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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | #include <linux/mount.h> |
| 46 | #include <linux/security.h> |
| 47 | #include <linux/syscalls.h> |
Jay Lan | 8f0ab51 | 2006-09-30 23:28:59 -0700 | [diff] [blame] | 48 | #include <linux/tsacct_kern.h> |
Matt Helsley | 9f46080 | 2005-11-07 00:59:16 -0800 | [diff] [blame] | 49 | #include <linux/cn_proc.h> |
Al Viro | 473ae30 | 2006-04-26 14:04:08 -0400 | [diff] [blame] | 50 | #include <linux/audit.h> |
Roland McGrath | 6341c39 | 2008-07-25 19:45:44 -0700 | [diff] [blame] | 51 | #include <linux/tracehook.h> |
Johannes Berg | 5f4123b | 2008-07-09 10:28:40 +0200 | [diff] [blame] | 52 | #include <linux/kmod.h> |
Eric Paris | 6110e3a | 2008-12-17 13:53:20 -0500 | [diff] [blame] | 53 | #include <linux/fsnotify.h> |
Al Viro | 5ad4e53 | 2009-03-29 19:50:06 -0400 | [diff] [blame] | 54 | #include <linux/fs_struct.h> |
Neil Horman | 61be228 | 2009-09-23 15:56:58 -0700 | [diff] [blame] | 55 | #include <linux/pipe_fs_i.h> |
Ying Han | 3d5992d | 2010-10-26 14:21:23 -0700 | [diff] [blame] | 56 | #include <linux/oom.h> |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 57 | #include <linux/compat.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | |
| 59 | #include <asm/uaccess.h> |
| 60 | #include <asm/mmu_context.h> |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 61 | #include <asm/tlb.h> |
KAMEZAWA Hiroyuki | 43d2b11 | 2012-01-10 15:08:09 -0800 | [diff] [blame] | 62 | |
| 63 | #include <trace/events/task.h> |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 64 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | |
David Smith | 4ff16c2 | 2012-02-07 10:11:05 -0600 | [diff] [blame] | 66 | #include <trace/events/sched.h> |
| 67 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | int core_uses_pid; |
Dan Aloni | 71ce92f | 2007-05-16 22:11:16 -0700 | [diff] [blame] | 69 | char core_pattern[CORENAME_MAX_SIZE] = "core"; |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 70 | unsigned int core_pipe_limit; |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 71 | int suid_dumpable = 0; |
| 72 | |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 73 | struct core_name { |
| 74 | char *corename; |
| 75 | int used, size; |
| 76 | }; |
| 77 | static atomic_t call_count = ATOMIC_INIT(1); |
| 78 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | /* The maximal length of core_pattern is also specified in sysctl.c */ |
| 80 | |
Alexey Dobriyan | e4dc1b1 | 2007-10-16 23:26:03 -0700 | [diff] [blame] | 81 | static LIST_HEAD(formats); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | static DEFINE_RWLOCK(binfmt_lock); |
| 83 | |
Al Viro | 8fc3dc5 | 2012-03-17 03:05:16 -0400 | [diff] [blame] | 84 | void __register_binfmt(struct linux_binfmt * fmt, int insert) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | { |
Al Viro | 8fc3dc5 | 2012-03-17 03:05:16 -0400 | [diff] [blame] | 86 | BUG_ON(!fmt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | write_lock(&binfmt_lock); |
Ivan Kokshaysky | 74641f5 | 2009-04-30 15:08:49 -0700 | [diff] [blame] | 88 | insert ? list_add(&fmt->lh, &formats) : |
| 89 | list_add_tail(&fmt->lh, &formats); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | write_unlock(&binfmt_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | } |
| 92 | |
Ivan Kokshaysky | 74641f5 | 2009-04-30 15:08:49 -0700 | [diff] [blame] | 93 | EXPORT_SYMBOL(__register_binfmt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | |
Alexey Dobriyan | f6b450d | 2007-10-16 23:26:04 -0700 | [diff] [blame] | 95 | void unregister_binfmt(struct linux_binfmt * fmt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | write_lock(&binfmt_lock); |
Alexey Dobriyan | e4dc1b1 | 2007-10-16 23:26:03 -0700 | [diff] [blame] | 98 | list_del(&fmt->lh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | write_unlock(&binfmt_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | } |
| 101 | |
| 102 | EXPORT_SYMBOL(unregister_binfmt); |
| 103 | |
| 104 | static inline void put_binfmt(struct linux_binfmt * fmt) |
| 105 | { |
| 106 | module_put(fmt->module); |
| 107 | } |
| 108 | |
| 109 | /* |
| 110 | * Note that a shared library must be both readable and executable due to |
| 111 | * security reasons. |
| 112 | * |
| 113 | * Also note that we take the address to load from from the file itself. |
| 114 | */ |
Heiko Carstens | 1e7bfb2 | 2009-01-14 14:14:29 +0100 | [diff] [blame] | 115 | SYSCALL_DEFINE1(uselib, const char __user *, library) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | { |
Al Viro | 964bd18 | 2008-07-26 03:33:14 -0400 | [diff] [blame] | 117 | struct file *file; |
Al Viro | 964bd18 | 2008-07-26 03:33:14 -0400 | [diff] [blame] | 118 | char *tmp = getname(library); |
| 119 | int error = PTR_ERR(tmp); |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 120 | static const struct open_flags uselib_flags = { |
| 121 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, |
| 122 | .acc_mode = MAY_READ | MAY_EXEC | MAY_OPEN, |
| 123 | .intent = LOOKUP_OPEN |
| 124 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 126 | if (IS_ERR(tmp)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | goto out; |
| 128 | |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 129 | file = do_filp_open(AT_FDCWD, tmp, &uselib_flags, LOOKUP_FOLLOW); |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 130 | putname(tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | error = PTR_ERR(file); |
| 132 | if (IS_ERR(file)) |
| 133 | goto out; |
| 134 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 135 | error = -EINVAL; |
| 136 | if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
| 137 | goto exit; |
| 138 | |
| 139 | error = -EACCES; |
| 140 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
| 141 | goto exit; |
| 142 | |
Eric Paris | 2a12a9d | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 143 | fsnotify_open(file); |
Eric Paris | 6110e3a | 2008-12-17 13:53:20 -0500 | [diff] [blame] | 144 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | error = -ENOEXEC; |
| 146 | if(file->f_op) { |
| 147 | struct linux_binfmt * fmt; |
| 148 | |
| 149 | read_lock(&binfmt_lock); |
Alexey Dobriyan | e4dc1b1 | 2007-10-16 23:26:03 -0700 | [diff] [blame] | 150 | list_for_each_entry(fmt, &formats, lh) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | if (!fmt->load_shlib) |
| 152 | continue; |
| 153 | if (!try_module_get(fmt->module)) |
| 154 | continue; |
| 155 | read_unlock(&binfmt_lock); |
| 156 | error = fmt->load_shlib(file); |
| 157 | read_lock(&binfmt_lock); |
| 158 | put_binfmt(fmt); |
| 159 | if (error != -ENOEXEC) |
| 160 | break; |
| 161 | } |
| 162 | read_unlock(&binfmt_lock); |
| 163 | } |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 164 | exit: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | fput(file); |
| 166 | out: |
| 167 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | } |
| 169 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 170 | #ifdef CONFIG_MMU |
Oleg Nesterov | ae6b585 | 2011-03-06 18:03:11 +0100 | [diff] [blame] | 171 | /* |
| 172 | * The nascent bprm->mm is not visible until exec_mmap() but it can |
| 173 | * use a lot of memory, account these pages in current->mm temporary |
| 174 | * for oom_badness()->get_mm_rss(). Once exec succeeds or fails, we |
| 175 | * change the counter back via acct_arg_size(0). |
| 176 | */ |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 177 | static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 178 | { |
| 179 | struct mm_struct *mm = current->mm; |
| 180 | long diff = (long)(pages - bprm->vma_pages); |
| 181 | |
| 182 | if (!mm || !diff) |
| 183 | return; |
| 184 | |
| 185 | bprm->vma_pages = pages; |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 186 | add_mm_counter(mm, MM_ANONPAGES, diff); |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 187 | } |
| 188 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 189 | 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] | 190 | int write) |
| 191 | { |
| 192 | struct page *page; |
| 193 | int ret; |
| 194 | |
| 195 | #ifdef CONFIG_STACK_GROWSUP |
| 196 | if (write) { |
Michal Hocko | d05f316 | 2011-05-24 17:11:44 -0700 | [diff] [blame] | 197 | ret = expand_downwards(bprm->vma, pos); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 198 | if (ret < 0) |
| 199 | return NULL; |
| 200 | } |
| 201 | #endif |
| 202 | ret = get_user_pages(current, bprm->mm, pos, |
| 203 | 1, write, 1, &page, NULL); |
| 204 | if (ret <= 0) |
| 205 | return NULL; |
| 206 | |
| 207 | if (write) { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 208 | unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start; |
Linus Torvalds | a64e715 | 2008-03-03 10:12:14 -0800 | [diff] [blame] | 209 | struct rlimit *rlim; |
| 210 | |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 211 | acct_arg_size(bprm, size / PAGE_SIZE); |
| 212 | |
Linus Torvalds | a64e715 | 2008-03-03 10:12:14 -0800 | [diff] [blame] | 213 | /* |
| 214 | * We've historically supported up to 32 pages (ARG_MAX) |
| 215 | * of argument strings even with small stacks |
| 216 | */ |
| 217 | if (size <= ARG_MAX) |
| 218 | return page; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 219 | |
| 220 | /* |
| 221 | * Limit to 1/4-th the stack size for the argv+env strings. |
| 222 | * This ensures that: |
| 223 | * - the remaining binfmt code will not run out of stack space, |
| 224 | * - the program will have a reasonable amount of stack left |
| 225 | * to work from. |
| 226 | */ |
Linus Torvalds | a64e715 | 2008-03-03 10:12:14 -0800 | [diff] [blame] | 227 | rlim = current->signal->rlim; |
Jiri Slaby | d554ed89 | 2010-03-05 13:42:42 -0800 | [diff] [blame] | 228 | if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur) / 4) { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 229 | put_page(page); |
| 230 | return NULL; |
| 231 | } |
| 232 | } |
| 233 | |
| 234 | return page; |
| 235 | } |
| 236 | |
| 237 | static void put_arg_page(struct page *page) |
| 238 | { |
| 239 | put_page(page); |
| 240 | } |
| 241 | |
| 242 | static void free_arg_page(struct linux_binprm *bprm, int i) |
| 243 | { |
| 244 | } |
| 245 | |
| 246 | static void free_arg_pages(struct linux_binprm *bprm) |
| 247 | { |
| 248 | } |
| 249 | |
| 250 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, |
| 251 | struct page *page) |
| 252 | { |
| 253 | flush_cache_page(bprm->vma, pos, page_to_pfn(page)); |
| 254 | } |
| 255 | |
| 256 | static int __bprm_mm_init(struct linux_binprm *bprm) |
| 257 | { |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 258 | int err; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 259 | struct vm_area_struct *vma = NULL; |
| 260 | struct mm_struct *mm = bprm->mm; |
| 261 | |
| 262 | bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); |
| 263 | if (!vma) |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 264 | return -ENOMEM; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 265 | |
| 266 | down_write(&mm->mmap_sem); |
| 267 | vma->vm_mm = mm; |
| 268 | |
| 269 | /* |
| 270 | * Place the stack at the largest stack address the architecture |
| 271 | * supports. Later, we'll move this to an appropriate place. We don't |
| 272 | * use STACK_TOP because that can depend on attributes which aren't |
| 273 | * configured yet. |
| 274 | */ |
Michal Hocko | aacb3d1 | 2011-07-26 16:08:40 -0700 | [diff] [blame] | 275 | BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 276 | vma->vm_end = STACK_TOP_MAX; |
| 277 | vma->vm_start = vma->vm_end - PAGE_SIZE; |
Mel Gorman | a8bef8ff | 2010-05-24 14:32:24 -0700 | [diff] [blame] | 278 | vma->vm_flags = VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP; |
Coly Li | 3ed75eb | 2007-10-18 23:39:15 -0700 | [diff] [blame] | 279 | vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); |
Rik van Riel | 5beb493 | 2010-03-05 13:42:07 -0800 | [diff] [blame] | 280 | INIT_LIST_HEAD(&vma->anon_vma_chain); |
Tavis Ormandy | 462e635e | 2010-12-09 15:29:42 +0100 | [diff] [blame] | 281 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 282 | err = insert_vm_struct(mm, vma); |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 283 | if (err) |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 284 | goto err; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 285 | |
| 286 | mm->stack_vm = mm->total_vm = 1; |
| 287 | up_write(&mm->mmap_sem); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 288 | bprm->p = vma->vm_end - sizeof(void *); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 289 | return 0; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 290 | err: |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 291 | up_write(&mm->mmap_sem); |
| 292 | bprm->vma = NULL; |
| 293 | kmem_cache_free(vm_area_cachep, vma); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 294 | return err; |
| 295 | } |
| 296 | |
| 297 | static bool valid_arg_len(struct linux_binprm *bprm, long len) |
| 298 | { |
| 299 | return len <= MAX_ARG_STRLEN; |
| 300 | } |
| 301 | |
| 302 | #else |
| 303 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 304 | 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] | 305 | { |
| 306 | } |
| 307 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 308 | 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] | 309 | int write) |
| 310 | { |
| 311 | struct page *page; |
| 312 | |
| 313 | page = bprm->page[pos / PAGE_SIZE]; |
| 314 | if (!page && write) { |
| 315 | page = alloc_page(GFP_HIGHUSER|__GFP_ZERO); |
| 316 | if (!page) |
| 317 | return NULL; |
| 318 | bprm->page[pos / PAGE_SIZE] = page; |
| 319 | } |
| 320 | |
| 321 | return page; |
| 322 | } |
| 323 | |
| 324 | static void put_arg_page(struct page *page) |
| 325 | { |
| 326 | } |
| 327 | |
| 328 | static void free_arg_page(struct linux_binprm *bprm, int i) |
| 329 | { |
| 330 | if (bprm->page[i]) { |
| 331 | __free_page(bprm->page[i]); |
| 332 | bprm->page[i] = NULL; |
| 333 | } |
| 334 | } |
| 335 | |
| 336 | static void free_arg_pages(struct linux_binprm *bprm) |
| 337 | { |
| 338 | int i; |
| 339 | |
| 340 | for (i = 0; i < MAX_ARG_PAGES; i++) |
| 341 | free_arg_page(bprm, i); |
| 342 | } |
| 343 | |
| 344 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, |
| 345 | struct page *page) |
| 346 | { |
| 347 | } |
| 348 | |
| 349 | static int __bprm_mm_init(struct linux_binprm *bprm) |
| 350 | { |
| 351 | bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *); |
| 352 | return 0; |
| 353 | } |
| 354 | |
| 355 | static bool valid_arg_len(struct linux_binprm *bprm, long len) |
| 356 | { |
| 357 | return len <= bprm->p; |
| 358 | } |
| 359 | |
| 360 | #endif /* CONFIG_MMU */ |
| 361 | |
| 362 | /* |
| 363 | * Create a new mm_struct and populate it with a temporary stack |
| 364 | * vm_area_struct. We don't have enough context at this point to set the stack |
| 365 | * flags, permissions, and offset, so we use temporary values. We'll update |
| 366 | * them later in setup_arg_pages(). |
| 367 | */ |
| 368 | int bprm_mm_init(struct linux_binprm *bprm) |
| 369 | { |
| 370 | int err; |
| 371 | struct mm_struct *mm = NULL; |
| 372 | |
| 373 | bprm->mm = mm = mm_alloc(); |
| 374 | err = -ENOMEM; |
| 375 | if (!mm) |
| 376 | goto err; |
| 377 | |
| 378 | err = init_new_context(current, mm); |
| 379 | if (err) |
| 380 | goto err; |
| 381 | |
| 382 | err = __bprm_mm_init(bprm); |
| 383 | if (err) |
| 384 | goto err; |
| 385 | |
| 386 | return 0; |
| 387 | |
| 388 | err: |
| 389 | if (mm) { |
| 390 | bprm->mm = NULL; |
| 391 | mmdrop(mm); |
| 392 | } |
| 393 | |
| 394 | return err; |
| 395 | } |
| 396 | |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 397 | struct user_arg_ptr { |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 398 | #ifdef CONFIG_COMPAT |
| 399 | bool is_compat; |
| 400 | #endif |
| 401 | union { |
| 402 | const char __user *const __user *native; |
| 403 | #ifdef CONFIG_COMPAT |
| 404 | compat_uptr_t __user *compat; |
| 405 | #endif |
| 406 | } ptr; |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 407 | }; |
| 408 | |
| 409 | 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] | 410 | { |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 411 | const char __user *native; |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 412 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 413 | #ifdef CONFIG_COMPAT |
| 414 | if (unlikely(argv.is_compat)) { |
| 415 | compat_uptr_t compat; |
| 416 | |
| 417 | if (get_user(compat, argv.ptr.compat + nr)) |
| 418 | return ERR_PTR(-EFAULT); |
| 419 | |
| 420 | return compat_ptr(compat); |
| 421 | } |
| 422 | #endif |
| 423 | |
| 424 | if (get_user(native, argv.ptr.native + nr)) |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 425 | return ERR_PTR(-EFAULT); |
| 426 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 427 | return native; |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 428 | } |
| 429 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | /* |
| 431 | * count() counts the number of strings in array ARGV. |
| 432 | */ |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 433 | static int count(struct user_arg_ptr argv, int max) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | { |
| 435 | int i = 0; |
| 436 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 437 | if (argv.ptr.native != NULL) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | for (;;) { |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 439 | const char __user *p = get_user_arg_ptr(argv, i); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | if (!p) |
| 442 | break; |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 443 | |
| 444 | if (IS_ERR(p)) |
| 445 | return -EFAULT; |
| 446 | |
Jason Baron | 362e666 | 2008-10-15 22:01:52 -0700 | [diff] [blame] | 447 | if (i++ >= max) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | return -E2BIG; |
Roland McGrath | 9aea5a6 | 2010-09-07 19:37:06 -0700 | [diff] [blame] | 449 | |
| 450 | if (fatal_signal_pending(current)) |
| 451 | return -ERESTARTNOHAND; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | cond_resched(); |
| 453 | } |
| 454 | } |
| 455 | return i; |
| 456 | } |
| 457 | |
| 458 | /* |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 459 | * 'copy_strings()' copies argument/environment strings from the old |
| 460 | * processes's memory to the new process's stack. The call to get_user_pages() |
| 461 | * ensures the destination page is created and not swapped out. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | */ |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 463 | static int copy_strings(int argc, struct user_arg_ptr argv, |
Adrian Bunk | 75c96f8 | 2005-05-05 16:16:09 -0700 | [diff] [blame] | 464 | struct linux_binprm *bprm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | { |
| 466 | struct page *kmapped_page = NULL; |
| 467 | char *kaddr = NULL; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 468 | unsigned long kpos = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 469 | int ret; |
| 470 | |
| 471 | while (argc-- > 0) { |
David Howells | d762746 | 2010-08-17 23:52:56 +0100 | [diff] [blame] | 472 | const char __user *str; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | int len; |
| 474 | unsigned long pos; |
| 475 | |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 476 | ret = -EFAULT; |
| 477 | str = get_user_arg_ptr(argv, argc); |
| 478 | if (IS_ERR(str)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 480 | |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 481 | len = strnlen_user(str, MAX_ARG_STRLEN); |
| 482 | if (!len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 483 | goto out; |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 484 | |
| 485 | ret = -E2BIG; |
| 486 | if (!valid_arg_len(bprm, len)) |
| 487 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 489 | /* We're going to work our way backwords. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | pos = bprm->p; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 491 | str += len; |
| 492 | bprm->p -= len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | |
| 494 | while (len > 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | int offset, bytes_to_copy; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | |
Roland McGrath | 9aea5a6 | 2010-09-07 19:37:06 -0700 | [diff] [blame] | 497 | if (fatal_signal_pending(current)) { |
| 498 | ret = -ERESTARTNOHAND; |
| 499 | goto out; |
| 500 | } |
Roland McGrath | 7993bc1 | 2010-09-07 19:36:28 -0700 | [diff] [blame] | 501 | cond_resched(); |
| 502 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | offset = pos % PAGE_SIZE; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 504 | if (offset == 0) |
| 505 | offset = PAGE_SIZE; |
| 506 | |
| 507 | bytes_to_copy = offset; |
| 508 | if (bytes_to_copy > len) |
| 509 | bytes_to_copy = len; |
| 510 | |
| 511 | offset -= bytes_to_copy; |
| 512 | pos -= bytes_to_copy; |
| 513 | str -= bytes_to_copy; |
| 514 | len -= bytes_to_copy; |
| 515 | |
| 516 | if (!kmapped_page || kpos != (pos & PAGE_MASK)) { |
| 517 | struct page *page; |
| 518 | |
| 519 | page = get_arg_page(bprm, pos, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | if (!page) { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 521 | ret = -E2BIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | goto out; |
| 523 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 524 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 525 | if (kmapped_page) { |
| 526 | flush_kernel_dcache_page(kmapped_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | kunmap(kmapped_page); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 528 | put_arg_page(kmapped_page); |
| 529 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | kmapped_page = page; |
| 531 | kaddr = kmap(kmapped_page); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 532 | kpos = pos & PAGE_MASK; |
| 533 | flush_arg_page(bprm, kpos, kmapped_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 534 | } |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 535 | if (copy_from_user(kaddr+offset, str, bytes_to_copy)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 536 | ret = -EFAULT; |
| 537 | goto out; |
| 538 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | } |
| 540 | } |
| 541 | ret = 0; |
| 542 | out: |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 543 | if (kmapped_page) { |
| 544 | flush_kernel_dcache_page(kmapped_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | kunmap(kmapped_page); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 546 | put_arg_page(kmapped_page); |
| 547 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | return ret; |
| 549 | } |
| 550 | |
| 551 | /* |
| 552 | * Like copy_strings, but get argv and its values from kernel memory. |
| 553 | */ |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 554 | int copy_strings_kernel(int argc, const char *const *__argv, |
David Howells | d762746 | 2010-08-17 23:52:56 +0100 | [diff] [blame] | 555 | struct linux_binprm *bprm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 556 | { |
| 557 | int r; |
| 558 | mm_segment_t oldfs = get_fs(); |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 559 | struct user_arg_ptr argv = { |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 560 | .ptr.native = (const char __user *const __user *)__argv, |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 561 | }; |
| 562 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 563 | set_fs(KERNEL_DS); |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 564 | r = copy_strings(argc, argv, bprm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | set_fs(oldfs); |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 566 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | return r; |
| 568 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 569 | EXPORT_SYMBOL(copy_strings_kernel); |
| 570 | |
| 571 | #ifdef CONFIG_MMU |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 572 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | /* |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 574 | * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once |
| 575 | * the binfmt code determines where the new stack should reside, we shift it to |
| 576 | * its final location. The process proceeds as follows: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | * |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 578 | * 1) Use shift to calculate the new vma endpoints. |
| 579 | * 2) Extend vma to cover both the old and new ranges. This ensures the |
| 580 | * arguments passed to subsequent functions are consistent. |
| 581 | * 3) Move vma's page tables to the new range. |
| 582 | * 4) Free up any cleared pgd range. |
| 583 | * 5) Shrink the vma to cover only the new range. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | */ |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 585 | 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] | 586 | { |
| 587 | struct mm_struct *mm = vma->vm_mm; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 588 | unsigned long old_start = vma->vm_start; |
| 589 | unsigned long old_end = vma->vm_end; |
| 590 | unsigned long length = old_end - old_start; |
| 591 | unsigned long new_start = old_start - shift; |
| 592 | unsigned long new_end = old_end - shift; |
Peter Zijlstra | d16dfc5 | 2011-05-24 17:11:45 -0700 | [diff] [blame] | 593 | struct mmu_gather tlb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 595 | BUG_ON(new_start > new_end); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 596 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 597 | /* |
| 598 | * ensure there are no vmas between where we want to go |
| 599 | * and where we are |
| 600 | */ |
| 601 | if (vma != find_vma(mm, new_start)) |
| 602 | return -EFAULT; |
| 603 | |
| 604 | /* |
| 605 | * cover the whole range: [new_start, old_end) |
| 606 | */ |
Rik van Riel | 5beb493 | 2010-03-05 13:42:07 -0800 | [diff] [blame] | 607 | if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL)) |
| 608 | return -ENOMEM; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 609 | |
| 610 | /* |
| 611 | * move the page tables downwards, on failure we rely on |
| 612 | * process cleanup to remove whatever mess we made. |
| 613 | */ |
| 614 | if (length != move_page_tables(vma, old_start, |
| 615 | vma, new_start, length)) |
| 616 | return -ENOMEM; |
| 617 | |
| 618 | lru_add_drain(); |
Peter Zijlstra | d16dfc5 | 2011-05-24 17:11:45 -0700 | [diff] [blame] | 619 | tlb_gather_mmu(&tlb, mm, 0); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 620 | if (new_end > old_start) { |
| 621 | /* |
| 622 | * when the old and new regions overlap clear from new_end. |
| 623 | */ |
Peter Zijlstra | d16dfc5 | 2011-05-24 17:11:45 -0700 | [diff] [blame] | 624 | free_pgd_range(&tlb, new_end, old_end, new_end, |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 625 | vma->vm_next ? vma->vm_next->vm_start : 0); |
| 626 | } else { |
| 627 | /* |
| 628 | * otherwise, clean from old_start; this is done to not touch |
| 629 | * the address space in [new_end, old_start) some architectures |
| 630 | * have constraints on va-space that make this illegal (IA64) - |
| 631 | * for the others its just a little faster. |
| 632 | */ |
Peter Zijlstra | d16dfc5 | 2011-05-24 17:11:45 -0700 | [diff] [blame] | 633 | free_pgd_range(&tlb, old_start, old_end, new_end, |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 634 | vma->vm_next ? vma->vm_next->vm_start : 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 635 | } |
Peter Zijlstra | d16dfc5 | 2011-05-24 17:11:45 -0700 | [diff] [blame] | 636 | tlb_finish_mmu(&tlb, new_end, old_end); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 637 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 638 | /* |
Rik van Riel | 5beb493 | 2010-03-05 13:42:07 -0800 | [diff] [blame] | 639 | * Shrink the vma to just the new range. Always succeeds. |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 640 | */ |
| 641 | vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); |
| 642 | |
| 643 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | } |
| 645 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 646 | /* |
| 647 | * Finalizes the stack vm_area_struct. The flags and permissions are updated, |
| 648 | * the stack is optionally relocated, and some extra space is added. |
| 649 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | int setup_arg_pages(struct linux_binprm *bprm, |
| 651 | unsigned long stack_top, |
| 652 | int executable_stack) |
| 653 | { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 654 | unsigned long ret; |
| 655 | unsigned long stack_shift; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 656 | struct mm_struct *mm = current->mm; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 657 | struct vm_area_struct *vma = bprm->vma; |
| 658 | struct vm_area_struct *prev = NULL; |
| 659 | unsigned long vm_flags; |
| 660 | unsigned long stack_base; |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 661 | unsigned long stack_size; |
| 662 | unsigned long stack_expand; |
| 663 | unsigned long rlim_stack; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 664 | |
| 665 | #ifdef CONFIG_STACK_GROWSUP |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | /* Limit stack size to 1GB */ |
Jiri Slaby | d554ed89 | 2010-03-05 13:42:42 -0800 | [diff] [blame] | 667 | stack_base = rlimit_max(RLIMIT_STACK); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 668 | if (stack_base > (1 << 30)) |
| 669 | stack_base = 1 << 30; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 670 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 671 | /* Make sure we didn't let the argument array grow too large. */ |
| 672 | if (vma->vm_end - vma->vm_start > stack_base) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | return -ENOMEM; |
| 674 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 675 | stack_base = PAGE_ALIGN(stack_top - stack_base); |
| 676 | |
| 677 | stack_shift = vma->vm_start - stack_base; |
| 678 | mm->arg_start = bprm->p - stack_shift; |
| 679 | bprm->p = vma->vm_end - stack_shift; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 680 | #else |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 681 | stack_top = arch_align_stack(stack_top); |
| 682 | stack_top = PAGE_ALIGN(stack_top); |
Roland McGrath | 1b52818 | 2010-09-07 19:35:49 -0700 | [diff] [blame] | 683 | |
| 684 | if (unlikely(stack_top < mmap_min_addr) || |
| 685 | unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr)) |
| 686 | return -ENOMEM; |
| 687 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 688 | stack_shift = vma->vm_end - stack_top; |
| 689 | |
| 690 | bprm->p -= stack_shift; |
| 691 | mm->arg_start = bprm->p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 692 | #endif |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 693 | |
| 694 | if (bprm->loader) |
| 695 | bprm->loader -= stack_shift; |
| 696 | bprm->exec -= stack_shift; |
| 697 | |
| 698 | down_write(&mm->mmap_sem); |
Hugh Dickins | 96a8e13 | 2008-07-10 21:19:20 +0100 | [diff] [blame] | 699 | vm_flags = VM_STACK_FLAGS; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 700 | |
| 701 | /* |
| 702 | * Adjust stack execute permissions; explicitly enable for |
| 703 | * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone |
| 704 | * (arch default) otherwise. |
| 705 | */ |
| 706 | if (unlikely(executable_stack == EXSTACK_ENABLE_X)) |
| 707 | vm_flags |= VM_EXEC; |
| 708 | else if (executable_stack == EXSTACK_DISABLE_X) |
| 709 | vm_flags &= ~VM_EXEC; |
| 710 | vm_flags |= mm->def_flags; |
Mel Gorman | a8bef8ff | 2010-05-24 14:32:24 -0700 | [diff] [blame] | 711 | vm_flags |= VM_STACK_INCOMPLETE_SETUP; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 712 | |
| 713 | ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end, |
| 714 | vm_flags); |
| 715 | if (ret) |
| 716 | goto out_unlock; |
| 717 | BUG_ON(prev != vma); |
| 718 | |
| 719 | /* Move stack pages down in memory. */ |
| 720 | if (stack_shift) { |
| 721 | ret = shift_arg_pages(vma, stack_shift); |
Anton Blanchard | fc63cf2 | 2009-11-11 14:26:48 -0800 | [diff] [blame] | 722 | if (ret) |
| 723 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | } |
| 725 | |
Mel Gorman | a8bef8ff | 2010-05-24 14:32:24 -0700 | [diff] [blame] | 726 | /* mprotect_fixup is overkill to remove the temporary stack flags */ |
| 727 | vma->vm_flags &= ~VM_STACK_INCOMPLETE_SETUP; |
| 728 | |
Michael Neuling | 5ef097d | 2010-03-05 13:42:57 -0800 | [diff] [blame] | 729 | stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */ |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 730 | stack_size = vma->vm_end - vma->vm_start; |
| 731 | /* |
| 732 | * Align this down to a page boundary as expand_stack |
| 733 | * will align it up. |
| 734 | */ |
| 735 | rlim_stack = rlimit(RLIMIT_STACK) & PAGE_MASK; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 736 | #ifdef CONFIG_STACK_GROWSUP |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 737 | if (stack_size + stack_expand > rlim_stack) |
| 738 | stack_base = vma->vm_start + rlim_stack; |
| 739 | else |
| 740 | stack_base = vma->vm_end + stack_expand; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 741 | #else |
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_end - rlim_stack; |
| 744 | else |
| 745 | stack_base = vma->vm_start - stack_expand; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 746 | #endif |
Eric B Munson | 3af9e85 | 2010-05-18 15:30:49 +0100 | [diff] [blame] | 747 | current->mm->start_stack = bprm->p; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 748 | ret = expand_stack(vma, stack_base); |
| 749 | if (ret) |
| 750 | ret = -EFAULT; |
| 751 | |
| 752 | out_unlock: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | up_write(&mm->mmap_sem); |
Anton Blanchard | fc63cf2 | 2009-11-11 14:26:48 -0800 | [diff] [blame] | 754 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 755 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 756 | EXPORT_SYMBOL(setup_arg_pages); |
| 757 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 758 | #endif /* CONFIG_MMU */ |
| 759 | |
| 760 | struct file *open_exec(const char *name) |
| 761 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 762 | struct file *file; |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 763 | int err; |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 764 | static const struct open_flags open_exec_flags = { |
| 765 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, |
| 766 | .acc_mode = MAY_EXEC | MAY_OPEN, |
| 767 | .intent = LOOKUP_OPEN |
| 768 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 769 | |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 770 | file = do_filp_open(AT_FDCWD, name, &open_exec_flags, LOOKUP_FOLLOW); |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 771 | if (IS_ERR(file)) |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 772 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 774 | err = -EACCES; |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 775 | if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
| 776 | goto exit; |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 777 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 778 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
| 779 | goto exit; |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 780 | |
Eric Paris | 2a12a9d | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 781 | fsnotify_open(file); |
Eric Paris | 6110e3a | 2008-12-17 13:53:20 -0500 | [diff] [blame] | 782 | |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 783 | err = deny_write_access(file); |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 784 | if (err) |
| 785 | goto exit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 787 | out: |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 788 | return file; |
| 789 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 790 | exit: |
| 791 | fput(file); |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 792 | return ERR_PTR(err); |
| 793 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 794 | EXPORT_SYMBOL(open_exec); |
| 795 | |
Mimi Zohar | 6777d77 | 2009-08-21 14:32:48 -0400 | [diff] [blame] | 796 | int kernel_read(struct file *file, loff_t offset, |
| 797 | char *addr, unsigned long count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | { |
| 799 | mm_segment_t old_fs; |
| 800 | loff_t pos = offset; |
| 801 | int result; |
| 802 | |
| 803 | old_fs = get_fs(); |
| 804 | set_fs(get_ds()); |
| 805 | /* The cast to a user pointer is valid due to the set_fs() */ |
| 806 | result = vfs_read(file, (void __user *)addr, count, &pos); |
| 807 | set_fs(old_fs); |
| 808 | return result; |
| 809 | } |
| 810 | |
| 811 | EXPORT_SYMBOL(kernel_read); |
| 812 | |
| 813 | static int exec_mmap(struct mm_struct *mm) |
| 814 | { |
| 815 | struct task_struct *tsk; |
| 816 | struct mm_struct * old_mm, *active_mm; |
| 817 | |
| 818 | /* Notify parent that we're no longer interested in the old VM */ |
| 819 | tsk = current; |
| 820 | old_mm = current->mm; |
| 821 | mm_release(tsk, old_mm); |
| 822 | |
| 823 | if (old_mm) { |
Konstantin Khlebnikov | 4fe7efd | 2012-06-20 12:53:01 -0700 | [diff] [blame] | 824 | sync_mm_rss(old_mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 825 | /* |
| 826 | * Make sure that if there is a core dump in progress |
| 827 | * for the old mm, we get out and die instead of going |
| 828 | * through with the exec. We must hold mmap_sem around |
Oleg Nesterov | 999d9fc | 2008-07-25 01:47:41 -0700 | [diff] [blame] | 829 | * checking core_state and changing tsk->mm. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | */ |
| 831 | down_read(&old_mm->mmap_sem); |
Oleg Nesterov | 999d9fc | 2008-07-25 01:47:41 -0700 | [diff] [blame] | 832 | if (unlikely(old_mm->core_state)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 833 | up_read(&old_mm->mmap_sem); |
| 834 | return -EINTR; |
| 835 | } |
| 836 | } |
| 837 | task_lock(tsk); |
| 838 | active_mm = tsk->active_mm; |
| 839 | tsk->mm = mm; |
| 840 | tsk->active_mm = mm; |
| 841 | activate_mm(active_mm, mm); |
| 842 | task_unlock(tsk); |
| 843 | arch_pick_mmap_layout(mm); |
| 844 | if (old_mm) { |
| 845 | up_read(&old_mm->mmap_sem); |
Eric Sesterhenn | 7dddb12 | 2006-04-01 01:13:38 +0200 | [diff] [blame] | 846 | BUG_ON(active_mm != old_mm); |
Oleg Nesterov | 701085b | 2012-03-19 17:04:01 +0100 | [diff] [blame] | 847 | setmax_mm_hiwater_rss(&tsk->signal->maxrss, old_mm); |
Balbir Singh | 31a78f2 | 2008-09-28 23:09:31 +0100 | [diff] [blame] | 848 | mm_update_next_owner(old_mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 849 | mmput(old_mm); |
| 850 | return 0; |
| 851 | } |
| 852 | mmdrop(active_mm); |
| 853 | return 0; |
| 854 | } |
| 855 | |
| 856 | /* |
| 857 | * This function makes sure the current process has its own signal table, |
| 858 | * so that flush_signal_handlers can later reset the handlers without |
| 859 | * disturbing other processes. (Other processes might share the signal |
| 860 | * table via the CLONE_SIGHAND option to clone().) |
| 861 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 862 | static int de_thread(struct task_struct *tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 863 | { |
| 864 | struct signal_struct *sig = tsk->signal; |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 865 | struct sighand_struct *oldsighand = tsk->sighand; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 866 | spinlock_t *lock = &oldsighand->siglock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 867 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 868 | if (thread_group_empty(tsk)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 869 | goto no_thread_group; |
| 870 | |
| 871 | /* |
| 872 | * Kill all other threads in the thread group. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 873 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 874 | spin_lock_irq(lock); |
Oleg Nesterov | ed5d2ca | 2008-02-04 22:27:24 -0800 | [diff] [blame] | 875 | if (signal_group_exit(sig)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 876 | /* |
| 877 | * Another group action in progress, just |
| 878 | * return so that the signal is processed. |
| 879 | */ |
| 880 | spin_unlock_irq(lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 881 | return -EAGAIN; |
| 882 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 883 | |
Oleg Nesterov | d344193 | 2010-05-26 14:43:11 -0700 | [diff] [blame] | 884 | sig->group_exit_task = tsk; |
| 885 | sig->notify_count = zap_other_threads(tsk); |
| 886 | if (!thread_group_leader(tsk)) |
| 887 | sig->notify_count--; |
| 888 | |
| 889 | while (sig->notify_count) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 890 | __set_current_state(TASK_UNINTERRUPTIBLE); |
| 891 | spin_unlock_irq(lock); |
| 892 | schedule(); |
| 893 | spin_lock_irq(lock); |
| 894 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 895 | spin_unlock_irq(lock); |
| 896 | |
| 897 | /* |
| 898 | * At this point all other threads have exited, all we have to |
| 899 | * do is to wait for the thread group leader to become inactive, |
| 900 | * and to assume its PID: |
| 901 | */ |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 902 | if (!thread_group_leader(tsk)) { |
Oleg Nesterov | 8187926 | 2008-12-01 14:18:16 -0800 | [diff] [blame] | 903 | struct task_struct *leader = tsk->group_leader; |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 904 | |
Oleg Nesterov | 2800d8d | 2008-04-30 00:53:12 -0700 | [diff] [blame] | 905 | sig->notify_count = -1; /* for exit_notify() */ |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 906 | for (;;) { |
| 907 | write_lock_irq(&tasklist_lock); |
| 908 | if (likely(leader->exit_state)) |
| 909 | break; |
| 910 | __set_current_state(TASK_UNINTERRUPTIBLE); |
| 911 | write_unlock_irq(&tasklist_lock); |
| 912 | schedule(); |
| 913 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 914 | |
Roland McGrath | f5e9028 | 2006-04-10 22:54:16 -0700 | [diff] [blame] | 915 | /* |
| 916 | * The only record we have of the real-time age of a |
| 917 | * process, regardless of execs it's done, is start_time. |
| 918 | * All the past CPU time is accumulated in signal_struct |
| 919 | * from sister threads now dead. But in this non-leader |
| 920 | * exec, nothing survives from the original leader thread, |
| 921 | * whose birth marks the true age of this process now. |
| 922 | * When we take on its identity by switching to its PID, we |
| 923 | * also take its birthdate (always earlier than our own). |
| 924 | */ |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 925 | tsk->start_time = leader->start_time; |
Roland McGrath | f5e9028 | 2006-04-10 22:54:16 -0700 | [diff] [blame] | 926 | |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 927 | BUG_ON(!same_thread_group(leader, tsk)); |
| 928 | BUG_ON(has_group_leader_pid(tsk)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 929 | /* |
| 930 | * An exec() starts a new thread group with the |
| 931 | * TGID of the previous thread group. Rehash the |
| 932 | * two threads with a switched PID, and release |
| 933 | * the former thread group leader: |
| 934 | */ |
Eric W. Biederman | d73d652 | 2006-03-28 16:11:03 -0800 | [diff] [blame] | 935 | |
| 936 | /* Become a process group leader with the old leader's pid. |
Eric W. Biederman | c18258c | 2006-09-27 01:51:06 -0700 | [diff] [blame] | 937 | * The old leader becomes a thread of the this thread group. |
| 938 | * Note: The old leader also uses this pid until release_task |
Eric W. Biederman | d73d652 | 2006-03-28 16:11:03 -0800 | [diff] [blame] | 939 | * is called. Odd but simple and correct. |
| 940 | */ |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 941 | detach_pid(tsk, PIDTYPE_PID); |
| 942 | tsk->pid = leader->pid; |
Sukadev Bhattiprolu | 3743ca0 | 2007-10-18 23:39:51 -0700 | [diff] [blame] | 943 | attach_pid(tsk, PIDTYPE_PID, task_pid(leader)); |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 944 | transfer_pid(leader, tsk, PIDTYPE_PGID); |
| 945 | transfer_pid(leader, tsk, PIDTYPE_SID); |
Oleg Nesterov | 9cd80bb | 2009-12-17 15:27:15 -0800 | [diff] [blame] | 946 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 947 | list_replace_rcu(&leader->tasks, &tsk->tasks); |
Oleg Nesterov | 9cd80bb | 2009-12-17 15:27:15 -0800 | [diff] [blame] | 948 | list_replace_init(&leader->sibling, &tsk->sibling); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 949 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 950 | tsk->group_leader = tsk; |
| 951 | leader->group_leader = tsk; |
Eric W. Biederman | de12a78 | 2006-04-10 17:16:49 -0600 | [diff] [blame] | 952 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 953 | tsk->exit_signal = SIGCHLD; |
Oleg Nesterov | 087806b | 2011-06-22 23:10:26 +0200 | [diff] [blame] | 954 | leader->exit_signal = -1; |
Oleg Nesterov | 962b564 | 2005-11-23 13:37:43 -0800 | [diff] [blame] | 955 | |
| 956 | BUG_ON(leader->exit_state != EXIT_ZOMBIE); |
| 957 | leader->exit_state = EXIT_DEAD; |
Oleg Nesterov | eac1b5e | 2011-07-21 20:00:43 +0200 | [diff] [blame] | 958 | |
| 959 | /* |
| 960 | * We are going to release_task()->ptrace_unlink() silently, |
| 961 | * the tracer can sleep in do_wait(). EXIT_DEAD guarantees |
| 962 | * the tracer wont't block again waiting for this thread. |
| 963 | */ |
| 964 | if (unlikely(leader->ptrace)) |
| 965 | __wake_up_parent(leader, leader->parent); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 966 | write_unlock_irq(&tasklist_lock); |
Oleg Nesterov | 8187926 | 2008-12-01 14:18:16 -0800 | [diff] [blame] | 967 | |
| 968 | release_task(leader); |
Oleg Nesterov | ed5d2ca | 2008-02-04 22:27:24 -0800 | [diff] [blame] | 969 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 970 | |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 971 | sig->group_exit_task = NULL; |
| 972 | sig->notify_count = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 973 | |
| 974 | no_thread_group: |
Oleg Nesterov | e636825 | 2012-03-19 17:03:22 +0100 | [diff] [blame] | 975 | /* we have changed execution domain */ |
| 976 | tsk->exit_signal = SIGCHLD; |
| 977 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 978 | exit_itimers(sig); |
Oleg Nesterov | cbaffba | 2008-05-26 20:55:42 +0400 | [diff] [blame] | 979 | flush_itimer_signals(); |
Oleg Nesterov | 329f7db | 2005-11-07 21:12:43 +0300 | [diff] [blame] | 980 | |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 981 | if (atomic_read(&oldsighand->count) != 1) { |
| 982 | struct sighand_struct *newsighand; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 983 | /* |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 984 | * This ->sighand is shared with the CLONE_SIGHAND |
| 985 | * but not CLONE_THREAD task, switch to the new one. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 986 | */ |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 987 | newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); |
| 988 | if (!newsighand) |
| 989 | return -ENOMEM; |
| 990 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 991 | atomic_set(&newsighand->count, 1); |
| 992 | memcpy(newsighand->action, oldsighand->action, |
| 993 | sizeof(newsighand->action)); |
| 994 | |
| 995 | write_lock_irq(&tasklist_lock); |
| 996 | spin_lock(&oldsighand->siglock); |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 997 | rcu_assign_pointer(tsk->sighand, newsighand); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 998 | spin_unlock(&oldsighand->siglock); |
| 999 | write_unlock_irq(&tasklist_lock); |
| 1000 | |
Davide Libenzi | fba2afa | 2007-05-10 22:23:13 -0700 | [diff] [blame] | 1001 | __cleanup_sighand(oldsighand); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1002 | } |
| 1003 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 1004 | BUG_ON(!thread_group_leader(tsk)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1005 | return 0; |
| 1006 | } |
Oleg Nesterov | 0840a90 | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 1007 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1008 | /* |
| 1009 | * These functions flushes out all traces of the currently running executable |
| 1010 | * so that a new one can be started |
| 1011 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 1012 | static void flush_old_files(struct files_struct * files) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1013 | { |
| 1014 | long j = -1; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1015 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1016 | |
| 1017 | spin_lock(&files->file_lock); |
| 1018 | for (;;) { |
| 1019 | unsigned long set, i; |
| 1020 | |
| 1021 | j++; |
Josh Boyer | 8ded2bb | 2012-07-25 10:40:34 -0400 | [diff] [blame] | 1022 | i = j * BITS_PER_LONG; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1023 | fdt = files_fdtable(files); |
Vadim Lobanov | bbea9f6 | 2006-12-10 02:21:12 -0800 | [diff] [blame] | 1024 | if (i >= fdt->max_fds) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1025 | break; |
David Howells | 1fd36ad | 2012-02-16 17:49:54 +0000 | [diff] [blame] | 1026 | set = fdt->close_on_exec[j]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1027 | if (!set) |
| 1028 | continue; |
David Howells | 1fd36ad | 2012-02-16 17:49:54 +0000 | [diff] [blame] | 1029 | fdt->close_on_exec[j] = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | spin_unlock(&files->file_lock); |
| 1031 | for ( ; set ; i++,set >>= 1) { |
| 1032 | if (set & 1) { |
| 1033 | sys_close(i); |
| 1034 | } |
| 1035 | } |
| 1036 | spin_lock(&files->file_lock); |
| 1037 | |
| 1038 | } |
| 1039 | spin_unlock(&files->file_lock); |
| 1040 | } |
| 1041 | |
Andrew Morton | 59714d6 | 2008-02-04 22:27:21 -0800 | [diff] [blame] | 1042 | char *get_task_comm(char *buf, struct task_struct *tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1043 | { |
| 1044 | /* buf must be at least sizeof(tsk->comm) in size */ |
| 1045 | task_lock(tsk); |
| 1046 | strncpy(buf, tsk->comm, sizeof(tsk->comm)); |
| 1047 | task_unlock(tsk); |
Andrew Morton | 59714d6 | 2008-02-04 22:27:21 -0800 | [diff] [blame] | 1048 | return buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1049 | } |
J Freyensee | 7d74f49 | 2011-05-06 16:56:47 -0700 | [diff] [blame] | 1050 | EXPORT_SYMBOL_GPL(get_task_comm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1051 | |
| 1052 | void set_task_comm(struct task_struct *tsk, char *buf) |
| 1053 | { |
| 1054 | task_lock(tsk); |
john stultz | 4614a696b | 2009-12-14 18:00:05 -0800 | [diff] [blame] | 1055 | |
KAMEZAWA Hiroyuki | 43d2b11 | 2012-01-10 15:08:09 -0800 | [diff] [blame] | 1056 | trace_task_rename(tsk, buf); |
| 1057 | |
john stultz | 4614a696b | 2009-12-14 18:00:05 -0800 | [diff] [blame] | 1058 | /* |
| 1059 | * Threads may access current->comm without holding |
| 1060 | * the task lock, so write the string carefully. |
| 1061 | * Readers without a lock may see incomplete new |
| 1062 | * names but are safe from non-terminating string reads. |
| 1063 | */ |
| 1064 | memset(tsk->comm, 0, TASK_COMM_LEN); |
| 1065 | wmb(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1066 | strlcpy(tsk->comm, buf, sizeof(tsk->comm)); |
| 1067 | task_unlock(tsk); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1068 | perf_event_comm(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1069 | } |
| 1070 | |
Heiko Carstens | 96e02d1 | 2012-02-04 10:47:10 +0100 | [diff] [blame] | 1071 | static void filename_to_taskname(char *tcomm, const char *fn, unsigned int len) |
| 1072 | { |
| 1073 | int i, ch; |
| 1074 | |
| 1075 | /* Copies the binary name from after last slash */ |
| 1076 | for (i = 0; (ch = *(fn++)) != '\0';) { |
| 1077 | if (ch == '/') |
| 1078 | i = 0; /* overwrite what we wrote */ |
| 1079 | else |
| 1080 | if (i < len - 1) |
| 1081 | tcomm[i++] = ch; |
| 1082 | } |
| 1083 | tcomm[i] = '\0'; |
| 1084 | } |
| 1085 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1086 | int flush_old_exec(struct linux_binprm * bprm) |
| 1087 | { |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1088 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1089 | |
| 1090 | /* |
| 1091 | * Make sure we have a private signal table and that |
| 1092 | * we are unassociated from the previous thread group. |
| 1093 | */ |
| 1094 | retval = de_thread(current); |
| 1095 | if (retval) |
| 1096 | goto out; |
| 1097 | |
Matt Helsley | 925d1c4 | 2008-04-29 01:01:36 -0700 | [diff] [blame] | 1098 | set_mm_exe_file(bprm->mm, bprm->file); |
| 1099 | |
Heiko Carstens | 96e02d1 | 2012-02-04 10:47:10 +0100 | [diff] [blame] | 1100 | filename_to_taskname(bprm->tcomm, bprm->filename, sizeof(bprm->tcomm)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1101 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1102 | * Release all of the old mmap stuff |
| 1103 | */ |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 1104 | acct_arg_size(bprm, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1105 | retval = exec_mmap(bprm->mm); |
| 1106 | if (retval) |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1107 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1108 | |
| 1109 | bprm->mm = NULL; /* We're using it now */ |
Linus Torvalds | 7ab02af | 2010-02-02 12:37:44 -0800 | [diff] [blame] | 1110 | |
Mathias Krause | dac853a | 2011-06-09 20:05:18 +0200 | [diff] [blame] | 1111 | set_fs(USER_DS); |
Al Viro | 19e5109 | 2012-02-23 22:29:17 -0500 | [diff] [blame] | 1112 | current->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD); |
Linus Torvalds | 7ab02af | 2010-02-02 12:37:44 -0800 | [diff] [blame] | 1113 | flush_thread(); |
| 1114 | current->personality &= ~bprm->per_clear; |
| 1115 | |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1116 | return 0; |
| 1117 | |
| 1118 | out: |
| 1119 | return retval; |
| 1120 | } |
| 1121 | EXPORT_SYMBOL(flush_old_exec); |
| 1122 | |
Al Viro | 1b5d783 | 2011-06-19 12:49:47 -0400 | [diff] [blame] | 1123 | void would_dump(struct linux_binprm *bprm, struct file *file) |
| 1124 | { |
| 1125 | if (inode_permission(file->f_path.dentry->d_inode, MAY_READ) < 0) |
| 1126 | bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; |
| 1127 | } |
| 1128 | EXPORT_SYMBOL(would_dump); |
| 1129 | |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1130 | void setup_new_exec(struct linux_binprm * bprm) |
| 1131 | { |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1132 | arch_pick_mmap_layout(current->mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1133 | |
| 1134 | /* This is the point of no return */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1135 | current->sas_ss_sp = current->sas_ss_size = 0; |
| 1136 | |
Eric W. Biederman | 8e96e3b | 2012-03-03 21:17:15 -0800 | [diff] [blame] | 1137 | if (uid_eq(current_euid(), current_uid()) && gid_eq(current_egid(), current_gid())) |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1138 | set_dumpable(current->mm, 1); |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 1139 | else |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1140 | set_dumpable(current->mm, suid_dumpable); |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 1141 | |
Heiko Carstens | 96e02d1 | 2012-02-04 10:47:10 +0100 | [diff] [blame] | 1142 | set_task_comm(current, bprm->tcomm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1143 | |
Benjamin Herrenschmidt | 0551fbd | 2006-02-28 16:59:19 -0800 | [diff] [blame] | 1144 | /* Set the new mm task size. We have to do that late because it may |
| 1145 | * depend on TIF_32BIT which is only updated in flush_thread() on |
| 1146 | * some architectures like powerpc |
| 1147 | */ |
| 1148 | current->mm->task_size = TASK_SIZE; |
| 1149 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1150 | /* install the new credentials */ |
Eric W. Biederman | 8e96e3b | 2012-03-03 21:17:15 -0800 | [diff] [blame] | 1151 | if (!uid_eq(bprm->cred->uid, current_euid()) || |
| 1152 | !gid_eq(bprm->cred->gid, current_egid())) { |
Marcel Holtmann | d2d56c5 | 2007-08-17 21:47:58 +0200 | [diff] [blame] | 1153 | current->pdeath_signal = 0; |
Al Viro | 1b5d783 | 2011-06-19 12:49:47 -0400 | [diff] [blame] | 1154 | } else { |
| 1155 | would_dump(bprm, bprm->file); |
| 1156 | if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP) |
| 1157 | set_dumpable(current->mm, suid_dumpable); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1158 | } |
| 1159 | |
Ingo Molnar | f65cb45 | 2008-12-16 13:40:44 +0100 | [diff] [blame] | 1160 | /* |
| 1161 | * Flush performance counters when crossing a |
| 1162 | * security domain: |
| 1163 | */ |
| 1164 | if (!get_dumpable(current->mm)) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1165 | perf_event_exit_task(current); |
Ingo Molnar | f65cb45 | 2008-12-16 13:40:44 +0100 | [diff] [blame] | 1166 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1167 | /* An exec changes our domain. We are no longer part of the thread |
| 1168 | group */ |
| 1169 | |
| 1170 | current->self_exec_id++; |
| 1171 | |
| 1172 | flush_signal_handlers(current, 0); |
| 1173 | flush_old_files(current->files); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1174 | } |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1175 | EXPORT_SYMBOL(setup_new_exec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1176 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1177 | /* |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1178 | * Prepare credentials and lock ->cred_guard_mutex. |
| 1179 | * install_exec_creds() commits the new creds and drops the lock. |
| 1180 | * Or, if exec fails before, free_bprm() should release ->cred and |
| 1181 | * and unlock. |
| 1182 | */ |
| 1183 | int prepare_bprm_creds(struct linux_binprm *bprm) |
| 1184 | { |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1185 | if (mutex_lock_interruptible(¤t->signal->cred_guard_mutex)) |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1186 | return -ERESTARTNOINTR; |
| 1187 | |
| 1188 | bprm->cred = prepare_exec_creds(); |
| 1189 | if (likely(bprm->cred)) |
| 1190 | return 0; |
| 1191 | |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1192 | mutex_unlock(¤t->signal->cred_guard_mutex); |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1193 | return -ENOMEM; |
| 1194 | } |
| 1195 | |
| 1196 | void free_bprm(struct linux_binprm *bprm) |
| 1197 | { |
| 1198 | free_arg_pages(bprm); |
| 1199 | if (bprm->cred) { |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1200 | mutex_unlock(¤t->signal->cred_guard_mutex); |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1201 | abort_creds(bprm->cred); |
| 1202 | } |
| 1203 | kfree(bprm); |
| 1204 | } |
| 1205 | |
| 1206 | /* |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1207 | * install the new credentials for this executable |
| 1208 | */ |
| 1209 | void install_exec_creds(struct linux_binprm *bprm) |
| 1210 | { |
| 1211 | security_bprm_committing_creds(bprm); |
| 1212 | |
| 1213 | commit_creds(bprm->cred); |
| 1214 | bprm->cred = NULL; |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1215 | /* |
| 1216 | * 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] | 1217 | * ptrace_attach() from altering our determination of the task's |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1218 | * credentials; any time after this it may be unlocked. |
| 1219 | */ |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1220 | security_bprm_committed_creds(bprm); |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1221 | mutex_unlock(¤t->signal->cred_guard_mutex); |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1222 | } |
| 1223 | EXPORT_SYMBOL(install_exec_creds); |
| 1224 | |
| 1225 | /* |
| 1226 | * determine how safe it is to execute the proposed program |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1227 | * - the caller must hold ->cred_guard_mutex to protect against |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1228 | * PTRACE_ATTACH |
| 1229 | */ |
Al Viro | f47ec3f | 2011-11-21 21:15:42 -0500 | [diff] [blame] | 1230 | static int check_unsafe_exec(struct linux_binprm *bprm) |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1231 | { |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1232 | struct task_struct *p = current, *t; |
Al Viro | f1191b5 | 2009-03-30 07:35:18 -0400 | [diff] [blame] | 1233 | unsigned n_fs; |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1234 | int res = 0; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1235 | |
Tejun Heo | 4b9d33e | 2011-06-17 16:50:38 +0200 | [diff] [blame] | 1236 | if (p->ptrace) { |
| 1237 | if (p->ptrace & PT_PTRACE_CAP) |
| 1238 | bprm->unsafe |= LSM_UNSAFE_PTRACE_CAP; |
| 1239 | else |
| 1240 | bprm->unsafe |= LSM_UNSAFE_PTRACE; |
| 1241 | } |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1242 | |
Andy Lutomirski | 259e5e6 | 2012-04-12 16:47:50 -0500 | [diff] [blame] | 1243 | /* |
| 1244 | * This isn't strictly necessary, but it makes it harder for LSMs to |
| 1245 | * mess up. |
| 1246 | */ |
| 1247 | if (current->no_new_privs) |
| 1248 | bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS; |
| 1249 | |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1250 | n_fs = 1; |
Nick Piggin | 2a4419b | 2010-08-18 04:37:33 +1000 | [diff] [blame] | 1251 | spin_lock(&p->fs->lock); |
Oleg Nesterov | 437f7fd | 2009-04-24 01:02:45 +0200 | [diff] [blame] | 1252 | rcu_read_lock(); |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1253 | for (t = next_thread(p); t != p; t = next_thread(t)) { |
| 1254 | if (t->fs == p->fs) |
| 1255 | n_fs++; |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1256 | } |
Oleg Nesterov | 437f7fd | 2009-04-24 01:02:45 +0200 | [diff] [blame] | 1257 | rcu_read_unlock(); |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1258 | |
Al Viro | f1191b5 | 2009-03-30 07:35:18 -0400 | [diff] [blame] | 1259 | if (p->fs->users > n_fs) { |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1260 | bprm->unsafe |= LSM_UNSAFE_SHARE; |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1261 | } else { |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1262 | res = -EAGAIN; |
| 1263 | if (!p->fs->in_exec) { |
| 1264 | p->fs->in_exec = 1; |
| 1265 | res = 1; |
| 1266 | } |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1267 | } |
Nick Piggin | 2a4419b | 2010-08-18 04:37:33 +1000 | [diff] [blame] | 1268 | spin_unlock(&p->fs->lock); |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1269 | |
| 1270 | return res; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1271 | } |
| 1272 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1273 | /* |
| 1274 | * Fill the binprm structure from the inode. |
| 1275 | * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1276 | * |
| 1277 | * This may be called multiple times for binary chains (scripts for example). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1278 | */ |
| 1279 | int prepare_binprm(struct linux_binprm *bprm) |
| 1280 | { |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1281 | umode_t mode; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 1282 | struct inode * inode = bprm->file->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1283 | int retval; |
| 1284 | |
| 1285 | mode = inode->i_mode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1286 | if (bprm->file->f_op == NULL) |
| 1287 | return -EACCES; |
| 1288 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1289 | /* clear any previous set[ug]id data from a previous binary */ |
| 1290 | bprm->cred->euid = current_euid(); |
| 1291 | bprm->cred->egid = current_egid(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1292 | |
Andy Lutomirski | 259e5e6 | 2012-04-12 16:47:50 -0500 | [diff] [blame] | 1293 | if (!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) && |
| 1294 | !current->no_new_privs) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1295 | /* Set-uid? */ |
| 1296 | if (mode & S_ISUID) { |
Eric W. Biederman | 9e4a36e | 2011-11-16 23:37:59 -0800 | [diff] [blame] | 1297 | if (!kuid_has_mapping(bprm->cred->user_ns, inode->i_uid)) |
| 1298 | return -EPERM; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1299 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
| 1300 | bprm->cred->euid = inode->i_uid; |
Eric W. Biederman | 9e4a36e | 2011-11-16 23:37:59 -0800 | [diff] [blame] | 1301 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1302 | } |
| 1303 | |
| 1304 | /* Set-gid? */ |
| 1305 | /* |
| 1306 | * If setgid is set but no group execute bit then this |
| 1307 | * is a candidate for mandatory locking, not a setgid |
| 1308 | * executable. |
| 1309 | */ |
| 1310 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { |
Eric W. Biederman | 9e4a36e | 2011-11-16 23:37:59 -0800 | [diff] [blame] | 1311 | if (!kgid_has_mapping(bprm->cred->user_ns, inode->i_gid)) |
| 1312 | return -EPERM; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1313 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
| 1314 | bprm->cred->egid = inode->i_gid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1315 | } |
| 1316 | } |
| 1317 | |
| 1318 | /* fill in binprm security blob */ |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1319 | retval = security_bprm_set_creds(bprm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1320 | if (retval) |
| 1321 | return retval; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1322 | bprm->cred_prepared = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1323 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1324 | memset(bprm->buf, 0, BINPRM_BUF_SIZE); |
| 1325 | return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1326 | } |
| 1327 | |
| 1328 | EXPORT_SYMBOL(prepare_binprm); |
| 1329 | |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1330 | /* |
| 1331 | * Arguments are '\0' separated strings found at the location bprm->p |
| 1332 | * points to; chop off the first by relocating brpm->p to right after |
| 1333 | * the first '\0' encountered. |
| 1334 | */ |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1335 | int remove_arg_zero(struct linux_binprm *bprm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1336 | { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1337 | int ret = 0; |
| 1338 | unsigned long offset; |
| 1339 | char *kaddr; |
| 1340 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1341 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1342 | if (!bprm->argc) |
| 1343 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1344 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1345 | do { |
| 1346 | offset = bprm->p & ~PAGE_MASK; |
| 1347 | page = get_arg_page(bprm, bprm->p, 0); |
| 1348 | if (!page) { |
| 1349 | ret = -EFAULT; |
| 1350 | goto out; |
| 1351 | } |
Cong Wang | e8e3c3d | 2011-11-25 23:14:27 +0800 | [diff] [blame] | 1352 | kaddr = kmap_atomic(page); |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1353 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1354 | for (; offset < PAGE_SIZE && kaddr[offset]; |
| 1355 | offset++, bprm->p++) |
| 1356 | ; |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1357 | |
Cong Wang | e8e3c3d | 2011-11-25 23:14:27 +0800 | [diff] [blame] | 1358 | kunmap_atomic(kaddr); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1359 | put_arg_page(page); |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1360 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1361 | if (offset == PAGE_SIZE) |
| 1362 | free_arg_page(bprm, (bprm->p >> PAGE_SHIFT) - 1); |
| 1363 | } while (offset == PAGE_SIZE); |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1364 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1365 | bprm->p++; |
| 1366 | bprm->argc--; |
| 1367 | ret = 0; |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1368 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1369 | out: |
| 1370 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1371 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1372 | EXPORT_SYMBOL(remove_arg_zero); |
| 1373 | |
| 1374 | /* |
| 1375 | * cycle the list of binary formats handler, until one recognizes the image |
| 1376 | */ |
| 1377 | int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) |
| 1378 | { |
Roland McGrath | 85f3346 | 2008-12-09 19:36:38 -0800 | [diff] [blame] | 1379 | unsigned int depth = bprm->recursion_depth; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1380 | int try,retval; |
| 1381 | struct linux_binfmt *fmt; |
Oleg Nesterov | 6308191 | 2012-03-30 18:26:36 +0200 | [diff] [blame] | 1382 | pid_t old_pid, old_vpid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1383 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1384 | retval = security_bprm_check(bprm); |
| 1385 | if (retval) |
| 1386 | return retval; |
| 1387 | |
Al Viro | 473ae30 | 2006-04-26 14:04:08 -0400 | [diff] [blame] | 1388 | retval = audit_bprm(bprm); |
| 1389 | if (retval) |
| 1390 | return retval; |
| 1391 | |
Denys Vlasenko | bb188d7 | 2011-06-29 04:13:39 +0200 | [diff] [blame] | 1392 | /* Need to fetch pid before load_binary changes it */ |
Oleg Nesterov | 6308191 | 2012-03-30 18:26:36 +0200 | [diff] [blame] | 1393 | old_pid = current->pid; |
Denys Vlasenko | bb188d7 | 2011-06-29 04:13:39 +0200 | [diff] [blame] | 1394 | rcu_read_lock(); |
Oleg Nesterov | 6308191 | 2012-03-30 18:26:36 +0200 | [diff] [blame] | 1395 | old_vpid = task_pid_nr_ns(current, task_active_pid_ns(current->parent)); |
Denys Vlasenko | bb188d7 | 2011-06-29 04:13:39 +0200 | [diff] [blame] | 1396 | rcu_read_unlock(); |
| 1397 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1398 | retval = -ENOENT; |
| 1399 | for (try=0; try<2; try++) { |
| 1400 | read_lock(&binfmt_lock); |
Alexey Dobriyan | e4dc1b1 | 2007-10-16 23:26:03 -0700 | [diff] [blame] | 1401 | list_for_each_entry(fmt, &formats, lh) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1402 | int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary; |
| 1403 | if (!fn) |
| 1404 | continue; |
| 1405 | if (!try_module_get(fmt->module)) |
| 1406 | continue; |
| 1407 | read_unlock(&binfmt_lock); |
| 1408 | retval = fn(bprm, regs); |
Roland McGrath | 85f3346 | 2008-12-09 19:36:38 -0800 | [diff] [blame] | 1409 | /* |
| 1410 | * Restore the depth counter to its starting value |
| 1411 | * in this call, so we don't have to rely on every |
| 1412 | * load_binary function to restore it on return. |
| 1413 | */ |
| 1414 | bprm->recursion_depth = depth; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1415 | if (retval >= 0) { |
David Smith | 4ff16c2 | 2012-02-07 10:11:05 -0600 | [diff] [blame] | 1416 | if (depth == 0) { |
| 1417 | trace_sched_process_exec(current, old_pid, bprm); |
Oleg Nesterov | 6308191 | 2012-03-30 18:26:36 +0200 | [diff] [blame] | 1418 | ptrace_event(PTRACE_EVENT_EXEC, old_vpid); |
David Smith | 4ff16c2 | 2012-02-07 10:11:05 -0600 | [diff] [blame] | 1419 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1420 | put_binfmt(fmt); |
| 1421 | allow_write_access(bprm->file); |
| 1422 | if (bprm->file) |
| 1423 | fput(bprm->file); |
| 1424 | bprm->file = NULL; |
| 1425 | current->did_exec = 1; |
Matt Helsley | 9f46080 | 2005-11-07 00:59:16 -0800 | [diff] [blame] | 1426 | proc_exec_connector(current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1427 | return retval; |
| 1428 | } |
| 1429 | read_lock(&binfmt_lock); |
| 1430 | put_binfmt(fmt); |
| 1431 | if (retval != -ENOEXEC || bprm->mm == NULL) |
| 1432 | break; |
| 1433 | if (!bprm->file) { |
| 1434 | read_unlock(&binfmt_lock); |
| 1435 | return retval; |
| 1436 | } |
| 1437 | } |
| 1438 | read_unlock(&binfmt_lock); |
Tetsuo Handa | b4edf8b | 2011-07-26 16:08:42 -0700 | [diff] [blame] | 1439 | #ifdef CONFIG_MODULES |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1440 | if (retval != -ENOEXEC || bprm->mm == NULL) { |
| 1441 | break; |
Johannes Berg | 5f4123b | 2008-07-09 10:28:40 +0200 | [diff] [blame] | 1442 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1443 | #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) |
| 1444 | if (printable(bprm->buf[0]) && |
| 1445 | printable(bprm->buf[1]) && |
| 1446 | printable(bprm->buf[2]) && |
| 1447 | printable(bprm->buf[3])) |
| 1448 | break; /* -ENOEXEC */ |
Tetsuo Handa | 9121935 | 2011-07-26 16:08:41 -0700 | [diff] [blame] | 1449 | if (try) |
| 1450 | break; /* -ENOEXEC */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1451 | request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2])); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1452 | } |
Tetsuo Handa | b4edf8b | 2011-07-26 16:08:42 -0700 | [diff] [blame] | 1453 | #else |
| 1454 | break; |
| 1455 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1456 | } |
| 1457 | return retval; |
| 1458 | } |
| 1459 | |
| 1460 | EXPORT_SYMBOL(search_binary_handler); |
| 1461 | |
| 1462 | /* |
| 1463 | * sys_execve() executes a new program. |
| 1464 | */ |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 1465 | static int do_execve_common(const char *filename, |
| 1466 | struct user_arg_ptr argv, |
| 1467 | struct user_arg_ptr envp, |
| 1468 | struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1469 | { |
| 1470 | struct linux_binprm *bprm; |
| 1471 | struct file *file; |
Al Viro | 3b12538 | 2008-04-22 05:31:30 -0400 | [diff] [blame] | 1472 | struct files_struct *displaced; |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1473 | bool clear_in_exec; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1474 | int retval; |
Vasiliy Kulikov | 72fa599 | 2011-08-08 19:02:04 +0400 | [diff] [blame] | 1475 | const struct cred *cred = current_cred(); |
| 1476 | |
| 1477 | /* |
| 1478 | * We move the actual failure in case of RLIMIT_NPROC excess from |
| 1479 | * set*uid() to execve() because too many poorly written programs |
| 1480 | * don't check setuid() return code. Here we additionally recheck |
| 1481 | * whether NPROC limit is still exceeded. |
| 1482 | */ |
| 1483 | if ((current->flags & PF_NPROC_EXCEEDED) && |
| 1484 | atomic_read(&cred->user->processes) > rlimit(RLIMIT_NPROC)) { |
| 1485 | retval = -EAGAIN; |
| 1486 | goto out_ret; |
| 1487 | } |
| 1488 | |
| 1489 | /* We're below the limit (still or again), so we don't want to make |
| 1490 | * further execve() calls fail. */ |
| 1491 | current->flags &= ~PF_NPROC_EXCEEDED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1492 | |
Al Viro | 3b12538 | 2008-04-22 05:31:30 -0400 | [diff] [blame] | 1493 | retval = unshare_files(&displaced); |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1494 | if (retval) |
| 1495 | goto out_ret; |
| 1496 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1497 | retval = -ENOMEM; |
Oliver Neukum | 11b0b5a | 2006-03-25 03:08:13 -0800 | [diff] [blame] | 1498 | bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1499 | if (!bprm) |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1500 | goto out_files; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1501 | |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1502 | retval = prepare_bprm_creds(bprm); |
| 1503 | if (retval) |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1504 | goto out_free; |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1505 | |
| 1506 | retval = check_unsafe_exec(bprm); |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1507 | if (retval < 0) |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1508 | goto out_free; |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1509 | clear_in_exec = retval; |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1510 | current->in_execve = 1; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1511 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1512 | file = open_exec(filename); |
| 1513 | retval = PTR_ERR(file); |
| 1514 | if (IS_ERR(file)) |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1515 | goto out_unmark; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1516 | |
| 1517 | sched_exec(); |
| 1518 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1519 | bprm->file = file; |
| 1520 | bprm->filename = filename; |
| 1521 | bprm->interp = filename; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1522 | |
| 1523 | retval = bprm_mm_init(bprm); |
| 1524 | if (retval) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1525 | goto out_file; |
| 1526 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1527 | bprm->argc = count(argv, MAX_ARG_STRINGS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1528 | if ((retval = bprm->argc) < 0) |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1529 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1530 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1531 | bprm->envc = count(envp, MAX_ARG_STRINGS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1532 | if ((retval = bprm->envc) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1533 | goto out; |
| 1534 | |
| 1535 | retval = prepare_binprm(bprm); |
| 1536 | if (retval < 0) |
| 1537 | goto out; |
| 1538 | |
| 1539 | retval = copy_strings_kernel(1, &bprm->filename, bprm); |
| 1540 | if (retval < 0) |
| 1541 | goto out; |
| 1542 | |
| 1543 | bprm->exec = bprm->p; |
| 1544 | retval = copy_strings(bprm->envc, envp, bprm); |
| 1545 | if (retval < 0) |
| 1546 | goto out; |
| 1547 | |
| 1548 | retval = copy_strings(bprm->argc, argv, bprm); |
| 1549 | if (retval < 0) |
| 1550 | goto out; |
| 1551 | |
| 1552 | retval = search_binary_handler(bprm,regs); |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1553 | if (retval < 0) |
| 1554 | goto out; |
| 1555 | |
| 1556 | /* execve succeeded */ |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1557 | current->fs->in_exec = 0; |
Kentaro Takeda | f9ce1f1 | 2009-02-05 17:18:11 +0900 | [diff] [blame] | 1558 | current->in_execve = 0; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1559 | acct_update_integrals(current); |
| 1560 | free_bprm(bprm); |
| 1561 | if (displaced) |
| 1562 | put_files_struct(displaced); |
| 1563 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1564 | |
| 1565 | out: |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 1566 | if (bprm->mm) { |
| 1567 | acct_arg_size(bprm, 0); |
| 1568 | mmput(bprm->mm); |
| 1569 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1570 | |
| 1571 | out_file: |
| 1572 | if (bprm->file) { |
| 1573 | allow_write_access(bprm->file); |
| 1574 | fput(bprm->file); |
| 1575 | } |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1576 | |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1577 | out_unmark: |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1578 | if (clear_in_exec) |
| 1579 | current->fs->in_exec = 0; |
Kentaro Takeda | f9ce1f1 | 2009-02-05 17:18:11 +0900 | [diff] [blame] | 1580 | current->in_execve = 0; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1581 | |
| 1582 | out_free: |
Al Viro | 08a6fac | 2008-05-10 16:38:25 -0400 | [diff] [blame] | 1583 | free_bprm(bprm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1584 | |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1585 | out_files: |
Al Viro | 3b12538 | 2008-04-22 05:31:30 -0400 | [diff] [blame] | 1586 | if (displaced) |
| 1587 | reset_files_struct(displaced); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1588 | out_ret: |
| 1589 | return retval; |
| 1590 | } |
| 1591 | |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 1592 | int do_execve(const char *filename, |
| 1593 | const char __user *const __user *__argv, |
| 1594 | const char __user *const __user *__envp, |
| 1595 | struct pt_regs *regs) |
| 1596 | { |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 1597 | struct user_arg_ptr argv = { .ptr.native = __argv }; |
| 1598 | struct user_arg_ptr envp = { .ptr.native = __envp }; |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 1599 | return do_execve_common(filename, argv, envp, regs); |
| 1600 | } |
| 1601 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 1602 | #ifdef CONFIG_COMPAT |
| 1603 | int compat_do_execve(char *filename, |
| 1604 | compat_uptr_t __user *__argv, |
| 1605 | compat_uptr_t __user *__envp, |
| 1606 | struct pt_regs *regs) |
| 1607 | { |
| 1608 | struct user_arg_ptr argv = { |
| 1609 | .is_compat = true, |
| 1610 | .ptr.compat = __argv, |
| 1611 | }; |
| 1612 | struct user_arg_ptr envp = { |
| 1613 | .is_compat = true, |
| 1614 | .ptr.compat = __envp, |
| 1615 | }; |
| 1616 | return do_execve_common(filename, argv, envp, regs); |
| 1617 | } |
| 1618 | #endif |
| 1619 | |
Oleg Nesterov | 964ee7d | 2009-09-23 15:56:59 -0700 | [diff] [blame] | 1620 | void set_binfmt(struct linux_binfmt *new) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1621 | { |
Hiroshi Shimamoto | 801460d | 2009-09-23 15:57:41 -0700 | [diff] [blame] | 1622 | struct mm_struct *mm = current->mm; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1623 | |
Hiroshi Shimamoto | 801460d | 2009-09-23 15:57:41 -0700 | [diff] [blame] | 1624 | if (mm->binfmt) |
| 1625 | module_put(mm->binfmt->module); |
| 1626 | |
| 1627 | mm->binfmt = new; |
Oleg Nesterov | 964ee7d | 2009-09-23 15:56:59 -0700 | [diff] [blame] | 1628 | if (new) |
| 1629 | __module_get(new->module); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1630 | } |
| 1631 | |
| 1632 | EXPORT_SYMBOL(set_binfmt); |
| 1633 | |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1634 | static int expand_corename(struct core_name *cn) |
| 1635 | { |
| 1636 | char *old_corename = cn->corename; |
| 1637 | |
| 1638 | cn->size = CORENAME_MAX_SIZE * atomic_inc_return(&call_count); |
| 1639 | cn->corename = krealloc(old_corename, cn->size, GFP_KERNEL); |
| 1640 | |
| 1641 | if (!cn->corename) { |
| 1642 | kfree(old_corename); |
| 1643 | return -ENOMEM; |
| 1644 | } |
| 1645 | |
| 1646 | return 0; |
| 1647 | } |
| 1648 | |
| 1649 | static int cn_printf(struct core_name *cn, const char *fmt, ...) |
| 1650 | { |
| 1651 | char *cur; |
| 1652 | int need; |
| 1653 | int ret; |
| 1654 | va_list arg; |
| 1655 | |
| 1656 | va_start(arg, fmt); |
| 1657 | need = vsnprintf(NULL, 0, fmt, arg); |
| 1658 | va_end(arg); |
| 1659 | |
| 1660 | if (likely(need < cn->size - cn->used - 1)) |
| 1661 | goto out_printf; |
| 1662 | |
| 1663 | ret = expand_corename(cn); |
| 1664 | if (ret) |
| 1665 | goto expand_fail; |
| 1666 | |
| 1667 | out_printf: |
| 1668 | cur = cn->corename + cn->used; |
| 1669 | va_start(arg, fmt); |
| 1670 | vsnprintf(cur, need + 1, fmt, arg); |
| 1671 | va_end(arg); |
| 1672 | cn->used += need; |
| 1673 | return 0; |
| 1674 | |
| 1675 | expand_fail: |
| 1676 | return ret; |
| 1677 | } |
| 1678 | |
Jiri Slaby | 2c56373 | 2011-07-26 16:08:33 -0700 | [diff] [blame] | 1679 | static void cn_escape(char *str) |
| 1680 | { |
| 1681 | for (; *str; str++) |
| 1682 | if (*str == '/') |
| 1683 | *str = '!'; |
| 1684 | } |
| 1685 | |
Jiri Slaby | 57cc083 | 2011-05-26 16:25:46 -0700 | [diff] [blame] | 1686 | static int cn_print_exe_file(struct core_name *cn) |
| 1687 | { |
| 1688 | struct file *exe_file; |
Jiri Slaby | 2c56373 | 2011-07-26 16:08:33 -0700 | [diff] [blame] | 1689 | char *pathbuf, *path; |
Jiri Slaby | 57cc083 | 2011-05-26 16:25:46 -0700 | [diff] [blame] | 1690 | int ret; |
| 1691 | |
| 1692 | exe_file = get_mm_exe_file(current->mm); |
Jiri Slaby | 2c56373 | 2011-07-26 16:08:33 -0700 | [diff] [blame] | 1693 | if (!exe_file) { |
| 1694 | char *commstart = cn->corename + cn->used; |
| 1695 | ret = cn_printf(cn, "%s (path unknown)", current->comm); |
| 1696 | cn_escape(commstart); |
| 1697 | return ret; |
| 1698 | } |
Jiri Slaby | 57cc083 | 2011-05-26 16:25:46 -0700 | [diff] [blame] | 1699 | |
| 1700 | pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY); |
| 1701 | if (!pathbuf) { |
| 1702 | ret = -ENOMEM; |
| 1703 | goto put_exe_file; |
| 1704 | } |
| 1705 | |
| 1706 | path = d_path(&exe_file->f_path, pathbuf, PATH_MAX); |
| 1707 | if (IS_ERR(path)) { |
| 1708 | ret = PTR_ERR(path); |
| 1709 | goto free_buf; |
| 1710 | } |
| 1711 | |
Jiri Slaby | 2c56373 | 2011-07-26 16:08:33 -0700 | [diff] [blame] | 1712 | cn_escape(path); |
Jiri Slaby | 57cc083 | 2011-05-26 16:25:46 -0700 | [diff] [blame] | 1713 | |
| 1714 | ret = cn_printf(cn, "%s", path); |
| 1715 | |
| 1716 | free_buf: |
| 1717 | kfree(pathbuf); |
| 1718 | put_exe_file: |
| 1719 | fput(exe_file); |
| 1720 | return ret; |
| 1721 | } |
| 1722 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1723 | /* format_corename will inspect the pattern parameter, and output a |
| 1724 | * name into corename, which must have space for at least |
| 1725 | * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator. |
| 1726 | */ |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1727 | static int format_corename(struct core_name *cn, long signr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1728 | { |
David Howells | 86a264a | 2008-11-14 10:39:18 +1100 | [diff] [blame] | 1729 | const struct cred *cred = current_cred(); |
Oleg Nesterov | 565b9b1 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 1730 | const char *pat_ptr = core_pattern; |
| 1731 | int ispipe = (*pat_ptr == '|'); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1732 | int pid_in_pattern = 0; |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1733 | int err = 0; |
| 1734 | |
| 1735 | cn->size = CORENAME_MAX_SIZE * atomic_read(&call_count); |
| 1736 | cn->corename = kmalloc(cn->size, GFP_KERNEL); |
| 1737 | cn->used = 0; |
| 1738 | |
| 1739 | if (!cn->corename) |
| 1740 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1741 | |
| 1742 | /* Repeat as long as we have more pattern to process and more output |
| 1743 | space */ |
| 1744 | while (*pat_ptr) { |
| 1745 | if (*pat_ptr != '%') { |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1746 | if (*pat_ptr == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1747 | goto out; |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1748 | err = cn_printf(cn, "%c", *pat_ptr++); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1749 | } else { |
| 1750 | switch (*++pat_ptr) { |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1751 | /* single % at the end, drop that */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1752 | case 0: |
| 1753 | goto out; |
| 1754 | /* Double percent, output one percent */ |
| 1755 | case '%': |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1756 | err = cn_printf(cn, "%c", '%'); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1757 | break; |
| 1758 | /* pid */ |
| 1759 | case 'p': |
| 1760 | pid_in_pattern = 1; |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1761 | err = cn_printf(cn, "%d", |
| 1762 | task_tgid_vnr(current)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1763 | break; |
| 1764 | /* uid */ |
| 1765 | case 'u': |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1766 | err = cn_printf(cn, "%d", cred->uid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1767 | break; |
| 1768 | /* gid */ |
| 1769 | case 'g': |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1770 | err = cn_printf(cn, "%d", cred->gid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1771 | break; |
| 1772 | /* signal that caused the coredump */ |
| 1773 | case 's': |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1774 | err = cn_printf(cn, "%ld", signr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1775 | break; |
| 1776 | /* UNIX time of coredump */ |
| 1777 | case 't': { |
| 1778 | struct timeval tv; |
| 1779 | do_gettimeofday(&tv); |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1780 | err = cn_printf(cn, "%lu", tv.tv_sec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1781 | break; |
| 1782 | } |
| 1783 | /* hostname */ |
Jiri Slaby | 2c56373 | 2011-07-26 16:08:33 -0700 | [diff] [blame] | 1784 | case 'h': { |
| 1785 | char *namestart = cn->corename + cn->used; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1786 | down_read(&uts_sem); |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1787 | err = cn_printf(cn, "%s", |
| 1788 | utsname()->nodename); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1789 | up_read(&uts_sem); |
Jiri Slaby | 2c56373 | 2011-07-26 16:08:33 -0700 | [diff] [blame] | 1790 | cn_escape(namestart); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1791 | break; |
Jiri Slaby | 2c56373 | 2011-07-26 16:08:33 -0700 | [diff] [blame] | 1792 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1793 | /* executable */ |
Jiri Slaby | 2c56373 | 2011-07-26 16:08:33 -0700 | [diff] [blame] | 1794 | case 'e': { |
| 1795 | char *commstart = cn->corename + cn->used; |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1796 | err = cn_printf(cn, "%s", current->comm); |
Jiri Slaby | 2c56373 | 2011-07-26 16:08:33 -0700 | [diff] [blame] | 1797 | cn_escape(commstart); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1798 | break; |
Jiri Slaby | 2c56373 | 2011-07-26 16:08:33 -0700 | [diff] [blame] | 1799 | } |
Jiri Slaby | 57cc083 | 2011-05-26 16:25:46 -0700 | [diff] [blame] | 1800 | case 'E': |
| 1801 | err = cn_print_exe_file(cn); |
| 1802 | break; |
Neil Horman | 74aadce | 2007-10-16 23:26:35 -0700 | [diff] [blame] | 1803 | /* core limit size */ |
| 1804 | case 'c': |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1805 | err = cn_printf(cn, "%lu", |
| 1806 | rlimit(RLIMIT_CORE)); |
Neil Horman | 74aadce | 2007-10-16 23:26:35 -0700 | [diff] [blame] | 1807 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1808 | default: |
| 1809 | break; |
| 1810 | } |
| 1811 | ++pat_ptr; |
| 1812 | } |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1813 | |
| 1814 | if (err) |
| 1815 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1816 | } |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1817 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1818 | /* Backward compatibility with core_uses_pid: |
| 1819 | * |
| 1820 | * If core_pattern does not include a %p (as is the default) |
| 1821 | * and core_uses_pid is set, then .%pid will be appended to |
Alan Cox | c4bbafd | 2007-04-16 22:53:13 -0700 | [diff] [blame] | 1822 | * the filename. Do not do this for piped commands. */ |
Oleg Nesterov | 6409324 | 2008-10-18 20:28:22 -0700 | [diff] [blame] | 1823 | if (!ispipe && !pid_in_pattern && core_uses_pid) { |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1824 | err = cn_printf(cn, ".%d", task_tgid_vnr(current)); |
| 1825 | if (err) |
| 1826 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1827 | } |
Alan Cox | c4bbafd | 2007-04-16 22:53:13 -0700 | [diff] [blame] | 1828 | out: |
Alan Cox | c4bbafd | 2007-04-16 22:53:13 -0700 | [diff] [blame] | 1829 | return ispipe; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1830 | } |
| 1831 | |
Oleg Nesterov | 5c99cbf | 2010-03-05 13:44:14 -0800 | [diff] [blame] | 1832 | static int zap_process(struct task_struct *start, int exit_code) |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1833 | { |
| 1834 | struct task_struct *t; |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1835 | int nr = 0; |
Oleg Nesterov | 281de33 | 2006-06-26 00:26:06 -0700 | [diff] [blame] | 1836 | |
Oleg Nesterov | d5f70c0 | 2006-06-26 00:26:07 -0700 | [diff] [blame] | 1837 | start->signal->flags = SIGNAL_GROUP_EXIT; |
Oleg Nesterov | 5c99cbf | 2010-03-05 13:44:14 -0800 | [diff] [blame] | 1838 | start->signal->group_exit_code = exit_code; |
Oleg Nesterov | d5f70c0 | 2006-06-26 00:26:07 -0700 | [diff] [blame] | 1839 | start->signal->group_stop_count = 0; |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1840 | |
| 1841 | t = start; |
| 1842 | do { |
Tejun Heo | 6dfca32 | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 1843 | task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK); |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1844 | if (t != current && t->mm) { |
Oleg Nesterov | 281de33 | 2006-06-26 00:26:06 -0700 | [diff] [blame] | 1845 | sigaddset(&t->pending.signal, SIGKILL); |
| 1846 | signal_wake_up(t, 1); |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1847 | nr++; |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1848 | } |
Oleg Nesterov | e4901f9 | 2008-07-25 01:47:31 -0700 | [diff] [blame] | 1849 | } while_each_thread(start, t); |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1850 | |
| 1851 | return nr; |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1852 | } |
| 1853 | |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1854 | 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] | 1855 | struct core_state *core_state, int exit_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1856 | { |
| 1857 | struct task_struct *g, *p; |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1858 | unsigned long flags; |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1859 | int nr = -EAGAIN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1860 | |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1861 | spin_lock_irq(&tsk->sighand->siglock); |
Oleg Nesterov | ed5d2ca | 2008-02-04 22:27:24 -0800 | [diff] [blame] | 1862 | if (!signal_group_exit(tsk->signal)) { |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1863 | mm->core_state = core_state; |
Oleg Nesterov | 5c99cbf | 2010-03-05 13:44:14 -0800 | [diff] [blame] | 1864 | nr = zap_process(tsk, exit_code); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1865 | } |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1866 | spin_unlock_irq(&tsk->sighand->siglock); |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1867 | if (unlikely(nr < 0)) |
| 1868 | return nr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1869 | |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1870 | if (atomic_read(&mm->mm_users) == nr + 1) |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1871 | goto done; |
Oleg Nesterov | e4901f9 | 2008-07-25 01:47:31 -0700 | [diff] [blame] | 1872 | /* |
| 1873 | * 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] | 1874 | * count them correctly into ->nr_threads. We don't take tasklist |
Oleg Nesterov | e4901f9 | 2008-07-25 01:47:31 -0700 | [diff] [blame] | 1875 | * lock, but this is safe wrt: |
| 1876 | * |
| 1877 | * fork: |
| 1878 | * None of sub-threads can fork after zap_process(leader). All |
| 1879 | * processes which were created before this point should be |
| 1880 | * visible to zap_threads() because copy_process() adds the new |
| 1881 | * process to the tail of init_task.tasks list, and lock/unlock |
| 1882 | * of ->siglock provides a memory barrier. |
| 1883 | * |
| 1884 | * do_exit: |
| 1885 | * The caller holds mm->mmap_sem. This means that the task which |
| 1886 | * uses this mm can't pass exit_mm(), so it can't exit or clear |
| 1887 | * its ->mm. |
| 1888 | * |
| 1889 | * de_thread: |
| 1890 | * It does list_replace_rcu(&leader->tasks, ¤t->tasks), |
| 1891 | * we must see either old or new leader, this does not matter. |
| 1892 | * However, it can change p->sighand, so lock_task_sighand(p) |
| 1893 | * must be used. Since p->mm != NULL and we hold ->mmap_sem |
| 1894 | * it can't fail. |
| 1895 | * |
| 1896 | * Note also that "g" can be the old leader with ->mm == NULL |
| 1897 | * and already unhashed and thus removed from ->thread_group. |
| 1898 | * This is OK, __unhash_process()->list_del_rcu() does not |
| 1899 | * clear the ->next pointer, we will find the new leader via |
| 1900 | * next_thread(). |
| 1901 | */ |
Oleg Nesterov | 7b1c615 | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1902 | rcu_read_lock(); |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1903 | for_each_process(g) { |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1904 | if (g == tsk->group_leader) |
| 1905 | continue; |
Oleg Nesterov | 15b9f36 | 2008-07-25 01:47:39 -0700 | [diff] [blame] | 1906 | if (g->flags & PF_KTHREAD) |
| 1907 | continue; |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1908 | p = g; |
| 1909 | do { |
| 1910 | if (p->mm) { |
Oleg Nesterov | 15b9f36 | 2008-07-25 01:47:39 -0700 | [diff] [blame] | 1911 | if (unlikely(p->mm == mm)) { |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1912 | lock_task_sighand(p, &flags); |
Oleg Nesterov | 5c99cbf | 2010-03-05 13:44:14 -0800 | [diff] [blame] | 1913 | nr += zap_process(p, exit_code); |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1914 | unlock_task_sighand(p, &flags); |
| 1915 | } |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1916 | break; |
| 1917 | } |
Oleg Nesterov | e4901f9 | 2008-07-25 01:47:31 -0700 | [diff] [blame] | 1918 | } while_each_thread(g, p); |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1919 | } |
Oleg Nesterov | 7b1c615 | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1920 | rcu_read_unlock(); |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1921 | done: |
Oleg Nesterov | c5f1cc8 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1922 | atomic_set(&core_state->nr_threads, nr); |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1923 | return nr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1924 | } |
| 1925 | |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 1926 | static int coredump_wait(int exit_code, struct core_state *core_state) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1927 | { |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1928 | struct task_struct *tsk = current; |
| 1929 | struct mm_struct *mm = tsk->mm; |
Oleg Nesterov | 269b005 | 2010-05-26 14:43:08 -0700 | [diff] [blame] | 1930 | int core_waiters = -EBUSY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1931 | |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 1932 | init_completion(&core_state->startup); |
Oleg Nesterov | b564daf | 2008-07-25 01:47:44 -0700 | [diff] [blame] | 1933 | core_state->dumper.task = tsk; |
| 1934 | core_state->dumper.next = NULL; |
Oleg Nesterov | 269b005 | 2010-05-26 14:43:08 -0700 | [diff] [blame] | 1935 | |
| 1936 | down_write(&mm->mmap_sem); |
| 1937 | if (!mm->core_state) |
| 1938 | core_waiters = zap_threads(tsk, mm, core_state, exit_code); |
Oleg Nesterov | 2384f55 | 2005-10-30 15:02:47 -0800 | [diff] [blame] | 1939 | up_write(&mm->mmap_sem); |
| 1940 | |
Suresh Siddha | 11aeca0 | 2012-05-16 15:03:52 -0700 | [diff] [blame] | 1941 | if (core_waiters > 0) { |
| 1942 | struct core_thread *ptr; |
| 1943 | |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 1944 | wait_for_completion(&core_state->startup); |
Suresh Siddha | 11aeca0 | 2012-05-16 15:03:52 -0700 | [diff] [blame] | 1945 | /* |
| 1946 | * Wait for all the threads to become inactive, so that |
| 1947 | * all the thread context (extended register state, like |
| 1948 | * fpu etc) gets copied to the memory. |
| 1949 | */ |
| 1950 | ptr = core_state->dumper.next; |
| 1951 | while (ptr != NULL) { |
| 1952 | wait_task_inactive(ptr->task, 0); |
| 1953 | ptr = ptr->next; |
| 1954 | } |
| 1955 | } |
Oleg Nesterov | 57b59c4 | 2012-03-05 14:59:13 -0800 | [diff] [blame] | 1956 | |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1957 | return core_waiters; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1958 | } |
| 1959 | |
Oleg Nesterov | a94e2d4 | 2008-07-25 01:47:46 -0700 | [diff] [blame] | 1960 | static void coredump_finish(struct mm_struct *mm) |
| 1961 | { |
| 1962 | struct core_thread *curr, *next; |
| 1963 | struct task_struct *task; |
| 1964 | |
| 1965 | next = mm->core_state->dumper.next; |
| 1966 | while ((curr = next) != NULL) { |
| 1967 | next = curr->next; |
| 1968 | task = curr->task; |
| 1969 | /* |
| 1970 | * see exit_mm(), curr->task must not see |
| 1971 | * ->task == NULL before we read ->next. |
| 1972 | */ |
| 1973 | smp_mb(); |
| 1974 | curr->task = NULL; |
| 1975 | wake_up_process(task); |
| 1976 | } |
| 1977 | |
| 1978 | mm->core_state = NULL; |
| 1979 | } |
| 1980 | |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1981 | /* |
| 1982 | * set_dumpable converts traditional three-value dumpable to two flags and |
| 1983 | * stores them into mm->flags. It modifies lower two bits of mm->flags, but |
| 1984 | * these bits are not changed atomically. So get_dumpable can observe the |
| 1985 | * intermediate state. To avoid doing unexpected behavior, get get_dumpable |
| 1986 | * return either old dumpable or new one by paying attention to the order of |
| 1987 | * modifying the bits. |
| 1988 | * |
| 1989 | * dumpable | mm->flags (binary) |
| 1990 | * old new | initial interim final |
| 1991 | * ---------+----------------------- |
| 1992 | * 0 1 | 00 01 01 |
| 1993 | * 0 2 | 00 10(*) 11 |
| 1994 | * 1 0 | 01 00 00 |
| 1995 | * 1 2 | 01 11 11 |
| 1996 | * 2 0 | 11 10(*) 00 |
| 1997 | * 2 1 | 11 11 01 |
| 1998 | * |
| 1999 | * (*) get_dumpable regards interim value of 10 as 11. |
| 2000 | */ |
| 2001 | void set_dumpable(struct mm_struct *mm, int value) |
| 2002 | { |
| 2003 | switch (value) { |
Kees Cook | 54b5019 | 2012-07-30 14:39:18 -0700 | [diff] [blame] | 2004 | case SUID_DUMPABLE_DISABLED: |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 2005 | clear_bit(MMF_DUMPABLE, &mm->flags); |
| 2006 | smp_wmb(); |
| 2007 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); |
| 2008 | break; |
Kees Cook | 54b5019 | 2012-07-30 14:39:18 -0700 | [diff] [blame] | 2009 | case SUID_DUMPABLE_ENABLED: |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 2010 | set_bit(MMF_DUMPABLE, &mm->flags); |
| 2011 | smp_wmb(); |
| 2012 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); |
| 2013 | break; |
Kees Cook | 54b5019 | 2012-07-30 14:39:18 -0700 | [diff] [blame] | 2014 | case SUID_DUMPABLE_SAFE: |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 2015 | set_bit(MMF_DUMP_SECURELY, &mm->flags); |
| 2016 | smp_wmb(); |
| 2017 | set_bit(MMF_DUMPABLE, &mm->flags); |
| 2018 | break; |
| 2019 | } |
| 2020 | } |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 2021 | |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 2022 | static int __get_dumpable(unsigned long mm_flags) |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 2023 | { |
| 2024 | int ret; |
| 2025 | |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 2026 | ret = mm_flags & MMF_DUMPABLE_MASK; |
Kees Cook | 54b5019 | 2012-07-30 14:39:18 -0700 | [diff] [blame] | 2027 | return (ret > SUID_DUMPABLE_ENABLED) ? SUID_DUMPABLE_SAFE : ret; |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 2028 | } |
| 2029 | |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 2030 | int get_dumpable(struct mm_struct *mm) |
| 2031 | { |
| 2032 | return __get_dumpable(mm->flags); |
| 2033 | } |
| 2034 | |
Neil Horman | 61be228 | 2009-09-23 15:56:58 -0700 | [diff] [blame] | 2035 | static void wait_for_dump_helpers(struct file *file) |
| 2036 | { |
| 2037 | struct pipe_inode_info *pipe; |
| 2038 | |
| 2039 | pipe = file->f_path.dentry->d_inode->i_pipe; |
| 2040 | |
| 2041 | pipe_lock(pipe); |
| 2042 | pipe->readers++; |
| 2043 | pipe->writers--; |
| 2044 | |
| 2045 | while ((pipe->readers > 1) && (!signal_pending(current))) { |
| 2046 | wake_up_interruptible_sync(&pipe->wait); |
| 2047 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
| 2048 | pipe_wait(pipe); |
| 2049 | } |
| 2050 | |
| 2051 | pipe->readers--; |
| 2052 | pipe->writers++; |
| 2053 | pipe_unlock(pipe); |
| 2054 | |
| 2055 | } |
| 2056 | |
| 2057 | |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 2058 | /* |
Holger Hans Peter Freyther | 1bef829 | 2011-02-24 17:46:49 +0100 | [diff] [blame] | 2059 | * umh_pipe_setup |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 2060 | * helper function to customize the process used |
| 2061 | * to collect the core in userspace. Specifically |
| 2062 | * it sets up a pipe and installs it as fd 0 (stdin) |
| 2063 | * for the process. Returns 0 on success, or |
| 2064 | * PTR_ERR on failure. |
| 2065 | * Note that it also sets the core limit to 1. This |
| 2066 | * is a special value that we use to trap recursive |
| 2067 | * core dumps |
| 2068 | */ |
David Howells | 8796699 | 2011-06-17 11:25:59 +0100 | [diff] [blame] | 2069 | static int umh_pipe_setup(struct subprocess_info *info, struct cred *new) |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 2070 | { |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 2071 | struct file *files[2]; |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 2072 | struct fdtable *fdt; |
| 2073 | struct coredump_params *cp = (struct coredump_params *)info->data; |
| 2074 | struct files_struct *cf = current->files; |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 2075 | int err = create_pipe_files(files, 0); |
| 2076 | if (err) |
| 2077 | return err; |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 2078 | |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 2079 | cp->file = files[1]; |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 2080 | |
| 2081 | sys_close(0); |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 2082 | fd_install(0, files[0]); |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 2083 | spin_lock(&cf->file_lock); |
| 2084 | fdt = files_fdtable(cf); |
David Howells | 1dce27c | 2012-02-16 17:49:42 +0000 | [diff] [blame] | 2085 | __set_open_fd(0, fdt); |
| 2086 | __clear_close_on_exec(0, fdt); |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 2087 | spin_unlock(&cf->file_lock); |
| 2088 | |
| 2089 | /* and disallow core files too */ |
| 2090 | current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1}; |
| 2091 | |
| 2092 | return 0; |
| 2093 | } |
| 2094 | |
WANG Cong | 8cd3ac3 | 2009-01-06 14:42:48 -0800 | [diff] [blame] | 2095 | void do_coredump(long signr, int exit_code, struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2096 | { |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 2097 | struct core_state core_state; |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 2098 | struct core_name cn; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2099 | struct mm_struct *mm = current->mm; |
| 2100 | struct linux_binfmt * binfmt; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 2101 | const struct cred *old_cred; |
| 2102 | struct cred *cred; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2103 | int retval = 0; |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 2104 | int flag = 0; |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2105 | int ispipe; |
Kees Cook | 9520628 | 2012-07-30 14:39:15 -0700 | [diff] [blame] | 2106 | bool need_nonrelative = false; |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 2107 | static atomic_t core_dump_count = ATOMIC_INIT(0); |
Masami Hiramatsu | f6151df | 2009-12-17 15:27:16 -0800 | [diff] [blame] | 2108 | struct coredump_params cprm = { |
| 2109 | .signr = signr, |
| 2110 | .regs = regs, |
Jiri Slaby | d554ed89 | 2010-03-05 13:42:42 -0800 | [diff] [blame] | 2111 | .limit = rlimit(RLIMIT_CORE), |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 2112 | /* |
| 2113 | * We must use the same mm->flags while dumping core to avoid |
| 2114 | * inconsistency of bit flags, since this flag is not protected |
| 2115 | * by any locks. |
| 2116 | */ |
| 2117 | .mm_flags = mm->flags, |
Masami Hiramatsu | f6151df | 2009-12-17 15:27:16 -0800 | [diff] [blame] | 2118 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2119 | |
Steve Grubb | 0a4ff8c | 2007-04-19 10:28:21 -0400 | [diff] [blame] | 2120 | audit_core_dumps(signr); |
| 2121 | |
Hiroshi Shimamoto | 801460d | 2009-09-23 15:57:41 -0700 | [diff] [blame] | 2122 | binfmt = mm->binfmt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2123 | if (!binfmt || !binfmt->core_dump) |
| 2124 | goto fail; |
Oleg Nesterov | 269b005 | 2010-05-26 14:43:08 -0700 | [diff] [blame] | 2125 | if (!__get_dumpable(cprm.mm_flags)) |
| 2126 | goto fail; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 2127 | |
| 2128 | cred = prepare_creds(); |
Oleg Nesterov | 5e43aef5 | 2010-05-26 14:43:07 -0700 | [diff] [blame] | 2129 | if (!cred) |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 2130 | goto fail; |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 2131 | /* |
Kees Cook | 9520628 | 2012-07-30 14:39:15 -0700 | [diff] [blame] | 2132 | * We cannot trust fsuid as being the "true" uid of the process |
| 2133 | * nor do we know its entire history. We only know it was tainted |
| 2134 | * so we dump it as root in mode 2, and only into a controlled |
| 2135 | * environment (pipe handler or fully qualified path). |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 2136 | */ |
Kees Cook | 54b5019 | 2012-07-30 14:39:18 -0700 | [diff] [blame] | 2137 | if (__get_dumpable(cprm.mm_flags) == SUID_DUMPABLE_SAFE) { |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 2138 | /* Setuid core dump mode */ |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 2139 | flag = O_EXCL; /* Stop rewrite attacks */ |
Eric W. Biederman | 8e96e3b | 2012-03-03 21:17:15 -0800 | [diff] [blame] | 2140 | cred->fsuid = GLOBAL_ROOT_UID; /* Dump root private */ |
Kees Cook | 9520628 | 2012-07-30 14:39:15 -0700 | [diff] [blame] | 2141 | need_nonrelative = true; |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 2142 | } |
Oleg Nesterov | 1291cf4 | 2005-10-30 15:02:54 -0800 | [diff] [blame] | 2143 | |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 2144 | retval = coredump_wait(exit_code, &core_state); |
Oleg Nesterov | 5e43aef5 | 2010-05-26 14:43:07 -0700 | [diff] [blame] | 2145 | if (retval < 0) |
| 2146 | goto fail_creds; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 2147 | |
| 2148 | old_cred = override_creds(cred); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2149 | |
| 2150 | /* |
| 2151 | * Clear any false indication of pending signals that might |
| 2152 | * be seen by the filesystem code called to write the core file. |
| 2153 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2154 | clear_thread_flag(TIF_SIGPENDING); |
| 2155 | |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 2156 | ispipe = format_corename(&cn, signr); |
| 2157 | |
Alan Cox | c4bbafd | 2007-04-16 22:53:13 -0700 | [diff] [blame] | 2158 | if (ispipe) { |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2159 | int dump_count; |
| 2160 | char **helper_argv; |
| 2161 | |
Oleg Nesterov | 99b6456 | 2011-07-26 16:08:34 -0700 | [diff] [blame] | 2162 | if (ispipe < 0) { |
| 2163 | printk(KERN_WARNING "format_corename failed\n"); |
| 2164 | printk(KERN_WARNING "Aborting core\n"); |
| 2165 | goto fail_corename; |
| 2166 | } |
| 2167 | |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 2168 | if (cprm.limit == 1) { |
Jovi Zhang | 108ceeb | 2012-07-30 14:42:23 -0700 | [diff] [blame] | 2169 | /* See umh_pipe_setup() which sets RLIMIT_CORE = 1. |
| 2170 | * |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 2171 | * Normally core limits are irrelevant to pipes, since |
| 2172 | * we're not writing to the file system, but we use |
Jovi Zhang | 108ceeb | 2012-07-30 14:42:23 -0700 | [diff] [blame] | 2173 | * cprm.limit of 1 here as a speacial value, this is a |
| 2174 | * consistent way to catch recursive crashes. |
| 2175 | * We can still crash if the core_pattern binary sets |
| 2176 | * RLIM_CORE = !1, but it runs as root, and can do |
| 2177 | * lots of stupid things. |
| 2178 | * |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 2179 | * Note that we use task_tgid_vnr here to grab the pid |
| 2180 | * of the process group leader. That way we get the |
| 2181 | * right pid if a thread in a multi-threaded |
| 2182 | * core_pattern process dies. |
| 2183 | */ |
| 2184 | printk(KERN_WARNING |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 2185 | "Process %d(%s) has RLIMIT_CORE set to 1\n", |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 2186 | task_tgid_vnr(current), current->comm); |
| 2187 | printk(KERN_WARNING "Aborting core\n"); |
| 2188 | goto fail_unlock; |
| 2189 | } |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2190 | cprm.limit = RLIM_INFINITY; |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 2191 | |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 2192 | dump_count = atomic_inc_return(&core_dump_count); |
| 2193 | if (core_pipe_limit && (core_pipe_limit < dump_count)) { |
| 2194 | printk(KERN_WARNING "Pid %d(%s) over core_pipe_limit\n", |
| 2195 | task_tgid_vnr(current), current->comm); |
| 2196 | printk(KERN_WARNING "Skipping core dump\n"); |
| 2197 | goto fail_dropcount; |
| 2198 | } |
| 2199 | |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 2200 | helper_argv = argv_split(GFP_KERNEL, cn.corename+1, NULL); |
Tetsuo Handa | 350eaf7 | 2009-01-06 14:41:11 -0800 | [diff] [blame] | 2201 | if (!helper_argv) { |
| 2202 | printk(KERN_WARNING "%s failed to allocate memory\n", |
| 2203 | __func__); |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 2204 | goto fail_dropcount; |
Tetsuo Handa | 350eaf7 | 2009-01-06 14:41:11 -0800 | [diff] [blame] | 2205 | } |
Neil Horman | 3232113 | 2007-10-16 23:26:36 -0700 | [diff] [blame] | 2206 | |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2207 | retval = call_usermodehelper_fns(helper_argv[0], helper_argv, |
| 2208 | NULL, UMH_WAIT_EXEC, umh_pipe_setup, |
| 2209 | NULL, &cprm); |
| 2210 | argv_free(helper_argv); |
| 2211 | if (retval) { |
Andi Kleen | d025c9d | 2006-09-30 23:29:28 -0700 | [diff] [blame] | 2212 | printk(KERN_INFO "Core dump to %s pipe failed\n", |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 2213 | cn.corename); |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2214 | goto close_fail; |
Andi Kleen | d025c9d | 2006-09-30 23:29:28 -0700 | [diff] [blame] | 2215 | } |
Oleg Nesterov | c713541 | 2010-05-26 14:43:05 -0700 | [diff] [blame] | 2216 | } else { |
| 2217 | struct inode *inode; |
| 2218 | |
| 2219 | if (cprm.limit < binfmt->min_coredump) |
| 2220 | goto fail_unlock; |
| 2221 | |
Kees Cook | 9520628 | 2012-07-30 14:39:15 -0700 | [diff] [blame] | 2222 | if (need_nonrelative && cn.corename[0] != '/') { |
| 2223 | printk(KERN_WARNING "Pid %d(%s) can only dump core "\ |
| 2224 | "to fully qualified path!\n", |
| 2225 | task_tgid_vnr(current), current->comm); |
| 2226 | printk(KERN_WARNING "Skipping core dump\n"); |
| 2227 | goto fail_unlock; |
| 2228 | } |
| 2229 | |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 2230 | cprm.file = filp_open(cn.corename, |
Alexey Dobriyan | 6d4df67 | 2006-12-06 20:40:39 -0800 | [diff] [blame] | 2231 | O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag, |
| 2232 | 0600); |
Oleg Nesterov | c713541 | 2010-05-26 14:43:05 -0700 | [diff] [blame] | 2233 | if (IS_ERR(cprm.file)) |
| 2234 | goto fail_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2235 | |
Oleg Nesterov | c713541 | 2010-05-26 14:43:05 -0700 | [diff] [blame] | 2236 | inode = cprm.file->f_path.dentry->d_inode; |
| 2237 | if (inode->i_nlink > 1) |
| 2238 | goto close_fail; |
| 2239 | if (d_unhashed(cprm.file->f_path.dentry)) |
| 2240 | goto close_fail; |
| 2241 | /* |
| 2242 | * AK: actually i see no reason to not allow this for named |
| 2243 | * pipes etc, but keep the previous behaviour for now. |
| 2244 | */ |
| 2245 | if (!S_ISREG(inode->i_mode)) |
| 2246 | goto close_fail; |
| 2247 | /* |
| 2248 | * Dont allow local users get cute and trick others to coredump |
| 2249 | * into their pre-created files. |
| 2250 | */ |
Eric W. Biederman | 8e96e3b | 2012-03-03 21:17:15 -0800 | [diff] [blame] | 2251 | if (!uid_eq(inode->i_uid, current_fsuid())) |
Oleg Nesterov | c713541 | 2010-05-26 14:43:05 -0700 | [diff] [blame] | 2252 | goto close_fail; |
| 2253 | if (!cprm.file->f_op || !cprm.file->f_op->write) |
| 2254 | goto close_fail; |
| 2255 | if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file)) |
| 2256 | goto close_fail; |
| 2257 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2258 | |
Masami Hiramatsu | f6151df | 2009-12-17 15:27:16 -0800 | [diff] [blame] | 2259 | retval = binfmt->core_dump(&cprm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2260 | if (retval) |
| 2261 | current->signal->group_exit_code |= 0x80; |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2262 | |
Neil Horman | 61be228 | 2009-09-23 15:56:58 -0700 | [diff] [blame] | 2263 | if (ispipe && core_pipe_limit) |
Masami Hiramatsu | f6151df | 2009-12-17 15:27:16 -0800 | [diff] [blame] | 2264 | wait_for_dump_helpers(cprm.file); |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2265 | close_fail: |
| 2266 | if (cprm.file) |
| 2267 | filp_close(cprm.file, NULL); |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 2268 | fail_dropcount: |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 2269 | if (ispipe) |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 2270 | atomic_dec(&core_dump_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2271 | fail_unlock: |
Xiaotian Feng | 1b0d300 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 2272 | kfree(cn.corename); |
| 2273 | fail_corename: |
Oleg Nesterov | a94e2d4 | 2008-07-25 01:47:46 -0700 | [diff] [blame] | 2274 | coredump_finish(mm); |
Oleg Nesterov | 5e43aef5 | 2010-05-26 14:43:07 -0700 | [diff] [blame] | 2275 | revert_creds(old_cred); |
| 2276 | fail_creds: |
| 2277 | put_cred(cred); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2278 | fail: |
WANG Cong | 8cd3ac3 | 2009-01-06 14:42:48 -0800 | [diff] [blame] | 2279 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2280 | } |
Linus Torvalds | 3aa0ce8 | 2010-10-14 14:32:06 -0700 | [diff] [blame] | 2281 | |
| 2282 | /* |
| 2283 | * Core dumping helper functions. These are the only things you should |
| 2284 | * do on a core-file: use only these functions to write out all the |
| 2285 | * necessary info. |
| 2286 | */ |
| 2287 | int dump_write(struct file *file, const void *addr, int nr) |
| 2288 | { |
| 2289 | return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr; |
| 2290 | } |
Linus Torvalds | 8fd01d6 | 2010-10-14 19:15:28 -0700 | [diff] [blame] | 2291 | EXPORT_SYMBOL(dump_write); |
Linus Torvalds | 3aa0ce8 | 2010-10-14 14:32:06 -0700 | [diff] [blame] | 2292 | |
| 2293 | int dump_seek(struct file *file, loff_t off) |
| 2294 | { |
| 2295 | int ret = 1; |
| 2296 | |
| 2297 | if (file->f_op->llseek && file->f_op->llseek != no_llseek) { |
| 2298 | if (file->f_op->llseek(file, off, SEEK_CUR) < 0) |
| 2299 | return 0; |
| 2300 | } else { |
| 2301 | char *buf = (char *)get_zeroed_page(GFP_KERNEL); |
| 2302 | |
| 2303 | if (!buf) |
| 2304 | return 0; |
| 2305 | while (off > 0) { |
| 2306 | unsigned long n = off; |
| 2307 | |
| 2308 | if (n > PAGE_SIZE) |
| 2309 | n = PAGE_SIZE; |
| 2310 | if (!dump_write(file, buf, n)) { |
| 2311 | ret = 0; |
| 2312 | break; |
| 2313 | } |
| 2314 | off -= n; |
| 2315 | } |
| 2316 | free_page((unsigned long)buf); |
| 2317 | } |
| 2318 | return ret; |
| 2319 | } |
Linus Torvalds | 8fd01d6 | 2010-10-14 19:15:28 -0700 | [diff] [blame] | 2320 | EXPORT_SYMBOL(dump_seek); |
Al Viro | 282124d | 2012-09-30 13:20:09 -0400 | [diff] [blame^] | 2321 | |
| 2322 | #ifdef __ARCH_WANT_KERNEL_EXECVE |
| 2323 | int kernel_execve(const char *filename, |
| 2324 | const char *const argv[], |
| 2325 | const char *const envp[]) |
| 2326 | { |
| 2327 | struct pt_regs *p = current_pt_regs(); |
| 2328 | int ret; |
| 2329 | |
| 2330 | ret = do_execve(filename, |
| 2331 | (const char __user *const __user *)argv, |
| 2332 | (const char __user *const __user *)envp, p); |
| 2333 | if (ret < 0) |
| 2334 | return ret; |
| 2335 | |
| 2336 | /* |
| 2337 | * We were successful. We won't be returning to our caller, but |
| 2338 | * instead to user space by manipulating the kernel stack. |
| 2339 | */ |
| 2340 | ret_from_kernel_execve(p); |
| 2341 | } |
| 2342 | #endif |