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Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu
[mirror_ubuntu-artful-kernel.git] / fs / binfmt_elf_fdpic.c
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 <linux/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_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
71 struct file *,
72 struct mm_struct *);
73 #endif
74
75 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
76 struct file *, struct mm_struct *);
77
78 #ifdef CONFIG_ELF_CORE
79 static int elf_fdpic_core_dump(struct coredump_params *cprm);
80 #endif
81
82 static struct linux_binfmt elf_fdpic_format = {
83 .module = THIS_MODULE,
84 .load_binary = load_elf_fdpic_binary,
85 #ifdef CONFIG_ELF_CORE
86 .core_dump = elf_fdpic_core_dump,
87 #endif
88 .min_coredump = ELF_EXEC_PAGESIZE,
89 };
90
91 static int __init init_elf_fdpic_binfmt(void)
92 {
93 register_binfmt(&elf_fdpic_format);
94 return 0;
95 }
96
97 static void __exit exit_elf_fdpic_binfmt(void)
98 {
99 unregister_binfmt(&elf_fdpic_format);
100 }
101
102 core_initcall(init_elf_fdpic_binfmt);
103 module_exit(exit_elf_fdpic_binfmt);
104
105 static int is_elf(struct elfhdr *hdr, struct file *file)
106 {
107 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
108 return 0;
109 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
110 return 0;
111 if (!elf_check_arch(hdr))
112 return 0;
113 if (!file->f_op->mmap)
114 return 0;
115 return 1;
116 }
117
118 #ifndef elf_check_fdpic
119 #define elf_check_fdpic(x) 0
120 #endif
121
122 #ifndef elf_check_const_displacement
123 #define elf_check_const_displacement(x) 0
124 #endif
125
126 static int is_constdisp(struct elfhdr *hdr)
127 {
128 if (!elf_check_fdpic(hdr))
129 return 1;
130 if (elf_check_const_displacement(hdr))
131 return 1;
132 return 0;
133 }
134
135 /*****************************************************************************/
136 /*
137 * read the program headers table into memory
138 */
139 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
140 struct file *file)
141 {
142 struct elf32_phdr *phdr;
143 unsigned long size;
144 int retval, loop;
145
146 if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
147 return -ENOMEM;
148 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
149 return -ENOMEM;
150
151 size = params->hdr.e_phnum * sizeof(struct elf_phdr);
152 params->phdrs = kmalloc(size, GFP_KERNEL);
153 if (!params->phdrs)
154 return -ENOMEM;
155
156 retval = kernel_read(file, params->hdr.e_phoff,
157 (char *) params->phdrs, size);
158 if (unlikely(retval != size))
159 return retval < 0 ? retval : -ENOEXEC;
160
161 /* determine stack size for this binary */
162 phdr = params->phdrs;
163 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
164 if (phdr->p_type != PT_GNU_STACK)
165 continue;
166
167 if (phdr->p_flags & PF_X)
168 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
169 else
170 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
171
172 params->stack_size = phdr->p_memsz;
173 break;
174 }
175
176 return 0;
177 }
178
179 /*****************************************************************************/
180 /*
181 * load an fdpic binary into various bits of memory
182 */
183 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
184 {
185 struct elf_fdpic_params exec_params, interp_params;
186 struct pt_regs *regs = current_pt_regs();
187 struct elf_phdr *phdr;
188 unsigned long stack_size, entryaddr;
189 #ifdef ELF_FDPIC_PLAT_INIT
190 unsigned long dynaddr;
191 #endif
192 #ifndef CONFIG_MMU
193 unsigned long stack_prot;
194 #endif
195 struct file *interpreter = NULL; /* to shut gcc up */
196 char *interpreter_name = NULL;
197 int executable_stack;
198 int retval, i;
199
200 kdebug("____ LOAD %d ____", current->pid);
201
202 memset(&exec_params, 0, sizeof(exec_params));
203 memset(&interp_params, 0, sizeof(interp_params));
204
205 exec_params.hdr = *(struct elfhdr *) bprm->buf;
206 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
207
208 /* check that this is a binary we know how to deal with */
209 retval = -ENOEXEC;
210 if (!is_elf(&exec_params.hdr, bprm->file))
211 goto error;
212 if (!elf_check_fdpic(&exec_params.hdr)) {
213 #ifdef CONFIG_MMU
214 /* binfmt_elf handles non-fdpic elf except on nommu */
215 goto error;
216 #else
217 /* nommu can only load ET_DYN (PIE) ELF */
218 if (exec_params.hdr.e_type != ET_DYN)
219 goto error;
220 #endif
221 }
222
223 /* read the program header table */
224 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
225 if (retval < 0)
226 goto error;
227
228 /* scan for a program header that specifies an interpreter */
229 phdr = exec_params.phdrs;
230
231 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
232 switch (phdr->p_type) {
233 case PT_INTERP:
234 retval = -ENOMEM;
235 if (phdr->p_filesz > PATH_MAX)
236 goto error;
237 retval = -ENOENT;
238 if (phdr->p_filesz < 2)
239 goto error;
240
241 /* read the name of the interpreter into memory */
242 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
243 if (!interpreter_name)
244 goto error;
245
246 retval = kernel_read(bprm->file,
247 phdr->p_offset,
248 interpreter_name,
249 phdr->p_filesz);
250 if (unlikely(retval != phdr->p_filesz)) {
251 if (retval >= 0)
252 retval = -ENOEXEC;
253 goto error;
254 }
255
256 retval = -ENOENT;
257 if (interpreter_name[phdr->p_filesz - 1] != '\0')
258 goto error;
259
260 kdebug("Using ELF interpreter %s", interpreter_name);
261
262 /* replace the program with the interpreter */
263 interpreter = open_exec(interpreter_name);
264 retval = PTR_ERR(interpreter);
265 if (IS_ERR(interpreter)) {
266 interpreter = NULL;
267 goto error;
268 }
269
270 /*
271 * If the binary is not readable then enforce
272 * mm->dumpable = 0 regardless of the interpreter's
273 * permissions.
274 */
275 would_dump(bprm, interpreter);
276
277 retval = kernel_read(interpreter, 0, bprm->buf,
278 BINPRM_BUF_SIZE);
279 if (unlikely(retval != BINPRM_BUF_SIZE)) {
280 if (retval >= 0)
281 retval = -ENOEXEC;
282 goto error;
283 }
284
285 interp_params.hdr = *((struct elfhdr *) bprm->buf);
286 break;
287
288 case PT_LOAD:
289 #ifdef CONFIG_MMU
290 if (exec_params.load_addr == 0)
291 exec_params.load_addr = phdr->p_vaddr;
292 #endif
293 break;
294 }
295
296 }
297
298 if (is_constdisp(&exec_params.hdr))
299 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
300
301 /* perform insanity checks on the interpreter */
302 if (interpreter_name) {
303 retval = -ELIBBAD;
304 if (!is_elf(&interp_params.hdr, interpreter))
305 goto error;
306
307 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
308
309 /* read the interpreter's program header table */
310 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
311 if (retval < 0)
312 goto error;
313 }
314
315 stack_size = exec_params.stack_size;
316 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
317 executable_stack = EXSTACK_ENABLE_X;
318 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
319 executable_stack = EXSTACK_DISABLE_X;
320 else
321 executable_stack = EXSTACK_DEFAULT;
322
323 if (stack_size == 0) {
324 stack_size = interp_params.stack_size;
325 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
326 executable_stack = EXSTACK_ENABLE_X;
327 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
328 executable_stack = EXSTACK_DISABLE_X;
329 else
330 executable_stack = EXSTACK_DEFAULT;
331 }
332
333 retval = -ENOEXEC;
334 if (stack_size == 0)
335 stack_size = 131072UL; /* same as exec.c's default commit */
336
337 if (is_constdisp(&interp_params.hdr))
338 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
339
340 /* flush all traces of the currently running executable */
341 retval = flush_old_exec(bprm);
342 if (retval)
343 goto error;
344
345 /* there's now no turning back... the old userspace image is dead,
346 * defunct, deceased, etc.
347 */
348 if (elf_check_fdpic(&exec_params.hdr))
349 set_personality(PER_LINUX_FDPIC);
350 else
351 set_personality(PER_LINUX);
352 if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
353 current->personality |= READ_IMPLIES_EXEC;
354
355 setup_new_exec(bprm);
356
357 set_binfmt(&elf_fdpic_format);
358
359 current->mm->start_code = 0;
360 current->mm->end_code = 0;
361 current->mm->start_stack = 0;
362 current->mm->start_data = 0;
363 current->mm->end_data = 0;
364 current->mm->context.exec_fdpic_loadmap = 0;
365 current->mm->context.interp_fdpic_loadmap = 0;
366
367 #ifdef CONFIG_MMU
368 elf_fdpic_arch_lay_out_mm(&exec_params,
369 &interp_params,
370 &current->mm->start_stack,
371 &current->mm->start_brk);
372
373 retval = setup_arg_pages(bprm, current->mm->start_stack,
374 executable_stack);
375 if (retval < 0)
376 goto error;
377 #endif
378
379 /* load the executable and interpreter into memory */
380 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
381 "executable");
382 if (retval < 0)
383 goto error;
384
385 if (interpreter_name) {
386 retval = elf_fdpic_map_file(&interp_params, interpreter,
387 current->mm, "interpreter");
388 if (retval < 0) {
389 printk(KERN_ERR "Unable to load interpreter\n");
390 goto error;
391 }
392
393 allow_write_access(interpreter);
394 fput(interpreter);
395 interpreter = NULL;
396 }
397
398 #ifdef CONFIG_MMU
399 if (!current->mm->start_brk)
400 current->mm->start_brk = current->mm->end_data;
401
402 current->mm->brk = current->mm->start_brk =
403 PAGE_ALIGN(current->mm->start_brk);
404
405 #else
406 /* create a stack area and zero-size brk area */
407 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
408 if (stack_size < PAGE_SIZE * 2)
409 stack_size = PAGE_SIZE * 2;
410
411 stack_prot = PROT_READ | PROT_WRITE;
412 if (executable_stack == EXSTACK_ENABLE_X ||
413 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
414 stack_prot |= PROT_EXEC;
415
416 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
417 MAP_PRIVATE | MAP_ANONYMOUS |
418 MAP_UNINITIALIZED | MAP_GROWSDOWN,
419 0);
420
421 if (IS_ERR_VALUE(current->mm->start_brk)) {
422 retval = current->mm->start_brk;
423 current->mm->start_brk = 0;
424 goto error;
425 }
426
427 current->mm->brk = current->mm->start_brk;
428 current->mm->context.end_brk = current->mm->start_brk;
429 current->mm->start_stack = current->mm->start_brk + stack_size;
430 #endif
431
432 install_exec_creds(bprm);
433 if (create_elf_fdpic_tables(bprm, current->mm,
434 &exec_params, &interp_params) < 0)
435 goto error;
436
437 kdebug("- start_code %lx", current->mm->start_code);
438 kdebug("- end_code %lx", current->mm->end_code);
439 kdebug("- start_data %lx", current->mm->start_data);
440 kdebug("- end_data %lx", current->mm->end_data);
441 kdebug("- start_brk %lx", current->mm->start_brk);
442 kdebug("- brk %lx", current->mm->brk);
443 kdebug("- start_stack %lx", current->mm->start_stack);
444
445 #ifdef ELF_FDPIC_PLAT_INIT
446 /*
447 * The ABI may specify that certain registers be set up in special
448 * ways (on i386 %edx is the address of a DT_FINI function, for
449 * example. This macro performs whatever initialization to
450 * the regs structure is required.
451 */
452 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
453 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
454 dynaddr);
455 #endif
456
457 /* everything is now ready... get the userspace context ready to roll */
458 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
459 start_thread(regs, entryaddr, current->mm->start_stack);
460
461 retval = 0;
462
463 error:
464 if (interpreter) {
465 allow_write_access(interpreter);
466 fput(interpreter);
467 }
468 kfree(interpreter_name);
469 kfree(exec_params.phdrs);
470 kfree(exec_params.loadmap);
471 kfree(interp_params.phdrs);
472 kfree(interp_params.loadmap);
473 return retval;
474 }
475
476 /*****************************************************************************/
477
478 #ifndef ELF_BASE_PLATFORM
479 /*
480 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
481 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
482 * will be copied to the user stack in the same manner as AT_PLATFORM.
483 */
484 #define ELF_BASE_PLATFORM NULL
485 #endif
486
487 /*
488 * present useful information to the program by shovelling it onto the new
489 * process's stack
490 */
491 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
492 struct mm_struct *mm,
493 struct elf_fdpic_params *exec_params,
494 struct elf_fdpic_params *interp_params)
495 {
496 const struct cred *cred = current_cred();
497 unsigned long sp, csp, nitems;
498 elf_caddr_t __user *argv, *envp;
499 size_t platform_len = 0, len;
500 char *k_platform, *k_base_platform;
501 char __user *u_platform, *u_base_platform, *p;
502 int loop;
503 int nr; /* reset for each csp adjustment */
504
505 #ifdef CONFIG_MMU
506 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
507 * by the processes running on the same package. One thing we can do is
508 * to shuffle the initial stack for them, so we give the architecture
509 * an opportunity to do so here.
510 */
511 sp = arch_align_stack(bprm->p);
512 #else
513 sp = mm->start_stack;
514
515 /* stack the program arguments and environment */
516 if (transfer_args_to_stack(bprm, &sp) < 0)
517 return -EFAULT;
518 sp &= ~15;
519 #endif
520
521 /*
522 * If this architecture has a platform capability string, copy it
523 * to userspace. In some cases (Sparc), this info is impossible
524 * for userspace to get any other way, in others (i386) it is
525 * merely difficult.
526 */
527 k_platform = ELF_PLATFORM;
528 u_platform = NULL;
529
530 if (k_platform) {
531 platform_len = strlen(k_platform) + 1;
532 sp -= platform_len;
533 u_platform = (char __user *) sp;
534 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
535 return -EFAULT;
536 }
537
538 /*
539 * If this architecture has a "base" platform capability
540 * string, copy it to userspace.
541 */
542 k_base_platform = ELF_BASE_PLATFORM;
543 u_base_platform = NULL;
544
545 if (k_base_platform) {
546 platform_len = strlen(k_base_platform) + 1;
547 sp -= platform_len;
548 u_base_platform = (char __user *) sp;
549 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
550 return -EFAULT;
551 }
552
553 sp &= ~7UL;
554
555 /* stack the load map(s) */
556 len = sizeof(struct elf32_fdpic_loadmap);
557 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
558 sp = (sp - len) & ~7UL;
559 exec_params->map_addr = sp;
560
561 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
562 return -EFAULT;
563
564 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
565
566 if (interp_params->loadmap) {
567 len = sizeof(struct elf32_fdpic_loadmap);
568 len += sizeof(struct elf32_fdpic_loadseg) *
569 interp_params->loadmap->nsegs;
570 sp = (sp - len) & ~7UL;
571 interp_params->map_addr = sp;
572
573 if (copy_to_user((void __user *) sp, interp_params->loadmap,
574 len) != 0)
575 return -EFAULT;
576
577 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
578 }
579
580 /* force 16 byte _final_ alignment here for generality */
581 #define DLINFO_ITEMS 15
582
583 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
584 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
585
586 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
587 nitems++;
588
589 csp = sp;
590 sp -= nitems * 2 * sizeof(unsigned long);
591 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
592 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
593 sp -= 1 * sizeof(unsigned long); /* argc */
594
595 csp -= sp & 15UL;
596 sp -= sp & 15UL;
597
598 /* put the ELF interpreter info on the stack */
599 #define NEW_AUX_ENT(id, val) \
600 do { \
601 struct { unsigned long _id, _val; } __user *ent; \
602 \
603 ent = (void __user *) csp; \
604 __put_user((id), &ent[nr]._id); \
605 __put_user((val), &ent[nr]._val); \
606 nr++; \
607 } while (0)
608
609 nr = 0;
610 csp -= 2 * sizeof(unsigned long);
611 NEW_AUX_ENT(AT_NULL, 0);
612 if (k_platform) {
613 nr = 0;
614 csp -= 2 * sizeof(unsigned long);
615 NEW_AUX_ENT(AT_PLATFORM,
616 (elf_addr_t) (unsigned long) u_platform);
617 }
618
619 if (k_base_platform) {
620 nr = 0;
621 csp -= 2 * sizeof(unsigned long);
622 NEW_AUX_ENT(AT_BASE_PLATFORM,
623 (elf_addr_t) (unsigned long) u_base_platform);
624 }
625
626 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
627 nr = 0;
628 csp -= 2 * sizeof(unsigned long);
629 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
630 }
631
632 nr = 0;
633 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
634 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
635 #ifdef ELF_HWCAP2
636 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
637 #endif
638 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
639 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
640 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
641 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
642 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
643 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
644 NEW_AUX_ENT(AT_FLAGS, 0);
645 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
646 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
647 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
648 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
649 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
650 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
651 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
652
653 #ifdef ARCH_DLINFO
654 nr = 0;
655 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
656
657 /* ARCH_DLINFO must come last so platform specific code can enforce
658 * special alignment requirements on the AUXV if necessary (eg. PPC).
659 */
660 ARCH_DLINFO;
661 #endif
662 #undef NEW_AUX_ENT
663
664 /* allocate room for argv[] and envv[] */
665 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
666 envp = (elf_caddr_t __user *) csp;
667 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
668 argv = (elf_caddr_t __user *) csp;
669
670 /* stack argc */
671 csp -= sizeof(unsigned long);
672 __put_user(bprm->argc, (unsigned long __user *) csp);
673
674 BUG_ON(csp != sp);
675
676 /* fill in the argv[] array */
677 #ifdef CONFIG_MMU
678 current->mm->arg_start = bprm->p;
679 #else
680 current->mm->arg_start = current->mm->start_stack -
681 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
682 #endif
683
684 p = (char __user *) current->mm->arg_start;
685 for (loop = bprm->argc; loop > 0; loop--) {
686 __put_user((elf_caddr_t) p, argv++);
687 len = strnlen_user(p, MAX_ARG_STRLEN);
688 if (!len || len > MAX_ARG_STRLEN)
689 return -EINVAL;
690 p += len;
691 }
692 __put_user(NULL, argv);
693 current->mm->arg_end = (unsigned long) p;
694
695 /* fill in the envv[] array */
696 current->mm->env_start = (unsigned long) p;
697 for (loop = bprm->envc; loop > 0; loop--) {
698 __put_user((elf_caddr_t)(unsigned long) p, envp++);
699 len = strnlen_user(p, MAX_ARG_STRLEN);
700 if (!len || len > MAX_ARG_STRLEN)
701 return -EINVAL;
702 p += len;
703 }
704 __put_user(NULL, envp);
705 current->mm->env_end = (unsigned long) p;
706
707 mm->start_stack = (unsigned long) sp;
708 return 0;
709 }
710
711 /*****************************************************************************/
712 /*
713 * load the appropriate binary image (executable or interpreter) into memory
714 * - we assume no MMU is available
715 * - if no other PIC bits are set in params->hdr->e_flags
716 * - we assume that the LOADable segments in the binary are independently relocatable
717 * - we assume R/O executable segments are shareable
718 * - else
719 * - we assume the loadable parts of the image to require fixed displacement
720 * - the image is not shareable
721 */
722 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
723 struct file *file,
724 struct mm_struct *mm,
725 const char *what)
726 {
727 struct elf32_fdpic_loadmap *loadmap;
728 #ifdef CONFIG_MMU
729 struct elf32_fdpic_loadseg *mseg;
730 #endif
731 struct elf32_fdpic_loadseg *seg;
732 struct elf32_phdr *phdr;
733 unsigned long load_addr, stop;
734 unsigned nloads, tmp;
735 size_t size;
736 int loop, ret;
737
738 /* allocate a load map table */
739 nloads = 0;
740 for (loop = 0; loop < params->hdr.e_phnum; loop++)
741 if (params->phdrs[loop].p_type == PT_LOAD)
742 nloads++;
743
744 if (nloads == 0)
745 return -ELIBBAD;
746
747 size = sizeof(*loadmap) + nloads * sizeof(*seg);
748 loadmap = kzalloc(size, GFP_KERNEL);
749 if (!loadmap)
750 return -ENOMEM;
751
752 params->loadmap = loadmap;
753
754 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
755 loadmap->nsegs = nloads;
756
757 load_addr = params->load_addr;
758 seg = loadmap->segs;
759
760 /* map the requested LOADs into the memory space */
761 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
762 case ELF_FDPIC_FLAG_CONSTDISP:
763 case ELF_FDPIC_FLAG_CONTIGUOUS:
764 #ifndef CONFIG_MMU
765 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
766 if (ret < 0)
767 return ret;
768 break;
769 #endif
770 default:
771 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
772 if (ret < 0)
773 return ret;
774 break;
775 }
776
777 /* map the entry point */
778 if (params->hdr.e_entry) {
779 seg = loadmap->segs;
780 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
781 if (params->hdr.e_entry >= seg->p_vaddr &&
782 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
783 params->entry_addr =
784 (params->hdr.e_entry - seg->p_vaddr) +
785 seg->addr;
786 break;
787 }
788 }
789 }
790
791 /* determine where the program header table has wound up if mapped */
792 stop = params->hdr.e_phoff;
793 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
794 phdr = params->phdrs;
795
796 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
797 if (phdr->p_type != PT_LOAD)
798 continue;
799
800 if (phdr->p_offset > params->hdr.e_phoff ||
801 phdr->p_offset + phdr->p_filesz < stop)
802 continue;
803
804 seg = loadmap->segs;
805 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
806 if (phdr->p_vaddr >= seg->p_vaddr &&
807 phdr->p_vaddr + phdr->p_filesz <=
808 seg->p_vaddr + seg->p_memsz) {
809 params->ph_addr =
810 (phdr->p_vaddr - seg->p_vaddr) +
811 seg->addr +
812 params->hdr.e_phoff - phdr->p_offset;
813 break;
814 }
815 }
816 break;
817 }
818
819 /* determine where the dynamic section has wound up if there is one */
820 phdr = params->phdrs;
821 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
822 if (phdr->p_type != PT_DYNAMIC)
823 continue;
824
825 seg = loadmap->segs;
826 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
827 if (phdr->p_vaddr >= seg->p_vaddr &&
828 phdr->p_vaddr + phdr->p_memsz <=
829 seg->p_vaddr + seg->p_memsz) {
830 params->dynamic_addr =
831 (phdr->p_vaddr - seg->p_vaddr) +
832 seg->addr;
833
834 /* check the dynamic section contains at least
835 * one item, and that the last item is a NULL
836 * entry */
837 if (phdr->p_memsz == 0 ||
838 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
839 goto dynamic_error;
840
841 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
842 if (((Elf32_Dyn *)
843 params->dynamic_addr)[tmp - 1].d_tag != 0)
844 goto dynamic_error;
845 break;
846 }
847 }
848 break;
849 }
850
851 /* now elide adjacent segments in the load map on MMU linux
852 * - on uClinux the holes between may actually be filled with system
853 * stuff or stuff from other processes
854 */
855 #ifdef CONFIG_MMU
856 nloads = loadmap->nsegs;
857 mseg = loadmap->segs;
858 seg = mseg + 1;
859 for (loop = 1; loop < nloads; loop++) {
860 /* see if we have a candidate for merging */
861 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
862 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
863 if (load_addr == (seg->addr & PAGE_MASK)) {
864 mseg->p_memsz +=
865 load_addr -
866 (mseg->addr + mseg->p_memsz);
867 mseg->p_memsz += seg->addr & ~PAGE_MASK;
868 mseg->p_memsz += seg->p_memsz;
869 loadmap->nsegs--;
870 continue;
871 }
872 }
873
874 mseg++;
875 if (mseg != seg)
876 *mseg = *seg;
877 }
878 #endif
879
880 kdebug("Mapped Object [%s]:", what);
881 kdebug("- elfhdr : %lx", params->elfhdr_addr);
882 kdebug("- entry : %lx", params->entry_addr);
883 kdebug("- PHDR[] : %lx", params->ph_addr);
884 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
885 seg = loadmap->segs;
886 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
887 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
888 loop,
889 seg->addr, seg->addr + seg->p_memsz - 1,
890 seg->p_vaddr, seg->p_memsz);
891
892 return 0;
893
894 dynamic_error:
895 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
896 what, file_inode(file)->i_ino);
897 return -ELIBBAD;
898 }
899
900 /*****************************************************************************/
901 /*
902 * map a file with constant displacement under uClinux
903 */
904 #ifndef CONFIG_MMU
905 static int elf_fdpic_map_file_constdisp_on_uclinux(
906 struct elf_fdpic_params *params,
907 struct file *file,
908 struct mm_struct *mm)
909 {
910 struct elf32_fdpic_loadseg *seg;
911 struct elf32_phdr *phdr;
912 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
913 int loop, ret;
914
915 load_addr = params->load_addr;
916 seg = params->loadmap->segs;
917
918 /* determine the bounds of the contiguous overall allocation we must
919 * make */
920 phdr = params->phdrs;
921 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
922 if (params->phdrs[loop].p_type != PT_LOAD)
923 continue;
924
925 if (base > phdr->p_vaddr)
926 base = phdr->p_vaddr;
927 if (top < phdr->p_vaddr + phdr->p_memsz)
928 top = phdr->p_vaddr + phdr->p_memsz;
929 }
930
931 /* allocate one big anon block for everything */
932 mflags = MAP_PRIVATE;
933 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
934 mflags |= MAP_EXECUTABLE;
935
936 maddr = vm_mmap(NULL, load_addr, top - base,
937 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
938 if (IS_ERR_VALUE(maddr))
939 return (int) maddr;
940
941 if (load_addr != 0)
942 load_addr += PAGE_ALIGN(top - base);
943
944 /* and then load the file segments into it */
945 phdr = params->phdrs;
946 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
947 if (params->phdrs[loop].p_type != PT_LOAD)
948 continue;
949
950 seg->addr = maddr + (phdr->p_vaddr - base);
951 seg->p_vaddr = phdr->p_vaddr;
952 seg->p_memsz = phdr->p_memsz;
953
954 ret = read_code(file, seg->addr, phdr->p_offset,
955 phdr->p_filesz);
956 if (ret < 0)
957 return ret;
958
959 /* map the ELF header address if in this segment */
960 if (phdr->p_offset == 0)
961 params->elfhdr_addr = seg->addr;
962
963 /* clear any space allocated but not loaded */
964 if (phdr->p_filesz < phdr->p_memsz) {
965 if (clear_user((void *) (seg->addr + phdr->p_filesz),
966 phdr->p_memsz - phdr->p_filesz))
967 return -EFAULT;
968 }
969
970 if (mm) {
971 if (phdr->p_flags & PF_X) {
972 if (!mm->start_code) {
973 mm->start_code = seg->addr;
974 mm->end_code = seg->addr +
975 phdr->p_memsz;
976 }
977 } else if (!mm->start_data) {
978 mm->start_data = seg->addr;
979 mm->end_data = seg->addr + phdr->p_memsz;
980 }
981 }
982
983 seg++;
984 }
985
986 return 0;
987 }
988 #endif
989
990 /*****************************************************************************/
991 /*
992 * map a binary by direct mmap() of the individual PT_LOAD segments
993 */
994 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
995 struct file *file,
996 struct mm_struct *mm)
997 {
998 struct elf32_fdpic_loadseg *seg;
999 struct elf32_phdr *phdr;
1000 unsigned long load_addr, delta_vaddr;
1001 int loop, dvset;
1002
1003 load_addr = params->load_addr;
1004 delta_vaddr = 0;
1005 dvset = 0;
1006
1007 seg = params->loadmap->segs;
1008
1009 /* deal with each load segment separately */
1010 phdr = params->phdrs;
1011 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1012 unsigned long maddr, disp, excess, excess1;
1013 int prot = 0, flags;
1014
1015 if (phdr->p_type != PT_LOAD)
1016 continue;
1017
1018 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1019 (unsigned long) phdr->p_vaddr,
1020 (unsigned long) phdr->p_offset,
1021 (unsigned long) phdr->p_filesz,
1022 (unsigned long) phdr->p_memsz);
1023
1024 /* determine the mapping parameters */
1025 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1026 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1027 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1028
1029 flags = MAP_PRIVATE | MAP_DENYWRITE;
1030 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1031 flags |= MAP_EXECUTABLE;
1032
1033 maddr = 0;
1034
1035 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1036 case ELF_FDPIC_FLAG_INDEPENDENT:
1037 /* PT_LOADs are independently locatable */
1038 break;
1039
1040 case ELF_FDPIC_FLAG_HONOURVADDR:
1041 /* the specified virtual address must be honoured */
1042 maddr = phdr->p_vaddr;
1043 flags |= MAP_FIXED;
1044 break;
1045
1046 case ELF_FDPIC_FLAG_CONSTDISP:
1047 /* constant displacement
1048 * - can be mapped anywhere, but must be mapped as a
1049 * unit
1050 */
1051 if (!dvset) {
1052 maddr = load_addr;
1053 delta_vaddr = phdr->p_vaddr;
1054 dvset = 1;
1055 } else {
1056 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1057 flags |= MAP_FIXED;
1058 }
1059 break;
1060
1061 case ELF_FDPIC_FLAG_CONTIGUOUS:
1062 /* contiguity handled later */
1063 break;
1064
1065 default:
1066 BUG();
1067 }
1068
1069 maddr &= PAGE_MASK;
1070
1071 /* create the mapping */
1072 disp = phdr->p_vaddr & ~PAGE_MASK;
1073 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1074 phdr->p_offset - disp);
1075
1076 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1077 loop, phdr->p_memsz + disp, prot, flags,
1078 phdr->p_offset - disp, maddr);
1079
1080 if (IS_ERR_VALUE(maddr))
1081 return (int) maddr;
1082
1083 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1084 ELF_FDPIC_FLAG_CONTIGUOUS)
1085 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1086
1087 seg->addr = maddr + disp;
1088 seg->p_vaddr = phdr->p_vaddr;
1089 seg->p_memsz = phdr->p_memsz;
1090
1091 /* map the ELF header address if in this segment */
1092 if (phdr->p_offset == 0)
1093 params->elfhdr_addr = seg->addr;
1094
1095 /* clear the bit between beginning of mapping and beginning of
1096 * PT_LOAD */
1097 if (prot & PROT_WRITE && disp > 0) {
1098 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1099 if (clear_user((void __user *) maddr, disp))
1100 return -EFAULT;
1101 maddr += disp;
1102 }
1103
1104 /* clear any space allocated but not loaded
1105 * - on uClinux we can just clear the lot
1106 * - on MMU linux we'll get a SIGBUS beyond the last page
1107 * extant in the file
1108 */
1109 excess = phdr->p_memsz - phdr->p_filesz;
1110 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1111
1112 #ifdef CONFIG_MMU
1113 if (excess > excess1) {
1114 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1115 unsigned long xmaddr;
1116
1117 flags |= MAP_FIXED | MAP_ANONYMOUS;
1118 xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1119 prot, flags, 0);
1120
1121 kdebug("mmap[%d] <anon>"
1122 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1123 loop, xaddr, excess - excess1, prot, flags,
1124 xmaddr);
1125
1126 if (xmaddr != xaddr)
1127 return -ENOMEM;
1128 }
1129
1130 if (prot & PROT_WRITE && excess1 > 0) {
1131 kdebug("clear[%d] ad=%lx sz=%lx",
1132 loop, maddr + phdr->p_filesz, excess1);
1133 if (clear_user((void __user *) maddr + phdr->p_filesz,
1134 excess1))
1135 return -EFAULT;
1136 }
1137
1138 #else
1139 if (excess > 0) {
1140 kdebug("clear[%d] ad=%lx sz=%lx",
1141 loop, maddr + phdr->p_filesz, excess);
1142 if (clear_user((void *) maddr + phdr->p_filesz, excess))
1143 return -EFAULT;
1144 }
1145 #endif
1146
1147 if (mm) {
1148 if (phdr->p_flags & PF_X) {
1149 if (!mm->start_code) {
1150 mm->start_code = maddr;
1151 mm->end_code = maddr + phdr->p_memsz;
1152 }
1153 } else if (!mm->start_data) {
1154 mm->start_data = maddr;
1155 mm->end_data = maddr + phdr->p_memsz;
1156 }
1157 }
1158
1159 seg++;
1160 }
1161
1162 return 0;
1163 }
1164
1165 /*****************************************************************************/
1166 /*
1167 * ELF-FDPIC core dumper
1168 *
1169 * Modelled on fs/exec.c:aout_core_dump()
1170 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1171 *
1172 * Modelled on fs/binfmt_elf.c core dumper
1173 */
1174 #ifdef CONFIG_ELF_CORE
1175
1176 /*
1177 * Decide whether a segment is worth dumping; default is yes to be
1178 * sure (missing info is worse than too much; etc).
1179 * Personally I'd include everything, and use the coredump limit...
1180 *
1181 * I think we should skip something. But I am not sure how. H.J.
1182 */
1183 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1184 {
1185 int dump_ok;
1186
1187 /* Do not dump I/O mapped devices or special mappings */
1188 if (vma->vm_flags & VM_IO) {
1189 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1190 return 0;
1191 }
1192
1193 /* If we may not read the contents, don't allow us to dump
1194 * them either. "dump_write()" can't handle it anyway.
1195 */
1196 if (!(vma->vm_flags & VM_READ)) {
1197 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1198 return 0;
1199 }
1200
1201 /* support for DAX */
1202 if (vma_is_dax(vma)) {
1203 if (vma->vm_flags & VM_SHARED) {
1204 dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags);
1205 kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start,
1206 vma->vm_flags, dump_ok ? "yes" : "no");
1207 } else {
1208 dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags);
1209 kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start,
1210 vma->vm_flags, dump_ok ? "yes" : "no");
1211 }
1212 return dump_ok;
1213 }
1214
1215 /* By default, dump shared memory if mapped from an anonymous file. */
1216 if (vma->vm_flags & VM_SHARED) {
1217 if (file_inode(vma->vm_file)->i_nlink == 0) {
1218 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1219 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1220 vma->vm_flags, dump_ok ? "yes" : "no");
1221 return dump_ok;
1222 }
1223
1224 dump_ok = test_bit(MMF_DUMP_MAPPED_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 #ifdef CONFIG_MMU
1231 /* By default, if it hasn't been written to, don't write it out */
1232 if (!vma->anon_vma) {
1233 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1234 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1235 vma->vm_flags, dump_ok ? "yes" : "no");
1236 return dump_ok;
1237 }
1238 #endif
1239
1240 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1241 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1242 dump_ok ? "yes" : "no");
1243 return dump_ok;
1244 }
1245
1246 /* An ELF note in memory */
1247 struct memelfnote
1248 {
1249 const char *name;
1250 int type;
1251 unsigned int datasz;
1252 void *data;
1253 };
1254
1255 static int notesize(struct memelfnote *en)
1256 {
1257 int sz;
1258
1259 sz = sizeof(struct elf_note);
1260 sz += roundup(strlen(en->name) + 1, 4);
1261 sz += roundup(en->datasz, 4);
1262
1263 return sz;
1264 }
1265
1266 /* #define DEBUG */
1267
1268 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1269 {
1270 struct elf_note en;
1271 en.n_namesz = strlen(men->name) + 1;
1272 en.n_descsz = men->datasz;
1273 en.n_type = men->type;
1274
1275 return dump_emit(cprm, &en, sizeof(en)) &&
1276 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1277 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1278 }
1279
1280 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1281 {
1282 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1283 elf->e_ident[EI_CLASS] = ELF_CLASS;
1284 elf->e_ident[EI_DATA] = ELF_DATA;
1285 elf->e_ident[EI_VERSION] = EV_CURRENT;
1286 elf->e_ident[EI_OSABI] = ELF_OSABI;
1287 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1288
1289 elf->e_type = ET_CORE;
1290 elf->e_machine = ELF_ARCH;
1291 elf->e_version = EV_CURRENT;
1292 elf->e_entry = 0;
1293 elf->e_phoff = sizeof(struct elfhdr);
1294 elf->e_shoff = 0;
1295 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1296 elf->e_ehsize = sizeof(struct elfhdr);
1297 elf->e_phentsize = sizeof(struct elf_phdr);
1298 elf->e_phnum = segs;
1299 elf->e_shentsize = 0;
1300 elf->e_shnum = 0;
1301 elf->e_shstrndx = 0;
1302 return;
1303 }
1304
1305 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1306 {
1307 phdr->p_type = PT_NOTE;
1308 phdr->p_offset = offset;
1309 phdr->p_vaddr = 0;
1310 phdr->p_paddr = 0;
1311 phdr->p_filesz = sz;
1312 phdr->p_memsz = 0;
1313 phdr->p_flags = 0;
1314 phdr->p_align = 0;
1315 return;
1316 }
1317
1318 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1319 unsigned int sz, void *data)
1320 {
1321 note->name = name;
1322 note->type = type;
1323 note->datasz = sz;
1324 note->data = data;
1325 return;
1326 }
1327
1328 /*
1329 * fill up all the fields in prstatus from the given task struct, except
1330 * registers which need to be filled up separately.
1331 */
1332 static void fill_prstatus(struct elf_prstatus *prstatus,
1333 struct task_struct *p, long signr)
1334 {
1335 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1336 prstatus->pr_sigpend = p->pending.signal.sig[0];
1337 prstatus->pr_sighold = p->blocked.sig[0];
1338 rcu_read_lock();
1339 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1340 rcu_read_unlock();
1341 prstatus->pr_pid = task_pid_vnr(p);
1342 prstatus->pr_pgrp = task_pgrp_vnr(p);
1343 prstatus->pr_sid = task_session_vnr(p);
1344 if (thread_group_leader(p)) {
1345 struct task_cputime cputime;
1346
1347 /*
1348 * This is the record for the group leader. It shows the
1349 * group-wide total, not its individual thread total.
1350 */
1351 thread_group_cputime(p, &cputime);
1352 prstatus->pr_utime = ns_to_timeval(cputime.utime);
1353 prstatus->pr_stime = ns_to_timeval(cputime.stime);
1354 } else {
1355 u64 utime, stime;
1356
1357 task_cputime(p, &utime, &stime);
1358 prstatus->pr_utime = ns_to_timeval(utime);
1359 prstatus->pr_stime = ns_to_timeval(stime);
1360 }
1361 prstatus->pr_cutime = ns_to_timeval(p->signal->cutime);
1362 prstatus->pr_cstime = ns_to_timeval(p->signal->cstime);
1363
1364 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1365 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1366 }
1367
1368 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1369 struct mm_struct *mm)
1370 {
1371 const struct cred *cred;
1372 unsigned int i, len;
1373
1374 /* first copy the parameters from user space */
1375 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1376
1377 len = mm->arg_end - mm->arg_start;
1378 if (len >= ELF_PRARGSZ)
1379 len = ELF_PRARGSZ - 1;
1380 if (copy_from_user(&psinfo->pr_psargs,
1381 (const char __user *) mm->arg_start, len))
1382 return -EFAULT;
1383 for (i = 0; i < len; i++)
1384 if (psinfo->pr_psargs[i] == 0)
1385 psinfo->pr_psargs[i] = ' ';
1386 psinfo->pr_psargs[len] = 0;
1387
1388 rcu_read_lock();
1389 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1390 rcu_read_unlock();
1391 psinfo->pr_pid = task_pid_vnr(p);
1392 psinfo->pr_pgrp = task_pgrp_vnr(p);
1393 psinfo->pr_sid = task_session_vnr(p);
1394
1395 i = p->state ? ffz(~p->state) + 1 : 0;
1396 psinfo->pr_state = i;
1397 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1398 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1399 psinfo->pr_nice = task_nice(p);
1400 psinfo->pr_flag = p->flags;
1401 rcu_read_lock();
1402 cred = __task_cred(p);
1403 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1404 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1405 rcu_read_unlock();
1406 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1407
1408 return 0;
1409 }
1410
1411 /* Here is the structure in which status of each thread is captured. */
1412 struct elf_thread_status
1413 {
1414 struct list_head list;
1415 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1416 elf_fpregset_t fpu; /* NT_PRFPREG */
1417 struct task_struct *thread;
1418 #ifdef ELF_CORE_COPY_XFPREGS
1419 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1420 #endif
1421 struct memelfnote notes[3];
1422 int num_notes;
1423 };
1424
1425 /*
1426 * In order to add the specific thread information for the elf file format,
1427 * we need to keep a linked list of every thread's pr_status and then create
1428 * a single section for them in the final core file.
1429 */
1430 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1431 {
1432 struct task_struct *p = t->thread;
1433 int sz = 0;
1434
1435 t->num_notes = 0;
1436
1437 fill_prstatus(&t->prstatus, p, signr);
1438 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1439
1440 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1441 &t->prstatus);
1442 t->num_notes++;
1443 sz += notesize(&t->notes[0]);
1444
1445 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1446 if (t->prstatus.pr_fpvalid) {
1447 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1448 &t->fpu);
1449 t->num_notes++;
1450 sz += notesize(&t->notes[1]);
1451 }
1452
1453 #ifdef ELF_CORE_COPY_XFPREGS
1454 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1455 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1456 sizeof(t->xfpu), &t->xfpu);
1457 t->num_notes++;
1458 sz += notesize(&t->notes[2]);
1459 }
1460 #endif
1461 return sz;
1462 }
1463
1464 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1465 elf_addr_t e_shoff, int segs)
1466 {
1467 elf->e_shoff = e_shoff;
1468 elf->e_shentsize = sizeof(*shdr4extnum);
1469 elf->e_shnum = 1;
1470 elf->e_shstrndx = SHN_UNDEF;
1471
1472 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1473
1474 shdr4extnum->sh_type = SHT_NULL;
1475 shdr4extnum->sh_size = elf->e_shnum;
1476 shdr4extnum->sh_link = elf->e_shstrndx;
1477 shdr4extnum->sh_info = segs;
1478 }
1479
1480 /*
1481 * dump the segments for an MMU process
1482 */
1483 static bool elf_fdpic_dump_segments(struct coredump_params *cprm)
1484 {
1485 struct vm_area_struct *vma;
1486
1487 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1488 unsigned long addr;
1489
1490 if (!maydump(vma, cprm->mm_flags))
1491 continue;
1492
1493 #ifdef CONFIG_MMU
1494 for (addr = vma->vm_start; addr < vma->vm_end;
1495 addr += PAGE_SIZE) {
1496 bool res;
1497 struct page *page = get_dump_page(addr);
1498 if (page) {
1499 void *kaddr = kmap(page);
1500 res = dump_emit(cprm, kaddr, PAGE_SIZE);
1501 kunmap(page);
1502 put_page(page);
1503 } else {
1504 res = dump_skip(cprm, PAGE_SIZE);
1505 }
1506 if (!res)
1507 return false;
1508 }
1509 #else
1510 if (!dump_emit(cprm, (void *) vma->vm_start,
1511 vma->vm_end - vma->vm_start))
1512 return false;
1513 #endif
1514 }
1515 return true;
1516 }
1517
1518 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1519 {
1520 struct vm_area_struct *vma;
1521 size_t size = 0;
1522
1523 for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1524 if (maydump(vma, mm_flags))
1525 size += vma->vm_end - vma->vm_start;
1526 return size;
1527 }
1528
1529 /*
1530 * Actual dumper
1531 *
1532 * This is a two-pass process; first we find the offsets of the bits,
1533 * and then they are actually written out. If we run out of core limit
1534 * we just truncate.
1535 */
1536 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1537 {
1538 #define NUM_NOTES 6
1539 int has_dumped = 0;
1540 mm_segment_t fs;
1541 int segs;
1542 int i;
1543 struct vm_area_struct *vma;
1544 struct elfhdr *elf = NULL;
1545 loff_t offset = 0, dataoff;
1546 int numnote;
1547 struct memelfnote *notes = NULL;
1548 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1549 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1550 LIST_HEAD(thread_list);
1551 struct list_head *t;
1552 elf_fpregset_t *fpu = NULL;
1553 #ifdef ELF_CORE_COPY_XFPREGS
1554 elf_fpxregset_t *xfpu = NULL;
1555 #endif
1556 int thread_status_size = 0;
1557 elf_addr_t *auxv;
1558 struct elf_phdr *phdr4note = NULL;
1559 struct elf_shdr *shdr4extnum = NULL;
1560 Elf_Half e_phnum;
1561 elf_addr_t e_shoff;
1562 struct core_thread *ct;
1563 struct elf_thread_status *tmp;
1564
1565 /*
1566 * We no longer stop all VM operations.
1567 *
1568 * This is because those proceses that could possibly change map_count
1569 * or the mmap / vma pages are now blocked in do_exit on current
1570 * finishing this core dump.
1571 *
1572 * Only ptrace can touch these memory addresses, but it doesn't change
1573 * the map_count or the pages allocated. So no possibility of crashing
1574 * exists while dumping the mm->vm_next areas to the core file.
1575 */
1576
1577 /* alloc memory for large data structures: too large to be on stack */
1578 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1579 if (!elf)
1580 goto cleanup;
1581 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1582 if (!prstatus)
1583 goto cleanup;
1584 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1585 if (!psinfo)
1586 goto cleanup;
1587 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1588 if (!notes)
1589 goto cleanup;
1590 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1591 if (!fpu)
1592 goto cleanup;
1593 #ifdef ELF_CORE_COPY_XFPREGS
1594 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1595 if (!xfpu)
1596 goto cleanup;
1597 #endif
1598
1599 for (ct = current->mm->core_state->dumper.next;
1600 ct; ct = ct->next) {
1601 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1602 if (!tmp)
1603 goto cleanup;
1604
1605 tmp->thread = ct->task;
1606 list_add(&tmp->list, &thread_list);
1607 }
1608
1609 list_for_each(t, &thread_list) {
1610 struct elf_thread_status *tmp;
1611 int sz;
1612
1613 tmp = list_entry(t, struct elf_thread_status, list);
1614 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1615 thread_status_size += sz;
1616 }
1617
1618 /* now collect the dump for the current */
1619 fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1620 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1621
1622 segs = current->mm->map_count;
1623 segs += elf_core_extra_phdrs();
1624
1625 /* for notes section */
1626 segs++;
1627
1628 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1629 * this, kernel supports extended numbering. Have a look at
1630 * include/linux/elf.h for further information. */
1631 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1632
1633 /* Set up header */
1634 fill_elf_fdpic_header(elf, e_phnum);
1635
1636 has_dumped = 1;
1637 /*
1638 * Set up the notes in similar form to SVR4 core dumps made
1639 * with info from their /proc.
1640 */
1641
1642 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1643 fill_psinfo(psinfo, current->group_leader, current->mm);
1644 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1645
1646 numnote = 2;
1647
1648 auxv = (elf_addr_t *) current->mm->saved_auxv;
1649
1650 i = 0;
1651 do
1652 i += 2;
1653 while (auxv[i - 2] != AT_NULL);
1654 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1655 i * sizeof(elf_addr_t), auxv);
1656
1657 /* Try to dump the FPU. */
1658 if ((prstatus->pr_fpvalid =
1659 elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1660 fill_note(notes + numnote++,
1661 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1662 #ifdef ELF_CORE_COPY_XFPREGS
1663 if (elf_core_copy_task_xfpregs(current, xfpu))
1664 fill_note(notes + numnote++,
1665 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1666 #endif
1667
1668 fs = get_fs();
1669 set_fs(KERNEL_DS);
1670
1671 offset += sizeof(*elf); /* Elf header */
1672 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1673
1674 /* Write notes phdr entry */
1675 {
1676 int sz = 0;
1677
1678 for (i = 0; i < numnote; i++)
1679 sz += notesize(notes + i);
1680
1681 sz += thread_status_size;
1682
1683 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1684 if (!phdr4note)
1685 goto end_coredump;
1686
1687 fill_elf_note_phdr(phdr4note, sz, offset);
1688 offset += sz;
1689 }
1690
1691 /* Page-align dumped data */
1692 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1693
1694 offset += elf_core_vma_data_size(cprm->mm_flags);
1695 offset += elf_core_extra_data_size();
1696 e_shoff = offset;
1697
1698 if (e_phnum == PN_XNUM) {
1699 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1700 if (!shdr4extnum)
1701 goto end_coredump;
1702 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1703 }
1704
1705 offset = dataoff;
1706
1707 if (!dump_emit(cprm, elf, sizeof(*elf)))
1708 goto end_coredump;
1709
1710 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1711 goto end_coredump;
1712
1713 /* write program headers for segments dump */
1714 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1715 struct elf_phdr phdr;
1716 size_t sz;
1717
1718 sz = vma->vm_end - vma->vm_start;
1719
1720 phdr.p_type = PT_LOAD;
1721 phdr.p_offset = offset;
1722 phdr.p_vaddr = vma->vm_start;
1723 phdr.p_paddr = 0;
1724 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1725 phdr.p_memsz = sz;
1726 offset += phdr.p_filesz;
1727 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1728 if (vma->vm_flags & VM_WRITE)
1729 phdr.p_flags |= PF_W;
1730 if (vma->vm_flags & VM_EXEC)
1731 phdr.p_flags |= PF_X;
1732 phdr.p_align = ELF_EXEC_PAGESIZE;
1733
1734 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1735 goto end_coredump;
1736 }
1737
1738 if (!elf_core_write_extra_phdrs(cprm, offset))
1739 goto end_coredump;
1740
1741 /* write out the notes section */
1742 for (i = 0; i < numnote; i++)
1743 if (!writenote(notes + i, cprm))
1744 goto end_coredump;
1745
1746 /* write out the thread status notes section */
1747 list_for_each(t, &thread_list) {
1748 struct elf_thread_status *tmp =
1749 list_entry(t, struct elf_thread_status, list);
1750
1751 for (i = 0; i < tmp->num_notes; i++)
1752 if (!writenote(&tmp->notes[i], cprm))
1753 goto end_coredump;
1754 }
1755
1756 if (!dump_skip(cprm, dataoff - cprm->pos))
1757 goto end_coredump;
1758
1759 if (!elf_fdpic_dump_segments(cprm))
1760 goto end_coredump;
1761
1762 if (!elf_core_write_extra_data(cprm))
1763 goto end_coredump;
1764
1765 if (e_phnum == PN_XNUM) {
1766 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1767 goto end_coredump;
1768 }
1769
1770 if (cprm->file->f_pos != offset) {
1771 /* Sanity check */
1772 printk(KERN_WARNING
1773 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1774 cprm->file->f_pos, offset);
1775 }
1776
1777 end_coredump:
1778 set_fs(fs);
1779
1780 cleanup:
1781 while (!list_empty(&thread_list)) {
1782 struct list_head *tmp = thread_list.next;
1783 list_del(tmp);
1784 kfree(list_entry(tmp, struct elf_thread_status, list));
1785 }
1786 kfree(phdr4note);
1787 kfree(elf);
1788 kfree(prstatus);
1789 kfree(psinfo);
1790 kfree(notes);
1791 kfree(fpu);
1792 kfree(shdr4extnum);
1793 #ifdef ELF_CORE_COPY_XFPREGS
1794 kfree(xfpu);
1795 #endif
1796 return has_dumped;
1797 #undef NUM_NOTES
1798 }
1799
1800 #endif /* CONFIG_ELF_CORE */
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