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xen-balloon: clean up unused functions
[linux-2.6/linux-2.6-openrd.git] / fs / binfmt_elf_fdpic.c
blobfdeadab2f18bb030288f00e98755bfb2b4cba1e3
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
474 /* we're going to shovel a whole load of stuff onto the stack */
475 #ifdef CONFIG_MMU
476 sp = bprm->p;
477 #else
478 sp = mm->start_stack;
479
480 /* stack the program arguments and environment */
481 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
482 return -EFAULT;
483 #endif
484
485 /* get hold of platform and hardware capabilities masks for the machine
486 * we are running on. In some cases (Sparc), this info is impossible
487 * to get, in others (i386) it is merely difficult.
488 */
489 hwcap = ELF_HWCAP;
490 k_platform = ELF_PLATFORM;
491 u_platform = NULL;
492
493 if (k_platform) {
494 platform_len = strlen(k_platform) + 1;
495 sp -= platform_len;
496 u_platform = (char __user *) sp;
497 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
498 return -EFAULT;
499 }
500
501 #if defined(__i386__) && defined(CONFIG_SMP)
502 /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
503 * by the processes running on the same package. One thing we can do is
504 * to shuffle the initial stack for them.
505 *
506 * the conditionals here are unneeded, but kept in to make the code
507 * behaviour the same as pre change unless we have hyperthreaded
508 * processors. This keeps Mr Marcelo Person happier but should be
509 * removed for 2.5
510 */
511 if (smp_num_siblings > 1)
512 sp = sp - ((current->pid % 64) << 7);
513 #endif
514
515 sp &= ~7UL;
516
517 /* stack the load map(s) */
518 len = sizeof(struct elf32_fdpic_loadmap);
519 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
520 sp = (sp - len) & ~7UL;
521 exec_params->map_addr = sp;
522
523 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
524 return -EFAULT;
525
526 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
527
528 if (interp_params->loadmap) {
529 len = sizeof(struct elf32_fdpic_loadmap);
530 len += sizeof(struct elf32_fdpic_loadseg) *
531 interp_params->loadmap->nsegs;
532 sp = (sp - len) & ~7UL;
533 interp_params->map_addr = sp;
534
535 if (copy_to_user((void __user *) sp, interp_params->loadmap,
536 len) != 0)
537 return -EFAULT;
538
539 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
540 }
541
542 /* force 16 byte _final_ alignment here for generality */
543 #define DLINFO_ITEMS 13
544
545 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0);
546 #ifdef DLINFO_ARCH_ITEMS
547 nitems += DLINFO_ARCH_ITEMS;
548 #endif
549
550 csp = sp;
551 sp -= nitems * 2 * sizeof(unsigned long);
552 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
553 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
554 sp -= 1 * sizeof(unsigned long); /* argc */
555
556 csp -= sp & 15UL;
557 sp -= sp & 15UL;
558
559 /* put the ELF interpreter info on the stack */
560 #define NEW_AUX_ENT(nr, id, val) \
561 do { \
562 struct { unsigned long _id, _val; } __user *ent; \
563 \
564 ent = (void __user *) csp; \
565 __put_user((id), &ent[nr]._id); \
566 __put_user((val), &ent[nr]._val); \
567 } while (0)
568
569 csp -= 2 * sizeof(unsigned long);
570 NEW_AUX_ENT(0, AT_NULL, 0);
571 if (k_platform) {
572 csp -= 2 * sizeof(unsigned long);
573 NEW_AUX_ENT(0, AT_PLATFORM,
574 (elf_addr_t) (unsigned long) u_platform);
575 }
576
577 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
578 NEW_AUX_ENT( 0, AT_HWCAP, hwcap);
579 NEW_AUX_ENT( 1, AT_PAGESZ, PAGE_SIZE);
580 NEW_AUX_ENT( 2, AT_CLKTCK, CLOCKS_PER_SEC);
581 NEW_AUX_ENT( 3, AT_PHDR, exec_params->ph_addr);
582 NEW_AUX_ENT( 4, AT_PHENT, sizeof(struct elf_phdr));
583 NEW_AUX_ENT( 5, AT_PHNUM, exec_params->hdr.e_phnum);
584 NEW_AUX_ENT( 6, AT_BASE, interp_params->elfhdr_addr);
585 NEW_AUX_ENT( 7, AT_FLAGS, 0);
586 NEW_AUX_ENT( 8, AT_ENTRY, exec_params->entry_addr);
587 NEW_AUX_ENT( 9, AT_UID, (elf_addr_t) current->uid);
588 NEW_AUX_ENT(10, AT_EUID, (elf_addr_t) current->euid);
589 NEW_AUX_ENT(11, AT_GID, (elf_addr_t) current->gid);
590 NEW_AUX_ENT(12, AT_EGID, (elf_addr_t) current->egid);
591
592 #ifdef ARCH_DLINFO
593 /* ARCH_DLINFO must come last so platform specific code can enforce
594 * special alignment requirements on the AUXV if necessary (eg. PPC).
595 */
596 ARCH_DLINFO;
597 #endif
598 #undef NEW_AUX_ENT
599
600 /* allocate room for argv[] and envv[] */
601 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
602 envp = (elf_caddr_t __user *) csp;
603 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
604 argv = (elf_caddr_t __user *) csp;
605
606 /* stack argc */
607 csp -= sizeof(unsigned long);
608 __put_user(bprm->argc, (unsigned long __user *) csp);
609
610 BUG_ON(csp != sp);
611
612 /* fill in the argv[] array */
613 #ifdef CONFIG_MMU
614 current->mm->arg_start = bprm->p;
615 #else
616 current->mm->arg_start = current->mm->start_stack -
617 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
618 #endif
619
620 p = (char __user *) current->mm->arg_start;
621 for (loop = bprm->argc; loop > 0; loop--) {
622 __put_user((elf_caddr_t) p, argv++);
623 len = strnlen_user(p, MAX_ARG_STRLEN);
624 if (!len || len > MAX_ARG_STRLEN)
625 return -EINVAL;
626 p += len;
627 }
628 __put_user(NULL, argv);
629 current->mm->arg_end = (unsigned long) p;
630
631 /* fill in the envv[] array */
632 current->mm->env_start = (unsigned long) p;
633 for (loop = bprm->envc; loop > 0; loop--) {
634 __put_user((elf_caddr_t)(unsigned long) p, envp++);
635 len = strnlen_user(p, MAX_ARG_STRLEN);
636 if (!len || len > MAX_ARG_STRLEN)
637 return -EINVAL;
638 p += len;
639 }
640 __put_user(NULL, envp);
641 current->mm->env_end = (unsigned long) p;
642
643 mm->start_stack = (unsigned long) sp;
644 return 0;
645 }
646
647 /*****************************************************************************/
648 /*
649 * transfer the program arguments and environment from the holding pages onto
650 * the stack
651 */
652 #ifndef CONFIG_MMU
653 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
654 unsigned long *_sp)
655 {
656 unsigned long index, stop, sp;
657 char *src;
658 int ret = 0;
659
660 stop = bprm->p >> PAGE_SHIFT;
661 sp = *_sp;
662
663 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
664 src = kmap(bprm->page[index]);
665 sp -= PAGE_SIZE;
666 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
667 ret = -EFAULT;
668 kunmap(bprm->page[index]);
669 if (ret < 0)
670 goto out;
671 }
672
673 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
674
675 out:
676 return ret;
677 }
678 #endif
679
680 /*****************************************************************************/
681 /*
682 * load the appropriate binary image (executable or interpreter) into memory
683 * - we assume no MMU is available
684 * - if no other PIC bits are set in params->hdr->e_flags
685 * - we assume that the LOADable segments in the binary are independently relocatable
686 * - we assume R/O executable segments are shareable
687 * - else
688 * - we assume the loadable parts of the image to require fixed displacement
689 * - the image is not shareable
690 */
691 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
692 struct file *file,
693 struct mm_struct *mm,
694 const char *what)
695 {
696 struct elf32_fdpic_loadmap *loadmap;
697 #ifdef CONFIG_MMU
698 struct elf32_fdpic_loadseg *mseg;
699 #endif
700 struct elf32_fdpic_loadseg *seg;
701 struct elf32_phdr *phdr;
702 unsigned long load_addr, stop;
703 unsigned nloads, tmp;
704 size_t size;
705 int loop, ret;
706
707 /* allocate a load map table */
708 nloads = 0;
709 for (loop = 0; loop < params->hdr.e_phnum; loop++)
710 if (params->phdrs[loop].p_type == PT_LOAD)
711 nloads++;
712
713 if (nloads == 0)
714 return -ELIBBAD;
715
716 size = sizeof(*loadmap) + nloads * sizeof(*seg);
717 loadmap = kzalloc(size, GFP_KERNEL);
718 if (!loadmap)
719 return -ENOMEM;
720
721 params->loadmap = loadmap;
722
723 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
724 loadmap->nsegs = nloads;
725
726 load_addr = params->load_addr;
727 seg = loadmap->segs;
728
729 /* map the requested LOADs into the memory space */
730 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
731 case ELF_FDPIC_FLAG_CONSTDISP:
732 case ELF_FDPIC_FLAG_CONTIGUOUS:
733 #ifndef CONFIG_MMU
734 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
735 if (ret < 0)
736 return ret;
737 break;
738 #endif
739 default:
740 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
741 if (ret < 0)
742 return ret;
743 break;
744 }
745
746 /* map the entry point */
747 if (params->hdr.e_entry) {
748 seg = loadmap->segs;
749 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
750 if (params->hdr.e_entry >= seg->p_vaddr &&
751 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
752 params->entry_addr =
753 (params->hdr.e_entry - seg->p_vaddr) +
754 seg->addr;
755 break;
756 }
757 }
758 }
759
760 /* determine where the program header table has wound up if mapped */
761 stop = params->hdr.e_phoff;
762 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
763 phdr = params->phdrs;
764
765 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
766 if (phdr->p_type != PT_LOAD)
767 continue;
768
769 if (phdr->p_offset > params->hdr.e_phoff ||
770 phdr->p_offset + phdr->p_filesz < stop)
771 continue;
772
773 seg = loadmap->segs;
774 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
775 if (phdr->p_vaddr >= seg->p_vaddr &&
776 phdr->p_vaddr + phdr->p_filesz <=
777 seg->p_vaddr + seg->p_memsz) {
778 params->ph_addr =
779 (phdr->p_vaddr - seg->p_vaddr) +
780 seg->addr +
781 params->hdr.e_phoff - phdr->p_offset;
782 break;
783 }
784 }
785 break;
786 }
787
788 /* determine where the dynamic section has wound up if there is one */
789 phdr = params->phdrs;
790 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
791 if (phdr->p_type != PT_DYNAMIC)
792 continue;
793
794 seg = loadmap->segs;
795 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
796 if (phdr->p_vaddr >= seg->p_vaddr &&
797 phdr->p_vaddr + phdr->p_memsz <=
798 seg->p_vaddr + seg->p_memsz) {
799 params->dynamic_addr =
800 (phdr->p_vaddr - seg->p_vaddr) +
801 seg->addr;
802
803 /* check the dynamic section contains at least
804 * one item, and that the last item is a NULL
805 * entry */
806 if (phdr->p_memsz == 0 ||
807 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
808 goto dynamic_error;
809
810 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
811 if (((Elf32_Dyn *)
812 params->dynamic_addr)[tmp - 1].d_tag != 0)
813 goto dynamic_error;
814 break;
815 }
816 }
817 break;
818 }
819
820 /* now elide adjacent segments in the load map on MMU linux
821 * - on uClinux the holes between may actually be filled with system
822 * stuff or stuff from other processes
823 */
824 #ifdef CONFIG_MMU
825 nloads = loadmap->nsegs;
826 mseg = loadmap->segs;
827 seg = mseg + 1;
828 for (loop = 1; loop < nloads; loop++) {
829 /* see if we have a candidate for merging */
830 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
831 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
832 if (load_addr == (seg->addr & PAGE_MASK)) {
833 mseg->p_memsz +=
834 load_addr -
835 (mseg->addr + mseg->p_memsz);
836 mseg->p_memsz += seg->addr & ~PAGE_MASK;
837 mseg->p_memsz += seg->p_memsz;
838 loadmap->nsegs--;
839 continue;
840 }
841 }
842
843 mseg++;
844 if (mseg != seg)
845 *mseg = *seg;
846 }
847 #endif
848
849 kdebug("Mapped Object [%s]:", what);
850 kdebug("- elfhdr : %lx", params->elfhdr_addr);
851 kdebug("- entry : %lx", params->entry_addr);
852 kdebug("- PHDR[] : %lx", params->ph_addr);
853 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
854 seg = loadmap->segs;
855 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
856 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
857 loop,
858 seg->addr, seg->addr + seg->p_memsz - 1,
859 seg->p_vaddr, seg->p_memsz);
860
861 return 0;
862
863 dynamic_error:
864 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
865 what, file->f_path.dentry->d_inode->i_ino);
866 return -ELIBBAD;
867 }
868
869 /*****************************************************************************/
870 /*
871 * map a file with constant displacement under uClinux
872 */
873 #ifndef CONFIG_MMU
874 static int elf_fdpic_map_file_constdisp_on_uclinux(
875 struct elf_fdpic_params *params,
876 struct file *file,
877 struct mm_struct *mm)
878 {
879 struct elf32_fdpic_loadseg *seg;
880 struct elf32_phdr *phdr;
881 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
882 loff_t fpos;
883 int loop, ret;
884
885 load_addr = params->load_addr;
886 seg = params->loadmap->segs;
887
888 /* determine the bounds of the contiguous overall allocation we must
889 * make */
890 phdr = params->phdrs;
891 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
892 if (params->phdrs[loop].p_type != PT_LOAD)
893 continue;
894
895 if (base > phdr->p_vaddr)
896 base = phdr->p_vaddr;
897 if (top < phdr->p_vaddr + phdr->p_memsz)
898 top = phdr->p_vaddr + phdr->p_memsz;
899 }
900
901 /* allocate one big anon block for everything */
902 mflags = MAP_PRIVATE;
903 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
904 mflags |= MAP_EXECUTABLE;
905
906 down_write(&mm->mmap_sem);
907 maddr = do_mmap(NULL, load_addr, top - base,
908 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
909 up_write(&mm->mmap_sem);
910 if (IS_ERR_VALUE(maddr))
911 return (int) maddr;
912
913 if (load_addr != 0)
914 load_addr += PAGE_ALIGN(top - base);
915
916 /* and then load the file segments into it */
917 phdr = params->phdrs;
918 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
919 if (params->phdrs[loop].p_type != PT_LOAD)
920 continue;
921
922 fpos = phdr->p_offset;
923
924 seg->addr = maddr + (phdr->p_vaddr - base);
925 seg->p_vaddr = phdr->p_vaddr;
926 seg->p_memsz = phdr->p_memsz;
927
928 ret = file->f_op->read(file, (void *) seg->addr,
929 phdr->p_filesz, &fpos);
930 if (ret < 0)
931 return ret;
932
933 /* map the ELF header address if in this segment */
934 if (phdr->p_offset == 0)
935 params->elfhdr_addr = seg->addr;
936
937 /* clear any space allocated but not loaded */
938 if (phdr->p_filesz < phdr->p_memsz)
939 clear_user((void *) (seg->addr + phdr->p_filesz),
940 phdr->p_memsz - phdr->p_filesz);
941
942 if (mm) {
943 if (phdr->p_flags & PF_X) {
944 if (!mm->start_code) {
945 mm->start_code = seg->addr;
946 mm->end_code = seg->addr +
947 phdr->p_memsz;
948 }
949 } else if (!mm->start_data) {
950 mm->start_data = seg->addr;
951 #ifndef CONFIG_MMU
952 mm->end_data = seg->addr + phdr->p_memsz;
953 #endif
954 }
955
956 #ifdef CONFIG_MMU
957 if (seg->addr + phdr->p_memsz > mm->end_data)
958 mm->end_data = seg->addr + phdr->p_memsz;
959 #endif
960 }
961
962 seg++;
963 }
964
965 return 0;
966 }
967 #endif
968
969 /*****************************************************************************/
970 /*
971 * map a binary by direct mmap() of the individual PT_LOAD segments
972 */
973 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
974 struct file *file,
975 struct mm_struct *mm)
976 {
977 struct elf32_fdpic_loadseg *seg;
978 struct elf32_phdr *phdr;
979 unsigned long load_addr, delta_vaddr;
980 int loop, dvset;
981
982 load_addr = params->load_addr;
983 delta_vaddr = 0;
984 dvset = 0;
985
986 seg = params->loadmap->segs;
987
988 /* deal with each load segment separately */
989 phdr = params->phdrs;
990 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
991 unsigned long maddr, disp, excess, excess1;
992 int prot = 0, flags;
993
994 if (phdr->p_type != PT_LOAD)
995 continue;
996
997 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
998 (unsigned long) phdr->p_vaddr,
999 (unsigned long) phdr->p_offset,
1000 (unsigned long) phdr->p_filesz,
1001 (unsigned long) phdr->p_memsz);
1002
1003 /* determine the mapping parameters */
1004 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1005 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1006 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1007
1008 flags = MAP_PRIVATE | MAP_DENYWRITE;
1009 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1010 flags |= MAP_EXECUTABLE;
1011
1012 maddr = 0;
1013
1014 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1015 case ELF_FDPIC_FLAG_INDEPENDENT:
1016 /* PT_LOADs are independently locatable */
1017 break;
1018
1019 case ELF_FDPIC_FLAG_HONOURVADDR:
1020 /* the specified virtual address must be honoured */
1021 maddr = phdr->p_vaddr;
1022 flags |= MAP_FIXED;
1023 break;
1024
1025 case ELF_FDPIC_FLAG_CONSTDISP:
1026 /* constant displacement
1027 * - can be mapped anywhere, but must be mapped as a
1028 * unit
1029 */
1030 if (!dvset) {
1031 maddr = load_addr;
1032 delta_vaddr = phdr->p_vaddr;
1033 dvset = 1;
1034 } else {
1035 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1036 flags |= MAP_FIXED;
1037 }
1038 break;
1039
1040 case ELF_FDPIC_FLAG_CONTIGUOUS:
1041 /* contiguity handled later */
1042 break;
1043
1044 default:
1045 BUG();
1046 }
1047
1048 maddr &= PAGE_MASK;
1049
1050 /* create the mapping */
1051 disp = phdr->p_vaddr & ~PAGE_MASK;
1052 down_write(&mm->mmap_sem);
1053 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1054 phdr->p_offset - disp);
1055 up_write(&mm->mmap_sem);
1056
1057 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1058 loop, phdr->p_memsz + disp, prot, flags,
1059 phdr->p_offset - disp, maddr);
1060
1061 if (IS_ERR_VALUE(maddr))
1062 return (int) maddr;
1063
1064 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1065 ELF_FDPIC_FLAG_CONTIGUOUS)
1066 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1067
1068 seg->addr = maddr + disp;
1069 seg->p_vaddr = phdr->p_vaddr;
1070 seg->p_memsz = phdr->p_memsz;
1071
1072 /* map the ELF header address if in this segment */
1073 if (phdr->p_offset == 0)
1074 params->elfhdr_addr = seg->addr;
1075
1076 /* clear the bit between beginning of mapping and beginning of
1077 * PT_LOAD */
1078 if (prot & PROT_WRITE && disp > 0) {
1079 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1080 clear_user((void __user *) maddr, disp);
1081 maddr += disp;
1082 }
1083
1084 /* clear any space allocated but not loaded
1085 * - on uClinux we can just clear the lot
1086 * - on MMU linux we'll get a SIGBUS beyond the last page
1087 * extant in the file
1088 */
1089 excess = phdr->p_memsz - phdr->p_filesz;
1090 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1091
1092 #ifdef CONFIG_MMU
1093 if (excess > excess1) {
1094 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1095 unsigned long xmaddr;
1096
1097 flags |= MAP_FIXED | MAP_ANONYMOUS;
1098 down_write(&mm->mmap_sem);
1099 xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1100 prot, flags, 0);
1101 up_write(&mm->mmap_sem);
1102
1103 kdebug("mmap[%d] <anon>"
1104 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1105 loop, xaddr, excess - excess1, prot, flags,
1106 xmaddr);
1107
1108 if (xmaddr != xaddr)
1109 return -ENOMEM;
1110 }
1111
1112 if (prot & PROT_WRITE && excess1 > 0) {
1113 kdebug("clear[%d] ad=%lx sz=%lx",
1114 loop, maddr + phdr->p_filesz, excess1);
1115 clear_user((void __user *) maddr + phdr->p_filesz,
1116 excess1);
1117 }
1118
1119 #else
1120 if (excess > 0) {
1121 kdebug("clear[%d] ad=%lx sz=%lx",
1122 loop, maddr + phdr->p_filesz, excess);
1123 clear_user((void *) maddr + phdr->p_filesz, excess);
1124 }
1125 #endif
1126
1127 if (mm) {
1128 if (phdr->p_flags & PF_X) {
1129 if (!mm->start_code) {
1130 mm->start_code = maddr;
1131 mm->end_code = maddr + phdr->p_memsz;
1132 }
1133 } else if (!mm->start_data) {
1134 mm->start_data = maddr;
1135 mm->end_data = maddr + phdr->p_memsz;
1136 }
1137 }
1138
1139 seg++;
1140 }
1141
1142 return 0;
1143 }
1144
1145 /*****************************************************************************/
1146 /*
1147 * ELF-FDPIC core dumper
1148 *
1149 * Modelled on fs/exec.c:aout_core_dump()
1150 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1151 *
1152 * Modelled on fs/binfmt_elf.c core dumper
1153 */
1154 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1155
1156 /*
1157 * These are the only things you should do on a core-file: use only these
1158 * functions to write out all the necessary info.
1159 */
1160 static int dump_write(struct file *file, const void *addr, int nr)
1161 {
1162 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1163 }
1164
1165 static int dump_seek(struct file *file, loff_t off)
1166 {
1167 if (file->f_op->llseek) {
1168 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1169 return 0;
1170 } else {
1171 file->f_pos = off;
1172 }
1173 return 1;
1174 }
1175
1176 /*
1177 * Decide whether a segment is worth dumping; default is yes to be
1178 * sure (missing info is worse than too much; etc).
1179 * Personally I'd include everything, and use the coredump limit...
1180 *
1181 * I think we should skip something. But I am not sure how. H.J.
1182 */
1183 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1184 {
1185 int dump_ok;
1186
1187 /* Do not dump I/O mapped devices or special mappings */
1188 if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1189 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1190 return 0;
1191 }
1192
1193 /* If we may not read the contents, don't allow us to dump
1194 * them either. "dump_write()" can't handle it anyway.
1195 */
1196 if (!(vma->vm_flags & VM_READ)) {
1197 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1198 return 0;
1199 }
1200
1201 /* By default, dump shared memory if mapped from an anonymous file. */
1202 if (vma->vm_flags & VM_SHARED) {
1203 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1204 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1205 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1206 vma->vm_flags, dump_ok ? "yes" : "no");
1207 return dump_ok;
1208 }
1209
1210 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1211 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1212 vma->vm_flags, dump_ok ? "yes" : "no");
1213 return dump_ok;
1214 }
1215
1216 #ifdef CONFIG_MMU
1217 /* By default, if it hasn't been written to, don't write it out */
1218 if (!vma->anon_vma) {
1219 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1220 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1221 vma->vm_flags, dump_ok ? "yes" : "no");
1222 return dump_ok;
1223 }
1224 #endif
1225
1226 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1227 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1228 dump_ok ? "yes" : "no");
1229 return dump_ok;
1230 }
1231
1232 /* An ELF note in memory */
1233 struct memelfnote
1234 {
1235 const char *name;
1236 int type;
1237 unsigned int datasz;
1238 void *data;
1239 };
1240
1241 static int notesize(struct memelfnote *en)
1242 {
1243 int sz;
1244
1245 sz = sizeof(struct elf_note);
1246 sz += roundup(strlen(en->name) + 1, 4);
1247 sz += roundup(en->datasz, 4);
1248
1249 return sz;
1250 }
1251
1252 /* #define DEBUG */
1253
1254 #define DUMP_WRITE(addr, nr) \
1255 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1256 #define DUMP_SEEK(off) \
1257 do { if (!dump_seek(file, (off))) return 0; } while(0)
1258
1259 static int writenote(struct memelfnote *men, struct file *file)
1260 {
1261 struct elf_note en;
1262
1263 en.n_namesz = strlen(men->name) + 1;
1264 en.n_descsz = men->datasz;
1265 en.n_type = men->type;
1266
1267 DUMP_WRITE(&en, sizeof(en));
1268 DUMP_WRITE(men->name, en.n_namesz);
1269 /* XXX - cast from long long to long to avoid need for libgcc.a */
1270 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1271 DUMP_WRITE(men->data, men->datasz);
1272 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1273
1274 return 1;
1275 }
1276 #undef DUMP_WRITE
1277 #undef DUMP_SEEK
1278
1279 #define DUMP_WRITE(addr, nr) \
1280 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1281 goto end_coredump;
1282 #define DUMP_SEEK(off) \
1283 if (!dump_seek(file, (off))) \
1284 goto end_coredump;
1285
1286 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1287 {
1288 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1289 elf->e_ident[EI_CLASS] = ELF_CLASS;
1290 elf->e_ident[EI_DATA] = ELF_DATA;
1291 elf->e_ident[EI_VERSION] = EV_CURRENT;
1292 elf->e_ident[EI_OSABI] = ELF_OSABI;
1293 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1294
1295 elf->e_type = ET_CORE;
1296 elf->e_machine = ELF_ARCH;
1297 elf->e_version = EV_CURRENT;
1298 elf->e_entry = 0;
1299 elf->e_phoff = sizeof(struct elfhdr);
1300 elf->e_shoff = 0;
1301 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1302 elf->e_ehsize = sizeof(struct elfhdr);
1303 elf->e_phentsize = sizeof(struct elf_phdr);
1304 elf->e_phnum = segs;
1305 elf->e_shentsize = 0;
1306 elf->e_shnum = 0;
1307 elf->e_shstrndx = 0;
1308 return;
1309 }
1310
1311 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1312 {
1313 phdr->p_type = PT_NOTE;
1314 phdr->p_offset = offset;
1315 phdr->p_vaddr = 0;
1316 phdr->p_paddr = 0;
1317 phdr->p_filesz = sz;
1318 phdr->p_memsz = 0;
1319 phdr->p_flags = 0;
1320 phdr->p_align = 0;
1321 return;
1322 }
1323
1324 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1325 unsigned int sz, void *data)
1326 {
1327 note->name = name;
1328 note->type = type;
1329 note->datasz = sz;
1330 note->data = data;
1331 return;
1332 }
1333
1334 /*
1335 * fill up all the fields in prstatus from the given task struct, except
1336 * registers which need to be filled up seperately.
1337 */
1338 static void fill_prstatus(struct elf_prstatus *prstatus,
1339 struct task_struct *p, long signr)
1340 {
1341 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1342 prstatus->pr_sigpend = p->pending.signal.sig[0];
1343 prstatus->pr_sighold = p->blocked.sig[0];
1344 prstatus->pr_pid = task_pid_vnr(p);
1345 prstatus->pr_ppid = task_pid_vnr(p->parent);
1346 prstatus->pr_pgrp = task_pgrp_vnr(p);
1347 prstatus->pr_sid = task_session_vnr(p);
1348 if (thread_group_leader(p)) {
1349 /*
1350 * This is the record for the group leader. Add in the
1351 * cumulative times of previous dead threads. This total
1352 * won't include the time of each live thread whose state
1353 * is included in the core dump. The final total reported
1354 * to our parent process when it calls wait4 will include
1355 * those sums as well as the little bit more time it takes
1356 * this and each other thread to finish dying after the
1357 * core dump synchronization phase.
1358 */
1359 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1360 &prstatus->pr_utime);
1361 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1362 &prstatus->pr_stime);
1363 } else {
1364 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1365 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1366 }
1367 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1368 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1369
1370 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1371 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1372 }
1373
1374 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1375 struct mm_struct *mm)
1376 {
1377 unsigned int i, len;
1378
1379 /* first copy the parameters from user space */
1380 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1381
1382 len = mm->arg_end - mm->arg_start;
1383 if (len >= ELF_PRARGSZ)
1384 len = ELF_PRARGSZ - 1;
1385 if (copy_from_user(&psinfo->pr_psargs,
1386 (const char __user *) mm->arg_start, len))
1387 return -EFAULT;
1388 for (i = 0; i < len; i++)
1389 if (psinfo->pr_psargs[i] == 0)
1390 psinfo->pr_psargs[i] = ' ';
1391 psinfo->pr_psargs[len] = 0;
1392
1393 psinfo->pr_pid = task_pid_vnr(p);
1394 psinfo->pr_ppid = task_pid_vnr(p->parent);
1395 psinfo->pr_pgrp = task_pgrp_vnr(p);
1396 psinfo->pr_sid = task_session_vnr(p);
1397
1398 i = p->state ? ffz(~p->state) + 1 : 0;
1399 psinfo->pr_state = i;
1400 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1401 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1402 psinfo->pr_nice = task_nice(p);
1403 psinfo->pr_flag = p->flags;
1404 SET_UID(psinfo->pr_uid, p->uid);
1405 SET_GID(psinfo->pr_gid, p->gid);
1406 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1407
1408 return 0;
1409 }
1410
1411 /* Here is the structure in which status of each thread is captured. */
1412 struct elf_thread_status
1413 {
1414 struct list_head list;
1415 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1416 elf_fpregset_t fpu; /* NT_PRFPREG */
1417 struct task_struct *thread;
1418 #ifdef ELF_CORE_COPY_XFPREGS
1419 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1420 #endif
1421 struct memelfnote notes[3];
1422 int num_notes;
1423 };
1424
1425 /*
1426 * In order to add the specific thread information for the elf file format,
1427 * we need to keep a linked list of every thread's pr_status and then create
1428 * a single section for them in the final core file.
1429 */
1430 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1431 {
1432 struct task_struct *p = t->thread;
1433 int sz = 0;
1434
1435 t->num_notes = 0;
1436
1437 fill_prstatus(&t->prstatus, p, signr);
1438 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1439
1440 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1441 &t->prstatus);
1442 t->num_notes++;
1443 sz += notesize(&t->notes[0]);
1444
1445 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1446 if (t->prstatus.pr_fpvalid) {
1447 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1448 &t->fpu);
1449 t->num_notes++;
1450 sz += notesize(&t->notes[1]);
1451 }
1452
1453 #ifdef ELF_CORE_COPY_XFPREGS
1454 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1455 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1456 sizeof(t->xfpu), &t->xfpu);
1457 t->num_notes++;
1458 sz += notesize(&t->notes[2]);
1459 }
1460 #endif
1461 return sz;
1462 }
1463
1464 /*
1465 * dump the segments for an MMU process
1466 */
1467 #ifdef CONFIG_MMU
1468 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1469 unsigned long *limit, unsigned long mm_flags)
1470 {
1471 struct vm_area_struct *vma;
1472
1473 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1474 unsigned long addr;
1475
1476 if (!maydump(vma, mm_flags))
1477 continue;
1478
1479 for (addr = vma->vm_start;
1480 addr < vma->vm_end;
1481 addr += PAGE_SIZE
1482 ) {
1483 struct vm_area_struct *vma;
1484 struct page *page;
1485
1486 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1487 &page, &vma) <= 0) {
1488 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1489 }
1490 else if (page == ZERO_PAGE(0)) {
1491 page_cache_release(page);
1492 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1493 }
1494 else {
1495 void *kaddr;
1496
1497 flush_cache_page(vma, addr, page_to_pfn(page));
1498 kaddr = kmap(page);
1499 if ((*size += PAGE_SIZE) > *limit ||
1500 !dump_write(file, kaddr, PAGE_SIZE)
1501 ) {
1502 kunmap(page);
1503 page_cache_release(page);
1504 return -EIO;
1505 }
1506 kunmap(page);
1507 page_cache_release(page);
1508 }
1509 }
1510 }
1511
1512 return 0;
1513
1514 end_coredump:
1515 return -EFBIG;
1516 }
1517 #endif
1518
1519 /*
1520 * dump the segments for a NOMMU process
1521 */
1522 #ifndef CONFIG_MMU
1523 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1524 unsigned long *limit, unsigned long mm_flags)
1525 {
1526 struct vm_list_struct *vml;
1527
1528 for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
1529 struct vm_area_struct *vma = vml->vma;
1530
1531 if (!maydump(vma, mm_flags))
1532 continue;
1533
1534 if ((*size += PAGE_SIZE) > *limit)
1535 return -EFBIG;
1536
1537 if (!dump_write(file, (void *) vma->vm_start,
1538 vma->vm_end - vma->vm_start))
1539 return -EIO;
1540 }
1541
1542 return 0;
1543 }
1544 #endif
1545
1546 /*
1547 * Actual dumper
1548 *
1549 * This is a two-pass process; first we find the offsets of the bits,
1550 * and then they are actually written out. If we run out of core limit
1551 * we just truncate.
1552 */
1553 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1554 struct file *file, unsigned long limit)
1555 {
1556 #define NUM_NOTES 6
1557 int has_dumped = 0;
1558 mm_segment_t fs;
1559 int segs;
1560 size_t size = 0;
1561 int i;
1562 struct vm_area_struct *vma;
1563 struct elfhdr *elf = NULL;
1564 loff_t offset = 0, dataoff;
1565 int numnote;
1566 struct memelfnote *notes = NULL;
1567 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1568 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1569 LIST_HEAD(thread_list);
1570 struct list_head *t;
1571 elf_fpregset_t *fpu = NULL;
1572 #ifdef ELF_CORE_COPY_XFPREGS
1573 elf_fpxregset_t *xfpu = NULL;
1574 #endif
1575 int thread_status_size = 0;
1576 #ifndef CONFIG_MMU
1577 struct vm_list_struct *vml;
1578 #endif
1579 elf_addr_t *auxv;
1580 unsigned long mm_flags;
1581
1582 /*
1583 * We no longer stop all VM operations.
1584 *
1585 * This is because those proceses that could possibly change map_count
1586 * or the mmap / vma pages are now blocked in do_exit on current
1587 * finishing this core dump.
1588 *
1589 * Only ptrace can touch these memory addresses, but it doesn't change
1590 * the map_count or the pages allocated. So no possibility of crashing
1591 * exists while dumping the mm->vm_next areas to the core file.
1592 */
1593
1594 /* alloc memory for large data structures: too large to be on stack */
1595 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1596 if (!elf)
1597 goto cleanup;
1598 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1599 if (!prstatus)
1600 goto cleanup;
1601 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1602 if (!psinfo)
1603 goto cleanup;
1604 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1605 if (!notes)
1606 goto cleanup;
1607 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1608 if (!fpu)
1609 goto cleanup;
1610 #ifdef ELF_CORE_COPY_XFPREGS
1611 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1612 if (!xfpu)
1613 goto cleanup;
1614 #endif
1615
1616 if (signr) {
1617 struct core_thread *ct;
1618 struct elf_thread_status *tmp;
1619
1620 for (ct = current->mm->core_state->dumper.next;
1621 ct; ct = ct->next) {
1622 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1623 if (!tmp)
1624 goto cleanup;
1625
1626 tmp->thread = ct->task;
1627 list_add(&tmp->list, &thread_list);
1628 }
1629
1630 list_for_each(t, &thread_list) {
1631 struct elf_thread_status *tmp;
1632 int sz;
1633
1634 tmp = list_entry(t, struct elf_thread_status, list);
1635 sz = elf_dump_thread_status(signr, tmp);
1636 thread_status_size += sz;
1637 }
1638 }
1639
1640 /* now collect the dump for the current */
1641 fill_prstatus(prstatus, current, signr);
1642 elf_core_copy_regs(&prstatus->pr_reg, regs);
1643
1644 #ifdef CONFIG_MMU
1645 segs = current->mm->map_count;
1646 #else
1647 segs = 0;
1648 for (vml = current->mm->context.vmlist; vml; vml = vml->next)
1649 segs++;
1650 #endif
1651 #ifdef ELF_CORE_EXTRA_PHDRS
1652 segs += ELF_CORE_EXTRA_PHDRS;
1653 #endif
1654
1655 /* Set up header */
1656 fill_elf_fdpic_header(elf, segs + 1); /* including notes section */
1657
1658 has_dumped = 1;
1659 current->flags |= PF_DUMPCORE;
1660
1661 /*
1662 * Set up the notes in similar form to SVR4 core dumps made
1663 * with info from their /proc.
1664 */
1665
1666 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1667 fill_psinfo(psinfo, current->group_leader, current->mm);
1668 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1669
1670 numnote = 2;
1671
1672 auxv = (elf_addr_t *) current->mm->saved_auxv;
1673
1674 i = 0;
1675 do
1676 i += 2;
1677 while (auxv[i - 2] != AT_NULL);
1678 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1679 i * sizeof(elf_addr_t), auxv);
1680
1681 /* Try to dump the FPU. */
1682 if ((prstatus->pr_fpvalid =
1683 elf_core_copy_task_fpregs(current, regs, fpu)))
1684 fill_note(notes + numnote++,
1685 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1686 #ifdef ELF_CORE_COPY_XFPREGS
1687 if (elf_core_copy_task_xfpregs(current, xfpu))
1688 fill_note(notes + numnote++,
1689 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1690 #endif
1691
1692 fs = get_fs();
1693 set_fs(KERNEL_DS);
1694
1695 DUMP_WRITE(elf, sizeof(*elf));
1696 offset += sizeof(*elf); /* Elf header */
1697 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */
1698
1699 /* Write notes phdr entry */
1700 {
1701 struct elf_phdr phdr;
1702 int sz = 0;
1703
1704 for (i = 0; i < numnote; i++)
1705 sz += notesize(notes + i);
1706
1707 sz += thread_status_size;
1708
1709 fill_elf_note_phdr(&phdr, sz, offset);
1710 offset += sz;
1711 DUMP_WRITE(&phdr, sizeof(phdr));
1712 }
1713
1714 /* Page-align dumped data */
1715 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1716
1717 /*
1718 * We must use the same mm->flags while dumping core to avoid
1719 * inconsistency between the program headers and bodies, otherwise an
1720 * unusable core file can be generated.
1721 */
1722 mm_flags = current->mm->flags;
1723
1724 /* write program headers for segments dump */
1725 for (
1726 #ifdef CONFIG_MMU
1727 vma = current->mm->mmap; vma; vma = vma->vm_next
1728 #else
1729 vml = current->mm->context.vmlist; vml; vml = vml->next
1730 #endif
1731 ) {
1732 struct elf_phdr phdr;
1733 size_t sz;
1734
1735 #ifndef CONFIG_MMU
1736 vma = vml->vma;
1737 #endif
1738
1739 sz = vma->vm_end - vma->vm_start;
1740
1741 phdr.p_type = PT_LOAD;
1742 phdr.p_offset = offset;
1743 phdr.p_vaddr = vma->vm_start;
1744 phdr.p_paddr = 0;
1745 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
1746 phdr.p_memsz = sz;
1747 offset += phdr.p_filesz;
1748 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1749 if (vma->vm_flags & VM_WRITE)
1750 phdr.p_flags |= PF_W;
1751 if (vma->vm_flags & VM_EXEC)
1752 phdr.p_flags |= PF_X;
1753 phdr.p_align = ELF_EXEC_PAGESIZE;
1754
1755 DUMP_WRITE(&phdr, sizeof(phdr));
1756 }
1757
1758 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1759 ELF_CORE_WRITE_EXTRA_PHDRS;
1760 #endif
1761
1762 /* write out the notes section */
1763 for (i = 0; i < numnote; i++)
1764 if (!writenote(notes + i, file))
1765 goto end_coredump;
1766
1767 /* write out the thread status notes section */
1768 list_for_each(t, &thread_list) {
1769 struct elf_thread_status *tmp =
1770 list_entry(t, struct elf_thread_status, list);
1771
1772 for (i = 0; i < tmp->num_notes; i++)
1773 if (!writenote(&tmp->notes[i], file))
1774 goto end_coredump;
1775 }
1776
1777 DUMP_SEEK(dataoff);
1778
1779 if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
1780 goto end_coredump;
1781
1782 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1783 ELF_CORE_WRITE_EXTRA_DATA;
1784 #endif
1785
1786 if (file->f_pos != offset) {
1787 /* Sanity check */
1788 printk(KERN_WARNING
1789 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1790 file->f_pos, offset);
1791 }
1792
1793 end_coredump:
1794 set_fs(fs);
1795
1796 cleanup:
1797 while (!list_empty(&thread_list)) {
1798 struct list_head *tmp = thread_list.next;
1799 list_del(tmp);
1800 kfree(list_entry(tmp, struct elf_thread_status, list));
1801 }
1802
1803 kfree(elf);
1804 kfree(prstatus);
1805 kfree(psinfo);
1806 kfree(notes);
1807 kfree(fpu);
1808 #ifdef ELF_CORE_COPY_XFPREGS
1809 kfree(xfpu);
1810 #endif
1811 return has_dumped;
1812 #undef NUM_NOTES
1813 }
1814
1815 #endif /* USE_ELF_CORE_DUMP */
linux 2.6 git repository for openrd