]>
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> |
5f921ae9 | 38 | #include <linux/mutex.h> |
4e982311 | 39 | #include <linux/nsproxy.h> |
bc56bba8 | 40 | #include <linux/mount.h> |
7d87e14c | 41 | |
1da177e4 LT |
42 | #include <asm/uaccess.h> |
43 | ||
44 | #include "util.h" | |
45 | ||
bc56bba8 EB |
46 | struct shm_file_data { |
47 | int id; | |
48 | struct ipc_namespace *ns; | |
49 | struct file *file; | |
50 | const struct vm_operations_struct *vm_ops; | |
51 | }; | |
52 | ||
53 | #define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data)) | |
54 | ||
9a32144e | 55 | static const struct file_operations shm_file_operations; |
1da177e4 LT |
56 | static struct vm_operations_struct shm_vm_ops; |
57 | ||
4e982311 KK |
58 | static struct ipc_ids init_shm_ids; |
59 | ||
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) | |
4e982311 KK |
64 | #define shm_buildid(ns, id, seq) \ |
65 | ipc_buildid(&shm_ids(ns), id, seq) | |
1da177e4 | 66 | |
7748dbfa | 67 | static int newseg(struct ipc_namespace *, struct ipc_params *); |
bc56bba8 EB |
68 | static void shm_open(struct vm_area_struct *vma); |
69 | static void shm_close(struct vm_area_struct *vma); | |
4e982311 | 70 | static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp); |
1da177e4 | 71 | #ifdef CONFIG_PROC_FS |
19b4946c | 72 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it); |
1da177e4 LT |
73 | #endif |
74 | ||
7d69a1f4 | 75 | static void __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids) |
4e982311 KK |
76 | { |
77 | ns->ids[IPC_SHM_IDS] = ids; | |
78 | ns->shm_ctlmax = SHMMAX; | |
79 | ns->shm_ctlall = SHMALL; | |
80 | ns->shm_ctlmni = SHMMNI; | |
81 | ns->shm_tot = 0; | |
7ca7e564 | 82 | ipc_init_ids(ids); |
4e982311 KK |
83 | } |
84 | ||
85 | static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp) | |
86 | { | |
87 | if (shp->shm_nattch){ | |
88 | shp->shm_perm.mode |= SHM_DEST; | |
89 | /* Do not find it any more */ | |
90 | shp->shm_perm.key = IPC_PRIVATE; | |
91 | shm_unlock(shp); | |
92 | } else | |
93 | shm_destroy(ns, shp); | |
94 | } | |
95 | ||
4e982311 KK |
96 | int shm_init_ns(struct ipc_namespace *ns) |
97 | { | |
98 | struct ipc_ids *ids; | |
99 | ||
100 | ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL); | |
101 | if (ids == NULL) | |
102 | return -ENOMEM; | |
1da177e4 | 103 | |
4e982311 KK |
104 | __shm_init_ns(ns, ids); |
105 | return 0; | |
106 | } | |
107 | ||
108 | void shm_exit_ns(struct ipc_namespace *ns) | |
109 | { | |
4e982311 | 110 | struct shmid_kernel *shp; |
7ca7e564 ND |
111 | int next_id; |
112 | int total, in_use; | |
4e982311 KK |
113 | |
114 | mutex_lock(&shm_ids(ns).mutex); | |
7ca7e564 ND |
115 | |
116 | in_use = shm_ids(ns).in_use; | |
117 | ||
118 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
119 | shp = idr_find(&shm_ids(ns).ipcs_idr, next_id); | |
4e982311 KK |
120 | if (shp == NULL) |
121 | continue; | |
7ca7e564 | 122 | ipc_lock_by_ptr(&shp->shm_perm); |
4e982311 | 123 | do_shm_rmid(ns, shp); |
7ca7e564 | 124 | total++; |
4e982311 KK |
125 | } |
126 | mutex_unlock(&shm_ids(ns).mutex); | |
127 | ||
128 | kfree(ns->ids[IPC_SHM_IDS]); | |
129 | ns->ids[IPC_SHM_IDS] = NULL; | |
130 | } | |
1da177e4 LT |
131 | |
132 | void __init shm_init (void) | |
133 | { | |
4e982311 | 134 | __shm_init_ns(&init_ipc_ns, &init_shm_ids); |
19b4946c MW |
135 | ipc_init_proc_interface("sysvipc/shm", |
136 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n", | |
4e982311 | 137 | IPC_SHM_IDS, sysvipc_shm_proc_show); |
1da177e4 LT |
138 | } |
139 | ||
023a5355 | 140 | static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id) |
1da177e4 | 141 | { |
03f02c76 ND |
142 | struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id); |
143 | ||
144 | return container_of(ipcp, struct shmid_kernel, shm_perm); | |
023a5355 ND |
145 | } |
146 | ||
147 | static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns, | |
148 | int id) | |
149 | { | |
03f02c76 ND |
150 | struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id); |
151 | ||
152 | return container_of(ipcp, struct shmid_kernel, shm_perm); | |
1da177e4 LT |
153 | } |
154 | ||
7ca7e564 | 155 | static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s) |
1da177e4 | 156 | { |
7ca7e564 | 157 | ipc_rmid(&shm_ids(ns), &s->shm_perm); |
1da177e4 LT |
158 | } |
159 | ||
4e982311 | 160 | static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 161 | { |
4e982311 | 162 | return ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
1da177e4 LT |
163 | } |
164 | ||
165 | ||
166 | ||
bc56bba8 EB |
167 | /* This is called by fork, once for every shm attach. */ |
168 | static void shm_open(struct vm_area_struct *vma) | |
4e982311 | 169 | { |
bc56bba8 EB |
170 | struct file *file = vma->vm_file; |
171 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 LT |
172 | struct shmid_kernel *shp; |
173 | ||
bc56bba8 | 174 | shp = shm_lock(sfd->ns, sfd->id); |
023a5355 | 175 | BUG_ON(IS_ERR(shp)); |
1da177e4 | 176 | shp->shm_atim = get_seconds(); |
b488893a | 177 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
178 | shp->shm_nattch++; |
179 | shm_unlock(shp); | |
180 | } | |
181 | ||
1da177e4 LT |
182 | /* |
183 | * shm_destroy - free the struct shmid_kernel | |
184 | * | |
185 | * @shp: struct to free | |
186 | * | |
5f921ae9 | 187 | * It has to be called with shp and shm_ids.mutex locked, |
1da177e4 LT |
188 | * but returns with shp unlocked and freed. |
189 | */ | |
4e982311 | 190 | static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 191 | { |
4e982311 | 192 | ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; |
7ca7e564 | 193 | shm_rmid(ns, shp); |
1da177e4 LT |
194 | shm_unlock(shp); |
195 | if (!is_file_hugepages(shp->shm_file)) | |
196 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
197 | else | |
6d63079a | 198 | user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size, |
1da177e4 LT |
199 | shp->mlock_user); |
200 | fput (shp->shm_file); | |
201 | security_shm_free(shp); | |
202 | ipc_rcu_putref(shp); | |
203 | } | |
204 | ||
205 | /* | |
bc56bba8 | 206 | * remove the attach descriptor vma. |
1da177e4 LT |
207 | * free memory for segment if it is marked destroyed. |
208 | * The descriptor has already been removed from the current->mm->mmap list | |
209 | * and will later be kfree()d. | |
210 | */ | |
bc56bba8 | 211 | static void shm_close(struct vm_area_struct *vma) |
1da177e4 | 212 | { |
bc56bba8 EB |
213 | struct file * file = vma->vm_file; |
214 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 | 215 | struct shmid_kernel *shp; |
bc56bba8 | 216 | struct ipc_namespace *ns = sfd->ns; |
4e982311 KK |
217 | |
218 | mutex_lock(&shm_ids(ns).mutex); | |
1da177e4 | 219 | /* remove from the list of attaches of the shm segment */ |
bc56bba8 | 220 | shp = shm_lock(ns, sfd->id); |
023a5355 | 221 | BUG_ON(IS_ERR(shp)); |
b488893a | 222 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
223 | shp->shm_dtim = get_seconds(); |
224 | shp->shm_nattch--; | |
225 | if(shp->shm_nattch == 0 && | |
b33291c0 | 226 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 227 | shm_destroy(ns, shp); |
1da177e4 LT |
228 | else |
229 | shm_unlock(shp); | |
4e982311 | 230 | mutex_unlock(&shm_ids(ns).mutex); |
1da177e4 LT |
231 | } |
232 | ||
d0217ac0 | 233 | static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
bc56bba8 EB |
234 | { |
235 | struct file *file = vma->vm_file; | |
236 | struct shm_file_data *sfd = shm_file_data(file); | |
237 | ||
d0217ac0 | 238 | return sfd->vm_ops->fault(vma, vmf); |
bc56bba8 EB |
239 | } |
240 | ||
241 | #ifdef CONFIG_NUMA | |
d823e3e7 | 242 | static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
bc56bba8 EB |
243 | { |
244 | struct file *file = vma->vm_file; | |
245 | struct shm_file_data *sfd = shm_file_data(file); | |
246 | int err = 0; | |
247 | if (sfd->vm_ops->set_policy) | |
248 | err = sfd->vm_ops->set_policy(vma, new); | |
249 | return err; | |
250 | } | |
251 | ||
d823e3e7 AB |
252 | static struct mempolicy *shm_get_policy(struct vm_area_struct *vma, |
253 | unsigned long addr) | |
bc56bba8 EB |
254 | { |
255 | struct file *file = vma->vm_file; | |
256 | struct shm_file_data *sfd = shm_file_data(file); | |
257 | struct mempolicy *pol = NULL; | |
258 | ||
259 | if (sfd->vm_ops->get_policy) | |
260 | pol = sfd->vm_ops->get_policy(vma, addr); | |
22741925 | 261 | else if (vma->vm_policy) |
bc56bba8 | 262 | pol = vma->vm_policy; |
22741925 AL |
263 | else |
264 | pol = current->mempolicy; | |
bc56bba8 EB |
265 | return pol; |
266 | } | |
267 | #endif | |
268 | ||
1da177e4 LT |
269 | static int shm_mmap(struct file * file, struct vm_area_struct * vma) |
270 | { | |
bc56bba8 | 271 | struct shm_file_data *sfd = shm_file_data(file); |
b0e15190 DH |
272 | int ret; |
273 | ||
bc56bba8 EB |
274 | ret = sfd->file->f_op->mmap(sfd->file, vma); |
275 | if (ret != 0) | |
276 | return ret; | |
277 | sfd->vm_ops = vma->vm_ops; | |
2e92a3ba | 278 | #ifdef CONFIG_MMU |
54cb8821 | 279 | BUG_ON(!sfd->vm_ops->fault); |
2e92a3ba | 280 | #endif |
bc56bba8 EB |
281 | vma->vm_ops = &shm_vm_ops; |
282 | shm_open(vma); | |
b0e15190 DH |
283 | |
284 | return ret; | |
1da177e4 LT |
285 | } |
286 | ||
4e982311 KK |
287 | static int shm_release(struct inode *ino, struct file *file) |
288 | { | |
bc56bba8 | 289 | struct shm_file_data *sfd = shm_file_data(file); |
4e982311 | 290 | |
bc56bba8 EB |
291 | put_ipc_ns(sfd->ns); |
292 | shm_file_data(file) = NULL; | |
293 | kfree(sfd); | |
4e982311 KK |
294 | return 0; |
295 | } | |
296 | ||
516dffdc AL |
297 | static int shm_fsync(struct file *file, struct dentry *dentry, int datasync) |
298 | { | |
299 | int (*fsync) (struct file *, struct dentry *, int datasync); | |
300 | struct shm_file_data *sfd = shm_file_data(file); | |
301 | int ret = -EINVAL; | |
302 | ||
303 | fsync = sfd->file->f_op->fsync; | |
304 | if (fsync) | |
305 | ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync); | |
306 | return ret; | |
307 | } | |
308 | ||
bc56bba8 EB |
309 | static unsigned long shm_get_unmapped_area(struct file *file, |
310 | unsigned long addr, unsigned long len, unsigned long pgoff, | |
311 | unsigned long flags) | |
312 | { | |
313 | struct shm_file_data *sfd = shm_file_data(file); | |
516dffdc AL |
314 | return get_unmapped_area(sfd->file, addr, len, pgoff, flags); |
315 | } | |
316 | ||
317 | int is_file_shm_hugepages(struct file *file) | |
318 | { | |
319 | int ret = 0; | |
320 | ||
321 | if (file->f_op == &shm_file_operations) { | |
322 | struct shm_file_data *sfd; | |
323 | sfd = shm_file_data(file); | |
324 | ret = is_file_hugepages(sfd->file); | |
325 | } | |
326 | return ret; | |
bc56bba8 | 327 | } |
bc56bba8 | 328 | |
9a32144e | 329 | static const struct file_operations shm_file_operations = { |
4e982311 | 330 | .mmap = shm_mmap, |
516dffdc | 331 | .fsync = shm_fsync, |
4e982311 | 332 | .release = shm_release, |
bc56bba8 | 333 | .get_unmapped_area = shm_get_unmapped_area, |
1da177e4 LT |
334 | }; |
335 | ||
336 | static struct vm_operations_struct shm_vm_ops = { | |
337 | .open = shm_open, /* callback for a new vm-area open */ | |
338 | .close = shm_close, /* callback for when the vm-area is released */ | |
54cb8821 | 339 | .fault = shm_fault, |
bc56bba8 EB |
340 | #if defined(CONFIG_NUMA) |
341 | .set_policy = shm_set_policy, | |
342 | .get_policy = shm_get_policy, | |
1da177e4 LT |
343 | #endif |
344 | }; | |
345 | ||
7748dbfa | 346 | static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 347 | { |
7748dbfa ND |
348 | key_t key = params->key; |
349 | int shmflg = params->flg; | |
350 | size_t size = params->u.size; | |
1da177e4 LT |
351 | int error; |
352 | struct shmid_kernel *shp; | |
353 | int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; | |
354 | struct file * file; | |
355 | char name[13]; | |
356 | int id; | |
357 | ||
4e982311 | 358 | if (size < SHMMIN || size > ns->shm_ctlmax) |
1da177e4 LT |
359 | return -EINVAL; |
360 | ||
f66d45e9 | 361 | if (ns->shm_tot + numpages > ns->shm_ctlall) |
1da177e4 LT |
362 | return -ENOSPC; |
363 | ||
364 | shp = ipc_rcu_alloc(sizeof(*shp)); | |
365 | if (!shp) | |
366 | return -ENOMEM; | |
367 | ||
368 | shp->shm_perm.key = key; | |
b33291c0 | 369 | shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
1da177e4 LT |
370 | shp->mlock_user = NULL; |
371 | ||
372 | shp->shm_perm.security = NULL; | |
373 | error = security_shm_alloc(shp); | |
374 | if (error) { | |
375 | ipc_rcu_putref(shp); | |
376 | return error; | |
377 | } | |
378 | ||
9d66586f | 379 | sprintf (name, "SYSV%08x", key); |
1da177e4 | 380 | if (shmflg & SHM_HUGETLB) { |
9d66586f EB |
381 | /* hugetlb_file_setup takes care of mlock user accounting */ |
382 | file = hugetlb_file_setup(name, size); | |
1da177e4 LT |
383 | shp->mlock_user = current->user; |
384 | } else { | |
bf8f972d BP |
385 | int acctflag = VM_ACCOUNT; |
386 | /* | |
387 | * Do not allow no accounting for OVERCOMMIT_NEVER, even | |
388 | * if it's asked for. | |
389 | */ | |
390 | if ((shmflg & SHM_NORESERVE) && | |
391 | sysctl_overcommit_memory != OVERCOMMIT_NEVER) | |
392 | acctflag = 0; | |
bf8f972d | 393 | file = shmem_file_setup(name, size, acctflag); |
1da177e4 LT |
394 | } |
395 | error = PTR_ERR(file); | |
396 | if (IS_ERR(file)) | |
397 | goto no_file; | |
398 | ||
399 | error = -ENOSPC; | |
4e982311 | 400 | id = shm_addid(ns, shp); |
1da177e4 LT |
401 | if(id == -1) |
402 | goto no_id; | |
403 | ||
b488893a | 404 | shp->shm_cprid = task_tgid_vnr(current); |
1da177e4 LT |
405 | shp->shm_lprid = 0; |
406 | shp->shm_atim = shp->shm_dtim = 0; | |
407 | shp->shm_ctim = get_seconds(); | |
408 | shp->shm_segsz = size; | |
409 | shp->shm_nattch = 0; | |
7ca7e564 | 410 | shp->shm_perm.id = shm_buildid(ns, id, shp->shm_perm.seq); |
1da177e4 | 411 | shp->shm_file = file; |
30475cc1 BP |
412 | /* |
413 | * shmid gets reported as "inode#" in /proc/pid/maps. | |
414 | * proc-ps tools use this. Changing this will break them. | |
415 | */ | |
7ca7e564 | 416 | file->f_dentry->d_inode->i_ino = shp->shm_perm.id; |
551110a9 | 417 | |
4e982311 | 418 | ns->shm_tot += numpages; |
7ca7e564 | 419 | error = shp->shm_perm.id; |
1da177e4 | 420 | shm_unlock(shp); |
7ca7e564 | 421 | return error; |
1da177e4 LT |
422 | |
423 | no_id: | |
424 | fput(file); | |
425 | no_file: | |
426 | security_shm_free(shp); | |
427 | ipc_rcu_putref(shp); | |
428 | return error; | |
429 | } | |
430 | ||
03f02c76 | 431 | static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg) |
7748dbfa | 432 | { |
03f02c76 ND |
433 | struct shmid_kernel *shp; |
434 | ||
435 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
436 | return security_shm_associate(shp, shmflg); | |
7748dbfa ND |
437 | } |
438 | ||
03f02c76 ND |
439 | static inline int shm_more_checks(struct kern_ipc_perm *ipcp, |
440 | struct ipc_params *params) | |
7748dbfa | 441 | { |
03f02c76 ND |
442 | struct shmid_kernel *shp; |
443 | ||
444 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
445 | if (shp->shm_segsz < params->u.size) | |
7748dbfa ND |
446 | return -EINVAL; |
447 | ||
448 | return 0; | |
449 | } | |
450 | ||
1da177e4 LT |
451 | asmlinkage long sys_shmget (key_t key, size_t size, int shmflg) |
452 | { | |
4e982311 | 453 | struct ipc_namespace *ns; |
7748dbfa ND |
454 | struct ipc_ops shm_ops; |
455 | struct ipc_params shm_params; | |
4e982311 KK |
456 | |
457 | ns = current->nsproxy->ipc_ns; | |
1da177e4 | 458 | |
7748dbfa ND |
459 | shm_ops.getnew = newseg; |
460 | shm_ops.associate = shm_security; | |
461 | shm_ops.more_checks = shm_more_checks; | |
7ca7e564 | 462 | |
7748dbfa ND |
463 | shm_params.key = key; |
464 | shm_params.flg = shmflg; | |
465 | shm_params.u.size = size; | |
1da177e4 | 466 | |
7748dbfa | 467 | return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); |
1da177e4 LT |
468 | } |
469 | ||
470 | static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) | |
471 | { | |
472 | switch(version) { | |
473 | case IPC_64: | |
474 | return copy_to_user(buf, in, sizeof(*in)); | |
475 | case IPC_OLD: | |
476 | { | |
477 | struct shmid_ds out; | |
478 | ||
479 | ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); | |
480 | out.shm_segsz = in->shm_segsz; | |
481 | out.shm_atime = in->shm_atime; | |
482 | out.shm_dtime = in->shm_dtime; | |
483 | out.shm_ctime = in->shm_ctime; | |
484 | out.shm_cpid = in->shm_cpid; | |
485 | out.shm_lpid = in->shm_lpid; | |
486 | out.shm_nattch = in->shm_nattch; | |
487 | ||
488 | return copy_to_user(buf, &out, sizeof(out)); | |
489 | } | |
490 | default: | |
491 | return -EINVAL; | |
492 | } | |
493 | } | |
494 | ||
495 | struct shm_setbuf { | |
496 | uid_t uid; | |
497 | gid_t gid; | |
498 | mode_t mode; | |
499 | }; | |
500 | ||
501 | static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version) | |
502 | { | |
503 | switch(version) { | |
504 | case IPC_64: | |
505 | { | |
506 | struct shmid64_ds tbuf; | |
507 | ||
508 | if (copy_from_user(&tbuf, buf, sizeof(tbuf))) | |
509 | return -EFAULT; | |
510 | ||
511 | out->uid = tbuf.shm_perm.uid; | |
512 | out->gid = tbuf.shm_perm.gid; | |
b33291c0 | 513 | out->mode = tbuf.shm_perm.mode; |
1da177e4 LT |
514 | |
515 | return 0; | |
516 | } | |
517 | case IPC_OLD: | |
518 | { | |
519 | struct shmid_ds tbuf_old; | |
520 | ||
521 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) | |
522 | return -EFAULT; | |
523 | ||
524 | out->uid = tbuf_old.shm_perm.uid; | |
525 | out->gid = tbuf_old.shm_perm.gid; | |
b33291c0 | 526 | out->mode = tbuf_old.shm_perm.mode; |
1da177e4 LT |
527 | |
528 | return 0; | |
529 | } | |
530 | default: | |
531 | return -EINVAL; | |
532 | } | |
533 | } | |
534 | ||
535 | static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version) | |
536 | { | |
537 | switch(version) { | |
538 | case IPC_64: | |
539 | return copy_to_user(buf, in, sizeof(*in)); | |
540 | case IPC_OLD: | |
541 | { | |
542 | struct shminfo out; | |
543 | ||
544 | if(in->shmmax > INT_MAX) | |
545 | out.shmmax = INT_MAX; | |
546 | else | |
547 | out.shmmax = (int)in->shmmax; | |
548 | ||
549 | out.shmmin = in->shmmin; | |
550 | out.shmmni = in->shmmni; | |
551 | out.shmseg = in->shmseg; | |
552 | out.shmall = in->shmall; | |
553 | ||
554 | return copy_to_user(buf, &out, sizeof(out)); | |
555 | } | |
556 | default: | |
557 | return -EINVAL; | |
558 | } | |
559 | } | |
560 | ||
4e982311 KK |
561 | static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, |
562 | unsigned long *swp) | |
1da177e4 | 563 | { |
7ca7e564 ND |
564 | int next_id; |
565 | int total, in_use; | |
1da177e4 LT |
566 | |
567 | *rss = 0; | |
568 | *swp = 0; | |
569 | ||
7ca7e564 ND |
570 | in_use = shm_ids(ns).in_use; |
571 | ||
572 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
1da177e4 LT |
573 | struct shmid_kernel *shp; |
574 | struct inode *inode; | |
575 | ||
637c3663 ND |
576 | /* |
577 | * idr_find() is called via shm_get(), so with shm_ids.mutex | |
578 | * locked. Since ipc_addid() is also called with | |
579 | * shm_ids.mutex down, there is no need to add read barriers | |
580 | * here to gurantee the writes in ipc_addid() are seen in | |
581 | * order here (for Alpha). | |
582 | * However idr_find() itself does not necessary require | |
583 | * ipc_ids.mutex down. So if idr_find() is used by other | |
584 | * places without ipc_ids.mutex down, then it needs read | |
585 | * read memory barriers as ipc_lock() does. | |
586 | */ | |
587 | ||
588 | shp = idr_find(&shm_ids(ns).ipcs_idr, next_id); | |
7ca7e564 | 589 | if (shp == NULL) |
1da177e4 LT |
590 | continue; |
591 | ||
6d63079a | 592 | inode = shp->shm_file->f_path.dentry->d_inode; |
1da177e4 LT |
593 | |
594 | if (is_file_hugepages(shp->shm_file)) { | |
595 | struct address_space *mapping = inode->i_mapping; | |
596 | *rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages; | |
597 | } else { | |
598 | struct shmem_inode_info *info = SHMEM_I(inode); | |
599 | spin_lock(&info->lock); | |
600 | *rss += inode->i_mapping->nrpages; | |
601 | *swp += info->swapped; | |
602 | spin_unlock(&info->lock); | |
603 | } | |
7ca7e564 ND |
604 | |
605 | total++; | |
1da177e4 LT |
606 | } |
607 | } | |
608 | ||
609 | asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) | |
610 | { | |
611 | struct shm_setbuf setbuf; | |
612 | struct shmid_kernel *shp; | |
613 | int err, version; | |
4e982311 | 614 | struct ipc_namespace *ns; |
1da177e4 LT |
615 | |
616 | if (cmd < 0 || shmid < 0) { | |
617 | err = -EINVAL; | |
618 | goto out; | |
619 | } | |
620 | ||
621 | version = ipc_parse_version(&cmd); | |
4e982311 | 622 | ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
623 | |
624 | switch (cmd) { /* replace with proc interface ? */ | |
625 | case IPC_INFO: | |
626 | { | |
627 | struct shminfo64 shminfo; | |
628 | ||
629 | err = security_shm_shmctl(NULL, cmd); | |
630 | if (err) | |
631 | return err; | |
632 | ||
633 | memset(&shminfo,0,sizeof(shminfo)); | |
4e982311 KK |
634 | shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni; |
635 | shminfo.shmmax = ns->shm_ctlmax; | |
636 | shminfo.shmall = ns->shm_ctlall; | |
1da177e4 LT |
637 | |
638 | shminfo.shmmin = SHMMIN; | |
639 | if(copy_shminfo_to_user (buf, &shminfo, version)) | |
640 | return -EFAULT; | |
641 | /* reading a integer is always atomic */ | |
7ca7e564 | 642 | err = ipc_get_maxid(&shm_ids(ns)); |
1da177e4 LT |
643 | if(err<0) |
644 | err = 0; | |
645 | goto out; | |
646 | } | |
647 | case SHM_INFO: | |
648 | { | |
649 | struct shm_info shm_info; | |
650 | ||
651 | err = security_shm_shmctl(NULL, cmd); | |
652 | if (err) | |
653 | return err; | |
654 | ||
655 | memset(&shm_info,0,sizeof(shm_info)); | |
4e982311 KK |
656 | mutex_lock(&shm_ids(ns).mutex); |
657 | shm_info.used_ids = shm_ids(ns).in_use; | |
658 | shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp); | |
659 | shm_info.shm_tot = ns->shm_tot; | |
1da177e4 LT |
660 | shm_info.swap_attempts = 0; |
661 | shm_info.swap_successes = 0; | |
7ca7e564 | 662 | err = ipc_get_maxid(&shm_ids(ns)); |
4e982311 | 663 | mutex_unlock(&shm_ids(ns).mutex); |
1da177e4 LT |
664 | if(copy_to_user (buf, &shm_info, sizeof(shm_info))) { |
665 | err = -EFAULT; | |
666 | goto out; | |
667 | } | |
668 | ||
669 | err = err < 0 ? 0 : err; | |
670 | goto out; | |
671 | } | |
672 | case SHM_STAT: | |
673 | case IPC_STAT: | |
674 | { | |
675 | struct shmid64_ds tbuf; | |
676 | int result; | |
023a5355 ND |
677 | |
678 | if (!buf) { | |
679 | err = -EFAULT; | |
1da177e4 | 680 | goto out; |
023a5355 ND |
681 | } |
682 | ||
683 | if (cmd == SHM_STAT) { | |
684 | shp = shm_lock(ns, shmid); | |
685 | if (IS_ERR(shp)) { | |
686 | err = PTR_ERR(shp); | |
687 | goto out; | |
688 | } | |
7ca7e564 | 689 | result = shp->shm_perm.id; |
1da177e4 | 690 | } else { |
023a5355 ND |
691 | shp = shm_lock_check(ns, shmid); |
692 | if (IS_ERR(shp)) { | |
693 | err = PTR_ERR(shp); | |
694 | goto out; | |
695 | } | |
1da177e4 LT |
696 | result = 0; |
697 | } | |
698 | err=-EACCES; | |
699 | if (ipcperms (&shp->shm_perm, S_IRUGO)) | |
700 | goto out_unlock; | |
701 | err = security_shm_shmctl(shp, cmd); | |
702 | if (err) | |
703 | goto out_unlock; | |
023a5355 | 704 | memset(&tbuf, 0, sizeof(tbuf)); |
1da177e4 LT |
705 | kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm); |
706 | tbuf.shm_segsz = shp->shm_segsz; | |
707 | tbuf.shm_atime = shp->shm_atim; | |
708 | tbuf.shm_dtime = shp->shm_dtim; | |
709 | tbuf.shm_ctime = shp->shm_ctim; | |
710 | tbuf.shm_cpid = shp->shm_cprid; | |
711 | tbuf.shm_lpid = shp->shm_lprid; | |
bc56bba8 | 712 | tbuf.shm_nattch = shp->shm_nattch; |
1da177e4 LT |
713 | shm_unlock(shp); |
714 | if(copy_shmid_to_user (buf, &tbuf, version)) | |
715 | err = -EFAULT; | |
716 | else | |
717 | err = result; | |
718 | goto out; | |
719 | } | |
720 | case SHM_LOCK: | |
721 | case SHM_UNLOCK: | |
722 | { | |
023a5355 ND |
723 | shp = shm_lock_check(ns, shmid); |
724 | if (IS_ERR(shp)) { | |
725 | err = PTR_ERR(shp); | |
1da177e4 LT |
726 | goto out; |
727 | } | |
1da177e4 | 728 | |
073115d6 SG |
729 | err = audit_ipc_obj(&(shp->shm_perm)); |
730 | if (err) | |
731 | goto out_unlock; | |
732 | ||
1da177e4 LT |
733 | if (!capable(CAP_IPC_LOCK)) { |
734 | err = -EPERM; | |
735 | if (current->euid != shp->shm_perm.uid && | |
736 | current->euid != shp->shm_perm.cuid) | |
737 | goto out_unlock; | |
738 | if (cmd == SHM_LOCK && | |
739 | !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur) | |
740 | goto out_unlock; | |
741 | } | |
742 | ||
743 | err = security_shm_shmctl(shp, cmd); | |
744 | if (err) | |
745 | goto out_unlock; | |
746 | ||
747 | if(cmd==SHM_LOCK) { | |
748 | struct user_struct * user = current->user; | |
749 | if (!is_file_hugepages(shp->shm_file)) { | |
750 | err = shmem_lock(shp->shm_file, 1, user); | |
7be77e20 | 751 | if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){ |
b33291c0 | 752 | shp->shm_perm.mode |= SHM_LOCKED; |
1da177e4 LT |
753 | shp->mlock_user = user; |
754 | } | |
755 | } | |
756 | } else if (!is_file_hugepages(shp->shm_file)) { | |
757 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
b33291c0 | 758 | shp->shm_perm.mode &= ~SHM_LOCKED; |
1da177e4 LT |
759 | shp->mlock_user = NULL; |
760 | } | |
761 | shm_unlock(shp); | |
762 | goto out; | |
763 | } | |
764 | case IPC_RMID: | |
765 | { | |
766 | /* | |
767 | * We cannot simply remove the file. The SVID states | |
768 | * that the block remains until the last person | |
769 | * detaches from it, then is deleted. A shmat() on | |
770 | * an RMID segment is legal in older Linux and if | |
771 | * we change it apps break... | |
772 | * | |
773 | * Instead we set a destroyed flag, and then blow | |
774 | * the name away when the usage hits zero. | |
775 | */ | |
4e982311 | 776 | mutex_lock(&shm_ids(ns).mutex); |
023a5355 ND |
777 | shp = shm_lock_check(ns, shmid); |
778 | if (IS_ERR(shp)) { | |
779 | err = PTR_ERR(shp); | |
1da177e4 | 780 | goto out_up; |
023a5355 | 781 | } |
1da177e4 | 782 | |
073115d6 SG |
783 | err = audit_ipc_obj(&(shp->shm_perm)); |
784 | if (err) | |
785 | goto out_unlock_up; | |
786 | ||
1da177e4 LT |
787 | if (current->euid != shp->shm_perm.uid && |
788 | current->euid != shp->shm_perm.cuid && | |
789 | !capable(CAP_SYS_ADMIN)) { | |
790 | err=-EPERM; | |
791 | goto out_unlock_up; | |
792 | } | |
793 | ||
794 | err = security_shm_shmctl(shp, cmd); | |
795 | if (err) | |
796 | goto out_unlock_up; | |
797 | ||
4e982311 KK |
798 | do_shm_rmid(ns, shp); |
799 | mutex_unlock(&shm_ids(ns).mutex); | |
1da177e4 LT |
800 | goto out; |
801 | } | |
802 | ||
803 | case IPC_SET: | |
804 | { | |
023a5355 ND |
805 | if (!buf) { |
806 | err = -EFAULT; | |
807 | goto out; | |
808 | } | |
809 | ||
1da177e4 LT |
810 | if (copy_shmid_from_user (&setbuf, buf, version)) { |
811 | err = -EFAULT; | |
812 | goto out; | |
813 | } | |
4e982311 | 814 | mutex_lock(&shm_ids(ns).mutex); |
023a5355 ND |
815 | shp = shm_lock_check(ns, shmid); |
816 | if (IS_ERR(shp)) { | |
817 | err = PTR_ERR(shp); | |
1da177e4 | 818 | goto out_up; |
023a5355 | 819 | } |
073115d6 SG |
820 | err = audit_ipc_obj(&(shp->shm_perm)); |
821 | if (err) | |
822 | goto out_unlock_up; | |
ac03221a | 823 | err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode); |
073115d6 SG |
824 | if (err) |
825 | goto out_unlock_up; | |
1da177e4 LT |
826 | err=-EPERM; |
827 | if (current->euid != shp->shm_perm.uid && | |
828 | current->euid != shp->shm_perm.cuid && | |
829 | !capable(CAP_SYS_ADMIN)) { | |
830 | goto out_unlock_up; | |
831 | } | |
832 | ||
833 | err = security_shm_shmctl(shp, cmd); | |
834 | if (err) | |
835 | goto out_unlock_up; | |
836 | ||
837 | shp->shm_perm.uid = setbuf.uid; | |
838 | shp->shm_perm.gid = setbuf.gid; | |
b33291c0 | 839 | shp->shm_perm.mode = (shp->shm_perm.mode & ~S_IRWXUGO) |
1da177e4 LT |
840 | | (setbuf.mode & S_IRWXUGO); |
841 | shp->shm_ctim = get_seconds(); | |
842 | break; | |
843 | } | |
844 | ||
845 | default: | |
846 | err = -EINVAL; | |
847 | goto out; | |
848 | } | |
849 | ||
850 | err = 0; | |
851 | out_unlock_up: | |
852 | shm_unlock(shp); | |
853 | out_up: | |
4e982311 | 854 | mutex_unlock(&shm_ids(ns).mutex); |
1da177e4 LT |
855 | goto out; |
856 | out_unlock: | |
857 | shm_unlock(shp); | |
858 | out: | |
859 | return err; | |
860 | } | |
861 | ||
862 | /* | |
863 | * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists. | |
864 | * | |
865 | * NOTE! Despite the name, this is NOT a direct system call entrypoint. The | |
866 | * "raddr" thing points to kernel space, and there has to be a wrapper around | |
867 | * this. | |
868 | */ | |
869 | long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) | |
870 | { | |
871 | struct shmid_kernel *shp; | |
872 | unsigned long addr; | |
873 | unsigned long size; | |
874 | struct file * file; | |
875 | int err; | |
876 | unsigned long flags; | |
877 | unsigned long prot; | |
1da177e4 | 878 | int acc_mode; |
bc56bba8 | 879 | unsigned long user_addr; |
4e982311 | 880 | struct ipc_namespace *ns; |
bc56bba8 EB |
881 | struct shm_file_data *sfd; |
882 | struct path path; | |
883 | mode_t f_mode; | |
1da177e4 | 884 | |
bc56bba8 EB |
885 | err = -EINVAL; |
886 | if (shmid < 0) | |
1da177e4 | 887 | goto out; |
bc56bba8 | 888 | else if ((addr = (ulong)shmaddr)) { |
1da177e4 LT |
889 | if (addr & (SHMLBA-1)) { |
890 | if (shmflg & SHM_RND) | |
891 | addr &= ~(SHMLBA-1); /* round down */ | |
892 | else | |
893 | #ifndef __ARCH_FORCE_SHMLBA | |
894 | if (addr & ~PAGE_MASK) | |
895 | #endif | |
bc56bba8 | 896 | goto out; |
1da177e4 LT |
897 | } |
898 | flags = MAP_SHARED | MAP_FIXED; | |
899 | } else { | |
900 | if ((shmflg & SHM_REMAP)) | |
bc56bba8 | 901 | goto out; |
1da177e4 LT |
902 | |
903 | flags = MAP_SHARED; | |
904 | } | |
905 | ||
906 | if (shmflg & SHM_RDONLY) { | |
907 | prot = PROT_READ; | |
1da177e4 | 908 | acc_mode = S_IRUGO; |
bc56bba8 | 909 | f_mode = FMODE_READ; |
1da177e4 LT |
910 | } else { |
911 | prot = PROT_READ | PROT_WRITE; | |
1da177e4 | 912 | acc_mode = S_IRUGO | S_IWUGO; |
bc56bba8 | 913 | f_mode = FMODE_READ | FMODE_WRITE; |
1da177e4 LT |
914 | } |
915 | if (shmflg & SHM_EXEC) { | |
916 | prot |= PROT_EXEC; | |
917 | acc_mode |= S_IXUGO; | |
918 | } | |
919 | ||
920 | /* | |
921 | * We cannot rely on the fs check since SYSV IPC does have an | |
922 | * additional creator id... | |
923 | */ | |
4e982311 | 924 | ns = current->nsproxy->ipc_ns; |
023a5355 ND |
925 | shp = shm_lock_check(ns, shmid); |
926 | if (IS_ERR(shp)) { | |
927 | err = PTR_ERR(shp); | |
1da177e4 | 928 | goto out; |
023a5355 | 929 | } |
bc56bba8 EB |
930 | |
931 | err = -EACCES; | |
932 | if (ipcperms(&shp->shm_perm, acc_mode)) | |
933 | goto out_unlock; | |
1da177e4 LT |
934 | |
935 | err = security_shm_shmat(shp, shmaddr, shmflg); | |
bc56bba8 EB |
936 | if (err) |
937 | goto out_unlock; | |
938 | ||
939 | path.dentry = dget(shp->shm_file->f_path.dentry); | |
ce8d2cdf | 940 | path.mnt = shp->shm_file->f_path.mnt; |
1da177e4 | 941 | shp->shm_nattch++; |
bc56bba8 | 942 | size = i_size_read(path.dentry->d_inode); |
1da177e4 LT |
943 | shm_unlock(shp); |
944 | ||
bc56bba8 EB |
945 | err = -ENOMEM; |
946 | sfd = kzalloc(sizeof(*sfd), GFP_KERNEL); | |
947 | if (!sfd) | |
ce8d2cdf | 948 | goto out_put_dentry; |
bc56bba8 EB |
949 | |
950 | err = -ENOMEM; | |
ce8d2cdf DH |
951 | |
952 | file = alloc_file(path.mnt, path.dentry, f_mode, &shm_file_operations); | |
bc56bba8 EB |
953 | if (!file) |
954 | goto out_free; | |
955 | ||
bc56bba8 | 956 | file->private_data = sfd; |
bc56bba8 | 957 | file->f_mapping = shp->shm_file->f_mapping; |
7ca7e564 | 958 | sfd->id = shp->shm_perm.id; |
bc56bba8 EB |
959 | sfd->ns = get_ipc_ns(ns); |
960 | sfd->file = shp->shm_file; | |
961 | sfd->vm_ops = NULL; | |
962 | ||
1da177e4 LT |
963 | down_write(¤t->mm->mmap_sem); |
964 | if (addr && !(shmflg & SHM_REMAP)) { | |
bc56bba8 | 965 | err = -EINVAL; |
1da177e4 LT |
966 | if (find_vma_intersection(current->mm, addr, addr + size)) |
967 | goto invalid; | |
968 | /* | |
969 | * If shm segment goes below stack, make sure there is some | |
970 | * space left for the stack to grow (at least 4 pages). | |
971 | */ | |
972 | if (addr < current->mm->start_stack && | |
973 | addr > current->mm->start_stack - size - PAGE_SIZE * 5) | |
974 | goto invalid; | |
975 | } | |
976 | ||
bc56bba8 EB |
977 | user_addr = do_mmap (file, addr, size, prot, flags, 0); |
978 | *raddr = user_addr; | |
979 | err = 0; | |
980 | if (IS_ERR_VALUE(user_addr)) | |
981 | err = (long)user_addr; | |
1da177e4 LT |
982 | invalid: |
983 | up_write(¤t->mm->mmap_sem); | |
984 | ||
bc56bba8 EB |
985 | fput(file); |
986 | ||
987 | out_nattch: | |
4e982311 KK |
988 | mutex_lock(&shm_ids(ns).mutex); |
989 | shp = shm_lock(ns, shmid); | |
023a5355 | 990 | BUG_ON(IS_ERR(shp)); |
1da177e4 LT |
991 | shp->shm_nattch--; |
992 | if(shp->shm_nattch == 0 && | |
b33291c0 | 993 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 994 | shm_destroy(ns, shp); |
1da177e4 LT |
995 | else |
996 | shm_unlock(shp); | |
4e982311 | 997 | mutex_unlock(&shm_ids(ns).mutex); |
1da177e4 | 998 | |
1da177e4 LT |
999 | out: |
1000 | return err; | |
bc56bba8 EB |
1001 | |
1002 | out_unlock: | |
1003 | shm_unlock(shp); | |
1004 | goto out; | |
1005 | ||
1006 | out_free: | |
1007 | kfree(sfd); | |
ce8d2cdf | 1008 | out_put_dentry: |
bc56bba8 | 1009 | dput(path.dentry); |
bc56bba8 | 1010 | goto out_nattch; |
1da177e4 LT |
1011 | } |
1012 | ||
7d87e14c SR |
1013 | asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg) |
1014 | { | |
1015 | unsigned long ret; | |
1016 | long err; | |
1017 | ||
1018 | err = do_shmat(shmid, shmaddr, shmflg, &ret); | |
1019 | if (err) | |
1020 | return err; | |
1021 | force_successful_syscall_return(); | |
1022 | return (long)ret; | |
1023 | } | |
1024 | ||
1da177e4 LT |
1025 | /* |
1026 | * detach and kill segment if marked destroyed. | |
1027 | * The work is done in shm_close. | |
1028 | */ | |
1029 | asmlinkage long sys_shmdt(char __user *shmaddr) | |
1030 | { | |
1031 | struct mm_struct *mm = current->mm; | |
1032 | struct vm_area_struct *vma, *next; | |
1033 | unsigned long addr = (unsigned long)shmaddr; | |
1034 | loff_t size = 0; | |
1035 | int retval = -EINVAL; | |
1036 | ||
df1e2fb5 HD |
1037 | if (addr & ~PAGE_MASK) |
1038 | return retval; | |
1039 | ||
1da177e4 LT |
1040 | down_write(&mm->mmap_sem); |
1041 | ||
1042 | /* | |
1043 | * This function tries to be smart and unmap shm segments that | |
1044 | * were modified by partial mlock or munmap calls: | |
1045 | * - It first determines the size of the shm segment that should be | |
1046 | * unmapped: It searches for a vma that is backed by shm and that | |
1047 | * started at address shmaddr. It records it's size and then unmaps | |
1048 | * it. | |
1049 | * - Then it unmaps all shm vmas that started at shmaddr and that | |
1050 | * are within the initially determined size. | |
1051 | * Errors from do_munmap are ignored: the function only fails if | |
1052 | * it's called with invalid parameters or if it's called to unmap | |
1053 | * a part of a vma. Both calls in this function are for full vmas, | |
1054 | * the parameters are directly copied from the vma itself and always | |
1055 | * valid - therefore do_munmap cannot fail. (famous last words?) | |
1056 | */ | |
1057 | /* | |
1058 | * If it had been mremap()'d, the starting address would not | |
1059 | * match the usual checks anyway. So assume all vma's are | |
1060 | * above the starting address given. | |
1061 | */ | |
1062 | vma = find_vma(mm, addr); | |
1063 | ||
1064 | while (vma) { | |
1065 | next = vma->vm_next; | |
1066 | ||
1067 | /* | |
1068 | * Check if the starting address would match, i.e. it's | |
1069 | * a fragment created by mprotect() and/or munmap(), or it | |
1070 | * otherwise it starts at this address with no hassles. | |
1071 | */ | |
bc56bba8 | 1072 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1073 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { |
1074 | ||
1075 | ||
6d63079a | 1076 | size = vma->vm_file->f_path.dentry->d_inode->i_size; |
1da177e4 LT |
1077 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
1078 | /* | |
1079 | * We discovered the size of the shm segment, so | |
1080 | * break out of here and fall through to the next | |
1081 | * loop that uses the size information to stop | |
1082 | * searching for matching vma's. | |
1083 | */ | |
1084 | retval = 0; | |
1085 | vma = next; | |
1086 | break; | |
1087 | } | |
1088 | vma = next; | |
1089 | } | |
1090 | ||
1091 | /* | |
1092 | * We need look no further than the maximum address a fragment | |
1093 | * could possibly have landed at. Also cast things to loff_t to | |
1094 | * prevent overflows and make comparisions vs. equal-width types. | |
1095 | */ | |
8e36709d | 1096 | size = PAGE_ALIGN(size); |
1da177e4 LT |
1097 | while (vma && (loff_t)(vma->vm_end - addr) <= size) { |
1098 | next = vma->vm_next; | |
1099 | ||
1100 | /* finding a matching vma now does not alter retval */ | |
bc56bba8 | 1101 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1102 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) |
1103 | ||
1104 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
1105 | vma = next; | |
1106 | } | |
1107 | ||
1108 | up_write(&mm->mmap_sem); | |
1109 | return retval; | |
1110 | } | |
1111 | ||
1112 | #ifdef CONFIG_PROC_FS | |
19b4946c | 1113 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
1da177e4 | 1114 | { |
19b4946c MW |
1115 | struct shmid_kernel *shp = it; |
1116 | char *format; | |
1da177e4 | 1117 | |
1da177e4 LT |
1118 | #define SMALL_STRING "%10d %10d %4o %10u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" |
1119 | #define BIG_STRING "%10d %10d %4o %21u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" | |
1da177e4 | 1120 | |
19b4946c MW |
1121 | if (sizeof(size_t) <= sizeof(int)) |
1122 | format = SMALL_STRING; | |
1123 | else | |
1124 | format = BIG_STRING; | |
1125 | return seq_printf(s, format, | |
1126 | shp->shm_perm.key, | |
7ca7e564 | 1127 | shp->shm_perm.id, |
b33291c0 | 1128 | shp->shm_perm.mode, |
19b4946c MW |
1129 | shp->shm_segsz, |
1130 | shp->shm_cprid, | |
1131 | shp->shm_lprid, | |
bc56bba8 | 1132 | shp->shm_nattch, |
19b4946c MW |
1133 | shp->shm_perm.uid, |
1134 | shp->shm_perm.gid, | |
1135 | shp->shm_perm.cuid, | |
1136 | shp->shm_perm.cgid, | |
1137 | shp->shm_atim, | |
1138 | shp->shm_dtim, | |
1139 | shp->shm_ctim); | |
1da177e4 LT |
1140 | } |
1141 | #endif |