Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/exec.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | /* |
| 8 | * #!-checking implemented by tytso. |
| 9 | */ |
| 10 | /* |
| 11 | * Demand-loading implemented 01.12.91 - no need to read anything but |
| 12 | * the header into memory. The inode of the executable is put into |
| 13 | * "current->executable", and page faults do the actual loading. Clean. |
| 14 | * |
| 15 | * Once more I can proudly say that linux stood up to being changed: it |
| 16 | * was less than 2 hours work to get demand-loading completely implemented. |
| 17 | * |
| 18 | * Demand loading changed July 1993 by Eric Youngdale. Use mmap instead, |
| 19 | * current->executable is only used by the procfs. This allows a dispatch |
| 20 | * table to check for several different types of binary formats. We keep |
| 21 | * trying until we recognize the file or we run out of supported binary |
| 22 | * formats. |
| 23 | */ |
| 24 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <linux/slab.h> |
| 26 | #include <linux/file.h> |
Al Viro | 9f3acc3 | 2008-04-24 07:44:08 -0400 | [diff] [blame] | 27 | #include <linux/fdtable.h> |
Hugh Dickins | ba92a43 | 2008-07-25 01:45:43 -0700 | [diff] [blame] | 28 | #include <linux/mm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #include <linux/stat.h> |
| 30 | #include <linux/fcntl.h> |
Hugh Dickins | ba92a43 | 2008-07-25 01:45:43 -0700 | [diff] [blame] | 31 | #include <linux/swap.h> |
Neil Horman | 74aadce | 2007-10-16 23:26:35 -0700 | [diff] [blame] | 32 | #include <linux/string.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | #include <linux/init.h> |
Hugh Dickins | ca5b172 | 2008-07-28 15:46:18 -0700 | [diff] [blame] | 34 | #include <linux/pagemap.h> |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 35 | #include <linux/perf_event.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | #include <linux/highmem.h> |
| 37 | #include <linux/spinlock.h> |
| 38 | #include <linux/key.h> |
| 39 | #include <linux/personality.h> |
| 40 | #include <linux/binfmts.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | #include <linux/utsname.h> |
Sukadev Bhattiprolu | 84d7378 | 2006-12-08 02:38:01 -0800 | [diff] [blame] | 42 | #include <linux/pid_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | #include <linux/module.h> |
| 44 | #include <linux/namei.h> |
| 45 | #include <linux/proc_fs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | #include <linux/mount.h> |
| 47 | #include <linux/security.h> |
| 48 | #include <linux/syscalls.h> |
Jay Lan | 8f0ab51 | 2006-09-30 23:28:59 -0700 | [diff] [blame] | 49 | #include <linux/tsacct_kern.h> |
Matt Helsley | 9f46080 | 2005-11-07 00:59:16 -0800 | [diff] [blame] | 50 | #include <linux/cn_proc.h> |
Al Viro | 473ae30 | 2006-04-26 14:04:08 -0400 | [diff] [blame] | 51 | #include <linux/audit.h> |
Roland McGrath | 6341c39 | 2008-07-25 19:45:44 -0700 | [diff] [blame] | 52 | #include <linux/tracehook.h> |
Johannes Berg | 5f4123b | 2008-07-09 10:28:40 +0200 | [diff] [blame] | 53 | #include <linux/kmod.h> |
Eric Paris | 6110e3a | 2008-12-17 13:53:20 -0500 | [diff] [blame] | 54 | #include <linux/fsnotify.h> |
Al Viro | 5ad4e53 | 2009-03-29 19:50:06 -0400 | [diff] [blame] | 55 | #include <linux/fs_struct.h> |
Neil Horman | 61be228 | 2009-09-23 15:56:58 -0700 | [diff] [blame] | 56 | #include <linux/pipe_fs_i.h> |
Ying Han | 3d5992d | 2010-10-26 14:21:23 -0700 | [diff] [blame] | 57 | #include <linux/oom.h> |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame^] | 58 | #include <linux/compat.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | |
| 60 | #include <asm/uaccess.h> |
| 61 | #include <asm/mmu_context.h> |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 62 | #include <asm/tlb.h> |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 63 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | int core_uses_pid; |
Dan Aloni | 71ce92f | 2007-05-16 22:11:16 -0700 | [diff] [blame] | 66 | char core_pattern[CORENAME_MAX_SIZE] = "core"; |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 67 | unsigned int core_pipe_limit; |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 68 | int suid_dumpable = 0; |
| 69 | |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 70 | struct core_name { |
| 71 | char *corename; |
| 72 | int used, size; |
| 73 | }; |
| 74 | static atomic_t call_count = ATOMIC_INIT(1); |
| 75 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | /* The maximal length of core_pattern is also specified in sysctl.c */ |
| 77 | |
Alexey Dobriyan | e4dc1b1 | 2007-10-16 23:26:03 -0700 | [diff] [blame] | 78 | static LIST_HEAD(formats); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | static DEFINE_RWLOCK(binfmt_lock); |
| 80 | |
Ivan Kokshaysky | 74641f5 | 2009-04-30 15:08:49 -0700 | [diff] [blame] | 81 | int __register_binfmt(struct linux_binfmt * fmt, int insert) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | if (!fmt) |
| 84 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | write_lock(&binfmt_lock); |
Ivan Kokshaysky | 74641f5 | 2009-04-30 15:08:49 -0700 | [diff] [blame] | 86 | insert ? list_add(&fmt->lh, &formats) : |
| 87 | list_add_tail(&fmt->lh, &formats); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | write_unlock(&binfmt_lock); |
| 89 | return 0; |
| 90 | } |
| 91 | |
Ivan Kokshaysky | 74641f5 | 2009-04-30 15:08:49 -0700 | [diff] [blame] | 92 | EXPORT_SYMBOL(__register_binfmt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | |
Alexey Dobriyan | f6b450d | 2007-10-16 23:26:04 -0700 | [diff] [blame] | 94 | void unregister_binfmt(struct linux_binfmt * fmt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | write_lock(&binfmt_lock); |
Alexey Dobriyan | e4dc1b1 | 2007-10-16 23:26:03 -0700 | [diff] [blame] | 97 | list_del(&fmt->lh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | write_unlock(&binfmt_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | } |
| 100 | |
| 101 | EXPORT_SYMBOL(unregister_binfmt); |
| 102 | |
| 103 | static inline void put_binfmt(struct linux_binfmt * fmt) |
| 104 | { |
| 105 | module_put(fmt->module); |
| 106 | } |
| 107 | |
| 108 | /* |
| 109 | * Note that a shared library must be both readable and executable due to |
| 110 | * security reasons. |
| 111 | * |
| 112 | * Also note that we take the address to load from from the file itself. |
| 113 | */ |
Heiko Carstens | 1e7bfb2 | 2009-01-14 14:14:29 +0100 | [diff] [blame] | 114 | SYSCALL_DEFINE1(uselib, const char __user *, library) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | { |
Al Viro | 964bd18 | 2008-07-26 03:33:14 -0400 | [diff] [blame] | 116 | struct file *file; |
Al Viro | 964bd18 | 2008-07-26 03:33:14 -0400 | [diff] [blame] | 117 | char *tmp = getname(library); |
| 118 | int error = PTR_ERR(tmp); |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 119 | static const struct open_flags uselib_flags = { |
| 120 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, |
| 121 | .acc_mode = MAY_READ | MAY_EXEC | MAY_OPEN, |
| 122 | .intent = LOOKUP_OPEN |
| 123 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 125 | if (IS_ERR(tmp)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | goto out; |
| 127 | |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 128 | file = do_filp_open(AT_FDCWD, tmp, &uselib_flags, LOOKUP_FOLLOW); |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 129 | putname(tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | error = PTR_ERR(file); |
| 131 | if (IS_ERR(file)) |
| 132 | goto out; |
| 133 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 134 | error = -EINVAL; |
| 135 | if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
| 136 | goto exit; |
| 137 | |
| 138 | error = -EACCES; |
| 139 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
| 140 | goto exit; |
| 141 | |
Eric Paris | 2a12a9d | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 142 | fsnotify_open(file); |
Eric Paris | 6110e3a | 2008-12-17 13:53:20 -0500 | [diff] [blame] | 143 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | error = -ENOEXEC; |
| 145 | if(file->f_op) { |
| 146 | struct linux_binfmt * fmt; |
| 147 | |
| 148 | read_lock(&binfmt_lock); |
Alexey Dobriyan | e4dc1b1 | 2007-10-16 23:26:03 -0700 | [diff] [blame] | 149 | list_for_each_entry(fmt, &formats, lh) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | if (!fmt->load_shlib) |
| 151 | continue; |
| 152 | if (!try_module_get(fmt->module)) |
| 153 | continue; |
| 154 | read_unlock(&binfmt_lock); |
| 155 | error = fmt->load_shlib(file); |
| 156 | read_lock(&binfmt_lock); |
| 157 | put_binfmt(fmt); |
| 158 | if (error != -ENOEXEC) |
| 159 | break; |
| 160 | } |
| 161 | read_unlock(&binfmt_lock); |
| 162 | } |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 163 | exit: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | fput(file); |
| 165 | out: |
| 166 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | } |
| 168 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 169 | #ifdef CONFIG_MMU |
| 170 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame^] | 171 | static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 172 | { |
| 173 | struct mm_struct *mm = current->mm; |
| 174 | long diff = (long)(pages - bprm->vma_pages); |
| 175 | |
| 176 | if (!mm || !diff) |
| 177 | return; |
| 178 | |
| 179 | bprm->vma_pages = pages; |
| 180 | |
| 181 | #ifdef SPLIT_RSS_COUNTING |
| 182 | add_mm_counter(mm, MM_ANONPAGES, diff); |
| 183 | #else |
| 184 | spin_lock(&mm->page_table_lock); |
| 185 | add_mm_counter(mm, MM_ANONPAGES, diff); |
| 186 | spin_unlock(&mm->page_table_lock); |
| 187 | #endif |
| 188 | } |
| 189 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame^] | 190 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 191 | int write) |
| 192 | { |
| 193 | struct page *page; |
| 194 | int ret; |
| 195 | |
| 196 | #ifdef CONFIG_STACK_GROWSUP |
| 197 | if (write) { |
| 198 | ret = expand_stack_downwards(bprm->vma, pos); |
| 199 | if (ret < 0) |
| 200 | return NULL; |
| 201 | } |
| 202 | #endif |
| 203 | ret = get_user_pages(current, bprm->mm, pos, |
| 204 | 1, write, 1, &page, NULL); |
| 205 | if (ret <= 0) |
| 206 | return NULL; |
| 207 | |
| 208 | if (write) { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 209 | unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start; |
Linus Torvalds | a64e715 | 2008-03-03 10:12:14 -0800 | [diff] [blame] | 210 | struct rlimit *rlim; |
| 211 | |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 212 | acct_arg_size(bprm, size / PAGE_SIZE); |
| 213 | |
Linus Torvalds | a64e715 | 2008-03-03 10:12:14 -0800 | [diff] [blame] | 214 | /* |
| 215 | * We've historically supported up to 32 pages (ARG_MAX) |
| 216 | * of argument strings even with small stacks |
| 217 | */ |
| 218 | if (size <= ARG_MAX) |
| 219 | return page; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 220 | |
| 221 | /* |
| 222 | * Limit to 1/4-th the stack size for the argv+env strings. |
| 223 | * This ensures that: |
| 224 | * - the remaining binfmt code will not run out of stack space, |
| 225 | * - the program will have a reasonable amount of stack left |
| 226 | * to work from. |
| 227 | */ |
Linus Torvalds | a64e715 | 2008-03-03 10:12:14 -0800 | [diff] [blame] | 228 | rlim = current->signal->rlim; |
Jiri Slaby | d554ed89 | 2010-03-05 13:42:42 -0800 | [diff] [blame] | 229 | if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur) / 4) { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 230 | put_page(page); |
| 231 | return NULL; |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | return page; |
| 236 | } |
| 237 | |
| 238 | static void put_arg_page(struct page *page) |
| 239 | { |
| 240 | put_page(page); |
| 241 | } |
| 242 | |
| 243 | static void free_arg_page(struct linux_binprm *bprm, int i) |
| 244 | { |
| 245 | } |
| 246 | |
| 247 | static void free_arg_pages(struct linux_binprm *bprm) |
| 248 | { |
| 249 | } |
| 250 | |
| 251 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, |
| 252 | struct page *page) |
| 253 | { |
| 254 | flush_cache_page(bprm->vma, pos, page_to_pfn(page)); |
| 255 | } |
| 256 | |
| 257 | static int __bprm_mm_init(struct linux_binprm *bprm) |
| 258 | { |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 259 | int err; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 260 | struct vm_area_struct *vma = NULL; |
| 261 | struct mm_struct *mm = bprm->mm; |
| 262 | |
| 263 | bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); |
| 264 | if (!vma) |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 265 | return -ENOMEM; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 266 | |
| 267 | down_write(&mm->mmap_sem); |
| 268 | vma->vm_mm = mm; |
| 269 | |
| 270 | /* |
| 271 | * Place the stack at the largest stack address the architecture |
| 272 | * supports. Later, we'll move this to an appropriate place. We don't |
| 273 | * use STACK_TOP because that can depend on attributes which aren't |
| 274 | * configured yet. |
| 275 | */ |
Mel Gorman | a8bef8ff | 2010-05-24 14:32:24 -0700 | [diff] [blame] | 276 | BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 277 | vma->vm_end = STACK_TOP_MAX; |
| 278 | vma->vm_start = vma->vm_end - PAGE_SIZE; |
Mel Gorman | a8bef8ff | 2010-05-24 14:32:24 -0700 | [diff] [blame] | 279 | vma->vm_flags = VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP; |
Coly Li | 3ed75eb | 2007-10-18 23:39:15 -0700 | [diff] [blame] | 280 | vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); |
Rik van Riel | 5beb493 | 2010-03-05 13:42:07 -0800 | [diff] [blame] | 281 | INIT_LIST_HEAD(&vma->anon_vma_chain); |
Tavis Ormandy | 462e635e | 2010-12-09 15:29:42 +0100 | [diff] [blame] | 282 | |
| 283 | err = security_file_mmap(NULL, 0, 0, 0, vma->vm_start, 1); |
| 284 | if (err) |
| 285 | goto err; |
| 286 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 287 | err = insert_vm_struct(mm, vma); |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 288 | if (err) |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 289 | goto err; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 290 | |
| 291 | mm->stack_vm = mm->total_vm = 1; |
| 292 | up_write(&mm->mmap_sem); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 293 | bprm->p = vma->vm_end - sizeof(void *); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 294 | return 0; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 295 | err: |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 296 | up_write(&mm->mmap_sem); |
| 297 | bprm->vma = NULL; |
| 298 | kmem_cache_free(vm_area_cachep, vma); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 299 | return err; |
| 300 | } |
| 301 | |
| 302 | static bool valid_arg_len(struct linux_binprm *bprm, long len) |
| 303 | { |
| 304 | return len <= MAX_ARG_STRLEN; |
| 305 | } |
| 306 | |
| 307 | #else |
| 308 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame^] | 309 | static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 310 | { |
| 311 | } |
| 312 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame^] | 313 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 314 | int write) |
| 315 | { |
| 316 | struct page *page; |
| 317 | |
| 318 | page = bprm->page[pos / PAGE_SIZE]; |
| 319 | if (!page && write) { |
| 320 | page = alloc_page(GFP_HIGHUSER|__GFP_ZERO); |
| 321 | if (!page) |
| 322 | return NULL; |
| 323 | bprm->page[pos / PAGE_SIZE] = page; |
| 324 | } |
| 325 | |
| 326 | return page; |
| 327 | } |
| 328 | |
| 329 | static void put_arg_page(struct page *page) |
| 330 | { |
| 331 | } |
| 332 | |
| 333 | static void free_arg_page(struct linux_binprm *bprm, int i) |
| 334 | { |
| 335 | if (bprm->page[i]) { |
| 336 | __free_page(bprm->page[i]); |
| 337 | bprm->page[i] = NULL; |
| 338 | } |
| 339 | } |
| 340 | |
| 341 | static void free_arg_pages(struct linux_binprm *bprm) |
| 342 | { |
| 343 | int i; |
| 344 | |
| 345 | for (i = 0; i < MAX_ARG_PAGES; i++) |
| 346 | free_arg_page(bprm, i); |
| 347 | } |
| 348 | |
| 349 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, |
| 350 | struct page *page) |
| 351 | { |
| 352 | } |
| 353 | |
| 354 | static int __bprm_mm_init(struct linux_binprm *bprm) |
| 355 | { |
| 356 | bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *); |
| 357 | return 0; |
| 358 | } |
| 359 | |
| 360 | static bool valid_arg_len(struct linux_binprm *bprm, long len) |
| 361 | { |
| 362 | return len <= bprm->p; |
| 363 | } |
| 364 | |
| 365 | #endif /* CONFIG_MMU */ |
| 366 | |
| 367 | /* |
| 368 | * Create a new mm_struct and populate it with a temporary stack |
| 369 | * vm_area_struct. We don't have enough context at this point to set the stack |
| 370 | * flags, permissions, and offset, so we use temporary values. We'll update |
| 371 | * them later in setup_arg_pages(). |
| 372 | */ |
| 373 | int bprm_mm_init(struct linux_binprm *bprm) |
| 374 | { |
| 375 | int err; |
| 376 | struct mm_struct *mm = NULL; |
| 377 | |
| 378 | bprm->mm = mm = mm_alloc(); |
| 379 | err = -ENOMEM; |
| 380 | if (!mm) |
| 381 | goto err; |
| 382 | |
| 383 | err = init_new_context(current, mm); |
| 384 | if (err) |
| 385 | goto err; |
| 386 | |
| 387 | err = __bprm_mm_init(bprm); |
| 388 | if (err) |
| 389 | goto err; |
| 390 | |
| 391 | return 0; |
| 392 | |
| 393 | err: |
| 394 | if (mm) { |
| 395 | bprm->mm = NULL; |
| 396 | mmdrop(mm); |
| 397 | } |
| 398 | |
| 399 | return err; |
| 400 | } |
| 401 | |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 402 | struct user_arg_ptr { |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame^] | 403 | #ifdef CONFIG_COMPAT |
| 404 | bool is_compat; |
| 405 | #endif |
| 406 | union { |
| 407 | const char __user *const __user *native; |
| 408 | #ifdef CONFIG_COMPAT |
| 409 | compat_uptr_t __user *compat; |
| 410 | #endif |
| 411 | } ptr; |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 412 | }; |
| 413 | |
| 414 | static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr) |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 415 | { |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame^] | 416 | const char __user *native; |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 417 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame^] | 418 | #ifdef CONFIG_COMPAT |
| 419 | if (unlikely(argv.is_compat)) { |
| 420 | compat_uptr_t compat; |
| 421 | |
| 422 | if (get_user(compat, argv.ptr.compat + nr)) |
| 423 | return ERR_PTR(-EFAULT); |
| 424 | |
| 425 | return compat_ptr(compat); |
| 426 | } |
| 427 | #endif |
| 428 | |
| 429 | if (get_user(native, argv.ptr.native + nr)) |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 430 | return ERR_PTR(-EFAULT); |
| 431 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame^] | 432 | return native; |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 433 | } |
| 434 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | /* |
| 436 | * count() counts the number of strings in array ARGV. |
| 437 | */ |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 438 | static int count(struct user_arg_ptr argv, int max) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | { |
| 440 | int i = 0; |
| 441 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame^] | 442 | if (argv.ptr.native != NULL) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | for (;;) { |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 444 | const char __user *p = get_user_arg_ptr(argv, i); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | if (!p) |
| 447 | break; |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 448 | |
| 449 | if (IS_ERR(p)) |
| 450 | return -EFAULT; |
| 451 | |
Jason Baron | 362e666 | 2008-10-15 22:01:52 -0700 | [diff] [blame] | 452 | if (i++ >= max) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | return -E2BIG; |
Roland McGrath | 9aea5a6 | 2010-09-07 19:37:06 -0700 | [diff] [blame] | 454 | |
| 455 | if (fatal_signal_pending(current)) |
| 456 | return -ERESTARTNOHAND; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 457 | cond_resched(); |
| 458 | } |
| 459 | } |
| 460 | return i; |
| 461 | } |
| 462 | |
| 463 | /* |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 464 | * 'copy_strings()' copies argument/environment strings from the old |
| 465 | * processes's memory to the new process's stack. The call to get_user_pages() |
| 466 | * ensures the destination page is created and not swapped out. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | */ |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 468 | static int copy_strings(int argc, struct user_arg_ptr argv, |
Adrian Bunk | 75c96f8 | 2005-05-05 16:16:09 -0700 | [diff] [blame] | 469 | struct linux_binprm *bprm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | { |
| 471 | struct page *kmapped_page = NULL; |
| 472 | char *kaddr = NULL; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 473 | unsigned long kpos = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 474 | int ret; |
| 475 | |
| 476 | while (argc-- > 0) { |
David Howells | d762746 | 2010-08-17 23:52:56 +0100 | [diff] [blame] | 477 | const char __user *str; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | int len; |
| 479 | unsigned long pos; |
| 480 | |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 481 | ret = -EFAULT; |
| 482 | str = get_user_arg_ptr(argv, argc); |
| 483 | if (IS_ERR(str)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 486 | len = strnlen_user(str, MAX_ARG_STRLEN); |
| 487 | if (!len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | goto out; |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 489 | |
| 490 | ret = -E2BIG; |
| 491 | if (!valid_arg_len(bprm, len)) |
| 492 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 494 | /* We're going to work our way backwords. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | pos = bprm->p; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 496 | str += len; |
| 497 | bprm->p -= len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | |
| 499 | while (len > 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | int offset, bytes_to_copy; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 501 | |
Roland McGrath | 9aea5a6 | 2010-09-07 19:37:06 -0700 | [diff] [blame] | 502 | if (fatal_signal_pending(current)) { |
| 503 | ret = -ERESTARTNOHAND; |
| 504 | goto out; |
| 505 | } |
Roland McGrath | 7993bc1 | 2010-09-07 19:36:28 -0700 | [diff] [blame] | 506 | cond_resched(); |
| 507 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | offset = pos % PAGE_SIZE; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 509 | if (offset == 0) |
| 510 | offset = PAGE_SIZE; |
| 511 | |
| 512 | bytes_to_copy = offset; |
| 513 | if (bytes_to_copy > len) |
| 514 | bytes_to_copy = len; |
| 515 | |
| 516 | offset -= bytes_to_copy; |
| 517 | pos -= bytes_to_copy; |
| 518 | str -= bytes_to_copy; |
| 519 | len -= bytes_to_copy; |
| 520 | |
| 521 | if (!kmapped_page || kpos != (pos & PAGE_MASK)) { |
| 522 | struct page *page; |
| 523 | |
| 524 | page = get_arg_page(bprm, pos, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 525 | if (!page) { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 526 | ret = -E2BIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | goto out; |
| 528 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 529 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 530 | if (kmapped_page) { |
| 531 | flush_kernel_dcache_page(kmapped_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | kunmap(kmapped_page); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 533 | put_arg_page(kmapped_page); |
| 534 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 535 | kmapped_page = page; |
| 536 | kaddr = kmap(kmapped_page); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 537 | kpos = pos & PAGE_MASK; |
| 538 | flush_arg_page(bprm, kpos, kmapped_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | } |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 540 | if (copy_from_user(kaddr+offset, str, bytes_to_copy)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | ret = -EFAULT; |
| 542 | goto out; |
| 543 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | } |
| 545 | } |
| 546 | ret = 0; |
| 547 | out: |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 548 | if (kmapped_page) { |
| 549 | flush_kernel_dcache_page(kmapped_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 550 | kunmap(kmapped_page); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 551 | put_arg_page(kmapped_page); |
| 552 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | return ret; |
| 554 | } |
| 555 | |
| 556 | /* |
| 557 | * Like copy_strings, but get argv and its values from kernel memory. |
| 558 | */ |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 559 | int copy_strings_kernel(int argc, const char *const *__argv, |
David Howells | d762746 | 2010-08-17 23:52:56 +0100 | [diff] [blame] | 560 | struct linux_binprm *bprm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 561 | { |
| 562 | int r; |
| 563 | mm_segment_t oldfs = get_fs(); |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 564 | struct user_arg_ptr argv = { |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame^] | 565 | .ptr.native = (const char __user *const __user *)__argv, |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 566 | }; |
| 567 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 568 | set_fs(KERNEL_DS); |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 569 | r = copy_strings(argc, argv, bprm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | set_fs(oldfs); |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 571 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 572 | return r; |
| 573 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | EXPORT_SYMBOL(copy_strings_kernel); |
| 575 | |
| 576 | #ifdef CONFIG_MMU |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 577 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | /* |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 579 | * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once |
| 580 | * the binfmt code determines where the new stack should reside, we shift it to |
| 581 | * its final location. The process proceeds as follows: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | * |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 583 | * 1) Use shift to calculate the new vma endpoints. |
| 584 | * 2) Extend vma to cover both the old and new ranges. This ensures the |
| 585 | * arguments passed to subsequent functions are consistent. |
| 586 | * 3) Move vma's page tables to the new range. |
| 587 | * 4) Free up any cleared pgd range. |
| 588 | * 5) Shrink the vma to cover only the new range. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 589 | */ |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 590 | static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 591 | { |
| 592 | struct mm_struct *mm = vma->vm_mm; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 593 | unsigned long old_start = vma->vm_start; |
| 594 | unsigned long old_end = vma->vm_end; |
| 595 | unsigned long length = old_end - old_start; |
| 596 | unsigned long new_start = old_start - shift; |
| 597 | unsigned long new_end = old_end - shift; |
| 598 | struct mmu_gather *tlb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 600 | BUG_ON(new_start > new_end); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 602 | /* |
| 603 | * ensure there are no vmas between where we want to go |
| 604 | * and where we are |
| 605 | */ |
| 606 | if (vma != find_vma(mm, new_start)) |
| 607 | return -EFAULT; |
| 608 | |
| 609 | /* |
| 610 | * cover the whole range: [new_start, old_end) |
| 611 | */ |
Rik van Riel | 5beb493 | 2010-03-05 13:42:07 -0800 | [diff] [blame] | 612 | if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL)) |
| 613 | return -ENOMEM; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 614 | |
| 615 | /* |
| 616 | * move the page tables downwards, on failure we rely on |
| 617 | * process cleanup to remove whatever mess we made. |
| 618 | */ |
| 619 | if (length != move_page_tables(vma, old_start, |
| 620 | vma, new_start, length)) |
| 621 | return -ENOMEM; |
| 622 | |
| 623 | lru_add_drain(); |
| 624 | tlb = tlb_gather_mmu(mm, 0); |
| 625 | if (new_end > old_start) { |
| 626 | /* |
| 627 | * when the old and new regions overlap clear from new_end. |
| 628 | */ |
Jan Beulich | 42b7772 | 2008-07-23 21:27:10 -0700 | [diff] [blame] | 629 | free_pgd_range(tlb, new_end, old_end, new_end, |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 630 | vma->vm_next ? vma->vm_next->vm_start : 0); |
| 631 | } else { |
| 632 | /* |
| 633 | * otherwise, clean from old_start; this is done to not touch |
| 634 | * the address space in [new_end, old_start) some architectures |
| 635 | * have constraints on va-space that make this illegal (IA64) - |
| 636 | * for the others its just a little faster. |
| 637 | */ |
Jan Beulich | 42b7772 | 2008-07-23 21:27:10 -0700 | [diff] [blame] | 638 | free_pgd_range(tlb, old_start, old_end, new_end, |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 639 | vma->vm_next ? vma->vm_next->vm_start : 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 640 | } |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 641 | tlb_finish_mmu(tlb, new_end, old_end); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 642 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 643 | /* |
Rik van Riel | 5beb493 | 2010-03-05 13:42:07 -0800 | [diff] [blame] | 644 | * Shrink the vma to just the new range. Always succeeds. |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 645 | */ |
| 646 | vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); |
| 647 | |
| 648 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 649 | } |
| 650 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 651 | /* |
| 652 | * Finalizes the stack vm_area_struct. The flags and permissions are updated, |
| 653 | * the stack is optionally relocated, and some extra space is added. |
| 654 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 655 | int setup_arg_pages(struct linux_binprm *bprm, |
| 656 | unsigned long stack_top, |
| 657 | int executable_stack) |
| 658 | { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 659 | unsigned long ret; |
| 660 | unsigned long stack_shift; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 661 | struct mm_struct *mm = current->mm; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 662 | struct vm_area_struct *vma = bprm->vma; |
| 663 | struct vm_area_struct *prev = NULL; |
| 664 | unsigned long vm_flags; |
| 665 | unsigned long stack_base; |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 666 | unsigned long stack_size; |
| 667 | unsigned long stack_expand; |
| 668 | unsigned long rlim_stack; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | |
| 670 | #ifdef CONFIG_STACK_GROWSUP |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | /* Limit stack size to 1GB */ |
Jiri Slaby | d554ed89 | 2010-03-05 13:42:42 -0800 | [diff] [blame] | 672 | stack_base = rlimit_max(RLIMIT_STACK); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | if (stack_base > (1 << 30)) |
| 674 | stack_base = 1 << 30; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 676 | /* Make sure we didn't let the argument array grow too large. */ |
| 677 | if (vma->vm_end - vma->vm_start > stack_base) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 678 | return -ENOMEM; |
| 679 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 680 | stack_base = PAGE_ALIGN(stack_top - stack_base); |
| 681 | |
| 682 | stack_shift = vma->vm_start - stack_base; |
| 683 | mm->arg_start = bprm->p - stack_shift; |
| 684 | bprm->p = vma->vm_end - stack_shift; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 685 | #else |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 686 | stack_top = arch_align_stack(stack_top); |
| 687 | stack_top = PAGE_ALIGN(stack_top); |
Roland McGrath | 1b52818 | 2010-09-07 19:35:49 -0700 | [diff] [blame] | 688 | |
| 689 | if (unlikely(stack_top < mmap_min_addr) || |
| 690 | unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr)) |
| 691 | return -ENOMEM; |
| 692 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 693 | stack_shift = vma->vm_end - stack_top; |
| 694 | |
| 695 | bprm->p -= stack_shift; |
| 696 | mm->arg_start = bprm->p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 697 | #endif |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 698 | |
| 699 | if (bprm->loader) |
| 700 | bprm->loader -= stack_shift; |
| 701 | bprm->exec -= stack_shift; |
| 702 | |
| 703 | down_write(&mm->mmap_sem); |
Hugh Dickins | 96a8e13 | 2008-07-10 21:19:20 +0100 | [diff] [blame] | 704 | vm_flags = VM_STACK_FLAGS; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 705 | |
| 706 | /* |
| 707 | * Adjust stack execute permissions; explicitly enable for |
| 708 | * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone |
| 709 | * (arch default) otherwise. |
| 710 | */ |
| 711 | if (unlikely(executable_stack == EXSTACK_ENABLE_X)) |
| 712 | vm_flags |= VM_EXEC; |
| 713 | else if (executable_stack == EXSTACK_DISABLE_X) |
| 714 | vm_flags &= ~VM_EXEC; |
| 715 | vm_flags |= mm->def_flags; |
Mel Gorman | a8bef8ff | 2010-05-24 14:32:24 -0700 | [diff] [blame] | 716 | vm_flags |= VM_STACK_INCOMPLETE_SETUP; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 717 | |
| 718 | ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end, |
| 719 | vm_flags); |
| 720 | if (ret) |
| 721 | goto out_unlock; |
| 722 | BUG_ON(prev != vma); |
| 723 | |
| 724 | /* Move stack pages down in memory. */ |
| 725 | if (stack_shift) { |
| 726 | ret = shift_arg_pages(vma, stack_shift); |
Anton Blanchard | fc63cf2 | 2009-11-11 14:26:48 -0800 | [diff] [blame] | 727 | if (ret) |
| 728 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 729 | } |
| 730 | |
Mel Gorman | a8bef8ff | 2010-05-24 14:32:24 -0700 | [diff] [blame] | 731 | /* mprotect_fixup is overkill to remove the temporary stack flags */ |
| 732 | vma->vm_flags &= ~VM_STACK_INCOMPLETE_SETUP; |
| 733 | |
Michael Neuling | 5ef097d | 2010-03-05 13:42:57 -0800 | [diff] [blame] | 734 | stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */ |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 735 | stack_size = vma->vm_end - vma->vm_start; |
| 736 | /* |
| 737 | * Align this down to a page boundary as expand_stack |
| 738 | * will align it up. |
| 739 | */ |
| 740 | rlim_stack = rlimit(RLIMIT_STACK) & PAGE_MASK; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 741 | #ifdef CONFIG_STACK_GROWSUP |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 742 | if (stack_size + stack_expand > rlim_stack) |
| 743 | stack_base = vma->vm_start + rlim_stack; |
| 744 | else |
| 745 | stack_base = vma->vm_end + stack_expand; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 746 | #else |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 747 | if (stack_size + stack_expand > rlim_stack) |
| 748 | stack_base = vma->vm_end - rlim_stack; |
| 749 | else |
| 750 | stack_base = vma->vm_start - stack_expand; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 751 | #endif |
Eric B Munson | 3af9e85 | 2010-05-18 15:30:49 +0100 | [diff] [blame] | 752 | current->mm->start_stack = bprm->p; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 753 | ret = expand_stack(vma, stack_base); |
| 754 | if (ret) |
| 755 | ret = -EFAULT; |
| 756 | |
| 757 | out_unlock: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 758 | up_write(&mm->mmap_sem); |
Anton Blanchard | fc63cf2 | 2009-11-11 14:26:48 -0800 | [diff] [blame] | 759 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 760 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 761 | EXPORT_SYMBOL(setup_arg_pages); |
| 762 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 763 | #endif /* CONFIG_MMU */ |
| 764 | |
| 765 | struct file *open_exec(const char *name) |
| 766 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 767 | struct file *file; |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 768 | int err; |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 769 | static const struct open_flags open_exec_flags = { |
| 770 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, |
| 771 | .acc_mode = MAY_EXEC | MAY_OPEN, |
| 772 | .intent = LOOKUP_OPEN |
| 773 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 774 | |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 775 | file = do_filp_open(AT_FDCWD, name, &open_exec_flags, LOOKUP_FOLLOW); |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 776 | if (IS_ERR(file)) |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 777 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 779 | err = -EACCES; |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 780 | if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
| 781 | goto exit; |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 782 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 783 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
| 784 | goto exit; |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 785 | |
Eric Paris | 2a12a9d | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 786 | fsnotify_open(file); |
Eric Paris | 6110e3a | 2008-12-17 13:53:20 -0500 | [diff] [blame] | 787 | |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 788 | err = deny_write_access(file); |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 789 | if (err) |
| 790 | goto exit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 791 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 792 | out: |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 793 | return file; |
| 794 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 795 | exit: |
| 796 | fput(file); |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 797 | return ERR_PTR(err); |
| 798 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 799 | EXPORT_SYMBOL(open_exec); |
| 800 | |
Mimi Zohar | 6777d77 | 2009-08-21 14:32:48 -0400 | [diff] [blame] | 801 | int kernel_read(struct file *file, loff_t offset, |
| 802 | char *addr, unsigned long count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 803 | { |
| 804 | mm_segment_t old_fs; |
| 805 | loff_t pos = offset; |
| 806 | int result; |
| 807 | |
| 808 | old_fs = get_fs(); |
| 809 | set_fs(get_ds()); |
| 810 | /* The cast to a user pointer is valid due to the set_fs() */ |
| 811 | result = vfs_read(file, (void __user *)addr, count, &pos); |
| 812 | set_fs(old_fs); |
| 813 | return result; |
| 814 | } |
| 815 | |
| 816 | EXPORT_SYMBOL(kernel_read); |
| 817 | |
| 818 | static int exec_mmap(struct mm_struct *mm) |
| 819 | { |
| 820 | struct task_struct *tsk; |
| 821 | struct mm_struct * old_mm, *active_mm; |
| 822 | |
| 823 | /* Notify parent that we're no longer interested in the old VM */ |
| 824 | tsk = current; |
| 825 | old_mm = current->mm; |
KAMEZAWA Hiroyuki | 34e5523 | 2010-03-05 13:41:40 -0800 | [diff] [blame] | 826 | sync_mm_rss(tsk, old_mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | mm_release(tsk, old_mm); |
| 828 | |
| 829 | if (old_mm) { |
| 830 | /* |
| 831 | * Make sure that if there is a core dump in progress |
| 832 | * for the old mm, we get out and die instead of going |
| 833 | * through with the exec. We must hold mmap_sem around |
Oleg Nesterov | 999d9fc | 2008-07-25 01:47:41 -0700 | [diff] [blame] | 834 | * checking core_state and changing tsk->mm. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 835 | */ |
| 836 | down_read(&old_mm->mmap_sem); |
Oleg Nesterov | 999d9fc | 2008-07-25 01:47:41 -0700 | [diff] [blame] | 837 | if (unlikely(old_mm->core_state)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 838 | up_read(&old_mm->mmap_sem); |
| 839 | return -EINTR; |
| 840 | } |
| 841 | } |
| 842 | task_lock(tsk); |
| 843 | active_mm = tsk->active_mm; |
| 844 | tsk->mm = mm; |
| 845 | tsk->active_mm = mm; |
| 846 | activate_mm(active_mm, mm); |
Ying Han | 3d5992d | 2010-10-26 14:21:23 -0700 | [diff] [blame] | 847 | if (old_mm && tsk->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) { |
| 848 | atomic_dec(&old_mm->oom_disable_count); |
| 849 | atomic_inc(&tsk->mm->oom_disable_count); |
| 850 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 851 | task_unlock(tsk); |
| 852 | arch_pick_mmap_layout(mm); |
| 853 | if (old_mm) { |
| 854 | up_read(&old_mm->mmap_sem); |
Eric Sesterhenn | 7dddb12 | 2006-04-01 01:13:38 +0200 | [diff] [blame] | 855 | BUG_ON(active_mm != old_mm); |
Balbir Singh | 31a78f2 | 2008-09-28 23:09:31 +0100 | [diff] [blame] | 856 | mm_update_next_owner(old_mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 857 | mmput(old_mm); |
| 858 | return 0; |
| 859 | } |
| 860 | mmdrop(active_mm); |
| 861 | return 0; |
| 862 | } |
| 863 | |
| 864 | /* |
| 865 | * This function makes sure the current process has its own signal table, |
| 866 | * so that flush_signal_handlers can later reset the handlers without |
| 867 | * disturbing other processes. (Other processes might share the signal |
| 868 | * table via the CLONE_SIGHAND option to clone().) |
| 869 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 870 | static int de_thread(struct task_struct *tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 871 | { |
| 872 | struct signal_struct *sig = tsk->signal; |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 873 | struct sighand_struct *oldsighand = tsk->sighand; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 874 | spinlock_t *lock = &oldsighand->siglock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 875 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 876 | if (thread_group_empty(tsk)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 877 | goto no_thread_group; |
| 878 | |
| 879 | /* |
| 880 | * Kill all other threads in the thread group. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 881 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 882 | spin_lock_irq(lock); |
Oleg Nesterov | ed5d2ca | 2008-02-04 22:27:24 -0800 | [diff] [blame] | 883 | if (signal_group_exit(sig)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 884 | /* |
| 885 | * Another group action in progress, just |
| 886 | * return so that the signal is processed. |
| 887 | */ |
| 888 | spin_unlock_irq(lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 889 | return -EAGAIN; |
| 890 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 891 | |
Oleg Nesterov | d344193 | 2010-05-26 14:43:11 -0700 | [diff] [blame] | 892 | sig->group_exit_task = tsk; |
| 893 | sig->notify_count = zap_other_threads(tsk); |
| 894 | if (!thread_group_leader(tsk)) |
| 895 | sig->notify_count--; |
| 896 | |
| 897 | while (sig->notify_count) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 898 | __set_current_state(TASK_UNINTERRUPTIBLE); |
| 899 | spin_unlock_irq(lock); |
| 900 | schedule(); |
| 901 | spin_lock_irq(lock); |
| 902 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | spin_unlock_irq(lock); |
| 904 | |
| 905 | /* |
| 906 | * At this point all other threads have exited, all we have to |
| 907 | * do is to wait for the thread group leader to become inactive, |
| 908 | * and to assume its PID: |
| 909 | */ |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 910 | if (!thread_group_leader(tsk)) { |
Oleg Nesterov | 8187926 | 2008-12-01 14:18:16 -0800 | [diff] [blame] | 911 | struct task_struct *leader = tsk->group_leader; |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 912 | |
Oleg Nesterov | 2800d8d | 2008-04-30 00:53:12 -0700 | [diff] [blame] | 913 | sig->notify_count = -1; /* for exit_notify() */ |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 914 | for (;;) { |
| 915 | write_lock_irq(&tasklist_lock); |
| 916 | if (likely(leader->exit_state)) |
| 917 | break; |
| 918 | __set_current_state(TASK_UNINTERRUPTIBLE); |
| 919 | write_unlock_irq(&tasklist_lock); |
| 920 | schedule(); |
| 921 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 922 | |
Roland McGrath | f5e9028 | 2006-04-10 22:54:16 -0700 | [diff] [blame] | 923 | /* |
| 924 | * The only record we have of the real-time age of a |
| 925 | * process, regardless of execs it's done, is start_time. |
| 926 | * All the past CPU time is accumulated in signal_struct |
| 927 | * from sister threads now dead. But in this non-leader |
| 928 | * exec, nothing survives from the original leader thread, |
| 929 | * whose birth marks the true age of this process now. |
| 930 | * When we take on its identity by switching to its PID, we |
| 931 | * also take its birthdate (always earlier than our own). |
| 932 | */ |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 933 | tsk->start_time = leader->start_time; |
Roland McGrath | f5e9028 | 2006-04-10 22:54:16 -0700 | [diff] [blame] | 934 | |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 935 | BUG_ON(!same_thread_group(leader, tsk)); |
| 936 | BUG_ON(has_group_leader_pid(tsk)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 937 | /* |
| 938 | * An exec() starts a new thread group with the |
| 939 | * TGID of the previous thread group. Rehash the |
| 940 | * two threads with a switched PID, and release |
| 941 | * the former thread group leader: |
| 942 | */ |
Eric W. Biederman | d73d652 | 2006-03-28 16:11:03 -0800 | [diff] [blame] | 943 | |
| 944 | /* Become a process group leader with the old leader's pid. |
Eric W. Biederman | c18258c | 2006-09-27 01:51:06 -0700 | [diff] [blame] | 945 | * The old leader becomes a thread of the this thread group. |
| 946 | * Note: The old leader also uses this pid until release_task |
Eric W. Biederman | d73d652 | 2006-03-28 16:11:03 -0800 | [diff] [blame] | 947 | * is called. Odd but simple and correct. |
| 948 | */ |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 949 | detach_pid(tsk, PIDTYPE_PID); |
| 950 | tsk->pid = leader->pid; |
Sukadev Bhattiprolu | 3743ca0 | 2007-10-18 23:39:51 -0700 | [diff] [blame] | 951 | attach_pid(tsk, PIDTYPE_PID, task_pid(leader)); |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 952 | transfer_pid(leader, tsk, PIDTYPE_PGID); |
| 953 | transfer_pid(leader, tsk, PIDTYPE_SID); |
Oleg Nesterov | 9cd80bb | 2009-12-17 15:27:15 -0800 | [diff] [blame] | 954 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 955 | list_replace_rcu(&leader->tasks, &tsk->tasks); |
Oleg Nesterov | 9cd80bb | 2009-12-17 15:27:15 -0800 | [diff] [blame] | 956 | list_replace_init(&leader->sibling, &tsk->sibling); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 957 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 958 | tsk->group_leader = tsk; |
| 959 | leader->group_leader = tsk; |
Eric W. Biederman | de12a78 | 2006-04-10 17:16:49 -0600 | [diff] [blame] | 960 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 961 | tsk->exit_signal = SIGCHLD; |
Oleg Nesterov | 962b564 | 2005-11-23 13:37:43 -0800 | [diff] [blame] | 962 | |
| 963 | BUG_ON(leader->exit_state != EXIT_ZOMBIE); |
| 964 | leader->exit_state = EXIT_DEAD; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 965 | write_unlock_irq(&tasklist_lock); |
Oleg Nesterov | 8187926 | 2008-12-01 14:18:16 -0800 | [diff] [blame] | 966 | |
| 967 | release_task(leader); |
Oleg Nesterov | ed5d2ca | 2008-02-04 22:27:24 -0800 | [diff] [blame] | 968 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 969 | |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 970 | sig->group_exit_task = NULL; |
| 971 | sig->notify_count = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 972 | |
| 973 | no_thread_group: |
Jiri Pirko | 1f10206 | 2009-09-22 16:44:10 -0700 | [diff] [blame] | 974 | if (current->mm) |
| 975 | setmax_mm_hiwater_rss(&sig->maxrss, current->mm); |
| 976 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 977 | exit_itimers(sig); |
Oleg Nesterov | cbaffba | 2008-05-26 20:55:42 +0400 | [diff] [blame] | 978 | flush_itimer_signals(); |
Oleg Nesterov | 329f7db | 2005-11-07 21:12:43 +0300 | [diff] [blame] | 979 | |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 980 | if (atomic_read(&oldsighand->count) != 1) { |
| 981 | struct sighand_struct *newsighand; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 982 | /* |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 983 | * This ->sighand is shared with the CLONE_SIGHAND |
| 984 | * but not CLONE_THREAD task, switch to the new one. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 985 | */ |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 986 | newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); |
| 987 | if (!newsighand) |
| 988 | return -ENOMEM; |
| 989 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 990 | atomic_set(&newsighand->count, 1); |
| 991 | memcpy(newsighand->action, oldsighand->action, |
| 992 | sizeof(newsighand->action)); |
| 993 | |
| 994 | write_lock_irq(&tasklist_lock); |
| 995 | spin_lock(&oldsighand->siglock); |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 996 | rcu_assign_pointer(tsk->sighand, newsighand); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 997 | spin_unlock(&oldsighand->siglock); |
| 998 | write_unlock_irq(&tasklist_lock); |
| 999 | |
Davide Libenzi | fba2afa | 2007-05-10 22:23:13 -0700 | [diff] [blame] | 1000 | __cleanup_sighand(oldsighand); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1001 | } |
| 1002 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 1003 | BUG_ON(!thread_group_leader(tsk)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1004 | return 0; |
| 1005 | } |
Oleg Nesterov | 0840a90 | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 1006 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1007 | /* |
| 1008 | * These functions flushes out all traces of the currently running executable |
| 1009 | * so that a new one can be started |
| 1010 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 1011 | static void flush_old_files(struct files_struct * files) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1012 | { |
| 1013 | long j = -1; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1014 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1015 | |
| 1016 | spin_lock(&files->file_lock); |
| 1017 | for (;;) { |
| 1018 | unsigned long set, i; |
| 1019 | |
| 1020 | j++; |
| 1021 | i = j * __NFDBITS; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1022 | fdt = files_fdtable(files); |
Vadim Lobanov | bbea9f6 | 2006-12-10 02:21:12 -0800 | [diff] [blame] | 1023 | if (i >= fdt->max_fds) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1024 | break; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1025 | set = fdt->close_on_exec->fds_bits[j]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1026 | if (!set) |
| 1027 | continue; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1028 | fdt->close_on_exec->fds_bits[j] = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1029 | spin_unlock(&files->file_lock); |
| 1030 | for ( ; set ; i++,set >>= 1) { |
| 1031 | if (set & 1) { |
| 1032 | sys_close(i); |
| 1033 | } |
| 1034 | } |
| 1035 | spin_lock(&files->file_lock); |
| 1036 | |
| 1037 | } |
| 1038 | spin_unlock(&files->file_lock); |
| 1039 | } |
| 1040 | |
Andrew Morton | 59714d6 | 2008-02-04 22:27:21 -0800 | [diff] [blame] | 1041 | char *get_task_comm(char *buf, struct task_struct *tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1042 | { |
| 1043 | /* buf must be at least sizeof(tsk->comm) in size */ |
| 1044 | task_lock(tsk); |
| 1045 | strncpy(buf, tsk->comm, sizeof(tsk->comm)); |
| 1046 | task_unlock(tsk); |
Andrew Morton | 59714d6 | 2008-02-04 22:27:21 -0800 | [diff] [blame] | 1047 | return buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1048 | } |
| 1049 | |
| 1050 | void set_task_comm(struct task_struct *tsk, char *buf) |
| 1051 | { |
| 1052 | task_lock(tsk); |
john stultz | 4614a696b | 2009-12-14 18:00:05 -0800 | [diff] [blame] | 1053 | |
| 1054 | /* |
| 1055 | * Threads may access current->comm without holding |
| 1056 | * the task lock, so write the string carefully. |
| 1057 | * Readers without a lock may see incomplete new |
| 1058 | * names but are safe from non-terminating string reads. |
| 1059 | */ |
| 1060 | memset(tsk->comm, 0, TASK_COMM_LEN); |
| 1061 | wmb(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1062 | strlcpy(tsk->comm, buf, sizeof(tsk->comm)); |
| 1063 | task_unlock(tsk); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1064 | perf_event_comm(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1065 | } |
| 1066 | |
| 1067 | int flush_old_exec(struct linux_binprm * bprm) |
| 1068 | { |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1069 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1070 | |
| 1071 | /* |
| 1072 | * Make sure we have a private signal table and that |
| 1073 | * we are unassociated from the previous thread group. |
| 1074 | */ |
| 1075 | retval = de_thread(current); |
| 1076 | if (retval) |
| 1077 | goto out; |
| 1078 | |
Matt Helsley | 925d1c4 | 2008-04-29 01:01:36 -0700 | [diff] [blame] | 1079 | set_mm_exe_file(bprm->mm, bprm->file); |
| 1080 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1081 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1082 | * Release all of the old mmap stuff |
| 1083 | */ |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 1084 | acct_arg_size(bprm, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1085 | retval = exec_mmap(bprm->mm); |
| 1086 | if (retval) |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1087 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1088 | |
| 1089 | bprm->mm = NULL; /* We're using it now */ |
Linus Torvalds | 7ab02af | 2010-02-02 12:37:44 -0800 | [diff] [blame] | 1090 | |
KOSAKI Motohiro | 98391cf | 2010-10-27 15:34:16 -0700 | [diff] [blame] | 1091 | current->flags &= ~(PF_RANDOMIZE | PF_KTHREAD); |
Linus Torvalds | 7ab02af | 2010-02-02 12:37:44 -0800 | [diff] [blame] | 1092 | flush_thread(); |
| 1093 | current->personality &= ~bprm->per_clear; |
| 1094 | |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1095 | return 0; |
| 1096 | |
| 1097 | out: |
| 1098 | return retval; |
| 1099 | } |
| 1100 | EXPORT_SYMBOL(flush_old_exec); |
| 1101 | |
| 1102 | void setup_new_exec(struct linux_binprm * bprm) |
| 1103 | { |
| 1104 | int i, ch; |
David Howells | d762746 | 2010-08-17 23:52:56 +0100 | [diff] [blame] | 1105 | const char *name; |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1106 | char tcomm[sizeof(current->comm)]; |
| 1107 | |
| 1108 | arch_pick_mmap_layout(current->mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1109 | |
| 1110 | /* This is the point of no return */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1111 | current->sas_ss_sp = current->sas_ss_size = 0; |
| 1112 | |
David Howells | da9592e | 2008-11-14 10:39:05 +1100 | [diff] [blame] | 1113 | if (current_euid() == current_uid() && current_egid() == current_gid()) |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1114 | set_dumpable(current->mm, 1); |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 1115 | else |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1116 | set_dumpable(current->mm, suid_dumpable); |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 1117 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1118 | name = bprm->filename; |
Paolo 'Blaisorblade' Giarrusso | 3677209 | 2005-05-05 16:16:12 -0700 | [diff] [blame] | 1119 | |
| 1120 | /* Copies the binary name from after last slash */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1121 | for (i=0; (ch = *(name++)) != '\0';) { |
| 1122 | if (ch == '/') |
Paolo 'Blaisorblade' Giarrusso | 3677209 | 2005-05-05 16:16:12 -0700 | [diff] [blame] | 1123 | i = 0; /* overwrite what we wrote */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1124 | else |
| 1125 | if (i < (sizeof(tcomm) - 1)) |
| 1126 | tcomm[i++] = ch; |
| 1127 | } |
| 1128 | tcomm[i] = '\0'; |
| 1129 | set_task_comm(current, tcomm); |
| 1130 | |
Benjamin Herrenschmidt | 0551fbd | 2006-02-28 16:59:19 -0800 | [diff] [blame] | 1131 | /* Set the new mm task size. We have to do that late because it may |
| 1132 | * depend on TIF_32BIT which is only updated in flush_thread() on |
| 1133 | * some architectures like powerpc |
| 1134 | */ |
| 1135 | current->mm->task_size = TASK_SIZE; |
| 1136 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1137 | /* install the new credentials */ |
| 1138 | if (bprm->cred->uid != current_euid() || |
| 1139 | bprm->cred->gid != current_egid()) { |
Marcel Holtmann | d2d56c5 | 2007-08-17 21:47:58 +0200 | [diff] [blame] | 1140 | current->pdeath_signal = 0; |
| 1141 | } else if (file_permission(bprm->file, MAY_READ) || |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1142 | bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP) { |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1143 | set_dumpable(current->mm, suid_dumpable); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1144 | } |
| 1145 | |
Ingo Molnar | f65cb45 | 2008-12-16 13:40:44 +0100 | [diff] [blame] | 1146 | /* |
| 1147 | * Flush performance counters when crossing a |
| 1148 | * security domain: |
| 1149 | */ |
| 1150 | if (!get_dumpable(current->mm)) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1151 | perf_event_exit_task(current); |
Ingo Molnar | f65cb45 | 2008-12-16 13:40:44 +0100 | [diff] [blame] | 1152 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1153 | /* An exec changes our domain. We are no longer part of the thread |
| 1154 | group */ |
| 1155 | |
| 1156 | current->self_exec_id++; |
| 1157 | |
| 1158 | flush_signal_handlers(current, 0); |
| 1159 | flush_old_files(current->files); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1160 | } |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1161 | EXPORT_SYMBOL(setup_new_exec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1162 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1163 | /* |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1164 | * Prepare credentials and lock ->cred_guard_mutex. |
| 1165 | * install_exec_creds() commits the new creds and drops the lock. |
| 1166 | * Or, if exec fails before, free_bprm() should release ->cred and |
| 1167 | * and unlock. |
| 1168 | */ |
| 1169 | int prepare_bprm_creds(struct linux_binprm *bprm) |
| 1170 | { |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1171 | if (mutex_lock_interruptible(¤t->signal->cred_guard_mutex)) |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1172 | return -ERESTARTNOINTR; |
| 1173 | |
| 1174 | bprm->cred = prepare_exec_creds(); |
| 1175 | if (likely(bprm->cred)) |
| 1176 | return 0; |
| 1177 | |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1178 | mutex_unlock(¤t->signal->cred_guard_mutex); |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1179 | return -ENOMEM; |
| 1180 | } |
| 1181 | |
| 1182 | void free_bprm(struct linux_binprm *bprm) |
| 1183 | { |
| 1184 | free_arg_pages(bprm); |
| 1185 | if (bprm->cred) { |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1186 | mutex_unlock(¤t->signal->cred_guard_mutex); |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1187 | abort_creds(bprm->cred); |
| 1188 | } |
| 1189 | kfree(bprm); |
| 1190 | } |
| 1191 | |
| 1192 | /* |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1193 | * install the new credentials for this executable |
| 1194 | */ |
| 1195 | void install_exec_creds(struct linux_binprm *bprm) |
| 1196 | { |
| 1197 | security_bprm_committing_creds(bprm); |
| 1198 | |
| 1199 | commit_creds(bprm->cred); |
| 1200 | bprm->cred = NULL; |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1201 | /* |
| 1202 | * cred_guard_mutex must be held at least to this point to prevent |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1203 | * ptrace_attach() from altering our determination of the task's |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1204 | * credentials; any time after this it may be unlocked. |
| 1205 | */ |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1206 | security_bprm_committed_creds(bprm); |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1207 | mutex_unlock(¤t->signal->cred_guard_mutex); |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1208 | } |
| 1209 | EXPORT_SYMBOL(install_exec_creds); |
| 1210 | |
| 1211 | /* |
| 1212 | * determine how safe it is to execute the proposed program |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1213 | * - the caller must hold ->cred_guard_mutex to protect against |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1214 | * PTRACE_ATTACH |
| 1215 | */ |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1216 | int check_unsafe_exec(struct linux_binprm *bprm) |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1217 | { |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1218 | struct task_struct *p = current, *t; |
Al Viro | f1191b5 | 2009-03-30 07:35:18 -0400 | [diff] [blame] | 1219 | unsigned n_fs; |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1220 | int res = 0; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1221 | |
| 1222 | bprm->unsafe = tracehook_unsafe_exec(p); |
| 1223 | |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1224 | n_fs = 1; |
Nick Piggin | 2a4419b | 2010-08-18 04:37:33 +1000 | [diff] [blame] | 1225 | spin_lock(&p->fs->lock); |
Oleg Nesterov | 437f7fd | 2009-04-24 01:02:45 +0200 | [diff] [blame] | 1226 | rcu_read_lock(); |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1227 | for (t = next_thread(p); t != p; t = next_thread(t)) { |
| 1228 | if (t->fs == p->fs) |
| 1229 | n_fs++; |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1230 | } |
Oleg Nesterov | 437f7fd | 2009-04-24 01:02:45 +0200 | [diff] [blame] | 1231 | rcu_read_unlock(); |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1232 | |
Al Viro | f1191b5 | 2009-03-30 07:35:18 -0400 | [diff] [blame] | 1233 | if (p->fs->users > n_fs) { |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1234 | bprm->unsafe |= LSM_UNSAFE_SHARE; |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1235 | } else { |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1236 | res = -EAGAIN; |
| 1237 | if (!p->fs->in_exec) { |
| 1238 | p->fs->in_exec = 1; |
| 1239 | res = 1; |
| 1240 | } |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1241 | } |
Nick Piggin | 2a4419b | 2010-08-18 04:37:33 +1000 | [diff] [blame] | 1242 | spin_unlock(&p->fs->lock); |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1243 | |
| 1244 | return res; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1245 | } |
| 1246 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1247 | /* |
| 1248 | * Fill the binprm structure from the inode. |
| 1249 | * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1250 | * |
| 1251 | * This may be called multiple times for binary chains (scripts for example). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1252 | */ |
| 1253 | int prepare_binprm(struct linux_binprm *bprm) |
| 1254 | { |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1255 | umode_t mode; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 1256 | struct inode * inode = bprm->file->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1257 | int retval; |
| 1258 | |
| 1259 | mode = inode->i_mode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1260 | if (bprm->file->f_op == NULL) |
| 1261 | return -EACCES; |
| 1262 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1263 | /* clear any previous set[ug]id data from a previous binary */ |
| 1264 | bprm->cred->euid = current_euid(); |
| 1265 | bprm->cred->egid = current_egid(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1266 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1267 | if (!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1268 | /* Set-uid? */ |
| 1269 | if (mode & S_ISUID) { |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1270 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
| 1271 | bprm->cred->euid = inode->i_uid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1272 | } |
| 1273 | |
| 1274 | /* Set-gid? */ |
| 1275 | /* |
| 1276 | * If setgid is set but no group execute bit then this |
| 1277 | * is a candidate for mandatory locking, not a setgid |
| 1278 | * executable. |
| 1279 | */ |
| 1280 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1281 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
| 1282 | bprm->cred->egid = inode->i_gid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1283 | } |
| 1284 | } |
| 1285 | |
| 1286 | /* fill in binprm security blob */ |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1287 | retval = security_bprm_set_creds(bprm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1288 | if (retval) |
| 1289 | return retval; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1290 | bprm->cred_prepared = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1291 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1292 | memset(bprm->buf, 0, BINPRM_BUF_SIZE); |
| 1293 | return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1294 | } |
| 1295 | |
| 1296 | EXPORT_SYMBOL(prepare_binprm); |
| 1297 | |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1298 | /* |
| 1299 | * Arguments are '\0' separated strings found at the location bprm->p |
| 1300 | * points to; chop off the first by relocating brpm->p to right after |
| 1301 | * the first '\0' encountered. |
| 1302 | */ |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1303 | int remove_arg_zero(struct linux_binprm *bprm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1304 | { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1305 | int ret = 0; |
| 1306 | unsigned long offset; |
| 1307 | char *kaddr; |
| 1308 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1309 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1310 | if (!bprm->argc) |
| 1311 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1312 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1313 | do { |
| 1314 | offset = bprm->p & ~PAGE_MASK; |
| 1315 | page = get_arg_page(bprm, bprm->p, 0); |
| 1316 | if (!page) { |
| 1317 | ret = -EFAULT; |
| 1318 | goto out; |
| 1319 | } |
| 1320 | kaddr = kmap_atomic(page, KM_USER0); |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1321 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1322 | for (; offset < PAGE_SIZE && kaddr[offset]; |
| 1323 | offset++, bprm->p++) |
| 1324 | ; |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1325 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1326 | kunmap_atomic(kaddr, KM_USER0); |
| 1327 | put_arg_page(page); |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1328 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1329 | if (offset == PAGE_SIZE) |
| 1330 | free_arg_page(bprm, (bprm->p >> PAGE_SHIFT) - 1); |
| 1331 | } while (offset == PAGE_SIZE); |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1332 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1333 | bprm->p++; |
| 1334 | bprm->argc--; |
| 1335 | ret = 0; |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1336 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1337 | out: |
| 1338 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1339 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1340 | EXPORT_SYMBOL(remove_arg_zero); |
| 1341 | |
| 1342 | /* |
| 1343 | * cycle the list of binary formats handler, until one recognizes the image |
| 1344 | */ |
| 1345 | int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) |
| 1346 | { |
Roland McGrath | 85f3346 | 2008-12-09 19:36:38 -0800 | [diff] [blame] | 1347 | unsigned int depth = bprm->recursion_depth; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1348 | int try,retval; |
| 1349 | struct linux_binfmt *fmt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1350 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1351 | retval = security_bprm_check(bprm); |
| 1352 | if (retval) |
| 1353 | return retval; |
| 1354 | |
| 1355 | /* kernel module loader fixup */ |
| 1356 | /* so we don't try to load run modprobe in kernel space. */ |
| 1357 | set_fs(USER_DS); |
Al Viro | 473ae30 | 2006-04-26 14:04:08 -0400 | [diff] [blame] | 1358 | |
| 1359 | retval = audit_bprm(bprm); |
| 1360 | if (retval) |
| 1361 | return retval; |
| 1362 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1363 | retval = -ENOENT; |
| 1364 | for (try=0; try<2; try++) { |
| 1365 | read_lock(&binfmt_lock); |
Alexey Dobriyan | e4dc1b1 | 2007-10-16 23:26:03 -0700 | [diff] [blame] | 1366 | list_for_each_entry(fmt, &formats, lh) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1367 | int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary; |
| 1368 | if (!fn) |
| 1369 | continue; |
| 1370 | if (!try_module_get(fmt->module)) |
| 1371 | continue; |
| 1372 | read_unlock(&binfmt_lock); |
| 1373 | retval = fn(bprm, regs); |
Roland McGrath | 85f3346 | 2008-12-09 19:36:38 -0800 | [diff] [blame] | 1374 | /* |
| 1375 | * Restore the depth counter to its starting value |
| 1376 | * in this call, so we don't have to rely on every |
| 1377 | * load_binary function to restore it on return. |
| 1378 | */ |
| 1379 | bprm->recursion_depth = depth; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1380 | if (retval >= 0) { |
Roland McGrath | 85f3346 | 2008-12-09 19:36:38 -0800 | [diff] [blame] | 1381 | if (depth == 0) |
| 1382 | tracehook_report_exec(fmt, bprm, regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1383 | put_binfmt(fmt); |
| 1384 | allow_write_access(bprm->file); |
| 1385 | if (bprm->file) |
| 1386 | fput(bprm->file); |
| 1387 | bprm->file = NULL; |
| 1388 | current->did_exec = 1; |
Matt Helsley | 9f46080 | 2005-11-07 00:59:16 -0800 | [diff] [blame] | 1389 | proc_exec_connector(current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1390 | return retval; |
| 1391 | } |
| 1392 | read_lock(&binfmt_lock); |
| 1393 | put_binfmt(fmt); |
| 1394 | if (retval != -ENOEXEC || bprm->mm == NULL) |
| 1395 | break; |
| 1396 | if (!bprm->file) { |
| 1397 | read_unlock(&binfmt_lock); |
| 1398 | return retval; |
| 1399 | } |
| 1400 | } |
| 1401 | read_unlock(&binfmt_lock); |
| 1402 | if (retval != -ENOEXEC || bprm->mm == NULL) { |
| 1403 | break; |
Johannes Berg | 5f4123b | 2008-07-09 10:28:40 +0200 | [diff] [blame] | 1404 | #ifdef CONFIG_MODULES |
| 1405 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1406 | #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) |
| 1407 | if (printable(bprm->buf[0]) && |
| 1408 | printable(bprm->buf[1]) && |
| 1409 | printable(bprm->buf[2]) && |
| 1410 | printable(bprm->buf[3])) |
| 1411 | break; /* -ENOEXEC */ |
| 1412 | request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2])); |
| 1413 | #endif |
| 1414 | } |
| 1415 | } |
| 1416 | return retval; |
| 1417 | } |
| 1418 | |
| 1419 | EXPORT_SYMBOL(search_binary_handler); |
| 1420 | |
| 1421 | /* |
| 1422 | * sys_execve() executes a new program. |
| 1423 | */ |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 1424 | static int do_execve_common(const char *filename, |
| 1425 | struct user_arg_ptr argv, |
| 1426 | struct user_arg_ptr envp, |
| 1427 | struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1428 | { |
| 1429 | struct linux_binprm *bprm; |
| 1430 | struct file *file; |
Al Viro | 3b12538 | 2008-04-22 05:31:30 -0400 | [diff] [blame] | 1431 | struct files_struct *displaced; |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1432 | bool clear_in_exec; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1433 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1434 | |
Al Viro | 3b12538 | 2008-04-22 05:31:30 -0400 | [diff] [blame] | 1435 | retval = unshare_files(&displaced); |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1436 | if (retval) |
| 1437 | goto out_ret; |
| 1438 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1439 | retval = -ENOMEM; |
Oliver Neukum | 11b0b5a | 2006-03-25 03:08:13 -0800 | [diff] [blame] | 1440 | bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1441 | if (!bprm) |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1442 | goto out_files; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1443 | |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1444 | retval = prepare_bprm_creds(bprm); |
| 1445 | if (retval) |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1446 | goto out_free; |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1447 | |
| 1448 | retval = check_unsafe_exec(bprm); |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1449 | if (retval < 0) |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1450 | goto out_free; |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1451 | clear_in_exec = retval; |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1452 | current->in_execve = 1; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1453 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1454 | file = open_exec(filename); |
| 1455 | retval = PTR_ERR(file); |
| 1456 | if (IS_ERR(file)) |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1457 | goto out_unmark; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1458 | |
| 1459 | sched_exec(); |
| 1460 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1461 | bprm->file = file; |
| 1462 | bprm->filename = filename; |
| 1463 | bprm->interp = filename; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1464 | |
| 1465 | retval = bprm_mm_init(bprm); |
| 1466 | if (retval) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1467 | goto out_file; |
| 1468 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1469 | bprm->argc = count(argv, MAX_ARG_STRINGS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1470 | if ((retval = bprm->argc) < 0) |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1471 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1472 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1473 | bprm->envc = count(envp, MAX_ARG_STRINGS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1474 | if ((retval = bprm->envc) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1475 | goto out; |
| 1476 | |
| 1477 | retval = prepare_binprm(bprm); |
| 1478 | if (retval < 0) |
| 1479 | goto out; |
| 1480 | |
| 1481 | retval = copy_strings_kernel(1, &bprm->filename, bprm); |
| 1482 | if (retval < 0) |
| 1483 | goto out; |
| 1484 | |
| 1485 | bprm->exec = bprm->p; |
| 1486 | retval = copy_strings(bprm->envc, envp, bprm); |
| 1487 | if (retval < 0) |
| 1488 | goto out; |
| 1489 | |
| 1490 | retval = copy_strings(bprm->argc, argv, bprm); |
| 1491 | if (retval < 0) |
| 1492 | goto out; |
| 1493 | |
| 1494 | retval = search_binary_handler(bprm,regs); |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1495 | if (retval < 0) |
| 1496 | goto out; |
| 1497 | |
| 1498 | /* execve succeeded */ |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1499 | current->fs->in_exec = 0; |
Kentaro Takeda | f9ce1f1 | 2009-02-05 17:18:11 +0900 | [diff] [blame] | 1500 | current->in_execve = 0; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1501 | acct_update_integrals(current); |
| 1502 | free_bprm(bprm); |
| 1503 | if (displaced) |
| 1504 | put_files_struct(displaced); |
| 1505 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1506 | |
| 1507 | out: |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 1508 | if (bprm->mm) { |
| 1509 | acct_arg_size(bprm, 0); |
| 1510 | mmput(bprm->mm); |
| 1511 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1512 | |
| 1513 | out_file: |
| 1514 | if (bprm->file) { |
| 1515 | allow_write_access(bprm->file); |
| 1516 | fput(bprm->file); |
| 1517 | } |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1518 | |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1519 | out_unmark: |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1520 | if (clear_in_exec) |
| 1521 | current->fs->in_exec = 0; |
Kentaro Takeda | f9ce1f1 | 2009-02-05 17:18:11 +0900 | [diff] [blame] | 1522 | current->in_execve = 0; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1523 | |
| 1524 | out_free: |
Al Viro | 08a6fac | 2008-05-10 16:38:25 -0400 | [diff] [blame] | 1525 | free_bprm(bprm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1526 | |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1527 | out_files: |
Al Viro | 3b12538 | 2008-04-22 05:31:30 -0400 | [diff] [blame] | 1528 | if (displaced) |
| 1529 | reset_files_struct(displaced); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1530 | out_ret: |
| 1531 | return retval; |
| 1532 | } |
| 1533 | |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 1534 | int do_execve(const char *filename, |
| 1535 | const char __user *const __user *__argv, |
| 1536 | const char __user *const __user *__envp, |
| 1537 | struct pt_regs *regs) |
| 1538 | { |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame^] | 1539 | struct user_arg_ptr argv = { .ptr.native = __argv }; |
| 1540 | struct user_arg_ptr envp = { .ptr.native = __envp }; |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 1541 | return do_execve_common(filename, argv, envp, regs); |
| 1542 | } |
| 1543 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame^] | 1544 | #ifdef CONFIG_COMPAT |
| 1545 | int compat_do_execve(char *filename, |
| 1546 | compat_uptr_t __user *__argv, |
| 1547 | compat_uptr_t __user *__envp, |
| 1548 | struct pt_regs *regs) |
| 1549 | { |
| 1550 | struct user_arg_ptr argv = { |
| 1551 | .is_compat = true, |
| 1552 | .ptr.compat = __argv, |
| 1553 | }; |
| 1554 | struct user_arg_ptr envp = { |
| 1555 | .is_compat = true, |
| 1556 | .ptr.compat = __envp, |
| 1557 | }; |
| 1558 | return do_execve_common(filename, argv, envp, regs); |
| 1559 | } |
| 1560 | #endif |
| 1561 | |
Oleg Nesterov | 964ee7d | 2009-09-23 15:56:59 -0700 | [diff] [blame] | 1562 | void set_binfmt(struct linux_binfmt *new) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1563 | { |
Hiroshi Shimamoto | 801460d | 2009-09-23 15:57:41 -0700 | [diff] [blame] | 1564 | struct mm_struct *mm = current->mm; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1565 | |
Hiroshi Shimamoto | 801460d | 2009-09-23 15:57:41 -0700 | [diff] [blame] | 1566 | if (mm->binfmt) |
| 1567 | module_put(mm->binfmt->module); |
| 1568 | |
| 1569 | mm->binfmt = new; |
Oleg Nesterov | 964ee7d | 2009-09-23 15:56:59 -0700 | [diff] [blame] | 1570 | if (new) |
| 1571 | __module_get(new->module); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1572 | } |
| 1573 | |
| 1574 | EXPORT_SYMBOL(set_binfmt); |
| 1575 | |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1576 | static int expand_corename(struct core_name *cn) |
| 1577 | { |
| 1578 | char *old_corename = cn->corename; |
| 1579 | |
| 1580 | cn->size = CORENAME_MAX_SIZE * atomic_inc_return(&call_count); |
| 1581 | cn->corename = krealloc(old_corename, cn->size, GFP_KERNEL); |
| 1582 | |
| 1583 | if (!cn->corename) { |
| 1584 | kfree(old_corename); |
| 1585 | return -ENOMEM; |
| 1586 | } |
| 1587 | |
| 1588 | return 0; |
| 1589 | } |
| 1590 | |
| 1591 | static int cn_printf(struct core_name *cn, const char *fmt, ...) |
| 1592 | { |
| 1593 | char *cur; |
| 1594 | int need; |
| 1595 | int ret; |
| 1596 | va_list arg; |
| 1597 | |
| 1598 | va_start(arg, fmt); |
| 1599 | need = vsnprintf(NULL, 0, fmt, arg); |
| 1600 | va_end(arg); |
| 1601 | |
| 1602 | if (likely(need < cn->size - cn->used - 1)) |
| 1603 | goto out_printf; |
| 1604 | |
| 1605 | ret = expand_corename(cn); |
| 1606 | if (ret) |
| 1607 | goto expand_fail; |
| 1608 | |
| 1609 | out_printf: |
| 1610 | cur = cn->corename + cn->used; |
| 1611 | va_start(arg, fmt); |
| 1612 | vsnprintf(cur, need + 1, fmt, arg); |
| 1613 | va_end(arg); |
| 1614 | cn->used += need; |
| 1615 | return 0; |
| 1616 | |
| 1617 | expand_fail: |
| 1618 | return ret; |
| 1619 | } |
| 1620 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1621 | /* format_corename will inspect the pattern parameter, and output a |
| 1622 | * name into corename, which must have space for at least |
| 1623 | * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator. |
| 1624 | */ |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1625 | static int format_corename(struct core_name *cn, long signr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1626 | { |
David Howells | 86a264a | 2008-11-14 10:39:18 +1100 | [diff] [blame] | 1627 | const struct cred *cred = current_cred(); |
Oleg Nesterov | 565b9b1 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 1628 | const char *pat_ptr = core_pattern; |
| 1629 | int ispipe = (*pat_ptr == '|'); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1630 | int pid_in_pattern = 0; |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1631 | int err = 0; |
| 1632 | |
| 1633 | cn->size = CORENAME_MAX_SIZE * atomic_read(&call_count); |
| 1634 | cn->corename = kmalloc(cn->size, GFP_KERNEL); |
| 1635 | cn->used = 0; |
| 1636 | |
| 1637 | if (!cn->corename) |
| 1638 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1639 | |
| 1640 | /* Repeat as long as we have more pattern to process and more output |
| 1641 | space */ |
| 1642 | while (*pat_ptr) { |
| 1643 | if (*pat_ptr != '%') { |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1644 | if (*pat_ptr == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1645 | goto out; |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1646 | err = cn_printf(cn, "%c", *pat_ptr++); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1647 | } else { |
| 1648 | switch (*++pat_ptr) { |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1649 | /* single % at the end, drop that */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1650 | case 0: |
| 1651 | goto out; |
| 1652 | /* Double percent, output one percent */ |
| 1653 | case '%': |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1654 | err = cn_printf(cn, "%c", '%'); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1655 | break; |
| 1656 | /* pid */ |
| 1657 | case 'p': |
| 1658 | pid_in_pattern = 1; |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1659 | err = cn_printf(cn, "%d", |
| 1660 | task_tgid_vnr(current)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1661 | break; |
| 1662 | /* uid */ |
| 1663 | case 'u': |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1664 | err = cn_printf(cn, "%d", cred->uid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1665 | break; |
| 1666 | /* gid */ |
| 1667 | case 'g': |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1668 | err = cn_printf(cn, "%d", cred->gid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1669 | break; |
| 1670 | /* signal that caused the coredump */ |
| 1671 | case 's': |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1672 | err = cn_printf(cn, "%ld", signr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1673 | break; |
| 1674 | /* UNIX time of coredump */ |
| 1675 | case 't': { |
| 1676 | struct timeval tv; |
| 1677 | do_gettimeofday(&tv); |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1678 | err = cn_printf(cn, "%lu", tv.tv_sec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1679 | break; |
| 1680 | } |
| 1681 | /* hostname */ |
| 1682 | case 'h': |
| 1683 | down_read(&uts_sem); |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1684 | err = cn_printf(cn, "%s", |
| 1685 | utsname()->nodename); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1686 | up_read(&uts_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1687 | break; |
| 1688 | /* executable */ |
| 1689 | case 'e': |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1690 | err = cn_printf(cn, "%s", current->comm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1691 | break; |
Neil Horman | 74aadce | 2007-10-16 23:26:35 -0700 | [diff] [blame] | 1692 | /* core limit size */ |
| 1693 | case 'c': |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1694 | err = cn_printf(cn, "%lu", |
| 1695 | rlimit(RLIMIT_CORE)); |
Neil Horman | 74aadce | 2007-10-16 23:26:35 -0700 | [diff] [blame] | 1696 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1697 | default: |
| 1698 | break; |
| 1699 | } |
| 1700 | ++pat_ptr; |
| 1701 | } |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1702 | |
| 1703 | if (err) |
| 1704 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1705 | } |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1706 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1707 | /* Backward compatibility with core_uses_pid: |
| 1708 | * |
| 1709 | * If core_pattern does not include a %p (as is the default) |
| 1710 | * and core_uses_pid is set, then .%pid will be appended to |
Alan Cox | c4bbafd | 2007-04-16 22:53:13 -0700 | [diff] [blame] | 1711 | * the filename. Do not do this for piped commands. */ |
Oleg Nesterov | 6409324 | 2008-10-18 20:28:22 -0700 | [diff] [blame] | 1712 | if (!ispipe && !pid_in_pattern && core_uses_pid) { |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1713 | err = cn_printf(cn, ".%d", task_tgid_vnr(current)); |
| 1714 | if (err) |
| 1715 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1716 | } |
Alan Cox | c4bbafd | 2007-04-16 22:53:13 -0700 | [diff] [blame] | 1717 | out: |
Alan Cox | c4bbafd | 2007-04-16 22:53:13 -0700 | [diff] [blame] | 1718 | return ispipe; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1719 | } |
| 1720 | |
Oleg Nesterov | 5c99cbf | 2010-03-05 13:44:14 -0800 | [diff] [blame] | 1721 | static int zap_process(struct task_struct *start, int exit_code) |
Oleg Nesterov | aceecc0 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1722 | { |
| 1723 | struct task_struct *t; |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1724 | int nr = 0; |
Oleg Nesterov | 281de33 | 2006-06-26 00:26:06 -0700 | [diff] [blame] | 1725 | |
Oleg Nesterov | d5f70c0 | 2006-06-26 00:26:07 -0700 | [diff] [blame] | 1726 | start->signal->flags = SIGNAL_GROUP_EXIT; |
Oleg Nesterov | 5c99cbf | 2010-03-05 13:44:14 -0800 | [diff] [blame] | 1727 | start->signal->group_exit_code = exit_code; |
Oleg Nesterov | d5f70c0 | 2006-06-26 00:26:07 -0700 | [diff] [blame] | 1728 | start->signal->group_stop_count = 0; |
Oleg Nesterov | aceecc0 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1729 | |
| 1730 | t = start; |
| 1731 | do { |
| 1732 | if (t != current && t->mm) { |
Oleg Nesterov | 281de33 | 2006-06-26 00:26:06 -0700 | [diff] [blame] | 1733 | sigaddset(&t->pending.signal, SIGKILL); |
| 1734 | signal_wake_up(t, 1); |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1735 | nr++; |
Oleg Nesterov | aceecc0 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1736 | } |
Oleg Nesterov | e4901f9 | 2008-07-25 01:47:31 -0700 | [diff] [blame] | 1737 | } while_each_thread(start, t); |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1738 | |
| 1739 | return nr; |
Oleg Nesterov | aceecc0 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1740 | } |
| 1741 | |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1742 | static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm, |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1743 | struct core_state *core_state, int exit_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1744 | { |
| 1745 | struct task_struct *g, *p; |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1746 | unsigned long flags; |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1747 | int nr = -EAGAIN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1748 | |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1749 | spin_lock_irq(&tsk->sighand->siglock); |
Oleg Nesterov | ed5d2ca | 2008-02-04 22:27:24 -0800 | [diff] [blame] | 1750 | if (!signal_group_exit(tsk->signal)) { |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1751 | mm->core_state = core_state; |
Oleg Nesterov | 5c99cbf | 2010-03-05 13:44:14 -0800 | [diff] [blame] | 1752 | nr = zap_process(tsk, exit_code); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1753 | } |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1754 | spin_unlock_irq(&tsk->sighand->siglock); |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1755 | if (unlikely(nr < 0)) |
| 1756 | return nr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1757 | |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1758 | if (atomic_read(&mm->mm_users) == nr + 1) |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1759 | goto done; |
Oleg Nesterov | e4901f9 | 2008-07-25 01:47:31 -0700 | [diff] [blame] | 1760 | /* |
| 1761 | * We should find and kill all tasks which use this mm, and we should |
Oleg Nesterov | 999d9fc | 2008-07-25 01:47:41 -0700 | [diff] [blame] | 1762 | * count them correctly into ->nr_threads. We don't take tasklist |
Oleg Nesterov | e4901f9 | 2008-07-25 01:47:31 -0700 | [diff] [blame] | 1763 | * lock, but this is safe wrt: |
| 1764 | * |
| 1765 | * fork: |
| 1766 | * None of sub-threads can fork after zap_process(leader). All |
| 1767 | * processes which were created before this point should be |
| 1768 | * visible to zap_threads() because copy_process() adds the new |
| 1769 | * process to the tail of init_task.tasks list, and lock/unlock |
| 1770 | * of ->siglock provides a memory barrier. |
| 1771 | * |
| 1772 | * do_exit: |
| 1773 | * The caller holds mm->mmap_sem. This means that the task which |
| 1774 | * uses this mm can't pass exit_mm(), so it can't exit or clear |
| 1775 | * its ->mm. |
| 1776 | * |
| 1777 | * de_thread: |
| 1778 | * It does list_replace_rcu(&leader->tasks, ¤t->tasks), |
| 1779 | * we must see either old or new leader, this does not matter. |
| 1780 | * However, it can change p->sighand, so lock_task_sighand(p) |
| 1781 | * must be used. Since p->mm != NULL and we hold ->mmap_sem |
| 1782 | * it can't fail. |
| 1783 | * |
| 1784 | * Note also that "g" can be the old leader with ->mm == NULL |
| 1785 | * and already unhashed and thus removed from ->thread_group. |
| 1786 | * This is OK, __unhash_process()->list_del_rcu() does not |
| 1787 | * clear the ->next pointer, we will find the new leader via |
| 1788 | * next_thread(). |
| 1789 | */ |
Oleg Nesterov | 7b1c615 | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1790 | rcu_read_lock(); |
Oleg Nesterov | aceecc0 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1791 | for_each_process(g) { |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1792 | if (g == tsk->group_leader) |
| 1793 | continue; |
Oleg Nesterov | 15b9f36 | 2008-07-25 01:47:39 -0700 | [diff] [blame] | 1794 | if (g->flags & PF_KTHREAD) |
| 1795 | continue; |
Oleg Nesterov | aceecc0 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1796 | p = g; |
| 1797 | do { |
| 1798 | if (p->mm) { |
Oleg Nesterov | 15b9f36 | 2008-07-25 01:47:39 -0700 | [diff] [blame] | 1799 | if (unlikely(p->mm == mm)) { |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1800 | lock_task_sighand(p, &flags); |
Oleg Nesterov | 5c99cbf | 2010-03-05 13:44:14 -0800 | [diff] [blame] | 1801 | nr += zap_process(p, exit_code); |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1802 | unlock_task_sighand(p, &flags); |
| 1803 | } |
Oleg Nesterov | aceecc0 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1804 | break; |
| 1805 | } |
Oleg Nesterov | e4901f9 | 2008-07-25 01:47:31 -0700 | [diff] [blame] | 1806 | } while_each_thread(g, p); |
Oleg Nesterov | aceecc0 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1807 | } |
Oleg Nesterov | 7b1c615 | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1808 | rcu_read_unlock(); |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1809 | done: |
Oleg Nesterov | c5f1cc8 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1810 | atomic_set(&core_state->nr_threads, nr); |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1811 | return nr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1812 | } |
| 1813 | |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 1814 | static int coredump_wait(int exit_code, struct core_state *core_state) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1815 | { |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1816 | struct task_struct *tsk = current; |
| 1817 | struct mm_struct *mm = tsk->mm; |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1818 | struct completion *vfork_done; |
Oleg Nesterov | 269b005 | 2010-05-26 14:43:08 -0700 | [diff] [blame] | 1819 | int core_waiters = -EBUSY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1820 | |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 1821 | init_completion(&core_state->startup); |
Oleg Nesterov | b564daf | 2008-07-25 01:47:44 -0700 | [diff] [blame] | 1822 | core_state->dumper.task = tsk; |
| 1823 | core_state->dumper.next = NULL; |
Oleg Nesterov | 269b005 | 2010-05-26 14:43:08 -0700 | [diff] [blame] | 1824 | |
| 1825 | down_write(&mm->mmap_sem); |
| 1826 | if (!mm->core_state) |
| 1827 | core_waiters = zap_threads(tsk, mm, core_state, exit_code); |
Oleg Nesterov | 2384f55 | 2005-10-30 15:02:47 -0800 | [diff] [blame] | 1828 | up_write(&mm->mmap_sem); |
| 1829 | |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1830 | if (unlikely(core_waiters < 0)) |
| 1831 | goto fail; |
| 1832 | |
| 1833 | /* |
| 1834 | * Make sure nobody is waiting for us to release the VM, |
| 1835 | * otherwise we can deadlock when we wait on each other |
| 1836 | */ |
| 1837 | vfork_done = tsk->vfork_done; |
| 1838 | if (vfork_done) { |
| 1839 | tsk->vfork_done = NULL; |
| 1840 | complete(vfork_done); |
| 1841 | } |
| 1842 | |
Oleg Nesterov | 2384f55 | 2005-10-30 15:02:47 -0800 | [diff] [blame] | 1843 | if (core_waiters) |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 1844 | wait_for_completion(&core_state->startup); |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1845 | fail: |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1846 | return core_waiters; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1847 | } |
| 1848 | |
Oleg Nesterov | a94e2d4 | 2008-07-25 01:47:46 -0700 | [diff] [blame] | 1849 | static void coredump_finish(struct mm_struct *mm) |
| 1850 | { |
| 1851 | struct core_thread *curr, *next; |
| 1852 | struct task_struct *task; |
| 1853 | |
| 1854 | next = mm->core_state->dumper.next; |
| 1855 | while ((curr = next) != NULL) { |
| 1856 | next = curr->next; |
| 1857 | task = curr->task; |
| 1858 | /* |
| 1859 | * see exit_mm(), curr->task must not see |
| 1860 | * ->task == NULL before we read ->next. |
| 1861 | */ |
| 1862 | smp_mb(); |
| 1863 | curr->task = NULL; |
| 1864 | wake_up_process(task); |
| 1865 | } |
| 1866 | |
| 1867 | mm->core_state = NULL; |
| 1868 | } |
| 1869 | |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1870 | /* |
| 1871 | * set_dumpable converts traditional three-value dumpable to two flags and |
| 1872 | * stores them into mm->flags. It modifies lower two bits of mm->flags, but |
| 1873 | * these bits are not changed atomically. So get_dumpable can observe the |
| 1874 | * intermediate state. To avoid doing unexpected behavior, get get_dumpable |
| 1875 | * return either old dumpable or new one by paying attention to the order of |
| 1876 | * modifying the bits. |
| 1877 | * |
| 1878 | * dumpable | mm->flags (binary) |
| 1879 | * old new | initial interim final |
| 1880 | * ---------+----------------------- |
| 1881 | * 0 1 | 00 01 01 |
| 1882 | * 0 2 | 00 10(*) 11 |
| 1883 | * 1 0 | 01 00 00 |
| 1884 | * 1 2 | 01 11 11 |
| 1885 | * 2 0 | 11 10(*) 00 |
| 1886 | * 2 1 | 11 11 01 |
| 1887 | * |
| 1888 | * (*) get_dumpable regards interim value of 10 as 11. |
| 1889 | */ |
| 1890 | void set_dumpable(struct mm_struct *mm, int value) |
| 1891 | { |
| 1892 | switch (value) { |
| 1893 | case 0: |
| 1894 | clear_bit(MMF_DUMPABLE, &mm->flags); |
| 1895 | smp_wmb(); |
| 1896 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); |
| 1897 | break; |
| 1898 | case 1: |
| 1899 | set_bit(MMF_DUMPABLE, &mm->flags); |
| 1900 | smp_wmb(); |
| 1901 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); |
| 1902 | break; |
| 1903 | case 2: |
| 1904 | set_bit(MMF_DUMP_SECURELY, &mm->flags); |
| 1905 | smp_wmb(); |
| 1906 | set_bit(MMF_DUMPABLE, &mm->flags); |
| 1907 | break; |
| 1908 | } |
| 1909 | } |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1910 | |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 1911 | static int __get_dumpable(unsigned long mm_flags) |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1912 | { |
| 1913 | int ret; |
| 1914 | |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 1915 | ret = mm_flags & MMF_DUMPABLE_MASK; |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1916 | return (ret >= 2) ? 2 : ret; |
| 1917 | } |
| 1918 | |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 1919 | int get_dumpable(struct mm_struct *mm) |
| 1920 | { |
| 1921 | return __get_dumpable(mm->flags); |
| 1922 | } |
| 1923 | |
Neil Horman | 61be228 | 2009-09-23 15:56:58 -0700 | [diff] [blame] | 1924 | static void wait_for_dump_helpers(struct file *file) |
| 1925 | { |
| 1926 | struct pipe_inode_info *pipe; |
| 1927 | |
| 1928 | pipe = file->f_path.dentry->d_inode->i_pipe; |
| 1929 | |
| 1930 | pipe_lock(pipe); |
| 1931 | pipe->readers++; |
| 1932 | pipe->writers--; |
| 1933 | |
| 1934 | while ((pipe->readers > 1) && (!signal_pending(current))) { |
| 1935 | wake_up_interruptible_sync(&pipe->wait); |
| 1936 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
| 1937 | pipe_wait(pipe); |
| 1938 | } |
| 1939 | |
| 1940 | pipe->readers--; |
| 1941 | pipe->writers++; |
| 1942 | pipe_unlock(pipe); |
| 1943 | |
| 1944 | } |
| 1945 | |
| 1946 | |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 1947 | /* |
Holger Hans Peter Freyther | 1bef829 | 2011-02-24 17:46:49 +0100 | [diff] [blame] | 1948 | * umh_pipe_setup |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 1949 | * helper function to customize the process used |
| 1950 | * to collect the core in userspace. Specifically |
| 1951 | * it sets up a pipe and installs it as fd 0 (stdin) |
| 1952 | * for the process. Returns 0 on success, or |
| 1953 | * PTR_ERR on failure. |
| 1954 | * Note that it also sets the core limit to 1. This |
| 1955 | * is a special value that we use to trap recursive |
| 1956 | * core dumps |
| 1957 | */ |
| 1958 | static int umh_pipe_setup(struct subprocess_info *info) |
| 1959 | { |
| 1960 | struct file *rp, *wp; |
| 1961 | struct fdtable *fdt; |
| 1962 | struct coredump_params *cp = (struct coredump_params *)info->data; |
| 1963 | struct files_struct *cf = current->files; |
| 1964 | |
| 1965 | wp = create_write_pipe(0); |
| 1966 | if (IS_ERR(wp)) |
| 1967 | return PTR_ERR(wp); |
| 1968 | |
| 1969 | rp = create_read_pipe(wp, 0); |
| 1970 | if (IS_ERR(rp)) { |
| 1971 | free_write_pipe(wp); |
| 1972 | return PTR_ERR(rp); |
| 1973 | } |
| 1974 | |
| 1975 | cp->file = wp; |
| 1976 | |
| 1977 | sys_close(0); |
| 1978 | fd_install(0, rp); |
| 1979 | spin_lock(&cf->file_lock); |
| 1980 | fdt = files_fdtable(cf); |
| 1981 | FD_SET(0, fdt->open_fds); |
| 1982 | FD_CLR(0, fdt->close_on_exec); |
| 1983 | spin_unlock(&cf->file_lock); |
| 1984 | |
| 1985 | /* and disallow core files too */ |
| 1986 | current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1}; |
| 1987 | |
| 1988 | return 0; |
| 1989 | } |
| 1990 | |
WANG Cong | 8cd3ac3 | 2009-01-06 14:42:48 -0800 | [diff] [blame] | 1991 | void do_coredump(long signr, int exit_code, struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1992 | { |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 1993 | struct core_state core_state; |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1994 | struct core_name cn; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1995 | struct mm_struct *mm = current->mm; |
| 1996 | struct linux_binfmt * binfmt; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 1997 | const struct cred *old_cred; |
| 1998 | struct cred *cred; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1999 | int retval = 0; |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 2000 | int flag = 0; |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2001 | int ispipe; |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 2002 | static atomic_t core_dump_count = ATOMIC_INIT(0); |
Masami Hiramatsu | f6151df | 2009-12-17 15:27:16 -0800 | [diff] [blame] | 2003 | struct coredump_params cprm = { |
| 2004 | .signr = signr, |
| 2005 | .regs = regs, |
Jiri Slaby | d554ed89 | 2010-03-05 13:42:42 -0800 | [diff] [blame] | 2006 | .limit = rlimit(RLIMIT_CORE), |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 2007 | /* |
| 2008 | * We must use the same mm->flags while dumping core to avoid |
| 2009 | * inconsistency of bit flags, since this flag is not protected |
| 2010 | * by any locks. |
| 2011 | */ |
| 2012 | .mm_flags = mm->flags, |
Masami Hiramatsu | f6151df | 2009-12-17 15:27:16 -0800 | [diff] [blame] | 2013 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2014 | |
Steve Grubb | 0a4ff8c | 2007-04-19 10:28:21 -0400 | [diff] [blame] | 2015 | audit_core_dumps(signr); |
| 2016 | |
Hiroshi Shimamoto | 801460d | 2009-09-23 15:57:41 -0700 | [diff] [blame] | 2017 | binfmt = mm->binfmt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2018 | if (!binfmt || !binfmt->core_dump) |
| 2019 | goto fail; |
Oleg Nesterov | 269b005 | 2010-05-26 14:43:08 -0700 | [diff] [blame] | 2020 | if (!__get_dumpable(cprm.mm_flags)) |
| 2021 | goto fail; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 2022 | |
| 2023 | cred = prepare_creds(); |
Oleg Nesterov | 5e43aef | 2010-05-26 14:43:07 -0700 | [diff] [blame] | 2024 | if (!cred) |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 2025 | goto fail; |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 2026 | /* |
| 2027 | * We cannot trust fsuid as being the "true" uid of the |
| 2028 | * process nor do we know its entire history. We only know it |
| 2029 | * was tainted so we dump it as root in mode 2. |
| 2030 | */ |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 2031 | if (__get_dumpable(cprm.mm_flags) == 2) { |
| 2032 | /* Setuid core dump mode */ |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 2033 | flag = O_EXCL; /* Stop rewrite attacks */ |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 2034 | cred->fsuid = 0; /* Dump root private */ |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 2035 | } |
Oleg Nesterov | 1291cf4 | 2005-10-30 15:02:54 -0800 | [diff] [blame] | 2036 | |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 2037 | retval = coredump_wait(exit_code, &core_state); |
Oleg Nesterov | 5e43aef | 2010-05-26 14:43:07 -0700 | [diff] [blame] | 2038 | if (retval < 0) |
| 2039 | goto fail_creds; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 2040 | |
| 2041 | old_cred = override_creds(cred); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2042 | |
| 2043 | /* |
| 2044 | * Clear any false indication of pending signals that might |
| 2045 | * be seen by the filesystem code called to write the core file. |
| 2046 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2047 | clear_thread_flag(TIF_SIGPENDING); |
| 2048 | |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 2049 | ispipe = format_corename(&cn, signr); |
| 2050 | |
| 2051 | if (ispipe == -ENOMEM) { |
| 2052 | printk(KERN_WARNING "format_corename failed\n"); |
| 2053 | printk(KERN_WARNING "Aborting core\n"); |
| 2054 | goto fail_corename; |
| 2055 | } |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 2056 | |
Alan Cox | c4bbafd | 2007-04-16 22:53:13 -0700 | [diff] [blame] | 2057 | if (ispipe) { |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2058 | int dump_count; |
| 2059 | char **helper_argv; |
| 2060 | |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 2061 | if (cprm.limit == 1) { |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 2062 | /* |
| 2063 | * Normally core limits are irrelevant to pipes, since |
| 2064 | * we're not writing to the file system, but we use |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 2065 | * cprm.limit of 1 here as a speacial value. Any |
| 2066 | * non-1 limit gets set to RLIM_INFINITY below, but |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 2067 | * a limit of 0 skips the dump. This is a consistent |
| 2068 | * way to catch recursive crashes. We can still crash |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 2069 | * if the core_pattern binary sets RLIM_CORE = !1 |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 2070 | * but it runs as root, and can do lots of stupid things |
| 2071 | * Note that we use task_tgid_vnr here to grab the pid |
| 2072 | * of the process group leader. That way we get the |
| 2073 | * right pid if a thread in a multi-threaded |
| 2074 | * core_pattern process dies. |
| 2075 | */ |
| 2076 | printk(KERN_WARNING |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 2077 | "Process %d(%s) has RLIMIT_CORE set to 1\n", |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 2078 | task_tgid_vnr(current), current->comm); |
| 2079 | printk(KERN_WARNING "Aborting core\n"); |
| 2080 | goto fail_unlock; |
| 2081 | } |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2082 | cprm.limit = RLIM_INFINITY; |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 2083 | |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 2084 | dump_count = atomic_inc_return(&core_dump_count); |
| 2085 | if (core_pipe_limit && (core_pipe_limit < dump_count)) { |
| 2086 | printk(KERN_WARNING "Pid %d(%s) over core_pipe_limit\n", |
| 2087 | task_tgid_vnr(current), current->comm); |
| 2088 | printk(KERN_WARNING "Skipping core dump\n"); |
| 2089 | goto fail_dropcount; |
| 2090 | } |
| 2091 | |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 2092 | helper_argv = argv_split(GFP_KERNEL, cn.corename+1, NULL); |
Tetsuo Handa | 350eaf7 | 2009-01-06 14:41:11 -0800 | [diff] [blame] | 2093 | if (!helper_argv) { |
| 2094 | printk(KERN_WARNING "%s failed to allocate memory\n", |
| 2095 | __func__); |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 2096 | goto fail_dropcount; |
Tetsuo Handa | 350eaf7 | 2009-01-06 14:41:11 -0800 | [diff] [blame] | 2097 | } |
Neil Horman | 3232113 | 2007-10-16 23:26:36 -0700 | [diff] [blame] | 2098 | |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2099 | retval = call_usermodehelper_fns(helper_argv[0], helper_argv, |
| 2100 | NULL, UMH_WAIT_EXEC, umh_pipe_setup, |
| 2101 | NULL, &cprm); |
| 2102 | argv_free(helper_argv); |
| 2103 | if (retval) { |
Andi Kleen | d025c9d | 2006-09-30 23:29:28 -0700 | [diff] [blame] | 2104 | printk(KERN_INFO "Core dump to %s pipe failed\n", |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 2105 | cn.corename); |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2106 | goto close_fail; |
Andi Kleen | d025c9d | 2006-09-30 23:29:28 -0700 | [diff] [blame] | 2107 | } |
Oleg Nesterov | c713541 | 2010-05-26 14:43:05 -0700 | [diff] [blame] | 2108 | } else { |
| 2109 | struct inode *inode; |
| 2110 | |
| 2111 | if (cprm.limit < binfmt->min_coredump) |
| 2112 | goto fail_unlock; |
| 2113 | |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 2114 | cprm.file = filp_open(cn.corename, |
Alexey Dobriyan | 6d4df67 | 2006-12-06 20:40:39 -0800 | [diff] [blame] | 2115 | O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag, |
| 2116 | 0600); |
Oleg Nesterov | c713541 | 2010-05-26 14:43:05 -0700 | [diff] [blame] | 2117 | if (IS_ERR(cprm.file)) |
| 2118 | goto fail_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2119 | |
Oleg Nesterov | c713541 | 2010-05-26 14:43:05 -0700 | [diff] [blame] | 2120 | inode = cprm.file->f_path.dentry->d_inode; |
| 2121 | if (inode->i_nlink > 1) |
| 2122 | goto close_fail; |
| 2123 | if (d_unhashed(cprm.file->f_path.dentry)) |
| 2124 | goto close_fail; |
| 2125 | /* |
| 2126 | * AK: actually i see no reason to not allow this for named |
| 2127 | * pipes etc, but keep the previous behaviour for now. |
| 2128 | */ |
| 2129 | if (!S_ISREG(inode->i_mode)) |
| 2130 | goto close_fail; |
| 2131 | /* |
| 2132 | * Dont allow local users get cute and trick others to coredump |
| 2133 | * into their pre-created files. |
| 2134 | */ |
| 2135 | if (inode->i_uid != current_fsuid()) |
| 2136 | goto close_fail; |
| 2137 | if (!cprm.file->f_op || !cprm.file->f_op->write) |
| 2138 | goto close_fail; |
| 2139 | if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file)) |
| 2140 | goto close_fail; |
| 2141 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2142 | |
Masami Hiramatsu | f6151df | 2009-12-17 15:27:16 -0800 | [diff] [blame] | 2143 | retval = binfmt->core_dump(&cprm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2144 | if (retval) |
| 2145 | current->signal->group_exit_code |= 0x80; |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2146 | |
Neil Horman | 61be228 | 2009-09-23 15:56:58 -0700 | [diff] [blame] | 2147 | if (ispipe && core_pipe_limit) |
Masami Hiramatsu | f6151df | 2009-12-17 15:27:16 -0800 | [diff] [blame] | 2148 | wait_for_dump_helpers(cprm.file); |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2149 | close_fail: |
| 2150 | if (cprm.file) |
| 2151 | filp_close(cprm.file, NULL); |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 2152 | fail_dropcount: |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2153 | if (ispipe) |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 2154 | atomic_dec(&core_dump_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2155 | fail_unlock: |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 2156 | kfree(cn.corename); |
| 2157 | fail_corename: |
Oleg Nesterov | a94e2d4 | 2008-07-25 01:47:46 -0700 | [diff] [blame] | 2158 | coredump_finish(mm); |
Oleg Nesterov | 5e43aef | 2010-05-26 14:43:07 -0700 | [diff] [blame] | 2159 | revert_creds(old_cred); |
| 2160 | fail_creds: |
| 2161 | put_cred(cred); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2162 | fail: |
WANG Cong | 8cd3ac3 | 2009-01-06 14:42:48 -0800 | [diff] [blame] | 2163 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2164 | } |
Linus Torvalds | 3aa0ce8 | 2010-10-14 14:32:06 -0700 | [diff] [blame] | 2165 | |
| 2166 | /* |
| 2167 | * Core dumping helper functions. These are the only things you should |
| 2168 | * do on a core-file: use only these functions to write out all the |
| 2169 | * necessary info. |
| 2170 | */ |
| 2171 | int dump_write(struct file *file, const void *addr, int nr) |
| 2172 | { |
| 2173 | return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr; |
| 2174 | } |
Linus Torvalds | 8fd01d6 | 2010-10-14 19:15:28 -0700 | [diff] [blame] | 2175 | EXPORT_SYMBOL(dump_write); |
Linus Torvalds | 3aa0ce8 | 2010-10-14 14:32:06 -0700 | [diff] [blame] | 2176 | |
| 2177 | int dump_seek(struct file *file, loff_t off) |
| 2178 | { |
| 2179 | int ret = 1; |
| 2180 | |
| 2181 | if (file->f_op->llseek && file->f_op->llseek != no_llseek) { |
| 2182 | if (file->f_op->llseek(file, off, SEEK_CUR) < 0) |
| 2183 | return 0; |
| 2184 | } else { |
| 2185 | char *buf = (char *)get_zeroed_page(GFP_KERNEL); |
| 2186 | |
| 2187 | if (!buf) |
| 2188 | return 0; |
| 2189 | while (off > 0) { |
| 2190 | unsigned long n = off; |
| 2191 | |
| 2192 | if (n > PAGE_SIZE) |
| 2193 | n = PAGE_SIZE; |
| 2194 | if (!dump_write(file, buf, n)) { |
| 2195 | ret = 0; |
| 2196 | break; |
| 2197 | } |
| 2198 | off -= n; |
| 2199 | } |
| 2200 | free_page((unsigned long)buf); |
| 2201 | } |
| 2202 | return ret; |
| 2203 | } |
Linus Torvalds | 8fd01d6 | 2010-10-14 19:15:28 -0700 | [diff] [blame] | 2204 | EXPORT_SYMBOL(dump_seek); |