Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/kernel/fork.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | /* |
| 8 | * 'fork.c' contains the help-routines for the 'fork' system call |
| 9 | * (see also entry.S and others). |
| 10 | * Fork is rather simple, once you get the hang of it, but the memory |
| 11 | * management can be a bitch. See 'mm/memory.c': 'copy_page_range()' |
| 12 | */ |
| 13 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | #include <linux/slab.h> |
| 15 | #include <linux/init.h> |
| 16 | #include <linux/unistd.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/module.h> |
| 18 | #include <linux/vmalloc.h> |
| 19 | #include <linux/completion.h> |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 20 | #include <linux/mnt_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #include <linux/personality.h> |
| 22 | #include <linux/mempolicy.h> |
| 23 | #include <linux/sem.h> |
| 24 | #include <linux/file.h> |
Al Viro | 9f3acc3 | 2008-04-24 07:44:08 -0400 | [diff] [blame] | 25 | #include <linux/fdtable.h> |
Jens Axboe | da9cbc8 | 2008-06-30 20:42:08 +0200 | [diff] [blame] | 26 | #include <linux/iocontext.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | #include <linux/key.h> |
| 28 | #include <linux/binfmts.h> |
| 29 | #include <linux/mman.h> |
Andrea Arcangeli | cddb8a5 | 2008-07-28 15:46:29 -0700 | [diff] [blame] | 30 | #include <linux/mmu_notifier.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | #include <linux/fs.h> |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 32 | #include <linux/nsproxy.h> |
Randy.Dunlap | c59ede7 | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 33 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | #include <linux/cpu.h> |
Paul Menage | b4f48b6 | 2007-10-18 23:39:33 -0700 | [diff] [blame] | 35 | #include <linux/cgroup.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | #include <linux/security.h> |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 37 | #include <linux/hugetlb.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | #include <linux/swap.h> |
| 39 | #include <linux/syscalls.h> |
| 40 | #include <linux/jiffies.h> |
Roland McGrath | 09a0539 | 2008-07-25 19:45:47 -0700 | [diff] [blame] | 41 | #include <linux/tracehook.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | #include <linux/futex.h> |
Linus Torvalds | 8141c7f | 2008-11-15 10:20:36 -0800 | [diff] [blame] | 43 | #include <linux/compat.h> |
Andrew Morton | 7c3ab738 | 2006-12-10 02:19:19 -0800 | [diff] [blame] | 44 | #include <linux/task_io_accounting_ops.h> |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 45 | #include <linux/rcupdate.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | #include <linux/ptrace.h> |
| 47 | #include <linux/mount.h> |
| 48 | #include <linux/audit.h> |
Pavel Emelianov | 78fb746 | 2008-02-07 00:13:51 -0800 | [diff] [blame] | 49 | #include <linux/memcontrol.h> |
Frederic Weisbecker | f201ae2 | 2008-11-23 06:22:56 +0100 | [diff] [blame] | 50 | #include <linux/ftrace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | #include <linux/profile.h> |
| 52 | #include <linux/rmap.h> |
| 53 | #include <linux/acct.h> |
Jay Lan | 8f0ab51 | 2006-09-30 23:28:59 -0700 | [diff] [blame] | 54 | #include <linux/tsacct_kern.h> |
Matt Helsley | 9f46080 | 2005-11-07 00:59:16 -0800 | [diff] [blame] | 55 | #include <linux/cn_proc.h> |
Rafael J. Wysocki | ba96a0c | 2007-05-23 13:57:25 -0700 | [diff] [blame] | 56 | #include <linux/freezer.h> |
Shailabh Nagar | ca74e92 | 2006-07-14 00:24:36 -0700 | [diff] [blame] | 57 | #include <linux/delayacct.h> |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame] | 58 | #include <linux/taskstats_kern.h> |
Arjan van de Ven | 0a425405 | 2006-09-26 10:52:38 +0200 | [diff] [blame] | 59 | #include <linux/random.h> |
Miloslav Trmac | 522ed77 | 2007-07-15 23:40:56 -0700 | [diff] [blame] | 60 | #include <linux/tty.h> |
Pavel Emelyanov | 6f4e643 | 2007-10-18 23:40:11 -0700 | [diff] [blame] | 61 | #include <linux/proc_fs.h> |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 62 | #include <linux/blkdev.h> |
Mathieu Desnoyers | 0a16b60 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 63 | #include <trace/sched.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | |
| 65 | #include <asm/pgtable.h> |
| 66 | #include <asm/pgalloc.h> |
| 67 | #include <asm/uaccess.h> |
| 68 | #include <asm/mmu_context.h> |
| 69 | #include <asm/cacheflush.h> |
| 70 | #include <asm/tlbflush.h> |
| 71 | |
| 72 | /* |
| 73 | * Protected counters by write_lock_irq(&tasklist_lock) |
| 74 | */ |
| 75 | unsigned long total_forks; /* Handle normal Linux uptimes. */ |
| 76 | int nr_threads; /* The idle threads do not count.. */ |
| 77 | |
| 78 | int max_threads; /* tunable limit on nr_threads */ |
| 79 | |
| 80 | DEFINE_PER_CPU(unsigned long, process_counts) = 0; |
| 81 | |
Christoph Hellwig | c59923a | 2006-07-10 04:45:40 -0700 | [diff] [blame] | 82 | __cacheline_aligned DEFINE_RWLOCK(tasklist_lock); /* outer */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | |
Mathieu Desnoyers | 7e066fb | 2008-11-14 17:47:47 -0500 | [diff] [blame] | 84 | DEFINE_TRACE(sched_process_fork); |
| 85 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | int nr_processes(void) |
| 87 | { |
| 88 | int cpu; |
| 89 | int total = 0; |
| 90 | |
| 91 | for_each_online_cpu(cpu) |
| 92 | total += per_cpu(process_counts, cpu); |
| 93 | |
| 94 | return total; |
| 95 | } |
| 96 | |
| 97 | #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR |
| 98 | # define alloc_task_struct() kmem_cache_alloc(task_struct_cachep, GFP_KERNEL) |
| 99 | # define free_task_struct(tsk) kmem_cache_free(task_struct_cachep, (tsk)) |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 100 | static struct kmem_cache *task_struct_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | #endif |
| 102 | |
FUJITA Tomonori | b69c49b | 2008-07-25 01:45:40 -0700 | [diff] [blame] | 103 | #ifndef __HAVE_ARCH_THREAD_INFO_ALLOCATOR |
| 104 | static inline struct thread_info *alloc_thread_info(struct task_struct *tsk) |
| 105 | { |
| 106 | #ifdef CONFIG_DEBUG_STACK_USAGE |
| 107 | gfp_t mask = GFP_KERNEL | __GFP_ZERO; |
| 108 | #else |
| 109 | gfp_t mask = GFP_KERNEL; |
| 110 | #endif |
| 111 | return (struct thread_info *)__get_free_pages(mask, THREAD_SIZE_ORDER); |
| 112 | } |
| 113 | |
| 114 | static inline void free_thread_info(struct thread_info *ti) |
| 115 | { |
| 116 | free_pages((unsigned long)ti, THREAD_SIZE_ORDER); |
| 117 | } |
| 118 | #endif |
| 119 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | /* SLAB cache for signal_struct structures (tsk->signal) */ |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 121 | static struct kmem_cache *signal_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | |
| 123 | /* SLAB cache for sighand_struct structures (tsk->sighand) */ |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 124 | struct kmem_cache *sighand_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | |
| 126 | /* SLAB cache for files_struct structures (tsk->files) */ |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 127 | struct kmem_cache *files_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | |
| 129 | /* SLAB cache for fs_struct structures (tsk->fs) */ |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 130 | struct kmem_cache *fs_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | |
| 132 | /* SLAB cache for vm_area_struct structures */ |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 133 | struct kmem_cache *vm_area_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | |
| 135 | /* SLAB cache for mm_struct structures (tsk->mm) */ |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 136 | static struct kmem_cache *mm_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | |
| 138 | void free_task(struct task_struct *tsk) |
| 139 | { |
Peter Zijlstra | 3e26c14 | 2007-10-16 23:25:50 -0700 | [diff] [blame] | 140 | prop_local_destroy_single(&tsk->dirties); |
Roman Zippel | f7e4217 | 2007-05-09 02:35:17 -0700 | [diff] [blame] | 141 | free_thread_info(tsk->stack); |
Ingo Molnar | 23f78d4a | 2006-06-27 02:54:53 -0700 | [diff] [blame] | 142 | rt_mutex_debug_task_free(tsk); |
Frederic Weisbecker | fb52607 | 2008-11-25 21:07:04 +0100 | [diff] [blame] | 143 | ftrace_graph_exit_task(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | free_task_struct(tsk); |
| 145 | } |
| 146 | EXPORT_SYMBOL(free_task); |
| 147 | |
Andrew Morton | 158d9eb | 2006-03-31 02:31:34 -0800 | [diff] [blame] | 148 | void __put_task_struct(struct task_struct *tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | { |
Eugene Teo | 270f722 | 2007-10-18 23:40:38 -0700 | [diff] [blame] | 150 | WARN_ON(!tsk->exit_state); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | WARN_ON(atomic_read(&tsk->usage)); |
| 152 | WARN_ON(tsk == current); |
| 153 | |
David Howells | 3b11a1d | 2008-11-14 10:39:26 +1100 | [diff] [blame] | 154 | put_cred(tsk->real_cred); |
David Howells | f1752ee | 2008-11-14 10:39:17 +1100 | [diff] [blame] | 155 | put_cred(tsk->cred); |
Shailabh Nagar | 35df17c | 2006-08-31 21:27:38 -0700 | [diff] [blame] | 156 | delayacct_tsk_free(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | |
| 158 | if (!profile_handoff_task(tsk)) |
| 159 | free_task(tsk); |
| 160 | } |
| 161 | |
Suresh Siddha | 2adee9b | 2008-04-16 10:25:35 +0200 | [diff] [blame] | 162 | /* |
| 163 | * macro override instead of weak attribute alias, to workaround |
| 164 | * gcc 4.1.0 and 4.1.1 bugs with weak attribute and empty functions. |
| 165 | */ |
| 166 | #ifndef arch_task_cache_init |
| 167 | #define arch_task_cache_init() |
| 168 | #endif |
Suresh Siddha | 61c4628 | 2008-03-10 15:28:04 -0700 | [diff] [blame] | 169 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | void __init fork_init(unsigned long mempages) |
| 171 | { |
| 172 | #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR |
| 173 | #ifndef ARCH_MIN_TASKALIGN |
| 174 | #define ARCH_MIN_TASKALIGN L1_CACHE_BYTES |
| 175 | #endif |
| 176 | /* create a slab on which task_structs can be allocated */ |
| 177 | task_struct_cachep = |
| 178 | kmem_cache_create("task_struct", sizeof(struct task_struct), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 179 | ARCH_MIN_TASKALIGN, SLAB_PANIC, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | #endif |
| 181 | |
Suresh Siddha | 61c4628 | 2008-03-10 15:28:04 -0700 | [diff] [blame] | 182 | /* do the arch specific task caches init */ |
| 183 | arch_task_cache_init(); |
| 184 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | /* |
| 186 | * The default maximum number of threads is set to a safe |
| 187 | * value: the thread structures can take up at most half |
| 188 | * of memory. |
| 189 | */ |
| 190 | max_threads = mempages / (8 * THREAD_SIZE / PAGE_SIZE); |
| 191 | |
| 192 | /* |
| 193 | * we need to allow at least 20 threads to boot a system |
| 194 | */ |
| 195 | if(max_threads < 20) |
| 196 | max_threads = 20; |
| 197 | |
| 198 | init_task.signal->rlim[RLIMIT_NPROC].rlim_cur = max_threads/2; |
| 199 | init_task.signal->rlim[RLIMIT_NPROC].rlim_max = max_threads/2; |
| 200 | init_task.signal->rlim[RLIMIT_SIGPENDING] = |
| 201 | init_task.signal->rlim[RLIMIT_NPROC]; |
| 202 | } |
| 203 | |
Suresh Siddha | 61c4628 | 2008-03-10 15:28:04 -0700 | [diff] [blame] | 204 | int __attribute__((weak)) arch_dup_task_struct(struct task_struct *dst, |
| 205 | struct task_struct *src) |
| 206 | { |
| 207 | *dst = *src; |
| 208 | return 0; |
| 209 | } |
| 210 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | static struct task_struct *dup_task_struct(struct task_struct *orig) |
| 212 | { |
| 213 | struct task_struct *tsk; |
| 214 | struct thread_info *ti; |
Peter Zijlstra | 3e26c14 | 2007-10-16 23:25:50 -0700 | [diff] [blame] | 215 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | |
| 217 | prepare_to_copy(orig); |
| 218 | |
| 219 | tsk = alloc_task_struct(); |
| 220 | if (!tsk) |
| 221 | return NULL; |
| 222 | |
| 223 | ti = alloc_thread_info(tsk); |
| 224 | if (!ti) { |
| 225 | free_task_struct(tsk); |
| 226 | return NULL; |
| 227 | } |
| 228 | |
Suresh Siddha | 61c4628 | 2008-03-10 15:28:04 -0700 | [diff] [blame] | 229 | err = arch_dup_task_struct(tsk, orig); |
| 230 | if (err) |
| 231 | goto out; |
| 232 | |
Roman Zippel | f7e4217 | 2007-05-09 02:35:17 -0700 | [diff] [blame] | 233 | tsk->stack = ti; |
Peter Zijlstra | 3e26c14 | 2007-10-16 23:25:50 -0700 | [diff] [blame] | 234 | |
| 235 | err = prop_local_init_single(&tsk->dirties); |
Suresh Siddha | 61c4628 | 2008-03-10 15:28:04 -0700 | [diff] [blame] | 236 | if (err) |
| 237 | goto out; |
Peter Zijlstra | 3e26c14 | 2007-10-16 23:25:50 -0700 | [diff] [blame] | 238 | |
Al Viro | 10ebffd | 2005-11-13 16:06:56 -0800 | [diff] [blame] | 239 | setup_thread_stack(tsk, orig); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | |
Arjan van de Ven | 0a425405 | 2006-09-26 10:52:38 +0200 | [diff] [blame] | 241 | #ifdef CONFIG_CC_STACKPROTECTOR |
| 242 | tsk->stack_canary = get_random_int(); |
| 243 | #endif |
| 244 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | /* One for us, one for whoever does the "release_task()" (usually parent) */ |
| 246 | atomic_set(&tsk->usage,2); |
Giancarlo Formicuccia | 4b5d37a | 2005-09-09 13:01:22 -0700 | [diff] [blame] | 247 | atomic_set(&tsk->fs_excl, 0); |
Alexey Dobriyan | 6c5c934 | 2006-09-29 01:59:40 -0700 | [diff] [blame] | 248 | #ifdef CONFIG_BLK_DEV_IO_TRACE |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 249 | tsk->btrace_seq = 0; |
Alexey Dobriyan | 6c5c934 | 2006-09-29 01:59:40 -0700 | [diff] [blame] | 250 | #endif |
Jens Axboe | a0aa7f6 | 2006-04-20 13:05:33 +0200 | [diff] [blame] | 251 | tsk->splice_pipe = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 252 | return tsk; |
Suresh Siddha | 61c4628 | 2008-03-10 15:28:04 -0700 | [diff] [blame] | 253 | |
| 254 | out: |
| 255 | free_thread_info(ti); |
| 256 | free_task_struct(tsk); |
| 257 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | } |
| 259 | |
| 260 | #ifdef CONFIG_MMU |
Alexey Dobriyan | a39bc51 | 2007-10-18 23:41:10 -0700 | [diff] [blame] | 261 | static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | { |
Hugh Dickins | fd3e42f | 2005-10-29 18:16:06 -0700 | [diff] [blame] | 263 | struct vm_area_struct *mpnt, *tmp, **pprev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | struct rb_node **rb_link, *rb_parent; |
| 265 | int retval; |
| 266 | unsigned long charge; |
| 267 | struct mempolicy *pol; |
| 268 | |
| 269 | down_write(&oldmm->mmap_sem); |
Ralf Baechle | ec8c044 | 2006-12-12 17:14:57 +0000 | [diff] [blame] | 270 | flush_cache_dup_mm(oldmm); |
Ingo Molnar | ad33945 | 2006-07-03 00:25:15 -0700 | [diff] [blame] | 271 | /* |
| 272 | * Not linked in yet - no deadlock potential: |
| 273 | */ |
| 274 | down_write_nested(&mm->mmap_sem, SINGLE_DEPTH_NESTING); |
Hugh Dickins | 7ee7823 | 2005-10-29 18:16:08 -0700 | [diff] [blame] | 275 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 276 | mm->locked_vm = 0; |
| 277 | mm->mmap = NULL; |
| 278 | mm->mmap_cache = NULL; |
| 279 | mm->free_area_cache = oldmm->mmap_base; |
Wolfgang Wander | 1363c3c | 2005-06-21 17:14:49 -0700 | [diff] [blame] | 280 | mm->cached_hole_size = ~0UL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | mm->map_count = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 282 | cpus_clear(mm->cpu_vm_mask); |
| 283 | mm->mm_rb = RB_ROOT; |
| 284 | rb_link = &mm->mm_rb.rb_node; |
| 285 | rb_parent = NULL; |
| 286 | pprev = &mm->mmap; |
| 287 | |
Hugh Dickins | fd3e42f | 2005-10-29 18:16:06 -0700 | [diff] [blame] | 288 | for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | struct file *file; |
| 290 | |
| 291 | if (mpnt->vm_flags & VM_DONTCOPY) { |
Hugh Dickins | 3b6bfcd | 2005-07-12 13:58:09 -0700 | [diff] [blame] | 292 | long pages = vma_pages(mpnt); |
| 293 | mm->total_vm -= pages; |
Hugh Dickins | ab50b8e | 2005-10-29 18:15:56 -0700 | [diff] [blame] | 294 | vm_stat_account(mm, mpnt->vm_flags, mpnt->vm_file, |
Hugh Dickins | 3b6bfcd | 2005-07-12 13:58:09 -0700 | [diff] [blame] | 295 | -pages); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | continue; |
| 297 | } |
| 298 | charge = 0; |
| 299 | if (mpnt->vm_flags & VM_ACCOUNT) { |
| 300 | unsigned int len = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT; |
| 301 | if (security_vm_enough_memory(len)) |
| 302 | goto fail_nomem; |
| 303 | charge = len; |
| 304 | } |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 305 | tmp = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 306 | if (!tmp) |
| 307 | goto fail_nomem; |
| 308 | *tmp = *mpnt; |
Lee Schermerhorn | 846a16b | 2008-04-28 02:13:09 -0700 | [diff] [blame] | 309 | pol = mpol_dup(vma_policy(mpnt)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | retval = PTR_ERR(pol); |
| 311 | if (IS_ERR(pol)) |
| 312 | goto fail_nomem_policy; |
| 313 | vma_set_policy(tmp, pol); |
| 314 | tmp->vm_flags &= ~VM_LOCKED; |
| 315 | tmp->vm_mm = mm; |
| 316 | tmp->vm_next = NULL; |
| 317 | anon_vma_link(tmp); |
| 318 | file = tmp->vm_file; |
| 319 | if (file) { |
Josef "Jeff" Sipek | f3a43f3 | 2006-12-08 02:36:43 -0800 | [diff] [blame] | 320 | struct inode *inode = file->f_path.dentry->d_inode; |
Hugh Dickins | b88ed20 | 2008-12-10 20:48:52 +0000 | [diff] [blame] | 321 | struct address_space *mapping = file->f_mapping; |
| 322 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | get_file(file); |
| 324 | if (tmp->vm_flags & VM_DENYWRITE) |
| 325 | atomic_dec(&inode->i_writecount); |
Hugh Dickins | b88ed20 | 2008-12-10 20:48:52 +0000 | [diff] [blame] | 326 | spin_lock(&mapping->i_mmap_lock); |
| 327 | if (tmp->vm_flags & VM_SHARED) |
| 328 | mapping->i_mmap_writable++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | tmp->vm_truncate_count = mpnt->vm_truncate_count; |
Hugh Dickins | b88ed20 | 2008-12-10 20:48:52 +0000 | [diff] [blame] | 330 | flush_dcache_mmap_lock(mapping); |
| 331 | /* insert tmp into the share list, just after mpnt */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | vma_prio_tree_add(tmp, mpnt); |
Hugh Dickins | b88ed20 | 2008-12-10 20:48:52 +0000 | [diff] [blame] | 333 | flush_dcache_mmap_unlock(mapping); |
| 334 | spin_unlock(&mapping->i_mmap_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | } |
| 336 | |
| 337 | /* |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 338 | * Clear hugetlb-related page reserves for children. This only |
| 339 | * affects MAP_PRIVATE mappings. Faults generated by the child |
| 340 | * are not guaranteed to succeed, even if read-only |
| 341 | */ |
| 342 | if (is_vm_hugetlb_page(tmp)) |
| 343 | reset_vma_resv_huge_pages(tmp); |
| 344 | |
| 345 | /* |
Hugh Dickins | 7ee7823 | 2005-10-29 18:16:08 -0700 | [diff] [blame] | 346 | * Link in the new vma and copy the page table entries. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | *pprev = tmp; |
| 349 | pprev = &tmp->vm_next; |
| 350 | |
| 351 | __vma_link_rb(mm, tmp, rb_link, rb_parent); |
| 352 | rb_link = &tmp->vm_rb.rb_right; |
| 353 | rb_parent = &tmp->vm_rb; |
| 354 | |
| 355 | mm->map_count++; |
Hugh Dickins | 0b0db14 | 2005-11-21 21:32:20 -0800 | [diff] [blame] | 356 | retval = copy_page_range(mm, oldmm, mpnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | |
| 358 | if (tmp->vm_ops && tmp->vm_ops->open) |
| 359 | tmp->vm_ops->open(tmp); |
| 360 | |
| 361 | if (retval) |
| 362 | goto out; |
| 363 | } |
Jeremy Fitzhardinge | d6dd61c | 2007-05-02 19:27:14 +0200 | [diff] [blame] | 364 | /* a new mm has just been created */ |
| 365 | arch_dup_mmap(oldmm, mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | retval = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | out: |
Hugh Dickins | 7ee7823 | 2005-10-29 18:16:08 -0700 | [diff] [blame] | 368 | up_write(&mm->mmap_sem); |
Hugh Dickins | fd3e42f | 2005-10-29 18:16:06 -0700 | [diff] [blame] | 369 | flush_tlb_mm(oldmm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 370 | up_write(&oldmm->mmap_sem); |
| 371 | return retval; |
| 372 | fail_nomem_policy: |
| 373 | kmem_cache_free(vm_area_cachep, tmp); |
| 374 | fail_nomem: |
| 375 | retval = -ENOMEM; |
| 376 | vm_unacct_memory(charge); |
| 377 | goto out; |
| 378 | } |
| 379 | |
| 380 | static inline int mm_alloc_pgd(struct mm_struct * mm) |
| 381 | { |
| 382 | mm->pgd = pgd_alloc(mm); |
| 383 | if (unlikely(!mm->pgd)) |
| 384 | return -ENOMEM; |
| 385 | return 0; |
| 386 | } |
| 387 | |
| 388 | static inline void mm_free_pgd(struct mm_struct * mm) |
| 389 | { |
Benjamin Herrenschmidt | 5e54197 | 2008-02-04 22:29:14 -0800 | [diff] [blame] | 390 | pgd_free(mm, mm->pgd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | } |
| 392 | #else |
| 393 | #define dup_mmap(mm, oldmm) (0) |
| 394 | #define mm_alloc_pgd(mm) (0) |
| 395 | #define mm_free_pgd(mm) |
| 396 | #endif /* CONFIG_MMU */ |
| 397 | |
Daniel Walker | 23ff444 | 2007-10-18 03:06:07 -0700 | [diff] [blame] | 398 | __cacheline_aligned_in_smp DEFINE_SPINLOCK(mmlist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 400 | #define allocate_mm() (kmem_cache_alloc(mm_cachep, GFP_KERNEL)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | #define free_mm(mm) (kmem_cache_free(mm_cachep, (mm))) |
| 402 | |
Hidehiro Kawai | 4cb0e11 | 2009-01-06 14:42:47 -0800 | [diff] [blame] | 403 | static unsigned long default_dump_filter = MMF_DUMP_FILTER_DEFAULT; |
| 404 | |
| 405 | static int __init coredump_filter_setup(char *s) |
| 406 | { |
| 407 | default_dump_filter = |
| 408 | (simple_strtoul(s, NULL, 0) << MMF_DUMP_FILTER_SHIFT) & |
| 409 | MMF_DUMP_FILTER_MASK; |
| 410 | return 1; |
| 411 | } |
| 412 | |
| 413 | __setup("coredump_filter=", coredump_filter_setup); |
| 414 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | #include <linux/init_task.h> |
| 416 | |
Pavel Emelianov | 78fb746 | 2008-02-07 00:13:51 -0800 | [diff] [blame] | 417 | static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | { |
| 419 | atomic_set(&mm->mm_users, 1); |
| 420 | atomic_set(&mm->mm_count, 1); |
| 421 | init_rwsem(&mm->mmap_sem); |
| 422 | INIT_LIST_HEAD(&mm->mmlist); |
Hidehiro Kawai | 4cb0e11 | 2009-01-06 14:42:47 -0800 | [diff] [blame] | 423 | mm->flags = (current->mm) ? current->mm->flags : default_dump_filter; |
Oleg Nesterov | 999d9fc | 2008-07-25 01:47:41 -0700 | [diff] [blame] | 424 | mm->core_state = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 425 | mm->nr_ptes = 0; |
Hugh Dickins | 4294621 | 2005-10-29 18:16:05 -0700 | [diff] [blame] | 426 | set_mm_counter(mm, file_rss, 0); |
Hugh Dickins | 404351e | 2005-10-29 18:16:04 -0700 | [diff] [blame] | 427 | set_mm_counter(mm, anon_rss, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | spin_lock_init(&mm->page_table_lock); |
Jens Axboe | abf137d | 2008-12-09 08:11:22 +0100 | [diff] [blame] | 429 | spin_lock_init(&mm->ioctx_lock); |
| 430 | INIT_HLIST_HEAD(&mm->ioctx_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | mm->free_area_cache = TASK_UNMAPPED_BASE; |
Wolfgang Wander | 1363c3c | 2005-06-21 17:14:49 -0700 | [diff] [blame] | 432 | mm->cached_hole_size = ~0UL; |
Balbir Singh | cf475ad | 2008-04-29 01:00:16 -0700 | [diff] [blame] | 433 | mm_init_owner(mm, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | |
| 435 | if (likely(!mm_alloc_pgd(mm))) { |
| 436 | mm->def_flags = 0; |
Andrea Arcangeli | cddb8a5 | 2008-07-28 15:46:29 -0700 | [diff] [blame] | 437 | mmu_notifier_mm_init(mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | return mm; |
| 439 | } |
Pavel Emelianov | 78fb746 | 2008-02-07 00:13:51 -0800 | [diff] [blame] | 440 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | free_mm(mm); |
| 442 | return NULL; |
| 443 | } |
| 444 | |
| 445 | /* |
| 446 | * Allocate and initialize an mm_struct. |
| 447 | */ |
| 448 | struct mm_struct * mm_alloc(void) |
| 449 | { |
| 450 | struct mm_struct * mm; |
| 451 | |
| 452 | mm = allocate_mm(); |
| 453 | if (mm) { |
| 454 | memset(mm, 0, sizeof(*mm)); |
Pavel Emelianov | 78fb746 | 2008-02-07 00:13:51 -0800 | [diff] [blame] | 455 | mm = mm_init(mm, current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | } |
| 457 | return mm; |
| 458 | } |
| 459 | |
| 460 | /* |
| 461 | * Called when the last reference to the mm |
| 462 | * is dropped: either by a lazy thread or by |
| 463 | * mmput. Free the page directory and the mm. |
| 464 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 465 | void __mmdrop(struct mm_struct *mm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | { |
| 467 | BUG_ON(mm == &init_mm); |
| 468 | mm_free_pgd(mm); |
| 469 | destroy_context(mm); |
Andrea Arcangeli | cddb8a5 | 2008-07-28 15:46:29 -0700 | [diff] [blame] | 470 | mmu_notifier_mm_destroy(mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | free_mm(mm); |
| 472 | } |
Avi Kivity | 6d4e4c4 | 2007-11-21 16:41:05 +0200 | [diff] [blame] | 473 | EXPORT_SYMBOL_GPL(__mmdrop); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 474 | |
| 475 | /* |
| 476 | * Decrement the use count and release all resources for an mm. |
| 477 | */ |
| 478 | void mmput(struct mm_struct *mm) |
| 479 | { |
Andrew Morton | 0ae26f1 | 2006-06-23 02:05:15 -0700 | [diff] [blame] | 480 | might_sleep(); |
| 481 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | if (atomic_dec_and_test(&mm->mm_users)) { |
| 483 | exit_aio(mm); |
| 484 | exit_mmap(mm); |
Matt Helsley | 925d1c4 | 2008-04-29 01:01:36 -0700 | [diff] [blame] | 485 | set_mm_exe_file(mm, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | if (!list_empty(&mm->mmlist)) { |
| 487 | spin_lock(&mmlist_lock); |
| 488 | list_del(&mm->mmlist); |
| 489 | spin_unlock(&mmlist_lock); |
| 490 | } |
| 491 | put_swap_token(mm); |
| 492 | mmdrop(mm); |
| 493 | } |
| 494 | } |
| 495 | EXPORT_SYMBOL_GPL(mmput); |
| 496 | |
| 497 | /** |
| 498 | * get_task_mm - acquire a reference to the task's mm |
| 499 | * |
Oleg Nesterov | 246bb0b | 2008-07-25 01:47:38 -0700 | [diff] [blame] | 500 | * Returns %NULL if the task has no mm. Checks PF_KTHREAD (meaning |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 501 | * this kernel workthread has transiently adopted a user mm with use_mm, |
| 502 | * to do its AIO) is not set and if so returns a reference to it, after |
| 503 | * bumping up the use count. User must release the mm via mmput() |
| 504 | * after use. Typically used by /proc and ptrace. |
| 505 | */ |
| 506 | struct mm_struct *get_task_mm(struct task_struct *task) |
| 507 | { |
| 508 | struct mm_struct *mm; |
| 509 | |
| 510 | task_lock(task); |
| 511 | mm = task->mm; |
| 512 | if (mm) { |
Oleg Nesterov | 246bb0b | 2008-07-25 01:47:38 -0700 | [diff] [blame] | 513 | if (task->flags & PF_KTHREAD) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | mm = NULL; |
| 515 | else |
| 516 | atomic_inc(&mm->mm_users); |
| 517 | } |
| 518 | task_unlock(task); |
| 519 | return mm; |
| 520 | } |
| 521 | EXPORT_SYMBOL_GPL(get_task_mm); |
| 522 | |
| 523 | /* Please note the differences between mmput and mm_release. |
| 524 | * mmput is called whenever we stop holding onto a mm_struct, |
| 525 | * error success whatever. |
| 526 | * |
| 527 | * mm_release is called after a mm_struct has been removed |
| 528 | * from the current process. |
| 529 | * |
| 530 | * This difference is important for error handling, when we |
| 531 | * only half set up a mm_struct for a new process and need to restore |
| 532 | * the old one. Because we mmput the new mm_struct before |
| 533 | * restoring the old one. . . |
| 534 | * Eric Biederman 10 January 1998 |
| 535 | */ |
| 536 | void mm_release(struct task_struct *tsk, struct mm_struct *mm) |
| 537 | { |
| 538 | struct completion *vfork_done = tsk->vfork_done; |
| 539 | |
Linus Torvalds | 8141c7f | 2008-11-15 10:20:36 -0800 | [diff] [blame] | 540 | /* Get rid of any futexes when releasing the mm */ |
| 541 | #ifdef CONFIG_FUTEX |
| 542 | if (unlikely(tsk->robust_list)) |
| 543 | exit_robust_list(tsk); |
| 544 | #ifdef CONFIG_COMPAT |
| 545 | if (unlikely(tsk->compat_robust_list)) |
| 546 | compat_exit_robust_list(tsk); |
| 547 | #endif |
| 548 | #endif |
| 549 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 550 | /* Get rid of any cached register state */ |
| 551 | deactivate_mm(tsk, mm); |
| 552 | |
| 553 | /* notify parent sleeping on vfork() */ |
| 554 | if (vfork_done) { |
| 555 | tsk->vfork_done = NULL; |
| 556 | complete(vfork_done); |
| 557 | } |
Roland McGrath | fec1d01 | 2006-12-06 20:36:34 -0800 | [diff] [blame] | 558 | |
| 559 | /* |
| 560 | * If we're exiting normally, clear a user-space tid field if |
| 561 | * requested. We leave this alone when dying by signal, to leave |
| 562 | * the value intact in a core dump, and to save the unnecessary |
| 563 | * trouble otherwise. Userland only wants this done for a sys_exit. |
| 564 | */ |
| 565 | if (tsk->clear_child_tid |
| 566 | && !(tsk->flags & PF_SIGNALED) |
| 567 | && atomic_read(&mm->mm_users) > 1) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 568 | u32 __user * tidptr = tsk->clear_child_tid; |
| 569 | tsk->clear_child_tid = NULL; |
| 570 | |
| 571 | /* |
| 572 | * We don't check the error code - if userspace has |
| 573 | * not set up a proper pointer then tough luck. |
| 574 | */ |
| 575 | put_user(0, tidptr); |
| 576 | sys_futex(tidptr, FUTEX_WAKE, 1, NULL, NULL, 0); |
| 577 | } |
| 578 | } |
| 579 | |
JANAK DESAI | a0a7ec3 | 2006-02-07 12:59:01 -0800 | [diff] [blame] | 580 | /* |
| 581 | * Allocate a new mm structure and copy contents from the |
| 582 | * mm structure of the passed in task structure. |
| 583 | */ |
Carsten Otte | 402b086 | 2008-03-25 18:47:10 +0100 | [diff] [blame] | 584 | struct mm_struct *dup_mm(struct task_struct *tsk) |
JANAK DESAI | a0a7ec3 | 2006-02-07 12:59:01 -0800 | [diff] [blame] | 585 | { |
| 586 | struct mm_struct *mm, *oldmm = current->mm; |
| 587 | int err; |
| 588 | |
| 589 | if (!oldmm) |
| 590 | return NULL; |
| 591 | |
| 592 | mm = allocate_mm(); |
| 593 | if (!mm) |
| 594 | goto fail_nomem; |
| 595 | |
| 596 | memcpy(mm, oldmm, sizeof(*mm)); |
| 597 | |
Ashwin Chaugule | 7602bdf | 2006-12-06 20:31:57 -0800 | [diff] [blame] | 598 | /* Initializing for Swap token stuff */ |
| 599 | mm->token_priority = 0; |
| 600 | mm->last_interval = 0; |
| 601 | |
Pavel Emelianov | 78fb746 | 2008-02-07 00:13:51 -0800 | [diff] [blame] | 602 | if (!mm_init(mm, tsk)) |
JANAK DESAI | a0a7ec3 | 2006-02-07 12:59:01 -0800 | [diff] [blame] | 603 | goto fail_nomem; |
| 604 | |
| 605 | if (init_new_context(tsk, mm)) |
| 606 | goto fail_nocontext; |
| 607 | |
Matt Helsley | 925d1c4 | 2008-04-29 01:01:36 -0700 | [diff] [blame] | 608 | dup_mm_exe_file(oldmm, mm); |
| 609 | |
JANAK DESAI | a0a7ec3 | 2006-02-07 12:59:01 -0800 | [diff] [blame] | 610 | err = dup_mmap(mm, oldmm); |
| 611 | if (err) |
| 612 | goto free_pt; |
| 613 | |
| 614 | mm->hiwater_rss = get_mm_rss(mm); |
| 615 | mm->hiwater_vm = mm->total_vm; |
| 616 | |
| 617 | return mm; |
| 618 | |
| 619 | free_pt: |
| 620 | mmput(mm); |
| 621 | |
| 622 | fail_nomem: |
| 623 | return NULL; |
| 624 | |
| 625 | fail_nocontext: |
| 626 | /* |
| 627 | * If init_new_context() failed, we cannot use mmput() to free the mm |
| 628 | * because it calls destroy_context() |
| 629 | */ |
| 630 | mm_free_pgd(mm); |
| 631 | free_mm(mm); |
| 632 | return NULL; |
| 633 | } |
| 634 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 635 | static int copy_mm(unsigned long clone_flags, struct task_struct * tsk) |
| 636 | { |
| 637 | struct mm_struct * mm, *oldmm; |
| 638 | int retval; |
| 639 | |
| 640 | tsk->min_flt = tsk->maj_flt = 0; |
| 641 | tsk->nvcsw = tsk->nivcsw = 0; |
| 642 | |
| 643 | tsk->mm = NULL; |
| 644 | tsk->active_mm = NULL; |
| 645 | |
| 646 | /* |
| 647 | * Are we cloning a kernel thread? |
| 648 | * |
| 649 | * We need to steal a active VM for that.. |
| 650 | */ |
| 651 | oldmm = current->mm; |
| 652 | if (!oldmm) |
| 653 | return 0; |
| 654 | |
| 655 | if (clone_flags & CLONE_VM) { |
| 656 | atomic_inc(&oldmm->mm_users); |
| 657 | mm = oldmm; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 658 | goto good_mm; |
| 659 | } |
| 660 | |
| 661 | retval = -ENOMEM; |
JANAK DESAI | a0a7ec3 | 2006-02-07 12:59:01 -0800 | [diff] [blame] | 662 | mm = dup_mm(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | if (!mm) |
| 664 | goto fail_nomem; |
| 665 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | good_mm: |
Ashwin Chaugule | 7602bdf | 2006-12-06 20:31:57 -0800 | [diff] [blame] | 667 | /* Initializing for Swap token stuff */ |
| 668 | mm->token_priority = 0; |
| 669 | mm->last_interval = 0; |
| 670 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | tsk->mm = mm; |
| 672 | tsk->active_mm = mm; |
| 673 | return 0; |
| 674 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | fail_nomem: |
| 676 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | } |
| 678 | |
Alexey Dobriyan | a39bc51 | 2007-10-18 23:41:10 -0700 | [diff] [blame] | 679 | static struct fs_struct *__copy_fs_struct(struct fs_struct *old) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 680 | { |
| 681 | struct fs_struct *fs = kmem_cache_alloc(fs_cachep, GFP_KERNEL); |
| 682 | /* We don't need to lock fs - think why ;-) */ |
| 683 | if (fs) { |
| 684 | atomic_set(&fs->count, 1); |
| 685 | rwlock_init(&fs->lock); |
| 686 | fs->umask = old->umask; |
| 687 | read_lock(&old->lock); |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 688 | fs->root = old->root; |
| 689 | path_get(&old->root); |
| 690 | fs->pwd = old->pwd; |
| 691 | path_get(&old->pwd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 692 | read_unlock(&old->lock); |
| 693 | } |
| 694 | return fs; |
| 695 | } |
| 696 | |
| 697 | struct fs_struct *copy_fs_struct(struct fs_struct *old) |
| 698 | { |
| 699 | return __copy_fs_struct(old); |
| 700 | } |
| 701 | |
| 702 | EXPORT_SYMBOL_GPL(copy_fs_struct); |
| 703 | |
Alexey Dobriyan | a39bc51 | 2007-10-18 23:41:10 -0700 | [diff] [blame] | 704 | static int copy_fs(unsigned long clone_flags, struct task_struct *tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | { |
| 706 | if (clone_flags & CLONE_FS) { |
| 707 | atomic_inc(¤t->fs->count); |
| 708 | return 0; |
| 709 | } |
| 710 | tsk->fs = __copy_fs_struct(current->fs); |
| 711 | if (!tsk->fs) |
| 712 | return -ENOMEM; |
| 713 | return 0; |
| 714 | } |
| 715 | |
JANAK DESAI | a016f33 | 2006-02-07 12:59:02 -0800 | [diff] [blame] | 716 | static int copy_files(unsigned long clone_flags, struct task_struct * tsk) |
| 717 | { |
| 718 | struct files_struct *oldf, *newf; |
| 719 | int error = 0; |
| 720 | |
| 721 | /* |
| 722 | * A background process may not have any files ... |
| 723 | */ |
| 724 | oldf = current->files; |
| 725 | if (!oldf) |
| 726 | goto out; |
| 727 | |
| 728 | if (clone_flags & CLONE_FILES) { |
| 729 | atomic_inc(&oldf->count); |
| 730 | goto out; |
| 731 | } |
| 732 | |
JANAK DESAI | a016f33 | 2006-02-07 12:59:02 -0800 | [diff] [blame] | 733 | newf = dup_fd(oldf, &error); |
| 734 | if (!newf) |
| 735 | goto out; |
| 736 | |
| 737 | tsk->files = newf; |
| 738 | error = 0; |
| 739 | out: |
| 740 | return error; |
| 741 | } |
| 742 | |
Jens Axboe | fadad878 | 2008-01-24 08:54:47 +0100 | [diff] [blame] | 743 | static int copy_io(unsigned long clone_flags, struct task_struct *tsk) |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 744 | { |
| 745 | #ifdef CONFIG_BLOCK |
| 746 | struct io_context *ioc = current->io_context; |
| 747 | |
| 748 | if (!ioc) |
| 749 | return 0; |
Jens Axboe | fadad878 | 2008-01-24 08:54:47 +0100 | [diff] [blame] | 750 | /* |
| 751 | * Share io context with parent, if CLONE_IO is set |
| 752 | */ |
| 753 | if (clone_flags & CLONE_IO) { |
| 754 | tsk->io_context = ioc_task_link(ioc); |
| 755 | if (unlikely(!tsk->io_context)) |
| 756 | return -ENOMEM; |
| 757 | } else if (ioprio_valid(ioc->ioprio)) { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 758 | tsk->io_context = alloc_io_context(GFP_KERNEL, -1); |
| 759 | if (unlikely(!tsk->io_context)) |
| 760 | return -ENOMEM; |
| 761 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 762 | tsk->io_context->ioprio = ioc->ioprio; |
| 763 | } |
| 764 | #endif |
| 765 | return 0; |
| 766 | } |
| 767 | |
Alexey Dobriyan | a39bc51 | 2007-10-18 23:41:10 -0700 | [diff] [blame] | 768 | static int copy_sighand(unsigned long clone_flags, struct task_struct *tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 769 | { |
| 770 | struct sighand_struct *sig; |
| 771 | |
Zhaolei | 6034880 | 2009-01-06 14:40:46 -0800 | [diff] [blame] | 772 | if (clone_flags & CLONE_SIGHAND) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | atomic_inc(¤t->sighand->count); |
| 774 | return 0; |
| 775 | } |
| 776 | sig = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); |
Ingo Molnar | e56d090 | 2006-01-08 01:01:37 -0800 | [diff] [blame] | 777 | rcu_assign_pointer(tsk->sighand, sig); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | if (!sig) |
| 779 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 780 | atomic_set(&sig->count, 1); |
| 781 | memcpy(sig->action, current->sighand->action, sizeof(sig->action)); |
| 782 | return 0; |
| 783 | } |
| 784 | |
Oleg Nesterov | a7e5328 | 2006-03-28 16:11:27 -0800 | [diff] [blame] | 785 | void __cleanup_sighand(struct sighand_struct *sighand) |
Oleg Nesterov | c81addc | 2006-03-28 16:11:17 -0800 | [diff] [blame] | 786 | { |
Oleg Nesterov | c81addc | 2006-03-28 16:11:17 -0800 | [diff] [blame] | 787 | if (atomic_dec_and_test(&sighand->count)) |
| 788 | kmem_cache_free(sighand_cachep, sighand); |
| 789 | } |
| 790 | |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 791 | |
| 792 | /* |
| 793 | * Initialize POSIX timer handling for a thread group. |
| 794 | */ |
| 795 | static void posix_cpu_timers_init_group(struct signal_struct *sig) |
| 796 | { |
| 797 | /* Thread group counters. */ |
| 798 | thread_group_cputime_init(sig); |
| 799 | |
| 800 | /* Expiration times and increments. */ |
| 801 | sig->it_virt_expires = cputime_zero; |
| 802 | sig->it_virt_incr = cputime_zero; |
| 803 | sig->it_prof_expires = cputime_zero; |
| 804 | sig->it_prof_incr = cputime_zero; |
| 805 | |
| 806 | /* Cached expiration times. */ |
| 807 | sig->cputime_expires.prof_exp = cputime_zero; |
| 808 | sig->cputime_expires.virt_exp = cputime_zero; |
| 809 | sig->cputime_expires.sched_exp = 0; |
| 810 | |
| 811 | /* The timer lists. */ |
| 812 | INIT_LIST_HEAD(&sig->cpu_timers[0]); |
| 813 | INIT_LIST_HEAD(&sig->cpu_timers[1]); |
| 814 | INIT_LIST_HEAD(&sig->cpu_timers[2]); |
| 815 | } |
| 816 | |
Alexey Dobriyan | a39bc51 | 2007-10-18 23:41:10 -0700 | [diff] [blame] | 817 | static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 818 | { |
| 819 | struct signal_struct *sig; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 820 | |
| 821 | if (clone_flags & CLONE_THREAD) { |
Peter Zijlstra | 490dea4 | 2008-11-24 17:06:57 +0100 | [diff] [blame] | 822 | atomic_inc(¤t->signal->count); |
| 823 | atomic_inc(¤t->signal->live); |
| 824 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 825 | } |
| 826 | sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL); |
Peter Zijlstra | 490dea4 | 2008-11-24 17:06:57 +0100 | [diff] [blame] | 827 | |
| 828 | if (sig) |
| 829 | posix_cpu_timers_init_group(sig); |
| 830 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 831 | tsk->signal = sig; |
| 832 | if (!sig) |
| 833 | return -ENOMEM; |
| 834 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 835 | atomic_set(&sig->count, 1); |
| 836 | atomic_set(&sig->live, 1); |
| 837 | init_waitqueue_head(&sig->wait_chldexit); |
| 838 | sig->flags = 0; |
| 839 | sig->group_exit_code = 0; |
| 840 | sig->group_exit_task = NULL; |
| 841 | sig->group_stop_count = 0; |
Oleg Nesterov | db51aec | 2008-04-30 00:52:52 -0700 | [diff] [blame] | 842 | sig->curr_target = tsk; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 843 | init_sigpending(&sig->shared_pending); |
| 844 | INIT_LIST_HEAD(&sig->posix_timers); |
| 845 | |
Thomas Gleixner | c9cb2e3 | 2007-02-16 01:27:49 -0800 | [diff] [blame] | 846 | hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
Thomas Gleixner | 2ff678b | 2006-01-09 20:52:34 -0800 | [diff] [blame] | 847 | sig->it_real_incr.tv64 = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 848 | sig->real_timer.function = it_real_fn; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 849 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | sig->leader = 0; /* session leadership doesn't inherit */ |
Eric W. Biederman | ab521dc | 2007-02-12 00:53:00 -0800 | [diff] [blame] | 851 | sig->tty_old_pgrp = NULL; |
Alan Cox | 9c9f4de | 2008-10-13 10:37:26 +0100 | [diff] [blame] | 852 | sig->tty = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 853 | |
Peter Zijlstra | 32bd671 | 2009-02-05 12:24:15 +0100 | [diff] [blame] | 854 | sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero; |
Laurent Vivier | 9ac5231 | 2007-10-15 17:00:19 +0200 | [diff] [blame] | 855 | sig->gtime = cputime_zero; |
| 856 | sig->cgtime = cputime_zero; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 857 | sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0; |
| 858 | sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0; |
Eric Dumazet | 6eaeeab | 2007-05-10 22:22:37 -0700 | [diff] [blame] | 859 | sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0; |
Andrea Righi | 5995477 | 2008-07-27 17:29:15 +0200 | [diff] [blame] | 860 | task_io_accounting_init(&sig->ioac); |
Peter Zijlstra | 32bd671 | 2009-02-05 12:24:15 +0100 | [diff] [blame] | 861 | sig->sum_sched_runtime = 0; |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame] | 862 | taskstats_tgid_init(sig); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 863 | |
| 864 | task_lock(current->group_leader); |
| 865 | memcpy(sig->rlim, current->signal->rlim, sizeof sig->rlim); |
| 866 | task_unlock(current->group_leader); |
| 867 | |
KaiGai Kohei | 0e46481 | 2006-06-25 05:49:24 -0700 | [diff] [blame] | 868 | acct_init_pacct(&sig->pacct); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 869 | |
Miloslav Trmac | 522ed77 | 2007-07-15 23:40:56 -0700 | [diff] [blame] | 870 | tty_audit_fork(sig); |
| 871 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 872 | return 0; |
| 873 | } |
| 874 | |
Oleg Nesterov | 6b3934ef | 2006-03-28 16:11:16 -0800 | [diff] [blame] | 875 | void __cleanup_signal(struct signal_struct *sig) |
| 876 | { |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 877 | thread_group_cputime_free(sig); |
Alan Cox | 9c9f4de | 2008-10-13 10:37:26 +0100 | [diff] [blame] | 878 | tty_kref_put(sig->tty); |
Oleg Nesterov | 6b3934ef | 2006-03-28 16:11:16 -0800 | [diff] [blame] | 879 | kmem_cache_free(signal_cachep, sig); |
| 880 | } |
| 881 | |
Alexey Dobriyan | a39bc51 | 2007-10-18 23:41:10 -0700 | [diff] [blame] | 882 | static void cleanup_signal(struct task_struct *tsk) |
Oleg Nesterov | 6b3934ef | 2006-03-28 16:11:16 -0800 | [diff] [blame] | 883 | { |
| 884 | struct signal_struct *sig = tsk->signal; |
| 885 | |
| 886 | atomic_dec(&sig->live); |
| 887 | |
| 888 | if (atomic_dec_and_test(&sig->count)) |
| 889 | __cleanup_signal(sig); |
| 890 | } |
| 891 | |
Alexey Dobriyan | a39bc51 | 2007-10-18 23:41:10 -0700 | [diff] [blame] | 892 | static void copy_flags(unsigned long clone_flags, struct task_struct *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 893 | { |
| 894 | unsigned long new_flags = p->flags; |
| 895 | |
Rafael J. Wysocki | 8314418 | 2007-07-17 04:03:35 -0700 | [diff] [blame] | 896 | new_flags &= ~PF_SUPERPRIV; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 897 | new_flags |= PF_FORKNOEXEC; |
Roland McGrath | 09a0539 | 2008-07-25 19:45:47 -0700 | [diff] [blame] | 898 | new_flags |= PF_STARTING; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 899 | p->flags = new_flags; |
Rafael J. Wysocki | 2e13189 | 2007-10-18 03:04:45 -0700 | [diff] [blame] | 900 | clear_freeze_flag(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 901 | } |
| 902 | |
Heiko Carstens | 17da2bd | 2009-01-14 14:14:10 +0100 | [diff] [blame] | 903 | SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 904 | { |
| 905 | current->clear_child_tid = tidptr; |
| 906 | |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 907 | return task_pid_vnr(current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 908 | } |
| 909 | |
Alexey Dobriyan | a39bc51 | 2007-10-18 23:41:10 -0700 | [diff] [blame] | 910 | static void rt_mutex_init_task(struct task_struct *p) |
Ingo Molnar | 23f78d4a | 2006-06-27 02:54:53 -0700 | [diff] [blame] | 911 | { |
Ingo Molnar | 23f78d4a | 2006-06-27 02:54:53 -0700 | [diff] [blame] | 912 | spin_lock_init(&p->pi_lock); |
Zilvinas Valinskas | e29e175 | 2007-03-16 13:38:34 -0800 | [diff] [blame] | 913 | #ifdef CONFIG_RT_MUTEXES |
Ingo Molnar | 23f78d4a | 2006-06-27 02:54:53 -0700 | [diff] [blame] | 914 | plist_head_init(&p->pi_waiters, &p->pi_lock); |
| 915 | p->pi_blocked_on = NULL; |
Ingo Molnar | 23f78d4a | 2006-06-27 02:54:53 -0700 | [diff] [blame] | 916 | #endif |
| 917 | } |
| 918 | |
Balbir Singh | cf475ad | 2008-04-29 01:00:16 -0700 | [diff] [blame] | 919 | #ifdef CONFIG_MM_OWNER |
| 920 | void mm_init_owner(struct mm_struct *mm, struct task_struct *p) |
| 921 | { |
| 922 | mm->owner = p; |
| 923 | } |
| 924 | #endif /* CONFIG_MM_OWNER */ |
| 925 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 926 | /* |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 927 | * Initialize POSIX timer handling for a single task. |
| 928 | */ |
| 929 | static void posix_cpu_timers_init(struct task_struct *tsk) |
| 930 | { |
| 931 | tsk->cputime_expires.prof_exp = cputime_zero; |
| 932 | tsk->cputime_expires.virt_exp = cputime_zero; |
| 933 | tsk->cputime_expires.sched_exp = 0; |
| 934 | INIT_LIST_HEAD(&tsk->cpu_timers[0]); |
| 935 | INIT_LIST_HEAD(&tsk->cpu_timers[1]); |
| 936 | INIT_LIST_HEAD(&tsk->cpu_timers[2]); |
| 937 | } |
| 938 | |
| 939 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 940 | * This creates a new process as a copy of the old one, |
| 941 | * but does not actually start it yet. |
| 942 | * |
| 943 | * It copies the registers, and all the appropriate |
| 944 | * parts of the process environment (as per the clone |
| 945 | * flags). The actual kick-off is left to the caller. |
| 946 | */ |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 947 | static struct task_struct *copy_process(unsigned long clone_flags, |
| 948 | unsigned long stack_start, |
| 949 | struct pt_regs *regs, |
| 950 | unsigned long stack_size, |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 951 | int __user *child_tidptr, |
Roland McGrath | 09a0539 | 2008-07-25 19:45:47 -0700 | [diff] [blame] | 952 | struct pid *pid, |
| 953 | int trace) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 954 | { |
| 955 | int retval; |
Mariusz Kozlowski | a24efe6 | 2007-10-18 23:41:09 -0700 | [diff] [blame] | 956 | struct task_struct *p; |
Paul Menage | b4f48b6 | 2007-10-18 23:39:33 -0700 | [diff] [blame] | 957 | int cgroup_callbacks_done = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 958 | |
| 959 | if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS)) |
| 960 | return ERR_PTR(-EINVAL); |
| 961 | |
| 962 | /* |
| 963 | * Thread groups must share signals as well, and detached threads |
| 964 | * can only be started up within the thread group. |
| 965 | */ |
| 966 | if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND)) |
| 967 | return ERR_PTR(-EINVAL); |
| 968 | |
| 969 | /* |
| 970 | * Shared signal handlers imply shared VM. By way of the above, |
| 971 | * thread groups also imply shared VM. Blocking this case allows |
| 972 | * for various simplifications in other code. |
| 973 | */ |
| 974 | if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM)) |
| 975 | return ERR_PTR(-EINVAL); |
| 976 | |
| 977 | retval = security_task_create(clone_flags); |
| 978 | if (retval) |
| 979 | goto fork_out; |
| 980 | |
| 981 | retval = -ENOMEM; |
| 982 | p = dup_task_struct(current); |
| 983 | if (!p) |
| 984 | goto fork_out; |
| 985 | |
Peter Zijlstra | bea493a | 2006-10-17 00:10:33 -0700 | [diff] [blame] | 986 | rt_mutex_init_task(p); |
| 987 | |
Ingo Molnar | d12c1a3 | 2008-07-14 12:09:28 +0200 | [diff] [blame] | 988 | #ifdef CONFIG_PROVE_LOCKING |
Ingo Molnar | de30a2b | 2006-07-03 00:24:42 -0700 | [diff] [blame] | 989 | DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled); |
| 990 | DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled); |
| 991 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 992 | retval = -EAGAIN; |
David Howells | 3b11a1d | 2008-11-14 10:39:26 +1100 | [diff] [blame] | 993 | if (atomic_read(&p->real_cred->user->processes) >= |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 994 | p->signal->rlim[RLIMIT_NPROC].rlim_cur) { |
| 995 | if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) && |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 996 | p->real_cred->user != INIT_USER) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 997 | goto bad_fork_free; |
| 998 | } |
| 999 | |
David Howells | f1752ee | 2008-11-14 10:39:17 +1100 | [diff] [blame] | 1000 | retval = copy_creds(p, clone_flags); |
| 1001 | if (retval < 0) |
| 1002 | goto bad_fork_free; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1003 | |
| 1004 | /* |
| 1005 | * If multiple threads are within copy_process(), then this check |
| 1006 | * triggers too late. This doesn't hurt, the check is only there |
| 1007 | * to stop root fork bombs. |
| 1008 | */ |
Li Zefan | 04ec93f | 2009-02-06 08:17:19 +0000 | [diff] [blame] | 1009 | retval = -EAGAIN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1010 | if (nr_threads >= max_threads) |
| 1011 | goto bad_fork_cleanup_count; |
| 1012 | |
Al Viro | a1261f54 | 2005-11-13 16:06:55 -0800 | [diff] [blame] | 1013 | if (!try_module_get(task_thread_info(p)->exec_domain->module)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1014 | goto bad_fork_cleanup_count; |
| 1015 | |
| 1016 | if (p->binfmt && !try_module_get(p->binfmt->module)) |
| 1017 | goto bad_fork_cleanup_put_domain; |
| 1018 | |
| 1019 | p->did_exec = 0; |
Shailabh Nagar | ca74e92 | 2006-07-14 00:24:36 -0700 | [diff] [blame] | 1020 | delayacct_tsk_init(p); /* Must remain after dup_task_struct() */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1021 | copy_flags(clone_flags, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1022 | INIT_LIST_HEAD(&p->children); |
| 1023 | INIT_LIST_HEAD(&p->sibling); |
Paul E. McKenney | e260be6 | 2008-01-25 21:08:24 +0100 | [diff] [blame] | 1024 | #ifdef CONFIG_PREEMPT_RCU |
| 1025 | p->rcu_read_lock_nesting = 0; |
| 1026 | p->rcu_flipctr_idx = 0; |
| 1027 | #endif /* #ifdef CONFIG_PREEMPT_RCU */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1028 | p->vfork_done = NULL; |
| 1029 | spin_lock_init(&p->alloc_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | |
| 1031 | clear_tsk_thread_flag(p, TIF_SIGPENDING); |
| 1032 | init_sigpending(&p->pending); |
| 1033 | |
| 1034 | p->utime = cputime_zero; |
| 1035 | p->stime = cputime_zero; |
Laurent Vivier | 9ac5231 | 2007-10-15 17:00:19 +0200 | [diff] [blame] | 1036 | p->gtime = cputime_zero; |
Michael Neuling | c66f08b | 2007-10-18 03:06:34 -0700 | [diff] [blame] | 1037 | p->utimescaled = cputime_zero; |
| 1038 | p->stimescaled = cputime_zero; |
Peter Zijlstra | 73a2bcb | 2007-10-29 21:18:11 +0100 | [diff] [blame] | 1039 | p->prev_utime = cputime_zero; |
Balbir Singh | 9301899 | 2007-10-30 00:26:32 +0100 | [diff] [blame] | 1040 | p->prev_stime = cputime_zero; |
Balbir Singh | 172ba84 | 2007-07-09 18:52:00 +0200 | [diff] [blame] | 1041 | |
Arjan van de Ven | 6976675 | 2008-09-01 15:52:40 -0700 | [diff] [blame] | 1042 | p->default_timer_slack_ns = current->timer_slack_ns; |
| 1043 | |
Ingo Molnar | 82a1fcb | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 1044 | #ifdef CONFIG_DETECT_SOFTLOCKUP |
| 1045 | p->last_switch_count = 0; |
| 1046 | p->last_switch_timestamp = 0; |
| 1047 | #endif |
| 1048 | |
Andrea Righi | 5995477 | 2008-07-27 17:29:15 +0200 | [diff] [blame] | 1049 | task_io_accounting_init(&p->ioac); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1050 | acct_clear_integrals(p); |
| 1051 | |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1052 | posix_cpu_timers_init(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1053 | |
| 1054 | p->lock_depth = -1; /* -1 = no lock */ |
| 1055 | do_posix_clock_monotonic_gettime(&p->start_time); |
Tomas Janousek | 924b42d | 2007-07-15 23:39:42 -0700 | [diff] [blame] | 1056 | p->real_start_time = p->start_time; |
| 1057 | monotonic_to_bootbased(&p->real_start_time); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1058 | p->io_context = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1059 | p->audit_context = NULL; |
Paul Menage | b4f48b6 | 2007-10-18 23:39:33 -0700 | [diff] [blame] | 1060 | cgroup_fork(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1061 | #ifdef CONFIG_NUMA |
Lee Schermerhorn | 846a16b | 2008-04-28 02:13:09 -0700 | [diff] [blame] | 1062 | p->mempolicy = mpol_dup(p->mempolicy); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1063 | if (IS_ERR(p->mempolicy)) { |
| 1064 | retval = PTR_ERR(p->mempolicy); |
| 1065 | p->mempolicy = NULL; |
Paul Menage | b4f48b6 | 2007-10-18 23:39:33 -0700 | [diff] [blame] | 1066 | goto bad_fork_cleanup_cgroup; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1067 | } |
Paul Jackson | c61afb1 | 2006-03-24 03:16:08 -0800 | [diff] [blame] | 1068 | mpol_fix_fork_child_flag(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1069 | #endif |
Ingo Molnar | de30a2b | 2006-07-03 00:24:42 -0700 | [diff] [blame] | 1070 | #ifdef CONFIG_TRACE_IRQFLAGS |
| 1071 | p->irq_events = 0; |
Russell King | b36e475 | 2006-08-27 12:26:34 +0100 | [diff] [blame] | 1072 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
| 1073 | p->hardirqs_enabled = 1; |
| 1074 | #else |
Ingo Molnar | de30a2b | 2006-07-03 00:24:42 -0700 | [diff] [blame] | 1075 | p->hardirqs_enabled = 0; |
Russell King | b36e475 | 2006-08-27 12:26:34 +0100 | [diff] [blame] | 1076 | #endif |
Ingo Molnar | de30a2b | 2006-07-03 00:24:42 -0700 | [diff] [blame] | 1077 | p->hardirq_enable_ip = 0; |
| 1078 | p->hardirq_enable_event = 0; |
| 1079 | p->hardirq_disable_ip = _THIS_IP_; |
| 1080 | p->hardirq_disable_event = 0; |
| 1081 | p->softirqs_enabled = 1; |
| 1082 | p->softirq_enable_ip = _THIS_IP_; |
| 1083 | p->softirq_enable_event = 0; |
| 1084 | p->softirq_disable_ip = 0; |
| 1085 | p->softirq_disable_event = 0; |
| 1086 | p->hardirq_context = 0; |
| 1087 | p->softirq_context = 0; |
| 1088 | #endif |
Ingo Molnar | fbb9ce95 | 2006-07-03 00:24:50 -0700 | [diff] [blame] | 1089 | #ifdef CONFIG_LOCKDEP |
| 1090 | p->lockdep_depth = 0; /* no locks held yet */ |
| 1091 | p->curr_chain_key = 0; |
| 1092 | p->lockdep_recursion = 0; |
| 1093 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1094 | |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 1095 | #ifdef CONFIG_DEBUG_MUTEXES |
| 1096 | p->blocked_on = NULL; /* not blocked yet */ |
| 1097 | #endif |
Oleg Nesterov | 06eb23b | 2009-02-09 02:02:33 +0100 | [diff] [blame] | 1098 | if (unlikely(current->ptrace)) |
Markus Metzger | bf53de9 | 2008-12-19 15:10:24 +0100 | [diff] [blame] | 1099 | ptrace_fork(p, clone_flags); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 1100 | |
Srivatsa Vaddagiri | 3c90e6e | 2007-11-09 22:39:39 +0100 | [diff] [blame] | 1101 | /* Perform scheduler related setup. Assign this task to a CPU. */ |
| 1102 | sched_fork(p, clone_flags); |
| 1103 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1104 | if ((retval = audit_alloc(p))) |
David Howells | f1752ee | 2008-11-14 10:39:17 +1100 | [diff] [blame] | 1105 | goto bad_fork_cleanup_policy; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1106 | /* copy all the process information */ |
| 1107 | if ((retval = copy_semundo(clone_flags, p))) |
| 1108 | goto bad_fork_cleanup_audit; |
| 1109 | if ((retval = copy_files(clone_flags, p))) |
| 1110 | goto bad_fork_cleanup_semundo; |
| 1111 | if ((retval = copy_fs(clone_flags, p))) |
| 1112 | goto bad_fork_cleanup_files; |
| 1113 | if ((retval = copy_sighand(clone_flags, p))) |
| 1114 | goto bad_fork_cleanup_fs; |
| 1115 | if ((retval = copy_signal(clone_flags, p))) |
| 1116 | goto bad_fork_cleanup_sighand; |
| 1117 | if ((retval = copy_mm(clone_flags, p))) |
| 1118 | goto bad_fork_cleanup_signal; |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 1119 | if ((retval = copy_namespaces(clone_flags, p))) |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 1120 | goto bad_fork_cleanup_mm; |
Jens Axboe | fadad878 | 2008-01-24 08:54:47 +0100 | [diff] [blame] | 1121 | if ((retval = copy_io(clone_flags, p))) |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1122 | goto bad_fork_cleanup_namespaces; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1123 | retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs); |
| 1124 | if (retval) |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1125 | goto bad_fork_cleanup_io; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1126 | |
Pavel Emelyanov | 425fb2b | 2007-10-18 23:40:07 -0700 | [diff] [blame] | 1127 | if (pid != &init_struct_pid) { |
| 1128 | retval = -ENOMEM; |
Eric W. Biederman | 61bce0f | 2009-01-07 18:08:49 -0800 | [diff] [blame] | 1129 | pid = alloc_pid(p->nsproxy->pid_ns); |
Pavel Emelyanov | 425fb2b | 2007-10-18 23:40:07 -0700 | [diff] [blame] | 1130 | if (!pid) |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1131 | goto bad_fork_cleanup_io; |
Pavel Emelyanov | 6f4e643 | 2007-10-18 23:40:11 -0700 | [diff] [blame] | 1132 | |
| 1133 | if (clone_flags & CLONE_NEWPID) { |
Eric W. Biederman | 61bce0f | 2009-01-07 18:08:49 -0800 | [diff] [blame] | 1134 | retval = pid_ns_prepare_proc(p->nsproxy->pid_ns); |
Pavel Emelyanov | 6f4e643 | 2007-10-18 23:40:11 -0700 | [diff] [blame] | 1135 | if (retval < 0) |
| 1136 | goto bad_fork_free_pid; |
| 1137 | } |
Pavel Emelyanov | 425fb2b | 2007-10-18 23:40:07 -0700 | [diff] [blame] | 1138 | } |
| 1139 | |
Steven Rostedt | e8e1abe | 2008-12-03 11:04:51 -0500 | [diff] [blame] | 1140 | ftrace_graph_init_task(p); |
| 1141 | |
Pavel Emelyanov | 425fb2b | 2007-10-18 23:40:07 -0700 | [diff] [blame] | 1142 | p->pid = pid_nr(pid); |
| 1143 | p->tgid = p->pid; |
| 1144 | if (clone_flags & CLONE_THREAD) |
| 1145 | p->tgid = current->tgid; |
| 1146 | |
Serge E. Hallyn | e885dcd | 2008-07-25 01:47:06 -0700 | [diff] [blame] | 1147 | if (current->nsproxy != p->nsproxy) { |
| 1148 | retval = ns_cgroup_clone(p, pid); |
| 1149 | if (retval) |
Steven Rostedt | e8e1abe | 2008-12-03 11:04:51 -0500 | [diff] [blame] | 1150 | goto bad_fork_free_graph; |
Serge E. Hallyn | e885dcd | 2008-07-25 01:47:06 -0700 | [diff] [blame] | 1151 | } |
| 1152 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1153 | p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL; |
| 1154 | /* |
| 1155 | * Clear TID on mm_release()? |
| 1156 | */ |
| 1157 | p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL; |
Alexey Dobriyan | 42b2dd0 | 2007-10-16 23:27:30 -0700 | [diff] [blame] | 1158 | #ifdef CONFIG_FUTEX |
Ingo Molnar | 8f17d3a | 2006-03-27 01:16:27 -0800 | [diff] [blame] | 1159 | p->robust_list = NULL; |
| 1160 | #ifdef CONFIG_COMPAT |
| 1161 | p->compat_robust_list = NULL; |
| 1162 | #endif |
Ingo Molnar | c87e283 | 2006-06-27 02:54:58 -0700 | [diff] [blame] | 1163 | INIT_LIST_HEAD(&p->pi_state_list); |
| 1164 | p->pi_state_cache = NULL; |
Alexey Dobriyan | 42b2dd0 | 2007-10-16 23:27:30 -0700 | [diff] [blame] | 1165 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1166 | /* |
GOTO Masanori | f9a3879 | 2006-03-13 21:20:44 -0800 | [diff] [blame] | 1167 | * sigaltstack should be cleared when sharing the same VM |
| 1168 | */ |
| 1169 | if ((clone_flags & (CLONE_VM|CLONE_VFORK)) == CLONE_VM) |
| 1170 | p->sas_ss_sp = p->sas_ss_size = 0; |
| 1171 | |
| 1172 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1173 | * Syscall tracing should be turned off in the child regardless |
| 1174 | * of CLONE_PTRACE. |
| 1175 | */ |
| 1176 | clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE); |
Laurent Vivier | ed75e8d | 2005-09-03 15:57:18 -0700 | [diff] [blame] | 1177 | #ifdef TIF_SYSCALL_EMU |
| 1178 | clear_tsk_thread_flag(p, TIF_SYSCALL_EMU); |
| 1179 | #endif |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 1180 | clear_all_latency_tracing(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1181 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1182 | /* ok, now we should be set up.. */ |
| 1183 | p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL); |
| 1184 | p->pdeath_signal = 0; |
| 1185 | p->exit_state = 0; |
| 1186 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1187 | /* |
| 1188 | * Ok, make it visible to the rest of the system. |
| 1189 | * We dont wake it up yet. |
| 1190 | */ |
| 1191 | p->group_leader = p; |
Oleg Nesterov | 47e6532 | 2006-03-28 16:11:25 -0800 | [diff] [blame] | 1192 | INIT_LIST_HEAD(&p->thread_group); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1193 | |
Paul Menage | b4f48b6 | 2007-10-18 23:39:33 -0700 | [diff] [blame] | 1194 | /* Now that the task is set up, run cgroup callbacks if |
| 1195 | * necessary. We need to run them before the task is visible |
| 1196 | * on the tasklist. */ |
| 1197 | cgroup_fork_callbacks(p); |
| 1198 | cgroup_callbacks_done = 1; |
| 1199 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1200 | /* Need tasklist lock for parent etc handling! */ |
| 1201 | write_lock_irq(&tasklist_lock); |
| 1202 | |
| 1203 | /* |
Nick Piggin | 476d139 | 2005-06-25 14:57:29 -0700 | [diff] [blame] | 1204 | * The task hasn't been attached yet, so its cpus_allowed mask will |
| 1205 | * not be changed, nor will its assigned CPU. |
| 1206 | * |
| 1207 | * The cpus_allowed mask of the parent may have changed after it was |
| 1208 | * copied first time - so re-copy it here, then check the child's CPU |
| 1209 | * to ensure it is on a valid CPU (and if not, just force it back to |
| 1210 | * parent's CPU). This avoids alot of nasty races. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1211 | */ |
| 1212 | p->cpus_allowed = current->cpus_allowed; |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1213 | p->rt.nr_cpus_allowed = current->rt.nr_cpus_allowed; |
Srivatsa Vaddagiri | 26ff6ad | 2005-09-16 19:27:40 -0700 | [diff] [blame] | 1214 | if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) || |
| 1215 | !cpu_online(task_cpu(p)))) |
Nick Piggin | 476d139 | 2005-06-25 14:57:29 -0700 | [diff] [blame] | 1216 | set_task_cpu(p, smp_processor_id()); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1217 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1218 | /* CLONE_PARENT re-uses the old parent */ |
Oleg Nesterov | 2d5516c | 2009-03-02 22:58:45 +0100 | [diff] [blame] | 1219 | if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1220 | p->real_parent = current->real_parent; |
Oleg Nesterov | 2d5516c | 2009-03-02 22:58:45 +0100 | [diff] [blame] | 1221 | p->parent_exec_id = current->parent_exec_id; |
| 1222 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1223 | p->real_parent = current; |
Oleg Nesterov | 2d5516c | 2009-03-02 22:58:45 +0100 | [diff] [blame] | 1224 | p->parent_exec_id = current->self_exec_id; |
| 1225 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1226 | |
Oleg Nesterov | 3f17da6 | 2006-02-15 22:13:24 +0300 | [diff] [blame] | 1227 | spin_lock(¤t->sighand->siglock); |
Oleg Nesterov | 4a2c7a7 | 2006-03-28 16:11:26 -0800 | [diff] [blame] | 1228 | |
| 1229 | /* |
| 1230 | * Process group and session signals need to be delivered to just the |
| 1231 | * parent before the fork or both the parent and the child after the |
| 1232 | * fork. Restart if a signal comes in before we add the new process to |
| 1233 | * it's process group. |
| 1234 | * A fatal signal pending means that current will exit, so the new |
| 1235 | * thread can't slip out of an OOM kill (or normal SIGKILL). |
| 1236 | */ |
Daniel Walker | 23ff444 | 2007-10-18 03:06:07 -0700 | [diff] [blame] | 1237 | recalc_sigpending(); |
Oleg Nesterov | 4a2c7a7 | 2006-03-28 16:11:26 -0800 | [diff] [blame] | 1238 | if (signal_pending(current)) { |
| 1239 | spin_unlock(¤t->sighand->siglock); |
| 1240 | write_unlock_irq(&tasklist_lock); |
| 1241 | retval = -ERESTARTNOINTR; |
Steven Rostedt | e8e1abe | 2008-12-03 11:04:51 -0500 | [diff] [blame] | 1242 | goto bad_fork_free_graph; |
Oleg Nesterov | 4a2c7a7 | 2006-03-28 16:11:26 -0800 | [diff] [blame] | 1243 | } |
| 1244 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1245 | if (clone_flags & CLONE_THREAD) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1246 | p->group_leader = current->group_leader; |
Oleg Nesterov | 47e6532 | 2006-03-28 16:11:25 -0800 | [diff] [blame] | 1247 | list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1248 | } |
| 1249 | |
Oleg Nesterov | 73b9ebf | 2006-03-28 16:11:07 -0800 | [diff] [blame] | 1250 | if (likely(p->pid)) { |
Roland McGrath | f470021 | 2008-03-24 18:36:23 -0700 | [diff] [blame] | 1251 | list_add_tail(&p->sibling, &p->real_parent->children); |
Roland McGrath | 09a0539 | 2008-07-25 19:45:47 -0700 | [diff] [blame] | 1252 | tracehook_finish_clone(p, clone_flags, trace); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1253 | |
Oleg Nesterov | 73b9ebf | 2006-03-28 16:11:07 -0800 | [diff] [blame] | 1254 | if (thread_group_leader(p)) { |
Eric W. Biederman | 5cd1756 | 2007-12-04 23:45:04 -0800 | [diff] [blame] | 1255 | if (clone_flags & CLONE_NEWPID) |
Pavel Emelyanov | 30e49c2 | 2007-10-18 23:40:10 -0700 | [diff] [blame] | 1256 | p->nsproxy->pid_ns->child_reaper = p; |
Oleg Nesterov | c97d989 | 2006-03-28 16:11:06 -0800 | [diff] [blame] | 1257 | |
Oleg Nesterov | fea9d17 | 2008-02-08 04:19:19 -0800 | [diff] [blame] | 1258 | p->signal->leader_pid = pid; |
Alan Cox | 9c9f4de | 2008-10-13 10:37:26 +0100 | [diff] [blame] | 1259 | tty_kref_put(p->signal->tty); |
| 1260 | p->signal->tty = tty_kref_get(current->signal->tty); |
Eric W. Biederman | 5cd1756 | 2007-12-04 23:45:04 -0800 | [diff] [blame] | 1261 | set_task_pgrp(p, task_pgrp_nr(current)); |
| 1262 | set_task_session(p, task_session_nr(current)); |
| 1263 | attach_pid(p, PIDTYPE_PGID, task_pgrp(current)); |
| 1264 | attach_pid(p, PIDTYPE_SID, task_session(current)); |
Eric W. Biederman | 5e85d4a | 2006-04-18 22:20:16 -0700 | [diff] [blame] | 1265 | list_add_tail_rcu(&p->tasks, &init_task.tasks); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1266 | __get_cpu_var(process_counts)++; |
Oleg Nesterov | 73b9ebf | 2006-03-28 16:11:07 -0800 | [diff] [blame] | 1267 | } |
Sukadev Bhattiprolu | 8586899 | 2007-05-10 22:23:03 -0700 | [diff] [blame] | 1268 | attach_pid(p, PIDTYPE_PID, pid); |
Oleg Nesterov | 73b9ebf | 2006-03-28 16:11:07 -0800 | [diff] [blame] | 1269 | nr_threads++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1270 | } |
| 1271 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1272 | total_forks++; |
Oleg Nesterov | 3f17da6 | 2006-02-15 22:13:24 +0300 | [diff] [blame] | 1273 | spin_unlock(¤t->sighand->siglock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1274 | write_unlock_irq(&tasklist_lock); |
Andrew Morton | c13cf85 | 2005-11-28 13:43:48 -0800 | [diff] [blame] | 1275 | proc_fork_connector(p); |
Paul Menage | 817929e | 2007-10-18 23:39:36 -0700 | [diff] [blame] | 1276 | cgroup_post_fork(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1277 | return p; |
| 1278 | |
Steven Rostedt | e8e1abe | 2008-12-03 11:04:51 -0500 | [diff] [blame] | 1279 | bad_fork_free_graph: |
| 1280 | ftrace_graph_exit_task(p); |
Pavel Emelyanov | 425fb2b | 2007-10-18 23:40:07 -0700 | [diff] [blame] | 1281 | bad_fork_free_pid: |
| 1282 | if (pid != &init_struct_pid) |
| 1283 | free_pid(pid); |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1284 | bad_fork_cleanup_io: |
| 1285 | put_io_context(p->io_context); |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 1286 | bad_fork_cleanup_namespaces: |
Linus Torvalds | 444f378 | 2007-01-30 13:35:18 -0800 | [diff] [blame] | 1287 | exit_task_namespaces(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1288 | bad_fork_cleanup_mm: |
| 1289 | if (p->mm) |
| 1290 | mmput(p->mm); |
| 1291 | bad_fork_cleanup_signal: |
Oleg Nesterov | 6b3934ef | 2006-03-28 16:11:16 -0800 | [diff] [blame] | 1292 | cleanup_signal(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1293 | bad_fork_cleanup_sighand: |
Oleg Nesterov | a7e5328 | 2006-03-28 16:11:27 -0800 | [diff] [blame] | 1294 | __cleanup_sighand(p->sighand); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1295 | bad_fork_cleanup_fs: |
| 1296 | exit_fs(p); /* blocking */ |
| 1297 | bad_fork_cleanup_files: |
| 1298 | exit_files(p); /* blocking */ |
| 1299 | bad_fork_cleanup_semundo: |
| 1300 | exit_sem(p); |
| 1301 | bad_fork_cleanup_audit: |
| 1302 | audit_free(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1303 | bad_fork_cleanup_policy: |
| 1304 | #ifdef CONFIG_NUMA |
Lee Schermerhorn | f0be3d3 | 2008-04-28 02:13:08 -0700 | [diff] [blame] | 1305 | mpol_put(p->mempolicy); |
Paul Menage | b4f48b6 | 2007-10-18 23:39:33 -0700 | [diff] [blame] | 1306 | bad_fork_cleanup_cgroup: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1307 | #endif |
Paul Menage | b4f48b6 | 2007-10-18 23:39:33 -0700 | [diff] [blame] | 1308 | cgroup_exit(p, cgroup_callbacks_done); |
Shailabh Nagar | 35df17c | 2006-08-31 21:27:38 -0700 | [diff] [blame] | 1309 | delayacct_tsk_free(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1310 | if (p->binfmt) |
| 1311 | module_put(p->binfmt->module); |
| 1312 | bad_fork_cleanup_put_domain: |
Al Viro | a1261f54 | 2005-11-13 16:06:55 -0800 | [diff] [blame] | 1313 | module_put(task_thread_info(p)->exec_domain->module); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1314 | bad_fork_cleanup_count: |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 1315 | atomic_dec(&p->cred->user->processes); |
David Howells | 3b11a1d | 2008-11-14 10:39:26 +1100 | [diff] [blame] | 1316 | put_cred(p->real_cred); |
David Howells | f1752ee | 2008-11-14 10:39:17 +1100 | [diff] [blame] | 1317 | put_cred(p->cred); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1318 | bad_fork_free: |
| 1319 | free_task(p); |
Oleg Nesterov | fe7d37d | 2006-01-08 01:04:02 -0800 | [diff] [blame] | 1320 | fork_out: |
| 1321 | return ERR_PTR(retval); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1322 | } |
| 1323 | |
Adrian Bunk | 6b2fb3c | 2008-02-06 01:37:55 -0800 | [diff] [blame] | 1324 | noinline struct pt_regs * __cpuinit __attribute__((weak)) idle_regs(struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1325 | { |
| 1326 | memset(regs, 0, sizeof(struct pt_regs)); |
| 1327 | return regs; |
| 1328 | } |
| 1329 | |
Al Viro | 9abcf40 | 2007-02-01 13:52:48 +0000 | [diff] [blame] | 1330 | struct task_struct * __cpuinit fork_idle(int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1331 | { |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 1332 | struct task_struct *task; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1333 | struct pt_regs regs; |
| 1334 | |
Pavel Emelyanov | 30e49c2 | 2007-10-18 23:40:10 -0700 | [diff] [blame] | 1335 | task = copy_process(CLONE_VM, 0, idle_regs(®s), 0, NULL, |
Roland McGrath | 09a0539 | 2008-07-25 19:45:47 -0700 | [diff] [blame] | 1336 | &init_struct_pid, 0); |
Akinobu Mita | 753ca4f | 2006-11-25 11:09:34 -0800 | [diff] [blame] | 1337 | if (!IS_ERR(task)) |
| 1338 | init_idle(task, cpu); |
Oleg Nesterov | 73b9ebf | 2006-03-28 16:11:07 -0800 | [diff] [blame] | 1339 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1340 | return task; |
| 1341 | } |
| 1342 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1343 | /* |
| 1344 | * Ok, this is the main fork-routine. |
| 1345 | * |
| 1346 | * It copies the process, and if successful kick-starts |
| 1347 | * it and waits for it to finish using the VM if required. |
| 1348 | */ |
| 1349 | long do_fork(unsigned long clone_flags, |
| 1350 | unsigned long stack_start, |
| 1351 | struct pt_regs *regs, |
| 1352 | unsigned long stack_size, |
| 1353 | int __user *parent_tidptr, |
| 1354 | int __user *child_tidptr) |
| 1355 | { |
| 1356 | struct task_struct *p; |
| 1357 | int trace = 0; |
Eric W. Biederman | 92476d7 | 2006-03-31 02:31:42 -0800 | [diff] [blame] | 1358 | long nr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1359 | |
Andrew Morton | bdff746 | 2008-02-04 22:27:22 -0800 | [diff] [blame] | 1360 | /* |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 1361 | * Do some preliminary argument and permissions checking before we |
| 1362 | * actually start allocating stuff |
| 1363 | */ |
| 1364 | if (clone_flags & CLONE_NEWUSER) { |
| 1365 | if (clone_flags & CLONE_THREAD) |
| 1366 | return -EINVAL; |
| 1367 | /* hopefully this check will go away when userns support is |
| 1368 | * complete |
| 1369 | */ |
Serge E. Hallyn | 7657d90 | 2008-12-03 13:17:33 -0600 | [diff] [blame] | 1370 | if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SETUID) || |
| 1371 | !capable(CAP_SETGID)) |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 1372 | return -EPERM; |
| 1373 | } |
| 1374 | |
| 1375 | /* |
Andrew Morton | bdff746 | 2008-02-04 22:27:22 -0800 | [diff] [blame] | 1376 | * We hope to recycle these flags after 2.6.26 |
| 1377 | */ |
| 1378 | if (unlikely(clone_flags & CLONE_STOPPED)) { |
| 1379 | static int __read_mostly count = 100; |
| 1380 | |
| 1381 | if (count > 0 && printk_ratelimit()) { |
| 1382 | char comm[TASK_COMM_LEN]; |
| 1383 | |
| 1384 | count--; |
| 1385 | printk(KERN_INFO "fork(): process `%s' used deprecated " |
| 1386 | "clone flags 0x%lx\n", |
| 1387 | get_task_comm(comm, current), |
| 1388 | clone_flags & CLONE_STOPPED); |
| 1389 | } |
| 1390 | } |
| 1391 | |
Roland McGrath | 09a0539 | 2008-07-25 19:45:47 -0700 | [diff] [blame] | 1392 | /* |
| 1393 | * When called from kernel_thread, don't do user tracing stuff. |
| 1394 | */ |
| 1395 | if (likely(user_mode(regs))) |
| 1396 | trace = tracehook_prepare_clone(clone_flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1397 | |
Sukadev Bhattiprolu | a6f5e06 | 2007-10-18 23:39:53 -0700 | [diff] [blame] | 1398 | p = copy_process(clone_flags, stack_start, regs, stack_size, |
Roland McGrath | 09a0539 | 2008-07-25 19:45:47 -0700 | [diff] [blame] | 1399 | child_tidptr, NULL, trace); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1400 | /* |
| 1401 | * Do this prior waking up the new thread - the thread pointer |
| 1402 | * might get invalid after that point, if the thread exits quickly. |
| 1403 | */ |
| 1404 | if (!IS_ERR(p)) { |
| 1405 | struct completion vfork; |
| 1406 | |
Mathieu Desnoyers | 0a16b60 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 1407 | trace_sched_process_fork(current, p); |
| 1408 | |
Pavel Emelyanov | 6c5f3e7 | 2008-02-08 04:19:20 -0800 | [diff] [blame] | 1409 | nr = task_pid_vnr(p); |
Pavel Emelyanov | 30e49c2 | 2007-10-18 23:40:10 -0700 | [diff] [blame] | 1410 | |
| 1411 | if (clone_flags & CLONE_PARENT_SETTID) |
| 1412 | put_user(nr, parent_tidptr); |
Sukadev Bhattiprolu | a6f5e06 | 2007-10-18 23:39:53 -0700 | [diff] [blame] | 1413 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1414 | if (clone_flags & CLONE_VFORK) { |
| 1415 | p->vfork_done = &vfork; |
| 1416 | init_completion(&vfork); |
| 1417 | } |
| 1418 | |
Al Viro | a64e649 | 2008-11-12 18:37:41 -0500 | [diff] [blame] | 1419 | audit_finish_fork(p); |
Roland McGrath | 09a0539 | 2008-07-25 19:45:47 -0700 | [diff] [blame] | 1420 | tracehook_report_clone(trace, regs, clone_flags, nr, p); |
| 1421 | |
| 1422 | /* |
| 1423 | * We set PF_STARTING at creation in case tracing wants to |
| 1424 | * use this to distinguish a fully live task from one that |
| 1425 | * hasn't gotten to tracehook_report_clone() yet. Now we |
| 1426 | * clear it and set the child going. |
| 1427 | */ |
| 1428 | p->flags &= ~PF_STARTING; |
| 1429 | |
| 1430 | if (unlikely(clone_flags & CLONE_STOPPED)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1431 | /* |
| 1432 | * We'll start up with an immediate SIGSTOP. |
| 1433 | */ |
| 1434 | sigaddset(&p->pending.signal, SIGSTOP); |
| 1435 | set_tsk_thread_flag(p, TIF_SIGPENDING); |
Oleg Nesterov | d9ae90a | 2008-02-06 01:36:13 -0800 | [diff] [blame] | 1436 | __set_task_state(p, TASK_STOPPED); |
Roland McGrath | 09a0539 | 2008-07-25 19:45:47 -0700 | [diff] [blame] | 1437 | } else { |
| 1438 | wake_up_new_task(p, clone_flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1439 | } |
| 1440 | |
Roland McGrath | 09a0539 | 2008-07-25 19:45:47 -0700 | [diff] [blame] | 1441 | tracehook_report_clone_complete(trace, regs, |
| 1442 | clone_flags, nr, p); |
| 1443 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1444 | if (clone_flags & CLONE_VFORK) { |
Rafael J. Wysocki | ba96a0c | 2007-05-23 13:57:25 -0700 | [diff] [blame] | 1445 | freezer_do_not_count(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1446 | wait_for_completion(&vfork); |
Rafael J. Wysocki | ba96a0c | 2007-05-23 13:57:25 -0700 | [diff] [blame] | 1447 | freezer_count(); |
Roland McGrath | daded34 | 2008-07-25 19:45:47 -0700 | [diff] [blame] | 1448 | tracehook_report_vfork_done(p, nr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1449 | } |
| 1450 | } else { |
Eric W. Biederman | 92476d7 | 2006-03-31 02:31:42 -0800 | [diff] [blame] | 1451 | nr = PTR_ERR(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1452 | } |
Eric W. Biederman | 92476d7 | 2006-03-31 02:31:42 -0800 | [diff] [blame] | 1453 | return nr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1454 | } |
| 1455 | |
Ravikiran G Thirumalai | 5fd63b3 | 2006-01-11 22:46:15 +0100 | [diff] [blame] | 1456 | #ifndef ARCH_MIN_MMSTRUCT_ALIGN |
| 1457 | #define ARCH_MIN_MMSTRUCT_ALIGN 0 |
| 1458 | #endif |
| 1459 | |
Alexey Dobriyan | 51cc506 | 2008-07-25 19:45:34 -0700 | [diff] [blame] | 1460 | static void sighand_ctor(void *data) |
Oleg Nesterov | aa1757f | 2006-03-28 16:11:12 -0800 | [diff] [blame] | 1461 | { |
| 1462 | struct sighand_struct *sighand = data; |
| 1463 | |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 1464 | spin_lock_init(&sighand->siglock); |
Davide Libenzi | b8fceee | 2007-09-20 12:40:16 -0700 | [diff] [blame] | 1465 | init_waitqueue_head(&sighand->signalfd_wqh); |
Oleg Nesterov | aa1757f | 2006-03-28 16:11:12 -0800 | [diff] [blame] | 1466 | } |
| 1467 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1468 | void __init proc_caches_init(void) |
| 1469 | { |
| 1470 | sighand_cachep = kmem_cache_create("sighand_cache", |
| 1471 | sizeof(struct sighand_struct), 0, |
Oleg Nesterov | aa1757f | 2006-03-28 16:11:12 -0800 | [diff] [blame] | 1472 | SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_DESTROY_BY_RCU, |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1473 | sighand_ctor); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1474 | signal_cachep = kmem_cache_create("signal_cache", |
| 1475 | sizeof(struct signal_struct), 0, |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1476 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
| 1477 | files_cachep = kmem_cache_create("files_cache", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1478 | sizeof(struct files_struct), 0, |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1479 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
| 1480 | fs_cachep = kmem_cache_create("fs_cache", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1481 | sizeof(struct fs_struct), 0, |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1482 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1483 | mm_cachep = kmem_cache_create("mm_struct", |
Ravikiran G Thirumalai | 5fd63b3 | 2006-01-11 22:46:15 +0100 | [diff] [blame] | 1484 | sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN, |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1485 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1486 | mmap_init(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1487 | } |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1488 | |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1489 | /* |
| 1490 | * Check constraints on flags passed to the unshare system call and |
| 1491 | * force unsharing of additional process context as appropriate. |
| 1492 | */ |
Alexey Dobriyan | a39bc51 | 2007-10-18 23:41:10 -0700 | [diff] [blame] | 1493 | static void check_unshare_flags(unsigned long *flags_ptr) |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1494 | { |
| 1495 | /* |
| 1496 | * If unsharing a thread from a thread group, must also |
| 1497 | * unshare vm. |
| 1498 | */ |
| 1499 | if (*flags_ptr & CLONE_THREAD) |
| 1500 | *flags_ptr |= CLONE_VM; |
| 1501 | |
| 1502 | /* |
| 1503 | * If unsharing vm, must also unshare signal handlers. |
| 1504 | */ |
| 1505 | if (*flags_ptr & CLONE_VM) |
| 1506 | *flags_ptr |= CLONE_SIGHAND; |
| 1507 | |
| 1508 | /* |
| 1509 | * If unsharing signal handlers and the task was created |
| 1510 | * using CLONE_THREAD, then must unshare the thread |
| 1511 | */ |
| 1512 | if ((*flags_ptr & CLONE_SIGHAND) && |
| 1513 | (atomic_read(¤t->signal->count) > 1)) |
| 1514 | *flags_ptr |= CLONE_THREAD; |
| 1515 | |
| 1516 | /* |
| 1517 | * If unsharing namespace, must also unshare filesystem information. |
| 1518 | */ |
| 1519 | if (*flags_ptr & CLONE_NEWNS) |
| 1520 | *flags_ptr |= CLONE_FS; |
| 1521 | } |
| 1522 | |
| 1523 | /* |
| 1524 | * Unsharing of tasks created with CLONE_THREAD is not supported yet |
| 1525 | */ |
| 1526 | static int unshare_thread(unsigned long unshare_flags) |
| 1527 | { |
| 1528 | if (unshare_flags & CLONE_THREAD) |
| 1529 | return -EINVAL; |
| 1530 | |
| 1531 | return 0; |
| 1532 | } |
| 1533 | |
| 1534 | /* |
JANAK DESAI | 99d1419 | 2006-02-07 12:58:59 -0800 | [diff] [blame] | 1535 | * Unshare the filesystem structure if it is being shared |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1536 | */ |
| 1537 | static int unshare_fs(unsigned long unshare_flags, struct fs_struct **new_fsp) |
| 1538 | { |
| 1539 | struct fs_struct *fs = current->fs; |
| 1540 | |
| 1541 | if ((unshare_flags & CLONE_FS) && |
JANAK DESAI | 99d1419 | 2006-02-07 12:58:59 -0800 | [diff] [blame] | 1542 | (fs && atomic_read(&fs->count) > 1)) { |
| 1543 | *new_fsp = __copy_fs_struct(current->fs); |
| 1544 | if (!*new_fsp) |
| 1545 | return -ENOMEM; |
| 1546 | } |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1547 | |
| 1548 | return 0; |
| 1549 | } |
| 1550 | |
| 1551 | /* |
Oleg Nesterov | dae3c5a | 2006-12-08 02:36:09 -0800 | [diff] [blame] | 1552 | * Unsharing of sighand is not supported yet |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1553 | */ |
| 1554 | static int unshare_sighand(unsigned long unshare_flags, struct sighand_struct **new_sighp) |
| 1555 | { |
| 1556 | struct sighand_struct *sigh = current->sighand; |
| 1557 | |
Oleg Nesterov | dae3c5a | 2006-12-08 02:36:09 -0800 | [diff] [blame] | 1558 | if ((unshare_flags & CLONE_SIGHAND) && atomic_read(&sigh->count) > 1) |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1559 | return -EINVAL; |
| 1560 | else |
| 1561 | return 0; |
| 1562 | } |
| 1563 | |
| 1564 | /* |
JANAK DESAI | a0a7ec3 | 2006-02-07 12:59:01 -0800 | [diff] [blame] | 1565 | * Unshare vm if it is being shared |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1566 | */ |
| 1567 | static int unshare_vm(unsigned long unshare_flags, struct mm_struct **new_mmp) |
| 1568 | { |
| 1569 | struct mm_struct *mm = current->mm; |
| 1570 | |
| 1571 | if ((unshare_flags & CLONE_VM) && |
JANAK DESAI | a0a7ec3 | 2006-02-07 12:59:01 -0800 | [diff] [blame] | 1572 | (mm && atomic_read(&mm->mm_users) > 1)) { |
Oleg Nesterov | 2d61b867 | 2006-03-18 20:41:10 +0300 | [diff] [blame] | 1573 | return -EINVAL; |
JANAK DESAI | a0a7ec3 | 2006-02-07 12:59:01 -0800 | [diff] [blame] | 1574 | } |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1575 | |
| 1576 | return 0; |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1577 | } |
| 1578 | |
| 1579 | /* |
JANAK DESAI | a016f33 | 2006-02-07 12:59:02 -0800 | [diff] [blame] | 1580 | * Unshare file descriptor table if it is being shared |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1581 | */ |
| 1582 | static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp) |
| 1583 | { |
| 1584 | struct files_struct *fd = current->files; |
JANAK DESAI | a016f33 | 2006-02-07 12:59:02 -0800 | [diff] [blame] | 1585 | int error = 0; |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1586 | |
| 1587 | if ((unshare_flags & CLONE_FILES) && |
JANAK DESAI | a016f33 | 2006-02-07 12:59:02 -0800 | [diff] [blame] | 1588 | (fd && atomic_read(&fd->count) > 1)) { |
| 1589 | *new_fdp = dup_fd(fd, &error); |
| 1590 | if (!*new_fdp) |
| 1591 | return error; |
| 1592 | } |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1593 | |
| 1594 | return 0; |
| 1595 | } |
| 1596 | |
| 1597 | /* |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1598 | * unshare allows a process to 'unshare' part of the process |
| 1599 | * context which was originally shared using clone. copy_* |
| 1600 | * functions used by do_fork() cannot be used here directly |
| 1601 | * because they modify an inactive task_struct that is being |
| 1602 | * constructed. Here we are modifying the current, active, |
| 1603 | * task_struct. |
| 1604 | */ |
Heiko Carstens | 6559eed8 | 2009-01-14 14:14:32 +0100 | [diff] [blame] | 1605 | SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags) |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1606 | { |
| 1607 | int err = 0; |
| 1608 | struct fs_struct *fs, *new_fs = NULL; |
Oleg Nesterov | dae3c5a | 2006-12-08 02:36:09 -0800 | [diff] [blame] | 1609 | struct sighand_struct *new_sigh = NULL; |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1610 | struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL; |
| 1611 | struct files_struct *fd, *new_fd = NULL; |
Pavel Emelyanov | cf7b708 | 2007-10-18 23:39:54 -0700 | [diff] [blame] | 1612 | struct nsproxy *new_nsproxy = NULL; |
Manfred Spraul | 9edff4a | 2008-04-29 01:00:57 -0700 | [diff] [blame] | 1613 | int do_sysvsem = 0; |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1614 | |
| 1615 | check_unshare_flags(&unshare_flags); |
| 1616 | |
Eric W. Biederman | 06f9d4f | 2006-03-22 00:07:40 -0800 | [diff] [blame] | 1617 | /* Return -EINVAL for all unsupported flags */ |
| 1618 | err = -EINVAL; |
| 1619 | if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND| |
Kirill Korotaev | 25b21cb | 2006-10-02 02:18:19 -0700 | [diff] [blame] | 1620 | CLONE_VM|CLONE_FILES|CLONE_SYSVSEM| |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 1621 | CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET)) |
Eric W. Biederman | 06f9d4f | 2006-03-22 00:07:40 -0800 | [diff] [blame] | 1622 | goto bad_unshare_out; |
| 1623 | |
Manfred Spraul | 6013f67 | 2008-04-29 01:00:59 -0700 | [diff] [blame] | 1624 | /* |
| 1625 | * CLONE_NEWIPC must also detach from the undolist: after switching |
| 1626 | * to a new ipc namespace, the semaphore arrays from the old |
| 1627 | * namespace are unreachable. |
| 1628 | */ |
| 1629 | if (unshare_flags & (CLONE_NEWIPC|CLONE_SYSVSEM)) |
Manfred Spraul | 9edff4a | 2008-04-29 01:00:57 -0700 | [diff] [blame] | 1630 | do_sysvsem = 1; |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1631 | if ((err = unshare_thread(unshare_flags))) |
| 1632 | goto bad_unshare_out; |
| 1633 | if ((err = unshare_fs(unshare_flags, &new_fs))) |
| 1634 | goto bad_unshare_cleanup_thread; |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1635 | if ((err = unshare_sighand(unshare_flags, &new_sigh))) |
Badari Pulavarty | e3222c4 | 2007-05-08 00:25:21 -0700 | [diff] [blame] | 1636 | goto bad_unshare_cleanup_fs; |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1637 | if ((err = unshare_vm(unshare_flags, &new_mm))) |
| 1638 | goto bad_unshare_cleanup_sigh; |
| 1639 | if ((err = unshare_fd(unshare_flags, &new_fd))) |
| 1640 | goto bad_unshare_cleanup_vm; |
Badari Pulavarty | e3222c4 | 2007-05-08 00:25:21 -0700 | [diff] [blame] | 1641 | if ((err = unshare_nsproxy_namespaces(unshare_flags, &new_nsproxy, |
| 1642 | new_fs))) |
Manfred Spraul | 9edff4a | 2008-04-29 01:00:57 -0700 | [diff] [blame] | 1643 | goto bad_unshare_cleanup_fd; |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1644 | |
Manfred Spraul | 9edff4a | 2008-04-29 01:00:57 -0700 | [diff] [blame] | 1645 | if (new_fs || new_mm || new_fd || do_sysvsem || new_nsproxy) { |
| 1646 | if (do_sysvsem) { |
| 1647 | /* |
| 1648 | * CLONE_SYSVSEM is equivalent to sys_exit(). |
| 1649 | */ |
| 1650 | exit_sem(current); |
| 1651 | } |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 1652 | |
Serge Hallyn | c0b2fc3 | 2006-10-02 02:18:18 -0700 | [diff] [blame] | 1653 | if (new_nsproxy) { |
Pavel Emelyanov | cf7b708 | 2007-10-18 23:39:54 -0700 | [diff] [blame] | 1654 | switch_task_namespaces(current, new_nsproxy); |
| 1655 | new_nsproxy = NULL; |
Serge Hallyn | c0b2fc3 | 2006-10-02 02:18:18 -0700 | [diff] [blame] | 1656 | } |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1657 | |
Pavel Emelyanov | cf7b708 | 2007-10-18 23:39:54 -0700 | [diff] [blame] | 1658 | task_lock(current); |
| 1659 | |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1660 | if (new_fs) { |
| 1661 | fs = current->fs; |
| 1662 | current->fs = new_fs; |
| 1663 | new_fs = fs; |
| 1664 | } |
| 1665 | |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1666 | if (new_mm) { |
| 1667 | mm = current->mm; |
| 1668 | active_mm = current->active_mm; |
| 1669 | current->mm = new_mm; |
| 1670 | current->active_mm = new_mm; |
| 1671 | activate_mm(active_mm, new_mm); |
| 1672 | new_mm = mm; |
| 1673 | } |
| 1674 | |
| 1675 | if (new_fd) { |
| 1676 | fd = current->files; |
| 1677 | current->files = new_fd; |
| 1678 | new_fd = fd; |
| 1679 | } |
| 1680 | |
| 1681 | task_unlock(current); |
| 1682 | } |
| 1683 | |
Serge Hallyn | c0b2fc3 | 2006-10-02 02:18:18 -0700 | [diff] [blame] | 1684 | if (new_nsproxy) |
Linus Torvalds | 444f378 | 2007-01-30 13:35:18 -0800 | [diff] [blame] | 1685 | put_nsproxy(new_nsproxy); |
Serge Hallyn | c0b2fc3 | 2006-10-02 02:18:18 -0700 | [diff] [blame] | 1686 | |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1687 | bad_unshare_cleanup_fd: |
| 1688 | if (new_fd) |
| 1689 | put_files_struct(new_fd); |
| 1690 | |
| 1691 | bad_unshare_cleanup_vm: |
| 1692 | if (new_mm) |
| 1693 | mmput(new_mm); |
| 1694 | |
| 1695 | bad_unshare_cleanup_sigh: |
| 1696 | if (new_sigh) |
| 1697 | if (atomic_dec_and_test(&new_sigh->count)) |
| 1698 | kmem_cache_free(sighand_cachep, new_sigh); |
| 1699 | |
JANAK DESAI | cf2e340 | 2006-02-07 12:58:58 -0800 | [diff] [blame] | 1700 | bad_unshare_cleanup_fs: |
| 1701 | if (new_fs) |
| 1702 | put_fs_struct(new_fs); |
| 1703 | |
| 1704 | bad_unshare_cleanup_thread: |
| 1705 | bad_unshare_out: |
| 1706 | return err; |
| 1707 | } |
Al Viro | 3b12538 | 2008-04-22 05:31:30 -0400 | [diff] [blame] | 1708 | |
| 1709 | /* |
| 1710 | * Helper to unshare the files of the current task. |
| 1711 | * We don't want to expose copy_files internals to |
| 1712 | * the exec layer of the kernel. |
| 1713 | */ |
| 1714 | |
| 1715 | int unshare_files(struct files_struct **displaced) |
| 1716 | { |
| 1717 | struct task_struct *task = current; |
Al Viro | 5070451 | 2008-04-26 05:25:00 +0100 | [diff] [blame] | 1718 | struct files_struct *copy = NULL; |
Al Viro | 3b12538 | 2008-04-22 05:31:30 -0400 | [diff] [blame] | 1719 | int error; |
| 1720 | |
| 1721 | error = unshare_fd(CLONE_FILES, ©); |
| 1722 | if (error || !copy) { |
| 1723 | *displaced = NULL; |
| 1724 | return error; |
| 1725 | } |
| 1726 | *displaced = task->files; |
| 1727 | task_lock(task); |
| 1728 | task->files = copy; |
| 1729 | task_unlock(task); |
| 1730 | return 0; |
| 1731 | } |