binfmt_elf.c 45.7 KB
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/*
 * linux/fs/binfmt_elf.c
 *
 * These are the functions used to load ELF format executables as used
 * on SVr4 machines.  Information on the format may be found in the book
 * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
 * Tools".
 *
 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/a.out.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/binfmts.h>
#include <linux/string.h>
#include <linux/file.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/shm.h>
#include <linux/personality.h>
#include <linux/elfcore.h>
#include <linux/init.h>
#include <linux/highuid.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/compiler.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/random.h>
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#include <linux/elf.h>
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#include <asm/uaccess.h>
#include <asm/param.h>
#include <asm/page.h>

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static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
static int load_elf_library(struct file *);
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static unsigned long elf_map (struct file *, unsigned long, struct elf_phdr *, int, int);

/*
 * If we don't support core dumping, then supply a NULL so we
 * don't even try.
 */
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#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
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static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file);
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#else
#define elf_core_dump	NULL
#endif

#if ELF_EXEC_PAGESIZE > PAGE_SIZE
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#define ELF_MIN_ALIGN	ELF_EXEC_PAGESIZE
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#else
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#define ELF_MIN_ALIGN	PAGE_SIZE
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#endif

#ifndef ELF_CORE_EFLAGS
#define ELF_CORE_EFLAGS	0
#endif

#define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
#define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
#define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))

static struct linux_binfmt elf_format = {
		.module		= THIS_MODULE,
		.load_binary	= load_elf_binary,
		.load_shlib	= load_elf_library,
		.core_dump	= elf_core_dump,
		.min_coredump	= ELF_EXEC_PAGESIZE
};

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#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
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static int set_brk(unsigned long start, unsigned long end)
{
	start = ELF_PAGEALIGN(start);
	end = ELF_PAGEALIGN(end);
	if (end > start) {
		unsigned long addr;
		down_write(&current->mm->mmap_sem);
		addr = do_brk(start, end - start);
		up_write(&current->mm->mmap_sem);
		if (BAD_ADDR(addr))
			return addr;
	}
	current->mm->start_brk = current->mm->brk = end;
	return 0;
}

/* We need to explicitly zero any fractional pages
   after the data section (i.e. bss).  This would
   contain the junk from the file that should not
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   be in memory
 */
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static int padzero(unsigned long elf_bss)
{
	unsigned long nbyte;

	nbyte = ELF_PAGEOFFSET(elf_bss);
	if (nbyte) {
		nbyte = ELF_MIN_ALIGN - nbyte;
		if (clear_user((void __user *) elf_bss, nbyte))
			return -EFAULT;
	}
	return 0;
}

/* Let's use some macros to make this stack manipulation a litle clearer */
#ifdef CONFIG_STACK_GROWSUP
#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
#define STACK_ROUND(sp, items) \
	((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
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#define STACK_ALLOC(sp, len) ({ \
	elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
	old_sp; })
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#else
#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
#define STACK_ROUND(sp, items) \
	(((unsigned long) (sp - items)) &~ 15UL)
#define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
#endif

static int
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create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
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		int interp_aout, unsigned long load_addr,
		unsigned long interp_load_addr)
{
	unsigned long p = bprm->p;
	int argc = bprm->argc;
	int envc = bprm->envc;
	elf_addr_t __user *argv;
	elf_addr_t __user *envp;
	elf_addr_t __user *sp;
	elf_addr_t __user *u_platform;
	const char *k_platform = ELF_PLATFORM;
	int items;
	elf_addr_t *elf_info;
	int ei_index = 0;
	struct task_struct *tsk = current;

	/*
	 * If this architecture has a platform capability string, copy it
	 * to userspace.  In some cases (Sparc), this info is impossible
	 * for userspace to get any other way, in others (i386) it is
	 * merely difficult.
	 */
	u_platform = NULL;
	if (k_platform) {
		size_t len = strlen(k_platform) + 1;

		/*
		 * In some cases (e.g. Hyper-Threading), we want to avoid L1
		 * evictions by the processes running on the same package. One
		 * thing we can do is to shuffle the initial stack for them.
		 */
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		p = arch_align_stack(p);

		u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
		if (__copy_to_user(u_platform, k_platform, len))
			return -EFAULT;
	}

	/* Create the ELF interpreter info */
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	elf_info = (elf_addr_t *)current->mm->saved_auxv;
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#define NEW_AUX_ENT(id, val) \
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	do { \
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		elf_info[ei_index++] = id; \
		elf_info[ei_index++] = val; \
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	} while (0)
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#ifdef ARCH_DLINFO
	/* 
	 * ARCH_DLINFO must come first so PPC can do its special alignment of
	 * AUXV.
	 */
	ARCH_DLINFO;
#endif
	NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
	NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
	NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
	NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
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	NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
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	NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
	NEW_AUX_ENT(AT_BASE, interp_load_addr);
	NEW_AUX_ENT(AT_FLAGS, 0);
	NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
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	NEW_AUX_ENT(AT_UID, tsk->uid);
	NEW_AUX_ENT(AT_EUID, tsk->euid);
	NEW_AUX_ENT(AT_GID, tsk->gid);
	NEW_AUX_ENT(AT_EGID, tsk->egid);
 	NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
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	if (k_platform) {
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		NEW_AUX_ENT(AT_PLATFORM,
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			    (elf_addr_t)(unsigned long)u_platform);
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	}
	if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
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		NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
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	}
#undef NEW_AUX_ENT
	/* AT_NULL is zero; clear the rest too */
	memset(&elf_info[ei_index], 0,
	       sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);

	/* And advance past the AT_NULL entry.  */
	ei_index += 2;

	sp = STACK_ADD(p, ei_index);

	items = (argc + 1) + (envc + 1);
	if (interp_aout) {
		items += 3; /* a.out interpreters require argv & envp too */
	} else {
		items += 1; /* ELF interpreters only put argc on the stack */
	}
	bprm->p = STACK_ROUND(sp, items);

	/* Point sp at the lowest address on the stack */
#ifdef CONFIG_STACK_GROWSUP
	sp = (elf_addr_t __user *)bprm->p - items - ei_index;
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	bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
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#else
	sp = (elf_addr_t __user *)bprm->p;
#endif

	/* Now, let's put argc (and argv, envp if appropriate) on the stack */
	if (__put_user(argc, sp++))
		return -EFAULT;
	if (interp_aout) {
		argv = sp + 2;
		envp = argv + argc + 1;
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		if (__put_user((elf_addr_t)(unsigned long)argv, sp++) ||
		    __put_user((elf_addr_t)(unsigned long)envp, sp++))
			return -EFAULT;
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	} else {
		argv = sp;
		envp = argv + argc + 1;
	}

	/* Populate argv and envp */
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	p = current->mm->arg_end = current->mm->arg_start;
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	while (argc-- > 0) {
		size_t len;
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		if (__put_user((elf_addr_t)p, argv++))
			return -EFAULT;
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		len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
		if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
			return 0;
		p += len;
	}
	if (__put_user(0, argv))
		return -EFAULT;
	current->mm->arg_end = current->mm->env_start = p;
	while (envc-- > 0) {
		size_t len;
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		if (__put_user((elf_addr_t)p, envp++))
			return -EFAULT;
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		len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
		if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
			return 0;
		p += len;
	}
	if (__put_user(0, envp))
		return -EFAULT;
	current->mm->env_end = p;

	/* Put the elf_info on the stack in the right place.  */
	sp = (elf_addr_t __user *)envp + 1;
	if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
		return -EFAULT;
	return 0;
}

#ifndef elf_map

static unsigned long elf_map(struct file *filep, unsigned long addr,
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		struct elf_phdr *eppnt, int prot, int type)
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{
	unsigned long map_addr;
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	unsigned long pageoffset = ELF_PAGEOFFSET(eppnt->p_vaddr);
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	down_write(&current->mm->mmap_sem);
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	/* mmap() will return -EINVAL if given a zero size, but a
	 * segment with zero filesize is perfectly valid */
	if (eppnt->p_filesz + pageoffset)
		map_addr = do_mmap(filep, ELF_PAGESTART(addr),
				   eppnt->p_filesz + pageoffset, prot, type,
				   eppnt->p_offset - pageoffset);
	else
		map_addr = ELF_PAGESTART(addr);
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	up_write(&current->mm->mmap_sem);
	return(map_addr);
}

#endif /* !elf_map */

/* This is much more generalized than the library routine read function,
   so we keep this separate.  Technically the library read function
   is only provided so that we can read a.out libraries that have
   an ELF header */

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static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
		struct file *interpreter, unsigned long *interp_load_addr)
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{
	struct elf_phdr *elf_phdata;
	struct elf_phdr *eppnt;
	unsigned long load_addr = 0;
	int load_addr_set = 0;
	unsigned long last_bss = 0, elf_bss = 0;
	unsigned long error = ~0UL;
	int retval, i, size;

	/* First of all, some simple consistency checks */
	if (interp_elf_ex->e_type != ET_EXEC &&
	    interp_elf_ex->e_type != ET_DYN)
		goto out;
	if (!elf_check_arch(interp_elf_ex))
		goto out;
	if (!interpreter->f_op || !interpreter->f_op->mmap)
		goto out;

	/*
	 * If the size of this structure has changed, then punt, since
	 * we will be doing the wrong thing.
	 */
	if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
		goto out;
	if (interp_elf_ex->e_phnum < 1 ||
		interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
		goto out;

	/* Now read in all of the header information */
	size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
	if (size > ELF_MIN_ALIGN)
		goto out;
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	elf_phdata = kmalloc(size, GFP_KERNEL);
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	if (!elf_phdata)
		goto out;

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	retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
			     (char *)elf_phdata,size);
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	error = -EIO;
	if (retval != size) {
		if (retval < 0)
			error = retval;	
		goto out_close;
	}

	eppnt = elf_phdata;
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	for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
		if (eppnt->p_type == PT_LOAD) {
			int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
			int elf_prot = 0;
			unsigned long vaddr = 0;
			unsigned long k, map_addr;

			if (eppnt->p_flags & PF_R)
		    		elf_prot = PROT_READ;
			if (eppnt->p_flags & PF_W)
				elf_prot |= PROT_WRITE;
			if (eppnt->p_flags & PF_X)
				elf_prot |= PROT_EXEC;
			vaddr = eppnt->p_vaddr;
			if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
				elf_type |= MAP_FIXED;

			map_addr = elf_map(interpreter, load_addr + vaddr,
					   eppnt, elf_prot, elf_type);
			error = map_addr;
			if (BAD_ADDR(map_addr))
				goto out_close;

			if (!load_addr_set &&
			    interp_elf_ex->e_type == ET_DYN) {
				load_addr = map_addr - ELF_PAGESTART(vaddr);
				load_addr_set = 1;
			}

			/*
			 * Check to see if the section's size will overflow the
			 * allowed task size. Note that p_filesz must always be
			 * <= p_memsize so it's only necessary to check p_memsz.
			 */
			k = load_addr + eppnt->p_vaddr;
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			if (BAD_ADDR(k) ||
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			    eppnt->p_filesz > eppnt->p_memsz ||
			    eppnt->p_memsz > TASK_SIZE ||
			    TASK_SIZE - eppnt->p_memsz < k) {
				error = -ENOMEM;
				goto out_close;
			}

			/*
			 * Find the end of the file mapping for this phdr, and
			 * keep track of the largest address we see for this.
			 */
			k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
			if (k > elf_bss)
				elf_bss = k;

			/*
			 * Do the same thing for the memory mapping - between
			 * elf_bss and last_bss is the bss section.
			 */
			k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
			if (k > last_bss)
				last_bss = k;
		}
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	}

	/*
	 * Now fill out the bss section.  First pad the last page up
	 * to the page boundary, and then perform a mmap to make sure
	 * that there are zero-mapped pages up to and including the 
	 * last bss page.
	 */
	if (padzero(elf_bss)) {
		error = -EFAULT;
		goto out_close;
	}

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	/* What we have mapped so far */
	elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
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	/* Map the last of the bss segment */
	if (last_bss > elf_bss) {
		down_write(&current->mm->mmap_sem);
		error = do_brk(elf_bss, last_bss - elf_bss);
		up_write(&current->mm->mmap_sem);
		if (BAD_ADDR(error))
			goto out_close;
	}

	*interp_load_addr = load_addr;
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	error = ((unsigned long)interp_elf_ex->e_entry) + load_addr;
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out_close:
	kfree(elf_phdata);
out:
	return error;
}

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static unsigned long load_aout_interp(struct exec *interp_ex,
		struct file *interpreter)
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{
	unsigned long text_data, elf_entry = ~0UL;
	char __user * addr;
	loff_t offset;

	current->mm->end_code = interp_ex->a_text;
	text_data = interp_ex->a_text + interp_ex->a_data;
	current->mm->end_data = text_data;
	current->mm->brk = interp_ex->a_bss + text_data;

	switch (N_MAGIC(*interp_ex)) {
	case OMAGIC:
		offset = 32;
		addr = (char __user *)0;
		break;
	case ZMAGIC:
	case QMAGIC:
		offset = N_TXTOFF(*interp_ex);
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		addr = (char __user *)N_TXTADDR(*interp_ex);
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		break;
	default:
		goto out;
	}

	down_write(&current->mm->mmap_sem);	
	do_brk(0, text_data);
	up_write(&current->mm->mmap_sem);
	if (!interpreter->f_op || !interpreter->f_op->read)
		goto out;
	if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0)
		goto out;
	flush_icache_range((unsigned long)addr,
	                   (unsigned long)addr + text_data);

	down_write(&current->mm->mmap_sem);	
	do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
		interp_ex->a_bss);
	up_write(&current->mm->mmap_sem);
	elf_entry = interp_ex->a_entry;

out:
	return elf_entry;
}

/*
 * These are the functions used to load ELF style executables and shared
 * libraries.  There is no binary dependent code anywhere else.
 */

#define INTERPRETER_NONE 0
#define INTERPRETER_AOUT 1
#define INTERPRETER_ELF 2

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#ifndef STACK_RND_MASK
#define STACK_RND_MASK 0x7ff		/* with 4K pages 8MB of VA */
#endif
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static unsigned long randomize_stack_top(unsigned long stack_top)
{
	unsigned int random_variable = 0;

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	if ((current->flags & PF_RANDOMIZE) &&
		!(current->personality & ADDR_NO_RANDOMIZE)) {
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		random_variable = get_random_int() & STACK_RND_MASK;
		random_variable <<= PAGE_SHIFT;
	}
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#ifdef CONFIG_STACK_GROWSUP
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	return PAGE_ALIGN(stack_top) + random_variable;
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#else
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	return PAGE_ALIGN(stack_top) - random_variable;
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#endif
}

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static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
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{
	struct file *interpreter = NULL; /* to shut gcc up */
 	unsigned long load_addr = 0, load_bias = 0;
	int load_addr_set = 0;
	char * elf_interpreter = NULL;
	unsigned int interpreter_type = INTERPRETER_NONE;
	unsigned char ibcs2_interpreter = 0;
	unsigned long error;
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	struct elf_phdr *elf_ppnt, *elf_phdata;
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	unsigned long elf_bss, elf_brk;
	int elf_exec_fileno;
	int retval, i;
	unsigned int size;
	unsigned long elf_entry, interp_load_addr = 0;
	unsigned long start_code, end_code, start_data, end_data;
	unsigned long reloc_func_desc = 0;
	char passed_fileno[6];
	struct files_struct *files;
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	int executable_stack = EXSTACK_DEFAULT;
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	unsigned long def_flags = 0;
	struct {
		struct elfhdr elf_ex;
		struct elfhdr interp_elf_ex;
  		struct exec interp_ex;
	} *loc;

	loc = kmalloc(sizeof(*loc), GFP_KERNEL);
	if (!loc) {
		retval = -ENOMEM;
		goto out_ret;
	}
	
	/* Get the exec-header */
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	loc->elf_ex = *((struct elfhdr *)bprm->buf);
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	retval = -ENOEXEC;
	/* First of all, some simple consistency checks */
	if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
		goto out;

	if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
		goto out;
	if (!elf_check_arch(&loc->elf_ex))
		goto out;
	if (!bprm->file->f_op||!bprm->file->f_op->mmap)
		goto out;

	/* Now read in all of the header information */
	if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
		goto out;
	if (loc->elf_ex.e_phnum < 1 ||
	 	loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
		goto out;
	size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
	retval = -ENOMEM;
584
	elf_phdata = kmalloc(size, GFP_KERNEL);
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	if (!elf_phdata)
		goto out;

588 589
	retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
			     (char *)elf_phdata, size);
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	if (retval != size) {
		if (retval >= 0)
			retval = -EIO;
		goto out_free_ph;
	}

596
	files = current->files;	/* Refcounted so ok */
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	retval = unshare_files();
	if (retval < 0)
		goto out_free_ph;
	if (files == current->files) {
		put_files_struct(files);
		files = NULL;
	}

	/* exec will make our files private anyway, but for the a.out
	   loader stuff we need to do it earlier */
	retval = get_unused_fd();
	if (retval < 0)
		goto out_free_fh;
	get_file(bprm->file);
	fd_install(elf_exec_fileno = retval, bprm->file);

	elf_ppnt = elf_phdata;
	elf_bss = 0;
	elf_brk = 0;

	start_code = ~0UL;
	end_code = 0;
	start_data = 0;
	end_data = 0;

	for (i = 0; i < loc->elf_ex.e_phnum; i++) {
		if (elf_ppnt->p_type == PT_INTERP) {
			/* This is the program interpreter used for
			 * shared libraries - for now assume that this
			 * is an a.out format binary
			 */
			retval = -ENOEXEC;
			if (elf_ppnt->p_filesz > PATH_MAX || 
			    elf_ppnt->p_filesz < 2)
				goto out_free_file;

			retval = -ENOMEM;
634
			elf_interpreter = kmalloc(elf_ppnt->p_filesz,
635
						  GFP_KERNEL);
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			if (!elf_interpreter)
				goto out_free_file;

			retval = kernel_read(bprm->file, elf_ppnt->p_offset,
640 641
					     elf_interpreter,
					     elf_ppnt->p_filesz);
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			if (retval != elf_ppnt->p_filesz) {
				if (retval >= 0)
					retval = -EIO;
				goto out_free_interp;
			}
			/* make sure path is NULL terminated */
			retval = -ENOEXEC;
			if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
				goto out_free_interp;

			/* If the program interpreter is one of these two,
			 * then assume an iBCS2 image. Otherwise assume
			 * a native linux image.
			 */
			if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
			    strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0)
				ibcs2_interpreter = 1;

			/*
			 * The early SET_PERSONALITY here is so that the lookup
			 * for the interpreter happens in the namespace of the 
			 * to-be-execed image.  SET_PERSONALITY can select an
			 * alternate root.
			 *
			 * However, SET_PERSONALITY is NOT allowed to switch
			 * this task into the new images's memory mapping
			 * policy - that is, TASK_SIZE must still evaluate to
			 * that which is appropriate to the execing application.
			 * This is because exit_mmap() needs to have TASK_SIZE
			 * evaluate to the size of the old image.
			 *
			 * So if (say) a 64-bit application is execing a 32-bit
			 * application it is the architecture's responsibility
			 * to defer changing the value of TASK_SIZE until the
			 * switch really is going to happen - do this in
			 * flush_thread().	- akpm
			 */
			SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);

			interpreter = open_exec(elf_interpreter);
			retval = PTR_ERR(interpreter);
			if (IS_ERR(interpreter))
				goto out_free_interp;
685 686
			retval = kernel_read(interpreter, 0, bprm->buf,
					     BINPRM_BUF_SIZE);
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			if (retval != BINPRM_BUF_SIZE) {
				if (retval >= 0)
					retval = -EIO;
				goto out_free_dentry;
			}

			/* Get the exec headers */
694 695
			loc->interp_ex = *((struct exec *)bprm->buf);
			loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
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			break;
		}
		elf_ppnt++;
	}

	elf_ppnt = elf_phdata;
	for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
		if (elf_ppnt->p_type == PT_GNU_STACK) {
			if (elf_ppnt->p_flags & PF_X)
				executable_stack = EXSTACK_ENABLE_X;
			else
				executable_stack = EXSTACK_DISABLE_X;
			break;
		}

	/* Some simple consistency checks for the interpreter */
	if (elf_interpreter) {
		interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;

		/* Now figure out which format our binary is */
		if ((N_MAGIC(loc->interp_ex) != OMAGIC) &&
		    (N_MAGIC(loc->interp_ex) != ZMAGIC) &&
		    (N_MAGIC(loc->interp_ex) != QMAGIC))
			interpreter_type = INTERPRETER_ELF;

		if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
			interpreter_type &= ~INTERPRETER_ELF;

		retval = -ELIBBAD;
		if (!interpreter_type)
			goto out_free_dentry;

		/* Make sure only one type was selected */
		if ((interpreter_type & INTERPRETER_ELF) &&
		     interpreter_type != INTERPRETER_ELF) {
	     		// FIXME - ratelimit this before re-enabling
			// printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n");
			interpreter_type = INTERPRETER_ELF;
		}
		/* Verify the interpreter has a valid arch */
		if ((interpreter_type == INTERPRETER_ELF) &&
		    !elf_check_arch(&loc->interp_elf_ex))
			goto out_free_dentry;
	} else {
		/* Executables without an interpreter also need a personality  */
		SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
	}

	/* OK, we are done with that, now set up the arg stuff,
	   and then start this sucker up */
	if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) {
		char *passed_p = passed_fileno;
		sprintf(passed_fileno, "%d", elf_exec_fileno);

		if (elf_interpreter) {
			retval = copy_strings_kernel(1, &passed_p, bprm);
			if (retval)
				goto out_free_dentry; 
			bprm->argc++;
		}
	}

	/* Flush all traces of the currently running executable */
	retval = flush_old_exec(bprm);
	if (retval)
		goto out_free_dentry;

	/* Discard our unneeded old files struct */
	if (files) {
		put_files_struct(files);
		files = NULL;
	}

	/* OK, This is the point of no return */
	current->mm->start_data = 0;
	current->mm->end_data = 0;
	current->mm->end_code = 0;
	current->mm->mmap = NULL;
	current->flags &= ~PF_FORKNOEXEC;
	current->mm->def_flags = def_flags;

	/* Do this immediately, since STACK_TOP as used in setup_arg_pages
	   may depend on the personality.  */
	SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
	if (elf_read_implies_exec(loc->elf_ex, executable_stack))
		current->personality |= READ_IMPLIES_EXEC;

783
	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
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		current->flags |= PF_RANDOMIZE;
	arch_pick_mmap_layout(current->mm);

	/* Do this so that we can load the interpreter, if need be.  We will
	   change some of these later */
	current->mm->free_area_cache = current->mm->mmap_base;
790
	current->mm->cached_hole_size = 0;
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	retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
				 executable_stack);
	if (retval < 0) {
		send_sig(SIGKILL, current, 0);
		goto out_free_dentry;
	}
	
	current->mm->start_stack = bprm->p;

	/* Now we do a little grungy work by mmaping the ELF image into
	   the correct location in memory.  At this point, we assume that
	   the image should be loaded at fixed address, not at a variable
	   address. */
804 805
	for(i = 0, elf_ppnt = elf_phdata;
	    i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
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		int elf_prot = 0, elf_flags;
		unsigned long k, vaddr;

		if (elf_ppnt->p_type != PT_LOAD)
			continue;

		if (unlikely (elf_brk > elf_bss)) {
			unsigned long nbyte;
	            
			/* There was a PT_LOAD segment with p_memsz > p_filesz
			   before this one. Map anonymous pages, if needed,
			   and clear the area.  */
			retval = set_brk (elf_bss + load_bias,
					  elf_brk + load_bias);
			if (retval) {
				send_sig(SIGKILL, current, 0);
				goto out_free_dentry;
			}
			nbyte = ELF_PAGEOFFSET(elf_bss);
			if (nbyte) {
				nbyte = ELF_MIN_ALIGN - nbyte;
				if (nbyte > elf_brk - elf_bss)
					nbyte = elf_brk - elf_bss;
				if (clear_user((void __user *)elf_bss +
							load_bias, nbyte)) {
					/*
					 * This bss-zeroing can fail if the ELF
833
					 * file specifies odd protections. So
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					 * we don't check the return value
					 */
				}
			}
		}

840 841 842 843 844 845
		if (elf_ppnt->p_flags & PF_R)
			elf_prot |= PROT_READ;
		if (elf_ppnt->p_flags & PF_W)
			elf_prot |= PROT_WRITE;
		if (elf_ppnt->p_flags & PF_X)
			elf_prot |= PROT_EXEC;
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847
		elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
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		vaddr = elf_ppnt->p_vaddr;
		if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
			elf_flags |= MAP_FIXED;
		} else if (loc->elf_ex.e_type == ET_DYN) {
853 854 855 856
			/* Try and get dynamic programs out of the way of the
			 * default mmap base, as well as whatever program they
			 * might try to exec.  This is because the brk will
			 * follow the loader, and is not movable.  */
857
			load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
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		}

860 861
		error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
				elf_prot, elf_flags);
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		if (BAD_ADDR(error)) {
			send_sig(SIGKILL, current, 0);
			goto out_free_dentry;
		}

		if (!load_addr_set) {
			load_addr_set = 1;
			load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
			if (loc->elf_ex.e_type == ET_DYN) {
				load_bias += error -
				             ELF_PAGESTART(load_bias + vaddr);
				load_addr += load_bias;
				reloc_func_desc = load_bias;
			}
		}
		k = elf_ppnt->p_vaddr;
878 879 880 881
		if (k < start_code)
			start_code = k;
		if (start_data < k)
			start_data = k;
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		/*
		 * Check to see if the section's size will overflow the
		 * allowed task size. Note that p_filesz must always be
		 * <= p_memsz so it is only necessary to check p_memsz.
		 */
888
		if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
L
Linus Torvalds 已提交
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		    elf_ppnt->p_memsz > TASK_SIZE ||
		    TASK_SIZE - elf_ppnt->p_memsz < k) {
891
			/* set_brk can never work. Avoid overflows. */
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Linus Torvalds 已提交
892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926
			send_sig(SIGKILL, current, 0);
			goto out_free_dentry;
		}

		k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;

		if (k > elf_bss)
			elf_bss = k;
		if ((elf_ppnt->p_flags & PF_X) && end_code < k)
			end_code = k;
		if (end_data < k)
			end_data = k;
		k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
		if (k > elf_brk)
			elf_brk = k;
	}

	loc->elf_ex.e_entry += load_bias;
	elf_bss += load_bias;
	elf_brk += load_bias;
	start_code += load_bias;
	end_code += load_bias;
	start_data += load_bias;
	end_data += load_bias;

	/* Calling set_brk effectively mmaps the pages that we need
	 * for the bss and break sections.  We must do this before
	 * mapping in the interpreter, to make sure it doesn't wind
	 * up getting placed where the bss needs to go.
	 */
	retval = set_brk(elf_bss, elf_brk);
	if (retval) {
		send_sig(SIGKILL, current, 0);
		goto out_free_dentry;
	}
A
akpm@osdl.org 已提交
927
	if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
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928 929 930 931 932 933 934 935 936 937 938 939 940 941 942
		send_sig(SIGSEGV, current, 0);
		retval = -EFAULT; /* Nobody gets to see this, but.. */
		goto out_free_dentry;
	}

	if (elf_interpreter) {
		if (interpreter_type == INTERPRETER_AOUT)
			elf_entry = load_aout_interp(&loc->interp_ex,
						     interpreter);
		else
			elf_entry = load_elf_interp(&loc->interp_elf_ex,
						    interpreter,
						    &interp_load_addr);
		if (BAD_ADDR(elf_entry)) {
			force_sig(SIGSEGV, current);
943 944
			retval = IS_ERR((void *)elf_entry) ?
					(int)elf_entry : -EINVAL;
L
Linus Torvalds 已提交
945 946 947 948 949 950 951 952 953
			goto out_free_dentry;
		}
		reloc_func_desc = interp_load_addr;

		allow_write_access(interpreter);
		fput(interpreter);
		kfree(elf_interpreter);
	} else {
		elf_entry = loc->elf_ex.e_entry;
954
		if (BAD_ADDR(elf_entry)) {
955 956
			force_sig(SIGSEGV, current);
			retval = -EINVAL;
957 958
			goto out_free_dentry;
		}
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Linus Torvalds 已提交
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	}

	kfree(elf_phdata);

	if (interpreter_type != INTERPRETER_AOUT)
		sys_close(elf_exec_fileno);

	set_binfmt(&elf_format);

968 969 970 971
#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
	retval = arch_setup_additional_pages(bprm, executable_stack);
	if (retval < 0) {
		send_sig(SIGKILL, current, 0);
972
		goto out;
973 974 975
	}
#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */

L
Linus Torvalds 已提交
976 977
	compute_creds(bprm);
	current->flags &= ~PF_FORKNOEXEC;
978 979 980
	create_elf_tables(bprm, &loc->elf_ex,
			  (interpreter_type == INTERPRETER_AOUT),
			  load_addr, interp_load_addr);
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981 982 983 984 985 986 987 988 989 990 991 992 993
	/* N.B. passed_fileno might not be initialized? */
	if (interpreter_type == INTERPRETER_AOUT)
		current->mm->arg_start += strlen(passed_fileno) + 1;
	current->mm->end_code = end_code;
	current->mm->start_code = start_code;
	current->mm->start_data = start_data;
	current->mm->end_data = end_data;
	current->mm->start_stack = bprm->p;

	if (current->personality & MMAP_PAGE_ZERO) {
		/* Why this, you ask???  Well SVr4 maps page 0 as read-only,
		   and some applications "depend" upon this behavior.
		   Since we do not have the power to recompile these, we
994
		   emulate the SVr4 behavior. Sigh. */
L
Linus Torvalds 已提交
995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033
		down_write(&current->mm->mmap_sem);
		error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
				MAP_FIXED | MAP_PRIVATE, 0);
		up_write(&current->mm->mmap_sem);
	}

#ifdef ELF_PLAT_INIT
	/*
	 * The ABI may specify that certain registers be set up in special
	 * ways (on i386 %edx is the address of a DT_FINI function, for
	 * example.  In addition, it may also specify (eg, PowerPC64 ELF)
	 * that the e_entry field is the address of the function descriptor
	 * for the startup routine, rather than the address of the startup
	 * routine itself.  This macro performs whatever initialization to
	 * the regs structure is required as well as any relocations to the
	 * function descriptor entries when executing dynamically links apps.
	 */
	ELF_PLAT_INIT(regs, reloc_func_desc);
#endif

	start_thread(regs, elf_entry, bprm->p);
	if (unlikely(current->ptrace & PT_PTRACED)) {
		if (current->ptrace & PT_TRACE_EXEC)
			ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
		else
			send_sig(SIGTRAP, current, 0);
	}
	retval = 0;
out:
	kfree(loc);
out_ret:
	return retval;

	/* error cleanup */
out_free_dentry:
	allow_write_access(interpreter);
	if (interpreter)
		fput(interpreter);
out_free_interp:
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Jesper Juhl 已提交
1034
	kfree(elf_interpreter);
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1035 1036 1037
out_free_file:
	sys_close(elf_exec_fileno);
out_free_fh:
1038 1039
	if (files)
		reset_files_struct(current, files);
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1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055
out_free_ph:
	kfree(elf_phdata);
	goto out;
}

/* This is really simpleminded and specialized - we are loading an
   a.out library that is given an ELF header. */
static int load_elf_library(struct file *file)
{
	struct elf_phdr *elf_phdata;
	struct elf_phdr *eppnt;
	unsigned long elf_bss, bss, len;
	int retval, error, i, j;
	struct elfhdr elf_ex;

	error = -ENOEXEC;
1056
	retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
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	if (retval != sizeof(elf_ex))
		goto out;

	if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
		goto out;

	/* First of all, some simple consistency checks */
	if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1065
	    !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
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1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112
		goto out;

	/* Now read in all of the header information */

	j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
	/* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */

	error = -ENOMEM;
	elf_phdata = kmalloc(j, GFP_KERNEL);
	if (!elf_phdata)
		goto out;

	eppnt = elf_phdata;
	error = -ENOEXEC;
	retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
	if (retval != j)
		goto out_free_ph;

	for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
		if ((eppnt + i)->p_type == PT_LOAD)
			j++;
	if (j != 1)
		goto out_free_ph;

	while (eppnt->p_type != PT_LOAD)
		eppnt++;

	/* Now use mmap to map the library into memory. */
	down_write(&current->mm->mmap_sem);
	error = do_mmap(file,
			ELF_PAGESTART(eppnt->p_vaddr),
			(eppnt->p_filesz +
			 ELF_PAGEOFFSET(eppnt->p_vaddr)),
			PROT_READ | PROT_WRITE | PROT_EXEC,
			MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
			(eppnt->p_offset -
			 ELF_PAGEOFFSET(eppnt->p_vaddr)));
	up_write(&current->mm->mmap_sem);
	if (error != ELF_PAGESTART(eppnt->p_vaddr))
		goto out_free_ph;

	elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
	if (padzero(elf_bss)) {
		error = -EFAULT;
		goto out_free_ph;
	}

1113 1114
	len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
			    ELF_MIN_ALIGN - 1);
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	bss = eppnt->p_memsz + eppnt->p_vaddr;
	if (bss > len) {
		down_write(&current->mm->mmap_sem);
		do_brk(len, bss - len);
		up_write(&current->mm->mmap_sem);
	}
	error = 0;

out_free_ph:
	kfree(elf_phdata);
out:
	return error;
}

/*
 * Note that some platforms still use traditional core dumps and not
 * the ELF core dump.  Each platform can select it as appropriate.
 */
1133
#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
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/*
 * ELF core dumper
 *
 * Modelled on fs/exec.c:aout_core_dump()
 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
 */
/*
 * These are the only things you should do on a core-file: use only these
 * functions to write out all the necessary info.
 */
static int dump_write(struct file *file, const void *addr, int nr)
{
	return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
}

1150
static int dump_seek(struct file *file, loff_t off)
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{
1152
	if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1153
		if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
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			return 0;
1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168
	} else {
		char *buf = (char *)get_zeroed_page(GFP_KERNEL);
		if (!buf)
			return 0;
		while (off > 0) {
			unsigned long n = off;
			if (n > PAGE_SIZE)
				n = PAGE_SIZE;
			if (!dump_write(file, buf, n))
				return 0;
			off -= n;
		}
		free_page((unsigned long)buf);
	}
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	return 1;
}

/*
 * Decide whether a segment is worth dumping; default is yes to be
 * sure (missing info is worse than too much; etc).
 * Personally I'd include everything, and use the coredump limit...
 *
 * I think we should skip something. But I am not sure how. H.J.
 */
static int maydump(struct vm_area_struct *vma)
{
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	/* The vma can be set up to tell us the answer directly.  */
	if (vma->vm_flags & VM_ALWAYSDUMP)
		return 1;

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	/* Do not dump I/O mapped devices or special mappings */
	if (vma->vm_flags & (VM_IO | VM_RESERVED))
		return 0;

1189
	/* Dump shared memory only if mapped from an anonymous file. */
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	if (vma->vm_flags & VM_SHARED)
1191
		return vma->vm_file->f_path.dentry->d_inode->i_nlink == 0;
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	/* If it hasn't been written to, don't write it out */
	if (!vma->anon_vma)
		return 0;

	return 1;
}

/* An ELF note in memory */
struct memelfnote
{
	const char *name;
	int type;
	unsigned int datasz;
	void *data;
};

static int notesize(struct memelfnote *en)
{
	int sz;

	sz = sizeof(struct elf_note);
	sz += roundup(strlen(en->name) + 1, 4);
	sz += roundup(en->datasz, 4);

	return sz;
}

1220 1221
#define DUMP_WRITE(addr, nr, foffset)	\
	do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
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1223
static int alignfile(struct file *file, loff_t *foffset)
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{
1225
	static const char buf[4] = { 0, };
1226 1227 1228
	DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
	return 1;
}
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1230 1231 1232 1233
static int writenote(struct memelfnote *men, struct file *file,
			loff_t *foffset)
{
	struct elf_note en;
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	en.n_namesz = strlen(men->name) + 1;
	en.n_descsz = men->datasz;
	en.n_type = men->type;

1238 1239 1240 1241 1242 1243 1244
	DUMP_WRITE(&en, sizeof(en), foffset);
	DUMP_WRITE(men->name, en.n_namesz, foffset);
	if (!alignfile(file, foffset))
		return 0;
	DUMP_WRITE(men->data, men->datasz, foffset);
	if (!alignfile(file, foffset))
		return 0;
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	return 1;
}
#undef DUMP_WRITE

#define DUMP_WRITE(addr, nr)	\
	if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
		goto end_coredump;
#define DUMP_SEEK(off)	\
	if (!dump_seek(file, (off))) \
		goto end_coredump;

1257
static void fill_elf_header(struct elfhdr *elf, int segs)
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{
	memcpy(elf->e_ident, ELFMAG, SELFMAG);
	elf->e_ident[EI_CLASS] = ELF_CLASS;
	elf->e_ident[EI_DATA] = ELF_DATA;
	elf->e_ident[EI_VERSION] = EV_CURRENT;
	elf->e_ident[EI_OSABI] = ELF_OSABI;
	memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);

	elf->e_type = ET_CORE;
	elf->e_machine = ELF_ARCH;
	elf->e_version = EV_CURRENT;
	elf->e_entry = 0;
	elf->e_phoff = sizeof(struct elfhdr);
	elf->e_shoff = 0;
	elf->e_flags = ELF_CORE_EFLAGS;
	elf->e_ehsize = sizeof(struct elfhdr);
	elf->e_phentsize = sizeof(struct elf_phdr);
	elf->e_phnum = segs;
	elf->e_shentsize = 0;
	elf->e_shnum = 0;
	elf->e_shstrndx = 0;
	return;
}

1282
static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
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{
	phdr->p_type = PT_NOTE;
	phdr->p_offset = offset;
	phdr->p_vaddr = 0;
	phdr->p_paddr = 0;
	phdr->p_filesz = sz;
	phdr->p_memsz = 0;
	phdr->p_flags = 0;
	phdr->p_align = 0;
	return;
}

static void fill_note(struct memelfnote *note, const char *name, int type, 
		unsigned int sz, void *data)
{
	note->name = name;
	note->type = type;
	note->datasz = sz;
	note->data = data;
	return;
}

/*
1306 1307
 * fill up all the fields in prstatus from the given task struct, except
 * registers which need to be filled up separately.
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 */
static void fill_prstatus(struct elf_prstatus *prstatus,
1310
		struct task_struct *p, long signr)
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{
	prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
	prstatus->pr_sigpend = p->pending.signal.sig[0];
	prstatus->pr_sighold = p->blocked.sig[0];
	prstatus->pr_pid = p->pid;
	prstatus->pr_ppid = p->parent->pid;
	prstatus->pr_pgrp = process_group(p);
1318
	prstatus->pr_sid = process_session(p);
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	if (thread_group_leader(p)) {
		/*
		 * This is the record for the group leader.  Add in the
		 * cumulative times of previous dead threads.  This total
		 * won't include the time of each live thread whose state
		 * is included in the core dump.  The final total reported
		 * to our parent process when it calls wait4 will include
		 * those sums as well as the little bit more time it takes
		 * this and each other thread to finish dying after the
		 * core dump synchronization phase.
		 */
		cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
				   &prstatus->pr_utime);
		cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
				   &prstatus->pr_stime);
	} else {
		cputime_to_timeval(p->utime, &prstatus->pr_utime);
		cputime_to_timeval(p->stime, &prstatus->pr_stime);
	}
	cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
	cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
}

static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
		       struct mm_struct *mm)
{
1345
	unsigned int i, len;
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	/* first copy the parameters from user space */
	memset(psinfo, 0, sizeof(struct elf_prpsinfo));

	len = mm->arg_end - mm->arg_start;
	if (len >= ELF_PRARGSZ)
		len = ELF_PRARGSZ-1;
	if (copy_from_user(&psinfo->pr_psargs,
		           (const char __user *)mm->arg_start, len))
		return -EFAULT;
	for(i = 0; i < len; i++)
		if (psinfo->pr_psargs[i] == 0)
			psinfo->pr_psargs[i] = ' ';
	psinfo->pr_psargs[len] = 0;

	psinfo->pr_pid = p->pid;
	psinfo->pr_ppid = p->parent->pid;
	psinfo->pr_pgrp = process_group(p);
1364
	psinfo->pr_sid = process_session(p);
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	i = p->state ? ffz(~p->state) + 1 : 0;
	psinfo->pr_state = i;
1368
	psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
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	psinfo->pr_zomb = psinfo->pr_sname == 'Z';
	psinfo->pr_nice = task_nice(p);
	psinfo->pr_flag = p->flags;
	SET_UID(psinfo->pr_uid, p->uid);
	SET_GID(psinfo->pr_gid, p->gid);
	strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
	
	return 0;
}

/* Here is the structure in which status of each thread is captured. */
struct elf_thread_status
{
	struct list_head list;
	struct elf_prstatus prstatus;	/* NT_PRSTATUS */
	elf_fpregset_t fpu;		/* NT_PRFPREG */
	struct task_struct *thread;
#ifdef ELF_CORE_COPY_XFPREGS
	elf_fpxregset_t xfpu;		/* NT_PRXFPREG */
#endif
	struct memelfnote notes[3];
	int num_notes;
};

/*
 * In order to add the specific thread information for the elf file format,
1395 1396
 * we need to keep a linked list of every threads pr_status and then create
 * a single section for them in the final core file.
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 */
static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
{
	int sz = 0;
	struct task_struct *p = t->thread;
	t->num_notes = 0;

	fill_prstatus(&t->prstatus, p, signr);
	elf_core_copy_task_regs(p, &t->prstatus.pr_reg);	
	
1407 1408
	fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
		  &(t->prstatus));
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	t->num_notes++;
	sz += notesize(&t->notes[0]);

1412 1413 1414 1415
	if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
								&t->fpu))) {
		fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
			  &(t->fpu));
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		t->num_notes++;
		sz += notesize(&t->notes[1]);
	}

#ifdef ELF_CORE_COPY_XFPREGS
	if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1422 1423
		fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
			  &t->xfpu);
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		t->num_notes++;
		sz += notesize(&t->notes[2]);
	}
#endif	
	return sz;
}

/*
 * Actual dumper
 *
 * This is a two-pass process; first we find the offsets of the bits,
 * and then they are actually written out.  If we run out of core limit
 * we just truncate.
 */
1438
static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
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{
#define	NUM_NOTES	6
	int has_dumped = 0;
	mm_segment_t fs;
	int segs;
	size_t size = 0;
	int i;
	struct vm_area_struct *vma;
	struct elfhdr *elf = NULL;
1448
	loff_t offset = 0, dataoff, foffset;
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	unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
	int numnote;
	struct memelfnote *notes = NULL;
	struct elf_prstatus *prstatus = NULL;	/* NT_PRSTATUS */
	struct elf_prpsinfo *psinfo = NULL;	/* NT_PRPSINFO */
 	struct task_struct *g, *p;
 	LIST_HEAD(thread_list);
 	struct list_head *t;
	elf_fpregset_t *fpu = NULL;
#ifdef ELF_CORE_COPY_XFPREGS
	elf_fpxregset_t *xfpu = NULL;
#endif
	int thread_status_size = 0;
	elf_addr_t *auxv;

	/*
	 * We no longer stop all VM operations.
	 * 
1467 1468 1469
	 * This is because those proceses that could possibly change map_count
	 * or the mmap / vma pages are now blocked in do_exit on current
	 * finishing this core dump.
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	 *
	 * Only ptrace can touch these memory addresses, but it doesn't change
1472
	 * the map_count or the pages allocated. So no possibility of crashing
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	 * exists while dumping the mm->vm_next areas to the core file.
	 */
  
	/* alloc memory for large data structures: too large to be on stack */
	elf = kmalloc(sizeof(*elf), GFP_KERNEL);
	if (!elf)
		goto cleanup;
	prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
	if (!prstatus)
		goto cleanup;
	psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
	if (!psinfo)
		goto cleanup;
	notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
	if (!notes)
		goto cleanup;
	fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
	if (!fpu)
		goto cleanup;
#ifdef ELF_CORE_COPY_XFPREGS
	xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
	if (!xfpu)
		goto cleanup;
#endif

	if (signr) {
		struct elf_thread_status *tmp;
1500
		rcu_read_lock();
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		do_each_thread(g,p)
			if (current->mm == p->mm && current != p) {
1503
				tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
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				if (!tmp) {
1505
					rcu_read_unlock();
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					goto cleanup;
				}
				tmp->thread = p;
				list_add(&tmp->list, &thread_list);
			}
		while_each_thread(g,p);
1512
		rcu_read_unlock();
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		list_for_each(t, &thread_list) {
			struct elf_thread_status *tmp;
			int sz;

			tmp = list_entry(t, struct elf_thread_status, list);
			sz = elf_dump_thread_status(signr, tmp);
			thread_status_size += sz;
		}
	}
	/* now collect the dump for the current */
	memset(prstatus, 0, sizeof(*prstatus));
	fill_prstatus(prstatus, current, signr);
	elf_core_copy_regs(&prstatus->pr_reg, regs);
	
	segs = current->mm->map_count;
#ifdef ELF_CORE_EXTRA_PHDRS
	segs += ELF_CORE_EXTRA_PHDRS;
#endif

	/* Set up header */
1533
	fill_elf_header(elf, segs + 1);	/* including notes section */
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	has_dumped = 1;
	current->flags |= PF_DUMPCORE;

	/*
	 * Set up the notes in similar form to SVR4 core dumps made
	 * with info from their /proc.
	 */

1543
	fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
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	fill_psinfo(psinfo, current->group_leader, current->mm);
1545
	fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
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1546
	
1547
	numnote = 2;
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1548

1549
	auxv = (elf_addr_t *)current->mm->saved_auxv;
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1550 1551 1552 1553 1554 1555

	i = 0;
	do
		i += 2;
	while (auxv[i - 2] != AT_NULL);
	fill_note(&notes[numnote++], "CORE", NT_AUXV,
1556
		  i * sizeof(elf_addr_t), auxv);
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  	/* Try to dump the FPU. */
1559 1560
	if ((prstatus->pr_fpvalid =
	     elf_core_copy_task_fpregs(current, regs, fpu)))
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		fill_note(notes + numnote++,
			  "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
#ifdef ELF_CORE_COPY_XFPREGS
	if (elf_core_copy_task_xfpregs(current, xfpu))
		fill_note(notes + numnote++,
			  "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
#endif	
  
	fs = get_fs();
	set_fs(KERNEL_DS);

	DUMP_WRITE(elf, sizeof(*elf));
	offset += sizeof(*elf);				/* Elf header */
1574 1575
	offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
	foffset = offset;
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	/* Write notes phdr entry */
	{
		struct elf_phdr phdr;
		int sz = 0;

		for (i = 0; i < numnote; i++)
			sz += notesize(notes + i);
		
		sz += thread_status_size;

1587 1588 1589 1590
#ifdef ELF_CORE_WRITE_EXTRA_NOTES
		sz += ELF_CORE_EXTRA_NOTES_SIZE;
#endif

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		fill_elf_note_phdr(&phdr, sz, offset);
		offset += sz;
		DUMP_WRITE(&phdr, sizeof(phdr));
	}

	dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);

	/* Write program headers for segments dump */
	for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
		struct elf_phdr phdr;
		size_t sz;

		sz = vma->vm_end - vma->vm_start;

		phdr.p_type = PT_LOAD;
		phdr.p_offset = offset;
		phdr.p_vaddr = vma->vm_start;
		phdr.p_paddr = 0;
		phdr.p_filesz = maydump(vma) ? sz : 0;
		phdr.p_memsz = sz;
		offset += phdr.p_filesz;
		phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1613 1614 1615 1616
		if (vma->vm_flags & VM_WRITE)
			phdr.p_flags |= PF_W;
		if (vma->vm_flags & VM_EXEC)
			phdr.p_flags |= PF_X;
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		phdr.p_align = ELF_EXEC_PAGESIZE;

		DUMP_WRITE(&phdr, sizeof(phdr));
	}

#ifdef ELF_CORE_WRITE_EXTRA_PHDRS
	ELF_CORE_WRITE_EXTRA_PHDRS;
#endif

 	/* write out the notes section */
	for (i = 0; i < numnote; i++)
1628
		if (!writenote(notes + i, file, &foffset))
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			goto end_coredump;

1631 1632 1633 1634
#ifdef ELF_CORE_WRITE_EXTRA_NOTES
	ELF_CORE_WRITE_EXTRA_NOTES;
#endif

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	/* write out the thread status notes section */
	list_for_each(t, &thread_list) {
1637 1638 1639
		struct elf_thread_status *tmp =
				list_entry(t, struct elf_thread_status, list);

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		for (i = 0; i < tmp->num_notes; i++)
1641
			if (!writenote(&tmp->notes[i], file, &foffset))
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				goto end_coredump;
	}
1644 1645 1646

	/* Align to page */
	DUMP_SEEK(dataoff - foffset);
L
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	for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
		unsigned long addr;

		if (!maydump(vma))
			continue;

		for (addr = vma->vm_start;
		     addr < vma->vm_end;
		     addr += PAGE_SIZE) {
1657
			struct page *page;
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			struct vm_area_struct *vma;

			if (get_user_pages(current, current->mm, addr, 1, 0, 1,
						&page, &vma) <= 0) {
1662
				DUMP_SEEK(PAGE_SIZE);
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			} else {
				if (page == ZERO_PAGE(addr)) {
1665
					DUMP_SEEK(PAGE_SIZE);
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				} else {
					void *kaddr;
1668 1669
					flush_cache_page(vma, addr,
							 page_to_pfn(page));
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					kaddr = kmap(page);
					if ((size += PAGE_SIZE) > limit ||
					    !dump_write(file, kaddr,
					    PAGE_SIZE)) {
						kunmap(page);
						page_cache_release(page);
						goto end_coredump;
					}
					kunmap(page);
				}
				page_cache_release(page);
			}
		}
	}

#ifdef ELF_CORE_WRITE_EXTRA_DATA
	ELF_CORE_WRITE_EXTRA_DATA;
#endif

end_coredump:
	set_fs(fs);

cleanup:
1693
	while (!list_empty(&thread_list)) {
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		struct list_head *tmp = thread_list.next;
		list_del(tmp);
		kfree(list_entry(tmp, struct elf_thread_status, list));
	}

	kfree(elf);
	kfree(prstatus);
	kfree(psinfo);
	kfree(notes);
	kfree(fpu);
#ifdef ELF_CORE_COPY_XFPREGS
	kfree(xfpu);
#endif
	return has_dumped;
#undef NUM_NOTES
}

#endif		/* USE_ELF_CORE_DUMP */

static int __init init_elf_binfmt(void)
{
	return register_binfmt(&elf_format);
}

static void __exit exit_elf_binfmt(void)
{
	/* Remove the COFF and ELF loaders. */
	unregister_binfmt(&elf_format);
}

core_initcall(init_elf_binfmt);
module_exit(exit_elf_binfmt);
MODULE_LICENSE("GPL");