xref: /openbmc/linux/fs/binfmt_elf.c (revision 9dbbc3b9)
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 static int set_brk(unsigned long start, unsigned long end, int prot)
111 {
112 	start = ELF_PAGEALIGN(start);
113 	end = ELF_PAGEALIGN(end);
114 	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 		int error = vm_brk_flags(start, end - start,
121 				prot & PROT_EXEC ? VM_EXEC : 0);
122 		if (error)
123 			return error;
124 	}
125 	current->mm->start_brk = current->mm->brk = end;
126 	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 static int padzero(unsigned long elf_bss)
135 {
136 	unsigned long nbyte;
137 
138 	nbyte = ELF_PAGEOFFSET(elf_bss);
139 	if (nbyte) {
140 		nbyte = ELF_MIN_ALIGN - nbyte;
141 		if (clear_user((void __user *) elf_bss, nbyte))
142 			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 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 	struct mm_struct *mm = current->mm;
177 	unsigned long p = bprm->p;
178 	int argc = bprm->argc;
179 	int envc = bprm->envc;
180 	elf_addr_t __user *sp;
181 	elf_addr_t __user *u_platform;
182 	elf_addr_t __user *u_base_platform;
183 	elf_addr_t __user *u_rand_bytes;
184 	const char *k_platform = ELF_PLATFORM;
185 	const char *k_base_platform = ELF_BASE_PLATFORM;
186 	unsigned char k_rand_bytes[16];
187 	int items;
188 	elf_addr_t *elf_info;
189 	elf_addr_t flags = 0;
190 	int ei_index;
191 	const struct cred *cred = current_cred();
192 	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 	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 	u_platform = NULL;
209 	if (k_platform) {
210 		size_t len = strlen(k_platform) + 1;
211 
212 		u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
213 		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 	u_base_platform = NULL;
222 	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 	get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
234 	u_rand_bytes = (elf_addr_t __user *)
235 		       STACK_ALLOC(p, sizeof(k_rand_bytes));
236 	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 	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 	ARCH_DLINFO;
256 #endif
257 	NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
258 	NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
259 	NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
260 	NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
261 	NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
262 	NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
263 	NEW_AUX_ENT(AT_BASE, interp_load_addr);
264 	if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
265 		flags |= AT_FLAGS_PRESERVE_ARGV0;
266 	NEW_AUX_ENT(AT_FLAGS, flags);
267 	NEW_AUX_ENT(AT_ENTRY, e_entry);
268 	NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
269 	NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
270 	NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
271 	NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
272 	NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
273 	NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
274 #ifdef ELF_HWCAP2
275 	NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
276 #endif
277 	NEW_AUX_ENT(AT_EXECFN, bprm->exec);
278 	if (k_platform) {
279 		NEW_AUX_ENT(AT_PLATFORM,
280 			    (elf_addr_t)(unsigned long)u_platform);
281 	}
282 	if (k_base_platform) {
283 		NEW_AUX_ENT(AT_BASE_PLATFORM,
284 			    (elf_addr_t)(unsigned long)u_base_platform);
285 	}
286 	if (bprm->have_execfd) {
287 		NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
288 	}
289 #undef NEW_AUX_ENT
290 	/* AT_NULL is zero; clear the rest too */
291 	memset(elf_info, 0, (char *)mm->saved_auxv +
292 			sizeof(mm->saved_auxv) - (char *)elf_info);
293 
294 	/* And advance past the AT_NULL entry.  */
295 	elf_info += 2;
296 
297 	ei_index = elf_info - (elf_addr_t *)mm->saved_auxv;
298 	sp = STACK_ADD(p, ei_index);
299 
300 	items = (argc + 1) + (envc + 1) + 1;
301 	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 	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 	if (mmap_read_lock_killable(mm))
317 		return -EINTR;
318 	vma = find_extend_vma(mm, bprm->p);
319 	mmap_read_unlock(mm);
320 	if (!vma)
321 		return -EFAULT;
322 
323 	/* Now, let's put argc (and argv, envp if appropriate) on the stack */
324 	if (put_user(argc, sp++))
325 		return -EFAULT;
326 
327 	/* Populate list of argv pointers back to argv strings. */
328 	p = mm->arg_end = mm->arg_start;
329 	while (argc-- > 0) {
330 		size_t len;
331 		if (put_user((elf_addr_t)p, sp++))
332 			return -EFAULT;
333 		len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
334 		if (!len || len > MAX_ARG_STRLEN)
335 			return -EINVAL;
336 		p += len;
337 	}
338 	if (put_user(0, sp++))
339 		return -EFAULT;
340 	mm->arg_end = p;
341 
342 	/* Populate list of envp pointers back to envp strings. */
343 	mm->env_end = mm->env_start = p;
344 	while (envc-- > 0) {
345 		size_t len;
346 		if (put_user((elf_addr_t)p, sp++))
347 			return -EFAULT;
348 		len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
349 		if (!len || len > MAX_ARG_STRLEN)
350 			return -EINVAL;
351 		p += len;
352 	}
353 	if (put_user(0, sp++))
354 		return -EFAULT;
355 	mm->env_end = p;
356 
357 	/* Put the elf_info on the stack in the right place.  */
358 	if (copy_to_user(sp, mm->saved_auxv, ei_index * sizeof(elf_addr_t)))
359 		return -EFAULT;
360 	return 0;
361 }
362 
363 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 	unsigned long map_addr;
368 	unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
369 	unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
370 	addr = ELF_PAGESTART(addr);
371 	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 	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 	if (total_size) {
387 		total_size = ELF_PAGEALIGN(total_size);
388 		map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
389 		if (!BAD_ADDR(map_addr))
390 			vm_munmap(map_addr+size, total_size-size);
391 	} else
392 		map_addr = vm_mmap(filep, addr, size, prot, type, off);
393 
394 	if ((type & MAP_FIXED_NOREPLACE) &&
395 	    PTR_ERR((void *)map_addr) == -EEXIST)
396 		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 static unsigned long total_mapping_size(const struct elf_phdr *cmds, int nr)
403 {
404 	int i, first_idx = -1, last_idx = -1;
405 
406 	for (i = 0; i < nr; i++) {
407 		if (cmds[i].p_type == PT_LOAD) {
408 			last_idx = i;
409 			if (first_idx == -1)
410 				first_idx = i;
411 		}
412 	}
413 	if (first_idx == -1)
414 		return 0;
415 
416 	return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
417 				ELF_PAGESTART(cmds[first_idx].p_vaddr);
418 }
419 
420 static int elf_read(struct file *file, void *buf, size_t len, loff_t pos)
421 {
422 	ssize_t rv;
423 
424 	rv = kernel_read(file, buf, len, &pos);
425 	if (unlikely(rv != len)) {
426 		return (rv < 0) ? rv : -EIO;
427 	}
428 	return 0;
429 }
430 
431 static unsigned long maximum_alignment(struct elf_phdr *cmds, int nr)
432 {
433 	unsigned long alignment = 0;
434 	int i;
435 
436 	for (i = 0; i < nr; i++) {
437 		if (cmds[i].p_type == PT_LOAD) {
438 			unsigned long p_align = cmds[i].p_align;
439 
440 			/* skip non-power of two alignments as invalid */
441 			if (!is_power_of_2(p_align))
442 				continue;
443 			alignment = max(alignment, p_align);
444 		}
445 	}
446 
447 	/* ensure we align to at least one page */
448 	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 static struct elf_phdr *load_elf_phdrs(const struct elfhdr *elf_ex,
461 				       struct file *elf_file)
462 {
463 	struct elf_phdr *elf_phdata = NULL;
464 	int retval, err = -1;
465 	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 	if (elf_ex->e_phentsize != sizeof(struct elf_phdr))
472 		goto out;
473 
474 	/* Sanity check the number of program headers... */
475 	/* ...and their total size. */
476 	size = sizeof(struct elf_phdr) * elf_ex->e_phnum;
477 	if (size == 0 || size > 65536 || size > ELF_MIN_ALIGN)
478 		goto out;
479 
480 	elf_phdata = kmalloc(size, GFP_KERNEL);
481 	if (!elf_phdata)
482 		goto out;
483 
484 	/* Read in the program headers */
485 	retval = elf_read(elf_file, elf_phdata, size, elf_ex->e_phoff);
486 	if (retval < 0) {
487 		err = retval;
488 		goto out;
489 	}
490 
491 	/* Success! */
492 	err = 0;
493 out:
494 	if (err) {
495 		kfree(elf_phdata);
496 		elf_phdata = NULL;
497 	}
498 	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 	int prot = 0;
575 
576 	if (p_flags & PF_R)
577 		prot |= PROT_READ;
578 	if (p_flags & PF_W)
579 		prot |= PROT_WRITE;
580 	if (p_flags & PF_X)
581 		prot |= PROT_EXEC;
582 
583 	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 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 	unsigned long load_addr = 0;
598 	int load_addr_set = 0;
599 	unsigned long last_bss = 0, elf_bss = 0;
600 	int bss_prot = 0;
601 	unsigned long error = ~0UL;
602 	unsigned long total_size;
603 	int i;
604 
605 	/* First of all, some simple consistency checks */
606 	if (interp_elf_ex->e_type != ET_EXEC &&
607 	    interp_elf_ex->e_type != ET_DYN)
608 		goto out;
609 	if (!elf_check_arch(interp_elf_ex) ||
610 	    elf_check_fdpic(interp_elf_ex))
611 		goto out;
612 	if (!interpreter->f_op->mmap)
613 		goto out;
614 
615 	total_size = total_mapping_size(interp_elf_phdata,
616 					interp_elf_ex->e_phnum);
617 	if (!total_size) {
618 		error = -EINVAL;
619 		goto out;
620 	}
621 
622 	eppnt = interp_elf_phdata;
623 	for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
624 		if (eppnt->p_type == PT_LOAD) {
625 			int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
626 			int elf_prot = make_prot(eppnt->p_flags, arch_state,
627 						 true, true);
628 			unsigned long vaddr = 0;
629 			unsigned long k, map_addr;
630 
631 			vaddr = eppnt->p_vaddr;
632 			if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
633 				elf_type |= MAP_FIXED_NOREPLACE;
634 			else if (no_base && interp_elf_ex->e_type == ET_DYN)
635 				load_addr = -vaddr;
636 
637 			map_addr = elf_map(interpreter, load_addr + vaddr,
638 					eppnt, elf_prot, elf_type, total_size);
639 			total_size = 0;
640 			error = map_addr;
641 			if (BAD_ADDR(map_addr))
642 				goto out;
643 
644 			if (!load_addr_set &&
645 			    interp_elf_ex->e_type == ET_DYN) {
646 				load_addr = map_addr - ELF_PAGESTART(vaddr);
647 				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 			k = load_addr + eppnt->p_vaddr;
656 			if (BAD_ADDR(k) ||
657 			    eppnt->p_filesz > eppnt->p_memsz ||
658 			    eppnt->p_memsz > TASK_SIZE ||
659 			    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 			k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
669 			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 			k = load_addr + eppnt->p_vaddr + eppnt->p_memsz;
677 			if (k > last_bss) {
678 				last_bss = k;
679 				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 	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 	elf_bss = ELF_PAGEALIGN(elf_bss);
699 	last_bss = ELF_PAGEALIGN(last_bss);
700 	/* Finally, if there is still more bss to allocate, do it. */
701 	if (last_bss > elf_bss) {
702 		error = vm_brk_flags(elf_bss, last_bss - elf_bss,
703 				bss_prot & PROT_EXEC ? VM_EXEC : 0);
704 		if (error)
705 			goto out;
706 	}
707 
708 	error = load_addr;
709 out:
710 	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, &note, 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 static int load_elf_binary(struct linux_binprm *bprm)
824 {
825 	struct file *interpreter = NULL; /* to shut gcc up */
826  	unsigned long load_addr = 0, load_bias = 0;
827 	int load_addr_set = 0;
828 	unsigned long error;
829 	struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
830 	struct elf_phdr *elf_property_phdata = NULL;
831 	unsigned long elf_bss, elf_brk;
832 	int bss_prot = 0;
833 	int retval, i;
834 	unsigned long elf_entry;
835 	unsigned long e_entry;
836 	unsigned long interp_load_addr = 0;
837 	unsigned long start_code, end_code, start_data, end_data;
838 	unsigned long reloc_func_desc __maybe_unused = 0;
839 	int executable_stack = EXSTACK_DEFAULT;
840 	struct elfhdr *elf_ex = (struct elfhdr *)bprm->buf;
841 	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 	retval = -ENOEXEC;
847 	/* First of all, some simple consistency checks */
848 	if (memcmp(elf_ex->e_ident, ELFMAG, SELFMAG) != 0)
849 		goto out;
850 
851 	if (elf_ex->e_type != ET_EXEC && elf_ex->e_type != ET_DYN)
852 		goto out;
853 	if (!elf_check_arch(elf_ex))
854 		goto out;
855 	if (elf_check_fdpic(elf_ex))
856 		goto out;
857 	if (!bprm->file->f_op->mmap)
858 		goto out;
859 
860 	elf_phdata = load_elf_phdrs(elf_ex, bprm->file);
861 	if (!elf_phdata)
862 		goto out;
863 
864 	elf_ppnt = elf_phdata;
865 	for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++) {
866 		char *elf_interpreter;
867 
868 		if (elf_ppnt->p_type == PT_GNU_PROPERTY) {
869 			elf_property_phdata = elf_ppnt;
870 			continue;
871 		}
872 
873 		if (elf_ppnt->p_type != PT_INTERP)
874 			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 		retval = -ENOEXEC;
881 		if (elf_ppnt->p_filesz > PATH_MAX || elf_ppnt->p_filesz < 2)
882 			goto out_free_ph;
883 
884 		retval = -ENOMEM;
885 		elf_interpreter = kmalloc(elf_ppnt->p_filesz, GFP_KERNEL);
886 		if (!elf_interpreter)
887 			goto out_free_ph;
888 
889 		retval = elf_read(bprm->file, elf_interpreter, elf_ppnt->p_filesz,
890 				  elf_ppnt->p_offset);
891 		if (retval < 0)
892 			goto out_free_interp;
893 		/* make sure path is NULL terminated */
894 		retval = -ENOEXEC;
895 		if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
896 			goto out_free_interp;
897 
898 		interpreter = open_exec(elf_interpreter);
899 		kfree(elf_interpreter);
900 		retval = PTR_ERR(interpreter);
901 		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 		would_dump(bprm, interpreter);
909 
910 		interp_elf_ex = kmalloc(sizeof(*interp_elf_ex), GFP_KERNEL);
911 		if (!interp_elf_ex) {
912 			retval = -ENOMEM;
913 			goto out_free_ph;
914 		}
915 
916 		/* Get the exec headers */
917 		retval = elf_read(interpreter, interp_elf_ex,
918 				  sizeof(*interp_elf_ex), 0);
919 		if (retval < 0)
920 			goto out_free_dentry;
921 
922 		break;
923 
924 out_free_interp:
925 		kfree(elf_interpreter);
926 		goto out_free_ph;
927 	}
928 
929 	elf_ppnt = elf_phdata;
930 	for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++)
931 		switch (elf_ppnt->p_type) {
932 		case PT_GNU_STACK:
933 			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 			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 	if (interpreter) {
950 		retval = -ELIBBAD;
951 		/* Not an ELF interpreter */
952 		if (memcmp(interp_elf_ex->e_ident, ELFMAG, SELFMAG) != 0)
953 			goto out_free_dentry;
954 		/* Verify the interpreter has a valid arch */
955 		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 		interp_elf_phdata = load_elf_phdrs(interp_elf_ex,
961 						   interpreter);
962 		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 		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 	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 	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 	retval = begin_new_exec(bprm);
1002 	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 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
1012 		current->flags |= PF_RANDOMIZE;
1013 
1014 	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 	retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
1019 				 executable_stack);
1020 	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 	for(i = 0, elf_ppnt = elf_phdata;
1034 	    i < elf_ex->e_phnum; i++, elf_ppnt++) {
1035 		int elf_prot, elf_flags;
1036 		unsigned long k, vaddr;
1037 		unsigned long total_size = 0;
1038 		unsigned long alignment;
1039 
1040 		if (elf_ppnt->p_type != PT_LOAD)
1041 			continue;
1042 
1043 		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 			retval = set_brk(elf_bss + load_bias,
1050 					 elf_brk + load_bias,
1051 					 bss_prot);
1052 			if (retval)
1053 				goto out_free_dentry;
1054 			nbyte = ELF_PAGEOFFSET(elf_bss);
1055 			if (nbyte) {
1056 				nbyte = ELF_MIN_ALIGN - nbyte;
1057 				if (nbyte > elf_brk - elf_bss)
1058 					nbyte = elf_brk - elf_bss;
1059 				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 		elf_prot = make_prot(elf_ppnt->p_flags, &arch_state,
1071 				     !!interpreter, false);
1072 
1073 		elf_flags = MAP_PRIVATE | MAP_DENYWRITE;
1074 
1075 		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 		if (elf_ex->e_type == ET_EXEC || load_addr_set) {
1081 			elf_flags |= MAP_FIXED;
1082 		} 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 			if (interpreter) {
1114 				load_bias = ELF_ET_DYN_BASE;
1115 				if (current->flags & PF_RANDOMIZE)
1116 					load_bias += arch_mmap_rnd();
1117 				alignment = maximum_alignment(elf_phdata, elf_ex->e_phnum);
1118 				if (alignment)
1119 					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 			load_bias = ELF_PAGESTART(load_bias - vaddr);
1132 
1133 			total_size = total_mapping_size(elf_phdata,
1134 							elf_ex->e_phnum);
1135 			if (!total_size) {
1136 				retval = -EINVAL;
1137 				goto out_free_dentry;
1138 			}
1139 		}
1140 
1141 		error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
1142 				elf_prot, elf_flags, total_size);
1143 		if (BAD_ADDR(error)) {
1144 			retval = IS_ERR((void *)error) ?
1145 				PTR_ERR((void*)error) : -EINVAL;
1146 			goto out_free_dentry;
1147 		}
1148 
1149 		if (!load_addr_set) {
1150 			load_addr_set = 1;
1151 			load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
1152 			if (elf_ex->e_type == ET_DYN) {
1153 				load_bias += error -
1154 				             ELF_PAGESTART(load_bias + vaddr);
1155 				load_addr += load_bias;
1156 				reloc_func_desc = load_bias;
1157 			}
1158 		}
1159 		k = elf_ppnt->p_vaddr;
1160 		if ((elf_ppnt->p_flags & PF_X) && k < start_code)
1161 			start_code = k;
1162 		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 		if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
1171 		    elf_ppnt->p_memsz > TASK_SIZE ||
1172 		    TASK_SIZE - elf_ppnt->p_memsz < k) {
1173 			/* set_brk can never work. Avoid overflows. */
1174 			retval = -EINVAL;
1175 			goto out_free_dentry;
1176 		}
1177 
1178 		k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
1179 
1180 		if (k > elf_bss)
1181 			elf_bss = k;
1182 		if ((elf_ppnt->p_flags & PF_X) && end_code < k)
1183 			end_code = k;
1184 		if (end_data < k)
1185 			end_data = k;
1186 		k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
1187 		if (k > elf_brk) {
1188 			bss_prot = elf_prot;
1189 			elf_brk = k;
1190 		}
1191 	}
1192 
1193 	e_entry = elf_ex->e_entry + load_bias;
1194 	elf_bss += load_bias;
1195 	elf_brk += load_bias;
1196 	start_code += load_bias;
1197 	end_code += load_bias;
1198 	start_data += load_bias;
1199 	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 	retval = set_brk(elf_bss, elf_brk, bss_prot);
1207 	if (retval)
1208 		goto out_free_dentry;
1209 	if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
1210 		retval = -EFAULT; /* Nobody gets to see this, but.. */
1211 		goto out_free_dentry;
1212 	}
1213 
1214 	if (interpreter) {
1215 		elf_entry = load_elf_interp(interp_elf_ex,
1216 					    interpreter,
1217 					    load_bias, interp_elf_phdata,
1218 					    &arch_state);
1219 		if (!IS_ERR((void *)elf_entry)) {
1220 			/*
1221 			 * load_elf_interp() returns relocation
1222 			 * adjustment
1223 			 */
1224 			interp_load_addr = elf_entry;
1225 			elf_entry += interp_elf_ex->e_entry;
1226 		}
1227 		if (BAD_ADDR(elf_entry)) {
1228 			retval = IS_ERR((void *)elf_entry) ?
1229 					(int)elf_entry : -EINVAL;
1230 			goto out_free_dentry;
1231 		}
1232 		reloc_func_desc = interp_load_addr;
1233 
1234 		allow_write_access(interpreter);
1235 		fput(interpreter);
1236 
1237 		kfree(interp_elf_ex);
1238 		kfree(interp_elf_phdata);
1239 	} else {
1240 		elf_entry = e_entry;
1241 		if (BAD_ADDR(elf_entry)) {
1242 			retval = -EINVAL;
1243 			goto out_free_dentry;
1244 		}
1245 	}
1246 
1247 	kfree(elf_phdata);
1248 
1249 	set_binfmt(&elf_format);
1250 
1251 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
1252 	retval = ARCH_SETUP_ADDITIONAL_PAGES(bprm, elf_ex, !!interpreter);
1253 	if (retval < 0)
1254 		goto out;
1255 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
1256 
1257 	retval = create_elf_tables(bprm, elf_ex,
1258 			  load_addr, interp_load_addr, e_entry);
1259 	if (retval < 0)
1260 		goto out;
1261 
1262 	mm = current->mm;
1263 	mm->end_code = end_code;
1264 	mm->start_code = start_code;
1265 	mm->start_data = start_data;
1266 	mm->end_data = end_data;
1267 	mm->start_stack = bprm->p;
1268 
1269 	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 		if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) &&
1278 		    elf_ex->e_type == ET_DYN && !interpreter) {
1279 			mm->brk = mm->start_brk = ELF_ET_DYN_BASE;
1280 		}
1281 
1282 		mm->brk = mm->start_brk = arch_randomize_brk(mm);
1283 #ifdef compat_brk_randomized
1284 		current->brk_randomized = 1;
1285 #endif
1286 	}
1287 
1288 	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 		error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1294 				MAP_FIXED | MAP_PRIVATE, 0);
1295 	}
1296 
1297 	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 	ELF_PLAT_INIT(regs, reloc_func_desc);
1310 #endif
1311 
1312 	finalize_exec(bprm);
1313 	START_THREAD(elf_ex, regs, elf_entry, bprm->p);
1314 	retval = 0;
1315 out:
1316 	return retval;
1317 
1318 	/* error cleanup */
1319 out_free_dentry:
1320 	kfree(interp_elf_ex);
1321 	kfree(interp_elf_phdata);
1322 	allow_write_access(interpreter);
1323 	if (interpreter)
1324 		fput(interpreter);
1325 out_free_ph:
1326 	kfree(elf_phdata);
1327 	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 	unsigned int state;
1541 
1542 	/* first copy the parameters from user space */
1543 	memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1544 
1545 	len = mm->arg_end - mm->arg_start;
1546 	if (len >= ELF_PRARGSZ)
1547 		len = ELF_PRARGSZ-1;
1548 	if (copy_from_user(&psinfo->pr_psargs,
1549 		           (const char __user *)mm->arg_start, len))
1550 		return -EFAULT;
1551 	for(i = 0; i < len; i++)
1552 		if (psinfo->pr_psargs[i] == 0)
1553 			psinfo->pr_psargs[i] = ' ';
1554 	psinfo->pr_psargs[len] = 0;
1555 
1556 	rcu_read_lock();
1557 	psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1558 	rcu_read_unlock();
1559 	psinfo->pr_pid = task_pid_vnr(p);
1560 	psinfo->pr_pgrp = task_pgrp_vnr(p);
1561 	psinfo->pr_sid = task_session_vnr(p);
1562 
1563 	state = READ_ONCE(p->__state);
1564 	i = state ? ffz(~state) + 1 : 0;
1565 	psinfo->pr_state = i;
1566 	psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1567 	psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1568 	psinfo->pr_nice = task_nice(p);
1569 	psinfo->pr_flag = p->flags;
1570 	rcu_read_lock();
1571 	cred = __task_cred(p);
1572 	SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1573 	SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1574 	rcu_read_unlock();
1575 	strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1576 
1577 	return 0;
1578 }
1579 
1580 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1581 {
1582 	elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1583 	int i = 0;
1584 	do
1585 		i += 2;
1586 	while (auxv[i - 2] != AT_NULL);
1587 	fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1588 }
1589 
1590 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1591 		const kernel_siginfo_t *siginfo)
1592 {
1593 	copy_siginfo_to_external(csigdata, siginfo);
1594 	fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1595 }
1596 
1597 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1598 /*
1599  * Format of NT_FILE note:
1600  *
1601  * long count     -- how many files are mapped
1602  * long page_size -- units for file_ofs
1603  * array of [COUNT] elements of
1604  *   long start
1605  *   long end
1606  *   long file_ofs
1607  * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1608  */
1609 static int fill_files_note(struct memelfnote *note)
1610 {
1611 	struct mm_struct *mm = current->mm;
1612 	struct vm_area_struct *vma;
1613 	unsigned count, size, names_ofs, remaining, n;
1614 	user_long_t *data;
1615 	user_long_t *start_end_ofs;
1616 	char *name_base, *name_curpos;
1617 
1618 	/* *Estimated* file count and total data size needed */
1619 	count = mm->map_count;
1620 	if (count > UINT_MAX / 64)
1621 		return -EINVAL;
1622 	size = count * 64;
1623 
1624 	names_ofs = (2 + 3 * count) * sizeof(data[0]);
1625  alloc:
1626 	if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1627 		return -EINVAL;
1628 	size = round_up(size, PAGE_SIZE);
1629 	/*
1630 	 * "size" can be 0 here legitimately.
1631 	 * Let it ENOMEM and omit NT_FILE section which will be empty anyway.
1632 	 */
1633 	data = kvmalloc(size, GFP_KERNEL);
1634 	if (ZERO_OR_NULL_PTR(data))
1635 		return -ENOMEM;
1636 
1637 	start_end_ofs = data + 2;
1638 	name_base = name_curpos = ((char *)data) + names_ofs;
1639 	remaining = size - names_ofs;
1640 	count = 0;
1641 	for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
1642 		struct file *file;
1643 		const char *filename;
1644 
1645 		file = vma->vm_file;
1646 		if (!file)
1647 			continue;
1648 		filename = file_path(file, name_curpos, remaining);
1649 		if (IS_ERR(filename)) {
1650 			if (PTR_ERR(filename) == -ENAMETOOLONG) {
1651 				kvfree(data);
1652 				size = size * 5 / 4;
1653 				goto alloc;
1654 			}
1655 			continue;
1656 		}
1657 
1658 		/* file_path() fills at the end, move name down */
1659 		/* n = strlen(filename) + 1: */
1660 		n = (name_curpos + remaining) - filename;
1661 		remaining = filename - name_curpos;
1662 		memmove(name_curpos, filename, n);
1663 		name_curpos += n;
1664 
1665 		*start_end_ofs++ = vma->vm_start;
1666 		*start_end_ofs++ = vma->vm_end;
1667 		*start_end_ofs++ = vma->vm_pgoff;
1668 		count++;
1669 	}
1670 
1671 	/* Now we know exact count of files, can store it */
1672 	data[0] = count;
1673 	data[1] = PAGE_SIZE;
1674 	/*
1675 	 * Count usually is less than mm->map_count,
1676 	 * we need to move filenames down.
1677 	 */
1678 	n = mm->map_count - count;
1679 	if (n != 0) {
1680 		unsigned shift_bytes = n * 3 * sizeof(data[0]);
1681 		memmove(name_base - shift_bytes, name_base,
1682 			name_curpos - name_base);
1683 		name_curpos -= shift_bytes;
1684 	}
1685 
1686 	size = name_curpos - (char *)data;
1687 	fill_note(note, "CORE", NT_FILE, size, data);
1688 	return 0;
1689 }
1690 
1691 #ifdef CORE_DUMP_USE_REGSET
1692 #include <linux/regset.h>
1693 
1694 struct elf_thread_core_info {
1695 	struct elf_thread_core_info *next;
1696 	struct task_struct *task;
1697 	struct elf_prstatus prstatus;
1698 	struct memelfnote notes[];
1699 };
1700 
1701 struct elf_note_info {
1702 	struct elf_thread_core_info *thread;
1703 	struct memelfnote psinfo;
1704 	struct memelfnote signote;
1705 	struct memelfnote auxv;
1706 	struct memelfnote files;
1707 	user_siginfo_t csigdata;
1708 	size_t size;
1709 	int thread_notes;
1710 };
1711 
1712 /*
1713  * When a regset has a writeback hook, we call it on each thread before
1714  * dumping user memory.  On register window machines, this makes sure the
1715  * user memory backing the register data is up to date before we read it.
1716  */
1717 static void do_thread_regset_writeback(struct task_struct *task,
1718 				       const struct user_regset *regset)
1719 {
1720 	if (regset->writeback)
1721 		regset->writeback(task, regset, 1);
1722 }
1723 
1724 #ifndef PRSTATUS_SIZE
1725 #define PRSTATUS_SIZE sizeof(struct elf_prstatus)
1726 #endif
1727 
1728 #ifndef SET_PR_FPVALID
1729 #define SET_PR_FPVALID(S) ((S)->pr_fpvalid = 1)
1730 #endif
1731 
1732 static int fill_thread_core_info(struct elf_thread_core_info *t,
1733 				 const struct user_regset_view *view,
1734 				 long signr, size_t *total)
1735 {
1736 	unsigned int i;
1737 
1738 	/*
1739 	 * NT_PRSTATUS is the one special case, because the regset data
1740 	 * goes into the pr_reg field inside the note contents, rather
1741 	 * than being the whole note contents.  We fill the reset in here.
1742 	 * We assume that regset 0 is NT_PRSTATUS.
1743 	 */
1744 	fill_prstatus(&t->prstatus.common, t->task, signr);
1745 	regset_get(t->task, &view->regsets[0],
1746 		   sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1747 
1748 	fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1749 		  PRSTATUS_SIZE, &t->prstatus);
1750 	*total += notesize(&t->notes[0]);
1751 
1752 	do_thread_regset_writeback(t->task, &view->regsets[0]);
1753 
1754 	/*
1755 	 * Each other regset might generate a note too.  For each regset
1756 	 * that has no core_note_type or is inactive, we leave t->notes[i]
1757 	 * all zero and we'll know to skip writing it later.
1758 	 */
1759 	for (i = 1; i < view->n; ++i) {
1760 		const struct user_regset *regset = &view->regsets[i];
1761 		int note_type = regset->core_note_type;
1762 		bool is_fpreg = note_type == NT_PRFPREG;
1763 		void *data;
1764 		int ret;
1765 
1766 		do_thread_regset_writeback(t->task, regset);
1767 		if (!note_type) // not for coredumps
1768 			continue;
1769 		if (regset->active && regset->active(t->task, regset) <= 0)
1770 			continue;
1771 
1772 		ret = regset_get_alloc(t->task, regset, ~0U, &data);
1773 		if (ret < 0)
1774 			continue;
1775 
1776 		if (is_fpreg)
1777 			SET_PR_FPVALID(&t->prstatus);
1778 
1779 		fill_note(&t->notes[i], is_fpreg ? "CORE" : "LINUX",
1780 			  note_type, ret, data);
1781 
1782 		*total += notesize(&t->notes[i]);
1783 	}
1784 
1785 	return 1;
1786 }
1787 
1788 static int fill_note_info(struct elfhdr *elf, int phdrs,
1789 			  struct elf_note_info *info,
1790 			  const kernel_siginfo_t *siginfo, struct pt_regs *regs)
1791 {
1792 	struct task_struct *dump_task = current;
1793 	const struct user_regset_view *view = task_user_regset_view(dump_task);
1794 	struct elf_thread_core_info *t;
1795 	struct elf_prpsinfo *psinfo;
1796 	struct core_thread *ct;
1797 	unsigned int i;
1798 
1799 	info->size = 0;
1800 	info->thread = NULL;
1801 
1802 	psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1803 	if (psinfo == NULL) {
1804 		info->psinfo.data = NULL; /* So we don't free this wrongly */
1805 		return 0;
1806 	}
1807 
1808 	fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1809 
1810 	/*
1811 	 * Figure out how many notes we're going to need for each thread.
1812 	 */
1813 	info->thread_notes = 0;
1814 	for (i = 0; i < view->n; ++i)
1815 		if (view->regsets[i].core_note_type != 0)
1816 			++info->thread_notes;
1817 
1818 	/*
1819 	 * Sanity check.  We rely on regset 0 being in NT_PRSTATUS,
1820 	 * since it is our one special case.
1821 	 */
1822 	if (unlikely(info->thread_notes == 0) ||
1823 	    unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1824 		WARN_ON(1);
1825 		return 0;
1826 	}
1827 
1828 	/*
1829 	 * Initialize the ELF file header.
1830 	 */
1831 	fill_elf_header(elf, phdrs,
1832 			view->e_machine, view->e_flags);
1833 
1834 	/*
1835 	 * Allocate a structure for each thread.
1836 	 */
1837 	for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1838 		t = kzalloc(offsetof(struct elf_thread_core_info,
1839 				     notes[info->thread_notes]),
1840 			    GFP_KERNEL);
1841 		if (unlikely(!t))
1842 			return 0;
1843 
1844 		t->task = ct->task;
1845 		if (ct->task == dump_task || !info->thread) {
1846 			t->next = info->thread;
1847 			info->thread = t;
1848 		} else {
1849 			/*
1850 			 * Make sure to keep the original task at
1851 			 * the head of the list.
1852 			 */
1853 			t->next = info->thread->next;
1854 			info->thread->next = t;
1855 		}
1856 	}
1857 
1858 	/*
1859 	 * Now fill in each thread's information.
1860 	 */
1861 	for (t = info->thread; t != NULL; t = t->next)
1862 		if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1863 			return 0;
1864 
1865 	/*
1866 	 * Fill in the two process-wide notes.
1867 	 */
1868 	fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1869 	info->size += notesize(&info->psinfo);
1870 
1871 	fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1872 	info->size += notesize(&info->signote);
1873 
1874 	fill_auxv_note(&info->auxv, current->mm);
1875 	info->size += notesize(&info->auxv);
1876 
1877 	if (fill_files_note(&info->files) == 0)
1878 		info->size += notesize(&info->files);
1879 
1880 	return 1;
1881 }
1882 
1883 static size_t get_note_info_size(struct elf_note_info *info)
1884 {
1885 	return info->size;
1886 }
1887 
1888 /*
1889  * Write all the notes for each thread.  When writing the first thread, the
1890  * process-wide notes are interleaved after the first thread-specific note.
1891  */
1892 static int write_note_info(struct elf_note_info *info,
1893 			   struct coredump_params *cprm)
1894 {
1895 	bool first = true;
1896 	struct elf_thread_core_info *t = info->thread;
1897 
1898 	do {
1899 		int i;
1900 
1901 		if (!writenote(&t->notes[0], cprm))
1902 			return 0;
1903 
1904 		if (first && !writenote(&info->psinfo, cprm))
1905 			return 0;
1906 		if (first && !writenote(&info->signote, cprm))
1907 			return 0;
1908 		if (first && !writenote(&info->auxv, cprm))
1909 			return 0;
1910 		if (first && info->files.data &&
1911 				!writenote(&info->files, cprm))
1912 			return 0;
1913 
1914 		for (i = 1; i < info->thread_notes; ++i)
1915 			if (t->notes[i].data &&
1916 			    !writenote(&t->notes[i], cprm))
1917 				return 0;
1918 
1919 		first = false;
1920 		t = t->next;
1921 	} while (t);
1922 
1923 	return 1;
1924 }
1925 
1926 static void free_note_info(struct elf_note_info *info)
1927 {
1928 	struct elf_thread_core_info *threads = info->thread;
1929 	while (threads) {
1930 		unsigned int i;
1931 		struct elf_thread_core_info *t = threads;
1932 		threads = t->next;
1933 		WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1934 		for (i = 1; i < info->thread_notes; ++i)
1935 			kfree(t->notes[i].data);
1936 		kfree(t);
1937 	}
1938 	kfree(info->psinfo.data);
1939 	kvfree(info->files.data);
1940 }
1941 
1942 #else
1943 
1944 /* Here is the structure in which status of each thread is captured. */
1945 struct elf_thread_status
1946 {
1947 	struct list_head list;
1948 	struct elf_prstatus prstatus;	/* NT_PRSTATUS */
1949 	elf_fpregset_t fpu;		/* NT_PRFPREG */
1950 	struct task_struct *thread;
1951 	struct memelfnote notes[3];
1952 	int num_notes;
1953 };
1954 
1955 /*
1956  * In order to add the specific thread information for the elf file format,
1957  * we need to keep a linked list of every threads pr_status and then create
1958  * a single section for them in the final core file.
1959  */
1960 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1961 {
1962 	int sz = 0;
1963 	struct task_struct *p = t->thread;
1964 	t->num_notes = 0;
1965 
1966 	fill_prstatus(&t->prstatus.common, p, signr);
1967 	elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1968 
1969 	fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1970 		  &(t->prstatus));
1971 	t->num_notes++;
1972 	sz += notesize(&t->notes[0]);
1973 
1974 	if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1975 								&t->fpu))) {
1976 		fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1977 			  &(t->fpu));
1978 		t->num_notes++;
1979 		sz += notesize(&t->notes[1]);
1980 	}
1981 	return sz;
1982 }
1983 
1984 struct elf_note_info {
1985 	struct memelfnote *notes;
1986 	struct memelfnote *notes_files;
1987 	struct elf_prstatus *prstatus;	/* NT_PRSTATUS */
1988 	struct elf_prpsinfo *psinfo;	/* NT_PRPSINFO */
1989 	struct list_head thread_list;
1990 	elf_fpregset_t *fpu;
1991 	user_siginfo_t csigdata;
1992 	int thread_status_size;
1993 	int numnote;
1994 };
1995 
1996 static int elf_note_info_init(struct elf_note_info *info)
1997 {
1998 	memset(info, 0, sizeof(*info));
1999 	INIT_LIST_HEAD(&info->thread_list);
2000 
2001 	/* Allocate space for ELF notes */
2002 	info->notes = kmalloc_array(8, sizeof(struct memelfnote), GFP_KERNEL);
2003 	if (!info->notes)
2004 		return 0;
2005 	info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
2006 	if (!info->psinfo)
2007 		return 0;
2008 	info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
2009 	if (!info->prstatus)
2010 		return 0;
2011 	info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
2012 	if (!info->fpu)
2013 		return 0;
2014 	return 1;
2015 }
2016 
2017 static int fill_note_info(struct elfhdr *elf, int phdrs,
2018 			  struct elf_note_info *info,
2019 			  const kernel_siginfo_t *siginfo, struct pt_regs *regs)
2020 {
2021 	struct core_thread *ct;
2022 	struct elf_thread_status *ets;
2023 
2024 	if (!elf_note_info_init(info))
2025 		return 0;
2026 
2027 	for (ct = current->mm->core_state->dumper.next;
2028 					ct; ct = ct->next) {
2029 		ets = kzalloc(sizeof(*ets), GFP_KERNEL);
2030 		if (!ets)
2031 			return 0;
2032 
2033 		ets->thread = ct->task;
2034 		list_add(&ets->list, &info->thread_list);
2035 	}
2036 
2037 	list_for_each_entry(ets, &info->thread_list, list) {
2038 		int sz;
2039 
2040 		sz = elf_dump_thread_status(siginfo->si_signo, ets);
2041 		info->thread_status_size += sz;
2042 	}
2043 	/* now collect the dump for the current */
2044 	memset(info->prstatus, 0, sizeof(*info->prstatus));
2045 	fill_prstatus(&info->prstatus->common, current, siginfo->si_signo);
2046 	elf_core_copy_regs(&info->prstatus->pr_reg, regs);
2047 
2048 	/* Set up header */
2049 	fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
2050 
2051 	/*
2052 	 * Set up the notes in similar form to SVR4 core dumps made
2053 	 * with info from their /proc.
2054 	 */
2055 
2056 	fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
2057 		  sizeof(*info->prstatus), info->prstatus);
2058 	fill_psinfo(info->psinfo, current->group_leader, current->mm);
2059 	fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
2060 		  sizeof(*info->psinfo), info->psinfo);
2061 
2062 	fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
2063 	fill_auxv_note(info->notes + 3, current->mm);
2064 	info->numnote = 4;
2065 
2066 	if (fill_files_note(info->notes + info->numnote) == 0) {
2067 		info->notes_files = info->notes + info->numnote;
2068 		info->numnote++;
2069 	}
2070 
2071 	/* Try to dump the FPU. */
2072 	info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
2073 							       info->fpu);
2074 	if (info->prstatus->pr_fpvalid)
2075 		fill_note(info->notes + info->numnote++,
2076 			  "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
2077 	return 1;
2078 }
2079 
2080 static size_t get_note_info_size(struct elf_note_info *info)
2081 {
2082 	int sz = 0;
2083 	int i;
2084 
2085 	for (i = 0; i < info->numnote; i++)
2086 		sz += notesize(info->notes + i);
2087 
2088 	sz += info->thread_status_size;
2089 
2090 	return sz;
2091 }
2092 
2093 static int write_note_info(struct elf_note_info *info,
2094 			   struct coredump_params *cprm)
2095 {
2096 	struct elf_thread_status *ets;
2097 	int i;
2098 
2099 	for (i = 0; i < info->numnote; i++)
2100 		if (!writenote(info->notes + i, cprm))
2101 			return 0;
2102 
2103 	/* write out the thread status notes section */
2104 	list_for_each_entry(ets, &info->thread_list, list) {
2105 		for (i = 0; i < ets->num_notes; i++)
2106 			if (!writenote(&ets->notes[i], cprm))
2107 				return 0;
2108 	}
2109 
2110 	return 1;
2111 }
2112 
2113 static void free_note_info(struct elf_note_info *info)
2114 {
2115 	while (!list_empty(&info->thread_list)) {
2116 		struct list_head *tmp = info->thread_list.next;
2117 		list_del(tmp);
2118 		kfree(list_entry(tmp, struct elf_thread_status, list));
2119 	}
2120 
2121 	/* Free data possibly allocated by fill_files_note(): */
2122 	if (info->notes_files)
2123 		kvfree(info->notes_files->data);
2124 
2125 	kfree(info->prstatus);
2126 	kfree(info->psinfo);
2127 	kfree(info->notes);
2128 	kfree(info->fpu);
2129 }
2130 
2131 #endif
2132 
2133 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
2134 			     elf_addr_t e_shoff, int segs)
2135 {
2136 	elf->e_shoff = e_shoff;
2137 	elf->e_shentsize = sizeof(*shdr4extnum);
2138 	elf->e_shnum = 1;
2139 	elf->e_shstrndx = SHN_UNDEF;
2140 
2141 	memset(shdr4extnum, 0, sizeof(*shdr4extnum));
2142 
2143 	shdr4extnum->sh_type = SHT_NULL;
2144 	shdr4extnum->sh_size = elf->e_shnum;
2145 	shdr4extnum->sh_link = elf->e_shstrndx;
2146 	shdr4extnum->sh_info = segs;
2147 }
2148 
2149 /*
2150  * Actual dumper
2151  *
2152  * This is a two-pass process; first we find the offsets of the bits,
2153  * and then they are actually written out.  If we run out of core limit
2154  * we just truncate.
2155  */
2156 static int elf_core_dump(struct coredump_params *cprm)
2157 {
2158 	int has_dumped = 0;
2159 	int vma_count, segs, i;
2160 	size_t vma_data_size;
2161 	struct elfhdr elf;
2162 	loff_t offset = 0, dataoff;
2163 	struct elf_note_info info = { };
2164 	struct elf_phdr *phdr4note = NULL;
2165 	struct elf_shdr *shdr4extnum = NULL;
2166 	Elf_Half e_phnum;
2167 	elf_addr_t e_shoff;
2168 	struct core_vma_metadata *vma_meta;
2169 
2170 	if (dump_vma_snapshot(cprm, &vma_count, &vma_meta, &vma_data_size))
2171 		return 0;
2172 
2173 	/*
2174 	 * The number of segs are recored into ELF header as 16bit value.
2175 	 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2176 	 */
2177 	segs = vma_count + elf_core_extra_phdrs();
2178 
2179 	/* for notes section */
2180 	segs++;
2181 
2182 	/* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2183 	 * this, kernel supports extended numbering. Have a look at
2184 	 * include/linux/elf.h for further information. */
2185 	e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2186 
2187 	/*
2188 	 * Collect all the non-memory information about the process for the
2189 	 * notes.  This also sets up the file header.
2190 	 */
2191 	if (!fill_note_info(&elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2192 		goto end_coredump;
2193 
2194 	has_dumped = 1;
2195 
2196 	offset += sizeof(elf);				/* Elf header */
2197 	offset += segs * sizeof(struct elf_phdr);	/* Program headers */
2198 
2199 	/* Write notes phdr entry */
2200 	{
2201 		size_t sz = get_note_info_size(&info);
2202 
2203 		/* For cell spufs */
2204 		sz += elf_coredump_extra_notes_size();
2205 
2206 		phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2207 		if (!phdr4note)
2208 			goto end_coredump;
2209 
2210 		fill_elf_note_phdr(phdr4note, sz, offset);
2211 		offset += sz;
2212 	}
2213 
2214 	dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2215 
2216 	offset += vma_data_size;
2217 	offset += elf_core_extra_data_size();
2218 	e_shoff = offset;
2219 
2220 	if (e_phnum == PN_XNUM) {
2221 		shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2222 		if (!shdr4extnum)
2223 			goto end_coredump;
2224 		fill_extnum_info(&elf, shdr4extnum, e_shoff, segs);
2225 	}
2226 
2227 	offset = dataoff;
2228 
2229 	if (!dump_emit(cprm, &elf, sizeof(elf)))
2230 		goto end_coredump;
2231 
2232 	if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
2233 		goto end_coredump;
2234 
2235 	/* Write program headers for segments dump */
2236 	for (i = 0; i < vma_count; i++) {
2237 		struct core_vma_metadata *meta = vma_meta + i;
2238 		struct elf_phdr phdr;
2239 
2240 		phdr.p_type = PT_LOAD;
2241 		phdr.p_offset = offset;
2242 		phdr.p_vaddr = meta->start;
2243 		phdr.p_paddr = 0;
2244 		phdr.p_filesz = meta->dump_size;
2245 		phdr.p_memsz = meta->end - meta->start;
2246 		offset += phdr.p_filesz;
2247 		phdr.p_flags = 0;
2248 		if (meta->flags & VM_READ)
2249 			phdr.p_flags |= PF_R;
2250 		if (meta->flags & VM_WRITE)
2251 			phdr.p_flags |= PF_W;
2252 		if (meta->flags & VM_EXEC)
2253 			phdr.p_flags |= PF_X;
2254 		phdr.p_align = ELF_EXEC_PAGESIZE;
2255 
2256 		if (!dump_emit(cprm, &phdr, sizeof(phdr)))
2257 			goto end_coredump;
2258 	}
2259 
2260 	if (!elf_core_write_extra_phdrs(cprm, offset))
2261 		goto end_coredump;
2262 
2263  	/* write out the notes section */
2264 	if (!write_note_info(&info, cprm))
2265 		goto end_coredump;
2266 
2267 	/* For cell spufs */
2268 	if (elf_coredump_extra_notes_write(cprm))
2269 		goto end_coredump;
2270 
2271 	/* Align to page */
2272 	dump_skip_to(cprm, dataoff);
2273 
2274 	for (i = 0; i < vma_count; i++) {
2275 		struct core_vma_metadata *meta = vma_meta + i;
2276 
2277 		if (!dump_user_range(cprm, meta->start, meta->dump_size))
2278 			goto end_coredump;
2279 	}
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 static int __init init_elf_binfmt(void)
2300 {
2301 	register_binfmt(&elf_format);
2302 	return 0;
2303 }
2304 
2305 static void __exit exit_elf_binfmt(void)
2306 {
2307 	/* Remove the COFF and ELF loaders. */
2308 	unregister_binfmt(&elf_format);
2309 }
2310 
2311 core_initcall(init_elf_binfmt);
2312 module_exit(exit_elf_binfmt);
2313 MODULE_LICENSE("GPL");
2314