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> |
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) | |
1b531f21 | 64 | #define shm_buildid(id, seq) ipc_buildid(id, seq) |
1da177e4 | 65 | |
7748dbfa | 66 | static int newseg(struct ipc_namespace *, struct ipc_params *); |
bc56bba8 EB |
67 | static void shm_open(struct vm_area_struct *vma); |
68 | static void shm_close(struct vm_area_struct *vma); | |
4e982311 | 69 | static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp); |
1da177e4 | 70 | #ifdef CONFIG_PROC_FS |
19b4946c | 71 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it); |
1da177e4 LT |
72 | #endif |
73 | ||
7d69a1f4 | 74 | static void __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids) |
4e982311 KK |
75 | { |
76 | ns->ids[IPC_SHM_IDS] = ids; | |
77 | ns->shm_ctlmax = SHMMAX; | |
78 | ns->shm_ctlall = SHMALL; | |
79 | ns->shm_ctlmni = SHMMNI; | |
80 | ns->shm_tot = 0; | |
7ca7e564 | 81 | ipc_init_ids(ids); |
4e982311 KK |
82 | } |
83 | ||
f4566f04 | 84 | /* |
3e148c79 ND |
85 | * Called with shm_ids.rw_mutex (writer) and the shp structure locked. |
86 | * Only shm_ids.rw_mutex remains locked on exit. | |
f4566f04 | 87 | */ |
4e982311 KK |
88 | static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp) |
89 | { | |
90 | if (shp->shm_nattch){ | |
91 | shp->shm_perm.mode |= SHM_DEST; | |
92 | /* Do not find it any more */ | |
93 | shp->shm_perm.key = IPC_PRIVATE; | |
94 | shm_unlock(shp); | |
95 | } else | |
96 | shm_destroy(ns, shp); | |
97 | } | |
98 | ||
4e982311 KK |
99 | int shm_init_ns(struct ipc_namespace *ns) |
100 | { | |
101 | struct ipc_ids *ids; | |
102 | ||
103 | ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL); | |
104 | if (ids == NULL) | |
105 | return -ENOMEM; | |
1da177e4 | 106 | |
4e982311 KK |
107 | __shm_init_ns(ns, ids); |
108 | return 0; | |
109 | } | |
110 | ||
111 | void shm_exit_ns(struct ipc_namespace *ns) | |
112 | { | |
4e982311 | 113 | struct shmid_kernel *shp; |
b1ed88b4 | 114 | struct kern_ipc_perm *perm; |
7ca7e564 ND |
115 | int next_id; |
116 | int total, in_use; | |
4e982311 | 117 | |
3e148c79 | 118 | down_write(&shm_ids(ns).rw_mutex); |
7ca7e564 ND |
119 | |
120 | in_use = shm_ids(ns).in_use; | |
121 | ||
122 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
b1ed88b4 PP |
123 | perm = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
124 | if (perm == NULL) | |
4e982311 | 125 | continue; |
b1ed88b4 PP |
126 | ipc_lock_by_ptr(perm); |
127 | shp = container_of(perm, struct shmid_kernel, shm_perm); | |
4e982311 | 128 | do_shm_rmid(ns, shp); |
7ca7e564 | 129 | total++; |
4e982311 | 130 | } |
3e148c79 | 131 | up_write(&shm_ids(ns).rw_mutex); |
4e982311 KK |
132 | |
133 | kfree(ns->ids[IPC_SHM_IDS]); | |
134 | ns->ids[IPC_SHM_IDS] = NULL; | |
135 | } | |
1da177e4 LT |
136 | |
137 | void __init shm_init (void) | |
138 | { | |
4e982311 | 139 | __shm_init_ns(&init_ipc_ns, &init_shm_ids); |
19b4946c MW |
140 | ipc_init_proc_interface("sysvipc/shm", |
141 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n", | |
4e982311 | 142 | IPC_SHM_IDS, sysvipc_shm_proc_show); |
1da177e4 LT |
143 | } |
144 | ||
3e148c79 ND |
145 | /* |
146 | * shm_lock_(check_)down routines are called in the paths where the rw_mutex | |
147 | * is held to protect access to the idr tree. | |
148 | */ | |
149 | static inline struct shmid_kernel *shm_lock_down(struct ipc_namespace *ns, | |
150 | int id) | |
151 | { | |
152 | struct kern_ipc_perm *ipcp = ipc_lock_down(&shm_ids(ns), id); | |
153 | ||
b1ed88b4 PP |
154 | if (IS_ERR(ipcp)) |
155 | return (struct shmid_kernel *)ipcp; | |
156 | ||
3e148c79 ND |
157 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
158 | } | |
159 | ||
160 | static inline struct shmid_kernel *shm_lock_check_down( | |
161 | struct ipc_namespace *ns, | |
162 | int id) | |
163 | { | |
164 | struct kern_ipc_perm *ipcp = ipc_lock_check_down(&shm_ids(ns), id); | |
165 | ||
b1ed88b4 PP |
166 | if (IS_ERR(ipcp)) |
167 | return (struct shmid_kernel *)ipcp; | |
168 | ||
3e148c79 ND |
169 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
170 | } | |
171 | ||
172 | /* | |
173 | * shm_lock_(check_) routines are called in the paths where the rw_mutex | |
174 | * is not held. | |
175 | */ | |
023a5355 | 176 | static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id) |
1da177e4 | 177 | { |
03f02c76 ND |
178 | struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id); |
179 | ||
b1ed88b4 PP |
180 | if (IS_ERR(ipcp)) |
181 | return (struct shmid_kernel *)ipcp; | |
182 | ||
03f02c76 | 183 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
023a5355 ND |
184 | } |
185 | ||
186 | static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns, | |
187 | int id) | |
188 | { | |
03f02c76 ND |
189 | struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id); |
190 | ||
b1ed88b4 PP |
191 | if (IS_ERR(ipcp)) |
192 | return (struct shmid_kernel *)ipcp; | |
193 | ||
03f02c76 | 194 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
1da177e4 LT |
195 | } |
196 | ||
7ca7e564 | 197 | static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s) |
1da177e4 | 198 | { |
7ca7e564 | 199 | ipc_rmid(&shm_ids(ns), &s->shm_perm); |
1da177e4 LT |
200 | } |
201 | ||
4e982311 | 202 | static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 203 | { |
4e982311 | 204 | return ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
1da177e4 LT |
205 | } |
206 | ||
207 | ||
208 | ||
bc56bba8 EB |
209 | /* This is called by fork, once for every shm attach. */ |
210 | static void shm_open(struct vm_area_struct *vma) | |
4e982311 | 211 | { |
bc56bba8 EB |
212 | struct file *file = vma->vm_file; |
213 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 LT |
214 | struct shmid_kernel *shp; |
215 | ||
bc56bba8 | 216 | shp = shm_lock(sfd->ns, sfd->id); |
023a5355 | 217 | BUG_ON(IS_ERR(shp)); |
1da177e4 | 218 | shp->shm_atim = get_seconds(); |
b488893a | 219 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
220 | shp->shm_nattch++; |
221 | shm_unlock(shp); | |
222 | } | |
223 | ||
1da177e4 LT |
224 | /* |
225 | * shm_destroy - free the struct shmid_kernel | |
226 | * | |
f4566f04 | 227 | * @ns: namespace |
1da177e4 LT |
228 | * @shp: struct to free |
229 | * | |
3e148c79 | 230 | * It has to be called with shp and shm_ids.rw_mutex (writer) locked, |
1da177e4 LT |
231 | * but returns with shp unlocked and freed. |
232 | */ | |
4e982311 | 233 | static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 234 | { |
4e982311 | 235 | ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; |
7ca7e564 | 236 | shm_rmid(ns, shp); |
1da177e4 LT |
237 | shm_unlock(shp); |
238 | if (!is_file_hugepages(shp->shm_file)) | |
239 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
240 | else | |
6d63079a | 241 | user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size, |
1da177e4 LT |
242 | shp->mlock_user); |
243 | fput (shp->shm_file); | |
244 | security_shm_free(shp); | |
245 | ipc_rcu_putref(shp); | |
246 | } | |
247 | ||
248 | /* | |
bc56bba8 | 249 | * remove the attach descriptor vma. |
1da177e4 LT |
250 | * free memory for segment if it is marked destroyed. |
251 | * The descriptor has already been removed from the current->mm->mmap list | |
252 | * and will later be kfree()d. | |
253 | */ | |
bc56bba8 | 254 | static void shm_close(struct vm_area_struct *vma) |
1da177e4 | 255 | { |
bc56bba8 EB |
256 | struct file * file = vma->vm_file; |
257 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 | 258 | struct shmid_kernel *shp; |
bc56bba8 | 259 | struct ipc_namespace *ns = sfd->ns; |
4e982311 | 260 | |
3e148c79 | 261 | down_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 262 | /* remove from the list of attaches of the shm segment */ |
3e148c79 | 263 | shp = shm_lock_down(ns, sfd->id); |
023a5355 | 264 | BUG_ON(IS_ERR(shp)); |
b488893a | 265 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
266 | shp->shm_dtim = get_seconds(); |
267 | shp->shm_nattch--; | |
268 | if(shp->shm_nattch == 0 && | |
b33291c0 | 269 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 270 | shm_destroy(ns, shp); |
1da177e4 LT |
271 | else |
272 | shm_unlock(shp); | |
3e148c79 | 273 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
274 | } |
275 | ||
d0217ac0 | 276 | static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
bc56bba8 EB |
277 | { |
278 | struct file *file = vma->vm_file; | |
279 | struct shm_file_data *sfd = shm_file_data(file); | |
280 | ||
d0217ac0 | 281 | return sfd->vm_ops->fault(vma, vmf); |
bc56bba8 EB |
282 | } |
283 | ||
284 | #ifdef CONFIG_NUMA | |
d823e3e7 | 285 | static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
bc56bba8 EB |
286 | { |
287 | struct file *file = vma->vm_file; | |
288 | struct shm_file_data *sfd = shm_file_data(file); | |
289 | int err = 0; | |
290 | if (sfd->vm_ops->set_policy) | |
291 | err = sfd->vm_ops->set_policy(vma, new); | |
292 | return err; | |
293 | } | |
294 | ||
d823e3e7 AB |
295 | static struct mempolicy *shm_get_policy(struct vm_area_struct *vma, |
296 | unsigned long addr) | |
bc56bba8 EB |
297 | { |
298 | struct file *file = vma->vm_file; | |
299 | struct shm_file_data *sfd = shm_file_data(file); | |
300 | struct mempolicy *pol = NULL; | |
301 | ||
302 | if (sfd->vm_ops->get_policy) | |
303 | pol = sfd->vm_ops->get_policy(vma, addr); | |
22741925 | 304 | else if (vma->vm_policy) |
bc56bba8 | 305 | pol = vma->vm_policy; |
22741925 AL |
306 | else |
307 | pol = current->mempolicy; | |
bc56bba8 EB |
308 | return pol; |
309 | } | |
310 | #endif | |
311 | ||
1da177e4 LT |
312 | static int shm_mmap(struct file * file, struct vm_area_struct * vma) |
313 | { | |
bc56bba8 | 314 | struct shm_file_data *sfd = shm_file_data(file); |
b0e15190 DH |
315 | int ret; |
316 | ||
bc56bba8 EB |
317 | ret = sfd->file->f_op->mmap(sfd->file, vma); |
318 | if (ret != 0) | |
319 | return ret; | |
320 | sfd->vm_ops = vma->vm_ops; | |
2e92a3ba | 321 | #ifdef CONFIG_MMU |
54cb8821 | 322 | BUG_ON(!sfd->vm_ops->fault); |
2e92a3ba | 323 | #endif |
bc56bba8 EB |
324 | vma->vm_ops = &shm_vm_ops; |
325 | shm_open(vma); | |
b0e15190 DH |
326 | |
327 | return ret; | |
1da177e4 LT |
328 | } |
329 | ||
4e982311 KK |
330 | static int shm_release(struct inode *ino, struct file *file) |
331 | { | |
bc56bba8 | 332 | struct shm_file_data *sfd = shm_file_data(file); |
4e982311 | 333 | |
bc56bba8 EB |
334 | put_ipc_ns(sfd->ns); |
335 | shm_file_data(file) = NULL; | |
336 | kfree(sfd); | |
4e982311 KK |
337 | return 0; |
338 | } | |
339 | ||
516dffdc AL |
340 | static int shm_fsync(struct file *file, struct dentry *dentry, int datasync) |
341 | { | |
342 | int (*fsync) (struct file *, struct dentry *, int datasync); | |
343 | struct shm_file_data *sfd = shm_file_data(file); | |
344 | int ret = -EINVAL; | |
345 | ||
346 | fsync = sfd->file->f_op->fsync; | |
347 | if (fsync) | |
348 | ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync); | |
349 | return ret; | |
350 | } | |
351 | ||
bc56bba8 EB |
352 | static unsigned long shm_get_unmapped_area(struct file *file, |
353 | unsigned long addr, unsigned long len, unsigned long pgoff, | |
354 | unsigned long flags) | |
355 | { | |
356 | struct shm_file_data *sfd = shm_file_data(file); | |
516dffdc AL |
357 | return get_unmapped_area(sfd->file, addr, len, pgoff, flags); |
358 | } | |
359 | ||
360 | int is_file_shm_hugepages(struct file *file) | |
361 | { | |
362 | int ret = 0; | |
363 | ||
364 | if (file->f_op == &shm_file_operations) { | |
365 | struct shm_file_data *sfd; | |
366 | sfd = shm_file_data(file); | |
367 | ret = is_file_hugepages(sfd->file); | |
368 | } | |
369 | return ret; | |
bc56bba8 | 370 | } |
bc56bba8 | 371 | |
9a32144e | 372 | static const struct file_operations shm_file_operations = { |
4e982311 | 373 | .mmap = shm_mmap, |
516dffdc | 374 | .fsync = shm_fsync, |
4e982311 | 375 | .release = shm_release, |
bc56bba8 | 376 | .get_unmapped_area = shm_get_unmapped_area, |
1da177e4 LT |
377 | }; |
378 | ||
379 | static struct vm_operations_struct shm_vm_ops = { | |
380 | .open = shm_open, /* callback for a new vm-area open */ | |
381 | .close = shm_close, /* callback for when the vm-area is released */ | |
54cb8821 | 382 | .fault = shm_fault, |
bc56bba8 EB |
383 | #if defined(CONFIG_NUMA) |
384 | .set_policy = shm_set_policy, | |
385 | .get_policy = shm_get_policy, | |
1da177e4 LT |
386 | #endif |
387 | }; | |
388 | ||
f4566f04 ND |
389 | /** |
390 | * newseg - Create a new shared memory segment | |
391 | * @ns: namespace | |
392 | * @params: ptr to the structure that contains key, size and shmflg | |
393 | * | |
3e148c79 | 394 | * Called with shm_ids.rw_mutex held as a writer. |
f4566f04 ND |
395 | */ |
396 | ||
7748dbfa | 397 | static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 398 | { |
7748dbfa ND |
399 | key_t key = params->key; |
400 | int shmflg = params->flg; | |
401 | size_t size = params->u.size; | |
1da177e4 LT |
402 | int error; |
403 | struct shmid_kernel *shp; | |
404 | int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; | |
405 | struct file * file; | |
406 | char name[13]; | |
407 | int id; | |
408 | ||
4e982311 | 409 | if (size < SHMMIN || size > ns->shm_ctlmax) |
1da177e4 LT |
410 | return -EINVAL; |
411 | ||
f66d45e9 | 412 | if (ns->shm_tot + numpages > ns->shm_ctlall) |
1da177e4 LT |
413 | return -ENOSPC; |
414 | ||
415 | shp = ipc_rcu_alloc(sizeof(*shp)); | |
416 | if (!shp) | |
417 | return -ENOMEM; | |
418 | ||
419 | shp->shm_perm.key = key; | |
b33291c0 | 420 | shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
1da177e4 LT |
421 | shp->mlock_user = NULL; |
422 | ||
423 | shp->shm_perm.security = NULL; | |
424 | error = security_shm_alloc(shp); | |
425 | if (error) { | |
426 | ipc_rcu_putref(shp); | |
427 | return error; | |
428 | } | |
429 | ||
9d66586f | 430 | sprintf (name, "SYSV%08x", key); |
1da177e4 | 431 | if (shmflg & SHM_HUGETLB) { |
9d66586f EB |
432 | /* hugetlb_file_setup takes care of mlock user accounting */ |
433 | file = hugetlb_file_setup(name, size); | |
1da177e4 LT |
434 | shp->mlock_user = current->user; |
435 | } else { | |
bf8f972d BP |
436 | int acctflag = VM_ACCOUNT; |
437 | /* | |
438 | * Do not allow no accounting for OVERCOMMIT_NEVER, even | |
439 | * if it's asked for. | |
440 | */ | |
441 | if ((shmflg & SHM_NORESERVE) && | |
442 | sysctl_overcommit_memory != OVERCOMMIT_NEVER) | |
443 | acctflag = 0; | |
bf8f972d | 444 | file = shmem_file_setup(name, size, acctflag); |
1da177e4 LT |
445 | } |
446 | error = PTR_ERR(file); | |
447 | if (IS_ERR(file)) | |
448 | goto no_file; | |
449 | ||
4e982311 | 450 | id = shm_addid(ns, shp); |
283bb7fa PP |
451 | if (id < 0) { |
452 | error = id; | |
1da177e4 | 453 | goto no_id; |
283bb7fa | 454 | } |
1da177e4 | 455 | |
b488893a | 456 | shp->shm_cprid = task_tgid_vnr(current); |
1da177e4 LT |
457 | shp->shm_lprid = 0; |
458 | shp->shm_atim = shp->shm_dtim = 0; | |
459 | shp->shm_ctim = get_seconds(); | |
460 | shp->shm_segsz = size; | |
461 | shp->shm_nattch = 0; | |
1b531f21 | 462 | shp->shm_perm.id = shm_buildid(id, shp->shm_perm.seq); |
1da177e4 | 463 | shp->shm_file = file; |
30475cc1 BP |
464 | /* |
465 | * shmid gets reported as "inode#" in /proc/pid/maps. | |
466 | * proc-ps tools use this. Changing this will break them. | |
467 | */ | |
7ca7e564 | 468 | file->f_dentry->d_inode->i_ino = shp->shm_perm.id; |
551110a9 | 469 | |
4e982311 | 470 | ns->shm_tot += numpages; |
7ca7e564 | 471 | error = shp->shm_perm.id; |
1da177e4 | 472 | shm_unlock(shp); |
7ca7e564 | 473 | return error; |
1da177e4 LT |
474 | |
475 | no_id: | |
476 | fput(file); | |
477 | no_file: | |
478 | security_shm_free(shp); | |
479 | ipc_rcu_putref(shp); | |
480 | return error; | |
481 | } | |
482 | ||
f4566f04 | 483 | /* |
3e148c79 | 484 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 485 | */ |
03f02c76 | 486 | static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg) |
7748dbfa | 487 | { |
03f02c76 ND |
488 | struct shmid_kernel *shp; |
489 | ||
490 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
491 | return security_shm_associate(shp, shmflg); | |
7748dbfa ND |
492 | } |
493 | ||
f4566f04 | 494 | /* |
3e148c79 | 495 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 496 | */ |
03f02c76 ND |
497 | static inline int shm_more_checks(struct kern_ipc_perm *ipcp, |
498 | struct ipc_params *params) | |
7748dbfa | 499 | { |
03f02c76 ND |
500 | struct shmid_kernel *shp; |
501 | ||
502 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
503 | if (shp->shm_segsz < params->u.size) | |
7748dbfa ND |
504 | return -EINVAL; |
505 | ||
506 | return 0; | |
507 | } | |
508 | ||
1da177e4 LT |
509 | asmlinkage long sys_shmget (key_t key, size_t size, int shmflg) |
510 | { | |
4e982311 | 511 | struct ipc_namespace *ns; |
7748dbfa ND |
512 | struct ipc_ops shm_ops; |
513 | struct ipc_params shm_params; | |
4e982311 KK |
514 | |
515 | ns = current->nsproxy->ipc_ns; | |
1da177e4 | 516 | |
7748dbfa ND |
517 | shm_ops.getnew = newseg; |
518 | shm_ops.associate = shm_security; | |
519 | shm_ops.more_checks = shm_more_checks; | |
7ca7e564 | 520 | |
7748dbfa ND |
521 | shm_params.key = key; |
522 | shm_params.flg = shmflg; | |
523 | shm_params.u.size = size; | |
1da177e4 | 524 | |
7748dbfa | 525 | return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); |
1da177e4 LT |
526 | } |
527 | ||
528 | static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) | |
529 | { | |
530 | switch(version) { | |
531 | case IPC_64: | |
532 | return copy_to_user(buf, in, sizeof(*in)); | |
533 | case IPC_OLD: | |
534 | { | |
535 | struct shmid_ds out; | |
536 | ||
537 | ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); | |
538 | out.shm_segsz = in->shm_segsz; | |
539 | out.shm_atime = in->shm_atime; | |
540 | out.shm_dtime = in->shm_dtime; | |
541 | out.shm_ctime = in->shm_ctime; | |
542 | out.shm_cpid = in->shm_cpid; | |
543 | out.shm_lpid = in->shm_lpid; | |
544 | out.shm_nattch = in->shm_nattch; | |
545 | ||
546 | return copy_to_user(buf, &out, sizeof(out)); | |
547 | } | |
548 | default: | |
549 | return -EINVAL; | |
550 | } | |
551 | } | |
552 | ||
553 | struct shm_setbuf { | |
554 | uid_t uid; | |
555 | gid_t gid; | |
556 | mode_t mode; | |
557 | }; | |
558 | ||
559 | static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version) | |
560 | { | |
561 | switch(version) { | |
562 | case IPC_64: | |
563 | { | |
564 | struct shmid64_ds tbuf; | |
565 | ||
566 | if (copy_from_user(&tbuf, buf, sizeof(tbuf))) | |
567 | return -EFAULT; | |
568 | ||
569 | out->uid = tbuf.shm_perm.uid; | |
570 | out->gid = tbuf.shm_perm.gid; | |
b33291c0 | 571 | out->mode = tbuf.shm_perm.mode; |
1da177e4 LT |
572 | |
573 | return 0; | |
574 | } | |
575 | case IPC_OLD: | |
576 | { | |
577 | struct shmid_ds tbuf_old; | |
578 | ||
579 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) | |
580 | return -EFAULT; | |
581 | ||
582 | out->uid = tbuf_old.shm_perm.uid; | |
583 | out->gid = tbuf_old.shm_perm.gid; | |
b33291c0 | 584 | out->mode = tbuf_old.shm_perm.mode; |
1da177e4 LT |
585 | |
586 | return 0; | |
587 | } | |
588 | default: | |
589 | return -EINVAL; | |
590 | } | |
591 | } | |
592 | ||
593 | static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version) | |
594 | { | |
595 | switch(version) { | |
596 | case IPC_64: | |
597 | return copy_to_user(buf, in, sizeof(*in)); | |
598 | case IPC_OLD: | |
599 | { | |
600 | struct shminfo out; | |
601 | ||
602 | if(in->shmmax > INT_MAX) | |
603 | out.shmmax = INT_MAX; | |
604 | else | |
605 | out.shmmax = (int)in->shmmax; | |
606 | ||
607 | out.shmmin = in->shmmin; | |
608 | out.shmmni = in->shmmni; | |
609 | out.shmseg = in->shmseg; | |
610 | out.shmall = in->shmall; | |
611 | ||
612 | return copy_to_user(buf, &out, sizeof(out)); | |
613 | } | |
614 | default: | |
615 | return -EINVAL; | |
616 | } | |
617 | } | |
618 | ||
f4566f04 | 619 | /* |
3e148c79 | 620 | * Called with shm_ids.rw_mutex held as a reader |
f4566f04 | 621 | */ |
4e982311 KK |
622 | static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, |
623 | unsigned long *swp) | |
1da177e4 | 624 | { |
7ca7e564 ND |
625 | int next_id; |
626 | int total, in_use; | |
1da177e4 LT |
627 | |
628 | *rss = 0; | |
629 | *swp = 0; | |
630 | ||
7ca7e564 ND |
631 | in_use = shm_ids(ns).in_use; |
632 | ||
633 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
1da177e4 LT |
634 | struct shmid_kernel *shp; |
635 | struct inode *inode; | |
636 | ||
637c3663 | 637 | shp = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
7ca7e564 | 638 | if (shp == NULL) |
1da177e4 LT |
639 | continue; |
640 | ||
6d63079a | 641 | inode = shp->shm_file->f_path.dentry->d_inode; |
1da177e4 LT |
642 | |
643 | if (is_file_hugepages(shp->shm_file)) { | |
644 | struct address_space *mapping = inode->i_mapping; | |
645 | *rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages; | |
646 | } else { | |
647 | struct shmem_inode_info *info = SHMEM_I(inode); | |
648 | spin_lock(&info->lock); | |
649 | *rss += inode->i_mapping->nrpages; | |
650 | *swp += info->swapped; | |
651 | spin_unlock(&info->lock); | |
652 | } | |
7ca7e564 ND |
653 | |
654 | total++; | |
1da177e4 LT |
655 | } |
656 | } | |
657 | ||
658 | asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) | |
659 | { | |
660 | struct shm_setbuf setbuf; | |
661 | struct shmid_kernel *shp; | |
662 | int err, version; | |
4e982311 | 663 | struct ipc_namespace *ns; |
1da177e4 LT |
664 | |
665 | if (cmd < 0 || shmid < 0) { | |
666 | err = -EINVAL; | |
667 | goto out; | |
668 | } | |
669 | ||
670 | version = ipc_parse_version(&cmd); | |
4e982311 | 671 | ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
672 | |
673 | switch (cmd) { /* replace with proc interface ? */ | |
674 | case IPC_INFO: | |
675 | { | |
676 | struct shminfo64 shminfo; | |
677 | ||
678 | err = security_shm_shmctl(NULL, cmd); | |
679 | if (err) | |
680 | return err; | |
681 | ||
682 | memset(&shminfo,0,sizeof(shminfo)); | |
4e982311 KK |
683 | shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni; |
684 | shminfo.shmmax = ns->shm_ctlmax; | |
685 | shminfo.shmall = ns->shm_ctlall; | |
1da177e4 LT |
686 | |
687 | shminfo.shmmin = SHMMIN; | |
688 | if(copy_shminfo_to_user (buf, &shminfo, version)) | |
689 | return -EFAULT; | |
f4566f04 | 690 | |
3e148c79 | 691 | down_read(&shm_ids(ns).rw_mutex); |
7ca7e564 | 692 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 693 | up_read(&shm_ids(ns).rw_mutex); |
f4566f04 | 694 | |
1da177e4 LT |
695 | if(err<0) |
696 | err = 0; | |
697 | goto out; | |
698 | } | |
699 | case SHM_INFO: | |
700 | { | |
701 | struct shm_info shm_info; | |
702 | ||
703 | err = security_shm_shmctl(NULL, cmd); | |
704 | if (err) | |
705 | return err; | |
706 | ||
707 | memset(&shm_info,0,sizeof(shm_info)); | |
3e148c79 | 708 | down_read(&shm_ids(ns).rw_mutex); |
4e982311 KK |
709 | shm_info.used_ids = shm_ids(ns).in_use; |
710 | shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp); | |
711 | shm_info.shm_tot = ns->shm_tot; | |
1da177e4 LT |
712 | shm_info.swap_attempts = 0; |
713 | shm_info.swap_successes = 0; | |
7ca7e564 | 714 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 715 | up_read(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
716 | if(copy_to_user (buf, &shm_info, sizeof(shm_info))) { |
717 | err = -EFAULT; | |
718 | goto out; | |
719 | } | |
720 | ||
721 | err = err < 0 ? 0 : err; | |
722 | goto out; | |
723 | } | |
724 | case SHM_STAT: | |
725 | case IPC_STAT: | |
726 | { | |
727 | struct shmid64_ds tbuf; | |
728 | int result; | |
023a5355 ND |
729 | |
730 | if (!buf) { | |
731 | err = -EFAULT; | |
1da177e4 | 732 | goto out; |
023a5355 ND |
733 | } |
734 | ||
735 | if (cmd == SHM_STAT) { | |
736 | shp = shm_lock(ns, shmid); | |
737 | if (IS_ERR(shp)) { | |
738 | err = PTR_ERR(shp); | |
739 | goto out; | |
740 | } | |
7ca7e564 | 741 | result = shp->shm_perm.id; |
1da177e4 | 742 | } else { |
023a5355 ND |
743 | shp = shm_lock_check(ns, shmid); |
744 | if (IS_ERR(shp)) { | |
745 | err = PTR_ERR(shp); | |
746 | goto out; | |
747 | } | |
1da177e4 LT |
748 | result = 0; |
749 | } | |
750 | err=-EACCES; | |
751 | if (ipcperms (&shp->shm_perm, S_IRUGO)) | |
752 | goto out_unlock; | |
753 | err = security_shm_shmctl(shp, cmd); | |
754 | if (err) | |
755 | goto out_unlock; | |
023a5355 | 756 | memset(&tbuf, 0, sizeof(tbuf)); |
1da177e4 LT |
757 | kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm); |
758 | tbuf.shm_segsz = shp->shm_segsz; | |
759 | tbuf.shm_atime = shp->shm_atim; | |
760 | tbuf.shm_dtime = shp->shm_dtim; | |
761 | tbuf.shm_ctime = shp->shm_ctim; | |
762 | tbuf.shm_cpid = shp->shm_cprid; | |
763 | tbuf.shm_lpid = shp->shm_lprid; | |
bc56bba8 | 764 | tbuf.shm_nattch = shp->shm_nattch; |
1da177e4 LT |
765 | shm_unlock(shp); |
766 | if(copy_shmid_to_user (buf, &tbuf, version)) | |
767 | err = -EFAULT; | |
768 | else | |
769 | err = result; | |
770 | goto out; | |
771 | } | |
772 | case SHM_LOCK: | |
773 | case SHM_UNLOCK: | |
774 | { | |
023a5355 ND |
775 | shp = shm_lock_check(ns, shmid); |
776 | if (IS_ERR(shp)) { | |
777 | err = PTR_ERR(shp); | |
1da177e4 LT |
778 | goto out; |
779 | } | |
1da177e4 | 780 | |
073115d6 SG |
781 | err = audit_ipc_obj(&(shp->shm_perm)); |
782 | if (err) | |
783 | goto out_unlock; | |
784 | ||
1da177e4 LT |
785 | if (!capable(CAP_IPC_LOCK)) { |
786 | err = -EPERM; | |
787 | if (current->euid != shp->shm_perm.uid && | |
788 | current->euid != shp->shm_perm.cuid) | |
789 | goto out_unlock; | |
790 | if (cmd == SHM_LOCK && | |
791 | !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur) | |
792 | goto out_unlock; | |
793 | } | |
794 | ||
795 | err = security_shm_shmctl(shp, cmd); | |
796 | if (err) | |
797 | goto out_unlock; | |
798 | ||
799 | if(cmd==SHM_LOCK) { | |
800 | struct user_struct * user = current->user; | |
801 | if (!is_file_hugepages(shp->shm_file)) { | |
802 | err = shmem_lock(shp->shm_file, 1, user); | |
7be77e20 | 803 | if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){ |
b33291c0 | 804 | shp->shm_perm.mode |= SHM_LOCKED; |
1da177e4 LT |
805 | shp->mlock_user = user; |
806 | } | |
807 | } | |
808 | } else if (!is_file_hugepages(shp->shm_file)) { | |
809 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
b33291c0 | 810 | shp->shm_perm.mode &= ~SHM_LOCKED; |
1da177e4 LT |
811 | shp->mlock_user = NULL; |
812 | } | |
813 | shm_unlock(shp); | |
814 | goto out; | |
815 | } | |
816 | case IPC_RMID: | |
817 | { | |
818 | /* | |
819 | * We cannot simply remove the file. The SVID states | |
820 | * that the block remains until the last person | |
821 | * detaches from it, then is deleted. A shmat() on | |
822 | * an RMID segment is legal in older Linux and if | |
823 | * we change it apps break... | |
824 | * | |
825 | * Instead we set a destroyed flag, and then blow | |
826 | * the name away when the usage hits zero. | |
827 | */ | |
3e148c79 ND |
828 | down_write(&shm_ids(ns).rw_mutex); |
829 | shp = shm_lock_check_down(ns, shmid); | |
023a5355 ND |
830 | if (IS_ERR(shp)) { |
831 | err = PTR_ERR(shp); | |
1da177e4 | 832 | goto out_up; |
023a5355 | 833 | } |
1da177e4 | 834 | |
073115d6 SG |
835 | err = audit_ipc_obj(&(shp->shm_perm)); |
836 | if (err) | |
837 | goto out_unlock_up; | |
838 | ||
1da177e4 LT |
839 | if (current->euid != shp->shm_perm.uid && |
840 | current->euid != shp->shm_perm.cuid && | |
841 | !capable(CAP_SYS_ADMIN)) { | |
842 | err=-EPERM; | |
843 | goto out_unlock_up; | |
844 | } | |
845 | ||
846 | err = security_shm_shmctl(shp, cmd); | |
847 | if (err) | |
848 | goto out_unlock_up; | |
849 | ||
4e982311 | 850 | do_shm_rmid(ns, shp); |
3e148c79 | 851 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
852 | goto out; |
853 | } | |
854 | ||
855 | case IPC_SET: | |
856 | { | |
023a5355 ND |
857 | if (!buf) { |
858 | err = -EFAULT; | |
859 | goto out; | |
860 | } | |
861 | ||
1da177e4 LT |
862 | if (copy_shmid_from_user (&setbuf, buf, version)) { |
863 | err = -EFAULT; | |
864 | goto out; | |
865 | } | |
3e148c79 ND |
866 | down_write(&shm_ids(ns).rw_mutex); |
867 | shp = shm_lock_check_down(ns, shmid); | |
023a5355 ND |
868 | if (IS_ERR(shp)) { |
869 | err = PTR_ERR(shp); | |
1da177e4 | 870 | goto out_up; |
023a5355 | 871 | } |
073115d6 SG |
872 | err = audit_ipc_obj(&(shp->shm_perm)); |
873 | if (err) | |
874 | goto out_unlock_up; | |
ac03221a | 875 | err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode); |
073115d6 SG |
876 | if (err) |
877 | goto out_unlock_up; | |
1da177e4 LT |
878 | err=-EPERM; |
879 | if (current->euid != shp->shm_perm.uid && | |
880 | current->euid != shp->shm_perm.cuid && | |
881 | !capable(CAP_SYS_ADMIN)) { | |
882 | goto out_unlock_up; | |
883 | } | |
884 | ||
885 | err = security_shm_shmctl(shp, cmd); | |
886 | if (err) | |
887 | goto out_unlock_up; | |
888 | ||
889 | shp->shm_perm.uid = setbuf.uid; | |
890 | shp->shm_perm.gid = setbuf.gid; | |
b33291c0 | 891 | shp->shm_perm.mode = (shp->shm_perm.mode & ~S_IRWXUGO) |
1da177e4 LT |
892 | | (setbuf.mode & S_IRWXUGO); |
893 | shp->shm_ctim = get_seconds(); | |
894 | break; | |
895 | } | |
896 | ||
897 | default: | |
898 | err = -EINVAL; | |
899 | goto out; | |
900 | } | |
901 | ||
902 | err = 0; | |
903 | out_unlock_up: | |
904 | shm_unlock(shp); | |
905 | out_up: | |
3e148c79 | 906 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
907 | goto out; |
908 | out_unlock: | |
909 | shm_unlock(shp); | |
910 | out: | |
911 | return err; | |
912 | } | |
913 | ||
914 | /* | |
915 | * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists. | |
916 | * | |
917 | * NOTE! Despite the name, this is NOT a direct system call entrypoint. The | |
918 | * "raddr" thing points to kernel space, and there has to be a wrapper around | |
919 | * this. | |
920 | */ | |
921 | long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) | |
922 | { | |
923 | struct shmid_kernel *shp; | |
924 | unsigned long addr; | |
925 | unsigned long size; | |
926 | struct file * file; | |
927 | int err; | |
928 | unsigned long flags; | |
929 | unsigned long prot; | |
1da177e4 | 930 | int acc_mode; |
bc56bba8 | 931 | unsigned long user_addr; |
4e982311 | 932 | struct ipc_namespace *ns; |
bc56bba8 EB |
933 | struct shm_file_data *sfd; |
934 | struct path path; | |
935 | mode_t f_mode; | |
1da177e4 | 936 | |
bc56bba8 EB |
937 | err = -EINVAL; |
938 | if (shmid < 0) | |
1da177e4 | 939 | goto out; |
bc56bba8 | 940 | else if ((addr = (ulong)shmaddr)) { |
1da177e4 LT |
941 | if (addr & (SHMLBA-1)) { |
942 | if (shmflg & SHM_RND) | |
943 | addr &= ~(SHMLBA-1); /* round down */ | |
944 | else | |
945 | #ifndef __ARCH_FORCE_SHMLBA | |
946 | if (addr & ~PAGE_MASK) | |
947 | #endif | |
bc56bba8 | 948 | goto out; |
1da177e4 LT |
949 | } |
950 | flags = MAP_SHARED | MAP_FIXED; | |
951 | } else { | |
952 | if ((shmflg & SHM_REMAP)) | |
bc56bba8 | 953 | goto out; |
1da177e4 LT |
954 | |
955 | flags = MAP_SHARED; | |
956 | } | |
957 | ||
958 | if (shmflg & SHM_RDONLY) { | |
959 | prot = PROT_READ; | |
1da177e4 | 960 | acc_mode = S_IRUGO; |
bc56bba8 | 961 | f_mode = FMODE_READ; |
1da177e4 LT |
962 | } else { |
963 | prot = PROT_READ | PROT_WRITE; | |
1da177e4 | 964 | acc_mode = S_IRUGO | S_IWUGO; |
bc56bba8 | 965 | f_mode = FMODE_READ | FMODE_WRITE; |
1da177e4 LT |
966 | } |
967 | if (shmflg & SHM_EXEC) { | |
968 | prot |= PROT_EXEC; | |
969 | acc_mode |= S_IXUGO; | |
970 | } | |
971 | ||
972 | /* | |
973 | * We cannot rely on the fs check since SYSV IPC does have an | |
974 | * additional creator id... | |
975 | */ | |
4e982311 | 976 | ns = current->nsproxy->ipc_ns; |
023a5355 ND |
977 | shp = shm_lock_check(ns, shmid); |
978 | if (IS_ERR(shp)) { | |
979 | err = PTR_ERR(shp); | |
1da177e4 | 980 | goto out; |
023a5355 | 981 | } |
bc56bba8 EB |
982 | |
983 | err = -EACCES; | |
984 | if (ipcperms(&shp->shm_perm, acc_mode)) | |
985 | goto out_unlock; | |
1da177e4 LT |
986 | |
987 | err = security_shm_shmat(shp, shmaddr, shmflg); | |
bc56bba8 EB |
988 | if (err) |
989 | goto out_unlock; | |
990 | ||
991 | path.dentry = dget(shp->shm_file->f_path.dentry); | |
ce8d2cdf | 992 | path.mnt = shp->shm_file->f_path.mnt; |
1da177e4 | 993 | shp->shm_nattch++; |
bc56bba8 | 994 | size = i_size_read(path.dentry->d_inode); |
1da177e4 LT |
995 | shm_unlock(shp); |
996 | ||
bc56bba8 EB |
997 | err = -ENOMEM; |
998 | sfd = kzalloc(sizeof(*sfd), GFP_KERNEL); | |
999 | if (!sfd) | |
ce8d2cdf | 1000 | goto out_put_dentry; |
bc56bba8 EB |
1001 | |
1002 | err = -ENOMEM; | |
ce8d2cdf DH |
1003 | |
1004 | file = alloc_file(path.mnt, path.dentry, f_mode, &shm_file_operations); | |
bc56bba8 EB |
1005 | if (!file) |
1006 | goto out_free; | |
1007 | ||
bc56bba8 | 1008 | file->private_data = sfd; |
bc56bba8 | 1009 | file->f_mapping = shp->shm_file->f_mapping; |
7ca7e564 | 1010 | sfd->id = shp->shm_perm.id; |
bc56bba8 EB |
1011 | sfd->ns = get_ipc_ns(ns); |
1012 | sfd->file = shp->shm_file; | |
1013 | sfd->vm_ops = NULL; | |
1014 | ||
1da177e4 LT |
1015 | down_write(¤t->mm->mmap_sem); |
1016 | if (addr && !(shmflg & SHM_REMAP)) { | |
bc56bba8 | 1017 | err = -EINVAL; |
1da177e4 LT |
1018 | if (find_vma_intersection(current->mm, addr, addr + size)) |
1019 | goto invalid; | |
1020 | /* | |
1021 | * If shm segment goes below stack, make sure there is some | |
1022 | * space left for the stack to grow (at least 4 pages). | |
1023 | */ | |
1024 | if (addr < current->mm->start_stack && | |
1025 | addr > current->mm->start_stack - size - PAGE_SIZE * 5) | |
1026 | goto invalid; | |
1027 | } | |
1028 | ||
bc56bba8 EB |
1029 | user_addr = do_mmap (file, addr, size, prot, flags, 0); |
1030 | *raddr = user_addr; | |
1031 | err = 0; | |
1032 | if (IS_ERR_VALUE(user_addr)) | |
1033 | err = (long)user_addr; | |
1da177e4 LT |
1034 | invalid: |
1035 | up_write(¤t->mm->mmap_sem); | |
1036 | ||
bc56bba8 EB |
1037 | fput(file); |
1038 | ||
1039 | out_nattch: | |
3e148c79 ND |
1040 | down_write(&shm_ids(ns).rw_mutex); |
1041 | shp = shm_lock_down(ns, shmid); | |
023a5355 | 1042 | BUG_ON(IS_ERR(shp)); |
1da177e4 LT |
1043 | shp->shm_nattch--; |
1044 | if(shp->shm_nattch == 0 && | |
b33291c0 | 1045 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 1046 | shm_destroy(ns, shp); |
1da177e4 LT |
1047 | else |
1048 | shm_unlock(shp); | |
3e148c79 | 1049 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 1050 | |
1da177e4 LT |
1051 | out: |
1052 | return err; | |
bc56bba8 EB |
1053 | |
1054 | out_unlock: | |
1055 | shm_unlock(shp); | |
1056 | goto out; | |
1057 | ||
1058 | out_free: | |
1059 | kfree(sfd); | |
ce8d2cdf | 1060 | out_put_dentry: |
bc56bba8 | 1061 | dput(path.dentry); |
bc56bba8 | 1062 | goto out_nattch; |
1da177e4 LT |
1063 | } |
1064 | ||
7d87e14c SR |
1065 | asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg) |
1066 | { | |
1067 | unsigned long ret; | |
1068 | long err; | |
1069 | ||
1070 | err = do_shmat(shmid, shmaddr, shmflg, &ret); | |
1071 | if (err) | |
1072 | return err; | |
1073 | force_successful_syscall_return(); | |
1074 | return (long)ret; | |
1075 | } | |
1076 | ||
1da177e4 LT |
1077 | /* |
1078 | * detach and kill segment if marked destroyed. | |
1079 | * The work is done in shm_close. | |
1080 | */ | |
1081 | asmlinkage long sys_shmdt(char __user *shmaddr) | |
1082 | { | |
1083 | struct mm_struct *mm = current->mm; | |
1084 | struct vm_area_struct *vma, *next; | |
1085 | unsigned long addr = (unsigned long)shmaddr; | |
1086 | loff_t size = 0; | |
1087 | int retval = -EINVAL; | |
1088 | ||
df1e2fb5 HD |
1089 | if (addr & ~PAGE_MASK) |
1090 | return retval; | |
1091 | ||
1da177e4 LT |
1092 | down_write(&mm->mmap_sem); |
1093 | ||
1094 | /* | |
1095 | * This function tries to be smart and unmap shm segments that | |
1096 | * were modified by partial mlock or munmap calls: | |
1097 | * - It first determines the size of the shm segment that should be | |
1098 | * unmapped: It searches for a vma that is backed by shm and that | |
1099 | * started at address shmaddr. It records it's size and then unmaps | |
1100 | * it. | |
1101 | * - Then it unmaps all shm vmas that started at shmaddr and that | |
1102 | * are within the initially determined size. | |
1103 | * Errors from do_munmap are ignored: the function only fails if | |
1104 | * it's called with invalid parameters or if it's called to unmap | |
1105 | * a part of a vma. Both calls in this function are for full vmas, | |
1106 | * the parameters are directly copied from the vma itself and always | |
1107 | * valid - therefore do_munmap cannot fail. (famous last words?) | |
1108 | */ | |
1109 | /* | |
1110 | * If it had been mremap()'d, the starting address would not | |
1111 | * match the usual checks anyway. So assume all vma's are | |
1112 | * above the starting address given. | |
1113 | */ | |
1114 | vma = find_vma(mm, addr); | |
1115 | ||
1116 | while (vma) { | |
1117 | next = vma->vm_next; | |
1118 | ||
1119 | /* | |
1120 | * Check if the starting address would match, i.e. it's | |
1121 | * a fragment created by mprotect() and/or munmap(), or it | |
1122 | * otherwise it starts at this address with no hassles. | |
1123 | */ | |
bc56bba8 | 1124 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1125 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { |
1126 | ||
1127 | ||
6d63079a | 1128 | size = vma->vm_file->f_path.dentry->d_inode->i_size; |
1da177e4 LT |
1129 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
1130 | /* | |
1131 | * We discovered the size of the shm segment, so | |
1132 | * break out of here and fall through to the next | |
1133 | * loop that uses the size information to stop | |
1134 | * searching for matching vma's. | |
1135 | */ | |
1136 | retval = 0; | |
1137 | vma = next; | |
1138 | break; | |
1139 | } | |
1140 | vma = next; | |
1141 | } | |
1142 | ||
1143 | /* | |
1144 | * We need look no further than the maximum address a fragment | |
1145 | * could possibly have landed at. Also cast things to loff_t to | |
1146 | * prevent overflows and make comparisions vs. equal-width types. | |
1147 | */ | |
8e36709d | 1148 | size = PAGE_ALIGN(size); |
1da177e4 LT |
1149 | while (vma && (loff_t)(vma->vm_end - addr) <= size) { |
1150 | next = vma->vm_next; | |
1151 | ||
1152 | /* finding a matching vma now does not alter retval */ | |
bc56bba8 | 1153 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1154 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) |
1155 | ||
1156 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
1157 | vma = next; | |
1158 | } | |
1159 | ||
1160 | up_write(&mm->mmap_sem); | |
1161 | return retval; | |
1162 | } | |
1163 | ||
1164 | #ifdef CONFIG_PROC_FS | |
19b4946c | 1165 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
1da177e4 | 1166 | { |
19b4946c MW |
1167 | struct shmid_kernel *shp = it; |
1168 | char *format; | |
1da177e4 | 1169 | |
1da177e4 LT |
1170 | #define SMALL_STRING "%10d %10d %4o %10u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" |
1171 | #define BIG_STRING "%10d %10d %4o %21u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" | |
1da177e4 | 1172 | |
19b4946c MW |
1173 | if (sizeof(size_t) <= sizeof(int)) |
1174 | format = SMALL_STRING; | |
1175 | else | |
1176 | format = BIG_STRING; | |
1177 | return seq_printf(s, format, | |
1178 | shp->shm_perm.key, | |
7ca7e564 | 1179 | shp->shm_perm.id, |
b33291c0 | 1180 | shp->shm_perm.mode, |
19b4946c MW |
1181 | shp->shm_segsz, |
1182 | shp->shm_cprid, | |
1183 | shp->shm_lprid, | |
bc56bba8 | 1184 | shp->shm_nattch, |
19b4946c MW |
1185 | shp->shm_perm.uid, |
1186 | shp->shm_perm.gid, | |
1187 | shp->shm_perm.cuid, | |
1188 | shp->shm_perm.cgid, | |
1189 | shp->shm_atim, | |
1190 | shp->shm_dtim, | |
1191 | shp->shm_ctim); | |
1da177e4 LT |
1192 | } |
1193 | #endif |