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 <linux/rseq.h>
50 : #include <asm/param.h>
51 : #include <asm/page.h>
52 :
53 : #ifndef ELF_COMPAT
54 : #define ELF_COMPAT 0
55 : #endif
56 :
57 : #ifndef user_long_t
58 : #define user_long_t long
59 : #endif
60 : #ifndef user_siginfo_t
61 : #define user_siginfo_t siginfo_t
62 : #endif
63 :
64 : /* That's for binfmt_elf_fdpic to deal with */
65 : #ifndef elf_check_fdpic
66 : #define elf_check_fdpic(ex) false
67 : #endif
68 :
69 : static int load_elf_binary(struct linux_binprm *bprm);
70 :
71 : #ifdef CONFIG_USELIB
72 : static int load_elf_library(struct file *);
73 : #else
74 : #define load_elf_library NULL
75 : #endif
76 :
77 : /*
78 : * If we don't support core dumping, then supply a NULL so we
79 : * don't even try.
80 : */
81 : #ifdef CONFIG_ELF_CORE
82 : static int elf_core_dump(struct coredump_params *cprm);
83 : #else
84 : #define elf_core_dump NULL
85 : #endif
86 :
87 : #if ELF_EXEC_PAGESIZE > PAGE_SIZE
88 : #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
89 : #else
90 : #define ELF_MIN_ALIGN PAGE_SIZE
91 : #endif
92 :
93 : #ifndef ELF_CORE_EFLAGS
94 : #define ELF_CORE_EFLAGS 0
95 : #endif
96 :
97 : #define ELF_PAGESTART(_v) ((_v) & ~(int)(ELF_MIN_ALIGN-1))
98 : #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
99 : #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
100 :
101 : static struct linux_binfmt elf_format = {
102 : .module = THIS_MODULE,
103 : .load_binary = load_elf_binary,
104 : .load_shlib = load_elf_library,
105 : #ifdef CONFIG_COREDUMP
106 : .core_dump = elf_core_dump,
107 : .min_coredump = ELF_EXEC_PAGESIZE,
108 : #endif
109 : };
110 :
111 : #define BAD_ADDR(x) (unlikely((unsigned long)(x) >= TASK_SIZE))
112 :
113 0 : static int set_brk(unsigned long start, unsigned long end, int prot)
114 : {
115 0 : start = ELF_PAGEALIGN(start);
116 0 : end = ELF_PAGEALIGN(end);
117 0 : if (end > start) {
118 : /*
119 : * Map the last of the bss segment.
120 : * If the header is requesting these pages to be
121 : * executable, honour that (ppc32 needs this).
122 : */
123 0 : int error = vm_brk_flags(start, end - start,
124 : prot & PROT_EXEC ? VM_EXEC : 0);
125 0 : if (error)
126 : return error;
127 : }
128 0 : current->mm->start_brk = current->mm->brk = end;
129 0 : return 0;
130 : }
131 :
132 : /* We need to explicitly zero any fractional pages
133 : after the data section (i.e. bss). This would
134 : contain the junk from the file that should not
135 : be in memory
136 : */
137 : static int padzero(unsigned long elf_bss)
138 : {
139 : unsigned long nbyte;
140 :
141 0 : nbyte = ELF_PAGEOFFSET(elf_bss);
142 0 : if (nbyte) {
143 0 : nbyte = ELF_MIN_ALIGN - nbyte;
144 0 : if (clear_user((void __user *) elf_bss, nbyte))
145 : return -EFAULT;
146 : }
147 : return 0;
148 : }
149 :
150 : /* Let's use some macros to make this stack manipulation a little clearer */
151 : #ifdef CONFIG_STACK_GROWSUP
152 : #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
153 : #define STACK_ROUND(sp, items) \
154 : ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
155 : #define STACK_ALLOC(sp, len) ({ \
156 : elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
157 : old_sp; })
158 : #else
159 : #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
160 : #define STACK_ROUND(sp, items) \
161 : (((unsigned long) (sp - items)) &~ 15UL)
162 : #define STACK_ALLOC(sp, len) (sp -= len)
163 : #endif
164 :
165 : #ifndef ELF_BASE_PLATFORM
166 : /*
167 : * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
168 : * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
169 : * will be copied to the user stack in the same manner as AT_PLATFORM.
170 : */
171 : #define ELF_BASE_PLATFORM NULL
172 : #endif
173 :
174 : static int
175 0 : create_elf_tables(struct linux_binprm *bprm, const struct elfhdr *exec,
176 : unsigned long interp_load_addr,
177 : unsigned long e_entry, unsigned long phdr_addr)
178 : {
179 0 : struct mm_struct *mm = current->mm;
180 0 : unsigned long p = bprm->p;
181 0 : int argc = bprm->argc;
182 0 : int envc = bprm->envc;
183 : elf_addr_t __user *sp;
184 : elf_addr_t __user *u_platform;
185 : elf_addr_t __user *u_base_platform;
186 : elf_addr_t __user *u_rand_bytes;
187 0 : const char *k_platform = ELF_PLATFORM;
188 0 : const char *k_base_platform = ELF_BASE_PLATFORM;
189 : unsigned char k_rand_bytes[16];
190 : int items;
191 : elf_addr_t *elf_info;
192 0 : elf_addr_t flags = 0;
193 : int ei_index;
194 0 : const struct cred *cred = current_cred();
195 : struct vm_area_struct *vma;
196 :
197 : /*
198 : * In some cases (e.g. Hyper-Threading), we want to avoid L1
199 : * evictions by the processes running on the same package. One
200 : * thing we can do is to shuffle the initial stack for them.
201 : */
202 :
203 0 : p = arch_align_stack(p);
204 :
205 : /*
206 : * If this architecture has a platform capability string, copy it
207 : * to userspace. In some cases (Sparc), this info is impossible
208 : * for userspace to get any other way, in others (i386) it is
209 : * merely difficult.
210 : */
211 0 : u_platform = NULL;
212 : if (k_platform) {
213 0 : size_t len = strlen(k_platform) + 1;
214 :
215 0 : u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
216 0 : if (copy_to_user(u_platform, k_platform, len))
217 : return -EFAULT;
218 : }
219 :
220 : /*
221 : * If this architecture has a "base" platform capability
222 : * string, copy it to userspace.
223 : */
224 0 : u_base_platform = NULL;
225 : if (k_base_platform) {
226 : size_t len = strlen(k_base_platform) + 1;
227 :
228 : u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
229 : if (copy_to_user(u_base_platform, k_base_platform, len))
230 : return -EFAULT;
231 : }
232 :
233 : /*
234 : * Generate 16 random bytes for userspace PRNG seeding.
235 : */
236 0 : get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
237 0 : u_rand_bytes = (elf_addr_t __user *)
238 0 : STACK_ALLOC(p, sizeof(k_rand_bytes));
239 0 : if (copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
240 : return -EFAULT;
241 :
242 : /* Create the ELF interpreter info */
243 0 : elf_info = (elf_addr_t *)mm->saved_auxv;
244 : /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
245 : #define NEW_AUX_ENT(id, val) \
246 : do { \
247 : *elf_info++ = id; \
248 : *elf_info++ = val; \
249 : } while (0)
250 :
251 : #ifdef ARCH_DLINFO
252 : /*
253 : * ARCH_DLINFO must come first so PPC can do its special alignment of
254 : * AUXV.
255 : * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
256 : * ARCH_DLINFO changes
257 : */
258 0 : ARCH_DLINFO;
259 : #endif
260 0 : NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
261 0 : NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
262 0 : NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
263 0 : NEW_AUX_ENT(AT_PHDR, phdr_addr);
264 0 : NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
265 0 : NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
266 0 : NEW_AUX_ENT(AT_BASE, interp_load_addr);
267 0 : if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
268 0 : flags |= AT_FLAGS_PRESERVE_ARGV0;
269 0 : NEW_AUX_ENT(AT_FLAGS, flags);
270 0 : NEW_AUX_ENT(AT_ENTRY, e_entry);
271 0 : NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
272 0 : NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
273 0 : NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
274 0 : NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
275 0 : NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
276 0 : NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
277 : #ifdef ELF_HWCAP2
278 : NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
279 : #endif
280 0 : NEW_AUX_ENT(AT_EXECFN, bprm->exec);
281 : if (k_platform) {
282 0 : NEW_AUX_ENT(AT_PLATFORM,
283 : (elf_addr_t)(unsigned long)u_platform);
284 : }
285 : if (k_base_platform) {
286 : NEW_AUX_ENT(AT_BASE_PLATFORM,
287 : (elf_addr_t)(unsigned long)u_base_platform);
288 : }
289 0 : if (bprm->have_execfd) {
290 0 : NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
291 : }
292 : #ifdef CONFIG_RSEQ
293 : NEW_AUX_ENT(AT_RSEQ_FEATURE_SIZE, offsetof(struct rseq, end));
294 : NEW_AUX_ENT(AT_RSEQ_ALIGN, __alignof__(struct rseq));
295 : #endif
296 : #undef NEW_AUX_ENT
297 : /* AT_NULL is zero; clear the rest too */
298 0 : memset(elf_info, 0, (char *)mm->saved_auxv +
299 : sizeof(mm->saved_auxv) - (char *)elf_info);
300 :
301 : /* And advance past the AT_NULL entry. */
302 0 : elf_info += 2;
303 :
304 0 : ei_index = elf_info - (elf_addr_t *)mm->saved_auxv;
305 0 : sp = STACK_ADD(p, ei_index);
306 :
307 0 : items = (argc + 1) + (envc + 1) + 1;
308 0 : bprm->p = STACK_ROUND(sp, items);
309 :
310 : /* Point sp at the lowest address on the stack */
311 : #ifdef CONFIG_STACK_GROWSUP
312 : sp = (elf_addr_t __user *)bprm->p - items - ei_index;
313 : bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
314 : #else
315 0 : sp = (elf_addr_t __user *)bprm->p;
316 : #endif
317 :
318 :
319 : /*
320 : * Grow the stack manually; some architectures have a limit on how
321 : * far ahead a user-space access may be in order to grow the stack.
322 : */
323 0 : if (mmap_write_lock_killable(mm))
324 : return -EINTR;
325 0 : vma = find_extend_vma_locked(mm, bprm->p);
326 0 : mmap_write_unlock(mm);
327 0 : if (!vma)
328 : return -EFAULT;
329 :
330 : /* Now, let's put argc (and argv, envp if appropriate) on the stack */
331 0 : if (put_user(argc, sp++))
332 : return -EFAULT;
333 :
334 : /* Populate list of argv pointers back to argv strings. */
335 0 : p = mm->arg_end = mm->arg_start;
336 0 : while (argc-- > 0) {
337 : size_t len;
338 0 : if (put_user((elf_addr_t)p, sp++))
339 : return -EFAULT;
340 0 : len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
341 0 : if (!len || len > MAX_ARG_STRLEN)
342 : return -EINVAL;
343 0 : p += len;
344 : }
345 0 : if (put_user(0, sp++))
346 : return -EFAULT;
347 0 : mm->arg_end = p;
348 :
349 : /* Populate list of envp pointers back to envp strings. */
350 0 : mm->env_end = mm->env_start = p;
351 0 : while (envc-- > 0) {
352 : size_t len;
353 0 : if (put_user((elf_addr_t)p, sp++))
354 : return -EFAULT;
355 0 : len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
356 0 : if (!len || len > MAX_ARG_STRLEN)
357 : return -EINVAL;
358 0 : p += len;
359 : }
360 0 : if (put_user(0, sp++))
361 : return -EFAULT;
362 0 : mm->env_end = p;
363 :
364 : /* Put the elf_info on the stack in the right place. */
365 0 : if (copy_to_user(sp, mm->saved_auxv, ei_index * sizeof(elf_addr_t)))
366 : return -EFAULT;
367 : return 0;
368 : }
369 :
370 0 : static unsigned long elf_map(struct file *filep, unsigned long addr,
371 : const struct elf_phdr *eppnt, int prot, int type,
372 : unsigned long total_size)
373 : {
374 : unsigned long map_addr;
375 0 : unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
376 0 : unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
377 0 : addr = ELF_PAGESTART(addr);
378 0 : size = ELF_PAGEALIGN(size);
379 :
380 : /* mmap() will return -EINVAL if given a zero size, but a
381 : * segment with zero filesize is perfectly valid */
382 0 : if (!size)
383 : return addr;
384 :
385 : /*
386 : * total_size is the size of the ELF (interpreter) image.
387 : * The _first_ mmap needs to know the full size, otherwise
388 : * randomization might put this image into an overlapping
389 : * position with the ELF binary image. (since size < total_size)
390 : * So we first map the 'big' image - and unmap the remainder at
391 : * the end. (which unmap is needed for ELF images with holes.)
392 : */
393 0 : if (total_size) {
394 0 : total_size = ELF_PAGEALIGN(total_size);
395 0 : map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
396 0 : if (!BAD_ADDR(map_addr))
397 0 : vm_munmap(map_addr+size, total_size-size);
398 : } else
399 0 : map_addr = vm_mmap(filep, addr, size, prot, type, off);
400 :
401 0 : if ((type & MAP_FIXED_NOREPLACE) &&
402 0 : PTR_ERR((void *)map_addr) == -EEXIST)
403 0 : pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n",
404 : task_pid_nr(current), current->comm, (void *)addr);
405 :
406 : return(map_addr);
407 : }
408 :
409 : static unsigned long total_mapping_size(const struct elf_phdr *phdr, int nr)
410 : {
411 0 : elf_addr_t min_addr = -1;
412 0 : elf_addr_t max_addr = 0;
413 0 : bool pt_load = false;
414 : int i;
415 :
416 0 : for (i = 0; i < nr; i++) {
417 0 : if (phdr[i].p_type == PT_LOAD) {
418 0 : min_addr = min(min_addr, ELF_PAGESTART(phdr[i].p_vaddr));
419 0 : max_addr = max(max_addr, phdr[i].p_vaddr + phdr[i].p_memsz);
420 0 : pt_load = true;
421 : }
422 : }
423 0 : return pt_load ? (max_addr - min_addr) : 0;
424 : }
425 :
426 : static int elf_read(struct file *file, void *buf, size_t len, loff_t pos)
427 : {
428 : ssize_t rv;
429 :
430 0 : rv = kernel_read(file, buf, len, &pos);
431 0 : if (unlikely(rv != len)) {
432 0 : return (rv < 0) ? rv : -EIO;
433 : }
434 : return 0;
435 : }
436 :
437 0 : static unsigned long maximum_alignment(struct elf_phdr *cmds, int nr)
438 : {
439 0 : unsigned long alignment = 0;
440 : int i;
441 :
442 0 : for (i = 0; i < nr; i++) {
443 0 : if (cmds[i].p_type == PT_LOAD) {
444 0 : unsigned long p_align = cmds[i].p_align;
445 :
446 : /* skip non-power of two alignments as invalid */
447 0 : if (!is_power_of_2(p_align))
448 0 : continue;
449 0 : alignment = max(alignment, p_align);
450 : }
451 : }
452 :
453 : /* ensure we align to at least one page */
454 0 : return ELF_PAGEALIGN(alignment);
455 : }
456 :
457 : /**
458 : * load_elf_phdrs() - load ELF program headers
459 : * @elf_ex: ELF header of the binary whose program headers should be loaded
460 : * @elf_file: the opened ELF binary file
461 : *
462 : * Loads ELF program headers from the binary file elf_file, which has the ELF
463 : * header pointed to by elf_ex, into a newly allocated array. The caller is
464 : * responsible for freeing the allocated data. Returns NULL upon failure.
465 : */
466 0 : static struct elf_phdr *load_elf_phdrs(const struct elfhdr *elf_ex,
467 : struct file *elf_file)
468 : {
469 0 : struct elf_phdr *elf_phdata = NULL;
470 0 : int retval = -1;
471 : unsigned int size;
472 :
473 : /*
474 : * If the size of this structure has changed, then punt, since
475 : * we will be doing the wrong thing.
476 : */
477 0 : if (elf_ex->e_phentsize != sizeof(struct elf_phdr))
478 : goto out;
479 :
480 : /* Sanity check the number of program headers... */
481 : /* ...and their total size. */
482 0 : size = sizeof(struct elf_phdr) * elf_ex->e_phnum;
483 0 : if (size == 0 || size > 65536 || size > ELF_MIN_ALIGN)
484 : goto out;
485 :
486 0 : elf_phdata = kmalloc(size, GFP_KERNEL);
487 0 : if (!elf_phdata)
488 : goto out;
489 :
490 : /* Read in the program headers */
491 0 : retval = elf_read(elf_file, elf_phdata, size, elf_ex->e_phoff);
492 :
493 : out:
494 0 : if (retval) {
495 0 : kfree(elf_phdata);
496 0 : elf_phdata = NULL;
497 : }
498 0 : return elf_phdata;
499 : }
500 :
501 : #ifndef CONFIG_ARCH_BINFMT_ELF_STATE
502 :
503 : /**
504 : * struct arch_elf_state - arch-specific ELF loading state
505 : *
506 : * This structure is used to preserve architecture specific data during
507 : * the loading of an ELF file, throughout the checking of architecture
508 : * specific ELF headers & through to the point where the ELF load is
509 : * known to be proceeding (ie. SET_PERSONALITY).
510 : *
511 : * This implementation is a dummy for architectures which require no
512 : * specific state.
513 : */
514 : struct arch_elf_state {
515 : };
516 :
517 : #define INIT_ARCH_ELF_STATE {}
518 :
519 : /**
520 : * arch_elf_pt_proc() - check a PT_LOPROC..PT_HIPROC ELF program header
521 : * @ehdr: The main ELF header
522 : * @phdr: The program header to check
523 : * @elf: The open ELF file
524 : * @is_interp: True if the phdr is from the interpreter of the ELF being
525 : * loaded, else false.
526 : * @state: Architecture-specific state preserved throughout the process
527 : * of loading the ELF.
528 : *
529 : * Inspects the program header phdr to validate its correctness and/or
530 : * suitability for the system. Called once per ELF program header in the
531 : * range PT_LOPROC to PT_HIPROC, for both the ELF being loaded and its
532 : * interpreter.
533 : *
534 : * Return: Zero to proceed with the ELF load, non-zero to fail the ELF load
535 : * with that return code.
536 : */
537 : static inline int arch_elf_pt_proc(struct elfhdr *ehdr,
538 : struct elf_phdr *phdr,
539 : struct file *elf, bool is_interp,
540 : struct arch_elf_state *state)
541 : {
542 : /* Dummy implementation, always proceed */
543 : return 0;
544 : }
545 :
546 : /**
547 : * arch_check_elf() - check an ELF executable
548 : * @ehdr: The main ELF header
549 : * @has_interp: True if the ELF has an interpreter, else false.
550 : * @interp_ehdr: The interpreter's ELF header
551 : * @state: Architecture-specific state preserved throughout the process
552 : * of loading the ELF.
553 : *
554 : * Provides a final opportunity for architecture code to reject the loading
555 : * of the ELF & cause an exec syscall to return an error. This is called after
556 : * all program headers to be checked by arch_elf_pt_proc have been.
557 : *
558 : * Return: Zero to proceed with the ELF load, non-zero to fail the ELF load
559 : * with that return code.
560 : */
561 : static inline int arch_check_elf(struct elfhdr *ehdr, bool has_interp,
562 : struct elfhdr *interp_ehdr,
563 : struct arch_elf_state *state)
564 : {
565 : /* Dummy implementation, always proceed */
566 : return 0;
567 : }
568 :
569 : #endif /* !CONFIG_ARCH_BINFMT_ELF_STATE */
570 :
571 : static inline int make_prot(u32 p_flags, struct arch_elf_state *arch_state,
572 : bool has_interp, bool is_interp)
573 : {
574 0 : int prot = 0;
575 :
576 0 : if (p_flags & PF_R)
577 0 : prot |= PROT_READ;
578 0 : if (p_flags & PF_W)
579 0 : prot |= PROT_WRITE;
580 0 : if (p_flags & PF_X)
581 0 : prot |= PROT_EXEC;
582 :
583 0 : return arch_elf_adjust_prot(prot, arch_state, has_interp, is_interp);
584 : }
585 :
586 : /* This is much more generalized than the library routine read function,
587 : so we keep this separate. Technically the library read function
588 : is only provided so that we can read a.out libraries that have
589 : an ELF header */
590 :
591 0 : static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
592 : struct file *interpreter,
593 : unsigned long no_base, struct elf_phdr *interp_elf_phdata,
594 : struct arch_elf_state *arch_state)
595 : {
596 : struct elf_phdr *eppnt;
597 0 : unsigned long load_addr = 0;
598 0 : int load_addr_set = 0;
599 0 : unsigned long last_bss = 0, elf_bss = 0;
600 0 : int bss_prot = 0;
601 0 : unsigned long error = ~0UL;
602 : unsigned long total_size;
603 : int i;
604 :
605 : /* First of all, some simple consistency checks */
606 0 : if (interp_elf_ex->e_type != ET_EXEC &&
607 : interp_elf_ex->e_type != ET_DYN)
608 : goto out;
609 0 : if (!elf_check_arch(interp_elf_ex) ||
610 : elf_check_fdpic(interp_elf_ex))
611 : goto out;
612 0 : if (!interpreter->f_op->mmap)
613 : goto out;
614 :
615 0 : total_size = total_mapping_size(interp_elf_phdata,
616 0 : interp_elf_ex->e_phnum);
617 0 : if (!total_size) {
618 : error = -EINVAL;
619 : goto out;
620 : }
621 :
622 : eppnt = interp_elf_phdata;
623 0 : for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
624 0 : if (eppnt->p_type == PT_LOAD) {
625 0 : int elf_type = MAP_PRIVATE;
626 0 : int elf_prot = make_prot(eppnt->p_flags, arch_state,
627 : true, true);
628 0 : unsigned long vaddr = 0;
629 : unsigned long k, map_addr;
630 :
631 0 : vaddr = eppnt->p_vaddr;
632 0 : if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
633 : elf_type |= MAP_FIXED;
634 0 : else if (no_base && interp_elf_ex->e_type == ET_DYN)
635 0 : load_addr = -vaddr;
636 :
637 0 : map_addr = elf_map(interpreter, load_addr + vaddr,
638 : eppnt, elf_prot, elf_type, total_size);
639 0 : total_size = 0;
640 0 : error = map_addr;
641 0 : if (BAD_ADDR(map_addr))
642 : goto out;
643 :
644 0 : if (!load_addr_set &&
645 0 : interp_elf_ex->e_type == ET_DYN) {
646 0 : load_addr = map_addr - ELF_PAGESTART(vaddr);
647 0 : load_addr_set = 1;
648 : }
649 :
650 : /*
651 : * Check to see if the section's size will overflow the
652 : * allowed task size. Note that p_filesz must always be
653 : * <= p_memsize so it's only necessary to check p_memsz.
654 : */
655 0 : k = load_addr + eppnt->p_vaddr;
656 0 : if (BAD_ADDR(k) ||
657 0 : eppnt->p_filesz > eppnt->p_memsz ||
658 0 : eppnt->p_memsz > TASK_SIZE ||
659 0 : TASK_SIZE - eppnt->p_memsz < k) {
660 : error = -ENOMEM;
661 : goto out;
662 : }
663 :
664 : /*
665 : * Find the end of the file mapping for this phdr, and
666 : * keep track of the largest address we see for this.
667 : */
668 0 : k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
669 0 : if (k > elf_bss)
670 0 : elf_bss = k;
671 :
672 : /*
673 : * Do the same thing for the memory mapping - between
674 : * elf_bss and last_bss is the bss section.
675 : */
676 0 : k = load_addr + eppnt->p_vaddr + eppnt->p_memsz;
677 0 : if (k > last_bss) {
678 0 : last_bss = k;
679 0 : bss_prot = elf_prot;
680 : }
681 : }
682 : }
683 :
684 : /*
685 : * Now fill out the bss section: first pad the last page from
686 : * the file up to the page boundary, and zero it from elf_bss
687 : * up to the end of the page.
688 : */
689 0 : if (padzero(elf_bss)) {
690 : error = -EFAULT;
691 : goto out;
692 : }
693 : /*
694 : * Next, align both the file and mem bss up to the page size,
695 : * since this is where elf_bss was just zeroed up to, and where
696 : * last_bss will end after the vm_brk_flags() below.
697 : */
698 0 : elf_bss = ELF_PAGEALIGN(elf_bss);
699 0 : last_bss = ELF_PAGEALIGN(last_bss);
700 : /* Finally, if there is still more bss to allocate, do it. */
701 0 : if (last_bss > elf_bss) {
702 0 : error = vm_brk_flags(elf_bss, last_bss - elf_bss,
703 : bss_prot & PROT_EXEC ? VM_EXEC : 0);
704 0 : if (error)
705 : goto out;
706 : }
707 :
708 : error = load_addr;
709 : out:
710 0 : return error;
711 : }
712 :
713 : /*
714 : * These are the functions used to load ELF style executables and shared
715 : * libraries. There is no binary dependent code anywhere else.
716 : */
717 :
718 : static int parse_elf_property(const char *data, size_t *off, size_t datasz,
719 : struct arch_elf_state *arch,
720 : bool have_prev_type, u32 *prev_type)
721 : {
722 : size_t o, step;
723 : const struct gnu_property *pr;
724 : int ret;
725 :
726 : if (*off == datasz)
727 : return -ENOENT;
728 :
729 : if (WARN_ON_ONCE(*off > datasz || *off % ELF_GNU_PROPERTY_ALIGN))
730 : return -EIO;
731 : o = *off;
732 : datasz -= *off;
733 :
734 : if (datasz < sizeof(*pr))
735 : return -ENOEXEC;
736 : pr = (const struct gnu_property *)(data + o);
737 : o += sizeof(*pr);
738 : datasz -= sizeof(*pr);
739 :
740 : if (pr->pr_datasz > datasz)
741 : return -ENOEXEC;
742 :
743 : WARN_ON_ONCE(o % ELF_GNU_PROPERTY_ALIGN);
744 : step = round_up(pr->pr_datasz, ELF_GNU_PROPERTY_ALIGN);
745 : if (step > datasz)
746 : return -ENOEXEC;
747 :
748 : /* Properties are supposed to be unique and sorted on pr_type: */
749 : if (have_prev_type && pr->pr_type <= *prev_type)
750 : return -ENOEXEC;
751 : *prev_type = pr->pr_type;
752 :
753 : ret = arch_parse_elf_property(pr->pr_type, data + o,
754 : pr->pr_datasz, ELF_COMPAT, arch);
755 : if (ret)
756 : return ret;
757 :
758 : *off = o + step;
759 : return 0;
760 : }
761 :
762 : #define NOTE_DATA_SZ SZ_1K
763 : #define GNU_PROPERTY_TYPE_0_NAME "GNU"
764 : #define NOTE_NAME_SZ (sizeof(GNU_PROPERTY_TYPE_0_NAME))
765 :
766 : static int parse_elf_properties(struct file *f, const struct elf_phdr *phdr,
767 : struct arch_elf_state *arch)
768 : {
769 : union {
770 : struct elf_note nhdr;
771 : char data[NOTE_DATA_SZ];
772 : } note;
773 : loff_t pos;
774 : ssize_t n;
775 : size_t off, datasz;
776 : int ret;
777 : bool have_prev_type;
778 : u32 prev_type;
779 :
780 : if (!IS_ENABLED(CONFIG_ARCH_USE_GNU_PROPERTY) || !phdr)
781 : return 0;
782 :
783 : /* load_elf_binary() shouldn't call us unless this is true... */
784 : if (WARN_ON_ONCE(phdr->p_type != PT_GNU_PROPERTY))
785 : return -ENOEXEC;
786 :
787 : /* If the properties are crazy large, that's too bad (for now): */
788 : if (phdr->p_filesz > sizeof(note))
789 : return -ENOEXEC;
790 :
791 : pos = phdr->p_offset;
792 : n = kernel_read(f, ¬e, phdr->p_filesz, &pos);
793 :
794 : BUILD_BUG_ON(sizeof(note) < sizeof(note.nhdr) + NOTE_NAME_SZ);
795 : if (n < 0 || n < sizeof(note.nhdr) + NOTE_NAME_SZ)
796 : return -EIO;
797 :
798 : if (note.nhdr.n_type != NT_GNU_PROPERTY_TYPE_0 ||
799 : note.nhdr.n_namesz != NOTE_NAME_SZ ||
800 : strncmp(note.data + sizeof(note.nhdr),
801 : GNU_PROPERTY_TYPE_0_NAME, n - sizeof(note.nhdr)))
802 : return -ENOEXEC;
803 :
804 : off = round_up(sizeof(note.nhdr) + NOTE_NAME_SZ,
805 : ELF_GNU_PROPERTY_ALIGN);
806 : if (off > n)
807 : return -ENOEXEC;
808 :
809 : if (note.nhdr.n_descsz > n - off)
810 : return -ENOEXEC;
811 : datasz = off + note.nhdr.n_descsz;
812 :
813 : have_prev_type = false;
814 : do {
815 : ret = parse_elf_property(note.data, &off, datasz, arch,
816 : have_prev_type, &prev_type);
817 : have_prev_type = true;
818 : } while (!ret);
819 :
820 : return ret == -ENOENT ? 0 : ret;
821 : }
822 :
823 0 : static int load_elf_binary(struct linux_binprm *bprm)
824 : {
825 0 : struct file *interpreter = NULL; /* to shut gcc up */
826 0 : unsigned long load_bias = 0, phdr_addr = 0;
827 0 : int first_pt_load = 1;
828 : unsigned long error;
829 0 : struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
830 0 : struct elf_phdr *elf_property_phdata = NULL;
831 : unsigned long elf_bss, elf_brk;
832 0 : int bss_prot = 0;
833 : int retval, i;
834 : unsigned long elf_entry;
835 : unsigned long e_entry;
836 0 : unsigned long interp_load_addr = 0;
837 : unsigned long start_code, end_code, start_data, end_data;
838 0 : unsigned long reloc_func_desc __maybe_unused = 0;
839 0 : int executable_stack = EXSTACK_DEFAULT;
840 0 : struct elfhdr *elf_ex = (struct elfhdr *)bprm->buf;
841 0 : struct elfhdr *interp_elf_ex = NULL;
842 : struct arch_elf_state arch_state = INIT_ARCH_ELF_STATE;
843 : struct mm_struct *mm;
844 : struct pt_regs *regs;
845 :
846 0 : retval = -ENOEXEC;
847 : /* First of all, some simple consistency checks */
848 0 : if (memcmp(elf_ex->e_ident, ELFMAG, SELFMAG) != 0)
849 : goto out;
850 :
851 0 : if (elf_ex->e_type != ET_EXEC && elf_ex->e_type != ET_DYN)
852 : goto out;
853 0 : if (!elf_check_arch(elf_ex))
854 : goto out;
855 : if (elf_check_fdpic(elf_ex))
856 : goto out;
857 0 : if (!bprm->file->f_op->mmap)
858 : goto out;
859 :
860 0 : elf_phdata = load_elf_phdrs(elf_ex, bprm->file);
861 0 : if (!elf_phdata)
862 : goto out;
863 :
864 : elf_ppnt = elf_phdata;
865 0 : for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++) {
866 : char *elf_interpreter;
867 :
868 0 : if (elf_ppnt->p_type == PT_GNU_PROPERTY) {
869 0 : elf_property_phdata = elf_ppnt;
870 0 : continue;
871 : }
872 :
873 0 : if (elf_ppnt->p_type != PT_INTERP)
874 0 : continue;
875 :
876 : /*
877 : * This is the program interpreter used for shared libraries -
878 : * for now assume that this is an a.out format binary.
879 : */
880 0 : retval = -ENOEXEC;
881 0 : if (elf_ppnt->p_filesz > PATH_MAX || elf_ppnt->p_filesz < 2)
882 : goto out_free_ph;
883 :
884 0 : retval = -ENOMEM;
885 0 : elf_interpreter = kmalloc(elf_ppnt->p_filesz, GFP_KERNEL);
886 0 : if (!elf_interpreter)
887 : goto out_free_ph;
888 :
889 0 : retval = elf_read(bprm->file, elf_interpreter, elf_ppnt->p_filesz,
890 0 : elf_ppnt->p_offset);
891 0 : if (retval < 0)
892 : goto out_free_interp;
893 : /* make sure path is NULL terminated */
894 0 : retval = -ENOEXEC;
895 0 : if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
896 : goto out_free_interp;
897 :
898 0 : interpreter = open_exec(elf_interpreter);
899 0 : kfree(elf_interpreter);
900 0 : retval = PTR_ERR(interpreter);
901 0 : if (IS_ERR(interpreter))
902 : goto out_free_ph;
903 :
904 : /*
905 : * If the binary is not readable then enforce mm->dumpable = 0
906 : * regardless of the interpreter's permissions.
907 : */
908 0 : would_dump(bprm, interpreter);
909 :
910 0 : interp_elf_ex = kmalloc(sizeof(*interp_elf_ex), GFP_KERNEL);
911 0 : if (!interp_elf_ex) {
912 : retval = -ENOMEM;
913 : goto out_free_file;
914 : }
915 :
916 : /* Get the exec headers */
917 0 : retval = elf_read(interpreter, interp_elf_ex,
918 : sizeof(*interp_elf_ex), 0);
919 0 : if (retval < 0)
920 : goto out_free_dentry;
921 :
922 : break;
923 :
924 : out_free_interp:
925 0 : kfree(elf_interpreter);
926 0 : goto out_free_ph;
927 : }
928 :
929 0 : elf_ppnt = elf_phdata;
930 0 : for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++)
931 0 : switch (elf_ppnt->p_type) {
932 : case PT_GNU_STACK:
933 0 : if (elf_ppnt->p_flags & PF_X)
934 : executable_stack = EXSTACK_ENABLE_X;
935 : else
936 0 : executable_stack = EXSTACK_DISABLE_X;
937 : break;
938 :
939 : case PT_LOPROC ... PT_HIPROC:
940 : retval = arch_elf_pt_proc(elf_ex, elf_ppnt,
941 : bprm->file, false,
942 : &arch_state);
943 : if (retval)
944 : goto out_free_dentry;
945 : break;
946 : }
947 :
948 : /* Some simple consistency checks for the interpreter */
949 0 : if (interpreter) {
950 0 : retval = -ELIBBAD;
951 : /* Not an ELF interpreter */
952 0 : if (memcmp(interp_elf_ex->e_ident, ELFMAG, SELFMAG) != 0)
953 : goto out_free_dentry;
954 : /* Verify the interpreter has a valid arch */
955 0 : if (!elf_check_arch(interp_elf_ex) ||
956 : elf_check_fdpic(interp_elf_ex))
957 : goto out_free_dentry;
958 :
959 : /* Load the interpreter program headers */
960 0 : interp_elf_phdata = load_elf_phdrs(interp_elf_ex,
961 : interpreter);
962 0 : if (!interp_elf_phdata)
963 : goto out_free_dentry;
964 :
965 : /* Pass PT_LOPROC..PT_HIPROC headers to arch code */
966 : elf_property_phdata = NULL;
967 : elf_ppnt = interp_elf_phdata;
968 0 : for (i = 0; i < interp_elf_ex->e_phnum; i++, elf_ppnt++)
969 : switch (elf_ppnt->p_type) {
970 : case PT_GNU_PROPERTY:
971 : elf_property_phdata = elf_ppnt;
972 : break;
973 :
974 : case PT_LOPROC ... PT_HIPROC:
975 : retval = arch_elf_pt_proc(interp_elf_ex,
976 : elf_ppnt, interpreter,
977 : true, &arch_state);
978 : if (retval)
979 : goto out_free_dentry;
980 : break;
981 : }
982 : }
983 :
984 0 : retval = parse_elf_properties(interpreter ?: bprm->file,
985 : elf_property_phdata, &arch_state);
986 : if (retval)
987 : goto out_free_dentry;
988 :
989 : /*
990 : * Allow arch code to reject the ELF at this point, whilst it's
991 : * still possible to return an error to the code that invoked
992 : * the exec syscall.
993 : */
994 0 : retval = arch_check_elf(elf_ex,
995 : !!interpreter, interp_elf_ex,
996 : &arch_state);
997 : if (retval)
998 : goto out_free_dentry;
999 :
1000 : /* Flush all traces of the currently running executable */
1001 0 : retval = begin_new_exec(bprm);
1002 0 : if (retval)
1003 : goto out_free_dentry;
1004 :
1005 : /* Do this immediately, since STACK_TOP as used in setup_arg_pages
1006 : may depend on the personality. */
1007 : SET_PERSONALITY2(*elf_ex, &arch_state);
1008 : if (elf_read_implies_exec(*elf_ex, executable_stack))
1009 : current->personality |= READ_IMPLIES_EXEC;
1010 :
1011 0 : if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
1012 0 : current->flags |= PF_RANDOMIZE;
1013 :
1014 0 : setup_new_exec(bprm);
1015 :
1016 : /* Do this so that we can load the interpreter, if need be. We will
1017 : change some of these later */
1018 0 : retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
1019 : executable_stack);
1020 0 : if (retval < 0)
1021 : goto out_free_dentry;
1022 :
1023 : elf_bss = 0;
1024 : elf_brk = 0;
1025 :
1026 : start_code = ~0UL;
1027 : end_code = 0;
1028 : start_data = 0;
1029 : end_data = 0;
1030 :
1031 : /* Now we do a little grungy work by mmapping the ELF image into
1032 : the correct location in memory. */
1033 0 : for(i = 0, elf_ppnt = elf_phdata;
1034 0 : i < elf_ex->e_phnum; i++, elf_ppnt++) {
1035 : int elf_prot, elf_flags;
1036 : unsigned long k, vaddr;
1037 0 : unsigned long total_size = 0;
1038 : unsigned long alignment;
1039 :
1040 0 : if (elf_ppnt->p_type != PT_LOAD)
1041 0 : continue;
1042 :
1043 0 : if (unlikely (elf_brk > elf_bss)) {
1044 : unsigned long nbyte;
1045 :
1046 : /* There was a PT_LOAD segment with p_memsz > p_filesz
1047 : before this one. Map anonymous pages, if needed,
1048 : and clear the area. */
1049 0 : retval = set_brk(elf_bss + load_bias,
1050 : elf_brk + load_bias,
1051 : bss_prot);
1052 0 : if (retval)
1053 : goto out_free_dentry;
1054 0 : nbyte = ELF_PAGEOFFSET(elf_bss);
1055 0 : if (nbyte) {
1056 0 : nbyte = ELF_MIN_ALIGN - nbyte;
1057 0 : if (nbyte > elf_brk - elf_bss)
1058 0 : nbyte = elf_brk - elf_bss;
1059 0 : if (clear_user((void __user *)elf_bss +
1060 : load_bias, nbyte)) {
1061 : /*
1062 : * This bss-zeroing can fail if the ELF
1063 : * file specifies odd protections. So
1064 : * we don't check the return value
1065 : */
1066 : }
1067 : }
1068 : }
1069 :
1070 0 : elf_prot = make_prot(elf_ppnt->p_flags, &arch_state,
1071 : !!interpreter, false);
1072 :
1073 0 : elf_flags = MAP_PRIVATE;
1074 :
1075 0 : vaddr = elf_ppnt->p_vaddr;
1076 : /*
1077 : * The first time through the loop, first_pt_load is true:
1078 : * layout will be calculated. Once set, use MAP_FIXED since
1079 : * we know we've already safely mapped the entire region with
1080 : * MAP_FIXED_NOREPLACE in the once-per-binary logic following.
1081 : */
1082 0 : if (!first_pt_load) {
1083 : elf_flags |= MAP_FIXED;
1084 0 : } else if (elf_ex->e_type == ET_EXEC) {
1085 : /*
1086 : * This logic is run once for the first LOAD Program
1087 : * Header for ET_EXEC binaries. No special handling
1088 : * is needed.
1089 : */
1090 : elf_flags |= MAP_FIXED_NOREPLACE;
1091 0 : } else if (elf_ex->e_type == ET_DYN) {
1092 : /*
1093 : * This logic is run once for the first LOAD Program
1094 : * Header for ET_DYN binaries to calculate the
1095 : * randomization (load_bias) for all the LOAD
1096 : * Program Headers.
1097 : *
1098 : * There are effectively two types of ET_DYN
1099 : * binaries: programs (i.e. PIE: ET_DYN with INTERP)
1100 : * and loaders (ET_DYN without INTERP, since they
1101 : * _are_ the ELF interpreter). The loaders must
1102 : * be loaded away from programs since the program
1103 : * may otherwise collide with the loader (especially
1104 : * for ET_EXEC which does not have a randomized
1105 : * position). For example to handle invocations of
1106 : * "./ld.so someprog" to test out a new version of
1107 : * the loader, the subsequent program that the
1108 : * loader loads must avoid the loader itself, so
1109 : * they cannot share the same load range. Sufficient
1110 : * room for the brk must be allocated with the
1111 : * loader as well, since brk must be available with
1112 : * the loader.
1113 : *
1114 : * Therefore, programs are loaded offset from
1115 : * ELF_ET_DYN_BASE and loaders are loaded into the
1116 : * independently randomized mmap region (0 load_bias
1117 : * without MAP_FIXED nor MAP_FIXED_NOREPLACE).
1118 : */
1119 0 : if (interpreter) {
1120 0 : load_bias = ELF_ET_DYN_BASE;
1121 0 : if (current->flags & PF_RANDOMIZE)
1122 : load_bias += arch_mmap_rnd();
1123 0 : alignment = maximum_alignment(elf_phdata, elf_ex->e_phnum);
1124 0 : if (alignment)
1125 0 : load_bias &= ~(alignment - 1);
1126 : elf_flags |= MAP_FIXED_NOREPLACE;
1127 : } else
1128 : load_bias = 0;
1129 :
1130 : /*
1131 : * Since load_bias is used for all subsequent loading
1132 : * calculations, we must lower it by the first vaddr
1133 : * so that the remaining calculations based on the
1134 : * ELF vaddrs will be correctly offset. The result
1135 : * is then page aligned.
1136 : */
1137 0 : load_bias = ELF_PAGESTART(load_bias - vaddr);
1138 :
1139 : /*
1140 : * Calculate the entire size of the ELF mapping
1141 : * (total_size), used for the initial mapping,
1142 : * due to load_addr_set which is set to true later
1143 : * once the initial mapping is performed.
1144 : *
1145 : * Note that this is only sensible when the LOAD
1146 : * segments are contiguous (or overlapping). If
1147 : * used for LOADs that are far apart, this would
1148 : * cause the holes between LOADs to be mapped,
1149 : * running the risk of having the mapping fail,
1150 : * as it would be larger than the ELF file itself.
1151 : *
1152 : * As a result, only ET_DYN does this, since
1153 : * some ET_EXEC (e.g. ia64) may have large virtual
1154 : * memory holes between LOADs.
1155 : *
1156 : */
1157 0 : total_size = total_mapping_size(elf_phdata,
1158 0 : elf_ex->e_phnum);
1159 0 : if (!total_size) {
1160 : retval = -EINVAL;
1161 : goto out_free_dentry;
1162 : }
1163 : }
1164 :
1165 0 : error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
1166 : elf_prot, elf_flags, total_size);
1167 0 : if (BAD_ADDR(error)) {
1168 0 : retval = IS_ERR_VALUE(error) ?
1169 0 : PTR_ERR((void*)error) : -EINVAL;
1170 : goto out_free_dentry;
1171 : }
1172 :
1173 0 : if (first_pt_load) {
1174 0 : first_pt_load = 0;
1175 0 : if (elf_ex->e_type == ET_DYN) {
1176 0 : load_bias += error -
1177 0 : ELF_PAGESTART(load_bias + vaddr);
1178 0 : reloc_func_desc = load_bias;
1179 : }
1180 : }
1181 :
1182 : /*
1183 : * Figure out which segment in the file contains the Program
1184 : * Header table, and map to the associated memory address.
1185 : */
1186 0 : if (elf_ppnt->p_offset <= elf_ex->e_phoff &&
1187 0 : elf_ex->e_phoff < elf_ppnt->p_offset + elf_ppnt->p_filesz) {
1188 0 : phdr_addr = elf_ex->e_phoff - elf_ppnt->p_offset +
1189 0 : elf_ppnt->p_vaddr;
1190 : }
1191 :
1192 0 : k = elf_ppnt->p_vaddr;
1193 0 : if ((elf_ppnt->p_flags & PF_X) && k < start_code)
1194 0 : start_code = k;
1195 0 : if (start_data < k)
1196 0 : start_data = k;
1197 :
1198 : /*
1199 : * Check to see if the section's size will overflow the
1200 : * allowed task size. Note that p_filesz must always be
1201 : * <= p_memsz so it is only necessary to check p_memsz.
1202 : */
1203 0 : if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
1204 0 : elf_ppnt->p_memsz > TASK_SIZE ||
1205 0 : TASK_SIZE - elf_ppnt->p_memsz < k) {
1206 : /* set_brk can never work. Avoid overflows. */
1207 : retval = -EINVAL;
1208 : goto out_free_dentry;
1209 : }
1210 :
1211 0 : k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
1212 :
1213 0 : if (k > elf_bss)
1214 0 : elf_bss = k;
1215 0 : if ((elf_ppnt->p_flags & PF_X) && end_code < k)
1216 0 : end_code = k;
1217 : if (end_data < k)
1218 : end_data = k;
1219 0 : k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
1220 0 : if (k > elf_brk) {
1221 0 : bss_prot = elf_prot;
1222 0 : elf_brk = k;
1223 : }
1224 : }
1225 :
1226 0 : e_entry = elf_ex->e_entry + load_bias;
1227 0 : phdr_addr += load_bias;
1228 0 : elf_bss += load_bias;
1229 0 : elf_brk += load_bias;
1230 0 : start_code += load_bias;
1231 0 : end_code += load_bias;
1232 0 : start_data += load_bias;
1233 0 : end_data += load_bias;
1234 :
1235 : /* Calling set_brk effectively mmaps the pages that we need
1236 : * for the bss and break sections. We must do this before
1237 : * mapping in the interpreter, to make sure it doesn't wind
1238 : * up getting placed where the bss needs to go.
1239 : */
1240 0 : retval = set_brk(elf_bss, elf_brk, bss_prot);
1241 0 : if (retval)
1242 : goto out_free_dentry;
1243 0 : if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
1244 : retval = -EFAULT; /* Nobody gets to see this, but.. */
1245 : goto out_free_dentry;
1246 : }
1247 :
1248 0 : if (interpreter) {
1249 0 : elf_entry = load_elf_interp(interp_elf_ex,
1250 : interpreter,
1251 : load_bias, interp_elf_phdata,
1252 : &arch_state);
1253 0 : if (!IS_ERR_VALUE(elf_entry)) {
1254 : /*
1255 : * load_elf_interp() returns relocation
1256 : * adjustment
1257 : */
1258 0 : interp_load_addr = elf_entry;
1259 0 : elf_entry += interp_elf_ex->e_entry;
1260 : }
1261 0 : if (BAD_ADDR(elf_entry)) {
1262 0 : retval = IS_ERR_VALUE(elf_entry) ?
1263 0 : (int)elf_entry : -EINVAL;
1264 : goto out_free_dentry;
1265 : }
1266 0 : reloc_func_desc = interp_load_addr;
1267 :
1268 0 : allow_write_access(interpreter);
1269 0 : fput(interpreter);
1270 :
1271 0 : kfree(interp_elf_ex);
1272 0 : kfree(interp_elf_phdata);
1273 : } else {
1274 0 : elf_entry = e_entry;
1275 0 : if (BAD_ADDR(elf_entry)) {
1276 : retval = -EINVAL;
1277 : goto out_free_dentry;
1278 : }
1279 : }
1280 :
1281 0 : kfree(elf_phdata);
1282 :
1283 0 : set_binfmt(&elf_format);
1284 :
1285 : #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
1286 0 : retval = ARCH_SETUP_ADDITIONAL_PAGES(bprm, elf_ex, !!interpreter);
1287 0 : if (retval < 0)
1288 : goto out;
1289 : #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
1290 :
1291 0 : retval = create_elf_tables(bprm, elf_ex, interp_load_addr,
1292 : e_entry, phdr_addr);
1293 0 : if (retval < 0)
1294 : goto out;
1295 :
1296 0 : mm = current->mm;
1297 0 : mm->end_code = end_code;
1298 0 : mm->start_code = start_code;
1299 0 : mm->start_data = start_data;
1300 0 : mm->end_data = end_data;
1301 0 : mm->start_stack = bprm->p;
1302 :
1303 0 : if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
1304 : /*
1305 : * For architectures with ELF randomization, when executing
1306 : * a loader directly (i.e. no interpreter listed in ELF
1307 : * headers), move the brk area out of the mmap region
1308 : * (since it grows up, and may collide early with the stack
1309 : * growing down), and into the unused ELF_ET_DYN_BASE region.
1310 : */
1311 : if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) &&
1312 : elf_ex->e_type == ET_DYN && !interpreter) {
1313 : mm->brk = mm->start_brk = ELF_ET_DYN_BASE;
1314 : }
1315 :
1316 0 : mm->brk = mm->start_brk = arch_randomize_brk(mm);
1317 : #ifdef compat_brk_randomized
1318 : current->brk_randomized = 1;
1319 : #endif
1320 : }
1321 :
1322 0 : if (current->personality & MMAP_PAGE_ZERO) {
1323 : /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
1324 : and some applications "depend" upon this behavior.
1325 : Since we do not have the power to recompile these, we
1326 : emulate the SVr4 behavior. Sigh. */
1327 0 : error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1328 : MAP_FIXED | MAP_PRIVATE, 0);
1329 : }
1330 :
1331 0 : regs = current_pt_regs();
1332 : #ifdef ELF_PLAT_INIT
1333 : /*
1334 : * The ABI may specify that certain registers be set up in special
1335 : * ways (on i386 %edx is the address of a DT_FINI function, for
1336 : * example. In addition, it may also specify (eg, PowerPC64 ELF)
1337 : * that the e_entry field is the address of the function descriptor
1338 : * for the startup routine, rather than the address of the startup
1339 : * routine itself. This macro performs whatever initialization to
1340 : * the regs structure is required as well as any relocations to the
1341 : * function descriptor entries when executing dynamically links apps.
1342 : */
1343 0 : ELF_PLAT_INIT(regs, reloc_func_desc);
1344 : #endif
1345 :
1346 0 : finalize_exec(bprm);
1347 0 : START_THREAD(elf_ex, regs, elf_entry, bprm->p);
1348 0 : retval = 0;
1349 : out:
1350 0 : return retval;
1351 :
1352 : /* error cleanup */
1353 : out_free_dentry:
1354 0 : kfree(interp_elf_ex);
1355 0 : kfree(interp_elf_phdata);
1356 : out_free_file:
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 0 : 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 0 : 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 = 4;
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 : 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 : #include <linux/regset.h>
1727 :
1728 : struct elf_thread_core_info {
1729 : struct elf_thread_core_info *next;
1730 : struct task_struct *task;
1731 : struct elf_prstatus prstatus;
1732 : struct memelfnote notes[];
1733 : };
1734 :
1735 : struct elf_note_info {
1736 : struct elf_thread_core_info *thread;
1737 : struct memelfnote psinfo;
1738 : struct memelfnote signote;
1739 : struct memelfnote auxv;
1740 : struct memelfnote files;
1741 : user_siginfo_t csigdata;
1742 : size_t size;
1743 : int thread_notes;
1744 : };
1745 :
1746 : #ifdef CORE_DUMP_USE_REGSET
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 regset 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 : #else
1827 0 : static int fill_thread_core_info(struct elf_thread_core_info *t,
1828 : const struct user_regset_view *view,
1829 : long signr, struct elf_note_info *info)
1830 : {
1831 0 : struct task_struct *p = t->task;
1832 : elf_fpregset_t *fpu;
1833 :
1834 0 : fill_prstatus(&t->prstatus.common, p, signr);
1835 0 : elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1836 :
1837 0 : fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1838 0 : &(t->prstatus));
1839 0 : info->size += notesize(&t->notes[0]);
1840 :
1841 0 : fpu = kzalloc(sizeof(elf_fpregset_t), GFP_KERNEL);
1842 0 : if (!fpu || !elf_core_copy_task_fpregs(p, fpu)) {
1843 0 : kfree(fpu);
1844 : return 1;
1845 : }
1846 :
1847 0 : t->prstatus.pr_fpvalid = 1;
1848 0 : fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1849 0 : info->size += notesize(&t->notes[1]);
1850 :
1851 : return 1;
1852 : }
1853 : #endif
1854 :
1855 0 : static int fill_note_info(struct elfhdr *elf, int phdrs,
1856 : struct elf_note_info *info,
1857 : struct coredump_params *cprm)
1858 : {
1859 0 : struct task_struct *dump_task = current;
1860 : const struct user_regset_view *view;
1861 : struct elf_thread_core_info *t;
1862 : struct elf_prpsinfo *psinfo;
1863 : struct core_thread *ct;
1864 :
1865 0 : psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1866 0 : if (!psinfo)
1867 : return 0;
1868 0 : fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1869 :
1870 : #ifdef CORE_DUMP_USE_REGSET
1871 : view = task_user_regset_view(dump_task);
1872 :
1873 : /*
1874 : * Figure out how many notes we're going to need for each thread.
1875 : */
1876 : info->thread_notes = 0;
1877 : for (int i = 0; i < view->n; ++i)
1878 : if (view->regsets[i].core_note_type != 0)
1879 : ++info->thread_notes;
1880 :
1881 : /*
1882 : * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1883 : * since it is our one special case.
1884 : */
1885 : if (unlikely(info->thread_notes == 0) ||
1886 : unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1887 : WARN_ON(1);
1888 : return 0;
1889 : }
1890 :
1891 : /*
1892 : * Initialize the ELF file header.
1893 : */
1894 : fill_elf_header(elf, phdrs,
1895 : view->e_machine, view->e_flags);
1896 : #else
1897 0 : view = NULL;
1898 0 : info->thread_notes = 2;
1899 0 : fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
1900 : #endif
1901 :
1902 : /*
1903 : * Allocate a structure for each thread.
1904 : */
1905 0 : info->thread = kzalloc(offsetof(struct elf_thread_core_info,
1906 : notes[info->thread_notes]),
1907 : GFP_KERNEL);
1908 0 : if (unlikely(!info->thread))
1909 : return 0;
1910 :
1911 0 : info->thread->task = dump_task;
1912 0 : for (ct = dump_task->signal->core_state->dumper.next; ct; ct = ct->next) {
1913 0 : t = kzalloc(offsetof(struct elf_thread_core_info,
1914 : notes[info->thread_notes]),
1915 : GFP_KERNEL);
1916 0 : if (unlikely(!t))
1917 : return 0;
1918 :
1919 0 : t->task = ct->task;
1920 0 : t->next = info->thread->next;
1921 0 : info->thread->next = t;
1922 : }
1923 :
1924 : /*
1925 : * Now fill in each thread's information.
1926 : */
1927 0 : for (t = info->thread; t != NULL; t = t->next)
1928 0 : if (!fill_thread_core_info(t, view, cprm->siginfo->si_signo, info))
1929 : return 0;
1930 :
1931 : /*
1932 : * Fill in the two process-wide notes.
1933 : */
1934 0 : fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1935 0 : info->size += notesize(&info->psinfo);
1936 :
1937 0 : fill_siginfo_note(&info->signote, &info->csigdata, cprm->siginfo);
1938 0 : info->size += notesize(&info->signote);
1939 :
1940 0 : fill_auxv_note(&info->auxv, current->mm);
1941 0 : info->size += notesize(&info->auxv);
1942 :
1943 0 : if (fill_files_note(&info->files, cprm) == 0)
1944 0 : info->size += notesize(&info->files);
1945 :
1946 : return 1;
1947 : }
1948 :
1949 : /*
1950 : * Write all the notes for each thread. When writing the first thread, the
1951 : * process-wide notes are interleaved after the first thread-specific note.
1952 : */
1953 0 : static int write_note_info(struct elf_note_info *info,
1954 : struct coredump_params *cprm)
1955 : {
1956 0 : bool first = true;
1957 0 : struct elf_thread_core_info *t = info->thread;
1958 :
1959 : do {
1960 : int i;
1961 :
1962 0 : if (!writenote(&t->notes[0], cprm))
1963 : return 0;
1964 :
1965 0 : if (first && !writenote(&info->psinfo, cprm))
1966 : return 0;
1967 0 : if (first && !writenote(&info->signote, cprm))
1968 : return 0;
1969 0 : if (first && !writenote(&info->auxv, cprm))
1970 : return 0;
1971 0 : if (first && info->files.data &&
1972 0 : !writenote(&info->files, cprm))
1973 : return 0;
1974 :
1975 0 : for (i = 1; i < info->thread_notes; ++i)
1976 0 : if (t->notes[i].data &&
1977 0 : !writenote(&t->notes[i], cprm))
1978 : return 0;
1979 :
1980 0 : first = false;
1981 0 : t = t->next;
1982 0 : } while (t);
1983 :
1984 : return 1;
1985 : }
1986 :
1987 0 : static void free_note_info(struct elf_note_info *info)
1988 : {
1989 0 : struct elf_thread_core_info *threads = info->thread;
1990 0 : while (threads) {
1991 : unsigned int i;
1992 0 : struct elf_thread_core_info *t = threads;
1993 0 : threads = t->next;
1994 0 : WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1995 0 : for (i = 1; i < info->thread_notes; ++i)
1996 0 : kfree(t->notes[i].data);
1997 0 : kfree(t);
1998 : }
1999 0 : kfree(info->psinfo.data);
2000 0 : kvfree(info->files.data);
2001 0 : }
2002 :
2003 0 : static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
2004 : elf_addr_t e_shoff, int segs)
2005 : {
2006 0 : elf->e_shoff = e_shoff;
2007 0 : elf->e_shentsize = sizeof(*shdr4extnum);
2008 0 : elf->e_shnum = 1;
2009 0 : elf->e_shstrndx = SHN_UNDEF;
2010 :
2011 0 : memset(shdr4extnum, 0, sizeof(*shdr4extnum));
2012 :
2013 0 : shdr4extnum->sh_type = SHT_NULL;
2014 0 : shdr4extnum->sh_size = elf->e_shnum;
2015 0 : shdr4extnum->sh_link = elf->e_shstrndx;
2016 0 : shdr4extnum->sh_info = segs;
2017 0 : }
2018 :
2019 : /*
2020 : * Actual dumper
2021 : *
2022 : * This is a two-pass process; first we find the offsets of the bits,
2023 : * and then they are actually written out. If we run out of core limit
2024 : * we just truncate.
2025 : */
2026 0 : static int elf_core_dump(struct coredump_params *cprm)
2027 : {
2028 0 : int has_dumped = 0;
2029 : int segs, i;
2030 : struct elfhdr elf;
2031 0 : loff_t offset = 0, dataoff;
2032 0 : struct elf_note_info info = { };
2033 0 : struct elf_phdr *phdr4note = NULL;
2034 0 : struct elf_shdr *shdr4extnum = NULL;
2035 : Elf_Half e_phnum;
2036 : elf_addr_t e_shoff;
2037 :
2038 : /*
2039 : * The number of segs are recored into ELF header as 16bit value.
2040 : * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2041 : */
2042 0 : segs = cprm->vma_count + elf_core_extra_phdrs(cprm);
2043 :
2044 : /* for notes section */
2045 0 : segs++;
2046 :
2047 : /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2048 : * this, kernel supports extended numbering. Have a look at
2049 : * include/linux/elf.h for further information. */
2050 0 : e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2051 :
2052 : /*
2053 : * Collect all the non-memory information about the process for the
2054 : * notes. This also sets up the file header.
2055 : */
2056 0 : if (!fill_note_info(&elf, e_phnum, &info, cprm))
2057 : goto end_coredump;
2058 :
2059 0 : has_dumped = 1;
2060 :
2061 0 : offset += sizeof(elf); /* ELF header */
2062 0 : offset += segs * sizeof(struct elf_phdr); /* Program headers */
2063 :
2064 : /* Write notes phdr entry */
2065 : {
2066 0 : size_t sz = info.size;
2067 :
2068 : /* For cell spufs */
2069 0 : sz += elf_coredump_extra_notes_size();
2070 :
2071 0 : phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2072 0 : if (!phdr4note)
2073 : goto end_coredump;
2074 :
2075 0 : fill_elf_note_phdr(phdr4note, sz, offset);
2076 0 : offset += sz;
2077 : }
2078 :
2079 0 : dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2080 :
2081 0 : offset += cprm->vma_data_size;
2082 0 : offset += elf_core_extra_data_size(cprm);
2083 0 : e_shoff = offset;
2084 :
2085 0 : if (e_phnum == PN_XNUM) {
2086 0 : shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2087 0 : if (!shdr4extnum)
2088 : goto end_coredump;
2089 0 : fill_extnum_info(&elf, shdr4extnum, e_shoff, segs);
2090 : }
2091 :
2092 0 : offset = dataoff;
2093 :
2094 0 : if (!dump_emit(cprm, &elf, sizeof(elf)))
2095 : goto end_coredump;
2096 :
2097 0 : if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
2098 : goto end_coredump;
2099 :
2100 : /* Write program headers for segments dump */
2101 0 : for (i = 0; i < cprm->vma_count; i++) {
2102 0 : struct core_vma_metadata *meta = cprm->vma_meta + i;
2103 : struct elf_phdr phdr;
2104 :
2105 0 : phdr.p_type = PT_LOAD;
2106 0 : phdr.p_offset = offset;
2107 0 : phdr.p_vaddr = meta->start;
2108 0 : phdr.p_paddr = 0;
2109 0 : phdr.p_filesz = meta->dump_size;
2110 0 : phdr.p_memsz = meta->end - meta->start;
2111 0 : offset += phdr.p_filesz;
2112 0 : phdr.p_flags = 0;
2113 0 : if (meta->flags & VM_READ)
2114 0 : phdr.p_flags |= PF_R;
2115 0 : if (meta->flags & VM_WRITE)
2116 0 : phdr.p_flags |= PF_W;
2117 0 : if (meta->flags & VM_EXEC)
2118 0 : phdr.p_flags |= PF_X;
2119 0 : phdr.p_align = ELF_EXEC_PAGESIZE;
2120 :
2121 0 : if (!dump_emit(cprm, &phdr, sizeof(phdr)))
2122 : goto end_coredump;
2123 : }
2124 :
2125 0 : if (!elf_core_write_extra_phdrs(cprm, offset))
2126 : goto end_coredump;
2127 :
2128 : /* write out the notes section */
2129 0 : if (!write_note_info(&info, cprm))
2130 : goto end_coredump;
2131 :
2132 : /* For cell spufs */
2133 0 : if (elf_coredump_extra_notes_write(cprm))
2134 : goto end_coredump;
2135 :
2136 : /* Align to page */
2137 0 : dump_skip_to(cprm, dataoff);
2138 :
2139 0 : for (i = 0; i < cprm->vma_count; i++) {
2140 0 : struct core_vma_metadata *meta = cprm->vma_meta + i;
2141 :
2142 0 : if (!dump_user_range(cprm, meta->start, meta->dump_size))
2143 : goto end_coredump;
2144 : }
2145 :
2146 0 : if (!elf_core_write_extra_data(cprm))
2147 : goto end_coredump;
2148 :
2149 0 : if (e_phnum == PN_XNUM) {
2150 0 : if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
2151 : goto end_coredump;
2152 : }
2153 :
2154 : end_coredump:
2155 0 : free_note_info(&info);
2156 0 : kfree(shdr4extnum);
2157 0 : kfree(phdr4note);
2158 0 : return has_dumped;
2159 : }
2160 :
2161 : #endif /* CONFIG_ELF_CORE */
2162 :
2163 1 : static int __init init_elf_binfmt(void)
2164 : {
2165 1 : register_binfmt(&elf_format);
2166 1 : return 0;
2167 : }
2168 :
2169 0 : static void __exit exit_elf_binfmt(void)
2170 : {
2171 : /* Remove the COFF and ELF loaders. */
2172 0 : unregister_binfmt(&elf_format);
2173 0 : }
2174 :
2175 : core_initcall(init_elf_binfmt);
2176 : module_exit(exit_elf_binfmt);
2177 :
2178 : #ifdef CONFIG_BINFMT_ELF_KUNIT_TEST
2179 : #include "binfmt_elf_test.c"
2180 : #endif
|
