binfmt_elf.c 57.6 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>
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#include <linux/vmalloc.h>
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#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 <linux/sched.h>
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#include <asm/uaccess.h>
#include <asm/param.h>
#include <asm/page.h>

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#ifndef user_long_t
#define user_long_t long
#endif
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#ifndef user_siginfo_t
#define user_siginfo_t siginfo_t
#endif

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static int load_elf_binary(struct linux_binprm *bprm);
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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;
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		addr = vm_brk(start, end - start);
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		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, from_kuid_munged(cred->user_ns, cred->uid));
	NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
	NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
	NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, 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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#ifdef ELF_HWCAP2
	NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
#endif
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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;
}

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#ifndef elf_map

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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;

	/*
	* 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);
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		map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
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		if (!BAD_ADDR(map_addr))
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			vm_munmap(map_addr+size, total_size-size);
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	} else
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		map_addr = vm_mmap(filep, addr, size, prot, type, off);
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	return(map_addr);
}

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#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;
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	if (!interpreter->f_op->mmap)
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		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 */
528
		error = vm_brk(elf_bss, last_bss - elf_bss);
L
Linus Torvalds 已提交
529 530 531 532
		if (BAD_ADDR(error))
			goto out_close;
	}

J
Jiri Kosina 已提交
533
	error = load_addr;
L
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534 535 536 537 538 539 540 541 542 543 544 545 546 547 548

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

549
#ifndef STACK_RND_MASK
550
#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12))	/* 8MB of VA */
551
#endif
L
Linus Torvalds 已提交
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static unsigned long randomize_stack_top(unsigned long stack_top)
{
	unsigned int random_variable = 0;

557 558
	if ((current->flags & PF_RANDOMIZE) &&
		!(current->personality & ADDR_NO_RANDOMIZE)) {
559 560 561
		random_variable = get_random_int() & STACK_RND_MASK;
		random_variable <<= PAGE_SHIFT;
	}
L
Linus Torvalds 已提交
562
#ifdef CONFIG_STACK_GROWSUP
563
	return PAGE_ALIGN(stack_top) + random_variable;
L
Linus Torvalds 已提交
564
#else
565
	return PAGE_ALIGN(stack_top) - random_variable;
L
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566 567 568
#endif
}

569
static int load_elf_binary(struct linux_binprm *bprm)
L
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570 571 572 573 574 575
{
	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;
576
	struct elf_phdr *elf_ppnt, *elf_phdata;
L
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577 578 579
	unsigned long elf_bss, elf_brk;
	int retval, i;
	unsigned int size;
J
Jiri Kosina 已提交
580 581
	unsigned long elf_entry;
	unsigned long interp_load_addr = 0;
L
Linus Torvalds 已提交
582
	unsigned long start_code, end_code, start_data, end_data;
583
	unsigned long reloc_func_desc __maybe_unused = 0;
584
	int executable_stack = EXSTACK_DEFAULT;
L
Linus Torvalds 已提交
585
	unsigned long def_flags = 0;
586
	struct pt_regs *regs = current_pt_regs();
L
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	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 */
599
	loc->elf_ex = *((struct elfhdr *)bprm->buf);
L
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600 601 602 603 604 605 606 607 608 609

	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;
A
Al Viro 已提交
610
	if (!bprm->file->f_op->mmap)
L
Linus Torvalds 已提交
611 612 613 614 615 616 617 618 619 620
		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;
621
	elf_phdata = kmalloc(size, GFP_KERNEL);
L
Linus Torvalds 已提交
622 623 624
	if (!elf_phdata)
		goto out;

625 626
	retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
			     (char *)elf_phdata, size);
L
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627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650
	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)
651
				goto out_free_ph;
L
Linus Torvalds 已提交
652 653

			retval = -ENOMEM;
654
			elf_interpreter = kmalloc(elf_ppnt->p_filesz,
655
						  GFP_KERNEL);
L
Linus Torvalds 已提交
656
			if (!elf_interpreter)
657
				goto out_free_ph;
L
Linus Torvalds 已提交
658 659

			retval = kernel_read(bprm->file, elf_ppnt->p_offset,
660 661
					     elf_interpreter,
					     elf_ppnt->p_filesz);
L
Linus Torvalds 已提交
662 663 664 665 666 667 668 669 670 671 672 673 674 675
			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;
676 677 678 679 680 681

			/*
			 * If the binary is not readable then enforce
			 * mm->dumpable = 0 regardless of the interpreter's
			 * permissions.
			 */
682
			would_dump(bprm, interpreter);
683

684 685
			retval = kernel_read(interpreter, 0, bprm->buf,
					     BINPRM_BUF_SIZE);
L
Linus Torvalds 已提交
686 687 688 689 690 691 692
			if (retval != BINPRM_BUF_SIZE) {
				if (retval >= 0)
					retval = -EIO;
				goto out_free_dentry;
			}

			/* Get the exec headers */
693
			loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
L
Linus Torvalds 已提交
694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711
			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;
712 713
		/* Not an ELF interpreter */
		if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
L
Linus Torvalds 已提交
714 715
			goto out_free_dentry;
		/* Verify the interpreter has a valid arch */
716
		if (!elf_check_arch(&loc->interp_elf_ex))
L
Linus Torvalds 已提交
717 718 719 720 721 722 723 724 725 726 727 728 729
			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->mm->def_flags = def_flags;

	/* Do this immediately, since STACK_TOP as used in setup_arg_pages
	   may depend on the personality.  */
730
	SET_PERSONALITY(loc->elf_ex);
L
Linus Torvalds 已提交
731 732 733
	if (elf_read_implies_exec(loc->elf_ex, executable_stack))
		current->personality |= READ_IMPLIES_EXEC;

734
	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
L
Linus Torvalds 已提交
735
		current->flags |= PF_RANDOMIZE;
736 737

	setup_new_exec(bprm);
L
Linus Torvalds 已提交
738 739 740 741 742 743 744 745 746 747 748 749

	/* Do this so that we can load the interpreter, if need be.  We will
	   change some of these later */
	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;

750
	/* Now we do a little grungy work by mmapping the ELF image into
J
Jiri Kosina 已提交
751
	   the correct location in memory. */
752 753
	for(i = 0, elf_ppnt = elf_phdata;
	    i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
L
Linus Torvalds 已提交
754 755 756 757 758 759 760 761 762 763 764 765
		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.  */
M
Mikael Pettersson 已提交
766 767
			retval = set_brk(elf_bss + load_bias,
					 elf_brk + load_bias);
L
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768 769 770 771 772 773 774 775 776 777 778 779 780
			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
781
					 * file specifies odd protections. So
L
Linus Torvalds 已提交
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					 * we don't check the return value
					 */
				}
			}
		}

788 789 790 791 792 793
		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;
L
Linus Torvalds 已提交
794

795
		elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
L
Linus Torvalds 已提交
796 797 798 799 800

		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) {
801 802 803 804
			/* 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.  */
805
#ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
806
			/* Memory randomization might have been switched off
807 808
			 * in runtime via sysctl or explicit setting of
			 * personality flags.
809 810 811 812 813 814 815 816
			 * 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);
J
Jiri Kosina 已提交
817
#else
818
			load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
J
Jiri Kosina 已提交
819
#endif
L
Linus Torvalds 已提交
820 821
		}

822
		error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
823
				elf_prot, elf_flags, 0);
L
Linus Torvalds 已提交
824 825
		if (BAD_ADDR(error)) {
			send_sig(SIGKILL, current, 0);
826 827
			retval = IS_ERR((void *)error) ?
				PTR_ERR((void*)error) : -EINVAL;
L
Linus Torvalds 已提交
828 829 830 831 832 833 834 835 836 837 838 839 840 841
			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;
842 843 844 845
		if (k < start_code)
			start_code = k;
		if (start_data < k)
			start_data = k;
L
Linus Torvalds 已提交
846 847 848 849 850 851

		/*
		 * 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.
		 */
852
		if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
L
Linus Torvalds 已提交
853 854
		    elf_ppnt->p_memsz > TASK_SIZE ||
		    TASK_SIZE - elf_ppnt->p_memsz < k) {
855
			/* set_brk can never work. Avoid overflows. */
L
Linus Torvalds 已提交
856
			send_sig(SIGKILL, current, 0);
857
			retval = -EINVAL;
L
Linus Torvalds 已提交
858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891
			goto out_free_dentry;
		}

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

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

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

	/* Calling set_brk effectively mmaps the pages that we need
	 * for the bss and break sections.  We must do this before
	 * mapping in the interpreter, to make sure it doesn't wind
	 * up getting placed where the bss needs to go.
	 */
	retval = set_brk(elf_bss, elf_brk);
	if (retval) {
		send_sig(SIGKILL, current, 0);
		goto out_free_dentry;
	}
A
akpm@osdl.org 已提交
892
	if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
L
Linus Torvalds 已提交
893 894 895 896 897 898
		send_sig(SIGSEGV, current, 0);
		retval = -EFAULT; /* Nobody gets to see this, but.. */
		goto out_free_dentry;
	}

	if (elf_interpreter) {
A
Alan Cox 已提交
899
		unsigned long interp_map_addr = 0;
900 901 902 903 904 905 906 907 908 909 910 911

		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
912
		}
L
Linus Torvalds 已提交
913 914
		if (BAD_ADDR(elf_entry)) {
			force_sig(SIGSEGV, current);
915 916
			retval = IS_ERR((void *)elf_entry) ?
					(int)elf_entry : -EINVAL;
L
Linus Torvalds 已提交
917 918 919 920 921 922 923 924 925
			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;
926
		if (BAD_ADDR(elf_entry)) {
927 928
			force_sig(SIGSEGV, current);
			retval = -EINVAL;
929 930
			goto out_free_dentry;
		}
L
Linus Torvalds 已提交
931 932 933 934 935 936
	}

	kfree(elf_phdata);

	set_binfmt(&elf_format);

937
#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
938
	retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
939 940
	if (retval < 0) {
		send_sig(SIGKILL, current, 0);
941
		goto out;
942 943 944
	}
#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */

945
	install_exec_creds(bprm);
946
	retval = create_elf_tables(bprm, &loc->elf_ex,
947
			  load_addr, interp_load_addr);
948 949 950 951
	if (retval < 0) {
		send_sig(SIGKILL, current, 0);
		goto out;
	}
L
Linus Torvalds 已提交
952 953 954 955 956 957 958
	/* 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;

J
Jiri Kosina 已提交
959
#ifdef arch_randomize_brk
960
	if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
J
Jiri Kosina 已提交
961 962
		current->mm->brk = current->mm->start_brk =
			arch_randomize_brk(current->mm);
963 964 965 966
#ifdef CONFIG_COMPAT_BRK
		current->brk_randomized = 1;
#endif
	}
J
Jiri Kosina 已提交
967 968
#endif

L
Linus Torvalds 已提交
969 970 971 972
	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
973
		   emulate the SVr4 behavior. Sigh. */
974
		error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
L
Linus Torvalds 已提交
975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004
				MAP_FIXED | MAP_PRIVATE, 0);
	}

#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:
J
Jesper Juhl 已提交
1005
	kfree(elf_interpreter);
L
Linus Torvalds 已提交
1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021
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;
1022
	retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
L
Linus Torvalds 已提交
1023 1024 1025 1026 1027 1028 1029 1030
	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 ||
A
Al Viro 已提交
1031
	    !elf_check_arch(&elf_ex) || !file->f_op->mmap)
L
Linus Torvalds 已提交
1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059
		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. */
1060
	error = vm_mmap(file,
L
Linus Torvalds 已提交
1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076
			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)));
	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;
	}

1077 1078
	len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
			    ELF_MIN_ALIGN - 1);
L
Linus Torvalds 已提交
1079
	bss = eppnt->p_memsz + eppnt->p_vaddr;
1080 1081
	if (bss > len)
		vm_brk(len, bss - len);
L
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1082 1083 1084 1085 1086 1087 1088 1089
	error = 0;

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

C
Christoph Hellwig 已提交
1090
#ifdef CONFIG_ELF_CORE
L
Linus Torvalds 已提交
1091 1092 1093 1094 1095 1096 1097
/*
 * ELF core dumper
 *
 * Modelled on fs/exec.c:aout_core_dump()
 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
 */

1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120
/*
 * The purpose of always_dump_vma() is to make sure that special kernel mappings
 * that are useful for post-mortem analysis are included in every core dump.
 * In that way we ensure that the core dump is fully interpretable later
 * without matching up the same kernel and hardware config to see what PC values
 * meant. These special mappings include - vDSO, vsyscall, and other
 * architecture specific mappings
 */
static bool always_dump_vma(struct vm_area_struct *vma)
{
	/* Any vsyscall mappings? */
	if (vma == get_gate_vma(vma->vm_mm))
		return true;
	/*
	 * arch_vma_name() returns non-NULL for special architecture mappings,
	 * such as vDSO sections.
	 */
	if (arch_vma_name(vma))
		return true;

	return false;
}

L
Linus Torvalds 已提交
1121
/*
R
Roland McGrath 已提交
1122
 * Decide what to dump of a segment, part, all or none.
L
Linus Torvalds 已提交
1123
 */
R
Roland McGrath 已提交
1124 1125
static unsigned long vma_dump_size(struct vm_area_struct *vma,
				   unsigned long mm_flags)
L
Linus Torvalds 已提交
1126
{
1127 1128
#define FILTER(type)	(mm_flags & (1UL << MMF_DUMP_##type))

1129 1130
	/* always dump the vdso and vsyscall sections */
	if (always_dump_vma(vma))
R
Roland McGrath 已提交
1131
		goto whole;
R
Roland McGrath 已提交
1132

1133
	if (vma->vm_flags & VM_DONTDUMP)
1134 1135
		return 0;

1136 1137 1138 1139 1140 1141
	/* 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;
1142
		return 0;
1143 1144
	}

L
Linus Torvalds 已提交
1145
	/* Do not dump I/O mapped devices or special mappings */
1146
	if (vma->vm_flags & VM_IO)
L
Linus Torvalds 已提交
1147 1148
		return 0;

1149 1150
	/* By default, dump shared memory if mapped from an anonymous file. */
	if (vma->vm_flags & VM_SHARED) {
A
Al Viro 已提交
1151
		if (file_inode(vma->vm_file)->i_nlink == 0 ?
R
Roland McGrath 已提交
1152 1153 1154
		    FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
			goto whole;
		return 0;
1155
	}
L
Linus Torvalds 已提交
1156

R
Roland McGrath 已提交
1157 1158 1159 1160 1161
	/* 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
1162

R
Roland McGrath 已提交
1163 1164 1165 1166 1167 1168 1169 1170
	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
1171 1172
	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
1175
		mm_segment_t fs = get_fs();
R
Roland McGrath 已提交
1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187
		/*
		 * 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
1188 1189 1190 1191 1192 1193 1194 1195 1196
		/*
		 * 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)
R
Roland McGrath 已提交
1197 1198 1199 1200 1201 1202 1203 1204 1205
			return PAGE_SIZE;
	}

#undef	FILTER

	return 0;

whole:
	return vma->vm_end - vma->vm_start;
L
Linus Torvalds 已提交
1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227
}

/* 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;
}

A
Al Viro 已提交
1228
static int alignfile(struct coredump_params *cprm)
L
Linus Torvalds 已提交
1229
{
1230
	static const char buf[4] = { 0, };
A
Al Viro 已提交
1231
	return dump_emit(cprm, buf, roundup(cprm->written, 4) - cprm->written);
1232
}
L
Linus Torvalds 已提交
1233

A
Al Viro 已提交
1234
static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1235 1236
{
	struct elf_note en;
L
Linus Torvalds 已提交
1237 1238 1239 1240
	en.n_namesz = strlen(men->name) + 1;
	en.n_descsz = men->datasz;
	en.n_type = men->type;

A
Al Viro 已提交
1241 1242 1243
	return dump_emit(cprm, &en, sizeof(en)) &&
	    dump_emit(cprm, men->name, en.n_namesz) && alignfile(cprm) &&
	    dump_emit(cprm, men->data, men->datasz) && alignfile(cprm);
L
Linus Torvalds 已提交
1244 1245
}

R
Roland McGrath 已提交
1246
static void fill_elf_header(struct elfhdr *elf, int segs,
1247
			    u16 machine, u32 flags)
L
Linus Torvalds 已提交
1248
{
1249 1250
	memset(elf, 0, sizeof(*elf));

L
Linus Torvalds 已提交
1251 1252 1253 1254 1255 1256 1257
	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;
R
Roland McGrath 已提交
1258
	elf->e_machine = machine;
L
Linus Torvalds 已提交
1259 1260
	elf->e_version = EV_CURRENT;
	elf->e_phoff = sizeof(struct elfhdr);
R
Roland McGrath 已提交
1261
	elf->e_flags = flags;
L
Linus Torvalds 已提交
1262 1263 1264
	elf->e_ehsize = sizeof(struct elfhdr);
	elf->e_phentsize = sizeof(struct elf_phdr);
	elf->e_phnum = segs;
1265

L
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1266 1267 1268
	return;
}

1269
static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
L
Linus Torvalds 已提交
1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292
{
	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;
}

/*
1293 1294
 * fill up all the fields in prstatus from the given task struct, except
 * registers which need to be filled up separately.
L
Linus Torvalds 已提交
1295 1296
 */
static void fill_prstatus(struct elf_prstatus *prstatus,
1297
		struct task_struct *p, long signr)
L
Linus Torvalds 已提交
1298 1299 1300 1301
{
	prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
	prstatus->pr_sigpend = p->pending.signal.sig[0];
	prstatus->pr_sighold = p->blocked.sig[0];
1302 1303 1304
	rcu_read_lock();
	prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
	rcu_read_unlock();
1305 1306 1307
	prstatus->pr_pid = task_pid_vnr(p);
	prstatus->pr_pgrp = task_pgrp_vnr(p);
	prstatus->pr_sid = task_session_vnr(p);
L
Linus Torvalds 已提交
1308
	if (thread_group_leader(p)) {
1309 1310
		struct task_cputime cputime;

L
Linus Torvalds 已提交
1311
		/*
1312 1313
		 * This is the record for the group leader.  It shows the
		 * group-wide total, not its individual thread total.
L
Linus Torvalds 已提交
1314
		 */
1315 1316 1317
		thread_group_cputime(p, &cputime);
		cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
		cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
L
Linus Torvalds 已提交
1318
	} else {
1319 1320 1321 1322 1323
		cputime_t utime, stime;

		task_cputime(p, &utime, &stime);
		cputime_to_timeval(utime, &prstatus->pr_utime);
		cputime_to_timeval(stime, &prstatus->pr_stime);
L
Linus Torvalds 已提交
1324 1325 1326 1327 1328 1329 1330 1331
	}
	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)
{
1332
	const struct cred *cred;
1333
	unsigned int i, len;
L
Linus Torvalds 已提交
1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348
	
	/* 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;

1349 1350 1351
	rcu_read_lock();
	psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
	rcu_read_unlock();
1352 1353 1354
	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
1355 1356 1357

	i = p->state ? ffz(~p->state) + 1 : 0;
	psinfo->pr_state = i;
1358
	psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
L
Linus Torvalds 已提交
1359 1360 1361
	psinfo->pr_zomb = psinfo->pr_sname == 'Z';
	psinfo->pr_nice = task_nice(p);
	psinfo->pr_flag = p->flags;
1362 1363
	rcu_read_lock();
	cred = __task_cred(p);
1364 1365
	SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
	SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1366
	rcu_read_unlock();
L
Linus Torvalds 已提交
1367 1368 1369 1370 1371
	strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
	
	return 0;
}

R
Roland McGrath 已提交
1372 1373 1374 1375 1376 1377 1378 1379 1380 1381
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);
}

1382 1383 1384 1385 1386 1387 1388 1389 1390 1391
static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
		siginfo_t *siginfo)
{
	mm_segment_t old_fs = get_fs();
	set_fs(KERNEL_DS);
	copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
	set_fs(old_fs);
	fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
}

1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403
#define MAX_FILE_NOTE_SIZE (4*1024*1024)
/*
 * Format of NT_FILE note:
 *
 * long count     -- how many files are mapped
 * long page_size -- units for file_ofs
 * array of [COUNT] elements of
 *   long start
 *   long end
 *   long file_ofs
 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
 */
1404
static int fill_files_note(struct memelfnote *note)
1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418
{
	struct vm_area_struct *vma;
	unsigned count, size, names_ofs, remaining, n;
	user_long_t *data;
	user_long_t *start_end_ofs;
	char *name_base, *name_curpos;

	/* *Estimated* file count and total data size needed */
	count = current->mm->map_count;
	size = count * 64;

	names_ofs = (2 + 3 * count) * sizeof(data[0]);
 alloc:
	if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1419
		return -EINVAL;
1420 1421 1422
	size = round_up(size, PAGE_SIZE);
	data = vmalloc(size);
	if (!data)
1423
		return -ENOMEM;
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 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475

	start_end_ofs = data + 2;
	name_base = name_curpos = ((char *)data) + names_ofs;
	remaining = size - names_ofs;
	count = 0;
	for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
		struct file *file;
		const char *filename;

		file = vma->vm_file;
		if (!file)
			continue;
		filename = d_path(&file->f_path, name_curpos, remaining);
		if (IS_ERR(filename)) {
			if (PTR_ERR(filename) == -ENAMETOOLONG) {
				vfree(data);
				size = size * 5 / 4;
				goto alloc;
			}
			continue;
		}

		/* d_path() fills at the end, move name down */
		/* n = strlen(filename) + 1: */
		n = (name_curpos + remaining) - filename;
		remaining = filename - name_curpos;
		memmove(name_curpos, filename, n);
		name_curpos += n;

		*start_end_ofs++ = vma->vm_start;
		*start_end_ofs++ = vma->vm_end;
		*start_end_ofs++ = vma->vm_pgoff;
		count++;
	}

	/* Now we know exact count of files, can store it */
	data[0] = count;
	data[1] = PAGE_SIZE;
	/*
	 * Count usually is less than current->mm->map_count,
	 * we need to move filenames down.
	 */
	n = current->mm->map_count - count;
	if (n != 0) {
		unsigned shift_bytes = n * 3 * sizeof(data[0]);
		memmove(name_base - shift_bytes, name_base,
			name_curpos - name_base);
		name_curpos -= shift_bytes;
	}

	size = name_curpos - (char *)data;
	fill_note(note, "CORE", NT_FILE, size, data);
1476
	return 0;
1477 1478
}

1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491
#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;
1492
	struct memelfnote signote;
1493
	struct memelfnote auxv;
1494
	struct memelfnote files;
1495
	user_siginfo_t csigdata;
1496 1497 1498 1499
	size_t size;
	int thread_notes;
};

1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511
/*
 * 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);
}

1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527
#ifndef PR_REG_SIZE
#define PR_REG_SIZE(S) sizeof(S)
#endif

#ifndef PRSTATUS_SIZE
#define PRSTATUS_SIZE(S) sizeof(S)
#endif

#ifndef PR_REG_PTR
#define PR_REG_PTR(S) (&((S)->pr_reg))
#endif

#ifndef SET_PR_FPVALID
#define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V))
#endif

1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541
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],
1542 1543
				    0, PR_REG_SIZE(t->prstatus.pr_reg),
				    PR_REG_PTR(&t->prstatus), NULL);
1544 1545

	fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1546
		  PRSTATUS_SIZE(t->prstatus), &t->prstatus);
1547 1548
	*total += notesize(&t->notes[0]);

1549 1550
	do_thread_regset_writeback(t->task, &view->regsets[0]);

1551 1552 1553 1554 1555 1556 1557
	/*
	 * 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];
1558
		do_thread_regset_writeback(t->task, regset);
1559
		if (regset->core_note_type && regset->get &&
1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575
		    (!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 {
1576
					SET_PR_FPVALID(&t->prstatus, 1);
1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589
					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,
1590
			  siginfo_t *siginfo, struct pt_regs *regs)
1591 1592 1593 1594 1595
{
	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;
1596
	struct core_thread *ct;
1597 1598 1599 1600 1601 1602
	unsigned int i;

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

	psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1603 1604
	if (psinfo == NULL) {
		info->psinfo.data = NULL; /* So we don't free this wrongly */
1605
		return 0;
1606
	}
1607

A
Amerigo Wang 已提交
1608 1609
	fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);

1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631
	/*
	 * 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,
1632
			view->e_machine, view->e_flags);
1633 1634 1635 1636

	/*
	 * Allocate a structure for each thread.
	 */
1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654
	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;
1655
		}
1656
	}
1657 1658 1659 1660 1661

	/*
	 * Now fill in each thread's information.
	 */
	for (t = info->thread; t != NULL; t = t->next)
1662
		if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1663 1664 1665 1666 1667 1668 1669 1670
			return 0;

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

1671 1672 1673
	fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
	info->size += notesize(&info->signote);

1674 1675 1676
	fill_auxv_note(&info->auxv, current->mm);
	info->size += notesize(&info->auxv);

1677 1678
	if (fill_files_note(&info->files) == 0)
		info->size += notesize(&info->files);
1679

1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692
	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,
A
Al Viro 已提交
1693
			   struct coredump_params *cprm)
1694 1695 1696 1697 1698 1699 1700
{
	bool first = 1;
	struct elf_thread_core_info *t = info->thread;

	do {
		int i;

A
Al Viro 已提交
1701
		if (!writenote(&t->notes[0], cprm))
1702 1703
			return 0;

A
Al Viro 已提交
1704
		if (first && !writenote(&info->psinfo, cprm))
1705
			return 0;
A
Al Viro 已提交
1706
		if (first && !writenote(&info->signote, cprm))
1707
			return 0;
A
Al Viro 已提交
1708
		if (first && !writenote(&info->auxv, cprm))
1709
			return 0;
1710
		if (first && info->files.data &&
A
Al Viro 已提交
1711
				!writenote(&info->files, cprm))
1712
			return 0;
1713 1714 1715

		for (i = 1; i < info->thread_notes; ++i)
			if (t->notes[i].data &&
A
Al Viro 已提交
1716
			    !writenote(&t->notes[i], cprm))
1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738
				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);
1739
	vfree(info->files.data);
1740 1741 1742 1743
}

#else

L
Linus Torvalds 已提交
1744 1745 1746 1747 1748 1749 1750 1751
/* 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
1752
	elf_fpxregset_t xfpu;		/* ELF_CORE_XFPREG_TYPE */
L
Linus Torvalds 已提交
1753 1754 1755 1756 1757 1758 1759
#endif
	struct memelfnote notes[3];
	int num_notes;
};

/*
 * In order to add the specific thread information for the elf file format,
1760 1761
 * 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
1762 1763 1764 1765 1766 1767 1768 1769 1770 1771
 */
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);	
	
1772 1773
	fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
		  &(t->prstatus));
L
Linus Torvalds 已提交
1774 1775 1776
	t->num_notes++;
	sz += notesize(&t->notes[0]);

1777 1778 1779 1780
	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
1781 1782 1783 1784 1785 1786
		t->num_notes++;
		sz += notesize(&t->notes[1]);
	}

#ifdef ELF_CORE_COPY_XFPREGS
	if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1787 1788
		fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
			  sizeof(t->xfpu), &t->xfpu);
L
Linus Torvalds 已提交
1789 1790 1791 1792 1793 1794 1795
		t->num_notes++;
		sz += notesize(&t->notes[2]);
	}
#endif	
	return sz;
}

R
Roland McGrath 已提交
1796 1797
struct elf_note_info {
	struct memelfnote *notes;
1798
	struct memelfnote *notes_files;
R
Roland McGrath 已提交
1799 1800 1801 1802 1803 1804 1805
	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
1806
	user_siginfo_t csigdata;
R
Roland McGrath 已提交
1807 1808 1809 1810
	int thread_status_size;
	int numnote;
};

A
Amerigo Wang 已提交
1811
static int elf_note_info_init(struct elf_note_info *info)
R
Roland McGrath 已提交
1812
{
A
Amerigo Wang 已提交
1813
	memset(info, 0, sizeof(*info));
R
Roland McGrath 已提交
1814 1815
	INIT_LIST_HEAD(&info->thread_list);

1816
	/* Allocate space for ELF notes */
1817
	info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL);
R
Roland McGrath 已提交
1818 1819 1820 1821
	if (!info->notes)
		return 0;
	info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
	if (!info->psinfo)
1822
		return 0;
R
Roland McGrath 已提交
1823 1824
	info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
	if (!info->prstatus)
1825
		return 0;
R
Roland McGrath 已提交
1826 1827
	info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
	if (!info->fpu)
1828
		return 0;
R
Roland McGrath 已提交
1829 1830 1831
#ifdef ELF_CORE_COPY_XFPREGS
	info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
	if (!info->xfpu)
1832
		return 0;
R
Roland McGrath 已提交
1833
#endif
A
Amerigo Wang 已提交
1834 1835 1836 1837 1838
	return 1;
}

static int fill_note_info(struct elfhdr *elf, int phdrs,
			  struct elf_note_info *info,
1839
			  siginfo_t *siginfo, struct pt_regs *regs)
A
Amerigo Wang 已提交
1840 1841 1842 1843 1844
{
	struct list_head *t;

	if (!elf_note_info_init(info))
		return 0;
R
Roland McGrath 已提交
1845

1846
	if (siginfo->si_signo) {
1847
		struct core_thread *ct;
1848
		struct elf_thread_status *ets;
1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859

		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
1860 1861 1862
		list_for_each(t, &info->thread_list) {
			int sz;

1863
			ets = list_entry(t, struct elf_thread_status, list);
1864
			sz = elf_dump_thread_status(siginfo->si_signo, ets);
R
Roland McGrath 已提交
1865 1866 1867 1868 1869
			info->thread_status_size += sz;
		}
	}
	/* now collect the dump for the current */
	memset(info->prstatus, 0, sizeof(*info->prstatus));
1870
	fill_prstatus(info->prstatus, current, siginfo->si_signo);
R
Roland McGrath 已提交
1871 1872 1873
	elf_core_copy_regs(&info->prstatus->pr_reg, regs);

	/* Set up header */
1874
	fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
R
Roland McGrath 已提交
1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886

	/*
	 * 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);

1887 1888
	fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
	fill_auxv_note(info->notes + 3, current->mm);
1889
	info->numnote = 4;
R
Roland McGrath 已提交
1890

1891 1892 1893 1894
	if (fill_files_note(info->notes + info->numnote) == 0) {
		info->notes_files = info->notes + info->numnote;
		info->numnote++;
	}
R
Roland McGrath 已提交
1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925

	/* 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,
A
Al Viro 已提交
1926
			   struct coredump_params *cprm)
R
Roland McGrath 已提交
1927 1928 1929 1930 1931
{
	int i;
	struct list_head *t;

	for (i = 0; i < info->numnote; i++)
A
Al Viro 已提交
1932
		if (!writenote(info->notes + i, cprm))
R
Roland McGrath 已提交
1933 1934 1935 1936 1937 1938 1939 1940
			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++)
A
Al Viro 已提交
1941
			if (!writenote(&tmp->notes[i], cprm))
R
Roland McGrath 已提交
1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955
				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));
	}

1956 1957 1958
	/* Free data possibly allocated by fill_files_note(): */
	if (info->notes_files)
		vfree(info->notes_files->data);
1959

R
Roland McGrath 已提交
1960 1961 1962 1963 1964 1965 1966 1967 1968
	kfree(info->prstatus);
	kfree(info->psinfo);
	kfree(info->notes);
	kfree(info->fpu);
#ifdef ELF_CORE_COPY_XFPREGS
	kfree(info->xfpu);
#endif
}

1969 1970
#endif

1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996
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;
}

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024
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
2025 2026 2027 2028 2029 2030 2031
/*
 * 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.
 */
2032
static int elf_core_dump(struct coredump_params *cprm)
L
Linus Torvalds 已提交
2033 2034 2035 2036 2037
{
	int has_dumped = 0;
	mm_segment_t fs;
	int segs;
	size_t size = 0;
2038
	struct vm_area_struct *vma, *gate_vma;
L
Linus Torvalds 已提交
2039
	struct elfhdr *elf = NULL;
2040
	loff_t offset = 0, dataoff, foffset;
2041
	struct elf_note_info info = { };
2042
	struct elf_phdr *phdr4note = NULL;
2043 2044 2045
	struct elf_shdr *shdr4extnum = NULL;
	Elf_Half e_phnum;
	elf_addr_t e_shoff;
L
Linus Torvalds 已提交
2046 2047 2048 2049

	/*
	 * We no longer stop all VM operations.
	 * 
2050 2051 2052
	 * 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
2053 2054
	 *
	 * Only ptrace can touch these memory addresses, but it doesn't change
2055
	 * the map_count or the pages allocated. So no possibility of crashing
L
Linus Torvalds 已提交
2056 2057 2058 2059 2060 2061
	 * 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)
2062
		goto out;
2063 2064 2065 2066
	/*
	 * 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
2067
	segs = current->mm->map_count;
2068
	segs += elf_core_extra_phdrs();
L
Linus Torvalds 已提交
2069

2070
	gate_vma = get_gate_vma(current->mm);
2071 2072 2073
	if (gate_vma != NULL)
		segs++;

2074 2075 2076 2077 2078 2079 2080 2081
	/* 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
2082
	/*
R
Roland McGrath 已提交
2083 2084
	 * 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
2085
	 */
2086
	if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs))
R
Roland McGrath 已提交
2087
		goto cleanup;
L
Linus Torvalds 已提交
2088

R
Roland McGrath 已提交
2089
	has_dumped = 1;
2090

L
Linus Torvalds 已提交
2091 2092 2093 2094
	fs = get_fs();
	set_fs(KERNEL_DS);

	offset += sizeof(*elf);				/* Elf header */
2095
	offset += segs * sizeof(struct elf_phdr);	/* Program headers */
2096
	foffset = offset;
L
Linus Torvalds 已提交
2097 2098 2099

	/* Write notes phdr entry */
	{
R
Roland McGrath 已提交
2100
		size_t sz = get_note_info_size(&info);
L
Linus Torvalds 已提交
2101

2102
		sz += elf_coredump_extra_notes_size();
2103

2104 2105
		phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
		if (!phdr4note)
2106
			goto end_coredump;
2107 2108 2109

		fill_elf_note_phdr(phdr4note, sz, offset);
		offset += sz;
L
Linus Torvalds 已提交
2110 2111 2112 2113
	}

	dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);

2114
	offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126
	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;

A
Al Viro 已提交
2127
	if (!dump_emit(cprm, elf, sizeof(*elf)))
2128 2129
		goto end_coredump;

A
Al Viro 已提交
2130
	if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
2131 2132
		goto end_coredump;

L
Linus Torvalds 已提交
2133
	/* Write program headers for segments dump */
2134 2135
	for (vma = first_vma(current, gate_vma); vma != NULL;
			vma = next_vma(vma, gate_vma)) {
L
Linus Torvalds 已提交
2136 2137 2138 2139 2140 2141
		struct elf_phdr phdr;

		phdr.p_type = PT_LOAD;
		phdr.p_offset = offset;
		phdr.p_vaddr = vma->vm_start;
		phdr.p_paddr = 0;
2142
		phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
R
Roland McGrath 已提交
2143
		phdr.p_memsz = vma->vm_end - vma->vm_start;
L
Linus Torvalds 已提交
2144 2145
		offset += phdr.p_filesz;
		phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2146 2147 2148 2149
		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
2150 2151
		phdr.p_align = ELF_EXEC_PAGESIZE;

A
Al Viro 已提交
2152
		if (!dump_emit(cprm, &phdr, sizeof(phdr)))
2153
			goto end_coredump;
L
Linus Torvalds 已提交
2154 2155
	}

2156
	if (!elf_core_write_extra_phdrs(cprm, offset))
2157
		goto end_coredump;
L
Linus Torvalds 已提交
2158

2159
	size = cprm->written;
A
Al Viro 已提交
2160
	cprm->written = foffset;	/* will disappear */
L
Linus Torvalds 已提交
2161
 	/* write out the notes section */
A
Al Viro 已提交
2162
	if (!write_note_info(&info, cprm))
R
Roland McGrath 已提交
2163
		goto end_coredump;
L
Linus Torvalds 已提交
2164

A
Al Viro 已提交
2165
	foffset = cprm->written;
2166
	if (elf_coredump_extra_notes_write(cprm->file, &foffset))
2167
		goto end_coredump;
2168

2169
	/* Align to page */
2170
	if (!dump_seek(cprm->file, dataoff - foffset))
H
Hugh Dickins 已提交
2171
		goto end_coredump;
L
Linus Torvalds 已提交
2172

2173 2174
	for (vma = first_vma(current, gate_vma); vma != NULL;
			vma = next_vma(vma, gate_vma)) {
L
Linus Torvalds 已提交
2175
		unsigned long addr;
R
Roland McGrath 已提交
2176
		unsigned long end;
L
Linus Torvalds 已提交
2177

2178
		end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
L
Linus Torvalds 已提交
2179

R
Roland McGrath 已提交
2180
		for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2181
			struct page *page;
H
Hugh Dickins 已提交
2182 2183 2184 2185 2186
			int stop;

			page = get_dump_page(addr);
			if (page) {
				void *kaddr = kmap(page);
2187 2188 2189
				stop = ((size += PAGE_SIZE) > cprm->limit) ||
					!dump_write(cprm->file, kaddr,
						    PAGE_SIZE);
H
Hugh Dickins 已提交
2190
				kunmap(page);
L
Linus Torvalds 已提交
2191
				page_cache_release(page);
H
Hugh Dickins 已提交
2192
			} else
2193
				stop = !dump_seek(cprm->file, PAGE_SIZE);
H
Hugh Dickins 已提交
2194 2195
			if (stop)
				goto end_coredump;
L
Linus Torvalds 已提交
2196 2197 2198
		}
	}

2199 2200
	cprm->written = size;
	if (!elf_core_write_extra_data(cprm))
2201
		goto end_coredump;
2202
	size = cprm->written;
L
Linus Torvalds 已提交
2203

2204 2205 2206 2207 2208 2209 2210 2211
	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
2212 2213 2214 2215
end_coredump:
	set_fs(fs);

cleanup:
R
Roland McGrath 已提交
2216
	free_note_info(&info);
2217
	kfree(shdr4extnum);
2218
	kfree(phdr4note);
2219 2220
	kfree(elf);
out:
L
Linus Torvalds 已提交
2221 2222 2223
	return has_dumped;
}

C
Christoph Hellwig 已提交
2224
#endif		/* CONFIG_ELF_CORE */
L
Linus Torvalds 已提交
2225 2226 2227

static int __init init_elf_binfmt(void)
{
A
Al Viro 已提交
2228 2229
	register_binfmt(&elf_format);
	return 0;
L
Linus Torvalds 已提交
2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240
}

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");