. This total
1357 * won't include the time of each live thread whose state
1358 * is included in the core dump. The final total reported
1359 * to our parent process when it calls wait4 will include
1360 * those sums as well as the little bit more time it takes
1361 * this and each other thread to finish dying after the
1362 * core dump synchronization phase.
1363 */
1364 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1365 &prstatus->pr_utime);
1366 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1367 &prstatus->pr_stime);
1368 } else {
1369 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1370 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1371 }
1372 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1373 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1374
1375 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1376 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1377 }
1378
1379 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1380 struct mm_struct *mm)
1381 {
1382 unsigned int i, len;
1383
1384 /* first copy the parameters from user space */
1385 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1386
1387 len = mm->arg_end - mm->arg_start;
1388 if (len >= ELF_PRARGSZ)
1389 len = ELF_PRARGSZ - 1;
1390 if (copy_from_user(&psinfo->pr_psargs,
1391 (const char __user *) mm->arg_start, len))
1392 return -EFAULT;
1393 for (i = 0; i < len; i++)
1394 if (psinfo->pr_psargs[i] == 0)
1395 psinfo->pr_psargs[i] = ' ';
1396 psinfo->pr_psargs[len] = 0;
1397
1398 psinfo->pr_pid = task_pid_vnr(p);
1399 psinfo->pr_ppid = task_pid_vnr(p->parent);
1400 psinfo->pr_pgrp = task_pgrp_vnr(p);
1401 psinfo->pr_sid = task_session_vnr(p);
1402
1403 i = p->state ? ffz(~p->state) + 1 : 0;
1404 psinfo->pr_state = i;
1405 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1406 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1407 psinfo->pr_nice = task_nice(p);
1408 psinfo->pr_flag = p->flags;
1409 SET_UID(psinfo->pr_uid, p->uid);
1410 SET_GID(psinfo->pr_gid, p->gid);
1411 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1412
1413 return 0;
1414 }
1415
1416 /* Here is the structure in which status of each thread is captured. */
1417 struct elf_thread_status
1418 {
1419 struct list_head list;
1420 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1421 elf_fpregset_t fpu; /* NT_PRFPREG */
1422 struct task_struct *thread;
1423 #ifdef ELF_CORE_COPY_XFPREGS
1424 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1425 #endif
1426 struct memelfnote notes[3];
1427 int num_notes;
1428 };
1429
1430 /*
1431 * In order to add the specific thread information for the elf file format,
1432 * we need to keep a linked list of every thread's pr_status and then create
1433 * a single section for them in the final core file.
1434 */
1435 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1436 {
1437 struct task_struct *p = t->thread;
1438 int sz = 0;
1439
1440 t->num_notes = 0;
1441
1442 fill_prstatus(&t->prstatus, p, signr);
1443 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1444
1445 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1446 &t->prstatus);
1447 t->num_notes++;
1448 sz += notesize(&t->notes[0]);
1449
1450 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1451 if (t->prstatus.pr_fpvalid) {
1452 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1453 &t->fpu);
1454 t->num_notes++;
1455 sz += notesize(&t->notes[1]);
1456 }
1457
1458 #ifdef ELF_CORE_COPY_XFPREGS
1459 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1460 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1461 sizeof(t->xfpu), &t->xfpu);
1462 t->num_notes++;
1463 sz += notesize(&t->notes[2]);
1464 }
1465 #endif
1466 return sz;
1467 }
1468
1469 /*
1470 * dump the segments for an MMU process
1471 */
1472 #ifdef CONFIG_MMU
1473 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1474 unsigned long *limit, unsigned long mm_flags)
1475 {
1476 struct vm_area_struct *vma;
1477
1478 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1479 unsigned long addr;
1480
1481 if (!maydump(vma, mm_flags))
1482 continue;
1483
1484 for (addr = vma->vm_start;
1485 addr < vma->vm_end;
1486 addr += PAGE_SIZE
1487 ) {
1488 struct vm_area_struct *vma;
1489 struct page *page;
1490
1491 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1492 &page, &vma) <= 0) {
1493 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1494 }
1495 else if (page == ZERO_PAGE(0)) {
1496 page_cache_release(page);
1497 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1498 }
1499 else {
1500 void *kaddr;
1501
1502 flush_cache_page(vma, addr, page_to_pfn(page));
1503 kaddr = kmap(page);
1504 if ((*size += PAGE_SIZE) > *limit ||
1505 !dump_write(file, kaddr, PAGE_SIZE)
1506 ) {
1507 kunmap(page);
1508 page_cache_release(page);
1509 return -EIO;
1510 }
1511 kunmap(page);
1512 page_cache_release(page);
1513 }
1514 }
1515 }
1516
1517 return 0;
1518
1519 end_coredump:
1520 return -EFBIG;
1521 }
1522 #endif
1523
1524 /*
1525 * dump the segments for a NOMMU process
1526 */
1527 #ifndef CONFIG_MMU
1528 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1529 unsigned long *limit, unsigned long mm_flags)
1530 {
1531 struct vm_list_struct *vml;
1532
1533 for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
1534 struct vm_area_struct *vma = vml->vma;
1535
1536 if (!maydump(vma, mm_flags))
1537 continue;
1538
1539 if ((*size += PAGE_SIZE) > *limit)
1540 return -EFBIG;
1541
1542 if (!dump_write(file, (void *) vma->vm_start,
1543 vma->vm_end - vma->vm_start))
1544 return -EIO;
1545 }
1546
1547 return 0;
1548 }
1549 #endif
1550
1551 /*
1552 * Actual dumper
1553 *
1554 * This is a two-pass process; first we find the offsets of the bits,
1555 * and then they are actually written out. If we run out of core limit
1556 * we just truncate.
1557 */
1558 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1559 struct file *file, unsigned long limit)
1560 {
1561 #define NUM_NOTES 6
1562 int has_dumped = 0;
1563 mm_segment_t fs;
1564 int segs;
1565 size_t size = 0;
1566 int i;
1567 struct vm_area_struct *vma;
1568 struct elfhdr *elf = NULL;
1569 loff_t offset = 0, dataoff;
1570 int numnote;
1571 struct memelfnote *notes = NULL;
1572 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1573 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1574 LIST_HEAD(thread_list);
1575 struct list_head *t;
1576 elf_fpregset_t *fpu = NULL;
1577 #ifdef ELF_CORE_COPY_XFPREGS
1578 elf_fpxregset_t *xfpu = NULL;
1579 #endif
1580 int thread_status_size = 0;
1581 #ifndef CONFIG_MMU
1582 struct vm_list_struct *vml;
1583 #endif
1584 elf_addr_t *auxv;
1585 unsigned long mm_flags;
1586
1587 /*
1588 * We no longer stop all VM operations.
1589 *
1590 * This is because those proceses that could possibly change map_count
1591 * or the mmap / vma pages are now blocked in do_exit on current
1592 * finishing this core dump.
1593 *
1594 * Only ptrace can touch these memory addresses, but it doesn't change
1595 * the map_count or the pages allocated. So no possibility of crashing
1596 * exists while dumping the mm->vm_next areas to the core file.
1597 */
1598
1599 /* alloc memory for large data structures: too large to be on stack */
1600 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1601 if (!elf)
1602 goto cleanup;
1603 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1604 if (!prstatus)
1605 goto cleanup;
1606 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1607 if (!psinfo)
1608 goto cleanup;
1609 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1610 if (!notes)
1611 goto cleanup;
1612 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1613 if (!fpu)
1614 goto cleanup;
1615 #ifdef ELF_CORE_COPY_XFPREGS
1616 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1617 if (!xfpu)
1618 goto cleanup;
1619 #endif
1620
1621 if (signr) {
1622 struct core_thread *ct;
1623 struct elf_thread_status *tmp;
1624
1625 for (ct = current->mm->core_state->dumper.next;
1626 ct; ct = ct->next) {
1627 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1628 if (!tmp)
1629 goto cleanup;
1630
1631 tmp->thread = ct->task;
1632 list_add(&tmp->list, &thread_list);
1633 }
1634
1635 list_for_each(t, &thread_list) {
1636 struct elf_thread_status *tmp;
1637 int sz;
1638
1639 tmp = list_entry(t, struct elf_thread_status, list);
1640 sz = elf_dump_thread_status(signr, tmp);
1641 thread_status_size += sz;
1642 }
1643 }
1644
1645 /* now collect the dump for the current */
1646 fill_prstatus(prstatus, current, signr);
1647 elf_core_copy_regs(&prstatus->pr_reg, regs);
1648
1649 #ifdef CONFIG_MMU
1650 segs = current->mm->map_count;
1651 #else
1652 segs = 0;
1653 for (vml = current->mm->context.vmlist; vml; vml = vml->next)
1654 segs++;
1655 #endif
1656 #ifdef ELF_CORE_EXTRA_PHDRS
1657 segs += ELF_CORE_EXTRA_PHDRS;
1658 #endif
1659
1660 /* Set up header */
1661 fill_elf_fdpic_header(elf, segs + 1); /* including notes section */
1662
1663 has_dumped = 1;
1664 current->flags |= PF_DUMPCORE;
1665
1666 /*
1667 * Set up the notes in similar form to SVR4 core dumps made
1668 * with info from their /proc.
1669 */
1670
1671 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1672 fill_psinfo(psinfo, current->group_leader, current->mm);
1673 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1674
1675 numnote = 2;
1676
1677 auxv = (elf_addr_t *) current->mm->saved_auxv;
1678
1679 i = 0;
1680 do
1681 i += 2;
1682 while (auxv[i - 2] != AT_NULL);
1683 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1684 i * sizeof(elf_addr_t), auxv);
1685
1686 /* Try to dump the FPU. */
1687 if ((prstatus->pr_fpvalid =
1688 elf_core_copy_task_fpregs(current, regs, fpu)))
1689 fill_note(notes + numnote++,
1690 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1691 #ifdef ELF_CORE_COPY_XFPREGS
1692 if (elf_core_copy_task_xfpregs(current, xfpu))
1693 fill_note(notes + numnote++,
1694 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1695 #endif
1696
1697 fs = get_fs();
1698 set_fs(KERNEL_DS);
1699
1700 DUMP_WRITE(elf, sizeof(*elf));
1701 offset += sizeof(*elf); /* Elf header */
1702 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */
1703
1704 /* Write notes phdr entry */
1705 {
1706 struct elf_phdr phdr;
1707 int sz = 0;
1708
1709 for (i = 0; i < numnote; i++)
1710 sz += notesize(notes + i);
1711
1712 sz += thread_status_size;
1713
1714 fill_elf_note_phdr(&phdr, sz, offset);
1715 offset += sz;
1716 DUMP_WRITE(&phdr, sizeof(phdr));
1717 }
1718
1719 /* Page-align dumped data */
1720 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1721
1722 /*
1723 * We must use the same mm->flags while dumping core to avoid
1724 * inconsistency between the program headers and bodies, otherwise an
1725 * unusable core file can be generated.
1726 */
1727 mm_flags = current->mm->flags;
1728
1729 /* write program headers for segments dump */
1730 for (
1731 #ifdef CONFIG_MMU
1732 vma = current->mm->mmap; vma; vma = vma->vm_next
1733 #else
1734 vml = current->mm->context.vmlist; vml; vml = vml->next
1735 #endif
1736 ) {
1737 struct elf_phdr phdr;
1738 size_t sz;
1739
1740 #ifndef CONFIG_MMU
1741 vma = vml->vma;
1742 #endif
1743
1744 sz = vma->vm_end - vma->vm_start;
1745
1746 phdr.p_type = PT_LOAD;
1747 phdr.p_offset = offset;
1748 phdr.p_vaddr = vma->vm_start;
1749 phdr.p_paddr = 0;
1750 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
1751 phdr.p_memsz = sz;
1752 offset += phdr.p_filesz;
1753 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1754 if (vma->vm_flags & VM_WRITE)
1755 phdr.p_flags |= PF_W;
1756 if (vma->vm_flags & VM_EXEC)
1757 phdr.p_flags |= PF_X;
1758 phdr.p_align = ELF_EXEC_PAGESIZE;
1759
1760 DUMP_WRITE(&phdr, sizeof(phdr));
1761 }
1762
1763 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1764 ELF_CORE_WRITE_EXTRA_PHDRS;
1765 #endif
1766
1767 /* write out the notes section */
1768 for (i = 0; i < numnote; i++)
1769 if (!writenote(notes + i, file))
1770 goto end_coredump;
1771
1772 /* write out the thread status notes section */
1773 list_for_each(t, &thread_list) {
1774 struct elf_thread_status *tmp =
1775 list_entry(t, struct elf_thread_status, list);
1776
1777 for (i = 0; i < tmp->num_notes; i++)
1778 if (!writenote(&tmp->notes[i], file))
1779 goto end_coredump;
1780 }
1781
1782 DUMP_SEEK(dataoff);
1783
1784 if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
1785 goto end_coredump;
1786
1787 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1788 ELF_CORE_WRITE_EXTRA_DATA;
1789 #endif
1790
1791 if (file->f_pos != offset) {
1792 /* Sanity check */
1793 printk(KERN_WARNING
1794 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1795 file->f_pos, offset);
1796 }
1797
1798 end_coredump:
1799 set_fs(fs);
1800
1801 cleanup:
1802 while (!list_empty(&thread_list)) {
1803 struct list_head *tmp = thread_list.next;
1804 list_del(tmp);
1805 kfree(list_entry(tmp, struct elf_thread_status, list));
1806 }
1807
1808 kfree(elf);
1809 kfree(prstatus);
1810 kfree(psinfo);
1811 kfree(notes);
1812 kfree(fpu);
1813 #ifdef ELF_CORE_COPY_XFPREGS
1814 kfree(xfpu);
1815 #endif
1816 return has_dumped;
1817 #undef NUM_NOTES
1818 }
1819
1820 #endif /* USE_ELF_CORE_DUMP */
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