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slub/memcg: cure the brainless abuse of sysfs attributes
[linux/fpc-iii.git] / fs / binfmt_elf_fdpic.c
blobb1adb92e69de7a8049dd914f3f8bb83d8d8b9c7f
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 #include <linux/dax.h>
39
40 #include <asm/uaccess.h>
41 #include <asm/param.h>
42 #include <asm/pgalloc.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 *);
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(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))
114 return 0;
115 if (!file->f_op->mmap)
116 return 0;
117 return 1;
118 }
119
120 #ifndef elf_check_fdpic
121 #define elf_check_fdpic(x) 0
122 #endif
123
124 #ifndef elf_check_const_displacement
125 #define elf_check_const_displacement(x) 0
126 #endif
127
128 static int is_constdisp(struct elfhdr *hdr)
129 {
130 if (!elf_check_fdpic(hdr))
131 return 1;
132 if (elf_check_const_displacement(hdr))
133 return 1;
134 return 0;
135 }
136
137 /*****************************************************************************/
138 /*
139 * read the program headers table into memory
140 */
141 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
142 struct file *file)
143 {
144 struct elf32_phdr *phdr;
145 unsigned long size;
146 int retval, loop;
147
148 if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
149 return -ENOMEM;
150 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
151 return -ENOMEM;
152
153 size = params->hdr.e_phnum * sizeof(struct elf_phdr);
154 params->phdrs = kmalloc(size, GFP_KERNEL);
155 if (!params->phdrs)
156 return -ENOMEM;
157
158 retval = kernel_read(file, params->hdr.e_phoff,
159 (char *) params->phdrs, size);
160 if (unlikely(retval != size))
161 return retval < 0 ? retval : -ENOEXEC;
162
163 /* determine stack size for this binary */
164 phdr = params->phdrs;
165 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
166 if (phdr->p_type != PT_GNU_STACK)
167 continue;
168
169 if (phdr->p_flags & PF_X)
170 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
171 else
172 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
173
174 params->stack_size = phdr->p_memsz;
175 break;
176 }
177
178 return 0;
179 }
180
181 /*****************************************************************************/
182 /*
183 * load an fdpic binary into various bits of memory
184 */
185 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
186 {
187 struct elf_fdpic_params exec_params, interp_params;
188 struct pt_regs *regs = current_pt_regs();
189 struct elf_phdr *phdr;
190 unsigned long stack_size, entryaddr;
191 #ifdef ELF_FDPIC_PLAT_INIT
192 unsigned long dynaddr;
193 #endif
194 #ifndef CONFIG_MMU
195 unsigned long stack_prot;
196 #endif
197 struct file *interpreter = NULL; /* to shut gcc up */
198 char *interpreter_name = NULL;
199 int executable_stack;
200 int retval, i;
201
202 kdebug("____ LOAD %d ____", current->pid);
203
204 memset(&exec_params, 0, sizeof(exec_params));
205 memset(&interp_params, 0, sizeof(interp_params));
206
207 exec_params.hdr = *(struct elfhdr *) bprm->buf;
208 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
209
210 /* check that this is a binary we know how to deal with */
211 retval = -ENOEXEC;
212 if (!is_elf(&exec_params.hdr, bprm->file))
213 goto error;
214 if (!elf_check_fdpic(&exec_params.hdr)) {
215 #ifdef CONFIG_MMU
216 /* binfmt_elf handles non-fdpic elf except on nommu */
217 goto error;
218 #else
219 /* nommu can only load ET_DYN (PIE) ELF */
220 if (exec_params.hdr.e_type != ET_DYN)
221 goto error;
222 #endif
223 }
224
225 /* read the program header table */
226 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
227 if (retval < 0)
228 goto error;
229
230 /* scan for a program header that specifies an interpreter */
231 phdr = exec_params.phdrs;
232
233 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
234 switch (phdr->p_type) {
235 case PT_INTERP:
236 retval = -ENOMEM;
237 if (phdr->p_filesz > PATH_MAX)
238 goto error;
239 retval = -ENOENT;
240 if (phdr->p_filesz < 2)
241 goto error;
242
243 /* read the name of the interpreter into memory */
244 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
245 if (!interpreter_name)
246 goto error;
247
248 retval = kernel_read(bprm->file,
249 phdr->p_offset,
250 interpreter_name,
251 phdr->p_filesz);
252 if (unlikely(retval != phdr->p_filesz)) {
253 if (retval >= 0)
254 retval = -ENOEXEC;
255 goto error;
256 }
257
258 retval = -ENOENT;
259 if (interpreter_name[phdr->p_filesz - 1] != '\0')
260 goto error;
261
262 kdebug("Using ELF interpreter %s", interpreter_name);
263
264 /* replace the program with the interpreter */
265 interpreter = open_exec(interpreter_name);
266 retval = PTR_ERR(interpreter);
267 if (IS_ERR(interpreter)) {
268 interpreter = NULL;
269 goto error;
270 }
271
272 /*
273 * If the binary is not readable then enforce
274 * mm->dumpable = 0 regardless of the interpreter's
275 * permissions.
276 */
277 would_dump(bprm, interpreter);
278
279 retval = kernel_read(interpreter, 0, bprm->buf,
280 BINPRM_BUF_SIZE);
281 if (unlikely(retval != BINPRM_BUF_SIZE)) {
282 if (retval >= 0)
283 retval = -ENOEXEC;
284 goto error;
285 }
286
287 interp_params.hdr = *((struct elfhdr *) bprm->buf);
288 break;
289
290 case PT_LOAD:
291 #ifdef CONFIG_MMU
292 if (exec_params.load_addr == 0)
293 exec_params.load_addr = phdr->p_vaddr;
294 #endif
295 break;
296 }
297
298 }
299
300 if (is_constdisp(&exec_params.hdr))
301 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
302
303 /* perform insanity checks on the interpreter */
304 if (interpreter_name) {
305 retval = -ELIBBAD;
306 if (!is_elf(&interp_params.hdr, interpreter))
307 goto error;
308
309 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
310
311 /* read the interpreter's program header table */
312 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
313 if (retval < 0)
314 goto error;
315 }
316
317 stack_size = exec_params.stack_size;
318 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
319 executable_stack = EXSTACK_ENABLE_X;
320 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
321 executable_stack = EXSTACK_DISABLE_X;
322 else
323 executable_stack = EXSTACK_DEFAULT;
324
325 if (stack_size == 0) {
326 stack_size = interp_params.stack_size;
327 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
328 executable_stack = EXSTACK_ENABLE_X;
329 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
330 executable_stack = EXSTACK_DISABLE_X;
331 else
332 executable_stack = EXSTACK_DEFAULT;
333 }
334
335 retval = -ENOEXEC;
336 if (stack_size == 0)
337 stack_size = 131072UL; /* same as exec.c's default commit */
338
339 if (is_constdisp(&interp_params.hdr))
340 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
341
342 /* flush all traces of the currently running executable */
343 retval = flush_old_exec(bprm);
344 if (retval)
345 goto error;
346
347 /* there's now no turning back... the old userspace image is dead,
348 * defunct, deceased, etc.
349 */
350 if (elf_check_fdpic(&exec_params.hdr))
351 set_personality(PER_LINUX_FDPIC);
352 else
353 set_personality(PER_LINUX);
354 if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
355 current->personality |= READ_IMPLIES_EXEC;
356
357 setup_new_exec(bprm);
358
359 set_binfmt(&elf_fdpic_format);
360
361 current->mm->start_code = 0;
362 current->mm->end_code = 0;
363 current->mm->start_stack = 0;
364 current->mm->start_data = 0;
365 current->mm->end_data = 0;
366 current->mm->context.exec_fdpic_loadmap = 0;
367 current->mm->context.interp_fdpic_loadmap = 0;
368
369 #ifdef CONFIG_MMU
370 elf_fdpic_arch_lay_out_mm(&exec_params,
371 &interp_params,
372 &current->mm->start_stack,
373 &current->mm->start_brk);
374
375 retval = setup_arg_pages(bprm, current->mm->start_stack,
376 executable_stack);
377 if (retval < 0)
378 goto error;
379 #endif
380
381 /* load the executable and interpreter into memory */
382 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
383 "executable");
384 if (retval < 0)
385 goto error;
386
387 if (interpreter_name) {
388 retval = elf_fdpic_map_file(&interp_params, interpreter,
389 current->mm, "interpreter");
390 if (retval < 0) {
391 printk(KERN_ERR "Unable to load interpreter\n");
392 goto error;
393 }
394
395 allow_write_access(interpreter);
396 fput(interpreter);
397 interpreter = NULL;
398 }
399
400 #ifdef CONFIG_MMU
401 if (!current->mm->start_brk)
402 current->mm->start_brk = current->mm->end_data;
403
404 current->mm->brk = current->mm->start_brk =
405 PAGE_ALIGN(current->mm->start_brk);
406
407 #else
408 /* create a stack area and zero-size brk area */
409 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
410 if (stack_size < PAGE_SIZE * 2)
411 stack_size = PAGE_SIZE * 2;
412
413 stack_prot = PROT_READ | PROT_WRITE;
414 if (executable_stack == EXSTACK_ENABLE_X ||
415 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
416 stack_prot |= PROT_EXEC;
417
418 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
419 MAP_PRIVATE | MAP_ANONYMOUS |
420 MAP_UNINITIALIZED | MAP_GROWSDOWN,
421 0);
422
423 if (IS_ERR_VALUE(current->mm->start_brk)) {
424 retval = current->mm->start_brk;
425 current->mm->start_brk = 0;
426 goto error;
427 }
428
429 current->mm->brk = current->mm->start_brk;
430 current->mm->context.end_brk = current->mm->start_brk;
431 current->mm->start_stack = current->mm->start_brk + stack_size;
432 #endif
433
434 install_exec_creds(bprm);
435 if (create_elf_fdpic_tables(bprm, current->mm,
436 &exec_params, &interp_params) < 0)
437 goto error;
438
439 kdebug("- start_code %lx", current->mm->start_code);
440 kdebug("- end_code %lx", current->mm->end_code);
441 kdebug("- start_data %lx", current->mm->start_data);
442 kdebug("- end_data %lx", current->mm->end_data);
443 kdebug("- start_brk %lx", current->mm->start_brk);
444 kdebug("- brk %lx", current->mm->brk);
445 kdebug("- start_stack %lx", current->mm->start_stack);
446
447 #ifdef ELF_FDPIC_PLAT_INIT
448 /*
449 * The ABI may specify that certain registers be set up in special
450 * ways (on i386 %edx is the address of a DT_FINI function, for
451 * example. This macro performs whatever initialization to
452 * the regs structure is required.
453 */
454 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
455 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
456 dynaddr);
457 #endif
458
459 /* everything is now ready... get the userspace context ready to roll */
460 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
461 start_thread(regs, entryaddr, current->mm->start_stack);
462
463 retval = 0;
464
465 error:
466 if (interpreter) {
467 allow_write_access(interpreter);
468 fput(interpreter);
469 }
470 kfree(interpreter_name);
471 kfree(exec_params.phdrs);
472 kfree(exec_params.loadmap);
473 kfree(interp_params.phdrs);
474 kfree(interp_params.loadmap);
475 return retval;
476 }
477
478 /*****************************************************************************/
479
480 #ifndef ELF_BASE_PLATFORM
481 /*
482 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
483 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
484 * will be copied to the user stack in the same manner as AT_PLATFORM.
485 */
486 #define ELF_BASE_PLATFORM NULL
487 #endif
488
489 /*
490 * present useful information to the program by shovelling it onto the new
491 * process's stack
492 */
493 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
494 struct mm_struct *mm,
495 struct elf_fdpic_params *exec_params,
496 struct elf_fdpic_params *interp_params)
497 {
498 const struct cred *cred = current_cred();
499 unsigned long sp, csp, nitems;
500 elf_caddr_t __user *argv, *envp;
501 size_t platform_len = 0, len;
502 char *k_platform, *k_base_platform;
503 char __user *u_platform, *u_base_platform, *p;
504 int loop;
505 int nr; /* reset for each csp adjustment */
506
507 #ifdef CONFIG_MMU
508 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
509 * by the processes running on the same package. One thing we can do is
510 * to shuffle the initial stack for them, so we give the architecture
511 * an opportunity to do so here.
512 */
513 sp = arch_align_stack(bprm->p);
514 #else
515 sp = mm->start_stack;
516
517 /* stack the program arguments and environment */
518 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
519 return -EFAULT;
520 #endif
521
522 /*
523 * If this architecture has a platform capability string, copy it
524 * to userspace. In some cases (Sparc), this info is impossible
525 * for userspace to get any other way, in others (i386) it is
526 * merely difficult.
527 */
528 k_platform = ELF_PLATFORM;
529 u_platform = NULL;
530
531 if (k_platform) {
532 platform_len = strlen(k_platform) + 1;
533 sp -= platform_len;
534 u_platform = (char __user *) sp;
535 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
536 return -EFAULT;
537 }
538
539 /*
540 * If this architecture has a "base" platform capability
541 * string, copy it to userspace.
542 */
543 k_base_platform = ELF_BASE_PLATFORM;
544 u_base_platform = NULL;
545
546 if (k_base_platform) {
547 platform_len = strlen(k_base_platform) + 1;
548 sp -= platform_len;
549 u_base_platform = (char __user *) sp;
550 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
551 return -EFAULT;
552 }
553
554 sp &= ~7UL;
555
556 /* stack the load map(s) */
557 len = sizeof(struct elf32_fdpic_loadmap);
558 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
559 sp = (sp - len) & ~7UL;
560 exec_params->map_addr = sp;
561
562 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
563 return -EFAULT;
564
565 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
566
567 if (interp_params->loadmap) {
568 len = sizeof(struct elf32_fdpic_loadmap);
569 len += sizeof(struct elf32_fdpic_loadseg) *
570 interp_params->loadmap->nsegs;
571 sp = (sp - len) & ~7UL;
572 interp_params->map_addr = sp;
573
574 if (copy_to_user((void __user *) sp, interp_params->loadmap,
575 len) != 0)
576 return -EFAULT;
577
578 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
579 }
580
581 /* force 16 byte _final_ alignment here for generality */
582 #define DLINFO_ITEMS 15
583
584 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
585 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
586
587 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
588 nitems++;
589
590 csp = sp;
591 sp -= nitems * 2 * sizeof(unsigned long);
592 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
593 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
594 sp -= 1 * sizeof(unsigned long); /* argc */
595
596 csp -= sp & 15UL;
597 sp -= sp & 15UL;
598
599 /* put the ELF interpreter info on the stack */
600 #define NEW_AUX_ENT(id, val) \
601 do { \
602 struct { unsigned long _id, _val; } __user *ent; \
603 \
604 ent = (void __user *) csp; \
605 __put_user((id), &ent[nr]._id); \
606 __put_user((val), &ent[nr]._val); \
607 nr++; \
608 } while (0)
609
610 nr = 0;
611 csp -= 2 * sizeof(unsigned long);
612 NEW_AUX_ENT(AT_NULL, 0);
613 if (k_platform) {
614 nr = 0;
615 csp -= 2 * sizeof(unsigned long);
616 NEW_AUX_ENT(AT_PLATFORM,
617 (elf_addr_t) (unsigned long) u_platform);
618 }
619
620 if (k_base_platform) {
621 nr = 0;
622 csp -= 2 * sizeof(unsigned long);
623 NEW_AUX_ENT(AT_BASE_PLATFORM,
624 (elf_addr_t) (unsigned long) u_base_platform);
625 }
626
627 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
628 nr = 0;
629 csp -= 2 * sizeof(unsigned long);
630 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
631 }
632
633 nr = 0;
634 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
635 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
636 #ifdef ELF_HWCAP2
637 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
638 #endif
639 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
640 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
641 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
642 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
643 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
644 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
645 NEW_AUX_ENT(AT_FLAGS, 0);
646 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
647 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
648 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
649 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
650 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
651 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
652 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
653
654 #ifdef ARCH_DLINFO
655 nr = 0;
656 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
657
658 /* ARCH_DLINFO must come last so platform specific code can enforce
659 * special alignment requirements on the AUXV if necessary (eg. PPC).
660 */
661 ARCH_DLINFO;
662 #endif
663 #undef NEW_AUX_ENT
664
665 /* allocate room for argv[] and envv[] */
666 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
667 envp = (elf_caddr_t __user *) csp;
668 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
669 argv = (elf_caddr_t __user *) csp;
670
671 /* stack argc */
672 csp -= sizeof(unsigned long);
673 __put_user(bprm->argc, (unsigned long __user *) csp);
674
675 BUG_ON(csp != sp);
676
677 /* fill in the argv[] array */
678 #ifdef CONFIG_MMU
679 current->mm->arg_start = bprm->p;
680 #else
681 current->mm->arg_start = current->mm->start_stack -
682 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
683 #endif
684
685 p = (char __user *) current->mm->arg_start;
686 for (loop = bprm->argc; loop > 0; loop--) {
687 __put_user((elf_caddr_t) p, argv++);
688 len = strnlen_user(p, MAX_ARG_STRLEN);
689 if (!len || len > MAX_ARG_STRLEN)
690 return -EINVAL;
691 p += len;
692 }
693 __put_user(NULL, argv);
694 current->mm->arg_end = (unsigned long) p;
695
696 /* fill in the envv[] array */
697 current->mm->env_start = (unsigned long) p;
698 for (loop = bprm->envc; loop > 0; loop--) {
699 __put_user((elf_caddr_t)(unsigned long) p, envp++);
700 len = strnlen_user(p, MAX_ARG_STRLEN);
701 if (!len || len > MAX_ARG_STRLEN)
702 return -EINVAL;
703 p += len;
704 }
705 __put_user(NULL, envp);
706 current->mm->env_end = (unsigned long) p;
707
708 mm->start_stack = (unsigned long) sp;
709 return 0;
710 }
711
712 /*****************************************************************************/
713 /*
714 * transfer the program arguments and environment from the holding pages onto
715 * the stack
716 */
717 #ifndef CONFIG_MMU
718 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
719 unsigned long *_sp)
720 {
721 unsigned long index, stop, sp;
722 char *src;
723 int ret = 0;
724
725 stop = bprm->p >> PAGE_SHIFT;
726 sp = *_sp;
727
728 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
729 src = kmap(bprm->page[index]);
730 sp -= PAGE_SIZE;
731 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
732 ret = -EFAULT;
733 kunmap(bprm->page[index]);
734 if (ret < 0)
735 goto out;
736 }
737
738 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
739
740 out:
741 return ret;
742 }
743 #endif
744
745 /*****************************************************************************/
746 /*
747 * load the appropriate binary image (executable or interpreter) into memory
748 * - we assume no MMU is available
749 * - if no other PIC bits are set in params->hdr->e_flags
750 * - we assume that the LOADable segments in the binary are independently relocatable
751 * - we assume R/O executable segments are shareable
752 * - else
753 * - we assume the loadable parts of the image to require fixed displacement
754 * - the image is not shareable
755 */
756 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
757 struct file *file,
758 struct mm_struct *mm,
759 const char *what)
760 {
761 struct elf32_fdpic_loadmap *loadmap;
762 #ifdef CONFIG_MMU
763 struct elf32_fdpic_loadseg *mseg;
764 #endif
765 struct elf32_fdpic_loadseg *seg;
766 struct elf32_phdr *phdr;
767 unsigned long load_addr, stop;
768 unsigned nloads, tmp;
769 size_t size;
770 int loop, ret;
771
772 /* allocate a load map table */
773 nloads = 0;
774 for (loop = 0; loop < params->hdr.e_phnum; loop++)
775 if (params->phdrs[loop].p_type == PT_LOAD)
776 nloads++;
777
778 if (nloads == 0)
779 return -ELIBBAD;
780
781 size = sizeof(*loadmap) + nloads * sizeof(*seg);
782 loadmap = kzalloc(size, GFP_KERNEL);
783 if (!loadmap)
784 return -ENOMEM;
785
786 params->loadmap = loadmap;
787
788 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
789 loadmap->nsegs = nloads;
790
791 load_addr = params->load_addr;
792 seg = loadmap->segs;
793
794 /* map the requested LOADs into the memory space */
795 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
796 case ELF_FDPIC_FLAG_CONSTDISP:
797 case ELF_FDPIC_FLAG_CONTIGUOUS:
798 #ifndef CONFIG_MMU
799 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
800 if (ret < 0)
801 return ret;
802 break;
803 #endif
804 default:
805 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
806 if (ret < 0)
807 return ret;
808 break;
809 }
810
811 /* map the entry point */
812 if (params->hdr.e_entry) {
813 seg = loadmap->segs;
814 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
815 if (params->hdr.e_entry >= seg->p_vaddr &&
816 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
817 params->entry_addr =
818 (params->hdr.e_entry - seg->p_vaddr) +
819 seg->addr;
820 break;
821 }
822 }
823 }
824
825 /* determine where the program header table has wound up if mapped */
826 stop = params->hdr.e_phoff;
827 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
828 phdr = params->phdrs;
829
830 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
831 if (phdr->p_type != PT_LOAD)
832 continue;
833
834 if (phdr->p_offset > params->hdr.e_phoff ||
835 phdr->p_offset + phdr->p_filesz < stop)
836 continue;
837
838 seg = loadmap->segs;
839 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
840 if (phdr->p_vaddr >= seg->p_vaddr &&
841 phdr->p_vaddr + phdr->p_filesz <=
842 seg->p_vaddr + seg->p_memsz) {
843 params->ph_addr =
844 (phdr->p_vaddr - seg->p_vaddr) +
845 seg->addr +
846 params->hdr.e_phoff - phdr->p_offset;
847 break;
848 }
849 }
850 break;
851 }
852
853 /* determine where the dynamic section has wound up if there is one */
854 phdr = params->phdrs;
855 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
856 if (phdr->p_type != PT_DYNAMIC)
857 continue;
858
859 seg = loadmap->segs;
860 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
861 if (phdr->p_vaddr >= seg->p_vaddr &&
862 phdr->p_vaddr + phdr->p_memsz <=
863 seg->p_vaddr + seg->p_memsz) {
864 params->dynamic_addr =
865 (phdr->p_vaddr - seg->p_vaddr) +
866 seg->addr;
867
868 /* check the dynamic section contains at least
869 * one item, and that the last item is a NULL
870 * entry */
871 if (phdr->p_memsz == 0 ||
872 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
873 goto dynamic_error;
874
875 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
876 if (((Elf32_Dyn *)
877 params->dynamic_addr)[tmp - 1].d_tag != 0)
878 goto dynamic_error;
879 break;
880 }
881 }
882 break;
883 }
884
885 /* now elide adjacent segments in the load map on MMU linux
886 * - on uClinux the holes between may actually be filled with system
887 * stuff or stuff from other processes
888 */
889 #ifdef CONFIG_MMU
890 nloads = loadmap->nsegs;
891 mseg = loadmap->segs;
892 seg = mseg + 1;
893 for (loop = 1; loop < nloads; loop++) {
894 /* see if we have a candidate for merging */
895 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
896 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
897 if (load_addr == (seg->addr & PAGE_MASK)) {
898 mseg->p_memsz +=
899 load_addr -
900 (mseg->addr + mseg->p_memsz);
901 mseg->p_memsz += seg->addr & ~PAGE_MASK;
902 mseg->p_memsz += seg->p_memsz;
903 loadmap->nsegs--;
904 continue;
905 }
906 }
907
908 mseg++;
909 if (mseg != seg)
910 *mseg = *seg;
911 }
912 #endif
913
914 kdebug("Mapped Object [%s]:", what);
915 kdebug("- elfhdr : %lx", params->elfhdr_addr);
916 kdebug("- entry : %lx", params->entry_addr);
917 kdebug("- PHDR[] : %lx", params->ph_addr);
918 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
919 seg = loadmap->segs;
920 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
921 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
922 loop,
923 seg->addr, seg->addr + seg->p_memsz - 1,
924 seg->p_vaddr, seg->p_memsz);
925
926 return 0;
927
928 dynamic_error:
929 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
930 what, file_inode(file)->i_ino);
931 return -ELIBBAD;
932 }
933
934 /*****************************************************************************/
935 /*
936 * map a file with constant displacement under uClinux
937 */
938 #ifndef CONFIG_MMU
939 static int elf_fdpic_map_file_constdisp_on_uclinux(
940 struct elf_fdpic_params *params,
941 struct file *file,
942 struct mm_struct *mm)
943 {
944 struct elf32_fdpic_loadseg *seg;
945 struct elf32_phdr *phdr;
946 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
947 int loop, ret;
948
949 load_addr = params->load_addr;
950 seg = params->loadmap->segs;
951
952 /* determine the bounds of the contiguous overall allocation we must
953 * make */
954 phdr = params->phdrs;
955 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
956 if (params->phdrs[loop].p_type != PT_LOAD)
957 continue;
958
959 if (base > phdr->p_vaddr)
960 base = phdr->p_vaddr;
961 if (top < phdr->p_vaddr + phdr->p_memsz)
962 top = phdr->p_vaddr + phdr->p_memsz;
963 }
964
965 /* allocate one big anon block for everything */
966 mflags = MAP_PRIVATE;
967 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
968 mflags |= MAP_EXECUTABLE;
969
970 maddr = vm_mmap(NULL, load_addr, top - base,
971 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
972 if (IS_ERR_VALUE(maddr))
973 return (int) maddr;
974
975 if (load_addr != 0)
976 load_addr += PAGE_ALIGN(top - base);
977
978 /* and then load the file segments into it */
979 phdr = params->phdrs;
980 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
981 if (params->phdrs[loop].p_type != PT_LOAD)
982 continue;
983
984 seg->addr = maddr + (phdr->p_vaddr - base);
985 seg->p_vaddr = phdr->p_vaddr;
986 seg->p_memsz = phdr->p_memsz;
987
988 ret = read_code(file, seg->addr, phdr->p_offset,
989 phdr->p_filesz);
990 if (ret < 0)
991 return ret;
992
993 /* map the ELF header address if in this segment */
994 if (phdr->p_offset == 0)
995 params->elfhdr_addr = seg->addr;
996
997 /* clear any space allocated but not loaded */
998 if (phdr->p_filesz < phdr->p_memsz) {
999 if (clear_user((void *) (seg->addr + phdr->p_filesz),
1000 phdr->p_memsz - phdr->p_filesz))
1001 return -EFAULT;
1002 }
1003
1004 if (mm) {
1005 if (phdr->p_flags & PF_X) {
1006 if (!mm->start_code) {
1007 mm->start_code = seg->addr;
1008 mm->end_code = seg->addr +
1009 phdr->p_memsz;
1010 }
1011 } else if (!mm->start_data) {
1012 mm->start_data = seg->addr;
1013 mm->end_data = seg->addr + phdr->p_memsz;
1014 }
1015 }
1016
1017 seg++;
1018 }
1019
1020 return 0;
1021 }
1022 #endif
1023
1024 /*****************************************************************************/
1025 /*
1026 * map a binary by direct mmap() of the individual PT_LOAD segments
1027 */
1028 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1029 struct file *file,
1030 struct mm_struct *mm)
1031 {
1032 struct elf32_fdpic_loadseg *seg;
1033 struct elf32_phdr *phdr;
1034 unsigned long load_addr, delta_vaddr;
1035 int loop, dvset;
1036
1037 load_addr = params->load_addr;
1038 delta_vaddr = 0;
1039 dvset = 0;
1040
1041 seg = params->loadmap->segs;
1042
1043 /* deal with each load segment separately */
1044 phdr = params->phdrs;
1045 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1046 unsigned long maddr, disp, excess, excess1;
1047 int prot = 0, flags;
1048
1049 if (phdr->p_type != PT_LOAD)
1050 continue;
1051
1052 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1053 (unsigned long) phdr->p_vaddr,
1054 (unsigned long) phdr->p_offset,
1055 (unsigned long) phdr->p_filesz,
1056 (unsigned long) phdr->p_memsz);
1057
1058 /* determine the mapping parameters */
1059 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1060 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1061 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1062
1063 flags = MAP_PRIVATE | MAP_DENYWRITE;
1064 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1065 flags |= MAP_EXECUTABLE;
1066
1067 maddr = 0;
1068
1069 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1070 case ELF_FDPIC_FLAG_INDEPENDENT:
1071 /* PT_LOADs are independently locatable */
1072 break;
1073
1074 case ELF_FDPIC_FLAG_HONOURVADDR:
1075 /* the specified virtual address must be honoured */
1076 maddr = phdr->p_vaddr;
1077 flags |= MAP_FIXED;
1078 break;
1079
1080 case ELF_FDPIC_FLAG_CONSTDISP:
1081 /* constant displacement
1082 * - can be mapped anywhere, but must be mapped as a
1083 * unit
1084 */
1085 if (!dvset) {
1086 maddr = load_addr;
1087 delta_vaddr = phdr->p_vaddr;
1088 dvset = 1;
1089 } else {
1090 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1091 flags |= MAP_FIXED;
1092 }
1093 break;
1094
1095 case ELF_FDPIC_FLAG_CONTIGUOUS:
1096 /* contiguity handled later */
1097 break;
1098
1099 default:
1100 BUG();
1101 }
1102
1103 maddr &= PAGE_MASK;
1104
1105 /* create the mapping */
1106 disp = phdr->p_vaddr & ~PAGE_MASK;
1107 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1108 phdr->p_offset - disp);
1109
1110 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1111 loop, phdr->p_memsz + disp, prot, flags,
1112 phdr->p_offset - disp, maddr);
1113
1114 if (IS_ERR_VALUE(maddr))
1115 return (int) maddr;
1116
1117 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1118 ELF_FDPIC_FLAG_CONTIGUOUS)
1119 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1120
1121 seg->addr = maddr + disp;
1122 seg->p_vaddr = phdr->p_vaddr;
1123 seg->p_memsz = phdr->p_memsz;
1124
1125 /* map the ELF header address if in this segment */
1126 if (phdr->p_offset == 0)
1127 params->elfhdr_addr = seg->addr;
1128
1129 /* clear the bit between beginning of mapping and beginning of
1130 * PT_LOAD */
1131 if (prot & PROT_WRITE && disp > 0) {
1132 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1133 if (clear_user((void __user *) maddr, disp))
1134 return -EFAULT;
1135 maddr += disp;
1136 }
1137
1138 /* clear any space allocated but not loaded
1139 * - on uClinux we can just clear the lot
1140 * - on MMU linux we'll get a SIGBUS beyond the last page
1141 * extant in the file
1142 */
1143 excess = phdr->p_memsz - phdr->p_filesz;
1144 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1145
1146 #ifdef CONFIG_MMU
1147 if (excess > excess1) {
1148 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1149 unsigned long xmaddr;
1150
1151 flags |= MAP_FIXED | MAP_ANONYMOUS;
1152 xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1153 prot, flags, 0);
1154
1155 kdebug("mmap[%d] <anon>"
1156 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1157 loop, xaddr, excess - excess1, prot, flags,
1158 xmaddr);
1159
1160 if (xmaddr != xaddr)
1161 return -ENOMEM;
1162 }
1163
1164 if (prot & PROT_WRITE && excess1 > 0) {
1165 kdebug("clear[%d] ad=%lx sz=%lx",
1166 loop, maddr + phdr->p_filesz, excess1);
1167 if (clear_user((void __user *) maddr + phdr->p_filesz,
1168 excess1))
1169 return -EFAULT;
1170 }
1171
1172 #else
1173 if (excess > 0) {
1174 kdebug("clear[%d] ad=%lx sz=%lx",
1175 loop, maddr + phdr->p_filesz, excess);
1176 if (clear_user((void *) maddr + phdr->p_filesz, excess))
1177 return -EFAULT;
1178 }
1179 #endif
1180
1181 if (mm) {
1182 if (phdr->p_flags & PF_X) {
1183 if (!mm->start_code) {
1184 mm->start_code = maddr;
1185 mm->end_code = maddr + phdr->p_memsz;
1186 }
1187 } else if (!mm->start_data) {
1188 mm->start_data = maddr;
1189 mm->end_data = maddr + phdr->p_memsz;
1190 }
1191 }
1192
1193 seg++;
1194 }
1195
1196 return 0;
1197 }
1198
1199 /*****************************************************************************/
1200 /*
1201 * ELF-FDPIC core dumper
1202 *
1203 * Modelled on fs/exec.c:aout_core_dump()
1204 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1205 *
1206 * Modelled on fs/binfmt_elf.c core dumper
1207 */
1208 #ifdef CONFIG_ELF_CORE
1209
1210 /*
1211 * Decide whether a segment is worth dumping; default is yes to be
1212 * sure (missing info is worse than too much; etc).
1213 * Personally I'd include everything, and use the coredump limit...
1214 *
1215 * I think we should skip something. But I am not sure how. H.J.
1216 */
1217 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1218 {
1219 int dump_ok;
1220
1221 /* Do not dump I/O mapped devices or special mappings */
1222 if (vma->vm_flags & VM_IO) {
1223 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1224 return 0;
1225 }
1226
1227 /* If we may not read the contents, don't allow us to dump
1228 * them either. "dump_write()" can't handle it anyway.
1229 */
1230 if (!(vma->vm_flags & VM_READ)) {
1231 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1232 return 0;
1233 }
1234
1235 /* support for DAX */
1236 if (vma_is_dax(vma)) {
1237 if (vma->vm_flags & VM_SHARED) {
1238 dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags);
1239 kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start,
1240 vma->vm_flags, dump_ok ? "yes" : "no");
1241 } else {
1242 dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags);
1243 kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start,
1244 vma->vm_flags, dump_ok ? "yes" : "no");
1245 }
1246 return dump_ok;
1247 }
1248
1249 /* By default, dump shared memory if mapped from an anonymous file. */
1250 if (vma->vm_flags & VM_SHARED) {
1251 if (file_inode(vma->vm_file)->i_nlink == 0) {
1252 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1253 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1254 vma->vm_flags, dump_ok ? "yes" : "no");
1255 return dump_ok;
1256 }
1257
1258 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1259 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1260 vma->vm_flags, dump_ok ? "yes" : "no");
1261 return dump_ok;
1262 }
1263
1264 #ifdef CONFIG_MMU
1265 /* By default, if it hasn't been written to, don't write it out */
1266 if (!vma->anon_vma) {
1267 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1268 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1269 vma->vm_flags, dump_ok ? "yes" : "no");
1270 return dump_ok;
1271 }
1272 #endif
1273
1274 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1275 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1276 dump_ok ? "yes" : "no");
1277 return dump_ok;
1278 }
1279
1280 /* An ELF note in memory */
1281 struct memelfnote
1282 {
1283 const char *name;
1284 int type;
1285 unsigned int datasz;
1286 void *data;
1287 };
1288
1289 static int notesize(struct memelfnote *en)
1290 {
1291 int sz;
1292
1293 sz = sizeof(struct elf_note);
1294 sz += roundup(strlen(en->name) + 1, 4);
1295 sz += roundup(en->datasz, 4);
1296
1297 return sz;
1298 }
1299
1300 /* #define DEBUG */
1301
1302 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1303 {
1304 struct elf_note en;
1305 en.n_namesz = strlen(men->name) + 1;
1306 en.n_descsz = men->datasz;
1307 en.n_type = men->type;
1308
1309 return dump_emit(cprm, &en, sizeof(en)) &&
1310 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1311 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1312 }
1313
1314 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1315 {
1316 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1317 elf->e_ident[EI_CLASS] = ELF_CLASS;
1318 elf->e_ident[EI_DATA] = ELF_DATA;
1319 elf->e_ident[EI_VERSION] = EV_CURRENT;
1320 elf->e_ident[EI_OSABI] = ELF_OSABI;
1321 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1322
1323 elf->e_type = ET_CORE;
1324 elf->e_machine = ELF_ARCH;
1325 elf->e_version = EV_CURRENT;
1326 elf->e_entry = 0;
1327 elf->e_phoff = sizeof(struct elfhdr);
1328 elf->e_shoff = 0;
1329 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1330 elf->e_ehsize = sizeof(struct elfhdr);
1331 elf->e_phentsize = sizeof(struct elf_phdr);
1332 elf->e_phnum = segs;
1333 elf->e_shentsize = 0;
1334 elf->e_shnum = 0;
1335 elf->e_shstrndx = 0;
1336 return;
1337 }
1338
1339 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1340 {
1341 phdr->p_type = PT_NOTE;
1342 phdr->p_offset = offset;
1343 phdr->p_vaddr = 0;
1344 phdr->p_paddr = 0;
1345 phdr->p_filesz = sz;
1346 phdr->p_memsz = 0;
1347 phdr->p_flags = 0;
1348 phdr->p_align = 0;
1349 return;
1350 }
1351
1352 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1353 unsigned int sz, void *data)
1354 {
1355 note->name = name;
1356 note->type = type;
1357 note->datasz = sz;
1358 note->data = data;
1359 return;
1360 }
1361
1362 /*
1363 * fill up all the fields in prstatus from the given task struct, except
1364 * registers which need to be filled up separately.
1365 */
1366 static void fill_prstatus(struct elf_prstatus *prstatus,
1367 struct task_struct *p, long signr)
1368 {
1369 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1370 prstatus->pr_sigpend = p->pending.signal.sig[0];
1371 prstatus->pr_sighold = p->blocked.sig[0];
1372 rcu_read_lock();
1373 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1374 rcu_read_unlock();
1375 prstatus->pr_pid = task_pid_vnr(p);
1376 prstatus->pr_pgrp = task_pgrp_vnr(p);
1377 prstatus->pr_sid = task_session_vnr(p);
1378 if (thread_group_leader(p)) {
1379 struct task_cputime cputime;
1380
1381 /*
1382 * This is the record for the group leader. It shows the
1383 * group-wide total, not its individual thread total.
1384 */
1385 thread_group_cputime(p, &cputime);
1386 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1387 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1388 } else {
1389 cputime_t utime, stime;
1390
1391 task_cputime(p, &utime, &stime);
1392 cputime_to_timeval(utime, &prstatus->pr_utime);
1393 cputime_to_timeval(stime, &prstatus->pr_stime);
1394 }
1395 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1396 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1397
1398 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1399 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1400 }
1401
1402 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1403 struct mm_struct *mm)
1404 {
1405 const struct cred *cred;
1406 unsigned int i, len;
1407
1408 /* first copy the parameters from user space */
1409 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1410
1411 len = mm->arg_end - mm->arg_start;
1412 if (len >= ELF_PRARGSZ)
1413 len = ELF_PRARGSZ - 1;
1414 if (copy_from_user(&psinfo->pr_psargs,
1415 (const char __user *) mm->arg_start, len))
1416 return -EFAULT;
1417 for (i = 0; i < len; i++)
1418 if (psinfo->pr_psargs[i] == 0)
1419 psinfo->pr_psargs[i] = ' ';
1420 psinfo->pr_psargs[len] = 0;
1421
1422 rcu_read_lock();
1423 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1424 rcu_read_unlock();
1425 psinfo->pr_pid = task_pid_vnr(p);
1426 psinfo->pr_pgrp = task_pgrp_vnr(p);
1427 psinfo->pr_sid = task_session_vnr(p);
1428
1429 i = p->state ? ffz(~p->state) + 1 : 0;
1430 psinfo->pr_state = i;
1431 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1432 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1433 psinfo->pr_nice = task_nice(p);
1434 psinfo->pr_flag = p->flags;
1435 rcu_read_lock();
1436 cred = __task_cred(p);
1437 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1438 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1439 rcu_read_unlock();
1440 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1441
1442 return 0;
1443 }
1444
1445 /* Here is the structure in which status of each thread is captured. */
1446 struct elf_thread_status
1447 {
1448 struct list_head list;
1449 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1450 elf_fpregset_t fpu; /* NT_PRFPREG */
1451 struct task_struct *thread;
1452 #ifdef ELF_CORE_COPY_XFPREGS
1453 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1454 #endif
1455 struct memelfnote notes[3];
1456 int num_notes;
1457 };
1458
1459 /*
1460 * In order to add the specific thread information for the elf file format,
1461 * we need to keep a linked list of every thread's pr_status and then create
1462 * a single section for them in the final core file.
1463 */
1464 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1465 {
1466 struct task_struct *p = t->thread;
1467 int sz = 0;
1468
1469 t->num_notes = 0;
1470
1471 fill_prstatus(&t->prstatus, p, signr);
1472 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1473
1474 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1475 &t->prstatus);
1476 t->num_notes++;
1477 sz += notesize(&t->notes[0]);
1478
1479 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1480 if (t->prstatus.pr_fpvalid) {
1481 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1482 &t->fpu);
1483 t->num_notes++;
1484 sz += notesize(&t->notes[1]);
1485 }
1486
1487 #ifdef ELF_CORE_COPY_XFPREGS
1488 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1489 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1490 sizeof(t->xfpu), &t->xfpu);
1491 t->num_notes++;
1492 sz += notesize(&t->notes[2]);
1493 }
1494 #endif
1495 return sz;
1496 }
1497
1498 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1499 elf_addr_t e_shoff, int segs)
1500 {
1501 elf->e_shoff = e_shoff;
1502 elf->e_shentsize = sizeof(*shdr4extnum);
1503 elf->e_shnum = 1;
1504 elf->e_shstrndx = SHN_UNDEF;
1505
1506 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1507
1508 shdr4extnum->sh_type = SHT_NULL;
1509 shdr4extnum->sh_size = elf->e_shnum;
1510 shdr4extnum->sh_link = elf->e_shstrndx;
1511 shdr4extnum->sh_info = segs;
1512 }
1513
1514 /*
1515 * dump the segments for an MMU process
1516 */
1517 static bool elf_fdpic_dump_segments(struct coredump_params *cprm)
1518 {
1519 struct vm_area_struct *vma;
1520
1521 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1522 unsigned long addr;
1523
1524 if (!maydump(vma, cprm->mm_flags))
1525 continue;
1526
1527 #ifdef CONFIG_MMU
1528 for (addr = vma->vm_start; addr < vma->vm_end;
1529 addr += PAGE_SIZE) {
1530 bool res;
1531 struct page *page = get_dump_page(addr);
1532 if (page) {
1533 void *kaddr = kmap(page);
1534 res = dump_emit(cprm, kaddr, PAGE_SIZE);
1535 kunmap(page);
1536 page_cache_release(page);
1537 } else {
1538 res = dump_skip(cprm, PAGE_SIZE);
1539 }
1540 if (!res)
1541 return false;
1542 }
1543 #else
1544 if (!dump_emit(cprm, (void *) vma->vm_start,
1545 vma->vm_end - vma->vm_start))
1546 return false;
1547 #endif
1548 }
1549 return true;
1550 }
1551
1552 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1553 {
1554 struct vm_area_struct *vma;
1555 size_t size = 0;
1556
1557 for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1558 if (maydump(vma, mm_flags))
1559 size += vma->vm_end - vma->vm_start;
1560 return size;
1561 }
1562
1563 /*
1564 * Actual dumper
1565 *
1566 * This is a two-pass process; first we find the offsets of the bits,
1567 * and then they are actually written out. If we run out of core limit
1568 * we just truncate.
1569 */
1570 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1571 {
1572 #define NUM_NOTES 6
1573 int has_dumped = 0;
1574 mm_segment_t fs;
1575 int segs;
1576 int i;
1577 struct vm_area_struct *vma;
1578 struct elfhdr *elf = NULL;
1579 loff_t offset = 0, dataoff;
1580 int numnote;
1581 struct memelfnote *notes = NULL;
1582 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1583 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1584 LIST_HEAD(thread_list);
1585 struct list_head *t;
1586 elf_fpregset_t *fpu = NULL;
1587 #ifdef ELF_CORE_COPY_XFPREGS
1588 elf_fpxregset_t *xfpu = NULL;
1589 #endif
1590 int thread_status_size = 0;
1591 elf_addr_t *auxv;
1592 struct elf_phdr *phdr4note = NULL;
1593 struct elf_shdr *shdr4extnum = NULL;
1594 Elf_Half e_phnum;
1595 elf_addr_t e_shoff;
1596 struct core_thread *ct;
1597 struct elf_thread_status *tmp;
1598
1599 /*
1600 * We no longer stop all VM operations.
1601 *
1602 * This is because those proceses that could possibly change map_count
1603 * or the mmap / vma pages are now blocked in do_exit on current
1604 * finishing this core dump.
1605 *
1606 * Only ptrace can touch these memory addresses, but it doesn't change
1607 * the map_count or the pages allocated. So no possibility of crashing
1608 * exists while dumping the mm->vm_next areas to the core file.
1609 */
1610
1611 /* alloc memory for large data structures: too large to be on stack */
1612 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1613 if (!elf)
1614 goto cleanup;
1615 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1616 if (!prstatus)
1617 goto cleanup;
1618 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1619 if (!psinfo)
1620 goto cleanup;
1621 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1622 if (!notes)
1623 goto cleanup;
1624 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1625 if (!fpu)
1626 goto cleanup;
1627 #ifdef ELF_CORE_COPY_XFPREGS
1628 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1629 if (!xfpu)
1630 goto cleanup;
1631 #endif
1632
1633 for (ct = current->mm->core_state->dumper.next;
1634 ct; ct = ct->next) {
1635 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1636 if (!tmp)
1637 goto cleanup;
1638
1639 tmp->thread = ct->task;
1640 list_add(&tmp->list, &thread_list);
1641 }
1642
1643 list_for_each(t, &thread_list) {
1644 struct elf_thread_status *tmp;
1645 int sz;
1646
1647 tmp = list_entry(t, struct elf_thread_status, list);
1648 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1649 thread_status_size += sz;
1650 }
1651
1652 /* now collect the dump for the current */
1653 fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1654 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1655
1656 segs = current->mm->map_count;
1657 segs += elf_core_extra_phdrs();
1658
1659 /* for notes section */
1660 segs++;
1661
1662 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1663 * this, kernel supports extended numbering. Have a look at
1664 * include/linux/elf.h for further information. */
1665 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1666
1667 /* Set up header */
1668 fill_elf_fdpic_header(elf, e_phnum);
1669
1670 has_dumped = 1;
1671 /*
1672 * Set up the notes in similar form to SVR4 core dumps made
1673 * with info from their /proc.
1674 */
1675
1676 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1677 fill_psinfo(psinfo, current->group_leader, current->mm);
1678 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1679
1680 numnote = 2;
1681
1682 auxv = (elf_addr_t *) current->mm->saved_auxv;
1683
1684 i = 0;
1685 do
1686 i += 2;
1687 while (auxv[i - 2] != AT_NULL);
1688 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1689 i * sizeof(elf_addr_t), auxv);
1690
1691 /* Try to dump the FPU. */
1692 if ((prstatus->pr_fpvalid =
1693 elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1694 fill_note(notes + numnote++,
1695 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1696 #ifdef ELF_CORE_COPY_XFPREGS
1697 if (elf_core_copy_task_xfpregs(current, xfpu))
1698 fill_note(notes + numnote++,
1699 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1700 #endif
1701
1702 fs = get_fs();
1703 set_fs(KERNEL_DS);
1704
1705 offset += sizeof(*elf); /* Elf header */
1706 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1707
1708 /* Write notes phdr entry */
1709 {
1710 int sz = 0;
1711
1712 for (i = 0; i < numnote; i++)
1713 sz += notesize(notes + i);
1714
1715 sz += thread_status_size;
1716
1717 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1718 if (!phdr4note)
1719 goto end_coredump;
1720
1721 fill_elf_note_phdr(phdr4note, sz, offset);
1722 offset += sz;
1723 }
1724
1725 /* Page-align dumped data */
1726 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1727
1728 offset += elf_core_vma_data_size(cprm->mm_flags);
1729 offset += elf_core_extra_data_size();
1730 e_shoff = offset;
1731
1732 if (e_phnum == PN_XNUM) {
1733 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1734 if (!shdr4extnum)
1735 goto end_coredump;
1736 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1737 }
1738
1739 offset = dataoff;
1740
1741 if (!dump_emit(cprm, elf, sizeof(*elf)))
1742 goto end_coredump;
1743
1744 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1745 goto end_coredump;
1746
1747 /* write program headers for segments dump */
1748 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1749 struct elf_phdr phdr;
1750 size_t sz;
1751
1752 sz = vma->vm_end - vma->vm_start;
1753
1754 phdr.p_type = PT_LOAD;
1755 phdr.p_offset = offset;
1756 phdr.p_vaddr = vma->vm_start;
1757 phdr.p_paddr = 0;
1758 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1759 phdr.p_memsz = sz;
1760 offset += phdr.p_filesz;
1761 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1762 if (vma->vm_flags & VM_WRITE)
1763 phdr.p_flags |= PF_W;
1764 if (vma->vm_flags & VM_EXEC)
1765 phdr.p_flags |= PF_X;
1766 phdr.p_align = ELF_EXEC_PAGESIZE;
1767
1768 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1769 goto end_coredump;
1770 }
1771
1772 if (!elf_core_write_extra_phdrs(cprm, offset))
1773 goto end_coredump;
1774
1775 /* write out the notes section */
1776 for (i = 0; i < numnote; i++)
1777 if (!writenote(notes + i, cprm))
1778 goto end_coredump;
1779
1780 /* write out the thread status notes section */
1781 list_for_each(t, &thread_list) {
1782 struct elf_thread_status *tmp =
1783 list_entry(t, struct elf_thread_status, list);
1784
1785 for (i = 0; i < tmp->num_notes; i++)
1786 if (!writenote(&tmp->notes[i], cprm))
1787 goto end_coredump;
1788 }
1789
1790 if (!dump_skip(cprm, dataoff - cprm->written))
1791 goto end_coredump;
1792
1793 if (!elf_fdpic_dump_segments(cprm))
1794 goto end_coredump;
1795
1796 if (!elf_core_write_extra_data(cprm))
1797 goto end_coredump;
1798
1799 if (e_phnum == PN_XNUM) {
1800 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1801 goto end_coredump;
1802 }
1803
1804 if (cprm->file->f_pos != offset) {
1805 /* Sanity check */
1806 printk(KERN_WARNING
1807 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1808 cprm->file->f_pos, offset);
1809 }
1810
1811 end_coredump:
1812 set_fs(fs);
1813
1814 cleanup:
1815 while (!list_empty(&thread_list)) {
1816 struct list_head *tmp = thread_list.next;
1817 list_del(tmp);
1818 kfree(list_entry(tmp, struct elf_thread_status, list));
1819 }
1820 kfree(phdr4note);
1821 kfree(elf);
1822 kfree(prstatus);
1823 kfree(psinfo);
1824 kfree(notes);
1825 kfree(fpu);
1826 kfree(shdr4extnum);
1827 #ifdef ELF_CORE_COPY_XFPREGS
1828 kfree(xfpu);
1829 #endif
1830 return has_dumped;
1831 #undef NUM_NOTES
1832 }
1833
1834 #endif /* CONFIG_ELF_CORE */
Linux with added FPC-III support