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; |
1da177e4 LT |
57 | static struct vm_operations_struct shm_vm_ops; |
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; | |
ed2ddbf8 | 78 | ipc_init_ids(&ns->ids[IPC_SHM_IDS]); |
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); |
4e982311 | 103 | } |
ae5e1b22 | 104 | #endif |
1da177e4 LT |
105 | |
106 | void __init shm_init (void) | |
107 | { | |
ed2ddbf8 | 108 | shm_init_ns(&init_ipc_ns); |
19b4946c MW |
109 | ipc_init_proc_interface("sysvipc/shm", |
110 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n", | |
4e982311 | 111 | IPC_SHM_IDS, sysvipc_shm_proc_show); |
1da177e4 LT |
112 | } |
113 | ||
3e148c79 ND |
114 | /* |
115 | * shm_lock_(check_)down routines are called in the paths where the rw_mutex | |
116 | * is held to protect access to the idr tree. | |
117 | */ | |
118 | static inline struct shmid_kernel *shm_lock_down(struct ipc_namespace *ns, | |
119 | int id) | |
120 | { | |
121 | struct kern_ipc_perm *ipcp = ipc_lock_down(&shm_ids(ns), id); | |
122 | ||
b1ed88b4 PP |
123 | if (IS_ERR(ipcp)) |
124 | return (struct shmid_kernel *)ipcp; | |
125 | ||
3e148c79 ND |
126 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
127 | } | |
128 | ||
129 | static inline struct shmid_kernel *shm_lock_check_down( | |
130 | struct ipc_namespace *ns, | |
131 | int id) | |
132 | { | |
133 | struct kern_ipc_perm *ipcp = ipc_lock_check_down(&shm_ids(ns), id); | |
134 | ||
b1ed88b4 PP |
135 | if (IS_ERR(ipcp)) |
136 | return (struct shmid_kernel *)ipcp; | |
137 | ||
3e148c79 ND |
138 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
139 | } | |
140 | ||
141 | /* | |
142 | * shm_lock_(check_) routines are called in the paths where the rw_mutex | |
143 | * is not held. | |
144 | */ | |
023a5355 | 145 | static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id) |
1da177e4 | 146 | { |
03f02c76 ND |
147 | struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id); |
148 | ||
b1ed88b4 PP |
149 | if (IS_ERR(ipcp)) |
150 | return (struct shmid_kernel *)ipcp; | |
151 | ||
03f02c76 | 152 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
023a5355 ND |
153 | } |
154 | ||
155 | static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns, | |
156 | int id) | |
157 | { | |
03f02c76 ND |
158 | struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id); |
159 | ||
b1ed88b4 PP |
160 | if (IS_ERR(ipcp)) |
161 | return (struct shmid_kernel *)ipcp; | |
162 | ||
03f02c76 | 163 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
1da177e4 LT |
164 | } |
165 | ||
7ca7e564 | 166 | static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s) |
1da177e4 | 167 | { |
7ca7e564 | 168 | ipc_rmid(&shm_ids(ns), &s->shm_perm); |
1da177e4 LT |
169 | } |
170 | ||
1da177e4 | 171 | |
bc56bba8 EB |
172 | /* This is called by fork, once for every shm attach. */ |
173 | static void shm_open(struct vm_area_struct *vma) | |
4e982311 | 174 | { |
bc56bba8 EB |
175 | struct file *file = vma->vm_file; |
176 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 LT |
177 | struct shmid_kernel *shp; |
178 | ||
bc56bba8 | 179 | shp = shm_lock(sfd->ns, sfd->id); |
023a5355 | 180 | BUG_ON(IS_ERR(shp)); |
1da177e4 | 181 | shp->shm_atim = get_seconds(); |
b488893a | 182 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
183 | shp->shm_nattch++; |
184 | shm_unlock(shp); | |
185 | } | |
186 | ||
1da177e4 LT |
187 | /* |
188 | * shm_destroy - free the struct shmid_kernel | |
189 | * | |
f4566f04 | 190 | * @ns: namespace |
1da177e4 LT |
191 | * @shp: struct to free |
192 | * | |
3e148c79 | 193 | * It has to be called with shp and shm_ids.rw_mutex (writer) locked, |
1da177e4 LT |
194 | * but returns with shp unlocked and freed. |
195 | */ | |
4e982311 | 196 | static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 197 | { |
4e982311 | 198 | ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; |
7ca7e564 | 199 | shm_rmid(ns, shp); |
1da177e4 LT |
200 | shm_unlock(shp); |
201 | if (!is_file_hugepages(shp->shm_file)) | |
202 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
203 | else | |
6d63079a | 204 | user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size, |
1da177e4 LT |
205 | shp->mlock_user); |
206 | fput (shp->shm_file); | |
207 | security_shm_free(shp); | |
208 | ipc_rcu_putref(shp); | |
209 | } | |
210 | ||
211 | /* | |
bc56bba8 | 212 | * remove the attach descriptor vma. |
1da177e4 LT |
213 | * free memory for segment if it is marked destroyed. |
214 | * The descriptor has already been removed from the current->mm->mmap list | |
215 | * and will later be kfree()d. | |
216 | */ | |
bc56bba8 | 217 | static void shm_close(struct vm_area_struct *vma) |
1da177e4 | 218 | { |
bc56bba8 EB |
219 | struct file * file = vma->vm_file; |
220 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 | 221 | struct shmid_kernel *shp; |
bc56bba8 | 222 | struct ipc_namespace *ns = sfd->ns; |
4e982311 | 223 | |
3e148c79 | 224 | down_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 225 | /* remove from the list of attaches of the shm segment */ |
3e148c79 | 226 | shp = shm_lock_down(ns, sfd->id); |
023a5355 | 227 | BUG_ON(IS_ERR(shp)); |
b488893a | 228 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
229 | shp->shm_dtim = get_seconds(); |
230 | shp->shm_nattch--; | |
231 | if(shp->shm_nattch == 0 && | |
b33291c0 | 232 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 233 | shm_destroy(ns, shp); |
1da177e4 LT |
234 | else |
235 | shm_unlock(shp); | |
3e148c79 | 236 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
237 | } |
238 | ||
d0217ac0 | 239 | static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
bc56bba8 EB |
240 | { |
241 | struct file *file = vma->vm_file; | |
242 | struct shm_file_data *sfd = shm_file_data(file); | |
243 | ||
d0217ac0 | 244 | return sfd->vm_ops->fault(vma, vmf); |
bc56bba8 EB |
245 | } |
246 | ||
247 | #ifdef CONFIG_NUMA | |
d823e3e7 | 248 | static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
bc56bba8 EB |
249 | { |
250 | struct file *file = vma->vm_file; | |
251 | struct shm_file_data *sfd = shm_file_data(file); | |
252 | int err = 0; | |
253 | if (sfd->vm_ops->set_policy) | |
254 | err = sfd->vm_ops->set_policy(vma, new); | |
255 | return err; | |
256 | } | |
257 | ||
d823e3e7 AB |
258 | static struct mempolicy *shm_get_policy(struct vm_area_struct *vma, |
259 | unsigned long addr) | |
bc56bba8 EB |
260 | { |
261 | struct file *file = vma->vm_file; | |
262 | struct shm_file_data *sfd = shm_file_data(file); | |
263 | struct mempolicy *pol = NULL; | |
264 | ||
265 | if (sfd->vm_ops->get_policy) | |
266 | pol = sfd->vm_ops->get_policy(vma, addr); | |
52cd3b07 | 267 | else if (vma->vm_policy) |
bc56bba8 | 268 | pol = vma->vm_policy; |
52cd3b07 | 269 | |
bc56bba8 EB |
270 | return pol; |
271 | } | |
272 | #endif | |
273 | ||
1da177e4 LT |
274 | static int shm_mmap(struct file * file, struct vm_area_struct * vma) |
275 | { | |
bc56bba8 | 276 | struct shm_file_data *sfd = shm_file_data(file); |
b0e15190 DH |
277 | int ret; |
278 | ||
bc56bba8 EB |
279 | ret = sfd->file->f_op->mmap(sfd->file, vma); |
280 | if (ret != 0) | |
281 | return ret; | |
282 | sfd->vm_ops = vma->vm_ops; | |
2e92a3ba | 283 | #ifdef CONFIG_MMU |
54cb8821 | 284 | BUG_ON(!sfd->vm_ops->fault); |
2e92a3ba | 285 | #endif |
bc56bba8 EB |
286 | vma->vm_ops = &shm_vm_ops; |
287 | shm_open(vma); | |
b0e15190 DH |
288 | |
289 | return ret; | |
1da177e4 LT |
290 | } |
291 | ||
4e982311 KK |
292 | static int shm_release(struct inode *ino, struct file *file) |
293 | { | |
bc56bba8 | 294 | struct shm_file_data *sfd = shm_file_data(file); |
4e982311 | 295 | |
bc56bba8 EB |
296 | put_ipc_ns(sfd->ns); |
297 | shm_file_data(file) = NULL; | |
298 | kfree(sfd); | |
4e982311 KK |
299 | return 0; |
300 | } | |
301 | ||
516dffdc AL |
302 | static int shm_fsync(struct file *file, struct dentry *dentry, int datasync) |
303 | { | |
304 | int (*fsync) (struct file *, struct dentry *, int datasync); | |
305 | struct shm_file_data *sfd = shm_file_data(file); | |
306 | int ret = -EINVAL; | |
307 | ||
308 | fsync = sfd->file->f_op->fsync; | |
309 | if (fsync) | |
310 | ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync); | |
311 | return ret; | |
312 | } | |
313 | ||
bc56bba8 EB |
314 | static unsigned long shm_get_unmapped_area(struct file *file, |
315 | unsigned long addr, unsigned long len, unsigned long pgoff, | |
316 | unsigned long flags) | |
317 | { | |
318 | struct shm_file_data *sfd = shm_file_data(file); | |
516dffdc AL |
319 | return get_unmapped_area(sfd->file, addr, len, pgoff, flags); |
320 | } | |
321 | ||
322 | int is_file_shm_hugepages(struct file *file) | |
323 | { | |
324 | int ret = 0; | |
325 | ||
326 | if (file->f_op == &shm_file_operations) { | |
327 | struct shm_file_data *sfd; | |
328 | sfd = shm_file_data(file); | |
329 | ret = is_file_hugepages(sfd->file); | |
330 | } | |
331 | return ret; | |
bc56bba8 | 332 | } |
bc56bba8 | 333 | |
9a32144e | 334 | static const struct file_operations shm_file_operations = { |
4e982311 | 335 | .mmap = shm_mmap, |
516dffdc | 336 | .fsync = shm_fsync, |
4e982311 | 337 | .release = shm_release, |
bc56bba8 | 338 | .get_unmapped_area = shm_get_unmapped_area, |
1da177e4 LT |
339 | }; |
340 | ||
341 | static struct vm_operations_struct shm_vm_ops = { | |
342 | .open = shm_open, /* callback for a new vm-area open */ | |
343 | .close = shm_close, /* callback for when the vm-area is released */ | |
54cb8821 | 344 | .fault = shm_fault, |
bc56bba8 EB |
345 | #if defined(CONFIG_NUMA) |
346 | .set_policy = shm_set_policy, | |
347 | .get_policy = shm_get_policy, | |
1da177e4 LT |
348 | #endif |
349 | }; | |
350 | ||
f4566f04 ND |
351 | /** |
352 | * newseg - Create a new shared memory segment | |
353 | * @ns: namespace | |
354 | * @params: ptr to the structure that contains key, size and shmflg | |
355 | * | |
3e148c79 | 356 | * Called with shm_ids.rw_mutex held as a writer. |
f4566f04 ND |
357 | */ |
358 | ||
7748dbfa | 359 | static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 360 | { |
7748dbfa ND |
361 | key_t key = params->key; |
362 | int shmflg = params->flg; | |
363 | size_t size = params->u.size; | |
1da177e4 LT |
364 | int error; |
365 | struct shmid_kernel *shp; | |
366 | int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; | |
367 | struct file * file; | |
368 | char name[13]; | |
369 | int id; | |
370 | ||
4e982311 | 371 | if (size < SHMMIN || size > ns->shm_ctlmax) |
1da177e4 LT |
372 | return -EINVAL; |
373 | ||
f66d45e9 | 374 | if (ns->shm_tot + numpages > ns->shm_ctlall) |
1da177e4 LT |
375 | return -ENOSPC; |
376 | ||
377 | shp = ipc_rcu_alloc(sizeof(*shp)); | |
378 | if (!shp) | |
379 | return -ENOMEM; | |
380 | ||
381 | shp->shm_perm.key = key; | |
b33291c0 | 382 | shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
1da177e4 LT |
383 | shp->mlock_user = NULL; |
384 | ||
385 | shp->shm_perm.security = NULL; | |
386 | error = security_shm_alloc(shp); | |
387 | if (error) { | |
388 | ipc_rcu_putref(shp); | |
389 | return error; | |
390 | } | |
391 | ||
9d66586f | 392 | sprintf (name, "SYSV%08x", key); |
1da177e4 | 393 | if (shmflg & SHM_HUGETLB) { |
9d66586f EB |
394 | /* hugetlb_file_setup takes care of mlock user accounting */ |
395 | file = hugetlb_file_setup(name, size); | |
1da177e4 LT |
396 | shp->mlock_user = current->user; |
397 | } else { | |
bf8f972d BP |
398 | int acctflag = VM_ACCOUNT; |
399 | /* | |
400 | * Do not allow no accounting for OVERCOMMIT_NEVER, even | |
401 | * if it's asked for. | |
402 | */ | |
403 | if ((shmflg & SHM_NORESERVE) && | |
404 | sysctl_overcommit_memory != OVERCOMMIT_NEVER) | |
405 | acctflag = 0; | |
bf8f972d | 406 | file = shmem_file_setup(name, size, acctflag); |
1da177e4 LT |
407 | } |
408 | error = PTR_ERR(file); | |
409 | if (IS_ERR(file)) | |
410 | goto no_file; | |
411 | ||
48dea404 | 412 | id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
283bb7fa PP |
413 | if (id < 0) { |
414 | error = id; | |
1da177e4 | 415 | goto no_id; |
283bb7fa | 416 | } |
1da177e4 | 417 | |
b488893a | 418 | shp->shm_cprid = task_tgid_vnr(current); |
1da177e4 LT |
419 | shp->shm_lprid = 0; |
420 | shp->shm_atim = shp->shm_dtim = 0; | |
421 | shp->shm_ctim = get_seconds(); | |
422 | shp->shm_segsz = size; | |
423 | shp->shm_nattch = 0; | |
1da177e4 | 424 | shp->shm_file = file; |
30475cc1 BP |
425 | /* |
426 | * shmid gets reported as "inode#" in /proc/pid/maps. | |
427 | * proc-ps tools use this. Changing this will break them. | |
428 | */ | |
7ca7e564 | 429 | file->f_dentry->d_inode->i_ino = shp->shm_perm.id; |
551110a9 | 430 | |
4e982311 | 431 | ns->shm_tot += numpages; |
7ca7e564 | 432 | error = shp->shm_perm.id; |
1da177e4 | 433 | shm_unlock(shp); |
7ca7e564 | 434 | return error; |
1da177e4 LT |
435 | |
436 | no_id: | |
437 | fput(file); | |
438 | no_file: | |
439 | security_shm_free(shp); | |
440 | ipc_rcu_putref(shp); | |
441 | return error; | |
442 | } | |
443 | ||
f4566f04 | 444 | /* |
3e148c79 | 445 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 446 | */ |
03f02c76 | 447 | static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg) |
7748dbfa | 448 | { |
03f02c76 ND |
449 | struct shmid_kernel *shp; |
450 | ||
451 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
452 | return security_shm_associate(shp, shmflg); | |
7748dbfa ND |
453 | } |
454 | ||
f4566f04 | 455 | /* |
3e148c79 | 456 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 457 | */ |
03f02c76 ND |
458 | static inline int shm_more_checks(struct kern_ipc_perm *ipcp, |
459 | struct ipc_params *params) | |
7748dbfa | 460 | { |
03f02c76 ND |
461 | struct shmid_kernel *shp; |
462 | ||
463 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
464 | if (shp->shm_segsz < params->u.size) | |
7748dbfa ND |
465 | return -EINVAL; |
466 | ||
467 | return 0; | |
468 | } | |
469 | ||
1da177e4 LT |
470 | asmlinkage long sys_shmget (key_t key, size_t size, int shmflg) |
471 | { | |
4e982311 | 472 | struct ipc_namespace *ns; |
7748dbfa ND |
473 | struct ipc_ops shm_ops; |
474 | struct ipc_params shm_params; | |
4e982311 KK |
475 | |
476 | ns = current->nsproxy->ipc_ns; | |
1da177e4 | 477 | |
7748dbfa ND |
478 | shm_ops.getnew = newseg; |
479 | shm_ops.associate = shm_security; | |
480 | shm_ops.more_checks = shm_more_checks; | |
7ca7e564 | 481 | |
7748dbfa ND |
482 | shm_params.key = key; |
483 | shm_params.flg = shmflg; | |
484 | shm_params.u.size = size; | |
1da177e4 | 485 | |
7748dbfa | 486 | return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); |
1da177e4 LT |
487 | } |
488 | ||
489 | static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) | |
490 | { | |
491 | switch(version) { | |
492 | case IPC_64: | |
493 | return copy_to_user(buf, in, sizeof(*in)); | |
494 | case IPC_OLD: | |
495 | { | |
496 | struct shmid_ds out; | |
497 | ||
498 | ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); | |
499 | out.shm_segsz = in->shm_segsz; | |
500 | out.shm_atime = in->shm_atime; | |
501 | out.shm_dtime = in->shm_dtime; | |
502 | out.shm_ctime = in->shm_ctime; | |
503 | out.shm_cpid = in->shm_cpid; | |
504 | out.shm_lpid = in->shm_lpid; | |
505 | out.shm_nattch = in->shm_nattch; | |
506 | ||
507 | return copy_to_user(buf, &out, sizeof(out)); | |
508 | } | |
509 | default: | |
510 | return -EINVAL; | |
511 | } | |
512 | } | |
513 | ||
016d7132 PP |
514 | static inline unsigned long |
515 | copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version) | |
1da177e4 LT |
516 | { |
517 | switch(version) { | |
518 | case IPC_64: | |
016d7132 | 519 | if (copy_from_user(out, buf, sizeof(*out))) |
1da177e4 | 520 | return -EFAULT; |
1da177e4 | 521 | return 0; |
1da177e4 LT |
522 | case IPC_OLD: |
523 | { | |
524 | struct shmid_ds tbuf_old; | |
525 | ||
526 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) | |
527 | return -EFAULT; | |
528 | ||
016d7132 PP |
529 | out->shm_perm.uid = tbuf_old.shm_perm.uid; |
530 | out->shm_perm.gid = tbuf_old.shm_perm.gid; | |
531 | out->shm_perm.mode = tbuf_old.shm_perm.mode; | |
1da177e4 LT |
532 | |
533 | return 0; | |
534 | } | |
535 | default: | |
536 | return -EINVAL; | |
537 | } | |
538 | } | |
539 | ||
540 | static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version) | |
541 | { | |
542 | switch(version) { | |
543 | case IPC_64: | |
544 | return copy_to_user(buf, in, sizeof(*in)); | |
545 | case IPC_OLD: | |
546 | { | |
547 | struct shminfo out; | |
548 | ||
549 | if(in->shmmax > INT_MAX) | |
550 | out.shmmax = INT_MAX; | |
551 | else | |
552 | out.shmmax = (int)in->shmmax; | |
553 | ||
554 | out.shmmin = in->shmmin; | |
555 | out.shmmni = in->shmmni; | |
556 | out.shmseg = in->shmseg; | |
557 | out.shmall = in->shmall; | |
558 | ||
559 | return copy_to_user(buf, &out, sizeof(out)); | |
560 | } | |
561 | default: | |
562 | return -EINVAL; | |
563 | } | |
564 | } | |
565 | ||
f4566f04 | 566 | /* |
3e148c79 | 567 | * Called with shm_ids.rw_mutex held as a reader |
f4566f04 | 568 | */ |
4e982311 KK |
569 | static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, |
570 | unsigned long *swp) | |
1da177e4 | 571 | { |
7ca7e564 ND |
572 | int next_id; |
573 | int total, in_use; | |
1da177e4 LT |
574 | |
575 | *rss = 0; | |
576 | *swp = 0; | |
577 | ||
7ca7e564 ND |
578 | in_use = shm_ids(ns).in_use; |
579 | ||
580 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
1da177e4 LT |
581 | struct shmid_kernel *shp; |
582 | struct inode *inode; | |
583 | ||
637c3663 | 584 | shp = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
7ca7e564 | 585 | if (shp == NULL) |
1da177e4 LT |
586 | continue; |
587 | ||
6d63079a | 588 | inode = shp->shm_file->f_path.dentry->d_inode; |
1da177e4 LT |
589 | |
590 | if (is_file_hugepages(shp->shm_file)) { | |
591 | struct address_space *mapping = inode->i_mapping; | |
592 | *rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages; | |
593 | } else { | |
594 | struct shmem_inode_info *info = SHMEM_I(inode); | |
595 | spin_lock(&info->lock); | |
596 | *rss += inode->i_mapping->nrpages; | |
597 | *swp += info->swapped; | |
598 | spin_unlock(&info->lock); | |
599 | } | |
7ca7e564 ND |
600 | |
601 | total++; | |
1da177e4 LT |
602 | } |
603 | } | |
604 | ||
8d4cc8b5 PP |
605 | /* |
606 | * This function handles some shmctl commands which require the rw_mutex | |
607 | * to be held in write mode. | |
608 | * NOTE: no locks must be held, the rw_mutex is taken inside this function. | |
609 | */ | |
610 | static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, | |
611 | struct shmid_ds __user *buf, int version) | |
1da177e4 | 612 | { |
8d4cc8b5 | 613 | struct kern_ipc_perm *ipcp; |
016d7132 | 614 | struct shmid64_ds shmid64; |
8d4cc8b5 PP |
615 | struct shmid_kernel *shp; |
616 | int err; | |
617 | ||
618 | if (cmd == IPC_SET) { | |
016d7132 | 619 | if (copy_shmid_from_user(&shmid64, buf, version)) |
8d4cc8b5 PP |
620 | return -EFAULT; |
621 | } | |
622 | ||
623 | down_write(&shm_ids(ns).rw_mutex); | |
624 | shp = shm_lock_check_down(ns, shmid); | |
625 | if (IS_ERR(shp)) { | |
626 | err = PTR_ERR(shp); | |
627 | goto out_up; | |
628 | } | |
629 | ||
630 | ipcp = &shp->shm_perm; | |
631 | ||
632 | err = audit_ipc_obj(ipcp); | |
633 | if (err) | |
634 | goto out_unlock; | |
635 | ||
636 | if (cmd == IPC_SET) { | |
016d7132 PP |
637 | err = audit_ipc_set_perm(0, shmid64.shm_perm.uid, |
638 | shmid64.shm_perm.gid, | |
639 | shmid64.shm_perm.mode); | |
8d4cc8b5 PP |
640 | if (err) |
641 | goto out_unlock; | |
642 | } | |
643 | ||
644 | if (current->euid != ipcp->uid && | |
645 | current->euid != ipcp->cuid && | |
646 | !capable(CAP_SYS_ADMIN)) { | |
647 | err = -EPERM; | |
648 | goto out_unlock; | |
649 | } | |
650 | ||
651 | err = security_shm_shmctl(shp, cmd); | |
652 | if (err) | |
653 | goto out_unlock; | |
654 | switch (cmd) { | |
655 | case IPC_RMID: | |
656 | do_shm_rmid(ns, ipcp); | |
657 | goto out_up; | |
658 | case IPC_SET: | |
8f4a3809 | 659 | ipc_update_perm(&shmid64.shm_perm, ipcp); |
8d4cc8b5 PP |
660 | shp->shm_ctim = get_seconds(); |
661 | break; | |
662 | default: | |
663 | err = -EINVAL; | |
664 | } | |
665 | out_unlock: | |
666 | shm_unlock(shp); | |
667 | out_up: | |
668 | up_write(&shm_ids(ns).rw_mutex); | |
669 | return err; | |
670 | } | |
671 | ||
672 | asmlinkage long sys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf) | |
673 | { | |
1da177e4 LT |
674 | struct shmid_kernel *shp; |
675 | int err, version; | |
4e982311 | 676 | struct ipc_namespace *ns; |
1da177e4 LT |
677 | |
678 | if (cmd < 0 || shmid < 0) { | |
679 | err = -EINVAL; | |
680 | goto out; | |
681 | } | |
682 | ||
683 | version = ipc_parse_version(&cmd); | |
4e982311 | 684 | ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
685 | |
686 | switch (cmd) { /* replace with proc interface ? */ | |
687 | case IPC_INFO: | |
688 | { | |
689 | struct shminfo64 shminfo; | |
690 | ||
691 | err = security_shm_shmctl(NULL, cmd); | |
692 | if (err) | |
693 | return err; | |
694 | ||
695 | memset(&shminfo,0,sizeof(shminfo)); | |
4e982311 KK |
696 | shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni; |
697 | shminfo.shmmax = ns->shm_ctlmax; | |
698 | shminfo.shmall = ns->shm_ctlall; | |
1da177e4 LT |
699 | |
700 | shminfo.shmmin = SHMMIN; | |
701 | if(copy_shminfo_to_user (buf, &shminfo, version)) | |
702 | return -EFAULT; | |
f4566f04 | 703 | |
3e148c79 | 704 | down_read(&shm_ids(ns).rw_mutex); |
7ca7e564 | 705 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 706 | up_read(&shm_ids(ns).rw_mutex); |
f4566f04 | 707 | |
1da177e4 LT |
708 | if(err<0) |
709 | err = 0; | |
710 | goto out; | |
711 | } | |
712 | case SHM_INFO: | |
713 | { | |
714 | struct shm_info shm_info; | |
715 | ||
716 | err = security_shm_shmctl(NULL, cmd); | |
717 | if (err) | |
718 | return err; | |
719 | ||
720 | memset(&shm_info,0,sizeof(shm_info)); | |
3e148c79 | 721 | down_read(&shm_ids(ns).rw_mutex); |
4e982311 KK |
722 | shm_info.used_ids = shm_ids(ns).in_use; |
723 | shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp); | |
724 | shm_info.shm_tot = ns->shm_tot; | |
1da177e4 LT |
725 | shm_info.swap_attempts = 0; |
726 | shm_info.swap_successes = 0; | |
7ca7e564 | 727 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 728 | up_read(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
729 | if(copy_to_user (buf, &shm_info, sizeof(shm_info))) { |
730 | err = -EFAULT; | |
731 | goto out; | |
732 | } | |
733 | ||
734 | err = err < 0 ? 0 : err; | |
735 | goto out; | |
736 | } | |
737 | case SHM_STAT: | |
738 | case IPC_STAT: | |
739 | { | |
740 | struct shmid64_ds tbuf; | |
741 | int result; | |
023a5355 ND |
742 | |
743 | if (!buf) { | |
744 | err = -EFAULT; | |
1da177e4 | 745 | goto out; |
023a5355 ND |
746 | } |
747 | ||
748 | if (cmd == SHM_STAT) { | |
749 | shp = shm_lock(ns, shmid); | |
750 | if (IS_ERR(shp)) { | |
751 | err = PTR_ERR(shp); | |
752 | goto out; | |
753 | } | |
7ca7e564 | 754 | result = shp->shm_perm.id; |
1da177e4 | 755 | } else { |
023a5355 ND |
756 | shp = shm_lock_check(ns, shmid); |
757 | if (IS_ERR(shp)) { | |
758 | err = PTR_ERR(shp); | |
759 | goto out; | |
760 | } | |
1da177e4 LT |
761 | result = 0; |
762 | } | |
763 | err=-EACCES; | |
764 | if (ipcperms (&shp->shm_perm, S_IRUGO)) | |
765 | goto out_unlock; | |
766 | err = security_shm_shmctl(shp, cmd); | |
767 | if (err) | |
768 | goto out_unlock; | |
023a5355 | 769 | memset(&tbuf, 0, sizeof(tbuf)); |
1da177e4 LT |
770 | kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm); |
771 | tbuf.shm_segsz = shp->shm_segsz; | |
772 | tbuf.shm_atime = shp->shm_atim; | |
773 | tbuf.shm_dtime = shp->shm_dtim; | |
774 | tbuf.shm_ctime = shp->shm_ctim; | |
775 | tbuf.shm_cpid = shp->shm_cprid; | |
776 | tbuf.shm_lpid = shp->shm_lprid; | |
bc56bba8 | 777 | tbuf.shm_nattch = shp->shm_nattch; |
1da177e4 LT |
778 | shm_unlock(shp); |
779 | if(copy_shmid_to_user (buf, &tbuf, version)) | |
780 | err = -EFAULT; | |
781 | else | |
782 | err = result; | |
783 | goto out; | |
784 | } | |
785 | case SHM_LOCK: | |
786 | case SHM_UNLOCK: | |
787 | { | |
023a5355 ND |
788 | shp = shm_lock_check(ns, shmid); |
789 | if (IS_ERR(shp)) { | |
790 | err = PTR_ERR(shp); | |
1da177e4 LT |
791 | goto out; |
792 | } | |
1da177e4 | 793 | |
073115d6 SG |
794 | err = audit_ipc_obj(&(shp->shm_perm)); |
795 | if (err) | |
796 | goto out_unlock; | |
797 | ||
1da177e4 LT |
798 | if (!capable(CAP_IPC_LOCK)) { |
799 | err = -EPERM; | |
800 | if (current->euid != shp->shm_perm.uid && | |
801 | current->euid != shp->shm_perm.cuid) | |
802 | goto out_unlock; | |
803 | if (cmd == SHM_LOCK && | |
804 | !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur) | |
805 | goto out_unlock; | |
806 | } | |
807 | ||
808 | err = security_shm_shmctl(shp, cmd); | |
809 | if (err) | |
810 | goto out_unlock; | |
811 | ||
812 | if(cmd==SHM_LOCK) { | |
813 | struct user_struct * user = current->user; | |
814 | if (!is_file_hugepages(shp->shm_file)) { | |
815 | err = shmem_lock(shp->shm_file, 1, user); | |
7be77e20 | 816 | if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){ |
b33291c0 | 817 | shp->shm_perm.mode |= SHM_LOCKED; |
1da177e4 LT |
818 | shp->mlock_user = user; |
819 | } | |
820 | } | |
821 | } else if (!is_file_hugepages(shp->shm_file)) { | |
822 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
b33291c0 | 823 | shp->shm_perm.mode &= ~SHM_LOCKED; |
1da177e4 LT |
824 | shp->mlock_user = NULL; |
825 | } | |
826 | shm_unlock(shp); | |
827 | goto out; | |
828 | } | |
829 | case IPC_RMID: | |
1da177e4 | 830 | case IPC_SET: |
8d4cc8b5 PP |
831 | err = shmctl_down(ns, shmid, cmd, buf, version); |
832 | return err; | |
1da177e4 | 833 | default: |
8d4cc8b5 | 834 | return -EINVAL; |
1da177e4 LT |
835 | } |
836 | ||
1da177e4 LT |
837 | out_unlock: |
838 | shm_unlock(shp); | |
839 | out: | |
840 | return err; | |
841 | } | |
842 | ||
843 | /* | |
844 | * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists. | |
845 | * | |
846 | * NOTE! Despite the name, this is NOT a direct system call entrypoint. The | |
847 | * "raddr" thing points to kernel space, and there has to be a wrapper around | |
848 | * this. | |
849 | */ | |
850 | long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) | |
851 | { | |
852 | struct shmid_kernel *shp; | |
853 | unsigned long addr; | |
854 | unsigned long size; | |
855 | struct file * file; | |
856 | int err; | |
857 | unsigned long flags; | |
858 | unsigned long prot; | |
1da177e4 | 859 | int acc_mode; |
bc56bba8 | 860 | unsigned long user_addr; |
4e982311 | 861 | struct ipc_namespace *ns; |
bc56bba8 EB |
862 | struct shm_file_data *sfd; |
863 | struct path path; | |
864 | mode_t f_mode; | |
1da177e4 | 865 | |
bc56bba8 EB |
866 | err = -EINVAL; |
867 | if (shmid < 0) | |
1da177e4 | 868 | goto out; |
bc56bba8 | 869 | else if ((addr = (ulong)shmaddr)) { |
1da177e4 LT |
870 | if (addr & (SHMLBA-1)) { |
871 | if (shmflg & SHM_RND) | |
872 | addr &= ~(SHMLBA-1); /* round down */ | |
873 | else | |
874 | #ifndef __ARCH_FORCE_SHMLBA | |
875 | if (addr & ~PAGE_MASK) | |
876 | #endif | |
bc56bba8 | 877 | goto out; |
1da177e4 LT |
878 | } |
879 | flags = MAP_SHARED | MAP_FIXED; | |
880 | } else { | |
881 | if ((shmflg & SHM_REMAP)) | |
bc56bba8 | 882 | goto out; |
1da177e4 LT |
883 | |
884 | flags = MAP_SHARED; | |
885 | } | |
886 | ||
887 | if (shmflg & SHM_RDONLY) { | |
888 | prot = PROT_READ; | |
1da177e4 | 889 | acc_mode = S_IRUGO; |
bc56bba8 | 890 | f_mode = FMODE_READ; |
1da177e4 LT |
891 | } else { |
892 | prot = PROT_READ | PROT_WRITE; | |
1da177e4 | 893 | acc_mode = S_IRUGO | S_IWUGO; |
bc56bba8 | 894 | f_mode = FMODE_READ | FMODE_WRITE; |
1da177e4 LT |
895 | } |
896 | if (shmflg & SHM_EXEC) { | |
897 | prot |= PROT_EXEC; | |
898 | acc_mode |= S_IXUGO; | |
899 | } | |
900 | ||
901 | /* | |
902 | * We cannot rely on the fs check since SYSV IPC does have an | |
903 | * additional creator id... | |
904 | */ | |
4e982311 | 905 | ns = current->nsproxy->ipc_ns; |
023a5355 ND |
906 | shp = shm_lock_check(ns, shmid); |
907 | if (IS_ERR(shp)) { | |
908 | err = PTR_ERR(shp); | |
1da177e4 | 909 | goto out; |
023a5355 | 910 | } |
bc56bba8 EB |
911 | |
912 | err = -EACCES; | |
913 | if (ipcperms(&shp->shm_perm, acc_mode)) | |
914 | goto out_unlock; | |
1da177e4 LT |
915 | |
916 | err = security_shm_shmat(shp, shmaddr, shmflg); | |
bc56bba8 EB |
917 | if (err) |
918 | goto out_unlock; | |
919 | ||
920 | path.dentry = dget(shp->shm_file->f_path.dentry); | |
ce8d2cdf | 921 | path.mnt = shp->shm_file->f_path.mnt; |
1da177e4 | 922 | shp->shm_nattch++; |
bc56bba8 | 923 | size = i_size_read(path.dentry->d_inode); |
1da177e4 LT |
924 | shm_unlock(shp); |
925 | ||
bc56bba8 EB |
926 | err = -ENOMEM; |
927 | sfd = kzalloc(sizeof(*sfd), GFP_KERNEL); | |
928 | if (!sfd) | |
ce8d2cdf | 929 | goto out_put_dentry; |
bc56bba8 EB |
930 | |
931 | err = -ENOMEM; | |
ce8d2cdf DH |
932 | |
933 | file = alloc_file(path.mnt, path.dentry, f_mode, &shm_file_operations); | |
bc56bba8 EB |
934 | if (!file) |
935 | goto out_free; | |
936 | ||
bc56bba8 | 937 | file->private_data = sfd; |
bc56bba8 | 938 | file->f_mapping = shp->shm_file->f_mapping; |
7ca7e564 | 939 | sfd->id = shp->shm_perm.id; |
bc56bba8 EB |
940 | sfd->ns = get_ipc_ns(ns); |
941 | sfd->file = shp->shm_file; | |
942 | sfd->vm_ops = NULL; | |
943 | ||
1da177e4 LT |
944 | down_write(¤t->mm->mmap_sem); |
945 | if (addr && !(shmflg & SHM_REMAP)) { | |
bc56bba8 | 946 | err = -EINVAL; |
1da177e4 LT |
947 | if (find_vma_intersection(current->mm, addr, addr + size)) |
948 | goto invalid; | |
949 | /* | |
950 | * If shm segment goes below stack, make sure there is some | |
951 | * space left for the stack to grow (at least 4 pages). | |
952 | */ | |
953 | if (addr < current->mm->start_stack && | |
954 | addr > current->mm->start_stack - size - PAGE_SIZE * 5) | |
955 | goto invalid; | |
956 | } | |
957 | ||
bc56bba8 EB |
958 | user_addr = do_mmap (file, addr, size, prot, flags, 0); |
959 | *raddr = user_addr; | |
960 | err = 0; | |
961 | if (IS_ERR_VALUE(user_addr)) | |
962 | err = (long)user_addr; | |
1da177e4 LT |
963 | invalid: |
964 | up_write(¤t->mm->mmap_sem); | |
965 | ||
bc56bba8 EB |
966 | fput(file); |
967 | ||
968 | out_nattch: | |
3e148c79 ND |
969 | down_write(&shm_ids(ns).rw_mutex); |
970 | shp = shm_lock_down(ns, shmid); | |
023a5355 | 971 | BUG_ON(IS_ERR(shp)); |
1da177e4 LT |
972 | shp->shm_nattch--; |
973 | if(shp->shm_nattch == 0 && | |
b33291c0 | 974 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 975 | shm_destroy(ns, shp); |
1da177e4 LT |
976 | else |
977 | shm_unlock(shp); | |
3e148c79 | 978 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 979 | |
1da177e4 LT |
980 | out: |
981 | return err; | |
bc56bba8 EB |
982 | |
983 | out_unlock: | |
984 | shm_unlock(shp); | |
985 | goto out; | |
986 | ||
987 | out_free: | |
988 | kfree(sfd); | |
ce8d2cdf | 989 | out_put_dentry: |
bc56bba8 | 990 | dput(path.dentry); |
bc56bba8 | 991 | goto out_nattch; |
1da177e4 LT |
992 | } |
993 | ||
7d87e14c SR |
994 | asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg) |
995 | { | |
996 | unsigned long ret; | |
997 | long err; | |
998 | ||
999 | err = do_shmat(shmid, shmaddr, shmflg, &ret); | |
1000 | if (err) | |
1001 | return err; | |
1002 | force_successful_syscall_return(); | |
1003 | return (long)ret; | |
1004 | } | |
1005 | ||
1da177e4 LT |
1006 | /* |
1007 | * detach and kill segment if marked destroyed. | |
1008 | * The work is done in shm_close. | |
1009 | */ | |
1010 | asmlinkage long sys_shmdt(char __user *shmaddr) | |
1011 | { | |
1012 | struct mm_struct *mm = current->mm; | |
1013 | struct vm_area_struct *vma, *next; | |
1014 | unsigned long addr = (unsigned long)shmaddr; | |
1015 | loff_t size = 0; | |
1016 | int retval = -EINVAL; | |
1017 | ||
df1e2fb5 HD |
1018 | if (addr & ~PAGE_MASK) |
1019 | return retval; | |
1020 | ||
1da177e4 LT |
1021 | down_write(&mm->mmap_sem); |
1022 | ||
1023 | /* | |
1024 | * This function tries to be smart and unmap shm segments that | |
1025 | * were modified by partial mlock or munmap calls: | |
1026 | * - It first determines the size of the shm segment that should be | |
1027 | * unmapped: It searches for a vma that is backed by shm and that | |
1028 | * started at address shmaddr. It records it's size and then unmaps | |
1029 | * it. | |
1030 | * - Then it unmaps all shm vmas that started at shmaddr and that | |
1031 | * are within the initially determined size. | |
1032 | * Errors from do_munmap are ignored: the function only fails if | |
1033 | * it's called with invalid parameters or if it's called to unmap | |
1034 | * a part of a vma. Both calls in this function are for full vmas, | |
1035 | * the parameters are directly copied from the vma itself and always | |
1036 | * valid - therefore do_munmap cannot fail. (famous last words?) | |
1037 | */ | |
1038 | /* | |
1039 | * If it had been mremap()'d, the starting address would not | |
1040 | * match the usual checks anyway. So assume all vma's are | |
1041 | * above the starting address given. | |
1042 | */ | |
1043 | vma = find_vma(mm, addr); | |
1044 | ||
1045 | while (vma) { | |
1046 | next = vma->vm_next; | |
1047 | ||
1048 | /* | |
1049 | * Check if the starting address would match, i.e. it's | |
1050 | * a fragment created by mprotect() and/or munmap(), or it | |
1051 | * otherwise it starts at this address with no hassles. | |
1052 | */ | |
bc56bba8 | 1053 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1054 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { |
1055 | ||
1056 | ||
6d63079a | 1057 | size = vma->vm_file->f_path.dentry->d_inode->i_size; |
1da177e4 LT |
1058 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
1059 | /* | |
1060 | * We discovered the size of the shm segment, so | |
1061 | * break out of here and fall through to the next | |
1062 | * loop that uses the size information to stop | |
1063 | * searching for matching vma's. | |
1064 | */ | |
1065 | retval = 0; | |
1066 | vma = next; | |
1067 | break; | |
1068 | } | |
1069 | vma = next; | |
1070 | } | |
1071 | ||
1072 | /* | |
1073 | * We need look no further than the maximum address a fragment | |
1074 | * could possibly have landed at. Also cast things to loff_t to | |
1075 | * prevent overflows and make comparisions vs. equal-width types. | |
1076 | */ | |
8e36709d | 1077 | size = PAGE_ALIGN(size); |
1da177e4 LT |
1078 | while (vma && (loff_t)(vma->vm_end - addr) <= size) { |
1079 | next = vma->vm_next; | |
1080 | ||
1081 | /* finding a matching vma now does not alter retval */ | |
bc56bba8 | 1082 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1083 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) |
1084 | ||
1085 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
1086 | vma = next; | |
1087 | } | |
1088 | ||
1089 | up_write(&mm->mmap_sem); | |
1090 | return retval; | |
1091 | } | |
1092 | ||
1093 | #ifdef CONFIG_PROC_FS | |
19b4946c | 1094 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
1da177e4 | 1095 | { |
19b4946c MW |
1096 | struct shmid_kernel *shp = it; |
1097 | char *format; | |
1da177e4 | 1098 | |
1da177e4 LT |
1099 | #define SMALL_STRING "%10d %10d %4o %10u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" |
1100 | #define BIG_STRING "%10d %10d %4o %21u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" | |
1da177e4 | 1101 | |
19b4946c MW |
1102 | if (sizeof(size_t) <= sizeof(int)) |
1103 | format = SMALL_STRING; | |
1104 | else | |
1105 | format = BIG_STRING; | |
1106 | return seq_printf(s, format, | |
1107 | shp->shm_perm.key, | |
7ca7e564 | 1108 | shp->shm_perm.id, |
b33291c0 | 1109 | shp->shm_perm.mode, |
19b4946c MW |
1110 | shp->shm_segsz, |
1111 | shp->shm_cprid, | |
1112 | shp->shm_lprid, | |
bc56bba8 | 1113 | shp->shm_nattch, |
19b4946c MW |
1114 | shp->shm_perm.uid, |
1115 | shp->shm_perm.gid, | |
1116 | shp->shm_perm.cuid, | |
1117 | shp->shm_perm.cgid, | |
1118 | shp->shm_atim, | |
1119 | shp->shm_dtim, | |
1120 | shp->shm_ctim); | |
1da177e4 LT |
1121 | } |
1122 | #endif |