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NFS41: fix error of setting blocklayoutdriver
[linux/fpc-iii.git] / fs / binfmt_elf_fdpic.c
blob3d77cf81ba3c82c8dbe7d80531e34bea4355250c
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/security.h>
29 #include <linux/highmem.h>
30 #include <linux/highuid.h>
31 #include <linux/personality.h>
32 #include <linux/ptrace.h>
33 #include <linux/init.h>
34 #include <linux/elf.h>
35 #include <linux/elf-fdpic.h>
36 #include <linux/elfcore.h>
37 #include <linux/coredump.h>
38
39 #include <asm/uaccess.h>
40 #include <asm/param.h>
41 #include <asm/pgalloc.h>
42 #include <asm/exec.h>
43
44 typedef char *elf_caddr_t;
45
46 #if 0
47 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
48 #else
49 #define kdebug(fmt, ...) do {} while(0)
50 #endif
51
52 #if 0
53 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
54 #else
55 #define kdcore(fmt, ...) do {} while(0)
56 #endif
57
58 MODULE_LICENSE("GPL");
59
60 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
61 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
62 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
63 struct mm_struct *, const char *);
64
65 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
66 struct elf_fdpic_params *,
67 struct elf_fdpic_params *);
68
69 #ifndef CONFIG_MMU
70 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
71 unsigned long *);
72 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
73 struct file *,
74 struct mm_struct *);
75 #endif
76
77 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
78 struct file *, struct mm_struct *);
79
80 #ifdef CONFIG_ELF_CORE
81 static int elf_fdpic_core_dump(struct coredump_params *cprm);
82 #endif
83
84 static struct linux_binfmt elf_fdpic_format = {
85 .module = THIS_MODULE,
86 .load_binary = load_elf_fdpic_binary,
87 #ifdef CONFIG_ELF_CORE
88 .core_dump = elf_fdpic_core_dump,
89 #endif
90 .min_coredump = ELF_EXEC_PAGESIZE,
91 };
92
93 static int __init init_elf_fdpic_binfmt(void)
94 {
95 register_binfmt(&elf_fdpic_format);
96 return 0;
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 (unlikely(retval != size))
144 return retval < 0 ? retval : -ENOEXEC;
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 #ifdef ELF_FDPIC_PLAT_INIT
175 unsigned long dynaddr;
176 #endif
177 #ifndef CONFIG_MMU
178 unsigned long stack_prot;
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 kdebug("____ LOAD %d ____", current->pid);
186
187 memset(&exec_params, 0, sizeof(exec_params));
188 memset(&interp_params, 0, sizeof(interp_params));
189
190 exec_params.hdr = *(struct elfhdr *) bprm->buf;
191 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
192
193 /* check that this is a binary we know how to deal with */
194 retval = -ENOEXEC;
195 if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
196 goto error;
197
198 /* read the program header table */
199 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
200 if (retval < 0)
201 goto error;
202
203 /* scan for a program header that specifies an interpreter */
204 phdr = exec_params.phdrs;
205
206 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
207 switch (phdr->p_type) {
208 case PT_INTERP:
209 retval = -ENOMEM;
210 if (phdr->p_filesz > PATH_MAX)
211 goto error;
212 retval = -ENOENT;
213 if (phdr->p_filesz < 2)
214 goto error;
215
216 /* read the name of the interpreter into memory */
217 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
218 if (!interpreter_name)
219 goto error;
220
221 retval = kernel_read(bprm->file,
222 phdr->p_offset,
223 interpreter_name,
224 phdr->p_filesz);
225 if (unlikely(retval != phdr->p_filesz)) {
226 if (retval >= 0)
227 retval = -ENOEXEC;
228 goto error;
229 }
230
231 retval = -ENOENT;
232 if (interpreter_name[phdr->p_filesz - 1] != '\0')
233 goto error;
234
235 kdebug("Using ELF interpreter %s", interpreter_name);
236
237 /* replace the program with the interpreter */
238 interpreter = open_exec(interpreter_name);
239 retval = PTR_ERR(interpreter);
240 if (IS_ERR(interpreter)) {
241 interpreter = NULL;
242 goto error;
243 }
244
245 /*
246 * If the binary is not readable then enforce
247 * mm->dumpable = 0 regardless of the interpreter's
248 * permissions.
249 */
250 would_dump(bprm, interpreter);
251
252 retval = kernel_read(interpreter, 0, bprm->buf,
253 BINPRM_BUF_SIZE);
254 if (unlikely(retval != BINPRM_BUF_SIZE)) {
255 if (retval >= 0)
256 retval = -ENOEXEC;
257 goto error;
258 }
259
260 interp_params.hdr = *((struct elfhdr *) bprm->buf);
261 break;
262
263 case PT_LOAD:
264 #ifdef CONFIG_MMU
265 if (exec_params.load_addr == 0)
266 exec_params.load_addr = phdr->p_vaddr;
267 #endif
268 break;
269 }
270
271 }
272
273 if (elf_check_const_displacement(&exec_params.hdr))
274 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
275
276 /* perform insanity checks on the interpreter */
277 if (interpreter_name) {
278 retval = -ELIBBAD;
279 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
280 goto error;
281
282 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
283
284 /* read the interpreter's program header table */
285 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
286 if (retval < 0)
287 goto error;
288 }
289
290 stack_size = exec_params.stack_size;
291 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
292 executable_stack = EXSTACK_ENABLE_X;
293 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
294 executable_stack = EXSTACK_DISABLE_X;
295 else
296 executable_stack = EXSTACK_DEFAULT;
297
298 if (stack_size == 0) {
299 stack_size = interp_params.stack_size;
300 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
301 executable_stack = EXSTACK_ENABLE_X;
302 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
303 executable_stack = EXSTACK_DISABLE_X;
304 else
305 executable_stack = EXSTACK_DEFAULT;
306 }
307
308 retval = -ENOEXEC;
309 if (stack_size == 0)
310 goto error;
311
312 if (elf_check_const_displacement(&interp_params.hdr))
313 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
314
315 /* flush all traces of the currently running executable */
316 retval = flush_old_exec(bprm);
317 if (retval)
318 goto error;
319
320 /* there's now no turning back... the old userspace image is dead,
321 * defunct, deceased, etc. after this point we have to exit via
322 * error_kill */
323 set_personality(PER_LINUX_FDPIC);
324 if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
325 current->personality |= READ_IMPLIES_EXEC;
326
327 setup_new_exec(bprm);
328
329 set_binfmt(&elf_fdpic_format);
330
331 current->mm->start_code = 0;
332 current->mm->end_code = 0;
333 current->mm->start_stack = 0;
334 current->mm->start_data = 0;
335 current->mm->end_data = 0;
336 current->mm->context.exec_fdpic_loadmap = 0;
337 current->mm->context.interp_fdpic_loadmap = 0;
338
339 #ifdef CONFIG_MMU
340 elf_fdpic_arch_lay_out_mm(&exec_params,
341 &interp_params,
342 &current->mm->start_stack,
343 &current->mm->start_brk);
344
345 retval = setup_arg_pages(bprm, current->mm->start_stack,
346 executable_stack);
347 if (retval < 0) {
348 send_sig(SIGKILL, current, 0);
349 goto error_kill;
350 }
351 #endif
352
353 /* load the executable and interpreter into memory */
354 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
355 "executable");
356 if (retval < 0)
357 goto error_kill;
358
359 if (interpreter_name) {
360 retval = elf_fdpic_map_file(&interp_params, interpreter,
361 current->mm, "interpreter");
362 if (retval < 0) {
363 printk(KERN_ERR "Unable to load interpreter\n");
364 goto error_kill;
365 }
366
367 allow_write_access(interpreter);
368 fput(interpreter);
369 interpreter = NULL;
370 }
371
372 #ifdef CONFIG_MMU
373 if (!current->mm->start_brk)
374 current->mm->start_brk = current->mm->end_data;
375
376 current->mm->brk = current->mm->start_brk =
377 PAGE_ALIGN(current->mm->start_brk);
378
379 #else
380 /* create a stack and brk area big enough for everyone
381 * - the brk heap starts at the bottom and works up
382 * - the stack starts at the top and works down
383 */
384 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
385 if (stack_size < PAGE_SIZE * 2)
386 stack_size = PAGE_SIZE * 2;
387
388 stack_prot = PROT_READ | PROT_WRITE;
389 if (executable_stack == EXSTACK_ENABLE_X ||
390 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
391 stack_prot |= PROT_EXEC;
392
393 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
394 MAP_PRIVATE | MAP_ANONYMOUS |
395 MAP_UNINITIALIZED | MAP_GROWSDOWN,
396 0);
397
398 if (IS_ERR_VALUE(current->mm->start_brk)) {
399 retval = current->mm->start_brk;
400 current->mm->start_brk = 0;
401 goto error_kill;
402 }
403
404 current->mm->brk = current->mm->start_brk;
405 current->mm->context.end_brk = current->mm->start_brk;
406 current->mm->context.end_brk +=
407 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
408 current->mm->start_stack = current->mm->start_brk + stack_size;
409 #endif
410
411 install_exec_creds(bprm);
412 if (create_elf_fdpic_tables(bprm, current->mm,
413 &exec_params, &interp_params) < 0)
414 goto error_kill;
415
416 kdebug("- start_code %lx", current->mm->start_code);
417 kdebug("- end_code %lx", current->mm->end_code);
418 kdebug("- start_data %lx", current->mm->start_data);
419 kdebug("- end_data %lx", current->mm->end_data);
420 kdebug("- start_brk %lx", current->mm->start_brk);
421 kdebug("- brk %lx", current->mm->brk);
422 kdebug("- start_stack %lx", current->mm->start_stack);
423
424 #ifdef ELF_FDPIC_PLAT_INIT
425 /*
426 * The ABI may specify that certain registers be set up in special
427 * ways (on i386 %edx is the address of a DT_FINI function, for
428 * example. This macro performs whatever initialization to
429 * the regs structure is required.
430 */
431 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
432 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
433 dynaddr);
434 #endif
435
436 /* everything is now ready... get the userspace context ready to roll */
437 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
438 start_thread(regs, entryaddr, current->mm->start_stack);
439
440 retval = 0;
441
442 error:
443 if (interpreter) {
444 allow_write_access(interpreter);
445 fput(interpreter);
446 }
447 kfree(interpreter_name);
448 kfree(exec_params.phdrs);
449 kfree(exec_params.loadmap);
450 kfree(interp_params.phdrs);
451 kfree(interp_params.loadmap);
452 return retval;
453
454 /* unrecoverable error - kill the process */
455 error_kill:
456 send_sig(SIGSEGV, current, 0);
457 goto error;
458
459 }
460
461 /*****************************************************************************/
462
463 #ifndef ELF_BASE_PLATFORM
464 /*
465 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
466 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
467 * will be copied to the user stack in the same manner as AT_PLATFORM.
468 */
469 #define ELF_BASE_PLATFORM NULL
470 #endif
471
472 /*
473 * present useful information to the program by shovelling it onto the new
474 * process's stack
475 */
476 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
477 struct mm_struct *mm,
478 struct elf_fdpic_params *exec_params,
479 struct elf_fdpic_params *interp_params)
480 {
481 const struct cred *cred = current_cred();
482 unsigned long sp, csp, nitems;
483 elf_caddr_t __user *argv, *envp;
484 size_t platform_len = 0, len;
485 char *k_platform, *k_base_platform;
486 char __user *u_platform, *u_base_platform, *p;
487 long hwcap;
488 int loop;
489 int nr; /* reset for each csp adjustment */
490
491 #ifdef CONFIG_MMU
492 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
493 * by the processes running on the same package. One thing we can do is
494 * to shuffle the initial stack for them, so we give the architecture
495 * an opportunity to do so here.
496 */
497 sp = arch_align_stack(bprm->p);
498 #else
499 sp = mm->start_stack;
500
501 /* stack the program arguments and environment */
502 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
503 return -EFAULT;
504 #endif
505
506 hwcap = ELF_HWCAP;
507
508 /*
509 * If this architecture has a platform capability string, copy it
510 * to userspace. In some cases (Sparc), this info is impossible
511 * for userspace to get any other way, in others (i386) it is
512 * merely difficult.
513 */
514 k_platform = ELF_PLATFORM;
515 u_platform = NULL;
516
517 if (k_platform) {
518 platform_len = strlen(k_platform) + 1;
519 sp -= platform_len;
520 u_platform = (char __user *) sp;
521 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
522 return -EFAULT;
523 }
524
525 /*
526 * If this architecture has a "base" platform capability
527 * string, copy it to userspace.
528 */
529 k_base_platform = ELF_BASE_PLATFORM;
530 u_base_platform = NULL;
531
532 if (k_base_platform) {
533 platform_len = strlen(k_base_platform) + 1;
534 sp -= platform_len;
535 u_base_platform = (char __user *) sp;
536 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
537 return -EFAULT;
538 }
539
540 sp &= ~7UL;
541
542 /* stack the load map(s) */
543 len = sizeof(struct elf32_fdpic_loadmap);
544 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
545 sp = (sp - len) & ~7UL;
546 exec_params->map_addr = sp;
547
548 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
549 return -EFAULT;
550
551 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
552
553 if (interp_params->loadmap) {
554 len = sizeof(struct elf32_fdpic_loadmap);
555 len += sizeof(struct elf32_fdpic_loadseg) *
556 interp_params->loadmap->nsegs;
557 sp = (sp - len) & ~7UL;
558 interp_params->map_addr = sp;
559
560 if (copy_to_user((void __user *) sp, interp_params->loadmap,
561 len) != 0)
562 return -EFAULT;
563
564 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
565 }
566
567 /* force 16 byte _final_ alignment here for generality */
568 #define DLINFO_ITEMS 15
569
570 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
571 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
572
573 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
574 nitems++;
575
576 csp = sp;
577 sp -= nitems * 2 * sizeof(unsigned long);
578 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
579 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
580 sp -= 1 * sizeof(unsigned long); /* argc */
581
582 csp -= sp & 15UL;
583 sp -= sp & 15UL;
584
585 /* put the ELF interpreter info on the stack */
586 #define NEW_AUX_ENT(id, val) \
587 do { \
588 struct { unsigned long _id, _val; } __user *ent; \
589 \
590 ent = (void __user *) csp; \
591 __put_user((id), &ent[nr]._id); \
592 __put_user((val), &ent[nr]._val); \
593 nr++; \
594 } while (0)
595
596 nr = 0;
597 csp -= 2 * sizeof(unsigned long);
598 NEW_AUX_ENT(AT_NULL, 0);
599 if (k_platform) {
600 nr = 0;
601 csp -= 2 * sizeof(unsigned long);
602 NEW_AUX_ENT(AT_PLATFORM,
603 (elf_addr_t) (unsigned long) u_platform);
604 }
605
606 if (k_base_platform) {
607 nr = 0;
608 csp -= 2 * sizeof(unsigned long);
609 NEW_AUX_ENT(AT_BASE_PLATFORM,
610 (elf_addr_t) (unsigned long) u_base_platform);
611 }
612
613 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
614 nr = 0;
615 csp -= 2 * sizeof(unsigned long);
616 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
617 }
618
619 nr = 0;
620 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
621 NEW_AUX_ENT(AT_HWCAP, hwcap);
622 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
623 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
624 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
625 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
626 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
627 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
628 NEW_AUX_ENT(AT_FLAGS, 0);
629 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
630 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
631 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
632 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
633 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
634 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
635 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
636
637 #ifdef ARCH_DLINFO
638 nr = 0;
639 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
640
641 /* ARCH_DLINFO must come last so platform specific code can enforce
642 * special alignment requirements on the AUXV if necessary (eg. PPC).
643 */
644 ARCH_DLINFO;
645 #endif
646 #undef NEW_AUX_ENT
647
648 /* allocate room for argv[] and envv[] */
649 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
650 envp = (elf_caddr_t __user *) csp;
651 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
652 argv = (elf_caddr_t __user *) csp;
653
654 /* stack argc */
655 csp -= sizeof(unsigned long);
656 __put_user(bprm->argc, (unsigned long __user *) csp);
657
658 BUG_ON(csp != sp);
659
660 /* fill in the argv[] array */
661 #ifdef CONFIG_MMU
662 current->mm->arg_start = bprm->p;
663 #else
664 current->mm->arg_start = current->mm->start_stack -
665 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
666 #endif
667
668 p = (char __user *) current->mm->arg_start;
669 for (loop = bprm->argc; loop > 0; loop--) {
670 __put_user((elf_caddr_t) p, argv++);
671 len = strnlen_user(p, MAX_ARG_STRLEN);
672 if (!len || len > MAX_ARG_STRLEN)
673 return -EINVAL;
674 p += len;
675 }
676 __put_user(NULL, argv);
677 current->mm->arg_end = (unsigned long) p;
678
679 /* fill in the envv[] array */
680 current->mm->env_start = (unsigned long) p;
681 for (loop = bprm->envc; loop > 0; loop--) {
682 __put_user((elf_caddr_t)(unsigned long) p, envp++);
683 len = strnlen_user(p, MAX_ARG_STRLEN);
684 if (!len || len > MAX_ARG_STRLEN)
685 return -EINVAL;
686 p += len;
687 }
688 __put_user(NULL, envp);
689 current->mm->env_end = (unsigned long) p;
690
691 mm->start_stack = (unsigned long) sp;
692 return 0;
693 }
694
695 /*****************************************************************************/
696 /*
697 * transfer the program arguments and environment from the holding pages onto
698 * the stack
699 */
700 #ifndef CONFIG_MMU
701 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
702 unsigned long *_sp)
703 {
704 unsigned long index, stop, sp;
705 char *src;
706 int ret = 0;
707
708 stop = bprm->p >> PAGE_SHIFT;
709 sp = *_sp;
710
711 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
712 src = kmap(bprm->page[index]);
713 sp -= PAGE_SIZE;
714 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
715 ret = -EFAULT;
716 kunmap(bprm->page[index]);
717 if (ret < 0)
718 goto out;
719 }
720
721 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
722
723 out:
724 return ret;
725 }
726 #endif
727
728 /*****************************************************************************/
729 /*
730 * load the appropriate binary image (executable or interpreter) into memory
731 * - we assume no MMU is available
732 * - if no other PIC bits are set in params->hdr->e_flags
733 * - we assume that the LOADable segments in the binary are independently relocatable
734 * - we assume R/O executable segments are shareable
735 * - else
736 * - we assume the loadable parts of the image to require fixed displacement
737 * - the image is not shareable
738 */
739 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
740 struct file *file,
741 struct mm_struct *mm,
742 const char *what)
743 {
744 struct elf32_fdpic_loadmap *loadmap;
745 #ifdef CONFIG_MMU
746 struct elf32_fdpic_loadseg *mseg;
747 #endif
748 struct elf32_fdpic_loadseg *seg;
749 struct elf32_phdr *phdr;
750 unsigned long load_addr, stop;
751 unsigned nloads, tmp;
752 size_t size;
753 int loop, ret;
754
755 /* allocate a load map table */
756 nloads = 0;
757 for (loop = 0; loop < params->hdr.e_phnum; loop++)
758 if (params->phdrs[loop].p_type == PT_LOAD)
759 nloads++;
760
761 if (nloads == 0)
762 return -ELIBBAD;
763
764 size = sizeof(*loadmap) + nloads * sizeof(*seg);
765 loadmap = kzalloc(size, GFP_KERNEL);
766 if (!loadmap)
767 return -ENOMEM;
768
769 params->loadmap = loadmap;
770
771 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
772 loadmap->nsegs = nloads;
773
774 load_addr = params->load_addr;
775 seg = loadmap->segs;
776
777 /* map the requested LOADs into the memory space */
778 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
779 case ELF_FDPIC_FLAG_CONSTDISP:
780 case ELF_FDPIC_FLAG_CONTIGUOUS:
781 #ifndef CONFIG_MMU
782 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
783 if (ret < 0)
784 return ret;
785 break;
786 #endif
787 default:
788 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
789 if (ret < 0)
790 return ret;
791 break;
792 }
793
794 /* map the entry point */
795 if (params->hdr.e_entry) {
796 seg = loadmap->segs;
797 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
798 if (params->hdr.e_entry >= seg->p_vaddr &&
799 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
800 params->entry_addr =
801 (params->hdr.e_entry - seg->p_vaddr) +
802 seg->addr;
803 break;
804 }
805 }
806 }
807
808 /* determine where the program header table has wound up if mapped */
809 stop = params->hdr.e_phoff;
810 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
811 phdr = params->phdrs;
812
813 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
814 if (phdr->p_type != PT_LOAD)
815 continue;
816
817 if (phdr->p_offset > params->hdr.e_phoff ||
818 phdr->p_offset + phdr->p_filesz < stop)
819 continue;
820
821 seg = loadmap->segs;
822 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
823 if (phdr->p_vaddr >= seg->p_vaddr &&
824 phdr->p_vaddr + phdr->p_filesz <=
825 seg->p_vaddr + seg->p_memsz) {
826 params->ph_addr =
827 (phdr->p_vaddr - seg->p_vaddr) +
828 seg->addr +
829 params->hdr.e_phoff - phdr->p_offset;
830 break;
831 }
832 }
833 break;
834 }
835
836 /* determine where the dynamic section has wound up if there is one */
837 phdr = params->phdrs;
838 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
839 if (phdr->p_type != PT_DYNAMIC)
840 continue;
841
842 seg = loadmap->segs;
843 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
844 if (phdr->p_vaddr >= seg->p_vaddr &&
845 phdr->p_vaddr + phdr->p_memsz <=
846 seg->p_vaddr + seg->p_memsz) {
847 params->dynamic_addr =
848 (phdr->p_vaddr - seg->p_vaddr) +
849 seg->addr;
850
851 /* check the dynamic section contains at least
852 * one item, and that the last item is a NULL
853 * entry */
854 if (phdr->p_memsz == 0 ||
855 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
856 goto dynamic_error;
857
858 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
859 if (((Elf32_Dyn *)
860 params->dynamic_addr)[tmp - 1].d_tag != 0)
861 goto dynamic_error;
862 break;
863 }
864 }
865 break;
866 }
867
868 /* now elide adjacent segments in the load map on MMU linux
869 * - on uClinux the holes between may actually be filled with system
870 * stuff or stuff from other processes
871 */
872 #ifdef CONFIG_MMU
873 nloads = loadmap->nsegs;
874 mseg = loadmap->segs;
875 seg = mseg + 1;
876 for (loop = 1; loop < nloads; loop++) {
877 /* see if we have a candidate for merging */
878 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
879 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
880 if (load_addr == (seg->addr & PAGE_MASK)) {
881 mseg->p_memsz +=
882 load_addr -
883 (mseg->addr + mseg->p_memsz);
884 mseg->p_memsz += seg->addr & ~PAGE_MASK;
885 mseg->p_memsz += seg->p_memsz;
886 loadmap->nsegs--;
887 continue;
888 }
889 }
890
891 mseg++;
892 if (mseg != seg)
893 *mseg = *seg;
894 }
895 #endif
896
897 kdebug("Mapped Object [%s]:", what);
898 kdebug("- elfhdr : %lx", params->elfhdr_addr);
899 kdebug("- entry : %lx", params->entry_addr);
900 kdebug("- PHDR[] : %lx", params->ph_addr);
901 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
902 seg = loadmap->segs;
903 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
904 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
905 loop,
906 seg->addr, seg->addr + seg->p_memsz - 1,
907 seg->p_vaddr, seg->p_memsz);
908
909 return 0;
910
911 dynamic_error:
912 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
913 what, file->f_path.dentry->d_inode->i_ino);
914 return -ELIBBAD;
915 }
916
917 /*****************************************************************************/
918 /*
919 * map a file with constant displacement under uClinux
920 */
921 #ifndef CONFIG_MMU
922 static int elf_fdpic_map_file_constdisp_on_uclinux(
923 struct elf_fdpic_params *params,
924 struct file *file,
925 struct mm_struct *mm)
926 {
927 struct elf32_fdpic_loadseg *seg;
928 struct elf32_phdr *phdr;
929 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
930 loff_t fpos;
931 int loop, ret;
932
933 load_addr = params->load_addr;
934 seg = params->loadmap->segs;
935
936 /* determine the bounds of the contiguous overall allocation we must
937 * make */
938 phdr = params->phdrs;
939 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
940 if (params->phdrs[loop].p_type != PT_LOAD)
941 continue;
942
943 if (base > phdr->p_vaddr)
944 base = phdr->p_vaddr;
945 if (top < phdr->p_vaddr + phdr->p_memsz)
946 top = phdr->p_vaddr + phdr->p_memsz;
947 }
948
949 /* allocate one big anon block for everything */
950 mflags = MAP_PRIVATE;
951 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
952 mflags |= MAP_EXECUTABLE;
953
954 maddr = vm_mmap(NULL, load_addr, top - base,
955 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
956 if (IS_ERR_VALUE(maddr))
957 return (int) maddr;
958
959 if (load_addr != 0)
960 load_addr += PAGE_ALIGN(top - base);
961
962 /* and then load the file segments into it */
963 phdr = params->phdrs;
964 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
965 if (params->phdrs[loop].p_type != PT_LOAD)
966 continue;
967
968 fpos = phdr->p_offset;
969
970 seg->addr = maddr + (phdr->p_vaddr - base);
971 seg->p_vaddr = phdr->p_vaddr;
972 seg->p_memsz = phdr->p_memsz;
973
974 ret = file->f_op->read(file, (void *) seg->addr,
975 phdr->p_filesz, &fpos);
976 if (ret < 0)
977 return ret;
978
979 /* map the ELF header address if in this segment */
980 if (phdr->p_offset == 0)
981 params->elfhdr_addr = seg->addr;
982
983 /* clear any space allocated but not loaded */
984 if (phdr->p_filesz < phdr->p_memsz) {
985 if (clear_user((void *) (seg->addr + phdr->p_filesz),
986 phdr->p_memsz - phdr->p_filesz))
987 return -EFAULT;
988 }
989
990 if (mm) {
991 if (phdr->p_flags & PF_X) {
992 if (!mm->start_code) {
993 mm->start_code = seg->addr;
994 mm->end_code = seg->addr +
995 phdr->p_memsz;
996 }
997 } else if (!mm->start_data) {
998 mm->start_data = seg->addr;
999 mm->end_data = seg->addr + phdr->p_memsz;
1000 }
1001 }
1002
1003 seg++;
1004 }
1005
1006 return 0;
1007 }
1008 #endif
1009
1010 /*****************************************************************************/
1011 /*
1012 * map a binary by direct mmap() of the individual PT_LOAD segments
1013 */
1014 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1015 struct file *file,
1016 struct mm_struct *mm)
1017 {
1018 struct elf32_fdpic_loadseg *seg;
1019 struct elf32_phdr *phdr;
1020 unsigned long load_addr, delta_vaddr;
1021 int loop, dvset;
1022
1023 load_addr = params->load_addr;
1024 delta_vaddr = 0;
1025 dvset = 0;
1026
1027 seg = params->loadmap->segs;
1028
1029 /* deal with each load segment separately */
1030 phdr = params->phdrs;
1031 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1032 unsigned long maddr, disp, excess, excess1;
1033 int prot = 0, flags;
1034
1035 if (phdr->p_type != PT_LOAD)
1036 continue;
1037
1038 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1039 (unsigned long) phdr->p_vaddr,
1040 (unsigned long) phdr->p_offset,
1041 (unsigned long) phdr->p_filesz,
1042 (unsigned long) phdr->p_memsz);
1043
1044 /* determine the mapping parameters */
1045 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1046 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1047 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1048
1049 flags = MAP_PRIVATE | MAP_DENYWRITE;
1050 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1051 flags |= MAP_EXECUTABLE;
1052
1053 maddr = 0;
1054
1055 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1056 case ELF_FDPIC_FLAG_INDEPENDENT:
1057 /* PT_LOADs are independently locatable */
1058 break;
1059
1060 case ELF_FDPIC_FLAG_HONOURVADDR:
1061 /* the specified virtual address must be honoured */
1062 maddr = phdr->p_vaddr;
1063 flags |= MAP_FIXED;
1064 break;
1065
1066 case ELF_FDPIC_FLAG_CONSTDISP:
1067 /* constant displacement
1068 * - can be mapped anywhere, but must be mapped as a
1069 * unit
1070 */
1071 if (!dvset) {
1072 maddr = load_addr;
1073 delta_vaddr = phdr->p_vaddr;
1074 dvset = 1;
1075 } else {
1076 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1077 flags |= MAP_FIXED;
1078 }
1079 break;
1080
1081 case ELF_FDPIC_FLAG_CONTIGUOUS:
1082 /* contiguity handled later */
1083 break;
1084
1085 default:
1086 BUG();
1087 }
1088
1089 maddr &= PAGE_MASK;
1090
1091 /* create the mapping */
1092 disp = phdr->p_vaddr & ~PAGE_MASK;
1093 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1094 phdr->p_offset - disp);
1095
1096 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1097 loop, phdr->p_memsz + disp, prot, flags,
1098 phdr->p_offset - disp, maddr);
1099
1100 if (IS_ERR_VALUE(maddr))
1101 return (int) maddr;
1102
1103 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1104 ELF_FDPIC_FLAG_CONTIGUOUS)
1105 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1106
1107 seg->addr = maddr + disp;
1108 seg->p_vaddr = phdr->p_vaddr;
1109 seg->p_memsz = phdr->p_memsz;
1110
1111 /* map the ELF header address if in this segment */
1112 if (phdr->p_offset == 0)
1113 params->elfhdr_addr = seg->addr;
1114
1115 /* clear the bit between beginning of mapping and beginning of
1116 * PT_LOAD */
1117 if (prot & PROT_WRITE && disp > 0) {
1118 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1119 if (clear_user((void __user *) maddr, disp))
1120 return -EFAULT;
1121 maddr += disp;
1122 }
1123
1124 /* clear any space allocated but not loaded
1125 * - on uClinux we can just clear the lot
1126 * - on MMU linux we'll get a SIGBUS beyond the last page
1127 * extant in the file
1128 */
1129 excess = phdr->p_memsz - phdr->p_filesz;
1130 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1131
1132 #ifdef CONFIG_MMU
1133 if (excess > excess1) {
1134 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1135 unsigned long xmaddr;
1136
1137 flags |= MAP_FIXED | MAP_ANONYMOUS;
1138 xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1139 prot, flags, 0);
1140
1141 kdebug("mmap[%d] <anon>"
1142 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1143 loop, xaddr, excess - excess1, prot, flags,
1144 xmaddr);
1145
1146 if (xmaddr != xaddr)
1147 return -ENOMEM;
1148 }
1149
1150 if (prot & PROT_WRITE && excess1 > 0) {
1151 kdebug("clear[%d] ad=%lx sz=%lx",
1152 loop, maddr + phdr->p_filesz, excess1);
1153 if (clear_user((void __user *) maddr + phdr->p_filesz,
1154 excess1))
1155 return -EFAULT;
1156 }
1157
1158 #else
1159 if (excess > 0) {
1160 kdebug("clear[%d] ad=%lx sz=%lx",
1161 loop, maddr + phdr->p_filesz, excess);
1162 if (clear_user((void *) maddr + phdr->p_filesz, excess))
1163 return -EFAULT;
1164 }
1165 #endif
1166
1167 if (mm) {
1168 if (phdr->p_flags & PF_X) {
1169 if (!mm->start_code) {
1170 mm->start_code = maddr;
1171 mm->end_code = maddr + phdr->p_memsz;
1172 }
1173 } else if (!mm->start_data) {
1174 mm->start_data = maddr;
1175 mm->end_data = maddr + phdr->p_memsz;
1176 }
1177 }
1178
1179 seg++;
1180 }
1181
1182 return 0;
1183 }
1184
1185 /*****************************************************************************/
1186 /*
1187 * ELF-FDPIC core dumper
1188 *
1189 * Modelled on fs/exec.c:aout_core_dump()
1190 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1191 *
1192 * Modelled on fs/binfmt_elf.c core dumper
1193 */
1194 #ifdef CONFIG_ELF_CORE
1195
1196 /*
1197 * Decide whether a segment is worth dumping; default is yes to be
1198 * sure (missing info is worse than too much; etc).
1199 * Personally I'd include everything, and use the coredump limit...
1200 *
1201 * I think we should skip something. But I am not sure how. H.J.
1202 */
1203 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1204 {
1205 int dump_ok;
1206
1207 /* Do not dump I/O mapped devices or special mappings */
1208 if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1209 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1210 return 0;
1211 }
1212
1213 /* If we may not read the contents, don't allow us to dump
1214 * them either. "dump_write()" can't handle it anyway.
1215 */
1216 if (!(vma->vm_flags & VM_READ)) {
1217 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1218 return 0;
1219 }
1220
1221 /* By default, dump shared memory if mapped from an anonymous file. */
1222 if (vma->vm_flags & VM_SHARED) {
1223 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1224 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1225 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1226 vma->vm_flags, dump_ok ? "yes" : "no");
1227 return dump_ok;
1228 }
1229
1230 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1231 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1232 vma->vm_flags, dump_ok ? "yes" : "no");
1233 return dump_ok;
1234 }
1235
1236 #ifdef CONFIG_MMU
1237 /* By default, if it hasn't been written to, don't write it out */
1238 if (!vma->anon_vma) {
1239 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1240 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1241 vma->vm_flags, dump_ok ? "yes" : "no");
1242 return dump_ok;
1243 }
1244 #endif
1245
1246 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1247 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1248 dump_ok ? "yes" : "no");
1249 return dump_ok;
1250 }
1251
1252 /* An ELF note in memory */
1253 struct memelfnote
1254 {
1255 const char *name;
1256 int type;
1257 unsigned int datasz;
1258 void *data;
1259 };
1260
1261 static int notesize(struct memelfnote *en)
1262 {
1263 int sz;
1264
1265 sz = sizeof(struct elf_note);
1266 sz += roundup(strlen(en->name) + 1, 4);
1267 sz += roundup(en->datasz, 4);
1268
1269 return sz;
1270 }
1271
1272 /* #define DEBUG */
1273
1274 #define DUMP_WRITE(addr, nr, foffset) \
1275 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1276
1277 static int alignfile(struct file *file, loff_t *foffset)
1278 {
1279 static const char buf[4] = { 0, };
1280 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1281 return 1;
1282 }
1283
1284 static int writenote(struct memelfnote *men, struct file *file,
1285 loff_t *foffset)
1286 {
1287 struct elf_note en;
1288 en.n_namesz = strlen(men->name) + 1;
1289 en.n_descsz = men->datasz;
1290 en.n_type = men->type;
1291
1292 DUMP_WRITE(&en, sizeof(en), foffset);
1293 DUMP_WRITE(men->name, en.n_namesz, foffset);
1294 if (!alignfile(file, foffset))
1295 return 0;
1296 DUMP_WRITE(men->data, men->datasz, foffset);
1297 if (!alignfile(file, foffset))
1298 return 0;
1299
1300 return 1;
1301 }
1302 #undef DUMP_WRITE
1303
1304 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1305 {
1306 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1307 elf->e_ident[EI_CLASS] = ELF_CLASS;
1308 elf->e_ident[EI_DATA] = ELF_DATA;
1309 elf->e_ident[EI_VERSION] = EV_CURRENT;
1310 elf->e_ident[EI_OSABI] = ELF_OSABI;
1311 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1312
1313 elf->e_type = ET_CORE;
1314 elf->e_machine = ELF_ARCH;
1315 elf->e_version = EV_CURRENT;
1316 elf->e_entry = 0;
1317 elf->e_phoff = sizeof(struct elfhdr);
1318 elf->e_shoff = 0;
1319 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1320 elf->e_ehsize = sizeof(struct elfhdr);
1321 elf->e_phentsize = sizeof(struct elf_phdr);
1322 elf->e_phnum = segs;
1323 elf->e_shentsize = 0;
1324 elf->e_shnum = 0;
1325 elf->e_shstrndx = 0;
1326 return;
1327 }
1328
1329 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1330 {
1331 phdr->p_type = PT_NOTE;
1332 phdr->p_offset = offset;
1333 phdr->p_vaddr = 0;
1334 phdr->p_paddr = 0;
1335 phdr->p_filesz = sz;
1336 phdr->p_memsz = 0;
1337 phdr->p_flags = 0;
1338 phdr->p_align = 0;
1339 return;
1340 }
1341
1342 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1343 unsigned int sz, void *data)
1344 {
1345 note->name = name;
1346 note->type = type;
1347 note->datasz = sz;
1348 note->data = data;
1349 return;
1350 }
1351
1352 /*
1353 * fill up all the fields in prstatus from the given task struct, except
1354 * registers which need to be filled up separately.
1355 */
1356 static void fill_prstatus(struct elf_prstatus *prstatus,
1357 struct task_struct *p, long signr)
1358 {
1359 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1360 prstatus->pr_sigpend = p->pending.signal.sig[0];
1361 prstatus->pr_sighold = p->blocked.sig[0];
1362 rcu_read_lock();
1363 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1364 rcu_read_unlock();
1365 prstatus->pr_pid = task_pid_vnr(p);
1366 prstatus->pr_pgrp = task_pgrp_vnr(p);
1367 prstatus->pr_sid = task_session_vnr(p);
1368 if (thread_group_leader(p)) {
1369 struct task_cputime cputime;
1370
1371 /*
1372 * This is the record for the group leader. It shows the
1373 * group-wide total, not its individual thread total.
1374 */
1375 thread_group_cputime(p, &cputime);
1376 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1377 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1378 } else {
1379 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1380 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1381 }
1382 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1383 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1384
1385 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1386 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1387 }
1388
1389 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1390 struct mm_struct *mm)
1391 {
1392 const struct cred *cred;
1393 unsigned int i, len;
1394
1395 /* first copy the parameters from user space */
1396 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1397
1398 len = mm->arg_end - mm->arg_start;
1399 if (len >= ELF_PRARGSZ)
1400 len = ELF_PRARGSZ - 1;
1401 if (copy_from_user(&psinfo->pr_psargs,
1402 (const char __user *) mm->arg_start, len))
1403 return -EFAULT;
1404 for (i = 0; i < len; i++)
1405 if (psinfo->pr_psargs[i] == 0)
1406 psinfo->pr_psargs[i] = ' ';
1407 psinfo->pr_psargs[len] = 0;
1408
1409 rcu_read_lock();
1410 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1411 rcu_read_unlock();
1412 psinfo->pr_pid = task_pid_vnr(p);
1413 psinfo->pr_pgrp = task_pgrp_vnr(p);
1414 psinfo->pr_sid = task_session_vnr(p);
1415
1416 i = p->state ? ffz(~p->state) + 1 : 0;
1417 psinfo->pr_state = i;
1418 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1419 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1420 psinfo->pr_nice = task_nice(p);
1421 psinfo->pr_flag = p->flags;
1422 rcu_read_lock();
1423 cred = __task_cred(p);
1424 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1425 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1426 rcu_read_unlock();
1427 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1428
1429 return 0;
1430 }
1431
1432 /* Here is the structure in which status of each thread is captured. */
1433 struct elf_thread_status
1434 {
1435 struct list_head list;
1436 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1437 elf_fpregset_t fpu; /* NT_PRFPREG */
1438 struct task_struct *thread;
1439 #ifdef ELF_CORE_COPY_XFPREGS
1440 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1441 #endif
1442 struct memelfnote notes[3];
1443 int num_notes;
1444 };
1445
1446 /*
1447 * In order to add the specific thread information for the elf file format,
1448 * we need to keep a linked list of every thread's pr_status and then create
1449 * a single section for them in the final core file.
1450 */
1451 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1452 {
1453 struct task_struct *p = t->thread;
1454 int sz = 0;
1455
1456 t->num_notes = 0;
1457
1458 fill_prstatus(&t->prstatus, p, signr);
1459 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1460
1461 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1462 &t->prstatus);
1463 t->num_notes++;
1464 sz += notesize(&t->notes[0]);
1465
1466 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1467 if (t->prstatus.pr_fpvalid) {
1468 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1469 &t->fpu);
1470 t->num_notes++;
1471 sz += notesize(&t->notes[1]);
1472 }
1473
1474 #ifdef ELF_CORE_COPY_XFPREGS
1475 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1476 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1477 sizeof(t->xfpu), &t->xfpu);
1478 t->num_notes++;
1479 sz += notesize(&t->notes[2]);
1480 }
1481 #endif
1482 return sz;
1483 }
1484
1485 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1486 elf_addr_t e_shoff, int segs)
1487 {
1488 elf->e_shoff = e_shoff;
1489 elf->e_shentsize = sizeof(*shdr4extnum);
1490 elf->e_shnum = 1;
1491 elf->e_shstrndx = SHN_UNDEF;
1492
1493 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1494
1495 shdr4extnum->sh_type = SHT_NULL;
1496 shdr4extnum->sh_size = elf->e_shnum;
1497 shdr4extnum->sh_link = elf->e_shstrndx;
1498 shdr4extnum->sh_info = segs;
1499 }
1500
1501 /*
1502 * dump the segments for an MMU process
1503 */
1504 #ifdef CONFIG_MMU
1505 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1506 unsigned long *limit, unsigned long mm_flags)
1507 {
1508 struct vm_area_struct *vma;
1509 int err = 0;
1510
1511 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1512 unsigned long addr;
1513
1514 if (!maydump(vma, mm_flags))
1515 continue;
1516
1517 for (addr = vma->vm_start; addr < vma->vm_end;
1518 addr += PAGE_SIZE) {
1519 struct page *page = get_dump_page(addr);
1520 if (page) {
1521 void *kaddr = kmap(page);
1522 *size += PAGE_SIZE;
1523 if (*size > *limit)
1524 err = -EFBIG;
1525 else if (!dump_write(file, kaddr, PAGE_SIZE))
1526 err = -EIO;
1527 kunmap(page);
1528 page_cache_release(page);
1529 } else if (!dump_seek(file, PAGE_SIZE))
1530 err = -EFBIG;
1531 if (err)
1532 goto out;
1533 }
1534 }
1535 out:
1536 return err;
1537 }
1538 #endif
1539
1540 /*
1541 * dump the segments for a NOMMU process
1542 */
1543 #ifndef CONFIG_MMU
1544 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1545 unsigned long *limit, unsigned long mm_flags)
1546 {
1547 struct vm_area_struct *vma;
1548
1549 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1550 if (!maydump(vma, mm_flags))
1551 continue;
1552
1553 if ((*size += PAGE_SIZE) > *limit)
1554 return -EFBIG;
1555
1556 if (!dump_write(file, (void *) vma->vm_start,
1557 vma->vm_end - vma->vm_start))
1558 return -EIO;
1559 }
1560
1561 return 0;
1562 }
1563 #endif
1564
1565 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1566 {
1567 struct vm_area_struct *vma;
1568 size_t size = 0;
1569
1570 for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1571 if (maydump(vma, mm_flags))
1572 size += vma->vm_end - vma->vm_start;
1573 return size;
1574 }
1575
1576 /*
1577 * Actual dumper
1578 *
1579 * This is a two-pass process; first we find the offsets of the bits,
1580 * and then they are actually written out. If we run out of core limit
1581 * we just truncate.
1582 */
1583 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1584 {
1585 #define NUM_NOTES 6
1586 int has_dumped = 0;
1587 mm_segment_t fs;
1588 int segs;
1589 size_t size = 0;
1590 int i;
1591 struct vm_area_struct *vma;
1592 struct elfhdr *elf = NULL;
1593 loff_t offset = 0, dataoff, foffset;
1594 int numnote;
1595 struct memelfnote *notes = NULL;
1596 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1597 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1598 LIST_HEAD(thread_list);
1599 struct list_head *t;
1600 elf_fpregset_t *fpu = NULL;
1601 #ifdef ELF_CORE_COPY_XFPREGS
1602 elf_fpxregset_t *xfpu = NULL;
1603 #endif
1604 int thread_status_size = 0;
1605 elf_addr_t *auxv;
1606 struct elf_phdr *phdr4note = NULL;
1607 struct elf_shdr *shdr4extnum = NULL;
1608 Elf_Half e_phnum;
1609 elf_addr_t e_shoff;
1610
1611 /*
1612 * We no longer stop all VM operations.
1613 *
1614 * This is because those proceses that could possibly change map_count
1615 * or the mmap / vma pages are now blocked in do_exit on current
1616 * finishing this core dump.
1617 *
1618 * Only ptrace can touch these memory addresses, but it doesn't change
1619 * the map_count or the pages allocated. So no possibility of crashing
1620 * exists while dumping the mm->vm_next areas to the core file.
1621 */
1622
1623 /* alloc memory for large data structures: too large to be on stack */
1624 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1625 if (!elf)
1626 goto cleanup;
1627 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1628 if (!prstatus)
1629 goto cleanup;
1630 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1631 if (!psinfo)
1632 goto cleanup;
1633 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1634 if (!notes)
1635 goto cleanup;
1636 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1637 if (!fpu)
1638 goto cleanup;
1639 #ifdef ELF_CORE_COPY_XFPREGS
1640 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1641 if (!xfpu)
1642 goto cleanup;
1643 #endif
1644
1645 if (cprm->signr) {
1646 struct core_thread *ct;
1647 struct elf_thread_status *tmp;
1648
1649 for (ct = current->mm->core_state->dumper.next;
1650 ct; ct = ct->next) {
1651 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1652 if (!tmp)
1653 goto cleanup;
1654
1655 tmp->thread = ct->task;
1656 list_add(&tmp->list, &thread_list);
1657 }
1658
1659 list_for_each(t, &thread_list) {
1660 struct elf_thread_status *tmp;
1661 int sz;
1662
1663 tmp = list_entry(t, struct elf_thread_status, list);
1664 sz = elf_dump_thread_status(cprm->signr, tmp);
1665 thread_status_size += sz;
1666 }
1667 }
1668
1669 /* now collect the dump for the current */
1670 fill_prstatus(prstatus, current, cprm->signr);
1671 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1672
1673 segs = current->mm->map_count;
1674 segs += elf_core_extra_phdrs();
1675
1676 /* for notes section */
1677 segs++;
1678
1679 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1680 * this, kernel supports extended numbering. Have a look at
1681 * include/linux/elf.h for further information. */
1682 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1683
1684 /* Set up header */
1685 fill_elf_fdpic_header(elf, e_phnum);
1686
1687 has_dumped = 1;
1688 current->flags |= PF_DUMPCORE;
1689
1690 /*
1691 * Set up the notes in similar form to SVR4 core dumps made
1692 * with info from their /proc.
1693 */
1694
1695 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1696 fill_psinfo(psinfo, current->group_leader, current->mm);
1697 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1698
1699 numnote = 2;
1700
1701 auxv = (elf_addr_t *) current->mm->saved_auxv;
1702
1703 i = 0;
1704 do
1705 i += 2;
1706 while (auxv[i - 2] != AT_NULL);
1707 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1708 i * sizeof(elf_addr_t), auxv);
1709
1710 /* Try to dump the FPU. */
1711 if ((prstatus->pr_fpvalid =
1712 elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1713 fill_note(notes + numnote++,
1714 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1715 #ifdef ELF_CORE_COPY_XFPREGS
1716 if (elf_core_copy_task_xfpregs(current, xfpu))
1717 fill_note(notes + numnote++,
1718 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1719 #endif
1720
1721 fs = get_fs();
1722 set_fs(KERNEL_DS);
1723
1724 offset += sizeof(*elf); /* Elf header */
1725 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1726 foffset = offset;
1727
1728 /* Write notes phdr entry */
1729 {
1730 int sz = 0;
1731
1732 for (i = 0; i < numnote; i++)
1733 sz += notesize(notes + i);
1734
1735 sz += thread_status_size;
1736
1737 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1738 if (!phdr4note)
1739 goto end_coredump;
1740
1741 fill_elf_note_phdr(phdr4note, sz, offset);
1742 offset += sz;
1743 }
1744
1745 /* Page-align dumped data */
1746 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1747
1748 offset += elf_core_vma_data_size(cprm->mm_flags);
1749 offset += elf_core_extra_data_size();
1750 e_shoff = offset;
1751
1752 if (e_phnum == PN_XNUM) {
1753 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1754 if (!shdr4extnum)
1755 goto end_coredump;
1756 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1757 }
1758
1759 offset = dataoff;
1760
1761 size += sizeof(*elf);
1762 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
1763 goto end_coredump;
1764
1765 size += sizeof(*phdr4note);
1766 if (size > cprm->limit
1767 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
1768 goto end_coredump;
1769
1770 /* write program headers for segments dump */
1771 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1772 struct elf_phdr phdr;
1773 size_t sz;
1774
1775 sz = vma->vm_end - vma->vm_start;
1776
1777 phdr.p_type = PT_LOAD;
1778 phdr.p_offset = offset;
1779 phdr.p_vaddr = vma->vm_start;
1780 phdr.p_paddr = 0;
1781 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1782 phdr.p_memsz = sz;
1783 offset += phdr.p_filesz;
1784 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1785 if (vma->vm_flags & VM_WRITE)
1786 phdr.p_flags |= PF_W;
1787 if (vma->vm_flags & VM_EXEC)
1788 phdr.p_flags |= PF_X;
1789 phdr.p_align = ELF_EXEC_PAGESIZE;
1790
1791 size += sizeof(phdr);
1792 if (size > cprm->limit
1793 || !dump_write(cprm->file, &phdr, sizeof(phdr)))
1794 goto end_coredump;
1795 }
1796
1797 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
1798 goto end_coredump;
1799
1800 /* write out the notes section */
1801 for (i = 0; i < numnote; i++)
1802 if (!writenote(notes + i, cprm->file, &foffset))
1803 goto end_coredump;
1804
1805 /* write out the thread status notes section */
1806 list_for_each(t, &thread_list) {
1807 struct elf_thread_status *tmp =
1808 list_entry(t, struct elf_thread_status, list);
1809
1810 for (i = 0; i < tmp->num_notes; i++)
1811 if (!writenote(&tmp->notes[i], cprm->file, &foffset))
1812 goto end_coredump;
1813 }
1814
1815 if (!dump_seek(cprm->file, dataoff - foffset))
1816 goto end_coredump;
1817
1818 if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit,
1819 cprm->mm_flags) < 0)
1820 goto end_coredump;
1821
1822 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
1823 goto end_coredump;
1824
1825 if (e_phnum == PN_XNUM) {
1826 size += sizeof(*shdr4extnum);
1827 if (size > cprm->limit
1828 || !dump_write(cprm->file, shdr4extnum,
1829 sizeof(*shdr4extnum)))
1830 goto end_coredump;
1831 }
1832
1833 if (cprm->file->f_pos != offset) {
1834 /* Sanity check */
1835 printk(KERN_WARNING
1836 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1837 cprm->file->f_pos, offset);
1838 }
1839
1840 end_coredump:
1841 set_fs(fs);
1842
1843 cleanup:
1844 while (!list_empty(&thread_list)) {
1845 struct list_head *tmp = thread_list.next;
1846 list_del(tmp);
1847 kfree(list_entry(tmp, struct elf_thread_status, list));
1848 }
1849 kfree(phdr4note);
1850 kfree(elf);
1851 kfree(prstatus);
1852 kfree(psinfo);
1853 kfree(notes);
1854 kfree(fpu);
1855 kfree(shdr4extnum);
1856 #ifdef ELF_CORE_COPY_XFPREGS
1857 kfree(xfpu);
1858 #endif
1859 return has_dumped;
1860 #undef NUM_NOTES
1861 }
1862
1863 #endif /* CONFIG_ELF_CORE */
Linux with added FPC-III support