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fs/binfmt_elf_fdpic.c 46.4 KB
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  /* binfmt_elf_fdpic.c: FDPIC ELF binary format
   *
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   * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
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   * 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>
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  #include <linux/pagemap.h>
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  #include <linux/highmem.h>
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  #include <linux/highuid.h>
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  #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;
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  #if 0
  #define kdebug(fmt, ...) printk("FDPIC "fmt"
  " ,##__VA_ARGS__ )
  #else
  #define kdebug(fmt, ...) do {} while(0)
  #endif
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  #if 0
  #define kdcore(fmt, ...) printk("FDPIC "fmt"
  " ,##__VA_ARGS__ )
  #else
  #define kdcore(fmt, ...) do {} while(0)
  #endif
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  MODULE_LICENSE("GPL");
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  static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
  static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  			      struct mm_struct *, const char *);
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  static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  				   struct elf_fdpic_params *,
  				   struct elf_fdpic_params *);
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  #ifndef CONFIG_MMU
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  static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
  					    unsigned long *);
  static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  						   struct file *,
  						   struct mm_struct *);
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  #endif
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  static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  					     struct file *, struct mm_struct *);
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  #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *);
  #endif
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  static struct linux_binfmt elf_fdpic_format = {
  	.module		= THIS_MODULE,
  	.load_binary	= load_elf_fdpic_binary,
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  #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  	.core_dump	= elf_fdpic_core_dump,
  #endif
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  	.min_coredump	= ELF_EXEC_PAGESIZE,
  };
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  static int __init init_elf_fdpic_binfmt(void)
  {
  	return register_binfmt(&elf_fdpic_format);
  }
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  static void __exit exit_elf_fdpic_binfmt(void)
  {
  	unregister_binfmt(&elf_fdpic_format);
  }
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  core_initcall(init_elf_fdpic_binfmt);
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  module_exit(exit_elf_fdpic_binfmt);
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  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
   */
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  static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
  				 struct file *file)
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  {
  	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;
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  	retval = kernel_read(file, params->hdr.e_phoff,
  			     (char *) params->phdrs, size);
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  	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;
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  }
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  /*****************************************************************************/
  /*
   * load an fdpic binary into various bits of memory
   */
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  static int load_elf_fdpic_binary(struct linux_binprm *bprm,
  				 struct pt_regs *regs)
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  {
  	struct elf_fdpic_params exec_params, interp_params;
  	struct elf_phdr *phdr;
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  	unsigned long stack_size, entryaddr;
  #ifndef CONFIG_MMU
  	unsigned long fullsize;
  #endif
  #ifdef ELF_FDPIC_PLAT_INIT
  	unsigned long dynaddr;
  #endif
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  	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 */
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  			interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
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  			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;
  			}
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  			retval = kernel_read(interpreter, 0, bprm->buf,
  					     BINPRM_BUF_SIZE);
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  			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);
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  	retval = setup_arg_pages(bprm, current->mm->start_stack,
  				 executable_stack);
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  	if (retval < 0) {
  		send_sig(SIGKILL, current, 0);
  		goto error_kill;
  	}
  #endif
  
  	/* load the executable and interpreter into memory */
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  	retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
  				    "executable");
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  	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
  ");
  			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;
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  	current->mm->brk = current->mm->start_brk =
  		PAGE_ALIGN(current->mm->start_brk);
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  #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);
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  	current->mm->start_brk = do_mmap(NULL, 0, stack_size,
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  					 PROT_READ | PROT_WRITE | PROT_EXEC,
  					 MAP_PRIVATE | MAP_ANON | MAP_GROWSDOWN,
  					 0);
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  	if (IS_ERR_VALUE(current->mm->start_brk)) {
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  		up_write(&current->mm->mmap_sem);
  		retval = current->mm->start_brk;
  		current->mm->start_brk = 0;
  		goto error_kill;
  	}
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  	/* expand the stack mapping to use up the entire allocation granule */
  	fullsize = ksize((char *) current->mm->start_brk);
  	if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
  				    fullsize, 0, 0)))
  		stack_size = fullsize;
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  	up_write(&current->mm->mmap_sem);
  
  	current->mm->brk = current->mm->start_brk;
  	current->mm->context.end_brk = current->mm->start_brk;
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  	current->mm->context.end_brk +=
  		(stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
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  	current->mm->start_stack = current->mm->start_brk + stack_size;
  #endif
  
  	compute_creds(bprm);
  	current->flags &= ~PF_FORKNOEXEC;
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  	if (create_elf_fdpic_tables(bprm, current->mm,
  				    &exec_params, &interp_params) < 0)
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  		goto error_kill;
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  	kdebug("- start_code  %lx", current->mm->start_code);
  	kdebug("- end_code    %lx", current->mm->end_code);
  	kdebug("- start_data  %lx", current->mm->start_data);
  	kdebug("- end_data    %lx", current->mm->end_data);
  	kdebug("- start_brk   %lx", current->mm->start_brk);
  	kdebug("- brk         %lx", current->mm->brk);
  	kdebug("- start_stack %lx", current->mm->start_stack);
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  #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.
  	 */
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  	dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
  	ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
  			    dynaddr);
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  #endif
  
  	/* everything is now ready... get the userspace context ready to roll */
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  	entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
  	start_thread(regs, entryaddr, current->mm->start_stack);
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  	if (unlikely(current->ptrace & PT_PTRACED)) {
  		if (current->ptrace & PT_TRACE_EXEC)
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
413
  			ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  		else
  			send_sig(SIGTRAP, current, 0);
  	}
  
  	retval = 0;
  
  error:
  	if (interpreter) {
  		allow_write_access(interpreter);
  		fput(interpreter);
  	}
f99d49adf   Jesper Juhl   [PATCH] kfree cle...
425
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429
  	kfree(interpreter_name);
  	kfree(exec_params.phdrs);
  	kfree(exec_params.loadmap);
  	kfree(interp_params.phdrs);
  	kfree(interp_params.loadmap);
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432
  	return retval;
  
  	/* unrecoverable error - kill the process */
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433
  error_kill:
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  	send_sig(SIGSEGV, current, 0);
  	goto error;
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
436
  }
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  /*****************************************************************************/
  /*
   * 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;
530018bf3   Al Viro   [PATCH] frv: binf...
448
  	elf_caddr_t __user *argv, *envp;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  	size_t platform_len = 0, len;
530018bf3   Al Viro   [PATCH] frv: binf...
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451
  	char *k_platform;
  	char __user *u_platform, *p;
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  	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;
1aeb21d62   David Howells   [PATCH] FDPIC: Fi...
472
  	u_platform = NULL;
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  	if (k_platform) {
  		platform_len = strlen(k_platform) + 1;
  		sp -= platform_len;
530018bf3   Al Viro   [PATCH] frv: binf...
477
  		u_platform = (char __user *) sp;
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  		if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
  			return -EFAULT;
  	}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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482
  #if defined(__i386__) && defined(CONFIG_SMP)
  	/* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
483
484
  	 * by the processes running on the same package. One thing we can do is
  	 * to shuffle the initial stack for them.
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
485
  	 *
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
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  	 * the conditionals here are unneeded, but kept in to make the code
  	 * behaviour the same as pre change unless we have hyperthreaded
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  	 * 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;
530018bf3   Al Viro   [PATCH] frv: binf...
502
  	if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  		return -EFAULT;
  
  	current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
  
  	if (interp_params->loadmap) {
  		len = sizeof(struct elf32_fdpic_loadmap);
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
509
510
  		len += sizeof(struct elf32_fdpic_loadseg) *
  			interp_params->loadmap->nsegs;
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511
512
  		sp = (sp - len) & ~7UL;
  		interp_params->map_addr = sp;
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
513
514
  		if (copy_to_user((void __user *) sp, interp_params->loadmap,
  				 len) != 0)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  			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 */
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
538
539
540
541
542
543
544
  #define NEW_AUX_ENT(nr, id, val)					\
  	do {								\
  		struct { unsigned long _id, _val; } __user *ent;	\
  									\
  		ent = (void __user *) csp;				\
  		__put_user((id), &ent[nr]._id);				\
  		__put_user((val), &ent[nr]._val);			\
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
545
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547
548
549
550
  	} while (0)
  
  	csp -= 2 * sizeof(unsigned long);
  	NEW_AUX_ENT(0, AT_NULL, 0);
  	if (k_platform) {
  		csp -= 2 * sizeof(unsigned long);
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
551
552
  		NEW_AUX_ENT(0, AT_PLATFORM,
  			    (elf_addr_t) (unsigned long) u_platform);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
553
554
555
  	}
  
  	csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
556
557
558
559
560
561
562
563
564
565
566
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568
  	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);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
569
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579
  
  #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);
530018bf3   Al Viro   [PATCH] frv: binf...
580
  	envp = (elf_caddr_t __user *) csp;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
581
  	csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
530018bf3   Al Viro   [PATCH] frv: binf...
582
  	argv = (elf_caddr_t __user *) csp;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
583
584
585
  
  	/* stack argc */
  	csp -= sizeof(unsigned long);
530018bf3   Al Viro   [PATCH] frv: binf...
586
  	__put_user(bprm->argc, (unsigned long __user *) csp);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
587

88bcd5126   Eric Sesterhenn   BUG_ON() Conversi...
588
  	BUG_ON(csp != sp);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
589
590
591
592
593
  
  	/* fill in the argv[] array */
  #ifdef CONFIG_MMU
  	current->mm->arg_start = bprm->p;
  #else
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
594
595
  	current->mm->arg_start = current->mm->start_stack -
  		(MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
596
  #endif
530018bf3   Al Viro   [PATCH] frv: binf...
597
  	p = (char __user *) current->mm->arg_start;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
598
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  	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;
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
622
  }
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
623
624
625
626
627
628
629
  
  /*****************************************************************************/
  /*
   * transfer the program arguments and environment from the holding pages onto
   * the stack
   */
  #ifndef CONFIG_MMU
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
630
631
  static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
  					    unsigned long *_sp)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
  {
  	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;
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
651
  out:
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
652
  	return ret;
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
653
  }
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
  #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);
b87576d59   Robert P. J. Day   fs: Convert kmall...
693
  	loadmap = kzalloc(size, GFP_KERNEL);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
694
695
696
697
  	if (!loadmap)
  		return -ENOMEM;
  
  	params->loadmap = loadmap;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
  
  	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 &&
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
727
  			    params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
728
  				params->entry_addr =
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
729
730
  					(params->hdr.e_entry - seg->p_vaddr) +
  					seg->addr;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
731
732
733
734
735
736
  				break;
  			}
  		}
  	}
  
  	/* determine where the program header table has wound up if mapped */
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
737
738
  	stop = params->hdr.e_phoff;
  	stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
739
740
741
742
743
744
745
746
747
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749
750
751
  	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 &&
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
752
753
754
755
756
  			    phdr->p_vaddr + phdr->p_filesz <=
  			    seg->p_vaddr + seg->p_memsz) {
  				params->ph_addr =
  					(phdr->p_vaddr - seg->p_vaddr) +
  					seg->addr +
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
757
758
759
760
761
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764
765
766
767
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770
771
772
  					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 &&
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
773
774
775
776
777
778
779
780
781
  			    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 */
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
782
783
784
785
786
  				if (phdr->p_memsz == 0 ||
  				    phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
  					goto dynamic_error;
  
  				tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
787
788
  				if (((Elf32_Dyn *)
  				     params->dynamic_addr)[tmp - 1].d_tag != 0)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
789
790
791
792
793
794
795
796
  					goto dynamic_error;
  				break;
  			}
  		}
  		break;
  	}
  
  	/* now elide adjacent segments in the load map on MMU linux
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
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798
  	 * - on uClinux the holes between may actually be filled with system
  	 *   stuff or stuff from other processes
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799
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801
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  	 */
  #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)) {
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
809
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  				mseg->p_memsz +=
  					load_addr -
  					(mseg->addr + mseg->p_memsz);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  				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;
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
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  dynamic_error:
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  	printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)
  ",
0f7fc9e4d   Josef "Jeff" Sipek   [PATCH] VFS: chan...
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  	       what, file->f_path.dentry->d_inode->i_ino);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  	return -ELIBBAD;
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  }
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  /*****************************************************************************/
  /*
   * map a file with constant displacement under uClinux
   */
  #ifndef CONFIG_MMU
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  static int elf_fdpic_map_file_constdisp_on_uclinux(
  	struct elf_fdpic_params *params,
  	struct file *file,
  	struct mm_struct *mm)
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  {
  	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;
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  	/* determine the bounds of the contiguous overall allocation we must
  	 * make */
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  	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);
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  	if (IS_ERR_VALUE(maddr))
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  		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;
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  		ret = file->f_op->read(file, (void *) seg->addr,
  				       phdr->p_filesz, &fpos);
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  		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;
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  			} else if (!mm->start_data) {
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  				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;
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
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  }
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  #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
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
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  			 * - can be mapped anywhere, but must be mapped as a
  			 *   unit
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  			 */
  			if (!dvset) {
  				maddr = load_addr;
  				delta_vaddr = phdr->p_vaddr;
  				dvset = 1;
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  			} else {
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  				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",
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
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  		       loop, phdr->p_memsz + disp, prot, flags,
  		       phdr->p_offset - disp, maddr);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
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  		if (IS_ERR_VALUE(maddr))
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  			return (int) maddr;
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  		if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
  		    ELF_FDPIC_FLAG_CONTIGUOUS)
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  			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;
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
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  		/* clear the bit between beginning of mapping and beginning of
  		 * PT_LOAD */
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  		if (prot & PROT_WRITE && disp > 0) {
  			kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
530018bf3   Al Viro   [PATCH] frv: binf...
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  			clear_user((void __user *) maddr, disp);
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  			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
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  		if (excess > excess1) {
  			unsigned long xaddr = maddr + phdr->p_filesz + excess1;
  			unsigned long xmaddr;
  
  			flags |= MAP_FIXED | MAP_ANONYMOUS;
  			down_write(&mm->mmap_sem);
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  			xmaddr = do_mmap(NULL, xaddr, excess - excess1,
  					 prot, flags, 0);
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  			up_write(&mm->mmap_sem);
  
  			kdebug("mmap[%d] <anon>"
  			       " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
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  			       loop, xaddr, excess - excess1, prot, flags,
  			       xmaddr);
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  			if (xmaddr != xaddr)
  				return -ENOMEM;
  		}
  
  		if (prot & PROT_WRITE && excess1 > 0) {
  			kdebug("clear[%d] ad=%lx sz=%lx",
  			       loop, maddr + phdr->p_filesz, excess1);
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
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  			clear_user((void __user *) maddr + phdr->p_filesz,
  				   excess1);
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  		}
  
  #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;
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  			} else if (!mm->start_data) {
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  				mm->start_data = maddr;
  				mm->end_data = maddr + phdr->p_memsz;
  			}
  		}
  
  		seg++;
  	}
  
  	return 0;
8a2ab7f5d   David Howells   [PATCH] FDPIC: Ad...
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  }
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  /*****************************************************************************/
  /*
   * ELF-FDPIC core dumper
   *
   * Modelled on fs/exec.c:aout_core_dump()
   * Jeremy Fitzhardinge <jeremy@sw.oz.au>
   *
   * Modelled on fs/binfmt_elf.c core dumper
   */
  #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  
  /*
   * These are the only things you should do on a core-file: use only these
   * functions to write out all the necessary info.
   */
  static int dump_write(struct file *file, const void *addr, int nr)
  {
  	return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
  }
  
  static int dump_seek(struct file *file, loff_t off)
  {
  	if (file->f_op->llseek) {
  		if (file->f_op->llseek(file, off, SEEK_SET) != off)
  			return 0;
  	} else {
  		file->f_pos = off;
  	}
  	return 1;
  }
  
  /*
   * Decide whether a segment is worth dumping; default is yes to be
   * sure (missing info is worse than too much; etc).
   * Personally I'd include everything, and use the coredump limit...
   *
   * I think we should skip something. But I am not sure how. H.J.
   */
  static int maydump(struct vm_area_struct *vma)
  {
  	/* Do not dump I/O mapped devices or special mappings */
  	if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
  		kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
  		return 0;
  	}
  
  	/* If we may not read the contents, don't allow us to dump
  	 * them either. "dump_write()" can't handle it anyway.
  	 */
  	if (!(vma->vm_flags & VM_READ)) {
  		kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
  		return 0;
  	}
  
  	/* Dump shared memory only if mapped from an anonymous file. */
  	if (vma->vm_flags & VM_SHARED) {
0f7fc9e4d   Josef "Jeff" Sipek   [PATCH] VFS: chan...
1168
  		if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
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  			kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
  			return 1;
  		}
  
  		kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
  		return 0;
  	}
  
  #ifdef CONFIG_MMU
  	/* If it hasn't been written to, don't write it out */
  	if (!vma->anon_vma) {
  		kdcore("%08lx: %08lx: no (!anon)", vma->vm_start, vma->vm_flags);
  		return 0;
  	}
  #endif
  
  	kdcore("%08lx: %08lx: yes", vma->vm_start, vma->vm_flags);
  	return 1;
  }
  
  /* 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;
  }
  
  /* #define DEBUG */
  
  #define DUMP_WRITE(addr, nr)	\
  	do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
  #define DUMP_SEEK(off)	\
  	do { if (!dump_seek(file, (off))) return 0; } while(0)
  
  static int writenote(struct memelfnote *men, struct file *file)
  {
  	struct elf_note en;
  
  	en.n_namesz = strlen(men->name) + 1;
  	en.n_descsz = men->datasz;
  	en.n_type = men->type;
  
  	DUMP_WRITE(&en, sizeof(en));
  	DUMP_WRITE(men->name, en.n_namesz);
  	/* XXX - cast from long long to long to avoid need for libgcc.a */
  	DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));	/* XXX */
  	DUMP_WRITE(men->data, men->datasz);
  	DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));	/* XXX */
  
  	return 1;
  }
  #undef DUMP_WRITE
  #undef DUMP_SEEK
  
  #define DUMP_WRITE(addr, nr)	\
  	if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
  		goto end_coredump;
  #define DUMP_SEEK(off)	\
  	if (!dump_seek(file, (off))) \
  		goto end_coredump;
  
  static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
  {
  	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;
  	memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
  
  	elf->e_type = ET_CORE;
  	elf->e_machine = ELF_ARCH;
  	elf->e_version = EV_CURRENT;
  	elf->e_entry = 0;
  	elf->e_phoff = sizeof(struct elfhdr);
  	elf->e_shoff = 0;
  	elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
  	elf->e_ehsize = sizeof(struct elfhdr);
  	elf->e_phentsize = sizeof(struct elf_phdr);
  	elf->e_phnum = segs;
  	elf->e_shentsize = 0;
  	elf->e_shnum = 0;
  	elf->e_shstrndx = 0;
  	return;
  }
  
  static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
  {
  	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 inline 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;
  }
  
  /*
   * fill up all the fields in prstatus from the given task struct, except
   * registers which need to be filled up seperately.
   */
  static void fill_prstatus(struct elf_prstatus *prstatus,
  			  struct task_struct *p, long signr)
  {
  	prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
  	prstatus->pr_sigpend = p->pending.signal.sig[0];
  	prstatus->pr_sighold = p->blocked.sig[0];
  	prstatus->pr_pid = p->pid;
  	prstatus->pr_ppid = p->parent->pid;
  	prstatus->pr_pgrp = process_group(p);
937949d9e   Cedric Le Goater   [PATCH] add proce...
1304
  	prstatus->pr_sid = process_session(p);
6d8c4e3b0   David Howells   [PATCH] FDPIC: Ad...
1305
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  	if (thread_group_leader(p)) {
  		/*
  		 * This is the record for the group leader.  Add in the
  		 * cumulative times of previous dead threads.  This total
  		 * won't include the time of each live thread whose state
  		 * is included in the core dump.  The final total reported
  		 * to our parent process when it calls wait4 will include
  		 * those sums as well as the little bit more time it takes
  		 * this and each other thread to finish dying after the
  		 * core dump synchronization phase.
  		 */
  		cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
  				   &prstatus->pr_utime);
  		cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
  				   &prstatus->pr_stime);
  	} else {
  		cputime_to_timeval(p->utime, &prstatus->pr_utime);
  		cputime_to_timeval(p->stime, &prstatus->pr_stime);
  	}
  	cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
  	cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
  
  	prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
  	prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
  }
  
  static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
  		       struct mm_struct *mm)
  {
  	unsigned int i, len;
  
  	/* 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;
  
  	psinfo->pr_pid = p->pid;
  	psinfo->pr_ppid = p->parent->pid;
  	psinfo->pr_pgrp = process_group(p);
937949d9e   Cedric Le Goater   [PATCH] add proce...
1353
  	psinfo->pr_sid = process_session(p);
6d8c4e3b0   David Howells   [PATCH] FDPIC: Ad...
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  	i = p->state ? ffz(~p->state) + 1 : 0;
  	psinfo->pr_state = i;
  	psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
  	psinfo->pr_zomb = psinfo->pr_sname == 'Z';
  	psinfo->pr_nice = task_nice(p);
  	psinfo->pr_flag = p->flags;
  	SET_UID(psinfo->pr_uid, p->uid);
  	SET_GID(psinfo->pr_gid, p->gid);
  	strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
  
  	return 0;
  }
  
  /* 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
  	elf_fpxregset_t xfpu;		/* NT_PRXFPREG */
  #endif
  	struct memelfnote notes[3];
  	int num_notes;
  };
  
  /*
   * In order to add the specific thread information for the elf file format,
   * we need to keep a linked list of every thread's pr_status and then create
   * a single section for them in the final core file.
   */
  static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
  {
  	struct task_struct *p = t->thread;
  	int sz = 0;
  
  	t->num_notes = 0;
  
  	fill_prstatus(&t->prstatus, p, signr);
  	elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
  
  	fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
  		  &t->prstatus);
  	t->num_notes++;
  	sz += notesize(&t->notes[0]);
  
  	t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
  	if (t->prstatus.pr_fpvalid) {
  		fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
  			  &t->fpu);
  		t->num_notes++;
  		sz += notesize(&t->notes[1]);
  	}
  
  #ifdef ELF_CORE_COPY_XFPREGS
  	if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
  		fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
  			  &t->xfpu);
  		t->num_notes++;
  		sz += notesize(&t->notes[2]);
  	}
  #endif
  	return sz;
  }
  
  /*
   * dump the segments for an MMU process
   */
  #ifdef CONFIG_MMU
  static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
  				   size_t *size, unsigned long *limit)
  {
  	struct vm_area_struct *vma;
  
  	for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
  		unsigned long addr;
  
  		if (!maydump(vma))
  			continue;
  
  		for (addr = vma->vm_start;
  		     addr < vma->vm_end;
  		     addr += PAGE_SIZE
  		     ) {
  			struct vm_area_struct *vma;
  			struct page *page;
  
  			if (get_user_pages(current, current->mm, addr, 1, 0, 1,
  					   &page, &vma) <= 0) {
  				DUMP_SEEK(file->f_pos + PAGE_SIZE);
  			}
  			else if (page == ZERO_PAGE(addr)) {
  				DUMP_SEEK(file->f_pos + PAGE_SIZE);
  				page_cache_release(page);
  			}
  			else {
  				void *kaddr;
  
  				flush_cache_page(vma, addr, page_to_pfn(page));
  				kaddr = kmap(page);
  				if ((*size += PAGE_SIZE) > *limit ||
  				    !dump_write(file, kaddr, PAGE_SIZE)
  				    ) {
  					kunmap(page);
  					page_cache_release(page);
  					return -EIO;
  				}
  				kunmap(page);
  				page_cache_release(page);
  			}
  		}
  	}
  
  	return 0;
  
  end_coredump:
  	return -EFBIG;
  }
  #endif
  
  /*
   * dump the segments for a NOMMU process
   */
  #ifndef CONFIG_MMU
  static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
  				   size_t *size, unsigned long *limit)
  {
  	struct vm_list_struct *vml;
  
  	for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
  	struct vm_area_struct *vma = vml->vma;
  
  		if (!maydump(vma))
  			continue;
  
  		if ((*size += PAGE_SIZE) > *limit)
  			return -EFBIG;
  
  		if (!dump_write(file, (void *) vma->vm_start,
  				vma->vm_end - vma->vm_start))
  			return -EIO;
  	}
  
  	return 0;
  }
  #endif
  
  /*
   * 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.
   */
  static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
  			       struct file *file)
  {
  #define	NUM_NOTES	6
  	int has_dumped = 0;
  	mm_segment_t fs;
  	int segs;
  	size_t size = 0;
  	int i;
  	struct vm_area_struct *vma;
  	struct elfhdr *elf = NULL;
  	loff_t offset = 0, dataoff;
  	unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
  	int numnote;
  	struct memelfnote *notes = NULL;
  	struct elf_prstatus *prstatus = NULL;	/* NT_PRSTATUS */
  	struct elf_prpsinfo *psinfo = NULL;	/* NT_PRPSINFO */
   	struct task_struct *g, *p;
   	LIST_HEAD(thread_list);
   	struct list_head *t;
  	elf_fpregset_t *fpu = NULL;
  #ifdef ELF_CORE_COPY_XFPREGS
  	elf_fpxregset_t *xfpu = NULL;
  #endif
  	int thread_status_size = 0;
  #ifndef CONFIG_MMU
  	struct vm_list_struct *vml;
  #endif
  	elf_addr_t *auxv;
  
  	/*
  	 * We no longer stop all VM operations.
  	 *
  	 * 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.
  	 *
  	 * Only ptrace can touch these memory addresses, but it doesn't change
  	 * the map_count or the pages allocated. So no possibility of crashing
  	 * 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)
  		goto cleanup;
  	prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
  	if (!prstatus)
  		goto cleanup;
  	psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
  	if (!psinfo)
  		goto cleanup;
  	notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
  	if (!notes)
  		goto cleanup;
  	fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
  	if (!fpu)
  		goto cleanup;
  #ifdef ELF_CORE_COPY_XFPREGS
  	xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
  	if (!xfpu)
  		goto cleanup;
  #endif
  
  	if (signr) {
  		struct elf_thread_status *tmp;
bce9a234c   Oleg Nesterov   [PATCH] elf_fdpic...
1576
  		rcu_read_lock();
6d8c4e3b0   David Howells   [PATCH] FDPIC: Ad...
1577
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  		do_each_thread(g,p)
  			if (current->mm == p->mm && current != p) {
  				tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
  				if (!tmp) {
bce9a234c   Oleg Nesterov   [PATCH] elf_fdpic...
1581
  					rcu_read_unlock();
6d8c4e3b0   David Howells   [PATCH] FDPIC: Ad...
1582
1583
  					goto cleanup;
  				}
6d8c4e3b0   David Howells   [PATCH] FDPIC: Ad...
1584
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1587
  				tmp->thread = p;
  				list_add(&tmp->list, &thread_list);
  			}
  		while_each_thread(g,p);
bce9a234c   Oleg Nesterov   [PATCH] elf_fdpic...
1588
  		rcu_read_unlock();
6d8c4e3b0   David Howells   [PATCH] FDPIC: Ad...
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  		list_for_each(t, &thread_list) {
  			struct elf_thread_status *tmp;
  			int sz;
  
  			tmp = list_entry(t, struct elf_thread_status, list);
  			sz = elf_dump_thread_status(signr, tmp);
  			thread_status_size += sz;
  		}
  	}
  
  	/* now collect the dump for the current */
  	fill_prstatus(prstatus, current, signr);
  	elf_core_copy_regs(&prstatus->pr_reg, regs);
  
  #ifdef CONFIG_MMU
  	segs = current->mm->map_count;
  #else
  	segs = 0;
  	for (vml = current->mm->context.vmlist; vml; vml = vml->next)
  	    segs++;
  #endif
  #ifdef ELF_CORE_EXTRA_PHDRS
  	segs += ELF_CORE_EXTRA_PHDRS;
  #endif
  
  	/* Set up header */
  	fill_elf_fdpic_header(elf, segs + 1);	/* including notes section */
  
  	has_dumped = 1;
  	current->flags |= PF_DUMPCORE;
  
  	/*
  	 * Set up the notes in similar form to SVR4 core dumps made
  	 * with info from their /proc.
  	 */
  
  	fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
  	fill_psinfo(psinfo, current->group_leader, current->mm);
  	fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
  
  	numnote = 2;
  
  	auxv = (elf_addr_t *) current->mm->saved_auxv;
  
  	i = 0;
  	do
  		i += 2;
  	while (auxv[i - 2] != AT_NULL);
  	fill_note(&notes[numnote++], "CORE", NT_AUXV,
  		  i * sizeof(elf_addr_t), auxv);
  
    	/* Try to dump the FPU. */
  	if ((prstatus->pr_fpvalid =
  	     elf_core_copy_task_fpregs(current, regs, fpu)))
  		fill_note(notes + numnote++,
  			  "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
  #ifdef ELF_CORE_COPY_XFPREGS
  	if (elf_core_copy_task_xfpregs(current, xfpu))
  		fill_note(notes + numnote++,
  			  "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
  #endif
  
  	fs = get_fs();
  	set_fs(KERNEL_DS);
  
  	DUMP_WRITE(elf, sizeof(*elf));
  	offset += sizeof(*elf);				/* Elf header */
  	offset += (segs+1) * sizeof(struct elf_phdr);	/* Program headers */
  
  	/* Write notes phdr entry */
  	{
  		struct elf_phdr phdr;
  		int sz = 0;
  
  		for (i = 0; i < numnote; i++)
  			sz += notesize(notes + i);
  
  		sz += thread_status_size;
  
  		fill_elf_note_phdr(&phdr, sz, offset);
  		offset += sz;
  		DUMP_WRITE(&phdr, sizeof(phdr));
  	}
  
  	/* Page-align dumped data */
  	dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
  
  	/* write program headers for segments dump */
  	for (
  #ifdef CONFIG_MMU
  		vma = current->mm->mmap; vma; vma = vma->vm_next
  #else
  			vml = current->mm->context.vmlist; vml; vml = vml->next
  #endif
  	     ) {
  		struct elf_phdr phdr;
  		size_t sz;
  
  #ifndef CONFIG_MMU
  		vma = vml->vma;
  #endif
  
  		sz = vma->vm_end - vma->vm_start;
  
  		phdr.p_type = PT_LOAD;
  		phdr.p_offset = offset;
  		phdr.p_vaddr = vma->vm_start;
  		phdr.p_paddr = 0;
  		phdr.p_filesz = maydump(vma) ? sz : 0;
  		phdr.p_memsz = sz;
  		offset += phdr.p_filesz;
  		phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
  		if (vma->vm_flags & VM_WRITE)
  			phdr.p_flags |= PF_W;
  		if (vma->vm_flags & VM_EXEC)
  			phdr.p_flags |= PF_X;
  		phdr.p_align = ELF_EXEC_PAGESIZE;
  
  		DUMP_WRITE(&phdr, sizeof(phdr));
  	}
  
  #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
  	ELF_CORE_WRITE_EXTRA_PHDRS;
  #endif
  
   	/* write out the notes section */
  	for (i = 0; i < numnote; i++)
  		if (!writenote(notes + i, file))
  			goto end_coredump;
  
  	/* write out the thread status notes section */
  	list_for_each(t, &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))
  				goto end_coredump;
  	}
  
  	DUMP_SEEK(dataoff);
  
  	if (elf_fdpic_dump_segments(file, current->mm, &size, &limit) < 0)
  		goto end_coredump;
  
  #ifdef ELF_CORE_WRITE_EXTRA_DATA
  	ELF_CORE_WRITE_EXTRA_DATA;
  #endif
  
  	if (file->f_pos != offset) {
  		/* Sanity check */
  		printk(KERN_WARNING
  		       "elf_core_dump: file->f_pos (%lld) != offset (%lld)
  ",
  		       file->f_pos, offset);
  	}
  
  end_coredump:
  	set_fs(fs);
  
  cleanup:
  	while (!list_empty(&thread_list)) {
  		struct list_head *tmp = thread_list.next;
  		list_del(tmp);
  		kfree(list_entry(tmp, struct elf_thread_status, list));
  	}
  
  	kfree(elf);
  	kfree(prstatus);
  	kfree(psinfo);
  	kfree(notes);
  	kfree(fpu);
  #ifdef ELF_CORE_COPY_XFPREGS
  	kfree(xfpu);
  #endif
  	return has_dumped;
  #undef NUM_NOTES
  }
  
  #endif		/* USE_ELF_CORE_DUMP */