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) & ~(unsigned long)(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 : .core_dump = elf_core_dump,
105 : .min_coredump = ELF_EXEC_PAGESIZE,
106 : };
107 :
108 : #define BAD_ADDR(x) (unlikely((unsigned long)(x) >= TASK_SIZE))
109 :
110 1129 : static int set_brk(unsigned long start, unsigned long end, int prot)
111 : {
112 1129 : start = ELF_PAGEALIGN(start);
113 1129 : end = ELF_PAGEALIGN(end);
114 1129 : if (end > start) {
115 : /*
116 : * Map the last of the bss segment.
117 : * If the header is requesting these pages to be
118 : * executable, honour that (ppc32 needs this).
119 : */
120 496 : int error = vm_brk_flags(start, end - start,
121 : prot & PROT_EXEC ? VM_EXEC : 0);
122 496 : if (error)
123 : return error;
124 : }
125 1129 : current->mm->start_brk = current->mm->brk = end;
126 1129 : return 0;
127 : }
128 :
129 : /* We need to explicitly zero any fractional pages
130 : after the data section (i.e. bss). This would
131 : contain the junk from the file that should not
132 : be in memory
133 : */
134 2256 : static int padzero(unsigned long elf_bss)
135 : {
136 2256 : unsigned long nbyte;
137 :
138 2256 : nbyte = ELF_PAGEOFFSET(elf_bss);
139 2256 : if (nbyte) {
140 2256 : nbyte = ELF_MIN_ALIGN - nbyte;
141 2256 : if (clear_user((void __user *) elf_bss, nbyte))
142 0 : return -EFAULT;
143 : }
144 : return 0;
145 : }
146 :
147 : /* Let's use some macros to make this stack manipulation a little clearer */
148 : #ifdef CONFIG_STACK_GROWSUP
149 : #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
150 : #define STACK_ROUND(sp, items) \
151 : ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
152 : #define STACK_ALLOC(sp, len) ({ \
153 : elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
154 : old_sp; })
155 : #else
156 : #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
157 : #define STACK_ROUND(sp, items) \
158 : (((unsigned long) (sp - items)) &~ 15UL)
159 : #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
160 : #endif
161 :
162 : #ifndef ELF_BASE_PLATFORM
163 : /*
164 : * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
165 : * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
166 : * will be copied to the user stack in the same manner as AT_PLATFORM.
167 : */
168 : #define ELF_BASE_PLATFORM NULL
169 : #endif
170 :
171 : static int
172 1129 : create_elf_tables(struct linux_binprm *bprm, const struct elfhdr *exec,
173 : unsigned long load_addr, unsigned long interp_load_addr,
174 : unsigned long e_entry)
175 : {
176 1129 : struct mm_struct *mm = current->mm;
177 1129 : unsigned long p = bprm->p;
178 1129 : int argc = bprm->argc;
179 1129 : int envc = bprm->envc;
180 1129 : elf_addr_t __user *sp;
181 1129 : elf_addr_t __user *u_platform;
182 1129 : elf_addr_t __user *u_base_platform;
183 1129 : elf_addr_t __user *u_rand_bytes;
184 1129 : const char *k_platform = ELF_PLATFORM;
185 1129 : const char *k_base_platform = ELF_BASE_PLATFORM;
186 1129 : unsigned char k_rand_bytes[16];
187 1129 : int items;
188 1129 : elf_addr_t *elf_info;
189 1129 : elf_addr_t flags = 0;
190 1129 : int ei_index;
191 1129 : const struct cred *cred = current_cred();
192 1129 : struct vm_area_struct *vma;
193 :
194 : /*
195 : * In some cases (e.g. Hyper-Threading), we want to avoid L1
196 : * evictions by the processes running on the same package. One
197 : * thing we can do is to shuffle the initial stack for them.
198 : */
199 :
200 1129 : p = arch_align_stack(p);
201 :
202 : /*
203 : * If this architecture has a platform capability string, copy it
204 : * to userspace. In some cases (Sparc), this info is impossible
205 : * for userspace to get any other way, in others (i386) it is
206 : * merely difficult.
207 : */
208 1129 : u_platform = NULL;
209 1129 : if (k_platform) {
210 1129 : size_t len = strlen(k_platform) + 1;
211 :
212 1129 : u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
213 1129 : if (copy_to_user(u_platform, k_platform, len))
214 : return -EFAULT;
215 : }
216 :
217 : /*
218 : * If this architecture has a "base" platform capability
219 : * string, copy it to userspace.
220 : */
221 1129 : u_base_platform = NULL;
222 1129 : if (k_base_platform) {
223 : size_t len = strlen(k_base_platform) + 1;
224 :
225 : u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
226 : if (copy_to_user(u_base_platform, k_base_platform, len))
227 : return -EFAULT;
228 : }
229 :
230 : /*
231 : * Generate 16 random bytes for userspace PRNG seeding.
232 : */
233 1129 : get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
234 1129 : u_rand_bytes = (elf_addr_t __user *)
235 1129 : STACK_ALLOC(p, sizeof(k_rand_bytes));
236 1129 : if (copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
237 : return -EFAULT;
238 :
239 : /* Create the ELF interpreter info */
240 1129 : elf_info = (elf_addr_t *)mm->saved_auxv;
241 : /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
242 : #define NEW_AUX_ENT(id, val) \
243 : do { \
244 : *elf_info++ = id; \
245 : *elf_info++ = val; \
246 : } while (0)
247 :
248 : #ifdef ARCH_DLINFO
249 : /*
250 : * ARCH_DLINFO must come first so PPC can do its special alignment of
251 : * AUXV.
252 : * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
253 : * ARCH_DLINFO changes
254 : */
255 1129 : ARCH_DLINFO;
256 : #endif
257 1129 : NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
258 1129 : NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
259 1129 : NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
260 1129 : NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
261 1129 : NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
262 1129 : NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
263 1129 : NEW_AUX_ENT(AT_BASE, interp_load_addr);
264 1129 : if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
265 0 : flags |= AT_FLAGS_PRESERVE_ARGV0;
266 1129 : NEW_AUX_ENT(AT_FLAGS, flags);
267 1129 : NEW_AUX_ENT(AT_ENTRY, e_entry);
268 1129 : NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
269 1129 : NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
270 1129 : NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
271 1129 : NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
272 1129 : NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
273 1129 : NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
274 : #ifdef ELF_HWCAP2
275 1129 : NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
276 : #endif
277 1129 : NEW_AUX_ENT(AT_EXECFN, bprm->exec);
278 1129 : if (k_platform) {
279 1129 : NEW_AUX_ENT(AT_PLATFORM,
280 : (elf_addr_t)(unsigned long)u_platform);
281 : }
282 1129 : if (k_base_platform) {
283 1129 : NEW_AUX_ENT(AT_BASE_PLATFORM,
284 : (elf_addr_t)(unsigned long)u_base_platform);
285 : }
286 1129 : if (bprm->have_execfd) {
287 0 : NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
288 : }
289 : #undef NEW_AUX_ENT
290 : /* AT_NULL is zero; clear the rest too */
291 1129 : memset(elf_info, 0, (char *)mm->saved_auxv +
292 1129 : sizeof(mm->saved_auxv) - (char *)elf_info);
293 :
294 : /* And advance past the AT_NULL entry. */
295 1129 : elf_info += 2;
296 :
297 1129 : ei_index = elf_info - (elf_addr_t *)mm->saved_auxv;
298 1129 : sp = STACK_ADD(p, ei_index);
299 :
300 1129 : items = (argc + 1) + (envc + 1) + 1;
301 1129 : bprm->p = STACK_ROUND(sp, items);
302 :
303 : /* Point sp at the lowest address on the stack */
304 : #ifdef CONFIG_STACK_GROWSUP
305 : sp = (elf_addr_t __user *)bprm->p - items - ei_index;
306 : bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
307 : #else
308 1129 : sp = (elf_addr_t __user *)bprm->p;
309 : #endif
310 :
311 :
312 : /*
313 : * Grow the stack manually; some architectures have a limit on how
314 : * far ahead a user-space access may be in order to grow the stack.
315 : */
316 1129 : if (mmap_read_lock_killable(mm))
317 : return -EINTR;
318 1129 : vma = find_extend_vma(mm, bprm->p);
319 1129 : mmap_read_unlock(mm);
320 1129 : if (!vma)
321 : return -EFAULT;
322 :
323 : /* Now, let's put argc (and argv, envp if appropriate) on the stack */
324 1129 : if (put_user(argc, sp++))
325 : return -EFAULT;
326 :
327 : /* Populate list of argv pointers back to argv strings. */
328 1129 : p = mm->arg_end = mm->arg_start;
329 4210 : while (argc-- > 0) {
330 3081 : size_t len;
331 3081 : if (put_user((elf_addr_t)p, sp++))
332 : return -EFAULT;
333 3081 : len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
334 3081 : if (!len || len > MAX_ARG_STRLEN)
335 : return -EINVAL;
336 3081 : p += len;
337 : }
338 1129 : if (put_user(0, sp++))
339 : return -EFAULT;
340 1129 : mm->arg_end = p;
341 :
342 : /* Populate list of envp pointers back to envp strings. */
343 1129 : mm->env_end = mm->env_start = p;
344 18273 : while (envc-- > 0) {
345 17144 : size_t len;
346 17144 : if (put_user((elf_addr_t)p, sp++))
347 : return -EFAULT;
348 17144 : len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
349 17144 : if (!len || len > MAX_ARG_STRLEN)
350 : return -EINVAL;
351 17144 : p += len;
352 : }
353 1129 : if (put_user(0, sp++))
354 : return -EFAULT;
355 1129 : mm->env_end = p;
356 :
357 : /* Put the elf_info on the stack in the right place. */
358 2258 : if (copy_to_user(sp, mm->saved_auxv, ei_index * sizeof(elf_addr_t)))
359 0 : return -EFAULT;
360 : return 0;
361 : }
362 :
363 9022 : static unsigned long elf_map(struct file *filep, unsigned long addr,
364 : const struct elf_phdr *eppnt, int prot, int type,
365 : unsigned long total_size)
366 : {
367 9022 : unsigned long map_addr;
368 9022 : unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
369 9022 : unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
370 9022 : addr = ELF_PAGESTART(addr);
371 9022 : size = ELF_PAGEALIGN(size);
372 :
373 : /* mmap() will return -EINVAL if given a zero size, but a
374 : * segment with zero filesize is perfectly valid */
375 9022 : if (!size)
376 : return addr;
377 :
378 : /*
379 : * total_size is the size of the ELF (interpreter) image.
380 : * The _first_ mmap needs to know the full size, otherwise
381 : * randomization might put this image into an overlapping
382 : * position with the ELF binary image. (since size < total_size)
383 : * So we first map the 'big' image - and unmap the remainder at
384 : * the end. (which unmap is needed for ELF images with holes.)
385 : */
386 9022 : if (total_size) {
387 2254 : total_size = ELF_PAGEALIGN(total_size);
388 2254 : map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
389 2254 : if (!BAD_ADDR(map_addr))
390 2254 : vm_munmap(map_addr+size, total_size-size);
391 : } else
392 6768 : map_addr = vm_mmap(filep, addr, size, prot, type, off);
393 :
394 9022 : if ((type & MAP_FIXED_NOREPLACE) &&
395 3381 : PTR_ERR((void *)map_addr) == -EEXIST)
396 0 : pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n",
397 : task_pid_nr(current), current->comm, (void *)addr);
398 :
399 : return(map_addr);
400 : }
401 :
402 2254 : static unsigned long total_mapping_size(const struct elf_phdr *cmds, int nr)
403 : {
404 2254 : int i, first_idx = -1, last_idx = -1;
405 :
406 24809 : for (i = 0; i < nr; i++) {
407 22555 : if (cmds[i].p_type == PT_LOAD) {
408 9014 : last_idx = i;
409 9014 : if (first_idx == -1)
410 2254 : first_idx = i;
411 : }
412 : }
413 2254 : if (first_idx == -1)
414 : return 0;
415 :
416 2254 : return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
417 2254 : ELF_PAGESTART(cmds[first_idx].p_vaddr);
418 : }
419 :
420 4510 : static int elf_read(struct file *file, void *buf, size_t len, loff_t pos)
421 : {
422 4510 : ssize_t rv;
423 :
424 4510 : rv = kernel_read(file, buf, len, &pos);
425 4510 : if (unlikely(rv != len)) {
426 0 : return (rv < 0) ? rv : -EIO;
427 : }
428 : return 0;
429 : }
430 :
431 1127 : static unsigned long maximum_alignment(struct elf_phdr *cmds, int nr)
432 : {
433 1127 : unsigned long alignment = 0;
434 1127 : int i;
435 :
436 13539 : for (i = 0; i < nr; i++) {
437 12412 : if (cmds[i].p_type == PT_LOAD) {
438 4506 : unsigned long p_align = cmds[i].p_align;
439 :
440 : /* skip non-power of two alignments as invalid */
441 9012 : if (!is_power_of_2(p_align))
442 0 : continue;
443 4506 : alignment = max(alignment, p_align);
444 : }
445 : }
446 :
447 : /* ensure we align to at least one page */
448 1127 : return ELF_PAGEALIGN(alignment);
449 : }
450 :
451 : /**
452 : * load_elf_phdrs() - load ELF program headers
453 : * @elf_ex: ELF header of the binary whose program headers should be loaded
454 : * @elf_file: the opened ELF binary file
455 : *
456 : * Loads ELF program headers from the binary file elf_file, which has the ELF
457 : * header pointed to by elf_ex, into a newly allocated array. The caller is
458 : * responsible for freeing the allocated data. Returns an ERR_PTR upon failure.
459 : */
460 2256 : static struct elf_phdr *load_elf_phdrs(const struct elfhdr *elf_ex,
461 : struct file *elf_file)
462 : {
463 2256 : struct elf_phdr *elf_phdata = NULL;
464 2256 : int retval, err = -1;
465 2256 : unsigned int size;
466 :
467 : /*
468 : * If the size of this structure has changed, then punt, since
469 : * we will be doing the wrong thing.
470 : */
471 2256 : if (elf_ex->e_phentsize != sizeof(struct elf_phdr))
472 0 : goto out;
473 :
474 : /* Sanity check the number of program headers... */
475 : /* ...and their total size. */
476 2256 : size = sizeof(struct elf_phdr) * elf_ex->e_phnum;
477 2256 : if (size == 0 || size > 65536 || size > ELF_MIN_ALIGN)
478 0 : goto out;
479 :
480 2256 : elf_phdata = kmalloc(size, GFP_KERNEL);
481 2256 : if (!elf_phdata)
482 0 : goto out;
483 :
484 : /* Read in the program headers */
485 2256 : retval = elf_read(elf_file, elf_phdata, size, elf_ex->e_phoff);
486 2256 : if (retval < 0) {
487 0 : err = retval;
488 0 : goto out;
489 : }
490 :
491 : /* Success! */
492 : err = 0;
493 0 : out:
494 0 : if (err) {
495 0 : kfree(elf_phdata);
496 0 : elf_phdata = NULL;
497 : }
498 2256 : 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 1129 : 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 1129 : return 0;
567 : }
568 :
569 : #endif /* !CONFIG_ARCH_BINFMT_ELF_STATE */
570 :
571 9022 : static inline int make_prot(u32 p_flags, struct arch_elf_state *arch_state,
572 : bool has_interp, bool is_interp)
573 : {
574 9022 : int prot = 0;
575 :
576 9022 : if (p_flags & PF_R)
577 9022 : prot |= PROT_READ;
578 9022 : if (p_flags & PF_W)
579 2256 : prot |= PROT_WRITE;
580 9022 : if (p_flags & PF_X)
581 2256 : prot |= PROT_EXEC;
582 :
583 9022 : 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 1127 : 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 1127 : struct elf_phdr *eppnt;
597 1127 : unsigned long load_addr = 0;
598 1127 : int load_addr_set = 0;
599 1127 : unsigned long last_bss = 0, elf_bss = 0;
600 1127 : int bss_prot = 0;
601 1127 : unsigned long error = ~0UL;
602 1127 : unsigned long total_size;
603 1127 : int i;
604 :
605 : /* First of all, some simple consistency checks */
606 1127 : if (interp_elf_ex->e_type != ET_EXEC &&
607 : interp_elf_ex->e_type != ET_DYN)
608 0 : goto out;
609 1127 : if (!elf_check_arch(interp_elf_ex) ||
610 : elf_check_fdpic(interp_elf_ex))
611 0 : goto out;
612 1127 : if (!interpreter->f_op->mmap)
613 0 : goto out;
614 :
615 1127 : total_size = total_mapping_size(interp_elf_phdata,
616 1127 : interp_elf_ex->e_phnum);
617 1127 : if (!total_size) {
618 0 : error = -EINVAL;
619 0 : goto out;
620 : }
621 :
622 : eppnt = interp_elf_phdata;
623 11270 : for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
624 10143 : if (eppnt->p_type == PT_LOAD) {
625 4508 : int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
626 4508 : int elf_prot = make_prot(eppnt->p_flags, arch_state,
627 : true, true);
628 4508 : unsigned long vaddr = 0;
629 4508 : unsigned long k, map_addr;
630 :
631 4508 : vaddr = eppnt->p_vaddr;
632 4508 : if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
633 : elf_type |= MAP_FIXED_NOREPLACE;
634 1127 : else if (no_base && interp_elf_ex->e_type == ET_DYN)
635 1127 : load_addr = -vaddr;
636 :
637 4508 : map_addr = elf_map(interpreter, load_addr + vaddr,
638 : eppnt, elf_prot, elf_type, total_size);
639 4508 : total_size = 0;
640 4508 : error = map_addr;
641 4508 : if (BAD_ADDR(map_addr))
642 0 : goto out;
643 :
644 4508 : if (!load_addr_set &&
645 1127 : interp_elf_ex->e_type == ET_DYN) {
646 1127 : load_addr = map_addr - ELF_PAGESTART(vaddr);
647 1127 : 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 4508 : k = load_addr + eppnt->p_vaddr;
656 4508 : if (BAD_ADDR(k) ||
657 9016 : eppnt->p_filesz > eppnt->p_memsz ||
658 4508 : eppnt->p_memsz > TASK_SIZE ||
659 4508 : TASK_SIZE - eppnt->p_memsz < k) {
660 0 : error = -ENOMEM;
661 0 : 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 4508 : k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
669 4508 : if (k > elf_bss)
670 : 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 4508 : k = load_addr + eppnt->p_vaddr + eppnt->p_memsz;
677 4508 : if (k > last_bss) {
678 4508 : last_bss = k;
679 4508 : 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 1127 : if (padzero(elf_bss)) {
690 0 : error = -EFAULT;
691 0 : 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 1127 : elf_bss = ELF_PAGEALIGN(elf_bss);
699 1127 : last_bss = ELF_PAGEALIGN(last_bss);
700 : /* Finally, if there is still more bss to allocate, do it. */
701 1127 : if (last_bss > elf_bss) {
702 1127 : error = vm_brk_flags(elf_bss, last_bss - elf_bss,
703 : bss_prot & PROT_EXEC ? VM_EXEC : 0);
704 1127 : if (error)
705 0 : goto out;
706 : }
707 :
708 : error = load_addr;
709 1127 : out:
710 1127 : 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 1129 : static int parse_elf_properties(struct file *f, const struct elf_phdr *phdr,
767 : struct arch_elf_state *arch)
768 : {
769 1129 : union {
770 : struct elf_note nhdr;
771 : char data[NOTE_DATA_SZ];
772 : } note;
773 1129 : loff_t pos;
774 1129 : ssize_t n;
775 1129 : size_t off, datasz;
776 1129 : int ret;
777 1129 : bool have_prev_type;
778 1129 : u32 prev_type;
779 :
780 1129 : if (!IS_ENABLED(CONFIG_ARCH_USE_GNU_PROPERTY) || !phdr)
781 1129 : 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 1129 : static int load_elf_binary(struct linux_binprm *bprm)
824 : {
825 1129 : struct file *interpreter = NULL; /* to shut gcc up */
826 1129 : unsigned long load_addr = 0, load_bias = 0;
827 1129 : int load_addr_set = 0;
828 1129 : unsigned long error;
829 1129 : struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
830 1129 : struct elf_phdr *elf_property_phdata = NULL;
831 1129 : unsigned long elf_bss, elf_brk;
832 1129 : int bss_prot = 0;
833 1129 : int retval, i;
834 1129 : unsigned long elf_entry;
835 1129 : unsigned long e_entry;
836 1129 : unsigned long interp_load_addr = 0;
837 1129 : unsigned long start_code, end_code, start_data, end_data;
838 1129 : unsigned long reloc_func_desc __maybe_unused = 0;
839 1129 : int executable_stack = EXSTACK_DEFAULT;
840 1129 : struct elfhdr *elf_ex = (struct elfhdr *)bprm->buf;
841 1129 : struct elfhdr *interp_elf_ex = NULL;
842 1129 : struct arch_elf_state arch_state = INIT_ARCH_ELF_STATE;
843 1129 : struct mm_struct *mm;
844 1129 : struct pt_regs *regs;
845 :
846 1129 : retval = -ENOEXEC;
847 : /* First of all, some simple consistency checks */
848 1129 : if (memcmp(elf_ex->e_ident, ELFMAG, SELFMAG) != 0)
849 0 : goto out;
850 :
851 1129 : if (elf_ex->e_type != ET_EXEC && elf_ex->e_type != ET_DYN)
852 0 : goto out;
853 1129 : if (!elf_check_arch(elf_ex))
854 0 : goto out;
855 1129 : if (elf_check_fdpic(elf_ex))
856 : goto out;
857 1129 : if (!bprm->file->f_op->mmap)
858 0 : goto out;
859 :
860 1129 : elf_phdata = load_elf_phdrs(elf_ex, bprm->file);
861 1129 : if (!elf_phdata)
862 0 : goto out;
863 :
864 : elf_ppnt = elf_phdata;
865 2272 : for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++) {
866 2270 : char *elf_interpreter;
867 :
868 2270 : if (elf_ppnt->p_type == PT_GNU_PROPERTY) {
869 0 : elf_property_phdata = elf_ppnt;
870 0 : continue;
871 : }
872 :
873 2270 : if (elf_ppnt->p_type != PT_INTERP)
874 1143 : 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 1127 : retval = -ENOEXEC;
881 1127 : if (elf_ppnt->p_filesz > PATH_MAX || elf_ppnt->p_filesz < 2)
882 0 : goto out_free_ph;
883 :
884 1127 : retval = -ENOMEM;
885 1127 : elf_interpreter = kmalloc(elf_ppnt->p_filesz, GFP_KERNEL);
886 1127 : if (!elf_interpreter)
887 0 : goto out_free_ph;
888 :
889 2254 : retval = elf_read(bprm->file, elf_interpreter, elf_ppnt->p_filesz,
890 1127 : elf_ppnt->p_offset);
891 1127 : if (retval < 0)
892 0 : goto out_free_interp;
893 : /* make sure path is NULL terminated */
894 1127 : retval = -ENOEXEC;
895 1127 : if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
896 0 : goto out_free_interp;
897 :
898 1127 : interpreter = open_exec(elf_interpreter);
899 1127 : kfree(elf_interpreter);
900 1127 : retval = PTR_ERR(interpreter);
901 1127 : if (IS_ERR(interpreter))
902 0 : 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 1127 : would_dump(bprm, interpreter);
909 :
910 1127 : interp_elf_ex = kmalloc(sizeof(*interp_elf_ex), GFP_KERNEL);
911 1127 : if (!interp_elf_ex) {
912 0 : retval = -ENOMEM;
913 0 : goto out_free_ph;
914 : }
915 :
916 : /* Get the exec headers */
917 1127 : retval = elf_read(interpreter, interp_elf_ex,
918 : sizeof(*interp_elf_ex), 0);
919 1127 : if (retval < 0)
920 0 : goto out_free_dentry;
921 :
922 : break;
923 :
924 0 : out_free_interp:
925 0 : kfree(elf_interpreter);
926 0 : goto out_free_ph;
927 : }
928 :
929 1129 : elf_ppnt = elf_phdata;
930 13557 : for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++)
931 12428 : switch (elf_ppnt->p_type) {
932 1129 : case PT_GNU_STACK:
933 1129 : if (elf_ppnt->p_flags & PF_X)
934 : executable_stack = EXSTACK_ENABLE_X;
935 : else
936 : executable_stack = EXSTACK_DISABLE_X;
937 : break;
938 :
939 : case PT_LOPROC ... PT_HIPROC:
940 12428 : 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 13557 : if (interpreter) {
950 1127 : retval = -ELIBBAD;
951 : /* Not an ELF interpreter */
952 1127 : if (memcmp(interp_elf_ex->e_ident, ELFMAG, SELFMAG) != 0)
953 0 : goto out_free_dentry;
954 : /* Verify the interpreter has a valid arch */
955 1127 : if (!elf_check_arch(interp_elf_ex) ||
956 : elf_check_fdpic(interp_elf_ex))
957 0 : goto out_free_dentry;
958 :
959 : /* Load the interpreter program headers */
960 1127 : interp_elf_phdata = load_elf_phdrs(interp_elf_ex,
961 : interpreter);
962 1127 : if (!interp_elf_phdata)
963 0 : 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 11270 : for (i = 0; i < interp_elf_ex->e_phnum; i++, elf_ppnt++)
969 10143 : 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 10143 : 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 10143 : }
983 :
984 1129 : retval = parse_elf_properties(interpreter ?: bprm->file,
985 : elf_property_phdata, &arch_state);
986 1129 : 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 1129 : retval = arch_check_elf(elf_ex,
995 : !!interpreter, interp_elf_ex,
996 : &arch_state);
997 1129 : if (retval)
998 : goto out_free_dentry;
999 :
1000 : /* Flush all traces of the currently running executable */
1001 1129 : retval = begin_new_exec(bprm);
1002 1129 : if (retval)
1003 0 : 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 1129 : SET_PERSONALITY2(*elf_ex, &arch_state);
1008 1129 : if (elf_read_implies_exec(*elf_ex, executable_stack))
1009 0 : current->personality |= READ_IMPLIES_EXEC;
1010 :
1011 1129 : if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
1012 1129 : current->flags |= PF_RANDOMIZE;
1013 :
1014 1129 : 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 1129 : retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
1019 : executable_stack);
1020 1129 : if (retval < 0)
1021 0 : 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 13557 : for(i = 0, elf_ppnt = elf_phdata;
1034 13557 : i < elf_ex->e_phnum; i++, elf_ppnt++) {
1035 12428 : int elf_prot, elf_flags;
1036 12428 : unsigned long k, vaddr;
1037 12428 : unsigned long total_size = 0;
1038 12428 : unsigned long alignment;
1039 :
1040 12428 : if (elf_ppnt->p_type != PT_LOAD)
1041 7914 : continue;
1042 :
1043 4514 : if (unlikely (elf_brk > elf_bss)) {
1044 0 : 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 0 : 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 : 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 4514 : }
1067 : }
1068 : }
1069 :
1070 4514 : elf_prot = make_prot(elf_ppnt->p_flags, &arch_state,
1071 : !!interpreter, false);
1072 :
1073 4514 : elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
1074 :
1075 4514 : vaddr = elf_ppnt->p_vaddr;
1076 : /*
1077 : * If we are loading ET_EXEC or we have already performed
1078 : * the ET_DYN load_addr calculations, proceed normally.
1079 : */
1080 4514 : if (elf_ex->e_type == ET_EXEC || load_addr_set) {
1081 : elf_flags |= MAP_FIXED;
1082 1127 : } else if (elf_ex->e_type == ET_DYN) {
1083 : /*
1084 : * This logic is run once for the first LOAD Program
1085 : * Header for ET_DYN binaries to calculate the
1086 : * randomization (load_bias) for all the LOAD
1087 : * Program Headers, and to calculate the entire
1088 : * size of the ELF mapping (total_size). (Note that
1089 : * load_addr_set is set to true later once the
1090 : * initial mapping is performed.)
1091 : *
1092 : * There are effectively two types of ET_DYN
1093 : * binaries: programs (i.e. PIE: ET_DYN with INTERP)
1094 : * and loaders (ET_DYN without INTERP, since they
1095 : * _are_ the ELF interpreter). The loaders must
1096 : * be loaded away from programs since the program
1097 : * may otherwise collide with the loader (especially
1098 : * for ET_EXEC which does not have a randomized
1099 : * position). For example to handle invocations of
1100 : * "./ld.so someprog" to test out a new version of
1101 : * the loader, the subsequent program that the
1102 : * loader loads must avoid the loader itself, so
1103 : * they cannot share the same load range. Sufficient
1104 : * room for the brk must be allocated with the
1105 : * loader as well, since brk must be available with
1106 : * the loader.
1107 : *
1108 : * Therefore, programs are loaded offset from
1109 : * ELF_ET_DYN_BASE and loaders are loaded into the
1110 : * independently randomized mmap region (0 load_bias
1111 : * without MAP_FIXED).
1112 : */
1113 1127 : if (interpreter) {
1114 1127 : load_bias = ELF_ET_DYN_BASE;
1115 1127 : if (current->flags & PF_RANDOMIZE)
1116 1127 : load_bias += arch_mmap_rnd();
1117 1127 : alignment = maximum_alignment(elf_phdata, elf_ex->e_phnum);
1118 1127 : if (alignment)
1119 1127 : load_bias &= ~(alignment - 1);
1120 : elf_flags |= MAP_FIXED;
1121 : } else
1122 : load_bias = 0;
1123 :
1124 : /*
1125 : * Since load_bias is used for all subsequent loading
1126 : * calculations, we must lower it by the first vaddr
1127 : * so that the remaining calculations based on the
1128 : * ELF vaddrs will be correctly offset. The result
1129 : * is then page aligned.
1130 : */
1131 1127 : load_bias = ELF_PAGESTART(load_bias - vaddr);
1132 :
1133 1127 : total_size = total_mapping_size(elf_phdata,
1134 1127 : elf_ex->e_phnum);
1135 1127 : if (!total_size) {
1136 0 : retval = -EINVAL;
1137 0 : goto out_free_dentry;
1138 : }
1139 : }
1140 :
1141 4514 : error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
1142 : elf_prot, elf_flags, total_size);
1143 4514 : if (BAD_ADDR(error)) {
1144 0 : retval = IS_ERR((void *)error) ?
1145 0 : PTR_ERR((void*)error) : -EINVAL;
1146 0 : goto out_free_dentry;
1147 : }
1148 :
1149 4514 : if (!load_addr_set) {
1150 1129 : load_addr_set = 1;
1151 1129 : load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
1152 1129 : if (elf_ex->e_type == ET_DYN) {
1153 1127 : load_bias += error -
1154 1127 : ELF_PAGESTART(load_bias + vaddr);
1155 1127 : load_addr += load_bias;
1156 1127 : reloc_func_desc = load_bias;
1157 : }
1158 : }
1159 4514 : k = elf_ppnt->p_vaddr;
1160 4514 : if ((elf_ppnt->p_flags & PF_X) && k < start_code)
1161 : start_code = k;
1162 4514 : if (start_data < k)
1163 : start_data = k;
1164 :
1165 : /*
1166 : * Check to see if the section's size will overflow the
1167 : * allowed task size. Note that p_filesz must always be
1168 : * <= p_memsz so it is only necessary to check p_memsz.
1169 : */
1170 9028 : if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
1171 4514 : elf_ppnt->p_memsz > TASK_SIZE ||
1172 4514 : TASK_SIZE - elf_ppnt->p_memsz < k) {
1173 : /* set_brk can never work. Avoid overflows. */
1174 0 : retval = -EINVAL;
1175 0 : goto out_free_dentry;
1176 : }
1177 :
1178 4514 : k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
1179 :
1180 4514 : if (k > elf_bss)
1181 : elf_bss = k;
1182 4514 : if ((elf_ppnt->p_flags & PF_X) && end_code < k)
1183 : end_code = k;
1184 4514 : if (end_data < k)
1185 : end_data = k;
1186 4514 : k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
1187 4514 : if (k > elf_brk) {
1188 4514 : bss_prot = elf_prot;
1189 4514 : elf_brk = k;
1190 : }
1191 : }
1192 :
1193 1129 : e_entry = elf_ex->e_entry + load_bias;
1194 1129 : elf_bss += load_bias;
1195 1129 : elf_brk += load_bias;
1196 1129 : start_code += load_bias;
1197 1129 : end_code += load_bias;
1198 1129 : start_data += load_bias;
1199 1129 : end_data += load_bias;
1200 :
1201 : /* Calling set_brk effectively mmaps the pages that we need
1202 : * for the bss and break sections. We must do this before
1203 : * mapping in the interpreter, to make sure it doesn't wind
1204 : * up getting placed where the bss needs to go.
1205 : */
1206 1129 : retval = set_brk(elf_bss, elf_brk, bss_prot);
1207 1129 : if (retval)
1208 0 : goto out_free_dentry;
1209 1129 : if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
1210 0 : retval = -EFAULT; /* Nobody gets to see this, but.. */
1211 0 : goto out_free_dentry;
1212 : }
1213 :
1214 1129 : if (interpreter) {
1215 1127 : elf_entry = load_elf_interp(interp_elf_ex,
1216 : interpreter,
1217 : load_bias, interp_elf_phdata,
1218 : &arch_state);
1219 1127 : if (!IS_ERR((void *)elf_entry)) {
1220 : /*
1221 : * load_elf_interp() returns relocation
1222 : * adjustment
1223 : */
1224 1127 : interp_load_addr = elf_entry;
1225 1127 : elf_entry += interp_elf_ex->e_entry;
1226 : }
1227 1127 : if (BAD_ADDR(elf_entry)) {
1228 0 : retval = IS_ERR((void *)elf_entry) ?
1229 0 : (int)elf_entry : -EINVAL;
1230 0 : goto out_free_dentry;
1231 : }
1232 1127 : reloc_func_desc = interp_load_addr;
1233 :
1234 1127 : allow_write_access(interpreter);
1235 1127 : fput(interpreter);
1236 :
1237 1127 : kfree(interp_elf_ex);
1238 1127 : kfree(interp_elf_phdata);
1239 : } else {
1240 2 : elf_entry = e_entry;
1241 2 : if (BAD_ADDR(elf_entry)) {
1242 0 : retval = -EINVAL;
1243 0 : goto out_free_dentry;
1244 : }
1245 : }
1246 :
1247 1129 : kfree(elf_phdata);
1248 :
1249 1129 : set_binfmt(&elf_format);
1250 :
1251 : #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
1252 1129 : retval = ARCH_SETUP_ADDITIONAL_PAGES(bprm, elf_ex, !!interpreter);
1253 1129 : if (retval < 0)
1254 0 : goto out;
1255 : #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
1256 :
1257 1129 : retval = create_elf_tables(bprm, elf_ex,
1258 : load_addr, interp_load_addr, e_entry);
1259 1129 : if (retval < 0)
1260 0 : goto out;
1261 :
1262 1129 : mm = current->mm;
1263 1129 : mm->end_code = end_code;
1264 1129 : mm->start_code = start_code;
1265 1129 : mm->start_data = start_data;
1266 1129 : mm->end_data = end_data;
1267 1129 : mm->start_stack = bprm->p;
1268 :
1269 1129 : if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
1270 : /*
1271 : * For architectures with ELF randomization, when executing
1272 : * a loader directly (i.e. no interpreter listed in ELF
1273 : * headers), move the brk area out of the mmap region
1274 : * (since it grows up, and may collide early with the stack
1275 : * growing down), and into the unused ELF_ET_DYN_BASE region.
1276 : */
1277 1129 : if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) &&
1278 1129 : elf_ex->e_type == ET_DYN && !interpreter) {
1279 0 : mm->brk = mm->start_brk = ELF_ET_DYN_BASE;
1280 : }
1281 :
1282 1129 : mm->brk = mm->start_brk = arch_randomize_brk(mm);
1283 : #ifdef compat_brk_randomized
1284 : current->brk_randomized = 1;
1285 : #endif
1286 : }
1287 :
1288 1129 : if (current->personality & MMAP_PAGE_ZERO) {
1289 : /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
1290 : and some applications "depend" upon this behavior.
1291 : Since we do not have the power to recompile these, we
1292 : emulate the SVr4 behavior. Sigh. */
1293 0 : error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1294 : MAP_FIXED | MAP_PRIVATE, 0);
1295 : }
1296 :
1297 1129 : regs = current_pt_regs();
1298 : #ifdef ELF_PLAT_INIT
1299 : /*
1300 : * The ABI may specify that certain registers be set up in special
1301 : * ways (on i386 %edx is the address of a DT_FINI function, for
1302 : * example. In addition, it may also specify (eg, PowerPC64 ELF)
1303 : * that the e_entry field is the address of the function descriptor
1304 : * for the startup routine, rather than the address of the startup
1305 : * routine itself. This macro performs whatever initialization to
1306 : * the regs structure is required as well as any relocations to the
1307 : * function descriptor entries when executing dynamically links apps.
1308 : */
1309 1129 : ELF_PLAT_INIT(regs, reloc_func_desc);
1310 : #endif
1311 :
1312 1129 : finalize_exec(bprm);
1313 1129 : START_THREAD(elf_ex, regs, elf_entry, bprm->p);
1314 1129 : retval = 0;
1315 1129 : out:
1316 1129 : return retval;
1317 :
1318 : /* error cleanup */
1319 0 : out_free_dentry:
1320 0 : kfree(interp_elf_ex);
1321 0 : kfree(interp_elf_phdata);
1322 0 : allow_write_access(interpreter);
1323 0 : if (interpreter)
1324 0 : fput(interpreter);
1325 0 : out_free_ph:
1326 0 : kfree(elf_phdata);
1327 0 : goto out;
1328 : }
1329 :
1330 : #ifdef CONFIG_USELIB
1331 : /* This is really simpleminded and specialized - we are loading an
1332 : a.out library that is given an ELF header. */
1333 : static int load_elf_library(struct file *file)
1334 : {
1335 : struct elf_phdr *elf_phdata;
1336 : struct elf_phdr *eppnt;
1337 : unsigned long elf_bss, bss, len;
1338 : int retval, error, i, j;
1339 : struct elfhdr elf_ex;
1340 :
1341 : error = -ENOEXEC;
1342 : retval = elf_read(file, &elf_ex, sizeof(elf_ex), 0);
1343 : if (retval < 0)
1344 : goto out;
1345 :
1346 : if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1347 : goto out;
1348 :
1349 : /* First of all, some simple consistency checks */
1350 : if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1351 : !elf_check_arch(&elf_ex) || !file->f_op->mmap)
1352 : goto out;
1353 : if (elf_check_fdpic(&elf_ex))
1354 : goto out;
1355 :
1356 : /* Now read in all of the header information */
1357 :
1358 : j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1359 : /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1360 :
1361 : error = -ENOMEM;
1362 : elf_phdata = kmalloc(j, GFP_KERNEL);
1363 : if (!elf_phdata)
1364 : goto out;
1365 :
1366 : eppnt = elf_phdata;
1367 : error = -ENOEXEC;
1368 : retval = elf_read(file, eppnt, j, elf_ex.e_phoff);
1369 : if (retval < 0)
1370 : goto out_free_ph;
1371 :
1372 : for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1373 : if ((eppnt + i)->p_type == PT_LOAD)
1374 : j++;
1375 : if (j != 1)
1376 : goto out_free_ph;
1377 :
1378 : while (eppnt->p_type != PT_LOAD)
1379 : eppnt++;
1380 :
1381 : /* Now use mmap to map the library into memory. */
1382 : error = vm_mmap(file,
1383 : ELF_PAGESTART(eppnt->p_vaddr),
1384 : (eppnt->p_filesz +
1385 : ELF_PAGEOFFSET(eppnt->p_vaddr)),
1386 : PROT_READ | PROT_WRITE | PROT_EXEC,
1387 : MAP_FIXED_NOREPLACE | MAP_PRIVATE | MAP_DENYWRITE,
1388 : (eppnt->p_offset -
1389 : ELF_PAGEOFFSET(eppnt->p_vaddr)));
1390 : if (error != ELF_PAGESTART(eppnt->p_vaddr))
1391 : goto out_free_ph;
1392 :
1393 : elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1394 : if (padzero(elf_bss)) {
1395 : error = -EFAULT;
1396 : goto out_free_ph;
1397 : }
1398 :
1399 : len = ELF_PAGEALIGN(eppnt->p_filesz + eppnt->p_vaddr);
1400 : bss = ELF_PAGEALIGN(eppnt->p_memsz + eppnt->p_vaddr);
1401 : if (bss > len) {
1402 : error = vm_brk(len, bss - len);
1403 : if (error)
1404 : goto out_free_ph;
1405 : }
1406 : error = 0;
1407 :
1408 : out_free_ph:
1409 : kfree(elf_phdata);
1410 : out:
1411 : return error;
1412 : }
1413 : #endif /* #ifdef CONFIG_USELIB */
1414 :
1415 : #ifdef CONFIG_ELF_CORE
1416 : /*
1417 : * ELF core dumper
1418 : *
1419 : * Modelled on fs/exec.c:aout_core_dump()
1420 : * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1421 : */
1422 :
1423 : /* An ELF note in memory */
1424 : struct memelfnote
1425 : {
1426 : const char *name;
1427 : int type;
1428 : unsigned int datasz;
1429 : void *data;
1430 : };
1431 :
1432 : static int notesize(struct memelfnote *en)
1433 : {
1434 : int sz;
1435 :
1436 : sz = sizeof(struct elf_note);
1437 : sz += roundup(strlen(en->name) + 1, 4);
1438 : sz += roundup(en->datasz, 4);
1439 :
1440 : return sz;
1441 : }
1442 :
1443 : static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1444 : {
1445 : struct elf_note en;
1446 : en.n_namesz = strlen(men->name) + 1;
1447 : en.n_descsz = men->datasz;
1448 : en.n_type = men->type;
1449 :
1450 : return dump_emit(cprm, &en, sizeof(en)) &&
1451 : dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1452 : dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1453 : }
1454 :
1455 : static void fill_elf_header(struct elfhdr *elf, int segs,
1456 : u16 machine, u32 flags)
1457 : {
1458 : memset(elf, 0, sizeof(*elf));
1459 :
1460 : memcpy(elf->e_ident, ELFMAG, SELFMAG);
1461 : elf->e_ident[EI_CLASS] = ELF_CLASS;
1462 : elf->e_ident[EI_DATA] = ELF_DATA;
1463 : elf->e_ident[EI_VERSION] = EV_CURRENT;
1464 : elf->e_ident[EI_OSABI] = ELF_OSABI;
1465 :
1466 : elf->e_type = ET_CORE;
1467 : elf->e_machine = machine;
1468 : elf->e_version = EV_CURRENT;
1469 : elf->e_phoff = sizeof(struct elfhdr);
1470 : elf->e_flags = flags;
1471 : elf->e_ehsize = sizeof(struct elfhdr);
1472 : elf->e_phentsize = sizeof(struct elf_phdr);
1473 : elf->e_phnum = segs;
1474 : }
1475 :
1476 : static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1477 : {
1478 : phdr->p_type = PT_NOTE;
1479 : phdr->p_offset = offset;
1480 : phdr->p_vaddr = 0;
1481 : phdr->p_paddr = 0;
1482 : phdr->p_filesz = sz;
1483 : phdr->p_memsz = 0;
1484 : phdr->p_flags = 0;
1485 : phdr->p_align = 0;
1486 : }
1487 :
1488 : static void fill_note(struct memelfnote *note, const char *name, int type,
1489 : unsigned int sz, void *data)
1490 : {
1491 : note->name = name;
1492 : note->type = type;
1493 : note->datasz = sz;
1494 : note->data = data;
1495 : }
1496 :
1497 : /*
1498 : * fill up all the fields in prstatus from the given task struct, except
1499 : * registers which need to be filled up separately.
1500 : */
1501 : static void fill_prstatus(struct elf_prstatus_common *prstatus,
1502 : struct task_struct *p, long signr)
1503 : {
1504 : prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1505 : prstatus->pr_sigpend = p->pending.signal.sig[0];
1506 : prstatus->pr_sighold = p->blocked.sig[0];
1507 : rcu_read_lock();
1508 : prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1509 : rcu_read_unlock();
1510 : prstatus->pr_pid = task_pid_vnr(p);
1511 : prstatus->pr_pgrp = task_pgrp_vnr(p);
1512 : prstatus->pr_sid = task_session_vnr(p);
1513 : if (thread_group_leader(p)) {
1514 : struct task_cputime cputime;
1515 :
1516 : /*
1517 : * This is the record for the group leader. It shows the
1518 : * group-wide total, not its individual thread total.
1519 : */
1520 : thread_group_cputime(p, &cputime);
1521 : prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1522 : prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1523 : } else {
1524 : u64 utime, stime;
1525 :
1526 : task_cputime(p, &utime, &stime);
1527 : prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1528 : prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1529 : }
1530 :
1531 : prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1532 : prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1533 : }
1534 :
1535 : static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1536 : struct mm_struct *mm)
1537 : {
1538 : const struct cred *cred;
1539 : unsigned int i, len;
1540 :
1541 : /* first copy the parameters from user space */
1542 : memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1543 :
1544 : len = mm->arg_end - mm->arg_start;
1545 : if (len >= ELF_PRARGSZ)
1546 : len = ELF_PRARGSZ-1;
1547 : if (copy_from_user(&psinfo->pr_psargs,
1548 : (const char __user *)mm->arg_start, len))
1549 : return -EFAULT;
1550 : for(i = 0; i < len; i++)
1551 : if (psinfo->pr_psargs[i] == 0)
1552 : psinfo->pr_psargs[i] = ' ';
1553 : psinfo->pr_psargs[len] = 0;
1554 :
1555 : rcu_read_lock();
1556 : psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1557 : rcu_read_unlock();
1558 : psinfo->pr_pid = task_pid_vnr(p);
1559 : psinfo->pr_pgrp = task_pgrp_vnr(p);
1560 : psinfo->pr_sid = task_session_vnr(p);
1561 :
1562 : i = p->state ? ffz(~p->state) + 1 : 0;
1563 : psinfo->pr_state = i;
1564 : psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1565 : psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1566 : psinfo->pr_nice = task_nice(p);
1567 : psinfo->pr_flag = p->flags;
1568 : rcu_read_lock();
1569 : cred = __task_cred(p);
1570 : SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1571 : SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1572 : rcu_read_unlock();
1573 : strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1574 :
1575 : return 0;
1576 : }
1577 :
1578 : static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1579 : {
1580 : elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1581 : int i = 0;
1582 : do
1583 : i += 2;
1584 : while (auxv[i - 2] != AT_NULL);
1585 : fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1586 : }
1587 :
1588 : static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1589 : const kernel_siginfo_t *siginfo)
1590 : {
1591 : copy_siginfo_to_external(csigdata, siginfo);
1592 : fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1593 : }
1594 :
1595 : #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1596 : /*
1597 : * Format of NT_FILE note:
1598 : *
1599 : * long count -- how many files are mapped
1600 : * long page_size -- units for file_ofs
1601 : * array of [COUNT] elements of
1602 : * long start
1603 : * long end
1604 : * long file_ofs
1605 : * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1606 : */
1607 : static int fill_files_note(struct memelfnote *note)
1608 : {
1609 : struct mm_struct *mm = current->mm;
1610 : struct vm_area_struct *vma;
1611 : unsigned count, size, names_ofs, remaining, n;
1612 : user_long_t *data;
1613 : user_long_t *start_end_ofs;
1614 : char *name_base, *name_curpos;
1615 :
1616 : /* *Estimated* file count and total data size needed */
1617 : count = mm->map_count;
1618 : if (count > UINT_MAX / 64)
1619 : return -EINVAL;
1620 : size = count * 64;
1621 :
1622 : names_ofs = (2 + 3 * count) * sizeof(data[0]);
1623 : alloc:
1624 : if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1625 : return -EINVAL;
1626 : size = round_up(size, PAGE_SIZE);
1627 : /*
1628 : * "size" can be 0 here legitimately.
1629 : * Let it ENOMEM and omit NT_FILE section which will be empty anyway.
1630 : */
1631 : data = kvmalloc(size, GFP_KERNEL);
1632 : if (ZERO_OR_NULL_PTR(data))
1633 : return -ENOMEM;
1634 :
1635 : start_end_ofs = data + 2;
1636 : name_base = name_curpos = ((char *)data) + names_ofs;
1637 : remaining = size - names_ofs;
1638 : count = 0;
1639 : for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
1640 : struct file *file;
1641 : const char *filename;
1642 :
1643 : file = vma->vm_file;
1644 : if (!file)
1645 : continue;
1646 : filename = file_path(file, name_curpos, remaining);
1647 : if (IS_ERR(filename)) {
1648 : if (PTR_ERR(filename) == -ENAMETOOLONG) {
1649 : kvfree(data);
1650 : size = size * 5 / 4;
1651 : goto alloc;
1652 : }
1653 : continue;
1654 : }
1655 :
1656 : /* file_path() fills at the end, move name down */
1657 : /* n = strlen(filename) + 1: */
1658 : n = (name_curpos + remaining) - filename;
1659 : remaining = filename - name_curpos;
1660 : memmove(name_curpos, filename, n);
1661 : name_curpos += n;
1662 :
1663 : *start_end_ofs++ = vma->vm_start;
1664 : *start_end_ofs++ = vma->vm_end;
1665 : *start_end_ofs++ = vma->vm_pgoff;
1666 : count++;
1667 : }
1668 :
1669 : /* Now we know exact count of files, can store it */
1670 : data[0] = count;
1671 : data[1] = PAGE_SIZE;
1672 : /*
1673 : * Count usually is less than mm->map_count,
1674 : * we need to move filenames down.
1675 : */
1676 : n = mm->map_count - count;
1677 : if (n != 0) {
1678 : unsigned shift_bytes = n * 3 * sizeof(data[0]);
1679 : memmove(name_base - shift_bytes, name_base,
1680 : name_curpos - name_base);
1681 : name_curpos -= shift_bytes;
1682 : }
1683 :
1684 : size = name_curpos - (char *)data;
1685 : fill_note(note, "CORE", NT_FILE, size, data);
1686 : return 0;
1687 : }
1688 :
1689 : #ifdef CORE_DUMP_USE_REGSET
1690 : #include <linux/regset.h>
1691 :
1692 : struct elf_thread_core_info {
1693 : struct elf_thread_core_info *next;
1694 : struct task_struct *task;
1695 : struct elf_prstatus prstatus;
1696 : struct memelfnote notes[];
1697 : };
1698 :
1699 : struct elf_note_info {
1700 : struct elf_thread_core_info *thread;
1701 : struct memelfnote psinfo;
1702 : struct memelfnote signote;
1703 : struct memelfnote auxv;
1704 : struct memelfnote files;
1705 : user_siginfo_t csigdata;
1706 : size_t size;
1707 : int thread_notes;
1708 : };
1709 :
1710 : /*
1711 : * When a regset has a writeback hook, we call it on each thread before
1712 : * dumping user memory. On register window machines, this makes sure the
1713 : * user memory backing the register data is up to date before we read it.
1714 : */
1715 : static void do_thread_regset_writeback(struct task_struct *task,
1716 : const struct user_regset *regset)
1717 : {
1718 : if (regset->writeback)
1719 : regset->writeback(task, regset, 1);
1720 : }
1721 :
1722 : #ifndef PRSTATUS_SIZE
1723 : #define PRSTATUS_SIZE sizeof(struct elf_prstatus)
1724 : #endif
1725 :
1726 : #ifndef SET_PR_FPVALID
1727 : #define SET_PR_FPVALID(S) ((S)->pr_fpvalid = 1)
1728 : #endif
1729 :
1730 : static int fill_thread_core_info(struct elf_thread_core_info *t,
1731 : const struct user_regset_view *view,
1732 : long signr, size_t *total)
1733 : {
1734 : unsigned int i;
1735 :
1736 : /*
1737 : * NT_PRSTATUS is the one special case, because the regset data
1738 : * goes into the pr_reg field inside the note contents, rather
1739 : * than being the whole note contents. We fill the reset in here.
1740 : * We assume that regset 0 is NT_PRSTATUS.
1741 : */
1742 : fill_prstatus(&t->prstatus.common, t->task, signr);
1743 : regset_get(t->task, &view->regsets[0],
1744 : sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1745 :
1746 : fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1747 : PRSTATUS_SIZE, &t->prstatus);
1748 : *total += notesize(&t->notes[0]);
1749 :
1750 : do_thread_regset_writeback(t->task, &view->regsets[0]);
1751 :
1752 : /*
1753 : * Each other regset might generate a note too. For each regset
1754 : * that has no core_note_type or is inactive, we leave t->notes[i]
1755 : * all zero and we'll know to skip writing it later.
1756 : */
1757 : for (i = 1; i < view->n; ++i) {
1758 : const struct user_regset *regset = &view->regsets[i];
1759 : int note_type = regset->core_note_type;
1760 : bool is_fpreg = note_type == NT_PRFPREG;
1761 : void *data;
1762 : int ret;
1763 :
1764 : do_thread_regset_writeback(t->task, regset);
1765 : if (!note_type) // not for coredumps
1766 : continue;
1767 : if (regset->active && regset->active(t->task, regset) <= 0)
1768 : continue;
1769 :
1770 : ret = regset_get_alloc(t->task, regset, ~0U, &data);
1771 : if (ret < 0)
1772 : continue;
1773 :
1774 : if (is_fpreg)
1775 : SET_PR_FPVALID(&t->prstatus);
1776 :
1777 : fill_note(&t->notes[i], is_fpreg ? "CORE" : "LINUX",
1778 : note_type, ret, data);
1779 :
1780 : *total += notesize(&t->notes[i]);
1781 : }
1782 :
1783 : return 1;
1784 : }
1785 :
1786 : static int fill_note_info(struct elfhdr *elf, int phdrs,
1787 : struct elf_note_info *info,
1788 : const kernel_siginfo_t *siginfo, struct pt_regs *regs)
1789 : {
1790 : struct task_struct *dump_task = current;
1791 : const struct user_regset_view *view = task_user_regset_view(dump_task);
1792 : struct elf_thread_core_info *t;
1793 : struct elf_prpsinfo *psinfo;
1794 : struct core_thread *ct;
1795 : unsigned int i;
1796 :
1797 : info->size = 0;
1798 : info->thread = NULL;
1799 :
1800 : psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1801 : if (psinfo == NULL) {
1802 : info->psinfo.data = NULL; /* So we don't free this wrongly */
1803 : return 0;
1804 : }
1805 :
1806 : fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1807 :
1808 : /*
1809 : * Figure out how many notes we're going to need for each thread.
1810 : */
1811 : info->thread_notes = 0;
1812 : for (i = 0; i < view->n; ++i)
1813 : if (view->regsets[i].core_note_type != 0)
1814 : ++info->thread_notes;
1815 :
1816 : /*
1817 : * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1818 : * since it is our one special case.
1819 : */
1820 : if (unlikely(info->thread_notes == 0) ||
1821 : unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1822 : WARN_ON(1);
1823 : return 0;
1824 : }
1825 :
1826 : /*
1827 : * Initialize the ELF file header.
1828 : */
1829 : fill_elf_header(elf, phdrs,
1830 : view->e_machine, view->e_flags);
1831 :
1832 : /*
1833 : * Allocate a structure for each thread.
1834 : */
1835 : for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1836 : t = kzalloc(offsetof(struct elf_thread_core_info,
1837 : notes[info->thread_notes]),
1838 : GFP_KERNEL);
1839 : if (unlikely(!t))
1840 : return 0;
1841 :
1842 : t->task = ct->task;
1843 : if (ct->task == dump_task || !info->thread) {
1844 : t->next = info->thread;
1845 : info->thread = t;
1846 : } else {
1847 : /*
1848 : * Make sure to keep the original task at
1849 : * the head of the list.
1850 : */
1851 : t->next = info->thread->next;
1852 : info->thread->next = t;
1853 : }
1854 : }
1855 :
1856 : /*
1857 : * Now fill in each thread's information.
1858 : */
1859 : for (t = info->thread; t != NULL; t = t->next)
1860 : if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1861 : return 0;
1862 :
1863 : /*
1864 : * Fill in the two process-wide notes.
1865 : */
1866 : fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1867 : info->size += notesize(&info->psinfo);
1868 :
1869 : fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1870 : info->size += notesize(&info->signote);
1871 :
1872 : fill_auxv_note(&info->auxv, current->mm);
1873 : info->size += notesize(&info->auxv);
1874 :
1875 : if (fill_files_note(&info->files) == 0)
1876 : info->size += notesize(&info->files);
1877 :
1878 : return 1;
1879 : }
1880 :
1881 : static size_t get_note_info_size(struct elf_note_info *info)
1882 : {
1883 : return info->size;
1884 : }
1885 :
1886 : /*
1887 : * Write all the notes for each thread. When writing the first thread, the
1888 : * process-wide notes are interleaved after the first thread-specific note.
1889 : */
1890 : static int write_note_info(struct elf_note_info *info,
1891 : struct coredump_params *cprm)
1892 : {
1893 : bool first = true;
1894 : struct elf_thread_core_info *t = info->thread;
1895 :
1896 : do {
1897 : int i;
1898 :
1899 : if (!writenote(&t->notes[0], cprm))
1900 : return 0;
1901 :
1902 : if (first && !writenote(&info->psinfo, cprm))
1903 : return 0;
1904 : if (first && !writenote(&info->signote, cprm))
1905 : return 0;
1906 : if (first && !writenote(&info->auxv, cprm))
1907 : return 0;
1908 : if (first && info->files.data &&
1909 : !writenote(&info->files, cprm))
1910 : return 0;
1911 :
1912 : for (i = 1; i < info->thread_notes; ++i)
1913 : if (t->notes[i].data &&
1914 : !writenote(&t->notes[i], cprm))
1915 : return 0;
1916 :
1917 : first = false;
1918 : t = t->next;
1919 : } while (t);
1920 :
1921 : return 1;
1922 : }
1923 :
1924 : static void free_note_info(struct elf_note_info *info)
1925 : {
1926 : struct elf_thread_core_info *threads = info->thread;
1927 : while (threads) {
1928 : unsigned int i;
1929 : struct elf_thread_core_info *t = threads;
1930 : threads = t->next;
1931 : WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1932 : for (i = 1; i < info->thread_notes; ++i)
1933 : kfree(t->notes[i].data);
1934 : kfree(t);
1935 : }
1936 : kfree(info->psinfo.data);
1937 : kvfree(info->files.data);
1938 : }
1939 :
1940 : #else
1941 :
1942 : /* Here is the structure in which status of each thread is captured. */
1943 : struct elf_thread_status
1944 : {
1945 : struct list_head list;
1946 : struct elf_prstatus prstatus; /* NT_PRSTATUS */
1947 : elf_fpregset_t fpu; /* NT_PRFPREG */
1948 : struct task_struct *thread;
1949 : struct memelfnote notes[3];
1950 : int num_notes;
1951 : };
1952 :
1953 : /*
1954 : * In order to add the specific thread information for the elf file format,
1955 : * we need to keep a linked list of every threads pr_status and then create
1956 : * a single section for them in the final core file.
1957 : */
1958 : static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1959 : {
1960 : int sz = 0;
1961 : struct task_struct *p = t->thread;
1962 : t->num_notes = 0;
1963 :
1964 : fill_prstatus(&t->prstatus.common, p, signr);
1965 : elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1966 :
1967 : fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1968 : &(t->prstatus));
1969 : t->num_notes++;
1970 : sz += notesize(&t->notes[0]);
1971 :
1972 : if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1973 : &t->fpu))) {
1974 : fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1975 : &(t->fpu));
1976 : t->num_notes++;
1977 : sz += notesize(&t->notes[1]);
1978 : }
1979 : return sz;
1980 : }
1981 :
1982 : struct elf_note_info {
1983 : struct memelfnote *notes;
1984 : struct memelfnote *notes_files;
1985 : struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1986 : struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1987 : struct list_head thread_list;
1988 : elf_fpregset_t *fpu;
1989 : user_siginfo_t csigdata;
1990 : int thread_status_size;
1991 : int numnote;
1992 : };
1993 :
1994 : static int elf_note_info_init(struct elf_note_info *info)
1995 : {
1996 : memset(info, 0, sizeof(*info));
1997 : INIT_LIST_HEAD(&info->thread_list);
1998 :
1999 : /* Allocate space for ELF notes */
2000 : info->notes = kmalloc_array(8, sizeof(struct memelfnote), GFP_KERNEL);
2001 : if (!info->notes)
2002 : return 0;
2003 : info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
2004 : if (!info->psinfo)
2005 : return 0;
2006 : info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
2007 : if (!info->prstatus)
2008 : return 0;
2009 : info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
2010 : if (!info->fpu)
2011 : return 0;
2012 : return 1;
2013 : }
2014 :
2015 : static int fill_note_info(struct elfhdr *elf, int phdrs,
2016 : struct elf_note_info *info,
2017 : const kernel_siginfo_t *siginfo, struct pt_regs *regs)
2018 : {
2019 : struct core_thread *ct;
2020 : struct elf_thread_status *ets;
2021 :
2022 : if (!elf_note_info_init(info))
2023 : return 0;
2024 :
2025 : for (ct = current->mm->core_state->dumper.next;
2026 : ct; ct = ct->next) {
2027 : ets = kzalloc(sizeof(*ets), GFP_KERNEL);
2028 : if (!ets)
2029 : return 0;
2030 :
2031 : ets->thread = ct->task;
2032 : list_add(&ets->list, &info->thread_list);
2033 : }
2034 :
2035 : list_for_each_entry(ets, &info->thread_list, list) {
2036 : int sz;
2037 :
2038 : sz = elf_dump_thread_status(siginfo->si_signo, ets);
2039 : info->thread_status_size += sz;
2040 : }
2041 : /* now collect the dump for the current */
2042 : memset(info->prstatus, 0, sizeof(*info->prstatus));
2043 : fill_prstatus(&info->prstatus->common, current, siginfo->si_signo);
2044 : elf_core_copy_regs(&info->prstatus->pr_reg, regs);
2045 :
2046 : /* Set up header */
2047 : fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
2048 :
2049 : /*
2050 : * Set up the notes in similar form to SVR4 core dumps made
2051 : * with info from their /proc.
2052 : */
2053 :
2054 : fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
2055 : sizeof(*info->prstatus), info->prstatus);
2056 : fill_psinfo(info->psinfo, current->group_leader, current->mm);
2057 : fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
2058 : sizeof(*info->psinfo), info->psinfo);
2059 :
2060 : fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
2061 : fill_auxv_note(info->notes + 3, current->mm);
2062 : info->numnote = 4;
2063 :
2064 : if (fill_files_note(info->notes + info->numnote) == 0) {
2065 : info->notes_files = info->notes + info->numnote;
2066 : info->numnote++;
2067 : }
2068 :
2069 : /* Try to dump the FPU. */
2070 : info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
2071 : info->fpu);
2072 : if (info->prstatus->pr_fpvalid)
2073 : fill_note(info->notes + info->numnote++,
2074 : "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
2075 : return 1;
2076 : }
2077 :
2078 : static size_t get_note_info_size(struct elf_note_info *info)
2079 : {
2080 : int sz = 0;
2081 : int i;
2082 :
2083 : for (i = 0; i < info->numnote; i++)
2084 : sz += notesize(info->notes + i);
2085 :
2086 : sz += info->thread_status_size;
2087 :
2088 : return sz;
2089 : }
2090 :
2091 : static int write_note_info(struct elf_note_info *info,
2092 : struct coredump_params *cprm)
2093 : {
2094 : struct elf_thread_status *ets;
2095 : int i;
2096 :
2097 : for (i = 0; i < info->numnote; i++)
2098 : if (!writenote(info->notes + i, cprm))
2099 : return 0;
2100 :
2101 : /* write out the thread status notes section */
2102 : list_for_each_entry(ets, &info->thread_list, list) {
2103 : for (i = 0; i < ets->num_notes; i++)
2104 : if (!writenote(&ets->notes[i], cprm))
2105 : return 0;
2106 : }
2107 :
2108 : return 1;
2109 : }
2110 :
2111 : static void free_note_info(struct elf_note_info *info)
2112 : {
2113 : while (!list_empty(&info->thread_list)) {
2114 : struct list_head *tmp = info->thread_list.next;
2115 : list_del(tmp);
2116 : kfree(list_entry(tmp, struct elf_thread_status, list));
2117 : }
2118 :
2119 : /* Free data possibly allocated by fill_files_note(): */
2120 : if (info->notes_files)
2121 : kvfree(info->notes_files->data);
2122 :
2123 : kfree(info->prstatus);
2124 : kfree(info->psinfo);
2125 : kfree(info->notes);
2126 : kfree(info->fpu);
2127 : }
2128 :
2129 : #endif
2130 :
2131 : static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
2132 : elf_addr_t e_shoff, int segs)
2133 : {
2134 : elf->e_shoff = e_shoff;
2135 : elf->e_shentsize = sizeof(*shdr4extnum);
2136 : elf->e_shnum = 1;
2137 : elf->e_shstrndx = SHN_UNDEF;
2138 :
2139 : memset(shdr4extnum, 0, sizeof(*shdr4extnum));
2140 :
2141 : shdr4extnum->sh_type = SHT_NULL;
2142 : shdr4extnum->sh_size = elf->e_shnum;
2143 : shdr4extnum->sh_link = elf->e_shstrndx;
2144 : shdr4extnum->sh_info = segs;
2145 : }
2146 :
2147 : /*
2148 : * Actual dumper
2149 : *
2150 : * This is a two-pass process; first we find the offsets of the bits,
2151 : * and then they are actually written out. If we run out of core limit
2152 : * we just truncate.
2153 : */
2154 : static int elf_core_dump(struct coredump_params *cprm)
2155 : {
2156 : int has_dumped = 0;
2157 : int vma_count, segs, i;
2158 : size_t vma_data_size;
2159 : struct elfhdr elf;
2160 : loff_t offset = 0, dataoff;
2161 : struct elf_note_info info = { };
2162 : struct elf_phdr *phdr4note = NULL;
2163 : struct elf_shdr *shdr4extnum = NULL;
2164 : Elf_Half e_phnum;
2165 : elf_addr_t e_shoff;
2166 : struct core_vma_metadata *vma_meta;
2167 :
2168 : if (dump_vma_snapshot(cprm, &vma_count, &vma_meta, &vma_data_size))
2169 : return 0;
2170 :
2171 : /*
2172 : * The number of segs are recored into ELF header as 16bit value.
2173 : * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2174 : */
2175 : segs = vma_count + elf_core_extra_phdrs();
2176 :
2177 : /* for notes section */
2178 : segs++;
2179 :
2180 : /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2181 : * this, kernel supports extended numbering. Have a look at
2182 : * include/linux/elf.h for further information. */
2183 : e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2184 :
2185 : /*
2186 : * Collect all the non-memory information about the process for the
2187 : * notes. This also sets up the file header.
2188 : */
2189 : if (!fill_note_info(&elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2190 : goto end_coredump;
2191 :
2192 : has_dumped = 1;
2193 :
2194 : offset += sizeof(elf); /* Elf header */
2195 : offset += segs * sizeof(struct elf_phdr); /* Program headers */
2196 :
2197 : /* Write notes phdr entry */
2198 : {
2199 : size_t sz = get_note_info_size(&info);
2200 :
2201 : /* For cell spufs */
2202 : sz += elf_coredump_extra_notes_size();
2203 :
2204 : phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2205 : if (!phdr4note)
2206 : goto end_coredump;
2207 :
2208 : fill_elf_note_phdr(phdr4note, sz, offset);
2209 : offset += sz;
2210 : }
2211 :
2212 : dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2213 :
2214 : offset += vma_data_size;
2215 : offset += elf_core_extra_data_size();
2216 : e_shoff = offset;
2217 :
2218 : if (e_phnum == PN_XNUM) {
2219 : shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2220 : if (!shdr4extnum)
2221 : goto end_coredump;
2222 : fill_extnum_info(&elf, shdr4extnum, e_shoff, segs);
2223 : }
2224 :
2225 : offset = dataoff;
2226 :
2227 : if (!dump_emit(cprm, &elf, sizeof(elf)))
2228 : goto end_coredump;
2229 :
2230 : if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
2231 : goto end_coredump;
2232 :
2233 : /* Write program headers for segments dump */
2234 : for (i = 0; i < vma_count; i++) {
2235 : struct core_vma_metadata *meta = vma_meta + i;
2236 : struct elf_phdr phdr;
2237 :
2238 : phdr.p_type = PT_LOAD;
2239 : phdr.p_offset = offset;
2240 : phdr.p_vaddr = meta->start;
2241 : phdr.p_paddr = 0;
2242 : phdr.p_filesz = meta->dump_size;
2243 : phdr.p_memsz = meta->end - meta->start;
2244 : offset += phdr.p_filesz;
2245 : phdr.p_flags = 0;
2246 : if (meta->flags & VM_READ)
2247 : phdr.p_flags |= PF_R;
2248 : if (meta->flags & VM_WRITE)
2249 : phdr.p_flags |= PF_W;
2250 : if (meta->flags & VM_EXEC)
2251 : phdr.p_flags |= PF_X;
2252 : phdr.p_align = ELF_EXEC_PAGESIZE;
2253 :
2254 : if (!dump_emit(cprm, &phdr, sizeof(phdr)))
2255 : goto end_coredump;
2256 : }
2257 :
2258 : if (!elf_core_write_extra_phdrs(cprm, offset))
2259 : goto end_coredump;
2260 :
2261 : /* write out the notes section */
2262 : if (!write_note_info(&info, cprm))
2263 : goto end_coredump;
2264 :
2265 : /* For cell spufs */
2266 : if (elf_coredump_extra_notes_write(cprm))
2267 : goto end_coredump;
2268 :
2269 : /* Align to page */
2270 : if (!dump_skip(cprm, dataoff - cprm->pos))
2271 : goto end_coredump;
2272 :
2273 : for (i = 0; i < vma_count; i++) {
2274 : struct core_vma_metadata *meta = vma_meta + i;
2275 :
2276 : if (!dump_user_range(cprm, meta->start, meta->dump_size))
2277 : goto end_coredump;
2278 : }
2279 : dump_truncate(cprm);
2280 :
2281 : if (!elf_core_write_extra_data(cprm))
2282 : goto end_coredump;
2283 :
2284 : if (e_phnum == PN_XNUM) {
2285 : if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
2286 : goto end_coredump;
2287 : }
2288 :
2289 : end_coredump:
2290 : free_note_info(&info);
2291 : kfree(shdr4extnum);
2292 : kvfree(vma_meta);
2293 : kfree(phdr4note);
2294 : return has_dumped;
2295 : }
2296 :
2297 : #endif /* CONFIG_ELF_CORE */
2298 :
2299 2 : static int __init init_elf_binfmt(void)
2300 : {
2301 2 : register_binfmt(&elf_format);
2302 2 : return 0;
2303 : }
2304 :
2305 0 : static void __exit exit_elf_binfmt(void)
2306 : {
2307 : /* Remove the COFF and ELF loaders. */
2308 0 : unregister_binfmt(&elf_format);
2309 0 : }
2310 :
2311 : core_initcall(init_elf_binfmt);
2312 : module_exit(exit_elf_binfmt);
2313 : MODULE_LICENSE("GPL");
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