1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
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>
31#include <linux/shmem_fs.h>
32#include <linux/security.h>
33#include <linux/syscalls.h>
34#include <linux/audit.h>
35#include <linux/capability.h>
36#include <linux/ptrace.h>
37#include <linux/seq_file.h>
38#include <linux/rwsem.h>
39#include <linux/nsproxy.h>
40#include <linux/mount.h>
41#include <linux/ipc_namespace.h>
42
43#include <asm/uaccess.h>
44
45#include "util.h"
46
47struct 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
56static const struct file_operations shm_file_operations;
57static const struct vm_operations_struct shm_vm_ops;
58
59#define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS])
60
61#define shm_unlock(shp) \
62 ipc_unlock(&(shp)->shm_perm)
63
64static int newseg(struct ipc_namespace *, struct ipc_params *);
65static void shm_open(struct vm_area_struct *vma);
66static void shm_close(struct vm_area_struct *vma);
67static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp);
68#ifdef CONFIG_PROC_FS
69static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
70#endif
71
72void shm_init_ns(struct ipc_namespace *ns)
73{
74 ns->shm_ctlmax = SHMMAX;
75 ns->shm_ctlall = SHMALL;
76 ns->shm_ctlmni = SHMMNI;
77 ns->shm_tot = 0;
78 ipc_init_ids(&shm_ids(ns));
79}
80
81
82
83
84
85static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
86{
87 struct shmid_kernel *shp;
88 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
89
90 if (shp->shm_nattch){
91 shp->shm_perm.mode |= SHM_DEST;
92
93 shp->shm_perm.key = IPC_PRIVATE;
94 shm_unlock(shp);
95 } else
96 shm_destroy(ns, shp);
97}
98
99#ifdef CONFIG_IPC_NS
100void shm_exit_ns(struct ipc_namespace *ns)
101{
102 free_ipcs(ns, &shm_ids(ns), do_shm_rmid);
103 idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr);
104}
105#endif
106
107void __init shm_init (void)
108{
109 shm_init_ns(&init_ipc_ns);
110 ipc_init_proc_interface("sysvipc/shm",
111#if BITS_PER_LONG <= 32
112 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n",
113#else
114 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n",
115#endif
116 IPC_SHM_IDS, sysvipc_shm_proc_show);
117}
118
119
120
121
122
123static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
124{
125 struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id);
126
127 if (IS_ERR(ipcp))
128 return (struct shmid_kernel *)ipcp;
129
130 return container_of(ipcp, struct shmid_kernel, shm_perm);
131}
132
133static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns,
134 int id)
135{
136 struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id);
137
138 if (IS_ERR(ipcp))
139 return (struct shmid_kernel *)ipcp;
140
141 return container_of(ipcp, struct shmid_kernel, shm_perm);
142}
143
144static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
145{
146 ipc_rmid(&shm_ids(ns), &s->shm_perm);
147}
148
149
150
151static void shm_open(struct vm_area_struct *vma)
152{
153 struct file *file = vma->vm_file;
154 struct shm_file_data *sfd = shm_file_data(file);
155 struct shmid_kernel *shp;
156
157 shp = shm_lock(sfd->ns, sfd->id);
158 BUG_ON(IS_ERR(shp));
159 shp->shm_atim = get_seconds();
160 shp->shm_lprid = task_tgid_vnr(current);
161 shp->shm_nattch++;
162 shm_unlock(shp);
163}
164
165
166
167
168
169
170
171
172
173
174static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
175{
176 ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
177 shm_rmid(ns, shp);
178 shm_unlock(shp);
179 if (!is_file_hugepages(shp->shm_file))
180 shmem_lock(shp->shm_file, 0, shp->mlock_user);
181 else if (shp->mlock_user)
182 user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size,
183 shp->mlock_user);
184 fput (shp->shm_file);
185 security_shm_free(shp);
186 ipc_rcu_putref(shp);
187}
188
189
190
191
192
193
194
195static void shm_close(struct vm_area_struct *vma)
196{
197 struct file * file = vma->vm_file;
198 struct shm_file_data *sfd = shm_file_data(file);
199 struct shmid_kernel *shp;
200 struct ipc_namespace *ns = sfd->ns;
201
202 down_write(&shm_ids(ns).rw_mutex);
203
204 shp = shm_lock(ns, sfd->id);
205 BUG_ON(IS_ERR(shp));
206 shp->shm_lprid = task_tgid_vnr(current);
207 shp->shm_dtim = get_seconds();
208 shp->shm_nattch--;
209 if(shp->shm_nattch == 0 &&
210 shp->shm_perm.mode & SHM_DEST)
211 shm_destroy(ns, shp);
212 else
213 shm_unlock(shp);
214 up_write(&shm_ids(ns).rw_mutex);
215}
216
217static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
218{
219 struct file *file = vma->vm_file;
220 struct shm_file_data *sfd = shm_file_data(file);
221
222 return sfd->vm_ops->fault(vma, vmf);
223}
224
225#ifdef CONFIG_NUMA
226static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
227{
228 struct file *file = vma->vm_file;
229 struct shm_file_data *sfd = shm_file_data(file);
230 int err = 0;
231 if (sfd->vm_ops->set_policy)
232 err = sfd->vm_ops->set_policy(vma, new);
233 return err;
234}
235
236static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
237 unsigned long addr)
238{
239 struct file *file = vma->vm_file;
240 struct shm_file_data *sfd = shm_file_data(file);
241 struct mempolicy *pol = NULL;
242
243 if (sfd->vm_ops->get_policy)
244 pol = sfd->vm_ops->get_policy(vma, addr);
245 else if (vma->vm_policy)
246 pol = vma->vm_policy;
247
248 return pol;
249}
250#endif
251
252static int shm_mmap(struct file * file, struct vm_area_struct * vma)
253{
254 struct shm_file_data *sfd = shm_file_data(file);
255 int ret;
256
257 ret = sfd->file->f_op->mmap(sfd->file, vma);
258 if (ret != 0)
259 return ret;
260 sfd->vm_ops = vma->vm_ops;
261#ifdef CONFIG_MMU
262 BUG_ON(!sfd->vm_ops->fault);
263#endif
264 vma->vm_ops = &shm_vm_ops;
265 shm_open(vma);
266
267 return ret;
268}
269
270static int shm_release(struct inode *ino, struct file *file)
271{
272 struct shm_file_data *sfd = shm_file_data(file);
273
274 put_ipc_ns(sfd->ns);
275 shm_file_data(file) = NULL;
276 kfree(sfd);
277 return 0;
278}
279
280static int shm_fsync(struct file *file, int datasync)
281{
282 struct shm_file_data *sfd = shm_file_data(file);
283
284 if (!sfd->file->f_op->fsync)
285 return -EINVAL;
286 return sfd->file->f_op->fsync(sfd->file, datasync);
287}
288
289static unsigned long shm_get_unmapped_area(struct file *file,
290 unsigned long addr, unsigned long len, unsigned long pgoff,
291 unsigned long flags)
292{
293 struct shm_file_data *sfd = shm_file_data(file);
294 return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len,
295 pgoff, flags);
296}
297
298static const struct file_operations shm_file_operations = {
299 .mmap = shm_mmap,
300 .fsync = shm_fsync,
301 .release = shm_release,
302#ifndef CONFIG_MMU
303 .get_unmapped_area = shm_get_unmapped_area,
304#endif
305 .llseek = noop_llseek,
306};
307
308static const struct file_operations shm_file_operations_huge = {
309 .mmap = shm_mmap,
310 .fsync = shm_fsync,
311 .release = shm_release,
312 .get_unmapped_area = shm_get_unmapped_area,
313 .llseek = noop_llseek,
314};
315
316int is_file_shm_hugepages(struct file *file)
317{
318 return file->f_op == &shm_file_operations_huge;
319}
320
321static const struct vm_operations_struct shm_vm_ops = {
322 .open = shm_open,
323 .close = shm_close,
324 .fault = shm_fault,
325#if defined(CONFIG_NUMA)
326 .set_policy = shm_set_policy,
327 .get_policy = shm_get_policy,
328#endif
329};
330
331
332
333
334
335
336
337
338
339static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
340{
341 key_t key = params->key;
342 int shmflg = params->flg;
343 size_t size = params->u.size;
344 int error;
345 struct shmid_kernel *shp;
346 int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
347 struct file * file;
348 char name[13];
349 int id;
350 int acctflag = 0;
351
352 if (size < SHMMIN || size > ns->shm_ctlmax)
353 return -EINVAL;
354
355 if (ns->shm_tot + numpages > ns->shm_ctlall)
356 return -ENOSPC;
357
358 shp = ipc_rcu_alloc(sizeof(*shp));
359 if (!shp)
360 return -ENOMEM;
361
362 shp->shm_perm.key = key;
363 shp->shm_perm.mode = (shmflg & S_IRWXUGO);
364 shp->mlock_user = NULL;
365
366 shp->shm_perm.security = NULL;
367 error = security_shm_alloc(shp);
368 if (error) {
369 ipc_rcu_putref(shp);
370 return error;
371 }
372
373 sprintf (name, "SYSV%08x", key);
374 if (shmflg & SHM_HUGETLB) {
375
376 if (shmflg & SHM_NORESERVE)
377 acctflag = VM_NORESERVE;
378 file = hugetlb_file_setup(name, size, acctflag,
379 &shp->mlock_user, HUGETLB_SHMFS_INODE);
380 } else {
381
382
383
384
385 if ((shmflg & SHM_NORESERVE) &&
386 sysctl_overcommit_memory != OVERCOMMIT_NEVER)
387 acctflag = VM_NORESERVE;
388 file = shmem_file_setup(name, size, acctflag);
389 }
390 error = PTR_ERR(file);
391 if (IS_ERR(file))
392 goto no_file;
393
394 id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
395 if (id < 0) {
396 error = id;
397 goto no_id;
398 }
399
400 shp->shm_cprid = task_tgid_vnr(current);
401 shp->shm_lprid = 0;
402 shp->shm_atim = shp->shm_dtim = 0;
403 shp->shm_ctim = get_seconds();
404 shp->shm_segsz = size;
405 shp->shm_nattch = 0;
406 shp->shm_file = file;
407
408
409
410
411 file->f_dentry->d_inode->i_ino = shp->shm_perm.id;
412
413 ns->shm_tot += numpages;
414 error = shp->shm_perm.id;
415 shm_unlock(shp);
416 return error;
417
418no_id:
419 if (is_file_hugepages(file) && shp->mlock_user)
420 user_shm_unlock(size, shp->mlock_user);
421 fput(file);
422no_file:
423 security_shm_free(shp);
424 ipc_rcu_putref(shp);
425 return error;
426}
427
428
429
430
431static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
432{
433 struct shmid_kernel *shp;
434
435 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
436 return security_shm_associate(shp, shmflg);
437}
438
439
440
441
442static inline int shm_more_checks(struct kern_ipc_perm *ipcp,
443 struct ipc_params *params)
444{
445 struct shmid_kernel *shp;
446
447 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
448 if (shp->shm_segsz < params->u.size)
449 return -EINVAL;
450
451 return 0;
452}
453
454SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
455{
456 struct ipc_namespace *ns;
457 struct ipc_ops shm_ops;
458 struct ipc_params shm_params;
459
460 ns = current->nsproxy->ipc_ns;
461
462 shm_ops.getnew = newseg;
463 shm_ops.associate = shm_security;
464 shm_ops.more_checks = shm_more_checks;
465
466 shm_params.key = key;
467 shm_params.flg = shmflg;
468 shm_params.u.size = size;
469
470 return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params);
471}
472
473static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
474{
475 switch(version) {
476 case IPC_64:
477 return copy_to_user(buf, in, sizeof(*in));
478 case IPC_OLD:
479 {
480 struct shmid_ds out;
481
482 memset(&out, 0, sizeof(out));
483 ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
484 out.shm_segsz = in->shm_segsz;
485 out.shm_atime = in->shm_atime;
486 out.shm_dtime = in->shm_dtime;
487 out.shm_ctime = in->shm_ctime;
488 out.shm_cpid = in->shm_cpid;
489 out.shm_lpid = in->shm_lpid;
490 out.shm_nattch = in->shm_nattch;
491
492 return copy_to_user(buf, &out, sizeof(out));
493 }
494 default:
495 return -EINVAL;
496 }
497}
498
499static inline unsigned long
500copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
501{
502 switch(version) {
503 case IPC_64:
504 if (copy_from_user(out, buf, sizeof(*out)))
505 return -EFAULT;
506 return 0;
507 case IPC_OLD:
508 {
509 struct shmid_ds tbuf_old;
510
511 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
512 return -EFAULT;
513
514 out->shm_perm.uid = tbuf_old.shm_perm.uid;
515 out->shm_perm.gid = tbuf_old.shm_perm.gid;
516 out->shm_perm.mode = tbuf_old.shm_perm.mode;
517
518 return 0;
519 }
520 default:
521 return -EINVAL;
522 }
523}
524
525static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
526{
527 switch(version) {
528 case IPC_64:
529 return copy_to_user(buf, in, sizeof(*in));
530 case IPC_OLD:
531 {
532 struct shminfo out;
533
534 if(in->shmmax > INT_MAX)
535 out.shmmax = INT_MAX;
536 else
537 out.shmmax = (int)in->shmmax;
538
539 out.shmmin = in->shmmin;
540 out.shmmni = in->shmmni;
541 out.shmseg = in->shmseg;
542 out.shmall = in->shmall;
543
544 return copy_to_user(buf, &out, sizeof(out));
545 }
546 default:
547 return -EINVAL;
548 }
549}
550
551
552
553
554
555static void shm_add_rss_swap(struct shmid_kernel *shp,
556 unsigned long *rss_add, unsigned long *swp_add)
557{
558 struct inode *inode;
559
560 inode = shp->shm_file->f_path.dentry->d_inode;
561
562 if (is_file_hugepages(shp->shm_file)) {
563 struct address_space *mapping = inode->i_mapping;
564 struct hstate *h = hstate_file(shp->shm_file);
565 *rss_add += pages_per_huge_page(h) * mapping->nrpages;
566 } else {
567#ifdef CONFIG_SHMEM
568 struct shmem_inode_info *info = SHMEM_I(inode);
569 spin_lock(&info->lock);
570 *rss_add += inode->i_mapping->nrpages;
571 *swp_add += info->swapped;
572 spin_unlock(&info->lock);
573#else
574 *rss_add += inode->i_mapping->nrpages;
575#endif
576 }
577}
578
579
580
581
582static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
583 unsigned long *swp)
584{
585 int next_id;
586 int total, in_use;
587
588 *rss = 0;
589 *swp = 0;
590
591 in_use = shm_ids(ns).in_use;
592
593 for (total = 0, next_id = 0; total < in_use; next_id++) {
594 struct kern_ipc_perm *ipc;
595 struct shmid_kernel *shp;
596
597 ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
598 if (ipc == NULL)
599 continue;
600 shp = container_of(ipc, struct shmid_kernel, shm_perm);
601
602 shm_add_rss_swap(shp, rss, swp);
603
604 total++;
605 }
606}
607
608
609
610
611
612
613static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
614 struct shmid_ds __user *buf, int version)
615{
616 struct kern_ipc_perm *ipcp;
617 struct shmid64_ds shmid64;
618 struct shmid_kernel *shp;
619 int err;
620
621 if (cmd == IPC_SET) {
622 if (copy_shmid_from_user(&shmid64, buf, version))
623 return -EFAULT;
624 }
625
626 ipcp = ipcctl_pre_down(ns, &shm_ids(ns), shmid, cmd,
627 &shmid64.shm_perm, 0);
628 if (IS_ERR(ipcp))
629 return PTR_ERR(ipcp);
630
631 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
632
633 err = security_shm_shmctl(shp, cmd);
634 if (err)
635 goto out_unlock;
636 switch (cmd) {
637 case IPC_RMID:
638 do_shm_rmid(ns, ipcp);
639 goto out_up;
640 case IPC_SET:
641 ipc_update_perm(&shmid64.shm_perm, ipcp);
642 shp->shm_ctim = get_seconds();
643 break;
644 default:
645 err = -EINVAL;
646 }
647out_unlock:
648 shm_unlock(shp);
649out_up:
650 up_write(&shm_ids(ns).rw_mutex);
651 return err;
652}
653
654SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
655{
656 struct shmid_kernel *shp;
657 int err, version;
658 struct ipc_namespace *ns;
659
660 if (cmd < 0 || shmid < 0) {
661 err = -EINVAL;
662 goto out;
663 }
664
665 version = ipc_parse_version(&cmd);
666 ns = current->nsproxy->ipc_ns;
667
668 switch (cmd) {
669 case IPC_INFO:
670 {
671 struct shminfo64 shminfo;
672
673 err = security_shm_shmctl(NULL, cmd);
674 if (err)
675 return err;
676
677 memset(&shminfo, 0, sizeof(shminfo));
678 shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
679 shminfo.shmmax = ns->shm_ctlmax;
680 shminfo.shmall = ns->shm_ctlall;
681
682 shminfo.shmmin = SHMMIN;
683 if(copy_shminfo_to_user (buf, &shminfo, version))
684 return -EFAULT;
685
686 down_read(&shm_ids(ns).rw_mutex);
687 err = ipc_get_maxid(&shm_ids(ns));
688 up_read(&shm_ids(ns).rw_mutex);
689
690 if(err<0)
691 err = 0;
692 goto out;
693 }
694 case SHM_INFO:
695 {
696 struct shm_info shm_info;
697
698 err = security_shm_shmctl(NULL, cmd);
699 if (err)
700 return err;
701
702 memset(&shm_info, 0, sizeof(shm_info));
703 down_read(&shm_ids(ns).rw_mutex);
704 shm_info.used_ids = shm_ids(ns).in_use;
705 shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp);
706 shm_info.shm_tot = ns->shm_tot;
707 shm_info.swap_attempts = 0;
708 shm_info.swap_successes = 0;
709 err = ipc_get_maxid(&shm_ids(ns));
710 up_read(&shm_ids(ns).rw_mutex);
711 if (copy_to_user(buf, &shm_info, sizeof(shm_info))) {
712 err = -EFAULT;
713 goto out;
714 }
715
716 err = err < 0 ? 0 : err;
717 goto out;
718 }
719 case SHM_STAT:
720 case IPC_STAT:
721 {
722 struct shmid64_ds tbuf;
723 int result;
724
725 if (cmd == SHM_STAT) {
726 shp = shm_lock(ns, shmid);
727 if (IS_ERR(shp)) {
728 err = PTR_ERR(shp);
729 goto out;
730 }
731 result = shp->shm_perm.id;
732 } else {
733 shp = shm_lock_check(ns, shmid);
734 if (IS_ERR(shp)) {
735 err = PTR_ERR(shp);
736 goto out;
737 }
738 result = 0;
739 }
740 err = -EACCES;
741 if (ipcperms(ns, &shp->shm_perm, S_IRUGO))
742 goto out_unlock;
743 err = security_shm_shmctl(shp, cmd);
744 if (err)
745 goto out_unlock;
746 memset(&tbuf, 0, sizeof(tbuf));
747 kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
748 tbuf.shm_segsz = shp->shm_segsz;
749 tbuf.shm_atime = shp->shm_atim;
750 tbuf.shm_dtime = shp->shm_dtim;
751 tbuf.shm_ctime = shp->shm_ctim;
752 tbuf.shm_cpid = shp->shm_cprid;
753 tbuf.shm_lpid = shp->shm_lprid;
754 tbuf.shm_nattch = shp->shm_nattch;
755 shm_unlock(shp);
756 if(copy_shmid_to_user (buf, &tbuf, version))
757 err = -EFAULT;
758 else
759 err = result;
760 goto out;
761 }
762 case SHM_LOCK:
763 case SHM_UNLOCK:
764 {
765 struct file *uninitialized_var(shm_file);
766
767 lru_add_drain_all();
768
769 shp = shm_lock_check(ns, shmid);
770 if (IS_ERR(shp)) {
771 err = PTR_ERR(shp);
772 goto out;
773 }
774
775 audit_ipc_obj(&(shp->shm_perm));
776
777 if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
778 uid_t euid = current_euid();
779 err = -EPERM;
780 if (euid != shp->shm_perm.uid &&
781 euid != shp->shm_perm.cuid)
782 goto out_unlock;
783 if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK))
784 goto out_unlock;
785 }
786
787 err = security_shm_shmctl(shp, cmd);
788 if (err)
789 goto out_unlock;
790
791 if(cmd==SHM_LOCK) {
792 struct user_struct *user = current_user();
793 if (!is_file_hugepages(shp->shm_file)) {
794 err = shmem_lock(shp->shm_file, 1, user);
795 if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){
796 shp->shm_perm.mode |= SHM_LOCKED;
797 shp->mlock_user = user;
798 }
799 }
800 } else if (!is_file_hugepages(shp->shm_file)) {
801 shmem_lock(shp->shm_file, 0, shp->mlock_user);
802 shp->shm_perm.mode &= ~SHM_LOCKED;
803 shp->mlock_user = NULL;
804 }
805 shm_unlock(shp);
806 goto out;
807 }
808 case IPC_RMID:
809 case IPC_SET:
810 err = shmctl_down(ns, shmid, cmd, buf, version);
811 return err;
812 default:
813 return -EINVAL;
814 }
815
816out_unlock:
817 shm_unlock(shp);
818out:
819 return err;
820}
821
822
823
824
825
826
827
828
829long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
830{
831 struct shmid_kernel *shp;
832 unsigned long addr;
833 unsigned long size;
834 struct file * file;
835 int err;
836 unsigned long flags;
837 unsigned long prot;
838 int acc_mode;
839 unsigned long user_addr;
840 struct ipc_namespace *ns;
841 struct shm_file_data *sfd;
842 struct path path;
843 fmode_t f_mode;
844
845 err = -EINVAL;
846 if (shmid < 0)
847 goto out;
848 else if ((addr = (ulong)shmaddr)) {
849 if (addr & (SHMLBA-1)) {
850 if (shmflg & SHM_RND)
851 addr &= ~(SHMLBA-1);
852 else
853#ifndef __ARCH_FORCE_SHMLBA
854 if (addr & ~PAGE_MASK)
855#endif
856 goto out;
857 }
858 flags = MAP_SHARED | MAP_FIXED;
859 } else {
860 if ((shmflg & SHM_REMAP))
861 goto out;
862
863 flags = MAP_SHARED;
864 }
865
866 if (shmflg & SHM_RDONLY) {
867 prot = PROT_READ;
868 acc_mode = S_IRUGO;
869 f_mode = FMODE_READ;
870 } else {
871 prot = PROT_READ | PROT_WRITE;
872 acc_mode = S_IRUGO | S_IWUGO;
873 f_mode = FMODE_READ | FMODE_WRITE;
874 }
875 if (shmflg & SHM_EXEC) {
876 prot |= PROT_EXEC;
877 acc_mode |= S_IXUGO;
878 }
879
880
881
882
883
884 ns = current->nsproxy->ipc_ns;
885 shp = shm_lock_check(ns, shmid);
886 if (IS_ERR(shp)) {
887 err = PTR_ERR(shp);
888 goto out;
889 }
890
891 err = -EACCES;
892 if (ipcperms(ns, &shp->shm_perm, acc_mode))
893 goto out_unlock;
894
895 err = security_shm_shmat(shp, shmaddr, shmflg);
896 if (err)
897 goto out_unlock;
898
899 path = shp->shm_file->f_path;
900 path_get(&path);
901 shp->shm_nattch++;
902 size = i_size_read(path.dentry->d_inode);
903 shm_unlock(shp);
904
905 err = -ENOMEM;
906 sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
907 if (!sfd)
908 goto out_put_dentry;
909
910 file = alloc_file(&path, f_mode,
911 is_file_hugepages(shp->shm_file) ?
912 &shm_file_operations_huge :
913 &shm_file_operations);
914 if (!file)
915 goto out_free;
916
917 file->private_data = sfd;
918 file->f_mapping = shp->shm_file->f_mapping;
919 sfd->id = shp->shm_perm.id;
920 sfd->ns = get_ipc_ns(ns);
921 sfd->file = shp->shm_file;
922 sfd->vm_ops = NULL;
923
924 down_write(¤t->mm->mmap_sem);
925 if (addr && !(shmflg & SHM_REMAP)) {
926 err = -EINVAL;
927 if (find_vma_intersection(current->mm, addr, addr + size))
928 goto invalid;
929
930
931
932
933 if (addr < current->mm->start_stack &&
934 addr > current->mm->start_stack - size - PAGE_SIZE * 5)
935 goto invalid;
936 }
937
938 user_addr = do_mmap (file, addr, size, prot, flags, 0);
939 *raddr = user_addr;
940 err = 0;
941 if (IS_ERR_VALUE(user_addr))
942 err = (long)user_addr;
943invalid:
944 up_write(¤t->mm->mmap_sem);
945
946 fput(file);
947
948out_nattch:
949 down_write(&shm_ids(ns).rw_mutex);
950 shp = shm_lock(ns, shmid);
951 BUG_ON(IS_ERR(shp));
952 shp->shm_nattch--;
953 if(shp->shm_nattch == 0 &&
954 shp->shm_perm.mode & SHM_DEST)
955 shm_destroy(ns, shp);
956 else
957 shm_unlock(shp);
958 up_write(&shm_ids(ns).rw_mutex);
959
960out:
961 return err;
962
963out_unlock:
964 shm_unlock(shp);
965 goto out;
966
967out_free:
968 kfree(sfd);
969out_put_dentry:
970 path_put(&path);
971 goto out_nattch;
972}
973
974SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg)
975{
976 unsigned long ret;
977 long err;
978
979 err = do_shmat(shmid, shmaddr, shmflg, &ret);
980 if (err)
981 return err;
982 force_successful_syscall_return();
983 return (long)ret;
984}
985
986
987
988
989
990SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
991{
992 struct mm_struct *mm = current->mm;
993 struct vm_area_struct *vma;
994 unsigned long addr = (unsigned long)shmaddr;
995 int retval = -EINVAL;
996#ifdef CONFIG_MMU
997 loff_t size = 0;
998 struct vm_area_struct *next;
999#endif
1000
1001 if (addr & ~PAGE_MASK)
1002 return retval;
1003
1004 down_write(&mm->mmap_sem);
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026 vma = find_vma(mm, addr);
1027
1028#ifdef CONFIG_MMU
1029 while (vma) {
1030 next = vma->vm_next;
1031
1032
1033
1034
1035
1036
1037 if ((vma->vm_ops == &shm_vm_ops) &&
1038 (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
1039
1040
1041 size = vma->vm_file->f_path.dentry->d_inode->i_size;
1042 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1043
1044
1045
1046
1047
1048
1049 retval = 0;
1050 vma = next;
1051 break;
1052 }
1053 vma = next;
1054 }
1055
1056
1057
1058
1059
1060
1061 size = PAGE_ALIGN(size);
1062 while (vma && (loff_t)(vma->vm_end - addr) <= size) {
1063 next = vma->vm_next;
1064
1065
1066 if ((vma->vm_ops == &shm_vm_ops) &&
1067 (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff)
1068
1069 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1070 vma = next;
1071 }
1072
1073#else
1074
1075
1076 retval = -EINVAL;
1077 if (vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
1078 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1079 retval = 0;
1080 }
1081
1082#endif
1083
1084 up_write(&mm->mmap_sem);
1085 return retval;
1086}
1087
1088#ifdef CONFIG_PROC_FS
1089static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
1090{
1091 struct shmid_kernel *shp = it;
1092 unsigned long rss = 0, swp = 0;
1093
1094 shm_add_rss_swap(shp, &rss, &swp);
1095
1096#if BITS_PER_LONG <= 32
1097#define SIZE_SPEC "%10lu"
1098#else
1099#define SIZE_SPEC "%21lu"
1100#endif
1101
1102 return seq_printf(s,
1103 "%10d %10d %4o " SIZE_SPEC " %5u %5u "
1104 "%5lu %5u %5u %5u %5u %10lu %10lu %10lu "
1105 SIZE_SPEC " " SIZE_SPEC "\n",
1106 shp->shm_perm.key,
1107 shp->shm_perm.id,
1108 shp->shm_perm.mode,
1109 shp->shm_segsz,
1110 shp->shm_cprid,
1111 shp->shm_lprid,
1112 shp->shm_nattch,
1113 shp->shm_perm.uid,
1114 shp->shm_perm.gid,
1115 shp->shm_perm.cuid,
1116 shp->shm_perm.cgid,
1117 shp->shm_atim,
1118 shp->shm_dtim,
1119 shp->shm_ctim,
1120 rss * PAGE_SIZE,
1121 swp * PAGE_SIZE);
1122}
1123#endif
1124