1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
3 *
4 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 * Derived from binfmt_elf.c
7 */
8
9 #include <linux/module.h>
10
11 #include <linux/fs.h>
12 #include <linux/stat.h>
13 #include <linux/sched.h>
14 #include <linux/sched/coredump.h>
15 #include <linux/sched/task_stack.h>
16 #include <linux/sched/cputime.h>
17 #include <linux/mm.h>
18 #include <linux/mman.h>
19 #include <linux/errno.h>
20 #include <linux/signal.h>
21 #include <linux/binfmts.h>
22 #include <linux/string.h>
23 #include <linux/file.h>
24 #include <linux/fcntl.h>
25 #include <linux/slab.h>
26 #include <linux/pagemap.h>
27 #include <linux/security.h>
28 #include <linux/highmem.h>
29 #include <linux/highuid.h>
30 #include <linux/personality.h>
31 #include <linux/ptrace.h>
32 #include <linux/init.h>
33 #include <linux/elf.h>
34 #include <linux/elf-fdpic.h>
35 #include <linux/elfcore.h>
36 #include <linux/coredump.h>
37 #include <linux/dax.h>
38 #include <linux/regset.h>
39
40 #include <linux/uaccess.h>
41 #include <asm/param.h>
42
43 typedef char *elf_caddr_t;
44
45 #if 0
46 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
47 #else
48 #define kdebug(fmt, ...) do {} while(0)
49 #endif
50
51 #if 0
52 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
53 #else
54 #define kdcore(fmt, ...) do {} while(0)
55 #endif
56
57 MODULE_LICENSE("GPL");
58
59 static int load_elf_fdpic_binary(struct linux_binprm *);
60 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
61 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
62 struct mm_struct *, const char *);
63
64 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
65 struct elf_fdpic_params *,
66 struct elf_fdpic_params *);
67
68 #ifndef CONFIG_MMU
69 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
70 struct file *,
71 struct mm_struct *);
72 #endif
73
74 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
75 struct file *, struct mm_struct *);
76
77 #ifdef CONFIG_ELF_CORE
78 static int elf_fdpic_core_dump(struct coredump_params *cprm);
79 #endif
80
81 static struct linux_binfmt elf_fdpic_format = {
82 .module = THIS_MODULE,
83 .load_binary = load_elf_fdpic_binary,
84 #ifdef CONFIG_ELF_CORE
85 .core_dump = elf_fdpic_core_dump,
86 .min_coredump = ELF_EXEC_PAGESIZE,
87 #endif
88 };
89
init_elf_fdpic_binfmt(void)90 static int __init init_elf_fdpic_binfmt(void)
91 {
92 register_binfmt(&elf_fdpic_format);
93 return 0;
94 }
95
exit_elf_fdpic_binfmt(void)96 static void __exit exit_elf_fdpic_binfmt(void)
97 {
98 unregister_binfmt(&elf_fdpic_format);
99 }
100
101 core_initcall(init_elf_fdpic_binfmt);
102 module_exit(exit_elf_fdpic_binfmt);
103
is_elf(struct elfhdr * hdr,struct file * file)104 static int is_elf(struct elfhdr *hdr, struct file *file)
105 {
106 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
107 return 0;
108 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
109 return 0;
110 if (!elf_check_arch(hdr))
111 return 0;
112 if (!can_mmap_file(file))
113 return 0;
114 return 1;
115 }
116
117 #ifndef elf_check_fdpic
118 #define elf_check_fdpic(x) 0
119 #endif
120
121 #ifndef elf_check_const_displacement
122 #define elf_check_const_displacement(x) 0
123 #endif
124
is_constdisp(struct elfhdr * hdr)125 static int is_constdisp(struct elfhdr *hdr)
126 {
127 if (!elf_check_fdpic(hdr))
128 return 1;
129 if (elf_check_const_displacement(hdr))
130 return 1;
131 return 0;
132 }
133
134 /*****************************************************************************/
135 /*
136 * read the program headers table into memory
137 */
elf_fdpic_fetch_phdrs(struct elf_fdpic_params * params,struct file * file)138 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
139 struct file *file)
140 {
141 struct elf_phdr *phdr;
142 unsigned long size;
143 int retval, loop;
144 loff_t pos = params->hdr.e_phoff;
145
146 if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
147 return -ENOMEM;
148 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
149 return -ENOMEM;
150
151 size = params->hdr.e_phnum * sizeof(struct elf_phdr);
152 params->phdrs = kmalloc(size, GFP_KERNEL);
153 if (!params->phdrs)
154 return -ENOMEM;
155
156 retval = kernel_read(file, params->phdrs, size, &pos);
157 if (unlikely(retval != size))
158 return retval < 0 ? retval : -ENOEXEC;
159
160 /* determine stack size for this binary */
161 phdr = params->phdrs;
162 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
163 if (phdr->p_type != PT_GNU_STACK)
164 continue;
165
166 if (phdr->p_flags & PF_X)
167 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
168 else
169 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
170
171 params->stack_size = phdr->p_memsz;
172 break;
173 }
174
175 return 0;
176 }
177
178 /*****************************************************************************/
179 /*
180 * load an fdpic binary into various bits of memory
181 */
load_elf_fdpic_binary(struct linux_binprm * bprm)182 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
183 {
184 struct elf_fdpic_params exec_params, interp_params;
185 struct pt_regs *regs = current_pt_regs();
186 struct elf_phdr *phdr;
187 unsigned long stack_size, entryaddr;
188 #ifdef ELF_FDPIC_PLAT_INIT
189 unsigned long dynaddr;
190 #endif
191 #ifndef CONFIG_MMU
192 unsigned long stack_prot;
193 #endif
194 struct file *interpreter = NULL; /* to shut gcc up */
195 char *interpreter_name = NULL;
196 int executable_stack;
197 int retval, i;
198 loff_t pos;
199
200 kdebug("____ LOAD %d ____", current->pid);
201
202 memset(&exec_params, 0, sizeof(exec_params));
203 memset(&interp_params, 0, sizeof(interp_params));
204
205 exec_params.hdr = *(struct elfhdr *) bprm->buf;
206 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
207
208 /* check that this is a binary we know how to deal with */
209 retval = -ENOEXEC;
210 if (!is_elf(&exec_params.hdr, bprm->file))
211 goto error;
212 if (!elf_check_fdpic(&exec_params.hdr)) {
213 #ifdef CONFIG_MMU
214 /* binfmt_elf handles non-fdpic elf except on nommu */
215 goto error;
216 #else
217 /* nommu can only load ET_DYN (PIE) ELF */
218 if (exec_params.hdr.e_type != ET_DYN)
219 goto error;
220 #endif
221 }
222
223 /* read the program header table */
224 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
225 if (retval < 0)
226 goto error;
227
228 /* scan for a program header that specifies an interpreter */
229 phdr = exec_params.phdrs;
230
231 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
232 switch (phdr->p_type) {
233 case PT_INTERP:
234 retval = -ENOMEM;
235 if (phdr->p_filesz > PATH_MAX)
236 goto error;
237 retval = -ENOENT;
238 if (phdr->p_filesz < 2)
239 goto error;
240
241 /* read the name of the interpreter into memory */
242 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
243 if (!interpreter_name)
244 goto error;
245
246 pos = phdr->p_offset;
247 retval = kernel_read(bprm->file, interpreter_name,
248 phdr->p_filesz, &pos);
249 if (unlikely(retval != phdr->p_filesz)) {
250 if (retval >= 0)
251 retval = -ENOEXEC;
252 goto error;
253 }
254
255 retval = -ENOENT;
256 if (interpreter_name[phdr->p_filesz - 1] != '\0')
257 goto error;
258
259 kdebug("Using ELF interpreter %s", interpreter_name);
260
261 /* replace the program with the interpreter */
262 interpreter = open_exec(interpreter_name);
263 retval = PTR_ERR(interpreter);
264 if (IS_ERR(interpreter)) {
265 interpreter = NULL;
266 goto error;
267 }
268
269 /*
270 * If the binary is not readable then enforce
271 * mm->dumpable = 0 regardless of the interpreter's
272 * permissions.
273 */
274 would_dump(bprm, interpreter);
275
276 pos = 0;
277 retval = kernel_read(interpreter, bprm->buf,
278 BINPRM_BUF_SIZE, &pos);
279 if (unlikely(retval != BINPRM_BUF_SIZE)) {
280 if (retval >= 0)
281 retval = -ENOEXEC;
282 goto error;
283 }
284
285 interp_params.hdr = *((struct elfhdr *) bprm->buf);
286 break;
287
288 case PT_LOAD:
289 #ifdef CONFIG_MMU
290 if (exec_params.load_addr == 0)
291 exec_params.load_addr = phdr->p_vaddr;
292 #endif
293 break;
294 }
295
296 }
297
298 if (is_constdisp(&exec_params.hdr))
299 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
300
301 /* perform insanity checks on the interpreter */
302 if (interpreter_name) {
303 retval = -ELIBBAD;
304 if (!is_elf(&interp_params.hdr, interpreter))
305 goto error;
306
307 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
308
309 /* read the interpreter's program header table */
310 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
311 if (retval < 0)
312 goto error;
313 }
314
315 stack_size = exec_params.stack_size;
316 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
317 executable_stack = EXSTACK_ENABLE_X;
318 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
319 executable_stack = EXSTACK_DISABLE_X;
320 else
321 executable_stack = EXSTACK_DEFAULT;
322
323 if (stack_size == 0 && interp_params.flags & ELF_FDPIC_FLAG_PRESENT) {
324 stack_size = interp_params.stack_size;
325 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
326 executable_stack = EXSTACK_ENABLE_X;
327 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
328 executable_stack = EXSTACK_DISABLE_X;
329 else
330 executable_stack = EXSTACK_DEFAULT;
331 }
332
333 retval = -ENOEXEC;
334 if (stack_size == 0)
335 stack_size = 131072UL; /* same as exec.c's default commit */
336
337 if (is_constdisp(&interp_params.hdr))
338 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
339
340 /* flush all traces of the currently running executable */
341 retval = begin_new_exec(bprm);
342 if (retval)
343 goto error;
344
345 /* there's now no turning back... the old userspace image is dead,
346 * defunct, deceased, etc.
347 */
348 SET_PERSONALITY(exec_params.hdr);
349 if (elf_check_fdpic(&exec_params.hdr))
350 current->personality |= PER_LINUX_FDPIC;
351 if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
352 current->personality |= READ_IMPLIES_EXEC;
353
354 setup_new_exec(bprm);
355
356 set_binfmt(&elf_fdpic_format);
357
358 current->mm->start_code = 0;
359 current->mm->end_code = 0;
360 current->mm->start_stack = 0;
361 current->mm->start_data = 0;
362 current->mm->end_data = 0;
363 current->mm->context.exec_fdpic_loadmap = 0;
364 current->mm->context.interp_fdpic_loadmap = 0;
365
366 #ifdef CONFIG_MMU
367 elf_fdpic_arch_lay_out_mm(&exec_params,
368 &interp_params,
369 ¤t->mm->start_stack,
370 ¤t->mm->start_brk);
371
372 retval = setup_arg_pages(bprm, current->mm->start_stack,
373 executable_stack);
374 if (retval < 0)
375 goto error;
376 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
377 retval = arch_setup_additional_pages(bprm, !!interpreter_name);
378 if (retval < 0)
379 goto error;
380 #endif
381 #endif
382
383 /* load the executable and interpreter into memory */
384 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
385 "executable");
386 if (retval < 0)
387 goto error;
388
389 if (interpreter_name) {
390 retval = elf_fdpic_map_file(&interp_params, interpreter,
391 current->mm, "interpreter");
392 if (retval < 0) {
393 printk(KERN_ERR "Unable to load interpreter\n");
394 goto error;
395 }
396
397 exe_file_allow_write_access(interpreter);
398 fput(interpreter);
399 interpreter = NULL;
400 }
401
402 #ifdef CONFIG_MMU
403 if (!current->mm->start_brk)
404 current->mm->start_brk = current->mm->end_data;
405
406 current->mm->brk = current->mm->start_brk =
407 PAGE_ALIGN(current->mm->start_brk);
408
409 #else
410 /* create a stack area and zero-size brk area */
411 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
412 if (stack_size < PAGE_SIZE * 2)
413 stack_size = PAGE_SIZE * 2;
414
415 stack_prot = PROT_READ | PROT_WRITE;
416 if (executable_stack == EXSTACK_ENABLE_X ||
417 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
418 stack_prot |= PROT_EXEC;
419
420 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
421 MAP_PRIVATE | MAP_ANONYMOUS |
422 MAP_UNINITIALIZED | MAP_GROWSDOWN,
423 0);
424
425 if (IS_ERR_VALUE(current->mm->start_brk)) {
426 retval = current->mm->start_brk;
427 current->mm->start_brk = 0;
428 goto error;
429 }
430
431 current->mm->brk = current->mm->start_brk;
432 current->mm->context.end_brk = current->mm->start_brk;
433 current->mm->start_stack = current->mm->start_brk + stack_size;
434 #endif
435
436 retval = create_elf_fdpic_tables(bprm, current->mm, &exec_params,
437 &interp_params);
438 if (retval < 0)
439 goto error;
440
441 kdebug("- start_code %lx", current->mm->start_code);
442 kdebug("- end_code %lx", current->mm->end_code);
443 kdebug("- start_data %lx", current->mm->start_data);
444 kdebug("- end_data %lx", current->mm->end_data);
445 kdebug("- start_brk %lx", current->mm->start_brk);
446 kdebug("- brk %lx", current->mm->brk);
447 kdebug("- start_stack %lx", current->mm->start_stack);
448
449 #ifdef ELF_FDPIC_PLAT_INIT
450 /*
451 * The ABI may specify that certain registers be set up in special
452 * ways (on i386 %edx is the address of a DT_FINI function, for
453 * example. This macro performs whatever initialization to
454 * the regs structure is required.
455 */
456 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
457 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
458 dynaddr);
459 #endif
460
461 finalize_exec(bprm);
462 /* everything is now ready... get the userspace context ready to roll */
463 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
464 start_thread(regs, entryaddr, current->mm->start_stack);
465
466 retval = 0;
467
468 error:
469 if (interpreter) {
470 exe_file_allow_write_access(interpreter);
471 fput(interpreter);
472 }
473 kfree(interpreter_name);
474 kfree(exec_params.phdrs);
475 kfree(exec_params.loadmap);
476 kfree(interp_params.phdrs);
477 kfree(interp_params.loadmap);
478 return retval;
479 }
480
481 /*****************************************************************************/
482
483 #ifndef ELF_BASE_PLATFORM
484 /*
485 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
486 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
487 * will be copied to the user stack in the same manner as AT_PLATFORM.
488 */
489 #define ELF_BASE_PLATFORM NULL
490 #endif
491
492 /*
493 * present useful information to the program by shovelling it onto the new
494 * process's stack
495 */
create_elf_fdpic_tables(struct linux_binprm * bprm,struct mm_struct * mm,struct elf_fdpic_params * exec_params,struct elf_fdpic_params * interp_params)496 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
497 struct mm_struct *mm,
498 struct elf_fdpic_params *exec_params,
499 struct elf_fdpic_params *interp_params)
500 {
501 const struct cred *cred = current_cred();
502 unsigned long sp, csp, nitems;
503 elf_caddr_t __user *argv, *envp;
504 size_t platform_len = 0, len;
505 char *k_platform, *k_base_platform;
506 char __user *u_platform, *u_base_platform, *p;
507 int loop;
508 unsigned long flags = 0;
509 int ei_index;
510 elf_addr_t *elf_info;
511
512 #ifdef CONFIG_MMU
513 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
514 * by the processes running on the same package. One thing we can do is
515 * to shuffle the initial stack for them, so we give the architecture
516 * an opportunity to do so here.
517 */
518 sp = arch_align_stack(bprm->p);
519 #else
520 sp = mm->start_stack;
521
522 /* stack the program arguments and environment */
523 if (transfer_args_to_stack(bprm, &sp) < 0)
524 return -EFAULT;
525 sp &= ~15;
526 #endif
527
528 /*
529 * If this architecture has a platform capability string, copy it
530 * to userspace. In some cases (Sparc), this info is impossible
531 * for userspace to get any other way, in others (i386) it is
532 * merely difficult.
533 */
534 k_platform = ELF_PLATFORM;
535 u_platform = NULL;
536
537 if (k_platform) {
538 platform_len = strlen(k_platform) + 1;
539 sp -= platform_len;
540 u_platform = (char __user *) sp;
541 if (copy_to_user(u_platform, k_platform, platform_len) != 0)
542 return -EFAULT;
543 }
544
545 /*
546 * If this architecture has a "base" platform capability
547 * string, copy it to userspace.
548 */
549 k_base_platform = ELF_BASE_PLATFORM;
550 u_base_platform = NULL;
551
552 if (k_base_platform) {
553 platform_len = strlen(k_base_platform) + 1;
554 sp -= platform_len;
555 u_base_platform = (char __user *) sp;
556 if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
557 return -EFAULT;
558 }
559
560 sp &= ~7UL;
561
562 /* stack the load map(s) */
563 len = sizeof(struct elf_fdpic_loadmap);
564 len += sizeof(struct elf_fdpic_loadseg) * exec_params->loadmap->nsegs;
565 sp = (sp - len) & ~7UL;
566 exec_params->map_addr = sp;
567
568 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
569 return -EFAULT;
570
571 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
572
573 if (interp_params->loadmap) {
574 len = sizeof(struct elf_fdpic_loadmap);
575 len += sizeof(struct elf_fdpic_loadseg) *
576 interp_params->loadmap->nsegs;
577 sp = (sp - len) & ~7UL;
578 interp_params->map_addr = sp;
579
580 if (copy_to_user((void __user *) sp, interp_params->loadmap,
581 len) != 0)
582 return -EFAULT;
583
584 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
585 }
586
587 /* force 16 byte _final_ alignment here for generality */
588 #define DLINFO_ITEMS 15
589
590 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
591 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
592
593 if (bprm->have_execfd)
594 nitems++;
595 #ifdef ELF_HWCAP2
596 nitems++;
597 #endif
598 #ifdef ELF_HWCAP3
599 nitems++;
600 #endif
601 #ifdef ELF_HWCAP4
602 nitems++;
603 #endif
604
605 csp = sp;
606 sp -= nitems * 2 * sizeof(unsigned long);
607 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
608 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
609 sp -= 1 * sizeof(unsigned long); /* argc */
610
611 csp -= sp & 15UL;
612 sp -= sp & 15UL;
613
614 /* Create the ELF interpreter info */
615 elf_info = (elf_addr_t *)mm->saved_auxv;
616 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
617 #define NEW_AUX_ENT(id, val) \
618 do { \
619 *elf_info++ = id; \
620 *elf_info++ = val; \
621 } while (0)
622
623 #ifdef ARCH_DLINFO
624 /*
625 * ARCH_DLINFO must come first so PPC can do its special alignment of
626 * AUXV.
627 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
628 * ARCH_DLINFO changes
629 */
630 ARCH_DLINFO;
631 #endif
632 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
633 #ifdef ELF_HWCAP2
634 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
635 #endif
636 #ifdef ELF_HWCAP3
637 NEW_AUX_ENT(AT_HWCAP3, ELF_HWCAP3);
638 #endif
639 #ifdef ELF_HWCAP4
640 NEW_AUX_ENT(AT_HWCAP4, ELF_HWCAP4);
641 #endif
642 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
643 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
644 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
645 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
646 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
647 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
648 if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
649 flags |= AT_FLAGS_PRESERVE_ARGV0;
650 NEW_AUX_ENT(AT_FLAGS, flags);
651 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
652 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
653 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
654 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
655 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
656 NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
657 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
658 if (k_platform)
659 NEW_AUX_ENT(AT_PLATFORM,
660 (elf_addr_t)(unsigned long)u_platform);
661 if (k_base_platform)
662 NEW_AUX_ENT(AT_BASE_PLATFORM,
663 (elf_addr_t)(unsigned long)u_base_platform);
664 if (bprm->have_execfd)
665 NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
666 #undef NEW_AUX_ENT
667 /* AT_NULL is zero; clear the rest too */
668 memset(elf_info, 0, (char *)mm->saved_auxv +
669 sizeof(mm->saved_auxv) - (char *)elf_info);
670
671 /* And advance past the AT_NULL entry. */
672 elf_info += 2;
673
674 ei_index = elf_info - (elf_addr_t *)mm->saved_auxv;
675 csp -= ei_index * sizeof(elf_addr_t);
676
677 /* Put the elf_info on the stack in the right place. */
678 if (copy_to_user((void __user *)csp, mm->saved_auxv,
679 ei_index * sizeof(elf_addr_t)))
680 return -EFAULT;
681
682 /* allocate room for argv[] and envv[] */
683 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
684 envp = (elf_caddr_t __user *) csp;
685 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
686 argv = (elf_caddr_t __user *) csp;
687
688 /* stack argc */
689 csp -= sizeof(unsigned long);
690 if (put_user(bprm->argc, (unsigned long __user *) csp))
691 return -EFAULT;
692
693 BUG_ON(csp != sp);
694
695 /* fill in the argv[] array */
696 #ifdef CONFIG_MMU
697 current->mm->arg_start = bprm->p;
698 #else
699 current->mm->arg_start = current->mm->start_stack -
700 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
701 #endif
702
703 p = (char __user *) current->mm->arg_start;
704 for (loop = bprm->argc; loop > 0; loop--) {
705 if (put_user((elf_caddr_t) p, argv++))
706 return -EFAULT;
707 len = strnlen_user(p, MAX_ARG_STRLEN);
708 if (!len || len > MAX_ARG_STRLEN)
709 return -EINVAL;
710 p += len;
711 }
712 if (put_user(NULL, argv))
713 return -EFAULT;
714 current->mm->arg_end = (unsigned long) p;
715
716 /* fill in the envv[] array */
717 current->mm->env_start = (unsigned long) p;
718 for (loop = bprm->envc; loop > 0; loop--) {
719 if (put_user((elf_caddr_t)(unsigned long) p, envp++))
720 return -EFAULT;
721 len = strnlen_user(p, MAX_ARG_STRLEN);
722 if (!len || len > MAX_ARG_STRLEN)
723 return -EINVAL;
724 p += len;
725 }
726 if (put_user(NULL, envp))
727 return -EFAULT;
728 current->mm->env_end = (unsigned long) p;
729
730 mm->start_stack = (unsigned long) sp;
731 return 0;
732 }
733
734 /*****************************************************************************/
735 /*
736 * load the appropriate binary image (executable or interpreter) into memory
737 * - we assume no MMU is available
738 * - if no other PIC bits are set in params->hdr->e_flags
739 * - we assume that the LOADable segments in the binary are independently relocatable
740 * - we assume R/O executable segments are shareable
741 * - else
742 * - we assume the loadable parts of the image to require fixed displacement
743 * - the image is not shareable
744 */
elf_fdpic_map_file(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm,const char * what)745 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
746 struct file *file,
747 struct mm_struct *mm,
748 const char *what)
749 {
750 struct elf_fdpic_loadmap *loadmap;
751 #ifdef CONFIG_MMU
752 struct elf_fdpic_loadseg *mseg;
753 unsigned long load_addr;
754 #endif
755 struct elf_fdpic_loadseg *seg;
756 struct elf_phdr *phdr;
757 unsigned nloads, tmp;
758 unsigned long stop;
759 int loop, ret;
760
761 /* allocate a load map table */
762 nloads = 0;
763 for (loop = 0; loop < params->hdr.e_phnum; loop++)
764 if (params->phdrs[loop].p_type == PT_LOAD)
765 nloads++;
766
767 if (nloads == 0)
768 return -ELIBBAD;
769
770 loadmap = kzalloc_flex(*loadmap, segs, nloads);
771 if (!loadmap)
772 return -ENOMEM;
773
774 params->loadmap = loadmap;
775
776 loadmap->version = ELF_FDPIC_LOADMAP_VERSION;
777 loadmap->nsegs = nloads;
778
779 /* map the requested LOADs into the memory space */
780 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
781 case ELF_FDPIC_FLAG_CONSTDISP:
782 case ELF_FDPIC_FLAG_CONTIGUOUS:
783 #ifndef CONFIG_MMU
784 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
785 if (ret < 0)
786 return ret;
787 break;
788 #endif
789 default:
790 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
791 if (ret < 0)
792 return ret;
793 break;
794 }
795
796 /* map the entry point */
797 if (params->hdr.e_entry) {
798 seg = loadmap->segs;
799 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
800 if (params->hdr.e_entry >= seg->p_vaddr &&
801 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
802 params->entry_addr =
803 (params->hdr.e_entry - seg->p_vaddr) +
804 seg->addr;
805 break;
806 }
807 }
808 }
809
810 /* determine where the program header table has wound up if mapped */
811 stop = params->hdr.e_phoff;
812 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
813 phdr = params->phdrs;
814
815 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
816 if (phdr->p_type != PT_LOAD)
817 continue;
818
819 if (phdr->p_offset > params->hdr.e_phoff ||
820 phdr->p_offset + phdr->p_filesz < stop)
821 continue;
822
823 seg = loadmap->segs;
824 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
825 if (phdr->p_vaddr >= seg->p_vaddr &&
826 phdr->p_vaddr + phdr->p_filesz <=
827 seg->p_vaddr + seg->p_memsz) {
828 params->ph_addr =
829 (phdr->p_vaddr - seg->p_vaddr) +
830 seg->addr +
831 params->hdr.e_phoff - phdr->p_offset;
832 break;
833 }
834 }
835 break;
836 }
837
838 /* determine where the dynamic section has wound up if there is one */
839 phdr = params->phdrs;
840 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
841 if (phdr->p_type != PT_DYNAMIC)
842 continue;
843
844 seg = loadmap->segs;
845 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
846 if (phdr->p_vaddr >= seg->p_vaddr &&
847 phdr->p_vaddr + phdr->p_memsz <=
848 seg->p_vaddr + seg->p_memsz) {
849 Elf_Dyn __user *dyn;
850 Elf_Sword d_tag;
851
852 params->dynamic_addr =
853 (phdr->p_vaddr - seg->p_vaddr) +
854 seg->addr;
855
856 /* check the dynamic section contains at least
857 * one item, and that the last item is a NULL
858 * entry */
859 if (phdr->p_memsz == 0 ||
860 phdr->p_memsz % sizeof(Elf_Dyn) != 0)
861 goto dynamic_error;
862
863 tmp = phdr->p_memsz / sizeof(Elf_Dyn);
864 dyn = (Elf_Dyn __user *)params->dynamic_addr;
865 if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
866 d_tag != 0)
867 goto dynamic_error;
868 break;
869 }
870 }
871 break;
872 }
873
874 /* now elide adjacent segments in the load map on MMU linux
875 * - on uClinux the holes between may actually be filled with system
876 * stuff or stuff from other processes
877 */
878 #ifdef CONFIG_MMU
879 nloads = loadmap->nsegs;
880 mseg = loadmap->segs;
881 seg = mseg + 1;
882 for (loop = 1; loop < nloads; loop++) {
883 /* see if we have a candidate for merging */
884 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
885 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
886 if (load_addr == (seg->addr & PAGE_MASK)) {
887 mseg->p_memsz +=
888 load_addr -
889 (mseg->addr + mseg->p_memsz);
890 mseg->p_memsz += seg->addr & ~PAGE_MASK;
891 mseg->p_memsz += seg->p_memsz;
892 loadmap->nsegs--;
893 continue;
894 }
895 }
896
897 mseg++;
898 if (mseg != seg)
899 *mseg = *seg;
900 }
901 #endif
902
903 kdebug("Mapped Object [%s]:", what);
904 kdebug("- elfhdr : %lx", params->elfhdr_addr);
905 kdebug("- entry : %lx", params->entry_addr);
906 kdebug("- PHDR[] : %lx", params->ph_addr);
907 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
908 seg = loadmap->segs;
909 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
910 kdebug("- LOAD[%d] : %08llx-%08llx [va=%llx ms=%llx]",
911 loop,
912 (unsigned long long) seg->addr,
913 (unsigned long long) seg->addr + seg->p_memsz - 1,
914 (unsigned long long) seg->p_vaddr,
915 (unsigned long long) seg->p_memsz);
916
917 return 0;
918
919 dynamic_error:
920 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
921 what, file_inode(file)->i_ino);
922 return -ELIBBAD;
923 }
924
925 /*****************************************************************************/
926 /*
927 * map a file with constant displacement under uClinux
928 */
929 #ifndef CONFIG_MMU
elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm)930 static int elf_fdpic_map_file_constdisp_on_uclinux(
931 struct elf_fdpic_params *params,
932 struct file *file,
933 struct mm_struct *mm)
934 {
935 struct elf_fdpic_loadseg *seg;
936 struct elf_phdr *phdr;
937 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0;
938 int loop, ret;
939
940 load_addr = params->load_addr;
941 seg = params->loadmap->segs;
942
943 /* determine the bounds of the contiguous overall allocation we must
944 * make */
945 phdr = params->phdrs;
946 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
947 if (params->phdrs[loop].p_type != PT_LOAD)
948 continue;
949
950 if (base > phdr->p_vaddr)
951 base = phdr->p_vaddr;
952 if (top < phdr->p_vaddr + phdr->p_memsz)
953 top = phdr->p_vaddr + phdr->p_memsz;
954 }
955
956 /* allocate one big anon block for everything */
957 maddr = vm_mmap(NULL, load_addr, top - base,
958 PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0);
959 if (IS_ERR_VALUE(maddr))
960 return (int) maddr;
961
962 if (load_addr != 0)
963 load_addr += PAGE_ALIGN(top - base);
964
965 /* and then load the file segments into it */
966 phdr = params->phdrs;
967 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
968 if (params->phdrs[loop].p_type != PT_LOAD)
969 continue;
970
971 seg->addr = maddr + (phdr->p_vaddr - base);
972 seg->p_vaddr = phdr->p_vaddr;
973 seg->p_memsz = phdr->p_memsz;
974
975 ret = read_code(file, seg->addr, phdr->p_offset,
976 phdr->p_filesz);
977 if (ret < 0)
978 return ret;
979
980 /* map the ELF header address if in this segment */
981 if (phdr->p_offset == 0)
982 params->elfhdr_addr = seg->addr;
983
984 /* clear any space allocated but not loaded */
985 if (phdr->p_filesz < phdr->p_memsz) {
986 if (clear_user((void *) (seg->addr + phdr->p_filesz),
987 phdr->p_memsz - phdr->p_filesz))
988 return -EFAULT;
989 }
990
991 if (mm) {
992 if (phdr->p_flags & PF_X) {
993 if (!mm->start_code) {
994 mm->start_code = seg->addr;
995 mm->end_code = seg->addr +
996 phdr->p_memsz;
997 }
998 } else if (!mm->start_data) {
999 mm->start_data = seg->addr;
1000 mm->end_data = seg->addr + phdr->p_memsz;
1001 }
1002 }
1003
1004 seg++;
1005 }
1006
1007 return 0;
1008 }
1009 #endif
1010
1011 /*****************************************************************************/
1012 /*
1013 * map a binary by direct mmap() of the individual PT_LOAD segments
1014 */
elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm)1015 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1016 struct file *file,
1017 struct mm_struct *mm)
1018 {
1019 struct elf_fdpic_loadseg *seg;
1020 struct elf_phdr *phdr;
1021 unsigned long load_addr, delta_vaddr;
1022 int loop, dvset;
1023
1024 load_addr = params->load_addr;
1025 delta_vaddr = 0;
1026 dvset = 0;
1027
1028 seg = params->loadmap->segs;
1029
1030 /* deal with each load segment separately */
1031 phdr = params->phdrs;
1032 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1033 unsigned long maddr, disp, excess;
1034 int prot = 0, flags;
1035
1036 if (phdr->p_type != PT_LOAD)
1037 continue;
1038
1039 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1040 (unsigned long) phdr->p_vaddr,
1041 (unsigned long) phdr->p_offset,
1042 (unsigned long) phdr->p_filesz,
1043 (unsigned long) phdr->p_memsz);
1044
1045 /* determine the mapping parameters */
1046 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1047 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1048 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1049
1050 flags = MAP_PRIVATE;
1051 maddr = 0;
1052
1053 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1054 case ELF_FDPIC_FLAG_INDEPENDENT:
1055 /* PT_LOADs are independently locatable */
1056 break;
1057
1058 case ELF_FDPIC_FLAG_HONOURVADDR:
1059 /* the specified virtual address must be honoured */
1060 maddr = phdr->p_vaddr;
1061 flags |= MAP_FIXED;
1062 break;
1063
1064 case ELF_FDPIC_FLAG_CONSTDISP:
1065 /* constant displacement
1066 * - can be mapped anywhere, but must be mapped as a
1067 * unit
1068 */
1069 if (!dvset) {
1070 maddr = load_addr;
1071 delta_vaddr = phdr->p_vaddr;
1072 dvset = 1;
1073 } else {
1074 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1075 flags |= MAP_FIXED;
1076 }
1077 break;
1078
1079 case ELF_FDPIC_FLAG_CONTIGUOUS:
1080 /* contiguity handled later */
1081 break;
1082
1083 default:
1084 BUG();
1085 }
1086
1087 maddr &= PAGE_MASK;
1088
1089 /* create the mapping */
1090 disp = phdr->p_vaddr & ~PAGE_MASK;
1091 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1092 phdr->p_offset - disp);
1093
1094 kdebug("mmap[%d] <file> sz=%llx pr=%x fl=%x of=%llx --> %08lx",
1095 loop, (unsigned long long) phdr->p_memsz + disp,
1096 prot, flags, (unsigned long long) phdr->p_offset - disp,
1097 maddr);
1098
1099 if (IS_ERR_VALUE(maddr))
1100 return (int) maddr;
1101
1102 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1103 ELF_FDPIC_FLAG_CONTIGUOUS)
1104 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1105
1106 seg->addr = maddr + disp;
1107 seg->p_vaddr = phdr->p_vaddr;
1108 seg->p_memsz = phdr->p_memsz;
1109
1110 /* map the ELF header address if in this segment */
1111 if (phdr->p_offset == 0)
1112 params->elfhdr_addr = seg->addr;
1113
1114 /* clear the bit between beginning of mapping and beginning of
1115 * PT_LOAD */
1116 if (prot & PROT_WRITE && disp > 0) {
1117 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1118 if (clear_user((void __user *) maddr, disp))
1119 return -EFAULT;
1120 maddr += disp;
1121 }
1122
1123 /* clear any space allocated but not loaded
1124 * - on uClinux we can just clear the lot
1125 * - on MMU linux we'll get a SIGBUS beyond the last page
1126 * extant in the file
1127 */
1128 excess = phdr->p_memsz - phdr->p_filesz;
1129
1130 #ifdef CONFIG_MMU
1131 unsigned long excess1
1132 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1133 if (excess > excess1) {
1134 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1135 unsigned long xmaddr;
1136
1137 flags |= MAP_FIXED | MAP_ANONYMOUS;
1138 xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1139 prot, flags, 0);
1140
1141 kdebug("mmap[%d] <anon>"
1142 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1143 loop, xaddr, excess - excess1, prot, flags,
1144 xmaddr);
1145
1146 if (xmaddr != xaddr)
1147 return -ENOMEM;
1148 }
1149
1150 if (prot & PROT_WRITE && excess1 > 0) {
1151 kdebug("clear[%d] ad=%lx sz=%lx",
1152 loop, maddr + phdr->p_filesz, excess1);
1153 if (clear_user((void __user *) maddr + phdr->p_filesz,
1154 excess1))
1155 return -EFAULT;
1156 }
1157
1158 #else
1159 if (excess > 0) {
1160 kdebug("clear[%d] ad=%llx sz=%lx", loop,
1161 (unsigned long long) maddr + phdr->p_filesz,
1162 excess);
1163 if (clear_user((void *) maddr + phdr->p_filesz, excess))
1164 return -EFAULT;
1165 }
1166 #endif
1167
1168 if (mm) {
1169 if (phdr->p_flags & PF_X) {
1170 if (!mm->start_code) {
1171 mm->start_code = maddr;
1172 mm->end_code = maddr + phdr->p_memsz;
1173 }
1174 } else if (!mm->start_data) {
1175 mm->start_data = maddr;
1176 mm->end_data = maddr + phdr->p_memsz;
1177 }
1178 }
1179
1180 seg++;
1181 }
1182
1183 return 0;
1184 }
1185
1186 /*****************************************************************************/
1187 /*
1188 * ELF-FDPIC core dumper
1189 *
1190 * Modelled on fs/exec.c:aout_core_dump()
1191 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1192 *
1193 * Modelled on fs/binfmt_elf.c core dumper
1194 */
1195 #ifdef CONFIG_ELF_CORE
1196
1197 struct elf_prstatus_fdpic
1198 {
1199 struct elf_prstatus_common common;
1200 elf_gregset_t pr_reg; /* GP registers */
1201 /* When using FDPIC, the loadmap addresses need to be communicated
1202 * to GDB in order for GDB to do the necessary relocations. The
1203 * fields (below) used to communicate this information are placed
1204 * immediately after ``pr_reg'', so that the loadmap addresses may
1205 * be viewed as part of the register set if so desired.
1206 */
1207 unsigned long pr_exec_fdpic_loadmap;
1208 unsigned long pr_interp_fdpic_loadmap;
1209 int pr_fpvalid; /* True if math co-processor being used. */
1210 };
1211
1212 /* An ELF note in memory */
1213 struct memelfnote
1214 {
1215 const char *name;
1216 int type;
1217 unsigned int datasz;
1218 void *data;
1219 };
1220
notesize(struct memelfnote * en)1221 static int notesize(struct memelfnote *en)
1222 {
1223 int sz;
1224
1225 sz = sizeof(struct elf_note);
1226 sz += roundup(strlen(en->name) + 1, 4);
1227 sz += roundup(en->datasz, 4);
1228
1229 return sz;
1230 }
1231
1232 /* #define DEBUG */
1233
writenote(struct memelfnote * men,struct coredump_params * cprm)1234 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1235 {
1236 struct elf_note en;
1237 en.n_namesz = strlen(men->name) + 1;
1238 en.n_descsz = men->datasz;
1239 en.n_type = men->type;
1240
1241 return dump_emit(cprm, &en, sizeof(en)) &&
1242 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1243 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1244 }
1245
fill_elf_fdpic_header(struct elfhdr * elf,int segs)1246 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1247 {
1248 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1249 elf->e_ident[EI_CLASS] = ELF_CLASS;
1250 elf->e_ident[EI_DATA] = ELF_DATA;
1251 elf->e_ident[EI_VERSION] = EV_CURRENT;
1252 elf->e_ident[EI_OSABI] = ELF_OSABI;
1253 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1254
1255 elf->e_type = ET_CORE;
1256 elf->e_machine = ELF_ARCH;
1257 elf->e_version = EV_CURRENT;
1258 elf->e_entry = 0;
1259 elf->e_phoff = sizeof(struct elfhdr);
1260 elf->e_shoff = 0;
1261 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1262 elf->e_ehsize = sizeof(struct elfhdr);
1263 elf->e_phentsize = sizeof(struct elf_phdr);
1264 elf->e_phnum = segs;
1265 elf->e_shentsize = 0;
1266 elf->e_shnum = 0;
1267 elf->e_shstrndx = 0;
1268 return;
1269 }
1270
fill_elf_note_phdr(struct elf_phdr * phdr,int sz,loff_t offset)1271 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1272 {
1273 phdr->p_type = PT_NOTE;
1274 phdr->p_offset = offset;
1275 phdr->p_vaddr = 0;
1276 phdr->p_paddr = 0;
1277 phdr->p_filesz = sz;
1278 phdr->p_memsz = 0;
1279 phdr->p_flags = 0;
1280 phdr->p_align = 4;
1281 return;
1282 }
1283
__fill_note(struct memelfnote * note,const char * name,int type,unsigned int sz,void * data)1284 static inline void __fill_note(struct memelfnote *note, const char *name, int type,
1285 unsigned int sz, void *data)
1286 {
1287 note->name = name;
1288 note->type = type;
1289 note->datasz = sz;
1290 note->data = data;
1291 return;
1292 }
1293
1294 #define fill_note(note, type, sz, data) \
1295 __fill_note(note, NN_ ## type, NT_ ## type, sz, data)
1296
1297 /*
1298 * fill up all the fields in prstatus from the given task struct, except
1299 * registers which need to be filled up separately.
1300 */
fill_prstatus(struct elf_prstatus_common * prstatus,struct task_struct * p,long signr)1301 static void fill_prstatus(struct elf_prstatus_common *prstatus,
1302 struct task_struct *p, long signr)
1303 {
1304 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1305 prstatus->pr_sigpend = p->pending.signal.sig[0];
1306 prstatus->pr_sighold = p->blocked.sig[0];
1307 rcu_read_lock();
1308 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1309 rcu_read_unlock();
1310 prstatus->pr_pid = task_pid_vnr(p);
1311 prstatus->pr_pgrp = task_pgrp_vnr(p);
1312 prstatus->pr_sid = task_session_vnr(p);
1313 if (thread_group_leader(p)) {
1314 struct task_cputime cputime;
1315
1316 /*
1317 * This is the record for the group leader. It shows the
1318 * group-wide total, not its individual thread total.
1319 */
1320 thread_group_cputime(p, &cputime);
1321 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1322 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1323 } else {
1324 u64 utime, stime;
1325
1326 task_cputime(p, &utime, &stime);
1327 prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1328 prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1329 }
1330 prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1331 prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1332 }
1333
fill_psinfo(struct elf_prpsinfo * psinfo,struct task_struct * p,struct mm_struct * mm)1334 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1335 struct mm_struct *mm)
1336 {
1337 const struct cred *cred;
1338 unsigned int i, len;
1339 unsigned int state;
1340
1341 /* first copy the parameters from user space */
1342 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1343
1344 len = mm->arg_end - mm->arg_start;
1345 if (len >= ELF_PRARGSZ)
1346 len = ELF_PRARGSZ - 1;
1347 if (copy_from_user(&psinfo->pr_psargs,
1348 (const char __user *) mm->arg_start, len))
1349 return -EFAULT;
1350 for (i = 0; i < len; i++)
1351 if (psinfo->pr_psargs[i] == 0)
1352 psinfo->pr_psargs[i] = ' ';
1353 psinfo->pr_psargs[len] = 0;
1354
1355 rcu_read_lock();
1356 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1357 rcu_read_unlock();
1358 psinfo->pr_pid = task_pid_vnr(p);
1359 psinfo->pr_pgrp = task_pgrp_vnr(p);
1360 psinfo->pr_sid = task_session_vnr(p);
1361
1362 state = READ_ONCE(p->__state);
1363 i = state ? ffz(~state) + 1 : 0;
1364 psinfo->pr_state = i;
1365 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1366 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1367 psinfo->pr_nice = task_nice(p);
1368 psinfo->pr_flag = p->flags;
1369 rcu_read_lock();
1370 cred = __task_cred(p);
1371 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1372 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1373 rcu_read_unlock();
1374 get_task_comm(psinfo->pr_fname, p);
1375
1376 return 0;
1377 }
1378
1379 /* Here is the structure in which status of each thread is captured. */
1380 struct elf_thread_status
1381 {
1382 struct elf_thread_status *next;
1383 struct elf_prstatus_fdpic prstatus; /* NT_PRSTATUS */
1384 elf_fpregset_t fpu; /* NT_PRFPREG */
1385 struct memelfnote notes[2];
1386 int num_notes;
1387 };
1388
1389 /*
1390 * In order to add the specific thread information for the elf file format,
1391 * we need to keep a linked list of every thread's pr_status and then create
1392 * a single section for them in the final core file.
1393 */
elf_dump_thread_status(long signr,struct task_struct * p,int * sz)1394 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz)
1395 {
1396 const struct user_regset_view *view = task_user_regset_view(p);
1397 struct elf_thread_status *t;
1398 int i, ret;
1399
1400 t = kzalloc_obj(struct elf_thread_status);
1401 if (!t)
1402 return t;
1403
1404 fill_prstatus(&t->prstatus.common, p, signr);
1405 t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1406 t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1407 regset_get(p, &view->regsets[0],
1408 sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1409
1410 fill_note(&t->notes[0], PRSTATUS, sizeof(t->prstatus), &t->prstatus);
1411 t->num_notes++;
1412 *sz += notesize(&t->notes[0]);
1413
1414 for (i = 1; i < view->n; ++i) {
1415 const struct user_regset *regset = &view->regsets[i];
1416 if (regset->core_note_type != NT_PRFPREG)
1417 continue;
1418 if (regset->active && regset->active(p, regset) <= 0)
1419 continue;
1420 ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu);
1421 if (ret >= 0)
1422 t->prstatus.pr_fpvalid = 1;
1423 break;
1424 }
1425
1426 if (t->prstatus.pr_fpvalid) {
1427 fill_note(&t->notes[1], PRFPREG, sizeof(t->fpu), &t->fpu);
1428 t->num_notes++;
1429 *sz += notesize(&t->notes[1]);
1430 }
1431 return t;
1432 }
1433
fill_extnum_info(struct elfhdr * elf,struct elf_shdr * shdr4extnum,elf_addr_t e_shoff,int segs)1434 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1435 elf_addr_t e_shoff, int segs)
1436 {
1437 elf->e_shoff = e_shoff;
1438 elf->e_shentsize = sizeof(*shdr4extnum);
1439 elf->e_shnum = 1;
1440 elf->e_shstrndx = SHN_UNDEF;
1441
1442 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1443
1444 shdr4extnum->sh_type = SHT_NULL;
1445 shdr4extnum->sh_size = elf->e_shnum;
1446 shdr4extnum->sh_link = elf->e_shstrndx;
1447 shdr4extnum->sh_info = segs;
1448 }
1449
1450 /*
1451 * dump the segments for an MMU process
1452 */
elf_fdpic_dump_segments(struct coredump_params * cprm,struct core_vma_metadata * vma_meta,int vma_count)1453 static bool elf_fdpic_dump_segments(struct coredump_params *cprm,
1454 struct core_vma_metadata *vma_meta,
1455 int vma_count)
1456 {
1457 int i;
1458
1459 for (i = 0; i < vma_count; i++) {
1460 struct core_vma_metadata *meta = vma_meta + i;
1461
1462 if (!dump_user_range(cprm, meta->start, meta->dump_size))
1463 return false;
1464 }
1465 return true;
1466 }
1467
1468 /*
1469 * Actual dumper
1470 *
1471 * This is a two-pass process; first we find the offsets of the bits,
1472 * and then they are actually written out. If we run out of core limit
1473 * we just truncate.
1474 */
elf_fdpic_core_dump(struct coredump_params * cprm)1475 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1476 {
1477 int has_dumped = 0;
1478 int segs;
1479 int i;
1480 struct elfhdr *elf = NULL;
1481 loff_t offset = 0, dataoff;
1482 struct memelfnote psinfo_note, auxv_note;
1483 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1484 struct elf_thread_status *thread_list = NULL;
1485 int thread_status_size = 0;
1486 elf_addr_t *auxv;
1487 struct elf_phdr *phdr4note = NULL;
1488 struct elf_shdr *shdr4extnum = NULL;
1489 Elf_Half e_phnum;
1490 elf_addr_t e_shoff;
1491 struct core_thread *ct;
1492 struct elf_thread_status *tmp;
1493
1494 /* alloc memory for large data structures: too large to be on stack */
1495 elf = kmalloc_obj(*elf);
1496 if (!elf)
1497 goto end_coredump;
1498 psinfo = kmalloc_obj(*psinfo);
1499 if (!psinfo)
1500 goto end_coredump;
1501
1502 for (ct = current->signal->core_state->dumper.next;
1503 ct; ct = ct->next) {
1504 tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1505 ct->task, &thread_status_size);
1506 if (!tmp)
1507 goto end_coredump;
1508
1509 tmp->next = thread_list;
1510 thread_list = tmp;
1511 }
1512
1513 /* now collect the dump for the current */
1514 tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1515 current, &thread_status_size);
1516 if (!tmp)
1517 goto end_coredump;
1518 tmp->next = thread_list;
1519 thread_list = tmp;
1520
1521 segs = cprm->vma_count + elf_core_extra_phdrs(cprm);
1522
1523 /* for notes section */
1524 segs++;
1525
1526 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1527 * this, kernel supports extended numbering. Have a look at
1528 * include/linux/elf.h for further information. */
1529 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1530
1531 /* Set up header */
1532 fill_elf_fdpic_header(elf, e_phnum);
1533
1534 has_dumped = 1;
1535 /*
1536 * Set up the notes in similar form to SVR4 core dumps made
1537 * with info from their /proc.
1538 */
1539
1540 fill_psinfo(psinfo, current->group_leader, current->mm);
1541 fill_note(&psinfo_note, PRPSINFO, sizeof(*psinfo), psinfo);
1542 thread_status_size += notesize(&psinfo_note);
1543
1544 auxv = (elf_addr_t *) current->mm->saved_auxv;
1545 i = 0;
1546 do
1547 i += 2;
1548 while (auxv[i - 2] != AT_NULL);
1549 fill_note(&auxv_note, AUXV, i * sizeof(elf_addr_t), auxv);
1550 thread_status_size += notesize(&auxv_note);
1551
1552 offset = sizeof(*elf); /* ELF header */
1553 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1554
1555 /* Write notes phdr entry */
1556 phdr4note = kmalloc_obj(*phdr4note);
1557 if (!phdr4note)
1558 goto end_coredump;
1559
1560 fill_elf_note_phdr(phdr4note, thread_status_size, offset);
1561 offset += thread_status_size;
1562
1563 /* Page-align dumped data */
1564 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1565
1566 offset += cprm->vma_data_size;
1567 offset += elf_core_extra_data_size(cprm);
1568 e_shoff = offset;
1569
1570 if (e_phnum == PN_XNUM) {
1571 shdr4extnum = kmalloc_obj(*shdr4extnum);
1572 if (!shdr4extnum)
1573 goto end_coredump;
1574 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1575 }
1576
1577 offset = dataoff;
1578
1579 if (!dump_emit(cprm, elf, sizeof(*elf)))
1580 goto end_coredump;
1581
1582 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1583 goto end_coredump;
1584
1585 /* write program headers for segments dump */
1586 for (i = 0; i < cprm->vma_count; i++) {
1587 struct core_vma_metadata *meta = cprm->vma_meta + i;
1588 struct elf_phdr phdr;
1589 size_t sz;
1590
1591 sz = meta->end - meta->start;
1592
1593 phdr.p_type = PT_LOAD;
1594 phdr.p_offset = offset;
1595 phdr.p_vaddr = meta->start;
1596 phdr.p_paddr = 0;
1597 phdr.p_filesz = meta->dump_size;
1598 phdr.p_memsz = sz;
1599 offset += phdr.p_filesz;
1600 phdr.p_flags = 0;
1601 if (meta->flags & VM_READ)
1602 phdr.p_flags |= PF_R;
1603 if (meta->flags & VM_WRITE)
1604 phdr.p_flags |= PF_W;
1605 if (meta->flags & VM_EXEC)
1606 phdr.p_flags |= PF_X;
1607 phdr.p_align = ELF_EXEC_PAGESIZE;
1608
1609 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1610 goto end_coredump;
1611 }
1612
1613 if (!elf_core_write_extra_phdrs(cprm, offset))
1614 goto end_coredump;
1615
1616 /* write out the notes section */
1617 if (!writenote(thread_list->notes, cprm))
1618 goto end_coredump;
1619 if (!writenote(&psinfo_note, cprm))
1620 goto end_coredump;
1621 if (!writenote(&auxv_note, cprm))
1622 goto end_coredump;
1623 for (i = 1; i < thread_list->num_notes; i++)
1624 if (!writenote(thread_list->notes + i, cprm))
1625 goto end_coredump;
1626
1627 /* write out the thread status notes section */
1628 for (tmp = thread_list->next; tmp; tmp = tmp->next) {
1629 for (i = 0; i < tmp->num_notes; i++)
1630 if (!writenote(&tmp->notes[i], cprm))
1631 goto end_coredump;
1632 }
1633
1634 dump_skip_to(cprm, dataoff);
1635
1636 if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count))
1637 goto end_coredump;
1638
1639 if (!elf_core_write_extra_data(cprm))
1640 goto end_coredump;
1641
1642 if (e_phnum == PN_XNUM) {
1643 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1644 goto end_coredump;
1645 }
1646
1647 if (cprm->file->f_pos != offset) {
1648 /* Sanity check */
1649 printk(KERN_WARNING
1650 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1651 cprm->file->f_pos, offset);
1652 }
1653
1654 end_coredump:
1655 while (thread_list) {
1656 tmp = thread_list;
1657 thread_list = thread_list->next;
1658 kfree(tmp);
1659 }
1660 kfree(phdr4note);
1661 kfree(elf);
1662 kfree(psinfo);
1663 kfree(shdr4extnum);
1664 return has_dumped;
1665 }
1666
1667 #endif /* CONFIG_ELF_CORE */
1668