Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/ipc/shm.c | |
3 | * Copyright (C) 1992, 1993 Krishna Balasubramanian | |
4 | * Many improvements/fixes by Bruno Haible. | |
5 | * Replaced `struct shm_desc' by `struct vm_area_struct', July 1994. | |
6 | * Fixed the shm swap deallocation (shm_unuse()), August 1998 Andrea Arcangeli. | |
7 | * | |
8 | * /proc/sysvipc/shm support (c) 1999 Dragos Acostachioaie <dragos@iname.com> | |
9 | * BIGMEM support, Andrea Arcangeli <andrea@suse.de> | |
10 | * SMP thread shm, Jean-Luc Boyard <jean-luc.boyard@siemens.fr> | |
11 | * HIGHMEM support, Ingo Molnar <mingo@redhat.com> | |
12 | * Make shmmax, shmall, shmmni sysctl'able, Christoph Rohland <cr@sap.com> | |
13 | * Shared /dev/zero support, Kanoj Sarcar <kanoj@sgi.com> | |
14 | * Move the mm functionality over to mm/shmem.c, Christoph Rohland <cr@sap.com> | |
15 | * | |
073115d6 SG |
16 | * support for audit of ipc object properties and permission changes |
17 | * Dustin Kirkland <dustin.kirkland@us.ibm.com> | |
4e982311 KK |
18 | * |
19 | * namespaces support | |
20 | * OpenVZ, SWsoft Inc. | |
21 | * Pavel Emelianov <xemul@openvz.org> | |
1da177e4 LT |
22 | */ |
23 | ||
1da177e4 LT |
24 | #include <linux/slab.h> |
25 | #include <linux/mm.h> | |
26 | #include <linux/hugetlb.h> | |
27 | #include <linux/shm.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/file.h> | |
30 | #include <linux/mman.h> | |
1da177e4 LT |
31 | #include <linux/shmem_fs.h> |
32 | #include <linux/security.h> | |
33 | #include <linux/syscalls.h> | |
34 | #include <linux/audit.h> | |
c59ede7b | 35 | #include <linux/capability.h> |
7d87e14c | 36 | #include <linux/ptrace.h> |
19b4946c | 37 | #include <linux/seq_file.h> |
3e148c79 | 38 | #include <linux/rwsem.h> |
4e982311 | 39 | #include <linux/nsproxy.h> |
bc56bba8 | 40 | #include <linux/mount.h> |
ae5e1b22 | 41 | #include <linux/ipc_namespace.h> |
7d87e14c | 42 | |
1da177e4 LT |
43 | #include <asm/uaccess.h> |
44 | ||
45 | #include "util.h" | |
46 | ||
bc56bba8 EB |
47 | struct shm_file_data { |
48 | int id; | |
49 | struct ipc_namespace *ns; | |
50 | struct file *file; | |
51 | const struct vm_operations_struct *vm_ops; | |
52 | }; | |
53 | ||
54 | #define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data)) | |
55 | ||
9a32144e | 56 | static const struct file_operations shm_file_operations; |
f0f37e2f | 57 | static const struct vm_operations_struct shm_vm_ops; |
1da177e4 | 58 | |
ed2ddbf8 | 59 | #define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS]) |
1da177e4 | 60 | |
4e982311 KK |
61 | #define shm_unlock(shp) \ |
62 | ipc_unlock(&(shp)->shm_perm) | |
1da177e4 | 63 | |
7748dbfa | 64 | static int newseg(struct ipc_namespace *, struct ipc_params *); |
bc56bba8 EB |
65 | static void shm_open(struct vm_area_struct *vma); |
66 | static void shm_close(struct vm_area_struct *vma); | |
4e982311 | 67 | static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp); |
1da177e4 | 68 | #ifdef CONFIG_PROC_FS |
19b4946c | 69 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it); |
1da177e4 LT |
70 | #endif |
71 | ||
ed2ddbf8 | 72 | void shm_init_ns(struct ipc_namespace *ns) |
4e982311 | 73 | { |
4e982311 KK |
74 | ns->shm_ctlmax = SHMMAX; |
75 | ns->shm_ctlall = SHMALL; | |
76 | ns->shm_ctlmni = SHMMNI; | |
77 | ns->shm_tot = 0; | |
e8148f75 | 78 | ipc_init_ids(&shm_ids(ns)); |
4e982311 KK |
79 | } |
80 | ||
f4566f04 | 81 | /* |
3e148c79 ND |
82 | * Called with shm_ids.rw_mutex (writer) and the shp structure locked. |
83 | * Only shm_ids.rw_mutex remains locked on exit. | |
f4566f04 | 84 | */ |
01b8b07a | 85 | static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) |
4e982311 | 86 | { |
01b8b07a PP |
87 | struct shmid_kernel *shp; |
88 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
89 | ||
4e982311 KK |
90 | if (shp->shm_nattch){ |
91 | shp->shm_perm.mode |= SHM_DEST; | |
92 | /* Do not find it any more */ | |
93 | shp->shm_perm.key = IPC_PRIVATE; | |
94 | shm_unlock(shp); | |
95 | } else | |
96 | shm_destroy(ns, shp); | |
97 | } | |
98 | ||
ae5e1b22 | 99 | #ifdef CONFIG_IPC_NS |
4e982311 KK |
100 | void shm_exit_ns(struct ipc_namespace *ns) |
101 | { | |
01b8b07a | 102 | free_ipcs(ns, &shm_ids(ns), do_shm_rmid); |
7d6feeb2 | 103 | idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr); |
4e982311 | 104 | } |
ae5e1b22 | 105 | #endif |
1da177e4 LT |
106 | |
107 | void __init shm_init (void) | |
108 | { | |
ed2ddbf8 | 109 | shm_init_ns(&init_ipc_ns); |
19b4946c MW |
110 | ipc_init_proc_interface("sysvipc/shm", |
111 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n", | |
4e982311 | 112 | IPC_SHM_IDS, sysvipc_shm_proc_show); |
1da177e4 LT |
113 | } |
114 | ||
3e148c79 ND |
115 | /* |
116 | * shm_lock_(check_) routines are called in the paths where the rw_mutex | |
00c2bf85 | 117 | * is not necessarily held. |
3e148c79 | 118 | */ |
023a5355 | 119 | static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id) |
1da177e4 | 120 | { |
03f02c76 ND |
121 | struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id); |
122 | ||
b1ed88b4 PP |
123 | if (IS_ERR(ipcp)) |
124 | return (struct shmid_kernel *)ipcp; | |
125 | ||
03f02c76 | 126 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
023a5355 ND |
127 | } |
128 | ||
129 | static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns, | |
130 | int id) | |
131 | { | |
03f02c76 ND |
132 | struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id); |
133 | ||
b1ed88b4 PP |
134 | if (IS_ERR(ipcp)) |
135 | return (struct shmid_kernel *)ipcp; | |
136 | ||
03f02c76 | 137 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
1da177e4 LT |
138 | } |
139 | ||
7ca7e564 | 140 | static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s) |
1da177e4 | 141 | { |
7ca7e564 | 142 | ipc_rmid(&shm_ids(ns), &s->shm_perm); |
1da177e4 LT |
143 | } |
144 | ||
1da177e4 | 145 | |
bc56bba8 EB |
146 | /* This is called by fork, once for every shm attach. */ |
147 | static void shm_open(struct vm_area_struct *vma) | |
4e982311 | 148 | { |
bc56bba8 EB |
149 | struct file *file = vma->vm_file; |
150 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 LT |
151 | struct shmid_kernel *shp; |
152 | ||
bc56bba8 | 153 | shp = shm_lock(sfd->ns, sfd->id); |
023a5355 | 154 | BUG_ON(IS_ERR(shp)); |
1da177e4 | 155 | shp->shm_atim = get_seconds(); |
b488893a | 156 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
157 | shp->shm_nattch++; |
158 | shm_unlock(shp); | |
159 | } | |
160 | ||
1da177e4 LT |
161 | /* |
162 | * shm_destroy - free the struct shmid_kernel | |
163 | * | |
f4566f04 | 164 | * @ns: namespace |
1da177e4 LT |
165 | * @shp: struct to free |
166 | * | |
3e148c79 | 167 | * It has to be called with shp and shm_ids.rw_mutex (writer) locked, |
1da177e4 LT |
168 | * but returns with shp unlocked and freed. |
169 | */ | |
4e982311 | 170 | static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 171 | { |
4e982311 | 172 | ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; |
7ca7e564 | 173 | shm_rmid(ns, shp); |
1da177e4 LT |
174 | shm_unlock(shp); |
175 | if (!is_file_hugepages(shp->shm_file)) | |
176 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
353d5c30 | 177 | else if (shp->mlock_user) |
6d63079a | 178 | user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size, |
1da177e4 LT |
179 | shp->mlock_user); |
180 | fput (shp->shm_file); | |
181 | security_shm_free(shp); | |
182 | ipc_rcu_putref(shp); | |
183 | } | |
184 | ||
185 | /* | |
bc56bba8 | 186 | * remove the attach descriptor vma. |
1da177e4 LT |
187 | * free memory for segment if it is marked destroyed. |
188 | * The descriptor has already been removed from the current->mm->mmap list | |
189 | * and will later be kfree()d. | |
190 | */ | |
bc56bba8 | 191 | static void shm_close(struct vm_area_struct *vma) |
1da177e4 | 192 | { |
bc56bba8 EB |
193 | struct file * file = vma->vm_file; |
194 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 | 195 | struct shmid_kernel *shp; |
bc56bba8 | 196 | struct ipc_namespace *ns = sfd->ns; |
4e982311 | 197 | |
3e148c79 | 198 | down_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 199 | /* remove from the list of attaches of the shm segment */ |
00c2bf85 | 200 | shp = shm_lock(ns, sfd->id); |
023a5355 | 201 | BUG_ON(IS_ERR(shp)); |
b488893a | 202 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
203 | shp->shm_dtim = get_seconds(); |
204 | shp->shm_nattch--; | |
205 | if(shp->shm_nattch == 0 && | |
b33291c0 | 206 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 207 | shm_destroy(ns, shp); |
1da177e4 LT |
208 | else |
209 | shm_unlock(shp); | |
3e148c79 | 210 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
211 | } |
212 | ||
d0217ac0 | 213 | static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
bc56bba8 EB |
214 | { |
215 | struct file *file = vma->vm_file; | |
216 | struct shm_file_data *sfd = shm_file_data(file); | |
217 | ||
d0217ac0 | 218 | return sfd->vm_ops->fault(vma, vmf); |
bc56bba8 EB |
219 | } |
220 | ||
221 | #ifdef CONFIG_NUMA | |
d823e3e7 | 222 | static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
bc56bba8 EB |
223 | { |
224 | struct file *file = vma->vm_file; | |
225 | struct shm_file_data *sfd = shm_file_data(file); | |
226 | int err = 0; | |
227 | if (sfd->vm_ops->set_policy) | |
228 | err = sfd->vm_ops->set_policy(vma, new); | |
229 | return err; | |
230 | } | |
231 | ||
d823e3e7 AB |
232 | static struct mempolicy *shm_get_policy(struct vm_area_struct *vma, |
233 | unsigned long addr) | |
bc56bba8 EB |
234 | { |
235 | struct file *file = vma->vm_file; | |
236 | struct shm_file_data *sfd = shm_file_data(file); | |
237 | struct mempolicy *pol = NULL; | |
238 | ||
239 | if (sfd->vm_ops->get_policy) | |
240 | pol = sfd->vm_ops->get_policy(vma, addr); | |
52cd3b07 | 241 | else if (vma->vm_policy) |
bc56bba8 | 242 | pol = vma->vm_policy; |
52cd3b07 | 243 | |
bc56bba8 EB |
244 | return pol; |
245 | } | |
246 | #endif | |
247 | ||
1da177e4 LT |
248 | static int shm_mmap(struct file * file, struct vm_area_struct * vma) |
249 | { | |
bc56bba8 | 250 | struct shm_file_data *sfd = shm_file_data(file); |
b0e15190 DH |
251 | int ret; |
252 | ||
bc56bba8 EB |
253 | ret = sfd->file->f_op->mmap(sfd->file, vma); |
254 | if (ret != 0) | |
255 | return ret; | |
256 | sfd->vm_ops = vma->vm_ops; | |
2e92a3ba | 257 | #ifdef CONFIG_MMU |
54cb8821 | 258 | BUG_ON(!sfd->vm_ops->fault); |
2e92a3ba | 259 | #endif |
bc56bba8 EB |
260 | vma->vm_ops = &shm_vm_ops; |
261 | shm_open(vma); | |
b0e15190 DH |
262 | |
263 | return ret; | |
1da177e4 LT |
264 | } |
265 | ||
4e982311 KK |
266 | static int shm_release(struct inode *ino, struct file *file) |
267 | { | |
bc56bba8 | 268 | struct shm_file_data *sfd = shm_file_data(file); |
4e982311 | 269 | |
bc56bba8 EB |
270 | put_ipc_ns(sfd->ns); |
271 | shm_file_data(file) = NULL; | |
272 | kfree(sfd); | |
4e982311 KK |
273 | return 0; |
274 | } | |
275 | ||
7ea80859 | 276 | static int shm_fsync(struct file *file, int datasync) |
516dffdc | 277 | { |
516dffdc | 278 | struct shm_file_data *sfd = shm_file_data(file); |
516dffdc | 279 | |
7ea80859 CH |
280 | if (!sfd->file->f_op->fsync) |
281 | return -EINVAL; | |
282 | return sfd->file->f_op->fsync(sfd->file, datasync); | |
516dffdc AL |
283 | } |
284 | ||
bc56bba8 EB |
285 | static unsigned long shm_get_unmapped_area(struct file *file, |
286 | unsigned long addr, unsigned long len, unsigned long pgoff, | |
287 | unsigned long flags) | |
288 | { | |
289 | struct shm_file_data *sfd = shm_file_data(file); | |
c4caa778 AV |
290 | return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len, |
291 | pgoff, flags); | |
bc56bba8 | 292 | } |
bc56bba8 | 293 | |
9a32144e | 294 | static const struct file_operations shm_file_operations = { |
4e982311 | 295 | .mmap = shm_mmap, |
516dffdc | 296 | .fsync = shm_fsync, |
4e982311 | 297 | .release = shm_release, |
ed5e5894 DH |
298 | #ifndef CONFIG_MMU |
299 | .get_unmapped_area = shm_get_unmapped_area, | |
300 | #endif | |
6038f373 | 301 | .llseek = noop_llseek, |
c4caa778 AV |
302 | }; |
303 | ||
304 | static const struct file_operations shm_file_operations_huge = { | |
305 | .mmap = shm_mmap, | |
306 | .fsync = shm_fsync, | |
307 | .release = shm_release, | |
bc56bba8 | 308 | .get_unmapped_area = shm_get_unmapped_area, |
6038f373 | 309 | .llseek = noop_llseek, |
1da177e4 LT |
310 | }; |
311 | ||
c4caa778 AV |
312 | int is_file_shm_hugepages(struct file *file) |
313 | { | |
314 | return file->f_op == &shm_file_operations_huge; | |
315 | } | |
316 | ||
f0f37e2f | 317 | static const struct vm_operations_struct shm_vm_ops = { |
1da177e4 LT |
318 | .open = shm_open, /* callback for a new vm-area open */ |
319 | .close = shm_close, /* callback for when the vm-area is released */ | |
54cb8821 | 320 | .fault = shm_fault, |
bc56bba8 EB |
321 | #if defined(CONFIG_NUMA) |
322 | .set_policy = shm_set_policy, | |
323 | .get_policy = shm_get_policy, | |
1da177e4 LT |
324 | #endif |
325 | }; | |
326 | ||
f4566f04 ND |
327 | /** |
328 | * newseg - Create a new shared memory segment | |
329 | * @ns: namespace | |
330 | * @params: ptr to the structure that contains key, size and shmflg | |
331 | * | |
3e148c79 | 332 | * Called with shm_ids.rw_mutex held as a writer. |
f4566f04 ND |
333 | */ |
334 | ||
7748dbfa | 335 | static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 336 | { |
7748dbfa ND |
337 | key_t key = params->key; |
338 | int shmflg = params->flg; | |
339 | size_t size = params->u.size; | |
1da177e4 LT |
340 | int error; |
341 | struct shmid_kernel *shp; | |
342 | int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; | |
343 | struct file * file; | |
344 | char name[13]; | |
345 | int id; | |
5a6fe125 | 346 | int acctflag = 0; |
1da177e4 | 347 | |
4e982311 | 348 | if (size < SHMMIN || size > ns->shm_ctlmax) |
1da177e4 LT |
349 | return -EINVAL; |
350 | ||
f66d45e9 | 351 | if (ns->shm_tot + numpages > ns->shm_ctlall) |
1da177e4 LT |
352 | return -ENOSPC; |
353 | ||
354 | shp = ipc_rcu_alloc(sizeof(*shp)); | |
355 | if (!shp) | |
356 | return -ENOMEM; | |
357 | ||
358 | shp->shm_perm.key = key; | |
b33291c0 | 359 | shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
1da177e4 LT |
360 | shp->mlock_user = NULL; |
361 | ||
362 | shp->shm_perm.security = NULL; | |
363 | error = security_shm_alloc(shp); | |
364 | if (error) { | |
365 | ipc_rcu_putref(shp); | |
366 | return error; | |
367 | } | |
368 | ||
9d66586f | 369 | sprintf (name, "SYSV%08x", key); |
1da177e4 | 370 | if (shmflg & SHM_HUGETLB) { |
5a6fe125 MG |
371 | /* hugetlb_file_setup applies strict accounting */ |
372 | if (shmflg & SHM_NORESERVE) | |
373 | acctflag = VM_NORESERVE; | |
353d5c30 | 374 | file = hugetlb_file_setup(name, size, acctflag, |
6bfde05b | 375 | &shp->mlock_user, HUGETLB_SHMFS_INODE); |
1da177e4 | 376 | } else { |
bf8f972d BP |
377 | /* |
378 | * Do not allow no accounting for OVERCOMMIT_NEVER, even | |
379 | * if it's asked for. | |
380 | */ | |
381 | if ((shmflg & SHM_NORESERVE) && | |
382 | sysctl_overcommit_memory != OVERCOMMIT_NEVER) | |
fc8744ad | 383 | acctflag = VM_NORESERVE; |
bf8f972d | 384 | file = shmem_file_setup(name, size, acctflag); |
1da177e4 LT |
385 | } |
386 | error = PTR_ERR(file); | |
387 | if (IS_ERR(file)) | |
388 | goto no_file; | |
389 | ||
48dea404 | 390 | id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
283bb7fa PP |
391 | if (id < 0) { |
392 | error = id; | |
1da177e4 | 393 | goto no_id; |
283bb7fa | 394 | } |
1da177e4 | 395 | |
b488893a | 396 | shp->shm_cprid = task_tgid_vnr(current); |
1da177e4 LT |
397 | shp->shm_lprid = 0; |
398 | shp->shm_atim = shp->shm_dtim = 0; | |
399 | shp->shm_ctim = get_seconds(); | |
400 | shp->shm_segsz = size; | |
401 | shp->shm_nattch = 0; | |
1da177e4 | 402 | shp->shm_file = file; |
30475cc1 BP |
403 | /* |
404 | * shmid gets reported as "inode#" in /proc/pid/maps. | |
405 | * proc-ps tools use this. Changing this will break them. | |
406 | */ | |
7ca7e564 | 407 | file->f_dentry->d_inode->i_ino = shp->shm_perm.id; |
551110a9 | 408 | |
4e982311 | 409 | ns->shm_tot += numpages; |
7ca7e564 | 410 | error = shp->shm_perm.id; |
1da177e4 | 411 | shm_unlock(shp); |
7ca7e564 | 412 | return error; |
1da177e4 LT |
413 | |
414 | no_id: | |
2195d281 | 415 | if (is_file_hugepages(file) && shp->mlock_user) |
353d5c30 | 416 | user_shm_unlock(size, shp->mlock_user); |
1da177e4 LT |
417 | fput(file); |
418 | no_file: | |
419 | security_shm_free(shp); | |
420 | ipc_rcu_putref(shp); | |
421 | return error; | |
422 | } | |
423 | ||
f4566f04 | 424 | /* |
3e148c79 | 425 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 426 | */ |
03f02c76 | 427 | static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg) |
7748dbfa | 428 | { |
03f02c76 ND |
429 | struct shmid_kernel *shp; |
430 | ||
431 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
432 | return security_shm_associate(shp, shmflg); | |
7748dbfa ND |
433 | } |
434 | ||
f4566f04 | 435 | /* |
3e148c79 | 436 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 437 | */ |
03f02c76 ND |
438 | static inline int shm_more_checks(struct kern_ipc_perm *ipcp, |
439 | struct ipc_params *params) | |
7748dbfa | 440 | { |
03f02c76 ND |
441 | struct shmid_kernel *shp; |
442 | ||
443 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
444 | if (shp->shm_segsz < params->u.size) | |
7748dbfa ND |
445 | return -EINVAL; |
446 | ||
447 | return 0; | |
448 | } | |
449 | ||
d5460c99 | 450 | SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg) |
1da177e4 | 451 | { |
4e982311 | 452 | struct ipc_namespace *ns; |
7748dbfa ND |
453 | struct ipc_ops shm_ops; |
454 | struct ipc_params shm_params; | |
4e982311 KK |
455 | |
456 | ns = current->nsproxy->ipc_ns; | |
1da177e4 | 457 | |
7748dbfa ND |
458 | shm_ops.getnew = newseg; |
459 | shm_ops.associate = shm_security; | |
460 | shm_ops.more_checks = shm_more_checks; | |
7ca7e564 | 461 | |
7748dbfa ND |
462 | shm_params.key = key; |
463 | shm_params.flg = shmflg; | |
464 | shm_params.u.size = size; | |
1da177e4 | 465 | |
7748dbfa | 466 | return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); |
1da177e4 LT |
467 | } |
468 | ||
469 | static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) | |
470 | { | |
471 | switch(version) { | |
472 | case IPC_64: | |
473 | return copy_to_user(buf, in, sizeof(*in)); | |
474 | case IPC_OLD: | |
475 | { | |
476 | struct shmid_ds out; | |
477 | ||
478 | ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); | |
479 | out.shm_segsz = in->shm_segsz; | |
480 | out.shm_atime = in->shm_atime; | |
481 | out.shm_dtime = in->shm_dtime; | |
482 | out.shm_ctime = in->shm_ctime; | |
483 | out.shm_cpid = in->shm_cpid; | |
484 | out.shm_lpid = in->shm_lpid; | |
485 | out.shm_nattch = in->shm_nattch; | |
486 | ||
487 | return copy_to_user(buf, &out, sizeof(out)); | |
488 | } | |
489 | default: | |
490 | return -EINVAL; | |
491 | } | |
492 | } | |
493 | ||
016d7132 PP |
494 | static inline unsigned long |
495 | copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version) | |
1da177e4 LT |
496 | { |
497 | switch(version) { | |
498 | case IPC_64: | |
016d7132 | 499 | if (copy_from_user(out, buf, sizeof(*out))) |
1da177e4 | 500 | return -EFAULT; |
1da177e4 | 501 | return 0; |
1da177e4 LT |
502 | case IPC_OLD: |
503 | { | |
504 | struct shmid_ds tbuf_old; | |
505 | ||
506 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) | |
507 | return -EFAULT; | |
508 | ||
016d7132 PP |
509 | out->shm_perm.uid = tbuf_old.shm_perm.uid; |
510 | out->shm_perm.gid = tbuf_old.shm_perm.gid; | |
511 | out->shm_perm.mode = tbuf_old.shm_perm.mode; | |
1da177e4 LT |
512 | |
513 | return 0; | |
514 | } | |
515 | default: | |
516 | return -EINVAL; | |
517 | } | |
518 | } | |
519 | ||
520 | static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version) | |
521 | { | |
522 | switch(version) { | |
523 | case IPC_64: | |
524 | return copy_to_user(buf, in, sizeof(*in)); | |
525 | case IPC_OLD: | |
526 | { | |
527 | struct shminfo out; | |
528 | ||
529 | if(in->shmmax > INT_MAX) | |
530 | out.shmmax = INT_MAX; | |
531 | else | |
532 | out.shmmax = (int)in->shmmax; | |
533 | ||
534 | out.shmmin = in->shmmin; | |
535 | out.shmmni = in->shmmni; | |
536 | out.shmseg = in->shmseg; | |
537 | out.shmall = in->shmall; | |
538 | ||
539 | return copy_to_user(buf, &out, sizeof(out)); | |
540 | } | |
541 | default: | |
542 | return -EINVAL; | |
543 | } | |
544 | } | |
545 | ||
f4566f04 | 546 | /* |
3e148c79 | 547 | * Called with shm_ids.rw_mutex held as a reader |
f4566f04 | 548 | */ |
4e982311 KK |
549 | static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, |
550 | unsigned long *swp) | |
1da177e4 | 551 | { |
7ca7e564 ND |
552 | int next_id; |
553 | int total, in_use; | |
1da177e4 LT |
554 | |
555 | *rss = 0; | |
556 | *swp = 0; | |
557 | ||
7ca7e564 ND |
558 | in_use = shm_ids(ns).in_use; |
559 | ||
560 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
e562aebc | 561 | struct kern_ipc_perm *ipc; |
1da177e4 LT |
562 | struct shmid_kernel *shp; |
563 | struct inode *inode; | |
564 | ||
e562aebc TB |
565 | ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
566 | if (ipc == NULL) | |
1da177e4 | 567 | continue; |
e562aebc | 568 | shp = container_of(ipc, struct shmid_kernel, shm_perm); |
1da177e4 | 569 | |
6d63079a | 570 | inode = shp->shm_file->f_path.dentry->d_inode; |
1da177e4 LT |
571 | |
572 | if (is_file_hugepages(shp->shm_file)) { | |
573 | struct address_space *mapping = inode->i_mapping; | |
a5516438 AK |
574 | struct hstate *h = hstate_file(shp->shm_file); |
575 | *rss += pages_per_huge_page(h) * mapping->nrpages; | |
1da177e4 | 576 | } else { |
a68e61e8 | 577 | #ifdef CONFIG_SHMEM |
1da177e4 LT |
578 | struct shmem_inode_info *info = SHMEM_I(inode); |
579 | spin_lock(&info->lock); | |
580 | *rss += inode->i_mapping->nrpages; | |
581 | *swp += info->swapped; | |
582 | spin_unlock(&info->lock); | |
a68e61e8 TB |
583 | #else |
584 | *rss += inode->i_mapping->nrpages; | |
585 | #endif | |
1da177e4 | 586 | } |
7ca7e564 ND |
587 | |
588 | total++; | |
1da177e4 LT |
589 | } |
590 | } | |
591 | ||
8d4cc8b5 PP |
592 | /* |
593 | * This function handles some shmctl commands which require the rw_mutex | |
594 | * to be held in write mode. | |
595 | * NOTE: no locks must be held, the rw_mutex is taken inside this function. | |
596 | */ | |
597 | static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, | |
598 | struct shmid_ds __user *buf, int version) | |
1da177e4 | 599 | { |
8d4cc8b5 | 600 | struct kern_ipc_perm *ipcp; |
016d7132 | 601 | struct shmid64_ds shmid64; |
8d4cc8b5 PP |
602 | struct shmid_kernel *shp; |
603 | int err; | |
604 | ||
605 | if (cmd == IPC_SET) { | |
016d7132 | 606 | if (copy_shmid_from_user(&shmid64, buf, version)) |
8d4cc8b5 PP |
607 | return -EFAULT; |
608 | } | |
609 | ||
a5f75e7f PP |
610 | ipcp = ipcctl_pre_down(&shm_ids(ns), shmid, cmd, &shmid64.shm_perm, 0); |
611 | if (IS_ERR(ipcp)) | |
612 | return PTR_ERR(ipcp); | |
8d4cc8b5 | 613 | |
a5f75e7f | 614 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
8d4cc8b5 PP |
615 | |
616 | err = security_shm_shmctl(shp, cmd); | |
617 | if (err) | |
618 | goto out_unlock; | |
619 | switch (cmd) { | |
620 | case IPC_RMID: | |
621 | do_shm_rmid(ns, ipcp); | |
622 | goto out_up; | |
623 | case IPC_SET: | |
8f4a3809 | 624 | ipc_update_perm(&shmid64.shm_perm, ipcp); |
8d4cc8b5 PP |
625 | shp->shm_ctim = get_seconds(); |
626 | break; | |
627 | default: | |
628 | err = -EINVAL; | |
629 | } | |
630 | out_unlock: | |
631 | shm_unlock(shp); | |
632 | out_up: | |
633 | up_write(&shm_ids(ns).rw_mutex); | |
634 | return err; | |
635 | } | |
636 | ||
d5460c99 | 637 | SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) |
8d4cc8b5 | 638 | { |
1da177e4 LT |
639 | struct shmid_kernel *shp; |
640 | int err, version; | |
4e982311 | 641 | struct ipc_namespace *ns; |
1da177e4 LT |
642 | |
643 | if (cmd < 0 || shmid < 0) { | |
644 | err = -EINVAL; | |
645 | goto out; | |
646 | } | |
647 | ||
648 | version = ipc_parse_version(&cmd); | |
4e982311 | 649 | ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
650 | |
651 | switch (cmd) { /* replace with proc interface ? */ | |
652 | case IPC_INFO: | |
653 | { | |
654 | struct shminfo64 shminfo; | |
655 | ||
656 | err = security_shm_shmctl(NULL, cmd); | |
657 | if (err) | |
658 | return err; | |
659 | ||
e8148f75 | 660 | memset(&shminfo, 0, sizeof(shminfo)); |
4e982311 KK |
661 | shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni; |
662 | shminfo.shmmax = ns->shm_ctlmax; | |
663 | shminfo.shmall = ns->shm_ctlall; | |
1da177e4 LT |
664 | |
665 | shminfo.shmmin = SHMMIN; | |
666 | if(copy_shminfo_to_user (buf, &shminfo, version)) | |
667 | return -EFAULT; | |
f4566f04 | 668 | |
3e148c79 | 669 | down_read(&shm_ids(ns).rw_mutex); |
7ca7e564 | 670 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 671 | up_read(&shm_ids(ns).rw_mutex); |
f4566f04 | 672 | |
1da177e4 LT |
673 | if(err<0) |
674 | err = 0; | |
675 | goto out; | |
676 | } | |
677 | case SHM_INFO: | |
678 | { | |
679 | struct shm_info shm_info; | |
680 | ||
681 | err = security_shm_shmctl(NULL, cmd); | |
682 | if (err) | |
683 | return err; | |
684 | ||
e8148f75 | 685 | memset(&shm_info, 0, sizeof(shm_info)); |
3e148c79 | 686 | down_read(&shm_ids(ns).rw_mutex); |
4e982311 KK |
687 | shm_info.used_ids = shm_ids(ns).in_use; |
688 | shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp); | |
689 | shm_info.shm_tot = ns->shm_tot; | |
1da177e4 LT |
690 | shm_info.swap_attempts = 0; |
691 | shm_info.swap_successes = 0; | |
7ca7e564 | 692 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 693 | up_read(&shm_ids(ns).rw_mutex); |
e8148f75 | 694 | if (copy_to_user(buf, &shm_info, sizeof(shm_info))) { |
1da177e4 LT |
695 | err = -EFAULT; |
696 | goto out; | |
697 | } | |
698 | ||
699 | err = err < 0 ? 0 : err; | |
700 | goto out; | |
701 | } | |
702 | case SHM_STAT: | |
703 | case IPC_STAT: | |
704 | { | |
705 | struct shmid64_ds tbuf; | |
706 | int result; | |
023a5355 | 707 | |
023a5355 ND |
708 | if (cmd == SHM_STAT) { |
709 | shp = shm_lock(ns, shmid); | |
710 | if (IS_ERR(shp)) { | |
711 | err = PTR_ERR(shp); | |
712 | goto out; | |
713 | } | |
7ca7e564 | 714 | result = shp->shm_perm.id; |
1da177e4 | 715 | } else { |
023a5355 ND |
716 | shp = shm_lock_check(ns, shmid); |
717 | if (IS_ERR(shp)) { | |
718 | err = PTR_ERR(shp); | |
719 | goto out; | |
720 | } | |
1da177e4 LT |
721 | result = 0; |
722 | } | |
e8148f75 | 723 | err = -EACCES; |
1da177e4 LT |
724 | if (ipcperms (&shp->shm_perm, S_IRUGO)) |
725 | goto out_unlock; | |
726 | err = security_shm_shmctl(shp, cmd); | |
727 | if (err) | |
728 | goto out_unlock; | |
023a5355 | 729 | memset(&tbuf, 0, sizeof(tbuf)); |
1da177e4 LT |
730 | kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm); |
731 | tbuf.shm_segsz = shp->shm_segsz; | |
732 | tbuf.shm_atime = shp->shm_atim; | |
733 | tbuf.shm_dtime = shp->shm_dtim; | |
734 | tbuf.shm_ctime = shp->shm_ctim; | |
735 | tbuf.shm_cpid = shp->shm_cprid; | |
736 | tbuf.shm_lpid = shp->shm_lprid; | |
bc56bba8 | 737 | tbuf.shm_nattch = shp->shm_nattch; |
1da177e4 LT |
738 | shm_unlock(shp); |
739 | if(copy_shmid_to_user (buf, &tbuf, version)) | |
740 | err = -EFAULT; | |
741 | else | |
742 | err = result; | |
743 | goto out; | |
744 | } | |
745 | case SHM_LOCK: | |
746 | case SHM_UNLOCK: | |
747 | { | |
89e004ea LS |
748 | struct file *uninitialized_var(shm_file); |
749 | ||
750 | lru_add_drain_all(); /* drain pagevecs to lru lists */ | |
751 | ||
023a5355 ND |
752 | shp = shm_lock_check(ns, shmid); |
753 | if (IS_ERR(shp)) { | |
754 | err = PTR_ERR(shp); | |
1da177e4 LT |
755 | goto out; |
756 | } | |
1da177e4 | 757 | |
a33e6751 | 758 | audit_ipc_obj(&(shp->shm_perm)); |
073115d6 | 759 | |
1da177e4 | 760 | if (!capable(CAP_IPC_LOCK)) { |
414c0708 | 761 | uid_t euid = current_euid(); |
1da177e4 | 762 | err = -EPERM; |
414c0708 DH |
763 | if (euid != shp->shm_perm.uid && |
764 | euid != shp->shm_perm.cuid) | |
1da177e4 | 765 | goto out_unlock; |
f1eb1332 | 766 | if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) |
1da177e4 LT |
767 | goto out_unlock; |
768 | } | |
769 | ||
770 | err = security_shm_shmctl(shp, cmd); | |
771 | if (err) | |
772 | goto out_unlock; | |
773 | ||
774 | if(cmd==SHM_LOCK) { | |
86a264ab | 775 | struct user_struct *user = current_user(); |
1da177e4 LT |
776 | if (!is_file_hugepages(shp->shm_file)) { |
777 | err = shmem_lock(shp->shm_file, 1, user); | |
7be77e20 | 778 | if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){ |
b33291c0 | 779 | shp->shm_perm.mode |= SHM_LOCKED; |
1da177e4 LT |
780 | shp->mlock_user = user; |
781 | } | |
782 | } | |
783 | } else if (!is_file_hugepages(shp->shm_file)) { | |
784 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
b33291c0 | 785 | shp->shm_perm.mode &= ~SHM_LOCKED; |
1da177e4 LT |
786 | shp->mlock_user = NULL; |
787 | } | |
788 | shm_unlock(shp); | |
789 | goto out; | |
790 | } | |
791 | case IPC_RMID: | |
1da177e4 | 792 | case IPC_SET: |
8d4cc8b5 PP |
793 | err = shmctl_down(ns, shmid, cmd, buf, version); |
794 | return err; | |
1da177e4 | 795 | default: |
8d4cc8b5 | 796 | return -EINVAL; |
1da177e4 LT |
797 | } |
798 | ||
1da177e4 LT |
799 | out_unlock: |
800 | shm_unlock(shp); | |
801 | out: | |
802 | return err; | |
803 | } | |
804 | ||
805 | /* | |
806 | * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists. | |
807 | * | |
808 | * NOTE! Despite the name, this is NOT a direct system call entrypoint. The | |
809 | * "raddr" thing points to kernel space, and there has to be a wrapper around | |
810 | * this. | |
811 | */ | |
812 | long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) | |
813 | { | |
814 | struct shmid_kernel *shp; | |
815 | unsigned long addr; | |
816 | unsigned long size; | |
817 | struct file * file; | |
818 | int err; | |
819 | unsigned long flags; | |
820 | unsigned long prot; | |
1da177e4 | 821 | int acc_mode; |
bc56bba8 | 822 | unsigned long user_addr; |
4e982311 | 823 | struct ipc_namespace *ns; |
bc56bba8 EB |
824 | struct shm_file_data *sfd; |
825 | struct path path; | |
aeb5d727 | 826 | fmode_t f_mode; |
1da177e4 | 827 | |
bc56bba8 EB |
828 | err = -EINVAL; |
829 | if (shmid < 0) | |
1da177e4 | 830 | goto out; |
bc56bba8 | 831 | else if ((addr = (ulong)shmaddr)) { |
1da177e4 LT |
832 | if (addr & (SHMLBA-1)) { |
833 | if (shmflg & SHM_RND) | |
834 | addr &= ~(SHMLBA-1); /* round down */ | |
835 | else | |
836 | #ifndef __ARCH_FORCE_SHMLBA | |
837 | if (addr & ~PAGE_MASK) | |
838 | #endif | |
bc56bba8 | 839 | goto out; |
1da177e4 LT |
840 | } |
841 | flags = MAP_SHARED | MAP_FIXED; | |
842 | } else { | |
843 | if ((shmflg & SHM_REMAP)) | |
bc56bba8 | 844 | goto out; |
1da177e4 LT |
845 | |
846 | flags = MAP_SHARED; | |
847 | } | |
848 | ||
849 | if (shmflg & SHM_RDONLY) { | |
850 | prot = PROT_READ; | |
1da177e4 | 851 | acc_mode = S_IRUGO; |
bc56bba8 | 852 | f_mode = FMODE_READ; |
1da177e4 LT |
853 | } else { |
854 | prot = PROT_READ | PROT_WRITE; | |
1da177e4 | 855 | acc_mode = S_IRUGO | S_IWUGO; |
bc56bba8 | 856 | f_mode = FMODE_READ | FMODE_WRITE; |
1da177e4 LT |
857 | } |
858 | if (shmflg & SHM_EXEC) { | |
859 | prot |= PROT_EXEC; | |
860 | acc_mode |= S_IXUGO; | |
861 | } | |
862 | ||
863 | /* | |
864 | * We cannot rely on the fs check since SYSV IPC does have an | |
865 | * additional creator id... | |
866 | */ | |
4e982311 | 867 | ns = current->nsproxy->ipc_ns; |
023a5355 ND |
868 | shp = shm_lock_check(ns, shmid); |
869 | if (IS_ERR(shp)) { | |
870 | err = PTR_ERR(shp); | |
1da177e4 | 871 | goto out; |
023a5355 | 872 | } |
bc56bba8 EB |
873 | |
874 | err = -EACCES; | |
875 | if (ipcperms(&shp->shm_perm, acc_mode)) | |
876 | goto out_unlock; | |
1da177e4 LT |
877 | |
878 | err = security_shm_shmat(shp, shmaddr, shmflg); | |
bc56bba8 EB |
879 | if (err) |
880 | goto out_unlock; | |
881 | ||
2c48b9c4 AV |
882 | path = shp->shm_file->f_path; |
883 | path_get(&path); | |
1da177e4 | 884 | shp->shm_nattch++; |
bc56bba8 | 885 | size = i_size_read(path.dentry->d_inode); |
1da177e4 LT |
886 | shm_unlock(shp); |
887 | ||
bc56bba8 EB |
888 | err = -ENOMEM; |
889 | sfd = kzalloc(sizeof(*sfd), GFP_KERNEL); | |
890 | if (!sfd) | |
ce8d2cdf | 891 | goto out_put_dentry; |
bc56bba8 | 892 | |
2c48b9c4 AV |
893 | file = alloc_file(&path, f_mode, |
894 | is_file_hugepages(shp->shm_file) ? | |
c4caa778 AV |
895 | &shm_file_operations_huge : |
896 | &shm_file_operations); | |
bc56bba8 EB |
897 | if (!file) |
898 | goto out_free; | |
899 | ||
bc56bba8 | 900 | file->private_data = sfd; |
bc56bba8 | 901 | file->f_mapping = shp->shm_file->f_mapping; |
7ca7e564 | 902 | sfd->id = shp->shm_perm.id; |
bc56bba8 EB |
903 | sfd->ns = get_ipc_ns(ns); |
904 | sfd->file = shp->shm_file; | |
905 | sfd->vm_ops = NULL; | |
906 | ||
1da177e4 LT |
907 | down_write(¤t->mm->mmap_sem); |
908 | if (addr && !(shmflg & SHM_REMAP)) { | |
bc56bba8 | 909 | err = -EINVAL; |
1da177e4 LT |
910 | if (find_vma_intersection(current->mm, addr, addr + size)) |
911 | goto invalid; | |
912 | /* | |
913 | * If shm segment goes below stack, make sure there is some | |
914 | * space left for the stack to grow (at least 4 pages). | |
915 | */ | |
916 | if (addr < current->mm->start_stack && | |
917 | addr > current->mm->start_stack - size - PAGE_SIZE * 5) | |
918 | goto invalid; | |
919 | } | |
920 | ||
bc56bba8 EB |
921 | user_addr = do_mmap (file, addr, size, prot, flags, 0); |
922 | *raddr = user_addr; | |
923 | err = 0; | |
924 | if (IS_ERR_VALUE(user_addr)) | |
925 | err = (long)user_addr; | |
1da177e4 LT |
926 | invalid: |
927 | up_write(¤t->mm->mmap_sem); | |
928 | ||
bc56bba8 EB |
929 | fput(file); |
930 | ||
931 | out_nattch: | |
3e148c79 | 932 | down_write(&shm_ids(ns).rw_mutex); |
00c2bf85 | 933 | shp = shm_lock(ns, shmid); |
023a5355 | 934 | BUG_ON(IS_ERR(shp)); |
1da177e4 LT |
935 | shp->shm_nattch--; |
936 | if(shp->shm_nattch == 0 && | |
b33291c0 | 937 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 938 | shm_destroy(ns, shp); |
1da177e4 LT |
939 | else |
940 | shm_unlock(shp); | |
3e148c79 | 941 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 942 | |
1da177e4 LT |
943 | out: |
944 | return err; | |
bc56bba8 EB |
945 | |
946 | out_unlock: | |
947 | shm_unlock(shp); | |
948 | goto out; | |
949 | ||
950 | out_free: | |
951 | kfree(sfd); | |
ce8d2cdf | 952 | out_put_dentry: |
2c48b9c4 | 953 | path_put(&path); |
bc56bba8 | 954 | goto out_nattch; |
1da177e4 LT |
955 | } |
956 | ||
d5460c99 | 957 | SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg) |
7d87e14c SR |
958 | { |
959 | unsigned long ret; | |
960 | long err; | |
961 | ||
962 | err = do_shmat(shmid, shmaddr, shmflg, &ret); | |
963 | if (err) | |
964 | return err; | |
965 | force_successful_syscall_return(); | |
966 | return (long)ret; | |
967 | } | |
968 | ||
1da177e4 LT |
969 | /* |
970 | * detach and kill segment if marked destroyed. | |
971 | * The work is done in shm_close. | |
972 | */ | |
d5460c99 | 973 | SYSCALL_DEFINE1(shmdt, char __user *, shmaddr) |
1da177e4 LT |
974 | { |
975 | struct mm_struct *mm = current->mm; | |
586c7e6a | 976 | struct vm_area_struct *vma; |
1da177e4 | 977 | unsigned long addr = (unsigned long)shmaddr; |
1da177e4 | 978 | int retval = -EINVAL; |
586c7e6a MF |
979 | #ifdef CONFIG_MMU |
980 | loff_t size = 0; | |
981 | struct vm_area_struct *next; | |
982 | #endif | |
1da177e4 | 983 | |
df1e2fb5 HD |
984 | if (addr & ~PAGE_MASK) |
985 | return retval; | |
986 | ||
1da177e4 LT |
987 | down_write(&mm->mmap_sem); |
988 | ||
989 | /* | |
990 | * This function tries to be smart and unmap shm segments that | |
991 | * were modified by partial mlock or munmap calls: | |
992 | * - It first determines the size of the shm segment that should be | |
993 | * unmapped: It searches for a vma that is backed by shm and that | |
994 | * started at address shmaddr. It records it's size and then unmaps | |
995 | * it. | |
996 | * - Then it unmaps all shm vmas that started at shmaddr and that | |
997 | * are within the initially determined size. | |
998 | * Errors from do_munmap are ignored: the function only fails if | |
999 | * it's called with invalid parameters or if it's called to unmap | |
1000 | * a part of a vma. Both calls in this function are for full vmas, | |
1001 | * the parameters are directly copied from the vma itself and always | |
1002 | * valid - therefore do_munmap cannot fail. (famous last words?) | |
1003 | */ | |
1004 | /* | |
1005 | * If it had been mremap()'d, the starting address would not | |
1006 | * match the usual checks anyway. So assume all vma's are | |
1007 | * above the starting address given. | |
1008 | */ | |
1009 | vma = find_vma(mm, addr); | |
1010 | ||
8feae131 | 1011 | #ifdef CONFIG_MMU |
1da177e4 LT |
1012 | while (vma) { |
1013 | next = vma->vm_next; | |
1014 | ||
1015 | /* | |
1016 | * Check if the starting address would match, i.e. it's | |
1017 | * a fragment created by mprotect() and/or munmap(), or it | |
1018 | * otherwise it starts at this address with no hassles. | |
1019 | */ | |
bc56bba8 | 1020 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1021 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { |
1022 | ||
1023 | ||
6d63079a | 1024 | size = vma->vm_file->f_path.dentry->d_inode->i_size; |
1da177e4 LT |
1025 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
1026 | /* | |
1027 | * We discovered the size of the shm segment, so | |
1028 | * break out of here and fall through to the next | |
1029 | * loop that uses the size information to stop | |
1030 | * searching for matching vma's. | |
1031 | */ | |
1032 | retval = 0; | |
1033 | vma = next; | |
1034 | break; | |
1035 | } | |
1036 | vma = next; | |
1037 | } | |
1038 | ||
1039 | /* | |
1040 | * We need look no further than the maximum address a fragment | |
1041 | * could possibly have landed at. Also cast things to loff_t to | |
1042 | * prevent overflows and make comparisions vs. equal-width types. | |
1043 | */ | |
8e36709d | 1044 | size = PAGE_ALIGN(size); |
1da177e4 LT |
1045 | while (vma && (loff_t)(vma->vm_end - addr) <= size) { |
1046 | next = vma->vm_next; | |
1047 | ||
1048 | /* finding a matching vma now does not alter retval */ | |
bc56bba8 | 1049 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1050 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) |
1051 | ||
1052 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
1053 | vma = next; | |
1054 | } | |
1055 | ||
8feae131 DH |
1056 | #else /* CONFIG_MMU */ |
1057 | /* under NOMMU conditions, the exact address to be destroyed must be | |
1058 | * given */ | |
1059 | retval = -EINVAL; | |
1060 | if (vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) { | |
1061 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
1062 | retval = 0; | |
1063 | } | |
1064 | ||
1065 | #endif | |
1066 | ||
1da177e4 LT |
1067 | up_write(&mm->mmap_sem); |
1068 | return retval; | |
1069 | } | |
1070 | ||
1071 | #ifdef CONFIG_PROC_FS | |
19b4946c | 1072 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
1da177e4 | 1073 | { |
19b4946c | 1074 | struct shmid_kernel *shp = it; |
1da177e4 | 1075 | |
6c826818 PM |
1076 | #if BITS_PER_LONG <= 32 |
1077 | #define SIZE_SPEC "%10lu" | |
1078 | #else | |
1079 | #define SIZE_SPEC "%21lu" | |
1080 | #endif | |
1da177e4 | 1081 | |
6c826818 PM |
1082 | return seq_printf(s, |
1083 | "%10d %10d %4o " SIZE_SPEC " %5u %5u " | |
1084 | "%5lu %5u %5u %5u %5u %10lu %10lu %10lu\n", | |
19b4946c | 1085 | shp->shm_perm.key, |
7ca7e564 | 1086 | shp->shm_perm.id, |
b33291c0 | 1087 | shp->shm_perm.mode, |
19b4946c MW |
1088 | shp->shm_segsz, |
1089 | shp->shm_cprid, | |
1090 | shp->shm_lprid, | |
bc56bba8 | 1091 | shp->shm_nattch, |
19b4946c MW |
1092 | shp->shm_perm.uid, |
1093 | shp->shm_perm.gid, | |
1094 | shp->shm_perm.cuid, | |
1095 | shp->shm_perm.cgid, | |
1096 | shp->shm_atim, | |
1097 | shp->shm_dtim, | |
1098 | shp->shm_ctim); | |
1da177e4 LT |
1099 | } |
1100 | #endif |