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) | |
1b531f21 | 63 | #define shm_buildid(id, seq) ipc_buildid(id, seq) |
1da177e4 | 64 | |
7748dbfa | 65 | static int newseg(struct ipc_namespace *, struct ipc_params *); |
bc56bba8 EB |
66 | static void shm_open(struct vm_area_struct *vma); |
67 | static void shm_close(struct vm_area_struct *vma); | |
4e982311 | 68 | static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp); |
1da177e4 | 69 | #ifdef CONFIG_PROC_FS |
19b4946c | 70 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it); |
1da177e4 LT |
71 | #endif |
72 | ||
ed2ddbf8 | 73 | void shm_init_ns(struct ipc_namespace *ns) |
4e982311 | 74 | { |
4e982311 KK |
75 | ns->shm_ctlmax = SHMMAX; |
76 | ns->shm_ctlall = SHMALL; | |
77 | ns->shm_ctlmni = SHMMNI; | |
78 | ns->shm_tot = 0; | |
ed2ddbf8 | 79 | ipc_init_ids(&ns->ids[IPC_SHM_IDS]); |
4e982311 KK |
80 | } |
81 | ||
f4566f04 | 82 | /* |
3e148c79 ND |
83 | * Called with shm_ids.rw_mutex (writer) and the shp structure locked. |
84 | * Only shm_ids.rw_mutex remains locked on exit. | |
f4566f04 | 85 | */ |
4e982311 KK |
86 | static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp) |
87 | { | |
88 | if (shp->shm_nattch){ | |
89 | shp->shm_perm.mode |= SHM_DEST; | |
90 | /* Do not find it any more */ | |
91 | shp->shm_perm.key = IPC_PRIVATE; | |
92 | shm_unlock(shp); | |
93 | } else | |
94 | shm_destroy(ns, shp); | |
95 | } | |
96 | ||
ae5e1b22 | 97 | #ifdef CONFIG_IPC_NS |
4e982311 KK |
98 | void shm_exit_ns(struct ipc_namespace *ns) |
99 | { | |
4e982311 | 100 | struct shmid_kernel *shp; |
b1ed88b4 | 101 | struct kern_ipc_perm *perm; |
7ca7e564 ND |
102 | int next_id; |
103 | int total, in_use; | |
4e982311 | 104 | |
3e148c79 | 105 | down_write(&shm_ids(ns).rw_mutex); |
7ca7e564 ND |
106 | |
107 | in_use = shm_ids(ns).in_use; | |
108 | ||
109 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
b1ed88b4 PP |
110 | perm = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
111 | if (perm == NULL) | |
4e982311 | 112 | continue; |
b1ed88b4 PP |
113 | ipc_lock_by_ptr(perm); |
114 | shp = container_of(perm, struct shmid_kernel, shm_perm); | |
4e982311 | 115 | do_shm_rmid(ns, shp); |
7ca7e564 | 116 | total++; |
4e982311 | 117 | } |
3e148c79 | 118 | up_write(&shm_ids(ns).rw_mutex); |
4e982311 | 119 | } |
ae5e1b22 | 120 | #endif |
1da177e4 LT |
121 | |
122 | void __init shm_init (void) | |
123 | { | |
ed2ddbf8 | 124 | shm_init_ns(&init_ipc_ns); |
19b4946c MW |
125 | ipc_init_proc_interface("sysvipc/shm", |
126 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n", | |
4e982311 | 127 | IPC_SHM_IDS, sysvipc_shm_proc_show); |
1da177e4 LT |
128 | } |
129 | ||
3e148c79 ND |
130 | /* |
131 | * shm_lock_(check_)down routines are called in the paths where the rw_mutex | |
132 | * is held to protect access to the idr tree. | |
133 | */ | |
134 | static inline struct shmid_kernel *shm_lock_down(struct ipc_namespace *ns, | |
135 | int id) | |
136 | { | |
137 | struct kern_ipc_perm *ipcp = ipc_lock_down(&shm_ids(ns), id); | |
138 | ||
b1ed88b4 PP |
139 | if (IS_ERR(ipcp)) |
140 | return (struct shmid_kernel *)ipcp; | |
141 | ||
3e148c79 ND |
142 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
143 | } | |
144 | ||
145 | static inline struct shmid_kernel *shm_lock_check_down( | |
146 | struct ipc_namespace *ns, | |
147 | int id) | |
148 | { | |
149 | struct kern_ipc_perm *ipcp = ipc_lock_check_down(&shm_ids(ns), id); | |
150 | ||
b1ed88b4 PP |
151 | if (IS_ERR(ipcp)) |
152 | return (struct shmid_kernel *)ipcp; | |
153 | ||
3e148c79 ND |
154 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
155 | } | |
156 | ||
157 | /* | |
158 | * shm_lock_(check_) routines are called in the paths where the rw_mutex | |
159 | * is not held. | |
160 | */ | |
023a5355 | 161 | static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id) |
1da177e4 | 162 | { |
03f02c76 ND |
163 | struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id); |
164 | ||
b1ed88b4 PP |
165 | if (IS_ERR(ipcp)) |
166 | return (struct shmid_kernel *)ipcp; | |
167 | ||
03f02c76 | 168 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
023a5355 ND |
169 | } |
170 | ||
171 | static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns, | |
172 | int id) | |
173 | { | |
03f02c76 ND |
174 | struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id); |
175 | ||
b1ed88b4 PP |
176 | if (IS_ERR(ipcp)) |
177 | return (struct shmid_kernel *)ipcp; | |
178 | ||
03f02c76 | 179 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
1da177e4 LT |
180 | } |
181 | ||
7ca7e564 | 182 | static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s) |
1da177e4 | 183 | { |
7ca7e564 | 184 | ipc_rmid(&shm_ids(ns), &s->shm_perm); |
1da177e4 LT |
185 | } |
186 | ||
4e982311 | 187 | static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 188 | { |
4e982311 | 189 | return ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
1da177e4 LT |
190 | } |
191 | ||
192 | ||
193 | ||
bc56bba8 EB |
194 | /* This is called by fork, once for every shm attach. */ |
195 | static void shm_open(struct vm_area_struct *vma) | |
4e982311 | 196 | { |
bc56bba8 EB |
197 | struct file *file = vma->vm_file; |
198 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 LT |
199 | struct shmid_kernel *shp; |
200 | ||
bc56bba8 | 201 | shp = shm_lock(sfd->ns, sfd->id); |
023a5355 | 202 | BUG_ON(IS_ERR(shp)); |
1da177e4 | 203 | shp->shm_atim = get_seconds(); |
b488893a | 204 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
205 | shp->shm_nattch++; |
206 | shm_unlock(shp); | |
207 | } | |
208 | ||
1da177e4 LT |
209 | /* |
210 | * shm_destroy - free the struct shmid_kernel | |
211 | * | |
f4566f04 | 212 | * @ns: namespace |
1da177e4 LT |
213 | * @shp: struct to free |
214 | * | |
3e148c79 | 215 | * It has to be called with shp and shm_ids.rw_mutex (writer) locked, |
1da177e4 LT |
216 | * but returns with shp unlocked and freed. |
217 | */ | |
4e982311 | 218 | static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 219 | { |
4e982311 | 220 | ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; |
7ca7e564 | 221 | shm_rmid(ns, shp); |
1da177e4 LT |
222 | shm_unlock(shp); |
223 | if (!is_file_hugepages(shp->shm_file)) | |
224 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
225 | else | |
6d63079a | 226 | user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size, |
1da177e4 LT |
227 | shp->mlock_user); |
228 | fput (shp->shm_file); | |
229 | security_shm_free(shp); | |
230 | ipc_rcu_putref(shp); | |
231 | } | |
232 | ||
233 | /* | |
bc56bba8 | 234 | * remove the attach descriptor vma. |
1da177e4 LT |
235 | * free memory for segment if it is marked destroyed. |
236 | * The descriptor has already been removed from the current->mm->mmap list | |
237 | * and will later be kfree()d. | |
238 | */ | |
bc56bba8 | 239 | static void shm_close(struct vm_area_struct *vma) |
1da177e4 | 240 | { |
bc56bba8 EB |
241 | struct file * file = vma->vm_file; |
242 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 | 243 | struct shmid_kernel *shp; |
bc56bba8 | 244 | struct ipc_namespace *ns = sfd->ns; |
4e982311 | 245 | |
3e148c79 | 246 | down_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 247 | /* remove from the list of attaches of the shm segment */ |
3e148c79 | 248 | shp = shm_lock_down(ns, sfd->id); |
023a5355 | 249 | BUG_ON(IS_ERR(shp)); |
b488893a | 250 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
251 | shp->shm_dtim = get_seconds(); |
252 | shp->shm_nattch--; | |
253 | if(shp->shm_nattch == 0 && | |
b33291c0 | 254 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 255 | shm_destroy(ns, shp); |
1da177e4 LT |
256 | else |
257 | shm_unlock(shp); | |
3e148c79 | 258 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
259 | } |
260 | ||
d0217ac0 | 261 | static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
bc56bba8 EB |
262 | { |
263 | struct file *file = vma->vm_file; | |
264 | struct shm_file_data *sfd = shm_file_data(file); | |
265 | ||
d0217ac0 | 266 | return sfd->vm_ops->fault(vma, vmf); |
bc56bba8 EB |
267 | } |
268 | ||
269 | #ifdef CONFIG_NUMA | |
d823e3e7 | 270 | static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
bc56bba8 EB |
271 | { |
272 | struct file *file = vma->vm_file; | |
273 | struct shm_file_data *sfd = shm_file_data(file); | |
274 | int err = 0; | |
275 | if (sfd->vm_ops->set_policy) | |
276 | err = sfd->vm_ops->set_policy(vma, new); | |
277 | return err; | |
278 | } | |
279 | ||
d823e3e7 AB |
280 | static struct mempolicy *shm_get_policy(struct vm_area_struct *vma, |
281 | unsigned long addr) | |
bc56bba8 EB |
282 | { |
283 | struct file *file = vma->vm_file; | |
284 | struct shm_file_data *sfd = shm_file_data(file); | |
285 | struct mempolicy *pol = NULL; | |
286 | ||
287 | if (sfd->vm_ops->get_policy) | |
288 | pol = sfd->vm_ops->get_policy(vma, addr); | |
22741925 | 289 | else if (vma->vm_policy) |
bc56bba8 | 290 | pol = vma->vm_policy; |
22741925 AL |
291 | else |
292 | pol = current->mempolicy; | |
bc56bba8 EB |
293 | return pol; |
294 | } | |
295 | #endif | |
296 | ||
1da177e4 LT |
297 | static int shm_mmap(struct file * file, struct vm_area_struct * vma) |
298 | { | |
bc56bba8 | 299 | struct shm_file_data *sfd = shm_file_data(file); |
b0e15190 DH |
300 | int ret; |
301 | ||
bc56bba8 EB |
302 | ret = sfd->file->f_op->mmap(sfd->file, vma); |
303 | if (ret != 0) | |
304 | return ret; | |
305 | sfd->vm_ops = vma->vm_ops; | |
2e92a3ba | 306 | #ifdef CONFIG_MMU |
54cb8821 | 307 | BUG_ON(!sfd->vm_ops->fault); |
2e92a3ba | 308 | #endif |
bc56bba8 EB |
309 | vma->vm_ops = &shm_vm_ops; |
310 | shm_open(vma); | |
b0e15190 DH |
311 | |
312 | return ret; | |
1da177e4 LT |
313 | } |
314 | ||
4e982311 KK |
315 | static int shm_release(struct inode *ino, struct file *file) |
316 | { | |
bc56bba8 | 317 | struct shm_file_data *sfd = shm_file_data(file); |
4e982311 | 318 | |
bc56bba8 EB |
319 | put_ipc_ns(sfd->ns); |
320 | shm_file_data(file) = NULL; | |
321 | kfree(sfd); | |
4e982311 KK |
322 | return 0; |
323 | } | |
324 | ||
516dffdc AL |
325 | static int shm_fsync(struct file *file, struct dentry *dentry, int datasync) |
326 | { | |
327 | int (*fsync) (struct file *, struct dentry *, int datasync); | |
328 | struct shm_file_data *sfd = shm_file_data(file); | |
329 | int ret = -EINVAL; | |
330 | ||
331 | fsync = sfd->file->f_op->fsync; | |
332 | if (fsync) | |
333 | ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync); | |
334 | return ret; | |
335 | } | |
336 | ||
bc56bba8 EB |
337 | static unsigned long shm_get_unmapped_area(struct file *file, |
338 | unsigned long addr, unsigned long len, unsigned long pgoff, | |
339 | unsigned long flags) | |
340 | { | |
341 | struct shm_file_data *sfd = shm_file_data(file); | |
516dffdc AL |
342 | return get_unmapped_area(sfd->file, addr, len, pgoff, flags); |
343 | } | |
344 | ||
345 | int is_file_shm_hugepages(struct file *file) | |
346 | { | |
347 | int ret = 0; | |
348 | ||
349 | if (file->f_op == &shm_file_operations) { | |
350 | struct shm_file_data *sfd; | |
351 | sfd = shm_file_data(file); | |
352 | ret = is_file_hugepages(sfd->file); | |
353 | } | |
354 | return ret; | |
bc56bba8 | 355 | } |
bc56bba8 | 356 | |
9a32144e | 357 | static const struct file_operations shm_file_operations = { |
4e982311 | 358 | .mmap = shm_mmap, |
516dffdc | 359 | .fsync = shm_fsync, |
4e982311 | 360 | .release = shm_release, |
bc56bba8 | 361 | .get_unmapped_area = shm_get_unmapped_area, |
1da177e4 LT |
362 | }; |
363 | ||
364 | static struct vm_operations_struct shm_vm_ops = { | |
365 | .open = shm_open, /* callback for a new vm-area open */ | |
366 | .close = shm_close, /* callback for when the vm-area is released */ | |
54cb8821 | 367 | .fault = shm_fault, |
bc56bba8 EB |
368 | #if defined(CONFIG_NUMA) |
369 | .set_policy = shm_set_policy, | |
370 | .get_policy = shm_get_policy, | |
1da177e4 LT |
371 | #endif |
372 | }; | |
373 | ||
f4566f04 ND |
374 | /** |
375 | * newseg - Create a new shared memory segment | |
376 | * @ns: namespace | |
377 | * @params: ptr to the structure that contains key, size and shmflg | |
378 | * | |
3e148c79 | 379 | * Called with shm_ids.rw_mutex held as a writer. |
f4566f04 ND |
380 | */ |
381 | ||
7748dbfa | 382 | static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 383 | { |
7748dbfa ND |
384 | key_t key = params->key; |
385 | int shmflg = params->flg; | |
386 | size_t size = params->u.size; | |
1da177e4 LT |
387 | int error; |
388 | struct shmid_kernel *shp; | |
389 | int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; | |
390 | struct file * file; | |
391 | char name[13]; | |
392 | int id; | |
393 | ||
4e982311 | 394 | if (size < SHMMIN || size > ns->shm_ctlmax) |
1da177e4 LT |
395 | return -EINVAL; |
396 | ||
f66d45e9 | 397 | if (ns->shm_tot + numpages > ns->shm_ctlall) |
1da177e4 LT |
398 | return -ENOSPC; |
399 | ||
400 | shp = ipc_rcu_alloc(sizeof(*shp)); | |
401 | if (!shp) | |
402 | return -ENOMEM; | |
403 | ||
404 | shp->shm_perm.key = key; | |
b33291c0 | 405 | shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
1da177e4 LT |
406 | shp->mlock_user = NULL; |
407 | ||
408 | shp->shm_perm.security = NULL; | |
409 | error = security_shm_alloc(shp); | |
410 | if (error) { | |
411 | ipc_rcu_putref(shp); | |
412 | return error; | |
413 | } | |
414 | ||
9d66586f | 415 | sprintf (name, "SYSV%08x", key); |
1da177e4 | 416 | if (shmflg & SHM_HUGETLB) { |
9d66586f EB |
417 | /* hugetlb_file_setup takes care of mlock user accounting */ |
418 | file = hugetlb_file_setup(name, size); | |
1da177e4 LT |
419 | shp->mlock_user = current->user; |
420 | } else { | |
bf8f972d BP |
421 | int acctflag = VM_ACCOUNT; |
422 | /* | |
423 | * Do not allow no accounting for OVERCOMMIT_NEVER, even | |
424 | * if it's asked for. | |
425 | */ | |
426 | if ((shmflg & SHM_NORESERVE) && | |
427 | sysctl_overcommit_memory != OVERCOMMIT_NEVER) | |
428 | acctflag = 0; | |
bf8f972d | 429 | file = shmem_file_setup(name, size, acctflag); |
1da177e4 LT |
430 | } |
431 | error = PTR_ERR(file); | |
432 | if (IS_ERR(file)) | |
433 | goto no_file; | |
434 | ||
4e982311 | 435 | id = shm_addid(ns, shp); |
283bb7fa PP |
436 | if (id < 0) { |
437 | error = id; | |
1da177e4 | 438 | goto no_id; |
283bb7fa | 439 | } |
1da177e4 | 440 | |
b488893a | 441 | shp->shm_cprid = task_tgid_vnr(current); |
1da177e4 LT |
442 | shp->shm_lprid = 0; |
443 | shp->shm_atim = shp->shm_dtim = 0; | |
444 | shp->shm_ctim = get_seconds(); | |
445 | shp->shm_segsz = size; | |
446 | shp->shm_nattch = 0; | |
1b531f21 | 447 | shp->shm_perm.id = shm_buildid(id, shp->shm_perm.seq); |
1da177e4 | 448 | shp->shm_file = file; |
30475cc1 BP |
449 | /* |
450 | * shmid gets reported as "inode#" in /proc/pid/maps. | |
451 | * proc-ps tools use this. Changing this will break them. | |
452 | */ | |
7ca7e564 | 453 | file->f_dentry->d_inode->i_ino = shp->shm_perm.id; |
551110a9 | 454 | |
4e982311 | 455 | ns->shm_tot += numpages; |
7ca7e564 | 456 | error = shp->shm_perm.id; |
1da177e4 | 457 | shm_unlock(shp); |
7ca7e564 | 458 | return error; |
1da177e4 LT |
459 | |
460 | no_id: | |
461 | fput(file); | |
462 | no_file: | |
463 | security_shm_free(shp); | |
464 | ipc_rcu_putref(shp); | |
465 | return error; | |
466 | } | |
467 | ||
f4566f04 | 468 | /* |
3e148c79 | 469 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 470 | */ |
03f02c76 | 471 | static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg) |
7748dbfa | 472 | { |
03f02c76 ND |
473 | struct shmid_kernel *shp; |
474 | ||
475 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
476 | return security_shm_associate(shp, shmflg); | |
7748dbfa ND |
477 | } |
478 | ||
f4566f04 | 479 | /* |
3e148c79 | 480 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 481 | */ |
03f02c76 ND |
482 | static inline int shm_more_checks(struct kern_ipc_perm *ipcp, |
483 | struct ipc_params *params) | |
7748dbfa | 484 | { |
03f02c76 ND |
485 | struct shmid_kernel *shp; |
486 | ||
487 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
488 | if (shp->shm_segsz < params->u.size) | |
7748dbfa ND |
489 | return -EINVAL; |
490 | ||
491 | return 0; | |
492 | } | |
493 | ||
1da177e4 LT |
494 | asmlinkage long sys_shmget (key_t key, size_t size, int shmflg) |
495 | { | |
4e982311 | 496 | struct ipc_namespace *ns; |
7748dbfa ND |
497 | struct ipc_ops shm_ops; |
498 | struct ipc_params shm_params; | |
4e982311 KK |
499 | |
500 | ns = current->nsproxy->ipc_ns; | |
1da177e4 | 501 | |
7748dbfa ND |
502 | shm_ops.getnew = newseg; |
503 | shm_ops.associate = shm_security; | |
504 | shm_ops.more_checks = shm_more_checks; | |
7ca7e564 | 505 | |
7748dbfa ND |
506 | shm_params.key = key; |
507 | shm_params.flg = shmflg; | |
508 | shm_params.u.size = size; | |
1da177e4 | 509 | |
7748dbfa | 510 | return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); |
1da177e4 LT |
511 | } |
512 | ||
513 | static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) | |
514 | { | |
515 | switch(version) { | |
516 | case IPC_64: | |
517 | return copy_to_user(buf, in, sizeof(*in)); | |
518 | case IPC_OLD: | |
519 | { | |
520 | struct shmid_ds out; | |
521 | ||
522 | ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); | |
523 | out.shm_segsz = in->shm_segsz; | |
524 | out.shm_atime = in->shm_atime; | |
525 | out.shm_dtime = in->shm_dtime; | |
526 | out.shm_ctime = in->shm_ctime; | |
527 | out.shm_cpid = in->shm_cpid; | |
528 | out.shm_lpid = in->shm_lpid; | |
529 | out.shm_nattch = in->shm_nattch; | |
530 | ||
531 | return copy_to_user(buf, &out, sizeof(out)); | |
532 | } | |
533 | default: | |
534 | return -EINVAL; | |
535 | } | |
536 | } | |
537 | ||
538 | struct shm_setbuf { | |
539 | uid_t uid; | |
540 | gid_t gid; | |
541 | mode_t mode; | |
542 | }; | |
543 | ||
544 | static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version) | |
545 | { | |
546 | switch(version) { | |
547 | case IPC_64: | |
548 | { | |
549 | struct shmid64_ds tbuf; | |
550 | ||
551 | if (copy_from_user(&tbuf, buf, sizeof(tbuf))) | |
552 | return -EFAULT; | |
553 | ||
554 | out->uid = tbuf.shm_perm.uid; | |
555 | out->gid = tbuf.shm_perm.gid; | |
b33291c0 | 556 | out->mode = tbuf.shm_perm.mode; |
1da177e4 LT |
557 | |
558 | return 0; | |
559 | } | |
560 | case IPC_OLD: | |
561 | { | |
562 | struct shmid_ds tbuf_old; | |
563 | ||
564 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) | |
565 | return -EFAULT; | |
566 | ||
567 | out->uid = tbuf_old.shm_perm.uid; | |
568 | out->gid = tbuf_old.shm_perm.gid; | |
b33291c0 | 569 | out->mode = tbuf_old.shm_perm.mode; |
1da177e4 LT |
570 | |
571 | return 0; | |
572 | } | |
573 | default: | |
574 | return -EINVAL; | |
575 | } | |
576 | } | |
577 | ||
578 | static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version) | |
579 | { | |
580 | switch(version) { | |
581 | case IPC_64: | |
582 | return copy_to_user(buf, in, sizeof(*in)); | |
583 | case IPC_OLD: | |
584 | { | |
585 | struct shminfo out; | |
586 | ||
587 | if(in->shmmax > INT_MAX) | |
588 | out.shmmax = INT_MAX; | |
589 | else | |
590 | out.shmmax = (int)in->shmmax; | |
591 | ||
592 | out.shmmin = in->shmmin; | |
593 | out.shmmni = in->shmmni; | |
594 | out.shmseg = in->shmseg; | |
595 | out.shmall = in->shmall; | |
596 | ||
597 | return copy_to_user(buf, &out, sizeof(out)); | |
598 | } | |
599 | default: | |
600 | return -EINVAL; | |
601 | } | |
602 | } | |
603 | ||
f4566f04 | 604 | /* |
3e148c79 | 605 | * Called with shm_ids.rw_mutex held as a reader |
f4566f04 | 606 | */ |
4e982311 KK |
607 | static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, |
608 | unsigned long *swp) | |
1da177e4 | 609 | { |
7ca7e564 ND |
610 | int next_id; |
611 | int total, in_use; | |
1da177e4 LT |
612 | |
613 | *rss = 0; | |
614 | *swp = 0; | |
615 | ||
7ca7e564 ND |
616 | in_use = shm_ids(ns).in_use; |
617 | ||
618 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
1da177e4 LT |
619 | struct shmid_kernel *shp; |
620 | struct inode *inode; | |
621 | ||
637c3663 | 622 | shp = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
7ca7e564 | 623 | if (shp == NULL) |
1da177e4 LT |
624 | continue; |
625 | ||
6d63079a | 626 | inode = shp->shm_file->f_path.dentry->d_inode; |
1da177e4 LT |
627 | |
628 | if (is_file_hugepages(shp->shm_file)) { | |
629 | struct address_space *mapping = inode->i_mapping; | |
630 | *rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages; | |
631 | } else { | |
632 | struct shmem_inode_info *info = SHMEM_I(inode); | |
633 | spin_lock(&info->lock); | |
634 | *rss += inode->i_mapping->nrpages; | |
635 | *swp += info->swapped; | |
636 | spin_unlock(&info->lock); | |
637 | } | |
7ca7e564 ND |
638 | |
639 | total++; | |
1da177e4 LT |
640 | } |
641 | } | |
642 | ||
643 | asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) | |
644 | { | |
645 | struct shm_setbuf setbuf; | |
646 | struct shmid_kernel *shp; | |
647 | int err, version; | |
4e982311 | 648 | struct ipc_namespace *ns; |
1da177e4 LT |
649 | |
650 | if (cmd < 0 || shmid < 0) { | |
651 | err = -EINVAL; | |
652 | goto out; | |
653 | } | |
654 | ||
655 | version = ipc_parse_version(&cmd); | |
4e982311 | 656 | ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
657 | |
658 | switch (cmd) { /* replace with proc interface ? */ | |
659 | case IPC_INFO: | |
660 | { | |
661 | struct shminfo64 shminfo; | |
662 | ||
663 | err = security_shm_shmctl(NULL, cmd); | |
664 | if (err) | |
665 | return err; | |
666 | ||
667 | memset(&shminfo,0,sizeof(shminfo)); | |
4e982311 KK |
668 | shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni; |
669 | shminfo.shmmax = ns->shm_ctlmax; | |
670 | shminfo.shmall = ns->shm_ctlall; | |
1da177e4 LT |
671 | |
672 | shminfo.shmmin = SHMMIN; | |
673 | if(copy_shminfo_to_user (buf, &shminfo, version)) | |
674 | return -EFAULT; | |
f4566f04 | 675 | |
3e148c79 | 676 | down_read(&shm_ids(ns).rw_mutex); |
7ca7e564 | 677 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 678 | up_read(&shm_ids(ns).rw_mutex); |
f4566f04 | 679 | |
1da177e4 LT |
680 | if(err<0) |
681 | err = 0; | |
682 | goto out; | |
683 | } | |
684 | case SHM_INFO: | |
685 | { | |
686 | struct shm_info shm_info; | |
687 | ||
688 | err = security_shm_shmctl(NULL, cmd); | |
689 | if (err) | |
690 | return err; | |
691 | ||
692 | memset(&shm_info,0,sizeof(shm_info)); | |
3e148c79 | 693 | down_read(&shm_ids(ns).rw_mutex); |
4e982311 KK |
694 | shm_info.used_ids = shm_ids(ns).in_use; |
695 | shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp); | |
696 | shm_info.shm_tot = ns->shm_tot; | |
1da177e4 LT |
697 | shm_info.swap_attempts = 0; |
698 | shm_info.swap_successes = 0; | |
7ca7e564 | 699 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 700 | up_read(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
701 | if(copy_to_user (buf, &shm_info, sizeof(shm_info))) { |
702 | err = -EFAULT; | |
703 | goto out; | |
704 | } | |
705 | ||
706 | err = err < 0 ? 0 : err; | |
707 | goto out; | |
708 | } | |
709 | case SHM_STAT: | |
710 | case IPC_STAT: | |
711 | { | |
712 | struct shmid64_ds tbuf; | |
713 | int result; | |
023a5355 ND |
714 | |
715 | if (!buf) { | |
716 | err = -EFAULT; | |
1da177e4 | 717 | goto out; |
023a5355 ND |
718 | } |
719 | ||
720 | if (cmd == SHM_STAT) { | |
721 | shp = shm_lock(ns, shmid); | |
722 | if (IS_ERR(shp)) { | |
723 | err = PTR_ERR(shp); | |
724 | goto out; | |
725 | } | |
7ca7e564 | 726 | result = shp->shm_perm.id; |
1da177e4 | 727 | } else { |
023a5355 ND |
728 | shp = shm_lock_check(ns, shmid); |
729 | if (IS_ERR(shp)) { | |
730 | err = PTR_ERR(shp); | |
731 | goto out; | |
732 | } | |
1da177e4 LT |
733 | result = 0; |
734 | } | |
735 | err=-EACCES; | |
736 | if (ipcperms (&shp->shm_perm, S_IRUGO)) | |
737 | goto out_unlock; | |
738 | err = security_shm_shmctl(shp, cmd); | |
739 | if (err) | |
740 | goto out_unlock; | |
023a5355 | 741 | memset(&tbuf, 0, sizeof(tbuf)); |
1da177e4 LT |
742 | kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm); |
743 | tbuf.shm_segsz = shp->shm_segsz; | |
744 | tbuf.shm_atime = shp->shm_atim; | |
745 | tbuf.shm_dtime = shp->shm_dtim; | |
746 | tbuf.shm_ctime = shp->shm_ctim; | |
747 | tbuf.shm_cpid = shp->shm_cprid; | |
748 | tbuf.shm_lpid = shp->shm_lprid; | |
bc56bba8 | 749 | tbuf.shm_nattch = shp->shm_nattch; |
1da177e4 LT |
750 | shm_unlock(shp); |
751 | if(copy_shmid_to_user (buf, &tbuf, version)) | |
752 | err = -EFAULT; | |
753 | else | |
754 | err = result; | |
755 | goto out; | |
756 | } | |
757 | case SHM_LOCK: | |
758 | case SHM_UNLOCK: | |
759 | { | |
023a5355 ND |
760 | shp = shm_lock_check(ns, shmid); |
761 | if (IS_ERR(shp)) { | |
762 | err = PTR_ERR(shp); | |
1da177e4 LT |
763 | goto out; |
764 | } | |
1da177e4 | 765 | |
073115d6 SG |
766 | err = audit_ipc_obj(&(shp->shm_perm)); |
767 | if (err) | |
768 | goto out_unlock; | |
769 | ||
1da177e4 LT |
770 | if (!capable(CAP_IPC_LOCK)) { |
771 | err = -EPERM; | |
772 | if (current->euid != shp->shm_perm.uid && | |
773 | current->euid != shp->shm_perm.cuid) | |
774 | goto out_unlock; | |
775 | if (cmd == SHM_LOCK && | |
776 | !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur) | |
777 | goto out_unlock; | |
778 | } | |
779 | ||
780 | err = security_shm_shmctl(shp, cmd); | |
781 | if (err) | |
782 | goto out_unlock; | |
783 | ||
784 | if(cmd==SHM_LOCK) { | |
785 | struct user_struct * user = current->user; | |
786 | if (!is_file_hugepages(shp->shm_file)) { | |
787 | err = shmem_lock(shp->shm_file, 1, user); | |
7be77e20 | 788 | if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){ |
b33291c0 | 789 | shp->shm_perm.mode |= SHM_LOCKED; |
1da177e4 LT |
790 | shp->mlock_user = user; |
791 | } | |
792 | } | |
793 | } else if (!is_file_hugepages(shp->shm_file)) { | |
794 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
b33291c0 | 795 | shp->shm_perm.mode &= ~SHM_LOCKED; |
1da177e4 LT |
796 | shp->mlock_user = NULL; |
797 | } | |
798 | shm_unlock(shp); | |
799 | goto out; | |
800 | } | |
801 | case IPC_RMID: | |
802 | { | |
803 | /* | |
804 | * We cannot simply remove the file. The SVID states | |
805 | * that the block remains until the last person | |
806 | * detaches from it, then is deleted. A shmat() on | |
807 | * an RMID segment is legal in older Linux and if | |
808 | * we change it apps break... | |
809 | * | |
810 | * Instead we set a destroyed flag, and then blow | |
811 | * the name away when the usage hits zero. | |
812 | */ | |
3e148c79 ND |
813 | down_write(&shm_ids(ns).rw_mutex); |
814 | shp = shm_lock_check_down(ns, shmid); | |
023a5355 ND |
815 | if (IS_ERR(shp)) { |
816 | err = PTR_ERR(shp); | |
1da177e4 | 817 | goto out_up; |
023a5355 | 818 | } |
1da177e4 | 819 | |
073115d6 SG |
820 | err = audit_ipc_obj(&(shp->shm_perm)); |
821 | if (err) | |
822 | goto out_unlock_up; | |
823 | ||
1da177e4 LT |
824 | if (current->euid != shp->shm_perm.uid && |
825 | current->euid != shp->shm_perm.cuid && | |
826 | !capable(CAP_SYS_ADMIN)) { | |
827 | err=-EPERM; | |
828 | goto out_unlock_up; | |
829 | } | |
830 | ||
831 | err = security_shm_shmctl(shp, cmd); | |
832 | if (err) | |
833 | goto out_unlock_up; | |
834 | ||
4e982311 | 835 | do_shm_rmid(ns, shp); |
3e148c79 | 836 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
837 | goto out; |
838 | } | |
839 | ||
840 | case IPC_SET: | |
841 | { | |
023a5355 ND |
842 | if (!buf) { |
843 | err = -EFAULT; | |
844 | goto out; | |
845 | } | |
846 | ||
1da177e4 LT |
847 | if (copy_shmid_from_user (&setbuf, buf, version)) { |
848 | err = -EFAULT; | |
849 | goto out; | |
850 | } | |
3e148c79 ND |
851 | down_write(&shm_ids(ns).rw_mutex); |
852 | shp = shm_lock_check_down(ns, shmid); | |
023a5355 ND |
853 | if (IS_ERR(shp)) { |
854 | err = PTR_ERR(shp); | |
1da177e4 | 855 | goto out_up; |
023a5355 | 856 | } |
073115d6 SG |
857 | err = audit_ipc_obj(&(shp->shm_perm)); |
858 | if (err) | |
859 | goto out_unlock_up; | |
ac03221a | 860 | err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode); |
073115d6 SG |
861 | if (err) |
862 | goto out_unlock_up; | |
1da177e4 LT |
863 | err=-EPERM; |
864 | if (current->euid != shp->shm_perm.uid && | |
865 | current->euid != shp->shm_perm.cuid && | |
866 | !capable(CAP_SYS_ADMIN)) { | |
867 | goto out_unlock_up; | |
868 | } | |
869 | ||
870 | err = security_shm_shmctl(shp, cmd); | |
871 | if (err) | |
872 | goto out_unlock_up; | |
873 | ||
874 | shp->shm_perm.uid = setbuf.uid; | |
875 | shp->shm_perm.gid = setbuf.gid; | |
b33291c0 | 876 | shp->shm_perm.mode = (shp->shm_perm.mode & ~S_IRWXUGO) |
1da177e4 LT |
877 | | (setbuf.mode & S_IRWXUGO); |
878 | shp->shm_ctim = get_seconds(); | |
879 | break; | |
880 | } | |
881 | ||
882 | default: | |
883 | err = -EINVAL; | |
884 | goto out; | |
885 | } | |
886 | ||
887 | err = 0; | |
888 | out_unlock_up: | |
889 | shm_unlock(shp); | |
890 | out_up: | |
3e148c79 | 891 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
892 | goto out; |
893 | out_unlock: | |
894 | shm_unlock(shp); | |
895 | out: | |
896 | return err; | |
897 | } | |
898 | ||
899 | /* | |
900 | * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists. | |
901 | * | |
902 | * NOTE! Despite the name, this is NOT a direct system call entrypoint. The | |
903 | * "raddr" thing points to kernel space, and there has to be a wrapper around | |
904 | * this. | |
905 | */ | |
906 | long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) | |
907 | { | |
908 | struct shmid_kernel *shp; | |
909 | unsigned long addr; | |
910 | unsigned long size; | |
911 | struct file * file; | |
912 | int err; | |
913 | unsigned long flags; | |
914 | unsigned long prot; | |
1da177e4 | 915 | int acc_mode; |
bc56bba8 | 916 | unsigned long user_addr; |
4e982311 | 917 | struct ipc_namespace *ns; |
bc56bba8 EB |
918 | struct shm_file_data *sfd; |
919 | struct path path; | |
920 | mode_t f_mode; | |
1da177e4 | 921 | |
bc56bba8 EB |
922 | err = -EINVAL; |
923 | if (shmid < 0) | |
1da177e4 | 924 | goto out; |
bc56bba8 | 925 | else if ((addr = (ulong)shmaddr)) { |
1da177e4 LT |
926 | if (addr & (SHMLBA-1)) { |
927 | if (shmflg & SHM_RND) | |
928 | addr &= ~(SHMLBA-1); /* round down */ | |
929 | else | |
930 | #ifndef __ARCH_FORCE_SHMLBA | |
931 | if (addr & ~PAGE_MASK) | |
932 | #endif | |
bc56bba8 | 933 | goto out; |
1da177e4 LT |
934 | } |
935 | flags = MAP_SHARED | MAP_FIXED; | |
936 | } else { | |
937 | if ((shmflg & SHM_REMAP)) | |
bc56bba8 | 938 | goto out; |
1da177e4 LT |
939 | |
940 | flags = MAP_SHARED; | |
941 | } | |
942 | ||
943 | if (shmflg & SHM_RDONLY) { | |
944 | prot = PROT_READ; | |
1da177e4 | 945 | acc_mode = S_IRUGO; |
bc56bba8 | 946 | f_mode = FMODE_READ; |
1da177e4 LT |
947 | } else { |
948 | prot = PROT_READ | PROT_WRITE; | |
1da177e4 | 949 | acc_mode = S_IRUGO | S_IWUGO; |
bc56bba8 | 950 | f_mode = FMODE_READ | FMODE_WRITE; |
1da177e4 LT |
951 | } |
952 | if (shmflg & SHM_EXEC) { | |
953 | prot |= PROT_EXEC; | |
954 | acc_mode |= S_IXUGO; | |
955 | } | |
956 | ||
957 | /* | |
958 | * We cannot rely on the fs check since SYSV IPC does have an | |
959 | * additional creator id... | |
960 | */ | |
4e982311 | 961 | ns = current->nsproxy->ipc_ns; |
023a5355 ND |
962 | shp = shm_lock_check(ns, shmid); |
963 | if (IS_ERR(shp)) { | |
964 | err = PTR_ERR(shp); | |
1da177e4 | 965 | goto out; |
023a5355 | 966 | } |
bc56bba8 EB |
967 | |
968 | err = -EACCES; | |
969 | if (ipcperms(&shp->shm_perm, acc_mode)) | |
970 | goto out_unlock; | |
1da177e4 LT |
971 | |
972 | err = security_shm_shmat(shp, shmaddr, shmflg); | |
bc56bba8 EB |
973 | if (err) |
974 | goto out_unlock; | |
975 | ||
976 | path.dentry = dget(shp->shm_file->f_path.dentry); | |
ce8d2cdf | 977 | path.mnt = shp->shm_file->f_path.mnt; |
1da177e4 | 978 | shp->shm_nattch++; |
bc56bba8 | 979 | size = i_size_read(path.dentry->d_inode); |
1da177e4 LT |
980 | shm_unlock(shp); |
981 | ||
bc56bba8 EB |
982 | err = -ENOMEM; |
983 | sfd = kzalloc(sizeof(*sfd), GFP_KERNEL); | |
984 | if (!sfd) | |
ce8d2cdf | 985 | goto out_put_dentry; |
bc56bba8 EB |
986 | |
987 | err = -ENOMEM; | |
ce8d2cdf DH |
988 | |
989 | file = alloc_file(path.mnt, path.dentry, f_mode, &shm_file_operations); | |
bc56bba8 EB |
990 | if (!file) |
991 | goto out_free; | |
992 | ||
bc56bba8 | 993 | file->private_data = sfd; |
bc56bba8 | 994 | file->f_mapping = shp->shm_file->f_mapping; |
7ca7e564 | 995 | sfd->id = shp->shm_perm.id; |
bc56bba8 EB |
996 | sfd->ns = get_ipc_ns(ns); |
997 | sfd->file = shp->shm_file; | |
998 | sfd->vm_ops = NULL; | |
999 | ||
1da177e4 LT |
1000 | down_write(¤t->mm->mmap_sem); |
1001 | if (addr && !(shmflg & SHM_REMAP)) { | |
bc56bba8 | 1002 | err = -EINVAL; |
1da177e4 LT |
1003 | if (find_vma_intersection(current->mm, addr, addr + size)) |
1004 | goto invalid; | |
1005 | /* | |
1006 | * If shm segment goes below stack, make sure there is some | |
1007 | * space left for the stack to grow (at least 4 pages). | |
1008 | */ | |
1009 | if (addr < current->mm->start_stack && | |
1010 | addr > current->mm->start_stack - size - PAGE_SIZE * 5) | |
1011 | goto invalid; | |
1012 | } | |
1013 | ||
bc56bba8 EB |
1014 | user_addr = do_mmap (file, addr, size, prot, flags, 0); |
1015 | *raddr = user_addr; | |
1016 | err = 0; | |
1017 | if (IS_ERR_VALUE(user_addr)) | |
1018 | err = (long)user_addr; | |
1da177e4 LT |
1019 | invalid: |
1020 | up_write(¤t->mm->mmap_sem); | |
1021 | ||
bc56bba8 EB |
1022 | fput(file); |
1023 | ||
1024 | out_nattch: | |
3e148c79 ND |
1025 | down_write(&shm_ids(ns).rw_mutex); |
1026 | shp = shm_lock_down(ns, shmid); | |
023a5355 | 1027 | BUG_ON(IS_ERR(shp)); |
1da177e4 LT |
1028 | shp->shm_nattch--; |
1029 | if(shp->shm_nattch == 0 && | |
b33291c0 | 1030 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 1031 | shm_destroy(ns, shp); |
1da177e4 LT |
1032 | else |
1033 | shm_unlock(shp); | |
3e148c79 | 1034 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 1035 | |
1da177e4 LT |
1036 | out: |
1037 | return err; | |
bc56bba8 EB |
1038 | |
1039 | out_unlock: | |
1040 | shm_unlock(shp); | |
1041 | goto out; | |
1042 | ||
1043 | out_free: | |
1044 | kfree(sfd); | |
ce8d2cdf | 1045 | out_put_dentry: |
bc56bba8 | 1046 | dput(path.dentry); |
bc56bba8 | 1047 | goto out_nattch; |
1da177e4 LT |
1048 | } |
1049 | ||
7d87e14c SR |
1050 | asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg) |
1051 | { | |
1052 | unsigned long ret; | |
1053 | long err; | |
1054 | ||
1055 | err = do_shmat(shmid, shmaddr, shmflg, &ret); | |
1056 | if (err) | |
1057 | return err; | |
1058 | force_successful_syscall_return(); | |
1059 | return (long)ret; | |
1060 | } | |
1061 | ||
1da177e4 LT |
1062 | /* |
1063 | * detach and kill segment if marked destroyed. | |
1064 | * The work is done in shm_close. | |
1065 | */ | |
1066 | asmlinkage long sys_shmdt(char __user *shmaddr) | |
1067 | { | |
1068 | struct mm_struct *mm = current->mm; | |
1069 | struct vm_area_struct *vma, *next; | |
1070 | unsigned long addr = (unsigned long)shmaddr; | |
1071 | loff_t size = 0; | |
1072 | int retval = -EINVAL; | |
1073 | ||
df1e2fb5 HD |
1074 | if (addr & ~PAGE_MASK) |
1075 | return retval; | |
1076 | ||
1da177e4 LT |
1077 | down_write(&mm->mmap_sem); |
1078 | ||
1079 | /* | |
1080 | * This function tries to be smart and unmap shm segments that | |
1081 | * were modified by partial mlock or munmap calls: | |
1082 | * - It first determines the size of the shm segment that should be | |
1083 | * unmapped: It searches for a vma that is backed by shm and that | |
1084 | * started at address shmaddr. It records it's size and then unmaps | |
1085 | * it. | |
1086 | * - Then it unmaps all shm vmas that started at shmaddr and that | |
1087 | * are within the initially determined size. | |
1088 | * Errors from do_munmap are ignored: the function only fails if | |
1089 | * it's called with invalid parameters or if it's called to unmap | |
1090 | * a part of a vma. Both calls in this function are for full vmas, | |
1091 | * the parameters are directly copied from the vma itself and always | |
1092 | * valid - therefore do_munmap cannot fail. (famous last words?) | |
1093 | */ | |
1094 | /* | |
1095 | * If it had been mremap()'d, the starting address would not | |
1096 | * match the usual checks anyway. So assume all vma's are | |
1097 | * above the starting address given. | |
1098 | */ | |
1099 | vma = find_vma(mm, addr); | |
1100 | ||
1101 | while (vma) { | |
1102 | next = vma->vm_next; | |
1103 | ||
1104 | /* | |
1105 | * Check if the starting address would match, i.e. it's | |
1106 | * a fragment created by mprotect() and/or munmap(), or it | |
1107 | * otherwise it starts at this address with no hassles. | |
1108 | */ | |
bc56bba8 | 1109 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1110 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { |
1111 | ||
1112 | ||
6d63079a | 1113 | size = vma->vm_file->f_path.dentry->d_inode->i_size; |
1da177e4 LT |
1114 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
1115 | /* | |
1116 | * We discovered the size of the shm segment, so | |
1117 | * break out of here and fall through to the next | |
1118 | * loop that uses the size information to stop | |
1119 | * searching for matching vma's. | |
1120 | */ | |
1121 | retval = 0; | |
1122 | vma = next; | |
1123 | break; | |
1124 | } | |
1125 | vma = next; | |
1126 | } | |
1127 | ||
1128 | /* | |
1129 | * We need look no further than the maximum address a fragment | |
1130 | * could possibly have landed at. Also cast things to loff_t to | |
1131 | * prevent overflows and make comparisions vs. equal-width types. | |
1132 | */ | |
8e36709d | 1133 | size = PAGE_ALIGN(size); |
1da177e4 LT |
1134 | while (vma && (loff_t)(vma->vm_end - addr) <= size) { |
1135 | next = vma->vm_next; | |
1136 | ||
1137 | /* finding a matching vma now does not alter retval */ | |
bc56bba8 | 1138 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1139 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) |
1140 | ||
1141 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
1142 | vma = next; | |
1143 | } | |
1144 | ||
1145 | up_write(&mm->mmap_sem); | |
1146 | return retval; | |
1147 | } | |
1148 | ||
1149 | #ifdef CONFIG_PROC_FS | |
19b4946c | 1150 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
1da177e4 | 1151 | { |
19b4946c MW |
1152 | struct shmid_kernel *shp = it; |
1153 | char *format; | |
1da177e4 | 1154 | |
1da177e4 LT |
1155 | #define SMALL_STRING "%10d %10d %4o %10u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" |
1156 | #define BIG_STRING "%10d %10d %4o %21u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" | |
1da177e4 | 1157 | |
19b4946c MW |
1158 | if (sizeof(size_t) <= sizeof(int)) |
1159 | format = SMALL_STRING; | |
1160 | else | |
1161 | format = BIG_STRING; | |
1162 | return seq_printf(s, format, | |
1163 | shp->shm_perm.key, | |
7ca7e564 | 1164 | shp->shm_perm.id, |
b33291c0 | 1165 | shp->shm_perm.mode, |
19b4946c MW |
1166 | shp->shm_segsz, |
1167 | shp->shm_cprid, | |
1168 | shp->shm_lprid, | |
bc56bba8 | 1169 | shp->shm_nattch, |
19b4946c MW |
1170 | shp->shm_perm.uid, |
1171 | shp->shm_perm.gid, | |
1172 | shp->shm_perm.cuid, | |
1173 | shp->shm_perm.cgid, | |
1174 | shp->shm_atim, | |
1175 | shp->shm_dtim, | |
1176 | shp->shm_ctim); | |
1da177e4 LT |
1177 | } |
1178 | #endif |