binfmt_elf.c 57.8 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;
	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 */
528
		error = vm_brk(elf_bss, last_bss - elf_bss);
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		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

549
#ifndef STACK_RND_MASK
550
#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12))	/* 8MB of VA */
551
#endif
L
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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
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#ifdef CONFIG_STACK_GROWSUP
563
	return PAGE_ALIGN(stack_top) + random_variable;
L
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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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{
	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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	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
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	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
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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);
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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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Mikael Pettersson 已提交
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	if (!bprm->file->f_op || !bprm->file->f_op->mmap)
L
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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;
621
	elf_phdata = kmalloc(size, GFP_KERNEL);
L
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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
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652 653

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

			retval = kernel_read(bprm->file, elf_ppnt->p_offset,
660 661
					     elf_interpreter,
					     elf_ppnt->p_filesz);
L
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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;
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
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			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
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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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			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 ||
1031
	    !elf_check_arch(&elf_ex) || !file->f_op || !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);
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	error = 0;

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

C
Christoph Hellwig 已提交
1090
#ifdef CONFIG_ELF_CORE
L
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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
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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
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		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
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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
1162

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
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	if (FILTER(ELF_HEADERS) &&
	    vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
R
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		u32 __user *header = (u32 __user *) vma->vm_start;
		u32 word;
R
Roland McGrath 已提交
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		mm_segment_t fs = get_fs();
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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)
R
Roland McGrath 已提交
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			return PAGE_SIZE;
	}

#undef	FILTER

	return 0;

whole:
	return vma->vm_end - vma->vm_start;
L
Linus Torvalds 已提交
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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;
}

1228 1229
#define DUMP_WRITE(addr, nr, foffset)	\
	do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
L
Linus Torvalds 已提交
1230

1231
static int alignfile(struct file *file, loff_t *foffset)
L
Linus Torvalds 已提交
1232
{
1233
	static const char buf[4] = { 0, };
1234 1235 1236
	DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
	return 1;
}
L
Linus Torvalds 已提交
1237

1238 1239 1240 1241
static int writenote(struct memelfnote *men, struct file *file,
			loff_t *foffset)
{
	struct elf_note en;
L
Linus Torvalds 已提交
1242 1243 1244 1245
	en.n_namesz = strlen(men->name) + 1;
	en.n_descsz = men->datasz;
	en.n_type = men->type;

1246 1247 1248 1249 1250 1251 1252
	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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1253 1254 1255 1256 1257

	return 1;
}
#undef DUMP_WRITE

R
Roland McGrath 已提交
1258
static void fill_elf_header(struct elfhdr *elf, int segs,
1259
			    u16 machine, u32 flags)
L
Linus Torvalds 已提交
1260
{
1261 1262
	memset(elf, 0, sizeof(*elf));

L
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1263 1264 1265 1266 1267 1268 1269
	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
1270
	elf->e_machine = machine;
L
Linus Torvalds 已提交
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	elf->e_version = EV_CURRENT;
	elf->e_phoff = sizeof(struct elfhdr);
R
Roland McGrath 已提交
1273
	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;
1277

L
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	return;
}

1281
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;
}

/*
1305 1306
 * 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
1307 1308
 */
static void fill_prstatus(struct elf_prstatus *prstatus,
1309
		struct task_struct *p, long signr)
L
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1310 1311 1312 1313
{
	prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
	prstatus->pr_sigpend = p->pending.signal.sig[0];
	prstatus->pr_sighold = p->blocked.sig[0];
1314 1315 1316
	rcu_read_lock();
	prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
	rcu_read_unlock();
1317 1318 1319
	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
1320
	if (thread_group_leader(p)) {
1321 1322
		struct task_cputime cputime;

L
Linus Torvalds 已提交
1323
		/*
1324 1325
		 * 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
1326
		 */
1327 1328 1329
		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
1330
	} else {
1331 1332 1333 1334 1335
		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
1336 1337 1338 1339 1340 1341 1342 1343
	}
	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)
{
1344
	const struct cred *cred;
1345
	unsigned int i, len;
L
Linus Torvalds 已提交
1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360
	
	/* 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;

1361 1362 1363
	rcu_read_lock();
	psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
	rcu_read_unlock();
1364 1365 1366
	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
1367 1368 1369

	i = p->state ? ffz(~p->state) + 1 : 0;
	psinfo->pr_state = i;
1370
	psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
L
Linus Torvalds 已提交
1371 1372 1373
	psinfo->pr_zomb = psinfo->pr_sname == 'Z';
	psinfo->pr_nice = task_nice(p);
	psinfo->pr_flag = p->flags;
1374 1375
	rcu_read_lock();
	cred = __task_cred(p);
1376 1377
	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));
1378
	rcu_read_unlock();
L
Linus Torvalds 已提交
1379 1380 1381 1382 1383
	strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
	
	return 0;
}

R
Roland McGrath 已提交
1384 1385 1386 1387 1388 1389 1390 1391 1392 1393
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);
}

1394 1395 1396 1397 1398 1399 1400 1401 1402 1403
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);
}

1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490
#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...
 */
static void fill_files_note(struct memelfnote *note)
{
	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 */
		goto err;
	size = round_up(size, PAGE_SIZE);
	data = vmalloc(size);
	if (!data)
		goto err;

	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);
 err: ;
}

1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503
#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;
1504
	struct memelfnote signote;
1505
	struct memelfnote auxv;
1506
	struct memelfnote files;
1507
	user_siginfo_t csigdata;
1508 1509 1510 1511
	size_t size;
	int thread_notes;
};

1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523
/*
 * 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);
}

1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539
#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

1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553
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],
1554 1555
				    0, PR_REG_SIZE(t->prstatus.pr_reg),
				    PR_REG_PTR(&t->prstatus), NULL);
1556 1557

	fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1558
		  PRSTATUS_SIZE(t->prstatus), &t->prstatus);
1559 1560
	*total += notesize(&t->notes[0]);

1561 1562
	do_thread_regset_writeback(t->task, &view->regsets[0]);

1563 1564 1565 1566 1567 1568 1569
	/*
	 * 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];
1570
		do_thread_regset_writeback(t->task, regset);
1571
		if (regset->core_note_type && regset->get &&
1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587
		    (!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 {
1588
					SET_PR_FPVALID(&t->prstatus, 1);
1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601
					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,
1602
			  siginfo_t *siginfo, struct pt_regs *regs)
1603 1604 1605 1606 1607
{
	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;
1608
	struct core_thread *ct;
1609 1610 1611 1612 1613 1614
	unsigned int i;

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

	psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1615 1616
	if (psinfo == NULL) {
		info->psinfo.data = NULL; /* So we don't free this wrongly */
1617
		return 0;
1618
	}
1619

A
Amerigo Wang 已提交
1620 1621
	fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);

1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643
	/*
	 * 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,
1644
			view->e_machine, view->e_flags);
1645 1646 1647 1648

	/*
	 * Allocate a structure for each thread.
	 */
1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666
	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;
1667
		}
1668
	}
1669 1670 1671 1672 1673

	/*
	 * Now fill in each thread's information.
	 */
	for (t = info->thread; t != NULL; t = t->next)
1674
		if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1675 1676 1677 1678 1679 1680 1681 1682
			return 0;

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

1683 1684 1685
	fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
	info->size += notesize(&info->signote);

1686 1687 1688
	fill_auxv_note(&info->auxv, current->mm);
	info->size += notesize(&info->auxv);

1689 1690 1691
	fill_files_note(&info->files);
	info->size += notesize(&info->files);

1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717
	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;
1718 1719
		if (first && !writenote(&info->signote, file, foffset))
			return 0;
1720 1721
		if (first && !writenote(&info->auxv, file, foffset))
			return 0;
1722 1723
		if (first && !writenote(&info->files, file, foffset))
			return 0;
1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749

		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);
1750
	vfree(info->files.data);
1751 1752 1753 1754
}

#else

L
Linus Torvalds 已提交
1755 1756 1757 1758 1759 1760 1761 1762
/* 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
1763
	elf_fpxregset_t xfpu;		/* ELF_CORE_XFPREG_TYPE */
L
Linus Torvalds 已提交
1764 1765 1766 1767 1768 1769 1770
#endif
	struct memelfnote notes[3];
	int num_notes;
};

/*
 * In order to add the specific thread information for the elf file format,
1771 1772
 * 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
1773 1774 1775 1776 1777 1778 1779 1780 1781 1782
 */
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);	
	
1783 1784
	fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
		  &(t->prstatus));
L
Linus Torvalds 已提交
1785 1786 1787
	t->num_notes++;
	sz += notesize(&t->notes[0]);

1788 1789 1790 1791
	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
1792 1793 1794 1795 1796 1797
		t->num_notes++;
		sz += notesize(&t->notes[1]);
	}

#ifdef ELF_CORE_COPY_XFPREGS
	if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1798 1799
		fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
			  sizeof(t->xfpu), &t->xfpu);
L
Linus Torvalds 已提交
1800 1801 1802 1803 1804 1805 1806
		t->num_notes++;
		sz += notesize(&t->notes[2]);
	}
#endif	
	return sz;
}

R
Roland McGrath 已提交
1807 1808 1809 1810 1811 1812 1813 1814 1815
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
1816
	user_siginfo_t csigdata;
R
Roland McGrath 已提交
1817 1818 1819 1820
	int thread_status_size;
	int numnote;
};

A
Amerigo Wang 已提交
1821
static int elf_note_info_init(struct elf_note_info *info)
R
Roland McGrath 已提交
1822
{
A
Amerigo Wang 已提交
1823
	memset(info, 0, sizeof(*info));
R
Roland McGrath 已提交
1824 1825
	INIT_LIST_HEAD(&info->thread_list);

1826
	/* Allocate space for ELF notes */
1827
	info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL);
R
Roland McGrath 已提交
1828 1829 1830 1831
	if (!info->notes)
		return 0;
	info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
	if (!info->psinfo)
1832
		return 0;
R
Roland McGrath 已提交
1833 1834
	info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
	if (!info->prstatus)
1835
		return 0;
R
Roland McGrath 已提交
1836 1837
	info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
	if (!info->fpu)
1838
		return 0;
R
Roland McGrath 已提交
1839 1840 1841
#ifdef ELF_CORE_COPY_XFPREGS
	info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
	if (!info->xfpu)
1842
		return 0;
R
Roland McGrath 已提交
1843
#endif
A
Amerigo Wang 已提交
1844 1845 1846 1847 1848
	return 1;
}

static int fill_note_info(struct elfhdr *elf, int phdrs,
			  struct elf_note_info *info,
1849
			  siginfo_t *siginfo, struct pt_regs *regs)
A
Amerigo Wang 已提交
1850 1851 1852 1853 1854
{
	struct list_head *t;

	if (!elf_note_info_init(info))
		return 0;
R
Roland McGrath 已提交
1855

1856
	if (siginfo->si_signo) {
1857
		struct core_thread *ct;
1858
		struct elf_thread_status *ets;
1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869

		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
1870 1871 1872
		list_for_each(t, &info->thread_list) {
			int sz;

1873
			ets = list_entry(t, struct elf_thread_status, list);
1874
			sz = elf_dump_thread_status(siginfo->si_signo, ets);
R
Roland McGrath 已提交
1875 1876 1877 1878 1879
			info->thread_status_size += sz;
		}
	}
	/* now collect the dump for the current */
	memset(info->prstatus, 0, sizeof(*info->prstatus));
1880
	fill_prstatus(info->prstatus, current, siginfo->si_signo);
R
Roland McGrath 已提交
1881 1882 1883
	elf_core_copy_regs(&info->prstatus->pr_reg, regs);

	/* Set up header */
1884
	fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
R
Roland McGrath 已提交
1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896

	/*
	 * 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);

1897 1898 1899
	fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
	fill_auxv_note(info->notes + 3, current->mm);
	fill_files_note(info->notes + 4);
R
Roland McGrath 已提交
1900

1901
	info->numnote = 5;
R
Roland McGrath 已提交
1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962

	/* 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));
	}

1963 1964 1965
	/* Free data allocated by fill_files_note(): */
	vfree(info->notes[4].data);

R
Roland McGrath 已提交
1966 1967 1968 1969 1970 1971 1972 1973 1974
	kfree(info->prstatus);
	kfree(info->psinfo);
	kfree(info->notes);
	kfree(info->fpu);
#ifdef ELF_CORE_COPY_XFPREGS
	kfree(info->xfpu);
#endif
}

1975 1976
#endif

1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
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;
}

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030
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
2031 2032 2033 2034 2035 2036 2037
/*
 * 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.
 */
2038
static int elf_core_dump(struct coredump_params *cprm)
L
Linus Torvalds 已提交
2039 2040 2041 2042 2043
{
	int has_dumped = 0;
	mm_segment_t fs;
	int segs;
	size_t size = 0;
2044
	struct vm_area_struct *vma, *gate_vma;
L
Linus Torvalds 已提交
2045
	struct elfhdr *elf = NULL;
2046
	loff_t offset = 0, dataoff, foffset;
R
Roland McGrath 已提交
2047
	struct elf_note_info info;
2048
	struct elf_phdr *phdr4note = NULL;
2049 2050 2051
	struct elf_shdr *shdr4extnum = NULL;
	Elf_Half e_phnum;
	elf_addr_t e_shoff;
L
Linus Torvalds 已提交
2052 2053 2054 2055

	/*
	 * We no longer stop all VM operations.
	 * 
2056 2057 2058
	 * 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
2059 2060
	 *
	 * Only ptrace can touch these memory addresses, but it doesn't change
2061
	 * the map_count or the pages allocated. So no possibility of crashing
L
Linus Torvalds 已提交
2062 2063 2064 2065 2066 2067
	 * 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)
2068
		goto out;
2069 2070 2071 2072
	/*
	 * 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
2073
	segs = current->mm->map_count;
2074
	segs += elf_core_extra_phdrs();
L
Linus Torvalds 已提交
2075

2076
	gate_vma = get_gate_vma(current->mm);
2077 2078 2079
	if (gate_vma != NULL)
		segs++;

2080 2081 2082 2083 2084 2085 2086 2087
	/* 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
2088
	/*
R
Roland McGrath 已提交
2089 2090
	 * 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
2091
	 */
2092
	if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs))
R
Roland McGrath 已提交
2093
		goto cleanup;
L
Linus Torvalds 已提交
2094

R
Roland McGrath 已提交
2095
	has_dumped = 1;
2096

L
Linus Torvalds 已提交
2097 2098 2099 2100
	fs = get_fs();
	set_fs(KERNEL_DS);

	offset += sizeof(*elf);				/* Elf header */
2101
	offset += segs * sizeof(struct elf_phdr);	/* Program headers */
2102
	foffset = offset;
L
Linus Torvalds 已提交
2103 2104 2105

	/* Write notes phdr entry */
	{
R
Roland McGrath 已提交
2106
		size_t sz = get_note_info_size(&info);
L
Linus Torvalds 已提交
2107

2108
		sz += elf_coredump_extra_notes_size();
2109

2110 2111
		phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
		if (!phdr4note)
2112
			goto end_coredump;
2113 2114 2115

		fill_elf_note_phdr(phdr4note, sz, offset);
		offset += sz;
L
Linus Torvalds 已提交
2116 2117 2118 2119
	}

	dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);

2120
	offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132
	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;

2133 2134 2135 2136 2137 2138 2139 2140 2141
	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
2142
	/* Write program headers for segments dump */
2143 2144
	for (vma = first_vma(current, gate_vma); vma != NULL;
			vma = next_vma(vma, gate_vma)) {
L
Linus Torvalds 已提交
2145 2146 2147 2148 2149 2150
		struct elf_phdr phdr;

		phdr.p_type = PT_LOAD;
		phdr.p_offset = offset;
		phdr.p_vaddr = vma->vm_start;
		phdr.p_paddr = 0;
2151
		phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
R
Roland McGrath 已提交
2152
		phdr.p_memsz = vma->vm_end - vma->vm_start;
L
Linus Torvalds 已提交
2153 2154
		offset += phdr.p_filesz;
		phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2155 2156 2157 2158
		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
2159 2160
		phdr.p_align = ELF_EXEC_PAGESIZE;

2161 2162 2163 2164
		size += sizeof(phdr);
		if (size > cprm->limit
		    || !dump_write(cprm->file, &phdr, sizeof(phdr)))
			goto end_coredump;
L
Linus Torvalds 已提交
2165 2166
	}

2167 2168
	if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
		goto end_coredump;
L
Linus Torvalds 已提交
2169 2170

 	/* write out the notes section */
2171
	if (!write_note_info(&info, cprm->file, &foffset))
R
Roland McGrath 已提交
2172
		goto end_coredump;
L
Linus Torvalds 已提交
2173

2174
	if (elf_coredump_extra_notes_write(cprm->file, &foffset))
2175
		goto end_coredump;
2176

2177
	/* Align to page */
2178
	if (!dump_seek(cprm->file, dataoff - foffset))
H
Hugh Dickins 已提交
2179
		goto end_coredump;
L
Linus Torvalds 已提交
2180

2181 2182
	for (vma = first_vma(current, gate_vma); vma != NULL;
			vma = next_vma(vma, gate_vma)) {
L
Linus Torvalds 已提交
2183
		unsigned long addr;
R
Roland McGrath 已提交
2184
		unsigned long end;
L
Linus Torvalds 已提交
2185

2186
		end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
L
Linus Torvalds 已提交
2187

R
Roland McGrath 已提交
2188
		for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2189
			struct page *page;
H
Hugh Dickins 已提交
2190 2191 2192 2193 2194
			int stop;

			page = get_dump_page(addr);
			if (page) {
				void *kaddr = kmap(page);
2195 2196 2197
				stop = ((size += PAGE_SIZE) > cprm->limit) ||
					!dump_write(cprm->file, kaddr,
						    PAGE_SIZE);
H
Hugh Dickins 已提交
2198
				kunmap(page);
L
Linus Torvalds 已提交
2199
				page_cache_release(page);
H
Hugh Dickins 已提交
2200
			} else
2201
				stop = !dump_seek(cprm->file, PAGE_SIZE);
H
Hugh Dickins 已提交
2202 2203
			if (stop)
				goto end_coredump;
L
Linus Torvalds 已提交
2204 2205 2206
		}
	}

2207 2208
	if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
		goto end_coredump;
L
Linus Torvalds 已提交
2209

2210 2211 2212 2213 2214 2215 2216 2217
	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
2218 2219 2220 2221
end_coredump:
	set_fs(fs);

cleanup:
R
Roland McGrath 已提交
2222
	free_note_info(&info);
2223
	kfree(shdr4extnum);
2224
	kfree(phdr4note);
2225 2226
	kfree(elf);
out:
L
Linus Torvalds 已提交
2227 2228 2229
	return has_dumped;
}

C
Christoph Hellwig 已提交
2230
#endif		/* CONFIG_ELF_CORE */
L
Linus Torvalds 已提交
2231 2232 2233

static int __init init_elf_binfmt(void)
{
A
Al Viro 已提交
2234 2235
	register_binfmt(&elf_format);
	return 0;
L
Linus Torvalds 已提交
2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246
}

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");