Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/ipc/shm.c | |
3 | * Copyright (C) 1992, 1993 Krishna Balasubramanian | |
4 | * Many improvements/fixes by Bruno Haible. | |
5 | * Replaced `struct shm_desc' by `struct vm_area_struct', July 1994. | |
6 | * Fixed the shm swap deallocation (shm_unuse()), August 1998 Andrea Arcangeli. | |
7 | * | |
8 | * /proc/sysvipc/shm support (c) 1999 Dragos Acostachioaie <dragos@iname.com> | |
9 | * BIGMEM support, Andrea Arcangeli <andrea@suse.de> | |
10 | * SMP thread shm, Jean-Luc Boyard <jean-luc.boyard@siemens.fr> | |
11 | * HIGHMEM support, Ingo Molnar <mingo@redhat.com> | |
12 | * Make shmmax, shmall, shmmni sysctl'able, Christoph Rohland <cr@sap.com> | |
13 | * Shared /dev/zero support, Kanoj Sarcar <kanoj@sgi.com> | |
14 | * Move the mm functionality over to mm/shmem.c, Christoph Rohland <cr@sap.com> | |
15 | * | |
073115d6 SG |
16 | * support for audit of ipc object properties and permission changes |
17 | * Dustin Kirkland <dustin.kirkland@us.ibm.com> | |
4e982311 KK |
18 | * |
19 | * namespaces support | |
20 | * OpenVZ, SWsoft Inc. | |
21 | * Pavel Emelianov <xemul@openvz.org> | |
1da177e4 LT |
22 | */ |
23 | ||
1da177e4 LT |
24 | #include <linux/slab.h> |
25 | #include <linux/mm.h> | |
26 | #include <linux/hugetlb.h> | |
27 | #include <linux/shm.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/file.h> | |
30 | #include <linux/mman.h> | |
1da177e4 LT |
31 | #include <linux/shmem_fs.h> |
32 | #include <linux/security.h> | |
33 | #include <linux/syscalls.h> | |
34 | #include <linux/audit.h> | |
c59ede7b | 35 | #include <linux/capability.h> |
7d87e14c | 36 | #include <linux/ptrace.h> |
19b4946c | 37 | #include <linux/seq_file.h> |
5f921ae9 | 38 | #include <linux/mutex.h> |
4e982311 | 39 | #include <linux/nsproxy.h> |
7d87e14c | 40 | |
1da177e4 LT |
41 | #include <asm/uaccess.h> |
42 | ||
43 | #include "util.h" | |
44 | ||
1da177e4 LT |
45 | static struct file_operations shm_file_operations; |
46 | static struct vm_operations_struct shm_vm_ops; | |
47 | ||
4e982311 KK |
48 | static struct ipc_ids init_shm_ids; |
49 | ||
50 | #define shm_ids(ns) (*((ns)->ids[IPC_SHM_IDS])) | |
1da177e4 | 51 | |
4e982311 KK |
52 | #define shm_lock(ns, id) \ |
53 | ((struct shmid_kernel*)ipc_lock(&shm_ids(ns),id)) | |
54 | #define shm_unlock(shp) \ | |
55 | ipc_unlock(&(shp)->shm_perm) | |
56 | #define shm_get(ns, id) \ | |
57 | ((struct shmid_kernel*)ipc_get(&shm_ids(ns),id)) | |
58 | #define shm_buildid(ns, id, seq) \ | |
59 | ipc_buildid(&shm_ids(ns), id, seq) | |
1da177e4 | 60 | |
4e982311 KK |
61 | static int newseg (struct ipc_namespace *ns, key_t key, |
62 | int shmflg, size_t size); | |
1da177e4 LT |
63 | static void shm_open (struct vm_area_struct *shmd); |
64 | static void shm_close (struct vm_area_struct *shmd); | |
4e982311 | 65 | static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp); |
1da177e4 | 66 | #ifdef CONFIG_PROC_FS |
19b4946c | 67 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it); |
1da177e4 LT |
68 | #endif |
69 | ||
4e982311 KK |
70 | static void __ipc_init __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids) |
71 | { | |
72 | ns->ids[IPC_SHM_IDS] = ids; | |
73 | ns->shm_ctlmax = SHMMAX; | |
74 | ns->shm_ctlall = SHMALL; | |
75 | ns->shm_ctlmni = SHMMNI; | |
76 | ns->shm_tot = 0; | |
77 | ipc_init_ids(ids, 1); | |
78 | } | |
79 | ||
80 | static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp) | |
81 | { | |
82 | if (shp->shm_nattch){ | |
83 | shp->shm_perm.mode |= SHM_DEST; | |
84 | /* Do not find it any more */ | |
85 | shp->shm_perm.key = IPC_PRIVATE; | |
86 | shm_unlock(shp); | |
87 | } else | |
88 | shm_destroy(ns, shp); | |
89 | } | |
90 | ||
91 | #ifdef CONFIG_IPC_NS | |
92 | int shm_init_ns(struct ipc_namespace *ns) | |
93 | { | |
94 | struct ipc_ids *ids; | |
95 | ||
96 | ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL); | |
97 | if (ids == NULL) | |
98 | return -ENOMEM; | |
1da177e4 | 99 | |
4e982311 KK |
100 | __shm_init_ns(ns, ids); |
101 | return 0; | |
102 | } | |
103 | ||
104 | void shm_exit_ns(struct ipc_namespace *ns) | |
105 | { | |
106 | int i; | |
107 | struct shmid_kernel *shp; | |
108 | ||
109 | mutex_lock(&shm_ids(ns).mutex); | |
110 | for (i = 0; i <= shm_ids(ns).max_id; i++) { | |
111 | shp = shm_lock(ns, i); | |
112 | if (shp == NULL) | |
113 | continue; | |
114 | ||
115 | do_shm_rmid(ns, shp); | |
116 | } | |
117 | mutex_unlock(&shm_ids(ns).mutex); | |
118 | ||
c7e12b83 | 119 | ipc_fini_ids(ns->ids[IPC_SHM_IDS]); |
4e982311 KK |
120 | kfree(ns->ids[IPC_SHM_IDS]); |
121 | ns->ids[IPC_SHM_IDS] = NULL; | |
122 | } | |
123 | #endif | |
1da177e4 LT |
124 | |
125 | void __init shm_init (void) | |
126 | { | |
4e982311 | 127 | __shm_init_ns(&init_ipc_ns, &init_shm_ids); |
19b4946c MW |
128 | ipc_init_proc_interface("sysvipc/shm", |
129 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n", | |
4e982311 | 130 | IPC_SHM_IDS, sysvipc_shm_proc_show); |
1da177e4 LT |
131 | } |
132 | ||
4e982311 KK |
133 | static inline int shm_checkid(struct ipc_namespace *ns, |
134 | struct shmid_kernel *s, int id) | |
1da177e4 | 135 | { |
4e982311 | 136 | if (ipc_checkid(&shm_ids(ns), &s->shm_perm, id)) |
1da177e4 LT |
137 | return -EIDRM; |
138 | return 0; | |
139 | } | |
140 | ||
4e982311 | 141 | static inline struct shmid_kernel *shm_rmid(struct ipc_namespace *ns, int id) |
1da177e4 | 142 | { |
4e982311 | 143 | return (struct shmid_kernel *)ipc_rmid(&shm_ids(ns), id); |
1da177e4 LT |
144 | } |
145 | ||
4e982311 | 146 | static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 147 | { |
4e982311 | 148 | return ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
1da177e4 LT |
149 | } |
150 | ||
151 | ||
152 | ||
4e982311 KK |
153 | static inline void shm_inc(struct ipc_namespace *ns, int id) |
154 | { | |
1da177e4 LT |
155 | struct shmid_kernel *shp; |
156 | ||
4e982311 | 157 | shp = shm_lock(ns, id); |
9ba025f1 | 158 | BUG_ON(!shp); |
1da177e4 LT |
159 | shp->shm_atim = get_seconds(); |
160 | shp->shm_lprid = current->tgid; | |
161 | shp->shm_nattch++; | |
162 | shm_unlock(shp); | |
163 | } | |
164 | ||
4e982311 KK |
165 | #define shm_file_ns(file) (*((struct ipc_namespace **)&(file)->private_data)) |
166 | ||
1da177e4 | 167 | /* This is called by fork, once for every shm attach. */ |
4e982311 | 168 | static void shm_open(struct vm_area_struct *shmd) |
1da177e4 | 169 | { |
4e982311 | 170 | shm_inc(shm_file_ns(shmd->vm_file), |
6d63079a | 171 | shmd->vm_file->f_path.dentry->d_inode->i_ino); |
1da177e4 LT |
172 | } |
173 | ||
174 | /* | |
175 | * shm_destroy - free the struct shmid_kernel | |
176 | * | |
177 | * @shp: struct to free | |
178 | * | |
5f921ae9 | 179 | * It has to be called with shp and shm_ids.mutex locked, |
1da177e4 LT |
180 | * but returns with shp unlocked and freed. |
181 | */ | |
4e982311 | 182 | static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 183 | { |
4e982311 KK |
184 | ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; |
185 | shm_rmid(ns, shp->id); | |
1da177e4 LT |
186 | shm_unlock(shp); |
187 | if (!is_file_hugepages(shp->shm_file)) | |
188 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
189 | else | |
6d63079a | 190 | user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size, |
1da177e4 LT |
191 | shp->mlock_user); |
192 | fput (shp->shm_file); | |
193 | security_shm_free(shp); | |
194 | ipc_rcu_putref(shp); | |
195 | } | |
196 | ||
197 | /* | |
198 | * remove the attach descriptor shmd. | |
199 | * free memory for segment if it is marked destroyed. | |
200 | * The descriptor has already been removed from the current->mm->mmap list | |
201 | * and will later be kfree()d. | |
202 | */ | |
203 | static void shm_close (struct vm_area_struct *shmd) | |
204 | { | |
205 | struct file * file = shmd->vm_file; | |
6d63079a | 206 | int id = file->f_path.dentry->d_inode->i_ino; |
1da177e4 | 207 | struct shmid_kernel *shp; |
4e982311 | 208 | struct ipc_namespace *ns; |
1da177e4 | 209 | |
4e982311 KK |
210 | ns = shm_file_ns(file); |
211 | ||
212 | mutex_lock(&shm_ids(ns).mutex); | |
1da177e4 | 213 | /* remove from the list of attaches of the shm segment */ |
4e982311 | 214 | shp = shm_lock(ns, id); |
9ba025f1 | 215 | BUG_ON(!shp); |
1da177e4 LT |
216 | shp->shm_lprid = current->tgid; |
217 | shp->shm_dtim = get_seconds(); | |
218 | shp->shm_nattch--; | |
219 | if(shp->shm_nattch == 0 && | |
b33291c0 | 220 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 221 | shm_destroy(ns, shp); |
1da177e4 LT |
222 | else |
223 | shm_unlock(shp); | |
4e982311 | 224 | mutex_unlock(&shm_ids(ns).mutex); |
1da177e4 LT |
225 | } |
226 | ||
227 | static int shm_mmap(struct file * file, struct vm_area_struct * vma) | |
228 | { | |
b0e15190 DH |
229 | int ret; |
230 | ||
231 | ret = shmem_mmap(file, vma); | |
232 | if (ret == 0) { | |
233 | vma->vm_ops = &shm_vm_ops; | |
b78b6af6 HD |
234 | if (!(vma->vm_flags & VM_WRITE)) |
235 | vma->vm_flags &= ~VM_MAYWRITE; | |
6d63079a | 236 | shm_inc(shm_file_ns(file), file->f_path.dentry->d_inode->i_ino); |
b0e15190 DH |
237 | } |
238 | ||
239 | return ret; | |
1da177e4 LT |
240 | } |
241 | ||
4e982311 KK |
242 | static int shm_release(struct inode *ino, struct file *file) |
243 | { | |
244 | struct ipc_namespace *ns; | |
245 | ||
246 | ns = shm_file_ns(file); | |
247 | put_ipc_ns(ns); | |
248 | shm_file_ns(file) = NULL; | |
249 | return 0; | |
250 | } | |
251 | ||
1da177e4 | 252 | static struct file_operations shm_file_operations = { |
4e982311 KK |
253 | .mmap = shm_mmap, |
254 | .release = shm_release, | |
b0e15190 DH |
255 | #ifndef CONFIG_MMU |
256 | .get_unmapped_area = shmem_get_unmapped_area, | |
257 | #endif | |
1da177e4 LT |
258 | }; |
259 | ||
260 | static struct vm_operations_struct shm_vm_ops = { | |
261 | .open = shm_open, /* callback for a new vm-area open */ | |
262 | .close = shm_close, /* callback for when the vm-area is released */ | |
263 | .nopage = shmem_nopage, | |
6ade43fb | 264 | #if defined(CONFIG_NUMA) && defined(CONFIG_SHMEM) |
1da177e4 LT |
265 | .set_policy = shmem_set_policy, |
266 | .get_policy = shmem_get_policy, | |
267 | #endif | |
268 | }; | |
269 | ||
4e982311 | 270 | static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size) |
1da177e4 LT |
271 | { |
272 | int error; | |
273 | struct shmid_kernel *shp; | |
274 | int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; | |
275 | struct file * file; | |
276 | char name[13]; | |
277 | int id; | |
278 | ||
4e982311 | 279 | if (size < SHMMIN || size > ns->shm_ctlmax) |
1da177e4 LT |
280 | return -EINVAL; |
281 | ||
f66d45e9 | 282 | if (ns->shm_tot + numpages > ns->shm_ctlall) |
1da177e4 LT |
283 | return -ENOSPC; |
284 | ||
285 | shp = ipc_rcu_alloc(sizeof(*shp)); | |
286 | if (!shp) | |
287 | return -ENOMEM; | |
288 | ||
289 | shp->shm_perm.key = key; | |
b33291c0 | 290 | shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
1da177e4 LT |
291 | shp->mlock_user = NULL; |
292 | ||
293 | shp->shm_perm.security = NULL; | |
294 | error = security_shm_alloc(shp); | |
295 | if (error) { | |
296 | ipc_rcu_putref(shp); | |
297 | return error; | |
298 | } | |
299 | ||
300 | if (shmflg & SHM_HUGETLB) { | |
301 | /* hugetlb_zero_setup takes care of mlock user accounting */ | |
302 | file = hugetlb_zero_setup(size); | |
303 | shp->mlock_user = current->user; | |
304 | } else { | |
bf8f972d BP |
305 | int acctflag = VM_ACCOUNT; |
306 | /* | |
307 | * Do not allow no accounting for OVERCOMMIT_NEVER, even | |
308 | * if it's asked for. | |
309 | */ | |
310 | if ((shmflg & SHM_NORESERVE) && | |
311 | sysctl_overcommit_memory != OVERCOMMIT_NEVER) | |
312 | acctflag = 0; | |
1da177e4 | 313 | sprintf (name, "SYSV%08x", key); |
bf8f972d | 314 | file = shmem_file_setup(name, size, acctflag); |
1da177e4 LT |
315 | } |
316 | error = PTR_ERR(file); | |
317 | if (IS_ERR(file)) | |
318 | goto no_file; | |
319 | ||
320 | error = -ENOSPC; | |
4e982311 | 321 | id = shm_addid(ns, shp); |
1da177e4 LT |
322 | if(id == -1) |
323 | goto no_id; | |
324 | ||
325 | shp->shm_cprid = current->tgid; | |
326 | shp->shm_lprid = 0; | |
327 | shp->shm_atim = shp->shm_dtim = 0; | |
328 | shp->shm_ctim = get_seconds(); | |
329 | shp->shm_segsz = size; | |
330 | shp->shm_nattch = 0; | |
4e982311 | 331 | shp->id = shm_buildid(ns, id, shp->shm_perm.seq); |
1da177e4 | 332 | shp->shm_file = file; |
6d63079a | 333 | file->f_path.dentry->d_inode->i_ino = shp->id; |
551110a9 | 334 | |
4e982311 KK |
335 | shm_file_ns(file) = get_ipc_ns(ns); |
336 | ||
551110a9 K |
337 | /* Hugetlb ops would have already been assigned. */ |
338 | if (!(shmflg & SHM_HUGETLB)) | |
1da177e4 | 339 | file->f_op = &shm_file_operations; |
551110a9 | 340 | |
4e982311 | 341 | ns->shm_tot += numpages; |
1da177e4 LT |
342 | shm_unlock(shp); |
343 | return shp->id; | |
344 | ||
345 | no_id: | |
346 | fput(file); | |
347 | no_file: | |
348 | security_shm_free(shp); | |
349 | ipc_rcu_putref(shp); | |
350 | return error; | |
351 | } | |
352 | ||
353 | asmlinkage long sys_shmget (key_t key, size_t size, int shmflg) | |
354 | { | |
355 | struct shmid_kernel *shp; | |
356 | int err, id = 0; | |
4e982311 KK |
357 | struct ipc_namespace *ns; |
358 | ||
359 | ns = current->nsproxy->ipc_ns; | |
1da177e4 | 360 | |
4e982311 | 361 | mutex_lock(&shm_ids(ns).mutex); |
1da177e4 | 362 | if (key == IPC_PRIVATE) { |
4e982311 KK |
363 | err = newseg(ns, key, shmflg, size); |
364 | } else if ((id = ipc_findkey(&shm_ids(ns), key)) == -1) { | |
1da177e4 LT |
365 | if (!(shmflg & IPC_CREAT)) |
366 | err = -ENOENT; | |
367 | else | |
4e982311 | 368 | err = newseg(ns, key, shmflg, size); |
1da177e4 LT |
369 | } else if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL)) { |
370 | err = -EEXIST; | |
371 | } else { | |
4e982311 | 372 | shp = shm_lock(ns, id); |
9ba025f1 | 373 | BUG_ON(shp==NULL); |
1da177e4 LT |
374 | if (shp->shm_segsz < size) |
375 | err = -EINVAL; | |
376 | else if (ipcperms(&shp->shm_perm, shmflg)) | |
377 | err = -EACCES; | |
378 | else { | |
4e982311 | 379 | int shmid = shm_buildid(ns, id, shp->shm_perm.seq); |
1da177e4 LT |
380 | err = security_shm_associate(shp, shmflg); |
381 | if (!err) | |
382 | err = shmid; | |
383 | } | |
384 | shm_unlock(shp); | |
385 | } | |
4e982311 | 386 | mutex_unlock(&shm_ids(ns).mutex); |
1da177e4 LT |
387 | |
388 | return err; | |
389 | } | |
390 | ||
391 | static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) | |
392 | { | |
393 | switch(version) { | |
394 | case IPC_64: | |
395 | return copy_to_user(buf, in, sizeof(*in)); | |
396 | case IPC_OLD: | |
397 | { | |
398 | struct shmid_ds out; | |
399 | ||
400 | ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); | |
401 | out.shm_segsz = in->shm_segsz; | |
402 | out.shm_atime = in->shm_atime; | |
403 | out.shm_dtime = in->shm_dtime; | |
404 | out.shm_ctime = in->shm_ctime; | |
405 | out.shm_cpid = in->shm_cpid; | |
406 | out.shm_lpid = in->shm_lpid; | |
407 | out.shm_nattch = in->shm_nattch; | |
408 | ||
409 | return copy_to_user(buf, &out, sizeof(out)); | |
410 | } | |
411 | default: | |
412 | return -EINVAL; | |
413 | } | |
414 | } | |
415 | ||
416 | struct shm_setbuf { | |
417 | uid_t uid; | |
418 | gid_t gid; | |
419 | mode_t mode; | |
420 | }; | |
421 | ||
422 | static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version) | |
423 | { | |
424 | switch(version) { | |
425 | case IPC_64: | |
426 | { | |
427 | struct shmid64_ds tbuf; | |
428 | ||
429 | if (copy_from_user(&tbuf, buf, sizeof(tbuf))) | |
430 | return -EFAULT; | |
431 | ||
432 | out->uid = tbuf.shm_perm.uid; | |
433 | out->gid = tbuf.shm_perm.gid; | |
b33291c0 | 434 | out->mode = tbuf.shm_perm.mode; |
1da177e4 LT |
435 | |
436 | return 0; | |
437 | } | |
438 | case IPC_OLD: | |
439 | { | |
440 | struct shmid_ds tbuf_old; | |
441 | ||
442 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) | |
443 | return -EFAULT; | |
444 | ||
445 | out->uid = tbuf_old.shm_perm.uid; | |
446 | out->gid = tbuf_old.shm_perm.gid; | |
b33291c0 | 447 | out->mode = tbuf_old.shm_perm.mode; |
1da177e4 LT |
448 | |
449 | return 0; | |
450 | } | |
451 | default: | |
452 | return -EINVAL; | |
453 | } | |
454 | } | |
455 | ||
456 | static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version) | |
457 | { | |
458 | switch(version) { | |
459 | case IPC_64: | |
460 | return copy_to_user(buf, in, sizeof(*in)); | |
461 | case IPC_OLD: | |
462 | { | |
463 | struct shminfo out; | |
464 | ||
465 | if(in->shmmax > INT_MAX) | |
466 | out.shmmax = INT_MAX; | |
467 | else | |
468 | out.shmmax = (int)in->shmmax; | |
469 | ||
470 | out.shmmin = in->shmmin; | |
471 | out.shmmni = in->shmmni; | |
472 | out.shmseg = in->shmseg; | |
473 | out.shmall = in->shmall; | |
474 | ||
475 | return copy_to_user(buf, &out, sizeof(out)); | |
476 | } | |
477 | default: | |
478 | return -EINVAL; | |
479 | } | |
480 | } | |
481 | ||
4e982311 KK |
482 | static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, |
483 | unsigned long *swp) | |
1da177e4 LT |
484 | { |
485 | int i; | |
486 | ||
487 | *rss = 0; | |
488 | *swp = 0; | |
489 | ||
4e982311 | 490 | for (i = 0; i <= shm_ids(ns).max_id; i++) { |
1da177e4 LT |
491 | struct shmid_kernel *shp; |
492 | struct inode *inode; | |
493 | ||
4e982311 | 494 | shp = shm_get(ns, i); |
1da177e4 LT |
495 | if(!shp) |
496 | continue; | |
497 | ||
6d63079a | 498 | inode = shp->shm_file->f_path.dentry->d_inode; |
1da177e4 LT |
499 | |
500 | if (is_file_hugepages(shp->shm_file)) { | |
501 | struct address_space *mapping = inode->i_mapping; | |
502 | *rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages; | |
503 | } else { | |
504 | struct shmem_inode_info *info = SHMEM_I(inode); | |
505 | spin_lock(&info->lock); | |
506 | *rss += inode->i_mapping->nrpages; | |
507 | *swp += info->swapped; | |
508 | spin_unlock(&info->lock); | |
509 | } | |
510 | } | |
511 | } | |
512 | ||
513 | asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) | |
514 | { | |
515 | struct shm_setbuf setbuf; | |
516 | struct shmid_kernel *shp; | |
517 | int err, version; | |
4e982311 | 518 | struct ipc_namespace *ns; |
1da177e4 LT |
519 | |
520 | if (cmd < 0 || shmid < 0) { | |
521 | err = -EINVAL; | |
522 | goto out; | |
523 | } | |
524 | ||
525 | version = ipc_parse_version(&cmd); | |
4e982311 | 526 | ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
527 | |
528 | switch (cmd) { /* replace with proc interface ? */ | |
529 | case IPC_INFO: | |
530 | { | |
531 | struct shminfo64 shminfo; | |
532 | ||
533 | err = security_shm_shmctl(NULL, cmd); | |
534 | if (err) | |
535 | return err; | |
536 | ||
537 | memset(&shminfo,0,sizeof(shminfo)); | |
4e982311 KK |
538 | shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni; |
539 | shminfo.shmmax = ns->shm_ctlmax; | |
540 | shminfo.shmall = ns->shm_ctlall; | |
1da177e4 LT |
541 | |
542 | shminfo.shmmin = SHMMIN; | |
543 | if(copy_shminfo_to_user (buf, &shminfo, version)) | |
544 | return -EFAULT; | |
545 | /* reading a integer is always atomic */ | |
4e982311 | 546 | err= shm_ids(ns).max_id; |
1da177e4 LT |
547 | if(err<0) |
548 | err = 0; | |
549 | goto out; | |
550 | } | |
551 | case SHM_INFO: | |
552 | { | |
553 | struct shm_info shm_info; | |
554 | ||
555 | err = security_shm_shmctl(NULL, cmd); | |
556 | if (err) | |
557 | return err; | |
558 | ||
559 | memset(&shm_info,0,sizeof(shm_info)); | |
4e982311 KK |
560 | mutex_lock(&shm_ids(ns).mutex); |
561 | shm_info.used_ids = shm_ids(ns).in_use; | |
562 | shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp); | |
563 | shm_info.shm_tot = ns->shm_tot; | |
1da177e4 LT |
564 | shm_info.swap_attempts = 0; |
565 | shm_info.swap_successes = 0; | |
4e982311 KK |
566 | err = shm_ids(ns).max_id; |
567 | mutex_unlock(&shm_ids(ns).mutex); | |
1da177e4 LT |
568 | if(copy_to_user (buf, &shm_info, sizeof(shm_info))) { |
569 | err = -EFAULT; | |
570 | goto out; | |
571 | } | |
572 | ||
573 | err = err < 0 ? 0 : err; | |
574 | goto out; | |
575 | } | |
576 | case SHM_STAT: | |
577 | case IPC_STAT: | |
578 | { | |
579 | struct shmid64_ds tbuf; | |
580 | int result; | |
581 | memset(&tbuf, 0, sizeof(tbuf)); | |
4e982311 | 582 | shp = shm_lock(ns, shmid); |
1da177e4 LT |
583 | if(shp==NULL) { |
584 | err = -EINVAL; | |
585 | goto out; | |
586 | } else if(cmd==SHM_STAT) { | |
587 | err = -EINVAL; | |
4e982311 | 588 | if (shmid > shm_ids(ns).max_id) |
1da177e4 | 589 | goto out_unlock; |
4e982311 | 590 | result = shm_buildid(ns, shmid, shp->shm_perm.seq); |
1da177e4 | 591 | } else { |
4e982311 | 592 | err = shm_checkid(ns, shp,shmid); |
1da177e4 LT |
593 | if(err) |
594 | goto out_unlock; | |
595 | result = 0; | |
596 | } | |
597 | err=-EACCES; | |
598 | if (ipcperms (&shp->shm_perm, S_IRUGO)) | |
599 | goto out_unlock; | |
600 | err = security_shm_shmctl(shp, cmd); | |
601 | if (err) | |
602 | goto out_unlock; | |
603 | kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm); | |
604 | tbuf.shm_segsz = shp->shm_segsz; | |
605 | tbuf.shm_atime = shp->shm_atim; | |
606 | tbuf.shm_dtime = shp->shm_dtim; | |
607 | tbuf.shm_ctime = shp->shm_ctim; | |
608 | tbuf.shm_cpid = shp->shm_cprid; | |
609 | tbuf.shm_lpid = shp->shm_lprid; | |
610 | if (!is_file_hugepages(shp->shm_file)) | |
611 | tbuf.shm_nattch = shp->shm_nattch; | |
612 | else | |
613 | tbuf.shm_nattch = file_count(shp->shm_file) - 1; | |
614 | shm_unlock(shp); | |
615 | if(copy_shmid_to_user (buf, &tbuf, version)) | |
616 | err = -EFAULT; | |
617 | else | |
618 | err = result; | |
619 | goto out; | |
620 | } | |
621 | case SHM_LOCK: | |
622 | case SHM_UNLOCK: | |
623 | { | |
4e982311 | 624 | shp = shm_lock(ns, shmid); |
1da177e4 LT |
625 | if(shp==NULL) { |
626 | err = -EINVAL; | |
627 | goto out; | |
628 | } | |
4e982311 | 629 | err = shm_checkid(ns, shp,shmid); |
1da177e4 LT |
630 | if(err) |
631 | goto out_unlock; | |
632 | ||
073115d6 SG |
633 | err = audit_ipc_obj(&(shp->shm_perm)); |
634 | if (err) | |
635 | goto out_unlock; | |
636 | ||
1da177e4 LT |
637 | if (!capable(CAP_IPC_LOCK)) { |
638 | err = -EPERM; | |
639 | if (current->euid != shp->shm_perm.uid && | |
640 | current->euid != shp->shm_perm.cuid) | |
641 | goto out_unlock; | |
642 | if (cmd == SHM_LOCK && | |
643 | !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur) | |
644 | goto out_unlock; | |
645 | } | |
646 | ||
647 | err = security_shm_shmctl(shp, cmd); | |
648 | if (err) | |
649 | goto out_unlock; | |
650 | ||
651 | if(cmd==SHM_LOCK) { | |
652 | struct user_struct * user = current->user; | |
653 | if (!is_file_hugepages(shp->shm_file)) { | |
654 | err = shmem_lock(shp->shm_file, 1, user); | |
655 | if (!err) { | |
b33291c0 | 656 | shp->shm_perm.mode |= SHM_LOCKED; |
1da177e4 LT |
657 | shp->mlock_user = user; |
658 | } | |
659 | } | |
660 | } else if (!is_file_hugepages(shp->shm_file)) { | |
661 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
b33291c0 | 662 | shp->shm_perm.mode &= ~SHM_LOCKED; |
1da177e4 LT |
663 | shp->mlock_user = NULL; |
664 | } | |
665 | shm_unlock(shp); | |
666 | goto out; | |
667 | } | |
668 | case IPC_RMID: | |
669 | { | |
670 | /* | |
671 | * We cannot simply remove the file. The SVID states | |
672 | * that the block remains until the last person | |
673 | * detaches from it, then is deleted. A shmat() on | |
674 | * an RMID segment is legal in older Linux and if | |
675 | * we change it apps break... | |
676 | * | |
677 | * Instead we set a destroyed flag, and then blow | |
678 | * the name away when the usage hits zero. | |
679 | */ | |
4e982311 KK |
680 | mutex_lock(&shm_ids(ns).mutex); |
681 | shp = shm_lock(ns, shmid); | |
1da177e4 LT |
682 | err = -EINVAL; |
683 | if (shp == NULL) | |
684 | goto out_up; | |
4e982311 | 685 | err = shm_checkid(ns, shp, shmid); |
1da177e4 LT |
686 | if(err) |
687 | goto out_unlock_up; | |
688 | ||
073115d6 SG |
689 | err = audit_ipc_obj(&(shp->shm_perm)); |
690 | if (err) | |
691 | goto out_unlock_up; | |
692 | ||
1da177e4 LT |
693 | if (current->euid != shp->shm_perm.uid && |
694 | current->euid != shp->shm_perm.cuid && | |
695 | !capable(CAP_SYS_ADMIN)) { | |
696 | err=-EPERM; | |
697 | goto out_unlock_up; | |
698 | } | |
699 | ||
700 | err = security_shm_shmctl(shp, cmd); | |
701 | if (err) | |
702 | goto out_unlock_up; | |
703 | ||
4e982311 KK |
704 | do_shm_rmid(ns, shp); |
705 | mutex_unlock(&shm_ids(ns).mutex); | |
1da177e4 LT |
706 | goto out; |
707 | } | |
708 | ||
709 | case IPC_SET: | |
710 | { | |
711 | if (copy_shmid_from_user (&setbuf, buf, version)) { | |
712 | err = -EFAULT; | |
713 | goto out; | |
714 | } | |
4e982311 KK |
715 | mutex_lock(&shm_ids(ns).mutex); |
716 | shp = shm_lock(ns, shmid); | |
1da177e4 LT |
717 | err=-EINVAL; |
718 | if(shp==NULL) | |
719 | goto out_up; | |
4e982311 | 720 | err = shm_checkid(ns, shp,shmid); |
1da177e4 LT |
721 | if(err) |
722 | goto out_unlock_up; | |
073115d6 SG |
723 | err = audit_ipc_obj(&(shp->shm_perm)); |
724 | if (err) | |
725 | goto out_unlock_up; | |
ac03221a | 726 | err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode); |
073115d6 SG |
727 | if (err) |
728 | goto out_unlock_up; | |
1da177e4 LT |
729 | err=-EPERM; |
730 | if (current->euid != shp->shm_perm.uid && | |
731 | current->euid != shp->shm_perm.cuid && | |
732 | !capable(CAP_SYS_ADMIN)) { | |
733 | goto out_unlock_up; | |
734 | } | |
735 | ||
736 | err = security_shm_shmctl(shp, cmd); | |
737 | if (err) | |
738 | goto out_unlock_up; | |
739 | ||
740 | shp->shm_perm.uid = setbuf.uid; | |
741 | shp->shm_perm.gid = setbuf.gid; | |
b33291c0 | 742 | shp->shm_perm.mode = (shp->shm_perm.mode & ~S_IRWXUGO) |
1da177e4 LT |
743 | | (setbuf.mode & S_IRWXUGO); |
744 | shp->shm_ctim = get_seconds(); | |
745 | break; | |
746 | } | |
747 | ||
748 | default: | |
749 | err = -EINVAL; | |
750 | goto out; | |
751 | } | |
752 | ||
753 | err = 0; | |
754 | out_unlock_up: | |
755 | shm_unlock(shp); | |
756 | out_up: | |
4e982311 | 757 | mutex_unlock(&shm_ids(ns).mutex); |
1da177e4 LT |
758 | goto out; |
759 | out_unlock: | |
760 | shm_unlock(shp); | |
761 | out: | |
762 | return err; | |
763 | } | |
764 | ||
765 | /* | |
766 | * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists. | |
767 | * | |
768 | * NOTE! Despite the name, this is NOT a direct system call entrypoint. The | |
769 | * "raddr" thing points to kernel space, and there has to be a wrapper around | |
770 | * this. | |
771 | */ | |
772 | long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) | |
773 | { | |
774 | struct shmid_kernel *shp; | |
775 | unsigned long addr; | |
776 | unsigned long size; | |
777 | struct file * file; | |
778 | int err; | |
779 | unsigned long flags; | |
780 | unsigned long prot; | |
1da177e4 LT |
781 | int acc_mode; |
782 | void *user_addr; | |
4e982311 | 783 | struct ipc_namespace *ns; |
1da177e4 LT |
784 | |
785 | if (shmid < 0) { | |
786 | err = -EINVAL; | |
787 | goto out; | |
788 | } else if ((addr = (ulong)shmaddr)) { | |
789 | if (addr & (SHMLBA-1)) { | |
790 | if (shmflg & SHM_RND) | |
791 | addr &= ~(SHMLBA-1); /* round down */ | |
792 | else | |
793 | #ifndef __ARCH_FORCE_SHMLBA | |
794 | if (addr & ~PAGE_MASK) | |
795 | #endif | |
796 | return -EINVAL; | |
797 | } | |
798 | flags = MAP_SHARED | MAP_FIXED; | |
799 | } else { | |
800 | if ((shmflg & SHM_REMAP)) | |
801 | return -EINVAL; | |
802 | ||
803 | flags = MAP_SHARED; | |
804 | } | |
805 | ||
806 | if (shmflg & SHM_RDONLY) { | |
807 | prot = PROT_READ; | |
1da177e4 LT |
808 | acc_mode = S_IRUGO; |
809 | } else { | |
810 | prot = PROT_READ | PROT_WRITE; | |
1da177e4 LT |
811 | acc_mode = S_IRUGO | S_IWUGO; |
812 | } | |
813 | if (shmflg & SHM_EXEC) { | |
814 | prot |= PROT_EXEC; | |
815 | acc_mode |= S_IXUGO; | |
816 | } | |
817 | ||
818 | /* | |
819 | * We cannot rely on the fs check since SYSV IPC does have an | |
820 | * additional creator id... | |
821 | */ | |
4e982311 KK |
822 | ns = current->nsproxy->ipc_ns; |
823 | shp = shm_lock(ns, shmid); | |
1da177e4 LT |
824 | if(shp == NULL) { |
825 | err = -EINVAL; | |
826 | goto out; | |
827 | } | |
4e982311 | 828 | err = shm_checkid(ns, shp,shmid); |
1da177e4 LT |
829 | if (err) { |
830 | shm_unlock(shp); | |
831 | goto out; | |
832 | } | |
833 | if (ipcperms(&shp->shm_perm, acc_mode)) { | |
834 | shm_unlock(shp); | |
835 | err = -EACCES; | |
836 | goto out; | |
837 | } | |
838 | ||
839 | err = security_shm_shmat(shp, shmaddr, shmflg); | |
840 | if (err) { | |
841 | shm_unlock(shp); | |
842 | return err; | |
843 | } | |
844 | ||
845 | file = shp->shm_file; | |
6d63079a | 846 | size = i_size_read(file->f_path.dentry->d_inode); |
1da177e4 LT |
847 | shp->shm_nattch++; |
848 | shm_unlock(shp); | |
849 | ||
850 | down_write(¤t->mm->mmap_sem); | |
851 | if (addr && !(shmflg & SHM_REMAP)) { | |
852 | user_addr = ERR_PTR(-EINVAL); | |
853 | if (find_vma_intersection(current->mm, addr, addr + size)) | |
854 | goto invalid; | |
855 | /* | |
856 | * If shm segment goes below stack, make sure there is some | |
857 | * space left for the stack to grow (at least 4 pages). | |
858 | */ | |
859 | if (addr < current->mm->start_stack && | |
860 | addr > current->mm->start_stack - size - PAGE_SIZE * 5) | |
861 | goto invalid; | |
862 | } | |
863 | ||
864 | user_addr = (void*) do_mmap (file, addr, size, prot, flags, 0); | |
865 | ||
866 | invalid: | |
867 | up_write(¤t->mm->mmap_sem); | |
868 | ||
4e982311 KK |
869 | mutex_lock(&shm_ids(ns).mutex); |
870 | shp = shm_lock(ns, shmid); | |
9ba025f1 | 871 | BUG_ON(!shp); |
1da177e4 LT |
872 | shp->shm_nattch--; |
873 | if(shp->shm_nattch == 0 && | |
b33291c0 | 874 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 875 | shm_destroy(ns, shp); |
1da177e4 LT |
876 | else |
877 | shm_unlock(shp); | |
4e982311 | 878 | mutex_unlock(&shm_ids(ns).mutex); |
1da177e4 LT |
879 | |
880 | *raddr = (unsigned long) user_addr; | |
881 | err = 0; | |
882 | if (IS_ERR(user_addr)) | |
883 | err = PTR_ERR(user_addr); | |
884 | out: | |
885 | return err; | |
886 | } | |
887 | ||
7d87e14c SR |
888 | asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg) |
889 | { | |
890 | unsigned long ret; | |
891 | long err; | |
892 | ||
893 | err = do_shmat(shmid, shmaddr, shmflg, &ret); | |
894 | if (err) | |
895 | return err; | |
896 | force_successful_syscall_return(); | |
897 | return (long)ret; | |
898 | } | |
899 | ||
1da177e4 LT |
900 | /* |
901 | * detach and kill segment if marked destroyed. | |
902 | * The work is done in shm_close. | |
903 | */ | |
904 | asmlinkage long sys_shmdt(char __user *shmaddr) | |
905 | { | |
906 | struct mm_struct *mm = current->mm; | |
907 | struct vm_area_struct *vma, *next; | |
908 | unsigned long addr = (unsigned long)shmaddr; | |
909 | loff_t size = 0; | |
910 | int retval = -EINVAL; | |
911 | ||
df1e2fb5 HD |
912 | if (addr & ~PAGE_MASK) |
913 | return retval; | |
914 | ||
1da177e4 LT |
915 | down_write(&mm->mmap_sem); |
916 | ||
917 | /* | |
918 | * This function tries to be smart and unmap shm segments that | |
919 | * were modified by partial mlock or munmap calls: | |
920 | * - It first determines the size of the shm segment that should be | |
921 | * unmapped: It searches for a vma that is backed by shm and that | |
922 | * started at address shmaddr. It records it's size and then unmaps | |
923 | * it. | |
924 | * - Then it unmaps all shm vmas that started at shmaddr and that | |
925 | * are within the initially determined size. | |
926 | * Errors from do_munmap are ignored: the function only fails if | |
927 | * it's called with invalid parameters or if it's called to unmap | |
928 | * a part of a vma. Both calls in this function are for full vmas, | |
929 | * the parameters are directly copied from the vma itself and always | |
930 | * valid - therefore do_munmap cannot fail. (famous last words?) | |
931 | */ | |
932 | /* | |
933 | * If it had been mremap()'d, the starting address would not | |
934 | * match the usual checks anyway. So assume all vma's are | |
935 | * above the starting address given. | |
936 | */ | |
937 | vma = find_vma(mm, addr); | |
938 | ||
939 | while (vma) { | |
940 | next = vma->vm_next; | |
941 | ||
942 | /* | |
943 | * Check if the starting address would match, i.e. it's | |
944 | * a fragment created by mprotect() and/or munmap(), or it | |
945 | * otherwise it starts at this address with no hassles. | |
946 | */ | |
947 | if ((vma->vm_ops == &shm_vm_ops || is_vm_hugetlb_page(vma)) && | |
948 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { | |
949 | ||
950 | ||
6d63079a | 951 | size = vma->vm_file->f_path.dentry->d_inode->i_size; |
1da177e4 LT |
952 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
953 | /* | |
954 | * We discovered the size of the shm segment, so | |
955 | * break out of here and fall through to the next | |
956 | * loop that uses the size information to stop | |
957 | * searching for matching vma's. | |
958 | */ | |
959 | retval = 0; | |
960 | vma = next; | |
961 | break; | |
962 | } | |
963 | vma = next; | |
964 | } | |
965 | ||
966 | /* | |
967 | * We need look no further than the maximum address a fragment | |
968 | * could possibly have landed at. Also cast things to loff_t to | |
969 | * prevent overflows and make comparisions vs. equal-width types. | |
970 | */ | |
8e36709d | 971 | size = PAGE_ALIGN(size); |
1da177e4 LT |
972 | while (vma && (loff_t)(vma->vm_end - addr) <= size) { |
973 | next = vma->vm_next; | |
974 | ||
975 | /* finding a matching vma now does not alter retval */ | |
976 | if ((vma->vm_ops == &shm_vm_ops || is_vm_hugetlb_page(vma)) && | |
977 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) | |
978 | ||
979 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
980 | vma = next; | |
981 | } | |
982 | ||
983 | up_write(&mm->mmap_sem); | |
984 | return retval; | |
985 | } | |
986 | ||
987 | #ifdef CONFIG_PROC_FS | |
19b4946c | 988 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
1da177e4 | 989 | { |
19b4946c MW |
990 | struct shmid_kernel *shp = it; |
991 | char *format; | |
1da177e4 | 992 | |
1da177e4 LT |
993 | #define SMALL_STRING "%10d %10d %4o %10u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" |
994 | #define BIG_STRING "%10d %10d %4o %21u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" | |
1da177e4 | 995 | |
19b4946c MW |
996 | if (sizeof(size_t) <= sizeof(int)) |
997 | format = SMALL_STRING; | |
998 | else | |
999 | format = BIG_STRING; | |
1000 | return seq_printf(s, format, | |
1001 | shp->shm_perm.key, | |
1002 | shp->id, | |
b33291c0 | 1003 | shp->shm_perm.mode, |
19b4946c MW |
1004 | shp->shm_segsz, |
1005 | shp->shm_cprid, | |
1006 | shp->shm_lprid, | |
1007 | is_file_hugepages(shp->shm_file) ? (file_count(shp->shm_file) - 1) : shp->shm_nattch, | |
1008 | shp->shm_perm.uid, | |
1009 | shp->shm_perm.gid, | |
1010 | shp->shm_perm.cuid, | |
1011 | shp->shm_perm.cgid, | |
1012 | shp->shm_atim, | |
1013 | shp->shm_dtim, | |
1014 | shp->shm_ctim); | |
1da177e4 LT |
1015 | } |
1016 | #endif |