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[PATCH] cdev.h: forward declarations
[linux-2.6/zen-sources.git] / fs / binfmt_elf_fdpic.c
bloba4d933a51208c5bcbfdd182b2412c3b1d369c140
1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
2 *
3 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 * Derived from binfmt_elf.c
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
13 #include <linux/module.h>
14
15 #include <linux/fs.h>
16 #include <linux/stat.h>
17 #include <linux/sched.h>
18 #include <linux/mm.h>
19 #include <linux/mman.h>
20 #include <linux/errno.h>
21 #include <linux/signal.h>
22 #include <linux/binfmts.h>
23 #include <linux/string.h>
24 #include <linux/file.h>
25 #include <linux/fcntl.h>
26 #include <linux/slab.h>
27 #include <linux/pagemap.h>
28 #include <linux/highmem.h>
29 #include <linux/highuid.h>
30 #include <linux/personality.h>
31 #include <linux/ptrace.h>
32 #include <linux/init.h>
33 #include <linux/smp_lock.h>
34 #include <linux/elf.h>
35 #include <linux/elf-fdpic.h>
36 #include <linux/elfcore.h>
37
38 #include <asm/uaccess.h>
39 #include <asm/param.h>
40 #include <asm/pgalloc.h>
41
42 typedef char *elf_caddr_t;
43
44 #if 0
45 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
46 #else
47 #define kdebug(fmt, ...) do {} while(0)
48 #endif
49
50 #if 0
51 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
52 #else
53 #define kdcore(fmt, ...) do {} while(0)
54 #endif
55
56 MODULE_LICENSE("GPL");
57
58 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
59 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
60 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
61 struct mm_struct *, const char *);
62
63 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
64 struct elf_fdpic_params *,
65 struct elf_fdpic_params *);
66
67 #ifndef CONFIG_MMU
68 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
69 unsigned long *);
70 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
71 struct file *,
72 struct mm_struct *);
73 #endif
74
75 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
76 struct file *, struct mm_struct *);
77
78 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
79 static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *);
80 #endif
81
82 static struct linux_binfmt elf_fdpic_format = {
83 .module = THIS_MODULE,
84 .load_binary = load_elf_fdpic_binary,
85 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
86 .core_dump = elf_fdpic_core_dump,
87 #endif
88 .min_coredump = ELF_EXEC_PAGESIZE,
89 };
90
91 static int __init init_elf_fdpic_binfmt(void)
92 {
93 return register_binfmt(&elf_fdpic_format);
94 }
95
96 static void __exit exit_elf_fdpic_binfmt(void)
97 {
98 unregister_binfmt(&elf_fdpic_format);
99 }
100
101 core_initcall(init_elf_fdpic_binfmt);
102 module_exit(exit_elf_fdpic_binfmt);
103
104 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
105 {
106 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
107 return 0;
108 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
109 return 0;
110 if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
111 return 0;
112 if (!file->f_op || !file->f_op->mmap)
113 return 0;
114 return 1;
115 }
116
117 /*****************************************************************************/
118 /*
119 * read the program headers table into memory
120 */
121 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
122 struct file *file)
123 {
124 struct elf32_phdr *phdr;
125 unsigned long size;
126 int retval, loop;
127
128 if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
129 return -ENOMEM;
130 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
131 return -ENOMEM;
132
133 size = params->hdr.e_phnum * sizeof(struct elf_phdr);
134 params->phdrs = kmalloc(size, GFP_KERNEL);
135 if (!params->phdrs)
136 return -ENOMEM;
137
138 retval = kernel_read(file, params->hdr.e_phoff,
139 (char *) params->phdrs, size);
140 if (retval < 0)
141 return retval;
142
143 /* determine stack size for this binary */
144 phdr = params->phdrs;
145 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
146 if (phdr->p_type != PT_GNU_STACK)
147 continue;
148
149 if (phdr->p_flags & PF_X)
150 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
151 else
152 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
153
154 params->stack_size = phdr->p_memsz;
155 break;
156 }
157
158 return 0;
159 }
160
161 /*****************************************************************************/
162 /*
163 * load an fdpic binary into various bits of memory
164 */
165 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
166 struct pt_regs *regs)
167 {
168 struct elf_fdpic_params exec_params, interp_params;
169 struct elf_phdr *phdr;
170 unsigned long stack_size, entryaddr;
171 #ifndef CONFIG_MMU
172 unsigned long fullsize;
173 #endif
174 #ifdef ELF_FDPIC_PLAT_INIT
175 unsigned long dynaddr;
176 #endif
177 struct file *interpreter = NULL; /* to shut gcc up */
178 char *interpreter_name = NULL;
179 int executable_stack;
180 int retval, i;
181
182 memset(&exec_params, 0, sizeof(exec_params));
183 memset(&interp_params, 0, sizeof(interp_params));
184
185 exec_params.hdr = *(struct elfhdr *) bprm->buf;
186 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
187
188 /* check that this is a binary we know how to deal with */
189 retval = -ENOEXEC;
190 if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
191 goto error;
192
193 /* read the program header table */
194 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
195 if (retval < 0)
196 goto error;
197
198 /* scan for a program header that specifies an interpreter */
199 phdr = exec_params.phdrs;
200
201 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
202 switch (phdr->p_type) {
203 case PT_INTERP:
204 retval = -ENOMEM;
205 if (phdr->p_filesz > PATH_MAX)
206 goto error;
207 retval = -ENOENT;
208 if (phdr->p_filesz < 2)
209 goto error;
210
211 /* read the name of the interpreter into memory */
212 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
213 if (!interpreter_name)
214 goto error;
215
216 retval = kernel_read(bprm->file,
217 phdr->p_offset,
218 interpreter_name,
219 phdr->p_filesz);
220 if (retval < 0)
221 goto error;
222
223 retval = -ENOENT;
224 if (interpreter_name[phdr->p_filesz - 1] != '\0')
225 goto error;
226
227 kdebug("Using ELF interpreter %s", interpreter_name);
228
229 /* replace the program with the interpreter */
230 interpreter = open_exec(interpreter_name);
231 retval = PTR_ERR(interpreter);
232 if (IS_ERR(interpreter)) {
233 interpreter = NULL;
234 goto error;
235 }
236
237 /*
238 * If the binary is not readable then enforce
239 * mm->dumpable = 0 regardless of the interpreter's
240 * permissions.
241 */
242 if (file_permission(interpreter, MAY_READ) < 0)
243 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
244
245 retval = kernel_read(interpreter, 0, bprm->buf,
246 BINPRM_BUF_SIZE);
247 if (retval < 0)
248 goto error;
249
250 interp_params.hdr = *((struct elfhdr *) bprm->buf);
251 break;
252
253 case PT_LOAD:
254 #ifdef CONFIG_MMU
255 if (exec_params.load_addr == 0)
256 exec_params.load_addr = phdr->p_vaddr;
257 #endif
258 break;
259 }
260
261 }
262
263 if (elf_check_const_displacement(&exec_params.hdr))
264 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
265
266 /* perform insanity checks on the interpreter */
267 if (interpreter_name) {
268 retval = -ELIBBAD;
269 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
270 goto error;
271
272 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
273
274 /* read the interpreter's program header table */
275 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
276 if (retval < 0)
277 goto error;
278 }
279
280 stack_size = exec_params.stack_size;
281 if (stack_size < interp_params.stack_size)
282 stack_size = interp_params.stack_size;
283
284 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
285 executable_stack = EXSTACK_ENABLE_X;
286 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
287 executable_stack = EXSTACK_DISABLE_X;
288 else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
289 executable_stack = EXSTACK_ENABLE_X;
290 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
291 executable_stack = EXSTACK_DISABLE_X;
292 else
293 executable_stack = EXSTACK_DEFAULT;
294
295 retval = -ENOEXEC;
296 if (stack_size == 0)
297 goto error;
298
299 if (elf_check_const_displacement(&interp_params.hdr))
300 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
301
302 /* flush all traces of the currently running executable */
303 retval = flush_old_exec(bprm);
304 if (retval)
305 goto error;
306
307 /* there's now no turning back... the old userspace image is dead,
308 * defunct, deceased, etc. after this point we have to exit via
309 * error_kill */
310 set_personality(PER_LINUX_FDPIC);
311 set_binfmt(&elf_fdpic_format);
312
313 current->mm->start_code = 0;
314 current->mm->end_code = 0;
315 current->mm->start_stack = 0;
316 current->mm->start_data = 0;
317 current->mm->end_data = 0;
318 current->mm->context.exec_fdpic_loadmap = 0;
319 current->mm->context.interp_fdpic_loadmap = 0;
320
321 current->flags &= ~PF_FORKNOEXEC;
322
323 #ifdef CONFIG_MMU
324 elf_fdpic_arch_lay_out_mm(&exec_params,
325 &interp_params,
326 &current->mm->start_stack,
327 &current->mm->start_brk);
328
329 retval = setup_arg_pages(bprm, current->mm->start_stack,
330 executable_stack);
331 if (retval < 0) {
332 send_sig(SIGKILL, current, 0);
333 goto error_kill;
334 }
335 #endif
336
337 /* load the executable and interpreter into memory */
338 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
339 "executable");
340 if (retval < 0)
341 goto error_kill;
342
343 if (interpreter_name) {
344 retval = elf_fdpic_map_file(&interp_params, interpreter,
345 current->mm, "interpreter");
346 if (retval < 0) {
347 printk(KERN_ERR "Unable to load interpreter\n");
348 goto error_kill;
349 }
350
351 allow_write_access(interpreter);
352 fput(interpreter);
353 interpreter = NULL;
354 }
355
356 #ifdef CONFIG_MMU
357 if (!current->mm->start_brk)
358 current->mm->start_brk = current->mm->end_data;
359
360 current->mm->brk = current->mm->start_brk =
361 PAGE_ALIGN(current->mm->start_brk);
362
363 #else
364 /* create a stack and brk area big enough for everyone
365 * - the brk heap starts at the bottom and works up
366 * - the stack starts at the top and works down
367 */
368 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
369 if (stack_size < PAGE_SIZE * 2)
370 stack_size = PAGE_SIZE * 2;
371
372 down_write(&current->mm->mmap_sem);
373 current->mm->start_brk = do_mmap(NULL, 0, stack_size,
374 PROT_READ | PROT_WRITE | PROT_EXEC,
375 MAP_PRIVATE | MAP_ANON | MAP_GROWSDOWN,
376 0);
377
378 if (IS_ERR_VALUE(current->mm->start_brk)) {
379 up_write(&current->mm->mmap_sem);
380 retval = current->mm->start_brk;
381 current->mm->start_brk = 0;
382 goto error_kill;
383 }
384
385 /* expand the stack mapping to use up the entire allocation granule */
386 fullsize = ksize((char *) current->mm->start_brk);
387 if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
388 fullsize, 0, 0)))
389 stack_size = fullsize;
390 up_write(&current->mm->mmap_sem);
391
392 current->mm->brk = current->mm->start_brk;
393 current->mm->context.end_brk = current->mm->start_brk;
394 current->mm->context.end_brk +=
395 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
396 current->mm->start_stack = current->mm->start_brk + stack_size;
397 #endif
398
399 compute_creds(bprm);
400 current->flags &= ~PF_FORKNOEXEC;
401 if (create_elf_fdpic_tables(bprm, current->mm,
402 &exec_params, &interp_params) < 0)
403 goto error_kill;
404
405 kdebug("- start_code %lx", current->mm->start_code);
406 kdebug("- end_code %lx", current->mm->end_code);
407 kdebug("- start_data %lx", current->mm->start_data);
408 kdebug("- end_data %lx", current->mm->end_data);
409 kdebug("- start_brk %lx", current->mm->start_brk);
410 kdebug("- brk %lx", current->mm->brk);
411 kdebug("- start_stack %lx", current->mm->start_stack);
412
413 #ifdef ELF_FDPIC_PLAT_INIT
414 /*
415 * The ABI may specify that certain registers be set up in special
416 * ways (on i386 %edx is the address of a DT_FINI function, for
417 * example. This macro performs whatever initialization to
418 * the regs structure is required.
419 */
420 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
421 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
422 dynaddr);
423 #endif
424
425 /* everything is now ready... get the userspace context ready to roll */
426 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
427 start_thread(regs, entryaddr, current->mm->start_stack);
428
429 if (unlikely(current->ptrace & PT_PTRACED)) {
430 if (current->ptrace & PT_TRACE_EXEC)
431 ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
432 else
433 send_sig(SIGTRAP, current, 0);
434 }
435
436 retval = 0;
437
438 error:
439 if (interpreter) {
440 allow_write_access(interpreter);
441 fput(interpreter);
442 }
443 kfree(interpreter_name);
444 kfree(exec_params.phdrs);
445 kfree(exec_params.loadmap);
446 kfree(interp_params.phdrs);
447 kfree(interp_params.loadmap);
448 return retval;
449
450 /* unrecoverable error - kill the process */
451 error_kill:
452 send_sig(SIGSEGV, current, 0);
453 goto error;
454
455 }
456
457 /*****************************************************************************/
458 /*
459 * present useful information to the program
460 */
461 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
462 struct mm_struct *mm,
463 struct elf_fdpic_params *exec_params,
464 struct elf_fdpic_params *interp_params)
465 {
466 unsigned long sp, csp, nitems;
467 elf_caddr_t __user *argv, *envp;
468 size_t platform_len = 0, len;
469 char *k_platform;
470 char __user *u_platform, *p;
471 long hwcap;
472 int loop;
473
474 /* we're going to shovel a whole load of stuff onto the stack */
475 #ifdef CONFIG_MMU
476 sp = bprm->p;
477 #else
478 sp = mm->start_stack;
479
480 /* stack the program arguments and environment */
481 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
482 return -EFAULT;
483 #endif
484
485 /* get hold of platform and hardware capabilities masks for the machine
486 * we are running on. In some cases (Sparc), this info is impossible
487 * to get, in others (i386) it is merely difficult.
488 */
489 hwcap = ELF_HWCAP;
490 k_platform = ELF_PLATFORM;
491 u_platform = NULL;
492
493 if (k_platform) {
494 platform_len = strlen(k_platform) + 1;
495 sp -= platform_len;
496 u_platform = (char __user *) sp;
497 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
498 return -EFAULT;
499 }
500
501 #if defined(__i386__) && defined(CONFIG_SMP)
502 /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
503 * by the processes running on the same package. One thing we can do is
504 * to shuffle the initial stack for them.
505 *
506 * the conditionals here are unneeded, but kept in to make the code
507 * behaviour the same as pre change unless we have hyperthreaded
508 * processors. This keeps Mr Marcelo Person happier but should be
509 * removed for 2.5
510 */
511 if (smp_num_siblings > 1)
512 sp = sp - ((current->pid % 64) << 7);
513 #endif
514
515 sp &= ~7UL;
516
517 /* stack the load map(s) */
518 len = sizeof(struct elf32_fdpic_loadmap);
519 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
520 sp = (sp - len) & ~7UL;
521 exec_params->map_addr = sp;
522
523 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
524 return -EFAULT;
525
526 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
527
528 if (interp_params->loadmap) {
529 len = sizeof(struct elf32_fdpic_loadmap);
530 len += sizeof(struct elf32_fdpic_loadseg) *
531 interp_params->loadmap->nsegs;
532 sp = (sp - len) & ~7UL;
533 interp_params->map_addr = sp;
534
535 if (copy_to_user((void __user *) sp, interp_params->loadmap,
536 len) != 0)
537 return -EFAULT;
538
539 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
540 }
541
542 /* force 16 byte _final_ alignment here for generality */
543 #define DLINFO_ITEMS 13
544
545 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0);
546 #ifdef DLINFO_ARCH_ITEMS
547 nitems += DLINFO_ARCH_ITEMS;
548 #endif
549
550 csp = sp;
551 sp -= nitems * 2 * sizeof(unsigned long);
552 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
553 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
554 sp -= 1 * sizeof(unsigned long); /* argc */
555
556 csp -= sp & 15UL;
557 sp -= sp & 15UL;
558
559 /* put the ELF interpreter info on the stack */
560 #define NEW_AUX_ENT(nr, id, val) \
561 do { \
562 struct { unsigned long _id, _val; } __user *ent; \
563 \
564 ent = (void __user *) csp; \
565 __put_user((id), &ent[nr]._id); \
566 __put_user((val), &ent[nr]._val); \
567 } while (0)
568
569 csp -= 2 * sizeof(unsigned long);
570 NEW_AUX_ENT(0, AT_NULL, 0);
571 if (k_platform) {
572 csp -= 2 * sizeof(unsigned long);
573 NEW_AUX_ENT(0, AT_PLATFORM,
574 (elf_addr_t) (unsigned long) u_platform);
575 }
576
577 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
578 NEW_AUX_ENT( 0, AT_HWCAP, hwcap);
579 NEW_AUX_ENT( 1, AT_PAGESZ, PAGE_SIZE);
580 NEW_AUX_ENT( 2, AT_CLKTCK, CLOCKS_PER_SEC);
581 NEW_AUX_ENT( 3, AT_PHDR, exec_params->ph_addr);
582 NEW_AUX_ENT( 4, AT_PHENT, sizeof(struct elf_phdr));
583 NEW_AUX_ENT( 5, AT_PHNUM, exec_params->hdr.e_phnum);
584 NEW_AUX_ENT( 6, AT_BASE, interp_params->elfhdr_addr);
585 NEW_AUX_ENT( 7, AT_FLAGS, 0);
586 NEW_AUX_ENT( 8, AT_ENTRY, exec_params->entry_addr);
587 NEW_AUX_ENT( 9, AT_UID, (elf_addr_t) current->uid);
588 NEW_AUX_ENT(10, AT_EUID, (elf_addr_t) current->euid);
589 NEW_AUX_ENT(11, AT_GID, (elf_addr_t) current->gid);
590 NEW_AUX_ENT(12, AT_EGID, (elf_addr_t) current->egid);
591
592 #ifdef ARCH_DLINFO
593 /* ARCH_DLINFO must come last so platform specific code can enforce
594 * special alignment requirements on the AUXV if necessary (eg. PPC).
595 */
596 ARCH_DLINFO;
597 #endif
598 #undef NEW_AUX_ENT
599
600 /* allocate room for argv[] and envv[] */
601 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
602 envp = (elf_caddr_t __user *) csp;
603 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
604 argv = (elf_caddr_t __user *) csp;
605
606 /* stack argc */
607 csp -= sizeof(unsigned long);
608 __put_user(bprm->argc, (unsigned long __user *) csp);
609
610 BUG_ON(csp != sp);
611
612 /* fill in the argv[] array */
613 #ifdef CONFIG_MMU
614 current->mm->arg_start = bprm->p;
615 #else
616 current->mm->arg_start = current->mm->start_stack -
617 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
618 #endif
619
620 p = (char __user *) current->mm->arg_start;
621 for (loop = bprm->argc; loop > 0; loop--) {
622 __put_user((elf_caddr_t) p, argv++);
623 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
624 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
625 return -EINVAL;
626 p += len;
627 }
628 __put_user(NULL, argv);
629 current->mm->arg_end = (unsigned long) p;
630
631 /* fill in the envv[] array */
632 current->mm->env_start = (unsigned long) p;
633 for (loop = bprm->envc; loop > 0; loop--) {
634 __put_user((elf_caddr_t)(unsigned long) p, envp++);
635 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
636 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
637 return -EINVAL;
638 p += len;
639 }
640 __put_user(NULL, envp);
641 current->mm->env_end = (unsigned long) p;
642
643 mm->start_stack = (unsigned long) sp;
644 return 0;
645 }
646
647 /*****************************************************************************/
648 /*
649 * transfer the program arguments and environment from the holding pages onto
650 * the stack
651 */
652 #ifndef CONFIG_MMU
653 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
654 unsigned long *_sp)
655 {
656 unsigned long index, stop, sp;
657 char *src;
658 int ret = 0;
659
660 stop = bprm->p >> PAGE_SHIFT;
661 sp = *_sp;
662
663 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
664 src = kmap(bprm->page[index]);
665 sp -= PAGE_SIZE;
666 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
667 ret = -EFAULT;
668 kunmap(bprm->page[index]);
669 if (ret < 0)
670 goto out;
671 }
672
673 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
674
675 out:
676 return ret;
677 }
678 #endif
679
680 /*****************************************************************************/
681 /*
682 * load the appropriate binary image (executable or interpreter) into memory
683 * - we assume no MMU is available
684 * - if no other PIC bits are set in params->hdr->e_flags
685 * - we assume that the LOADable segments in the binary are independently relocatable
686 * - we assume R/O executable segments are shareable
687 * - else
688 * - we assume the loadable parts of the image to require fixed displacement
689 * - the image is not shareable
690 */
691 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
692 struct file *file,
693 struct mm_struct *mm,
694 const char *what)
695 {
696 struct elf32_fdpic_loadmap *loadmap;
697 #ifdef CONFIG_MMU
698 struct elf32_fdpic_loadseg *mseg;
699 #endif
700 struct elf32_fdpic_loadseg *seg;
701 struct elf32_phdr *phdr;
702 unsigned long load_addr, stop;
703 unsigned nloads, tmp;
704 size_t size;
705 int loop, ret;
706
707 /* allocate a load map table */
708 nloads = 0;
709 for (loop = 0; loop < params->hdr.e_phnum; loop++)
710 if (params->phdrs[loop].p_type == PT_LOAD)
711 nloads++;
712
713 if (nloads == 0)
714 return -ELIBBAD;
715
716 size = sizeof(*loadmap) + nloads * sizeof(*seg);
717 loadmap = kzalloc(size, GFP_KERNEL);
718 if (!loadmap)
719 return -ENOMEM;
720
721 params->loadmap = loadmap;
722
723 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
724 loadmap->nsegs = nloads;
725
726 load_addr = params->load_addr;
727 seg = loadmap->segs;
728
729 /* map the requested LOADs into the memory space */
730 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
731 case ELF_FDPIC_FLAG_CONSTDISP:
732 case ELF_FDPIC_FLAG_CONTIGUOUS:
733 #ifndef CONFIG_MMU
734 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
735 if (ret < 0)
736 return ret;
737 break;
738 #endif
739 default:
740 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
741 if (ret < 0)
742 return ret;
743 break;
744 }
745
746 /* map the entry point */
747 if (params->hdr.e_entry) {
748 seg = loadmap->segs;
749 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
750 if (params->hdr.e_entry >= seg->p_vaddr &&
751 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
752 params->entry_addr =
753 (params->hdr.e_entry - seg->p_vaddr) +
754 seg->addr;
755 break;
756 }
757 }
758 }
759
760 /* determine where the program header table has wound up if mapped */
761 stop = params->hdr.e_phoff;
762 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
763 phdr = params->phdrs;
764
765 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
766 if (phdr->p_type != PT_LOAD)
767 continue;
768
769 if (phdr->p_offset > params->hdr.e_phoff ||
770 phdr->p_offset + phdr->p_filesz < stop)
771 continue;
772
773 seg = loadmap->segs;
774 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
775 if (phdr->p_vaddr >= seg->p_vaddr &&
776 phdr->p_vaddr + phdr->p_filesz <=
777 seg->p_vaddr + seg->p_memsz) {
778 params->ph_addr =
779 (phdr->p_vaddr - seg->p_vaddr) +
780 seg->addr +
781 params->hdr.e_phoff - phdr->p_offset;
782 break;
783 }
784 }
785 break;
786 }
787
788 /* determine where the dynamic section has wound up if there is one */
789 phdr = params->phdrs;
790 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
791 if (phdr->p_type != PT_DYNAMIC)
792 continue;
793
794 seg = loadmap->segs;
795 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
796 if (phdr->p_vaddr >= seg->p_vaddr &&
797 phdr->p_vaddr + phdr->p_memsz <=
798 seg->p_vaddr + seg->p_memsz) {
799 params->dynamic_addr =
800 (phdr->p_vaddr - seg->p_vaddr) +
801 seg->addr;
802
803 /* check the dynamic section contains at least
804 * one item, and that the last item is a NULL
805 * entry */
806 if (phdr->p_memsz == 0 ||
807 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
808 goto dynamic_error;
809
810 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
811 if (((Elf32_Dyn *)
812 params->dynamic_addr)[tmp - 1].d_tag != 0)
813 goto dynamic_error;
814 break;
815 }
816 }
817 break;
818 }
819
820 /* now elide adjacent segments in the load map on MMU linux
821 * - on uClinux the holes between may actually be filled with system
822 * stuff or stuff from other processes
823 */
824 #ifdef CONFIG_MMU
825 nloads = loadmap->nsegs;
826 mseg = loadmap->segs;
827 seg = mseg + 1;
828 for (loop = 1; loop < nloads; loop++) {
829 /* see if we have a candidate for merging */
830 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
831 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
832 if (load_addr == (seg->addr & PAGE_MASK)) {
833 mseg->p_memsz +=
834 load_addr -
835 (mseg->addr + mseg->p_memsz);
836 mseg->p_memsz += seg->addr & ~PAGE_MASK;
837 mseg->p_memsz += seg->p_memsz;
838 loadmap->nsegs--;
839 continue;
840 }
841 }
842
843 mseg++;
844 if (mseg != seg)
845 *mseg = *seg;
846 }
847 #endif
848
849 kdebug("Mapped Object [%s]:", what);
850 kdebug("- elfhdr : %lx", params->elfhdr_addr);
851 kdebug("- entry : %lx", params->entry_addr);
852 kdebug("- PHDR[] : %lx", params->ph_addr);
853 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
854 seg = loadmap->segs;
855 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
856 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
857 loop,
858 seg->addr, seg->addr + seg->p_memsz - 1,
859 seg->p_vaddr, seg->p_memsz);
860
861 return 0;
862
863 dynamic_error:
864 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
865 what, file->f_path.dentry->d_inode->i_ino);
866 return -ELIBBAD;
867 }
868
869 /*****************************************************************************/
870 /*
871 * map a file with constant displacement under uClinux
872 */
873 #ifndef CONFIG_MMU
874 static int elf_fdpic_map_file_constdisp_on_uclinux(
875 struct elf_fdpic_params *params,
876 struct file *file,
877 struct mm_struct *mm)
878 {
879 struct elf32_fdpic_loadseg *seg;
880 struct elf32_phdr *phdr;
881 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
882 loff_t fpos;
883 int loop, ret;
884
885 load_addr = params->load_addr;
886 seg = params->loadmap->segs;
887
888 /* determine the bounds of the contiguous overall allocation we must
889 * make */
890 phdr = params->phdrs;
891 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
892 if (params->phdrs[loop].p_type != PT_LOAD)
893 continue;
894
895 if (base > phdr->p_vaddr)
896 base = phdr->p_vaddr;
897 if (top < phdr->p_vaddr + phdr->p_memsz)
898 top = phdr->p_vaddr + phdr->p_memsz;
899 }
900
901 /* allocate one big anon block for everything */
902 mflags = MAP_PRIVATE;
903 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
904 mflags |= MAP_EXECUTABLE;
905
906 down_write(&mm->mmap_sem);
907 maddr = do_mmap(NULL, load_addr, top - base,
908 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
909 up_write(&mm->mmap_sem);
910 if (IS_ERR_VALUE(maddr))
911 return (int) maddr;
912
913 if (load_addr != 0)
914 load_addr += PAGE_ALIGN(top - base);
915
916 /* and then load the file segments into it */
917 phdr = params->phdrs;
918 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
919 if (params->phdrs[loop].p_type != PT_LOAD)
920 continue;
921
922 fpos = phdr->p_offset;
923
924 seg->addr = maddr + (phdr->p_vaddr - base);
925 seg->p_vaddr = phdr->p_vaddr;
926 seg->p_memsz = phdr->p_memsz;
927
928 ret = file->f_op->read(file, (void *) seg->addr,
929 phdr->p_filesz, &fpos);
930 if (ret < 0)
931 return ret;
932
933 /* map the ELF header address if in this segment */
934 if (phdr->p_offset == 0)
935 params->elfhdr_addr = seg->addr;
936
937 /* clear any space allocated but not loaded */
938 if (phdr->p_filesz < phdr->p_memsz)
939 clear_user((void *) (seg->addr + phdr->p_filesz),
940 phdr->p_memsz - phdr->p_filesz);
941
942 if (mm) {
943 if (phdr->p_flags & PF_X) {
944 mm->start_code = seg->addr;
945 mm->end_code = seg->addr + phdr->p_memsz;
946 } else if (!mm->start_data) {
947 mm->start_data = seg->addr;
948 #ifndef CONFIG_MMU
949 mm->end_data = seg->addr + phdr->p_memsz;
950 #endif
951 }
952
953 #ifdef CONFIG_MMU
954 if (seg->addr + phdr->p_memsz > mm->end_data)
955 mm->end_data = seg->addr + phdr->p_memsz;
956 #endif
957 }
958
959 seg++;
960 }
961
962 return 0;
963 }
964 #endif
965
966 /*****************************************************************************/
967 /*
968 * map a binary by direct mmap() of the individual PT_LOAD segments
969 */
970 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
971 struct file *file,
972 struct mm_struct *mm)
973 {
974 struct elf32_fdpic_loadseg *seg;
975 struct elf32_phdr *phdr;
976 unsigned long load_addr, delta_vaddr;
977 int loop, dvset;
978
979 load_addr = params->load_addr;
980 delta_vaddr = 0;
981 dvset = 0;
982
983 seg = params->loadmap->segs;
984
985 /* deal with each load segment separately */
986 phdr = params->phdrs;
987 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
988 unsigned long maddr, disp, excess, excess1;
989 int prot = 0, flags;
990
991 if (phdr->p_type != PT_LOAD)
992 continue;
993
994 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
995 (unsigned long) phdr->p_vaddr,
996 (unsigned long) phdr->p_offset,
997 (unsigned long) phdr->p_filesz,
998 (unsigned long) phdr->p_memsz);
999
1000 /* determine the mapping parameters */
1001 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1002 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1003 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1004
1005 flags = MAP_PRIVATE | MAP_DENYWRITE;
1006 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1007 flags |= MAP_EXECUTABLE;
1008
1009 maddr = 0;
1010
1011 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1012 case ELF_FDPIC_FLAG_INDEPENDENT:
1013 /* PT_LOADs are independently locatable */
1014 break;
1015
1016 case ELF_FDPIC_FLAG_HONOURVADDR:
1017 /* the specified virtual address must be honoured */
1018 maddr = phdr->p_vaddr;
1019 flags |= MAP_FIXED;
1020 break;
1021
1022 case ELF_FDPIC_FLAG_CONSTDISP:
1023 /* constant displacement
1024 * - can be mapped anywhere, but must be mapped as a
1025 * unit
1026 */
1027 if (!dvset) {
1028 maddr = load_addr;
1029 delta_vaddr = phdr->p_vaddr;
1030 dvset = 1;
1031 } else {
1032 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1033 flags |= MAP_FIXED;
1034 }
1035 break;
1036
1037 case ELF_FDPIC_FLAG_CONTIGUOUS:
1038 /* contiguity handled later */
1039 break;
1040
1041 default:
1042 BUG();
1043 }
1044
1045 maddr &= PAGE_MASK;
1046
1047 /* create the mapping */
1048 disp = phdr->p_vaddr & ~PAGE_MASK;
1049 down_write(&mm->mmap_sem);
1050 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1051 phdr->p_offset - disp);
1052 up_write(&mm->mmap_sem);
1053
1054 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1055 loop, phdr->p_memsz + disp, prot, flags,
1056 phdr->p_offset - disp, maddr);
1057
1058 if (IS_ERR_VALUE(maddr))
1059 return (int) maddr;
1060
1061 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1062 ELF_FDPIC_FLAG_CONTIGUOUS)
1063 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1064
1065 seg->addr = maddr + disp;
1066 seg->p_vaddr = phdr->p_vaddr;
1067 seg->p_memsz = phdr->p_memsz;
1068
1069 /* map the ELF header address if in this segment */
1070 if (phdr->p_offset == 0)
1071 params->elfhdr_addr = seg->addr;
1072
1073 /* clear the bit between beginning of mapping and beginning of
1074 * PT_LOAD */
1075 if (prot & PROT_WRITE && disp > 0) {
1076 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1077 clear_user((void __user *) maddr, disp);
1078 maddr += disp;
1079 }
1080
1081 /* clear any space allocated but not loaded
1082 * - on uClinux we can just clear the lot
1083 * - on MMU linux we'll get a SIGBUS beyond the last page
1084 * extant in the file
1085 */
1086 excess = phdr->p_memsz - phdr->p_filesz;
1087 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1088
1089 #ifdef CONFIG_MMU
1090 if (excess > excess1) {
1091 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1092 unsigned long xmaddr;
1093
1094 flags |= MAP_FIXED | MAP_ANONYMOUS;
1095 down_write(&mm->mmap_sem);
1096 xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1097 prot, flags, 0);
1098 up_write(&mm->mmap_sem);
1099
1100 kdebug("mmap[%d] <anon>"
1101 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1102 loop, xaddr, excess - excess1, prot, flags,
1103 xmaddr);
1104
1105 if (xmaddr != xaddr)
1106 return -ENOMEM;
1107 }
1108
1109 if (prot & PROT_WRITE && excess1 > 0) {
1110 kdebug("clear[%d] ad=%lx sz=%lx",
1111 loop, maddr + phdr->p_filesz, excess1);
1112 clear_user((void __user *) maddr + phdr->p_filesz,
1113 excess1);
1114 }
1115
1116 #else
1117 if (excess > 0) {
1118 kdebug("clear[%d] ad=%lx sz=%lx",
1119 loop, maddr + phdr->p_filesz, excess);
1120 clear_user((void *) maddr + phdr->p_filesz, excess);
1121 }
1122 #endif
1123
1124 if (mm) {
1125 if (phdr->p_flags & PF_X) {
1126 mm->start_code = maddr;
1127 mm->end_code = maddr + phdr->p_memsz;
1128 } else if (!mm->start_data) {
1129 mm->start_data = maddr;
1130 mm->end_data = maddr + phdr->p_memsz;
1131 }
1132 }
1133
1134 seg++;
1135 }
1136
1137 return 0;
1138 }
1139
1140 /*****************************************************************************/
1141 /*
1142 * ELF-FDPIC core dumper
1143 *
1144 * Modelled on fs/exec.c:aout_core_dump()
1145 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1146 *
1147 * Modelled on fs/binfmt_elf.c core dumper
1148 */
1149 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1150
1151 /*
1152 * These are the only things you should do on a core-file: use only these
1153 * functions to write out all the necessary info.
1154 */
1155 static int dump_write(struct file *file, const void *addr, int nr)
1156 {
1157 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1158 }
1159
1160 static int dump_seek(struct file *file, loff_t off)
1161 {
1162 if (file->f_op->llseek) {
1163 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1164 return 0;
1165 } else {
1166 file->f_pos = off;
1167 }
1168 return 1;
1169 }
1170
1171 /*
1172 * Decide whether a segment is worth dumping; default is yes to be
1173 * sure (missing info is worse than too much; etc).
1174 * Personally I'd include everything, and use the coredump limit...
1175 *
1176 * I think we should skip something. But I am not sure how. H.J.
1177 */
1178 static int maydump(struct vm_area_struct *vma)
1179 {
1180 /* Do not dump I/O mapped devices or special mappings */
1181 if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1182 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1183 return 0;
1184 }
1185
1186 /* If we may not read the contents, don't allow us to dump
1187 * them either. "dump_write()" can't handle it anyway.
1188 */
1189 if (!(vma->vm_flags & VM_READ)) {
1190 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1191 return 0;
1192 }
1193
1194 /* Dump shared memory only if mapped from an anonymous file. */
1195 if (vma->vm_flags & VM_SHARED) {
1196 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1197 kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
1198 return 1;
1199 }
1200
1201 kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
1202 return 0;
1203 }
1204
1205 #ifdef CONFIG_MMU
1206 /* If it hasn't been written to, don't write it out */
1207 if (!vma->anon_vma) {
1208 kdcore("%08lx: %08lx: no (!anon)", vma->vm_start, vma->vm_flags);
1209 return 0;
1210 }
1211 #endif
1212
1213 kdcore("%08lx: %08lx: yes", vma->vm_start, vma->vm_flags);
1214 return 1;
1215 }
1216
1217 /* An ELF note in memory */
1218 struct memelfnote
1219 {
1220 const char *name;
1221 int type;
1222 unsigned int datasz;
1223 void *data;
1224 };
1225
1226 static int notesize(struct memelfnote *en)
1227 {
1228 int sz;
1229
1230 sz = sizeof(struct elf_note);
1231 sz += roundup(strlen(en->name) + 1, 4);
1232 sz += roundup(en->datasz, 4);
1233
1234 return sz;
1235 }
1236
1237 /* #define DEBUG */
1238
1239 #define DUMP_WRITE(addr, nr) \
1240 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1241 #define DUMP_SEEK(off) \
1242 do { if (!dump_seek(file, (off))) return 0; } while(0)
1243
1244 static int writenote(struct memelfnote *men, struct file *file)
1245 {
1246 struct elf_note en;
1247
1248 en.n_namesz = strlen(men->name) + 1;
1249 en.n_descsz = men->datasz;
1250 en.n_type = men->type;
1251
1252 DUMP_WRITE(&en, sizeof(en));
1253 DUMP_WRITE(men->name, en.n_namesz);
1254 /* XXX - cast from long long to long to avoid need for libgcc.a */
1255 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1256 DUMP_WRITE(men->data, men->datasz);
1257 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1258
1259 return 1;
1260 }
1261 #undef DUMP_WRITE
1262 #undef DUMP_SEEK
1263
1264 #define DUMP_WRITE(addr, nr) \
1265 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1266 goto end_coredump;
1267 #define DUMP_SEEK(off) \
1268 if (!dump_seek(file, (off))) \
1269 goto end_coredump;
1270
1271 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1272 {
1273 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1274 elf->e_ident[EI_CLASS] = ELF_CLASS;
1275 elf->e_ident[EI_DATA] = ELF_DATA;
1276 elf->e_ident[EI_VERSION] = EV_CURRENT;
1277 elf->e_ident[EI_OSABI] = ELF_OSABI;
1278 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1279
1280 elf->e_type = ET_CORE;
1281 elf->e_machine = ELF_ARCH;
1282 elf->e_version = EV_CURRENT;
1283 elf->e_entry = 0;
1284 elf->e_phoff = sizeof(struct elfhdr);
1285 elf->e_shoff = 0;
1286 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1287 elf->e_ehsize = sizeof(struct elfhdr);
1288 elf->e_phentsize = sizeof(struct elf_phdr);
1289 elf->e_phnum = segs;
1290 elf->e_shentsize = 0;
1291 elf->e_shnum = 0;
1292 elf->e_shstrndx = 0;
1293 return;
1294 }
1295
1296 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1297 {
1298 phdr->p_type = PT_NOTE;
1299 phdr->p_offset = offset;
1300 phdr->p_vaddr = 0;
1301 phdr->p_paddr = 0;
1302 phdr->p_filesz = sz;
1303 phdr->p_memsz = 0;
1304 phdr->p_flags = 0;
1305 phdr->p_align = 0;
1306 return;
1307 }
1308
1309 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1310 unsigned int sz, void *data)
1311 {
1312 note->name = name;
1313 note->type = type;
1314 note->datasz = sz;
1315 note->data = data;
1316 return;
1317 }
1318
1319 /*
1320 * fill up all the fields in prstatus from the given task struct, except
1321 * registers which need to be filled up seperately.
1322 */
1323 static void fill_prstatus(struct elf_prstatus *prstatus,
1324 struct task_struct *p, long signr)
1325 {
1326 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1327 prstatus->pr_sigpend = p->pending.signal.sig[0];
1328 prstatus->pr_sighold = p->blocked.sig[0];
1329 prstatus->pr_pid = p->pid;
1330 prstatus->pr_ppid = p->parent->pid;
1331 prstatus->pr_pgrp = process_group(p);
1332 prstatus->pr_sid = process_session(p);
1333 if (thread_group_leader(p)) {
1334 /*
1335 * This is the record for the group leader. Add in the
1336 * cumulative times of previous dead threads. This total
1337 * won't include the time of each live thread whose state
1338 * is included in the core dump. The final total reported
1339 * to our parent process when it calls wait4 will include
1340 * those sums as well as the little bit more time it takes
1341 * this and each other thread to finish dying after the
1342 * core dump synchronization phase.
1343 */
1344 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1345 &prstatus->pr_utime);
1346 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1347 &prstatus->pr_stime);
1348 } else {
1349 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1350 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1351 }
1352 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1353 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1354
1355 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1356 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1357 }
1358
1359 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1360 struct mm_struct *mm)
1361 {
1362 unsigned int i, len;
1363
1364 /* first copy the parameters from user space */
1365 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1366
1367 len = mm->arg_end - mm->arg_start;
1368 if (len >= ELF_PRARGSZ)
1369 len = ELF_PRARGSZ - 1;
1370 if (copy_from_user(&psinfo->pr_psargs,
1371 (const char __user *) mm->arg_start, len))
1372 return -EFAULT;
1373 for (i = 0; i < len; i++)
1374 if (psinfo->pr_psargs[i] == 0)
1375 psinfo->pr_psargs[i] = ' ';
1376 psinfo->pr_psargs[len] = 0;
1377
1378 psinfo->pr_pid = p->pid;
1379 psinfo->pr_ppid = p->parent->pid;
1380 psinfo->pr_pgrp = process_group(p);
1381 psinfo->pr_sid = process_session(p);
1382
1383 i = p->state ? ffz(~p->state) + 1 : 0;
1384 psinfo->pr_state = i;
1385 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1386 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1387 psinfo->pr_nice = task_nice(p);
1388 psinfo->pr_flag = p->flags;
1389 SET_UID(psinfo->pr_uid, p->uid);
1390 SET_GID(psinfo->pr_gid, p->gid);
1391 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1392
1393 return 0;
1394 }
1395
1396 /* Here is the structure in which status of each thread is captured. */
1397 struct elf_thread_status
1398 {
1399 struct list_head list;
1400 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1401 elf_fpregset_t fpu; /* NT_PRFPREG */
1402 struct task_struct *thread;
1403 #ifdef ELF_CORE_COPY_XFPREGS
1404 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1405 #endif
1406 struct memelfnote notes[3];
1407 int num_notes;
1408 };
1409
1410 /*
1411 * In order to add the specific thread information for the elf file format,
1412 * we need to keep a linked list of every thread's pr_status and then create
1413 * a single section for them in the final core file.
1414 */
1415 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1416 {
1417 struct task_struct *p = t->thread;
1418 int sz = 0;
1419
1420 t->num_notes = 0;
1421
1422 fill_prstatus(&t->prstatus, p, signr);
1423 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1424
1425 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1426 &t->prstatus);
1427 t->num_notes++;
1428 sz += notesize(&t->notes[0]);
1429
1430 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1431 if (t->prstatus.pr_fpvalid) {
1432 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1433 &t->fpu);
1434 t->num_notes++;
1435 sz += notesize(&t->notes[1]);
1436 }
1437
1438 #ifdef ELF_CORE_COPY_XFPREGS
1439 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1440 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1441 &t->xfpu);
1442 t->num_notes++;
1443 sz += notesize(&t->notes[2]);
1444 }
1445 #endif
1446 return sz;
1447 }
1448
1449 /*
1450 * dump the segments for an MMU process
1451 */
1452 #ifdef CONFIG_MMU
1453 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
1454 size_t *size, unsigned long *limit)
1455 {
1456 struct vm_area_struct *vma;
1457
1458 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1459 unsigned long addr;
1460
1461 if (!maydump(vma))
1462 continue;
1463
1464 for (addr = vma->vm_start;
1465 addr < vma->vm_end;
1466 addr += PAGE_SIZE
1467 ) {
1468 struct vm_area_struct *vma;
1469 struct page *page;
1470
1471 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1472 &page, &vma) <= 0) {
1473 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1474 }
1475 else if (page == ZERO_PAGE(addr)) {
1476 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1477 page_cache_release(page);
1478 }
1479 else {
1480 void *kaddr;
1481
1482 flush_cache_page(vma, addr, page_to_pfn(page));
1483 kaddr = kmap(page);
1484 if ((*size += PAGE_SIZE) > *limit ||
1485 !dump_write(file, kaddr, PAGE_SIZE)
1486 ) {
1487 kunmap(page);
1488 page_cache_release(page);
1489 return -EIO;
1490 }
1491 kunmap(page);
1492 page_cache_release(page);
1493 }
1494 }
1495 }
1496
1497 return 0;
1498
1499 end_coredump:
1500 return -EFBIG;
1501 }
1502 #endif
1503
1504 /*
1505 * dump the segments for a NOMMU process
1506 */
1507 #ifndef CONFIG_MMU
1508 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
1509 size_t *size, unsigned long *limit)
1510 {
1511 struct vm_list_struct *vml;
1512
1513 for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
1514 struct vm_area_struct *vma = vml->vma;
1515
1516 if (!maydump(vma))
1517 continue;
1518
1519 if ((*size += PAGE_SIZE) > *limit)
1520 return -EFBIG;
1521
1522 if (!dump_write(file, (void *) vma->vm_start,
1523 vma->vm_end - vma->vm_start))
1524 return -EIO;
1525 }
1526
1527 return 0;
1528 }
1529 #endif
1530
1531 /*
1532 * Actual dumper
1533 *
1534 * This is a two-pass process; first we find the offsets of the bits,
1535 * and then they are actually written out. If we run out of core limit
1536 * we just truncate.
1537 */
1538 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1539 struct file *file)
1540 {
1541 #define NUM_NOTES 6
1542 int has_dumped = 0;
1543 mm_segment_t fs;
1544 int segs;
1545 size_t size = 0;
1546 int i;
1547 struct vm_area_struct *vma;
1548 struct elfhdr *elf = NULL;
1549 loff_t offset = 0, dataoff;
1550 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1551 int numnote;
1552 struct memelfnote *notes = NULL;
1553 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1554 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1555 struct task_struct *g, *p;
1556 LIST_HEAD(thread_list);
1557 struct list_head *t;
1558 elf_fpregset_t *fpu = NULL;
1559 #ifdef ELF_CORE_COPY_XFPREGS
1560 elf_fpxregset_t *xfpu = NULL;
1561 #endif
1562 int thread_status_size = 0;
1563 #ifndef CONFIG_MMU
1564 struct vm_list_struct *vml;
1565 #endif
1566 elf_addr_t *auxv;
1567
1568 /*
1569 * We no longer stop all VM operations.
1570 *
1571 * This is because those proceses that could possibly change map_count
1572 * or the mmap / vma pages are now blocked in do_exit on current
1573 * finishing this core dump.
1574 *
1575 * Only ptrace can touch these memory addresses, but it doesn't change
1576 * the map_count or the pages allocated. So no possibility of crashing
1577 * exists while dumping the mm->vm_next areas to the core file.
1578 */
1579
1580 /* alloc memory for large data structures: too large to be on stack */
1581 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1582 if (!elf)
1583 goto cleanup;
1584 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1585 if (!prstatus)
1586 goto cleanup;
1587 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1588 if (!psinfo)
1589 goto cleanup;
1590 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1591 if (!notes)
1592 goto cleanup;
1593 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1594 if (!fpu)
1595 goto cleanup;
1596 #ifdef ELF_CORE_COPY_XFPREGS
1597 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1598 if (!xfpu)
1599 goto cleanup;
1600 #endif
1601
1602 if (signr) {
1603 struct elf_thread_status *tmp;
1604 rcu_read_lock();
1605 do_each_thread(g,p)
1606 if (current->mm == p->mm && current != p) {
1607 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1608 if (!tmp) {
1609 rcu_read_unlock();
1610 goto cleanup;
1611 }
1612 tmp->thread = p;
1613 list_add(&tmp->list, &thread_list);
1614 }
1615 while_each_thread(g,p);
1616 rcu_read_unlock();
1617 list_for_each(t, &thread_list) {
1618 struct elf_thread_status *tmp;
1619 int sz;
1620
1621 tmp = list_entry(t, struct elf_thread_status, list);
1622 sz = elf_dump_thread_status(signr, tmp);
1623 thread_status_size += sz;
1624 }
1625 }
1626
1627 /* now collect the dump for the current */
1628 fill_prstatus(prstatus, current, signr);
1629 elf_core_copy_regs(&prstatus->pr_reg, regs);
1630
1631 #ifdef CONFIG_MMU
1632 segs = current->mm->map_count;
1633 #else
1634 segs = 0;
1635 for (vml = current->mm->context.vmlist; vml; vml = vml->next)
1636 segs++;
1637 #endif
1638 #ifdef ELF_CORE_EXTRA_PHDRS
1639 segs += ELF_CORE_EXTRA_PHDRS;
1640 #endif
1641
1642 /* Set up header */
1643 fill_elf_fdpic_header(elf, segs + 1); /* including notes section */
1644
1645 has_dumped = 1;
1646 current->flags |= PF_DUMPCORE;
1647
1648 /*
1649 * Set up the notes in similar form to SVR4 core dumps made
1650 * with info from their /proc.
1651 */
1652
1653 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1654 fill_psinfo(psinfo, current->group_leader, current->mm);
1655 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1656
1657 numnote = 2;
1658
1659 auxv = (elf_addr_t *) current->mm->saved_auxv;
1660
1661 i = 0;
1662 do
1663 i += 2;
1664 while (auxv[i - 2] != AT_NULL);
1665 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1666 i * sizeof(elf_addr_t), auxv);
1667
1668 /* Try to dump the FPU. */
1669 if ((prstatus->pr_fpvalid =
1670 elf_core_copy_task_fpregs(current, regs, fpu)))
1671 fill_note(notes + numnote++,
1672 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1673 #ifdef ELF_CORE_COPY_XFPREGS
1674 if (elf_core_copy_task_xfpregs(current, xfpu))
1675 fill_note(notes + numnote++,
1676 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1677 #endif
1678
1679 fs = get_fs();
1680 set_fs(KERNEL_DS);
1681
1682 DUMP_WRITE(elf, sizeof(*elf));
1683 offset += sizeof(*elf); /* Elf header */
1684 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */
1685
1686 /* Write notes phdr entry */
1687 {
1688 struct elf_phdr phdr;
1689 int sz = 0;
1690
1691 for (i = 0; i < numnote; i++)
1692 sz += notesize(notes + i);
1693
1694 sz += thread_status_size;
1695
1696 fill_elf_note_phdr(&phdr, sz, offset);
1697 offset += sz;
1698 DUMP_WRITE(&phdr, sizeof(phdr));
1699 }
1700
1701 /* Page-align dumped data */
1702 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1703
1704 /* write program headers for segments dump */
1705 for (
1706 #ifdef CONFIG_MMU
1707 vma = current->mm->mmap; vma; vma = vma->vm_next
1708 #else
1709 vml = current->mm->context.vmlist; vml; vml = vml->next
1710 #endif
1711 ) {
1712 struct elf_phdr phdr;
1713 size_t sz;
1714
1715 #ifndef CONFIG_MMU
1716 vma = vml->vma;
1717 #endif
1718
1719 sz = vma->vm_end - vma->vm_start;
1720
1721 phdr.p_type = PT_LOAD;
1722 phdr.p_offset = offset;
1723 phdr.p_vaddr = vma->vm_start;
1724 phdr.p_paddr = 0;
1725 phdr.p_filesz = maydump(vma) ? sz : 0;
1726 phdr.p_memsz = sz;
1727 offset += phdr.p_filesz;
1728 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1729 if (vma->vm_flags & VM_WRITE)
1730 phdr.p_flags |= PF_W;
1731 if (vma->vm_flags & VM_EXEC)
1732 phdr.p_flags |= PF_X;
1733 phdr.p_align = ELF_EXEC_PAGESIZE;
1734
1735 DUMP_WRITE(&phdr, sizeof(phdr));
1736 }
1737
1738 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1739 ELF_CORE_WRITE_EXTRA_PHDRS;
1740 #endif
1741
1742 /* write out the notes section */
1743 for (i = 0; i < numnote; i++)
1744 if (!writenote(notes + i, file))
1745 goto end_coredump;
1746
1747 /* write out the thread status notes section */
1748 list_for_each(t, &thread_list) {
1749 struct elf_thread_status *tmp =
1750 list_entry(t, struct elf_thread_status, list);
1751
1752 for (i = 0; i < tmp->num_notes; i++)
1753 if (!writenote(&tmp->notes[i], file))
1754 goto end_coredump;
1755 }
1756
1757 DUMP_SEEK(dataoff);
1758
1759 if (elf_fdpic_dump_segments(file, current->mm, &size, &limit) < 0)
1760 goto end_coredump;
1761
1762 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1763 ELF_CORE_WRITE_EXTRA_DATA;
1764 #endif
1765
1766 if (file->f_pos != offset) {
1767 /* Sanity check */
1768 printk(KERN_WARNING
1769 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1770 file->f_pos, offset);
1771 }
1772
1773 end_coredump:
1774 set_fs(fs);
1775
1776 cleanup:
1777 while (!list_empty(&thread_list)) {
1778 struct list_head *tmp = thread_list.next;
1779 list_del(tmp);
1780 kfree(list_entry(tmp, struct elf_thread_status, list));
1781 }
1782
1783 kfree(elf);
1784 kfree(prstatus);
1785 kfree(psinfo);
1786 kfree(notes);
1787 kfree(fpu);
1788 #ifdef ELF_CORE_COPY_XFPREGS
1789 kfree(xfpu);
1790 #endif
1791 return has_dumped;
1792 #undef NUM_NOTES
1793 }
1794
1795 #endif /* USE_ELF_CORE_DUMP */
Stable & featurefull patchset based on Linus's git branch