cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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binfmt_elf.c (63050B)


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