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
init_elf_fdpic_binfmt(void)94 static int __init init_elf_fdpic_binfmt(void)
95 {
96 register_binfmt(&elf_fdpic_format);
97 return 0;
98 }
99
exit_elf_fdpic_binfmt(void)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
is_elf(struct elfhdr * hdr,struct file * file)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
is_constdisp(struct elfhdr * hdr)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 */
elf_fdpic_fetch_phdrs(struct elf_fdpic_params * params,struct file * file)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 */
load_elf_fdpic_binary(struct linux_binprm * bprm)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 ¤t->mm->start_stack,
375 ¤t->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 finalize_exec(bprm);
467 /* everything is now ready... get the userspace context ready to roll */
468 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
469 start_thread(regs, entryaddr, current->mm->start_stack);
470
471 retval = 0;
472
473 error:
474 if (interpreter) {
475 allow_write_access(interpreter);
476 fput(interpreter);
477 }
478 kfree(interpreter_name);
479 kfree(exec_params.phdrs);
480 kfree(exec_params.loadmap);
481 kfree(interp_params.phdrs);
482 kfree(interp_params.loadmap);
483 return retval;
484 }
485
486 /*****************************************************************************/
487
488 #ifndef ELF_BASE_PLATFORM
489 /*
490 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
491 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
492 * will be copied to the user stack in the same manner as AT_PLATFORM.
493 */
494 #define ELF_BASE_PLATFORM NULL
495 #endif
496
497 /*
498 * present useful information to the program by shovelling it onto the new
499 * process's stack
500 */
create_elf_fdpic_tables(struct linux_binprm * bprm,struct mm_struct * mm,struct elf_fdpic_params * exec_params,struct elf_fdpic_params * interp_params)501 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
502 struct mm_struct *mm,
503 struct elf_fdpic_params *exec_params,
504 struct elf_fdpic_params *interp_params)
505 {
506 const struct cred *cred = current_cred();
507 unsigned long sp, csp, nitems;
508 elf_caddr_t __user *argv, *envp;
509 size_t platform_len = 0, len;
510 char *k_platform, *k_base_platform;
511 char __user *u_platform, *u_base_platform, *p;
512 int loop;
513 int nr; /* reset for each csp adjustment */
514
515 #ifdef CONFIG_MMU
516 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
517 * by the processes running on the same package. One thing we can do is
518 * to shuffle the initial stack for them, so we give the architecture
519 * an opportunity to do so here.
520 */
521 sp = arch_align_stack(bprm->p);
522 #else
523 sp = mm->start_stack;
524
525 /* stack the program arguments and environment */
526 if (transfer_args_to_stack(bprm, &sp) < 0)
527 return -EFAULT;
528 sp &= ~15;
529 #endif
530
531 /*
532 * If this architecture has a platform capability string, copy it
533 * to userspace. In some cases (Sparc), this info is impossible
534 * for userspace to get any other way, in others (i386) it is
535 * merely difficult.
536 */
537 k_platform = ELF_PLATFORM;
538 u_platform = NULL;
539
540 if (k_platform) {
541 platform_len = strlen(k_platform) + 1;
542 sp -= platform_len;
543 u_platform = (char __user *) sp;
544 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
545 return -EFAULT;
546 }
547
548 /*
549 * If this architecture has a "base" platform capability
550 * string, copy it to userspace.
551 */
552 k_base_platform = ELF_BASE_PLATFORM;
553 u_base_platform = NULL;
554
555 if (k_base_platform) {
556 platform_len = strlen(k_base_platform) + 1;
557 sp -= platform_len;
558 u_base_platform = (char __user *) sp;
559 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
560 return -EFAULT;
561 }
562
563 sp &= ~7UL;
564
565 /* stack the load map(s) */
566 len = sizeof(struct elf32_fdpic_loadmap);
567 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
568 sp = (sp - len) & ~7UL;
569 exec_params->map_addr = sp;
570
571 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
572 return -EFAULT;
573
574 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
575
576 if (interp_params->loadmap) {
577 len = sizeof(struct elf32_fdpic_loadmap);
578 len += sizeof(struct elf32_fdpic_loadseg) *
579 interp_params->loadmap->nsegs;
580 sp = (sp - len) & ~7UL;
581 interp_params->map_addr = sp;
582
583 if (copy_to_user((void __user *) sp, interp_params->loadmap,
584 len) != 0)
585 return -EFAULT;
586
587 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
588 }
589
590 /* force 16 byte _final_ alignment here for generality */
591 #define DLINFO_ITEMS 15
592
593 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
594 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
595
596 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
597 nitems++;
598
599 csp = sp;
600 sp -= nitems * 2 * sizeof(unsigned long);
601 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
602 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
603 sp -= 1 * sizeof(unsigned long); /* argc */
604
605 csp -= sp & 15UL;
606 sp -= sp & 15UL;
607
608 /* put the ELF interpreter info on the stack */
609 #define NEW_AUX_ENT(id, val) \
610 do { \
611 struct { unsigned long _id, _val; } __user *ent; \
612 \
613 ent = (void __user *) csp; \
614 __put_user((id), &ent[nr]._id); \
615 __put_user((val), &ent[nr]._val); \
616 nr++; \
617 } while (0)
618
619 nr = 0;
620 csp -= 2 * sizeof(unsigned long);
621 NEW_AUX_ENT(AT_NULL, 0);
622 if (k_platform) {
623 nr = 0;
624 csp -= 2 * sizeof(unsigned long);
625 NEW_AUX_ENT(AT_PLATFORM,
626 (elf_addr_t) (unsigned long) u_platform);
627 }
628
629 if (k_base_platform) {
630 nr = 0;
631 csp -= 2 * sizeof(unsigned long);
632 NEW_AUX_ENT(AT_BASE_PLATFORM,
633 (elf_addr_t) (unsigned long) u_base_platform);
634 }
635
636 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
637 nr = 0;
638 csp -= 2 * sizeof(unsigned long);
639 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
640 }
641
642 nr = 0;
643 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
644 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
645 #ifdef ELF_HWCAP2
646 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
647 #endif
648 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
649 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
650 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
651 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
652 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
653 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
654 NEW_AUX_ENT(AT_FLAGS, 0);
655 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
656 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
657 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
658 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
659 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
660 NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
661 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
662
663 #ifdef ARCH_DLINFO
664 nr = 0;
665 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
666
667 /* ARCH_DLINFO must come last so platform specific code can enforce
668 * special alignment requirements on the AUXV if necessary (eg. PPC).
669 */
670 ARCH_DLINFO;
671 #endif
672 #undef NEW_AUX_ENT
673
674 /* allocate room for argv[] and envv[] */
675 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
676 envp = (elf_caddr_t __user *) csp;
677 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
678 argv = (elf_caddr_t __user *) csp;
679
680 /* stack argc */
681 csp -= sizeof(unsigned long);
682 __put_user(bprm->argc, (unsigned long __user *) csp);
683
684 BUG_ON(csp != sp);
685
686 /* fill in the argv[] array */
687 #ifdef CONFIG_MMU
688 current->mm->arg_start = bprm->p;
689 #else
690 current->mm->arg_start = current->mm->start_stack -
691 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
692 #endif
693
694 p = (char __user *) current->mm->arg_start;
695 for (loop = bprm->argc; loop > 0; loop--) {
696 __put_user((elf_caddr_t) p, argv++);
697 len = strnlen_user(p, MAX_ARG_STRLEN);
698 if (!len || len > MAX_ARG_STRLEN)
699 return -EINVAL;
700 p += len;
701 }
702 __put_user(NULL, argv);
703 current->mm->arg_end = (unsigned long) p;
704
705 /* fill in the envv[] array */
706 current->mm->env_start = (unsigned long) p;
707 for (loop = bprm->envc; loop > 0; loop--) {
708 __put_user((elf_caddr_t)(unsigned long) p, envp++);
709 len = strnlen_user(p, MAX_ARG_STRLEN);
710 if (!len || len > MAX_ARG_STRLEN)
711 return -EINVAL;
712 p += len;
713 }
714 __put_user(NULL, envp);
715 current->mm->env_end = (unsigned long) p;
716
717 mm->start_stack = (unsigned long) sp;
718 return 0;
719 }
720
721 /*****************************************************************************/
722 /*
723 * load the appropriate binary image (executable or interpreter) into memory
724 * - we assume no MMU is available
725 * - if no other PIC bits are set in params->hdr->e_flags
726 * - we assume that the LOADable segments in the binary are independently relocatable
727 * - we assume R/O executable segments are shareable
728 * - else
729 * - we assume the loadable parts of the image to require fixed displacement
730 * - the image is not shareable
731 */
elf_fdpic_map_file(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm,const char * what)732 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
733 struct file *file,
734 struct mm_struct *mm,
735 const char *what)
736 {
737 struct elf32_fdpic_loadmap *loadmap;
738 #ifdef CONFIG_MMU
739 struct elf32_fdpic_loadseg *mseg;
740 #endif
741 struct elf32_fdpic_loadseg *seg;
742 struct elf32_phdr *phdr;
743 unsigned long load_addr, stop;
744 unsigned nloads, tmp;
745 size_t size;
746 int loop, ret;
747
748 /* allocate a load map table */
749 nloads = 0;
750 for (loop = 0; loop < params->hdr.e_phnum; loop++)
751 if (params->phdrs[loop].p_type == PT_LOAD)
752 nloads++;
753
754 if (nloads == 0)
755 return -ELIBBAD;
756
757 size = sizeof(*loadmap) + nloads * sizeof(*seg);
758 loadmap = kzalloc(size, GFP_KERNEL);
759 if (!loadmap)
760 return -ENOMEM;
761
762 params->loadmap = loadmap;
763
764 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
765 loadmap->nsegs = nloads;
766
767 load_addr = params->load_addr;
768 seg = loadmap->segs;
769
770 /* map the requested LOADs into the memory space */
771 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
772 case ELF_FDPIC_FLAG_CONSTDISP:
773 case ELF_FDPIC_FLAG_CONTIGUOUS:
774 #ifndef CONFIG_MMU
775 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
776 if (ret < 0)
777 return ret;
778 break;
779 #endif
780 default:
781 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
782 if (ret < 0)
783 return ret;
784 break;
785 }
786
787 /* map the entry point */
788 if (params->hdr.e_entry) {
789 seg = loadmap->segs;
790 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
791 if (params->hdr.e_entry >= seg->p_vaddr &&
792 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
793 params->entry_addr =
794 (params->hdr.e_entry - seg->p_vaddr) +
795 seg->addr;
796 break;
797 }
798 }
799 }
800
801 /* determine where the program header table has wound up if mapped */
802 stop = params->hdr.e_phoff;
803 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
804 phdr = params->phdrs;
805
806 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
807 if (phdr->p_type != PT_LOAD)
808 continue;
809
810 if (phdr->p_offset > params->hdr.e_phoff ||
811 phdr->p_offset + phdr->p_filesz < stop)
812 continue;
813
814 seg = loadmap->segs;
815 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
816 if (phdr->p_vaddr >= seg->p_vaddr &&
817 phdr->p_vaddr + phdr->p_filesz <=
818 seg->p_vaddr + seg->p_memsz) {
819 params->ph_addr =
820 (phdr->p_vaddr - seg->p_vaddr) +
821 seg->addr +
822 params->hdr.e_phoff - phdr->p_offset;
823 break;
824 }
825 }
826 break;
827 }
828
829 /* determine where the dynamic section has wound up if there is one */
830 phdr = params->phdrs;
831 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
832 if (phdr->p_type != PT_DYNAMIC)
833 continue;
834
835 seg = loadmap->segs;
836 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
837 if (phdr->p_vaddr >= seg->p_vaddr &&
838 phdr->p_vaddr + phdr->p_memsz <=
839 seg->p_vaddr + seg->p_memsz) {
840 Elf32_Dyn __user *dyn;
841 Elf32_Sword d_tag;
842
843 params->dynamic_addr =
844 (phdr->p_vaddr - seg->p_vaddr) +
845 seg->addr;
846
847 /* check the dynamic section contains at least
848 * one item, and that the last item is a NULL
849 * entry */
850 if (phdr->p_memsz == 0 ||
851 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
852 goto dynamic_error;
853
854 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
855 dyn = (Elf32_Dyn __user *)params->dynamic_addr;
856 __get_user(d_tag, &dyn[tmp - 1].d_tag);
857 if (d_tag != 0)
858 goto dynamic_error;
859 break;
860 }
861 }
862 break;
863 }
864
865 /* now elide adjacent segments in the load map on MMU linux
866 * - on uClinux the holes between may actually be filled with system
867 * stuff or stuff from other processes
868 */
869 #ifdef CONFIG_MMU
870 nloads = loadmap->nsegs;
871 mseg = loadmap->segs;
872 seg = mseg + 1;
873 for (loop = 1; loop < nloads; loop++) {
874 /* see if we have a candidate for merging */
875 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
876 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
877 if (load_addr == (seg->addr & PAGE_MASK)) {
878 mseg->p_memsz +=
879 load_addr -
880 (mseg->addr + mseg->p_memsz);
881 mseg->p_memsz += seg->addr & ~PAGE_MASK;
882 mseg->p_memsz += seg->p_memsz;
883 loadmap->nsegs--;
884 continue;
885 }
886 }
887
888 mseg++;
889 if (mseg != seg)
890 *mseg = *seg;
891 }
892 #endif
893
894 kdebug("Mapped Object [%s]:", what);
895 kdebug("- elfhdr : %lx", params->elfhdr_addr);
896 kdebug("- entry : %lx", params->entry_addr);
897 kdebug("- PHDR[] : %lx", params->ph_addr);
898 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
899 seg = loadmap->segs;
900 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
901 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
902 loop,
903 seg->addr, seg->addr + seg->p_memsz - 1,
904 seg->p_vaddr, seg->p_memsz);
905
906 return 0;
907
908 dynamic_error:
909 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
910 what, file_inode(file)->i_ino);
911 return -ELIBBAD;
912 }
913
914 /*****************************************************************************/
915 /*
916 * map a file with constant displacement under uClinux
917 */
918 #ifndef CONFIG_MMU
elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm)919 static int elf_fdpic_map_file_constdisp_on_uclinux(
920 struct elf_fdpic_params *params,
921 struct file *file,
922 struct mm_struct *mm)
923 {
924 struct elf32_fdpic_loadseg *seg;
925 struct elf32_phdr *phdr;
926 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
927 int loop, ret;
928
929 load_addr = params->load_addr;
930 seg = params->loadmap->segs;
931
932 /* determine the bounds of the contiguous overall allocation we must
933 * make */
934 phdr = params->phdrs;
935 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
936 if (params->phdrs[loop].p_type != PT_LOAD)
937 continue;
938
939 if (base > phdr->p_vaddr)
940 base = phdr->p_vaddr;
941 if (top < phdr->p_vaddr + phdr->p_memsz)
942 top = phdr->p_vaddr + phdr->p_memsz;
943 }
944
945 /* allocate one big anon block for everything */
946 mflags = MAP_PRIVATE;
947 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
948 mflags |= MAP_EXECUTABLE;
949
950 maddr = vm_mmap(NULL, load_addr, top - base,
951 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
952 if (IS_ERR_VALUE(maddr))
953 return (int) maddr;
954
955 if (load_addr != 0)
956 load_addr += PAGE_ALIGN(top - base);
957
958 /* and then load the file segments into it */
959 phdr = params->phdrs;
960 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
961 if (params->phdrs[loop].p_type != PT_LOAD)
962 continue;
963
964 seg->addr = maddr + (phdr->p_vaddr - base);
965 seg->p_vaddr = phdr->p_vaddr;
966 seg->p_memsz = phdr->p_memsz;
967
968 ret = read_code(file, seg->addr, phdr->p_offset,
969 phdr->p_filesz);
970 if (ret < 0)
971 return ret;
972
973 /* map the ELF header address if in this segment */
974 if (phdr->p_offset == 0)
975 params->elfhdr_addr = seg->addr;
976
977 /* clear any space allocated but not loaded */
978 if (phdr->p_filesz < phdr->p_memsz) {
979 if (clear_user((void *) (seg->addr + phdr->p_filesz),
980 phdr->p_memsz - phdr->p_filesz))
981 return -EFAULT;
982 }
983
984 if (mm) {
985 if (phdr->p_flags & PF_X) {
986 if (!mm->start_code) {
987 mm->start_code = seg->addr;
988 mm->end_code = seg->addr +
989 phdr->p_memsz;
990 }
991 } else if (!mm->start_data) {
992 mm->start_data = seg->addr;
993 mm->end_data = seg->addr + phdr->p_memsz;
994 }
995 }
996
997 seg++;
998 }
999
1000 return 0;
1001 }
1002 #endif
1003
1004 /*****************************************************************************/
1005 /*
1006 * map a binary by direct mmap() of the individual PT_LOAD segments
1007 */
elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm)1008 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1009 struct file *file,
1010 struct mm_struct *mm)
1011 {
1012 struct elf32_fdpic_loadseg *seg;
1013 struct elf32_phdr *phdr;
1014 unsigned long load_addr, delta_vaddr;
1015 int loop, dvset;
1016
1017 load_addr = params->load_addr;
1018 delta_vaddr = 0;
1019 dvset = 0;
1020
1021 seg = params->loadmap->segs;
1022
1023 /* deal with each load segment separately */
1024 phdr = params->phdrs;
1025 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1026 unsigned long maddr, disp, excess, excess1;
1027 int prot = 0, flags;
1028
1029 if (phdr->p_type != PT_LOAD)
1030 continue;
1031
1032 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1033 (unsigned long) phdr->p_vaddr,
1034 (unsigned long) phdr->p_offset,
1035 (unsigned long) phdr->p_filesz,
1036 (unsigned long) phdr->p_memsz);
1037
1038 /* determine the mapping parameters */
1039 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1040 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1041 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1042
1043 flags = MAP_PRIVATE | MAP_DENYWRITE;
1044 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1045 flags |= MAP_EXECUTABLE;
1046
1047 maddr = 0;
1048
1049 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1050 case ELF_FDPIC_FLAG_INDEPENDENT:
1051 /* PT_LOADs are independently locatable */
1052 break;
1053
1054 case ELF_FDPIC_FLAG_HONOURVADDR:
1055 /* the specified virtual address must be honoured */
1056 maddr = phdr->p_vaddr;
1057 flags |= MAP_FIXED;
1058 break;
1059
1060 case ELF_FDPIC_FLAG_CONSTDISP:
1061 /* constant displacement
1062 * - can be mapped anywhere, but must be mapped as a
1063 * unit
1064 */
1065 if (!dvset) {
1066 maddr = load_addr;
1067 delta_vaddr = phdr->p_vaddr;
1068 dvset = 1;
1069 } else {
1070 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1071 flags |= MAP_FIXED;
1072 }
1073 break;
1074
1075 case ELF_FDPIC_FLAG_CONTIGUOUS:
1076 /* contiguity handled later */
1077 break;
1078
1079 default:
1080 BUG();
1081 }
1082
1083 maddr &= PAGE_MASK;
1084
1085 /* create the mapping */
1086 disp = phdr->p_vaddr & ~PAGE_MASK;
1087 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1088 phdr->p_offset - disp);
1089
1090 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1091 loop, phdr->p_memsz + disp, prot, flags,
1092 phdr->p_offset - disp, maddr);
1093
1094 if (IS_ERR_VALUE(maddr))
1095 return (int) maddr;
1096
1097 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1098 ELF_FDPIC_FLAG_CONTIGUOUS)
1099 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1100
1101 seg->addr = maddr + disp;
1102 seg->p_vaddr = phdr->p_vaddr;
1103 seg->p_memsz = phdr->p_memsz;
1104
1105 /* map the ELF header address if in this segment */
1106 if (phdr->p_offset == 0)
1107 params->elfhdr_addr = seg->addr;
1108
1109 /* clear the bit between beginning of mapping and beginning of
1110 * PT_LOAD */
1111 if (prot & PROT_WRITE && disp > 0) {
1112 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1113 if (clear_user((void __user *) maddr, disp))
1114 return -EFAULT;
1115 maddr += disp;
1116 }
1117
1118 /* clear any space allocated but not loaded
1119 * - on uClinux we can just clear the lot
1120 * - on MMU linux we'll get a SIGBUS beyond the last page
1121 * extant in the file
1122 */
1123 excess = phdr->p_memsz - phdr->p_filesz;
1124 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1125
1126 #ifdef CONFIG_MMU
1127 if (excess > excess1) {
1128 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1129 unsigned long xmaddr;
1130
1131 flags |= MAP_FIXED | MAP_ANONYMOUS;
1132 xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1133 prot, flags, 0);
1134
1135 kdebug("mmap[%d] <anon>"
1136 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1137 loop, xaddr, excess - excess1, prot, flags,
1138 xmaddr);
1139
1140 if (xmaddr != xaddr)
1141 return -ENOMEM;
1142 }
1143
1144 if (prot & PROT_WRITE && excess1 > 0) {
1145 kdebug("clear[%d] ad=%lx sz=%lx",
1146 loop, maddr + phdr->p_filesz, excess1);
1147 if (clear_user((void __user *) maddr + phdr->p_filesz,
1148 excess1))
1149 return -EFAULT;
1150 }
1151
1152 #else
1153 if (excess > 0) {
1154 kdebug("clear[%d] ad=%lx sz=%lx",
1155 loop, maddr + phdr->p_filesz, excess);
1156 if (clear_user((void *) maddr + phdr->p_filesz, excess))
1157 return -EFAULT;
1158 }
1159 #endif
1160
1161 if (mm) {
1162 if (phdr->p_flags & PF_X) {
1163 if (!mm->start_code) {
1164 mm->start_code = maddr;
1165 mm->end_code = maddr + phdr->p_memsz;
1166 }
1167 } else if (!mm->start_data) {
1168 mm->start_data = maddr;
1169 mm->end_data = maddr + phdr->p_memsz;
1170 }
1171 }
1172
1173 seg++;
1174 }
1175
1176 return 0;
1177 }
1178
1179 /*****************************************************************************/
1180 /*
1181 * ELF-FDPIC core dumper
1182 *
1183 * Modelled on fs/exec.c:aout_core_dump()
1184 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1185 *
1186 * Modelled on fs/binfmt_elf.c core dumper
1187 */
1188 #ifdef CONFIG_ELF_CORE
1189
1190 /*
1191 * Decide whether a segment is worth dumping; default is yes to be
1192 * sure (missing info is worse than too much; etc).
1193 * Personally I'd include everything, and use the coredump limit...
1194 *
1195 * I think we should skip something. But I am not sure how. H.J.
1196 */
maydump(struct vm_area_struct * vma,unsigned long mm_flags)1197 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1198 {
1199 int dump_ok;
1200
1201 /* Do not dump I/O mapped devices or special mappings */
1202 if (vma->vm_flags & VM_IO) {
1203 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1204 return 0;
1205 }
1206
1207 /* If we may not read the contents, don't allow us to dump
1208 * them either. "dump_write()" can't handle it anyway.
1209 */
1210 if (!(vma->vm_flags & VM_READ)) {
1211 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1212 return 0;
1213 }
1214
1215 /* support for DAX */
1216 if (vma_is_dax(vma)) {
1217 if (vma->vm_flags & VM_SHARED) {
1218 dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags);
1219 kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start,
1220 vma->vm_flags, dump_ok ? "yes" : "no");
1221 } else {
1222 dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags);
1223 kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start,
1224 vma->vm_flags, dump_ok ? "yes" : "no");
1225 }
1226 return dump_ok;
1227 }
1228
1229 /* By default, dump shared memory if mapped from an anonymous file. */
1230 if (vma->vm_flags & VM_SHARED) {
1231 if (file_inode(vma->vm_file)->i_nlink == 0) {
1232 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1233 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1234 vma->vm_flags, dump_ok ? "yes" : "no");
1235 return dump_ok;
1236 }
1237
1238 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1239 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1240 vma->vm_flags, dump_ok ? "yes" : "no");
1241 return dump_ok;
1242 }
1243
1244 #ifdef CONFIG_MMU
1245 /* By default, if it hasn't been written to, don't write it out */
1246 if (!vma->anon_vma) {
1247 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1248 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1249 vma->vm_flags, dump_ok ? "yes" : "no");
1250 return dump_ok;
1251 }
1252 #endif
1253
1254 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1255 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1256 dump_ok ? "yes" : "no");
1257 return dump_ok;
1258 }
1259
1260 /* An ELF note in memory */
1261 struct memelfnote
1262 {
1263 const char *name;
1264 int type;
1265 unsigned int datasz;
1266 void *data;
1267 };
1268
notesize(struct memelfnote * en)1269 static int notesize(struct memelfnote *en)
1270 {
1271 int sz;
1272
1273 sz = sizeof(struct elf_note);
1274 sz += roundup(strlen(en->name) + 1, 4);
1275 sz += roundup(en->datasz, 4);
1276
1277 return sz;
1278 }
1279
1280 /* #define DEBUG */
1281
writenote(struct memelfnote * men,struct coredump_params * cprm)1282 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1283 {
1284 struct elf_note en;
1285 en.n_namesz = strlen(men->name) + 1;
1286 en.n_descsz = men->datasz;
1287 en.n_type = men->type;
1288
1289 return dump_emit(cprm, &en, sizeof(en)) &&
1290 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1291 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1292 }
1293
fill_elf_fdpic_header(struct elfhdr * elf,int segs)1294 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1295 {
1296 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1297 elf->e_ident[EI_CLASS] = ELF_CLASS;
1298 elf->e_ident[EI_DATA] = ELF_DATA;
1299 elf->e_ident[EI_VERSION] = EV_CURRENT;
1300 elf->e_ident[EI_OSABI] = ELF_OSABI;
1301 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1302
1303 elf->e_type = ET_CORE;
1304 elf->e_machine = ELF_ARCH;
1305 elf->e_version = EV_CURRENT;
1306 elf->e_entry = 0;
1307 elf->e_phoff = sizeof(struct elfhdr);
1308 elf->e_shoff = 0;
1309 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1310 elf->e_ehsize = sizeof(struct elfhdr);
1311 elf->e_phentsize = sizeof(struct elf_phdr);
1312 elf->e_phnum = segs;
1313 elf->e_shentsize = 0;
1314 elf->e_shnum = 0;
1315 elf->e_shstrndx = 0;
1316 return;
1317 }
1318
fill_elf_note_phdr(struct elf_phdr * phdr,int sz,loff_t offset)1319 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1320 {
1321 phdr->p_type = PT_NOTE;
1322 phdr->p_offset = offset;
1323 phdr->p_vaddr = 0;
1324 phdr->p_paddr = 0;
1325 phdr->p_filesz = sz;
1326 phdr->p_memsz = 0;
1327 phdr->p_flags = 0;
1328 phdr->p_align = 0;
1329 return;
1330 }
1331
fill_note(struct memelfnote * note,const char * name,int type,unsigned int sz,void * data)1332 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1333 unsigned int sz, void *data)
1334 {
1335 note->name = name;
1336 note->type = type;
1337 note->datasz = sz;
1338 note->data = data;
1339 return;
1340 }
1341
1342 /*
1343 * fill up all the fields in prstatus from the given task struct, except
1344 * registers which need to be filled up separately.
1345 */
fill_prstatus(struct elf_prstatus * prstatus,struct task_struct * p,long signr)1346 static void fill_prstatus(struct elf_prstatus *prstatus,
1347 struct task_struct *p, long signr)
1348 {
1349 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1350 prstatus->pr_sigpend = p->pending.signal.sig[0];
1351 prstatus->pr_sighold = p->blocked.sig[0];
1352 rcu_read_lock();
1353 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1354 rcu_read_unlock();
1355 prstatus->pr_pid = task_pid_vnr(p);
1356 prstatus->pr_pgrp = task_pgrp_vnr(p);
1357 prstatus->pr_sid = task_session_vnr(p);
1358 if (thread_group_leader(p)) {
1359 struct task_cputime cputime;
1360
1361 /*
1362 * This is the record for the group leader. It shows the
1363 * group-wide total, not its individual thread total.
1364 */
1365 thread_group_cputime(p, &cputime);
1366 prstatus->pr_utime = ns_to_timeval(cputime.utime);
1367 prstatus->pr_stime = ns_to_timeval(cputime.stime);
1368 } else {
1369 u64 utime, stime;
1370
1371 task_cputime(p, &utime, &stime);
1372 prstatus->pr_utime = ns_to_timeval(utime);
1373 prstatus->pr_stime = ns_to_timeval(stime);
1374 }
1375 prstatus->pr_cutime = ns_to_timeval(p->signal->cutime);
1376 prstatus->pr_cstime = ns_to_timeval(p->signal->cstime);
1377
1378 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1379 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1380 }
1381
fill_psinfo(struct elf_prpsinfo * psinfo,struct task_struct * p,struct mm_struct * mm)1382 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1383 struct mm_struct *mm)
1384 {
1385 const struct cred *cred;
1386 unsigned int i, len;
1387
1388 /* first copy the parameters from user space */
1389 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1390
1391 len = mm->arg_end - mm->arg_start;
1392 if (len >= ELF_PRARGSZ)
1393 len = ELF_PRARGSZ - 1;
1394 if (copy_from_user(&psinfo->pr_psargs,
1395 (const char __user *) mm->arg_start, len))
1396 return -EFAULT;
1397 for (i = 0; i < len; i++)
1398 if (psinfo->pr_psargs[i] == 0)
1399 psinfo->pr_psargs[i] = ' ';
1400 psinfo->pr_psargs[len] = 0;
1401
1402 rcu_read_lock();
1403 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1404 rcu_read_unlock();
1405 psinfo->pr_pid = task_pid_vnr(p);
1406 psinfo->pr_pgrp = task_pgrp_vnr(p);
1407 psinfo->pr_sid = task_session_vnr(p);
1408
1409 i = p->state ? ffz(~p->state) + 1 : 0;
1410 psinfo->pr_state = i;
1411 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1412 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1413 psinfo->pr_nice = task_nice(p);
1414 psinfo->pr_flag = p->flags;
1415 rcu_read_lock();
1416 cred = __task_cred(p);
1417 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1418 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1419 rcu_read_unlock();
1420 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1421
1422 return 0;
1423 }
1424
1425 /* Here is the structure in which status of each thread is captured. */
1426 struct elf_thread_status
1427 {
1428 struct list_head list;
1429 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1430 elf_fpregset_t fpu; /* NT_PRFPREG */
1431 struct task_struct *thread;
1432 #ifdef ELF_CORE_COPY_XFPREGS
1433 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1434 #endif
1435 struct memelfnote notes[3];
1436 int num_notes;
1437 };
1438
1439 /*
1440 * In order to add the specific thread information for the elf file format,
1441 * we need to keep a linked list of every thread's pr_status and then create
1442 * a single section for them in the final core file.
1443 */
elf_dump_thread_status(long signr,struct elf_thread_status * t)1444 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1445 {
1446 struct task_struct *p = t->thread;
1447 int sz = 0;
1448
1449 t->num_notes = 0;
1450
1451 fill_prstatus(&t->prstatus, p, signr);
1452 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1453
1454 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1455 &t->prstatus);
1456 t->num_notes++;
1457 sz += notesize(&t->notes[0]);
1458
1459 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1460 if (t->prstatus.pr_fpvalid) {
1461 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1462 &t->fpu);
1463 t->num_notes++;
1464 sz += notesize(&t->notes[1]);
1465 }
1466
1467 #ifdef ELF_CORE_COPY_XFPREGS
1468 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1469 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1470 sizeof(t->xfpu), &t->xfpu);
1471 t->num_notes++;
1472 sz += notesize(&t->notes[2]);
1473 }
1474 #endif
1475 return sz;
1476 }
1477
fill_extnum_info(struct elfhdr * elf,struct elf_shdr * shdr4extnum,elf_addr_t e_shoff,int segs)1478 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1479 elf_addr_t e_shoff, int segs)
1480 {
1481 elf->e_shoff = e_shoff;
1482 elf->e_shentsize = sizeof(*shdr4extnum);
1483 elf->e_shnum = 1;
1484 elf->e_shstrndx = SHN_UNDEF;
1485
1486 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1487
1488 shdr4extnum->sh_type = SHT_NULL;
1489 shdr4extnum->sh_size = elf->e_shnum;
1490 shdr4extnum->sh_link = elf->e_shstrndx;
1491 shdr4extnum->sh_info = segs;
1492 }
1493
1494 /*
1495 * dump the segments for an MMU process
1496 */
elf_fdpic_dump_segments(struct coredump_params * cprm)1497 static bool elf_fdpic_dump_segments(struct coredump_params *cprm)
1498 {
1499 struct vm_area_struct *vma;
1500
1501 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1502 #ifdef CONFIG_MMU
1503 unsigned long addr;
1504 #endif
1505
1506 if (!maydump(vma, cprm->mm_flags))
1507 continue;
1508
1509 #ifdef CONFIG_MMU
1510 for (addr = vma->vm_start; addr < vma->vm_end;
1511 addr += PAGE_SIZE) {
1512 bool res;
1513 struct page *page = get_dump_page(addr);
1514 if (page) {
1515 void *kaddr = kmap(page);
1516 res = dump_emit(cprm, kaddr, PAGE_SIZE);
1517 kunmap(page);
1518 put_page(page);
1519 } else {
1520 res = dump_skip(cprm, PAGE_SIZE);
1521 }
1522 if (!res)
1523 return false;
1524 }
1525 #else
1526 if (!dump_emit(cprm, (void *) vma->vm_start,
1527 vma->vm_end - vma->vm_start))
1528 return false;
1529 #endif
1530 }
1531 return true;
1532 }
1533
elf_core_vma_data_size(unsigned long mm_flags)1534 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1535 {
1536 struct vm_area_struct *vma;
1537 size_t size = 0;
1538
1539 for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1540 if (maydump(vma, mm_flags))
1541 size += vma->vm_end - vma->vm_start;
1542 return size;
1543 }
1544
1545 /*
1546 * Actual dumper
1547 *
1548 * This is a two-pass process; first we find the offsets of the bits,
1549 * and then they are actually written out. If we run out of core limit
1550 * we just truncate.
1551 */
elf_fdpic_core_dump(struct coredump_params * cprm)1552 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1553 {
1554 #define NUM_NOTES 6
1555 int has_dumped = 0;
1556 mm_segment_t fs;
1557 int segs;
1558 int i;
1559 struct vm_area_struct *vma;
1560 struct elfhdr *elf = NULL;
1561 loff_t offset = 0, dataoff;
1562 int numnote;
1563 struct memelfnote *notes = NULL;
1564 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1565 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1566 LIST_HEAD(thread_list);
1567 struct list_head *t;
1568 elf_fpregset_t *fpu = NULL;
1569 #ifdef ELF_CORE_COPY_XFPREGS
1570 elf_fpxregset_t *xfpu = NULL;
1571 #endif
1572 int thread_status_size = 0;
1573 elf_addr_t *auxv;
1574 struct elf_phdr *phdr4note = NULL;
1575 struct elf_shdr *shdr4extnum = NULL;
1576 Elf_Half e_phnum;
1577 elf_addr_t e_shoff;
1578 struct core_thread *ct;
1579 struct elf_thread_status *tmp;
1580
1581 /*
1582 * We no longer stop all VM operations.
1583 *
1584 * This is because those proceses that could possibly change map_count
1585 * or the mmap / vma pages are now blocked in do_exit on current
1586 * finishing this core dump.
1587 *
1588 * Only ptrace can touch these memory addresses, but it doesn't change
1589 * the map_count or the pages allocated. So no possibility of crashing
1590 * exists while dumping the mm->vm_next areas to the core file.
1591 */
1592
1593 /* alloc memory for large data structures: too large to be on stack */
1594 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1595 if (!elf)
1596 goto cleanup;
1597 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1598 if (!prstatus)
1599 goto cleanup;
1600 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1601 if (!psinfo)
1602 goto cleanup;
1603 notes = kmalloc_array(NUM_NOTES, sizeof(struct memelfnote),
1604 GFP_KERNEL);
1605 if (!notes)
1606 goto cleanup;
1607 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1608 if (!fpu)
1609 goto cleanup;
1610 #ifdef ELF_CORE_COPY_XFPREGS
1611 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1612 if (!xfpu)
1613 goto cleanup;
1614 #endif
1615
1616 for (ct = current->mm->core_state->dumper.next;
1617 ct; ct = ct->next) {
1618 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1619 if (!tmp)
1620 goto cleanup;
1621
1622 tmp->thread = ct->task;
1623 list_add(&tmp->list, &thread_list);
1624 }
1625
1626 list_for_each(t, &thread_list) {
1627 struct elf_thread_status *tmp;
1628 int sz;
1629
1630 tmp = list_entry(t, struct elf_thread_status, list);
1631 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1632 thread_status_size += sz;
1633 }
1634
1635 /* now collect the dump for the current */
1636 fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1637 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1638
1639 segs = current->mm->map_count;
1640 segs += elf_core_extra_phdrs();
1641
1642 /* for notes section */
1643 segs++;
1644
1645 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1646 * this, kernel supports extended numbering. Have a look at
1647 * include/linux/elf.h for further information. */
1648 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1649
1650 /* Set up header */
1651 fill_elf_fdpic_header(elf, e_phnum);
1652
1653 has_dumped = 1;
1654 /*
1655 * Set up the notes in similar form to SVR4 core dumps made
1656 * with info from their /proc.
1657 */
1658
1659 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1660 fill_psinfo(psinfo, current->group_leader, current->mm);
1661 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1662
1663 numnote = 2;
1664
1665 auxv = (elf_addr_t *) current->mm->saved_auxv;
1666
1667 i = 0;
1668 do
1669 i += 2;
1670 while (auxv[i - 2] != AT_NULL);
1671 fill_note(¬es[numnote++], "CORE", NT_AUXV,
1672 i * sizeof(elf_addr_t), auxv);
1673
1674 /* Try to dump the FPU. */
1675 if ((prstatus->pr_fpvalid =
1676 elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1677 fill_note(notes + numnote++,
1678 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1679 #ifdef ELF_CORE_COPY_XFPREGS
1680 if (elf_core_copy_task_xfpregs(current, xfpu))
1681 fill_note(notes + numnote++,
1682 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1683 #endif
1684
1685 fs = get_fs();
1686 set_fs(KERNEL_DS);
1687
1688 offset += sizeof(*elf); /* Elf header */
1689 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1690
1691 /* Write notes phdr entry */
1692 {
1693 int sz = 0;
1694
1695 for (i = 0; i < numnote; i++)
1696 sz += notesize(notes + i);
1697
1698 sz += thread_status_size;
1699
1700 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1701 if (!phdr4note)
1702 goto end_coredump;
1703
1704 fill_elf_note_phdr(phdr4note, sz, offset);
1705 offset += sz;
1706 }
1707
1708 /* Page-align dumped data */
1709 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1710
1711 offset += elf_core_vma_data_size(cprm->mm_flags);
1712 offset += elf_core_extra_data_size();
1713 e_shoff = offset;
1714
1715 if (e_phnum == PN_XNUM) {
1716 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1717 if (!shdr4extnum)
1718 goto end_coredump;
1719 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1720 }
1721
1722 offset = dataoff;
1723
1724 if (!dump_emit(cprm, elf, sizeof(*elf)))
1725 goto end_coredump;
1726
1727 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1728 goto end_coredump;
1729
1730 /* write program headers for segments dump */
1731 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1732 struct elf_phdr phdr;
1733 size_t sz;
1734
1735 sz = vma->vm_end - vma->vm_start;
1736
1737 phdr.p_type = PT_LOAD;
1738 phdr.p_offset = offset;
1739 phdr.p_vaddr = vma->vm_start;
1740 phdr.p_paddr = 0;
1741 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1742 phdr.p_memsz = sz;
1743 offset += phdr.p_filesz;
1744 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1745 if (vma->vm_flags & VM_WRITE)
1746 phdr.p_flags |= PF_W;
1747 if (vma->vm_flags & VM_EXEC)
1748 phdr.p_flags |= PF_X;
1749 phdr.p_align = ELF_EXEC_PAGESIZE;
1750
1751 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1752 goto end_coredump;
1753 }
1754
1755 if (!elf_core_write_extra_phdrs(cprm, offset))
1756 goto end_coredump;
1757
1758 /* write out the notes section */
1759 for (i = 0; i < numnote; i++)
1760 if (!writenote(notes + i, cprm))
1761 goto end_coredump;
1762
1763 /* write out the thread status notes section */
1764 list_for_each(t, &thread_list) {
1765 struct elf_thread_status *tmp =
1766 list_entry(t, struct elf_thread_status, list);
1767
1768 for (i = 0; i < tmp->num_notes; i++)
1769 if (!writenote(&tmp->notes[i], cprm))
1770 goto end_coredump;
1771 }
1772
1773 if (!dump_skip(cprm, dataoff - cprm->pos))
1774 goto end_coredump;
1775
1776 if (!elf_fdpic_dump_segments(cprm))
1777 goto end_coredump;
1778
1779 if (!elf_core_write_extra_data(cprm))
1780 goto end_coredump;
1781
1782 if (e_phnum == PN_XNUM) {
1783 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1784 goto end_coredump;
1785 }
1786
1787 if (cprm->file->f_pos != offset) {
1788 /* Sanity check */
1789 printk(KERN_WARNING
1790 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1791 cprm->file->f_pos, offset);
1792 }
1793
1794 end_coredump:
1795 set_fs(fs);
1796
1797 cleanup:
1798 while (!list_empty(&thread_list)) {
1799 struct list_head *tmp = thread_list.next;
1800 list_del(tmp);
1801 kfree(list_entry(tmp, struct elf_thread_status, list));
1802 }
1803 kfree(phdr4note);
1804 kfree(elf);
1805 kfree(prstatus);
1806 kfree(psinfo);
1807 kfree(notes);
1808 kfree(fpu);
1809 kfree(shdr4extnum);
1810 #ifdef ELF_CORE_COPY_XFPREGS
1811 kfree(xfpu);
1812 #endif
1813 return has_dumped;
1814 #undef NUM_NOTES
1815 }
1816
1817 #endif /* CONFIG_ELF_CORE */
1818
