]>
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> |
1df9f0a7 | 42 | #include <linux/ima.h> |
7d87e14c | 43 | |
1da177e4 LT |
44 | #include <asm/uaccess.h> |
45 | ||
46 | #include "util.h" | |
47 | ||
bc56bba8 EB |
48 | struct shm_file_data { |
49 | int id; | |
50 | struct ipc_namespace *ns; | |
51 | struct file *file; | |
52 | const struct vm_operations_struct *vm_ops; | |
53 | }; | |
54 | ||
55 | #define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data)) | |
56 | ||
9a32144e | 57 | static const struct file_operations shm_file_operations; |
f0f37e2f | 58 | static const struct vm_operations_struct shm_vm_ops; |
1da177e4 | 59 | |
ed2ddbf8 | 60 | #define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS]) |
1da177e4 | 61 | |
4e982311 KK |
62 | #define shm_unlock(shp) \ |
63 | ipc_unlock(&(shp)->shm_perm) | |
1da177e4 | 64 | |
7748dbfa | 65 | static int newseg(struct ipc_namespace *, struct ipc_params *); |
bc56bba8 EB |
66 | static void shm_open(struct vm_area_struct *vma); |
67 | static void shm_close(struct vm_area_struct *vma); | |
4e982311 | 68 | static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp); |
1da177e4 | 69 | #ifdef CONFIG_PROC_FS |
19b4946c | 70 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it); |
1da177e4 LT |
71 | #endif |
72 | ||
ed2ddbf8 | 73 | void shm_init_ns(struct ipc_namespace *ns) |
4e982311 | 74 | { |
4e982311 KK |
75 | ns->shm_ctlmax = SHMMAX; |
76 | ns->shm_ctlall = SHMALL; | |
77 | ns->shm_ctlmni = SHMMNI; | |
78 | ns->shm_tot = 0; | |
e8148f75 | 79 | ipc_init_ids(&shm_ids(ns)); |
4e982311 KK |
80 | } |
81 | ||
f4566f04 | 82 | /* |
3e148c79 ND |
83 | * Called with shm_ids.rw_mutex (writer) and the shp structure locked. |
84 | * Only shm_ids.rw_mutex remains locked on exit. | |
f4566f04 | 85 | */ |
01b8b07a | 86 | static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) |
4e982311 | 87 | { |
01b8b07a PP |
88 | struct shmid_kernel *shp; |
89 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
90 | ||
4e982311 KK |
91 | if (shp->shm_nattch){ |
92 | shp->shm_perm.mode |= SHM_DEST; | |
93 | /* Do not find it any more */ | |
94 | shp->shm_perm.key = IPC_PRIVATE; | |
95 | shm_unlock(shp); | |
96 | } else | |
97 | shm_destroy(ns, shp); | |
98 | } | |
99 | ||
ae5e1b22 | 100 | #ifdef CONFIG_IPC_NS |
4e982311 KK |
101 | void shm_exit_ns(struct ipc_namespace *ns) |
102 | { | |
01b8b07a | 103 | free_ipcs(ns, &shm_ids(ns), do_shm_rmid); |
7d6feeb2 | 104 | idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr); |
4e982311 | 105 | } |
ae5e1b22 | 106 | #endif |
1da177e4 LT |
107 | |
108 | void __init shm_init (void) | |
109 | { | |
ed2ddbf8 | 110 | shm_init_ns(&init_ipc_ns); |
19b4946c MW |
111 | ipc_init_proc_interface("sysvipc/shm", |
112 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n", | |
4e982311 | 113 | IPC_SHM_IDS, sysvipc_shm_proc_show); |
1da177e4 LT |
114 | } |
115 | ||
3e148c79 ND |
116 | /* |
117 | * shm_lock_(check_) routines are called in the paths where the rw_mutex | |
00c2bf85 | 118 | * is not necessarily held. |
3e148c79 | 119 | */ |
023a5355 | 120 | static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id) |
1da177e4 | 121 | { |
03f02c76 ND |
122 | struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id); |
123 | ||
b1ed88b4 PP |
124 | if (IS_ERR(ipcp)) |
125 | return (struct shmid_kernel *)ipcp; | |
126 | ||
03f02c76 | 127 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
023a5355 ND |
128 | } |
129 | ||
130 | static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns, | |
131 | int id) | |
132 | { | |
03f02c76 ND |
133 | struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id); |
134 | ||
b1ed88b4 PP |
135 | if (IS_ERR(ipcp)) |
136 | return (struct shmid_kernel *)ipcp; | |
137 | ||
03f02c76 | 138 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
1da177e4 LT |
139 | } |
140 | ||
7ca7e564 | 141 | static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s) |
1da177e4 | 142 | { |
7ca7e564 | 143 | ipc_rmid(&shm_ids(ns), &s->shm_perm); |
1da177e4 LT |
144 | } |
145 | ||
1da177e4 | 146 | |
bc56bba8 EB |
147 | /* This is called by fork, once for every shm attach. */ |
148 | static void shm_open(struct vm_area_struct *vma) | |
4e982311 | 149 | { |
bc56bba8 EB |
150 | struct file *file = vma->vm_file; |
151 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 LT |
152 | struct shmid_kernel *shp; |
153 | ||
bc56bba8 | 154 | shp = shm_lock(sfd->ns, sfd->id); |
023a5355 | 155 | BUG_ON(IS_ERR(shp)); |
1da177e4 | 156 | shp->shm_atim = get_seconds(); |
b488893a | 157 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
158 | shp->shm_nattch++; |
159 | shm_unlock(shp); | |
160 | } | |
161 | ||
1da177e4 LT |
162 | /* |
163 | * shm_destroy - free the struct shmid_kernel | |
164 | * | |
f4566f04 | 165 | * @ns: namespace |
1da177e4 LT |
166 | * @shp: struct to free |
167 | * | |
3e148c79 | 168 | * It has to be called with shp and shm_ids.rw_mutex (writer) locked, |
1da177e4 LT |
169 | * but returns with shp unlocked and freed. |
170 | */ | |
4e982311 | 171 | static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 172 | { |
4e982311 | 173 | ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; |
7ca7e564 | 174 | shm_rmid(ns, shp); |
1da177e4 LT |
175 | shm_unlock(shp); |
176 | if (!is_file_hugepages(shp->shm_file)) | |
177 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
353d5c30 | 178 | else if (shp->mlock_user) |
6d63079a | 179 | user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size, |
1da177e4 LT |
180 | shp->mlock_user); |
181 | fput (shp->shm_file); | |
182 | security_shm_free(shp); | |
183 | ipc_rcu_putref(shp); | |
184 | } | |
185 | ||
186 | /* | |
bc56bba8 | 187 | * remove the attach descriptor vma. |
1da177e4 LT |
188 | * free memory for segment if it is marked destroyed. |
189 | * The descriptor has already been removed from the current->mm->mmap list | |
190 | * and will later be kfree()d. | |
191 | */ | |
bc56bba8 | 192 | static void shm_close(struct vm_area_struct *vma) |
1da177e4 | 193 | { |
bc56bba8 EB |
194 | struct file * file = vma->vm_file; |
195 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 | 196 | struct shmid_kernel *shp; |
bc56bba8 | 197 | struct ipc_namespace *ns = sfd->ns; |
4e982311 | 198 | |
3e148c79 | 199 | down_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 200 | /* remove from the list of attaches of the shm segment */ |
00c2bf85 | 201 | shp = shm_lock(ns, sfd->id); |
023a5355 | 202 | BUG_ON(IS_ERR(shp)); |
b488893a | 203 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
204 | shp->shm_dtim = get_seconds(); |
205 | shp->shm_nattch--; | |
206 | if(shp->shm_nattch == 0 && | |
b33291c0 | 207 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 208 | shm_destroy(ns, shp); |
1da177e4 LT |
209 | else |
210 | shm_unlock(shp); | |
3e148c79 | 211 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
212 | } |
213 | ||
d0217ac0 | 214 | static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
bc56bba8 EB |
215 | { |
216 | struct file *file = vma->vm_file; | |
217 | struct shm_file_data *sfd = shm_file_data(file); | |
218 | ||
d0217ac0 | 219 | return sfd->vm_ops->fault(vma, vmf); |
bc56bba8 EB |
220 | } |
221 | ||
222 | #ifdef CONFIG_NUMA | |
d823e3e7 | 223 | static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
bc56bba8 EB |
224 | { |
225 | struct file *file = vma->vm_file; | |
226 | struct shm_file_data *sfd = shm_file_data(file); | |
227 | int err = 0; | |
228 | if (sfd->vm_ops->set_policy) | |
229 | err = sfd->vm_ops->set_policy(vma, new); | |
230 | return err; | |
231 | } | |
232 | ||
d823e3e7 AB |
233 | static struct mempolicy *shm_get_policy(struct vm_area_struct *vma, |
234 | unsigned long addr) | |
bc56bba8 EB |
235 | { |
236 | struct file *file = vma->vm_file; | |
237 | struct shm_file_data *sfd = shm_file_data(file); | |
238 | struct mempolicy *pol = NULL; | |
239 | ||
240 | if (sfd->vm_ops->get_policy) | |
241 | pol = sfd->vm_ops->get_policy(vma, addr); | |
52cd3b07 | 242 | else if (vma->vm_policy) |
bc56bba8 | 243 | pol = vma->vm_policy; |
52cd3b07 | 244 | |
bc56bba8 EB |
245 | return pol; |
246 | } | |
247 | #endif | |
248 | ||
1da177e4 LT |
249 | static int shm_mmap(struct file * file, struct vm_area_struct * vma) |
250 | { | |
bc56bba8 | 251 | struct shm_file_data *sfd = shm_file_data(file); |
b0e15190 DH |
252 | int ret; |
253 | ||
bc56bba8 EB |
254 | ret = sfd->file->f_op->mmap(sfd->file, vma); |
255 | if (ret != 0) | |
256 | return ret; | |
257 | sfd->vm_ops = vma->vm_ops; | |
2e92a3ba | 258 | #ifdef CONFIG_MMU |
54cb8821 | 259 | BUG_ON(!sfd->vm_ops->fault); |
2e92a3ba | 260 | #endif |
bc56bba8 EB |
261 | vma->vm_ops = &shm_vm_ops; |
262 | shm_open(vma); | |
b0e15190 DH |
263 | |
264 | return ret; | |
1da177e4 LT |
265 | } |
266 | ||
4e982311 KK |
267 | static int shm_release(struct inode *ino, struct file *file) |
268 | { | |
bc56bba8 | 269 | struct shm_file_data *sfd = shm_file_data(file); |
4e982311 | 270 | |
bc56bba8 EB |
271 | put_ipc_ns(sfd->ns); |
272 | shm_file_data(file) = NULL; | |
273 | kfree(sfd); | |
4e982311 KK |
274 | return 0; |
275 | } | |
276 | ||
516dffdc AL |
277 | static int shm_fsync(struct file *file, struct dentry *dentry, int datasync) |
278 | { | |
279 | int (*fsync) (struct file *, struct dentry *, int datasync); | |
280 | struct shm_file_data *sfd = shm_file_data(file); | |
281 | int ret = -EINVAL; | |
282 | ||
283 | fsync = sfd->file->f_op->fsync; | |
284 | if (fsync) | |
285 | ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync); | |
286 | return ret; | |
287 | } | |
288 | ||
bc56bba8 EB |
289 | static unsigned long shm_get_unmapped_area(struct file *file, |
290 | unsigned long addr, unsigned long len, unsigned long pgoff, | |
291 | unsigned long flags) | |
292 | { | |
293 | struct shm_file_data *sfd = shm_file_data(file); | |
c4caa778 AV |
294 | return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len, |
295 | pgoff, flags); | |
bc56bba8 | 296 | } |
bc56bba8 | 297 | |
9a32144e | 298 | static const struct file_operations shm_file_operations = { |
4e982311 | 299 | .mmap = shm_mmap, |
516dffdc | 300 | .fsync = shm_fsync, |
4e982311 | 301 | .release = shm_release, |
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, |
1da177e4 LT |
309 | }; |
310 | ||
c4caa778 AV |
311 | int is_file_shm_hugepages(struct file *file) |
312 | { | |
313 | return file->f_op == &shm_file_operations_huge; | |
314 | } | |
315 | ||
f0f37e2f | 316 | static const struct vm_operations_struct shm_vm_ops = { |
1da177e4 LT |
317 | .open = shm_open, /* callback for a new vm-area open */ |
318 | .close = shm_close, /* callback for when the vm-area is released */ | |
54cb8821 | 319 | .fault = shm_fault, |
bc56bba8 EB |
320 | #if defined(CONFIG_NUMA) |
321 | .set_policy = shm_set_policy, | |
322 | .get_policy = shm_get_policy, | |
1da177e4 LT |
323 | #endif |
324 | }; | |
325 | ||
f4566f04 ND |
326 | /** |
327 | * newseg - Create a new shared memory segment | |
328 | * @ns: namespace | |
329 | * @params: ptr to the structure that contains key, size and shmflg | |
330 | * | |
3e148c79 | 331 | * Called with shm_ids.rw_mutex held as a writer. |
f4566f04 ND |
332 | */ |
333 | ||
7748dbfa | 334 | static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 335 | { |
7748dbfa ND |
336 | key_t key = params->key; |
337 | int shmflg = params->flg; | |
338 | size_t size = params->u.size; | |
1da177e4 LT |
339 | int error; |
340 | struct shmid_kernel *shp; | |
341 | int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; | |
342 | struct file * file; | |
343 | char name[13]; | |
344 | int id; | |
5a6fe125 | 345 | int acctflag = 0; |
1da177e4 | 346 | |
4e982311 | 347 | if (size < SHMMIN || size > ns->shm_ctlmax) |
1da177e4 LT |
348 | return -EINVAL; |
349 | ||
f66d45e9 | 350 | if (ns->shm_tot + numpages > ns->shm_ctlall) |
1da177e4 LT |
351 | return -ENOSPC; |
352 | ||
353 | shp = ipc_rcu_alloc(sizeof(*shp)); | |
354 | if (!shp) | |
355 | return -ENOMEM; | |
356 | ||
357 | shp->shm_perm.key = key; | |
b33291c0 | 358 | shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
1da177e4 LT |
359 | shp->mlock_user = NULL; |
360 | ||
361 | shp->shm_perm.security = NULL; | |
362 | error = security_shm_alloc(shp); | |
363 | if (error) { | |
364 | ipc_rcu_putref(shp); | |
365 | return error; | |
366 | } | |
367 | ||
9d66586f | 368 | sprintf (name, "SYSV%08x", key); |
1da177e4 | 369 | if (shmflg & SHM_HUGETLB) { |
5a6fe125 MG |
370 | /* hugetlb_file_setup applies strict accounting */ |
371 | if (shmflg & SHM_NORESERVE) | |
372 | acctflag = VM_NORESERVE; | |
353d5c30 | 373 | file = hugetlb_file_setup(name, size, acctflag, |
6bfde05b | 374 | &shp->mlock_user, HUGETLB_SHMFS_INODE); |
1da177e4 | 375 | } else { |
bf8f972d BP |
376 | /* |
377 | * Do not allow no accounting for OVERCOMMIT_NEVER, even | |
378 | * if it's asked for. | |
379 | */ | |
380 | if ((shmflg & SHM_NORESERVE) && | |
381 | sysctl_overcommit_memory != OVERCOMMIT_NEVER) | |
fc8744ad | 382 | acctflag = VM_NORESERVE; |
bf8f972d | 383 | file = shmem_file_setup(name, size, acctflag); |
1da177e4 LT |
384 | } |
385 | error = PTR_ERR(file); | |
386 | if (IS_ERR(file)) | |
387 | goto no_file; | |
388 | ||
48dea404 | 389 | id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
283bb7fa PP |
390 | if (id < 0) { |
391 | error = id; | |
1da177e4 | 392 | goto no_id; |
283bb7fa | 393 | } |
1da177e4 | 394 | |
b488893a | 395 | shp->shm_cprid = task_tgid_vnr(current); |
1da177e4 LT |
396 | shp->shm_lprid = 0; |
397 | shp->shm_atim = shp->shm_dtim = 0; | |
398 | shp->shm_ctim = get_seconds(); | |
399 | shp->shm_segsz = size; | |
400 | shp->shm_nattch = 0; | |
1da177e4 | 401 | shp->shm_file = file; |
30475cc1 BP |
402 | /* |
403 | * shmid gets reported as "inode#" in /proc/pid/maps. | |
404 | * proc-ps tools use this. Changing this will break them. | |
405 | */ | |
7ca7e564 | 406 | file->f_dentry->d_inode->i_ino = shp->shm_perm.id; |
551110a9 | 407 | |
4e982311 | 408 | ns->shm_tot += numpages; |
7ca7e564 | 409 | error = shp->shm_perm.id; |
1da177e4 | 410 | shm_unlock(shp); |
7ca7e564 | 411 | return error; |
1da177e4 LT |
412 | |
413 | no_id: | |
2195d281 | 414 | if (is_file_hugepages(file) && shp->mlock_user) |
353d5c30 | 415 | user_shm_unlock(size, shp->mlock_user); |
1da177e4 LT |
416 | fput(file); |
417 | no_file: | |
418 | security_shm_free(shp); | |
419 | ipc_rcu_putref(shp); | |
420 | return error; | |
421 | } | |
422 | ||
f4566f04 | 423 | /* |
3e148c79 | 424 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 425 | */ |
03f02c76 | 426 | static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg) |
7748dbfa | 427 | { |
03f02c76 ND |
428 | struct shmid_kernel *shp; |
429 | ||
430 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
431 | return security_shm_associate(shp, shmflg); | |
7748dbfa ND |
432 | } |
433 | ||
f4566f04 | 434 | /* |
3e148c79 | 435 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 436 | */ |
03f02c76 ND |
437 | static inline int shm_more_checks(struct kern_ipc_perm *ipcp, |
438 | struct ipc_params *params) | |
7748dbfa | 439 | { |
03f02c76 ND |
440 | struct shmid_kernel *shp; |
441 | ||
442 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
443 | if (shp->shm_segsz < params->u.size) | |
7748dbfa ND |
444 | return -EINVAL; |
445 | ||
446 | return 0; | |
447 | } | |
448 | ||
d5460c99 | 449 | SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg) |
1da177e4 | 450 | { |
4e982311 | 451 | struct ipc_namespace *ns; |
7748dbfa ND |
452 | struct ipc_ops shm_ops; |
453 | struct ipc_params shm_params; | |
4e982311 KK |
454 | |
455 | ns = current->nsproxy->ipc_ns; | |
1da177e4 | 456 | |
7748dbfa ND |
457 | shm_ops.getnew = newseg; |
458 | shm_ops.associate = shm_security; | |
459 | shm_ops.more_checks = shm_more_checks; | |
7ca7e564 | 460 | |
7748dbfa ND |
461 | shm_params.key = key; |
462 | shm_params.flg = shmflg; | |
463 | shm_params.u.size = size; | |
1da177e4 | 464 | |
7748dbfa | 465 | return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); |
1da177e4 LT |
466 | } |
467 | ||
468 | static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) | |
469 | { | |
470 | switch(version) { | |
471 | case IPC_64: | |
472 | return copy_to_user(buf, in, sizeof(*in)); | |
473 | case IPC_OLD: | |
474 | { | |
475 | struct shmid_ds out; | |
476 | ||
477 | ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); | |
478 | out.shm_segsz = in->shm_segsz; | |
479 | out.shm_atime = in->shm_atime; | |
480 | out.shm_dtime = in->shm_dtime; | |
481 | out.shm_ctime = in->shm_ctime; | |
482 | out.shm_cpid = in->shm_cpid; | |
483 | out.shm_lpid = in->shm_lpid; | |
484 | out.shm_nattch = in->shm_nattch; | |
485 | ||
486 | return copy_to_user(buf, &out, sizeof(out)); | |
487 | } | |
488 | default: | |
489 | return -EINVAL; | |
490 | } | |
491 | } | |
492 | ||
016d7132 PP |
493 | static inline unsigned long |
494 | copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version) | |
1da177e4 LT |
495 | { |
496 | switch(version) { | |
497 | case IPC_64: | |
016d7132 | 498 | if (copy_from_user(out, buf, sizeof(*out))) |
1da177e4 | 499 | return -EFAULT; |
1da177e4 | 500 | return 0; |
1da177e4 LT |
501 | case IPC_OLD: |
502 | { | |
503 | struct shmid_ds tbuf_old; | |
504 | ||
505 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) | |
506 | return -EFAULT; | |
507 | ||
016d7132 PP |
508 | out->shm_perm.uid = tbuf_old.shm_perm.uid; |
509 | out->shm_perm.gid = tbuf_old.shm_perm.gid; | |
510 | out->shm_perm.mode = tbuf_old.shm_perm.mode; | |
1da177e4 LT |
511 | |
512 | return 0; | |
513 | } | |
514 | default: | |
515 | return -EINVAL; | |
516 | } | |
517 | } | |
518 | ||
519 | static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version) | |
520 | { | |
521 | switch(version) { | |
522 | case IPC_64: | |
523 | return copy_to_user(buf, in, sizeof(*in)); | |
524 | case IPC_OLD: | |
525 | { | |
526 | struct shminfo out; | |
527 | ||
528 | if(in->shmmax > INT_MAX) | |
529 | out.shmmax = INT_MAX; | |
530 | else | |
531 | out.shmmax = (int)in->shmmax; | |
532 | ||
533 | out.shmmin = in->shmmin; | |
534 | out.shmmni = in->shmmni; | |
535 | out.shmseg = in->shmseg; | |
536 | out.shmall = in->shmall; | |
537 | ||
538 | return copy_to_user(buf, &out, sizeof(out)); | |
539 | } | |
540 | default: | |
541 | return -EINVAL; | |
542 | } | |
543 | } | |
544 | ||
f4566f04 | 545 | /* |
3e148c79 | 546 | * Called with shm_ids.rw_mutex held as a reader |
f4566f04 | 547 | */ |
4e982311 KK |
548 | static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, |
549 | unsigned long *swp) | |
1da177e4 | 550 | { |
7ca7e564 ND |
551 | int next_id; |
552 | int total, in_use; | |
1da177e4 LT |
553 | |
554 | *rss = 0; | |
555 | *swp = 0; | |
556 | ||
7ca7e564 ND |
557 | in_use = shm_ids(ns).in_use; |
558 | ||
559 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
e562aebc | 560 | struct kern_ipc_perm *ipc; |
1da177e4 LT |
561 | struct shmid_kernel *shp; |
562 | struct inode *inode; | |
563 | ||
e562aebc TB |
564 | ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
565 | if (ipc == NULL) | |
1da177e4 | 566 | continue; |
e562aebc | 567 | shp = container_of(ipc, struct shmid_kernel, shm_perm); |
1da177e4 | 568 | |
6d63079a | 569 | inode = shp->shm_file->f_path.dentry->d_inode; |
1da177e4 LT |
570 | |
571 | if (is_file_hugepages(shp->shm_file)) { | |
572 | struct address_space *mapping = inode->i_mapping; | |
a5516438 AK |
573 | struct hstate *h = hstate_file(shp->shm_file); |
574 | *rss += pages_per_huge_page(h) * mapping->nrpages; | |
1da177e4 | 575 | } else { |
a68e61e8 | 576 | #ifdef CONFIG_SHMEM |
1da177e4 LT |
577 | struct shmem_inode_info *info = SHMEM_I(inode); |
578 | spin_lock(&info->lock); | |
579 | *rss += inode->i_mapping->nrpages; | |
580 | *swp += info->swapped; | |
581 | spin_unlock(&info->lock); | |
a68e61e8 TB |
582 | #else |
583 | *rss += inode->i_mapping->nrpages; | |
584 | #endif | |
1da177e4 | 585 | } |
7ca7e564 ND |
586 | |
587 | total++; | |
1da177e4 LT |
588 | } |
589 | } | |
590 | ||
8d4cc8b5 PP |
591 | /* |
592 | * This function handles some shmctl commands which require the rw_mutex | |
593 | * to be held in write mode. | |
594 | * NOTE: no locks must be held, the rw_mutex is taken inside this function. | |
595 | */ | |
596 | static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, | |
597 | struct shmid_ds __user *buf, int version) | |
1da177e4 | 598 | { |
8d4cc8b5 | 599 | struct kern_ipc_perm *ipcp; |
016d7132 | 600 | struct shmid64_ds shmid64; |
8d4cc8b5 PP |
601 | struct shmid_kernel *shp; |
602 | int err; | |
603 | ||
604 | if (cmd == IPC_SET) { | |
016d7132 | 605 | if (copy_shmid_from_user(&shmid64, buf, version)) |
8d4cc8b5 PP |
606 | return -EFAULT; |
607 | } | |
608 | ||
a5f75e7f PP |
609 | ipcp = ipcctl_pre_down(&shm_ids(ns), shmid, cmd, &shmid64.shm_perm, 0); |
610 | if (IS_ERR(ipcp)) | |
611 | return PTR_ERR(ipcp); | |
8d4cc8b5 | 612 | |
a5f75e7f | 613 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
8d4cc8b5 PP |
614 | |
615 | err = security_shm_shmctl(shp, cmd); | |
616 | if (err) | |
617 | goto out_unlock; | |
618 | switch (cmd) { | |
619 | case IPC_RMID: | |
620 | do_shm_rmid(ns, ipcp); | |
621 | goto out_up; | |
622 | case IPC_SET: | |
8f4a3809 | 623 | ipc_update_perm(&shmid64.shm_perm, ipcp); |
8d4cc8b5 PP |
624 | shp->shm_ctim = get_seconds(); |
625 | break; | |
626 | default: | |
627 | err = -EINVAL; | |
628 | } | |
629 | out_unlock: | |
630 | shm_unlock(shp); | |
631 | out_up: | |
632 | up_write(&shm_ids(ns).rw_mutex); | |
633 | return err; | |
634 | } | |
635 | ||
d5460c99 | 636 | SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) |
8d4cc8b5 | 637 | { |
1da177e4 LT |
638 | struct shmid_kernel *shp; |
639 | int err, version; | |
4e982311 | 640 | struct ipc_namespace *ns; |
1da177e4 LT |
641 | |
642 | if (cmd < 0 || shmid < 0) { | |
643 | err = -EINVAL; | |
644 | goto out; | |
645 | } | |
646 | ||
647 | version = ipc_parse_version(&cmd); | |
4e982311 | 648 | ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
649 | |
650 | switch (cmd) { /* replace with proc interface ? */ | |
651 | case IPC_INFO: | |
652 | { | |
653 | struct shminfo64 shminfo; | |
654 | ||
655 | err = security_shm_shmctl(NULL, cmd); | |
656 | if (err) | |
657 | return err; | |
658 | ||
e8148f75 | 659 | memset(&shminfo, 0, sizeof(shminfo)); |
4e982311 KK |
660 | shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni; |
661 | shminfo.shmmax = ns->shm_ctlmax; | |
662 | shminfo.shmall = ns->shm_ctlall; | |
1da177e4 LT |
663 | |
664 | shminfo.shmmin = SHMMIN; | |
665 | if(copy_shminfo_to_user (buf, &shminfo, version)) | |
666 | return -EFAULT; | |
f4566f04 | 667 | |
3e148c79 | 668 | down_read(&shm_ids(ns).rw_mutex); |
7ca7e564 | 669 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 670 | up_read(&shm_ids(ns).rw_mutex); |
f4566f04 | 671 | |
1da177e4 LT |
672 | if(err<0) |
673 | err = 0; | |
674 | goto out; | |
675 | } | |
676 | case SHM_INFO: | |
677 | { | |
678 | struct shm_info shm_info; | |
679 | ||
680 | err = security_shm_shmctl(NULL, cmd); | |
681 | if (err) | |
682 | return err; | |
683 | ||
e8148f75 | 684 | memset(&shm_info, 0, sizeof(shm_info)); |
3e148c79 | 685 | down_read(&shm_ids(ns).rw_mutex); |
4e982311 KK |
686 | shm_info.used_ids = shm_ids(ns).in_use; |
687 | shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp); | |
688 | shm_info.shm_tot = ns->shm_tot; | |
1da177e4 LT |
689 | shm_info.swap_attempts = 0; |
690 | shm_info.swap_successes = 0; | |
7ca7e564 | 691 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 692 | up_read(&shm_ids(ns).rw_mutex); |
e8148f75 | 693 | if (copy_to_user(buf, &shm_info, sizeof(shm_info))) { |
1da177e4 LT |
694 | err = -EFAULT; |
695 | goto out; | |
696 | } | |
697 | ||
698 | err = err < 0 ? 0 : err; | |
699 | goto out; | |
700 | } | |
701 | case SHM_STAT: | |
702 | case IPC_STAT: | |
703 | { | |
704 | struct shmid64_ds tbuf; | |
705 | int result; | |
023a5355 | 706 | |
023a5355 ND |
707 | if (cmd == SHM_STAT) { |
708 | shp = shm_lock(ns, shmid); | |
709 | if (IS_ERR(shp)) { | |
710 | err = PTR_ERR(shp); | |
711 | goto out; | |
712 | } | |
7ca7e564 | 713 | result = shp->shm_perm.id; |
1da177e4 | 714 | } else { |
023a5355 ND |
715 | shp = shm_lock_check(ns, shmid); |
716 | if (IS_ERR(shp)) { | |
717 | err = PTR_ERR(shp); | |
718 | goto out; | |
719 | } | |
1da177e4 LT |
720 | result = 0; |
721 | } | |
e8148f75 | 722 | err = -EACCES; |
1da177e4 LT |
723 | if (ipcperms (&shp->shm_perm, S_IRUGO)) |
724 | goto out_unlock; | |
725 | err = security_shm_shmctl(shp, cmd); | |
726 | if (err) | |
727 | goto out_unlock; | |
023a5355 | 728 | memset(&tbuf, 0, sizeof(tbuf)); |
1da177e4 LT |
729 | kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm); |
730 | tbuf.shm_segsz = shp->shm_segsz; | |
731 | tbuf.shm_atime = shp->shm_atim; | |
732 | tbuf.shm_dtime = shp->shm_dtim; | |
733 | tbuf.shm_ctime = shp->shm_ctim; | |
734 | tbuf.shm_cpid = shp->shm_cprid; | |
735 | tbuf.shm_lpid = shp->shm_lprid; | |
bc56bba8 | 736 | tbuf.shm_nattch = shp->shm_nattch; |
1da177e4 LT |
737 | shm_unlock(shp); |
738 | if(copy_shmid_to_user (buf, &tbuf, version)) | |
739 | err = -EFAULT; | |
740 | else | |
741 | err = result; | |
742 | goto out; | |
743 | } | |
744 | case SHM_LOCK: | |
745 | case SHM_UNLOCK: | |
746 | { | |
89e004ea LS |
747 | struct file *uninitialized_var(shm_file); |
748 | ||
749 | lru_add_drain_all(); /* drain pagevecs to lru lists */ | |
750 | ||
023a5355 ND |
751 | shp = shm_lock_check(ns, shmid); |
752 | if (IS_ERR(shp)) { | |
753 | err = PTR_ERR(shp); | |
1da177e4 LT |
754 | goto out; |
755 | } | |
1da177e4 | 756 | |
a33e6751 | 757 | audit_ipc_obj(&(shp->shm_perm)); |
073115d6 | 758 | |
1da177e4 | 759 | if (!capable(CAP_IPC_LOCK)) { |
414c0708 | 760 | uid_t euid = current_euid(); |
1da177e4 | 761 | err = -EPERM; |
414c0708 DH |
762 | if (euid != shp->shm_perm.uid && |
763 | euid != shp->shm_perm.cuid) | |
1da177e4 LT |
764 | goto out_unlock; |
765 | if (cmd == SHM_LOCK && | |
766 | !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur) | |
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 | ||
882 | path.dentry = dget(shp->shm_file->f_path.dentry); | |
ce8d2cdf | 883 | path.mnt = shp->shm_file->f_path.mnt; |
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 | |
c4caa778 AV |
893 | file = alloc_file(path.mnt, path.dentry, f_mode, |
894 | is_file_hugepages(shp->shm_file) ? | |
895 | &shm_file_operations_huge : | |
896 | &shm_file_operations); | |
bc56bba8 EB |
897 | if (!file) |
898 | goto out_free; | |
b9fc745d | 899 | ima_counts_get(file); |
bc56bba8 | 900 | |
bc56bba8 | 901 | file->private_data = sfd; |
bc56bba8 | 902 | file->f_mapping = shp->shm_file->f_mapping; |
7ca7e564 | 903 | sfd->id = shp->shm_perm.id; |
bc56bba8 EB |
904 | sfd->ns = get_ipc_ns(ns); |
905 | sfd->file = shp->shm_file; | |
906 | sfd->vm_ops = NULL; | |
907 | ||
1da177e4 LT |
908 | down_write(¤t->mm->mmap_sem); |
909 | if (addr && !(shmflg & SHM_REMAP)) { | |
bc56bba8 | 910 | err = -EINVAL; |
1da177e4 LT |
911 | if (find_vma_intersection(current->mm, addr, addr + size)) |
912 | goto invalid; | |
913 | /* | |
914 | * If shm segment goes below stack, make sure there is some | |
915 | * space left for the stack to grow (at least 4 pages). | |
916 | */ | |
917 | if (addr < current->mm->start_stack && | |
918 | addr > current->mm->start_stack - size - PAGE_SIZE * 5) | |
919 | goto invalid; | |
920 | } | |
921 | ||
bc56bba8 EB |
922 | user_addr = do_mmap (file, addr, size, prot, flags, 0); |
923 | *raddr = user_addr; | |
924 | err = 0; | |
925 | if (IS_ERR_VALUE(user_addr)) | |
926 | err = (long)user_addr; | |
1da177e4 LT |
927 | invalid: |
928 | up_write(¤t->mm->mmap_sem); | |
929 | ||
bc56bba8 EB |
930 | fput(file); |
931 | ||
932 | out_nattch: | |
3e148c79 | 933 | down_write(&shm_ids(ns).rw_mutex); |
00c2bf85 | 934 | shp = shm_lock(ns, shmid); |
023a5355 | 935 | BUG_ON(IS_ERR(shp)); |
1da177e4 LT |
936 | shp->shm_nattch--; |
937 | if(shp->shm_nattch == 0 && | |
b33291c0 | 938 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 939 | shm_destroy(ns, shp); |
1da177e4 LT |
940 | else |
941 | shm_unlock(shp); | |
3e148c79 | 942 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 943 | |
1da177e4 LT |
944 | out: |
945 | return err; | |
bc56bba8 EB |
946 | |
947 | out_unlock: | |
948 | shm_unlock(shp); | |
949 | goto out; | |
950 | ||
951 | out_free: | |
952 | kfree(sfd); | |
ce8d2cdf | 953 | out_put_dentry: |
bc56bba8 | 954 | dput(path.dentry); |
bc56bba8 | 955 | goto out_nattch; |
1da177e4 LT |
956 | } |
957 | ||
d5460c99 | 958 | SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg) |
7d87e14c SR |
959 | { |
960 | unsigned long ret; | |
961 | long err; | |
962 | ||
963 | err = do_shmat(shmid, shmaddr, shmflg, &ret); | |
964 | if (err) | |
965 | return err; | |
966 | force_successful_syscall_return(); | |
967 | return (long)ret; | |
968 | } | |
969 | ||
1da177e4 LT |
970 | /* |
971 | * detach and kill segment if marked destroyed. | |
972 | * The work is done in shm_close. | |
973 | */ | |
d5460c99 | 974 | SYSCALL_DEFINE1(shmdt, char __user *, shmaddr) |
1da177e4 LT |
975 | { |
976 | struct mm_struct *mm = current->mm; | |
586c7e6a | 977 | struct vm_area_struct *vma; |
1da177e4 | 978 | unsigned long addr = (unsigned long)shmaddr; |
1da177e4 | 979 | int retval = -EINVAL; |
586c7e6a MF |
980 | #ifdef CONFIG_MMU |
981 | loff_t size = 0; | |
982 | struct vm_area_struct *next; | |
983 | #endif | |
1da177e4 | 984 | |
df1e2fb5 HD |
985 | if (addr & ~PAGE_MASK) |
986 | return retval; | |
987 | ||
1da177e4 LT |
988 | down_write(&mm->mmap_sem); |
989 | ||
990 | /* | |
991 | * This function tries to be smart and unmap shm segments that | |
992 | * were modified by partial mlock or munmap calls: | |
993 | * - It first determines the size of the shm segment that should be | |
994 | * unmapped: It searches for a vma that is backed by shm and that | |
995 | * started at address shmaddr. It records it's size and then unmaps | |
996 | * it. | |
997 | * - Then it unmaps all shm vmas that started at shmaddr and that | |
998 | * are within the initially determined size. | |
999 | * Errors from do_munmap are ignored: the function only fails if | |
1000 | * it's called with invalid parameters or if it's called to unmap | |
1001 | * a part of a vma. Both calls in this function are for full vmas, | |
1002 | * the parameters are directly copied from the vma itself and always | |
1003 | * valid - therefore do_munmap cannot fail. (famous last words?) | |
1004 | */ | |
1005 | /* | |
1006 | * If it had been mremap()'d, the starting address would not | |
1007 | * match the usual checks anyway. So assume all vma's are | |
1008 | * above the starting address given. | |
1009 | */ | |
1010 | vma = find_vma(mm, addr); | |
1011 | ||
8feae131 | 1012 | #ifdef CONFIG_MMU |
1da177e4 LT |
1013 | while (vma) { |
1014 | next = vma->vm_next; | |
1015 | ||
1016 | /* | |
1017 | * Check if the starting address would match, i.e. it's | |
1018 | * a fragment created by mprotect() and/or munmap(), or it | |
1019 | * otherwise it starts at this address with no hassles. | |
1020 | */ | |
bc56bba8 | 1021 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1022 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { |
1023 | ||
1024 | ||
6d63079a | 1025 | size = vma->vm_file->f_path.dentry->d_inode->i_size; |
1da177e4 LT |
1026 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
1027 | /* | |
1028 | * We discovered the size of the shm segment, so | |
1029 | * break out of here and fall through to the next | |
1030 | * loop that uses the size information to stop | |
1031 | * searching for matching vma's. | |
1032 | */ | |
1033 | retval = 0; | |
1034 | vma = next; | |
1035 | break; | |
1036 | } | |
1037 | vma = next; | |
1038 | } | |
1039 | ||
1040 | /* | |
1041 | * We need look no further than the maximum address a fragment | |
1042 | * could possibly have landed at. Also cast things to loff_t to | |
1043 | * prevent overflows and make comparisions vs. equal-width types. | |
1044 | */ | |
8e36709d | 1045 | size = PAGE_ALIGN(size); |
1da177e4 LT |
1046 | while (vma && (loff_t)(vma->vm_end - addr) <= size) { |
1047 | next = vma->vm_next; | |
1048 | ||
1049 | /* finding a matching vma now does not alter retval */ | |
bc56bba8 | 1050 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1051 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) |
1052 | ||
1053 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
1054 | vma = next; | |
1055 | } | |
1056 | ||
8feae131 DH |
1057 | #else /* CONFIG_MMU */ |
1058 | /* under NOMMU conditions, the exact address to be destroyed must be | |
1059 | * given */ | |
1060 | retval = -EINVAL; | |
1061 | if (vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) { | |
1062 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
1063 | retval = 0; | |
1064 | } | |
1065 | ||
1066 | #endif | |
1067 | ||
1da177e4 LT |
1068 | up_write(&mm->mmap_sem); |
1069 | return retval; | |
1070 | } | |
1071 | ||
1072 | #ifdef CONFIG_PROC_FS | |
19b4946c | 1073 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
1da177e4 | 1074 | { |
19b4946c | 1075 | struct shmid_kernel *shp = it; |
1da177e4 | 1076 | |
6c826818 PM |
1077 | #if BITS_PER_LONG <= 32 |
1078 | #define SIZE_SPEC "%10lu" | |
1079 | #else | |
1080 | #define SIZE_SPEC "%21lu" | |
1081 | #endif | |
1da177e4 | 1082 | |
6c826818 PM |
1083 | return seq_printf(s, |
1084 | "%10d %10d %4o " SIZE_SPEC " %5u %5u " | |
1085 | "%5lu %5u %5u %5u %5u %10lu %10lu %10lu\n", | |
19b4946c | 1086 | shp->shm_perm.key, |
7ca7e564 | 1087 | shp->shm_perm.id, |
b33291c0 | 1088 | shp->shm_perm.mode, |
19b4946c MW |
1089 | shp->shm_segsz, |
1090 | shp->shm_cprid, | |
1091 | shp->shm_lprid, | |
bc56bba8 | 1092 | shp->shm_nattch, |
19b4946c MW |
1093 | shp->shm_perm.uid, |
1094 | shp->shm_perm.gid, | |
1095 | shp->shm_perm.cuid, | |
1096 | shp->shm_perm.cgid, | |
1097 | shp->shm_atim, | |
1098 | shp->shm_dtim, | |
1099 | shp->shm_ctim); | |
1da177e4 LT |
1100 | } |
1101 | #endif |