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uml: kernel segfaults should dump proper registers
[pv_ops_mirror.git] / fs / binfmt_elf_fdpic.c
blobf3ddca4a387b43f817b83ae85cd7aaf44b1c7398
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 kdebug("____ LOAD %d ____", current->pid);
183
184 memset(&exec_params, 0, sizeof(exec_params));
185 memset(&interp_params, 0, sizeof(interp_params));
186
187 exec_params.hdr = *(struct elfhdr *) bprm->buf;
188 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
189
190 /* check that this is a binary we know how to deal with */
191 retval = -ENOEXEC;
192 if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
193 goto error;
194
195 /* read the program header table */
196 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
197 if (retval < 0)
198 goto error;
199
200 /* scan for a program header that specifies an interpreter */
201 phdr = exec_params.phdrs;
202
203 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
204 switch (phdr->p_type) {
205 case PT_INTERP:
206 retval = -ENOMEM;
207 if (phdr->p_filesz > PATH_MAX)
208 goto error;
209 retval = -ENOENT;
210 if (phdr->p_filesz < 2)
211 goto error;
212
213 /* read the name of the interpreter into memory */
214 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
215 if (!interpreter_name)
216 goto error;
217
218 retval = kernel_read(bprm->file,
219 phdr->p_offset,
220 interpreter_name,
221 phdr->p_filesz);
222 if (retval < 0)
223 goto error;
224
225 retval = -ENOENT;
226 if (interpreter_name[phdr->p_filesz - 1] != '\0')
227 goto error;
228
229 kdebug("Using ELF interpreter %s", interpreter_name);
230
231 /* replace the program with the interpreter */
232 interpreter = open_exec(interpreter_name);
233 retval = PTR_ERR(interpreter);
234 if (IS_ERR(interpreter)) {
235 interpreter = NULL;
236 goto error;
237 }
238
239 /*
240 * If the binary is not readable then enforce
241 * mm->dumpable = 0 regardless of the interpreter's
242 * permissions.
243 */
244 if (file_permission(interpreter, MAY_READ) < 0)
245 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
246
247 retval = kernel_read(interpreter, 0, bprm->buf,
248 BINPRM_BUF_SIZE);
249 if (retval < 0)
250 goto error;
251
252 interp_params.hdr = *((struct elfhdr *) bprm->buf);
253 break;
254
255 case PT_LOAD:
256 #ifdef CONFIG_MMU
257 if (exec_params.load_addr == 0)
258 exec_params.load_addr = phdr->p_vaddr;
259 #endif
260 break;
261 }
262
263 }
264
265 if (elf_check_const_displacement(&exec_params.hdr))
266 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
267
268 /* perform insanity checks on the interpreter */
269 if (interpreter_name) {
270 retval = -ELIBBAD;
271 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
272 goto error;
273
274 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
275
276 /* read the interpreter's program header table */
277 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
278 if (retval < 0)
279 goto error;
280 }
281
282 stack_size = exec_params.stack_size;
283 if (stack_size < interp_params.stack_size)
284 stack_size = interp_params.stack_size;
285
286 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
287 executable_stack = EXSTACK_ENABLE_X;
288 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
289 executable_stack = EXSTACK_DISABLE_X;
290 else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
291 executable_stack = EXSTACK_ENABLE_X;
292 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
293 executable_stack = EXSTACK_DISABLE_X;
294 else
295 executable_stack = EXSTACK_DEFAULT;
296
297 retval = -ENOEXEC;
298 if (stack_size == 0)
299 goto error;
300
301 if (elf_check_const_displacement(&interp_params.hdr))
302 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
303
304 /* flush all traces of the currently running executable */
305 retval = flush_old_exec(bprm);
306 if (retval)
307 goto error;
308
309 /* there's now no turning back... the old userspace image is dead,
310 * defunct, deceased, etc. after this point we have to exit via
311 * error_kill */
312 set_personality(PER_LINUX_FDPIC);
313 set_binfmt(&elf_fdpic_format);
314
315 current->mm->start_code = 0;
316 current->mm->end_code = 0;
317 current->mm->start_stack = 0;
318 current->mm->start_data = 0;
319 current->mm->end_data = 0;
320 current->mm->context.exec_fdpic_loadmap = 0;
321 current->mm->context.interp_fdpic_loadmap = 0;
322
323 current->flags &= ~PF_FORKNOEXEC;
324
325 #ifdef CONFIG_MMU
326 elf_fdpic_arch_lay_out_mm(&exec_params,
327 &interp_params,
328 &current->mm->start_stack,
329 &current->mm->start_brk);
330
331 retval = setup_arg_pages(bprm, current->mm->start_stack,
332 executable_stack);
333 if (retval < 0) {
334 send_sig(SIGKILL, current, 0);
335 goto error_kill;
336 }
337 #endif
338
339 /* load the executable and interpreter into memory */
340 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
341 "executable");
342 if (retval < 0)
343 goto error_kill;
344
345 if (interpreter_name) {
346 retval = elf_fdpic_map_file(&interp_params, interpreter,
347 current->mm, "interpreter");
348 if (retval < 0) {
349 printk(KERN_ERR "Unable to load interpreter\n");
350 goto error_kill;
351 }
352
353 allow_write_access(interpreter);
354 fput(interpreter);
355 interpreter = NULL;
356 }
357
358 #ifdef CONFIG_MMU
359 if (!current->mm->start_brk)
360 current->mm->start_brk = current->mm->end_data;
361
362 current->mm->brk = current->mm->start_brk =
363 PAGE_ALIGN(current->mm->start_brk);
364
365 #else
366 /* create a stack and brk area big enough for everyone
367 * - the brk heap starts at the bottom and works up
368 * - the stack starts at the top and works down
369 */
370 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
371 if (stack_size < PAGE_SIZE * 2)
372 stack_size = PAGE_SIZE * 2;
373
374 down_write(&current->mm->mmap_sem);
375 current->mm->start_brk = do_mmap(NULL, 0, stack_size,
376 PROT_READ | PROT_WRITE | PROT_EXEC,
377 MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN,
378 0);
379
380 if (IS_ERR_VALUE(current->mm->start_brk)) {
381 up_write(&current->mm->mmap_sem);
382 retval = current->mm->start_brk;
383 current->mm->start_brk = 0;
384 goto error_kill;
385 }
386
387 /* expand the stack mapping to use up the entire allocation granule */
388 fullsize = ksize((char *) current->mm->start_brk);
389 if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
390 fullsize, 0, 0)))
391 stack_size = fullsize;
392 up_write(&current->mm->mmap_sem);
393
394 current->mm->brk = current->mm->start_brk;
395 current->mm->context.end_brk = current->mm->start_brk;
396 current->mm->context.end_brk +=
397 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
398 current->mm->start_stack = current->mm->start_brk + stack_size;
399 #endif
400
401 compute_creds(bprm);
402 current->flags &= ~PF_FORKNOEXEC;
403 if (create_elf_fdpic_tables(bprm, current->mm,
404 &exec_params, &interp_params) < 0)
405 goto error_kill;
406
407 kdebug("- start_code %lx", current->mm->start_code);
408 kdebug("- end_code %lx", current->mm->end_code);
409 kdebug("- start_data %lx", current->mm->start_data);
410 kdebug("- end_data %lx", current->mm->end_data);
411 kdebug("- start_brk %lx", current->mm->start_brk);
412 kdebug("- brk %lx", current->mm->brk);
413 kdebug("- start_stack %lx", current->mm->start_stack);
414
415 #ifdef ELF_FDPIC_PLAT_INIT
416 /*
417 * The ABI may specify that certain registers be set up in special
418 * ways (on i386 %edx is the address of a DT_FINI function, for
419 * example. This macro performs whatever initialization to
420 * the regs structure is required.
421 */
422 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
423 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
424 dynaddr);
425 #endif
426
427 /* everything is now ready... get the userspace context ready to roll */
428 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
429 start_thread(regs, entryaddr, current->mm->start_stack);
430
431 if (unlikely(current->ptrace & PT_PTRACED)) {
432 if (current->ptrace & PT_TRACE_EXEC)
433 ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
434 else
435 send_sig(SIGTRAP, current, 0);
436 }
437
438 retval = 0;
439
440 error:
441 if (interpreter) {
442 allow_write_access(interpreter);
443 fput(interpreter);
444 }
445 kfree(interpreter_name);
446 kfree(exec_params.phdrs);
447 kfree(exec_params.loadmap);
448 kfree(interp_params.phdrs);
449 kfree(interp_params.loadmap);
450 return retval;
451
452 /* unrecoverable error - kill the process */
453 error_kill:
454 send_sig(SIGSEGV, current, 0);
455 goto error;
456
457 }
458
459 /*****************************************************************************/
460 /*
461 * present useful information to the program
462 */
463 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
464 struct mm_struct *mm,
465 struct elf_fdpic_params *exec_params,
466 struct elf_fdpic_params *interp_params)
467 {
468 unsigned long sp, csp, nitems;
469 elf_caddr_t __user *argv, *envp;
470 size_t platform_len = 0, len;
471 char *k_platform;
472 char __user *u_platform, *p;
473 long hwcap;
474 int loop;
475
476 /* we're going to shovel a whole load of stuff onto the stack */
477 #ifdef CONFIG_MMU
478 sp = bprm->p;
479 #else
480 sp = mm->start_stack;
481
482 /* stack the program arguments and environment */
483 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
484 return -EFAULT;
485 #endif
486
487 /* get hold of platform and hardware capabilities masks for the machine
488 * we are running on. In some cases (Sparc), this info is impossible
489 * to get, in others (i386) it is merely difficult.
490 */
491 hwcap = ELF_HWCAP;
492 k_platform = ELF_PLATFORM;
493 u_platform = NULL;
494
495 if (k_platform) {
496 platform_len = strlen(k_platform) + 1;
497 sp -= platform_len;
498 u_platform = (char __user *) sp;
499 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
500 return -EFAULT;
501 }
502
503 #if defined(__i386__) && defined(CONFIG_SMP)
504 /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
505 * by the processes running on the same package. One thing we can do is
506 * to shuffle the initial stack for them.
507 *
508 * the conditionals here are unneeded, but kept in to make the code
509 * behaviour the same as pre change unless we have hyperthreaded
510 * processors. This keeps Mr Marcelo Person happier but should be
511 * removed for 2.5
512 */
513 if (smp_num_siblings > 1)
514 sp = sp - ((current->pid % 64) << 7);
515 #endif
516
517 sp &= ~7UL;
518
519 /* stack the load map(s) */
520 len = sizeof(struct elf32_fdpic_loadmap);
521 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
522 sp = (sp - len) & ~7UL;
523 exec_params->map_addr = sp;
524
525 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
526 return -EFAULT;
527
528 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
529
530 if (interp_params->loadmap) {
531 len = sizeof(struct elf32_fdpic_loadmap);
532 len += sizeof(struct elf32_fdpic_loadseg) *
533 interp_params->loadmap->nsegs;
534 sp = (sp - len) & ~7UL;
535 interp_params->map_addr = sp;
536
537 if (copy_to_user((void __user *) sp, interp_params->loadmap,
538 len) != 0)
539 return -EFAULT;
540
541 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
542 }
543
544 /* force 16 byte _final_ alignment here for generality */
545 #define DLINFO_ITEMS 13
546
547 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0);
548 #ifdef DLINFO_ARCH_ITEMS
549 nitems += DLINFO_ARCH_ITEMS;
550 #endif
551
552 csp = sp;
553 sp -= nitems * 2 * sizeof(unsigned long);
554 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
555 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
556 sp -= 1 * sizeof(unsigned long); /* argc */
557
558 csp -= sp & 15UL;
559 sp -= sp & 15UL;
560
561 /* put the ELF interpreter info on the stack */
562 #define NEW_AUX_ENT(nr, id, val) \
563 do { \
564 struct { unsigned long _id, _val; } __user *ent; \
565 \
566 ent = (void __user *) csp; \
567 __put_user((id), &ent[nr]._id); \
568 __put_user((val), &ent[nr]._val); \
569 } while (0)
570
571 csp -= 2 * sizeof(unsigned long);
572 NEW_AUX_ENT(0, AT_NULL, 0);
573 if (k_platform) {
574 csp -= 2 * sizeof(unsigned long);
575 NEW_AUX_ENT(0, AT_PLATFORM,
576 (elf_addr_t) (unsigned long) u_platform);
577 }
578
579 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
580 NEW_AUX_ENT( 0, AT_HWCAP, hwcap);
581 NEW_AUX_ENT( 1, AT_PAGESZ, PAGE_SIZE);
582 NEW_AUX_ENT( 2, AT_CLKTCK, CLOCKS_PER_SEC);
583 NEW_AUX_ENT( 3, AT_PHDR, exec_params->ph_addr);
584 NEW_AUX_ENT( 4, AT_PHENT, sizeof(struct elf_phdr));
585 NEW_AUX_ENT( 5, AT_PHNUM, exec_params->hdr.e_phnum);
586 NEW_AUX_ENT( 6, AT_BASE, interp_params->elfhdr_addr);
587 NEW_AUX_ENT( 7, AT_FLAGS, 0);
588 NEW_AUX_ENT( 8, AT_ENTRY, exec_params->entry_addr);
589 NEW_AUX_ENT( 9, AT_UID, (elf_addr_t) current->uid);
590 NEW_AUX_ENT(10, AT_EUID, (elf_addr_t) current->euid);
591 NEW_AUX_ENT(11, AT_GID, (elf_addr_t) current->gid);
592 NEW_AUX_ENT(12, AT_EGID, (elf_addr_t) current->egid);
593
594 #ifdef ARCH_DLINFO
595 /* ARCH_DLINFO must come last so platform specific code can enforce
596 * special alignment requirements on the AUXV if necessary (eg. PPC).
597 */
598 ARCH_DLINFO;
599 #endif
600 #undef NEW_AUX_ENT
601
602 /* allocate room for argv[] and envv[] */
603 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
604 envp = (elf_caddr_t __user *) csp;
605 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
606 argv = (elf_caddr_t __user *) csp;
607
608 /* stack argc */
609 csp -= sizeof(unsigned long);
610 __put_user(bprm->argc, (unsigned long __user *) csp);
611
612 BUG_ON(csp != sp);
613
614 /* fill in the argv[] array */
615 #ifdef CONFIG_MMU
616 current->mm->arg_start = bprm->p;
617 #else
618 current->mm->arg_start = current->mm->start_stack -
619 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
620 #endif
621
622 p = (char __user *) current->mm->arg_start;
623 for (loop = bprm->argc; loop > 0; loop--) {
624 __put_user((elf_caddr_t) p, argv++);
625 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
626 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
627 return -EINVAL;
628 p += len;
629 }
630 __put_user(NULL, argv);
631 current->mm->arg_end = (unsigned long) p;
632
633 /* fill in the envv[] array */
634 current->mm->env_start = (unsigned long) p;
635 for (loop = bprm->envc; loop > 0; loop--) {
636 __put_user((elf_caddr_t)(unsigned long) p, envp++);
637 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
638 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
639 return -EINVAL;
640 p += len;
641 }
642 __put_user(NULL, envp);
643 current->mm->env_end = (unsigned long) p;
644
645 mm->start_stack = (unsigned long) sp;
646 return 0;
647 }
648
649 /*****************************************************************************/
650 /*
651 * transfer the program arguments and environment from the holding pages onto
652 * the stack
653 */
654 #ifndef CONFIG_MMU
655 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
656 unsigned long *_sp)
657 {
658 unsigned long index, stop, sp;
659 char *src;
660 int ret = 0;
661
662 stop = bprm->p >> PAGE_SHIFT;
663 sp = *_sp;
664
665 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
666 src = kmap(bprm->page[index]);
667 sp -= PAGE_SIZE;
668 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
669 ret = -EFAULT;
670 kunmap(bprm->page[index]);
671 if (ret < 0)
672 goto out;
673 }
674
675 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
676
677 out:
678 return ret;
679 }
680 #endif
681
682 /*****************************************************************************/
683 /*
684 * load the appropriate binary image (executable or interpreter) into memory
685 * - we assume no MMU is available
686 * - if no other PIC bits are set in params->hdr->e_flags
687 * - we assume that the LOADable segments in the binary are independently relocatable
688 * - we assume R/O executable segments are shareable
689 * - else
690 * - we assume the loadable parts of the image to require fixed displacement
691 * - the image is not shareable
692 */
693 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
694 struct file *file,
695 struct mm_struct *mm,
696 const char *what)
697 {
698 struct elf32_fdpic_loadmap *loadmap;
699 #ifdef CONFIG_MMU
700 struct elf32_fdpic_loadseg *mseg;
701 #endif
702 struct elf32_fdpic_loadseg *seg;
703 struct elf32_phdr *phdr;
704 unsigned long load_addr, stop;
705 unsigned nloads, tmp;
706 size_t size;
707 int loop, ret;
708
709 /* allocate a load map table */
710 nloads = 0;
711 for (loop = 0; loop < params->hdr.e_phnum; loop++)
712 if (params->phdrs[loop].p_type == PT_LOAD)
713 nloads++;
714
715 if (nloads == 0)
716 return -ELIBBAD;
717
718 size = sizeof(*loadmap) + nloads * sizeof(*seg);
719 loadmap = kzalloc(size, GFP_KERNEL);
720 if (!loadmap)
721 return -ENOMEM;
722
723 params->loadmap = loadmap;
724
725 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
726 loadmap->nsegs = nloads;
727
728 load_addr = params->load_addr;
729 seg = loadmap->segs;
730
731 /* map the requested LOADs into the memory space */
732 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
733 case ELF_FDPIC_FLAG_CONSTDISP:
734 case ELF_FDPIC_FLAG_CONTIGUOUS:
735 #ifndef CONFIG_MMU
736 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
737 if (ret < 0)
738 return ret;
739 break;
740 #endif
741 default:
742 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
743 if (ret < 0)
744 return ret;
745 break;
746 }
747
748 /* map the entry point */
749 if (params->hdr.e_entry) {
750 seg = loadmap->segs;
751 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
752 if (params->hdr.e_entry >= seg->p_vaddr &&
753 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
754 params->entry_addr =
755 (params->hdr.e_entry - seg->p_vaddr) +
756 seg->addr;
757 break;
758 }
759 }
760 }
761
762 /* determine where the program header table has wound up if mapped */
763 stop = params->hdr.e_phoff;
764 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
765 phdr = params->phdrs;
766
767 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
768 if (phdr->p_type != PT_LOAD)
769 continue;
770
771 if (phdr->p_offset > params->hdr.e_phoff ||
772 phdr->p_offset + phdr->p_filesz < stop)
773 continue;
774
775 seg = loadmap->segs;
776 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
777 if (phdr->p_vaddr >= seg->p_vaddr &&
778 phdr->p_vaddr + phdr->p_filesz <=
779 seg->p_vaddr + seg->p_memsz) {
780 params->ph_addr =
781 (phdr->p_vaddr - seg->p_vaddr) +
782 seg->addr +
783 params->hdr.e_phoff - phdr->p_offset;
784 break;
785 }
786 }
787 break;
788 }
789
790 /* determine where the dynamic section has wound up if there is one */
791 phdr = params->phdrs;
792 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
793 if (phdr->p_type != PT_DYNAMIC)
794 continue;
795
796 seg = loadmap->segs;
797 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
798 if (phdr->p_vaddr >= seg->p_vaddr &&
799 phdr->p_vaddr + phdr->p_memsz <=
800 seg->p_vaddr + seg->p_memsz) {
801 params->dynamic_addr =
802 (phdr->p_vaddr - seg->p_vaddr) +
803 seg->addr;
804
805 /* check the dynamic section contains at least
806 * one item, and that the last item is a NULL
807 * entry */
808 if (phdr->p_memsz == 0 ||
809 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
810 goto dynamic_error;
811
812 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
813 if (((Elf32_Dyn *)
814 params->dynamic_addr)[tmp - 1].d_tag != 0)
815 goto dynamic_error;
816 break;
817 }
818 }
819 break;
820 }
821
822 /* now elide adjacent segments in the load map on MMU linux
823 * - on uClinux the holes between may actually be filled with system
824 * stuff or stuff from other processes
825 */
826 #ifdef CONFIG_MMU
827 nloads = loadmap->nsegs;
828 mseg = loadmap->segs;
829 seg = mseg + 1;
830 for (loop = 1; loop < nloads; loop++) {
831 /* see if we have a candidate for merging */
832 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
833 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
834 if (load_addr == (seg->addr & PAGE_MASK)) {
835 mseg->p_memsz +=
836 load_addr -
837 (mseg->addr + mseg->p_memsz);
838 mseg->p_memsz += seg->addr & ~PAGE_MASK;
839 mseg->p_memsz += seg->p_memsz;
840 loadmap->nsegs--;
841 continue;
842 }
843 }
844
845 mseg++;
846 if (mseg != seg)
847 *mseg = *seg;
848 }
849 #endif
850
851 kdebug("Mapped Object [%s]:", what);
852 kdebug("- elfhdr : %lx", params->elfhdr_addr);
853 kdebug("- entry : %lx", params->entry_addr);
854 kdebug("- PHDR[] : %lx", params->ph_addr);
855 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
856 seg = loadmap->segs;
857 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
858 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
859 loop,
860 seg->addr, seg->addr + seg->p_memsz - 1,
861 seg->p_vaddr, seg->p_memsz);
862
863 return 0;
864
865 dynamic_error:
866 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
867 what, file->f_path.dentry->d_inode->i_ino);
868 return -ELIBBAD;
869 }
870
871 /*****************************************************************************/
872 /*
873 * map a file with constant displacement under uClinux
874 */
875 #ifndef CONFIG_MMU
876 static int elf_fdpic_map_file_constdisp_on_uclinux(
877 struct elf_fdpic_params *params,
878 struct file *file,
879 struct mm_struct *mm)
880 {
881 struct elf32_fdpic_loadseg *seg;
882 struct elf32_phdr *phdr;
883 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
884 loff_t fpos;
885 int loop, ret;
886
887 load_addr = params->load_addr;
888 seg = params->loadmap->segs;
889
890 /* determine the bounds of the contiguous overall allocation we must
891 * make */
892 phdr = params->phdrs;
893 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
894 if (params->phdrs[loop].p_type != PT_LOAD)
895 continue;
896
897 if (base > phdr->p_vaddr)
898 base = phdr->p_vaddr;
899 if (top < phdr->p_vaddr + phdr->p_memsz)
900 top = phdr->p_vaddr + phdr->p_memsz;
901 }
902
903 /* allocate one big anon block for everything */
904 mflags = MAP_PRIVATE;
905 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
906 mflags |= MAP_EXECUTABLE;
907
908 down_write(&mm->mmap_sem);
909 maddr = do_mmap(NULL, load_addr, top - base,
910 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
911 up_write(&mm->mmap_sem);
912 if (IS_ERR_VALUE(maddr))
913 return (int) maddr;
914
915 if (load_addr != 0)
916 load_addr += PAGE_ALIGN(top - base);
917
918 /* and then load the file segments into it */
919 phdr = params->phdrs;
920 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
921 if (params->phdrs[loop].p_type != PT_LOAD)
922 continue;
923
924 fpos = phdr->p_offset;
925
926 seg->addr = maddr + (phdr->p_vaddr - base);
927 seg->p_vaddr = phdr->p_vaddr;
928 seg->p_memsz = phdr->p_memsz;
929
930 ret = file->f_op->read(file, (void *) seg->addr,
931 phdr->p_filesz, &fpos);
932 if (ret < 0)
933 return ret;
934
935 /* map the ELF header address if in this segment */
936 if (phdr->p_offset == 0)
937 params->elfhdr_addr = seg->addr;
938
939 /* clear any space allocated but not loaded */
940 if (phdr->p_filesz < phdr->p_memsz)
941 clear_user((void *) (seg->addr + phdr->p_filesz),
942 phdr->p_memsz - phdr->p_filesz);
943
944 if (mm) {
945 if (phdr->p_flags & PF_X) {
946 if (!mm->start_code) {
947 mm->start_code = seg->addr;
948 mm->end_code = seg->addr +
949 phdr->p_memsz;
950 }
951 } else if (!mm->start_data) {
952 mm->start_data = seg->addr;
953 #ifndef CONFIG_MMU
954 mm->end_data = seg->addr + phdr->p_memsz;
955 #endif
956 }
957
958 #ifdef CONFIG_MMU
959 if (seg->addr + phdr->p_memsz > mm->end_data)
960 mm->end_data = seg->addr + phdr->p_memsz;
961 #endif
962 }
963
964 seg++;
965 }
966
967 return 0;
968 }
969 #endif
970
971 /*****************************************************************************/
972 /*
973 * map a binary by direct mmap() of the individual PT_LOAD segments
974 */
975 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
976 struct file *file,
977 struct mm_struct *mm)
978 {
979 struct elf32_fdpic_loadseg *seg;
980 struct elf32_phdr *phdr;
981 unsigned long load_addr, delta_vaddr;
982 int loop, dvset;
983
984 load_addr = params->load_addr;
985 delta_vaddr = 0;
986 dvset = 0;
987
988 seg = params->loadmap->segs;
989
990 /* deal with each load segment separately */
991 phdr = params->phdrs;
992 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
993 unsigned long maddr, disp, excess, excess1;
994 int prot = 0, flags;
995
996 if (phdr->p_type != PT_LOAD)
997 continue;
998
999 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1000 (unsigned long) phdr->p_vaddr,
1001 (unsigned long) phdr->p_offset,
1002 (unsigned long) phdr->p_filesz,
1003 (unsigned long) phdr->p_memsz);
1004
1005 /* determine the mapping parameters */
1006 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1007 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1008 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1009
1010 flags = MAP_PRIVATE | MAP_DENYWRITE;
1011 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1012 flags |= MAP_EXECUTABLE;
1013
1014 maddr = 0;
1015
1016 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1017 case ELF_FDPIC_FLAG_INDEPENDENT:
1018 /* PT_LOADs are independently locatable */
1019 break;
1020
1021 case ELF_FDPIC_FLAG_HONOURVADDR:
1022 /* the specified virtual address must be honoured */
1023 maddr = phdr->p_vaddr;
1024 flags |= MAP_FIXED;
1025 break;
1026
1027 case ELF_FDPIC_FLAG_CONSTDISP:
1028 /* constant displacement
1029 * - can be mapped anywhere, but must be mapped as a
1030 * unit
1031 */
1032 if (!dvset) {
1033 maddr = load_addr;
1034 delta_vaddr = phdr->p_vaddr;
1035 dvset = 1;
1036 } else {
1037 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1038 flags |= MAP_FIXED;
1039 }
1040 break;
1041
1042 case ELF_FDPIC_FLAG_CONTIGUOUS:
1043 /* contiguity handled later */
1044 break;
1045
1046 default:
1047 BUG();
1048 }
1049
1050 maddr &= PAGE_MASK;
1051
1052 /* create the mapping */
1053 disp = phdr->p_vaddr & ~PAGE_MASK;
1054 down_write(&mm->mmap_sem);
1055 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1056 phdr->p_offset - disp);
1057 up_write(&mm->mmap_sem);
1058
1059 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1060 loop, phdr->p_memsz + disp, prot, flags,
1061 phdr->p_offset - disp, maddr);
1062
1063 if (IS_ERR_VALUE(maddr))
1064 return (int) maddr;
1065
1066 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1067 ELF_FDPIC_FLAG_CONTIGUOUS)
1068 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1069
1070 seg->addr = maddr + disp;
1071 seg->p_vaddr = phdr->p_vaddr;
1072 seg->p_memsz = phdr->p_memsz;
1073
1074 /* map the ELF header address if in this segment */
1075 if (phdr->p_offset == 0)
1076 params->elfhdr_addr = seg->addr;
1077
1078 /* clear the bit between beginning of mapping and beginning of
1079 * PT_LOAD */
1080 if (prot & PROT_WRITE && disp > 0) {
1081 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1082 clear_user((void __user *) maddr, disp);
1083 maddr += disp;
1084 }
1085
1086 /* clear any space allocated but not loaded
1087 * - on uClinux we can just clear the lot
1088 * - on MMU linux we'll get a SIGBUS beyond the last page
1089 * extant in the file
1090 */
1091 excess = phdr->p_memsz - phdr->p_filesz;
1092 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1093
1094 #ifdef CONFIG_MMU
1095 if (excess > excess1) {
1096 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1097 unsigned long xmaddr;
1098
1099 flags |= MAP_FIXED | MAP_ANONYMOUS;
1100 down_write(&mm->mmap_sem);
1101 xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1102 prot, flags, 0);
1103 up_write(&mm->mmap_sem);
1104
1105 kdebug("mmap[%d] <anon>"
1106 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1107 loop, xaddr, excess - excess1, prot, flags,
1108 xmaddr);
1109
1110 if (xmaddr != xaddr)
1111 return -ENOMEM;
1112 }
1113
1114 if (prot & PROT_WRITE && excess1 > 0) {
1115 kdebug("clear[%d] ad=%lx sz=%lx",
1116 loop, maddr + phdr->p_filesz, excess1);
1117 clear_user((void __user *) maddr + phdr->p_filesz,
1118 excess1);
1119 }
1120
1121 #else
1122 if (excess > 0) {
1123 kdebug("clear[%d] ad=%lx sz=%lx",
1124 loop, maddr + phdr->p_filesz, excess);
1125 clear_user((void *) maddr + phdr->p_filesz, excess);
1126 }
1127 #endif
1128
1129 if (mm) {
1130 if (phdr->p_flags & PF_X) {
1131 if (!mm->start_code) {
1132 mm->start_code = maddr;
1133 mm->end_code = maddr + phdr->p_memsz;
1134 }
1135 } else if (!mm->start_data) {
1136 mm->start_data = maddr;
1137 mm->end_data = maddr + phdr->p_memsz;
1138 }
1139 }
1140
1141 seg++;
1142 }
1143
1144 return 0;
1145 }
1146
1147 /*****************************************************************************/
1148 /*
1149 * ELF-FDPIC core dumper
1150 *
1151 * Modelled on fs/exec.c:aout_core_dump()
1152 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1153 *
1154 * Modelled on fs/binfmt_elf.c core dumper
1155 */
1156 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1157
1158 /*
1159 * These are the only things you should do on a core-file: use only these
1160 * functions to write out all the necessary info.
1161 */
1162 static int dump_write(struct file *file, const void *addr, int nr)
1163 {
1164 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1165 }
1166
1167 static int dump_seek(struct file *file, loff_t off)
1168 {
1169 if (file->f_op->llseek) {
1170 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1171 return 0;
1172 } else {
1173 file->f_pos = off;
1174 }
1175 return 1;
1176 }
1177
1178 /*
1179 * Decide whether a segment is worth dumping; default is yes to be
1180 * sure (missing info is worse than too much; etc).
1181 * Personally I'd include everything, and use the coredump limit...
1182 *
1183 * I think we should skip something. But I am not sure how. H.J.
1184 */
1185 static int maydump(struct vm_area_struct *vma)
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 /* Dump shared memory only 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 kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
1205 return 1;
1206 }
1207
1208 kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
1209 return 0;
1210 }
1211
1212 #ifdef CONFIG_MMU
1213 /* If it hasn't been written to, don't write it out */
1214 if (!vma->anon_vma) {
1215 kdcore("%08lx: %08lx: no (!anon)", vma->vm_start, vma->vm_flags);
1216 return 0;
1217 }
1218 #endif
1219
1220 kdcore("%08lx: %08lx: yes", vma->vm_start, vma->vm_flags);
1221 return 1;
1222 }
1223
1224 /* An ELF note in memory */
1225 struct memelfnote
1226 {
1227 const char *name;
1228 int type;
1229 unsigned int datasz;
1230 void *data;
1231 };
1232
1233 static int notesize(struct memelfnote *en)
1234 {
1235 int sz;
1236
1237 sz = sizeof(struct elf_note);
1238 sz += roundup(strlen(en->name) + 1, 4);
1239 sz += roundup(en->datasz, 4);
1240
1241 return sz;
1242 }
1243
1244 /* #define DEBUG */
1245
1246 #define DUMP_WRITE(addr, nr) \
1247 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1248 #define DUMP_SEEK(off) \
1249 do { if (!dump_seek(file, (off))) return 0; } while(0)
1250
1251 static int writenote(struct memelfnote *men, struct file *file)
1252 {
1253 struct elf_note en;
1254
1255 en.n_namesz = strlen(men->name) + 1;
1256 en.n_descsz = men->datasz;
1257 en.n_type = men->type;
1258
1259 DUMP_WRITE(&en, sizeof(en));
1260 DUMP_WRITE(men->name, en.n_namesz);
1261 /* XXX - cast from long long to long to avoid need for libgcc.a */
1262 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1263 DUMP_WRITE(men->data, men->datasz);
1264 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1265
1266 return 1;
1267 }
1268 #undef DUMP_WRITE
1269 #undef DUMP_SEEK
1270
1271 #define DUMP_WRITE(addr, nr) \
1272 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1273 goto end_coredump;
1274 #define DUMP_SEEK(off) \
1275 if (!dump_seek(file, (off))) \
1276 goto end_coredump;
1277
1278 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1279 {
1280 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1281 elf->e_ident[EI_CLASS] = ELF_CLASS;
1282 elf->e_ident[EI_DATA] = ELF_DATA;
1283 elf->e_ident[EI_VERSION] = EV_CURRENT;
1284 elf->e_ident[EI_OSABI] = ELF_OSABI;
1285 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1286
1287 elf->e_type = ET_CORE;
1288 elf->e_machine = ELF_ARCH;
1289 elf->e_version = EV_CURRENT;
1290 elf->e_entry = 0;
1291 elf->e_phoff = sizeof(struct elfhdr);
1292 elf->e_shoff = 0;
1293 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1294 elf->e_ehsize = sizeof(struct elfhdr);
1295 elf->e_phentsize = sizeof(struct elf_phdr);
1296 elf->e_phnum = segs;
1297 elf->e_shentsize = 0;
1298 elf->e_shnum = 0;
1299 elf->e_shstrndx = 0;
1300 return;
1301 }
1302
1303 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1304 {
1305 phdr->p_type = PT_NOTE;
1306 phdr->p_offset = offset;
1307 phdr->p_vaddr = 0;
1308 phdr->p_paddr = 0;
1309 phdr->p_filesz = sz;
1310 phdr->p_memsz = 0;
1311 phdr->p_flags = 0;
1312 phdr->p_align = 0;
1313 return;
1314 }
1315
1316 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1317 unsigned int sz, void *data)
1318 {
1319 note->name = name;
1320 note->type = type;
1321 note->datasz = sz;
1322 note->data = data;
1323 return;
1324 }
1325
1326 /*
1327 * fill up all the fields in prstatus from the given task struct, except
1328 * registers which need to be filled up seperately.
1329 */
1330 static void fill_prstatus(struct elf_prstatus *prstatus,
1331 struct task_struct *p, long signr)
1332 {
1333 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1334 prstatus->pr_sigpend = p->pending.signal.sig[0];
1335 prstatus->pr_sighold = p->blocked.sig[0];
1336 prstatus->pr_pid = p->pid;
1337 prstatus->pr_ppid = p->parent->pid;
1338 prstatus->pr_pgrp = process_group(p);
1339 prstatus->pr_sid = process_session(p);
1340 if (thread_group_leader(p)) {
1341 /*
1342 * This is the record for the group leader. Add in the
1343 * cumulative times of previous dead threads. This total
1344 * won't include the time of each live thread whose state
1345 * is included in the core dump. The final total reported
1346 * to our parent process when it calls wait4 will include
1347 * those sums as well as the little bit more time it takes
1348 * this and each other thread to finish dying after the
1349 * core dump synchronization phase.
1350 */
1351 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1352 &prstatus->pr_utime);
1353 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1354 &prstatus->pr_stime);
1355 } else {
1356 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1357 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1358 }
1359 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1360 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1361
1362 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1363 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1364 }
1365
1366 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1367 struct mm_struct *mm)
1368 {
1369 unsigned int i, len;
1370
1371 /* first copy the parameters from user space */
1372 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1373
1374 len = mm->arg_end - mm->arg_start;
1375 if (len >= ELF_PRARGSZ)
1376 len = ELF_PRARGSZ - 1;
1377 if (copy_from_user(&psinfo->pr_psargs,
1378 (const char __user *) mm->arg_start, len))
1379 return -EFAULT;
1380 for (i = 0; i < len; i++)
1381 if (psinfo->pr_psargs[i] == 0)
1382 psinfo->pr_psargs[i] = ' ';
1383 psinfo->pr_psargs[len] = 0;
1384
1385 psinfo->pr_pid = p->pid;
1386 psinfo->pr_ppid = p->parent->pid;
1387 psinfo->pr_pgrp = process_group(p);
1388 psinfo->pr_sid = process_session(p);
1389
1390 i = p->state ? ffz(~p->state) + 1 : 0;
1391 psinfo->pr_state = i;
1392 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1393 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1394 psinfo->pr_nice = task_nice(p);
1395 psinfo->pr_flag = p->flags;
1396 SET_UID(psinfo->pr_uid, p->uid);
1397 SET_GID(psinfo->pr_gid, p->gid);
1398 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1399
1400 return 0;
1401 }
1402
1403 /* Here is the structure in which status of each thread is captured. */
1404 struct elf_thread_status
1405 {
1406 struct list_head list;
1407 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1408 elf_fpregset_t fpu; /* NT_PRFPREG */
1409 struct task_struct *thread;
1410 #ifdef ELF_CORE_COPY_XFPREGS
1411 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1412 #endif
1413 struct memelfnote notes[3];
1414 int num_notes;
1415 };
1416
1417 /*
1418 * In order to add the specific thread information for the elf file format,
1419 * we need to keep a linked list of every thread's pr_status and then create
1420 * a single section for them in the final core file.
1421 */
1422 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1423 {
1424 struct task_struct *p = t->thread;
1425 int sz = 0;
1426
1427 t->num_notes = 0;
1428
1429 fill_prstatus(&t->prstatus, p, signr);
1430 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1431
1432 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1433 &t->prstatus);
1434 t->num_notes++;
1435 sz += notesize(&t->notes[0]);
1436
1437 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1438 if (t->prstatus.pr_fpvalid) {
1439 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1440 &t->fpu);
1441 t->num_notes++;
1442 sz += notesize(&t->notes[1]);
1443 }
1444
1445 #ifdef ELF_CORE_COPY_XFPREGS
1446 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1447 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1448 &t->xfpu);
1449 t->num_notes++;
1450 sz += notesize(&t->notes[2]);
1451 }
1452 #endif
1453 return sz;
1454 }
1455
1456 /*
1457 * dump the segments for an MMU process
1458 */
1459 #ifdef CONFIG_MMU
1460 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
1461 size_t *size, unsigned long *limit)
1462 {
1463 struct vm_area_struct *vma;
1464
1465 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1466 unsigned long addr;
1467
1468 if (!maydump(vma))
1469 continue;
1470
1471 for (addr = vma->vm_start;
1472 addr < vma->vm_end;
1473 addr += PAGE_SIZE
1474 ) {
1475 struct vm_area_struct *vma;
1476 struct page *page;
1477
1478 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1479 &page, &vma) <= 0) {
1480 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1481 }
1482 else if (page == ZERO_PAGE(addr)) {
1483 page_cache_release(page);
1484 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1485 }
1486 else {
1487 void *kaddr;
1488
1489 flush_cache_page(vma, addr, page_to_pfn(page));
1490 kaddr = kmap(page);
1491 if ((*size += PAGE_SIZE) > *limit ||
1492 !dump_write(file, kaddr, PAGE_SIZE)
1493 ) {
1494 kunmap(page);
1495 page_cache_release(page);
1496 return -EIO;
1497 }
1498 kunmap(page);
1499 page_cache_release(page);
1500 }
1501 }
1502 }
1503
1504 return 0;
1505
1506 end_coredump:
1507 return -EFBIG;
1508 }
1509 #endif
1510
1511 /*
1512 * dump the segments for a NOMMU process
1513 */
1514 #ifndef CONFIG_MMU
1515 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
1516 size_t *size, unsigned long *limit)
1517 {
1518 struct vm_list_struct *vml;
1519
1520 for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
1521 struct vm_area_struct *vma = vml->vma;
1522
1523 if (!maydump(vma))
1524 continue;
1525
1526 if ((*size += PAGE_SIZE) > *limit)
1527 return -EFBIG;
1528
1529 if (!dump_write(file, (void *) vma->vm_start,
1530 vma->vm_end - vma->vm_start))
1531 return -EIO;
1532 }
1533
1534 return 0;
1535 }
1536 #endif
1537
1538 /*
1539 * Actual dumper
1540 *
1541 * This is a two-pass process; first we find the offsets of the bits,
1542 * and then they are actually written out. If we run out of core limit
1543 * we just truncate.
1544 */
1545 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1546 struct file *file)
1547 {
1548 #define NUM_NOTES 6
1549 int has_dumped = 0;
1550 mm_segment_t fs;
1551 int segs;
1552 size_t size = 0;
1553 int i;
1554 struct vm_area_struct *vma;
1555 struct elfhdr *elf = NULL;
1556 loff_t offset = 0, dataoff;
1557 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1558 int numnote;
1559 struct memelfnote *notes = NULL;
1560 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1561 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1562 struct task_struct *g, *p;
1563 LIST_HEAD(thread_list);
1564 struct list_head *t;
1565 elf_fpregset_t *fpu = NULL;
1566 #ifdef ELF_CORE_COPY_XFPREGS
1567 elf_fpxregset_t *xfpu = NULL;
1568 #endif
1569 int thread_status_size = 0;
1570 #ifndef CONFIG_MMU
1571 struct vm_list_struct *vml;
1572 #endif
1573 elf_addr_t *auxv;
1574
1575 /*
1576 * We no longer stop all VM operations.
1577 *
1578 * This is because those proceses that could possibly change map_count
1579 * or the mmap / vma pages are now blocked in do_exit on current
1580 * finishing this core dump.
1581 *
1582 * Only ptrace can touch these memory addresses, but it doesn't change
1583 * the map_count or the pages allocated. So no possibility of crashing
1584 * exists while dumping the mm->vm_next areas to the core file.
1585 */
1586
1587 /* alloc memory for large data structures: too large to be on stack */
1588 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1589 if (!elf)
1590 goto cleanup;
1591 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1592 if (!prstatus)
1593 goto cleanup;
1594 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1595 if (!psinfo)
1596 goto cleanup;
1597 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1598 if (!notes)
1599 goto cleanup;
1600 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1601 if (!fpu)
1602 goto cleanup;
1603 #ifdef ELF_CORE_COPY_XFPREGS
1604 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1605 if (!xfpu)
1606 goto cleanup;
1607 #endif
1608
1609 if (signr) {
1610 struct elf_thread_status *tmp;
1611 rcu_read_lock();
1612 do_each_thread(g,p)
1613 if (current->mm == p->mm && current != p) {
1614 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1615 if (!tmp) {
1616 rcu_read_unlock();
1617 goto cleanup;
1618 }
1619 tmp->thread = p;
1620 list_add(&tmp->list, &thread_list);
1621 }
1622 while_each_thread(g,p);
1623 rcu_read_unlock();
1624 list_for_each(t, &thread_list) {
1625 struct elf_thread_status *tmp;
1626 int sz;
1627
1628 tmp = list_entry(t, struct elf_thread_status, list);
1629 sz = elf_dump_thread_status(signr, tmp);
1630 thread_status_size += sz;
1631 }
1632 }
1633
1634 /* now collect the dump for the current */
1635 fill_prstatus(prstatus, current, signr);
1636 elf_core_copy_regs(&prstatus->pr_reg, regs);
1637
1638 #ifdef CONFIG_MMU
1639 segs = current->mm->map_count;
1640 #else
1641 segs = 0;
1642 for (vml = current->mm->context.vmlist; vml; vml = vml->next)
1643 segs++;
1644 #endif
1645 #ifdef ELF_CORE_EXTRA_PHDRS
1646 segs += ELF_CORE_EXTRA_PHDRS;
1647 #endif
1648
1649 /* Set up header */
1650 fill_elf_fdpic_header(elf, segs + 1); /* including notes section */
1651
1652 has_dumped = 1;
1653 current->flags |= PF_DUMPCORE;
1654
1655 /*
1656 * Set up the notes in similar form to SVR4 core dumps made
1657 * with info from their /proc.
1658 */
1659
1660 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1661 fill_psinfo(psinfo, current->group_leader, current->mm);
1662 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1663
1664 numnote = 2;
1665
1666 auxv = (elf_addr_t *) current->mm->saved_auxv;
1667
1668 i = 0;
1669 do
1670 i += 2;
1671 while (auxv[i - 2] != AT_NULL);
1672 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1673 i * sizeof(elf_addr_t), auxv);
1674
1675 /* Try to dump the FPU. */
1676 if ((prstatus->pr_fpvalid =
1677 elf_core_copy_task_fpregs(current, regs, fpu)))
1678 fill_note(notes + numnote++,
1679 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1680 #ifdef ELF_CORE_COPY_XFPREGS
1681 if (elf_core_copy_task_xfpregs(current, xfpu))
1682 fill_note(notes + numnote++,
1683 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1684 #endif
1685
1686 fs = get_fs();
1687 set_fs(KERNEL_DS);
1688
1689 DUMP_WRITE(elf, sizeof(*elf));
1690 offset += sizeof(*elf); /* Elf header */
1691 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */
1692
1693 /* Write notes phdr entry */
1694 {
1695 struct elf_phdr phdr;
1696 int sz = 0;
1697
1698 for (i = 0; i < numnote; i++)
1699 sz += notesize(notes + i);
1700
1701 sz += thread_status_size;
1702
1703 fill_elf_note_phdr(&phdr, sz, offset);
1704 offset += sz;
1705 DUMP_WRITE(&phdr, sizeof(phdr));
1706 }
1707
1708 /* Page-align dumped data */
1709 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1710
1711 /* write program headers for segments dump */
1712 for (
1713 #ifdef CONFIG_MMU
1714 vma = current->mm->mmap; vma; vma = vma->vm_next
1715 #else
1716 vml = current->mm->context.vmlist; vml; vml = vml->next
1717 #endif
1718 ) {
1719 struct elf_phdr phdr;
1720 size_t sz;
1721
1722 #ifndef CONFIG_MMU
1723 vma = vml->vma;
1724 #endif
1725
1726 sz = vma->vm_end - vma->vm_start;
1727
1728 phdr.p_type = PT_LOAD;
1729 phdr.p_offset = offset;
1730 phdr.p_vaddr = vma->vm_start;
1731 phdr.p_paddr = 0;
1732 phdr.p_filesz = maydump(vma) ? sz : 0;
1733 phdr.p_memsz = sz;
1734 offset += phdr.p_filesz;
1735 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1736 if (vma->vm_flags & VM_WRITE)
1737 phdr.p_flags |= PF_W;
1738 if (vma->vm_flags & VM_EXEC)
1739 phdr.p_flags |= PF_X;
1740 phdr.p_align = ELF_EXEC_PAGESIZE;
1741
1742 DUMP_WRITE(&phdr, sizeof(phdr));
1743 }
1744
1745 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1746 ELF_CORE_WRITE_EXTRA_PHDRS;
1747 #endif
1748
1749 /* write out the notes section */
1750 for (i = 0; i < numnote; i++)
1751 if (!writenote(notes + i, file))
1752 goto end_coredump;
1753
1754 /* write out the thread status notes section */
1755 list_for_each(t, &thread_list) {
1756 struct elf_thread_status *tmp =
1757 list_entry(t, struct elf_thread_status, list);
1758
1759 for (i = 0; i < tmp->num_notes; i++)
1760 if (!writenote(&tmp->notes[i], file))
1761 goto end_coredump;
1762 }
1763
1764 DUMP_SEEK(dataoff);
1765
1766 if (elf_fdpic_dump_segments(file, current->mm, &size, &limit) < 0)
1767 goto end_coredump;
1768
1769 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1770 ELF_CORE_WRITE_EXTRA_DATA;
1771 #endif
1772
1773 if (file->f_pos != offset) {
1774 /* Sanity check */
1775 printk(KERN_WARNING
1776 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1777 file->f_pos, offset);
1778 }
1779
1780 end_coredump:
1781 set_fs(fs);
1782
1783 cleanup:
1784 while (!list_empty(&thread_list)) {
1785 struct list_head *tmp = thread_list.next;
1786 list_del(tmp);
1787 kfree(list_entry(tmp, struct elf_thread_status, list));
1788 }
1789
1790 kfree(elf);
1791 kfree(prstatus);
1792 kfree(psinfo);
1793 kfree(notes);
1794 kfree(fpu);
1795 #ifdef ELF_CORE_COPY_XFPREGS
1796 kfree(xfpu);
1797 #endif
1798 return has_dumped;
1799 #undef NUM_NOTES
1800 }
1801
1802 #endif /* USE_ELF_CORE_DUMP */
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