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Merge ../linus
[linux-2.6/next.git] / fs / binfmt_elf_fdpic.c
blob76f06f6bc2f6caee3579092b5cc938b40ce1faed
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/smp_lock.h>
34 #include <linux/elf.h>
35 #include <linux/elf-fdpic.h>
36 #include <linux/elfcore.h>
37
38 #include <asm/uaccess.h>
39 #include <asm/param.h>
40 #include <asm/pgalloc.h>
41
42 typedef char *elf_caddr_t;
43
44 #if 0
45 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
46 #else
47 #define kdebug(fmt, ...) do {} while(0)
48 #endif
49
50 #if 0
51 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
52 #else
53 #define kdcore(fmt, ...) do {} while(0)
54 #endif
55
56 MODULE_LICENSE("GPL");
57
58 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
59 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
60 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
61 struct mm_struct *, const char *);
62
63 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
64 struct elf_fdpic_params *,
65 struct elf_fdpic_params *);
66
67 #ifndef CONFIG_MMU
68 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
69 unsigned long *);
70 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
71 struct file *,
72 struct mm_struct *);
73 #endif
74
75 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
76 struct file *, struct mm_struct *);
77
78 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
79 static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *);
80 #endif
81
82 static struct linux_binfmt elf_fdpic_format = {
83 .module = THIS_MODULE,
84 .load_binary = load_elf_fdpic_binary,
85 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
86 .core_dump = elf_fdpic_core_dump,
87 #endif
88 .min_coredump = ELF_EXEC_PAGESIZE,
89 };
90
91 static int __init init_elf_fdpic_binfmt(void)
92 {
93 return register_binfmt(&elf_fdpic_format);
94 }
95
96 static void __exit exit_elf_fdpic_binfmt(void)
97 {
98 unregister_binfmt(&elf_fdpic_format);
99 }
100
101 core_initcall(init_elf_fdpic_binfmt);
102 module_exit(exit_elf_fdpic_binfmt);
103
104 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
105 {
106 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
107 return 0;
108 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
109 return 0;
110 if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
111 return 0;
112 if (!file->f_op || !file->f_op->mmap)
113 return 0;
114 return 1;
115 }
116
117 /*****************************************************************************/
118 /*
119 * read the program headers table into memory
120 */
121 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
122 struct file *file)
123 {
124 struct elf32_phdr *phdr;
125 unsigned long size;
126 int retval, loop;
127
128 if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
129 return -ENOMEM;
130 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
131 return -ENOMEM;
132
133 size = params->hdr.e_phnum * sizeof(struct elf_phdr);
134 params->phdrs = kmalloc(size, GFP_KERNEL);
135 if (!params->phdrs)
136 return -ENOMEM;
137
138 retval = kernel_read(file, params->hdr.e_phoff,
139 (char *) params->phdrs, size);
140 if (retval < 0)
141 return retval;
142
143 /* determine stack size for this binary */
144 phdr = params->phdrs;
145 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
146 if (phdr->p_type != PT_GNU_STACK)
147 continue;
148
149 if (phdr->p_flags & PF_X)
150 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
151 else
152 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
153
154 params->stack_size = phdr->p_memsz;
155 break;
156 }
157
158 return 0;
159 }
160
161 /*****************************************************************************/
162 /*
163 * load an fdpic binary into various bits of memory
164 */
165 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
166 struct pt_regs *regs)
167 {
168 struct elf_fdpic_params exec_params, interp_params;
169 struct elf_phdr *phdr;
170 unsigned long stack_size, entryaddr;
171 #ifndef CONFIG_MMU
172 unsigned long fullsize;
173 #endif
174 #ifdef ELF_FDPIC_PLAT_INIT
175 unsigned long dynaddr;
176 #endif
177 struct file *interpreter = NULL; /* to shut gcc up */
178 char *interpreter_name = NULL;
179 int executable_stack;
180 int retval, i;
181
182 memset(&exec_params, 0, sizeof(exec_params));
183 memset(&interp_params, 0, sizeof(interp_params));
184
185 exec_params.hdr = *(struct elfhdr *) bprm->buf;
186 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
187
188 /* check that this is a binary we know how to deal with */
189 retval = -ENOEXEC;
190 if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
191 goto error;
192
193 /* read the program header table */
194 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
195 if (retval < 0)
196 goto error;
197
198 /* scan for a program header that specifies an interpreter */
199 phdr = exec_params.phdrs;
200
201 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
202 switch (phdr->p_type) {
203 case PT_INTERP:
204 retval = -ENOMEM;
205 if (phdr->p_filesz > PATH_MAX)
206 goto error;
207 retval = -ENOENT;
208 if (phdr->p_filesz < 2)
209 goto error;
210
211 /* read the name of the interpreter into memory */
212 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
213 if (!interpreter_name)
214 goto error;
215
216 retval = kernel_read(bprm->file,
217 phdr->p_offset,
218 interpreter_name,
219 phdr->p_filesz);
220 if (retval < 0)
221 goto error;
222
223 retval = -ENOENT;
224 if (interpreter_name[phdr->p_filesz - 1] != '\0')
225 goto error;
226
227 kdebug("Using ELF interpreter %s", interpreter_name);
228
229 /* replace the program with the interpreter */
230 interpreter = open_exec(interpreter_name);
231 retval = PTR_ERR(interpreter);
232 if (IS_ERR(interpreter)) {
233 interpreter = NULL;
234 goto error;
235 }
236
237 retval = kernel_read(interpreter, 0, bprm->buf,
238 BINPRM_BUF_SIZE);
239 if (retval < 0)
240 goto error;
241
242 interp_params.hdr = *((struct elfhdr *) bprm->buf);
243 break;
244
245 case PT_LOAD:
246 #ifdef CONFIG_MMU
247 if (exec_params.load_addr == 0)
248 exec_params.load_addr = phdr->p_vaddr;
249 #endif
250 break;
251 }
252
253 }
254
255 if (elf_check_const_displacement(&exec_params.hdr))
256 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
257
258 /* perform insanity checks on the interpreter */
259 if (interpreter_name) {
260 retval = -ELIBBAD;
261 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
262 goto error;
263
264 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
265
266 /* read the interpreter's program header table */
267 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
268 if (retval < 0)
269 goto error;
270 }
271
272 stack_size = exec_params.stack_size;
273 if (stack_size < interp_params.stack_size)
274 stack_size = interp_params.stack_size;
275
276 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
277 executable_stack = EXSTACK_ENABLE_X;
278 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
279 executable_stack = EXSTACK_DISABLE_X;
280 else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
281 executable_stack = EXSTACK_ENABLE_X;
282 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
283 executable_stack = EXSTACK_DISABLE_X;
284 else
285 executable_stack = EXSTACK_DEFAULT;
286
287 retval = -ENOEXEC;
288 if (stack_size == 0)
289 goto error;
290
291 if (elf_check_const_displacement(&interp_params.hdr))
292 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
293
294 /* flush all traces of the currently running executable */
295 retval = flush_old_exec(bprm);
296 if (retval)
297 goto error;
298
299 /* there's now no turning back... the old userspace image is dead,
300 * defunct, deceased, etc. after this point we have to exit via
301 * error_kill */
302 set_personality(PER_LINUX_FDPIC);
303 set_binfmt(&elf_fdpic_format);
304
305 current->mm->start_code = 0;
306 current->mm->end_code = 0;
307 current->mm->start_stack = 0;
308 current->mm->start_data = 0;
309 current->mm->end_data = 0;
310 current->mm->context.exec_fdpic_loadmap = 0;
311 current->mm->context.interp_fdpic_loadmap = 0;
312
313 current->flags &= ~PF_FORKNOEXEC;
314
315 #ifdef CONFIG_MMU
316 elf_fdpic_arch_lay_out_mm(&exec_params,
317 &interp_params,
318 &current->mm->start_stack,
319 &current->mm->start_brk);
320
321 retval = setup_arg_pages(bprm, current->mm->start_stack,
322 executable_stack);
323 if (retval < 0) {
324 send_sig(SIGKILL, current, 0);
325 goto error_kill;
326 }
327 #endif
328
329 /* load the executable and interpreter into memory */
330 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
331 "executable");
332 if (retval < 0)
333 goto error_kill;
334
335 if (interpreter_name) {
336 retval = elf_fdpic_map_file(&interp_params, interpreter,
337 current->mm, "interpreter");
338 if (retval < 0) {
339 printk(KERN_ERR "Unable to load interpreter\n");
340 goto error_kill;
341 }
342
343 allow_write_access(interpreter);
344 fput(interpreter);
345 interpreter = NULL;
346 }
347
348 #ifdef CONFIG_MMU
349 if (!current->mm->start_brk)
350 current->mm->start_brk = current->mm->end_data;
351
352 current->mm->brk = current->mm->start_brk =
353 PAGE_ALIGN(current->mm->start_brk);
354
355 #else
356 /* create a stack and brk area big enough for everyone
357 * - the brk heap starts at the bottom and works up
358 * - the stack starts at the top and works down
359 */
360 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
361 if (stack_size < PAGE_SIZE * 2)
362 stack_size = PAGE_SIZE * 2;
363
364 down_write(&current->mm->mmap_sem);
365 current->mm->start_brk = do_mmap(NULL, 0, stack_size,
366 PROT_READ | PROT_WRITE | PROT_EXEC,
367 MAP_PRIVATE | MAP_ANON | MAP_GROWSDOWN,
368 0);
369
370 if (IS_ERR_VALUE(current->mm->start_brk)) {
371 up_write(&current->mm->mmap_sem);
372 retval = current->mm->start_brk;
373 current->mm->start_brk = 0;
374 goto error_kill;
375 }
376
377 /* expand the stack mapping to use up the entire allocation granule */
378 fullsize = ksize((char *) current->mm->start_brk);
379 if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
380 fullsize, 0, 0)))
381 stack_size = fullsize;
382 up_write(&current->mm->mmap_sem);
383
384 current->mm->brk = current->mm->start_brk;
385 current->mm->context.end_brk = current->mm->start_brk;
386 current->mm->context.end_brk +=
387 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
388 current->mm->start_stack = current->mm->start_brk + stack_size;
389 #endif
390
391 compute_creds(bprm);
392 current->flags &= ~PF_FORKNOEXEC;
393 if (create_elf_fdpic_tables(bprm, current->mm,
394 &exec_params, &interp_params) < 0)
395 goto error_kill;
396
397 kdebug("- start_code %lx", current->mm->start_code);
398 kdebug("- end_code %lx", current->mm->end_code);
399 kdebug("- start_data %lx", current->mm->start_data);
400 kdebug("- end_data %lx", current->mm->end_data);
401 kdebug("- start_brk %lx", current->mm->start_brk);
402 kdebug("- brk %lx", current->mm->brk);
403 kdebug("- start_stack %lx", current->mm->start_stack);
404
405 #ifdef ELF_FDPIC_PLAT_INIT
406 /*
407 * The ABI may specify that certain registers be set up in special
408 * ways (on i386 %edx is the address of a DT_FINI function, for
409 * example. This macro performs whatever initialization to
410 * the regs structure is required.
411 */
412 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
413 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
414 dynaddr);
415 #endif
416
417 /* everything is now ready... get the userspace context ready to roll */
418 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
419 start_thread(regs, entryaddr, current->mm->start_stack);
420
421 if (unlikely(current->ptrace & PT_PTRACED)) {
422 if (current->ptrace & PT_TRACE_EXEC)
423 ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
424 else
425 send_sig(SIGTRAP, current, 0);
426 }
427
428 retval = 0;
429
430 error:
431 if (interpreter) {
432 allow_write_access(interpreter);
433 fput(interpreter);
434 }
435 kfree(interpreter_name);
436 kfree(exec_params.phdrs);
437 kfree(exec_params.loadmap);
438 kfree(interp_params.phdrs);
439 kfree(interp_params.loadmap);
440 return retval;
441
442 /* unrecoverable error - kill the process */
443 error_kill:
444 send_sig(SIGSEGV, current, 0);
445 goto error;
446
447 }
448
449 /*****************************************************************************/
450 /*
451 * present useful information to the program
452 */
453 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
454 struct mm_struct *mm,
455 struct elf_fdpic_params *exec_params,
456 struct elf_fdpic_params *interp_params)
457 {
458 unsigned long sp, csp, nitems;
459 elf_caddr_t __user *argv, *envp;
460 size_t platform_len = 0, len;
461 char *k_platform;
462 char __user *u_platform, *p;
463 long hwcap;
464 int loop;
465
466 /* we're going to shovel a whole load of stuff onto the stack */
467 #ifdef CONFIG_MMU
468 sp = bprm->p;
469 #else
470 sp = mm->start_stack;
471
472 /* stack the program arguments and environment */
473 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
474 return -EFAULT;
475 #endif
476
477 /* get hold of platform and hardware capabilities masks for the machine
478 * we are running on. In some cases (Sparc), this info is impossible
479 * to get, in others (i386) it is merely difficult.
480 */
481 hwcap = ELF_HWCAP;
482 k_platform = ELF_PLATFORM;
483 u_platform = NULL;
484
485 if (k_platform) {
486 platform_len = strlen(k_platform) + 1;
487 sp -= platform_len;
488 u_platform = (char __user *) sp;
489 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
490 return -EFAULT;
491 }
492
493 #if defined(__i386__) && defined(CONFIG_SMP)
494 /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
495 * by the processes running on the same package. One thing we can do is
496 * to shuffle the initial stack for them.
497 *
498 * the conditionals here are unneeded, but kept in to make the code
499 * behaviour the same as pre change unless we have hyperthreaded
500 * processors. This keeps Mr Marcelo Person happier but should be
501 * removed for 2.5
502 */
503 if (smp_num_siblings > 1)
504 sp = sp - ((current->pid % 64) << 7);
505 #endif
506
507 sp &= ~7UL;
508
509 /* stack the load map(s) */
510 len = sizeof(struct elf32_fdpic_loadmap);
511 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
512 sp = (sp - len) & ~7UL;
513 exec_params->map_addr = sp;
514
515 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
516 return -EFAULT;
517
518 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
519
520 if (interp_params->loadmap) {
521 len = sizeof(struct elf32_fdpic_loadmap);
522 len += sizeof(struct elf32_fdpic_loadseg) *
523 interp_params->loadmap->nsegs;
524 sp = (sp - len) & ~7UL;
525 interp_params->map_addr = sp;
526
527 if (copy_to_user((void __user *) sp, interp_params->loadmap,
528 len) != 0)
529 return -EFAULT;
530
531 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
532 }
533
534 /* force 16 byte _final_ alignment here for generality */
535 #define DLINFO_ITEMS 13
536
537 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0);
538 #ifdef DLINFO_ARCH_ITEMS
539 nitems += DLINFO_ARCH_ITEMS;
540 #endif
541
542 csp = sp;
543 sp -= nitems * 2 * sizeof(unsigned long);
544 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
545 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
546 sp -= 1 * sizeof(unsigned long); /* argc */
547
548 csp -= sp & 15UL;
549 sp -= sp & 15UL;
550
551 /* put the ELF interpreter info on the stack */
552 #define NEW_AUX_ENT(nr, id, val) \
553 do { \
554 struct { unsigned long _id, _val; } __user *ent; \
555 \
556 ent = (void __user *) csp; \
557 __put_user((id), &ent[nr]._id); \
558 __put_user((val), &ent[nr]._val); \
559 } while (0)
560
561 csp -= 2 * sizeof(unsigned long);
562 NEW_AUX_ENT(0, AT_NULL, 0);
563 if (k_platform) {
564 csp -= 2 * sizeof(unsigned long);
565 NEW_AUX_ENT(0, AT_PLATFORM,
566 (elf_addr_t) (unsigned long) u_platform);
567 }
568
569 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
570 NEW_AUX_ENT( 0, AT_HWCAP, hwcap);
571 NEW_AUX_ENT( 1, AT_PAGESZ, PAGE_SIZE);
572 NEW_AUX_ENT( 2, AT_CLKTCK, CLOCKS_PER_SEC);
573 NEW_AUX_ENT( 3, AT_PHDR, exec_params->ph_addr);
574 NEW_AUX_ENT( 4, AT_PHENT, sizeof(struct elf_phdr));
575 NEW_AUX_ENT( 5, AT_PHNUM, exec_params->hdr.e_phnum);
576 NEW_AUX_ENT( 6, AT_BASE, interp_params->elfhdr_addr);
577 NEW_AUX_ENT( 7, AT_FLAGS, 0);
578 NEW_AUX_ENT( 8, AT_ENTRY, exec_params->entry_addr);
579 NEW_AUX_ENT( 9, AT_UID, (elf_addr_t) current->uid);
580 NEW_AUX_ENT(10, AT_EUID, (elf_addr_t) current->euid);
581 NEW_AUX_ENT(11, AT_GID, (elf_addr_t) current->gid);
582 NEW_AUX_ENT(12, AT_EGID, (elf_addr_t) current->egid);
583
584 #ifdef ARCH_DLINFO
585 /* ARCH_DLINFO must come last so platform specific code can enforce
586 * special alignment requirements on the AUXV if necessary (eg. PPC).
587 */
588 ARCH_DLINFO;
589 #endif
590 #undef NEW_AUX_ENT
591
592 /* allocate room for argv[] and envv[] */
593 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
594 envp = (elf_caddr_t __user *) csp;
595 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
596 argv = (elf_caddr_t __user *) csp;
597
598 /* stack argc */
599 csp -= sizeof(unsigned long);
600 __put_user(bprm->argc, (unsigned long __user *) csp);
601
602 BUG_ON(csp != sp);
603
604 /* fill in the argv[] array */
605 #ifdef CONFIG_MMU
606 current->mm->arg_start = bprm->p;
607 #else
608 current->mm->arg_start = current->mm->start_stack -
609 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
610 #endif
611
612 p = (char __user *) current->mm->arg_start;
613 for (loop = bprm->argc; loop > 0; loop--) {
614 __put_user((elf_caddr_t) p, argv++);
615 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
616 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
617 return -EINVAL;
618 p += len;
619 }
620 __put_user(NULL, argv);
621 current->mm->arg_end = (unsigned long) p;
622
623 /* fill in the envv[] array */
624 current->mm->env_start = (unsigned long) p;
625 for (loop = bprm->envc; loop > 0; loop--) {
626 __put_user((elf_caddr_t)(unsigned long) p, envp++);
627 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
628 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
629 return -EINVAL;
630 p += len;
631 }
632 __put_user(NULL, envp);
633 current->mm->env_end = (unsigned long) p;
634
635 mm->start_stack = (unsigned long) sp;
636 return 0;
637 }
638
639 /*****************************************************************************/
640 /*
641 * transfer the program arguments and environment from the holding pages onto
642 * the stack
643 */
644 #ifndef CONFIG_MMU
645 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
646 unsigned long *_sp)
647 {
648 unsigned long index, stop, sp;
649 char *src;
650 int ret = 0;
651
652 stop = bprm->p >> PAGE_SHIFT;
653 sp = *_sp;
654
655 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
656 src = kmap(bprm->page[index]);
657 sp -= PAGE_SIZE;
658 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
659 ret = -EFAULT;
660 kunmap(bprm->page[index]);
661 if (ret < 0)
662 goto out;
663 }
664
665 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
666
667 out:
668 return ret;
669 }
670 #endif
671
672 /*****************************************************************************/
673 /*
674 * load the appropriate binary image (executable or interpreter) into memory
675 * - we assume no MMU is available
676 * - if no other PIC bits are set in params->hdr->e_flags
677 * - we assume that the LOADable segments in the binary are independently relocatable
678 * - we assume R/O executable segments are shareable
679 * - else
680 * - we assume the loadable parts of the image to require fixed displacement
681 * - the image is not shareable
682 */
683 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
684 struct file *file,
685 struct mm_struct *mm,
686 const char *what)
687 {
688 struct elf32_fdpic_loadmap *loadmap;
689 #ifdef CONFIG_MMU
690 struct elf32_fdpic_loadseg *mseg;
691 #endif
692 struct elf32_fdpic_loadseg *seg;
693 struct elf32_phdr *phdr;
694 unsigned long load_addr, stop;
695 unsigned nloads, tmp;
696 size_t size;
697 int loop, ret;
698
699 /* allocate a load map table */
700 nloads = 0;
701 for (loop = 0; loop < params->hdr.e_phnum; loop++)
702 if (params->phdrs[loop].p_type == PT_LOAD)
703 nloads++;
704
705 if (nloads == 0)
706 return -ELIBBAD;
707
708 size = sizeof(*loadmap) + nloads * sizeof(*seg);
709 loadmap = kmalloc(size, GFP_KERNEL);
710 if (!loadmap)
711 return -ENOMEM;
712
713 params->loadmap = loadmap;
714 memset(loadmap, 0, size);
715
716 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
717 loadmap->nsegs = nloads;
718
719 load_addr = params->load_addr;
720 seg = loadmap->segs;
721
722 /* map the requested LOADs into the memory space */
723 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
724 case ELF_FDPIC_FLAG_CONSTDISP:
725 case ELF_FDPIC_FLAG_CONTIGUOUS:
726 #ifndef CONFIG_MMU
727 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
728 if (ret < 0)
729 return ret;
730 break;
731 #endif
732 default:
733 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
734 if (ret < 0)
735 return ret;
736 break;
737 }
738
739 /* map the entry point */
740 if (params->hdr.e_entry) {
741 seg = loadmap->segs;
742 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
743 if (params->hdr.e_entry >= seg->p_vaddr &&
744 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
745 params->entry_addr =
746 (params->hdr.e_entry - seg->p_vaddr) +
747 seg->addr;
748 break;
749 }
750 }
751 }
752
753 /* determine where the program header table has wound up if mapped */
754 stop = params->hdr.e_phoff;
755 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
756 phdr = params->phdrs;
757
758 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
759 if (phdr->p_type != PT_LOAD)
760 continue;
761
762 if (phdr->p_offset > params->hdr.e_phoff ||
763 phdr->p_offset + phdr->p_filesz < stop)
764 continue;
765
766 seg = loadmap->segs;
767 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
768 if (phdr->p_vaddr >= seg->p_vaddr &&
769 phdr->p_vaddr + phdr->p_filesz <=
770 seg->p_vaddr + seg->p_memsz) {
771 params->ph_addr =
772 (phdr->p_vaddr - seg->p_vaddr) +
773 seg->addr +
774 params->hdr.e_phoff - phdr->p_offset;
775 break;
776 }
777 }
778 break;
779 }
780
781 /* determine where the dynamic section has wound up if there is one */
782 phdr = params->phdrs;
783 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
784 if (phdr->p_type != PT_DYNAMIC)
785 continue;
786
787 seg = loadmap->segs;
788 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
789 if (phdr->p_vaddr >= seg->p_vaddr &&
790 phdr->p_vaddr + phdr->p_memsz <=
791 seg->p_vaddr + seg->p_memsz) {
792 params->dynamic_addr =
793 (phdr->p_vaddr - seg->p_vaddr) +
794 seg->addr;
795
796 /* check the dynamic section contains at least
797 * one item, and that the last item is a NULL
798 * entry */
799 if (phdr->p_memsz == 0 ||
800 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
801 goto dynamic_error;
802
803 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
804 if (((Elf32_Dyn *)
805 params->dynamic_addr)[tmp - 1].d_tag != 0)
806 goto dynamic_error;
807 break;
808 }
809 }
810 break;
811 }
812
813 /* now elide adjacent segments in the load map on MMU linux
814 * - on uClinux the holes between may actually be filled with system
815 * stuff or stuff from other processes
816 */
817 #ifdef CONFIG_MMU
818 nloads = loadmap->nsegs;
819 mseg = loadmap->segs;
820 seg = mseg + 1;
821 for (loop = 1; loop < nloads; loop++) {
822 /* see if we have a candidate for merging */
823 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
824 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
825 if (load_addr == (seg->addr & PAGE_MASK)) {
826 mseg->p_memsz +=
827 load_addr -
828 (mseg->addr + mseg->p_memsz);
829 mseg->p_memsz += seg->addr & ~PAGE_MASK;
830 mseg->p_memsz += seg->p_memsz;
831 loadmap->nsegs--;
832 continue;
833 }
834 }
835
836 mseg++;
837 if (mseg != seg)
838 *mseg = *seg;
839 }
840 #endif
841
842 kdebug("Mapped Object [%s]:", what);
843 kdebug("- elfhdr : %lx", params->elfhdr_addr);
844 kdebug("- entry : %lx", params->entry_addr);
845 kdebug("- PHDR[] : %lx", params->ph_addr);
846 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
847 seg = loadmap->segs;
848 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
849 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
850 loop,
851 seg->addr, seg->addr + seg->p_memsz - 1,
852 seg->p_vaddr, seg->p_memsz);
853
854 return 0;
855
856 dynamic_error:
857 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
858 what, file->f_path.dentry->d_inode->i_ino);
859 return -ELIBBAD;
860 }
861
862 /*****************************************************************************/
863 /*
864 * map a file with constant displacement under uClinux
865 */
866 #ifndef CONFIG_MMU
867 static int elf_fdpic_map_file_constdisp_on_uclinux(
868 struct elf_fdpic_params *params,
869 struct file *file,
870 struct mm_struct *mm)
871 {
872 struct elf32_fdpic_loadseg *seg;
873 struct elf32_phdr *phdr;
874 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
875 loff_t fpos;
876 int loop, ret;
877
878 load_addr = params->load_addr;
879 seg = params->loadmap->segs;
880
881 /* determine the bounds of the contiguous overall allocation we must
882 * make */
883 phdr = params->phdrs;
884 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
885 if (params->phdrs[loop].p_type != PT_LOAD)
886 continue;
887
888 if (base > phdr->p_vaddr)
889 base = phdr->p_vaddr;
890 if (top < phdr->p_vaddr + phdr->p_memsz)
891 top = phdr->p_vaddr + phdr->p_memsz;
892 }
893
894 /* allocate one big anon block for everything */
895 mflags = MAP_PRIVATE;
896 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
897 mflags |= MAP_EXECUTABLE;
898
899 down_write(&mm->mmap_sem);
900 maddr = do_mmap(NULL, load_addr, top - base,
901 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
902 up_write(&mm->mmap_sem);
903 if (IS_ERR_VALUE(maddr))
904 return (int) maddr;
905
906 if (load_addr != 0)
907 load_addr += PAGE_ALIGN(top - base);
908
909 /* and then load the file segments into it */
910 phdr = params->phdrs;
911 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
912 if (params->phdrs[loop].p_type != PT_LOAD)
913 continue;
914
915 fpos = phdr->p_offset;
916
917 seg->addr = maddr + (phdr->p_vaddr - base);
918 seg->p_vaddr = phdr->p_vaddr;
919 seg->p_memsz = phdr->p_memsz;
920
921 ret = file->f_op->read(file, (void *) seg->addr,
922 phdr->p_filesz, &fpos);
923 if (ret < 0)
924 return ret;
925
926 /* map the ELF header address if in this segment */
927 if (phdr->p_offset == 0)
928 params->elfhdr_addr = seg->addr;
929
930 /* clear any space allocated but not loaded */
931 if (phdr->p_filesz < phdr->p_memsz)
932 clear_user((void *) (seg->addr + phdr->p_filesz),
933 phdr->p_memsz - phdr->p_filesz);
934
935 if (mm) {
936 if (phdr->p_flags & PF_X) {
937 mm->start_code = seg->addr;
938 mm->end_code = seg->addr + phdr->p_memsz;
939 } else if (!mm->start_data) {
940 mm->start_data = seg->addr;
941 #ifndef CONFIG_MMU
942 mm->end_data = seg->addr + phdr->p_memsz;
943 #endif
944 }
945
946 #ifdef CONFIG_MMU
947 if (seg->addr + phdr->p_memsz > mm->end_data)
948 mm->end_data = seg->addr + phdr->p_memsz;
949 #endif
950 }
951
952 seg++;
953 }
954
955 return 0;
956 }
957 #endif
958
959 /*****************************************************************************/
960 /*
961 * map a binary by direct mmap() of the individual PT_LOAD segments
962 */
963 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
964 struct file *file,
965 struct mm_struct *mm)
966 {
967 struct elf32_fdpic_loadseg *seg;
968 struct elf32_phdr *phdr;
969 unsigned long load_addr, delta_vaddr;
970 int loop, dvset;
971
972 load_addr = params->load_addr;
973 delta_vaddr = 0;
974 dvset = 0;
975
976 seg = params->loadmap->segs;
977
978 /* deal with each load segment separately */
979 phdr = params->phdrs;
980 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
981 unsigned long maddr, disp, excess, excess1;
982 int prot = 0, flags;
983
984 if (phdr->p_type != PT_LOAD)
985 continue;
986
987 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
988 (unsigned long) phdr->p_vaddr,
989 (unsigned long) phdr->p_offset,
990 (unsigned long) phdr->p_filesz,
991 (unsigned long) phdr->p_memsz);
992
993 /* determine the mapping parameters */
994 if (phdr->p_flags & PF_R) prot |= PROT_READ;
995 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
996 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
997
998 flags = MAP_PRIVATE | MAP_DENYWRITE;
999 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1000 flags |= MAP_EXECUTABLE;
1001
1002 maddr = 0;
1003
1004 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1005 case ELF_FDPIC_FLAG_INDEPENDENT:
1006 /* PT_LOADs are independently locatable */
1007 break;
1008
1009 case ELF_FDPIC_FLAG_HONOURVADDR:
1010 /* the specified virtual address must be honoured */
1011 maddr = phdr->p_vaddr;
1012 flags |= MAP_FIXED;
1013 break;
1014
1015 case ELF_FDPIC_FLAG_CONSTDISP:
1016 /* constant displacement
1017 * - can be mapped anywhere, but must be mapped as a
1018 * unit
1019 */
1020 if (!dvset) {
1021 maddr = load_addr;
1022 delta_vaddr = phdr->p_vaddr;
1023 dvset = 1;
1024 } else {
1025 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1026 flags |= MAP_FIXED;
1027 }
1028 break;
1029
1030 case ELF_FDPIC_FLAG_CONTIGUOUS:
1031 /* contiguity handled later */
1032 break;
1033
1034 default:
1035 BUG();
1036 }
1037
1038 maddr &= PAGE_MASK;
1039
1040 /* create the mapping */
1041 disp = phdr->p_vaddr & ~PAGE_MASK;
1042 down_write(&mm->mmap_sem);
1043 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1044 phdr->p_offset - disp);
1045 up_write(&mm->mmap_sem);
1046
1047 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1048 loop, phdr->p_memsz + disp, prot, flags,
1049 phdr->p_offset - disp, maddr);
1050
1051 if (IS_ERR_VALUE(maddr))
1052 return (int) maddr;
1053
1054 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1055 ELF_FDPIC_FLAG_CONTIGUOUS)
1056 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1057
1058 seg->addr = maddr + disp;
1059 seg->p_vaddr = phdr->p_vaddr;
1060 seg->p_memsz = phdr->p_memsz;
1061
1062 /* map the ELF header address if in this segment */
1063 if (phdr->p_offset == 0)
1064 params->elfhdr_addr = seg->addr;
1065
1066 /* clear the bit between beginning of mapping and beginning of
1067 * PT_LOAD */
1068 if (prot & PROT_WRITE && disp > 0) {
1069 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1070 clear_user((void __user *) maddr, disp);
1071 maddr += disp;
1072 }
1073
1074 /* clear any space allocated but not loaded
1075 * - on uClinux we can just clear the lot
1076 * - on MMU linux we'll get a SIGBUS beyond the last page
1077 * extant in the file
1078 */
1079 excess = phdr->p_memsz - phdr->p_filesz;
1080 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1081
1082 #ifdef CONFIG_MMU
1083 if (excess > excess1) {
1084 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1085 unsigned long xmaddr;
1086
1087 flags |= MAP_FIXED | MAP_ANONYMOUS;
1088 down_write(&mm->mmap_sem);
1089 xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1090 prot, flags, 0);
1091 up_write(&mm->mmap_sem);
1092
1093 kdebug("mmap[%d] <anon>"
1094 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1095 loop, xaddr, excess - excess1, prot, flags,
1096 xmaddr);
1097
1098 if (xmaddr != xaddr)
1099 return -ENOMEM;
1100 }
1101
1102 if (prot & PROT_WRITE && excess1 > 0) {
1103 kdebug("clear[%d] ad=%lx sz=%lx",
1104 loop, maddr + phdr->p_filesz, excess1);
1105 clear_user((void __user *) maddr + phdr->p_filesz,
1106 excess1);
1107 }
1108
1109 #else
1110 if (excess > 0) {
1111 kdebug("clear[%d] ad=%lx sz=%lx",
1112 loop, maddr + phdr->p_filesz, excess);
1113 clear_user((void *) maddr + phdr->p_filesz, excess);
1114 }
1115 #endif
1116
1117 if (mm) {
1118 if (phdr->p_flags & PF_X) {
1119 mm->start_code = maddr;
1120 mm->end_code = maddr + phdr->p_memsz;
1121 } else if (!mm->start_data) {
1122 mm->start_data = maddr;
1123 mm->end_data = maddr + phdr->p_memsz;
1124 }
1125 }
1126
1127 seg++;
1128 }
1129
1130 return 0;
1131 }
1132
1133 /*****************************************************************************/
1134 /*
1135 * ELF-FDPIC core dumper
1136 *
1137 * Modelled on fs/exec.c:aout_core_dump()
1138 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1139 *
1140 * Modelled on fs/binfmt_elf.c core dumper
1141 */
1142 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1143
1144 /*
1145 * These are the only things you should do on a core-file: use only these
1146 * functions to write out all the necessary info.
1147 */
1148 static int dump_write(struct file *file, const void *addr, int nr)
1149 {
1150 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1151 }
1152
1153 static int dump_seek(struct file *file, loff_t off)
1154 {
1155 if (file->f_op->llseek) {
1156 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1157 return 0;
1158 } else {
1159 file->f_pos = off;
1160 }
1161 return 1;
1162 }
1163
1164 /*
1165 * Decide whether a segment is worth dumping; default is yes to be
1166 * sure (missing info is worse than too much; etc).
1167 * Personally I'd include everything, and use the coredump limit...
1168 *
1169 * I think we should skip something. But I am not sure how. H.J.
1170 */
1171 static int maydump(struct vm_area_struct *vma)
1172 {
1173 /* Do not dump I/O mapped devices or special mappings */
1174 if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1175 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1176 return 0;
1177 }
1178
1179 /* If we may not read the contents, don't allow us to dump
1180 * them either. "dump_write()" can't handle it anyway.
1181 */
1182 if (!(vma->vm_flags & VM_READ)) {
1183 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1184 return 0;
1185 }
1186
1187 /* Dump shared memory only if mapped from an anonymous file. */
1188 if (vma->vm_flags & VM_SHARED) {
1189 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1190 kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
1191 return 1;
1192 }
1193
1194 kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
1195 return 0;
1196 }
1197
1198 #ifdef CONFIG_MMU
1199 /* If it hasn't been written to, don't write it out */
1200 if (!vma->anon_vma) {
1201 kdcore("%08lx: %08lx: no (!anon)", vma->vm_start, vma->vm_flags);
1202 return 0;
1203 }
1204 #endif
1205
1206 kdcore("%08lx: %08lx: yes", vma->vm_start, vma->vm_flags);
1207 return 1;
1208 }
1209
1210 /* An ELF note in memory */
1211 struct memelfnote
1212 {
1213 const char *name;
1214 int type;
1215 unsigned int datasz;
1216 void *data;
1217 };
1218
1219 static int notesize(struct memelfnote *en)
1220 {
1221 int sz;
1222
1223 sz = sizeof(struct elf_note);
1224 sz += roundup(strlen(en->name) + 1, 4);
1225 sz += roundup(en->datasz, 4);
1226
1227 return sz;
1228 }
1229
1230 /* #define DEBUG */
1231
1232 #define DUMP_WRITE(addr, nr) \
1233 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1234 #define DUMP_SEEK(off) \
1235 do { if (!dump_seek(file, (off))) return 0; } while(0)
1236
1237 static int writenote(struct memelfnote *men, struct file *file)
1238 {
1239 struct elf_note en;
1240
1241 en.n_namesz = strlen(men->name) + 1;
1242 en.n_descsz = men->datasz;
1243 en.n_type = men->type;
1244
1245 DUMP_WRITE(&en, sizeof(en));
1246 DUMP_WRITE(men->name, en.n_namesz);
1247 /* XXX - cast from long long to long to avoid need for libgcc.a */
1248 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1249 DUMP_WRITE(men->data, men->datasz);
1250 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1251
1252 return 1;
1253 }
1254 #undef DUMP_WRITE
1255 #undef DUMP_SEEK
1256
1257 #define DUMP_WRITE(addr, nr) \
1258 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1259 goto end_coredump;
1260 #define DUMP_SEEK(off) \
1261 if (!dump_seek(file, (off))) \
1262 goto end_coredump;
1263
1264 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1265 {
1266 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1267 elf->e_ident[EI_CLASS] = ELF_CLASS;
1268 elf->e_ident[EI_DATA] = ELF_DATA;
1269 elf->e_ident[EI_VERSION] = EV_CURRENT;
1270 elf->e_ident[EI_OSABI] = ELF_OSABI;
1271 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1272
1273 elf->e_type = ET_CORE;
1274 elf->e_machine = ELF_ARCH;
1275 elf->e_version = EV_CURRENT;
1276 elf->e_entry = 0;
1277 elf->e_phoff = sizeof(struct elfhdr);
1278 elf->e_shoff = 0;
1279 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1280 elf->e_ehsize = sizeof(struct elfhdr);
1281 elf->e_phentsize = sizeof(struct elf_phdr);
1282 elf->e_phnum = segs;
1283 elf->e_shentsize = 0;
1284 elf->e_shnum = 0;
1285 elf->e_shstrndx = 0;
1286 return;
1287 }
1288
1289 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1290 {
1291 phdr->p_type = PT_NOTE;
1292 phdr->p_offset = offset;
1293 phdr->p_vaddr = 0;
1294 phdr->p_paddr = 0;
1295 phdr->p_filesz = sz;
1296 phdr->p_memsz = 0;
1297 phdr->p_flags = 0;
1298 phdr->p_align = 0;
1299 return;
1300 }
1301
1302 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1303 unsigned int sz, void *data)
1304 {
1305 note->name = name;
1306 note->type = type;
1307 note->datasz = sz;
1308 note->data = data;
1309 return;
1310 }
1311
1312 /*
1313 * fill up all the fields in prstatus from the given task struct, except
1314 * registers which need to be filled up seperately.
1315 */
1316 static void fill_prstatus(struct elf_prstatus *prstatus,
1317 struct task_struct *p, long signr)
1318 {
1319 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1320 prstatus->pr_sigpend = p->pending.signal.sig[0];
1321 prstatus->pr_sighold = p->blocked.sig[0];
1322 prstatus->pr_pid = p->pid;
1323 prstatus->pr_ppid = p->parent->pid;
1324 prstatus->pr_pgrp = process_group(p);
1325 prstatus->pr_sid = process_session(p);
1326 if (thread_group_leader(p)) {
1327 /*
1328 * This is the record for the group leader. Add in the
1329 * cumulative times of previous dead threads. This total
1330 * won't include the time of each live thread whose state
1331 * is included in the core dump. The final total reported
1332 * to our parent process when it calls wait4 will include
1333 * those sums as well as the little bit more time it takes
1334 * this and each other thread to finish dying after the
1335 * core dump synchronization phase.
1336 */
1337 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1338 &prstatus->pr_utime);
1339 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1340 &prstatus->pr_stime);
1341 } else {
1342 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1343 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1344 }
1345 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1346 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1347
1348 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1349 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1350 }
1351
1352 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1353 struct mm_struct *mm)
1354 {
1355 unsigned int i, len;
1356
1357 /* first copy the parameters from user space */
1358 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1359
1360 len = mm->arg_end - mm->arg_start;
1361 if (len >= ELF_PRARGSZ)
1362 len = ELF_PRARGSZ - 1;
1363 if (copy_from_user(&psinfo->pr_psargs,
1364 (const char __user *) mm->arg_start, len))
1365 return -EFAULT;
1366 for (i = 0; i < len; i++)
1367 if (psinfo->pr_psargs[i] == 0)
1368 psinfo->pr_psargs[i] = ' ';
1369 psinfo->pr_psargs[len] = 0;
1370
1371 psinfo->pr_pid = p->pid;
1372 psinfo->pr_ppid = p->parent->pid;
1373 psinfo->pr_pgrp = process_group(p);
1374 psinfo->pr_sid = process_session(p);
1375
1376 i = p->state ? ffz(~p->state) + 1 : 0;
1377 psinfo->pr_state = i;
1378 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1379 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1380 psinfo->pr_nice = task_nice(p);
1381 psinfo->pr_flag = p->flags;
1382 SET_UID(psinfo->pr_uid, p->uid);
1383 SET_GID(psinfo->pr_gid, p->gid);
1384 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1385
1386 return 0;
1387 }
1388
1389 /* Here is the structure in which status of each thread is captured. */
1390 struct elf_thread_status
1391 {
1392 struct list_head list;
1393 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1394 elf_fpregset_t fpu; /* NT_PRFPREG */
1395 struct task_struct *thread;
1396 #ifdef ELF_CORE_COPY_XFPREGS
1397 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1398 #endif
1399 struct memelfnote notes[3];
1400 int num_notes;
1401 };
1402
1403 /*
1404 * In order to add the specific thread information for the elf file format,
1405 * we need to keep a linked list of every thread's pr_status and then create
1406 * a single section for them in the final core file.
1407 */
1408 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1409 {
1410 struct task_struct *p = t->thread;
1411 int sz = 0;
1412
1413 t->num_notes = 0;
1414
1415 fill_prstatus(&t->prstatus, p, signr);
1416 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1417
1418 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1419 &t->prstatus);
1420 t->num_notes++;
1421 sz += notesize(&t->notes[0]);
1422
1423 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1424 if (t->prstatus.pr_fpvalid) {
1425 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1426 &t->fpu);
1427 t->num_notes++;
1428 sz += notesize(&t->notes[1]);
1429 }
1430
1431 #ifdef ELF_CORE_COPY_XFPREGS
1432 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1433 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1434 &t->xfpu);
1435 t->num_notes++;
1436 sz += notesize(&t->notes[2]);
1437 }
1438 #endif
1439 return sz;
1440 }
1441
1442 /*
1443 * dump the segments for an MMU process
1444 */
1445 #ifdef CONFIG_MMU
1446 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
1447 size_t *size, unsigned long *limit)
1448 {
1449 struct vm_area_struct *vma;
1450
1451 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1452 unsigned long addr;
1453
1454 if (!maydump(vma))
1455 continue;
1456
1457 for (addr = vma->vm_start;
1458 addr < vma->vm_end;
1459 addr += PAGE_SIZE
1460 ) {
1461 struct vm_area_struct *vma;
1462 struct page *page;
1463
1464 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1465 &page, &vma) <= 0) {
1466 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1467 }
1468 else if (page == ZERO_PAGE(addr)) {
1469 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1470 page_cache_release(page);
1471 }
1472 else {
1473 void *kaddr;
1474
1475 flush_cache_page(vma, addr, page_to_pfn(page));
1476 kaddr = kmap(page);
1477 if ((*size += PAGE_SIZE) > *limit ||
1478 !dump_write(file, kaddr, PAGE_SIZE)
1479 ) {
1480 kunmap(page);
1481 page_cache_release(page);
1482 return -EIO;
1483 }
1484 kunmap(page);
1485 page_cache_release(page);
1486 }
1487 }
1488 }
1489
1490 return 0;
1491
1492 end_coredump:
1493 return -EFBIG;
1494 }
1495 #endif
1496
1497 /*
1498 * dump the segments for a NOMMU process
1499 */
1500 #ifndef CONFIG_MMU
1501 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
1502 size_t *size, unsigned long *limit)
1503 {
1504 struct vm_list_struct *vml;
1505
1506 for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
1507 struct vm_area_struct *vma = vml->vma;
1508
1509 if (!maydump(vma))
1510 continue;
1511
1512 if ((*size += PAGE_SIZE) > *limit)
1513 return -EFBIG;
1514
1515 if (!dump_write(file, (void *) vma->vm_start,
1516 vma->vm_end - vma->vm_start))
1517 return -EIO;
1518 }
1519
1520 return 0;
1521 }
1522 #endif
1523
1524 /*
1525 * Actual dumper
1526 *
1527 * This is a two-pass process; first we find the offsets of the bits,
1528 * and then they are actually written out. If we run out of core limit
1529 * we just truncate.
1530 */
1531 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1532 struct file *file)
1533 {
1534 #define NUM_NOTES 6
1535 int has_dumped = 0;
1536 mm_segment_t fs;
1537 int segs;
1538 size_t size = 0;
1539 int i;
1540 struct vm_area_struct *vma;
1541 struct elfhdr *elf = NULL;
1542 loff_t offset = 0, dataoff;
1543 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1544 int numnote;
1545 struct memelfnote *notes = NULL;
1546 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1547 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1548 struct task_struct *g, *p;
1549 LIST_HEAD(thread_list);
1550 struct list_head *t;
1551 elf_fpregset_t *fpu = NULL;
1552 #ifdef ELF_CORE_COPY_XFPREGS
1553 elf_fpxregset_t *xfpu = NULL;
1554 #endif
1555 int thread_status_size = 0;
1556 #ifndef CONFIG_MMU
1557 struct vm_list_struct *vml;
1558 #endif
1559 elf_addr_t *auxv;
1560
1561 /*
1562 * We no longer stop all VM operations.
1563 *
1564 * This is because those proceses that could possibly change map_count
1565 * or the mmap / vma pages are now blocked in do_exit on current
1566 * finishing this core dump.
1567 *
1568 * Only ptrace can touch these memory addresses, but it doesn't change
1569 * the map_count or the pages allocated. So no possibility of crashing
1570 * exists while dumping the mm->vm_next areas to the core file.
1571 */
1572
1573 /* alloc memory for large data structures: too large to be on stack */
1574 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1575 if (!elf)
1576 goto cleanup;
1577 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1578 if (!prstatus)
1579 goto cleanup;
1580 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1581 if (!psinfo)
1582 goto cleanup;
1583 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1584 if (!notes)
1585 goto cleanup;
1586 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1587 if (!fpu)
1588 goto cleanup;
1589 #ifdef ELF_CORE_COPY_XFPREGS
1590 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1591 if (!xfpu)
1592 goto cleanup;
1593 #endif
1594
1595 if (signr) {
1596 struct elf_thread_status *tmp;
1597 rcu_read_lock();
1598 do_each_thread(g,p)
1599 if (current->mm == p->mm && current != p) {
1600 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1601 if (!tmp) {
1602 rcu_read_unlock();
1603 goto cleanup;
1604 }
1605 tmp->thread = p;
1606 list_add(&tmp->list, &thread_list);
1607 }
1608 while_each_thread(g,p);
1609 rcu_read_unlock();
1610 list_for_each(t, &thread_list) {
1611 struct elf_thread_status *tmp;
1612 int sz;
1613
1614 tmp = list_entry(t, struct elf_thread_status, list);
1615 sz = elf_dump_thread_status(signr, tmp);
1616 thread_status_size += sz;
1617 }
1618 }
1619
1620 /* now collect the dump for the current */
1621 fill_prstatus(prstatus, current, signr);
1622 elf_core_copy_regs(&prstatus->pr_reg, regs);
1623
1624 #ifdef CONFIG_MMU
1625 segs = current->mm->map_count;
1626 #else
1627 segs = 0;
1628 for (vml = current->mm->context.vmlist; vml; vml = vml->next)
1629 segs++;
1630 #endif
1631 #ifdef ELF_CORE_EXTRA_PHDRS
1632 segs += ELF_CORE_EXTRA_PHDRS;
1633 #endif
1634
1635 /* Set up header */
1636 fill_elf_fdpic_header(elf, segs + 1); /* including notes section */
1637
1638 has_dumped = 1;
1639 current->flags |= PF_DUMPCORE;
1640
1641 /*
1642 * Set up the notes in similar form to SVR4 core dumps made
1643 * with info from their /proc.
1644 */
1645
1646 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1647 fill_psinfo(psinfo, current->group_leader, current->mm);
1648 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1649
1650 numnote = 2;
1651
1652 auxv = (elf_addr_t *) current->mm->saved_auxv;
1653
1654 i = 0;
1655 do
1656 i += 2;
1657 while (auxv[i - 2] != AT_NULL);
1658 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1659 i * sizeof(elf_addr_t), auxv);
1660
1661 /* Try to dump the FPU. */
1662 if ((prstatus->pr_fpvalid =
1663 elf_core_copy_task_fpregs(current, regs, fpu)))
1664 fill_note(notes + numnote++,
1665 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1666 #ifdef ELF_CORE_COPY_XFPREGS
1667 if (elf_core_copy_task_xfpregs(current, xfpu))
1668 fill_note(notes + numnote++,
1669 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1670 #endif
1671
1672 fs = get_fs();
1673 set_fs(KERNEL_DS);
1674
1675 DUMP_WRITE(elf, sizeof(*elf));
1676 offset += sizeof(*elf); /* Elf header */
1677 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */
1678
1679 /* Write notes phdr entry */
1680 {
1681 struct elf_phdr phdr;
1682 int sz = 0;
1683
1684 for (i = 0; i < numnote; i++)
1685 sz += notesize(notes + i);
1686
1687 sz += thread_status_size;
1688
1689 fill_elf_note_phdr(&phdr, sz, offset);
1690 offset += sz;
1691 DUMP_WRITE(&phdr, sizeof(phdr));
1692 }
1693
1694 /* Page-align dumped data */
1695 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1696
1697 /* write program headers for segments dump */
1698 for (
1699 #ifdef CONFIG_MMU
1700 vma = current->mm->mmap; vma; vma = vma->vm_next
1701 #else
1702 vml = current->mm->context.vmlist; vml; vml = vml->next
1703 #endif
1704 ) {
1705 struct elf_phdr phdr;
1706 size_t sz;
1707
1708 #ifndef CONFIG_MMU
1709 vma = vml->vma;
1710 #endif
1711
1712 sz = vma->vm_end - vma->vm_start;
1713
1714 phdr.p_type = PT_LOAD;
1715 phdr.p_offset = offset;
1716 phdr.p_vaddr = vma->vm_start;
1717 phdr.p_paddr = 0;
1718 phdr.p_filesz = maydump(vma) ? sz : 0;
1719 phdr.p_memsz = sz;
1720 offset += phdr.p_filesz;
1721 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1722 if (vma->vm_flags & VM_WRITE)
1723 phdr.p_flags |= PF_W;
1724 if (vma->vm_flags & VM_EXEC)
1725 phdr.p_flags |= PF_X;
1726 phdr.p_align = ELF_EXEC_PAGESIZE;
1727
1728 DUMP_WRITE(&phdr, sizeof(phdr));
1729 }
1730
1731 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1732 ELF_CORE_WRITE_EXTRA_PHDRS;
1733 #endif
1734
1735 /* write out the notes section */
1736 for (i = 0; i < numnote; i++)
1737 if (!writenote(notes + i, file))
1738 goto end_coredump;
1739
1740 /* write out the thread status notes section */
1741 list_for_each(t, &thread_list) {
1742 struct elf_thread_status *tmp =
1743 list_entry(t, struct elf_thread_status, list);
1744
1745 for (i = 0; i < tmp->num_notes; i++)
1746 if (!writenote(&tmp->notes[i], file))
1747 goto end_coredump;
1748 }
1749
1750 DUMP_SEEK(dataoff);
1751
1752 if (elf_fdpic_dump_segments(file, current->mm, &size, &limit) < 0)
1753 goto end_coredump;
1754
1755 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1756 ELF_CORE_WRITE_EXTRA_DATA;
1757 #endif
1758
1759 if (file->f_pos != offset) {
1760 /* Sanity check */
1761 printk(KERN_WARNING
1762 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1763 file->f_pos, offset);
1764 }
1765
1766 end_coredump:
1767 set_fs(fs);
1768
1769 cleanup:
1770 while (!list_empty(&thread_list)) {
1771 struct list_head *tmp = thread_list.next;
1772 list_del(tmp);
1773 kfree(list_entry(tmp, struct elf_thread_status, list));
1774 }
1775
1776 kfree(elf);
1777 kfree(prstatus);
1778 kfree(psinfo);
1779 kfree(notes);
1780 kfree(fpu);
1781 #ifdef ELF_CORE_COPY_XFPREGS
1782 kfree(xfpu);
1783 #endif
1784 return has_dumped;
1785 #undef NUM_NOTES
1786 }
1787
1788 #endif /* USE_ELF_CORE_DUMP */
linux-next