1 files changed, 1101 insertions, 0 deletions

diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
new file mode 100644
index 00000000000..134c9c0d1f5
--- /dev/null
+++ b/fs/binfmt_elf_fdpic.c
@@ -0,0 +1,1101 @@
+/* binfmt_elf_fdpic.c: FDPIC ELF binary format
+ *
+ * Copyright (C) 2003, 2004 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ * Derived from binfmt_elf.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+
+#include <linux/fs.h>
+#include <linux/stat.h>
+#include <linux/sched.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/fcntl.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+#include <linux/personality.h>
+#include <linux/ptrace.h>
+#include <linux/init.h>
+#include <linux/smp_lock.h>
+#include <linux/elf.h>
+#include <linux/elf-fdpic.h>
+#include <linux/elfcore.h>
+
+#include <asm/uaccess.h>
+#include <asm/param.h>
+#include <asm/pgalloc.h>
+
+typedef char *elf_caddr_t;
+#ifndef elf_addr_t
+#define elf_addr_t unsigned long
+#endif
+
+#if 0
+#define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
+#else
+#define kdebug(fmt, ...) do {} while(0)
+#endif
+
+MODULE_LICENSE("GPL");
+
+static int load_elf_fdpic_binary(struct linux_binprm *bprm, struct pt_regs *regs);
+//static int load_elf_fdpic_library(struct file *);
+static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, struct file *file);
+static int elf_fdpic_map_file(struct elf_fdpic_params *params,
+			      struct file *file,
+			      struct mm_struct *mm,
+			      const char *what);
+
+static int create_elf_fdpic_tables(struct linux_binprm *bprm,
+				   struct mm_struct *mm,
+				   struct elf_fdpic_params *exec_params,
+				   struct elf_fdpic_params *interp_params);
+
+#ifndef CONFIG_MMU
+static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, unsigned long *_sp);
+static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *params,
+						   struct file *file,
+						   struct mm_struct *mm);
+#endif
+
+static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
+					     struct file *file,
+					     struct mm_struct *mm);
+
+static struct linux_binfmt elf_fdpic_format = {
+	.module		= THIS_MODULE,
+	.load_binary	= load_elf_fdpic_binary,
+//	.load_shlib	= load_elf_fdpic_library,
+//	.core_dump	= elf_fdpic_core_dump,
+	.min_coredump	= ELF_EXEC_PAGESIZE,
+};
+
+static int __init init_elf_fdpic_binfmt(void)  { return register_binfmt(&elf_fdpic_format); }
+static void __exit exit_elf_fdpic_binfmt(void) { unregister_binfmt(&elf_fdpic_format); }
+
+module_init(init_elf_fdpic_binfmt)
+module_exit(exit_elf_fdpic_binfmt)
+
+static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
+{
+	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
+		return 0;
+	if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
+		return 0;
+	if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
+		return 0;
+	if (!file->f_op || !file->f_op->mmap)
+		return 0;
+	return 1;
+}
+
+/*****************************************************************************/
+/*
+ * read the program headers table into memory
+ */
+static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, struct file *file)
+{
+	struct elf32_phdr *phdr;
+	unsigned long size;
+	int retval, loop;
+
+	if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
+		return -ENOMEM;
+	if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
+		return -ENOMEM;
+
+	size = params->hdr.e_phnum * sizeof(struct elf_phdr);
+	params->phdrs = kmalloc(size, GFP_KERNEL);
+	if (!params->phdrs)
+		return -ENOMEM;
+
+	retval = kernel_read(file, params->hdr.e_phoff, (char *) params->phdrs, size);
+	if (retval < 0)
+		return retval;
+
+	/* determine stack size for this binary */
+	phdr = params->phdrs;
+	for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
+		if (phdr->p_type != PT_GNU_STACK)
+			continue;
+
+		if (phdr->p_flags & PF_X)
+			params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
+		else
+			params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
+
+		params->stack_size = phdr->p_memsz;
+		break;
+	}
+
+	return 0;
+} /* end elf_fdpic_fetch_phdrs() */
+
+/*****************************************************************************/
+/*
+ * load an fdpic binary into various bits of memory
+ */
+static int load_elf_fdpic_binary(struct linux_binprm *bprm, struct pt_regs *regs)
+{
+	struct elf_fdpic_params exec_params, interp_params;
+	struct elf_phdr *phdr;
+	unsigned long stack_size;
+	struct file *interpreter = NULL; /* to shut gcc up */
+	char *interpreter_name = NULL;
+	int executable_stack;
+	int retval, i;
+
+	memset(&exec_params, 0, sizeof(exec_params));
+	memset(&interp_params, 0, sizeof(interp_params));
+
+	exec_params.hdr = *(struct elfhdr *) bprm->buf;
+	exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
+
+	/* check that this is a binary we know how to deal with */
+	retval = -ENOEXEC;
+	if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
+		goto error;
+
+	/* read the program header table */
+	retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
+	if (retval < 0)
+		goto error;
+
+	/* scan for a program header that specifies an interpreter */
+	phdr = exec_params.phdrs;
+
+	for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
+		switch (phdr->p_type) {
+		case PT_INTERP:
+			retval = -ENOMEM;
+			if (phdr->p_filesz > PATH_MAX)
+				goto error;
+			retval = -ENOENT;
+			if (phdr->p_filesz < 2)
+				goto error;
+
+			/* read the name of the interpreter into memory */
+			interpreter_name = (char *) kmalloc(phdr->p_filesz, GFP_KERNEL);
+			if (!interpreter_name)
+				goto error;
+
+			retval = kernel_read(bprm->file,
+					     phdr->p_offset,
+					     interpreter_name,
+					     phdr->p_filesz);
+			if (retval < 0)
+				goto error;
+
+			retval = -ENOENT;
+			if (interpreter_name[phdr->p_filesz - 1] != '\0')
+				goto error;
+
+			kdebug("Using ELF interpreter %s", interpreter_name);
+
+			/* replace the program with the interpreter */
+			interpreter = open_exec(interpreter_name);
+			retval = PTR_ERR(interpreter);
+			if (IS_ERR(interpreter)) {
+				interpreter = NULL;
+				goto error;
+			}
+
+			retval = kernel_read(interpreter, 0, bprm->buf, BINPRM_BUF_SIZE);
+			if (retval < 0)
+				goto error;
+
+			interp_params.hdr = *((struct elfhdr *) bprm->buf);
+			break;
+
+		case PT_LOAD:
+#ifdef CONFIG_MMU
+			if (exec_params.load_addr == 0)
+				exec_params.load_addr = phdr->p_vaddr;
+#endif
+			break;
+		}
+
+	}
+
+	if (elf_check_const_displacement(&exec_params.hdr))
+		exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
+
+	/* perform insanity checks on the interpreter */
+	if (interpreter_name) {
+		retval = -ELIBBAD;
+		if (!is_elf_fdpic(&interp_params.hdr, interpreter))
+			goto error;
+
+		interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
+
+		/* read the interpreter's program header table */
+		retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
+		if (retval < 0)
+			goto error;
+	}
+
+	stack_size = exec_params.stack_size;
+	if (stack_size < interp_params.stack_size)
+		stack_size = interp_params.stack_size;
+
+	if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
+		executable_stack = EXSTACK_ENABLE_X;
+	else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
+		executable_stack = EXSTACK_DISABLE_X;
+	else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
+		executable_stack = EXSTACK_ENABLE_X;
+	else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
+		executable_stack = EXSTACK_DISABLE_X;
+	else
+		executable_stack = EXSTACK_DEFAULT;
+
+	retval = -ENOEXEC;
+	if (stack_size == 0)
+		goto error;
+
+	if (elf_check_const_displacement(&interp_params.hdr))
+		interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
+
+	/* flush all traces of the currently running executable */
+	retval = flush_old_exec(bprm);
+	if (retval)
+		goto error;
+
+	/* there's now no turning back... the old userspace image is dead,
+	 * defunct, deceased, etc. after this point we have to exit via
+	 * error_kill */
+	set_personality(PER_LINUX_FDPIC);
+	set_binfmt(&elf_fdpic_format);
+
+	current->mm->start_code = 0;
+	current->mm->end_code = 0;
+	current->mm->start_stack = 0;
+	current->mm->start_data = 0;
+	current->mm->end_data = 0;
+	current->mm->context.exec_fdpic_loadmap = 0;
+	current->mm->context.interp_fdpic_loadmap = 0;
+
+	current->flags &= ~PF_FORKNOEXEC;
+
+#ifdef CONFIG_MMU
+	elf_fdpic_arch_lay_out_mm(&exec_params,
+				  &interp_params,
+				  &current->mm->start_stack,
+				  &current->mm->start_brk);
+#endif
+
+	/* do this so that we can load the interpreter, if need be
+	 * - we will change some of these later
+	 */
+	set_mm_counter(current->mm, rss, 0);
+
+#ifdef CONFIG_MMU
+	retval = setup_arg_pages(bprm, current->mm->start_stack, executable_stack);
+	if (retval < 0) {
+		send_sig(SIGKILL, current, 0);
+		goto error_kill;
+	}
+#endif
+
+	/* load the executable and interpreter into memory */
+	retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, "executable");
+	if (retval < 0)
+		goto error_kill;
+
+	if (interpreter_name) {
+		retval = elf_fdpic_map_file(&interp_params, interpreter,
+					    current->mm, "interpreter");
+		if (retval < 0) {
+			printk(KERN_ERR "Unable to load interpreter\n");
+			goto error_kill;
+		}
+
+		allow_write_access(interpreter);
+		fput(interpreter);
+		interpreter = NULL;
+	}
+
+#ifdef CONFIG_MMU
+	if (!current->mm->start_brk)
+		current->mm->start_brk = current->mm->end_data;
+
+	current->mm->brk = current->mm->start_brk = PAGE_ALIGN(current->mm->start_brk);
+
+#else
+	/* create a stack and brk area big enough for everyone
+	 * - the brk heap starts at the bottom and works up
+	 * - the stack starts at the top and works down
+	 */
+	stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
+	if (stack_size < PAGE_SIZE * 2)
+		stack_size = PAGE_SIZE * 2;
+
+	down_write(&current->mm->mmap_sem);
+	current->mm->start_brk = do_mmap(NULL,
+					 0,
+					 stack_size,
+					 PROT_READ | PROT_WRITE | PROT_EXEC,
+					 MAP_PRIVATE | MAP_ANON | MAP_GROWSDOWN,
+					 0);
+
+	if (IS_ERR((void *) current->mm->start_brk)) {
+		up_write(&current->mm->mmap_sem);
+		retval = current->mm->start_brk;
+		current->mm->start_brk = 0;
+		goto error_kill;
+	}
+
+	if (do_mremap(current->mm->start_brk,
+		      stack_size,
+		      ksize((char *) current->mm->start_brk),
+		      0, 0
+		      ) == current->mm->start_brk
+	    )
+		stack_size = ksize((char *) current->mm->start_brk);
+	up_write(&current->mm->mmap_sem);
+
+	current->mm->brk = current->mm->start_brk;
+	current->mm->context.end_brk = current->mm->start_brk;
+	current->mm->context.end_brk += (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
+	current->mm->start_stack = current->mm->start_brk + stack_size;
+#endif
+
+	compute_creds(bprm);
+	current->flags &= ~PF_FORKNOEXEC;
+	if (create_elf_fdpic_tables(bprm, current->mm, &exec_params, &interp_params) < 0)
+		goto error_kill;
+
+	kdebug("- start_code  %lx",	(long) current->mm->start_code);
+	kdebug("- end_code    %lx",	(long) current->mm->end_code);
+	kdebug("- start_data  %lx",	(long) current->mm->start_data);
+	kdebug("- end_data    %lx",	(long) current->mm->end_data);
+	kdebug("- start_brk   %lx",	(long) current->mm->start_brk);
+	kdebug("- brk         %lx",	(long) current->mm->brk);
+	kdebug("- start_stack %lx",	(long) current->mm->start_stack);
+
+#ifdef ELF_FDPIC_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.  This macro performs whatever initialization to
+	 * the regs structure is required.
+	 */
+	ELF_FDPIC_PLAT_INIT(regs,
+			    exec_params.map_addr,
+			    interp_params.map_addr,
+			    interp_params.dynamic_addr ?: exec_params.dynamic_addr
+			    );
+#endif
+
+	/* everything is now ready... get the userspace context ready to roll */
+	start_thread(regs,
+		     interp_params.entry_addr ?: exec_params.entry_addr,
+		     current->mm->start_stack);
+
+	if (unlikely(current->ptrace & PT_PTRACED)) {
+		if (current->ptrace & PT_TRACE_EXEC)
+			ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
+		else
+			send_sig(SIGTRAP, current, 0);
+	}
+
+	retval = 0;
+
+error:
+	if (interpreter) {
+		allow_write_access(interpreter);
+		fput(interpreter);
+	}
+	if (interpreter_name)
+		kfree(interpreter_name);
+	if (exec_params.phdrs)
+		kfree(exec_params.phdrs);
+	if (exec_params.loadmap)
+		kfree(exec_params.loadmap);
+	if (interp_params.phdrs)
+		kfree(interp_params.phdrs);
+	if (interp_params.loadmap)
+		kfree(interp_params.loadmap);
+	return retval;
+
+	/* unrecoverable error - kill the process */
+ error_kill:
+	send_sig(SIGSEGV, current, 0);
+	goto error;
+
+} /* end load_elf_fdpic_binary() */
+
+/*****************************************************************************/
+/*
+ * present useful information to the program
+ */
+static int create_elf_fdpic_tables(struct linux_binprm *bprm,
+				   struct mm_struct *mm,
+				   struct elf_fdpic_params *exec_params,
+				   struct elf_fdpic_params *interp_params)
+{
+	unsigned long sp, csp, nitems;
+	elf_caddr_t *argv, *envp;
+	size_t platform_len = 0, len;
+	char *k_platform, *u_platform, *p;
+	long hwcap;
+	int loop;
+
+	/* we're going to shovel a whole load of stuff onto the stack */
+#ifdef CONFIG_MMU
+	sp = bprm->p;
+#else
+	sp = mm->start_stack;
+
+	/* stack the program arguments and environment */
+	if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
+		return -EFAULT;
+#endif
+
+	/* get hold of platform and hardware capabilities masks for the machine
+	 * we are running on.  In some cases (Sparc), this info is impossible
+	 * to get, in others (i386) it is merely difficult.
+	 */
+	hwcap = ELF_HWCAP;
+	k_platform = ELF_PLATFORM;
+
+	if (k_platform) {
+		platform_len = strlen(k_platform) + 1;
+		sp -= platform_len;
+		if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
+			return -EFAULT;
+	}
+
+	u_platform = (char *) sp;
+
+#if defined(__i386__) && defined(CONFIG_SMP)
+	/* 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.
+	 *
+	 * the conditionals here are unneeded, but kept in to make the
+	 * code behaviour the same as pre change unless we have hyperthreaded
+	 * processors. This keeps Mr Marcelo Person happier but should be
+	 * removed for 2.5
+	 */
+	if (smp_num_siblings > 1)
+		sp = sp - ((current->pid % 64) << 7);
+#endif
+
+	sp &= ~7UL;
+
+	/* stack the load map(s) */
+	len = sizeof(struct elf32_fdpic_loadmap);
+	len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
+	sp = (sp - len) & ~7UL;
+	exec_params->map_addr = sp;
+
+	if (copy_to_user((void *) sp, exec_params->loadmap, len) != 0)
+		return -EFAULT;
+
+	current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
+
+	if (interp_params->loadmap) {
+		len = sizeof(struct elf32_fdpic_loadmap);
+		len += sizeof(struct elf32_fdpic_loadseg) * interp_params->loadmap->nsegs;
+		sp = (sp - len) & ~7UL;
+		interp_params->map_addr = sp;
+
+		if (copy_to_user((void *) sp, interp_params->loadmap, len) != 0)
+			return -EFAULT;
+
+		current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
+	}
+
+	/* force 16 byte _final_ alignment here for generality */
+#define DLINFO_ITEMS 13
+
+	nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0);
+#ifdef DLINFO_ARCH_ITEMS
+	nitems += DLINFO_ARCH_ITEMS;
+#endif
+
+	csp = sp;
+	sp -= nitems * 2 * sizeof(unsigned long);
+	sp -= (bprm->envc + 1) * sizeof(char *);	/* envv[] */
+	sp -= (bprm->argc + 1) * sizeof(char *);	/* argv[] */
+	sp -= 1 * sizeof(unsigned long);		/* argc */
+
+	csp -= sp & 15UL;
+	sp -= sp & 15UL;
+
+	/* put the ELF interpreter info on the stack */
+#define NEW_AUX_ENT(nr, id, val)						\
+	do {									\
+		struct { unsigned long _id, _val; } *ent = (void *) csp;	\
+		__put_user((id), &ent[nr]._id);					\
+		__put_user((val), &ent[nr]._val);				\
+	} while (0)
+
+	csp -= 2 * sizeof(unsigned long);
+	NEW_AUX_ENT(0, AT_NULL, 0);
+	if (k_platform) {
+		csp -= 2 * sizeof(unsigned long);
+		NEW_AUX_ENT(0, AT_PLATFORM, (elf_addr_t)(unsigned long) u_platform);
+	}
+
+	csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
+	NEW_AUX_ENT( 0, AT_HWCAP,		hwcap);
+	NEW_AUX_ENT( 1, AT_PAGESZ,		PAGE_SIZE);
+	NEW_AUX_ENT( 2, AT_CLKTCK,		CLOCKS_PER_SEC);
+	NEW_AUX_ENT( 3, AT_PHDR,		exec_params->ph_addr);
+	NEW_AUX_ENT( 4, AT_PHENT,		sizeof(struct elf_phdr));
+	NEW_AUX_ENT( 5, AT_PHNUM,		exec_params->hdr.e_phnum);
+	NEW_AUX_ENT( 6,	AT_BASE,		interp_params->elfhdr_addr);
+	NEW_AUX_ENT( 7, AT_FLAGS,		0);
+	NEW_AUX_ENT( 8, AT_ENTRY,		exec_params->entry_addr);
+	NEW_AUX_ENT( 9, AT_UID,			(elf_addr_t) current->uid);
+	NEW_AUX_ENT(10, AT_EUID,		(elf_addr_t) current->euid);
+	NEW_AUX_ENT(11, AT_GID,			(elf_addr_t) current->gid);
+	NEW_AUX_ENT(12, AT_EGID,		(elf_addr_t) current->egid);
+
+#ifdef ARCH_DLINFO
+	/* ARCH_DLINFO must come last so platform specific code can enforce
+	 * special alignment requirements on the AUXV if necessary (eg. PPC).
+	 */
+	ARCH_DLINFO;
+#endif
+#undef NEW_AUX_ENT
+
+	/* allocate room for argv[] and envv[] */
+	csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
+	envp = (elf_caddr_t *) csp;
+	csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
+	argv = (elf_caddr_t *) csp;
+
+	/* stack argc */
+	csp -= sizeof(unsigned long);
+	__put_user(bprm->argc, (unsigned long *) csp);
+
+	if (csp != sp)
+		BUG();
+
+	/* fill in the argv[] array */
+#ifdef CONFIG_MMU
+	current->mm->arg_start = bprm->p;
+#else
+	current->mm->arg_start = current->mm->start_stack - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
+#endif
+
+	p = (char *) current->mm->arg_start;
+	for (loop = bprm->argc; loop > 0; loop--) {
+		__put_user((elf_caddr_t) p, argv++);
+		len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
+		if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
+			return -EINVAL;
+		p += len;
+	}
+	__put_user(NULL, argv);
+	current->mm->arg_end = (unsigned long) p;
+
+	/* fill in the envv[] array */
+	current->mm->env_start = (unsigned long) p;
+	for (loop = bprm->envc; loop > 0; loop--) {
+		__put_user((elf_caddr_t)(unsigned long) p, envp++);
+		len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
+		if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
+			return -EINVAL;
+		p += len;
+	}
+	__put_user(NULL, envp);
+	current->mm->env_end = (unsigned long) p;
+
+	mm->start_stack = (unsigned long) sp;
+	return 0;
+} /* end create_elf_fdpic_tables() */
+
+/*****************************************************************************/
+/*
+ * transfer the program arguments and environment from the holding pages onto
+ * the stack
+ */
+#ifndef CONFIG_MMU
+static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, unsigned long *_sp)
+{
+	unsigned long index, stop, sp;
+	char *src;
+	int ret = 0;
+
+	stop = bprm->p >> PAGE_SHIFT;
+	sp = *_sp;
+
+	for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
+		src = kmap(bprm->page[index]);
+		sp -= PAGE_SIZE;
+		if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
+			ret = -EFAULT;
+		kunmap(bprm->page[index]);
+		if (ret < 0)
+			goto out;
+	}
+
+	*_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
+
+ out:
+	return ret;
+} /* end elf_fdpic_transfer_args_to_stack() */
+#endif
+
+/*****************************************************************************/
+/*
+ * load the appropriate binary image (executable or interpreter) into memory
+ * - we assume no MMU is available
+ * - if no other PIC bits are set in params->hdr->e_flags
+ *   - we assume that the LOADable segments in the binary are independently relocatable
+ *   - we assume R/O executable segments are shareable
+ * - else
+ *   - we assume the loadable parts of the image to require fixed displacement
+ *   - the image is not shareable
+ */
+static int elf_fdpic_map_file(struct elf_fdpic_params *params,
+			      struct file *file,
+			      struct mm_struct *mm,
+			      const char *what)
+{
+	struct elf32_fdpic_loadmap *loadmap;
+#ifdef CONFIG_MMU
+	struct elf32_fdpic_loadseg *mseg;
+#endif
+	struct elf32_fdpic_loadseg *seg;
+	struct elf32_phdr *phdr;
+	unsigned long load_addr, stop;
+	unsigned nloads, tmp;
+	size_t size;
+	int loop, ret;
+
+	/* allocate a load map table */
+	nloads = 0;
+	for (loop = 0; loop < params->hdr.e_phnum; loop++)
+		if (params->phdrs[loop].p_type == PT_LOAD)
+			nloads++;
+
+	if (nloads == 0)
+		return -ELIBBAD;
+
+	size = sizeof(*loadmap) + nloads * sizeof(*seg);
+	loadmap = kmalloc(size, GFP_KERNEL);
+	if (!loadmap)
+		return -ENOMEM;
+
+	params->loadmap = loadmap;
+	memset(loadmap, 0, size);
+
+	loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
+	loadmap->nsegs = nloads;
+
+	load_addr = params->load_addr;
+	seg = loadmap->segs;
+
+	/* map the requested LOADs into the memory space */
+	switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
+	case ELF_FDPIC_FLAG_CONSTDISP:
+	case ELF_FDPIC_FLAG_CONTIGUOUS:
+#ifndef CONFIG_MMU
+		ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
+		if (ret < 0)
+			return ret;
+		break;
+#endif
+	default:
+		ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
+		if (ret < 0)
+			return ret;
+		break;
+	}
+
+	/* map the entry point */
+	if (params->hdr.e_entry) {
+		seg = loadmap->segs;
+		for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
+			if (params->hdr.e_entry >= seg->p_vaddr &&
+			    params->hdr.e_entry < seg->p_vaddr + seg->p_memsz
+			    ) {
+				params->entry_addr =
+					(params->hdr.e_entry - seg->p_vaddr) + seg->addr;
+				break;
+			}
+		}
+	}
+
+	/* determine where the program header table has wound up if mapped */
+	stop = params->hdr.e_phoff + params->hdr.e_phnum * sizeof (struct elf_phdr);
+	phdr = params->phdrs;
+
+	for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
+		if (phdr->p_type != PT_LOAD)
+			continue;
+
+		if (phdr->p_offset > params->hdr.e_phoff ||
+		    phdr->p_offset + phdr->p_filesz < stop)
+			continue;
+
+		seg = loadmap->segs;
+		for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
+			if (phdr->p_vaddr >= seg->p_vaddr &&
+			    phdr->p_vaddr + phdr->p_filesz <= seg->p_vaddr + seg->p_memsz
+			    ) {
+				params->ph_addr = (phdr->p_vaddr - seg->p_vaddr) + seg->addr +
+					params->hdr.e_phoff - phdr->p_offset;
+				break;
+			}
+		}
+		break;
+	}
+
+	/* determine where the dynamic section has wound up if there is one */
+	phdr = params->phdrs;
+	for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
+		if (phdr->p_type != PT_DYNAMIC)
+			continue;
+
+		seg = loadmap->segs;
+		for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
+			if (phdr->p_vaddr >= seg->p_vaddr &&
+			    phdr->p_vaddr + phdr->p_memsz <= seg->p_vaddr + seg->p_memsz
+			    ) {
+				params->dynamic_addr = (phdr->p_vaddr - seg->p_vaddr) + seg->addr;
+
+				/* check the dynamic section contains at least one item, and that
+				 * the last item is a NULL entry */
+				if (phdr->p_memsz == 0 ||
+				    phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
+					goto dynamic_error;
+
+				tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
+				if (((Elf32_Dyn *) params->dynamic_addr)[tmp - 1].d_tag != 0)
+					goto dynamic_error;
+				break;
+			}
+		}
+		break;
+	}
+
+	/* now elide adjacent segments in the load map on MMU linux
+	 * - on uClinux the holes between may actually be filled with system stuff or stuff from
+	 *   other processes
+	 */
+#ifdef CONFIG_MMU
+	nloads = loadmap->nsegs;
+	mseg = loadmap->segs;
+	seg = mseg + 1;
+	for (loop = 1; loop < nloads; loop++) {
+		/* see if we have a candidate for merging */
+		if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
+			load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
+			if (load_addr == (seg->addr & PAGE_MASK)) {
+				mseg->p_memsz += load_addr - (mseg->addr + mseg->p_memsz);
+				mseg->p_memsz += seg->addr & ~PAGE_MASK;
+				mseg->p_memsz += seg->p_memsz;
+				loadmap->nsegs--;
+				continue;
+			}
+		}
+
+		mseg++;
+		if (mseg != seg)
+			*mseg = *seg;
+	}
+#endif
+
+	kdebug("Mapped Object [%s]:", what);
+	kdebug("- elfhdr   : %lx", params->elfhdr_addr);
+	kdebug("- entry    : %lx", params->entry_addr);
+	kdebug("- PHDR[]   : %lx", params->ph_addr);
+	kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
+	seg = loadmap->segs;
+	for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
+		kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
+		       loop,
+		       seg->addr, seg->addr + seg->p_memsz - 1,
+		       seg->p_vaddr, seg->p_memsz);
+
+	return 0;
+
+ dynamic_error:
+	printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
+	       what, file->f_dentry->d_inode->i_ino);
+	return -ELIBBAD;
+} /* end elf_fdpic_map_file() */
+
+/*****************************************************************************/
+/*
+ * map a file with constant displacement under uClinux
+ */
+#ifndef CONFIG_MMU
+static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *params,
+						   struct file *file,
+						   struct mm_struct *mm)
+{
+	struct elf32_fdpic_loadseg *seg;
+	struct elf32_phdr *phdr;
+	unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
+	loff_t fpos;
+	int loop, ret;
+
+	load_addr = params->load_addr;
+	seg = params->loadmap->segs;
+
+	/* determine the bounds of the contiguous overall allocation we must make */
+	phdr = params->phdrs;
+	for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
+		if (params->phdrs[loop].p_type != PT_LOAD)
+			continue;
+
+		if (base > phdr->p_vaddr)
+			base = phdr->p_vaddr;
+		if (top < phdr->p_vaddr + phdr->p_memsz)
+			top = phdr->p_vaddr + phdr->p_memsz;
+	}
+
+	/* allocate one big anon block for everything */
+	mflags = MAP_PRIVATE;
+	if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
+		mflags |= MAP_EXECUTABLE;
+
+	down_write(&mm->mmap_sem);
+	maddr = do_mmap(NULL, load_addr, top - base,
+			PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
+	up_write(&mm->mmap_sem);
+	if (IS_ERR((void *) maddr))
+		return (int) maddr;
+
+	if (load_addr != 0)
+		load_addr += PAGE_ALIGN(top - base);
+
+	/* and then load the file segments into it */
+	phdr = params->phdrs;
+	for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
+		if (params->phdrs[loop].p_type != PT_LOAD)
+			continue;
+
+		fpos = phdr->p_offset;
+
+		seg->addr = maddr + (phdr->p_vaddr - base);
+		seg->p_vaddr = phdr->p_vaddr;
+		seg->p_memsz = phdr->p_memsz;
+
+		ret = file->f_op->read(file, (void *) seg->addr, phdr->p_filesz, &fpos);
+		if (ret < 0)
+			return ret;
+
+		/* map the ELF header address if in this segment */
+		if (phdr->p_offset == 0)
+			params->elfhdr_addr = seg->addr;
+
+		/* clear any space allocated but not loaded */
+		if (phdr->p_filesz < phdr->p_memsz)
+			clear_user((void *) (seg->addr + phdr->p_filesz),
+				   phdr->p_memsz - phdr->p_filesz);
+
+		if (mm) {
+			if (phdr->p_flags & PF_X) {
+				mm->start_code = seg->addr;
+				mm->end_code = seg->addr + phdr->p_memsz;
+			}
+			else if (!mm->start_data) {
+				mm->start_data = seg->addr;
+#ifndef CONFIG_MMU
+				mm->end_data = seg->addr + phdr->p_memsz;
+#endif
+			}
+
+#ifdef CONFIG_MMU
+			if (seg->addr + phdr->p_memsz > mm->end_data)
+				mm->end_data = seg->addr + phdr->p_memsz;
+#endif
+		}
+
+		seg++;
+	}
+
+	return 0;
+} /* end elf_fdpic_map_file_constdisp_on_uclinux() */
+#endif
+
+/*****************************************************************************/
+/*
+ * map a binary by direct mmap() of the individual PT_LOAD segments
+ */
+static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
+					     struct file *file,
+					     struct mm_struct *mm)
+{
+	struct elf32_fdpic_loadseg *seg;
+	struct elf32_phdr *phdr;
+	unsigned long load_addr, delta_vaddr;
+	int loop, dvset;
+
+	load_addr = params->load_addr;
+	delta_vaddr = 0;
+	dvset = 0;
+
+	seg = params->loadmap->segs;
+
+	/* deal with each load segment separately */
+	phdr = params->phdrs;
+	for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
+		unsigned long maddr, disp, excess, excess1;
+		int prot = 0, flags;
+
+		if (phdr->p_type != PT_LOAD)
+			continue;
+
+		kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
+		       (unsigned long) phdr->p_vaddr,
+		       (unsigned long) phdr->p_offset,
+		       (unsigned long) phdr->p_filesz,
+		       (unsigned long) phdr->p_memsz);
+
+		/* determine the mapping parameters */
+		if (phdr->p_flags & PF_R) prot |= PROT_READ;
+		if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
+		if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
+
+		flags = MAP_PRIVATE | MAP_DENYWRITE;
+		if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
+			flags |= MAP_EXECUTABLE;
+
+		maddr = 0;
+
+		switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
+		case ELF_FDPIC_FLAG_INDEPENDENT:
+			/* PT_LOADs are independently locatable */
+			break;
+
+		case ELF_FDPIC_FLAG_HONOURVADDR:
+			/* the specified virtual address must be honoured */
+			maddr = phdr->p_vaddr;
+			flags |= MAP_FIXED;
+			break;
+
+		case ELF_FDPIC_FLAG_CONSTDISP:
+			/* constant displacement
+			 * - can be mapped anywhere, but must be mapped as a unit
+			 */
+			if (!dvset) {
+				maddr = load_addr;
+				delta_vaddr = phdr->p_vaddr;
+				dvset = 1;
+			}
+			else {
+				maddr = load_addr + phdr->p_vaddr - delta_vaddr;
+				flags |= MAP_FIXED;
+			}
+			break;
+
+		case ELF_FDPIC_FLAG_CONTIGUOUS:
+			/* contiguity handled later */
+			break;
+
+		default:
+			BUG();
+		}
+
+		maddr &= PAGE_MASK;
+
+		/* create the mapping */
+		disp = phdr->p_vaddr & ~PAGE_MASK;
+		down_write(&mm->mmap_sem);
+		maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
+				phdr->p_offset - disp);
+		up_write(&mm->mmap_sem);
+
+		kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
+		       loop, phdr->p_memsz + disp, prot, flags, phdr->p_offset - disp,
+		       maddr);
+
+		if (IS_ERR((void *) maddr))
+			return (int) maddr;
+
+		if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == ELF_FDPIC_FLAG_CONTIGUOUS)
+			load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
+
+		seg->addr = maddr + disp;
+		seg->p_vaddr = phdr->p_vaddr;
+		seg->p_memsz = phdr->p_memsz;
+
+		/* map the ELF header address if in this segment */
+		if (phdr->p_offset == 0)
+			params->elfhdr_addr = seg->addr;
+
+		/* clear the bit between beginning of mapping and beginning of PT_LOAD */
+		if (prot & PROT_WRITE && disp > 0) {
+			kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
+			clear_user((void *) maddr, disp);
+			maddr += disp;
+		}
+
+		/* clear any space allocated but not loaded
+		 * - on uClinux we can just clear the lot
+		 * - on MMU linux we'll get a SIGBUS beyond the last page
+		 *   extant in the file
+		 */
+		excess = phdr->p_memsz - phdr->p_filesz;
+		excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
+
+#ifdef CONFIG_MMU
+
+		if (excess > excess1) {
+			unsigned long xaddr = maddr + phdr->p_filesz + excess1;
+			unsigned long xmaddr;
+
+			flags |= MAP_FIXED | MAP_ANONYMOUS;
+			down_write(&mm->mmap_sem);
+			xmaddr = do_mmap(NULL, xaddr, excess - excess1, prot, flags, 0);
+			up_write(&mm->mmap_sem);
+
+			kdebug("mmap[%d] <anon>"
+			       " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
+			       loop, xaddr, excess - excess1, prot, flags, xmaddr);
+
+			if (xmaddr != xaddr)
+				return -ENOMEM;
+		}
+
+		if (prot & PROT_WRITE && excess1 > 0) {
+			kdebug("clear[%d] ad=%lx sz=%lx",
+			       loop, maddr + phdr->p_filesz, excess1);
+			clear_user((void *) maddr + phdr->p_filesz, excess1);
+		}
+
+#else
+		if (excess > 0) {
+			kdebug("clear[%d] ad=%lx sz=%lx",
+			       loop, maddr + phdr->p_filesz, excess);
+			clear_user((void *) maddr + phdr->p_filesz, excess);
+		}
+#endif
+
+		if (mm) {
+			if (phdr->p_flags & PF_X) {
+				mm->start_code = maddr;
+				mm->end_code = maddr + phdr->p_memsz;
+			}
+			else if (!mm->start_data) {
+				mm->start_data = maddr;
+				mm->end_data = maddr + phdr->p_memsz;
+			}
+		}
+
+		seg++;
+	}
+
+	return 0;
+} /* end elf_fdpic_map_file_by_direct_mmap() */