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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> |
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 | */ |
01b8b07a | 86 | static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) |
4e982311 | 87 | { |
01b8b07a PP |
88 | struct shmid_kernel *shp; |
89 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
90 | ||
4e982311 KK |
91 | if (shp->shm_nattch){ |
92 | shp->shm_perm.mode |= SHM_DEST; | |
93 | /* Do not find it any more */ | |
94 | shp->shm_perm.key = IPC_PRIVATE; | |
95 | shm_unlock(shp); | |
96 | } else | |
97 | shm_destroy(ns, shp); | |
98 | } | |
99 | ||
ae5e1b22 | 100 | #ifdef CONFIG_IPC_NS |
4e982311 KK |
101 | void shm_exit_ns(struct ipc_namespace *ns) |
102 | { | |
01b8b07a | 103 | free_ipcs(ns, &shm_ids(ns), do_shm_rmid); |
4e982311 | 104 | } |
ae5e1b22 | 105 | #endif |
1da177e4 LT |
106 | |
107 | void __init shm_init (void) | |
108 | { | |
ed2ddbf8 | 109 | shm_init_ns(&init_ipc_ns); |
19b4946c MW |
110 | ipc_init_proc_interface("sysvipc/shm", |
111 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n", | |
4e982311 | 112 | IPC_SHM_IDS, sysvipc_shm_proc_show); |
1da177e4 LT |
113 | } |
114 | ||
3e148c79 ND |
115 | /* |
116 | * shm_lock_(check_)down routines are called in the paths where the rw_mutex | |
117 | * is held to protect access to the idr tree. | |
118 | */ | |
119 | static inline struct shmid_kernel *shm_lock_down(struct ipc_namespace *ns, | |
120 | int id) | |
121 | { | |
122 | struct kern_ipc_perm *ipcp = ipc_lock_down(&shm_ids(ns), id); | |
123 | ||
b1ed88b4 PP |
124 | if (IS_ERR(ipcp)) |
125 | return (struct shmid_kernel *)ipcp; | |
126 | ||
3e148c79 ND |
127 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
128 | } | |
129 | ||
130 | static inline struct shmid_kernel *shm_lock_check_down( | |
131 | struct ipc_namespace *ns, | |
132 | int id) | |
133 | { | |
134 | struct kern_ipc_perm *ipcp = ipc_lock_check_down(&shm_ids(ns), id); | |
135 | ||
b1ed88b4 PP |
136 | if (IS_ERR(ipcp)) |
137 | return (struct shmid_kernel *)ipcp; | |
138 | ||
3e148c79 ND |
139 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
140 | } | |
141 | ||
142 | /* | |
143 | * shm_lock_(check_) routines are called in the paths where the rw_mutex | |
144 | * is not held. | |
145 | */ | |
023a5355 | 146 | static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id) |
1da177e4 | 147 | { |
03f02c76 ND |
148 | struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id); |
149 | ||
b1ed88b4 PP |
150 | if (IS_ERR(ipcp)) |
151 | return (struct shmid_kernel *)ipcp; | |
152 | ||
03f02c76 | 153 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
023a5355 ND |
154 | } |
155 | ||
156 | static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns, | |
157 | int id) | |
158 | { | |
03f02c76 ND |
159 | struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id); |
160 | ||
b1ed88b4 PP |
161 | if (IS_ERR(ipcp)) |
162 | return (struct shmid_kernel *)ipcp; | |
163 | ||
03f02c76 | 164 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
1da177e4 LT |
165 | } |
166 | ||
7ca7e564 | 167 | static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s) |
1da177e4 | 168 | { |
7ca7e564 | 169 | ipc_rmid(&shm_ids(ns), &s->shm_perm); |
1da177e4 LT |
170 | } |
171 | ||
4e982311 | 172 | static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 173 | { |
4e982311 | 174 | return ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
1da177e4 LT |
175 | } |
176 | ||
177 | ||
178 | ||
bc56bba8 EB |
179 | /* This is called by fork, once for every shm attach. */ |
180 | static void shm_open(struct vm_area_struct *vma) | |
4e982311 | 181 | { |
bc56bba8 EB |
182 | struct file *file = vma->vm_file; |
183 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 LT |
184 | struct shmid_kernel *shp; |
185 | ||
bc56bba8 | 186 | shp = shm_lock(sfd->ns, sfd->id); |
023a5355 | 187 | BUG_ON(IS_ERR(shp)); |
1da177e4 | 188 | shp->shm_atim = get_seconds(); |
b488893a | 189 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
190 | shp->shm_nattch++; |
191 | shm_unlock(shp); | |
192 | } | |
193 | ||
1da177e4 LT |
194 | /* |
195 | * shm_destroy - free the struct shmid_kernel | |
196 | * | |
f4566f04 | 197 | * @ns: namespace |
1da177e4 LT |
198 | * @shp: struct to free |
199 | * | |
3e148c79 | 200 | * It has to be called with shp and shm_ids.rw_mutex (writer) locked, |
1da177e4 LT |
201 | * but returns with shp unlocked and freed. |
202 | */ | |
4e982311 | 203 | static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 204 | { |
4e982311 | 205 | ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; |
7ca7e564 | 206 | shm_rmid(ns, shp); |
1da177e4 LT |
207 | shm_unlock(shp); |
208 | if (!is_file_hugepages(shp->shm_file)) | |
209 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
210 | else | |
6d63079a | 211 | user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size, |
1da177e4 LT |
212 | shp->mlock_user); |
213 | fput (shp->shm_file); | |
214 | security_shm_free(shp); | |
215 | ipc_rcu_putref(shp); | |
216 | } | |
217 | ||
218 | /* | |
bc56bba8 | 219 | * remove the attach descriptor vma. |
1da177e4 LT |
220 | * free memory for segment if it is marked destroyed. |
221 | * The descriptor has already been removed from the current->mm->mmap list | |
222 | * and will later be kfree()d. | |
223 | */ | |
bc56bba8 | 224 | static void shm_close(struct vm_area_struct *vma) |
1da177e4 | 225 | { |
bc56bba8 EB |
226 | struct file * file = vma->vm_file; |
227 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 | 228 | struct shmid_kernel *shp; |
bc56bba8 | 229 | struct ipc_namespace *ns = sfd->ns; |
4e982311 | 230 | |
3e148c79 | 231 | down_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 232 | /* remove from the list of attaches of the shm segment */ |
3e148c79 | 233 | shp = shm_lock_down(ns, sfd->id); |
023a5355 | 234 | BUG_ON(IS_ERR(shp)); |
b488893a | 235 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
236 | shp->shm_dtim = get_seconds(); |
237 | shp->shm_nattch--; | |
238 | if(shp->shm_nattch == 0 && | |
b33291c0 | 239 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 240 | shm_destroy(ns, shp); |
1da177e4 LT |
241 | else |
242 | shm_unlock(shp); | |
3e148c79 | 243 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
244 | } |
245 | ||
d0217ac0 | 246 | static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
bc56bba8 EB |
247 | { |
248 | struct file *file = vma->vm_file; | |
249 | struct shm_file_data *sfd = shm_file_data(file); | |
250 | ||
d0217ac0 | 251 | return sfd->vm_ops->fault(vma, vmf); |
bc56bba8 EB |
252 | } |
253 | ||
254 | #ifdef CONFIG_NUMA | |
d823e3e7 | 255 | static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
bc56bba8 EB |
256 | { |
257 | struct file *file = vma->vm_file; | |
258 | struct shm_file_data *sfd = shm_file_data(file); | |
259 | int err = 0; | |
260 | if (sfd->vm_ops->set_policy) | |
261 | err = sfd->vm_ops->set_policy(vma, new); | |
262 | return err; | |
263 | } | |
264 | ||
d823e3e7 AB |
265 | static struct mempolicy *shm_get_policy(struct vm_area_struct *vma, |
266 | unsigned long addr) | |
bc56bba8 EB |
267 | { |
268 | struct file *file = vma->vm_file; | |
269 | struct shm_file_data *sfd = shm_file_data(file); | |
270 | struct mempolicy *pol = NULL; | |
271 | ||
272 | if (sfd->vm_ops->get_policy) | |
273 | pol = sfd->vm_ops->get_policy(vma, addr); | |
22741925 | 274 | else if (vma->vm_policy) |
bc56bba8 | 275 | pol = vma->vm_policy; |
22741925 AL |
276 | else |
277 | pol = current->mempolicy; | |
bc56bba8 EB |
278 | return pol; |
279 | } | |
280 | #endif | |
281 | ||
1da177e4 LT |
282 | static int shm_mmap(struct file * file, struct vm_area_struct * vma) |
283 | { | |
bc56bba8 | 284 | struct shm_file_data *sfd = shm_file_data(file); |
b0e15190 DH |
285 | int ret; |
286 | ||
bc56bba8 EB |
287 | ret = sfd->file->f_op->mmap(sfd->file, vma); |
288 | if (ret != 0) | |
289 | return ret; | |
290 | sfd->vm_ops = vma->vm_ops; | |
2e92a3ba | 291 | #ifdef CONFIG_MMU |
54cb8821 | 292 | BUG_ON(!sfd->vm_ops->fault); |
2e92a3ba | 293 | #endif |
bc56bba8 EB |
294 | vma->vm_ops = &shm_vm_ops; |
295 | shm_open(vma); | |
b0e15190 DH |
296 | |
297 | return ret; | |
1da177e4 LT |
298 | } |
299 | ||
4e982311 KK |
300 | static int shm_release(struct inode *ino, struct file *file) |
301 | { | |
bc56bba8 | 302 | struct shm_file_data *sfd = shm_file_data(file); |
4e982311 | 303 | |
bc56bba8 EB |
304 | put_ipc_ns(sfd->ns); |
305 | shm_file_data(file) = NULL; | |
306 | kfree(sfd); | |
4e982311 KK |
307 | return 0; |
308 | } | |
309 | ||
516dffdc AL |
310 | static int shm_fsync(struct file *file, struct dentry *dentry, int datasync) |
311 | { | |
312 | int (*fsync) (struct file *, struct dentry *, int datasync); | |
313 | struct shm_file_data *sfd = shm_file_data(file); | |
314 | int ret = -EINVAL; | |
315 | ||
316 | fsync = sfd->file->f_op->fsync; | |
317 | if (fsync) | |
318 | ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync); | |
319 | return ret; | |
320 | } | |
321 | ||
bc56bba8 EB |
322 | static unsigned long shm_get_unmapped_area(struct file *file, |
323 | unsigned long addr, unsigned long len, unsigned long pgoff, | |
324 | unsigned long flags) | |
325 | { | |
326 | struct shm_file_data *sfd = shm_file_data(file); | |
516dffdc AL |
327 | return get_unmapped_area(sfd->file, addr, len, pgoff, flags); |
328 | } | |
329 | ||
330 | int is_file_shm_hugepages(struct file *file) | |
331 | { | |
332 | int ret = 0; | |
333 | ||
334 | if (file->f_op == &shm_file_operations) { | |
335 | struct shm_file_data *sfd; | |
336 | sfd = shm_file_data(file); | |
337 | ret = is_file_hugepages(sfd->file); | |
338 | } | |
339 | return ret; | |
bc56bba8 | 340 | } |
bc56bba8 | 341 | |
9a32144e | 342 | static const struct file_operations shm_file_operations = { |
4e982311 | 343 | .mmap = shm_mmap, |
516dffdc | 344 | .fsync = shm_fsync, |
4e982311 | 345 | .release = shm_release, |
bc56bba8 | 346 | .get_unmapped_area = shm_get_unmapped_area, |
1da177e4 LT |
347 | }; |
348 | ||
349 | static struct vm_operations_struct shm_vm_ops = { | |
350 | .open = shm_open, /* callback for a new vm-area open */ | |
351 | .close = shm_close, /* callback for when the vm-area is released */ | |
54cb8821 | 352 | .fault = shm_fault, |
bc56bba8 EB |
353 | #if defined(CONFIG_NUMA) |
354 | .set_policy = shm_set_policy, | |
355 | .get_policy = shm_get_policy, | |
1da177e4 LT |
356 | #endif |
357 | }; | |
358 | ||
f4566f04 ND |
359 | /** |
360 | * newseg - Create a new shared memory segment | |
361 | * @ns: namespace | |
362 | * @params: ptr to the structure that contains key, size and shmflg | |
363 | * | |
3e148c79 | 364 | * Called with shm_ids.rw_mutex held as a writer. |
f4566f04 ND |
365 | */ |
366 | ||
7748dbfa | 367 | static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 368 | { |
7748dbfa ND |
369 | key_t key = params->key; |
370 | int shmflg = params->flg; | |
371 | size_t size = params->u.size; | |
1da177e4 LT |
372 | int error; |
373 | struct shmid_kernel *shp; | |
374 | int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; | |
375 | struct file * file; | |
376 | char name[13]; | |
377 | int id; | |
378 | ||
4e982311 | 379 | if (size < SHMMIN || size > ns->shm_ctlmax) |
1da177e4 LT |
380 | return -EINVAL; |
381 | ||
f66d45e9 | 382 | if (ns->shm_tot + numpages > ns->shm_ctlall) |
1da177e4 LT |
383 | return -ENOSPC; |
384 | ||
385 | shp = ipc_rcu_alloc(sizeof(*shp)); | |
386 | if (!shp) | |
387 | return -ENOMEM; | |
388 | ||
389 | shp->shm_perm.key = key; | |
b33291c0 | 390 | shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
1da177e4 LT |
391 | shp->mlock_user = NULL; |
392 | ||
393 | shp->shm_perm.security = NULL; | |
394 | error = security_shm_alloc(shp); | |
395 | if (error) { | |
396 | ipc_rcu_putref(shp); | |
397 | return error; | |
398 | } | |
399 | ||
9d66586f | 400 | sprintf (name, "SYSV%08x", key); |
1da177e4 | 401 | if (shmflg & SHM_HUGETLB) { |
9d66586f EB |
402 | /* hugetlb_file_setup takes care of mlock user accounting */ |
403 | file = hugetlb_file_setup(name, size); | |
1da177e4 LT |
404 | shp->mlock_user = current->user; |
405 | } else { | |
bf8f972d BP |
406 | int acctflag = VM_ACCOUNT; |
407 | /* | |
408 | * Do not allow no accounting for OVERCOMMIT_NEVER, even | |
409 | * if it's asked for. | |
410 | */ | |
411 | if ((shmflg & SHM_NORESERVE) && | |
412 | sysctl_overcommit_memory != OVERCOMMIT_NEVER) | |
413 | acctflag = 0; | |
bf8f972d | 414 | file = shmem_file_setup(name, size, acctflag); |
1da177e4 LT |
415 | } |
416 | error = PTR_ERR(file); | |
417 | if (IS_ERR(file)) | |
418 | goto no_file; | |
419 | ||
4e982311 | 420 | id = shm_addid(ns, shp); |
283bb7fa PP |
421 | if (id < 0) { |
422 | error = id; | |
1da177e4 | 423 | goto no_id; |
283bb7fa | 424 | } |
1da177e4 | 425 | |
b488893a | 426 | shp->shm_cprid = task_tgid_vnr(current); |
1da177e4 LT |
427 | shp->shm_lprid = 0; |
428 | shp->shm_atim = shp->shm_dtim = 0; | |
429 | shp->shm_ctim = get_seconds(); | |
430 | shp->shm_segsz = size; | |
431 | shp->shm_nattch = 0; | |
1b531f21 | 432 | shp->shm_perm.id = shm_buildid(id, shp->shm_perm.seq); |
1da177e4 | 433 | shp->shm_file = file; |
30475cc1 BP |
434 | /* |
435 | * shmid gets reported as "inode#" in /proc/pid/maps. | |
436 | * proc-ps tools use this. Changing this will break them. | |
437 | */ | |
7ca7e564 | 438 | file->f_dentry->d_inode->i_ino = shp->shm_perm.id; |
551110a9 | 439 | |
4e982311 | 440 | ns->shm_tot += numpages; |
7ca7e564 | 441 | error = shp->shm_perm.id; |
1da177e4 | 442 | shm_unlock(shp); |
7ca7e564 | 443 | return error; |
1da177e4 LT |
444 | |
445 | no_id: | |
446 | fput(file); | |
447 | no_file: | |
448 | security_shm_free(shp); | |
449 | ipc_rcu_putref(shp); | |
450 | return error; | |
451 | } | |
452 | ||
f4566f04 | 453 | /* |
3e148c79 | 454 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 455 | */ |
03f02c76 | 456 | static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg) |
7748dbfa | 457 | { |
03f02c76 ND |
458 | struct shmid_kernel *shp; |
459 | ||
460 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
461 | return security_shm_associate(shp, shmflg); | |
7748dbfa ND |
462 | } |
463 | ||
f4566f04 | 464 | /* |
3e148c79 | 465 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 466 | */ |
03f02c76 ND |
467 | static inline int shm_more_checks(struct kern_ipc_perm *ipcp, |
468 | struct ipc_params *params) | |
7748dbfa | 469 | { |
03f02c76 ND |
470 | struct shmid_kernel *shp; |
471 | ||
472 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
473 | if (shp->shm_segsz < params->u.size) | |
7748dbfa ND |
474 | return -EINVAL; |
475 | ||
476 | return 0; | |
477 | } | |
478 | ||
1da177e4 LT |
479 | asmlinkage long sys_shmget (key_t key, size_t size, int shmflg) |
480 | { | |
4e982311 | 481 | struct ipc_namespace *ns; |
7748dbfa ND |
482 | struct ipc_ops shm_ops; |
483 | struct ipc_params shm_params; | |
4e982311 KK |
484 | |
485 | ns = current->nsproxy->ipc_ns; | |
1da177e4 | 486 | |
7748dbfa ND |
487 | shm_ops.getnew = newseg; |
488 | shm_ops.associate = shm_security; | |
489 | shm_ops.more_checks = shm_more_checks; | |
7ca7e564 | 490 | |
7748dbfa ND |
491 | shm_params.key = key; |
492 | shm_params.flg = shmflg; | |
493 | shm_params.u.size = size; | |
1da177e4 | 494 | |
7748dbfa | 495 | return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); |
1da177e4 LT |
496 | } |
497 | ||
498 | static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) | |
499 | { | |
500 | switch(version) { | |
501 | case IPC_64: | |
502 | return copy_to_user(buf, in, sizeof(*in)); | |
503 | case IPC_OLD: | |
504 | { | |
505 | struct shmid_ds out; | |
506 | ||
507 | ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); | |
508 | out.shm_segsz = in->shm_segsz; | |
509 | out.shm_atime = in->shm_atime; | |
510 | out.shm_dtime = in->shm_dtime; | |
511 | out.shm_ctime = in->shm_ctime; | |
512 | out.shm_cpid = in->shm_cpid; | |
513 | out.shm_lpid = in->shm_lpid; | |
514 | out.shm_nattch = in->shm_nattch; | |
515 | ||
516 | return copy_to_user(buf, &out, sizeof(out)); | |
517 | } | |
518 | default: | |
519 | return -EINVAL; | |
520 | } | |
521 | } | |
522 | ||
523 | struct shm_setbuf { | |
524 | uid_t uid; | |
525 | gid_t gid; | |
526 | mode_t mode; | |
527 | }; | |
528 | ||
529 | static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version) | |
530 | { | |
531 | switch(version) { | |
532 | case IPC_64: | |
533 | { | |
534 | struct shmid64_ds tbuf; | |
535 | ||
536 | if (copy_from_user(&tbuf, buf, sizeof(tbuf))) | |
537 | return -EFAULT; | |
538 | ||
539 | out->uid = tbuf.shm_perm.uid; | |
540 | out->gid = tbuf.shm_perm.gid; | |
b33291c0 | 541 | out->mode = tbuf.shm_perm.mode; |
1da177e4 LT |
542 | |
543 | return 0; | |
544 | } | |
545 | case IPC_OLD: | |
546 | { | |
547 | struct shmid_ds tbuf_old; | |
548 | ||
549 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) | |
550 | return -EFAULT; | |
551 | ||
552 | out->uid = tbuf_old.shm_perm.uid; | |
553 | out->gid = tbuf_old.shm_perm.gid; | |
b33291c0 | 554 | out->mode = tbuf_old.shm_perm.mode; |
1da177e4 LT |
555 | |
556 | return 0; | |
557 | } | |
558 | default: | |
559 | return -EINVAL; | |
560 | } | |
561 | } | |
562 | ||
563 | static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version) | |
564 | { | |
565 | switch(version) { | |
566 | case IPC_64: | |
567 | return copy_to_user(buf, in, sizeof(*in)); | |
568 | case IPC_OLD: | |
569 | { | |
570 | struct shminfo out; | |
571 | ||
572 | if(in->shmmax > INT_MAX) | |
573 | out.shmmax = INT_MAX; | |
574 | else | |
575 | out.shmmax = (int)in->shmmax; | |
576 | ||
577 | out.shmmin = in->shmmin; | |
578 | out.shmmni = in->shmmni; | |
579 | out.shmseg = in->shmseg; | |
580 | out.shmall = in->shmall; | |
581 | ||
582 | return copy_to_user(buf, &out, sizeof(out)); | |
583 | } | |
584 | default: | |
585 | return -EINVAL; | |
586 | } | |
587 | } | |
588 | ||
f4566f04 | 589 | /* |
3e148c79 | 590 | * Called with shm_ids.rw_mutex held as a reader |
f4566f04 | 591 | */ |
4e982311 KK |
592 | static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, |
593 | unsigned long *swp) | |
1da177e4 | 594 | { |
7ca7e564 ND |
595 | int next_id; |
596 | int total, in_use; | |
1da177e4 LT |
597 | |
598 | *rss = 0; | |
599 | *swp = 0; | |
600 | ||
7ca7e564 ND |
601 | in_use = shm_ids(ns).in_use; |
602 | ||
603 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
1da177e4 LT |
604 | struct shmid_kernel *shp; |
605 | struct inode *inode; | |
606 | ||
637c3663 | 607 | shp = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
7ca7e564 | 608 | if (shp == NULL) |
1da177e4 LT |
609 | continue; |
610 | ||
6d63079a | 611 | inode = shp->shm_file->f_path.dentry->d_inode; |
1da177e4 LT |
612 | |
613 | if (is_file_hugepages(shp->shm_file)) { | |
614 | struct address_space *mapping = inode->i_mapping; | |
615 | *rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages; | |
616 | } else { | |
617 | struct shmem_inode_info *info = SHMEM_I(inode); | |
618 | spin_lock(&info->lock); | |
619 | *rss += inode->i_mapping->nrpages; | |
620 | *swp += info->swapped; | |
621 | spin_unlock(&info->lock); | |
622 | } | |
7ca7e564 ND |
623 | |
624 | total++; | |
1da177e4 LT |
625 | } |
626 | } | |
627 | ||
628 | asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) | |
629 | { | |
630 | struct shm_setbuf setbuf; | |
631 | struct shmid_kernel *shp; | |
632 | int err, version; | |
4e982311 | 633 | struct ipc_namespace *ns; |
1da177e4 LT |
634 | |
635 | if (cmd < 0 || shmid < 0) { | |
636 | err = -EINVAL; | |
637 | goto out; | |
638 | } | |
639 | ||
640 | version = ipc_parse_version(&cmd); | |
4e982311 | 641 | ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
642 | |
643 | switch (cmd) { /* replace with proc interface ? */ | |
644 | case IPC_INFO: | |
645 | { | |
646 | struct shminfo64 shminfo; | |
647 | ||
648 | err = security_shm_shmctl(NULL, cmd); | |
649 | if (err) | |
650 | return err; | |
651 | ||
652 | memset(&shminfo,0,sizeof(shminfo)); | |
4e982311 KK |
653 | shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni; |
654 | shminfo.shmmax = ns->shm_ctlmax; | |
655 | shminfo.shmall = ns->shm_ctlall; | |
1da177e4 LT |
656 | |
657 | shminfo.shmmin = SHMMIN; | |
658 | if(copy_shminfo_to_user (buf, &shminfo, version)) | |
659 | return -EFAULT; | |
f4566f04 | 660 | |
3e148c79 | 661 | down_read(&shm_ids(ns).rw_mutex); |
7ca7e564 | 662 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 663 | up_read(&shm_ids(ns).rw_mutex); |
f4566f04 | 664 | |
1da177e4 LT |
665 | if(err<0) |
666 | err = 0; | |
667 | goto out; | |
668 | } | |
669 | case SHM_INFO: | |
670 | { | |
671 | struct shm_info shm_info; | |
672 | ||
673 | err = security_shm_shmctl(NULL, cmd); | |
674 | if (err) | |
675 | return err; | |
676 | ||
677 | memset(&shm_info,0,sizeof(shm_info)); | |
3e148c79 | 678 | down_read(&shm_ids(ns).rw_mutex); |
4e982311 KK |
679 | shm_info.used_ids = shm_ids(ns).in_use; |
680 | shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp); | |
681 | shm_info.shm_tot = ns->shm_tot; | |
1da177e4 LT |
682 | shm_info.swap_attempts = 0; |
683 | shm_info.swap_successes = 0; | |
7ca7e564 | 684 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 685 | up_read(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
686 | if(copy_to_user (buf, &shm_info, sizeof(shm_info))) { |
687 | err = -EFAULT; | |
688 | goto out; | |
689 | } | |
690 | ||
691 | err = err < 0 ? 0 : err; | |
692 | goto out; | |
693 | } | |
694 | case SHM_STAT: | |
695 | case IPC_STAT: | |
696 | { | |
697 | struct shmid64_ds tbuf; | |
698 | int result; | |
023a5355 ND |
699 | |
700 | if (!buf) { | |
701 | err = -EFAULT; | |
1da177e4 | 702 | goto out; |
023a5355 ND |
703 | } |
704 | ||
705 | if (cmd == SHM_STAT) { | |
706 | shp = shm_lock(ns, shmid); | |
707 | if (IS_ERR(shp)) { | |
708 | err = PTR_ERR(shp); | |
709 | goto out; | |
710 | } | |
7ca7e564 | 711 | result = shp->shm_perm.id; |
1da177e4 | 712 | } else { |
023a5355 ND |
713 | shp = shm_lock_check(ns, shmid); |
714 | if (IS_ERR(shp)) { | |
715 | err = PTR_ERR(shp); | |
716 | goto out; | |
717 | } | |
1da177e4 LT |
718 | result = 0; |
719 | } | |
720 | err=-EACCES; | |
721 | if (ipcperms (&shp->shm_perm, S_IRUGO)) | |
722 | goto out_unlock; | |
723 | err = security_shm_shmctl(shp, cmd); | |
724 | if (err) | |
725 | goto out_unlock; | |
023a5355 | 726 | memset(&tbuf, 0, sizeof(tbuf)); |
1da177e4 LT |
727 | kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm); |
728 | tbuf.shm_segsz = shp->shm_segsz; | |
729 | tbuf.shm_atime = shp->shm_atim; | |
730 | tbuf.shm_dtime = shp->shm_dtim; | |
731 | tbuf.shm_ctime = shp->shm_ctim; | |
732 | tbuf.shm_cpid = shp->shm_cprid; | |
733 | tbuf.shm_lpid = shp->shm_lprid; | |
bc56bba8 | 734 | tbuf.shm_nattch = shp->shm_nattch; |
1da177e4 LT |
735 | shm_unlock(shp); |
736 | if(copy_shmid_to_user (buf, &tbuf, version)) | |
737 | err = -EFAULT; | |
738 | else | |
739 | err = result; | |
740 | goto out; | |
741 | } | |
742 | case SHM_LOCK: | |
743 | case SHM_UNLOCK: | |
744 | { | |
023a5355 ND |
745 | shp = shm_lock_check(ns, shmid); |
746 | if (IS_ERR(shp)) { | |
747 | err = PTR_ERR(shp); | |
1da177e4 LT |
748 | goto out; |
749 | } | |
1da177e4 | 750 | |
073115d6 SG |
751 | err = audit_ipc_obj(&(shp->shm_perm)); |
752 | if (err) | |
753 | goto out_unlock; | |
754 | ||
1da177e4 LT |
755 | if (!capable(CAP_IPC_LOCK)) { |
756 | err = -EPERM; | |
757 | if (current->euid != shp->shm_perm.uid && | |
758 | current->euid != shp->shm_perm.cuid) | |
759 | goto out_unlock; | |
760 | if (cmd == SHM_LOCK && | |
761 | !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur) | |
762 | goto out_unlock; | |
763 | } | |
764 | ||
765 | err = security_shm_shmctl(shp, cmd); | |
766 | if (err) | |
767 | goto out_unlock; | |
768 | ||
769 | if(cmd==SHM_LOCK) { | |
770 | struct user_struct * user = current->user; | |
771 | if (!is_file_hugepages(shp->shm_file)) { | |
772 | err = shmem_lock(shp->shm_file, 1, user); | |
7be77e20 | 773 | if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){ |
b33291c0 | 774 | shp->shm_perm.mode |= SHM_LOCKED; |
1da177e4 LT |
775 | shp->mlock_user = user; |
776 | } | |
777 | } | |
778 | } else if (!is_file_hugepages(shp->shm_file)) { | |
779 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
b33291c0 | 780 | shp->shm_perm.mode &= ~SHM_LOCKED; |
1da177e4 LT |
781 | shp->mlock_user = NULL; |
782 | } | |
783 | shm_unlock(shp); | |
784 | goto out; | |
785 | } | |
786 | case IPC_RMID: | |
787 | { | |
788 | /* | |
789 | * We cannot simply remove the file. The SVID states | |
790 | * that the block remains until the last person | |
791 | * detaches from it, then is deleted. A shmat() on | |
792 | * an RMID segment is legal in older Linux and if | |
793 | * we change it apps break... | |
794 | * | |
795 | * Instead we set a destroyed flag, and then blow | |
796 | * the name away when the usage hits zero. | |
797 | */ | |
3e148c79 ND |
798 | down_write(&shm_ids(ns).rw_mutex); |
799 | shp = shm_lock_check_down(ns, shmid); | |
023a5355 ND |
800 | if (IS_ERR(shp)) { |
801 | err = PTR_ERR(shp); | |
1da177e4 | 802 | goto out_up; |
023a5355 | 803 | } |
1da177e4 | 804 | |
073115d6 SG |
805 | err = audit_ipc_obj(&(shp->shm_perm)); |
806 | if (err) | |
807 | goto out_unlock_up; | |
808 | ||
1da177e4 LT |
809 | if (current->euid != shp->shm_perm.uid && |
810 | current->euid != shp->shm_perm.cuid && | |
811 | !capable(CAP_SYS_ADMIN)) { | |
812 | err=-EPERM; | |
813 | goto out_unlock_up; | |
814 | } | |
815 | ||
816 | err = security_shm_shmctl(shp, cmd); | |
817 | if (err) | |
818 | goto out_unlock_up; | |
819 | ||
01b8b07a | 820 | do_shm_rmid(ns, &shp->shm_perm); |
3e148c79 | 821 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
822 | goto out; |
823 | } | |
824 | ||
825 | case IPC_SET: | |
826 | { | |
023a5355 ND |
827 | if (!buf) { |
828 | err = -EFAULT; | |
829 | goto out; | |
830 | } | |
831 | ||
1da177e4 LT |
832 | if (copy_shmid_from_user (&setbuf, buf, version)) { |
833 | err = -EFAULT; | |
834 | goto out; | |
835 | } | |
3e148c79 ND |
836 | down_write(&shm_ids(ns).rw_mutex); |
837 | shp = shm_lock_check_down(ns, shmid); | |
023a5355 ND |
838 | if (IS_ERR(shp)) { |
839 | err = PTR_ERR(shp); | |
1da177e4 | 840 | goto out_up; |
023a5355 | 841 | } |
073115d6 SG |
842 | err = audit_ipc_obj(&(shp->shm_perm)); |
843 | if (err) | |
844 | goto out_unlock_up; | |
ac03221a | 845 | err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode); |
073115d6 SG |
846 | if (err) |
847 | goto out_unlock_up; | |
1da177e4 LT |
848 | err=-EPERM; |
849 | if (current->euid != shp->shm_perm.uid && | |
850 | current->euid != shp->shm_perm.cuid && | |
851 | !capable(CAP_SYS_ADMIN)) { | |
852 | goto out_unlock_up; | |
853 | } | |
854 | ||
855 | err = security_shm_shmctl(shp, cmd); | |
856 | if (err) | |
857 | goto out_unlock_up; | |
858 | ||
859 | shp->shm_perm.uid = setbuf.uid; | |
860 | shp->shm_perm.gid = setbuf.gid; | |
b33291c0 | 861 | shp->shm_perm.mode = (shp->shm_perm.mode & ~S_IRWXUGO) |
1da177e4 LT |
862 | | (setbuf.mode & S_IRWXUGO); |
863 | shp->shm_ctim = get_seconds(); | |
864 | break; | |
865 | } | |
866 | ||
867 | default: | |
868 | err = -EINVAL; | |
869 | goto out; | |
870 | } | |
871 | ||
872 | err = 0; | |
873 | out_unlock_up: | |
874 | shm_unlock(shp); | |
875 | out_up: | |
3e148c79 | 876 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
877 | goto out; |
878 | out_unlock: | |
879 | shm_unlock(shp); | |
880 | out: | |
881 | return err; | |
882 | } | |
883 | ||
884 | /* | |
885 | * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists. | |
886 | * | |
887 | * NOTE! Despite the name, this is NOT a direct system call entrypoint. The | |
888 | * "raddr" thing points to kernel space, and there has to be a wrapper around | |
889 | * this. | |
890 | */ | |
891 | long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) | |
892 | { | |
893 | struct shmid_kernel *shp; | |
894 | unsigned long addr; | |
895 | unsigned long size; | |
896 | struct file * file; | |
897 | int err; | |
898 | unsigned long flags; | |
899 | unsigned long prot; | |
1da177e4 | 900 | int acc_mode; |
bc56bba8 | 901 | unsigned long user_addr; |
4e982311 | 902 | struct ipc_namespace *ns; |
bc56bba8 EB |
903 | struct shm_file_data *sfd; |
904 | struct path path; | |
905 | mode_t f_mode; | |
1da177e4 | 906 | |
bc56bba8 EB |
907 | err = -EINVAL; |
908 | if (shmid < 0) | |
1da177e4 | 909 | goto out; |
bc56bba8 | 910 | else if ((addr = (ulong)shmaddr)) { |
1da177e4 LT |
911 | if (addr & (SHMLBA-1)) { |
912 | if (shmflg & SHM_RND) | |
913 | addr &= ~(SHMLBA-1); /* round down */ | |
914 | else | |
915 | #ifndef __ARCH_FORCE_SHMLBA | |
916 | if (addr & ~PAGE_MASK) | |
917 | #endif | |
bc56bba8 | 918 | goto out; |
1da177e4 LT |
919 | } |
920 | flags = MAP_SHARED | MAP_FIXED; | |
921 | } else { | |
922 | if ((shmflg & SHM_REMAP)) | |
bc56bba8 | 923 | goto out; |
1da177e4 LT |
924 | |
925 | flags = MAP_SHARED; | |
926 | } | |
927 | ||
928 | if (shmflg & SHM_RDONLY) { | |
929 | prot = PROT_READ; | |
1da177e4 | 930 | acc_mode = S_IRUGO; |
bc56bba8 | 931 | f_mode = FMODE_READ; |
1da177e4 LT |
932 | } else { |
933 | prot = PROT_READ | PROT_WRITE; | |
1da177e4 | 934 | acc_mode = S_IRUGO | S_IWUGO; |
bc56bba8 | 935 | f_mode = FMODE_READ | FMODE_WRITE; |
1da177e4 LT |
936 | } |
937 | if (shmflg & SHM_EXEC) { | |
938 | prot |= PROT_EXEC; | |
939 | acc_mode |= S_IXUGO; | |
940 | } | |
941 | ||
942 | /* | |
943 | * We cannot rely on the fs check since SYSV IPC does have an | |
944 | * additional creator id... | |
945 | */ | |
4e982311 | 946 | ns = current->nsproxy->ipc_ns; |
023a5355 ND |
947 | shp = shm_lock_check(ns, shmid); |
948 | if (IS_ERR(shp)) { | |
949 | err = PTR_ERR(shp); | |
1da177e4 | 950 | goto out; |
023a5355 | 951 | } |
bc56bba8 EB |
952 | |
953 | err = -EACCES; | |
954 | if (ipcperms(&shp->shm_perm, acc_mode)) | |
955 | goto out_unlock; | |
1da177e4 LT |
956 | |
957 | err = security_shm_shmat(shp, shmaddr, shmflg); | |
bc56bba8 EB |
958 | if (err) |
959 | goto out_unlock; | |
960 | ||
961 | path.dentry = dget(shp->shm_file->f_path.dentry); | |
ce8d2cdf | 962 | path.mnt = shp->shm_file->f_path.mnt; |
1da177e4 | 963 | shp->shm_nattch++; |
bc56bba8 | 964 | size = i_size_read(path.dentry->d_inode); |
1da177e4 LT |
965 | shm_unlock(shp); |
966 | ||
bc56bba8 EB |
967 | err = -ENOMEM; |
968 | sfd = kzalloc(sizeof(*sfd), GFP_KERNEL); | |
969 | if (!sfd) | |
ce8d2cdf | 970 | goto out_put_dentry; |
bc56bba8 EB |
971 | |
972 | err = -ENOMEM; | |
ce8d2cdf DH |
973 | |
974 | file = alloc_file(path.mnt, path.dentry, f_mode, &shm_file_operations); | |
bc56bba8 EB |
975 | if (!file) |
976 | goto out_free; | |
977 | ||
bc56bba8 | 978 | file->private_data = sfd; |
bc56bba8 | 979 | file->f_mapping = shp->shm_file->f_mapping; |
7ca7e564 | 980 | sfd->id = shp->shm_perm.id; |
bc56bba8 EB |
981 | sfd->ns = get_ipc_ns(ns); |
982 | sfd->file = shp->shm_file; | |
983 | sfd->vm_ops = NULL; | |
984 | ||
1da177e4 LT |
985 | down_write(¤t->mm->mmap_sem); |
986 | if (addr && !(shmflg & SHM_REMAP)) { | |
bc56bba8 | 987 | err = -EINVAL; |
1da177e4 LT |
988 | if (find_vma_intersection(current->mm, addr, addr + size)) |
989 | goto invalid; | |
990 | /* | |
991 | * If shm segment goes below stack, make sure there is some | |
992 | * space left for the stack to grow (at least 4 pages). | |
993 | */ | |
994 | if (addr < current->mm->start_stack && | |
995 | addr > current->mm->start_stack - size - PAGE_SIZE * 5) | |
996 | goto invalid; | |
997 | } | |
998 | ||
bc56bba8 EB |
999 | user_addr = do_mmap (file, addr, size, prot, flags, 0); |
1000 | *raddr = user_addr; | |
1001 | err = 0; | |
1002 | if (IS_ERR_VALUE(user_addr)) | |
1003 | err = (long)user_addr; | |
1da177e4 LT |
1004 | invalid: |
1005 | up_write(¤t->mm->mmap_sem); | |
1006 | ||
bc56bba8 EB |
1007 | fput(file); |
1008 | ||
1009 | out_nattch: | |
3e148c79 ND |
1010 | down_write(&shm_ids(ns).rw_mutex); |
1011 | shp = shm_lock_down(ns, shmid); | |
023a5355 | 1012 | BUG_ON(IS_ERR(shp)); |
1da177e4 LT |
1013 | shp->shm_nattch--; |
1014 | if(shp->shm_nattch == 0 && | |
b33291c0 | 1015 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 1016 | shm_destroy(ns, shp); |
1da177e4 LT |
1017 | else |
1018 | shm_unlock(shp); | |
3e148c79 | 1019 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 1020 | |
1da177e4 LT |
1021 | out: |
1022 | return err; | |
bc56bba8 EB |
1023 | |
1024 | out_unlock: | |
1025 | shm_unlock(shp); | |
1026 | goto out; | |
1027 | ||
1028 | out_free: | |
1029 | kfree(sfd); | |
ce8d2cdf | 1030 | out_put_dentry: |
bc56bba8 | 1031 | dput(path.dentry); |
bc56bba8 | 1032 | goto out_nattch; |
1da177e4 LT |
1033 | } |
1034 | ||
7d87e14c SR |
1035 | asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg) |
1036 | { | |
1037 | unsigned long ret; | |
1038 | long err; | |
1039 | ||
1040 | err = do_shmat(shmid, shmaddr, shmflg, &ret); | |
1041 | if (err) | |
1042 | return err; | |
1043 | force_successful_syscall_return(); | |
1044 | return (long)ret; | |
1045 | } | |
1046 | ||
1da177e4 LT |
1047 | /* |
1048 | * detach and kill segment if marked destroyed. | |
1049 | * The work is done in shm_close. | |
1050 | */ | |
1051 | asmlinkage long sys_shmdt(char __user *shmaddr) | |
1052 | { | |
1053 | struct mm_struct *mm = current->mm; | |
1054 | struct vm_area_struct *vma, *next; | |
1055 | unsigned long addr = (unsigned long)shmaddr; | |
1056 | loff_t size = 0; | |
1057 | int retval = -EINVAL; | |
1058 | ||
df1e2fb5 HD |
1059 | if (addr & ~PAGE_MASK) |
1060 | return retval; | |
1061 | ||
1da177e4 LT |
1062 | down_write(&mm->mmap_sem); |
1063 | ||
1064 | /* | |
1065 | * This function tries to be smart and unmap shm segments that | |
1066 | * were modified by partial mlock or munmap calls: | |
1067 | * - It first determines the size of the shm segment that should be | |
1068 | * unmapped: It searches for a vma that is backed by shm and that | |
1069 | * started at address shmaddr. It records it's size and then unmaps | |
1070 | * it. | |
1071 | * - Then it unmaps all shm vmas that started at shmaddr and that | |
1072 | * are within the initially determined size. | |
1073 | * Errors from do_munmap are ignored: the function only fails if | |
1074 | * it's called with invalid parameters or if it's called to unmap | |
1075 | * a part of a vma. Both calls in this function are for full vmas, | |
1076 | * the parameters are directly copied from the vma itself and always | |
1077 | * valid - therefore do_munmap cannot fail. (famous last words?) | |
1078 | */ | |
1079 | /* | |
1080 | * If it had been mremap()'d, the starting address would not | |
1081 | * match the usual checks anyway. So assume all vma's are | |
1082 | * above the starting address given. | |
1083 | */ | |
1084 | vma = find_vma(mm, addr); | |
1085 | ||
1086 | while (vma) { | |
1087 | next = vma->vm_next; | |
1088 | ||
1089 | /* | |
1090 | * Check if the starting address would match, i.e. it's | |
1091 | * a fragment created by mprotect() and/or munmap(), or it | |
1092 | * otherwise it starts at this address with no hassles. | |
1093 | */ | |
bc56bba8 | 1094 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1095 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { |
1096 | ||
1097 | ||
6d63079a | 1098 | size = vma->vm_file->f_path.dentry->d_inode->i_size; |
1da177e4 LT |
1099 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
1100 | /* | |
1101 | * We discovered the size of the shm segment, so | |
1102 | * break out of here and fall through to the next | |
1103 | * loop that uses the size information to stop | |
1104 | * searching for matching vma's. | |
1105 | */ | |
1106 | retval = 0; | |
1107 | vma = next; | |
1108 | break; | |
1109 | } | |
1110 | vma = next; | |
1111 | } | |
1112 | ||
1113 | /* | |
1114 | * We need look no further than the maximum address a fragment | |
1115 | * could possibly have landed at. Also cast things to loff_t to | |
1116 | * prevent overflows and make comparisions vs. equal-width types. | |
1117 | */ | |
8e36709d | 1118 | size = PAGE_ALIGN(size); |
1da177e4 LT |
1119 | while (vma && (loff_t)(vma->vm_end - addr) <= size) { |
1120 | next = vma->vm_next; | |
1121 | ||
1122 | /* finding a matching vma now does not alter retval */ | |
bc56bba8 | 1123 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1124 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) |
1125 | ||
1126 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
1127 | vma = next; | |
1128 | } | |
1129 | ||
1130 | up_write(&mm->mmap_sem); | |
1131 | return retval; | |
1132 | } | |
1133 | ||
1134 | #ifdef CONFIG_PROC_FS | |
19b4946c | 1135 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
1da177e4 | 1136 | { |
19b4946c MW |
1137 | struct shmid_kernel *shp = it; |
1138 | char *format; | |
1da177e4 | 1139 | |
1da177e4 LT |
1140 | #define SMALL_STRING "%10d %10d %4o %10u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" |
1141 | #define BIG_STRING "%10d %10d %4o %21u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" | |
1da177e4 | 1142 | |
19b4946c MW |
1143 | if (sizeof(size_t) <= sizeof(int)) |
1144 | format = SMALL_STRING; | |
1145 | else | |
1146 | format = BIG_STRING; | |
1147 | return seq_printf(s, format, | |
1148 | shp->shm_perm.key, | |
7ca7e564 | 1149 | shp->shm_perm.id, |
b33291c0 | 1150 | shp->shm_perm.mode, |
19b4946c MW |
1151 | shp->shm_segsz, |
1152 | shp->shm_cprid, | |
1153 | shp->shm_lprid, | |
bc56bba8 | 1154 | shp->shm_nattch, |
19b4946c MW |
1155 | shp->shm_perm.uid, |
1156 | shp->shm_perm.gid, | |
1157 | shp->shm_perm.cuid, | |
1158 | shp->shm_perm.cgid, | |
1159 | shp->shm_atim, | |
1160 | shp->shm_dtim, | |
1161 | shp->shm_ctim); | |
1da177e4 LT |
1162 | } |
1163 | #endif |