binfmt_elf.c 53.9 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/mm.h>
#include <linux/mman.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/binfmts.h>
#include <linux/string.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/personality.h>
#include <linux/elfcore.h>
#include <linux/init.h>
#include <linux/highuid.h>
#include <linux/compiler.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/security.h>
#include <linux/random.h>
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#include <linux/elf.h>
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#include <linux/utsname.h>
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#include <linux/coredump.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, unsigned long);
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/*
 * If we don't support core dumping, then supply a NULL so we
 * don't even try.
 */
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#ifdef CONFIG_ELF_CORE
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static int elf_core_dump(struct coredump_params *cprm);
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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,
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		.min_coredump	= ELF_EXEC_PAGESIZE,
		.hasvdso	= 1
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};

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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;
}

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/* Let's use some macros to make this stack manipulation a little clearer */
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#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

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#ifndef ELF_BASE_PLATFORM
/*
 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 * will be copied to the user stack in the same manner as AT_PLATFORM.
 */
#define ELF_BASE_PLATFORM NULL
#endif

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static int
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create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
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		unsigned long load_addr, unsigned long interp_load_addr)
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{
	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;
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	elf_addr_t __user *u_base_platform;
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	elf_addr_t __user *u_rand_bytes;
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	const char *k_platform = ELF_PLATFORM;
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	const char *k_base_platform = ELF_BASE_PLATFORM;
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	unsigned char k_rand_bytes[16];
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	int items;
	elf_addr_t *elf_info;
	int ei_index = 0;
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	const struct cred *cred = current_cred();
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	struct vm_area_struct *vma;
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	/*
	 * 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.
	 */

	p = arch_align_stack(p);

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	/*
	 * 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;

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

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	/*
	 * If this architecture has a "base" platform capability
	 * string, copy it to userspace.
	 */
	u_base_platform = NULL;
	if (k_base_platform) {
		size_t len = strlen(k_base_platform) + 1;

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

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	/*
	 * Generate 16 random bytes for userspace PRNG seeding.
	 */
	get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
	u_rand_bytes = (elf_addr_t __user *)
		       STACK_ALLOC(p, sizeof(k_rand_bytes));
	if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
		return -EFAULT;

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	/* Create the ELF interpreter info */
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	elf_info = (elf_addr_t *)current->mm->saved_auxv;
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	/* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
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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.
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	 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
	 * ARCH_DLINFO changes
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	 */
	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, cred->uid);
	NEW_AUX_ENT(AT_EUID, cred->euid);
	NEW_AUX_ENT(AT_GID, cred->gid);
	NEW_AUX_ENT(AT_EGID, cred->egid);
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 	NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
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	NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
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	NEW_AUX_ENT(AT_EXECFN, bprm->exec);
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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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	}
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	if (k_base_platform) {
		NEW_AUX_ENT(AT_BASE_PLATFORM,
			    (elf_addr_t)(unsigned long)u_base_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);

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	items = (argc + 1) + (envc + 1) + 1;
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	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

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	/*
	 * Grow the stack manually; some architectures have a limit on how
	 * far ahead a user-space access may be in order to grow the stack.
	 */
	vma = find_extend_vma(current->mm, bprm->p);
	if (!vma)
		return -EFAULT;

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	/* Now, let's put argc (and argv, envp if appropriate) on the stack */
	if (__put_user(argc, sp++))
		return -EFAULT;
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	argv = sp;
	envp = argv + argc + 1;
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	/* 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, MAX_ARG_STRLEN);
		if (!len || len > MAX_ARG_STRLEN)
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			return -EINVAL;
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		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, MAX_ARG_STRLEN);
		if (!len || len > MAX_ARG_STRLEN)
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			return -EINVAL;
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		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,
		unsigned long total_size)
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{
	unsigned long map_addr;
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	unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
	unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
	addr = ELF_PAGESTART(addr);
	size = ELF_PAGEALIGN(size);
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	/* mmap() will return -EINVAL if given a zero size, but a
	 * segment with zero filesize is perfectly valid */
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	if (!size)
		return addr;

	down_write(&current->mm->mmap_sem);
	/*
	* total_size is the size of the ELF (interpreter) image.
	* The _first_ mmap needs to know the full size, otherwise
	* randomization might put this image into an overlapping
	* position with the ELF binary image. (since size < total_size)
	* So we first map the 'big' image - and unmap the remainder at
	* the end. (which unmap is needed for ELF images with holes.)
	*/
	if (total_size) {
		total_size = ELF_PAGEALIGN(total_size);
		map_addr = do_mmap(filep, addr, total_size, prot, type, off);
		if (!BAD_ADDR(map_addr))
			do_munmap(current->mm, map_addr+size, total_size-size);
	} else
		map_addr = do_mmap(filep, addr, size, prot, type, off);

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	up_write(&current->mm->mmap_sem);
	return(map_addr);
}

#endif /* !elf_map */

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static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
{
	int i, first_idx = -1, last_idx = -1;

	for (i = 0; i < nr; i++) {
		if (cmds[i].p_type == PT_LOAD) {
			last_idx = i;
			if (first_idx == -1)
				first_idx = i;
		}
	}
	if (first_idx == -1)
		return 0;

	return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
				ELF_PAGESTART(cmds[first_idx].p_vaddr);
}


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/* 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,
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		struct file *interpreter, unsigned long *interp_map_addr,
		unsigned long no_base)
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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;
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	unsigned long total_size;
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	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;
	}

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	total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
	if (!total_size) {
		error = -EINVAL;
		goto out_close;
	}

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	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;
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			else if (no_base && interp_elf_ex->e_type == ET_DYN)
				load_addr = -vaddr;
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			map_addr = elf_map(interpreter, load_addr + vaddr,
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					eppnt, elf_prot, elf_type, total_size);
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			total_size = 0;
			if (!*interp_map_addr)
				*interp_map_addr = map_addr;
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			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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	}

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	if (last_bss > elf_bss) {
		/*
		 * 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 */
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		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;
	}

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	error = load_addr;
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out_close:
	kfree(elf_phdata);
out:
	return error;
}

/*
 * 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_ELF 2

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#ifndef STACK_RND_MASK
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#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12))	/* 8MB of VA */
546
#endif
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static unsigned long randomize_stack_top(unsigned long stack_top)
{
	unsigned int random_variable = 0;

552 553
	if ((current->flags & PF_RANDOMIZE) &&
		!(current->personality & ADDR_NO_RANDOMIZE)) {
554 555 556
		random_variable = get_random_int() & STACK_RND_MASK;
		random_variable <<= PAGE_SHIFT;
	}
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#ifdef CONFIG_STACK_GROWSUP
558
	return PAGE_ALIGN(stack_top) + random_variable;
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#else
560
	return PAGE_ALIGN(stack_top) - random_variable;
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#endif
}

564
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 long error;
571
	struct elf_phdr *elf_ppnt, *elf_phdata;
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	unsigned long elf_bss, elf_brk;
	int retval, i;
	unsigned int size;
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	unsigned long elf_entry;
	unsigned long interp_load_addr = 0;
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	unsigned long start_code, end_code, start_data, end_data;
	unsigned long reloc_func_desc = 0;
579
	int executable_stack = EXSTACK_DEFAULT;
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	unsigned long def_flags = 0;
	struct {
		struct elfhdr elf_ex;
		struct elfhdr interp_elf_ex;
	} *loc;

	loc = kmalloc(sizeof(*loc), GFP_KERNEL);
	if (!loc) {
		retval = -ENOMEM;
		goto out_ret;
	}
	
	/* Get the exec-header */
593
	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;
615
	elf_phdata = kmalloc(size, GFP_KERNEL);
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	if (!elf_phdata)
		goto out;

619 620
	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;
	}

	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)
645
				goto out_free_ph;
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			retval = -ENOMEM;
648
			elf_interpreter = kmalloc(elf_ppnt->p_filesz,
649
						  GFP_KERNEL);
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			if (!elf_interpreter)
651
				goto out_free_ph;
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			retval = kernel_read(bprm->file, elf_ppnt->p_offset,
654 655
					     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;

			interpreter = open_exec(elf_interpreter);
			retval = PTR_ERR(interpreter);
			if (IS_ERR(interpreter))
				goto out_free_interp;
670 671 672 673 674 675 676 677 678

			/*
			 * If the binary is not readable then enforce
			 * mm->dumpable = 0 regardless of the interpreter's
			 * permissions.
			 */
			if (file_permission(interpreter, MAY_READ) < 0)
				bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;

679 680
			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 */
688
			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) {
		retval = -ELIBBAD;
707 708
		/* Not an ELF interpreter */
		if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
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			goto out_free_dentry;
		/* Verify the interpreter has a valid arch */
711
		if (!elf_check_arch(&loc->interp_elf_ex))
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			goto out_free_dentry;
	}

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

	/* OK, This is the point of no return */
	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.  */
726
	SET_PERSONALITY(loc->elf_ex);
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	if (elf_read_implies_exec(loc->elf_ex, executable_stack))
		current->personality |= READ_IMPLIES_EXEC;

730
	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
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		current->flags |= PF_RANDOMIZE;
732 733

	setup_new_exec(bprm);
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	/* 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;
738
	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;

748
	/* Now we do a little grungy work by mmapping the ELF image into
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Jiri Kosina 已提交
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	   the correct location in memory. */
750 751
	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
779
					 * file specifies odd protections. So
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					 * we don't check the return value
					 */
				}
			}
		}

786 787 788 789 790 791
		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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793
		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) {
799 800 801 802
			/* 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.  */
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#ifdef CONFIG_X86
			load_bias = 0;
#else
806
			load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
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#endif
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		}

810
		error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
811
				elf_prot, elf_flags, 0);
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		if (BAD_ADDR(error)) {
			send_sig(SIGKILL, current, 0);
814 815
			retval = IS_ERR((void *)error) ?
				PTR_ERR((void*)error) : -EINVAL;
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			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;
830 831 832 833
		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.
		 */
840
		if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
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		    elf_ppnt->p_memsz > TASK_SIZE ||
		    TASK_SIZE - elf_ppnt->p_memsz < k) {
843
			/* set_brk can never work. Avoid overflows. */
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			send_sig(SIGKILL, current, 0);
845
			retval = -EINVAL;
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			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;
	}
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akpm@osdl.org 已提交
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	if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
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		send_sig(SIGSEGV, current, 0);
		retval = -EFAULT; /* Nobody gets to see this, but.. */
		goto out_free_dentry;
	}

	if (elf_interpreter) {
887 888 889 890 891 892 893 894 895 896 897 898 899
		unsigned long uninitialized_var(interp_map_addr);

		elf_entry = load_elf_interp(&loc->interp_elf_ex,
					    interpreter,
					    &interp_map_addr,
					    load_bias);
		if (!IS_ERR((void *)elf_entry)) {
			/*
			 * load_elf_interp() returns relocation
			 * adjustment
			 */
			interp_load_addr = elf_entry;
			elf_entry += loc->interp_elf_ex.e_entry;
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		}
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		if (BAD_ADDR(elf_entry)) {
			force_sig(SIGSEGV, current);
903 904
			retval = IS_ERR((void *)elf_entry) ?
					(int)elf_entry : -EINVAL;
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			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;
914
		if (BAD_ADDR(elf_entry)) {
915 916
			force_sig(SIGSEGV, current);
			retval = -EINVAL;
917 918
			goto out_free_dentry;
		}
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	}

	kfree(elf_phdata);

	set_binfmt(&elf_format);

925
#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
926
	retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
927 928
	if (retval < 0) {
		send_sig(SIGKILL, current, 0);
929
		goto out;
930 931 932
	}
#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */

933
	install_exec_creds(bprm);
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	current->flags &= ~PF_FORKNOEXEC;
935
	retval = create_elf_tables(bprm, &loc->elf_ex,
936
			  load_addr, interp_load_addr);
937 938 939 940
	if (retval < 0) {
		send_sig(SIGKILL, current, 0);
		goto out;
	}
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	/* N.B. passed_fileno might not be initialized? */
	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;

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#ifdef arch_randomize_brk
949
	if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1))
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		current->mm->brk = current->mm->start_brk =
			arch_randomize_brk(current->mm);
#endif

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	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
958
		   emulate the SVr4 behavior. Sigh. */
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		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);
	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
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	kfree(elf_interpreter);
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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;
1009
	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 ||
1018
	    !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
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		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;
	}

1066 1067
	len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
			    ELF_MIN_ALIGN - 1);
L
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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;
}

C
Christoph Hellwig 已提交
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#ifdef CONFIG_ELF_CORE
L
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/*
 * ELF core dumper
 *
 * Modelled on fs/exec.c:aout_core_dump()
 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
 */

/*
R
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 * Decide what to dump of a segment, part, all or none.
L
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 */
R
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static unsigned long vma_dump_size(struct vm_area_struct *vma,
				   unsigned long mm_flags)
L
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{
1096 1097
#define FILTER(type)	(mm_flags & (1UL << MMF_DUMP_##type))

R
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	/* The vma can be set up to tell us the answer directly.  */
	if (vma->vm_flags & VM_ALWAYSDUMP)
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		goto whole;
R
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1102 1103 1104 1105 1106 1107 1108 1109
	/* Hugetlb memory check */
	if (vma->vm_flags & VM_HUGETLB) {
		if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
			goto whole;
		if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
			goto whole;
	}

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

1114 1115
	/* By default, dump shared memory if mapped from an anonymous file. */
	if (vma->vm_flags & VM_SHARED) {
R
Roland McGrath 已提交
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		if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
		    FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
			goto whole;
		return 0;
1120
	}
L
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R
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	/* Dump segments that have been written to.  */
	if (vma->anon_vma && FILTER(ANON_PRIVATE))
		goto whole;
	if (vma->vm_file == NULL)
		return 0;
L
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R
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	if (FILTER(MAPPED_PRIVATE))
		goto whole;

	/*
	 * If this looks like the beginning of a DSO or executable mapping,
	 * check for an ELF header.  If we find one, dump the first page to
	 * aid in determining what was mapped here.
	 */
R
Roland McGrath 已提交
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	if (FILTER(ELF_HEADERS) &&
	    vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
R
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		u32 __user *header = (u32 __user *) vma->vm_start;
		u32 word;
R
Roland McGrath 已提交
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		mm_segment_t fs = get_fs();
R
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		/*
		 * Doing it this way gets the constant folded by GCC.
		 */
		union {
			u32 cmp;
			char elfmag[SELFMAG];
		} magic;
		BUILD_BUG_ON(SELFMAG != sizeof word);
		magic.elfmag[EI_MAG0] = ELFMAG0;
		magic.elfmag[EI_MAG1] = ELFMAG1;
		magic.elfmag[EI_MAG2] = ELFMAG2;
		magic.elfmag[EI_MAG3] = ELFMAG3;
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		/*
		 * Switch to the user "segment" for get_user(),
		 * then put back what elf_core_dump() had in place.
		 */
		set_fs(USER_DS);
		if (unlikely(get_user(word, header)))
			word = 0;
		set_fs(fs);
		if (word == magic.cmp)
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			return PAGE_SIZE;
	}

#undef	FILTER

	return 0;

whole:
	return vma->vm_end - vma->vm_start;
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}

/* 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;
}

1193 1194
#define DUMP_WRITE(addr, nr, foffset)	\
	do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
L
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1196
static int alignfile(struct file *file, loff_t *foffset)
L
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{
1198
	static const char buf[4] = { 0, };
1199 1200 1201
	DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
	return 1;
}
L
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1203 1204 1205 1206
static int writenote(struct memelfnote *men, struct file *file,
			loff_t *foffset)
{
	struct elf_note en;
L
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	en.n_namesz = strlen(men->name) + 1;
	en.n_descsz = men->datasz;
	en.n_type = men->type;

1211 1212 1213 1214 1215 1216 1217
	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;
L
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	return 1;
}
#undef DUMP_WRITE

R
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static void fill_elf_header(struct elfhdr *elf, int segs,
			    u16 machine, u32 flags, u8 osabi)
L
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{
1226 1227
	memset(elf, 0, sizeof(*elf));

L
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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;

	elf->e_type = ET_CORE;
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	elf->e_machine = machine;
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	elf->e_version = EV_CURRENT;
	elf->e_phoff = sizeof(struct elfhdr);
R
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	elf->e_flags = flags;
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	elf->e_ehsize = sizeof(struct elfhdr);
	elf->e_phentsize = sizeof(struct elf_phdr);
	elf->e_phnum = segs;
1242

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	return;
}

1246
static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
L
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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;
}

/*
1270 1271
 * fill up all the fields in prstatus from the given task struct, except
 * registers which need to be filled up separately.
L
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 */
static void fill_prstatus(struct elf_prstatus *prstatus,
1274
		struct task_struct *p, long signr)
L
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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];
1279 1280 1281
	rcu_read_lock();
	prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
	rcu_read_unlock();
1282 1283 1284
	prstatus->pr_pid = task_pid_vnr(p);
	prstatus->pr_pgrp = task_pgrp_vnr(p);
	prstatus->pr_sid = task_session_vnr(p);
L
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	if (thread_group_leader(p)) {
1286 1287
		struct task_cputime cputime;

L
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		/*
1289 1290
		 * This is the record for the group leader.  It shows the
		 * group-wide total, not its individual thread total.
L
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		 */
1292 1293 1294
		thread_group_cputime(p, &cputime);
		cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
		cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
L
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	} 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)
{
1306
	const struct cred *cred;
1307
	unsigned int i, len;
L
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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;

1323 1324 1325
	rcu_read_lock();
	psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
	rcu_read_unlock();
1326 1327 1328
	psinfo->pr_pid = task_pid_vnr(p);
	psinfo->pr_pgrp = task_pgrp_vnr(p);
	psinfo->pr_sid = task_session_vnr(p);
L
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	i = p->state ? ffz(~p->state) + 1 : 0;
	psinfo->pr_state = i;
1332
	psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
L
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	psinfo->pr_zomb = psinfo->pr_sname == 'Z';
	psinfo->pr_nice = task_nice(p);
	psinfo->pr_flag = p->flags;
1336 1337 1338 1339 1340
	rcu_read_lock();
	cred = __task_cred(p);
	SET_UID(psinfo->pr_uid, cred->uid);
	SET_GID(psinfo->pr_gid, cred->gid);
	rcu_read_unlock();
L
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	strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
	
	return 0;
}

R
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static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
{
	elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
	int i = 0;
	do
		i += 2;
	while (auxv[i - 2] != AT_NULL);
	fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
}

1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373
#ifdef CORE_DUMP_USE_REGSET
#include <linux/regset.h>

struct elf_thread_core_info {
	struct elf_thread_core_info *next;
	struct task_struct *task;
	struct elf_prstatus prstatus;
	struct memelfnote notes[0];
};

struct elf_note_info {
	struct elf_thread_core_info *thread;
	struct memelfnote psinfo;
	struct memelfnote auxv;
	size_t size;
	int thread_notes;
};

1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385
/*
 * When a regset has a writeback hook, we call it on each thread before
 * dumping user memory.  On register window machines, this makes sure the
 * user memory backing the register data is up to date before we read it.
 */
static void do_thread_regset_writeback(struct task_struct *task,
				       const struct user_regset *regset)
{
	if (regset->writeback)
		regset->writeback(task, regset, 1);
}

1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406
static int fill_thread_core_info(struct elf_thread_core_info *t,
				 const struct user_regset_view *view,
				 long signr, size_t *total)
{
	unsigned int i;

	/*
	 * NT_PRSTATUS is the one special case, because the regset data
	 * goes into the pr_reg field inside the note contents, rather
	 * than being the whole note contents.  We fill the reset in here.
	 * We assume that regset 0 is NT_PRSTATUS.
	 */
	fill_prstatus(&t->prstatus, t->task, signr);
	(void) view->regsets[0].get(t->task, &view->regsets[0],
				    0, sizeof(t->prstatus.pr_reg),
				    &t->prstatus.pr_reg, NULL);

	fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
		  sizeof(t->prstatus), &t->prstatus);
	*total += notesize(&t->notes[0]);

1407 1408
	do_thread_regset_writeback(t->task, &view->regsets[0]);

1409 1410 1411 1412 1413 1414 1415
	/*
	 * Each other regset might generate a note too.  For each regset
	 * that has no core_note_type or is inactive, we leave t->notes[i]
	 * all zero and we'll know to skip writing it later.
	 */
	for (i = 1; i < view->n; ++i) {
		const struct user_regset *regset = &view->regsets[i];
1416
		do_thread_regset_writeback(t->task, regset);
1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453
		if (regset->core_note_type &&
		    (!regset->active || regset->active(t->task, regset))) {
			int ret;
			size_t size = regset->n * regset->size;
			void *data = kmalloc(size, GFP_KERNEL);
			if (unlikely(!data))
				return 0;
			ret = regset->get(t->task, regset,
					  0, size, data, NULL);
			if (unlikely(ret))
				kfree(data);
			else {
				if (regset->core_note_type != NT_PRFPREG)
					fill_note(&t->notes[i], "LINUX",
						  regset->core_note_type,
						  size, data);
				else {
					t->prstatus.pr_fpvalid = 1;
					fill_note(&t->notes[i], "CORE",
						  NT_PRFPREG, size, data);
				}
				*total += notesize(&t->notes[i]);
			}
		}
	}

	return 1;
}

static int fill_note_info(struct elfhdr *elf, int phdrs,
			  struct elf_note_info *info,
			  long signr, struct pt_regs *regs)
{
	struct task_struct *dump_task = current;
	const struct user_regset_view *view = task_user_regset_view(dump_task);
	struct elf_thread_core_info *t;
	struct elf_prpsinfo *psinfo;
1454
	struct core_thread *ct;
1455 1456 1457 1458 1459 1460 1461 1462 1463
	unsigned int i;

	info->size = 0;
	info->thread = NULL;

	psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
	if (psinfo == NULL)
		return 0;

A
Amerigo Wang 已提交
1464 1465
	fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);

1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492
	/*
	 * Figure out how many notes we're going to need for each thread.
	 */
	info->thread_notes = 0;
	for (i = 0; i < view->n; ++i)
		if (view->regsets[i].core_note_type != 0)
			++info->thread_notes;

	/*
	 * Sanity check.  We rely on regset 0 being in NT_PRSTATUS,
	 * since it is our one special case.
	 */
	if (unlikely(info->thread_notes == 0) ||
	    unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
		WARN_ON(1);
		return 0;
	}

	/*
	 * Initialize the ELF file header.
	 */
	fill_elf_header(elf, phdrs,
			view->e_machine, view->e_flags, view->ei_osabi);

	/*
	 * Allocate a structure for each thread.
	 */
1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510
	for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
		t = kzalloc(offsetof(struct elf_thread_core_info,
				     notes[info->thread_notes]),
			    GFP_KERNEL);
		if (unlikely(!t))
			return 0;

		t->task = ct->task;
		if (ct->task == dump_task || !info->thread) {
			t->next = info->thread;
			info->thread = t;
		} else {
			/*
			 * Make sure to keep the original task at
			 * the head of the list.
			 */
			t->next = info->thread->next;
			info->thread->next = t;
1511
		}
1512
	}
1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587

	/*
	 * Now fill in each thread's information.
	 */
	for (t = info->thread; t != NULL; t = t->next)
		if (!fill_thread_core_info(t, view, signr, &info->size))
			return 0;

	/*
	 * Fill in the two process-wide notes.
	 */
	fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
	info->size += notesize(&info->psinfo);

	fill_auxv_note(&info->auxv, current->mm);
	info->size += notesize(&info->auxv);

	return 1;
}

static size_t get_note_info_size(struct elf_note_info *info)
{
	return info->size;
}

/*
 * Write all the notes for each thread.  When writing the first thread, the
 * process-wide notes are interleaved after the first thread-specific note.
 */
static int write_note_info(struct elf_note_info *info,
			   struct file *file, loff_t *foffset)
{
	bool first = 1;
	struct elf_thread_core_info *t = info->thread;

	do {
		int i;

		if (!writenote(&t->notes[0], file, foffset))
			return 0;

		if (first && !writenote(&info->psinfo, file, foffset))
			return 0;
		if (first && !writenote(&info->auxv, file, foffset))
			return 0;

		for (i = 1; i < info->thread_notes; ++i)
			if (t->notes[i].data &&
			    !writenote(&t->notes[i], file, foffset))
				return 0;

		first = 0;
		t = t->next;
	} while (t);

	return 1;
}

static void free_note_info(struct elf_note_info *info)
{
	struct elf_thread_core_info *threads = info->thread;
	while (threads) {
		unsigned int i;
		struct elf_thread_core_info *t = threads;
		threads = t->next;
		WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
		for (i = 1; i < info->thread_notes; ++i)
			kfree(t->notes[i].data);
		kfree(t);
	}
	kfree(info->psinfo.data);
}

#else

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/* 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
1596
	elf_fpxregset_t xfpu;		/* ELF_CORE_XFPREG_TYPE */
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#endif
	struct memelfnote notes[3];
	int num_notes;
};

/*
 * In order to add the specific thread information for the elf file format,
1604 1605
 * 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);	
	
1616 1617
	fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
		  &(t->prstatus));
L
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1618 1619 1620
	t->num_notes++;
	sz += notesize(&t->notes[0]);

1621 1622 1623 1624
	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));
L
Linus Torvalds 已提交
1625 1626 1627 1628 1629 1630
		t->num_notes++;
		sz += notesize(&t->notes[1]);
	}

#ifdef ELF_CORE_COPY_XFPREGS
	if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1631 1632
		fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
			  sizeof(t->xfpu), &t->xfpu);
L
Linus Torvalds 已提交
1633 1634 1635 1636 1637 1638 1639
		t->num_notes++;
		sz += notesize(&t->notes[2]);
	}
#endif	
	return sz;
}

R
Roland McGrath 已提交
1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652
struct elf_note_info {
	struct memelfnote *notes;
	struct elf_prstatus *prstatus;	/* NT_PRSTATUS */
	struct elf_prpsinfo *psinfo;	/* NT_PRPSINFO */
	struct list_head thread_list;
	elf_fpregset_t *fpu;
#ifdef ELF_CORE_COPY_XFPREGS
	elf_fpxregset_t *xfpu;
#endif
	int thread_status_size;
	int numnote;
};

A
Amerigo Wang 已提交
1653
static int elf_note_info_init(struct elf_note_info *info)
R
Roland McGrath 已提交
1654
{
A
Amerigo Wang 已提交
1655
	memset(info, 0, sizeof(*info));
R
Roland McGrath 已提交
1656 1657
	INIT_LIST_HEAD(&info->thread_list);

A
Amerigo Wang 已提交
1658 1659
	/* Allocate space for six ELF notes */
	info->notes = kmalloc(6 * sizeof(struct memelfnote), GFP_KERNEL);
R
Roland McGrath 已提交
1660 1661 1662 1663
	if (!info->notes)
		return 0;
	info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
	if (!info->psinfo)
A
Amerigo Wang 已提交
1664
		goto notes_free;
R
Roland McGrath 已提交
1665 1666
	info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
	if (!info->prstatus)
A
Amerigo Wang 已提交
1667
		goto psinfo_free;
R
Roland McGrath 已提交
1668 1669
	info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
	if (!info->fpu)
A
Amerigo Wang 已提交
1670
		goto prstatus_free;
R
Roland McGrath 已提交
1671 1672 1673
#ifdef ELF_CORE_COPY_XFPREGS
	info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
	if (!info->xfpu)
A
Amerigo Wang 已提交
1674
		goto fpu_free;
R
Roland McGrath 已提交
1675
#endif
A
Amerigo Wang 已提交
1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697
	return 1;
#ifdef ELF_CORE_COPY_XFPREGS
 fpu_free:
	kfree(info->fpu);
#endif
 prstatus_free:
	kfree(info->prstatus);
 psinfo_free:
	kfree(info->psinfo);
 notes_free:
	kfree(info->notes);
	return 0;
}

static int fill_note_info(struct elfhdr *elf, int phdrs,
			  struct elf_note_info *info,
			  long signr, struct pt_regs *regs)
{
	struct list_head *t;

	if (!elf_note_info_init(info))
		return 0;
R
Roland McGrath 已提交
1698 1699

	if (signr) {
1700
		struct core_thread *ct;
1701
		struct elf_thread_status *ets;
1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712

		for (ct = current->mm->core_state->dumper.next;
						ct; ct = ct->next) {
			ets = kzalloc(sizeof(*ets), GFP_KERNEL);
			if (!ets)
				return 0;

			ets->thread = ct->task;
			list_add(&ets->list, &info->thread_list);
		}

R
Roland McGrath 已提交
1713 1714 1715
		list_for_each(t, &info->thread_list) {
			int sz;

1716 1717
			ets = list_entry(t, struct elf_thread_status, list);
			sz = elf_dump_thread_status(signr, ets);
R
Roland McGrath 已提交
1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812
			info->thread_status_size += sz;
		}
	}
	/* now collect the dump for the current */
	memset(info->prstatus, 0, sizeof(*info->prstatus));
	fill_prstatus(info->prstatus, current, signr);
	elf_core_copy_regs(&info->prstatus->pr_reg, regs);

	/* Set up header */
	fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);

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

	fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
		  sizeof(*info->prstatus), info->prstatus);
	fill_psinfo(info->psinfo, current->group_leader, current->mm);
	fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
		  sizeof(*info->psinfo), info->psinfo);

	info->numnote = 2;

	fill_auxv_note(&info->notes[info->numnote++], current->mm);

	/* Try to dump the FPU. */
	info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
							       info->fpu);
	if (info->prstatus->pr_fpvalid)
		fill_note(info->notes + info->numnote++,
			  "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
#ifdef ELF_CORE_COPY_XFPREGS
	if (elf_core_copy_task_xfpregs(current, info->xfpu))
		fill_note(info->notes + info->numnote++,
			  "LINUX", ELF_CORE_XFPREG_TYPE,
			  sizeof(*info->xfpu), info->xfpu);
#endif

	return 1;
}

static size_t get_note_info_size(struct elf_note_info *info)
{
	int sz = 0;
	int i;

	for (i = 0; i < info->numnote; i++)
		sz += notesize(info->notes + i);

	sz += info->thread_status_size;

	return sz;
}

static int write_note_info(struct elf_note_info *info,
			   struct file *file, loff_t *foffset)
{
	int i;
	struct list_head *t;

	for (i = 0; i < info->numnote; i++)
		if (!writenote(info->notes + i, file, foffset))
			return 0;

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

		for (i = 0; i < tmp->num_notes; i++)
			if (!writenote(&tmp->notes[i], file, foffset))
				return 0;
	}

	return 1;
}

static void free_note_info(struct elf_note_info *info)
{
	while (!list_empty(&info->thread_list)) {
		struct list_head *tmp = info->thread_list.next;
		list_del(tmp);
		kfree(list_entry(tmp, struct elf_thread_status, list));
	}

	kfree(info->prstatus);
	kfree(info->psinfo);
	kfree(info->notes);
	kfree(info->fpu);
#ifdef ELF_CORE_COPY_XFPREGS
	kfree(info->xfpu);
#endif
}

1813 1814
#endif

1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840
static struct vm_area_struct *first_vma(struct task_struct *tsk,
					struct vm_area_struct *gate_vma)
{
	struct vm_area_struct *ret = tsk->mm->mmap;

	if (ret)
		return ret;
	return gate_vma;
}
/*
 * Helper function for iterating across a vma list.  It ensures that the caller
 * will visit `gate_vma' prior to terminating the search.
 */
static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
					struct vm_area_struct *gate_vma)
{
	struct vm_area_struct *ret;

	ret = this_vma->vm_next;
	if (ret)
		return ret;
	if (this_vma == gate_vma)
		return NULL;
	return gate_vma;
}

1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868
static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
			     elf_addr_t e_shoff, int segs)
{
	elf->e_shoff = e_shoff;
	elf->e_shentsize = sizeof(*shdr4extnum);
	elf->e_shnum = 1;
	elf->e_shstrndx = SHN_UNDEF;

	memset(shdr4extnum, 0, sizeof(*shdr4extnum));

	shdr4extnum->sh_type = SHT_NULL;
	shdr4extnum->sh_size = elf->e_shnum;
	shdr4extnum->sh_link = elf->e_shstrndx;
	shdr4extnum->sh_info = segs;
}

static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
				     unsigned long mm_flags)
{
	struct vm_area_struct *vma;
	size_t size = 0;

	for (vma = first_vma(current, gate_vma); vma != NULL;
	     vma = next_vma(vma, gate_vma))
		size += vma_dump_size(vma, mm_flags);
	return size;
}

L
Linus Torvalds 已提交
1869 1870 1871 1872 1873 1874 1875
/*
 * 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.
 */
1876
static int elf_core_dump(struct coredump_params *cprm)
L
Linus Torvalds 已提交
1877 1878 1879 1880 1881
{
	int has_dumped = 0;
	mm_segment_t fs;
	int segs;
	size_t size = 0;
1882
	struct vm_area_struct *vma, *gate_vma;
L
Linus Torvalds 已提交
1883
	struct elfhdr *elf = NULL;
1884
	loff_t offset = 0, dataoff, foffset;
1885
	unsigned long mm_flags;
R
Roland McGrath 已提交
1886
	struct elf_note_info info;
1887
	struct elf_phdr *phdr4note = NULL;
1888 1889 1890
	struct elf_shdr *shdr4extnum = NULL;
	Elf_Half e_phnum;
	elf_addr_t e_shoff;
L
Linus Torvalds 已提交
1891 1892 1893 1894

	/*
	 * We no longer stop all VM operations.
	 * 
1895 1896 1897
	 * 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.
L
Linus Torvalds 已提交
1898 1899
	 *
	 * Only ptrace can touch these memory addresses, but it doesn't change
1900
	 * the map_count or the pages allocated. So no possibility of crashing
L
Linus Torvalds 已提交
1901 1902 1903 1904 1905 1906
	 * 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)
1907
		goto out;
1908 1909 1910 1911
	/*
	 * The number of segs are recored into ELF header as 16bit value.
	 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
	 */
L
Linus Torvalds 已提交
1912
	segs = current->mm->map_count;
1913
	segs += elf_core_extra_phdrs();
L
Linus Torvalds 已提交
1914

1915 1916 1917 1918
	gate_vma = get_gate_vma(current);
	if (gate_vma != NULL)
		segs++;

1919 1920 1921 1922 1923 1924 1925 1926
	/* for notes section */
	segs++;

	/* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
	 * this, kernel supports extended numbering. Have a look at
	 * include/linux/elf.h for further information. */
	e_phnum = segs > PN_XNUM ? PN_XNUM : segs;

L
Linus Torvalds 已提交
1927
	/*
R
Roland McGrath 已提交
1928 1929
	 * Collect all the non-memory information about the process for the
	 * notes.  This also sets up the file header.
L
Linus Torvalds 已提交
1930
	 */
1931
	if (!fill_note_info(elf, e_phnum, &info, cprm->signr, cprm->regs))
R
Roland McGrath 已提交
1932
		goto cleanup;
L
Linus Torvalds 已提交
1933

R
Roland McGrath 已提交
1934 1935
	has_dumped = 1;
	current->flags |= PF_DUMPCORE;
L
Linus Torvalds 已提交
1936 1937 1938 1939 1940
  
	fs = get_fs();
	set_fs(KERNEL_DS);

	offset += sizeof(*elf);				/* Elf header */
1941
	offset += segs * sizeof(struct elf_phdr);	/* Program headers */
1942
	foffset = offset;
L
Linus Torvalds 已提交
1943 1944 1945

	/* Write notes phdr entry */
	{
R
Roland McGrath 已提交
1946
		size_t sz = get_note_info_size(&info);
L
Linus Torvalds 已提交
1947

1948
		sz += elf_coredump_extra_notes_size();
1949

1950 1951
		phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
		if (!phdr4note)
1952
			goto end_coredump;
1953 1954 1955

		fill_elf_note_phdr(phdr4note, sz, offset);
		offset += sz;
L
Linus Torvalds 已提交
1956 1957 1958 1959
	}

	dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);

1960 1961 1962 1963 1964 1965 1966
	/*
	 * We must use the same mm->flags while dumping core to avoid
	 * inconsistency between the program headers and bodies, otherwise an
	 * unusable core file can be generated.
	 */
	mm_flags = current->mm->flags;

1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979
	offset += elf_core_vma_data_size(gate_vma, mm_flags);
	offset += elf_core_extra_data_size();
	e_shoff = offset;

	if (e_phnum == PN_XNUM) {
		shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
		if (!shdr4extnum)
			goto end_coredump;
		fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
	}

	offset = dataoff;

1980 1981 1982 1983 1984 1985 1986 1987 1988
	size += sizeof(*elf);
	if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
		goto end_coredump;

	size += sizeof(*phdr4note);
	if (size > cprm->limit
	    || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
		goto end_coredump;

L
Linus Torvalds 已提交
1989
	/* Write program headers for segments dump */
1990 1991
	for (vma = first_vma(current, gate_vma); vma != NULL;
			vma = next_vma(vma, gate_vma)) {
L
Linus Torvalds 已提交
1992 1993 1994 1995 1996 1997
		struct elf_phdr phdr;

		phdr.p_type = PT_LOAD;
		phdr.p_offset = offset;
		phdr.p_vaddr = vma->vm_start;
		phdr.p_paddr = 0;
R
Roland McGrath 已提交
1998 1999
		phdr.p_filesz = vma_dump_size(vma, mm_flags);
		phdr.p_memsz = vma->vm_end - vma->vm_start;
L
Linus Torvalds 已提交
2000 2001
		offset += phdr.p_filesz;
		phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2002 2003 2004 2005
		if (vma->vm_flags & VM_WRITE)
			phdr.p_flags |= PF_W;
		if (vma->vm_flags & VM_EXEC)
			phdr.p_flags |= PF_X;
L
Linus Torvalds 已提交
2006 2007
		phdr.p_align = ELF_EXEC_PAGESIZE;

2008 2009 2010 2011
		size += sizeof(phdr);
		if (size > cprm->limit
		    || !dump_write(cprm->file, &phdr, sizeof(phdr)))
			goto end_coredump;
L
Linus Torvalds 已提交
2012 2013
	}

2014 2015
	if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
		goto end_coredump;
L
Linus Torvalds 已提交
2016 2017

 	/* write out the notes section */
2018
	if (!write_note_info(&info, cprm->file, &foffset))
R
Roland McGrath 已提交
2019
		goto end_coredump;
L
Linus Torvalds 已提交
2020

2021
	if (elf_coredump_extra_notes_write(cprm->file, &foffset))
2022
		goto end_coredump;
2023

2024
	/* Align to page */
2025
	if (!dump_seek(cprm->file, dataoff - foffset))
H
Hugh Dickins 已提交
2026
		goto end_coredump;
L
Linus Torvalds 已提交
2027

2028 2029
	for (vma = first_vma(current, gate_vma); vma != NULL;
			vma = next_vma(vma, gate_vma)) {
L
Linus Torvalds 已提交
2030
		unsigned long addr;
R
Roland McGrath 已提交
2031
		unsigned long end;
L
Linus Torvalds 已提交
2032

R
Roland McGrath 已提交
2033
		end = vma->vm_start + vma_dump_size(vma, mm_flags);
L
Linus Torvalds 已提交
2034

R
Roland McGrath 已提交
2035
		for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2036
			struct page *page;
H
Hugh Dickins 已提交
2037 2038 2039 2040 2041
			int stop;

			page = get_dump_page(addr);
			if (page) {
				void *kaddr = kmap(page);
2042 2043 2044
				stop = ((size += PAGE_SIZE) > cprm->limit) ||
					!dump_write(cprm->file, kaddr,
						    PAGE_SIZE);
H
Hugh Dickins 已提交
2045
				kunmap(page);
L
Linus Torvalds 已提交
2046
				page_cache_release(page);
H
Hugh Dickins 已提交
2047
			} else
2048
				stop = !dump_seek(cprm->file, PAGE_SIZE);
H
Hugh Dickins 已提交
2049 2050
			if (stop)
				goto end_coredump;
L
Linus Torvalds 已提交
2051 2052 2053
		}
	}

2054 2055
	if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
		goto end_coredump;
L
Linus Torvalds 已提交
2056

2057 2058 2059 2060 2061 2062 2063 2064
	if (e_phnum == PN_XNUM) {
		size += sizeof(*shdr4extnum);
		if (size > cprm->limit
		    || !dump_write(cprm->file, shdr4extnum,
				   sizeof(*shdr4extnum)))
			goto end_coredump;
	}

L
Linus Torvalds 已提交
2065 2066 2067 2068
end_coredump:
	set_fs(fs);

cleanup:
R
Roland McGrath 已提交
2069
	free_note_info(&info);
2070
	kfree(shdr4extnum);
2071
	kfree(phdr4note);
2072 2073
	kfree(elf);
out:
L
Linus Torvalds 已提交
2074 2075 2076
	return has_dumped;
}

C
Christoph Hellwig 已提交
2077
#endif		/* CONFIG_ELF_CORE */
L
Linus Torvalds 已提交
2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092

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");