binfmt_elf.c 54.0 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 = {
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	.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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};

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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;
}

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);
}

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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,
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			     (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 */
541
#endif
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static unsigned long randomize_stack_top(unsigned long stack_top)
{
	unsigned int random_variable = 0;

547 548
	if ((current->flags & PF_RANDOMIZE) &&
		!(current->personality & ADDR_NO_RANDOMIZE)) {
549 550 551
		random_variable = get_random_int() & STACK_RND_MASK;
		random_variable <<= PAGE_SHIFT;
	}
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#ifdef CONFIG_STACK_GROWSUP
553
	return PAGE_ALIGN(stack_top) + random_variable;
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#else
555
	return PAGE_ALIGN(stack_top) - random_variable;
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#endif
}

559
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;
566
	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;
573
	unsigned long reloc_func_desc __maybe_unused = 0;
574
	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 */
588
	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;
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	if (!bprm->file->f_op || !bprm->file->f_op->mmap)
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		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;
610
	elf_phdata = kmalloc(size, GFP_KERNEL);
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	if (!elf_phdata)
		goto out;

614 615
	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)
640
				goto out_free_ph;
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			retval = -ENOMEM;
643
			elf_interpreter = kmalloc(elf_ppnt->p_filesz,
644
						  GFP_KERNEL);
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			if (!elf_interpreter)
646
				goto out_free_ph;
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			retval = kernel_read(bprm->file, elf_ppnt->p_offset,
649 650
					     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;
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			/*
			 * If the binary is not readable then enforce
			 * mm->dumpable = 0 regardless of the interpreter's
			 * permissions.
			 */
671
			would_dump(bprm, interpreter);
672

673 674
			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 */
682
			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;
701 702
		/* 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 */
705
		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.  */
720
	SET_PERSONALITY(loc->elf_ex);
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	if (elf_read_implies_exec(loc->elf_ex, executable_stack))
		current->personality |= READ_IMPLIES_EXEC;

724
	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
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		current->flags |= PF_RANDOMIZE;
726 727

	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;
732
	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;

742
	/* Now we do a little grungy work by mmapping the ELF image into
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	   the correct location in memory. */
744 745
	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.  */
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			retval = set_brk(elf_bss + load_bias,
					 elf_brk + load_bias);
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			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
773
					 * file specifies odd protections. So
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					 * we don't check the return value
					 */
				}
			}
		}

780 781 782 783 784 785
		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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787
		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) {
793 794 795 796
			/* 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.  */
797
#if defined(CONFIG_X86) || defined(CONFIG_ARM)
798 799 800 801 802 803 804 805 806 807
			/* Memory randomization might have been switched off
			 * in runtime via sysctl.
			 * If that is the case, retain the original non-zero
			 * load_bias value in order to establish proper
			 * non-randomized mappings.
			 */
			if (current->flags & PF_RANDOMIZE)
				load_bias = 0;
			else
				load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
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#else
809
			load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
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#endif
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		}

813
		error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
814
				elf_prot, elf_flags, 0);
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		if (BAD_ADDR(error)) {
			send_sig(SIGKILL, current, 0);
817 818
			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;
833 834 835 836
		if (k < start_code)
			start_code = k;
		if (start_data < k)
			start_data = k;
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837 838 839 840 841 842

		/*
		 * 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.
		 */
843
		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) {
846
			/* set_brk can never work. Avoid overflows. */
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			send_sig(SIGKILL, current, 0);
848
			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) {
890 891 892 893 894 895 896 897 898 899 900 901 902
		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;
J
Jiri Kosina 已提交
903
		}
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		if (BAD_ADDR(elf_entry)) {
			force_sig(SIGSEGV, current);
906 907
			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;
917
		if (BAD_ADDR(elf_entry)) {
918 919
			force_sig(SIGSEGV, current);
			retval = -EINVAL;
920 921
			goto out_free_dentry;
		}
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	}

	kfree(elf_phdata);

	set_binfmt(&elf_format);

928
#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
929
	retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
930 931
	if (retval < 0) {
		send_sig(SIGKILL, current, 0);
932
		goto out;
933 934 935
	}
#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */

936
	install_exec_creds(bprm);
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	current->flags &= ~PF_FORKNOEXEC;
938
	retval = create_elf_tables(bprm, &loc->elf_ex,
939
			  load_addr, interp_load_addr);
940 941 942 943
	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
952
	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);
955 956 957 958
#ifdef CONFIG_COMPAT_BRK
		current->brk_randomized = 1;
#endif
	}
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#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
965
		   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;
1016
	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 ||
1025
	    !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;
	}

1073 1074
	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;
}

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
Roland McGrath 已提交
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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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{
1103 1104
#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)
R
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		goto whole;
R
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1109 1110 1111 1112 1113 1114 1115 1116
	/* 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;

1121 1122
	/* 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;
1127
	}
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
Linus Torvalds 已提交
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R
Roland McGrath 已提交
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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
1143 1144
	if (FILTER(ELF_HEADERS) &&
	    vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
R
Roland McGrath 已提交
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		u32 __user *header = (u32 __user *) vma->vm_start;
		u32 word;
R
Roland McGrath 已提交
1147
		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;
R
Roland McGrath 已提交
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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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Roland McGrath 已提交
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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;
}

1200 1201
#define DUMP_WRITE(addr, nr, foffset)	\
	do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
L
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1203
static int alignfile(struct file *file, loff_t *foffset)
L
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{
1205
	static const char buf[4] = { 0, };
1206 1207 1208
	DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
	return 1;
}
L
Linus Torvalds 已提交
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1210 1211 1212 1213
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;

1218 1219 1220 1221 1222 1223 1224
	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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{
1233 1234
	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;
L
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	elf->e_version = EV_CURRENT;
	elf->e_phoff = sizeof(struct elfhdr);
R
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	elf->e_flags = flags;
L
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	elf->e_ehsize = sizeof(struct elfhdr);
	elf->e_phentsize = sizeof(struct elf_phdr);
	elf->e_phnum = segs;
1249

L
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	return;
}

1253
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;
}

/*
1277 1278
 * 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,
1281
		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];
1286 1287 1288
	rcu_read_lock();
	prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
	rcu_read_unlock();
1289 1290 1291
	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)) {
1293 1294
		struct task_cputime cputime;

L
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		/*
1296 1297
		 * This is the record for the group leader.  It shows the
		 * group-wide total, not its individual thread total.
L
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		 */
1299 1300 1301
		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)
{
1313
	const struct cred *cred;
1314
	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;

1330 1331 1332
	rcu_read_lock();
	psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
	rcu_read_unlock();
1333 1334 1335
	psinfo->pr_pid = task_pid_vnr(p);
	psinfo->pr_pgrp = task_pgrp_vnr(p);
	psinfo->pr_sid = task_session_vnr(p);
L
Linus Torvalds 已提交
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	i = p->state ? ffz(~p->state) + 1 : 0;
	psinfo->pr_state = i;
1339
	psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
L
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1340 1341 1342
	psinfo->pr_zomb = psinfo->pr_sname == 'Z';
	psinfo->pr_nice = task_nice(p);
	psinfo->pr_flag = p->flags;
1343 1344 1345 1346 1347
	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
Roland McGrath 已提交
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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);
}

1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380
#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;
};

1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392
/*
 * 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);
}

1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413
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]);

1414 1415
	do_thread_regset_writeback(t->task, &view->regsets[0]);

1416 1417 1418 1419 1420 1421 1422
	/*
	 * 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];
1423
		do_thread_regset_writeback(t->task, regset);
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 1454 1455 1456 1457 1458 1459 1460
		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;
1461
	struct core_thread *ct;
1462 1463 1464 1465 1466 1467 1468 1469 1470
	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
1471 1472
	fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);

1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499
	/*
	 * 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.
	 */
1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517
	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;
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 1588 1589 1590 1591 1592 1593 1594

	/*
	 * 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

L
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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
1603
	elf_fpxregset_t xfpu;		/* ELF_CORE_XFPREG_TYPE */
L
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1604 1605 1606 1607 1608 1609 1610
#endif
	struct memelfnote notes[3];
	int num_notes;
};

/*
 * In order to add the specific thread information for the elf file format,
1611 1612
 * 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.
L
Linus Torvalds 已提交
1613 1614 1615 1616 1617 1618 1619 1620 1621 1622
 */
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);	
	
1623 1624
	fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
		  &(t->prstatus));
L
Linus Torvalds 已提交
1625 1626 1627
	t->num_notes++;
	sz += notesize(&t->notes[0]);

1628 1629 1630 1631
	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
1632 1633 1634 1635 1636 1637
		t->num_notes++;
		sz += notesize(&t->notes[1]);
	}

#ifdef ELF_CORE_COPY_XFPREGS
	if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1638 1639
		fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
			  sizeof(t->xfpu), &t->xfpu);
L
Linus Torvalds 已提交
1640 1641 1642 1643 1644 1645 1646
		t->num_notes++;
		sz += notesize(&t->notes[2]);
	}
#endif	
	return sz;
}

R
Roland McGrath 已提交
1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659
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
1660
static int elf_note_info_init(struct elf_note_info *info)
R
Roland McGrath 已提交
1661
{
A
Amerigo Wang 已提交
1662
	memset(info, 0, sizeof(*info));
R
Roland McGrath 已提交
1663 1664
	INIT_LIST_HEAD(&info->thread_list);

A
Amerigo Wang 已提交
1665 1666
	/* Allocate space for six ELF notes */
	info->notes = kmalloc(6 * sizeof(struct memelfnote), GFP_KERNEL);
R
Roland McGrath 已提交
1667 1668 1669 1670
	if (!info->notes)
		return 0;
	info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
	if (!info->psinfo)
A
Amerigo Wang 已提交
1671
		goto notes_free;
R
Roland McGrath 已提交
1672 1673
	info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
	if (!info->prstatus)
A
Amerigo Wang 已提交
1674
		goto psinfo_free;
R
Roland McGrath 已提交
1675 1676
	info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
	if (!info->fpu)
A
Amerigo Wang 已提交
1677
		goto prstatus_free;
R
Roland McGrath 已提交
1678 1679 1680
#ifdef ELF_CORE_COPY_XFPREGS
	info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
	if (!info->xfpu)
A
Amerigo Wang 已提交
1681
		goto fpu_free;
R
Roland McGrath 已提交
1682
#endif
A
Amerigo Wang 已提交
1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704
	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
1705 1706

	if (signr) {
1707
		struct core_thread *ct;
1708
		struct elf_thread_status *ets;
1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719

		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
1720 1721 1722
		list_for_each(t, &info->thread_list) {
			int sz;

1723 1724
			ets = list_entry(t, struct elf_thread_status, list);
			sz = elf_dump_thread_status(signr, ets);
R
Roland McGrath 已提交
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 1813 1814 1815 1816 1817 1818 1819
			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
}

1820 1821
#endif

1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847
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;
}

1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875
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
1876 1877 1878 1879 1880 1881 1882
/*
 * 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.
 */
1883
static int elf_core_dump(struct coredump_params *cprm)
L
Linus Torvalds 已提交
1884 1885 1886 1887 1888
{
	int has_dumped = 0;
	mm_segment_t fs;
	int segs;
	size_t size = 0;
1889
	struct vm_area_struct *vma, *gate_vma;
L
Linus Torvalds 已提交
1890
	struct elfhdr *elf = NULL;
1891
	loff_t offset = 0, dataoff, foffset;
R
Roland McGrath 已提交
1892
	struct elf_note_info info;
1893
	struct elf_phdr *phdr4note = NULL;
1894 1895 1896
	struct elf_shdr *shdr4extnum = NULL;
	Elf_Half e_phnum;
	elf_addr_t e_shoff;
L
Linus Torvalds 已提交
1897 1898 1899 1900

	/*
	 * We no longer stop all VM operations.
	 * 
1901 1902 1903
	 * 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
1904 1905
	 *
	 * Only ptrace can touch these memory addresses, but it doesn't change
1906
	 * the map_count or the pages allocated. So no possibility of crashing
L
Linus Torvalds 已提交
1907 1908 1909 1910 1911 1912
	 * 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)
1913
		goto out;
1914 1915 1916 1917
	/*
	 * 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
1918
	segs = current->mm->map_count;
1919
	segs += elf_core_extra_phdrs();
L
Linus Torvalds 已提交
1920

1921
	gate_vma = get_gate_vma(current->mm);
1922 1923 1924
	if (gate_vma != NULL)
		segs++;

1925 1926 1927 1928 1929 1930 1931 1932
	/* 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
1933
	/*
R
Roland McGrath 已提交
1934 1935
	 * 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
1936
	 */
1937
	if (!fill_note_info(elf, e_phnum, &info, cprm->signr, cprm->regs))
R
Roland McGrath 已提交
1938
		goto cleanup;
L
Linus Torvalds 已提交
1939

R
Roland McGrath 已提交
1940 1941
	has_dumped = 1;
	current->flags |= PF_DUMPCORE;
L
Linus Torvalds 已提交
1942 1943 1944 1945 1946
  
	fs = get_fs();
	set_fs(KERNEL_DS);

	offset += sizeof(*elf);				/* Elf header */
1947
	offset += segs * sizeof(struct elf_phdr);	/* Program headers */
1948
	foffset = offset;
L
Linus Torvalds 已提交
1949 1950 1951

	/* Write notes phdr entry */
	{
R
Roland McGrath 已提交
1952
		size_t sz = get_note_info_size(&info);
L
Linus Torvalds 已提交
1953

1954
		sz += elf_coredump_extra_notes_size();
1955

1956 1957
		phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
		if (!phdr4note)
1958
			goto end_coredump;
1959 1960 1961

		fill_elf_note_phdr(phdr4note, sz, offset);
		offset += sz;
L
Linus Torvalds 已提交
1962 1963 1964 1965
	}

	dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);

1966
	offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978
	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;

1979 1980 1981 1982 1983 1984 1985 1986 1987
	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
1988
	/* Write program headers for segments dump */
1989 1990
	for (vma = first_vma(current, gate_vma); vma != NULL;
			vma = next_vma(vma, gate_vma)) {
L
Linus Torvalds 已提交
1991 1992 1993 1994 1995 1996
		struct elf_phdr phdr;

		phdr.p_type = PT_LOAD;
		phdr.p_offset = offset;
		phdr.p_vaddr = vma->vm_start;
		phdr.p_paddr = 0;
1997
		phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
R
Roland McGrath 已提交
1998
		phdr.p_memsz = vma->vm_end - vma->vm_start;
L
Linus Torvalds 已提交
1999 2000
		offset += phdr.p_filesz;
		phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2001 2002 2003 2004
		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
2005 2006
		phdr.p_align = ELF_EXEC_PAGESIZE;

2007 2008 2009 2010
		size += sizeof(phdr);
		if (size > cprm->limit
		    || !dump_write(cprm->file, &phdr, sizeof(phdr)))
			goto end_coredump;
L
Linus Torvalds 已提交
2011 2012
	}

2013 2014
	if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
		goto end_coredump;
L
Linus Torvalds 已提交
2015 2016

 	/* write out the notes section */
2017
	if (!write_note_info(&info, cprm->file, &foffset))
R
Roland McGrath 已提交
2018
		goto end_coredump;
L
Linus Torvalds 已提交
2019

2020
	if (elf_coredump_extra_notes_write(cprm->file, &foffset))
2021
		goto end_coredump;
2022

2023
	/* Align to page */
2024
	if (!dump_seek(cprm->file, dataoff - foffset))
H
Hugh Dickins 已提交
2025
		goto end_coredump;
L
Linus Torvalds 已提交
2026

2027 2028
	for (vma = first_vma(current, gate_vma); vma != NULL;
			vma = next_vma(vma, gate_vma)) {
L
Linus Torvalds 已提交
2029
		unsigned long addr;
R
Roland McGrath 已提交
2030
		unsigned long end;
L
Linus Torvalds 已提交
2031

2032
		end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
L
Linus Torvalds 已提交
2033

R
Roland McGrath 已提交
2034
		for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2035
			struct page *page;
H
Hugh Dickins 已提交
2036 2037 2038 2039 2040
			int stop;

			page = get_dump_page(addr);
			if (page) {
				void *kaddr = kmap(page);
2041 2042 2043
				stop = ((size += PAGE_SIZE) > cprm->limit) ||
					!dump_write(cprm->file, kaddr,
						    PAGE_SIZE);
H
Hugh Dickins 已提交
2044
				kunmap(page);
L
Linus Torvalds 已提交
2045
				page_cache_release(page);
H
Hugh Dickins 已提交
2046
			} else
2047
				stop = !dump_seek(cprm->file, PAGE_SIZE);
H
Hugh Dickins 已提交
2048 2049
			if (stop)
				goto end_coredump;
L
Linus Torvalds 已提交
2050 2051 2052
		}
	}

2053 2054
	if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
		goto end_coredump;
L
Linus Torvalds 已提交
2055

2056 2057 2058 2059 2060 2061 2062 2063
	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
2064 2065 2066 2067
end_coredump:
	set_fs(fs);

cleanup:
R
Roland McGrath 已提交
2068
	free_note_info(&info);
2069
	kfree(shdr4extnum);
2070
	kfree(phdr4note);
2071 2072
	kfree(elf);
out:
L
Linus Torvalds 已提交
2073 2074 2075
	return has_dumped;
}

C
Christoph Hellwig 已提交
2076
#endif		/* CONFIG_ELF_CORE */
L
Linus Torvalds 已提交
2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091

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");