Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-only
2 : /*
3 : * linux/fs/binfmt_elf.c
4 : *
5 : * These are the functions used to load ELF format executables as used
6 : * on SVr4 machines. Information on the format may be found in the book
7 : * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
8 : * Tools".
9 : *
10 : * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
11 : */
12 :
13 : #include <linux/module.h>
14 : #include <linux/kernel.h>
15 : #include <linux/fs.h>
16 : #include <linux/log2.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/slab.h>
25 : #include <linux/personality.h>
26 : #include <linux/elfcore.h>
27 : #include <linux/init.h>
28 : #include <linux/highuid.h>
29 : #include <linux/compiler.h>
30 : #include <linux/highmem.h>
31 : #include <linux/hugetlb.h>
32 : #include <linux/pagemap.h>
33 : #include <linux/vmalloc.h>
34 : #include <linux/security.h>
35 : #include <linux/random.h>
36 : #include <linux/elf.h>
37 : #include <linux/elf-randomize.h>
38 : #include <linux/utsname.h>
39 : #include <linux/coredump.h>
40 : #include <linux/sched.h>
41 : #include <linux/sched/coredump.h>
42 : #include <linux/sched/task_stack.h>
43 : #include <linux/sched/cputime.h>
44 : #include <linux/sizes.h>
45 : #include <linux/types.h>
46 : #include <linux/cred.h>
47 : #include <linux/dax.h>
48 : #include <linux/uaccess.h>
49 : #include <asm/param.h>
50 : #include <asm/page.h>
51 :
52 : #ifndef ELF_COMPAT
53 : #define ELF_COMPAT 0
54 : #endif
55 :
56 : #ifndef user_long_t
57 : #define user_long_t long
58 : #endif
59 : #ifndef user_siginfo_t
60 : #define user_siginfo_t siginfo_t
61 : #endif
62 :
63 : /* That's for binfmt_elf_fdpic to deal with */
64 : #ifndef elf_check_fdpic
65 : #define elf_check_fdpic(ex) false
66 : #endif
67 :
68 : static int load_elf_binary(struct linux_binprm *bprm);
69 :
70 : #ifdef CONFIG_USELIB
71 : static int load_elf_library(struct file *);
72 : #else
73 : #define load_elf_library NULL
74 : #endif
75 :
76 : /*
77 : * If we don't support core dumping, then supply a NULL so we
78 : * don't even try.
79 : */
80 : #ifdef CONFIG_ELF_CORE
81 : static int elf_core_dump(struct coredump_params *cprm);
82 : #else
83 : #define elf_core_dump NULL
84 : #endif
85 :
86 : #if ELF_EXEC_PAGESIZE > PAGE_SIZE
87 : #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
88 : #else
89 : #define ELF_MIN_ALIGN PAGE_SIZE
90 : #endif
91 :
92 : #ifndef ELF_CORE_EFLAGS
93 : #define ELF_CORE_EFLAGS 0
94 : #endif
95 :
96 : #define ELF_PAGESTART(_v) ((_v) & ~(int)(ELF_MIN_ALIGN-1))
97 : #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
98 : #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
99 :
100 : static struct linux_binfmt elf_format = {
101 : .module = THIS_MODULE,
102 : .load_binary = load_elf_binary,
103 : .load_shlib = load_elf_library,
104 : #ifdef CONFIG_COREDUMP
105 : .core_dump = elf_core_dump,
106 : .min_coredump = ELF_EXEC_PAGESIZE,
107 : #endif
108 : };
109 :
110 : #define BAD_ADDR(x) (unlikely((unsigned long)(x) >= TASK_SIZE))
111 :
112 0 : static int set_brk(unsigned long start, unsigned long end, int prot)
113 : {
114 0 : start = ELF_PAGEALIGN(start);
115 0 : end = ELF_PAGEALIGN(end);
116 0 : if (end > start) {
117 : /*
118 : * Map the last of the bss segment.
119 : * If the header is requesting these pages to be
120 : * executable, honour that (ppc32 needs this).
121 : */
122 0 : int error = vm_brk_flags(start, end - start,
123 : prot & PROT_EXEC ? VM_EXEC : 0);
124 0 : if (error)
125 : return error;
126 : }
127 0 : current->mm->start_brk = current->mm->brk = end;
128 0 : return 0;
129 : }
130 :
131 : /* We need to explicitly zero any fractional pages
132 : after the data section (i.e. bss). This would
133 : contain the junk from the file that should not
134 : be in memory
135 : */
136 : static int padzero(unsigned long elf_bss)
137 : {
138 : unsigned long nbyte;
139 :
140 0 : nbyte = ELF_PAGEOFFSET(elf_bss);
141 0 : if (nbyte) {
142 0 : nbyte = ELF_MIN_ALIGN - nbyte;
143 0 : if (clear_user((void __user *) elf_bss, nbyte))
144 : return -EFAULT;
145 : }
146 : return 0;
147 : }
148 :
149 : /* Let's use some macros to make this stack manipulation a little clearer */
150 : #ifdef CONFIG_STACK_GROWSUP
151 : #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
152 : #define STACK_ROUND(sp, items) \
153 : ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
154 : #define STACK_ALLOC(sp, len) ({ \
155 : elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
156 : old_sp; })
157 : #else
158 : #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
159 : #define STACK_ROUND(sp, items) \
160 : (((unsigned long) (sp - items)) &~ 15UL)
161 : #define STACK_ALLOC(sp, len) (sp -= len)
162 : #endif
163 :
164 : #ifndef ELF_BASE_PLATFORM
165 : /*
166 : * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
167 : * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
168 : * will be copied to the user stack in the same manner as AT_PLATFORM.
169 : */
170 : #define ELF_BASE_PLATFORM NULL
171 : #endif
172 :
173 : static int
174 0 : create_elf_tables(struct linux_binprm *bprm, const struct elfhdr *exec,
175 : unsigned long interp_load_addr,
176 : unsigned long e_entry, unsigned long phdr_addr)
177 : {
178 0 : struct mm_struct *mm = current->mm;
179 0 : unsigned long p = bprm->p;
180 0 : int argc = bprm->argc;
181 0 : int envc = bprm->envc;
182 : elf_addr_t __user *sp;
183 : elf_addr_t __user *u_platform;
184 : elf_addr_t __user *u_base_platform;
185 : elf_addr_t __user *u_rand_bytes;
186 0 : const char *k_platform = ELF_PLATFORM;
187 0 : const char *k_base_platform = ELF_BASE_PLATFORM;
188 : unsigned char k_rand_bytes[16];
189 : int items;
190 : elf_addr_t *elf_info;
191 0 : elf_addr_t flags = 0;
192 : int ei_index;
193 0 : const struct cred *cred = current_cred();
194 : struct vm_area_struct *vma;
195 :
196 : /*
197 : * In some cases (e.g. Hyper-Threading), we want to avoid L1
198 : * evictions by the processes running on the same package. One
199 : * thing we can do is to shuffle the initial stack for them.
200 : */
201 :
202 0 : p = arch_align_stack(p);
203 :
204 : /*
205 : * If this architecture has a platform capability string, copy it
206 : * to userspace. In some cases (Sparc), this info is impossible
207 : * for userspace to get any other way, in others (i386) it is
208 : * merely difficult.
209 : */
210 0 : u_platform = NULL;
211 : if (k_platform) {
212 0 : size_t len = strlen(k_platform) + 1;
213 :
214 0 : u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
215 0 : if (copy_to_user(u_platform, k_platform, len))
216 : return -EFAULT;
217 : }
218 :
219 : /*
220 : * If this architecture has a "base" platform capability
221 : * string, copy it to userspace.
222 : */
223 0 : u_base_platform = NULL;
224 : if (k_base_platform) {
225 : size_t len = strlen(k_base_platform) + 1;
226 :
227 : u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
228 : if (copy_to_user(u_base_platform, k_base_platform, len))
229 : return -EFAULT;
230 : }
231 :
232 : /*
233 : * Generate 16 random bytes for userspace PRNG seeding.
234 : */
235 0 : get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
236 0 : u_rand_bytes = (elf_addr_t __user *)
237 0 : STACK_ALLOC(p, sizeof(k_rand_bytes));
238 0 : if (copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
239 : return -EFAULT;
240 :
241 : /* Create the ELF interpreter info */
242 0 : elf_info = (elf_addr_t *)mm->saved_auxv;
243 : /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
244 : #define NEW_AUX_ENT(id, val) \
245 : do { \
246 : *elf_info++ = id; \
247 : *elf_info++ = val; \
248 : } while (0)
249 :
250 : #ifdef ARCH_DLINFO
251 : /*
252 : * ARCH_DLINFO must come first so PPC can do its special alignment of
253 : * AUXV.
254 : * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
255 : * ARCH_DLINFO changes
256 : */
257 0 : ARCH_DLINFO;
258 : #endif
259 0 : NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
260 0 : NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
261 0 : NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
262 0 : NEW_AUX_ENT(AT_PHDR, phdr_addr);
263 0 : NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
264 0 : NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
265 0 : NEW_AUX_ENT(AT_BASE, interp_load_addr);
266 0 : if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
267 0 : flags |= AT_FLAGS_PRESERVE_ARGV0;
268 0 : NEW_AUX_ENT(AT_FLAGS, flags);
269 0 : NEW_AUX_ENT(AT_ENTRY, e_entry);
270 0 : NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
271 0 : NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
272 0 : NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
273 0 : NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
274 0 : NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
275 0 : NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
276 : #ifdef ELF_HWCAP2
277 : NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
278 : #endif
279 0 : NEW_AUX_ENT(AT_EXECFN, bprm->exec);
280 : if (k_platform) {
281 0 : NEW_AUX_ENT(AT_PLATFORM,
282 : (elf_addr_t)(unsigned long)u_platform);
283 : }
284 : if (k_base_platform) {
285 : NEW_AUX_ENT(AT_BASE_PLATFORM,
286 : (elf_addr_t)(unsigned long)u_base_platform);
287 : }
288 0 : if (bprm->have_execfd) {
289 0 : NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
290 : }
291 : #undef NEW_AUX_ENT
292 : /* AT_NULL is zero; clear the rest too */
293 0 : memset(elf_info, 0, (char *)mm->saved_auxv +
294 0 : sizeof(mm->saved_auxv) - (char *)elf_info);
295 :
296 : /* And advance past the AT_NULL entry. */
297 0 : elf_info += 2;
298 :
299 0 : ei_index = elf_info - (elf_addr_t *)mm->saved_auxv;
300 0 : sp = STACK_ADD(p, ei_index);
301 :
302 0 : items = (argc + 1) + (envc + 1) + 1;
303 0 : bprm->p = STACK_ROUND(sp, items);
304 :
305 : /* Point sp at the lowest address on the stack */
306 : #ifdef CONFIG_STACK_GROWSUP
307 : sp = (elf_addr_t __user *)bprm->p - items - ei_index;
308 : bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
309 : #else
310 0 : sp = (elf_addr_t __user *)bprm->p;
311 : #endif
312 :
313 :
314 : /*
315 : * Grow the stack manually; some architectures have a limit on how
316 : * far ahead a user-space access may be in order to grow the stack.
317 : */
318 0 : if (mmap_read_lock_killable(mm))
319 : return -EINTR;
320 0 : vma = find_extend_vma(mm, bprm->p);
321 0 : mmap_read_unlock(mm);
322 0 : if (!vma)
323 : return -EFAULT;
324 :
325 : /* Now, let's put argc (and argv, envp if appropriate) on the stack */
326 0 : if (put_user(argc, sp++))
327 : return -EFAULT;
328 :
329 : /* Populate list of argv pointers back to argv strings. */
330 0 : p = mm->arg_end = mm->arg_start;
331 0 : while (argc-- > 0) {
332 : size_t len;
333 0 : if (put_user((elf_addr_t)p, sp++))
334 : return -EFAULT;
335 0 : len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
336 0 : if (!len || len > MAX_ARG_STRLEN)
337 : return -EINVAL;
338 0 : p += len;
339 : }
340 0 : if (put_user(0, sp++))
341 : return -EFAULT;
342 0 : mm->arg_end = p;
343 :
344 : /* Populate list of envp pointers back to envp strings. */
345 0 : mm->env_end = mm->env_start = p;
346 0 : while (envc-- > 0) {
347 : size_t len;
348 0 : if (put_user((elf_addr_t)p, sp++))
349 : return -EFAULT;
350 0 : len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
351 0 : if (!len || len > MAX_ARG_STRLEN)
352 : return -EINVAL;
353 0 : p += len;
354 : }
355 0 : if (put_user(0, sp++))
356 : return -EFAULT;
357 0 : mm->env_end = p;
358 :
359 : /* Put the elf_info on the stack in the right place. */
360 0 : if (copy_to_user(sp, mm->saved_auxv, ei_index * sizeof(elf_addr_t)))
361 : return -EFAULT;
362 : return 0;
363 : }
364 :
365 0 : static unsigned long elf_map(struct file *filep, unsigned long addr,
366 : const struct elf_phdr *eppnt, int prot, int type,
367 : unsigned long total_size)
368 : {
369 : unsigned long map_addr;
370 0 : unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
371 0 : unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
372 0 : addr = ELF_PAGESTART(addr);
373 0 : size = ELF_PAGEALIGN(size);
374 :
375 : /* mmap() will return -EINVAL if given a zero size, but a
376 : * segment with zero filesize is perfectly valid */
377 0 : if (!size)
378 : return addr;
379 :
380 : /*
381 : * total_size is the size of the ELF (interpreter) image.
382 : * The _first_ mmap needs to know the full size, otherwise
383 : * randomization might put this image into an overlapping
384 : * position with the ELF binary image. (since size < total_size)
385 : * So we first map the 'big' image - and unmap the remainder at
386 : * the end. (which unmap is needed for ELF images with holes.)
387 : */
388 0 : if (total_size) {
389 0 : total_size = ELF_PAGEALIGN(total_size);
390 0 : map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
391 0 : if (!BAD_ADDR(map_addr))
392 0 : vm_munmap(map_addr+size, total_size-size);
393 : } else
394 0 : map_addr = vm_mmap(filep, addr, size, prot, type, off);
395 :
396 0 : if ((type & MAP_FIXED_NOREPLACE) &&
397 0 : PTR_ERR((void *)map_addr) == -EEXIST)
398 0 : pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n",
399 : task_pid_nr(current), current->comm, (void *)addr);
400 :
401 : return(map_addr);
402 : }
403 :
404 : static unsigned long total_mapping_size(const struct elf_phdr *phdr, int nr)
405 : {
406 0 : elf_addr_t min_addr = -1;
407 0 : elf_addr_t max_addr = 0;
408 0 : bool pt_load = false;
409 : int i;
410 :
411 0 : for (i = 0; i < nr; i++) {
412 0 : if (phdr[i].p_type == PT_LOAD) {
413 0 : min_addr = min(min_addr, ELF_PAGESTART(phdr[i].p_vaddr));
414 0 : max_addr = max(max_addr, phdr[i].p_vaddr + phdr[i].p_memsz);
415 0 : pt_load = true;
416 : }
417 : }
418 0 : return pt_load ? (max_addr - min_addr) : 0;
419 : }
420 :
421 : static int elf_read(struct file *file, void *buf, size_t len, loff_t pos)
422 : {
423 : ssize_t rv;
424 :
425 0 : rv = kernel_read(file, buf, len, &pos);
426 0 : if (unlikely(rv != len)) {
427 0 : return (rv < 0) ? rv : -EIO;
428 : }
429 : return 0;
430 : }
431 :
432 0 : static unsigned long maximum_alignment(struct elf_phdr *cmds, int nr)
433 : {
434 0 : unsigned long alignment = 0;
435 : int i;
436 :
437 0 : for (i = 0; i < nr; i++) {
438 0 : if (cmds[i].p_type == PT_LOAD) {
439 0 : unsigned long p_align = cmds[i].p_align;
440 :
441 : /* skip non-power of two alignments as invalid */
442 0 : if (!is_power_of_2(p_align))
443 0 : continue;
444 0 : alignment = max(alignment, p_align);
445 : }
446 : }
447 :
448 : /* ensure we align to at least one page */
449 0 : return ELF_PAGEALIGN(alignment);
450 : }
451 :
452 : /**
453 : * load_elf_phdrs() - load ELF program headers
454 : * @elf_ex: ELF header of the binary whose program headers should be loaded
455 : * @elf_file: the opened ELF binary file
456 : *
457 : * Loads ELF program headers from the binary file elf_file, which has the ELF
458 : * header pointed to by elf_ex, into a newly allocated array. The caller is
459 : * responsible for freeing the allocated data. Returns an ERR_PTR upon failure.
460 : */
461 0 : static struct elf_phdr *load_elf_phdrs(const struct elfhdr *elf_ex,
462 : struct file *elf_file)
463 : {
464 0 : struct elf_phdr *elf_phdata = NULL;
465 0 : int retval, err = -1;
466 : unsigned int size;
467 :
468 : /*
469 : * If the size of this structure has changed, then punt, since
470 : * we will be doing the wrong thing.
471 : */
472 0 : if (elf_ex->e_phentsize != sizeof(struct elf_phdr))
473 : goto out;
474 :
475 : /* Sanity check the number of program headers... */
476 : /* ...and their total size. */
477 0 : size = sizeof(struct elf_phdr) * elf_ex->e_phnum;
478 0 : if (size == 0 || size > 65536 || size > ELF_MIN_ALIGN)
479 : goto out;
480 :
481 0 : elf_phdata = kmalloc(size, GFP_KERNEL);
482 0 : if (!elf_phdata)
483 : goto out;
484 :
485 : /* Read in the program headers */
486 0 : retval = elf_read(elf_file, elf_phdata, size, elf_ex->e_phoff);
487 0 : if (retval < 0) {
488 : err = retval;
489 : goto out;
490 : }
491 :
492 : /* Success! */
493 0 : err = 0;
494 : out:
495 0 : if (err) {
496 0 : kfree(elf_phdata);
497 0 : elf_phdata = NULL;
498 : }
499 0 : return elf_phdata;
500 : }
501 :
502 : #ifndef CONFIG_ARCH_BINFMT_ELF_STATE
503 :
504 : /**
505 : * struct arch_elf_state - arch-specific ELF loading state
506 : *
507 : * This structure is used to preserve architecture specific data during
508 : * the loading of an ELF file, throughout the checking of architecture
509 : * specific ELF headers & through to the point where the ELF load is
510 : * known to be proceeding (ie. SET_PERSONALITY).
511 : *
512 : * This implementation is a dummy for architectures which require no
513 : * specific state.
514 : */
515 : struct arch_elf_state {
516 : };
517 :
518 : #define INIT_ARCH_ELF_STATE {}
519 :
520 : /**
521 : * arch_elf_pt_proc() - check a PT_LOPROC..PT_HIPROC ELF program header
522 : * @ehdr: The main ELF header
523 : * @phdr: The program header to check
524 : * @elf: The open ELF file
525 : * @is_interp: True if the phdr is from the interpreter of the ELF being
526 : * loaded, else false.
527 : * @state: Architecture-specific state preserved throughout the process
528 : * of loading the ELF.
529 : *
530 : * Inspects the program header phdr to validate its correctness and/or
531 : * suitability for the system. Called once per ELF program header in the
532 : * range PT_LOPROC to PT_HIPROC, for both the ELF being loaded and its
533 : * interpreter.
534 : *
535 : * Return: Zero to proceed with the ELF load, non-zero to fail the ELF load
536 : * with that return code.
537 : */
538 : static inline int arch_elf_pt_proc(struct elfhdr *ehdr,
539 : struct elf_phdr *phdr,
540 : struct file *elf, bool is_interp,
541 : struct arch_elf_state *state)
542 : {
543 : /* Dummy implementation, always proceed */
544 : return 0;
545 : }
546 :
547 : /**
548 : * arch_check_elf() - check an ELF executable
549 : * @ehdr: The main ELF header
550 : * @has_interp: True if the ELF has an interpreter, else false.
551 : * @interp_ehdr: The interpreter's ELF header
552 : * @state: Architecture-specific state preserved throughout the process
553 : * of loading the ELF.
554 : *
555 : * Provides a final opportunity for architecture code to reject the loading
556 : * of the ELF & cause an exec syscall to return an error. This is called after
557 : * all program headers to be checked by arch_elf_pt_proc have been.
558 : *
559 : * Return: Zero to proceed with the ELF load, non-zero to fail the ELF load
560 : * with that return code.
561 : */
562 : static inline int arch_check_elf(struct elfhdr *ehdr, bool has_interp,
563 : struct elfhdr *interp_ehdr,
564 : struct arch_elf_state *state)
565 : {
566 : /* Dummy implementation, always proceed */
567 : return 0;
568 : }
569 :
570 : #endif /* !CONFIG_ARCH_BINFMT_ELF_STATE */
571 :
572 : static inline int make_prot(u32 p_flags, struct arch_elf_state *arch_state,
573 : bool has_interp, bool is_interp)
574 : {
575 0 : int prot = 0;
576 :
577 0 : if (p_flags & PF_R)
578 0 : prot |= PROT_READ;
579 0 : if (p_flags & PF_W)
580 0 : prot |= PROT_WRITE;
581 0 : if (p_flags & PF_X)
582 0 : prot |= PROT_EXEC;
583 :
584 0 : return arch_elf_adjust_prot(prot, arch_state, has_interp, is_interp);
585 : }
586 :
587 : /* This is much more generalized than the library routine read function,
588 : so we keep this separate. Technically the library read function
589 : is only provided so that we can read a.out libraries that have
590 : an ELF header */
591 :
592 0 : static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
593 : struct file *interpreter,
594 : unsigned long no_base, struct elf_phdr *interp_elf_phdata,
595 : struct arch_elf_state *arch_state)
596 : {
597 : struct elf_phdr *eppnt;
598 0 : unsigned long load_addr = 0;
599 0 : int load_addr_set = 0;
600 0 : unsigned long last_bss = 0, elf_bss = 0;
601 0 : int bss_prot = 0;
602 0 : unsigned long error = ~0UL;
603 : unsigned long total_size;
604 : int i;
605 :
606 : /* First of all, some simple consistency checks */
607 0 : if (interp_elf_ex->e_type != ET_EXEC &&
608 : interp_elf_ex->e_type != ET_DYN)
609 : goto out;
610 0 : if (!elf_check_arch(interp_elf_ex) ||
611 : elf_check_fdpic(interp_elf_ex))
612 : goto out;
613 0 : if (!interpreter->f_op->mmap)
614 : goto out;
615 :
616 0 : total_size = total_mapping_size(interp_elf_phdata,
617 0 : interp_elf_ex->e_phnum);
618 0 : if (!total_size) {
619 : error = -EINVAL;
620 : goto out;
621 : }
622 :
623 : eppnt = interp_elf_phdata;
624 0 : for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
625 0 : if (eppnt->p_type == PT_LOAD) {
626 0 : int elf_type = MAP_PRIVATE;
627 0 : int elf_prot = make_prot(eppnt->p_flags, arch_state,
628 : true, true);
629 0 : unsigned long vaddr = 0;
630 : unsigned long k, map_addr;
631 :
632 0 : vaddr = eppnt->p_vaddr;
633 0 : if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
634 : elf_type |= MAP_FIXED;
635 0 : else if (no_base && interp_elf_ex->e_type == ET_DYN)
636 0 : load_addr = -vaddr;
637 :
638 0 : map_addr = elf_map(interpreter, load_addr + vaddr,
639 : eppnt, elf_prot, elf_type, total_size);
640 0 : total_size = 0;
641 0 : error = map_addr;
642 0 : if (BAD_ADDR(map_addr))
643 : goto out;
644 :
645 0 : if (!load_addr_set &&
646 0 : interp_elf_ex->e_type == ET_DYN) {
647 0 : load_addr = map_addr - ELF_PAGESTART(vaddr);
648 0 : load_addr_set = 1;
649 : }
650 :
651 : /*
652 : * Check to see if the section's size will overflow the
653 : * allowed task size. Note that p_filesz must always be
654 : * <= p_memsize so it's only necessary to check p_memsz.
655 : */
656 0 : k = load_addr + eppnt->p_vaddr;
657 0 : if (BAD_ADDR(k) ||
658 0 : eppnt->p_filesz > eppnt->p_memsz ||
659 0 : eppnt->p_memsz > TASK_SIZE ||
660 0 : TASK_SIZE - eppnt->p_memsz < k) {
661 : error = -ENOMEM;
662 : goto out;
663 : }
664 :
665 : /*
666 : * Find the end of the file mapping for this phdr, and
667 : * keep track of the largest address we see for this.
668 : */
669 0 : k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
670 0 : if (k > elf_bss)
671 0 : elf_bss = k;
672 :
673 : /*
674 : * Do the same thing for the memory mapping - between
675 : * elf_bss and last_bss is the bss section.
676 : */
677 0 : k = load_addr + eppnt->p_vaddr + eppnt->p_memsz;
678 0 : if (k > last_bss) {
679 0 : last_bss = k;
680 0 : bss_prot = elf_prot;
681 : }
682 : }
683 : }
684 :
685 : /*
686 : * Now fill out the bss section: first pad the last page from
687 : * the file up to the page boundary, and zero it from elf_bss
688 : * up to the end of the page.
689 : */
690 0 : if (padzero(elf_bss)) {
691 : error = -EFAULT;
692 : goto out;
693 : }
694 : /*
695 : * Next, align both the file and mem bss up to the page size,
696 : * since this is where elf_bss was just zeroed up to, and where
697 : * last_bss will end after the vm_brk_flags() below.
698 : */
699 0 : elf_bss = ELF_PAGEALIGN(elf_bss);
700 0 : last_bss = ELF_PAGEALIGN(last_bss);
701 : /* Finally, if there is still more bss to allocate, do it. */
702 0 : if (last_bss > elf_bss) {
703 0 : error = vm_brk_flags(elf_bss, last_bss - elf_bss,
704 : bss_prot & PROT_EXEC ? VM_EXEC : 0);
705 0 : if (error)
706 : goto out;
707 : }
708 :
709 : error = load_addr;
710 : out:
711 0 : return error;
712 : }
713 :
714 : /*
715 : * These are the functions used to load ELF style executables and shared
716 : * libraries. There is no binary dependent code anywhere else.
717 : */
718 :
719 : static int parse_elf_property(const char *data, size_t *off, size_t datasz,
720 : struct arch_elf_state *arch,
721 : bool have_prev_type, u32 *prev_type)
722 : {
723 : size_t o, step;
724 : const struct gnu_property *pr;
725 : int ret;
726 :
727 : if (*off == datasz)
728 : return -ENOENT;
729 :
730 : if (WARN_ON_ONCE(*off > datasz || *off % ELF_GNU_PROPERTY_ALIGN))
731 : return -EIO;
732 : o = *off;
733 : datasz -= *off;
734 :
735 : if (datasz < sizeof(*pr))
736 : return -ENOEXEC;
737 : pr = (const struct gnu_property *)(data + o);
738 : o += sizeof(*pr);
739 : datasz -= sizeof(*pr);
740 :
741 : if (pr->pr_datasz > datasz)
742 : return -ENOEXEC;
743 :
744 : WARN_ON_ONCE(o % ELF_GNU_PROPERTY_ALIGN);
745 : step = round_up(pr->pr_datasz, ELF_GNU_PROPERTY_ALIGN);
746 : if (step > datasz)
747 : return -ENOEXEC;
748 :
749 : /* Properties are supposed to be unique and sorted on pr_type: */
750 : if (have_prev_type && pr->pr_type <= *prev_type)
751 : return -ENOEXEC;
752 : *prev_type = pr->pr_type;
753 :
754 : ret = arch_parse_elf_property(pr->pr_type, data + o,
755 : pr->pr_datasz, ELF_COMPAT, arch);
756 : if (ret)
757 : return ret;
758 :
759 : *off = o + step;
760 : return 0;
761 : }
762 :
763 : #define NOTE_DATA_SZ SZ_1K
764 : #define GNU_PROPERTY_TYPE_0_NAME "GNU"
765 : #define NOTE_NAME_SZ (sizeof(GNU_PROPERTY_TYPE_0_NAME))
766 :
767 : static int parse_elf_properties(struct file *f, const struct elf_phdr *phdr,
768 : struct arch_elf_state *arch)
769 : {
770 : union {
771 : struct elf_note nhdr;
772 : char data[NOTE_DATA_SZ];
773 : } note;
774 : loff_t pos;
775 : ssize_t n;
776 : size_t off, datasz;
777 : int ret;
778 : bool have_prev_type;
779 : u32 prev_type;
780 :
781 : if (!IS_ENABLED(CONFIG_ARCH_USE_GNU_PROPERTY) || !phdr)
782 : return 0;
783 :
784 : /* load_elf_binary() shouldn't call us unless this is true... */
785 : if (WARN_ON_ONCE(phdr->p_type != PT_GNU_PROPERTY))
786 : return -ENOEXEC;
787 :
788 : /* If the properties are crazy large, that's too bad (for now): */
789 : if (phdr->p_filesz > sizeof(note))
790 : return -ENOEXEC;
791 :
792 : pos = phdr->p_offset;
793 : n = kernel_read(f, ¬e, phdr->p_filesz, &pos);
794 :
795 : BUILD_BUG_ON(sizeof(note) < sizeof(note.nhdr) + NOTE_NAME_SZ);
796 : if (n < 0 || n < sizeof(note.nhdr) + NOTE_NAME_SZ)
797 : return -EIO;
798 :
799 : if (note.nhdr.n_type != NT_GNU_PROPERTY_TYPE_0 ||
800 : note.nhdr.n_namesz != NOTE_NAME_SZ ||
801 : strncmp(note.data + sizeof(note.nhdr),
802 : GNU_PROPERTY_TYPE_0_NAME, n - sizeof(note.nhdr)))
803 : return -ENOEXEC;
804 :
805 : off = round_up(sizeof(note.nhdr) + NOTE_NAME_SZ,
806 : ELF_GNU_PROPERTY_ALIGN);
807 : if (off > n)
808 : return -ENOEXEC;
809 :
810 : if (note.nhdr.n_descsz > n - off)
811 : return -ENOEXEC;
812 : datasz = off + note.nhdr.n_descsz;
813 :
814 : have_prev_type = false;
815 : do {
816 : ret = parse_elf_property(note.data, &off, datasz, arch,
817 : have_prev_type, &prev_type);
818 : have_prev_type = true;
819 : } while (!ret);
820 :
821 : return ret == -ENOENT ? 0 : ret;
822 : }
823 :
824 0 : static int load_elf_binary(struct linux_binprm *bprm)
825 : {
826 0 : struct file *interpreter = NULL; /* to shut gcc up */
827 0 : unsigned long load_bias = 0, phdr_addr = 0;
828 0 : int first_pt_load = 1;
829 : unsigned long error;
830 0 : struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
831 0 : struct elf_phdr *elf_property_phdata = NULL;
832 : unsigned long elf_bss, elf_brk;
833 0 : int bss_prot = 0;
834 : int retval, i;
835 : unsigned long elf_entry;
836 : unsigned long e_entry;
837 0 : unsigned long interp_load_addr = 0;
838 : unsigned long start_code, end_code, start_data, end_data;
839 0 : unsigned long reloc_func_desc __maybe_unused = 0;
840 0 : int executable_stack = EXSTACK_DEFAULT;
841 0 : struct elfhdr *elf_ex = (struct elfhdr *)bprm->buf;
842 0 : struct elfhdr *interp_elf_ex = NULL;
843 : struct arch_elf_state arch_state = INIT_ARCH_ELF_STATE;
844 : struct mm_struct *mm;
845 : struct pt_regs *regs;
846 :
847 0 : retval = -ENOEXEC;
848 : /* First of all, some simple consistency checks */
849 0 : if (memcmp(elf_ex->e_ident, ELFMAG, SELFMAG) != 0)
850 : goto out;
851 :
852 0 : if (elf_ex->e_type != ET_EXEC && elf_ex->e_type != ET_DYN)
853 : goto out;
854 0 : if (!elf_check_arch(elf_ex))
855 : goto out;
856 : if (elf_check_fdpic(elf_ex))
857 : goto out;
858 0 : if (!bprm->file->f_op->mmap)
859 : goto out;
860 :
861 0 : elf_phdata = load_elf_phdrs(elf_ex, bprm->file);
862 0 : if (!elf_phdata)
863 : goto out;
864 :
865 : elf_ppnt = elf_phdata;
866 0 : for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++) {
867 : char *elf_interpreter;
868 :
869 0 : if (elf_ppnt->p_type == PT_GNU_PROPERTY) {
870 0 : elf_property_phdata = elf_ppnt;
871 0 : continue;
872 : }
873 :
874 0 : if (elf_ppnt->p_type != PT_INTERP)
875 0 : continue;
876 :
877 : /*
878 : * This is the program interpreter used for shared libraries -
879 : * for now assume that this is an a.out format binary.
880 : */
881 0 : retval = -ENOEXEC;
882 0 : if (elf_ppnt->p_filesz > PATH_MAX || elf_ppnt->p_filesz < 2)
883 : goto out_free_ph;
884 :
885 0 : retval = -ENOMEM;
886 0 : elf_interpreter = kmalloc(elf_ppnt->p_filesz, GFP_KERNEL);
887 0 : if (!elf_interpreter)
888 : goto out_free_ph;
889 :
890 0 : retval = elf_read(bprm->file, elf_interpreter, elf_ppnt->p_filesz,
891 0 : elf_ppnt->p_offset);
892 0 : if (retval < 0)
893 : goto out_free_interp;
894 : /* make sure path is NULL terminated */
895 0 : retval = -ENOEXEC;
896 0 : if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
897 : goto out_free_interp;
898 :
899 0 : interpreter = open_exec(elf_interpreter);
900 0 : kfree(elf_interpreter);
901 0 : retval = PTR_ERR(interpreter);
902 0 : if (IS_ERR(interpreter))
903 : goto out_free_ph;
904 :
905 : /*
906 : * If the binary is not readable then enforce mm->dumpable = 0
907 : * regardless of the interpreter's permissions.
908 : */
909 0 : would_dump(bprm, interpreter);
910 :
911 0 : interp_elf_ex = kmalloc(sizeof(*interp_elf_ex), GFP_KERNEL);
912 0 : if (!interp_elf_ex) {
913 : retval = -ENOMEM;
914 : goto out_free_ph;
915 : }
916 :
917 : /* Get the exec headers */
918 0 : retval = elf_read(interpreter, interp_elf_ex,
919 : sizeof(*interp_elf_ex), 0);
920 0 : if (retval < 0)
921 : goto out_free_dentry;
922 :
923 : break;
924 :
925 : out_free_interp:
926 0 : kfree(elf_interpreter);
927 0 : goto out_free_ph;
928 : }
929 :
930 0 : elf_ppnt = elf_phdata;
931 0 : for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++)
932 0 : switch (elf_ppnt->p_type) {
933 : case PT_GNU_STACK:
934 0 : if (elf_ppnt->p_flags & PF_X)
935 : executable_stack = EXSTACK_ENABLE_X;
936 : else
937 0 : executable_stack = EXSTACK_DISABLE_X;
938 : break;
939 :
940 : case PT_LOPROC ... PT_HIPROC:
941 : retval = arch_elf_pt_proc(elf_ex, elf_ppnt,
942 : bprm->file, false,
943 : &arch_state);
944 : if (retval)
945 : goto out_free_dentry;
946 : break;
947 : }
948 :
949 : /* Some simple consistency checks for the interpreter */
950 0 : if (interpreter) {
951 0 : retval = -ELIBBAD;
952 : /* Not an ELF interpreter */
953 0 : if (memcmp(interp_elf_ex->e_ident, ELFMAG, SELFMAG) != 0)
954 : goto out_free_dentry;
955 : /* Verify the interpreter has a valid arch */
956 0 : if (!elf_check_arch(interp_elf_ex) ||
957 : elf_check_fdpic(interp_elf_ex))
958 : goto out_free_dentry;
959 :
960 : /* Load the interpreter program headers */
961 0 : interp_elf_phdata = load_elf_phdrs(interp_elf_ex,
962 : interpreter);
963 0 : if (!interp_elf_phdata)
964 : goto out_free_dentry;
965 :
966 : /* Pass PT_LOPROC..PT_HIPROC headers to arch code */
967 : elf_property_phdata = NULL;
968 : elf_ppnt = interp_elf_phdata;
969 0 : for (i = 0; i < interp_elf_ex->e_phnum; i++, elf_ppnt++)
970 : switch (elf_ppnt->p_type) {
971 : case PT_GNU_PROPERTY:
972 : elf_property_phdata = elf_ppnt;
973 : break;
974 :
975 : case PT_LOPROC ... PT_HIPROC:
976 : retval = arch_elf_pt_proc(interp_elf_ex,
977 : elf_ppnt, interpreter,
978 : true, &arch_state);
979 : if (retval)
980 : goto out_free_dentry;
981 : break;
982 : }
983 : }
984 :
985 0 : retval = parse_elf_properties(interpreter ?: bprm->file,
986 : elf_property_phdata, &arch_state);
987 : if (retval)
988 : goto out_free_dentry;
989 :
990 : /*
991 : * Allow arch code to reject the ELF at this point, whilst it's
992 : * still possible to return an error to the code that invoked
993 : * the exec syscall.
994 : */
995 0 : retval = arch_check_elf(elf_ex,
996 : !!interpreter, interp_elf_ex,
997 : &arch_state);
998 : if (retval)
999 : goto out_free_dentry;
1000 :
1001 : /* Flush all traces of the currently running executable */
1002 0 : retval = begin_new_exec(bprm);
1003 0 : if (retval)
1004 : goto out_free_dentry;
1005 :
1006 : /* Do this immediately, since STACK_TOP as used in setup_arg_pages
1007 : may depend on the personality. */
1008 : SET_PERSONALITY2(*elf_ex, &arch_state);
1009 : if (elf_read_implies_exec(*elf_ex, executable_stack))
1010 : current->personality |= READ_IMPLIES_EXEC;
1011 :
1012 0 : if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
1013 0 : current->flags |= PF_RANDOMIZE;
1014 :
1015 0 : setup_new_exec(bprm);
1016 :
1017 : /* Do this so that we can load the interpreter, if need be. We will
1018 : change some of these later */
1019 0 : retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
1020 : executable_stack);
1021 0 : if (retval < 0)
1022 : goto out_free_dentry;
1023 :
1024 : elf_bss = 0;
1025 : elf_brk = 0;
1026 :
1027 : start_code = ~0UL;
1028 : end_code = 0;
1029 : start_data = 0;
1030 : end_data = 0;
1031 :
1032 : /* Now we do a little grungy work by mmapping the ELF image into
1033 : the correct location in memory. */
1034 0 : for(i = 0, elf_ppnt = elf_phdata;
1035 0 : i < elf_ex->e_phnum; i++, elf_ppnt++) {
1036 : int elf_prot, elf_flags;
1037 : unsigned long k, vaddr;
1038 0 : unsigned long total_size = 0;
1039 : unsigned long alignment;
1040 :
1041 0 : if (elf_ppnt->p_type != PT_LOAD)
1042 0 : continue;
1043 :
1044 0 : if (unlikely (elf_brk > elf_bss)) {
1045 : unsigned long nbyte;
1046 :
1047 : /* There was a PT_LOAD segment with p_memsz > p_filesz
1048 : before this one. Map anonymous pages, if needed,
1049 : and clear the area. */
1050 0 : retval = set_brk(elf_bss + load_bias,
1051 : elf_brk + load_bias,
1052 : bss_prot);
1053 0 : if (retval)
1054 : goto out_free_dentry;
1055 0 : nbyte = ELF_PAGEOFFSET(elf_bss);
1056 0 : if (nbyte) {
1057 0 : nbyte = ELF_MIN_ALIGN - nbyte;
1058 0 : if (nbyte > elf_brk - elf_bss)
1059 0 : nbyte = elf_brk - elf_bss;
1060 0 : if (clear_user((void __user *)elf_bss +
1061 : load_bias, nbyte)) {
1062 : /*
1063 : * This bss-zeroing can fail if the ELF
1064 : * file specifies odd protections. So
1065 : * we don't check the return value
1066 : */
1067 : }
1068 : }
1069 : }
1070 :
1071 0 : elf_prot = make_prot(elf_ppnt->p_flags, &arch_state,
1072 : !!interpreter, false);
1073 :
1074 0 : elf_flags = MAP_PRIVATE;
1075 :
1076 0 : vaddr = elf_ppnt->p_vaddr;
1077 : /*
1078 : * The first time through the loop, first_pt_load is true:
1079 : * layout will be calculated. Once set, use MAP_FIXED since
1080 : * we know we've already safely mapped the entire region with
1081 : * MAP_FIXED_NOREPLACE in the once-per-binary logic following.
1082 : */
1083 0 : if (!first_pt_load) {
1084 : elf_flags |= MAP_FIXED;
1085 0 : } else if (elf_ex->e_type == ET_EXEC) {
1086 : /*
1087 : * This logic is run once for the first LOAD Program
1088 : * Header for ET_EXEC binaries. No special handling
1089 : * is needed.
1090 : */
1091 : elf_flags |= MAP_FIXED_NOREPLACE;
1092 0 : } else if (elf_ex->e_type == ET_DYN) {
1093 : /*
1094 : * This logic is run once for the first LOAD Program
1095 : * Header for ET_DYN binaries to calculate the
1096 : * randomization (load_bias) for all the LOAD
1097 : * Program Headers.
1098 : *
1099 : * There are effectively two types of ET_DYN
1100 : * binaries: programs (i.e. PIE: ET_DYN with INTERP)
1101 : * and loaders (ET_DYN without INTERP, since they
1102 : * _are_ the ELF interpreter). The loaders must
1103 : * be loaded away from programs since the program
1104 : * may otherwise collide with the loader (especially
1105 : * for ET_EXEC which does not have a randomized
1106 : * position). For example to handle invocations of
1107 : * "./ld.so someprog" to test out a new version of
1108 : * the loader, the subsequent program that the
1109 : * loader loads must avoid the loader itself, so
1110 : * they cannot share the same load range. Sufficient
1111 : * room for the brk must be allocated with the
1112 : * loader as well, since brk must be available with
1113 : * the loader.
1114 : *
1115 : * Therefore, programs are loaded offset from
1116 : * ELF_ET_DYN_BASE and loaders are loaded into the
1117 : * independently randomized mmap region (0 load_bias
1118 : * without MAP_FIXED nor MAP_FIXED_NOREPLACE).
1119 : */
1120 0 : if (interpreter) {
1121 0 : load_bias = ELF_ET_DYN_BASE;
1122 0 : if (current->flags & PF_RANDOMIZE)
1123 : load_bias += arch_mmap_rnd();
1124 0 : alignment = maximum_alignment(elf_phdata, elf_ex->e_phnum);
1125 0 : if (alignment)
1126 0 : load_bias &= ~(alignment - 1);
1127 : elf_flags |= MAP_FIXED_NOREPLACE;
1128 : } else
1129 : load_bias = 0;
1130 :
1131 : /*
1132 : * Since load_bias is used for all subsequent loading
1133 : * calculations, we must lower it by the first vaddr
1134 : * so that the remaining calculations based on the
1135 : * ELF vaddrs will be correctly offset. The result
1136 : * is then page aligned.
1137 : */
1138 0 : load_bias = ELF_PAGESTART(load_bias - vaddr);
1139 :
1140 : /*
1141 : * Calculate the entire size of the ELF mapping
1142 : * (total_size), used for the initial mapping,
1143 : * due to load_addr_set which is set to true later
1144 : * once the initial mapping is performed.
1145 : *
1146 : * Note that this is only sensible when the LOAD
1147 : * segments are contiguous (or overlapping). If
1148 : * used for LOADs that are far apart, this would
1149 : * cause the holes between LOADs to be mapped,
1150 : * running the risk of having the mapping fail,
1151 : * as it would be larger than the ELF file itself.
1152 : *
1153 : * As a result, only ET_DYN does this, since
1154 : * some ET_EXEC (e.g. ia64) may have large virtual
1155 : * memory holes between LOADs.
1156 : *
1157 : */
1158 0 : total_size = total_mapping_size(elf_phdata,
1159 0 : elf_ex->e_phnum);
1160 0 : if (!total_size) {
1161 : retval = -EINVAL;
1162 : goto out_free_dentry;
1163 : }
1164 : }
1165 :
1166 0 : error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
1167 : elf_prot, elf_flags, total_size);
1168 0 : if (BAD_ADDR(error)) {
1169 0 : retval = IS_ERR((void *)error) ?
1170 0 : PTR_ERR((void*)error) : -EINVAL;
1171 : goto out_free_dentry;
1172 : }
1173 :
1174 0 : if (first_pt_load) {
1175 0 : first_pt_load = 0;
1176 0 : if (elf_ex->e_type == ET_DYN) {
1177 0 : load_bias += error -
1178 0 : ELF_PAGESTART(load_bias + vaddr);
1179 0 : reloc_func_desc = load_bias;
1180 : }
1181 : }
1182 :
1183 : /*
1184 : * Figure out which segment in the file contains the Program
1185 : * Header table, and map to the associated memory address.
1186 : */
1187 0 : if (elf_ppnt->p_offset <= elf_ex->e_phoff &&
1188 0 : elf_ex->e_phoff < elf_ppnt->p_offset + elf_ppnt->p_filesz) {
1189 0 : phdr_addr = elf_ex->e_phoff - elf_ppnt->p_offset +
1190 0 : elf_ppnt->p_vaddr;
1191 : }
1192 :
1193 0 : k = elf_ppnt->p_vaddr;
1194 0 : if ((elf_ppnt->p_flags & PF_X) && k < start_code)
1195 0 : start_code = k;
1196 0 : if (start_data < k)
1197 0 : start_data = k;
1198 :
1199 : /*
1200 : * Check to see if the section's size will overflow the
1201 : * allowed task size. Note that p_filesz must always be
1202 : * <= p_memsz so it is only necessary to check p_memsz.
1203 : */
1204 0 : if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
1205 0 : elf_ppnt->p_memsz > TASK_SIZE ||
1206 0 : TASK_SIZE - elf_ppnt->p_memsz < k) {
1207 : /* set_brk can never work. Avoid overflows. */
1208 : retval = -EINVAL;
1209 : goto out_free_dentry;
1210 : }
1211 :
1212 0 : k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
1213 :
1214 0 : if (k > elf_bss)
1215 0 : elf_bss = k;
1216 0 : if ((elf_ppnt->p_flags & PF_X) && end_code < k)
1217 0 : end_code = k;
1218 : if (end_data < k)
1219 : end_data = k;
1220 0 : k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
1221 0 : if (k > elf_brk) {
1222 0 : bss_prot = elf_prot;
1223 0 : elf_brk = k;
1224 : }
1225 : }
1226 :
1227 0 : e_entry = elf_ex->e_entry + load_bias;
1228 0 : phdr_addr += load_bias;
1229 0 : elf_bss += load_bias;
1230 0 : elf_brk += load_bias;
1231 0 : start_code += load_bias;
1232 0 : end_code += load_bias;
1233 0 : start_data += load_bias;
1234 0 : end_data += load_bias;
1235 :
1236 : /* Calling set_brk effectively mmaps the pages that we need
1237 : * for the bss and break sections. We must do this before
1238 : * mapping in the interpreter, to make sure it doesn't wind
1239 : * up getting placed where the bss needs to go.
1240 : */
1241 0 : retval = set_brk(elf_bss, elf_brk, bss_prot);
1242 0 : if (retval)
1243 : goto out_free_dentry;
1244 0 : if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
1245 : retval = -EFAULT; /* Nobody gets to see this, but.. */
1246 : goto out_free_dentry;
1247 : }
1248 :
1249 0 : if (interpreter) {
1250 0 : elf_entry = load_elf_interp(interp_elf_ex,
1251 : interpreter,
1252 : load_bias, interp_elf_phdata,
1253 : &arch_state);
1254 0 : if (!IS_ERR((void *)elf_entry)) {
1255 : /*
1256 : * load_elf_interp() returns relocation
1257 : * adjustment
1258 : */
1259 0 : interp_load_addr = elf_entry;
1260 0 : elf_entry += interp_elf_ex->e_entry;
1261 : }
1262 0 : if (BAD_ADDR(elf_entry)) {
1263 0 : retval = IS_ERR((void *)elf_entry) ?
1264 0 : (int)elf_entry : -EINVAL;
1265 : goto out_free_dentry;
1266 : }
1267 0 : reloc_func_desc = interp_load_addr;
1268 :
1269 0 : allow_write_access(interpreter);
1270 0 : fput(interpreter);
1271 :
1272 0 : kfree(interp_elf_ex);
1273 0 : kfree(interp_elf_phdata);
1274 : } else {
1275 0 : elf_entry = e_entry;
1276 0 : if (BAD_ADDR(elf_entry)) {
1277 : retval = -EINVAL;
1278 : goto out_free_dentry;
1279 : }
1280 : }
1281 :
1282 0 : kfree(elf_phdata);
1283 :
1284 0 : set_binfmt(&elf_format);
1285 :
1286 : #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
1287 0 : retval = ARCH_SETUP_ADDITIONAL_PAGES(bprm, elf_ex, !!interpreter);
1288 0 : if (retval < 0)
1289 : goto out;
1290 : #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
1291 :
1292 0 : retval = create_elf_tables(bprm, elf_ex, interp_load_addr,
1293 : e_entry, phdr_addr);
1294 0 : if (retval < 0)
1295 : goto out;
1296 :
1297 0 : mm = current->mm;
1298 0 : mm->end_code = end_code;
1299 0 : mm->start_code = start_code;
1300 0 : mm->start_data = start_data;
1301 0 : mm->end_data = end_data;
1302 0 : mm->start_stack = bprm->p;
1303 :
1304 0 : if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
1305 : /*
1306 : * For architectures with ELF randomization, when executing
1307 : * a loader directly (i.e. no interpreter listed in ELF
1308 : * headers), move the brk area out of the mmap region
1309 : * (since it grows up, and may collide early with the stack
1310 : * growing down), and into the unused ELF_ET_DYN_BASE region.
1311 : */
1312 : if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) &&
1313 : elf_ex->e_type == ET_DYN && !interpreter) {
1314 : mm->brk = mm->start_brk = ELF_ET_DYN_BASE;
1315 : }
1316 :
1317 0 : mm->brk = mm->start_brk = arch_randomize_brk(mm);
1318 : #ifdef compat_brk_randomized
1319 : current->brk_randomized = 1;
1320 : #endif
1321 : }
1322 :
1323 0 : if (current->personality & MMAP_PAGE_ZERO) {
1324 : /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
1325 : and some applications "depend" upon this behavior.
1326 : Since we do not have the power to recompile these, we
1327 : emulate the SVr4 behavior. Sigh. */
1328 0 : error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1329 : MAP_FIXED | MAP_PRIVATE, 0);
1330 : }
1331 :
1332 0 : regs = current_pt_regs();
1333 : #ifdef ELF_PLAT_INIT
1334 : /*
1335 : * The ABI may specify that certain registers be set up in special
1336 : * ways (on i386 %edx is the address of a DT_FINI function, for
1337 : * example. In addition, it may also specify (eg, PowerPC64 ELF)
1338 : * that the e_entry field is the address of the function descriptor
1339 : * for the startup routine, rather than the address of the startup
1340 : * routine itself. This macro performs whatever initialization to
1341 : * the regs structure is required as well as any relocations to the
1342 : * function descriptor entries when executing dynamically links apps.
1343 : */
1344 0 : ELF_PLAT_INIT(regs, reloc_func_desc);
1345 : #endif
1346 :
1347 0 : finalize_exec(bprm);
1348 0 : START_THREAD(elf_ex, regs, elf_entry, bprm->p);
1349 0 : retval = 0;
1350 : out:
1351 0 : return retval;
1352 :
1353 : /* error cleanup */
1354 : out_free_dentry:
1355 0 : kfree(interp_elf_ex);
1356 0 : kfree(interp_elf_phdata);
1357 0 : allow_write_access(interpreter);
1358 0 : if (interpreter)
1359 0 : fput(interpreter);
1360 : out_free_ph:
1361 0 : kfree(elf_phdata);
1362 0 : goto out;
1363 : }
1364 :
1365 : #ifdef CONFIG_USELIB
1366 : /* This is really simpleminded and specialized - we are loading an
1367 : a.out library that is given an ELF header. */
1368 : static int load_elf_library(struct file *file)
1369 : {
1370 : struct elf_phdr *elf_phdata;
1371 : struct elf_phdr *eppnt;
1372 : unsigned long elf_bss, bss, len;
1373 : int retval, error, i, j;
1374 : struct elfhdr elf_ex;
1375 :
1376 : error = -ENOEXEC;
1377 : retval = elf_read(file, &elf_ex, sizeof(elf_ex), 0);
1378 : if (retval < 0)
1379 : goto out;
1380 :
1381 : if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1382 : goto out;
1383 :
1384 : /* First of all, some simple consistency checks */
1385 : if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1386 : !elf_check_arch(&elf_ex) || !file->f_op->mmap)
1387 : goto out;
1388 : if (elf_check_fdpic(&elf_ex))
1389 : goto out;
1390 :
1391 : /* Now read in all of the header information */
1392 :
1393 : j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1394 : /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1395 :
1396 : error = -ENOMEM;
1397 : elf_phdata = kmalloc(j, GFP_KERNEL);
1398 : if (!elf_phdata)
1399 : goto out;
1400 :
1401 : eppnt = elf_phdata;
1402 : error = -ENOEXEC;
1403 : retval = elf_read(file, eppnt, j, elf_ex.e_phoff);
1404 : if (retval < 0)
1405 : goto out_free_ph;
1406 :
1407 : for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1408 : if ((eppnt + i)->p_type == PT_LOAD)
1409 : j++;
1410 : if (j != 1)
1411 : goto out_free_ph;
1412 :
1413 : while (eppnt->p_type != PT_LOAD)
1414 : eppnt++;
1415 :
1416 : /* Now use mmap to map the library into memory. */
1417 : error = vm_mmap(file,
1418 : ELF_PAGESTART(eppnt->p_vaddr),
1419 : (eppnt->p_filesz +
1420 : ELF_PAGEOFFSET(eppnt->p_vaddr)),
1421 : PROT_READ | PROT_WRITE | PROT_EXEC,
1422 : MAP_FIXED_NOREPLACE | MAP_PRIVATE,
1423 : (eppnt->p_offset -
1424 : ELF_PAGEOFFSET(eppnt->p_vaddr)));
1425 : if (error != ELF_PAGESTART(eppnt->p_vaddr))
1426 : goto out_free_ph;
1427 :
1428 : elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1429 : if (padzero(elf_bss)) {
1430 : error = -EFAULT;
1431 : goto out_free_ph;
1432 : }
1433 :
1434 : len = ELF_PAGEALIGN(eppnt->p_filesz + eppnt->p_vaddr);
1435 : bss = ELF_PAGEALIGN(eppnt->p_memsz + eppnt->p_vaddr);
1436 : if (bss > len) {
1437 : error = vm_brk(len, bss - len);
1438 : if (error)
1439 : goto out_free_ph;
1440 : }
1441 : error = 0;
1442 :
1443 : out_free_ph:
1444 : kfree(elf_phdata);
1445 : out:
1446 : return error;
1447 : }
1448 : #endif /* #ifdef CONFIG_USELIB */
1449 :
1450 : #ifdef CONFIG_ELF_CORE
1451 : /*
1452 : * ELF core dumper
1453 : *
1454 : * Modelled on fs/exec.c:aout_core_dump()
1455 : * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1456 : */
1457 :
1458 : /* An ELF note in memory */
1459 : struct memelfnote
1460 : {
1461 : const char *name;
1462 : int type;
1463 : unsigned int datasz;
1464 : void *data;
1465 : };
1466 :
1467 : static int notesize(struct memelfnote *en)
1468 : {
1469 : int sz;
1470 :
1471 0 : sz = sizeof(struct elf_note);
1472 0 : sz += roundup(strlen(en->name) + 1, 4);
1473 0 : sz += roundup(en->datasz, 4);
1474 :
1475 : return sz;
1476 : }
1477 :
1478 0 : static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1479 : {
1480 : struct elf_note en;
1481 0 : en.n_namesz = strlen(men->name) + 1;
1482 0 : en.n_descsz = men->datasz;
1483 0 : en.n_type = men->type;
1484 :
1485 0 : return dump_emit(cprm, &en, sizeof(en)) &&
1486 0 : dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1487 0 : dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1488 : }
1489 :
1490 0 : static void fill_elf_header(struct elfhdr *elf, int segs,
1491 : u16 machine, u32 flags)
1492 : {
1493 0 : memset(elf, 0, sizeof(*elf));
1494 :
1495 0 : memcpy(elf->e_ident, ELFMAG, SELFMAG);
1496 0 : elf->e_ident[EI_CLASS] = ELF_CLASS;
1497 0 : elf->e_ident[EI_DATA] = ELF_DATA;
1498 0 : elf->e_ident[EI_VERSION] = EV_CURRENT;
1499 0 : elf->e_ident[EI_OSABI] = ELF_OSABI;
1500 :
1501 0 : elf->e_type = ET_CORE;
1502 0 : elf->e_machine = machine;
1503 0 : elf->e_version = EV_CURRENT;
1504 0 : elf->e_phoff = sizeof(struct elfhdr);
1505 0 : elf->e_flags = flags;
1506 0 : elf->e_ehsize = sizeof(struct elfhdr);
1507 0 : elf->e_phentsize = sizeof(struct elf_phdr);
1508 0 : elf->e_phnum = segs;
1509 0 : }
1510 :
1511 : static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1512 : {
1513 0 : phdr->p_type = PT_NOTE;
1514 0 : phdr->p_offset = offset;
1515 0 : phdr->p_vaddr = 0;
1516 0 : phdr->p_paddr = 0;
1517 0 : phdr->p_filesz = sz;
1518 0 : phdr->p_memsz = 0;
1519 0 : phdr->p_flags = 0;
1520 0 : phdr->p_align = 0;
1521 : }
1522 :
1523 : static void fill_note(struct memelfnote *note, const char *name, int type,
1524 : unsigned int sz, void *data)
1525 : {
1526 0 : note->name = name;
1527 0 : note->type = type;
1528 0 : note->datasz = sz;
1529 0 : note->data = data;
1530 : }
1531 :
1532 : /*
1533 : * fill up all the fields in prstatus from the given task struct, except
1534 : * registers which need to be filled up separately.
1535 : */
1536 0 : static void fill_prstatus(struct elf_prstatus_common *prstatus,
1537 : struct task_struct *p, long signr)
1538 : {
1539 0 : prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1540 0 : prstatus->pr_sigpend = p->pending.signal.sig[0];
1541 0 : prstatus->pr_sighold = p->blocked.sig[0];
1542 : rcu_read_lock();
1543 0 : prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1544 0 : rcu_read_unlock();
1545 0 : prstatus->pr_pid = task_pid_vnr(p);
1546 0 : prstatus->pr_pgrp = task_pgrp_vnr(p);
1547 0 : prstatus->pr_sid = task_session_vnr(p);
1548 0 : if (thread_group_leader(p)) {
1549 : struct task_cputime cputime;
1550 :
1551 : /*
1552 : * This is the record for the group leader. It shows the
1553 : * group-wide total, not its individual thread total.
1554 : */
1555 0 : thread_group_cputime(p, &cputime);
1556 0 : prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1557 0 : prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1558 : } else {
1559 : u64 utime, stime;
1560 :
1561 0 : task_cputime(p, &utime, &stime);
1562 0 : prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1563 0 : prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1564 : }
1565 :
1566 0 : prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1567 0 : prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1568 0 : }
1569 :
1570 0 : static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1571 : struct mm_struct *mm)
1572 : {
1573 : const struct cred *cred;
1574 : unsigned int i, len;
1575 : unsigned int state;
1576 :
1577 : /* first copy the parameters from user space */
1578 0 : memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1579 :
1580 0 : len = mm->arg_end - mm->arg_start;
1581 0 : if (len >= ELF_PRARGSZ)
1582 0 : len = ELF_PRARGSZ-1;
1583 0 : if (copy_from_user(&psinfo->pr_psargs,
1584 : (const char __user *)mm->arg_start, len))
1585 : return -EFAULT;
1586 0 : for(i = 0; i < len; i++)
1587 0 : if (psinfo->pr_psargs[i] == 0)
1588 0 : psinfo->pr_psargs[i] = ' ';
1589 0 : psinfo->pr_psargs[len] = 0;
1590 :
1591 : rcu_read_lock();
1592 0 : psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1593 0 : rcu_read_unlock();
1594 0 : psinfo->pr_pid = task_pid_vnr(p);
1595 0 : psinfo->pr_pgrp = task_pgrp_vnr(p);
1596 0 : psinfo->pr_sid = task_session_vnr(p);
1597 :
1598 0 : state = READ_ONCE(p->__state);
1599 0 : i = state ? ffz(~state) + 1 : 0;
1600 0 : psinfo->pr_state = i;
1601 0 : psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1602 0 : psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1603 0 : psinfo->pr_nice = task_nice(p);
1604 0 : psinfo->pr_flag = p->flags;
1605 : rcu_read_lock();
1606 0 : cred = __task_cred(p);
1607 0 : SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1608 0 : SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1609 : rcu_read_unlock();
1610 0 : get_task_comm(psinfo->pr_fname, p);
1611 :
1612 0 : return 0;
1613 : }
1614 :
1615 : static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1616 : {
1617 0 : elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1618 0 : int i = 0;
1619 : do
1620 0 : i += 2;
1621 0 : while (auxv[i - 2] != AT_NULL);
1622 0 : fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1623 : }
1624 :
1625 : static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1626 : const kernel_siginfo_t *siginfo)
1627 : {
1628 0 : copy_siginfo_to_external(csigdata, siginfo);
1629 0 : fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1630 : }
1631 :
1632 : #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1633 : /*
1634 : * Format of NT_FILE note:
1635 : *
1636 : * long count -- how many files are mapped
1637 : * long page_size -- units for file_ofs
1638 : * array of [COUNT] elements of
1639 : * long start
1640 : * long end
1641 : * long file_ofs
1642 : * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1643 : */
1644 0 : static int fill_files_note(struct memelfnote *note, struct coredump_params *cprm)
1645 : {
1646 : unsigned count, size, names_ofs, remaining, n;
1647 : user_long_t *data;
1648 : user_long_t *start_end_ofs;
1649 : char *name_base, *name_curpos;
1650 : int i;
1651 :
1652 : /* *Estimated* file count and total data size needed */
1653 0 : count = cprm->vma_count;
1654 0 : if (count > UINT_MAX / 64)
1655 : return -EINVAL;
1656 0 : size = count * 64;
1657 :
1658 0 : names_ofs = (2 + 3 * count) * sizeof(data[0]);
1659 : alloc:
1660 0 : if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1661 : return -EINVAL;
1662 0 : size = round_up(size, PAGE_SIZE);
1663 : /*
1664 : * "size" can be 0 here legitimately.
1665 : * Let it ENOMEM and omit NT_FILE section which will be empty anyway.
1666 : */
1667 0 : data = kvmalloc(size, GFP_KERNEL);
1668 0 : if (ZERO_OR_NULL_PTR(data))
1669 : return -ENOMEM;
1670 :
1671 0 : start_end_ofs = data + 2;
1672 0 : name_base = name_curpos = ((char *)data) + names_ofs;
1673 0 : remaining = size - names_ofs;
1674 0 : count = 0;
1675 0 : for (i = 0; i < cprm->vma_count; i++) {
1676 0 : struct core_vma_metadata *m = &cprm->vma_meta[i];
1677 : struct file *file;
1678 : const char *filename;
1679 :
1680 0 : file = m->file;
1681 0 : if (!file)
1682 0 : continue;
1683 0 : filename = file_path(file, name_curpos, remaining);
1684 0 : if (IS_ERR(filename)) {
1685 0 : if (PTR_ERR(filename) == -ENAMETOOLONG) {
1686 0 : kvfree(data);
1687 0 : size = size * 5 / 4;
1688 : goto alloc;
1689 : }
1690 0 : continue;
1691 : }
1692 :
1693 : /* file_path() fills at the end, move name down */
1694 : /* n = strlen(filename) + 1: */
1695 0 : n = (name_curpos + remaining) - filename;
1696 0 : remaining = filename - name_curpos;
1697 0 : memmove(name_curpos, filename, n);
1698 0 : name_curpos += n;
1699 :
1700 0 : *start_end_ofs++ = m->start;
1701 0 : *start_end_ofs++ = m->end;
1702 0 : *start_end_ofs++ = m->pgoff;
1703 0 : count++;
1704 : }
1705 :
1706 : /* Now we know exact count of files, can store it */
1707 0 : data[0] = count;
1708 0 : data[1] = PAGE_SIZE;
1709 : /*
1710 : * Count usually is less than mm->map_count,
1711 : * we need to move filenames down.
1712 : */
1713 0 : n = cprm->vma_count - count;
1714 0 : if (n != 0) {
1715 0 : unsigned shift_bytes = n * 3 * sizeof(data[0]);
1716 0 : memmove(name_base - shift_bytes, name_base,
1717 0 : name_curpos - name_base);
1718 0 : name_curpos -= shift_bytes;
1719 : }
1720 :
1721 0 : size = name_curpos - (char *)data;
1722 0 : fill_note(note, "CORE", NT_FILE, size, data);
1723 : return 0;
1724 : }
1725 :
1726 : #ifdef CORE_DUMP_USE_REGSET
1727 : #include <linux/regset.h>
1728 :
1729 : struct elf_thread_core_info {
1730 : struct elf_thread_core_info *next;
1731 : struct task_struct *task;
1732 : struct elf_prstatus prstatus;
1733 : struct memelfnote notes[];
1734 : };
1735 :
1736 : struct elf_note_info {
1737 : struct elf_thread_core_info *thread;
1738 : struct memelfnote psinfo;
1739 : struct memelfnote signote;
1740 : struct memelfnote auxv;
1741 : struct memelfnote files;
1742 : user_siginfo_t csigdata;
1743 : size_t size;
1744 : int thread_notes;
1745 : };
1746 :
1747 : /*
1748 : * When a regset has a writeback hook, we call it on each thread before
1749 : * dumping user memory. On register window machines, this makes sure the
1750 : * user memory backing the register data is up to date before we read it.
1751 : */
1752 : static void do_thread_regset_writeback(struct task_struct *task,
1753 : const struct user_regset *regset)
1754 : {
1755 : if (regset->writeback)
1756 : regset->writeback(task, regset, 1);
1757 : }
1758 :
1759 : #ifndef PRSTATUS_SIZE
1760 : #define PRSTATUS_SIZE sizeof(struct elf_prstatus)
1761 : #endif
1762 :
1763 : #ifndef SET_PR_FPVALID
1764 : #define SET_PR_FPVALID(S) ((S)->pr_fpvalid = 1)
1765 : #endif
1766 :
1767 : static int fill_thread_core_info(struct elf_thread_core_info *t,
1768 : const struct user_regset_view *view,
1769 : long signr, struct elf_note_info *info)
1770 : {
1771 : unsigned int note_iter, view_iter;
1772 :
1773 : /*
1774 : * NT_PRSTATUS is the one special case, because the regset data
1775 : * goes into the pr_reg field inside the note contents, rather
1776 : * than being the whole note contents. We fill the reset in here.
1777 : * We assume that regset 0 is NT_PRSTATUS.
1778 : */
1779 : fill_prstatus(&t->prstatus.common, t->task, signr);
1780 : regset_get(t->task, &view->regsets[0],
1781 : sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1782 :
1783 : fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1784 : PRSTATUS_SIZE, &t->prstatus);
1785 : info->size += notesize(&t->notes[0]);
1786 :
1787 : do_thread_regset_writeback(t->task, &view->regsets[0]);
1788 :
1789 : /*
1790 : * Each other regset might generate a note too. For each regset
1791 : * that has no core_note_type or is inactive, skip it.
1792 : */
1793 : note_iter = 1;
1794 : for (view_iter = 1; view_iter < view->n; ++view_iter) {
1795 : const struct user_regset *regset = &view->regsets[view_iter];
1796 : int note_type = regset->core_note_type;
1797 : bool is_fpreg = note_type == NT_PRFPREG;
1798 : void *data;
1799 : int ret;
1800 :
1801 : do_thread_regset_writeback(t->task, regset);
1802 : if (!note_type) // not for coredumps
1803 : continue;
1804 : if (regset->active && regset->active(t->task, regset) <= 0)
1805 : continue;
1806 :
1807 : ret = regset_get_alloc(t->task, regset, ~0U, &data);
1808 : if (ret < 0)
1809 : continue;
1810 :
1811 : if (WARN_ON_ONCE(note_iter >= info->thread_notes))
1812 : break;
1813 :
1814 : if (is_fpreg)
1815 : SET_PR_FPVALID(&t->prstatus);
1816 :
1817 : fill_note(&t->notes[note_iter], is_fpreg ? "CORE" : "LINUX",
1818 : note_type, ret, data);
1819 :
1820 : info->size += notesize(&t->notes[note_iter]);
1821 : note_iter++;
1822 : }
1823 :
1824 : return 1;
1825 : }
1826 :
1827 : static int fill_note_info(struct elfhdr *elf, int phdrs,
1828 : struct elf_note_info *info,
1829 : struct coredump_params *cprm)
1830 : {
1831 : struct task_struct *dump_task = current;
1832 : const struct user_regset_view *view = task_user_regset_view(dump_task);
1833 : struct elf_thread_core_info *t;
1834 : struct elf_prpsinfo *psinfo;
1835 : struct core_thread *ct;
1836 : unsigned int i;
1837 :
1838 : info->size = 0;
1839 : info->thread = NULL;
1840 :
1841 : psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1842 : if (psinfo == NULL) {
1843 : info->psinfo.data = NULL; /* So we don't free this wrongly */
1844 : return 0;
1845 : }
1846 :
1847 : fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1848 :
1849 : /*
1850 : * Figure out how many notes we're going to need for each thread.
1851 : */
1852 : info->thread_notes = 0;
1853 : for (i = 0; i < view->n; ++i)
1854 : if (view->regsets[i].core_note_type != 0)
1855 : ++info->thread_notes;
1856 :
1857 : /*
1858 : * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1859 : * since it is our one special case.
1860 : */
1861 : if (unlikely(info->thread_notes == 0) ||
1862 : unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1863 : WARN_ON(1);
1864 : return 0;
1865 : }
1866 :
1867 : /*
1868 : * Initialize the ELF file header.
1869 : */
1870 : fill_elf_header(elf, phdrs,
1871 : view->e_machine, view->e_flags);
1872 :
1873 : /*
1874 : * Allocate a structure for each thread.
1875 : */
1876 : for (ct = &dump_task->signal->core_state->dumper; ct; ct = ct->next) {
1877 : t = kzalloc(offsetof(struct elf_thread_core_info,
1878 : notes[info->thread_notes]),
1879 : GFP_KERNEL);
1880 : if (unlikely(!t))
1881 : return 0;
1882 :
1883 : t->task = ct->task;
1884 : if (ct->task == dump_task || !info->thread) {
1885 : t->next = info->thread;
1886 : info->thread = t;
1887 : } else {
1888 : /*
1889 : * Make sure to keep the original task at
1890 : * the head of the list.
1891 : */
1892 : t->next = info->thread->next;
1893 : info->thread->next = t;
1894 : }
1895 : }
1896 :
1897 : /*
1898 : * Now fill in each thread's information.
1899 : */
1900 : for (t = info->thread; t != NULL; t = t->next)
1901 : if (!fill_thread_core_info(t, view, cprm->siginfo->si_signo, info))
1902 : return 0;
1903 :
1904 : /*
1905 : * Fill in the two process-wide notes.
1906 : */
1907 : fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1908 : info->size += notesize(&info->psinfo);
1909 :
1910 : fill_siginfo_note(&info->signote, &info->csigdata, cprm->siginfo);
1911 : info->size += notesize(&info->signote);
1912 :
1913 : fill_auxv_note(&info->auxv, current->mm);
1914 : info->size += notesize(&info->auxv);
1915 :
1916 : if (fill_files_note(&info->files, cprm) == 0)
1917 : info->size += notesize(&info->files);
1918 :
1919 : return 1;
1920 : }
1921 :
1922 : static size_t get_note_info_size(struct elf_note_info *info)
1923 : {
1924 : return info->size;
1925 : }
1926 :
1927 : /*
1928 : * Write all the notes for each thread. When writing the first thread, the
1929 : * process-wide notes are interleaved after the first thread-specific note.
1930 : */
1931 : static int write_note_info(struct elf_note_info *info,
1932 : struct coredump_params *cprm)
1933 : {
1934 : bool first = true;
1935 : struct elf_thread_core_info *t = info->thread;
1936 :
1937 : do {
1938 : int i;
1939 :
1940 : if (!writenote(&t->notes[0], cprm))
1941 : return 0;
1942 :
1943 : if (first && !writenote(&info->psinfo, cprm))
1944 : return 0;
1945 : if (first && !writenote(&info->signote, cprm))
1946 : return 0;
1947 : if (first && !writenote(&info->auxv, cprm))
1948 : return 0;
1949 : if (first && info->files.data &&
1950 : !writenote(&info->files, cprm))
1951 : return 0;
1952 :
1953 : for (i = 1; i < info->thread_notes; ++i)
1954 : if (t->notes[i].data &&
1955 : !writenote(&t->notes[i], cprm))
1956 : return 0;
1957 :
1958 : first = false;
1959 : t = t->next;
1960 : } while (t);
1961 :
1962 : return 1;
1963 : }
1964 :
1965 : static void free_note_info(struct elf_note_info *info)
1966 : {
1967 : struct elf_thread_core_info *threads = info->thread;
1968 : while (threads) {
1969 : unsigned int i;
1970 : struct elf_thread_core_info *t = threads;
1971 : threads = t->next;
1972 : WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1973 : for (i = 1; i < info->thread_notes; ++i)
1974 : kfree(t->notes[i].data);
1975 : kfree(t);
1976 : }
1977 : kfree(info->psinfo.data);
1978 : kvfree(info->files.data);
1979 : }
1980 :
1981 : #else
1982 :
1983 : /* Here is the structure in which status of each thread is captured. */
1984 : struct elf_thread_status
1985 : {
1986 : struct list_head list;
1987 : struct elf_prstatus prstatus; /* NT_PRSTATUS */
1988 : elf_fpregset_t fpu; /* NT_PRFPREG */
1989 : struct task_struct *thread;
1990 : struct memelfnote notes[3];
1991 : int num_notes;
1992 : };
1993 :
1994 : /*
1995 : * In order to add the specific thread information for the elf file format,
1996 : * we need to keep a linked list of every threads pr_status and then create
1997 : * a single section for them in the final core file.
1998 : */
1999 0 : static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
2000 : {
2001 0 : int sz = 0;
2002 0 : struct task_struct *p = t->thread;
2003 0 : t->num_notes = 0;
2004 :
2005 0 : fill_prstatus(&t->prstatus.common, p, signr);
2006 0 : elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
2007 :
2008 0 : fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
2009 0 : &(t->prstatus));
2010 0 : t->num_notes++;
2011 0 : sz += notesize(&t->notes[0]);
2012 :
2013 0 : if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
2014 : &t->fpu))) {
2015 0 : fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
2016 : &(t->fpu));
2017 0 : t->num_notes++;
2018 0 : sz += notesize(&t->notes[1]);
2019 : }
2020 0 : return sz;
2021 : }
2022 :
2023 : struct elf_note_info {
2024 : struct memelfnote *notes;
2025 : struct memelfnote *notes_files;
2026 : struct elf_prstatus *prstatus; /* NT_PRSTATUS */
2027 : struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
2028 : struct list_head thread_list;
2029 : elf_fpregset_t *fpu;
2030 : user_siginfo_t csigdata;
2031 : int thread_status_size;
2032 : int numnote;
2033 : };
2034 :
2035 0 : static int elf_note_info_init(struct elf_note_info *info)
2036 : {
2037 0 : memset(info, 0, sizeof(*info));
2038 0 : INIT_LIST_HEAD(&info->thread_list);
2039 :
2040 : /* Allocate space for ELF notes */
2041 0 : info->notes = kmalloc_array(8, sizeof(struct memelfnote), GFP_KERNEL);
2042 0 : if (!info->notes)
2043 : return 0;
2044 0 : info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
2045 0 : if (!info->psinfo)
2046 : return 0;
2047 0 : info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
2048 0 : if (!info->prstatus)
2049 : return 0;
2050 0 : info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
2051 0 : if (!info->fpu)
2052 : return 0;
2053 0 : return 1;
2054 : }
2055 :
2056 0 : static int fill_note_info(struct elfhdr *elf, int phdrs,
2057 : struct elf_note_info *info,
2058 : struct coredump_params *cprm)
2059 : {
2060 : struct core_thread *ct;
2061 : struct elf_thread_status *ets;
2062 :
2063 0 : if (!elf_note_info_init(info))
2064 : return 0;
2065 :
2066 0 : for (ct = current->signal->core_state->dumper.next;
2067 0 : ct; ct = ct->next) {
2068 0 : ets = kzalloc(sizeof(*ets), GFP_KERNEL);
2069 0 : if (!ets)
2070 : return 0;
2071 :
2072 0 : ets->thread = ct->task;
2073 0 : list_add(&ets->list, &info->thread_list);
2074 : }
2075 :
2076 0 : list_for_each_entry(ets, &info->thread_list, list) {
2077 : int sz;
2078 :
2079 0 : sz = elf_dump_thread_status(cprm->siginfo->si_signo, ets);
2080 0 : info->thread_status_size += sz;
2081 : }
2082 : /* now collect the dump for the current */
2083 0 : memset(info->prstatus, 0, sizeof(*info->prstatus));
2084 0 : fill_prstatus(&info->prstatus->common, current, cprm->siginfo->si_signo);
2085 0 : elf_core_copy_regs(&info->prstatus->pr_reg, cprm->regs);
2086 :
2087 : /* Set up header */
2088 0 : fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
2089 :
2090 : /*
2091 : * Set up the notes in similar form to SVR4 core dumps made
2092 : * with info from their /proc.
2093 : */
2094 :
2095 0 : fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
2096 0 : sizeof(*info->prstatus), info->prstatus);
2097 0 : fill_psinfo(info->psinfo, current->group_leader, current->mm);
2098 0 : fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
2099 0 : sizeof(*info->psinfo), info->psinfo);
2100 :
2101 0 : fill_siginfo_note(info->notes + 2, &info->csigdata, cprm->siginfo);
2102 0 : fill_auxv_note(info->notes + 3, current->mm);
2103 0 : info->numnote = 4;
2104 :
2105 0 : if (fill_files_note(info->notes + info->numnote, cprm) == 0) {
2106 0 : info->notes_files = info->notes + info->numnote;
2107 0 : info->numnote++;
2108 : }
2109 :
2110 : /* Try to dump the FPU. */
2111 0 : info->prstatus->pr_fpvalid =
2112 0 : elf_core_copy_task_fpregs(current, cprm->regs, info->fpu);
2113 0 : if (info->prstatus->pr_fpvalid)
2114 0 : fill_note(info->notes + info->numnote++,
2115 0 : "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
2116 : return 1;
2117 : }
2118 :
2119 0 : static size_t get_note_info_size(struct elf_note_info *info)
2120 : {
2121 0 : int sz = 0;
2122 : int i;
2123 :
2124 0 : for (i = 0; i < info->numnote; i++)
2125 0 : sz += notesize(info->notes + i);
2126 :
2127 0 : sz += info->thread_status_size;
2128 :
2129 0 : return sz;
2130 : }
2131 :
2132 0 : static int write_note_info(struct elf_note_info *info,
2133 : struct coredump_params *cprm)
2134 : {
2135 : struct elf_thread_status *ets;
2136 : int i;
2137 :
2138 0 : for (i = 0; i < info->numnote; i++)
2139 0 : if (!writenote(info->notes + i, cprm))
2140 : return 0;
2141 :
2142 : /* write out the thread status notes section */
2143 0 : list_for_each_entry(ets, &info->thread_list, list) {
2144 0 : for (i = 0; i < ets->num_notes; i++)
2145 0 : if (!writenote(&ets->notes[i], cprm))
2146 : return 0;
2147 : }
2148 :
2149 : return 1;
2150 : }
2151 :
2152 0 : static void free_note_info(struct elf_note_info *info)
2153 : {
2154 0 : while (!list_empty(&info->thread_list)) {
2155 0 : struct list_head *tmp = info->thread_list.next;
2156 0 : list_del(tmp);
2157 0 : kfree(list_entry(tmp, struct elf_thread_status, list));
2158 : }
2159 :
2160 : /* Free data possibly allocated by fill_files_note(): */
2161 0 : if (info->notes_files)
2162 0 : kvfree(info->notes_files->data);
2163 :
2164 0 : kfree(info->prstatus);
2165 0 : kfree(info->psinfo);
2166 0 : kfree(info->notes);
2167 0 : kfree(info->fpu);
2168 0 : }
2169 :
2170 : #endif
2171 :
2172 : static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
2173 : elf_addr_t e_shoff, int segs)
2174 : {
2175 0 : elf->e_shoff = e_shoff;
2176 0 : elf->e_shentsize = sizeof(*shdr4extnum);
2177 0 : elf->e_shnum = 1;
2178 0 : elf->e_shstrndx = SHN_UNDEF;
2179 :
2180 0 : memset(shdr4extnum, 0, sizeof(*shdr4extnum));
2181 :
2182 0 : shdr4extnum->sh_type = SHT_NULL;
2183 0 : shdr4extnum->sh_size = elf->e_shnum;
2184 0 : shdr4extnum->sh_link = elf->e_shstrndx;
2185 0 : shdr4extnum->sh_info = segs;
2186 : }
2187 :
2188 : /*
2189 : * Actual dumper
2190 : *
2191 : * This is a two-pass process; first we find the offsets of the bits,
2192 : * and then they are actually written out. If we run out of core limit
2193 : * we just truncate.
2194 : */
2195 0 : static int elf_core_dump(struct coredump_params *cprm)
2196 : {
2197 0 : int has_dumped = 0;
2198 : int segs, i;
2199 : struct elfhdr elf;
2200 0 : loff_t offset = 0, dataoff;
2201 0 : struct elf_note_info info = { };
2202 0 : struct elf_phdr *phdr4note = NULL;
2203 0 : struct elf_shdr *shdr4extnum = NULL;
2204 : Elf_Half e_phnum;
2205 : elf_addr_t e_shoff;
2206 :
2207 : /*
2208 : * The number of segs are recored into ELF header as 16bit value.
2209 : * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2210 : */
2211 0 : segs = cprm->vma_count + elf_core_extra_phdrs();
2212 :
2213 : /* for notes section */
2214 0 : segs++;
2215 :
2216 : /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2217 : * this, kernel supports extended numbering. Have a look at
2218 : * include/linux/elf.h for further information. */
2219 0 : e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2220 :
2221 : /*
2222 : * Collect all the non-memory information about the process for the
2223 : * notes. This also sets up the file header.
2224 : */
2225 0 : if (!fill_note_info(&elf, e_phnum, &info, cprm))
2226 : goto end_coredump;
2227 :
2228 0 : has_dumped = 1;
2229 :
2230 0 : offset += sizeof(elf); /* Elf header */
2231 0 : offset += segs * sizeof(struct elf_phdr); /* Program headers */
2232 :
2233 : /* Write notes phdr entry */
2234 : {
2235 0 : size_t sz = get_note_info_size(&info);
2236 :
2237 : /* For cell spufs */
2238 0 : sz += elf_coredump_extra_notes_size();
2239 :
2240 0 : phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2241 0 : if (!phdr4note)
2242 : goto end_coredump;
2243 :
2244 0 : fill_elf_note_phdr(phdr4note, sz, offset);
2245 0 : offset += sz;
2246 : }
2247 :
2248 0 : dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2249 :
2250 0 : offset += cprm->vma_data_size;
2251 0 : offset += elf_core_extra_data_size();
2252 0 : e_shoff = offset;
2253 :
2254 0 : if (e_phnum == PN_XNUM) {
2255 0 : shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2256 0 : if (!shdr4extnum)
2257 : goto end_coredump;
2258 : fill_extnum_info(&elf, shdr4extnum, e_shoff, segs);
2259 : }
2260 :
2261 0 : offset = dataoff;
2262 :
2263 0 : if (!dump_emit(cprm, &elf, sizeof(elf)))
2264 : goto end_coredump;
2265 :
2266 0 : if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
2267 : goto end_coredump;
2268 :
2269 : /* Write program headers for segments dump */
2270 0 : for (i = 0; i < cprm->vma_count; i++) {
2271 0 : struct core_vma_metadata *meta = cprm->vma_meta + i;
2272 : struct elf_phdr phdr;
2273 :
2274 0 : phdr.p_type = PT_LOAD;
2275 0 : phdr.p_offset = offset;
2276 0 : phdr.p_vaddr = meta->start;
2277 0 : phdr.p_paddr = 0;
2278 0 : phdr.p_filesz = meta->dump_size;
2279 0 : phdr.p_memsz = meta->end - meta->start;
2280 0 : offset += phdr.p_filesz;
2281 0 : phdr.p_flags = 0;
2282 0 : if (meta->flags & VM_READ)
2283 0 : phdr.p_flags |= PF_R;
2284 0 : if (meta->flags & VM_WRITE)
2285 0 : phdr.p_flags |= PF_W;
2286 0 : if (meta->flags & VM_EXEC)
2287 0 : phdr.p_flags |= PF_X;
2288 0 : phdr.p_align = ELF_EXEC_PAGESIZE;
2289 :
2290 0 : if (!dump_emit(cprm, &phdr, sizeof(phdr)))
2291 : goto end_coredump;
2292 : }
2293 :
2294 0 : if (!elf_core_write_extra_phdrs(cprm, offset))
2295 : goto end_coredump;
2296 :
2297 : /* write out the notes section */
2298 0 : if (!write_note_info(&info, cprm))
2299 : goto end_coredump;
2300 :
2301 : /* For cell spufs */
2302 0 : if (elf_coredump_extra_notes_write(cprm))
2303 : goto end_coredump;
2304 :
2305 : /* Align to page */
2306 0 : dump_skip_to(cprm, dataoff);
2307 :
2308 0 : for (i = 0; i < cprm->vma_count; i++) {
2309 0 : struct core_vma_metadata *meta = cprm->vma_meta + i;
2310 :
2311 0 : if (!dump_user_range(cprm, meta->start, meta->dump_size))
2312 : goto end_coredump;
2313 : }
2314 :
2315 0 : if (!elf_core_write_extra_data(cprm))
2316 : goto end_coredump;
2317 :
2318 0 : if (e_phnum == PN_XNUM) {
2319 0 : if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
2320 : goto end_coredump;
2321 : }
2322 :
2323 : end_coredump:
2324 0 : free_note_info(&info);
2325 0 : kfree(shdr4extnum);
2326 0 : kfree(phdr4note);
2327 0 : return has_dumped;
2328 : }
2329 :
2330 : #endif /* CONFIG_ELF_CORE */
2331 :
2332 1 : static int __init init_elf_binfmt(void)
2333 : {
2334 1 : register_binfmt(&elf_format);
2335 1 : return 0;
2336 : }
2337 :
2338 0 : static void __exit exit_elf_binfmt(void)
2339 : {
2340 : /* Remove the COFF and ELF loaders. */
2341 0 : unregister_binfmt(&elf_format);
2342 0 : }
2343 :
2344 : core_initcall(init_elf_binfmt);
2345 : module_exit(exit_elf_binfmt);
2346 : MODULE_LICENSE("GPL");
2347 :
2348 : #ifdef CONFIG_BINFMT_ELF_KUNIT_TEST
2349 : #include "binfmt_elf_test.c"
2350 : #endif
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