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