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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/sched/coredump.h>
19 #include <linux/sched/task_stack.h>
20 #include <linux/sched/cputime.h>
21 #include <linux/mm.h>
22 #include <linux/mman.h>
23 #include <linux/errno.h>
24 #include <linux/signal.h>
25 #include <linux/binfmts.h>
26 #include <linux/string.h>
27 #include <linux/file.h>
28 #include <linux/fcntl.h>
29 #include <linux/slab.h>
30 #include <linux/pagemap.h>
31 #include <linux/security.h>
32 #include <linux/highmem.h>
33 #include <linux/highuid.h>
34 #include <linux/personality.h>
35 #include <linux/ptrace.h>
36 #include <linux/init.h>
37 #include <linux/elf.h>
38 #include <linux/elf-fdpic.h>
39 #include <linux/elfcore.h>
40 #include <linux/coredump.h>
41 #include <linux/dax.h>
42
43 #include <linux/uaccess.h>
44 #include <asm/param.h>
45 #include <asm/pgalloc.h>
46
47 typedef char *elf_caddr_t;
48
49 #if 0
50 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
51 #else
52 #define kdebug(fmt, ...) do {} while(0)
53 #endif
54
55 #if 0
56 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
57 #else
58 #define kdcore(fmt, ...) do {} while(0)
59 #endif
60
61 MODULE_LICENSE("GPL");
62
63 static int load_elf_fdpic_binary(struct linux_binprm *);
64 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
65 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
66 struct mm_struct *, const char *);
67
68 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
69 struct elf_fdpic_params *,
70 struct elf_fdpic_params *);
71
72 #ifndef CONFIG_MMU
73 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
74 struct file *,
75 struct mm_struct *);
76 #endif
77
78 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
79 struct file *, struct mm_struct *);
80
81 #ifdef CONFIG_ELF_CORE
82 static int elf_fdpic_core_dump(struct coredump_params *cprm);
83 #endif
84
85 static struct linux_binfmt elf_fdpic_format = {
86 .module = THIS_MODULE,
87 .load_binary = load_elf_fdpic_binary,
88 #ifdef CONFIG_ELF_CORE
89 .core_dump = elf_fdpic_core_dump,
90 #endif
91 .min_coredump = ELF_EXEC_PAGESIZE,
92 };
93
94 static int __init init_elf_fdpic_binfmt(void)
95 {
96 register_binfmt(&elf_fdpic_format);
97 return 0;
98 }
99
100 static void __exit exit_elf_fdpic_binfmt(void)
101 {
102 unregister_binfmt(&elf_fdpic_format);
103 }
104
105 core_initcall(init_elf_fdpic_binfmt);
106 module_exit(exit_elf_fdpic_binfmt);
107
108 static int is_elf(struct elfhdr *hdr, struct file *file)
109 {
110 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
111 return 0;
112 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
113 return 0;
114 if (!elf_check_arch(hdr))
115 return 0;
116 if (!file->f_op->mmap)
117 return 0;
118 return 1;
119 }
120
121 #ifndef elf_check_fdpic
122 #define elf_check_fdpic(x) 0
123 #endif
124
125 #ifndef elf_check_const_displacement
126 #define elf_check_const_displacement(x) 0
127 #endif
128
129 static int is_constdisp(struct elfhdr *hdr)
130 {
131 if (!elf_check_fdpic(hdr))
132 return 1;
133 if (elf_check_const_displacement(hdr))
134 return 1;
135 return 0;
136 }
137
138 /*****************************************************************************/
139 /*
140 * read the program headers table into memory
141 */
142 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
143 struct file *file)
144 {
145 struct elf32_phdr *phdr;
146 unsigned long size;
147 int retval, loop;
148 loff_t pos = params->hdr.e_phoff;
149
150 if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
151 return -ENOMEM;
152 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
153 return -ENOMEM;
154
155 size = params->hdr.e_phnum * sizeof(struct elf_phdr);
156 params->phdrs = kmalloc(size, GFP_KERNEL);
157 if (!params->phdrs)
158 return -ENOMEM;
159
160 retval = kernel_read(file, params->phdrs, size, &pos);
161 if (unlikely(retval != size))
162 return retval < 0 ? retval : -ENOEXEC;
163
164 /* determine stack size for this binary */
165 phdr = params->phdrs;
166 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
167 if (phdr->p_type != PT_GNU_STACK)
168 continue;
169
170 if (phdr->p_flags & PF_X)
171 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
172 else
173 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
174
175 params->stack_size = phdr->p_memsz;
176 break;
177 }
178
179 return 0;
180 }
181
182 /*****************************************************************************/
183 /*
184 * load an fdpic binary into various bits of memory
185 */
186 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
187 {
188 struct elf_fdpic_params exec_params, interp_params;
189 struct pt_regs *regs = current_pt_regs();
190 struct elf_phdr *phdr;
191 unsigned long stack_size, entryaddr;
192 #ifdef ELF_FDPIC_PLAT_INIT
193 unsigned long dynaddr;
194 #endif
195 #ifndef CONFIG_MMU
196 unsigned long stack_prot;
197 #endif
198 struct file *interpreter = NULL; /* to shut gcc up */
199 char *interpreter_name = NULL;
200 int executable_stack;
201 int retval, i;
202 loff_t pos;
203
204 kdebug("____ LOAD %d ____", current->pid);
205
206 memset(&exec_params, 0, sizeof(exec_params));
207 memset(&interp_params, 0, sizeof(interp_params));
208
209 exec_params.hdr = *(struct elfhdr *) bprm->buf;
210 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
211
212 /* check that this is a binary we know how to deal with */
213 retval = -ENOEXEC;
214 if (!is_elf(&exec_params.hdr, bprm->file))
215 goto error;
216 if (!elf_check_fdpic(&exec_params.hdr)) {
217 #ifdef CONFIG_MMU
218 /* binfmt_elf handles non-fdpic elf except on nommu */
219 goto error;
220 #else
221 /* nommu can only load ET_DYN (PIE) ELF */
222 if (exec_params.hdr.e_type != ET_DYN)
223 goto error;
224 #endif
225 }
226
227 /* read the program header table */
228 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
229 if (retval < 0)
230 goto error;
231
232 /* scan for a program header that specifies an interpreter */
233 phdr = exec_params.phdrs;
234
235 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
236 switch (phdr->p_type) {
237 case PT_INTERP:
238 retval = -ENOMEM;
239 if (phdr->p_filesz > PATH_MAX)
240 goto error;
241 retval = -ENOENT;
242 if (phdr->p_filesz < 2)
243 goto error;
244
245 /* read the name of the interpreter into memory */
246 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
247 if (!interpreter_name)
248 goto error;
249
250 pos = phdr->p_offset;
251 retval = kernel_read(bprm->file, interpreter_name,
252 phdr->p_filesz, &pos);
253 if (unlikely(retval != phdr->p_filesz)) {
254 if (retval >= 0)
255 retval = -ENOEXEC;
256 goto error;
257 }
258
259 retval = -ENOENT;
260 if (interpreter_name[phdr->p_filesz - 1] != '\0')
261 goto error;
262
263 kdebug("Using ELF interpreter %s", interpreter_name);
264
265 /* replace the program with the interpreter */
266 interpreter = open_exec(interpreter_name);
267 retval = PTR_ERR(interpreter);
268 if (IS_ERR(interpreter)) {
269 interpreter = NULL;
270 goto error;
271 }
272
273 /*
274 * If the binary is not readable then enforce
275 * mm->dumpable = 0 regardless of the interpreter's
276 * permissions.
277 */
278 would_dump(bprm, interpreter);
279
280 pos = 0;
281 retval = kernel_read(interpreter, bprm->buf,
282 BINPRM_BUF_SIZE, &pos);
283 if (unlikely(retval != BINPRM_BUF_SIZE)) {
284 if (retval >= 0)
285 retval = -ENOEXEC;
286 goto error;
287 }
288
289 interp_params.hdr = *((struct elfhdr *) bprm->buf);
290 break;
291
292 case PT_LOAD:
293 #ifdef CONFIG_MMU
294 if (exec_params.load_addr == 0)
295 exec_params.load_addr = phdr->p_vaddr;
296 #endif
297 break;
298 }
299
300 }
301
302 if (is_constdisp(&exec_params.hdr))
303 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
304
305 /* perform insanity checks on the interpreter */
306 if (interpreter_name) {
307 retval = -ELIBBAD;
308 if (!is_elf(&interp_params.hdr, interpreter))
309 goto error;
310
311 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
312
313 /* read the interpreter's program header table */
314 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
315 if (retval < 0)
316 goto error;
317 }
318
319 stack_size = exec_params.stack_size;
320 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
321 executable_stack = EXSTACK_ENABLE_X;
322 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
323 executable_stack = EXSTACK_DISABLE_X;
324 else
325 executable_stack = EXSTACK_DEFAULT;
326
327 if (stack_size == 0) {
328 stack_size = interp_params.stack_size;
329 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
330 executable_stack = EXSTACK_ENABLE_X;
331 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
332 executable_stack = EXSTACK_DISABLE_X;
333 else
334 executable_stack = EXSTACK_DEFAULT;
335 }
336
337 retval = -ENOEXEC;
338 if (stack_size == 0)
339 stack_size = 131072UL; /* same as exec.c's default commit */
340
341 if (is_constdisp(&interp_params.hdr))
342 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
343
344 /* flush all traces of the currently running executable */
345 retval = flush_old_exec(bprm);
346 if (retval)
347 goto error;
348
349 /* there's now no turning back... the old userspace image is dead,
350 * defunct, deceased, etc.
351 */
352 if (elf_check_fdpic(&exec_params.hdr))
353 set_personality(PER_LINUX_FDPIC);
354 else
355 set_personality(PER_LINUX);
356 if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
357 current->personality |= READ_IMPLIES_EXEC;
358
359 setup_new_exec(bprm);
360
361 set_binfmt(&elf_fdpic_format);
362
363 current->mm->start_code = 0;
364 current->mm->end_code = 0;
365 current->mm->start_stack = 0;
366 current->mm->start_data = 0;
367 current->mm->end_data = 0;
368 current->mm->context.exec_fdpic_loadmap = 0;
369 current->mm->context.interp_fdpic_loadmap = 0;
370
371 #ifdef CONFIG_MMU
372 elf_fdpic_arch_lay_out_mm(&exec_params,
373 &interp_params,
374 &current->mm->start_stack,
375 &current->mm->start_brk);
376
377 retval = setup_arg_pages(bprm, current->mm->start_stack,
378 executable_stack);
379 if (retval < 0)
380 goto error;
381 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
382 retval = arch_setup_additional_pages(bprm, !!interpreter_name);
383 if (retval < 0)
384 goto error;
385 #endif
386 #endif
387
388 /* load the executable and interpreter into memory */
389 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
390 "executable");
391 if (retval < 0)
392 goto error;
393
394 if (interpreter_name) {
395 retval = elf_fdpic_map_file(&interp_params, interpreter,
396 current->mm, "interpreter");
397 if (retval < 0) {
398 printk(KERN_ERR "Unable to load interpreter\n");
399 goto error;
400 }
401
402 allow_write_access(interpreter);
403 fput(interpreter);
404 interpreter = NULL;
405 }
406
407 #ifdef CONFIG_MMU
408 if (!current->mm->start_brk)
409 current->mm->start_brk = current->mm->end_data;
410
411 current->mm->brk = current->mm->start_brk =
412 PAGE_ALIGN(current->mm->start_brk);
413
414 #else
415 /* create a stack area and zero-size brk area */
416 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
417 if (stack_size < PAGE_SIZE * 2)
418 stack_size = PAGE_SIZE * 2;
419
420 stack_prot = PROT_READ | PROT_WRITE;
421 if (executable_stack == EXSTACK_ENABLE_X ||
422 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
423 stack_prot |= PROT_EXEC;
424
425 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
426 MAP_PRIVATE | MAP_ANONYMOUS |
427 MAP_UNINITIALIZED | MAP_GROWSDOWN,
428 0);
429
430 if (IS_ERR_VALUE(current->mm->start_brk)) {
431 retval = current->mm->start_brk;
432 current->mm->start_brk = 0;
433 goto error;
434 }
435
436 current->mm->brk = current->mm->start_brk;
437 current->mm->context.end_brk = current->mm->start_brk;
438 current->mm->start_stack = current->mm->start_brk + stack_size;
439 #endif
440
441 install_exec_creds(bprm);
442 if (create_elf_fdpic_tables(bprm, current->mm,
443 &exec_params, &interp_params) < 0)
444 goto error;
445
446 kdebug("- start_code %lx", current->mm->start_code);
447 kdebug("- end_code %lx", current->mm->end_code);
448 kdebug("- start_data %lx", current->mm->start_data);
449 kdebug("- end_data %lx", current->mm->end_data);
450 kdebug("- start_brk %lx", current->mm->start_brk);
451 kdebug("- brk %lx", current->mm->brk);
452 kdebug("- start_stack %lx", current->mm->start_stack);
453
454 #ifdef ELF_FDPIC_PLAT_INIT
455 /*
456 * The ABI may specify that certain registers be set up in special
457 * ways (on i386 %edx is the address of a DT_FINI function, for
458 * example. This macro performs whatever initialization to
459 * the regs structure is required.
460 */
461 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
462 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
463 dynaddr);
464 #endif
465
466 /* everything is now ready... get the userspace context ready to roll */
467 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
468 start_thread(regs, entryaddr, current->mm->start_stack);
469
470 retval = 0;
471
472 error:
473 if (interpreter) {
474 allow_write_access(interpreter);
475 fput(interpreter);
476 }
477 kfree(interpreter_name);
478 kfree(exec_params.phdrs);
479 kfree(exec_params.loadmap);
480 kfree(interp_params.phdrs);
481 kfree(interp_params.loadmap);
482 return retval;
483 }
484
485 /*****************************************************************************/
486
487 #ifndef ELF_BASE_PLATFORM
488 /*
489 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
490 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
491 * will be copied to the user stack in the same manner as AT_PLATFORM.
492 */
493 #define ELF_BASE_PLATFORM NULL
494 #endif
495
496 /*
497 * present useful information to the program by shovelling it onto the new
498 * process's stack
499 */
500 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
501 struct mm_struct *mm,
502 struct elf_fdpic_params *exec_params,
503 struct elf_fdpic_params *interp_params)
504 {
505 const struct cred *cred = current_cred();
506 unsigned long sp, csp, nitems;
507 elf_caddr_t __user *argv, *envp;
508 size_t platform_len = 0, len;
509 char *k_platform, *k_base_platform;
510 char __user *u_platform, *u_base_platform, *p;
511 int loop;
512 int nr; /* reset for each csp adjustment */
513
514 #ifdef CONFIG_MMU
515 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
516 * by the processes running on the same package. One thing we can do is
517 * to shuffle the initial stack for them, so we give the architecture
518 * an opportunity to do so here.
519 */
520 sp = arch_align_stack(bprm->p);
521 #else
522 sp = mm->start_stack;
523
524 /* stack the program arguments and environment */
525 if (transfer_args_to_stack(bprm, &sp) < 0)
526 return -EFAULT;
527 sp &= ~15;
528 #endif
529
530 /*
531 * If this architecture has a platform capability string, copy it
532 * to userspace. In some cases (Sparc), this info is impossible
533 * for userspace to get any other way, in others (i386) it is
534 * merely difficult.
535 */
536 k_platform = ELF_PLATFORM;
537 u_platform = NULL;
538
539 if (k_platform) {
540 platform_len = strlen(k_platform) + 1;
541 sp -= platform_len;
542 u_platform = (char __user *) sp;
543 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
544 return -EFAULT;
545 }
546
547 /*
548 * If this architecture has a "base" platform capability
549 * string, copy it to userspace.
550 */
551 k_base_platform = ELF_BASE_PLATFORM;
552 u_base_platform = NULL;
553
554 if (k_base_platform) {
555 platform_len = strlen(k_base_platform) + 1;
556 sp -= platform_len;
557 u_base_platform = (char __user *) sp;
558 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
559 return -EFAULT;
560 }
561
562 sp &= ~7UL;
563
564 /* stack the load map(s) */
565 len = sizeof(struct elf32_fdpic_loadmap);
566 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
567 sp = (sp - len) & ~7UL;
568 exec_params->map_addr = sp;
569
570 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
571 return -EFAULT;
572
573 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
574
575 if (interp_params->loadmap) {
576 len = sizeof(struct elf32_fdpic_loadmap);
577 len += sizeof(struct elf32_fdpic_loadseg) *
578 interp_params->loadmap->nsegs;
579 sp = (sp - len) & ~7UL;
580 interp_params->map_addr = sp;
581
582 if (copy_to_user((void __user *) sp, interp_params->loadmap,
583 len) != 0)
584 return -EFAULT;
585
586 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
587 }
588
589 /* force 16 byte _final_ alignment here for generality */
590 #define DLINFO_ITEMS 15
591
592 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
593 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
594
595 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
596 nitems++;
597
598 csp = sp;
599 sp -= nitems * 2 * sizeof(unsigned long);
600 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
601 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
602 sp -= 1 * sizeof(unsigned long); /* argc */
603
604 csp -= sp & 15UL;
605 sp -= sp & 15UL;
606
607 /* put the ELF interpreter info on the stack */
608 #define NEW_AUX_ENT(id, val) \
609 do { \
610 struct { unsigned long _id, _val; } __user *ent; \
611 \
612 ent = (void __user *) csp; \
613 __put_user((id), &ent[nr]._id); \
614 __put_user((val), &ent[nr]._val); \
615 nr++; \
616 } while (0)
617
618 nr = 0;
619 csp -= 2 * sizeof(unsigned long);
620 NEW_AUX_ENT(AT_NULL, 0);
621 if (k_platform) {
622 nr = 0;
623 csp -= 2 * sizeof(unsigned long);
624 NEW_AUX_ENT(AT_PLATFORM,
625 (elf_addr_t) (unsigned long) u_platform);
626 }
627
628 if (k_base_platform) {
629 nr = 0;
630 csp -= 2 * sizeof(unsigned long);
631 NEW_AUX_ENT(AT_BASE_PLATFORM,
632 (elf_addr_t) (unsigned long) u_base_platform);
633 }
634
635 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
636 nr = 0;
637 csp -= 2 * sizeof(unsigned long);
638 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
639 }
640
641 nr = 0;
642 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
643 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
644 #ifdef ELF_HWCAP2
645 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
646 #endif
647 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
648 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
649 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
650 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
651 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
652 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
653 NEW_AUX_ENT(AT_FLAGS, 0);
654 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
655 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
656 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
657 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
658 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
659 NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
660 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
661
662 #ifdef ARCH_DLINFO
663 nr = 0;
664 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
665
666 /* ARCH_DLINFO must come last so platform specific code can enforce
667 * special alignment requirements on the AUXV if necessary (eg. PPC).
668 */
669 ARCH_DLINFO;
670 #endif
671 #undef NEW_AUX_ENT
672
673 /* allocate room for argv[] and envv[] */
674 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
675 envp = (elf_caddr_t __user *) csp;
676 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
677 argv = (elf_caddr_t __user *) csp;
678
679 /* stack argc */
680 csp -= sizeof(unsigned long);
681 __put_user(bprm->argc, (unsigned long __user *) csp);
682
683 BUG_ON(csp != sp);
684
685 /* fill in the argv[] array */
686 #ifdef CONFIG_MMU
687 current->mm->arg_start = bprm->p;
688 #else
689 current->mm->arg_start = current->mm->start_stack -
690 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
691 #endif
692
693 p = (char __user *) current->mm->arg_start;
694 for (loop = bprm->argc; loop > 0; loop--) {
695 __put_user((elf_caddr_t) p, argv++);
696 len = strnlen_user(p, MAX_ARG_STRLEN);
697 if (!len || len > MAX_ARG_STRLEN)
698 return -EINVAL;
699 p += len;
700 }
701 __put_user(NULL, argv);
702 current->mm->arg_end = (unsigned long) p;
703
704 /* fill in the envv[] array */
705 current->mm->env_start = (unsigned long) p;
706 for (loop = bprm->envc; loop > 0; loop--) {
707 __put_user((elf_caddr_t)(unsigned long) p, envp++);
708 len = strnlen_user(p, MAX_ARG_STRLEN);
709 if (!len || len > MAX_ARG_STRLEN)
710 return -EINVAL;
711 p += len;
712 }
713 __put_user(NULL, envp);
714 current->mm->env_end = (unsigned long) p;
715
716 mm->start_stack = (unsigned long) sp;
717 return 0;
718 }
719
720 /*****************************************************************************/
721 /*
722 * load the appropriate binary image (executable or interpreter) into memory
723 * - we assume no MMU is available
724 * - if no other PIC bits are set in params->hdr->e_flags
725 * - we assume that the LOADable segments in the binary are independently relocatable
726 * - we assume R/O executable segments are shareable
727 * - else
728 * - we assume the loadable parts of the image to require fixed displacement
729 * - the image is not shareable
730 */
731 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
732 struct file *file,
733 struct mm_struct *mm,
734 const char *what)
735 {
736 struct elf32_fdpic_loadmap *loadmap;
737 #ifdef CONFIG_MMU
738 struct elf32_fdpic_loadseg *mseg;
739 #endif
740 struct elf32_fdpic_loadseg *seg;
741 struct elf32_phdr *phdr;
742 unsigned long load_addr, stop;
743 unsigned nloads, tmp;
744 size_t size;
745 int loop, ret;
746
747 /* allocate a load map table */
748 nloads = 0;
749 for (loop = 0; loop < params->hdr.e_phnum; loop++)
750 if (params->phdrs[loop].p_type == PT_LOAD)
751 nloads++;
752
753 if (nloads == 0)
754 return -ELIBBAD;
755
756 size = sizeof(*loadmap) + nloads * sizeof(*seg);
757 loadmap = kzalloc(size, GFP_KERNEL);
758 if (!loadmap)
759 return -ENOMEM;
760
761 params->loadmap = loadmap;
762
763 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
764 loadmap->nsegs = nloads;
765
766 load_addr = params->load_addr;
767 seg = loadmap->segs;
768
769 /* map the requested LOADs into the memory space */
770 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
771 case ELF_FDPIC_FLAG_CONSTDISP:
772 case ELF_FDPIC_FLAG_CONTIGUOUS:
773 #ifndef CONFIG_MMU
774 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
775 if (ret < 0)
776 return ret;
777 break;
778 #endif
779 default:
780 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
781 if (ret < 0)
782 return ret;
783 break;
784 }
785
786 /* map the entry point */
787 if (params->hdr.e_entry) {
788 seg = loadmap->segs;
789 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
790 if (params->hdr.e_entry >= seg->p_vaddr &&
791 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
792 params->entry_addr =
793 (params->hdr.e_entry - seg->p_vaddr) +
794 seg->addr;
795 break;
796 }
797 }
798 }
799
800 /* determine where the program header table has wound up if mapped */
801 stop = params->hdr.e_phoff;
802 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
803 phdr = params->phdrs;
804
805 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
806 if (phdr->p_type != PT_LOAD)
807 continue;
808
809 if (phdr->p_offset > params->hdr.e_phoff ||
810 phdr->p_offset + phdr->p_filesz < stop)
811 continue;
812
813 seg = loadmap->segs;
814 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
815 if (phdr->p_vaddr >= seg->p_vaddr &&
816 phdr->p_vaddr + phdr->p_filesz <=
817 seg->p_vaddr + seg->p_memsz) {
818 params->ph_addr =
819 (phdr->p_vaddr - seg->p_vaddr) +
820 seg->addr +
821 params->hdr.e_phoff - phdr->p_offset;
822 break;
823 }
824 }
825 break;
826 }
827
828 /* determine where the dynamic section has wound up if there is one */
829 phdr = params->phdrs;
830 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
831 if (phdr->p_type != PT_DYNAMIC)
832 continue;
833
834 seg = loadmap->segs;
835 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
836 if (phdr->p_vaddr >= seg->p_vaddr &&
837 phdr->p_vaddr + phdr->p_memsz <=
838 seg->p_vaddr + seg->p_memsz) {
839 Elf32_Dyn __user *dyn;
840 Elf32_Sword d_tag;
841
842 params->dynamic_addr =
843 (phdr->p_vaddr - seg->p_vaddr) +
844 seg->addr;
845
846 /* check the dynamic section contains at least
847 * one item, and that the last item is a NULL
848 * entry */
849 if (phdr->p_memsz == 0 ||
850 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
851 goto dynamic_error;
852
853 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
854 dyn = (Elf32_Dyn __user *)params->dynamic_addr;
855 __get_user(d_tag, &dyn[tmp - 1].d_tag);
856 if (d_tag != 0)
857 goto dynamic_error;
858 break;
859 }
860 }
861 break;
862 }
863
864 /* now elide adjacent segments in the load map on MMU linux
865 * - on uClinux the holes between may actually be filled with system
866 * stuff or stuff from other processes
867 */
868 #ifdef CONFIG_MMU
869 nloads = loadmap->nsegs;
870 mseg = loadmap->segs;
871 seg = mseg + 1;
872 for (loop = 1; loop < nloads; loop++) {
873 /* see if we have a candidate for merging */
874 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
875 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
876 if (load_addr == (seg->addr & PAGE_MASK)) {
877 mseg->p_memsz +=
878 load_addr -
879 (mseg->addr + mseg->p_memsz);
880 mseg->p_memsz += seg->addr & ~PAGE_MASK;
881 mseg->p_memsz += seg->p_memsz;
882 loadmap->nsegs--;
883 continue;
884 }
885 }
886
887 mseg++;
888 if (mseg != seg)
889 *mseg = *seg;
890 }
891 #endif
892
893 kdebug("Mapped Object [%s]:", what);
894 kdebug("- elfhdr : %lx", params->elfhdr_addr);
895 kdebug("- entry : %lx", params->entry_addr);
896 kdebug("- PHDR[] : %lx", params->ph_addr);
897 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
898 seg = loadmap->segs;
899 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
900 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
901 loop,
902 seg->addr, seg->addr + seg->p_memsz - 1,
903 seg->p_vaddr, seg->p_memsz);
904
905 return 0;
906
907 dynamic_error:
908 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
909 what, file_inode(file)->i_ino);
910 return -ELIBBAD;
911 }
912
913 /*****************************************************************************/
914 /*
915 * map a file with constant displacement under uClinux
916 */
917 #ifndef CONFIG_MMU
918 static int elf_fdpic_map_file_constdisp_on_uclinux(
919 struct elf_fdpic_params *params,
920 struct file *file,
921 struct mm_struct *mm)
922 {
923 struct elf32_fdpic_loadseg *seg;
924 struct elf32_phdr *phdr;
925 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
926 int loop, ret;
927
928 load_addr = params->load_addr;
929 seg = params->loadmap->segs;
930
931 /* determine the bounds of the contiguous overall allocation we must
932 * make */
933 phdr = params->phdrs;
934 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
935 if (params->phdrs[loop].p_type != PT_LOAD)
936 continue;
937
938 if (base > phdr->p_vaddr)
939 base = phdr->p_vaddr;
940 if (top < phdr->p_vaddr + phdr->p_memsz)
941 top = phdr->p_vaddr + phdr->p_memsz;
942 }
943
944 /* allocate one big anon block for everything */
945 mflags = MAP_PRIVATE;
946 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
947 mflags |= MAP_EXECUTABLE;
948
949 maddr = vm_mmap(NULL, load_addr, top - base,
950 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
951 if (IS_ERR_VALUE(maddr))
952 return (int) maddr;
953
954 if (load_addr != 0)
955 load_addr += PAGE_ALIGN(top - base);
956
957 /* and then load the file segments into it */
958 phdr = params->phdrs;
959 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
960 if (params->phdrs[loop].p_type != PT_LOAD)
961 continue;
962
963 seg->addr = maddr + (phdr->p_vaddr - base);
964 seg->p_vaddr = phdr->p_vaddr;
965 seg->p_memsz = phdr->p_memsz;
966
967 ret = read_code(file, seg->addr, phdr->p_offset,
968 phdr->p_filesz);
969 if (ret < 0)
970 return ret;
971
972 /* map the ELF header address if in this segment */
973 if (phdr->p_offset == 0)
974 params->elfhdr_addr = seg->addr;
975
976 /* clear any space allocated but not loaded */
977 if (phdr->p_filesz < phdr->p_memsz) {
978 if (clear_user((void *) (seg->addr + phdr->p_filesz),
979 phdr->p_memsz - phdr->p_filesz))
980 return -EFAULT;
981 }
982
983 if (mm) {
984 if (phdr->p_flags & PF_X) {
985 if (!mm->start_code) {
986 mm->start_code = seg->addr;
987 mm->end_code = seg->addr +
988 phdr->p_memsz;
989 }
990 } else if (!mm->start_data) {
991 mm->start_data = seg->addr;
992 mm->end_data = seg->addr + phdr->p_memsz;
993 }
994 }
995
996 seg++;
997 }
998
999 return 0;
1000 }
1001 #endif
1002
1003 /*****************************************************************************/
1004 /*
1005 * map a binary by direct mmap() of the individual PT_LOAD segments
1006 */
1007 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1008 struct file *file,
1009 struct mm_struct *mm)
1010 {
1011 struct elf32_fdpic_loadseg *seg;
1012 struct elf32_phdr *phdr;
1013 unsigned long load_addr, delta_vaddr;
1014 int loop, dvset;
1015
1016 load_addr = params->load_addr;
1017 delta_vaddr = 0;
1018 dvset = 0;
1019
1020 seg = params->loadmap->segs;
1021
1022 /* deal with each load segment separately */
1023 phdr = params->phdrs;
1024 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1025 unsigned long maddr, disp, excess, excess1;
1026 int prot = 0, flags;
1027
1028 if (phdr->p_type != PT_LOAD)
1029 continue;
1030
1031 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1032 (unsigned long) phdr->p_vaddr,
1033 (unsigned long) phdr->p_offset,
1034 (unsigned long) phdr->p_filesz,
1035 (unsigned long) phdr->p_memsz);
1036
1037 /* determine the mapping parameters */
1038 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1039 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1040 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1041
1042 flags = MAP_PRIVATE | MAP_DENYWRITE;
1043 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1044 flags |= MAP_EXECUTABLE;
1045
1046 maddr = 0;
1047
1048 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1049 case ELF_FDPIC_FLAG_INDEPENDENT:
1050 /* PT_LOADs are independently locatable */
1051 break;
1052
1053 case ELF_FDPIC_FLAG_HONOURVADDR:
1054 /* the specified virtual address must be honoured */
1055 maddr = phdr->p_vaddr;
1056 flags |= MAP_FIXED;
1057 break;
1058
1059 case ELF_FDPIC_FLAG_CONSTDISP:
1060 /* constant displacement
1061 * - can be mapped anywhere, but must be mapped as a
1062 * unit
1063 */
1064 if (!dvset) {
1065 maddr = load_addr;
1066 delta_vaddr = phdr->p_vaddr;
1067 dvset = 1;
1068 } else {
1069 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1070 flags |= MAP_FIXED;
1071 }
1072 break;
1073
1074 case ELF_FDPIC_FLAG_CONTIGUOUS:
1075 /* contiguity handled later */
1076 break;
1077
1078 default:
1079 BUG();
1080 }
1081
1082 maddr &= PAGE_MASK;
1083
1084 /* create the mapping */
1085 disp = phdr->p_vaddr & ~PAGE_MASK;
1086 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1087 phdr->p_offset - disp);
1088
1089 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1090 loop, phdr->p_memsz + disp, prot, flags,
1091 phdr->p_offset - disp, maddr);
1092
1093 if (IS_ERR_VALUE(maddr))
1094 return (int) maddr;
1095
1096 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1097 ELF_FDPIC_FLAG_CONTIGUOUS)
1098 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1099
1100 seg->addr = maddr + disp;
1101 seg->p_vaddr = phdr->p_vaddr;
1102 seg->p_memsz = phdr->p_memsz;
1103
1104 /* map the ELF header address if in this segment */
1105 if (phdr->p_offset == 0)
1106 params->elfhdr_addr = seg->addr;
1107
1108 /* clear the bit between beginning of mapping and beginning of
1109 * PT_LOAD */
1110 if (prot & PROT_WRITE && disp > 0) {
1111 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1112 if (clear_user((void __user *) maddr, disp))
1113 return -EFAULT;
1114 maddr += disp;
1115 }
1116
1117 /* clear any space allocated but not loaded
1118 * - on uClinux we can just clear the lot
1119 * - on MMU linux we'll get a SIGBUS beyond the last page
1120 * extant in the file
1121 */
1122 excess = phdr->p_memsz - phdr->p_filesz;
1123 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1124
1125 #ifdef CONFIG_MMU
1126 if (excess > excess1) {
1127 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1128 unsigned long xmaddr;
1129
1130 flags |= MAP_FIXED | MAP_ANONYMOUS;
1131 xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1132 prot, flags, 0);
1133
1134 kdebug("mmap[%d] <anon>"
1135 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1136 loop, xaddr, excess - excess1, prot, flags,
1137 xmaddr);
1138
1139 if (xmaddr != xaddr)
1140 return -ENOMEM;
1141 }
1142
1143 if (prot & PROT_WRITE && excess1 > 0) {
1144 kdebug("clear[%d] ad=%lx sz=%lx",
1145 loop, maddr + phdr->p_filesz, excess1);
1146 if (clear_user((void __user *) maddr + phdr->p_filesz,
1147 excess1))
1148 return -EFAULT;
1149 }
1150
1151 #else
1152 if (excess > 0) {
1153 kdebug("clear[%d] ad=%lx sz=%lx",
1154 loop, maddr + phdr->p_filesz, excess);
1155 if (clear_user((void *) maddr + phdr->p_filesz, excess))
1156 return -EFAULT;
1157 }
1158 #endif
1159
1160 if (mm) {
1161 if (phdr->p_flags & PF_X) {
1162 if (!mm->start_code) {
1163 mm->start_code = maddr;
1164 mm->end_code = maddr + phdr->p_memsz;
1165 }
1166 } else if (!mm->start_data) {
1167 mm->start_data = maddr;
1168 mm->end_data = maddr + phdr->p_memsz;
1169 }
1170 }
1171
1172 seg++;
1173 }
1174
1175 return 0;
1176 }
1177
1178 /*****************************************************************************/
1179 /*
1180 * ELF-FDPIC core dumper
1181 *
1182 * Modelled on fs/exec.c:aout_core_dump()
1183 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1184 *
1185 * Modelled on fs/binfmt_elf.c core dumper
1186 */
1187 #ifdef CONFIG_ELF_CORE
1188
1189 /*
1190 * Decide whether a segment is worth dumping; default is yes to be
1191 * sure (missing info is worse than too much; etc).
1192 * Personally I'd include everything, and use the coredump limit...
1193 *
1194 * I think we should skip something. But I am not sure how. H.J.
1195 */
1196 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1197 {
1198 int dump_ok;
1199
1200 /* Do not dump I/O mapped devices or special mappings */
1201 if (vma->vm_flags & VM_IO) {
1202 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1203 return 0;
1204 }
1205
1206 /* If we may not read the contents, don't allow us to dump
1207 * them either. "dump_write()" can't handle it anyway.
1208 */
1209 if (!(vma->vm_flags & VM_READ)) {
1210 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1211 return 0;
1212 }
1213
1214 /* support for DAX */
1215 if (vma_is_dax(vma)) {
1216 if (vma->vm_flags & VM_SHARED) {
1217 dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags);
1218 kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start,
1219 vma->vm_flags, dump_ok ? "yes" : "no");
1220 } else {
1221 dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags);
1222 kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start,
1223 vma->vm_flags, dump_ok ? "yes" : "no");
1224 }
1225 return dump_ok;
1226 }
1227
1228 /* By default, dump shared memory if mapped from an anonymous file. */
1229 if (vma->vm_flags & VM_SHARED) {
1230 if (file_inode(vma->vm_file)->i_nlink == 0) {
1231 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1232 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1233 vma->vm_flags, dump_ok ? "yes" : "no");
1234 return dump_ok;
1235 }
1236
1237 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1238 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1239 vma->vm_flags, dump_ok ? "yes" : "no");
1240 return dump_ok;
1241 }
1242
1243 #ifdef CONFIG_MMU
1244 /* By default, if it hasn't been written to, don't write it out */
1245 if (!vma->anon_vma) {
1246 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1247 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1248 vma->vm_flags, dump_ok ? "yes" : "no");
1249 return dump_ok;
1250 }
1251 #endif
1252
1253 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1254 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1255 dump_ok ? "yes" : "no");
1256 return dump_ok;
1257 }
1258
1259 /* An ELF note in memory */
1260 struct memelfnote
1261 {
1262 const char *name;
1263 int type;
1264 unsigned int datasz;
1265 void *data;
1266 };
1267
1268 static int notesize(struct memelfnote *en)
1269 {
1270 int sz;
1271
1272 sz = sizeof(struct elf_note);
1273 sz += roundup(strlen(en->name) + 1, 4);
1274 sz += roundup(en->datasz, 4);
1275
1276 return sz;
1277 }
1278
1279 /* #define DEBUG */
1280
1281 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1282 {
1283 struct elf_note en;
1284 en.n_namesz = strlen(men->name) + 1;
1285 en.n_descsz = men->datasz;
1286 en.n_type = men->type;
1287
1288 return dump_emit(cprm, &en, sizeof(en)) &&
1289 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1290 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1291 }
1292
1293 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1294 {
1295 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1296 elf->e_ident[EI_CLASS] = ELF_CLASS;
1297 elf->e_ident[EI_DATA] = ELF_DATA;
1298 elf->e_ident[EI_VERSION] = EV_CURRENT;
1299 elf->e_ident[EI_OSABI] = ELF_OSABI;
1300 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1301
1302 elf->e_type = ET_CORE;
1303 elf->e_machine = ELF_ARCH;
1304 elf->e_version = EV_CURRENT;
1305 elf->e_entry = 0;
1306 elf->e_phoff = sizeof(struct elfhdr);
1307 elf->e_shoff = 0;
1308 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1309 elf->e_ehsize = sizeof(struct elfhdr);
1310 elf->e_phentsize = sizeof(struct elf_phdr);
1311 elf->e_phnum = segs;
1312 elf->e_shentsize = 0;
1313 elf->e_shnum = 0;
1314 elf->e_shstrndx = 0;
1315 return;
1316 }
1317
1318 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1319 {
1320 phdr->p_type = PT_NOTE;
1321 phdr->p_offset = offset;
1322 phdr->p_vaddr = 0;
1323 phdr->p_paddr = 0;
1324 phdr->p_filesz = sz;
1325 phdr->p_memsz = 0;
1326 phdr->p_flags = 0;
1327 phdr->p_align = 0;
1328 return;
1329 }
1330
1331 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1332 unsigned int sz, void *data)
1333 {
1334 note->name = name;
1335 note->type = type;
1336 note->datasz = sz;
1337 note->data = data;
1338 return;
1339 }
1340
1341 /*
1342 * fill up all the fields in prstatus from the given task struct, except
1343 * registers which need to be filled up separately.
1344 */
1345 static void fill_prstatus(struct elf_prstatus *prstatus,
1346 struct task_struct *p, long signr)
1347 {
1348 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1349 prstatus->pr_sigpend = p->pending.signal.sig[0];
1350 prstatus->pr_sighold = p->blocked.sig[0];
1351 rcu_read_lock();
1352 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1353 rcu_read_unlock();
1354 prstatus->pr_pid = task_pid_vnr(p);
1355 prstatus->pr_pgrp = task_pgrp_vnr(p);
1356 prstatus->pr_sid = task_session_vnr(p);
1357 if (thread_group_leader(p)) {
1358 struct task_cputime cputime;
1359
1360 /*
1361 * This is the record for the group leader. It shows the
1362 * group-wide total, not its individual thread total.
1363 */
1364 thread_group_cputime(p, &cputime);
1365 prstatus->pr_utime = ns_to_timeval(cputime.utime);
1366 prstatus->pr_stime = ns_to_timeval(cputime.stime);
1367 } else {
1368 u64 utime, stime;
1369
1370 task_cputime(p, &utime, &stime);
1371 prstatus->pr_utime = ns_to_timeval(utime);
1372 prstatus->pr_stime = ns_to_timeval(stime);
1373 }
1374 prstatus->pr_cutime = ns_to_timeval(p->signal->cutime);
1375 prstatus->pr_cstime = ns_to_timeval(p->signal->cstime);
1376
1377 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1378 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1379 }
1380
1381 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1382 struct mm_struct *mm)
1383 {
1384 const struct cred *cred;
1385 unsigned int i, len;
1386
1387 /* first copy the parameters from user space */
1388 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1389
1390 len = mm->arg_end - mm->arg_start;
1391 if (len >= ELF_PRARGSZ)
1392 len = ELF_PRARGSZ - 1;
1393 if (copy_from_user(&psinfo->pr_psargs,
1394 (const char __user *) mm->arg_start, len))
1395 return -EFAULT;
1396 for (i = 0; i < len; i++)
1397 if (psinfo->pr_psargs[i] == 0)
1398 psinfo->pr_psargs[i] = ' ';
1399 psinfo->pr_psargs[len] = 0;
1400
1401 rcu_read_lock();
1402 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1403 rcu_read_unlock();
1404 psinfo->pr_pid = task_pid_vnr(p);
1405 psinfo->pr_pgrp = task_pgrp_vnr(p);
1406 psinfo->pr_sid = task_session_vnr(p);
1407
1408 i = p->state ? ffz(~p->state) + 1 : 0;
1409 psinfo->pr_state = i;
1410 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1411 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1412 psinfo->pr_nice = task_nice(p);
1413 psinfo->pr_flag = p->flags;
1414 rcu_read_lock();
1415 cred = __task_cred(p);
1416 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1417 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1418 rcu_read_unlock();
1419 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1420
1421 return 0;
1422 }
1423
1424 /* Here is the structure in which status of each thread is captured. */
1425 struct elf_thread_status
1426 {
1427 struct list_head list;
1428 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1429 elf_fpregset_t fpu; /* NT_PRFPREG */
1430 struct task_struct *thread;
1431 #ifdef ELF_CORE_COPY_XFPREGS
1432 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1433 #endif
1434 struct memelfnote notes[3];
1435 int num_notes;
1436 };
1437
1438 /*
1439 * In order to add the specific thread information for the elf file format,
1440 * we need to keep a linked list of every thread's pr_status and then create
1441 * a single section for them in the final core file.
1442 */
1443 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1444 {
1445 struct task_struct *p = t->thread;
1446 int sz = 0;
1447
1448 t->num_notes = 0;
1449
1450 fill_prstatus(&t->prstatus, p, signr);
1451 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1452
1453 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1454 &t->prstatus);
1455 t->num_notes++;
1456 sz += notesize(&t->notes[0]);
1457
1458 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1459 if (t->prstatus.pr_fpvalid) {
1460 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1461 &t->fpu);
1462 t->num_notes++;
1463 sz += notesize(&t->notes[1]);
1464 }
1465
1466 #ifdef ELF_CORE_COPY_XFPREGS
1467 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1468 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1469 sizeof(t->xfpu), &t->xfpu);
1470 t->num_notes++;
1471 sz += notesize(&t->notes[2]);
1472 }
1473 #endif
1474 return sz;
1475 }
1476
1477 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1478 elf_addr_t e_shoff, int segs)
1479 {
1480 elf->e_shoff = e_shoff;
1481 elf->e_shentsize = sizeof(*shdr4extnum);
1482 elf->e_shnum = 1;
1483 elf->e_shstrndx = SHN_UNDEF;
1484
1485 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1486
1487 shdr4extnum->sh_type = SHT_NULL;
1488 shdr4extnum->sh_size = elf->e_shnum;
1489 shdr4extnum->sh_link = elf->e_shstrndx;
1490 shdr4extnum->sh_info = segs;
1491 }
1492
1493 /*
1494 * dump the segments for an MMU process
1495 */
1496 static bool elf_fdpic_dump_segments(struct coredump_params *cprm)
1497 {
1498 struct vm_area_struct *vma;
1499
1500 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1501 #ifdef CONFIG_MMU
1502 unsigned long addr;
1503 #endif
1504
1505 if (!maydump(vma, cprm->mm_flags))
1506 continue;
1507
1508 #ifdef CONFIG_MMU
1509 for (addr = vma->vm_start; addr < vma->vm_end;
1510 addr += PAGE_SIZE) {
1511 bool res;
1512 struct page *page = get_dump_page(addr);
1513 if (page) {
1514 void *kaddr = kmap(page);
1515 res = dump_emit(cprm, kaddr, PAGE_SIZE);
1516 kunmap(page);
1517 put_page(page);
1518 } else {
1519 res = dump_skip(cprm, PAGE_SIZE);
1520 }
1521 if (!res)
1522 return false;
1523 }
1524 #else
1525 if (!dump_emit(cprm, (void *) vma->vm_start,
1526 vma->vm_end - vma->vm_start))
1527 return false;
1528 #endif
1529 }
1530 return true;
1531 }
1532
1533 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1534 {
1535 struct vm_area_struct *vma;
1536 size_t size = 0;
1537
1538 for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1539 if (maydump(vma, mm_flags))
1540 size += vma->vm_end - vma->vm_start;
1541 return size;
1542 }
1543
1544 /*
1545 * Actual dumper
1546 *
1547 * This is a two-pass process; first we find the offsets of the bits,
1548 * and then they are actually written out. If we run out of core limit
1549 * we just truncate.
1550 */
1551 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1552 {
1553 #define NUM_NOTES 6
1554 int has_dumped = 0;
1555 mm_segment_t fs;
1556 int segs;
1557 int i;
1558 struct vm_area_struct *vma;
1559 struct elfhdr *elf = NULL;
1560 loff_t offset = 0, dataoff;
1561 int numnote;
1562 struct memelfnote *notes = NULL;
1563 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1564 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1565 LIST_HEAD(thread_list);
1566 struct list_head *t;
1567 elf_fpregset_t *fpu = NULL;
1568 #ifdef ELF_CORE_COPY_XFPREGS
1569 elf_fpxregset_t *xfpu = NULL;
1570 #endif
1571 int thread_status_size = 0;
1572 elf_addr_t *auxv;
1573 struct elf_phdr *phdr4note = NULL;
1574 struct elf_shdr *shdr4extnum = NULL;
1575 Elf_Half e_phnum;
1576 elf_addr_t e_shoff;
1577 struct core_thread *ct;
1578 struct elf_thread_status *tmp;
1579
1580 /*
1581 * We no longer stop all VM operations.
1582 *
1583 * This is because those proceses that could possibly change map_count
1584 * or the mmap / vma pages are now blocked in do_exit on current
1585 * finishing this core dump.
1586 *
1587 * Only ptrace can touch these memory addresses, but it doesn't change
1588 * the map_count or the pages allocated. So no possibility of crashing
1589 * exists while dumping the mm->vm_next areas to the core file.
1590 */
1591
1592 /* alloc memory for large data structures: too large to be on stack */
1593 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1594 if (!elf)
1595 goto cleanup;
1596 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1597 if (!prstatus)
1598 goto cleanup;
1599 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1600 if (!psinfo)
1601 goto cleanup;
1602 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1603 if (!notes)
1604 goto cleanup;
1605 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1606 if (!fpu)
1607 goto cleanup;
1608 #ifdef ELF_CORE_COPY_XFPREGS
1609 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1610 if (!xfpu)
1611 goto cleanup;
1612 #endif
1613
1614 for (ct = current->mm->core_state->dumper.next;
1615 ct; ct = ct->next) {
1616 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1617 if (!tmp)
1618 goto cleanup;
1619
1620 tmp->thread = ct->task;
1621 list_add(&tmp->list, &thread_list);
1622 }
1623
1624 list_for_each(t, &thread_list) {
1625 struct elf_thread_status *tmp;
1626 int sz;
1627
1628 tmp = list_entry(t, struct elf_thread_status, list);
1629 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1630 thread_status_size += sz;
1631 }
1632
1633 /* now collect the dump for the current */
1634 fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1635 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1636
1637 segs = current->mm->map_count;
1638 segs += elf_core_extra_phdrs();
1639
1640 /* for notes section */
1641 segs++;
1642
1643 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1644 * this, kernel supports extended numbering. Have a look at
1645 * include/linux/elf.h for further information. */
1646 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1647
1648 /* Set up header */
1649 fill_elf_fdpic_header(elf, e_phnum);
1650
1651 has_dumped = 1;
1652 /*
1653 * Set up the notes in similar form to SVR4 core dumps made
1654 * with info from their /proc.
1655 */
1656
1657 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1658 fill_psinfo(psinfo, current->group_leader, current->mm);
1659 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1660
1661 numnote = 2;
1662
1663 auxv = (elf_addr_t *) current->mm->saved_auxv;
1664
1665 i = 0;
1666 do
1667 i += 2;
1668 while (auxv[i - 2] != AT_NULL);
1669 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1670 i * sizeof(elf_addr_t), auxv);
1671
1672 /* Try to dump the FPU. */
1673 if ((prstatus->pr_fpvalid =
1674 elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1675 fill_note(notes + numnote++,
1676 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1677 #ifdef ELF_CORE_COPY_XFPREGS
1678 if (elf_core_copy_task_xfpregs(current, xfpu))
1679 fill_note(notes + numnote++,
1680 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1681 #endif
1682
1683 fs = get_fs();
1684 set_fs(KERNEL_DS);
1685
1686 offset += sizeof(*elf); /* Elf header */
1687 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1688
1689 /* Write notes phdr entry */
1690 {
1691 int sz = 0;
1692
1693 for (i = 0; i < numnote; i++)
1694 sz += notesize(notes + i);
1695
1696 sz += thread_status_size;
1697
1698 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1699 if (!phdr4note)
1700 goto end_coredump;
1701
1702 fill_elf_note_phdr(phdr4note, sz, offset);
1703 offset += sz;
1704 }
1705
1706 /* Page-align dumped data */
1707 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1708
1709 offset += elf_core_vma_data_size(cprm->mm_flags);
1710 offset += elf_core_extra_data_size();
1711 e_shoff = offset;
1712
1713 if (e_phnum == PN_XNUM) {
1714 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1715 if (!shdr4extnum)
1716 goto end_coredump;
1717 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1718 }
1719
1720 offset = dataoff;
1721
1722 if (!dump_emit(cprm, elf, sizeof(*elf)))
1723 goto end_coredump;
1724
1725 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1726 goto end_coredump;
1727
1728 /* write program headers for segments dump */
1729 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1730 struct elf_phdr phdr;
1731 size_t sz;
1732
1733 sz = vma->vm_end - vma->vm_start;
1734
1735 phdr.p_type = PT_LOAD;
1736 phdr.p_offset = offset;
1737 phdr.p_vaddr = vma->vm_start;
1738 phdr.p_paddr = 0;
1739 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1740 phdr.p_memsz = sz;
1741 offset += phdr.p_filesz;
1742 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1743 if (vma->vm_flags & VM_WRITE)
1744 phdr.p_flags |= PF_W;
1745 if (vma->vm_flags & VM_EXEC)
1746 phdr.p_flags |= PF_X;
1747 phdr.p_align = ELF_EXEC_PAGESIZE;
1748
1749 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1750 goto end_coredump;
1751 }
1752
1753 if (!elf_core_write_extra_phdrs(cprm, offset))
1754 goto end_coredump;
1755
1756 /* write out the notes section */
1757 for (i = 0; i < numnote; i++)
1758 if (!writenote(notes + i, cprm))
1759 goto end_coredump;
1760
1761 /* write out the thread status notes section */
1762 list_for_each(t, &thread_list) {
1763 struct elf_thread_status *tmp =
1764 list_entry(t, struct elf_thread_status, list);
1765
1766 for (i = 0; i < tmp->num_notes; i++)
1767 if (!writenote(&tmp->notes[i], cprm))
1768 goto end_coredump;
1769 }
1770
1771 if (!dump_skip(cprm, dataoff - cprm->pos))
1772 goto end_coredump;
1773
1774 if (!elf_fdpic_dump_segments(cprm))
1775 goto end_coredump;
1776
1777 if (!elf_core_write_extra_data(cprm))
1778 goto end_coredump;
1779
1780 if (e_phnum == PN_XNUM) {
1781 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1782 goto end_coredump;
1783 }
1784
1785 if (cprm->file->f_pos != offset) {
1786 /* Sanity check */
1787 printk(KERN_WARNING
1788 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1789 cprm->file->f_pos, offset);
1790 }
1791
1792 end_coredump:
1793 set_fs(fs);
1794
1795 cleanup:
1796 while (!list_empty(&thread_list)) {
1797 struct list_head *tmp = thread_list.next;
1798 list_del(tmp);
1799 kfree(list_entry(tmp, struct elf_thread_status, list));
1800 }
1801 kfree(phdr4note);
1802 kfree(elf);
1803 kfree(prstatus);
1804 kfree(psinfo);
1805 kfree(notes);
1806 kfree(fpu);
1807 kfree(shdr4extnum);
1808 #ifdef ELF_CORE_COPY_XFPREGS
1809 kfree(xfpu);
1810 #endif
1811 return has_dumped;
1812 #undef NUM_NOTES
1813 }
1814
1815 #endif /* CONFIG_ELF_CORE */
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