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fs/exec.c 40.6 KB
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  /*
   *  linux/fs/exec.c
   *
   *  Copyright (C) 1991, 1992  Linus Torvalds
   */
  
  /*
   * #!-checking implemented by tytso.
   */
  /*
   * Demand-loading implemented 01.12.91 - no need to read anything but
   * the header into memory. The inode of the executable is put into
   * "current->executable", and page faults do the actual loading. Clean.
   *
   * Once more I can proudly say that linux stood up to being changed: it
   * was less than 2 hours work to get demand-loading completely implemented.
   *
   * Demand loading changed July 1993 by Eric Youngdale.   Use mmap instead,
   * current->executable is only used by the procfs.  This allows a dispatch
   * table to check for several different types  of binary formats.  We keep
   * trying until we recognize the file or we run out of supported binary
   * formats. 
   */
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  #include <linux/slab.h>
  #include <linux/file.h>
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  #include <linux/fdtable.h>
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  #include <linux/mm.h>
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  #include <linux/vmacache.h>
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  #include <linux/stat.h>
  #include <linux/fcntl.h>
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  #include <linux/swap.h>
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  #include <linux/string.h>
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  #include <linux/init.h>
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  #include <linux/pagemap.h>
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  #include <linux/perf_event.h>
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  #include <linux/highmem.h>
  #include <linux/spinlock.h>
  #include <linux/key.h>
  #include <linux/personality.h>
  #include <linux/binfmts.h>
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  #include <linux/utsname.h>
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  #include <linux/pid_namespace.h>
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  #include <linux/module.h>
  #include <linux/namei.h>
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  #include <linux/mount.h>
  #include <linux/security.h>
  #include <linux/syscalls.h>
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  #include <linux/tsacct_kern.h>
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  #include <linux/cn_proc.h>
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  #include <linux/audit.h>
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  #include <linux/tracehook.h>
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  #include <linux/kmod.h>
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  #include <linux/fsnotify.h>
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  #include <linux/fs_struct.h>
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  #include <linux/pipe_fs_i.h>
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  #include <linux/oom.h>
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  #include <linux/compat.h>
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  #include <asm/uaccess.h>
  #include <asm/mmu_context.h>
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  #include <asm/tlb.h>
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  #include <trace/events/task.h>
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  #include "internal.h"
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  #include <trace/events/sched.h>
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  int suid_dumpable = 0;
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  static LIST_HEAD(formats);
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  static DEFINE_RWLOCK(binfmt_lock);
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  void __register_binfmt(struct linux_binfmt * fmt, int insert)
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  {
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  	BUG_ON(!fmt);
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  	if (WARN_ON(!fmt->load_binary))
  		return;
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  	write_lock(&binfmt_lock);
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  	insert ? list_add(&fmt->lh, &formats) :
  		 list_add_tail(&fmt->lh, &formats);
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  	write_unlock(&binfmt_lock);
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  }
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  EXPORT_SYMBOL(__register_binfmt);
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  void unregister_binfmt(struct linux_binfmt * fmt)
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  {
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  	write_lock(&binfmt_lock);
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  	list_del(&fmt->lh);
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  	write_unlock(&binfmt_lock);
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  }
  
  EXPORT_SYMBOL(unregister_binfmt);
  
  static inline void put_binfmt(struct linux_binfmt * fmt)
  {
  	module_put(fmt->module);
  }
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  #ifdef CONFIG_USELIB
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  /*
   * Note that a shared library must be both readable and executable due to
   * security reasons.
   *
   * Also note that we take the address to load from from the file itself.
   */
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  SYSCALL_DEFINE1(uselib, const char __user *, library)
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  {
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  	struct linux_binfmt *fmt;
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  	struct file *file;
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  	struct filename *tmp = getname(library);
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  	int error = PTR_ERR(tmp);
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  	static const struct open_flags uselib_flags = {
  		.open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC,
  		.acc_mode = MAY_READ | MAY_EXEC | MAY_OPEN,
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  		.intent = LOOKUP_OPEN,
  		.lookup_flags = LOOKUP_FOLLOW,
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  	};
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  	if (IS_ERR(tmp))
  		goto out;
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  	file = do_filp_open(AT_FDCWD, tmp, &uselib_flags);
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  	putname(tmp);
  	error = PTR_ERR(file);
  	if (IS_ERR(file))
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  		goto out;
  
  	error = -EINVAL;
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  	if (!S_ISREG(file_inode(file)->i_mode))
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  		goto exit;
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  	error = -EACCES;
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  	if (file->f_path.mnt->mnt_flags & MNT_NOEXEC)
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  		goto exit;
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  	fsnotify_open(file);
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  	error = -ENOEXEC;
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  	read_lock(&binfmt_lock);
  	list_for_each_entry(fmt, &formats, lh) {
  		if (!fmt->load_shlib)
  			continue;
  		if (!try_module_get(fmt->module))
  			continue;
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  		read_unlock(&binfmt_lock);
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  		error = fmt->load_shlib(file);
  		read_lock(&binfmt_lock);
  		put_binfmt(fmt);
  		if (error != -ENOEXEC)
  			break;
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  	}
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  	read_unlock(&binfmt_lock);
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  exit:
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  	fput(file);
  out:
    	return error;
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  }
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  #endif /* #ifdef CONFIG_USELIB */
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  #ifdef CONFIG_MMU
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  /*
   * The nascent bprm->mm is not visible until exec_mmap() but it can
   * use a lot of memory, account these pages in current->mm temporary
   * for oom_badness()->get_mm_rss(). Once exec succeeds or fails, we
   * change the counter back via acct_arg_size(0).
   */
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  static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
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  {
  	struct mm_struct *mm = current->mm;
  	long diff = (long)(pages - bprm->vma_pages);
  
  	if (!mm || !diff)
  		return;
  
  	bprm->vma_pages = pages;
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  	add_mm_counter(mm, MM_ANONPAGES, diff);
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  }
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  static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
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  		int write)
  {
  	struct page *page;
  	int ret;
  
  #ifdef CONFIG_STACK_GROWSUP
  	if (write) {
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  		ret = expand_downwards(bprm->vma, pos);
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  		if (ret < 0)
  			return NULL;
  	}
  #endif
  	ret = get_user_pages(current, bprm->mm, pos,
  			1, write, 1, &page, NULL);
  	if (ret <= 0)
  		return NULL;
  
  	if (write) {
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  		unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start;
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  		struct rlimit *rlim;
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  		acct_arg_size(bprm, size / PAGE_SIZE);
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  		/*
  		 * We've historically supported up to 32 pages (ARG_MAX)
  		 * of argument strings even with small stacks
  		 */
  		if (size <= ARG_MAX)
  			return page;
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  		/*
  		 * Limit to 1/4-th the stack size for the argv+env strings.
  		 * This ensures that:
  		 *  - the remaining binfmt code will not run out of stack space,
  		 *  - the program will have a reasonable amount of stack left
  		 *    to work from.
  		 */
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  		rlim = current->signal->rlim;
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  		if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur) / 4) {
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  			put_page(page);
  			return NULL;
  		}
  	}
  
  	return page;
  }
  
  static void put_arg_page(struct page *page)
  {
  	put_page(page);
  }
  
  static void free_arg_page(struct linux_binprm *bprm, int i)
  {
  }
  
  static void free_arg_pages(struct linux_binprm *bprm)
  {
  }
  
  static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,
  		struct page *page)
  {
  	flush_cache_page(bprm->vma, pos, page_to_pfn(page));
  }
  
  static int __bprm_mm_init(struct linux_binprm *bprm)
  {
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  	int err;
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  	struct vm_area_struct *vma = NULL;
  	struct mm_struct *mm = bprm->mm;
  
  	bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
  	if (!vma)
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  		return -ENOMEM;
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  	down_write(&mm->mmap_sem);
  	vma->vm_mm = mm;
  
  	/*
  	 * Place the stack at the largest stack address the architecture
  	 * supports. Later, we'll move this to an appropriate place. We don't
  	 * use STACK_TOP because that can depend on attributes which aren't
  	 * configured yet.
  	 */
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  	BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP);
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  	vma->vm_end = STACK_TOP_MAX;
  	vma->vm_start = vma->vm_end - PAGE_SIZE;
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  	vma->vm_flags = VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP;
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  	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
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  	INIT_LIST_HEAD(&vma->anon_vma_chain);
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  	err = insert_vm_struct(mm, vma);
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  	if (err)
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  		goto err;
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  	mm->stack_vm = mm->total_vm = 1;
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  	arch_bprm_mm_init(mm, vma);
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  	up_write(&mm->mmap_sem);
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  	bprm->p = vma->vm_end - sizeof(void *);
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  	return 0;
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  err:
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  	up_write(&mm->mmap_sem);
  	bprm->vma = NULL;
  	kmem_cache_free(vm_area_cachep, vma);
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  	return err;
  }
  
  static bool valid_arg_len(struct linux_binprm *bprm, long len)
  {
  	return len <= MAX_ARG_STRLEN;
  }
  
  #else
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  static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
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  {
  }
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  static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
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  		int write)
  {
  	struct page *page;
  
  	page = bprm->page[pos / PAGE_SIZE];
  	if (!page && write) {
  		page = alloc_page(GFP_HIGHUSER|__GFP_ZERO);
  		if (!page)
  			return NULL;
  		bprm->page[pos / PAGE_SIZE] = page;
  	}
  
  	return page;
  }
  
  static void put_arg_page(struct page *page)
  {
  }
  
  static void free_arg_page(struct linux_binprm *bprm, int i)
  {
  	if (bprm->page[i]) {
  		__free_page(bprm->page[i]);
  		bprm->page[i] = NULL;
  	}
  }
  
  static void free_arg_pages(struct linux_binprm *bprm)
  {
  	int i;
  
  	for (i = 0; i < MAX_ARG_PAGES; i++)
  		free_arg_page(bprm, i);
  }
  
  static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,
  		struct page *page)
  {
  }
  
  static int __bprm_mm_init(struct linux_binprm *bprm)
  {
  	bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *);
  	return 0;
  }
  
  static bool valid_arg_len(struct linux_binprm *bprm, long len)
  {
  	return len <= bprm->p;
  }
  
  #endif /* CONFIG_MMU */
  
  /*
   * Create a new mm_struct and populate it with a temporary stack
   * vm_area_struct.  We don't have enough context at this point to set the stack
   * flags, permissions, and offset, so we use temporary values.  We'll update
   * them later in setup_arg_pages().
   */
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  static int bprm_mm_init(struct linux_binprm *bprm)
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  {
  	int err;
  	struct mm_struct *mm = NULL;
  
  	bprm->mm = mm = mm_alloc();
  	err = -ENOMEM;
  	if (!mm)
  		goto err;
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  	err = __bprm_mm_init(bprm);
  	if (err)
  		goto err;
  
  	return 0;
  
  err:
  	if (mm) {
  		bprm->mm = NULL;
  		mmdrop(mm);
  	}
  
  	return err;
  }
ba2d01629   Oleg Nesterov   exec: introduce s...
372
  struct user_arg_ptr {
0e028465d   Oleg Nesterov   exec: unify do_ex...
373
374
375
376
377
378
  #ifdef CONFIG_COMPAT
  	bool is_compat;
  #endif
  	union {
  		const char __user *const __user *native;
  #ifdef CONFIG_COMPAT
38b983b34   Al Viro   generic sys_execve()
379
  		const compat_uptr_t __user *compat;
0e028465d   Oleg Nesterov   exec: unify do_ex...
380
381
  #endif
  	} ptr;
ba2d01629   Oleg Nesterov   exec: introduce s...
382
383
384
  };
  
  static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr)
1d1dbf813   Oleg Nesterov   exec: introduce g...
385
  {
0e028465d   Oleg Nesterov   exec: unify do_ex...
386
387
388
389
390
391
392
393
  	const char __user *native;
  
  #ifdef CONFIG_COMPAT
  	if (unlikely(argv.is_compat)) {
  		compat_uptr_t compat;
  
  		if (get_user(compat, argv.ptr.compat + nr))
  			return ERR_PTR(-EFAULT);
1d1dbf813   Oleg Nesterov   exec: introduce g...
394

0e028465d   Oleg Nesterov   exec: unify do_ex...
395
396
397
398
399
  		return compat_ptr(compat);
  	}
  #endif
  
  	if (get_user(native, argv.ptr.native + nr))
1d1dbf813   Oleg Nesterov   exec: introduce g...
400
  		return ERR_PTR(-EFAULT);
0e028465d   Oleg Nesterov   exec: unify do_ex...
401
  	return native;
1d1dbf813   Oleg Nesterov   exec: introduce g...
402
  }
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
403
404
405
  /*
   * count() counts the number of strings in array ARGV.
   */
ba2d01629   Oleg Nesterov   exec: introduce s...
406
  static int count(struct user_arg_ptr argv, int max)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
407
408
  {
  	int i = 0;
0e028465d   Oleg Nesterov   exec: unify do_ex...
409
  	if (argv.ptr.native != NULL) {
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
410
  		for (;;) {
1d1dbf813   Oleg Nesterov   exec: introduce g...
411
  			const char __user *p = get_user_arg_ptr(argv, i);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
412

1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
413
414
  			if (!p)
  				break;
1d1dbf813   Oleg Nesterov   exec: introduce g...
415
416
417
  
  			if (IS_ERR(p))
  				return -EFAULT;
6d92d4f6a   Xi Wang   fs/exec.c: work a...
418
  			if (i >= max)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
419
  				return -E2BIG;
6d92d4f6a   Xi Wang   fs/exec.c: work a...
420
  			++i;
9aea5a65a   Roland McGrath   execve: make resp...
421
422
423
  
  			if (fatal_signal_pending(current))
  				return -ERESTARTNOHAND;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
424
425
426
427
428
429
430
  			cond_resched();
  		}
  	}
  	return i;
  }
  
  /*
b6a2fea39   Ollie Wild   mm: variable leng...
431
432
433
   * 'copy_strings()' copies argument/environment strings from the old
   * processes's memory to the new process's stack.  The call to get_user_pages()
   * ensures the destination page is created and not swapped out.
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
434
   */
ba2d01629   Oleg Nesterov   exec: introduce s...
435
  static int copy_strings(int argc, struct user_arg_ptr argv,
75c96f858   Adrian Bunk   [PATCH] make some...
436
  			struct linux_binprm *bprm)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
437
438
439
  {
  	struct page *kmapped_page = NULL;
  	char *kaddr = NULL;
b6a2fea39   Ollie Wild   mm: variable leng...
440
  	unsigned long kpos = 0;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
441
442
443
  	int ret;
  
  	while (argc-- > 0) {
d7627467b   David Howells   Make do_execve() ...
444
  		const char __user *str;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
445
446
  		int len;
  		unsigned long pos;
1d1dbf813   Oleg Nesterov   exec: introduce g...
447
448
449
  		ret = -EFAULT;
  		str = get_user_arg_ptr(argv, argc);
  		if (IS_ERR(str))
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
450
  			goto out;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
451

1d1dbf813   Oleg Nesterov   exec: introduce g...
452
453
454
455
456
457
  		len = strnlen_user(str, MAX_ARG_STRLEN);
  		if (!len)
  			goto out;
  
  		ret = -E2BIG;
  		if (!valid_arg_len(bprm, len))
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
458
  			goto out;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
459

b6a2fea39   Ollie Wild   mm: variable leng...
460
  		/* We're going to work our way backwords. */
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
461
  		pos = bprm->p;
b6a2fea39   Ollie Wild   mm: variable leng...
462
463
  		str += len;
  		bprm->p -= len;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
464
465
  
  		while (len > 0) {
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
466
  			int offset, bytes_to_copy;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
467

9aea5a65a   Roland McGrath   execve: make resp...
468
469
470
471
  			if (fatal_signal_pending(current)) {
  				ret = -ERESTARTNOHAND;
  				goto out;
  			}
7993bc1f4   Roland McGrath   execve: improve i...
472
  			cond_resched();
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
473
  			offset = pos % PAGE_SIZE;
b6a2fea39   Ollie Wild   mm: variable leng...
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
  			if (offset == 0)
  				offset = PAGE_SIZE;
  
  			bytes_to_copy = offset;
  			if (bytes_to_copy > len)
  				bytes_to_copy = len;
  
  			offset -= bytes_to_copy;
  			pos -= bytes_to_copy;
  			str -= bytes_to_copy;
  			len -= bytes_to_copy;
  
  			if (!kmapped_page || kpos != (pos & PAGE_MASK)) {
  				struct page *page;
  
  				page = get_arg_page(bprm, pos, 1);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
490
  				if (!page) {
b6a2fea39   Ollie Wild   mm: variable leng...
491
  					ret = -E2BIG;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
492
493
  					goto out;
  				}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
494

b6a2fea39   Ollie Wild   mm: variable leng...
495
496
  				if (kmapped_page) {
  					flush_kernel_dcache_page(kmapped_page);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
497
  					kunmap(kmapped_page);
b6a2fea39   Ollie Wild   mm: variable leng...
498
499
  					put_arg_page(kmapped_page);
  				}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
500
501
  				kmapped_page = page;
  				kaddr = kmap(kmapped_page);
b6a2fea39   Ollie Wild   mm: variable leng...
502
503
  				kpos = pos & PAGE_MASK;
  				flush_arg_page(bprm, kpos, kmapped_page);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
504
  			}
b6a2fea39   Ollie Wild   mm: variable leng...
505
  			if (copy_from_user(kaddr+offset, str, bytes_to_copy)) {
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
506
507
508
  				ret = -EFAULT;
  				goto out;
  			}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
509
510
511
512
  		}
  	}
  	ret = 0;
  out:
b6a2fea39   Ollie Wild   mm: variable leng...
513
514
  	if (kmapped_page) {
  		flush_kernel_dcache_page(kmapped_page);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
515
  		kunmap(kmapped_page);
b6a2fea39   Ollie Wild   mm: variable leng...
516
517
  		put_arg_page(kmapped_page);
  	}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
518
519
520
521
522
523
  	return ret;
  }
  
  /*
   * Like copy_strings, but get argv and its values from kernel memory.
   */
ba2d01629   Oleg Nesterov   exec: introduce s...
524
  int copy_strings_kernel(int argc, const char *const *__argv,
d7627467b   David Howells   Make do_execve() ...
525
  			struct linux_binprm *bprm)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
526
527
528
  {
  	int r;
  	mm_segment_t oldfs = get_fs();
ba2d01629   Oleg Nesterov   exec: introduce s...
529
  	struct user_arg_ptr argv = {
0e028465d   Oleg Nesterov   exec: unify do_ex...
530
  		.ptr.native = (const char __user *const  __user *)__argv,
ba2d01629   Oleg Nesterov   exec: introduce s...
531
  	};
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
532
  	set_fs(KERNEL_DS);
ba2d01629   Oleg Nesterov   exec: introduce s...
533
  	r = copy_strings(argc, argv, bprm);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
534
  	set_fs(oldfs);
ba2d01629   Oleg Nesterov   exec: introduce s...
535

1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
536
537
  	return r;
  }
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
538
539
540
  EXPORT_SYMBOL(copy_strings_kernel);
  
  #ifdef CONFIG_MMU
b6a2fea39   Ollie Wild   mm: variable leng...
541

1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
542
  /*
b6a2fea39   Ollie Wild   mm: variable leng...
543
544
545
   * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX.  Once
   * the binfmt code determines where the new stack should reside, we shift it to
   * its final location.  The process proceeds as follows:
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
546
   *
b6a2fea39   Ollie Wild   mm: variable leng...
547
548
549
550
551
552
   * 1) Use shift to calculate the new vma endpoints.
   * 2) Extend vma to cover both the old and new ranges.  This ensures the
   *    arguments passed to subsequent functions are consistent.
   * 3) Move vma's page tables to the new range.
   * 4) Free up any cleared pgd range.
   * 5) Shrink the vma to cover only the new range.
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
553
   */
b6a2fea39   Ollie Wild   mm: variable leng...
554
  static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
555
556
  {
  	struct mm_struct *mm = vma->vm_mm;
b6a2fea39   Ollie Wild   mm: variable leng...
557
558
559
560
561
  	unsigned long old_start = vma->vm_start;
  	unsigned long old_end = vma->vm_end;
  	unsigned long length = old_end - old_start;
  	unsigned long new_start = old_start - shift;
  	unsigned long new_end = old_end - shift;
d16dfc550   Peter Zijlstra   mm: mmu_gather re...
562
  	struct mmu_gather tlb;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
563

b6a2fea39   Ollie Wild   mm: variable leng...
564
  	BUG_ON(new_start > new_end);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
565

b6a2fea39   Ollie Wild   mm: variable leng...
566
567
568
569
570
571
572
573
574
575
  	/*
  	 * ensure there are no vmas between where we want to go
  	 * and where we are
  	 */
  	if (vma != find_vma(mm, new_start))
  		return -EFAULT;
  
  	/*
  	 * cover the whole range: [new_start, old_end)
  	 */
5beb49305   Rik van Riel   mm: change anon_v...
576
577
  	if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL))
  		return -ENOMEM;
b6a2fea39   Ollie Wild   mm: variable leng...
578
579
580
581
582
583
  
  	/*
  	 * move the page tables downwards, on failure we rely on
  	 * process cleanup to remove whatever mess we made.
  	 */
  	if (length != move_page_tables(vma, old_start,
38a76013a   Michel Lespinasse   mm: avoid taking ...
584
  				       vma, new_start, length, false))
b6a2fea39   Ollie Wild   mm: variable leng...
585
586
587
  		return -ENOMEM;
  
  	lru_add_drain();
2b047252d   Linus Torvalds   Fix TLB gather vi...
588
  	tlb_gather_mmu(&tlb, mm, old_start, old_end);
b6a2fea39   Ollie Wild   mm: variable leng...
589
590
591
592
  	if (new_end > old_start) {
  		/*
  		 * when the old and new regions overlap clear from new_end.
  		 */
d16dfc550   Peter Zijlstra   mm: mmu_gather re...
593
  		free_pgd_range(&tlb, new_end, old_end, new_end,
6ee8630e0   Hugh Dickins   mm: allow arch co...
594
  			vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING);
b6a2fea39   Ollie Wild   mm: variable leng...
595
596
597
598
599
600
601
  	} else {
  		/*
  		 * otherwise, clean from old_start; this is done to not touch
  		 * the address space in [new_end, old_start) some architectures
  		 * have constraints on va-space that make this illegal (IA64) -
  		 * for the others its just a little faster.
  		 */
d16dfc550   Peter Zijlstra   mm: mmu_gather re...
602
  		free_pgd_range(&tlb, old_start, old_end, new_end,
6ee8630e0   Hugh Dickins   mm: allow arch co...
603
  			vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
604
  	}
2b047252d   Linus Torvalds   Fix TLB gather vi...
605
  	tlb_finish_mmu(&tlb, old_start, old_end);
b6a2fea39   Ollie Wild   mm: variable leng...
606
607
  
  	/*
5beb49305   Rik van Riel   mm: change anon_v...
608
  	 * Shrink the vma to just the new range.  Always succeeds.
b6a2fea39   Ollie Wild   mm: variable leng...
609
610
611
612
  	 */
  	vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL);
  
  	return 0;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
613
  }
b6a2fea39   Ollie Wild   mm: variable leng...
614
615
616
617
  /*
   * Finalizes the stack vm_area_struct. The flags and permissions are updated,
   * the stack is optionally relocated, and some extra space is added.
   */
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
618
619
620
621
  int setup_arg_pages(struct linux_binprm *bprm,
  		    unsigned long stack_top,
  		    int executable_stack)
  {
b6a2fea39   Ollie Wild   mm: variable leng...
622
623
  	unsigned long ret;
  	unsigned long stack_shift;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
624
  	struct mm_struct *mm = current->mm;
b6a2fea39   Ollie Wild   mm: variable leng...
625
626
627
628
  	struct vm_area_struct *vma = bprm->vma;
  	struct vm_area_struct *prev = NULL;
  	unsigned long vm_flags;
  	unsigned long stack_base;
803bf5ec2   Michael Neuling   fs/exec.c: restri...
629
630
631
  	unsigned long stack_size;
  	unsigned long stack_expand;
  	unsigned long rlim_stack;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
632
633
  
  #ifdef CONFIG_STACK_GROWSUP
d71f290b4   James Hogan   metag: Reduce max...
634
  	/* Limit stack size */
d554ed895   Jiri Slaby   fs: use rlimit he...
635
  	stack_base = rlimit_max(RLIMIT_STACK);
d71f290b4   James Hogan   metag: Reduce max...
636
637
  	if (stack_base > STACK_SIZE_MAX)
  		stack_base = STACK_SIZE_MAX;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
638

d045c77c1   Helge Deller   parisc,metag: Fix...
639
640
  	/* Add space for stack randomization. */
  	stack_base += (STACK_RND_MASK << PAGE_SHIFT);
b6a2fea39   Ollie Wild   mm: variable leng...
641
642
643
  	/* Make sure we didn't let the argument array grow too large. */
  	if (vma->vm_end - vma->vm_start > stack_base)
  		return -ENOMEM;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
644

b6a2fea39   Ollie Wild   mm: variable leng...
645
  	stack_base = PAGE_ALIGN(stack_top - stack_base);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
646

b6a2fea39   Ollie Wild   mm: variable leng...
647
648
649
  	stack_shift = vma->vm_start - stack_base;
  	mm->arg_start = bprm->p - stack_shift;
  	bprm->p = vma->vm_end - stack_shift;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
650
  #else
b6a2fea39   Ollie Wild   mm: variable leng...
651
652
  	stack_top = arch_align_stack(stack_top);
  	stack_top = PAGE_ALIGN(stack_top);
1b528181b   Roland McGrath   setup_arg_pages: ...
653
654
655
656
  
  	if (unlikely(stack_top < mmap_min_addr) ||
  	    unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr))
  		return -ENOMEM;
b6a2fea39   Ollie Wild   mm: variable leng...
657
658
659
  	stack_shift = vma->vm_end - stack_top;
  
  	bprm->p -= stack_shift;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
660
  	mm->arg_start = bprm->p;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
661
  #endif
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
662
  	if (bprm->loader)
b6a2fea39   Ollie Wild   mm: variable leng...
663
664
  		bprm->loader -= stack_shift;
  	bprm->exec -= stack_shift;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
665

1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
666
  	down_write(&mm->mmap_sem);
96a8e13ed   Hugh Dickins   exec: fix stack e...
667
  	vm_flags = VM_STACK_FLAGS;
b6a2fea39   Ollie Wild   mm: variable leng...
668
669
670
671
672
673
674
675
676
677
678
  
  	/*
  	 * Adjust stack execute permissions; explicitly enable for
  	 * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone
  	 * (arch default) otherwise.
  	 */
  	if (unlikely(executable_stack == EXSTACK_ENABLE_X))
  		vm_flags |= VM_EXEC;
  	else if (executable_stack == EXSTACK_DISABLE_X)
  		vm_flags &= ~VM_EXEC;
  	vm_flags |= mm->def_flags;
a8bef8ff6   Mel Gorman   mm: migration: av...
679
  	vm_flags |= VM_STACK_INCOMPLETE_SETUP;
b6a2fea39   Ollie Wild   mm: variable leng...
680
681
682
683
684
685
686
687
688
689
  
  	ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end,
  			vm_flags);
  	if (ret)
  		goto out_unlock;
  	BUG_ON(prev != vma);
  
  	/* Move stack pages down in memory. */
  	if (stack_shift) {
  		ret = shift_arg_pages(vma, stack_shift);
fc63cf237   Anton Blanchard   exec: setup_arg_p...
690
691
  		if (ret)
  			goto out_unlock;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
692
  	}
a8bef8ff6   Mel Gorman   mm: migration: av...
693
694
  	/* mprotect_fixup is overkill to remove the temporary stack flags */
  	vma->vm_flags &= ~VM_STACK_INCOMPLETE_SETUP;
5ef097dd7   Michael Neuling   exec: create init...
695
  	stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */
803bf5ec2   Michael Neuling   fs/exec.c: restri...
696
697
698
699
700
701
  	stack_size = vma->vm_end - vma->vm_start;
  	/*
  	 * Align this down to a page boundary as expand_stack
  	 * will align it up.
  	 */
  	rlim_stack = rlimit(RLIMIT_STACK) & PAGE_MASK;
b6a2fea39   Ollie Wild   mm: variable leng...
702
  #ifdef CONFIG_STACK_GROWSUP
803bf5ec2   Michael Neuling   fs/exec.c: restri...
703
704
705
706
  	if (stack_size + stack_expand > rlim_stack)
  		stack_base = vma->vm_start + rlim_stack;
  	else
  		stack_base = vma->vm_end + stack_expand;
b6a2fea39   Ollie Wild   mm: variable leng...
707
  #else
803bf5ec2   Michael Neuling   fs/exec.c: restri...
708
709
710
711
  	if (stack_size + stack_expand > rlim_stack)
  		stack_base = vma->vm_end - rlim_stack;
  	else
  		stack_base = vma->vm_start - stack_expand;
b6a2fea39   Ollie Wild   mm: variable leng...
712
  #endif
3af9e8592   Eric B Munson   perf: Add non-exe...
713
  	current->mm->start_stack = bprm->p;
b6a2fea39   Ollie Wild   mm: variable leng...
714
715
716
717
718
  	ret = expand_stack(vma, stack_base);
  	if (ret)
  		ret = -EFAULT;
  
  out_unlock:
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
719
  	up_write(&mm->mmap_sem);
fc63cf237   Anton Blanchard   exec: setup_arg_p...
720
  	return ret;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
721
  }
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
722
  EXPORT_SYMBOL(setup_arg_pages);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
723
  #endif /* CONFIG_MMU */
51f39a1f0   David Drysdale   syscalls: impleme...
724
  static struct file *do_open_execat(int fd, struct filename *name, int flags)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
725
  {
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
726
  	struct file *file;
e56b6a5dd   Christoph Hellwig   Re: [PATCH 3/6] v...
727
  	int err;
51f39a1f0   David Drysdale   syscalls: impleme...
728
  	struct open_flags open_exec_flags = {
47c805dc2   Al Viro   switch do_filp_op...
729
730
  		.open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC,
  		.acc_mode = MAY_EXEC | MAY_OPEN,
f9652e10c   Al Viro   allow build_open_...
731
732
  		.intent = LOOKUP_OPEN,
  		.lookup_flags = LOOKUP_FOLLOW,
47c805dc2   Al Viro   switch do_filp_op...
733
  	};
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
734

51f39a1f0   David Drysdale   syscalls: impleme...
735
736
737
738
739
740
741
742
  	if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0)
  		return ERR_PTR(-EINVAL);
  	if (flags & AT_SYMLINK_NOFOLLOW)
  		open_exec_flags.lookup_flags &= ~LOOKUP_FOLLOW;
  	if (flags & AT_EMPTY_PATH)
  		open_exec_flags.lookup_flags |= LOOKUP_EMPTY;
  
  	file = do_filp_open(fd, name, &open_exec_flags);
6e8341a11   Al Viro   Switch open_exec(...
743
  	if (IS_ERR(file))
e56b6a5dd   Christoph Hellwig   Re: [PATCH 3/6] v...
744
745
746
  		goto out;
  
  	err = -EACCES;
496ad9aa8   Al Viro   new helper: file_...
747
  	if (!S_ISREG(file_inode(file)->i_mode))
6e8341a11   Al Viro   Switch open_exec(...
748
  		goto exit;
e56b6a5dd   Christoph Hellwig   Re: [PATCH 3/6] v...
749

6e8341a11   Al Viro   Switch open_exec(...
750
751
  	if (file->f_path.mnt->mnt_flags & MNT_NOEXEC)
  		goto exit;
e56b6a5dd   Christoph Hellwig   Re: [PATCH 3/6] v...
752
753
  
  	err = deny_write_access(file);
6e8341a11   Al Viro   Switch open_exec(...
754
755
  	if (err)
  		goto exit;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
756

51f39a1f0   David Drysdale   syscalls: impleme...
757
758
  	if (name->name[0] != '\0')
  		fsnotify_open(file);
6e8341a11   Al Viro   Switch open_exec(...
759
  out:
e56b6a5dd   Christoph Hellwig   Re: [PATCH 3/6] v...
760
  	return file;
6e8341a11   Al Viro   Switch open_exec(...
761
762
  exit:
  	fput(file);
e56b6a5dd   Christoph Hellwig   Re: [PATCH 3/6] v...
763
764
  	return ERR_PTR(err);
  }
c4ad8f98b   Linus Torvalds   execve: use 'stru...
765
766
767
  
  struct file *open_exec(const char *name)
  {
516891041   Paul Moore   fs: create proper...
768
769
770
771
772
773
774
775
  	struct filename *filename = getname_kernel(name);
  	struct file *f = ERR_CAST(filename);
  
  	if (!IS_ERR(filename)) {
  		f = do_open_execat(AT_FDCWD, filename, 0);
  		putname(filename);
  	}
  	return f;
c4ad8f98b   Linus Torvalds   execve: use 'stru...
776
  }
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
777
  EXPORT_SYMBOL(open_exec);
6777d773a   Mimi Zohar   kernel_read: rede...
778
779
  int kernel_read(struct file *file, loff_t offset,
  		char *addr, unsigned long count)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
780
781
782
783
784
785
786
787
788
789
790
791
792
793
  {
  	mm_segment_t old_fs;
  	loff_t pos = offset;
  	int result;
  
  	old_fs = get_fs();
  	set_fs(get_ds());
  	/* The cast to a user pointer is valid due to the set_fs() */
  	result = vfs_read(file, (void __user *)addr, count, &pos);
  	set_fs(old_fs);
  	return result;
  }
  
  EXPORT_SYMBOL(kernel_read);
3dc20cb28   Al Viro   new helper: read_...
794
795
  ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len)
  {
ec6955798   Al Viro   read_code(): go t...
796
  	ssize_t res = vfs_read(file, (void __user *)addr, len, &pos);
3dc20cb28   Al Viro   new helper: read_...
797
798
799
800
801
  	if (res > 0)
  		flush_icache_range(addr, addr + len);
  	return res;
  }
  EXPORT_SYMBOL(read_code);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
802
803
804
  static int exec_mmap(struct mm_struct *mm)
  {
  	struct task_struct *tsk;
615d6e875   Davidlohr Bueso   mm: per-thread vm...
805
  	struct mm_struct *old_mm, *active_mm;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
806
807
808
809
810
811
812
  
  	/* Notify parent that we're no longer interested in the old VM */
  	tsk = current;
  	old_mm = current->mm;
  	mm_release(tsk, old_mm);
  
  	if (old_mm) {
4fe7efdbd   Konstantin Khlebnikov   mm: correctly syn...
813
  		sync_mm_rss(old_mm);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
814
815
816
817
  		/*
  		 * Make sure that if there is a core dump in progress
  		 * for the old mm, we get out and die instead of going
  		 * through with the exec.  We must hold mmap_sem around
999d9fc16   Oleg Nesterov   coredump: move mm...
818
  		 * checking core_state and changing tsk->mm.
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
819
820
  		 */
  		down_read(&old_mm->mmap_sem);
999d9fc16   Oleg Nesterov   coredump: move mm...
821
  		if (unlikely(old_mm->core_state)) {
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
822
823
824
825
826
827
828
829
830
  			up_read(&old_mm->mmap_sem);
  			return -EINTR;
  		}
  	}
  	task_lock(tsk);
  	active_mm = tsk->active_mm;
  	tsk->mm = mm;
  	tsk->active_mm = mm;
  	activate_mm(active_mm, mm);
615d6e875   Davidlohr Bueso   mm: per-thread vm...
831
832
  	tsk->mm->vmacache_seqnum = 0;
  	vmacache_flush(tsk);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
833
  	task_unlock(tsk);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
834
835
  	if (old_mm) {
  		up_read(&old_mm->mmap_sem);
7dddb12c6   Eric Sesterhenn   BUG_ON() Conversi...
836
  		BUG_ON(active_mm != old_mm);
701085b21   Oleg Nesterov   exec: move de_thr...
837
  		setmax_mm_hiwater_rss(&tsk->signal->maxrss, old_mm);
31a78f23b   Balbir Singh   mm owner: fix rac...
838
  		mm_update_next_owner(old_mm);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
839
840
841
842
843
844
845
846
847
848
849
850
851
  		mmput(old_mm);
  		return 0;
  	}
  	mmdrop(active_mm);
  	return 0;
  }
  
  /*
   * This function makes sure the current process has its own signal table,
   * so that flush_signal_handlers can later reset the handlers without
   * disturbing other processes.  (Other processes might share the signal
   * table via the CLONE_SIGHAND option to clone().)
   */
858119e15   Arjan van de Ven   [PATCH] Unlinline...
852
  static int de_thread(struct task_struct *tsk)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
853
854
  {
  	struct signal_struct *sig = tsk->signal;
b2c903b87   Oleg Nesterov   exec: simplify th...
855
  	struct sighand_struct *oldsighand = tsk->sighand;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
856
  	spinlock_t *lock = &oldsighand->siglock;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
857

aafe6c2a2   Eric W. Biederman   [PATCH] de_thread...
858
  	if (thread_group_empty(tsk))
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
859
860
861
862
  		goto no_thread_group;
  
  	/*
  	 * Kill all other threads in the thread group.
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
863
  	 */
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
864
  	spin_lock_irq(lock);
ed5d2cac1   Oleg Nesterov   exec: rework the ...
865
  	if (signal_group_exit(sig)) {
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
866
867
868
869
870
  		/*
  		 * Another group action in progress, just
  		 * return so that the signal is processed.
  		 */
  		spin_unlock_irq(lock);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
871
872
  		return -EAGAIN;
  	}
d344193a0   Oleg Nesterov   exit: avoid sig->...
873

ed5d2cac1   Oleg Nesterov   exec: rework the ...
874
  	sig->group_exit_task = tsk;
d344193a0   Oleg Nesterov   exit: avoid sig->...
875
876
877
  	sig->notify_count = zap_other_threads(tsk);
  	if (!thread_group_leader(tsk))
  		sig->notify_count--;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
878

d344193a0   Oleg Nesterov   exit: avoid sig->...
879
  	while (sig->notify_count) {
d5bbd43d5   Oleg Nesterov   exec: make de_thr...
880
  		__set_current_state(TASK_KILLABLE);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
881
882
  		spin_unlock_irq(lock);
  		schedule();
d5bbd43d5   Oleg Nesterov   exec: make de_thr...
883
884
  		if (unlikely(__fatal_signal_pending(tsk)))
  			goto killed;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
885
886
  		spin_lock_irq(lock);
  	}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
887
888
889
890
891
892
893
  	spin_unlock_irq(lock);
  
  	/*
  	 * At this point all other threads have exited, all we have to
  	 * do is to wait for the thread group leader to become inactive,
  	 * and to assume its PID:
  	 */
aafe6c2a2   Eric W. Biederman   [PATCH] de_thread...
894
  	if (!thread_group_leader(tsk)) {
8187926bd   Oleg Nesterov   posix-timers: sim...
895
  		struct task_struct *leader = tsk->group_leader;
6db840fa7   Oleg Nesterov   exec: RT sub-thre...
896

6db840fa7   Oleg Nesterov   exec: RT sub-thre...
897
  		for (;;) {
e56fb2874   Oleg Nesterov   exec: do not abus...
898
  			threadgroup_change_begin(tsk);
6db840fa7   Oleg Nesterov   exec: RT sub-thre...
899
  			write_lock_irq(&tasklist_lock);
dfcce791f   Kirill Tkhai   fs/exec.c:de_thre...
900
901
902
903
904
  			/*
  			 * Do this under tasklist_lock to ensure that
  			 * exit_notify() can't miss ->group_exit_task
  			 */
  			sig->notify_count = -1;
6db840fa7   Oleg Nesterov   exec: RT sub-thre...
905
906
  			if (likely(leader->exit_state))
  				break;
d5bbd43d5   Oleg Nesterov   exec: make de_thr...
907
  			__set_current_state(TASK_KILLABLE);
6db840fa7   Oleg Nesterov   exec: RT sub-thre...
908
  			write_unlock_irq(&tasklist_lock);
e56fb2874   Oleg Nesterov   exec: do not abus...
909
  			threadgroup_change_end(tsk);
6db840fa7   Oleg Nesterov   exec: RT sub-thre...
910
  			schedule();
d5bbd43d5   Oleg Nesterov   exec: make de_thr...
911
912
  			if (unlikely(__fatal_signal_pending(tsk)))
  				goto killed;
6db840fa7   Oleg Nesterov   exec: RT sub-thre...
913
  		}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
914

f5e902817   Roland McGrath   [PATCH] process a...
915
916
917
918
919
920
921
922
923
924
  		/*
  		 * The only record we have of the real-time age of a
  		 * process, regardless of execs it's done, is start_time.
  		 * All the past CPU time is accumulated in signal_struct
  		 * from sister threads now dead.  But in this non-leader
  		 * exec, nothing survives from the original leader thread,
  		 * whose birth marks the true age of this process now.
  		 * When we take on its identity by switching to its PID, we
  		 * also take its birthdate (always earlier than our own).
  		 */
aafe6c2a2   Eric W. Biederman   [PATCH] de_thread...
925
  		tsk->start_time = leader->start_time;
266b7a021   Oleg Nesterov   fs/exec.c:de_thre...
926
  		tsk->real_start_time = leader->real_start_time;
f5e902817   Roland McGrath   [PATCH] process a...
927

bac0abd61   Pavel Emelyanov   Isolate some expl...
928
929
  		BUG_ON(!same_thread_group(leader, tsk));
  		BUG_ON(has_group_leader_pid(tsk));
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
930
931
932
933
934
935
  		/*
  		 * An exec() starts a new thread group with the
  		 * TGID of the previous thread group. Rehash the
  		 * two threads with a switched PID, and release
  		 * the former thread group leader:
  		 */
d73d65293   Eric W. Biederman   [PATCH] pidhash: ...
936
937
  
  		/* Become a process group leader with the old leader's pid.
c18258c6f   Eric W. Biederman   [PATCH] pid: Impl...
938
939
  		 * The old leader becomes a thread of the this thread group.
  		 * Note: The old leader also uses this pid until release_task
d73d65293   Eric W. Biederman   [PATCH] pidhash: ...
940
941
  		 *       is called.  Odd but simple and correct.
  		 */
aafe6c2a2   Eric W. Biederman   [PATCH] de_thread...
942
  		tsk->pid = leader->pid;
3f4185483   Oleg Nesterov   fs/exec.c:de_thre...
943
  		change_pid(tsk, PIDTYPE_PID, task_pid(leader));
aafe6c2a2   Eric W. Biederman   [PATCH] de_thread...
944
945
  		transfer_pid(leader, tsk, PIDTYPE_PGID);
  		transfer_pid(leader, tsk, PIDTYPE_SID);
9cd80bbb0   Oleg Nesterov   do_wait() optimiz...
946

aafe6c2a2   Eric W. Biederman   [PATCH] de_thread...
947
  		list_replace_rcu(&leader->tasks, &tsk->tasks);
9cd80bbb0   Oleg Nesterov   do_wait() optimiz...
948
  		list_replace_init(&leader->sibling, &tsk->sibling);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
949

aafe6c2a2   Eric W. Biederman   [PATCH] de_thread...
950
951
  		tsk->group_leader = tsk;
  		leader->group_leader = tsk;
de12a7878   Eric W. Biederman   [PATCH] de_thread...
952

aafe6c2a2   Eric W. Biederman   [PATCH] de_thread...
953
  		tsk->exit_signal = SIGCHLD;
087806b12   Oleg Nesterov   redefine thread_g...
954
  		leader->exit_signal = -1;
962b564cf   Oleg Nesterov   [PATCH] fix do_wa...
955
956
957
  
  		BUG_ON(leader->exit_state != EXIT_ZOMBIE);
  		leader->exit_state = EXIT_DEAD;
eac1b5e57   Oleg Nesterov   ptrace: do_wait(t...
958
959
960
961
962
963
964
965
  
  		/*
  		 * We are going to release_task()->ptrace_unlink() silently,
  		 * the tracer can sleep in do_wait(). EXIT_DEAD guarantees
  		 * the tracer wont't block again waiting for this thread.
  		 */
  		if (unlikely(leader->ptrace))
  			__wake_up_parent(leader, leader->parent);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
966
  		write_unlock_irq(&tasklist_lock);
e56fb2874   Oleg Nesterov   exec: do not abus...
967
  		threadgroup_change_end(tsk);
8187926bd   Oleg Nesterov   posix-timers: sim...
968
969
  
  		release_task(leader);
ed5d2cac1   Oleg Nesterov   exec: rework the ...
970
  	}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
971

6db840fa7   Oleg Nesterov   exec: RT sub-thre...
972
973
  	sig->group_exit_task = NULL;
  	sig->notify_count = 0;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
974
975
  
  no_thread_group:
e63682534   Oleg Nesterov   exit_signal: simp...
976
977
  	/* we have changed execution domain */
  	tsk->exit_signal = SIGCHLD;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
978
  	exit_itimers(sig);
cbaffba12   Oleg Nesterov   posix timers: dis...
979
  	flush_itimer_signals();
329f7dba5   Oleg Nesterov   [PATCH] fix de_th...
980

b2c903b87   Oleg Nesterov   exec: simplify th...
981
982
  	if (atomic_read(&oldsighand->count) != 1) {
  		struct sighand_struct *newsighand;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
983
  		/*
b2c903b87   Oleg Nesterov   exec: simplify th...
984
985
  		 * This ->sighand is shared with the CLONE_SIGHAND
  		 * but not CLONE_THREAD task, switch to the new one.
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
986
  		 */
b2c903b87   Oleg Nesterov   exec: simplify th...
987
988
989
  		newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
  		if (!newsighand)
  			return -ENOMEM;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
990
991
992
993
994
995
  		atomic_set(&newsighand->count, 1);
  		memcpy(newsighand->action, oldsighand->action,
  		       sizeof(newsighand->action));
  
  		write_lock_irq(&tasklist_lock);
  		spin_lock(&oldsighand->siglock);
aafe6c2a2   Eric W. Biederman   [PATCH] de_thread...
996
  		rcu_assign_pointer(tsk->sighand, newsighand);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
997
998
  		spin_unlock(&oldsighand->siglock);
  		write_unlock_irq(&tasklist_lock);
fba2afaae   Davide Libenzi   signal/timer/even...
999
  		__cleanup_sighand(oldsighand);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1000
  	}
aafe6c2a2   Eric W. Biederman   [PATCH] de_thread...
1001
  	BUG_ON(!thread_group_leader(tsk));
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1002
  	return 0;
d5bbd43d5   Oleg Nesterov   exec: make de_thr...
1003
1004
1005
1006
1007
1008
1009
1010
  
  killed:
  	/* protects against exit_notify() and __exit_signal() */
  	read_lock(&tasklist_lock);
  	sig->group_exit_task = NULL;
  	sig->notify_count = 0;
  	read_unlock(&tasklist_lock);
  	return -EAGAIN;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1011
  }
0840a90d9   Oleg Nesterov   exec: simplify ->...
1012

59714d65d   Andrew Morton   get_task_comm(): ...
1013
  char *get_task_comm(char *buf, struct task_struct *tsk)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1014
1015
1016
1017
1018
  {
  	/* buf must be at least sizeof(tsk->comm) in size */
  	task_lock(tsk);
  	strncpy(buf, tsk->comm, sizeof(tsk->comm));
  	task_unlock(tsk);
59714d65d   Andrew Morton   get_task_comm(): ...
1019
  	return buf;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1020
  }
7d74f492e   J Freyensee   export kernel cal...
1021
  EXPORT_SYMBOL_GPL(get_task_comm);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1022

6a6d27de3   Al Viro   take close-on-exe...
1023
1024
1025
1026
  /*
   * These functions flushes out all traces of the currently running executable
   * so that a new one can be started
   */
82b897782   Adrian Hunter   perf: Differentia...
1027
  void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1028
1029
  {
  	task_lock(tsk);
43d2b1132   KAMEZAWA Hiroyuki   tracepoint: add t...
1030
  	trace_task_rename(tsk, buf);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1031
1032
  	strlcpy(tsk->comm, buf, sizeof(tsk->comm));
  	task_unlock(tsk);
82b897782   Adrian Hunter   perf: Differentia...
1033
  	perf_event_comm(tsk, exec);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1034
1035
1036
1037
  }
  
  int flush_old_exec(struct linux_binprm * bprm)
  {
221af7f87   Linus Torvalds   Split 'flush_old_...
1038
  	int retval;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1039
1040
1041
1042
1043
1044
1045
1046
  
  	/*
  	 * Make sure we have a private signal table and that
  	 * we are unassociated from the previous thread group.
  	 */
  	retval = de_thread(current);
  	if (retval)
  		goto out;
6e399cd14   Davidlohr Bueso   prctl: avoid usin...
1047
1048
1049
1050
1051
  	/*
  	 * Must be called _before_ exec_mmap() as bprm->mm is
  	 * not visibile until then. This also enables the update
  	 * to be lockless.
  	 */
925d1c401   Matt Helsley   procfs task exe s...
1052
  	set_mm_exe_file(bprm->mm, bprm->file);
6e399cd14   Davidlohr Bueso   prctl: avoid usin...
1053

1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1054
  	/*
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1055
1056
  	 * Release all of the old mmap stuff
  	 */
3c77f8457   Oleg Nesterov   exec: make argv/e...
1057
  	acct_arg_size(bprm, 0);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1058
1059
  	retval = exec_mmap(bprm->mm);
  	if (retval)
fd8328be8   Al Viro   [PATCH] sanitize ...
1060
  		goto out;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1061
1062
  
  	bprm->mm = NULL;		/* We're using it now */
7ab02af42   Linus Torvalds   Fix 'flush_old_ex...
1063

dac853ae8   Mathias Krause   exec: delay addre...
1064
  	set_fs(USER_DS);
b88fae644   Zhang Yi   exec: avoid propa...
1065
1066
  	current->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD |
  					PF_NOFREEZE | PF_NO_SETAFFINITY);
7ab02af42   Linus Torvalds   Fix 'flush_old_ex...
1067
1068
  	flush_thread();
  	current->personality &= ~bprm->per_clear;
221af7f87   Linus Torvalds   Split 'flush_old_...
1069
1070
1071
1072
1073
1074
  	return 0;
  
  out:
  	return retval;
  }
  EXPORT_SYMBOL(flush_old_exec);
1b5d783c9   Al Viro   consolidate BINPR...
1075
1076
  void would_dump(struct linux_binprm *bprm, struct file *file)
  {
496ad9aa8   Al Viro   new helper: file_...
1077
  	if (inode_permission(file_inode(file), MAY_READ) < 0)
1b5d783c9   Al Viro   consolidate BINPR...
1078
1079
1080
  		bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
  }
  EXPORT_SYMBOL(would_dump);
221af7f87   Linus Torvalds   Split 'flush_old_...
1081
1082
  void setup_new_exec(struct linux_binprm * bprm)
  {
221af7f87   Linus Torvalds   Split 'flush_old_...
1083
  	arch_pick_mmap_layout(current->mm);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1084
1085
  
  	/* This is the point of no return */
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1086
  	current->sas_ss_sp = current->sas_ss_size = 0;
8e96e3b7b   Eric W. Biederman   userns: Use uid_e...
1087
  	if (uid_eq(current_euid(), current_uid()) && gid_eq(current_egid(), current_gid()))
e579d2c25   Kees Cook   coredump: remove ...
1088
  		set_dumpable(current->mm, SUID_DUMP_USER);
d6e711448   Alan Cox   [PATCH] setuid co...
1089
  	else
6c5d52382   Kawai, Hidehiro   coredump masking:...
1090
  		set_dumpable(current->mm, suid_dumpable);
d6e711448   Alan Cox   [PATCH] setuid co...
1091

e041e328c   Peter Zijlstra   perf: Fix perf_ev...
1092
  	perf_event_exec();
82b897782   Adrian Hunter   perf: Differentia...
1093
  	__set_task_comm(current, kbasename(bprm->filename), true);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1094

0551fbd29   Benjamin Herrenschmidt   [PATCH] Add mm->t...
1095
1096
1097
1098
1099
  	/* Set the new mm task size. We have to do that late because it may
  	 * depend on TIF_32BIT which is only updated in flush_thread() on
  	 * some architectures like powerpc
  	 */
  	current->mm->task_size = TASK_SIZE;
a6f76f23d   David Howells   CRED: Make execve...
1100
  	/* install the new credentials */
8e96e3b7b   Eric W. Biederman   userns: Use uid_e...
1101
1102
  	if (!uid_eq(bprm->cred->uid, current_euid()) ||
  	    !gid_eq(bprm->cred->gid, current_egid())) {
d2d56c5f5   Marcel Holtmann   Reset current->pd...
1103
  		current->pdeath_signal = 0;
1b5d783c9   Al Viro   consolidate BINPR...
1104
1105
1106
1107
  	} else {
  		would_dump(bprm, bprm->file);
  		if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)
  			set_dumpable(current->mm, suid_dumpable);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1108
1109
1110
1111
  	}
  
  	/* An exec changes our domain. We are no longer part of the thread
  	   group */
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1112
  	current->self_exec_id++;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1113
  	flush_signal_handlers(current, 0);
6a6d27de3   Al Viro   take close-on-exe...
1114
  	do_close_on_exec(current->files);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1115
  }
221af7f87   Linus Torvalds   Split 'flush_old_...
1116
  EXPORT_SYMBOL(setup_new_exec);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1117

a6f76f23d   David Howells   CRED: Make execve...
1118
  /*
a2a8474c3   Oleg Nesterov   exec: do not slee...
1119
1120
1121
1122
1123
1124
1125
   * Prepare credentials and lock ->cred_guard_mutex.
   * install_exec_creds() commits the new creds and drops the lock.
   * Or, if exec fails before, free_bprm() should release ->cred and
   * and unlock.
   */
  int prepare_bprm_creds(struct linux_binprm *bprm)
  {
9b1bf12d5   KOSAKI Motohiro   signals: move cre...
1126
  	if (mutex_lock_interruptible(&current->signal->cred_guard_mutex))
a2a8474c3   Oleg Nesterov   exec: do not slee...
1127
1128
1129
1130
1131
  		return -ERESTARTNOINTR;
  
  	bprm->cred = prepare_exec_creds();
  	if (likely(bprm->cred))
  		return 0;
9b1bf12d5   KOSAKI Motohiro   signals: move cre...
1132
  	mutex_unlock(&current->signal->cred_guard_mutex);
a2a8474c3   Oleg Nesterov   exec: do not slee...
1133
1134
  	return -ENOMEM;
  }
c4ad8f98b   Linus Torvalds   execve: use 'stru...
1135
  static void free_bprm(struct linux_binprm *bprm)
a2a8474c3   Oleg Nesterov   exec: do not slee...
1136
1137
1138
  {
  	free_arg_pages(bprm);
  	if (bprm->cred) {
9b1bf12d5   KOSAKI Motohiro   signals: move cre...
1139
  		mutex_unlock(&current->signal->cred_guard_mutex);
a2a8474c3   Oleg Nesterov   exec: do not slee...
1140
1141
  		abort_creds(bprm->cred);
  	}
63e46b95e   Oleg Nesterov   exec: move the fi...
1142
1143
1144
1145
  	if (bprm->file) {
  		allow_write_access(bprm->file);
  		fput(bprm->file);
  	}
b66c59840   Kees Cook   exec: do not leav...
1146
1147
1148
  	/* If a binfmt changed the interp, free it. */
  	if (bprm->interp != bprm->filename)
  		kfree(bprm->interp);
a2a8474c3   Oleg Nesterov   exec: do not slee...
1149
1150
  	kfree(bprm);
  }
b66c59840   Kees Cook   exec: do not leav...
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
  int bprm_change_interp(char *interp, struct linux_binprm *bprm)
  {
  	/* If a binfmt changed the interp, free it first. */
  	if (bprm->interp != bprm->filename)
  		kfree(bprm->interp);
  	bprm->interp = kstrdup(interp, GFP_KERNEL);
  	if (!bprm->interp)
  		return -ENOMEM;
  	return 0;
  }
  EXPORT_SYMBOL(bprm_change_interp);
a2a8474c3   Oleg Nesterov   exec: do not slee...
1162
  /*
a6f76f23d   David Howells   CRED: Make execve...
1163
1164
1165
1166
1167
1168
1169
1170
   * install the new credentials for this executable
   */
  void install_exec_creds(struct linux_binprm *bprm)
  {
  	security_bprm_committing_creds(bprm);
  
  	commit_creds(bprm->cred);
  	bprm->cred = NULL;
2976b10f0   Stephane Eranian   perf: Disable mon...
1171
1172
1173
1174
1175
1176
1177
1178
1179
  
  	/*
  	 * Disable monitoring for regular users
  	 * when executing setuid binaries. Must
  	 * wait until new credentials are committed
  	 * by commit_creds() above
  	 */
  	if (get_dumpable(current->mm) != SUID_DUMP_USER)
  		perf_event_exit_task(current);
a2a8474c3   Oleg Nesterov   exec: do not slee...
1180
1181
  	/*
  	 * cred_guard_mutex must be held at least to this point to prevent
a6f76f23d   David Howells   CRED: Make execve...
1182
  	 * ptrace_attach() from altering our determination of the task's
a2a8474c3   Oleg Nesterov   exec: do not slee...
1183
1184
  	 * credentials; any time after this it may be unlocked.
  	 */
a6f76f23d   David Howells   CRED: Make execve...
1185
  	security_bprm_committed_creds(bprm);
9b1bf12d5   KOSAKI Motohiro   signals: move cre...
1186
  	mutex_unlock(&current->signal->cred_guard_mutex);
a6f76f23d   David Howells   CRED: Make execve...
1187
1188
1189
1190
1191
  }
  EXPORT_SYMBOL(install_exec_creds);
  
  /*
   * determine how safe it is to execute the proposed program
9b1bf12d5   KOSAKI Motohiro   signals: move cre...
1192
   * - the caller must hold ->cred_guard_mutex to protect against
c2e1f2e30   Kees Cook   seccomp: implemen...
1193
   *   PTRACE_ATTACH or seccomp thread-sync
a6f76f23d   David Howells   CRED: Make execve...
1194
   */
9e00cdb09   Oleg Nesterov   exec:check_unsafe...
1195
  static void check_unsafe_exec(struct linux_binprm *bprm)
a6f76f23d   David Howells   CRED: Make execve...
1196
  {
0bf2f3aec   David Howells   CRED: Fix SUID ex...
1197
  	struct task_struct *p = current, *t;
f1191b50e   Al Viro   check_unsafe_exec...
1198
  	unsigned n_fs;
a6f76f23d   David Howells   CRED: Make execve...
1199

4b9d33e6d   Tejun Heo   ptrace: kill clon...
1200
1201
1202
1203
1204
1205
  	if (p->ptrace) {
  		if (p->ptrace & PT_PTRACE_CAP)
  			bprm->unsafe |= LSM_UNSAFE_PTRACE_CAP;
  		else
  			bprm->unsafe |= LSM_UNSAFE_PTRACE;
  	}
a6f76f23d   David Howells   CRED: Make execve...
1206

259e5e6c7   Andy Lutomirski   Add PR_{GET,SET}_...
1207
1208
1209
1210
  	/*
  	 * This isn't strictly necessary, but it makes it harder for LSMs to
  	 * mess up.
  	 */
1d4457f99   Kees Cook   sched: move no_ne...
1211
  	if (task_no_new_privs(current))
259e5e6c7   Andy Lutomirski   Add PR_{GET,SET}_...
1212
  		bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS;
83f62a2ea   Oleg Nesterov   exec:check_unsafe...
1213
  	t = p;
0bf2f3aec   David Howells   CRED: Fix SUID ex...
1214
  	n_fs = 1;
2a4419b5b   Nick Piggin   fs: fs_struct rwl...
1215
  	spin_lock(&p->fs->lock);
437f7fdb6   Oleg Nesterov   check_unsafe_exec...
1216
  	rcu_read_lock();
83f62a2ea   Oleg Nesterov   exec:check_unsafe...
1217
  	while_each_thread(p, t) {
0bf2f3aec   David Howells   CRED: Fix SUID ex...
1218
1219
  		if (t->fs == p->fs)
  			n_fs++;
0bf2f3aec   David Howells   CRED: Fix SUID ex...
1220
  	}
437f7fdb6   Oleg Nesterov   check_unsafe_exec...
1221
  	rcu_read_unlock();
0bf2f3aec   David Howells   CRED: Fix SUID ex...
1222

9e00cdb09   Oleg Nesterov   exec:check_unsafe...
1223
  	if (p->fs->users > n_fs)
a6f76f23d   David Howells   CRED: Make execve...
1224
  		bprm->unsafe |= LSM_UNSAFE_SHARE;
9e00cdb09   Oleg Nesterov   exec:check_unsafe...
1225
1226
  	else
  		p->fs->in_exec = 1;
2a4419b5b   Nick Piggin   fs: fs_struct rwl...
1227
  	spin_unlock(&p->fs->lock);
a6f76f23d   David Howells   CRED: Make execve...
1228
  }
8b01fc86b   Jann Horn   fs: take i_mutex ...
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
  static void bprm_fill_uid(struct linux_binprm *bprm)
  {
  	struct inode *inode;
  	unsigned int mode;
  	kuid_t uid;
  	kgid_t gid;
  
  	/* clear any previous set[ug]id data from a previous binary */
  	bprm->cred->euid = current_euid();
  	bprm->cred->egid = current_egid();
  
  	if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
  		return;
  
  	if (task_no_new_privs(current))
  		return;
  
  	inode = file_inode(bprm->file);
  	mode = READ_ONCE(inode->i_mode);
  	if (!(mode & (S_ISUID|S_ISGID)))
  		return;
  
  	/* Be careful if suid/sgid is set */
  	mutex_lock(&inode->i_mutex);
  
  	/* reload atomically mode/uid/gid now that lock held */
  	mode = inode->i_mode;
  	uid = inode->i_uid;
  	gid = inode->i_gid;
  	mutex_unlock(&inode->i_mutex);
  
  	/* We ignore suid/sgid if there are no mappings for them in the ns */
  	if (!kuid_has_mapping(bprm->cred->user_ns, uid) ||
  		 !kgid_has_mapping(bprm->cred->user_ns, gid))
  		return;
  
  	if (mode & S_ISUID) {
  		bprm->per_clear |= PER_CLEAR_ON_SETID;
  		bprm->cred->euid = uid;
  	}
  
  	if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
  		bprm->per_clear |= PER_CLEAR_ON_SETID;
  		bprm->cred->egid = gid;
  	}
  }
9e00cdb09   Oleg Nesterov   exec:check_unsafe...
1275
1276
  /*
   * Fill the binprm structure from the inode.
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1277
   * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes
a6f76f23d   David Howells   CRED: Make execve...
1278
1279
   *
   * This may be called multiple times for binary chains (scripts for example).
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1280
1281
1282
   */
  int prepare_binprm(struct linux_binprm *bprm)
  {
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1283
  	int retval;
8b01fc86b   Jann Horn   fs: take i_mutex ...
1284
  	bprm_fill_uid(bprm);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1285
1286
  
  	/* fill in binprm security blob */
a6f76f23d   David Howells   CRED: Make execve...
1287
  	retval = security_bprm_set_creds(bprm);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1288
1289
  	if (retval)
  		return retval;
a6f76f23d   David Howells   CRED: Make execve...
1290
  	bprm->cred_prepared = 1;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1291

a6f76f23d   David Howells   CRED: Make execve...
1292
1293
  	memset(bprm->buf, 0, BINPRM_BUF_SIZE);
  	return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1294
1295
1296
  }
  
  EXPORT_SYMBOL(prepare_binprm);
4fc75ff48   Nick Piggin   exec: fix remove_...
1297
1298
1299
1300
1301
  /*
   * Arguments are '\0' separated strings found at the location bprm->p
   * points to; chop off the first by relocating brpm->p to right after
   * the first '\0' encountered.
   */
b6a2fea39   Ollie Wild   mm: variable leng...
1302
  int remove_arg_zero(struct linux_binprm *bprm)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1303
  {
b6a2fea39   Ollie Wild   mm: variable leng...
1304
1305
1306
1307
  	int ret = 0;
  	unsigned long offset;
  	char *kaddr;
  	struct page *page;
4fc75ff48   Nick Piggin   exec: fix remove_...
1308

b6a2fea39   Ollie Wild   mm: variable leng...
1309
1310
  	if (!bprm->argc)
  		return 0;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1311

b6a2fea39   Ollie Wild   mm: variable leng...
1312
1313
1314
1315
1316
1317
1318
  	do {
  		offset = bprm->p & ~PAGE_MASK;
  		page = get_arg_page(bprm, bprm->p, 0);
  		if (!page) {
  			ret = -EFAULT;
  			goto out;
  		}
e8e3c3d66   Cong Wang   fs: remove the se...
1319
  		kaddr = kmap_atomic(page);
4fc75ff48   Nick Piggin   exec: fix remove_...
1320

b6a2fea39   Ollie Wild   mm: variable leng...
1321
1322
1323
  		for (; offset < PAGE_SIZE && kaddr[offset];
  				offset++, bprm->p++)
  			;
4fc75ff48   Nick Piggin   exec: fix remove_...
1324

e8e3c3d66   Cong Wang   fs: remove the se...
1325
  		kunmap_atomic(kaddr);
b6a2fea39   Ollie Wild   mm: variable leng...
1326
  		put_arg_page(page);
4fc75ff48   Nick Piggin   exec: fix remove_...
1327

b6a2fea39   Ollie Wild   mm: variable leng...
1328
1329
1330
  		if (offset == PAGE_SIZE)
  			free_arg_page(bprm, (bprm->p >> PAGE_SHIFT) - 1);
  	} while (offset == PAGE_SIZE);
4fc75ff48   Nick Piggin   exec: fix remove_...
1331

b6a2fea39   Ollie Wild   mm: variable leng...
1332
1333
1334
  	bprm->p++;
  	bprm->argc--;
  	ret = 0;
4fc75ff48   Nick Piggin   exec: fix remove_...
1335

b6a2fea39   Ollie Wild   mm: variable leng...
1336
1337
  out:
  	return ret;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1338
  }
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1339
  EXPORT_SYMBOL(remove_arg_zero);
cb7b6b1cb   Oleg Nesterov   exec: cleanup the...
1340
1341
  #define printable(c) (((c)=='\t') || ((c)=='
  ') || (0x20<=(c) && (c)<=0x7e))
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1342
1343
1344
  /*
   * cycle the list of binary formats handler, until one recognizes the image
   */
3c456bfc4   Al Viro   get rid of pt_reg...
1345
  int search_binary_handler(struct linux_binprm *bprm)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1346
  {
cb7b6b1cb   Oleg Nesterov   exec: cleanup the...
1347
  	bool need_retry = IS_ENABLED(CONFIG_MODULES);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1348
  	struct linux_binfmt *fmt;
cb7b6b1cb   Oleg Nesterov   exec: cleanup the...
1349
  	int retval;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1350

d74026986   Kees Cook   exec: use -ELOOP ...
1351
  	/* This allows 4 levels of binfmt rewrites before failing hard. */
131b2f9f1   Oleg Nesterov   exec: kill "int d...
1352
  	if (bprm->recursion_depth > 5)
d74026986   Kees Cook   exec: use -ELOOP ...
1353
  		return -ELOOP;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1354
1355
1356
  	retval = security_bprm_check(bprm);
  	if (retval)
  		return retval;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1357
  	retval = -ENOENT;
cb7b6b1cb   Oleg Nesterov   exec: cleanup the...
1358
1359
1360
1361
1362
1363
1364
1365
   retry:
  	read_lock(&binfmt_lock);
  	list_for_each_entry(fmt, &formats, lh) {
  		if (!try_module_get(fmt->module))
  			continue;
  		read_unlock(&binfmt_lock);
  		bprm->recursion_depth++;
  		retval = fmt->load_binary(bprm);
19d860a14   Al Viro   handle suicide on...
1366
1367
  		read_lock(&binfmt_lock);
  		put_binfmt(fmt);
cb7b6b1cb   Oleg Nesterov   exec: cleanup the...
1368
  		bprm->recursion_depth--;
19d860a14   Al Viro   handle suicide on...
1369
1370
1371
1372
1373
1374
1375
1376
  		if (retval < 0 && !bprm->mm) {
  			/* we got to flush_old_exec() and failed after it */
  			read_unlock(&binfmt_lock);
  			force_sigsegv(SIGSEGV, current);
  			return retval;
  		}
  		if (retval != -ENOEXEC || !bprm->file) {
  			read_unlock(&binfmt_lock);
cb7b6b1cb   Oleg Nesterov   exec: cleanup the...
1377
  			return retval;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1378
  		}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1379
  	}
cb7b6b1cb   Oleg Nesterov   exec: cleanup the...
1380
  	read_unlock(&binfmt_lock);
19d860a14   Al Viro   handle suicide on...
1381
  	if (need_retry) {
cb7b6b1cb   Oleg Nesterov   exec: cleanup the...
1382
1383
1384
  		if (printable(bprm->buf[0]) && printable(bprm->buf[1]) &&
  		    printable(bprm->buf[2]) && printable(bprm->buf[3]))
  			return retval;
4e0621a07   Oleg Nesterov   exec: don't retry...
1385
1386
  		if (request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2)) < 0)
  			return retval;
cb7b6b1cb   Oleg Nesterov   exec: cleanup the...
1387
1388
1389
  		need_retry = false;
  		goto retry;
  	}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1390
1391
  	return retval;
  }
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1392
  EXPORT_SYMBOL(search_binary_handler);
5d1baf3b6   Oleg Nesterov   exec: introduce e...
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
  static int exec_binprm(struct linux_binprm *bprm)
  {
  	pid_t old_pid, old_vpid;
  	int ret;
  
  	/* Need to fetch pid before load_binary changes it */
  	old_pid = current->pid;
  	rcu_read_lock();
  	old_vpid = task_pid_nr_ns(current, task_active_pid_ns(current->parent));
  	rcu_read_unlock();
  
  	ret = search_binary_handler(bprm);
  	if (ret >= 0) {
3eaded86a   Linus Torvalds   Merge git://git.i...
1406
  		audit_bprm(bprm);
5d1baf3b6   Oleg Nesterov   exec: introduce e...
1407
1408
  		trace_sched_process_exec(current, old_pid, bprm);
  		ptrace_event(PTRACE_EVENT_EXEC, old_vpid);
9beb266f2   Oleg Nesterov   exec: proc_exec_c...
1409
  		proc_exec_connector(current);
5d1baf3b6   Oleg Nesterov   exec: introduce e...
1410
1411
1412
1413
  	}
  
  	return ret;
  }
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1414
1415
1416
  /*
   * sys_execve() executes a new program.
   */
51f39a1f0   David Drysdale   syscalls: impleme...
1417
1418
1419
1420
  static int do_execveat_common(int fd, struct filename *filename,
  			      struct user_arg_ptr argv,
  			      struct user_arg_ptr envp,
  			      int flags)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1421
  {
51f39a1f0   David Drysdale   syscalls: impleme...
1422
  	char *pathbuf = NULL;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1423
1424
  	struct linux_binprm *bprm;
  	struct file *file;
3b1253880   Al Viro   [PATCH] sanitize ...
1425
  	struct files_struct *displaced;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1426
  	int retval;
72fa59970   Vasiliy Kulikov   move RLIMIT_NPROC...
1427

c4ad8f98b   Linus Torvalds   execve: use 'stru...
1428
1429
  	if (IS_ERR(filename))
  		return PTR_ERR(filename);
72fa59970   Vasiliy Kulikov   move RLIMIT_NPROC...
1430
1431
1432
1433
1434
1435
1436
  	/*
  	 * We move the actual failure in case of RLIMIT_NPROC excess from
  	 * set*uid() to execve() because too many poorly written programs
  	 * don't check setuid() return code.  Here we additionally recheck
  	 * whether NPROC limit is still exceeded.
  	 */
  	if ((current->flags & PF_NPROC_EXCEEDED) &&
bd9d43f47   Oleg Nesterov   fs/exec.c: do_exe...
1437
  	    atomic_read(&current_user()->processes) > rlimit(RLIMIT_NPROC)) {
72fa59970   Vasiliy Kulikov   move RLIMIT_NPROC...
1438
1439
1440
1441
1442
1443
1444
  		retval = -EAGAIN;
  		goto out_ret;
  	}
  
  	/* We're below the limit (still or again), so we don't want to make
  	 * further execve() calls fail. */
  	current->flags &= ~PF_NPROC_EXCEEDED;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1445

3b1253880   Al Viro   [PATCH] sanitize ...
1446
  	retval = unshare_files(&displaced);
fd8328be8   Al Viro   [PATCH] sanitize ...
1447
1448
  	if (retval)
  		goto out_ret;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1449
  	retval = -ENOMEM;
11b0b5abb   Oliver Neukum   [PATCH] use kzall...
1450
  	bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1451
  	if (!bprm)
fd8328be8   Al Viro   [PATCH] sanitize ...
1452
  		goto out_files;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1453

a2a8474c3   Oleg Nesterov   exec: do not slee...
1454
1455
  	retval = prepare_bprm_creds(bprm);
  	if (retval)
a6f76f23d   David Howells   CRED: Make execve...
1456
  		goto out_free;
498052bba   Al Viro   New locking/refco...
1457

9e00cdb09   Oleg Nesterov   exec:check_unsafe...
1458
  	check_unsafe_exec(bprm);
a2a8474c3   Oleg Nesterov   exec: do not slee...
1459
  	current->in_execve = 1;
a6f76f23d   David Howells   CRED: Make execve...
1460

51f39a1f0   David Drysdale   syscalls: impleme...
1461
  	file = do_open_execat(fd, filename, flags);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1462
1463
  	retval = PTR_ERR(file);
  	if (IS_ERR(file))
498052bba   Al Viro   New locking/refco...
1464
  		goto out_unmark;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1465
1466
  
  	sched_exec();
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1467
  	bprm->file = file;
51f39a1f0   David Drysdale   syscalls: impleme...
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
  	if (fd == AT_FDCWD || filename->name[0] == '/') {
  		bprm->filename = filename->name;
  	} else {
  		if (filename->name[0] == '\0')
  			pathbuf = kasprintf(GFP_TEMPORARY, "/dev/fd/%d", fd);
  		else
  			pathbuf = kasprintf(GFP_TEMPORARY, "/dev/fd/%d/%s",
  					    fd, filename->name);
  		if (!pathbuf) {
  			retval = -ENOMEM;
  			goto out_unmark;
  		}
  		/*
  		 * Record that a name derived from an O_CLOEXEC fd will be
  		 * inaccessible after exec. Relies on having exclusive access to
  		 * current->files (due to unshare_files above).
  		 */
  		if (close_on_exec(fd, rcu_dereference_raw(current->files->fdt)))
  			bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE;
  		bprm->filename = pathbuf;
  	}
  	bprm->interp = bprm->filename;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1490

b6a2fea39   Ollie Wild   mm: variable leng...
1491
1492
  	retval = bprm_mm_init(bprm);
  	if (retval)
63e46b95e   Oleg Nesterov   exec: move the fi...
1493
  		goto out_unmark;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1494

b6a2fea39   Ollie Wild   mm: variable leng...
1495
  	bprm->argc = count(argv, MAX_ARG_STRINGS);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1496
  	if ((retval = bprm->argc) < 0)
a6f76f23d   David Howells   CRED: Make execve...
1497
  		goto out;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1498

b6a2fea39   Ollie Wild   mm: variable leng...
1499
  	bprm->envc = count(envp, MAX_ARG_STRINGS);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1500
  	if ((retval = bprm->envc) < 0)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
  		goto out;
  
  	retval = prepare_binprm(bprm);
  	if (retval < 0)
  		goto out;
  
  	retval = copy_strings_kernel(1, &bprm->filename, bprm);
  	if (retval < 0)
  		goto out;
  
  	bprm->exec = bprm->p;
  	retval = copy_strings(bprm->envc, envp, bprm);
  	if (retval < 0)
  		goto out;
  
  	retval = copy_strings(bprm->argc, argv, bprm);
  	if (retval < 0)
  		goto out;
5d1baf3b6   Oleg Nesterov   exec: introduce e...
1519
  	retval = exec_binprm(bprm);
a6f76f23d   David Howells   CRED: Make execve...
1520
1521
  	if (retval < 0)
  		goto out;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1522

a6f76f23d   David Howells   CRED: Make execve...
1523
  	/* execve succeeded */
498052bba   Al Viro   New locking/refco...
1524
  	current->fs->in_exec = 0;
f9ce1f1cd   Kentaro Takeda   Add in_execve fla...
1525
  	current->in_execve = 0;
a6f76f23d   David Howells   CRED: Make execve...
1526
  	acct_update_integrals(current);
82727018b   Rik van Riel   sched/numa: Call ...
1527
  	task_numa_free(current);
a6f76f23d   David Howells   CRED: Make execve...
1528
  	free_bprm(bprm);
51f39a1f0   David Drysdale   syscalls: impleme...
1529
  	kfree(pathbuf);
c4ad8f98b   Linus Torvalds   execve: use 'stru...
1530
  	putname(filename);
a6f76f23d   David Howells   CRED: Make execve...
1531
1532
1533
  	if (displaced)
  		put_files_struct(displaced);
  	return retval;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1534

a6f76f23d   David Howells   CRED: Make execve...
1535
  out:
3c77f8457   Oleg Nesterov   exec: make argv/e...
1536
1537
1538
1539
  	if (bprm->mm) {
  		acct_arg_size(bprm, 0);
  		mmput(bprm->mm);
  	}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1540

498052bba   Al Viro   New locking/refco...
1541
  out_unmark:
9e00cdb09   Oleg Nesterov   exec:check_unsafe...
1542
  	current->fs->in_exec = 0;
f9ce1f1cd   Kentaro Takeda   Add in_execve fla...
1543
  	current->in_execve = 0;
a6f76f23d   David Howells   CRED: Make execve...
1544
1545
  
  out_free:
08a6fac1c   Al Viro   [PATCH] get rid o...
1546
  	free_bprm(bprm);
51f39a1f0   David Drysdale   syscalls: impleme...
1547
  	kfree(pathbuf);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1548

fd8328be8   Al Viro   [PATCH] sanitize ...
1549
  out_files:
3b1253880   Al Viro   [PATCH] sanitize ...
1550
1551
  	if (displaced)
  		reset_files_struct(displaced);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1552
  out_ret:
c4ad8f98b   Linus Torvalds   execve: use 'stru...
1553
  	putname(filename);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1554
1555
  	return retval;
  }
c4ad8f98b   Linus Torvalds   execve: use 'stru...
1556
  int do_execve(struct filename *filename,
ba2d01629   Oleg Nesterov   exec: introduce s...
1557
  	const char __user *const __user *__argv,
da3d4c5fa   Al Viro   get rid of pt_reg...
1558
  	const char __user *const __user *__envp)
ba2d01629   Oleg Nesterov   exec: introduce s...
1559
  {
0e028465d   Oleg Nesterov   exec: unify do_ex...
1560
1561
  	struct user_arg_ptr argv = { .ptr.native = __argv };
  	struct user_arg_ptr envp = { .ptr.native = __envp };
51f39a1f0   David Drysdale   syscalls: impleme...
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
  	return do_execveat_common(AT_FDCWD, filename, argv, envp, 0);
  }
  
  int do_execveat(int fd, struct filename *filename,
  		const char __user *const __user *__argv,
  		const char __user *const __user *__envp,
  		int flags)
  {
  	struct user_arg_ptr argv = { .ptr.native = __argv };
  	struct user_arg_ptr envp = { .ptr.native = __envp };
  
  	return do_execveat_common(fd, filename, argv, envp, flags);
0e028465d   Oleg Nesterov   exec: unify do_ex...
1574
1575
1576
  }
  
  #ifdef CONFIG_COMPAT
c4ad8f98b   Linus Torvalds   execve: use 'stru...
1577
  static int compat_do_execve(struct filename *filename,
38b983b34   Al Viro   generic sys_execve()
1578
  	const compat_uptr_t __user *__argv,
d03d26e58   Al Viro   make compat_do_ex...
1579
  	const compat_uptr_t __user *__envp)
0e028465d   Oleg Nesterov   exec: unify do_ex...
1580
1581
1582
1583
1584
1585
1586
1587
1588
  {
  	struct user_arg_ptr argv = {
  		.is_compat = true,
  		.ptr.compat = __argv,
  	};
  	struct user_arg_ptr envp = {
  		.is_compat = true,
  		.ptr.compat = __envp,
  	};
51f39a1f0   David Drysdale   syscalls: impleme...
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
  	return do_execveat_common(AT_FDCWD, filename, argv, envp, 0);
  }
  
  static int compat_do_execveat(int fd, struct filename *filename,
  			      const compat_uptr_t __user *__argv,
  			      const compat_uptr_t __user *__envp,
  			      int flags)
  {
  	struct user_arg_ptr argv = {
  		.is_compat = true,
  		.ptr.compat = __argv,
  	};
  	struct user_arg_ptr envp = {
  		.is_compat = true,
  		.ptr.compat = __envp,
  	};
  	return do_execveat_common(fd, filename, argv, envp, flags);
ba2d01629   Oleg Nesterov   exec: introduce s...
1606
  }
0e028465d   Oleg Nesterov   exec: unify do_ex...
1607
  #endif
ba2d01629   Oleg Nesterov   exec: introduce s...
1608

964ee7df9   Oleg Nesterov   exec: fix set_bin...
1609
  void set_binfmt(struct linux_binfmt *new)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1610
  {
801460d0c   Hiroshi Shimamoto   task_struct clean...
1611
1612
1613
1614
  	struct mm_struct *mm = current->mm;
  
  	if (mm->binfmt)
  		module_put(mm->binfmt->module);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1615

801460d0c   Hiroshi Shimamoto   task_struct clean...
1616
  	mm->binfmt = new;
964ee7df9   Oleg Nesterov   exec: fix set_bin...
1617
1618
  	if (new)
  		__module_get(new->module);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1619
  }
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
1620
  EXPORT_SYMBOL(set_binfmt);
6c5d52382   Kawai, Hidehiro   coredump masking:...
1621
  /*
7288e1187   Oleg Nesterov   coredump: kill MM...
1622
   * set_dumpable stores three-value SUID_DUMP_* into mm->flags.
6c5d52382   Kawai, Hidehiro   coredump masking:...
1623
1624
1625
   */
  void set_dumpable(struct mm_struct *mm, int value)
  {
abacd2fe3   Oleg Nesterov   coredump: set_dum...
1626
  	unsigned long old, new;
7288e1187   Oleg Nesterov   coredump: kill MM...
1627
1628
  	if (WARN_ON((unsigned)value > SUID_DUMP_ROOT))
  		return;
abacd2fe3   Oleg Nesterov   coredump: set_dum...
1629
1630
  	do {
  		old = ACCESS_ONCE(mm->flags);
7288e1187   Oleg Nesterov   coredump: kill MM...
1631
  		new = (old & ~MMF_DUMPABLE_MASK) | value;
abacd2fe3   Oleg Nesterov   coredump: set_dum...
1632
  	} while (cmpxchg(&mm->flags, old, new) != old);
6c5d52382   Kawai, Hidehiro   coredump masking:...
1633
  }
6c5d52382   Kawai, Hidehiro   coredump masking:...
1634

38b983b34   Al Viro   generic sys_execve()
1635
1636
1637
1638
1639
  SYSCALL_DEFINE3(execve,
  		const char __user *, filename,
  		const char __user *const __user *, argv,
  		const char __user *const __user *, envp)
  {
c4ad8f98b   Linus Torvalds   execve: use 'stru...
1640
  	return do_execve(getname(filename), argv, envp);
38b983b34   Al Viro   generic sys_execve()
1641
  }
51f39a1f0   David Drysdale   syscalls: impleme...
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
  
  SYSCALL_DEFINE5(execveat,
  		int, fd, const char __user *, filename,
  		const char __user *const __user *, argv,
  		const char __user *const __user *, envp,
  		int, flags)
  {
  	int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
  
  	return do_execveat(fd,
  			   getname_flags(filename, lookup_flags, NULL),
  			   argv, envp, flags);
  }
38b983b34   Al Viro   generic sys_execve()
1655
  #ifdef CONFIG_COMPAT
625b1d7e8   Heiko Carstens   fs/compat: conver...
1656
1657
1658
  COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename,
  	const compat_uptr_t __user *, argv,
  	const compat_uptr_t __user *, envp)
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  {
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  	return compat_do_execve(getname(filename), argv, envp);
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  }
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  COMPAT_SYSCALL_DEFINE5(execveat, int, fd,
  		       const char __user *, filename,
  		       const compat_uptr_t __user *, argv,
  		       const compat_uptr_t __user *, envp,
  		       int,  flags)
  {
  	int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
  
  	return compat_do_execveat(fd,
  				  getname_flags(filename, lookup_flags, NULL),
  				  argv, envp, flags);
  }
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  #endif