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[PATCH] arch/alpha: Use ARRAY_SIZE macro
[pohmelfs.git] / fs / binfmt_elf_fdpic.c
blob2f336582922940ffb9160d664f39acff70fe3ad1
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 #ifndef elf_addr_t
44 #define elf_addr_t unsigned long
45 #endif
46
47 #if 0
48 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
49 #else
50 #define kdebug(fmt, ...) do {} while(0)
51 #endif
52
53 #if 0
54 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
55 #else
56 #define kdcore(fmt, ...) do {} while(0)
57 #endif
58
59 MODULE_LICENSE("GPL");
60
61 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
62 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
63 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
64 struct mm_struct *, const char *);
65
66 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
67 struct elf_fdpic_params *,
68 struct elf_fdpic_params *);
69
70 #ifndef CONFIG_MMU
71 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
72 unsigned long *);
73 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
74 struct file *,
75 struct mm_struct *);
76 #endif
77
78 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
79 struct file *, struct mm_struct *);
80
81 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
82 static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *);
83 #endif
84
85 static struct linux_binfmt elf_fdpic_format = {
86 .module = THIS_MODULE,
87 .load_binary = load_elf_fdpic_binary,
88 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
89 .core_dump = elf_fdpic_core_dump,
90 #endif
91 .min_coredump = ELF_EXEC_PAGESIZE,
92 };
93
94 static int __init init_elf_fdpic_binfmt(void)
95 {
96 return register_binfmt(&elf_fdpic_format);
97 }
98
99 static void __exit exit_elf_fdpic_binfmt(void)
100 {
101 unregister_binfmt(&elf_fdpic_format);
102 }
103
104 core_initcall(init_elf_fdpic_binfmt);
105 module_exit(exit_elf_fdpic_binfmt);
106
107 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
108 {
109 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
110 return 0;
111 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
112 return 0;
113 if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
114 return 0;
115 if (!file->f_op || !file->f_op->mmap)
116 return 0;
117 return 1;
118 }
119
120 /*****************************************************************************/
121 /*
122 * read the program headers table into memory
123 */
124 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
125 struct file *file)
126 {
127 struct elf32_phdr *phdr;
128 unsigned long size;
129 int retval, loop;
130
131 if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
132 return -ENOMEM;
133 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
134 return -ENOMEM;
135
136 size = params->hdr.e_phnum * sizeof(struct elf_phdr);
137 params->phdrs = kmalloc(size, GFP_KERNEL);
138 if (!params->phdrs)
139 return -ENOMEM;
140
141 retval = kernel_read(file, params->hdr.e_phoff,
142 (char *) params->phdrs, size);
143 if (retval < 0)
144 return retval;
145
146 /* determine stack size for this binary */
147 phdr = params->phdrs;
148 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
149 if (phdr->p_type != PT_GNU_STACK)
150 continue;
151
152 if (phdr->p_flags & PF_X)
153 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
154 else
155 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
156
157 params->stack_size = phdr->p_memsz;
158 break;
159 }
160
161 return 0;
162 }
163
164 /*****************************************************************************/
165 /*
166 * load an fdpic binary into various bits of memory
167 */
168 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
169 struct pt_regs *regs)
170 {
171 struct elf_fdpic_params exec_params, interp_params;
172 struct elf_phdr *phdr;
173 unsigned long stack_size, entryaddr;
174 #ifndef CONFIG_MMU
175 unsigned long fullsize;
176 #endif
177 #ifdef ELF_FDPIC_PLAT_INIT
178 unsigned long dynaddr;
179 #endif
180 struct file *interpreter = NULL; /* to shut gcc up */
181 char *interpreter_name = NULL;
182 int executable_stack;
183 int retval, i;
184
185 memset(&exec_params, 0, sizeof(exec_params));
186 memset(&interp_params, 0, sizeof(interp_params));
187
188 exec_params.hdr = *(struct elfhdr *) bprm->buf;
189 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
190
191 /* check that this is a binary we know how to deal with */
192 retval = -ENOEXEC;
193 if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
194 goto error;
195
196 /* read the program header table */
197 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
198 if (retval < 0)
199 goto error;
200
201 /* scan for a program header that specifies an interpreter */
202 phdr = exec_params.phdrs;
203
204 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
205 switch (phdr->p_type) {
206 case PT_INTERP:
207 retval = -ENOMEM;
208 if (phdr->p_filesz > PATH_MAX)
209 goto error;
210 retval = -ENOENT;
211 if (phdr->p_filesz < 2)
212 goto error;
213
214 /* read the name of the interpreter into memory */
215 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
216 if (!interpreter_name)
217 goto error;
218
219 retval = kernel_read(bprm->file,
220 phdr->p_offset,
221 interpreter_name,
222 phdr->p_filesz);
223 if (retval < 0)
224 goto error;
225
226 retval = -ENOENT;
227 if (interpreter_name[phdr->p_filesz - 1] != '\0')
228 goto error;
229
230 kdebug("Using ELF interpreter %s", interpreter_name);
231
232 /* replace the program with the interpreter */
233 interpreter = open_exec(interpreter_name);
234 retval = PTR_ERR(interpreter);
235 if (IS_ERR(interpreter)) {
236 interpreter = NULL;
237 goto error;
238 }
239
240 retval = kernel_read(interpreter, 0, bprm->buf,
241 BINPRM_BUF_SIZE);
242 if (retval < 0)
243 goto error;
244
245 interp_params.hdr = *((struct elfhdr *) bprm->buf);
246 break;
247
248 case PT_LOAD:
249 #ifdef CONFIG_MMU
250 if (exec_params.load_addr == 0)
251 exec_params.load_addr = phdr->p_vaddr;
252 #endif
253 break;
254 }
255
256 }
257
258 if (elf_check_const_displacement(&exec_params.hdr))
259 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
260
261 /* perform insanity checks on the interpreter */
262 if (interpreter_name) {
263 retval = -ELIBBAD;
264 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
265 goto error;
266
267 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
268
269 /* read the interpreter's program header table */
270 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
271 if (retval < 0)
272 goto error;
273 }
274
275 stack_size = exec_params.stack_size;
276 if (stack_size < interp_params.stack_size)
277 stack_size = interp_params.stack_size;
278
279 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
280 executable_stack = EXSTACK_ENABLE_X;
281 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
282 executable_stack = EXSTACK_DISABLE_X;
283 else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
284 executable_stack = EXSTACK_ENABLE_X;
285 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
286 executable_stack = EXSTACK_DISABLE_X;
287 else
288 executable_stack = EXSTACK_DEFAULT;
289
290 retval = -ENOEXEC;
291 if (stack_size == 0)
292 goto error;
293
294 if (elf_check_const_displacement(&interp_params.hdr))
295 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
296
297 /* flush all traces of the currently running executable */
298 retval = flush_old_exec(bprm);
299 if (retval)
300 goto error;
301
302 /* there's now no turning back... the old userspace image is dead,
303 * defunct, deceased, etc. after this point we have to exit via
304 * error_kill */
305 set_personality(PER_LINUX_FDPIC);
306 set_binfmt(&elf_fdpic_format);
307
308 current->mm->start_code = 0;
309 current->mm->end_code = 0;
310 current->mm->start_stack = 0;
311 current->mm->start_data = 0;
312 current->mm->end_data = 0;
313 current->mm->context.exec_fdpic_loadmap = 0;
314 current->mm->context.interp_fdpic_loadmap = 0;
315
316 current->flags &= ~PF_FORKNOEXEC;
317
318 #ifdef CONFIG_MMU
319 elf_fdpic_arch_lay_out_mm(&exec_params,
320 &interp_params,
321 &current->mm->start_stack,
322 &current->mm->start_brk);
323
324 retval = setup_arg_pages(bprm, current->mm->start_stack,
325 executable_stack);
326 if (retval < 0) {
327 send_sig(SIGKILL, current, 0);
328 goto error_kill;
329 }
330 #endif
331
332 /* load the executable and interpreter into memory */
333 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
334 "executable");
335 if (retval < 0)
336 goto error_kill;
337
338 if (interpreter_name) {
339 retval = elf_fdpic_map_file(&interp_params, interpreter,
340 current->mm, "interpreter");
341 if (retval < 0) {
342 printk(KERN_ERR "Unable to load interpreter\n");
343 goto error_kill;
344 }
345
346 allow_write_access(interpreter);
347 fput(interpreter);
348 interpreter = NULL;
349 }
350
351 #ifdef CONFIG_MMU
352 if (!current->mm->start_brk)
353 current->mm->start_brk = current->mm->end_data;
354
355 current->mm->brk = current->mm->start_brk =
356 PAGE_ALIGN(current->mm->start_brk);
357
358 #else
359 /* create a stack and brk area big enough for everyone
360 * - the brk heap starts at the bottom and works up
361 * - the stack starts at the top and works down
362 */
363 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
364 if (stack_size < PAGE_SIZE * 2)
365 stack_size = PAGE_SIZE * 2;
366
367 down_write(&current->mm->mmap_sem);
368 current->mm->start_brk = do_mmap(NULL, 0, stack_size,
369 PROT_READ | PROT_WRITE | PROT_EXEC,
370 MAP_PRIVATE | MAP_ANON | MAP_GROWSDOWN,
371 0);
372
373 if (IS_ERR_VALUE(current->mm->start_brk)) {
374 up_write(&current->mm->mmap_sem);
375 retval = current->mm->start_brk;
376 current->mm->start_brk = 0;
377 goto error_kill;
378 }
379
380 /* expand the stack mapping to use up the entire allocation granule */
381 fullsize = ksize((char *) current->mm->start_brk);
382 if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
383 fullsize, 0, 0)))
384 stack_size = fullsize;
385 up_write(&current->mm->mmap_sem);
386
387 current->mm->brk = current->mm->start_brk;
388 current->mm->context.end_brk = current->mm->start_brk;
389 current->mm->context.end_brk +=
390 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
391 current->mm->start_stack = current->mm->start_brk + stack_size;
392 #endif
393
394 compute_creds(bprm);
395 current->flags &= ~PF_FORKNOEXEC;
396 if (create_elf_fdpic_tables(bprm, current->mm,
397 &exec_params, &interp_params) < 0)
398 goto error_kill;
399
400 kdebug("- start_code %lx", current->mm->start_code);
401 kdebug("- end_code %lx", current->mm->end_code);
402 kdebug("- start_data %lx", current->mm->start_data);
403 kdebug("- end_data %lx", current->mm->end_data);
404 kdebug("- start_brk %lx", current->mm->start_brk);
405 kdebug("- brk %lx", current->mm->brk);
406 kdebug("- start_stack %lx", current->mm->start_stack);
407
408 #ifdef ELF_FDPIC_PLAT_INIT
409 /*
410 * The ABI may specify that certain registers be set up in special
411 * ways (on i386 %edx is the address of a DT_FINI function, for
412 * example. This macro performs whatever initialization to
413 * the regs structure is required.
414 */
415 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
416 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
417 dynaddr);
418 #endif
419
420 /* everything is now ready... get the userspace context ready to roll */
421 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
422 start_thread(regs, entryaddr, current->mm->start_stack);
423
424 if (unlikely(current->ptrace & PT_PTRACED)) {
425 if (current->ptrace & PT_TRACE_EXEC)
426 ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
427 else
428 send_sig(SIGTRAP, current, 0);
429 }
430
431 retval = 0;
432
433 error:
434 if (interpreter) {
435 allow_write_access(interpreter);
436 fput(interpreter);
437 }
438 kfree(interpreter_name);
439 kfree(exec_params.phdrs);
440 kfree(exec_params.loadmap);
441 kfree(interp_params.phdrs);
442 kfree(interp_params.loadmap);
443 return retval;
444
445 /* unrecoverable error - kill the process */
446 error_kill:
447 send_sig(SIGSEGV, current, 0);
448 goto error;
449
450 }
451
452 /*****************************************************************************/
453 /*
454 * present useful information to the program
455 */
456 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
457 struct mm_struct *mm,
458 struct elf_fdpic_params *exec_params,
459 struct elf_fdpic_params *interp_params)
460 {
461 unsigned long sp, csp, nitems;
462 elf_caddr_t __user *argv, *envp;
463 size_t platform_len = 0, len;
464 char *k_platform;
465 char __user *u_platform, *p;
466 long hwcap;
467 int loop;
468
469 /* we're going to shovel a whole load of stuff onto the stack */
470 #ifdef CONFIG_MMU
471 sp = bprm->p;
472 #else
473 sp = mm->start_stack;
474
475 /* stack the program arguments and environment */
476 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
477 return -EFAULT;
478 #endif
479
480 /* get hold of platform and hardware capabilities masks for the machine
481 * we are running on. In some cases (Sparc), this info is impossible
482 * to get, in others (i386) it is merely difficult.
483 */
484 hwcap = ELF_HWCAP;
485 k_platform = ELF_PLATFORM;
486 u_platform = NULL;
487
488 if (k_platform) {
489 platform_len = strlen(k_platform) + 1;
490 sp -= platform_len;
491 u_platform = (char __user *) sp;
492 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
493 return -EFAULT;
494 }
495
496 #if defined(__i386__) && defined(CONFIG_SMP)
497 /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
498 * by the processes running on the same package. One thing we can do is
499 * to shuffle the initial stack for them.
500 *
501 * the conditionals here are unneeded, but kept in to make the code
502 * behaviour the same as pre change unless we have hyperthreaded
503 * processors. This keeps Mr Marcelo Person happier but should be
504 * removed for 2.5
505 */
506 if (smp_num_siblings > 1)
507 sp = sp - ((current->pid % 64) << 7);
508 #endif
509
510 sp &= ~7UL;
511
512 /* stack the load map(s) */
513 len = sizeof(struct elf32_fdpic_loadmap);
514 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
515 sp = (sp - len) & ~7UL;
516 exec_params->map_addr = sp;
517
518 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
519 return -EFAULT;
520
521 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
522
523 if (interp_params->loadmap) {
524 len = sizeof(struct elf32_fdpic_loadmap);
525 len += sizeof(struct elf32_fdpic_loadseg) *
526 interp_params->loadmap->nsegs;
527 sp = (sp - len) & ~7UL;
528 interp_params->map_addr = sp;
529
530 if (copy_to_user((void __user *) sp, interp_params->loadmap,
531 len) != 0)
532 return -EFAULT;
533
534 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
535 }
536
537 /* force 16 byte _final_ alignment here for generality */
538 #define DLINFO_ITEMS 13
539
540 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0);
541 #ifdef DLINFO_ARCH_ITEMS
542 nitems += DLINFO_ARCH_ITEMS;
543 #endif
544
545 csp = sp;
546 sp -= nitems * 2 * sizeof(unsigned long);
547 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
548 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
549 sp -= 1 * sizeof(unsigned long); /* argc */
550
551 csp -= sp & 15UL;
552 sp -= sp & 15UL;
553
554 /* put the ELF interpreter info on the stack */
555 #define NEW_AUX_ENT(nr, id, val) \
556 do { \
557 struct { unsigned long _id, _val; } __user *ent; \
558 \
559 ent = (void __user *) csp; \
560 __put_user((id), &ent[nr]._id); \
561 __put_user((val), &ent[nr]._val); \
562 } while (0)
563
564 csp -= 2 * sizeof(unsigned long);
565 NEW_AUX_ENT(0, AT_NULL, 0);
566 if (k_platform) {
567 csp -= 2 * sizeof(unsigned long);
568 NEW_AUX_ENT(0, AT_PLATFORM,
569 (elf_addr_t) (unsigned long) u_platform);
570 }
571
572 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
573 NEW_AUX_ENT( 0, AT_HWCAP, hwcap);
574 NEW_AUX_ENT( 1, AT_PAGESZ, PAGE_SIZE);
575 NEW_AUX_ENT( 2, AT_CLKTCK, CLOCKS_PER_SEC);
576 NEW_AUX_ENT( 3, AT_PHDR, exec_params->ph_addr);
577 NEW_AUX_ENT( 4, AT_PHENT, sizeof(struct elf_phdr));
578 NEW_AUX_ENT( 5, AT_PHNUM, exec_params->hdr.e_phnum);
579 NEW_AUX_ENT( 6, AT_BASE, interp_params->elfhdr_addr);
580 NEW_AUX_ENT( 7, AT_FLAGS, 0);
581 NEW_AUX_ENT( 8, AT_ENTRY, exec_params->entry_addr);
582 NEW_AUX_ENT( 9, AT_UID, (elf_addr_t) current->uid);
583 NEW_AUX_ENT(10, AT_EUID, (elf_addr_t) current->euid);
584 NEW_AUX_ENT(11, AT_GID, (elf_addr_t) current->gid);
585 NEW_AUX_ENT(12, AT_EGID, (elf_addr_t) current->egid);
586
587 #ifdef ARCH_DLINFO
588 /* ARCH_DLINFO must come last so platform specific code can enforce
589 * special alignment requirements on the AUXV if necessary (eg. PPC).
590 */
591 ARCH_DLINFO;
592 #endif
593 #undef NEW_AUX_ENT
594
595 /* allocate room for argv[] and envv[] */
596 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
597 envp = (elf_caddr_t __user *) csp;
598 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
599 argv = (elf_caddr_t __user *) csp;
600
601 /* stack argc */
602 csp -= sizeof(unsigned long);
603 __put_user(bprm->argc, (unsigned long __user *) csp);
604
605 BUG_ON(csp != sp);
606
607 /* fill in the argv[] array */
608 #ifdef CONFIG_MMU
609 current->mm->arg_start = bprm->p;
610 #else
611 current->mm->arg_start = current->mm->start_stack -
612 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
613 #endif
614
615 p = (char __user *) current->mm->arg_start;
616 for (loop = bprm->argc; loop > 0; loop--) {
617 __put_user((elf_caddr_t) p, argv++);
618 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
619 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
620 return -EINVAL;
621 p += len;
622 }
623 __put_user(NULL, argv);
624 current->mm->arg_end = (unsigned long) p;
625
626 /* fill in the envv[] array */
627 current->mm->env_start = (unsigned long) p;
628 for (loop = bprm->envc; loop > 0; loop--) {
629 __put_user((elf_caddr_t)(unsigned long) p, envp++);
630 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
631 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
632 return -EINVAL;
633 p += len;
634 }
635 __put_user(NULL, envp);
636 current->mm->env_end = (unsigned long) p;
637
638 mm->start_stack = (unsigned long) sp;
639 return 0;
640 }
641
642 /*****************************************************************************/
643 /*
644 * transfer the program arguments and environment from the holding pages onto
645 * the stack
646 */
647 #ifndef CONFIG_MMU
648 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
649 unsigned long *_sp)
650 {
651 unsigned long index, stop, sp;
652 char *src;
653 int ret = 0;
654
655 stop = bprm->p >> PAGE_SHIFT;
656 sp = *_sp;
657
658 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
659 src = kmap(bprm->page[index]);
660 sp -= PAGE_SIZE;
661 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
662 ret = -EFAULT;
663 kunmap(bprm->page[index]);
664 if (ret < 0)
665 goto out;
666 }
667
668 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
669
670 out:
671 return ret;
672 }
673 #endif
674
675 /*****************************************************************************/
676 /*
677 * load the appropriate binary image (executable or interpreter) into memory
678 * - we assume no MMU is available
679 * - if no other PIC bits are set in params->hdr->e_flags
680 * - we assume that the LOADable segments in the binary are independently relocatable
681 * - we assume R/O executable segments are shareable
682 * - else
683 * - we assume the loadable parts of the image to require fixed displacement
684 * - the image is not shareable
685 */
686 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
687 struct file *file,
688 struct mm_struct *mm,
689 const char *what)
690 {
691 struct elf32_fdpic_loadmap *loadmap;
692 #ifdef CONFIG_MMU
693 struct elf32_fdpic_loadseg *mseg;
694 #endif
695 struct elf32_fdpic_loadseg *seg;
696 struct elf32_phdr *phdr;
697 unsigned long load_addr, stop;
698 unsigned nloads, tmp;
699 size_t size;
700 int loop, ret;
701
702 /* allocate a load map table */
703 nloads = 0;
704 for (loop = 0; loop < params->hdr.e_phnum; loop++)
705 if (params->phdrs[loop].p_type == PT_LOAD)
706 nloads++;
707
708 if (nloads == 0)
709 return -ELIBBAD;
710
711 size = sizeof(*loadmap) + nloads * sizeof(*seg);
712 loadmap = kmalloc(size, GFP_KERNEL);
713 if (!loadmap)
714 return -ENOMEM;
715
716 params->loadmap = loadmap;
717 memset(loadmap, 0, size);
718
719 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
720 loadmap->nsegs = nloads;
721
722 load_addr = params->load_addr;
723 seg = loadmap->segs;
724
725 /* map the requested LOADs into the memory space */
726 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
727 case ELF_FDPIC_FLAG_CONSTDISP:
728 case ELF_FDPIC_FLAG_CONTIGUOUS:
729 #ifndef CONFIG_MMU
730 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
731 if (ret < 0)
732 return ret;
733 break;
734 #endif
735 default:
736 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
737 if (ret < 0)
738 return ret;
739 break;
740 }
741
742 /* map the entry point */
743 if (params->hdr.e_entry) {
744 seg = loadmap->segs;
745 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
746 if (params->hdr.e_entry >= seg->p_vaddr &&
747 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
748 params->entry_addr =
749 (params->hdr.e_entry - seg->p_vaddr) +
750 seg->addr;
751 break;
752 }
753 }
754 }
755
756 /* determine where the program header table has wound up if mapped */
757 stop = params->hdr.e_phoff;
758 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
759 phdr = params->phdrs;
760
761 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
762 if (phdr->p_type != PT_LOAD)
763 continue;
764
765 if (phdr->p_offset > params->hdr.e_phoff ||
766 phdr->p_offset + phdr->p_filesz < stop)
767 continue;
768
769 seg = loadmap->segs;
770 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
771 if (phdr->p_vaddr >= seg->p_vaddr &&
772 phdr->p_vaddr + phdr->p_filesz <=
773 seg->p_vaddr + seg->p_memsz) {
774 params->ph_addr =
775 (phdr->p_vaddr - seg->p_vaddr) +
776 seg->addr +
777 params->hdr.e_phoff - phdr->p_offset;
778 break;
779 }
780 }
781 break;
782 }
783
784 /* determine where the dynamic section has wound up if there is one */
785 phdr = params->phdrs;
786 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
787 if (phdr->p_type != PT_DYNAMIC)
788 continue;
789
790 seg = loadmap->segs;
791 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
792 if (phdr->p_vaddr >= seg->p_vaddr &&
793 phdr->p_vaddr + phdr->p_memsz <=
794 seg->p_vaddr + seg->p_memsz) {
795 params->dynamic_addr =
796 (phdr->p_vaddr - seg->p_vaddr) +
797 seg->addr;
798
799 /* check the dynamic section contains at least
800 * one item, and that the last item is a NULL
801 * entry */
802 if (phdr->p_memsz == 0 ||
803 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
804 goto dynamic_error;
805
806 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
807 if (((Elf32_Dyn *)
808 params->dynamic_addr)[tmp - 1].d_tag != 0)
809 goto dynamic_error;
810 break;
811 }
812 }
813 break;
814 }
815
816 /* now elide adjacent segments in the load map on MMU linux
817 * - on uClinux the holes between may actually be filled with system
818 * stuff or stuff from other processes
819 */
820 #ifdef CONFIG_MMU
821 nloads = loadmap->nsegs;
822 mseg = loadmap->segs;
823 seg = mseg + 1;
824 for (loop = 1; loop < nloads; loop++) {
825 /* see if we have a candidate for merging */
826 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
827 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
828 if (load_addr == (seg->addr & PAGE_MASK)) {
829 mseg->p_memsz +=
830 load_addr -
831 (mseg->addr + mseg->p_memsz);
832 mseg->p_memsz += seg->addr & ~PAGE_MASK;
833 mseg->p_memsz += seg->p_memsz;
834 loadmap->nsegs--;
835 continue;
836 }
837 }
838
839 mseg++;
840 if (mseg != seg)
841 *mseg = *seg;
842 }
843 #endif
844
845 kdebug("Mapped Object [%s]:", what);
846 kdebug("- elfhdr : %lx", params->elfhdr_addr);
847 kdebug("- entry : %lx", params->entry_addr);
848 kdebug("- PHDR[] : %lx", params->ph_addr);
849 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
850 seg = loadmap->segs;
851 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
852 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
853 loop,
854 seg->addr, seg->addr + seg->p_memsz - 1,
855 seg->p_vaddr, seg->p_memsz);
856
857 return 0;
858
859 dynamic_error:
860 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
861 what, file->f_dentry->d_inode->i_ino);
862 return -ELIBBAD;
863 }
864
865 /*****************************************************************************/
866 /*
867 * map a file with constant displacement under uClinux
868 */
869 #ifndef CONFIG_MMU
870 static int elf_fdpic_map_file_constdisp_on_uclinux(
871 struct elf_fdpic_params *params,
872 struct file *file,
873 struct mm_struct *mm)
874 {
875 struct elf32_fdpic_loadseg *seg;
876 struct elf32_phdr *phdr;
877 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
878 loff_t fpos;
879 int loop, ret;
880
881 load_addr = params->load_addr;
882 seg = params->loadmap->segs;
883
884 /* determine the bounds of the contiguous overall allocation we must
885 * make */
886 phdr = params->phdrs;
887 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
888 if (params->phdrs[loop].p_type != PT_LOAD)
889 continue;
890
891 if (base > phdr->p_vaddr)
892 base = phdr->p_vaddr;
893 if (top < phdr->p_vaddr + phdr->p_memsz)
894 top = phdr->p_vaddr + phdr->p_memsz;
895 }
896
897 /* allocate one big anon block for everything */
898 mflags = MAP_PRIVATE;
899 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
900 mflags |= MAP_EXECUTABLE;
901
902 down_write(&mm->mmap_sem);
903 maddr = do_mmap(NULL, load_addr, top - base,
904 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
905 up_write(&mm->mmap_sem);
906 if (IS_ERR_VALUE(maddr))
907 return (int) maddr;
908
909 if (load_addr != 0)
910 load_addr += PAGE_ALIGN(top - base);
911
912 /* and then load the file segments into it */
913 phdr = params->phdrs;
914 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
915 if (params->phdrs[loop].p_type != PT_LOAD)
916 continue;
917
918 fpos = phdr->p_offset;
919
920 seg->addr = maddr + (phdr->p_vaddr - base);
921 seg->p_vaddr = phdr->p_vaddr;
922 seg->p_memsz = phdr->p_memsz;
923
924 ret = file->f_op->read(file, (void *) seg->addr,
925 phdr->p_filesz, &fpos);
926 if (ret < 0)
927 return ret;
928
929 /* map the ELF header address if in this segment */
930 if (phdr->p_offset == 0)
931 params->elfhdr_addr = seg->addr;
932
933 /* clear any space allocated but not loaded */
934 if (phdr->p_filesz < phdr->p_memsz)
935 clear_user((void *) (seg->addr + phdr->p_filesz),
936 phdr->p_memsz - phdr->p_filesz);
937
938 if (mm) {
939 if (phdr->p_flags & PF_X) {
940 mm->start_code = seg->addr;
941 mm->end_code = seg->addr + phdr->p_memsz;
942 } else if (!mm->start_data) {
943 mm->start_data = seg->addr;
944 #ifndef CONFIG_MMU
945 mm->end_data = seg->addr + phdr->p_memsz;
946 #endif
947 }
948
949 #ifdef CONFIG_MMU
950 if (seg->addr + phdr->p_memsz > mm->end_data)
951 mm->end_data = seg->addr + phdr->p_memsz;
952 #endif
953 }
954
955 seg++;
956 }
957
958 return 0;
959 }
960 #endif
961
962 /*****************************************************************************/
963 /*
964 * map a binary by direct mmap() of the individual PT_LOAD segments
965 */
966 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
967 struct file *file,
968 struct mm_struct *mm)
969 {
970 struct elf32_fdpic_loadseg *seg;
971 struct elf32_phdr *phdr;
972 unsigned long load_addr, delta_vaddr;
973 int loop, dvset;
974
975 load_addr = params->load_addr;
976 delta_vaddr = 0;
977 dvset = 0;
978
979 seg = params->loadmap->segs;
980
981 /* deal with each load segment separately */
982 phdr = params->phdrs;
983 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
984 unsigned long maddr, disp, excess, excess1;
985 int prot = 0, flags;
986
987 if (phdr->p_type != PT_LOAD)
988 continue;
989
990 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
991 (unsigned long) phdr->p_vaddr,
992 (unsigned long) phdr->p_offset,
993 (unsigned long) phdr->p_filesz,
994 (unsigned long) phdr->p_memsz);
995
996 /* determine the mapping parameters */
997 if (phdr->p_flags & PF_R) prot |= PROT_READ;
998 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
999 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1000
1001 flags = MAP_PRIVATE | MAP_DENYWRITE;
1002 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1003 flags |= MAP_EXECUTABLE;
1004
1005 maddr = 0;
1006
1007 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1008 case ELF_FDPIC_FLAG_INDEPENDENT:
1009 /* PT_LOADs are independently locatable */
1010 break;
1011
1012 case ELF_FDPIC_FLAG_HONOURVADDR:
1013 /* the specified virtual address must be honoured */
1014 maddr = phdr->p_vaddr;
1015 flags |= MAP_FIXED;
1016 break;
1017
1018 case ELF_FDPIC_FLAG_CONSTDISP:
1019 /* constant displacement
1020 * - can be mapped anywhere, but must be mapped as a
1021 * unit
1022 */
1023 if (!dvset) {
1024 maddr = load_addr;
1025 delta_vaddr = phdr->p_vaddr;
1026 dvset = 1;
1027 } else {
1028 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1029 flags |= MAP_FIXED;
1030 }
1031 break;
1032
1033 case ELF_FDPIC_FLAG_CONTIGUOUS:
1034 /* contiguity handled later */
1035 break;
1036
1037 default:
1038 BUG();
1039 }
1040
1041 maddr &= PAGE_MASK;
1042
1043 /* create the mapping */
1044 disp = phdr->p_vaddr & ~PAGE_MASK;
1045 down_write(&mm->mmap_sem);
1046 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1047 phdr->p_offset - disp);
1048 up_write(&mm->mmap_sem);
1049
1050 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1051 loop, phdr->p_memsz + disp, prot, flags,
1052 phdr->p_offset - disp, maddr);
1053
1054 if (IS_ERR_VALUE(maddr))
1055 return (int) maddr;
1056
1057 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1058 ELF_FDPIC_FLAG_CONTIGUOUS)
1059 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1060
1061 seg->addr = maddr + disp;
1062 seg->p_vaddr = phdr->p_vaddr;
1063 seg->p_memsz = phdr->p_memsz;
1064
1065 /* map the ELF header address if in this segment */
1066 if (phdr->p_offset == 0)
1067 params->elfhdr_addr = seg->addr;
1068
1069 /* clear the bit between beginning of mapping and beginning of
1070 * PT_LOAD */
1071 if (prot & PROT_WRITE && disp > 0) {
1072 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1073 clear_user((void __user *) maddr, disp);
1074 maddr += disp;
1075 }
1076
1077 /* clear any space allocated but not loaded
1078 * - on uClinux we can just clear the lot
1079 * - on MMU linux we'll get a SIGBUS beyond the last page
1080 * extant in the file
1081 */
1082 excess = phdr->p_memsz - phdr->p_filesz;
1083 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1084
1085 #ifdef CONFIG_MMU
1086 if (excess > excess1) {
1087 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1088 unsigned long xmaddr;
1089
1090 flags |= MAP_FIXED | MAP_ANONYMOUS;
1091 down_write(&mm->mmap_sem);
1092 xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1093 prot, flags, 0);
1094 up_write(&mm->mmap_sem);
1095
1096 kdebug("mmap[%d] <anon>"
1097 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1098 loop, xaddr, excess - excess1, prot, flags,
1099 xmaddr);
1100
1101 if (xmaddr != xaddr)
1102 return -ENOMEM;
1103 }
1104
1105 if (prot & PROT_WRITE && excess1 > 0) {
1106 kdebug("clear[%d] ad=%lx sz=%lx",
1107 loop, maddr + phdr->p_filesz, excess1);
1108 clear_user((void __user *) maddr + phdr->p_filesz,
1109 excess1);
1110 }
1111
1112 #else
1113 if (excess > 0) {
1114 kdebug("clear[%d] ad=%lx sz=%lx",
1115 loop, maddr + phdr->p_filesz, excess);
1116 clear_user((void *) maddr + phdr->p_filesz, excess);
1117 }
1118 #endif
1119
1120 if (mm) {
1121 if (phdr->p_flags & PF_X) {
1122 mm->start_code = maddr;
1123 mm->end_code = maddr + phdr->p_memsz;
1124 } else if (!mm->start_data) {
1125 mm->start_data = maddr;
1126 mm->end_data = maddr + phdr->p_memsz;
1127 }
1128 }
1129
1130 seg++;
1131 }
1132
1133 return 0;
1134 }
1135
1136 /*****************************************************************************/
1137 /*
1138 * ELF-FDPIC core dumper
1139 *
1140 * Modelled on fs/exec.c:aout_core_dump()
1141 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1142 *
1143 * Modelled on fs/binfmt_elf.c core dumper
1144 */
1145 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1146
1147 /*
1148 * These are the only things you should do on a core-file: use only these
1149 * functions to write out all the necessary info.
1150 */
1151 static int dump_write(struct file *file, const void *addr, int nr)
1152 {
1153 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1154 }
1155
1156 static int dump_seek(struct file *file, loff_t off)
1157 {
1158 if (file->f_op->llseek) {
1159 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1160 return 0;
1161 } else {
1162 file->f_pos = off;
1163 }
1164 return 1;
1165 }
1166
1167 /*
1168 * Decide whether a segment is worth dumping; default is yes to be
1169 * sure (missing info is worse than too much; etc).
1170 * Personally I'd include everything, and use the coredump limit...
1171 *
1172 * I think we should skip something. But I am not sure how. H.J.
1173 */
1174 static int maydump(struct vm_area_struct *vma)
1175 {
1176 /* Do not dump I/O mapped devices or special mappings */
1177 if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1178 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1179 return 0;
1180 }
1181
1182 /* If we may not read the contents, don't allow us to dump
1183 * them either. "dump_write()" can't handle it anyway.
1184 */
1185 if (!(vma->vm_flags & VM_READ)) {
1186 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1187 return 0;
1188 }
1189
1190 /* Dump shared memory only if mapped from an anonymous file. */
1191 if (vma->vm_flags & VM_SHARED) {
1192 if (vma->vm_file->f_dentry->d_inode->i_nlink == 0) {
1193 kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
1194 return 1;
1195 }
1196
1197 kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
1198 return 0;
1199 }
1200
1201 #ifdef CONFIG_MMU
1202 /* If it hasn't been written to, don't write it out */
1203 if (!vma->anon_vma) {
1204 kdcore("%08lx: %08lx: no (!anon)", vma->vm_start, vma->vm_flags);
1205 return 0;
1206 }
1207 #endif
1208
1209 kdcore("%08lx: %08lx: yes", vma->vm_start, vma->vm_flags);
1210 return 1;
1211 }
1212
1213 /* An ELF note in memory */
1214 struct memelfnote
1215 {
1216 const char *name;
1217 int type;
1218 unsigned int datasz;
1219 void *data;
1220 };
1221
1222 static int notesize(struct memelfnote *en)
1223 {
1224 int sz;
1225
1226 sz = sizeof(struct elf_note);
1227 sz += roundup(strlen(en->name) + 1, 4);
1228 sz += roundup(en->datasz, 4);
1229
1230 return sz;
1231 }
1232
1233 /* #define DEBUG */
1234
1235 #define DUMP_WRITE(addr, nr) \
1236 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1237 #define DUMP_SEEK(off) \
1238 do { if (!dump_seek(file, (off))) return 0; } while(0)
1239
1240 static int writenote(struct memelfnote *men, struct file *file)
1241 {
1242 struct elf_note en;
1243
1244 en.n_namesz = strlen(men->name) + 1;
1245 en.n_descsz = men->datasz;
1246 en.n_type = men->type;
1247
1248 DUMP_WRITE(&en, sizeof(en));
1249 DUMP_WRITE(men->name, en.n_namesz);
1250 /* XXX - cast from long long to long to avoid need for libgcc.a */
1251 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1252 DUMP_WRITE(men->data, men->datasz);
1253 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1254
1255 return 1;
1256 }
1257 #undef DUMP_WRITE
1258 #undef DUMP_SEEK
1259
1260 #define DUMP_WRITE(addr, nr) \
1261 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1262 goto end_coredump;
1263 #define DUMP_SEEK(off) \
1264 if (!dump_seek(file, (off))) \
1265 goto end_coredump;
1266
1267 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1268 {
1269 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1270 elf->e_ident[EI_CLASS] = ELF_CLASS;
1271 elf->e_ident[EI_DATA] = ELF_DATA;
1272 elf->e_ident[EI_VERSION] = EV_CURRENT;
1273 elf->e_ident[EI_OSABI] = ELF_OSABI;
1274 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1275
1276 elf->e_type = ET_CORE;
1277 elf->e_machine = ELF_ARCH;
1278 elf->e_version = EV_CURRENT;
1279 elf->e_entry = 0;
1280 elf->e_phoff = sizeof(struct elfhdr);
1281 elf->e_shoff = 0;
1282 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1283 elf->e_ehsize = sizeof(struct elfhdr);
1284 elf->e_phentsize = sizeof(struct elf_phdr);
1285 elf->e_phnum = segs;
1286 elf->e_shentsize = 0;
1287 elf->e_shnum = 0;
1288 elf->e_shstrndx = 0;
1289 return;
1290 }
1291
1292 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1293 {
1294 phdr->p_type = PT_NOTE;
1295 phdr->p_offset = offset;
1296 phdr->p_vaddr = 0;
1297 phdr->p_paddr = 0;
1298 phdr->p_filesz = sz;
1299 phdr->p_memsz = 0;
1300 phdr->p_flags = 0;
1301 phdr->p_align = 0;
1302 return;
1303 }
1304
1305 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1306 unsigned int sz, void *data)
1307 {
1308 note->name = name;
1309 note->type = type;
1310 note->datasz = sz;
1311 note->data = data;
1312 return;
1313 }
1314
1315 /*
1316 * fill up all the fields in prstatus from the given task struct, except
1317 * registers which need to be filled up seperately.
1318 */
1319 static void fill_prstatus(struct elf_prstatus *prstatus,
1320 struct task_struct *p, long signr)
1321 {
1322 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1323 prstatus->pr_sigpend = p->pending.signal.sig[0];
1324 prstatus->pr_sighold = p->blocked.sig[0];
1325 prstatus->pr_pid = p->pid;
1326 prstatus->pr_ppid = p->parent->pid;
1327 prstatus->pr_pgrp = process_group(p);
1328 prstatus->pr_sid = p->signal->session;
1329 if (thread_group_leader(p)) {
1330 /*
1331 * This is the record for the group leader. Add in the
1332 * cumulative times of previous dead threads. This total
1333 * won't include the time of each live thread whose state
1334 * is included in the core dump. The final total reported
1335 * to our parent process when it calls wait4 will include
1336 * those sums as well as the little bit more time it takes
1337 * this and each other thread to finish dying after the
1338 * core dump synchronization phase.
1339 */
1340 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1341 &prstatus->pr_utime);
1342 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1343 &prstatus->pr_stime);
1344 } else {
1345 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1346 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1347 }
1348 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1349 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1350
1351 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1352 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1353 }
1354
1355 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1356 struct mm_struct *mm)
1357 {
1358 unsigned int i, len;
1359
1360 /* first copy the parameters from user space */
1361 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1362
1363 len = mm->arg_end - mm->arg_start;
1364 if (len >= ELF_PRARGSZ)
1365 len = ELF_PRARGSZ - 1;
1366 if (copy_from_user(&psinfo->pr_psargs,
1367 (const char __user *) mm->arg_start, len))
1368 return -EFAULT;
1369 for (i = 0; i < len; i++)
1370 if (psinfo->pr_psargs[i] == 0)
1371 psinfo->pr_psargs[i] = ' ';
1372 psinfo->pr_psargs[len] = 0;
1373
1374 psinfo->pr_pid = p->pid;
1375 psinfo->pr_ppid = p->parent->pid;
1376 psinfo->pr_pgrp = process_group(p);
1377 psinfo->pr_sid = p->signal->session;
1378
1379 i = p->state ? ffz(~p->state) + 1 : 0;
1380 psinfo->pr_state = i;
1381 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1382 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1383 psinfo->pr_nice = task_nice(p);
1384 psinfo->pr_flag = p->flags;
1385 SET_UID(psinfo->pr_uid, p->uid);
1386 SET_GID(psinfo->pr_gid, p->gid);
1387 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1388
1389 return 0;
1390 }
1391
1392 /* Here is the structure in which status of each thread is captured. */
1393 struct elf_thread_status
1394 {
1395 struct list_head list;
1396 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1397 elf_fpregset_t fpu; /* NT_PRFPREG */
1398 struct task_struct *thread;
1399 #ifdef ELF_CORE_COPY_XFPREGS
1400 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1401 #endif
1402 struct memelfnote notes[3];
1403 int num_notes;
1404 };
1405
1406 /*
1407 * In order to add the specific thread information for the elf file format,
1408 * we need to keep a linked list of every thread's pr_status and then create
1409 * a single section for them in the final core file.
1410 */
1411 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1412 {
1413 struct task_struct *p = t->thread;
1414 int sz = 0;
1415
1416 t->num_notes = 0;
1417
1418 fill_prstatus(&t->prstatus, p, signr);
1419 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1420
1421 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1422 &t->prstatus);
1423 t->num_notes++;
1424 sz += notesize(&t->notes[0]);
1425
1426 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1427 if (t->prstatus.pr_fpvalid) {
1428 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1429 &t->fpu);
1430 t->num_notes++;
1431 sz += notesize(&t->notes[1]);
1432 }
1433
1434 #ifdef ELF_CORE_COPY_XFPREGS
1435 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1436 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1437 &t->xfpu);
1438 t->num_notes++;
1439 sz += notesize(&t->notes[2]);
1440 }
1441 #endif
1442 return sz;
1443 }
1444
1445 /*
1446 * dump the segments for an MMU process
1447 */
1448 #ifdef CONFIG_MMU
1449 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
1450 size_t *size, unsigned long *limit)
1451 {
1452 struct vm_area_struct *vma;
1453
1454 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1455 unsigned long addr;
1456
1457 if (!maydump(vma))
1458 continue;
1459
1460 for (addr = vma->vm_start;
1461 addr < vma->vm_end;
1462 addr += PAGE_SIZE
1463 ) {
1464 struct vm_area_struct *vma;
1465 struct page *page;
1466
1467 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1468 &page, &vma) <= 0) {
1469 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1470 }
1471 else if (page == ZERO_PAGE(addr)) {
1472 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1473 page_cache_release(page);
1474 }
1475 else {
1476 void *kaddr;
1477
1478 flush_cache_page(vma, addr, page_to_pfn(page));
1479 kaddr = kmap(page);
1480 if ((*size += PAGE_SIZE) > *limit ||
1481 !dump_write(file, kaddr, PAGE_SIZE)
1482 ) {
1483 kunmap(page);
1484 page_cache_release(page);
1485 return -EIO;
1486 }
1487 kunmap(page);
1488 page_cache_release(page);
1489 }
1490 }
1491 }
1492
1493 return 0;
1494
1495 end_coredump:
1496 return -EFBIG;
1497 }
1498 #endif
1499
1500 /*
1501 * dump the segments for a NOMMU process
1502 */
1503 #ifndef CONFIG_MMU
1504 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
1505 size_t *size, unsigned long *limit)
1506 {
1507 struct vm_list_struct *vml;
1508
1509 for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
1510 struct vm_area_struct *vma = vml->vma;
1511
1512 if (!maydump(vma))
1513 continue;
1514
1515 if ((*size += PAGE_SIZE) > *limit)
1516 return -EFBIG;
1517
1518 if (!dump_write(file, (void *) vma->vm_start,
1519 vma->vm_end - vma->vm_start))
1520 return -EIO;
1521 }
1522
1523 return 0;
1524 }
1525 #endif
1526
1527 /*
1528 * Actual dumper
1529 *
1530 * This is a two-pass process; first we find the offsets of the bits,
1531 * and then they are actually written out. If we run out of core limit
1532 * we just truncate.
1533 */
1534 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1535 struct file *file)
1536 {
1537 #define NUM_NOTES 6
1538 int has_dumped = 0;
1539 mm_segment_t fs;
1540 int segs;
1541 size_t size = 0;
1542 int i;
1543 struct vm_area_struct *vma;
1544 struct elfhdr *elf = NULL;
1545 loff_t offset = 0, dataoff;
1546 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1547 int numnote;
1548 struct memelfnote *notes = NULL;
1549 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1550 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1551 struct task_struct *g, *p;
1552 LIST_HEAD(thread_list);
1553 struct list_head *t;
1554 elf_fpregset_t *fpu = NULL;
1555 #ifdef ELF_CORE_COPY_XFPREGS
1556 elf_fpxregset_t *xfpu = NULL;
1557 #endif
1558 int thread_status_size = 0;
1559 #ifndef CONFIG_MMU
1560 struct vm_list_struct *vml;
1561 #endif
1562 elf_addr_t *auxv;
1563
1564 /*
1565 * We no longer stop all VM operations.
1566 *
1567 * This is because those proceses that could possibly change map_count
1568 * or the mmap / vma pages are now blocked in do_exit on current
1569 * finishing this core dump.
1570 *
1571 * Only ptrace can touch these memory addresses, but it doesn't change
1572 * the map_count or the pages allocated. So no possibility of crashing
1573 * exists while dumping the mm->vm_next areas to the core file.
1574 */
1575
1576 /* alloc memory for large data structures: too large to be on stack */
1577 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1578 if (!elf)
1579 goto cleanup;
1580 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1581 if (!prstatus)
1582 goto cleanup;
1583 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1584 if (!psinfo)
1585 goto cleanup;
1586 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1587 if (!notes)
1588 goto cleanup;
1589 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1590 if (!fpu)
1591 goto cleanup;
1592 #ifdef ELF_CORE_COPY_XFPREGS
1593 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1594 if (!xfpu)
1595 goto cleanup;
1596 #endif
1597
1598 if (signr) {
1599 struct elf_thread_status *tmp;
1600 read_lock(&tasklist_lock);
1601 do_each_thread(g,p)
1602 if (current->mm == p->mm && current != p) {
1603 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1604 if (!tmp) {
1605 read_unlock(&tasklist_lock);
1606 goto cleanup;
1607 }
1608 INIT_LIST_HEAD(&tmp->list);
1609 tmp->thread = p;
1610 list_add(&tmp->list, &thread_list);
1611 }
1612 while_each_thread(g,p);
1613 read_unlock(&tasklist_lock);
1614 list_for_each(t, &thread_list) {
1615 struct elf_thread_status *tmp;
1616 int sz;
1617
1618 tmp = list_entry(t, struct elf_thread_status, list);
1619 sz = elf_dump_thread_status(signr, tmp);
1620 thread_status_size += sz;
1621 }
1622 }
1623
1624 /* now collect the dump for the current */
1625 fill_prstatus(prstatus, current, signr);
1626 elf_core_copy_regs(&prstatus->pr_reg, regs);
1627
1628 #ifdef CONFIG_MMU
1629 segs = current->mm->map_count;
1630 #else
1631 segs = 0;
1632 for (vml = current->mm->context.vmlist; vml; vml = vml->next)
1633 segs++;
1634 #endif
1635 #ifdef ELF_CORE_EXTRA_PHDRS
1636 segs += ELF_CORE_EXTRA_PHDRS;
1637 #endif
1638
1639 /* Set up header */
1640 fill_elf_fdpic_header(elf, segs + 1); /* including notes section */
1641
1642 has_dumped = 1;
1643 current->flags |= PF_DUMPCORE;
1644
1645 /*
1646 * Set up the notes in similar form to SVR4 core dumps made
1647 * with info from their /proc.
1648 */
1649
1650 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1651 fill_psinfo(psinfo, current->group_leader, current->mm);
1652 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1653
1654 numnote = 2;
1655
1656 auxv = (elf_addr_t *) current->mm->saved_auxv;
1657
1658 i = 0;
1659 do
1660 i += 2;
1661 while (auxv[i - 2] != AT_NULL);
1662 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1663 i * sizeof(elf_addr_t), auxv);
1664
1665 /* Try to dump the FPU. */
1666 if ((prstatus->pr_fpvalid =
1667 elf_core_copy_task_fpregs(current, regs, fpu)))
1668 fill_note(notes + numnote++,
1669 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1670 #ifdef ELF_CORE_COPY_XFPREGS
1671 if (elf_core_copy_task_xfpregs(current, xfpu))
1672 fill_note(notes + numnote++,
1673 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1674 #endif
1675
1676 fs = get_fs();
1677 set_fs(KERNEL_DS);
1678
1679 DUMP_WRITE(elf, sizeof(*elf));
1680 offset += sizeof(*elf); /* Elf header */
1681 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */
1682
1683 /* Write notes phdr entry */
1684 {
1685 struct elf_phdr phdr;
1686 int sz = 0;
1687
1688 for (i = 0; i < numnote; i++)
1689 sz += notesize(notes + i);
1690
1691 sz += thread_status_size;
1692
1693 fill_elf_note_phdr(&phdr, sz, offset);
1694 offset += sz;
1695 DUMP_WRITE(&phdr, sizeof(phdr));
1696 }
1697
1698 /* Page-align dumped data */
1699 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1700
1701 /* write program headers for segments dump */
1702 for (
1703 #ifdef CONFIG_MMU
1704 vma = current->mm->mmap; vma; vma = vma->vm_next
1705 #else
1706 vml = current->mm->context.vmlist; vml; vml = vml->next
1707 #endif
1708 ) {
1709 struct elf_phdr phdr;
1710 size_t sz;
1711
1712 #ifndef CONFIG_MMU
1713 vma = vml->vma;
1714 #endif
1715
1716 sz = vma->vm_end - vma->vm_start;
1717
1718 phdr.p_type = PT_LOAD;
1719 phdr.p_offset = offset;
1720 phdr.p_vaddr = vma->vm_start;
1721 phdr.p_paddr = 0;
1722 phdr.p_filesz = maydump(vma) ? sz : 0;
1723 phdr.p_memsz = sz;
1724 offset += phdr.p_filesz;
1725 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1726 if (vma->vm_flags & VM_WRITE)
1727 phdr.p_flags |= PF_W;
1728 if (vma->vm_flags & VM_EXEC)
1729 phdr.p_flags |= PF_X;
1730 phdr.p_align = ELF_EXEC_PAGESIZE;
1731
1732 DUMP_WRITE(&phdr, sizeof(phdr));
1733 }
1734
1735 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1736 ELF_CORE_WRITE_EXTRA_PHDRS;
1737 #endif
1738
1739 /* write out the notes section */
1740 for (i = 0; i < numnote; i++)
1741 if (!writenote(notes + i, file))
1742 goto end_coredump;
1743
1744 /* write out the thread status notes section */
1745 list_for_each(t, &thread_list) {
1746 struct elf_thread_status *tmp =
1747 list_entry(t, struct elf_thread_status, list);
1748
1749 for (i = 0; i < tmp->num_notes; i++)
1750 if (!writenote(&tmp->notes[i], file))
1751 goto end_coredump;
1752 }
1753
1754 DUMP_SEEK(dataoff);
1755
1756 if (elf_fdpic_dump_segments(file, current->mm, &size, &limit) < 0)
1757 goto end_coredump;
1758
1759 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1760 ELF_CORE_WRITE_EXTRA_DATA;
1761 #endif
1762
1763 if (file->f_pos != offset) {
1764 /* Sanity check */
1765 printk(KERN_WARNING
1766 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1767 file->f_pos, offset);
1768 }
1769
1770 end_coredump:
1771 set_fs(fs);
1772
1773 cleanup:
1774 while (!list_empty(&thread_list)) {
1775 struct list_head *tmp = thread_list.next;
1776 list_del(tmp);
1777 kfree(list_entry(tmp, struct elf_thread_status, list));
1778 }
1779
1780 kfree(elf);
1781 kfree(prstatus);
1782 kfree(psinfo);
1783 kfree(notes);
1784 kfree(fpu);
1785 #ifdef ELF_CORE_COPY_XFPREGS
1786 kfree(xfpu);
1787 #endif
1788 return has_dumped;
1789 #undef NUM_NOTES
1790 }
1791
1792 #endif /* USE_ELF_CORE_DUMP */