[Bluetooth] Handle return values from driver core functions
[linux-2.6.git] / ipc / shm.c
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  *
16  * support for audit of ipc object properties and permission changes
17  * Dustin Kirkland <dustin.kirkland@us.ibm.com>
18  *
19  * namespaces support
20  * OpenVZ, SWsoft Inc.
21  * Pavel Emelianov <xemul@openvz.org>
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/mutex.h>
39 #include <linux/nsproxy.h>
40
41 #include <asm/uaccess.h>
42
43 #include "util.h"
44
45 static struct file_operations shm_file_operations;
46 static struct vm_operations_struct shm_vm_ops;
47
48 static struct ipc_ids init_shm_ids;
49
50 #define shm_ids(ns)     (*((ns)->ids[IPC_SHM_IDS]))
51
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)
60
61 static int newseg (struct ipc_namespace *ns, key_t key,
62                 int shmflg, size_t size);
63 static void shm_open (struct vm_area_struct *shmd);
64 static void shm_close (struct vm_area_struct *shmd);
65 static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp);
66 #ifdef CONFIG_PROC_FS
67 static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
68 #endif
69
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;
99
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
119         kfree(ns->ids[IPC_SHM_IDS]);
120         ns->ids[IPC_SHM_IDS] = NULL;
121 }
122 #endif
123
124 void __init shm_init (void)
125 {
126         __shm_init_ns(&init_ipc_ns, &init_shm_ids);
127         ipc_init_proc_interface("sysvipc/shm",
128                                 "       key      shmid perms       size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime\n",
129                                 IPC_SHM_IDS, sysvipc_shm_proc_show);
130 }
131
132 static inline int shm_checkid(struct ipc_namespace *ns,
133                 struct shmid_kernel *s, int id)
134 {
135         if (ipc_checkid(&shm_ids(ns), &s->shm_perm, id))
136                 return -EIDRM;
137         return 0;
138 }
139
140 static inline struct shmid_kernel *shm_rmid(struct ipc_namespace *ns, int id)
141 {
142         return (struct shmid_kernel *)ipc_rmid(&shm_ids(ns), id);
143 }
144
145 static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp)
146 {
147         return ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
148 }
149
150
151
152 static inline void shm_inc(struct ipc_namespace *ns, int id)
153 {
154         struct shmid_kernel *shp;
155
156         shp = shm_lock(ns, id);
157         BUG_ON(!shp);
158         shp->shm_atim = get_seconds();
159         shp->shm_lprid = current->tgid;
160         shp->shm_nattch++;
161         shm_unlock(shp);
162 }
163
164 #define shm_file_ns(file) (*((struct ipc_namespace **)&(file)->private_data))
165
166 /* This is called by fork, once for every shm attach. */
167 static void shm_open(struct vm_area_struct *shmd)
168 {
169         shm_inc(shm_file_ns(shmd->vm_file),
170                         shmd->vm_file->f_dentry->d_inode->i_ino);
171 }
172
173 /*
174  * shm_destroy - free the struct shmid_kernel
175  *
176  * @shp: struct to free
177  *
178  * It has to be called with shp and shm_ids.mutex locked,
179  * but returns with shp unlocked and freed.
180  */
181 static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
182 {
183         ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
184         shm_rmid(ns, shp->id);
185         shm_unlock(shp);
186         if (!is_file_hugepages(shp->shm_file))
187                 shmem_lock(shp->shm_file, 0, shp->mlock_user);
188         else
189                 user_shm_unlock(shp->shm_file->f_dentry->d_inode->i_size,
190                                                 shp->mlock_user);
191         fput (shp->shm_file);
192         security_shm_free(shp);
193         ipc_rcu_putref(shp);
194 }
195
196 /*
197  * remove the attach descriptor shmd.
198  * free memory for segment if it is marked destroyed.
199  * The descriptor has already been removed from the current->mm->mmap list
200  * and will later be kfree()d.
201  */
202 static void shm_close (struct vm_area_struct *shmd)
203 {
204         struct file * file = shmd->vm_file;
205         int id = file->f_dentry->d_inode->i_ino;
206         struct shmid_kernel *shp;
207         struct ipc_namespace *ns;
208
209         ns = shm_file_ns(file);
210
211         mutex_lock(&shm_ids(ns).mutex);
212         /* remove from the list of attaches of the shm segment */
213         shp = shm_lock(ns, id);
214         BUG_ON(!shp);
215         shp->shm_lprid = current->tgid;
216         shp->shm_dtim = get_seconds();
217         shp->shm_nattch--;
218         if(shp->shm_nattch == 0 &&
219            shp->shm_perm.mode & SHM_DEST)
220                 shm_destroy(ns, shp);
221         else
222                 shm_unlock(shp);
223         mutex_unlock(&shm_ids(ns).mutex);
224 }
225
226 static int shm_mmap(struct file * file, struct vm_area_struct * vma)
227 {
228         int ret;
229
230         ret = shmem_mmap(file, vma);
231         if (ret == 0) {
232                 vma->vm_ops = &shm_vm_ops;
233                 if (!(vma->vm_flags & VM_WRITE))
234                         vma->vm_flags &= ~VM_MAYWRITE;
235                 shm_inc(shm_file_ns(file), file->f_dentry->d_inode->i_ino);
236         }
237
238         return ret;
239 }
240
241 static int shm_release(struct inode *ino, struct file *file)
242 {
243         struct ipc_namespace *ns;
244
245         ns = shm_file_ns(file);
246         put_ipc_ns(ns);
247         shm_file_ns(file) = NULL;
248         return 0;
249 }
250
251 static struct file_operations shm_file_operations = {
252         .mmap           = shm_mmap,
253         .release        = shm_release,
254 #ifndef CONFIG_MMU
255         .get_unmapped_area = shmem_get_unmapped_area,
256 #endif
257 };
258
259 static struct vm_operations_struct shm_vm_ops = {
260         .open   = shm_open,     /* callback for a new vm-area open */
261         .close  = shm_close,    /* callback for when the vm-area is released */
262         .nopage = shmem_nopage,
263 #if defined(CONFIG_NUMA) && defined(CONFIG_SHMEM)
264         .set_policy = shmem_set_policy,
265         .get_policy = shmem_get_policy,
266 #endif
267 };
268
269 static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
270 {
271         int error;
272         struct shmid_kernel *shp;
273         int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
274         struct file * file;
275         char name[13];
276         int id;
277
278         if (size < SHMMIN || size > ns->shm_ctlmax)
279                 return -EINVAL;
280
281         if (ns->shm_tot + numpages >= ns->shm_ctlall)
282                 return -ENOSPC;
283
284         shp = ipc_rcu_alloc(sizeof(*shp));
285         if (!shp)
286                 return -ENOMEM;
287
288         shp->shm_perm.key = key;
289         shp->shm_perm.mode = (shmflg & S_IRWXUGO);
290         shp->mlock_user = NULL;
291
292         shp->shm_perm.security = NULL;
293         error = security_shm_alloc(shp);
294         if (error) {
295                 ipc_rcu_putref(shp);
296                 return error;
297         }
298
299         if (shmflg & SHM_HUGETLB) {
300                 /* hugetlb_zero_setup takes care of mlock user accounting */
301                 file = hugetlb_zero_setup(size);
302                 shp->mlock_user = current->user;
303         } else {
304                 int acctflag = VM_ACCOUNT;
305                 /*
306                  * Do not allow no accounting for OVERCOMMIT_NEVER, even
307                  * if it's asked for.
308                  */
309                 if  ((shmflg & SHM_NORESERVE) &&
310                                 sysctl_overcommit_memory != OVERCOMMIT_NEVER)
311                         acctflag = 0;
312                 sprintf (name, "SYSV%08x", key);
313                 file = shmem_file_setup(name, size, acctflag);
314         }
315         error = PTR_ERR(file);
316         if (IS_ERR(file))
317                 goto no_file;
318
319         error = -ENOSPC;
320         id = shm_addid(ns, shp);
321         if(id == -1) 
322                 goto no_id;
323
324         shp->shm_cprid = current->tgid;
325         shp->shm_lprid = 0;
326         shp->shm_atim = shp->shm_dtim = 0;
327         shp->shm_ctim = get_seconds();
328         shp->shm_segsz = size;
329         shp->shm_nattch = 0;
330         shp->id = shm_buildid(ns, id, shp->shm_perm.seq);
331         shp->shm_file = file;
332         file->f_dentry->d_inode->i_ino = shp->id;
333
334         shm_file_ns(file) = get_ipc_ns(ns);
335
336         /* Hugetlb ops would have already been assigned. */
337         if (!(shmflg & SHM_HUGETLB))
338                 file->f_op = &shm_file_operations;
339
340         ns->shm_tot += numpages;
341         shm_unlock(shp);
342         return shp->id;
343
344 no_id:
345         fput(file);
346 no_file:
347         security_shm_free(shp);
348         ipc_rcu_putref(shp);
349         return error;
350 }
351
352 asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
353 {
354         struct shmid_kernel *shp;
355         int err, id = 0;
356         struct ipc_namespace *ns;
357
358         ns = current->nsproxy->ipc_ns;
359
360         mutex_lock(&shm_ids(ns).mutex);
361         if (key == IPC_PRIVATE) {
362                 err = newseg(ns, key, shmflg, size);
363         } else if ((id = ipc_findkey(&shm_ids(ns), key)) == -1) {
364                 if (!(shmflg & IPC_CREAT))
365                         err = -ENOENT;
366                 else
367                         err = newseg(ns, key, shmflg, size);
368         } else if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL)) {
369                 err = -EEXIST;
370         } else {
371                 shp = shm_lock(ns, id);
372                 BUG_ON(shp==NULL);
373                 if (shp->shm_segsz < size)
374                         err = -EINVAL;
375                 else if (ipcperms(&shp->shm_perm, shmflg))
376                         err = -EACCES;
377                 else {
378                         int shmid = shm_buildid(ns, id, shp->shm_perm.seq);
379                         err = security_shm_associate(shp, shmflg);
380                         if (!err)
381                                 err = shmid;
382                 }
383                 shm_unlock(shp);
384         }
385         mutex_unlock(&shm_ids(ns).mutex);
386
387         return err;
388 }
389
390 static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
391 {
392         switch(version) {
393         case IPC_64:
394                 return copy_to_user(buf, in, sizeof(*in));
395         case IPC_OLD:
396             {
397                 struct shmid_ds out;
398
399                 ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
400                 out.shm_segsz   = in->shm_segsz;
401                 out.shm_atime   = in->shm_atime;
402                 out.shm_dtime   = in->shm_dtime;
403                 out.shm_ctime   = in->shm_ctime;
404                 out.shm_cpid    = in->shm_cpid;
405                 out.shm_lpid    = in->shm_lpid;
406                 out.shm_nattch  = in->shm_nattch;
407
408                 return copy_to_user(buf, &out, sizeof(out));
409             }
410         default:
411                 return -EINVAL;
412         }
413 }
414
415 struct shm_setbuf {
416         uid_t   uid;
417         gid_t   gid;
418         mode_t  mode;
419 };      
420
421 static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version)
422 {
423         switch(version) {
424         case IPC_64:
425             {
426                 struct shmid64_ds tbuf;
427
428                 if (copy_from_user(&tbuf, buf, sizeof(tbuf)))
429                         return -EFAULT;
430
431                 out->uid        = tbuf.shm_perm.uid;
432                 out->gid        = tbuf.shm_perm.gid;
433                 out->mode       = tbuf.shm_perm.mode;
434
435                 return 0;
436             }
437         case IPC_OLD:
438             {
439                 struct shmid_ds tbuf_old;
440
441                 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
442                         return -EFAULT;
443
444                 out->uid        = tbuf_old.shm_perm.uid;
445                 out->gid        = tbuf_old.shm_perm.gid;
446                 out->mode       = tbuf_old.shm_perm.mode;
447
448                 return 0;
449             }
450         default:
451                 return -EINVAL;
452         }
453 }
454
455 static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
456 {
457         switch(version) {
458         case IPC_64:
459                 return copy_to_user(buf, in, sizeof(*in));
460         case IPC_OLD:
461             {
462                 struct shminfo out;
463
464                 if(in->shmmax > INT_MAX)
465                         out.shmmax = INT_MAX;
466                 else
467                         out.shmmax = (int)in->shmmax;
468
469                 out.shmmin      = in->shmmin;
470                 out.shmmni      = in->shmmni;
471                 out.shmseg      = in->shmseg;
472                 out.shmall      = in->shmall; 
473
474                 return copy_to_user(buf, &out, sizeof(out));
475             }
476         default:
477                 return -EINVAL;
478         }
479 }
480
481 static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
482                 unsigned long *swp)
483 {
484         int i;
485
486         *rss = 0;
487         *swp = 0;
488
489         for (i = 0; i <= shm_ids(ns).max_id; i++) {
490                 struct shmid_kernel *shp;
491                 struct inode *inode;
492
493                 shp = shm_get(ns, i);
494                 if(!shp)
495                         continue;
496
497                 inode = shp->shm_file->f_dentry->d_inode;
498
499                 if (is_file_hugepages(shp->shm_file)) {
500                         struct address_space *mapping = inode->i_mapping;
501                         *rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages;
502                 } else {
503                         struct shmem_inode_info *info = SHMEM_I(inode);
504                         spin_lock(&info->lock);
505                         *rss += inode->i_mapping->nrpages;
506                         *swp += info->swapped;
507                         spin_unlock(&info->lock);
508                 }
509         }
510 }
511
512 asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
513 {
514         struct shm_setbuf setbuf;
515         struct shmid_kernel *shp;
516         int err, version;
517         struct ipc_namespace *ns;
518
519         if (cmd < 0 || shmid < 0) {
520                 err = -EINVAL;
521                 goto out;
522         }
523
524         version = ipc_parse_version(&cmd);
525         ns = current->nsproxy->ipc_ns;
526
527         switch (cmd) { /* replace with proc interface ? */
528         case IPC_INFO:
529         {
530                 struct shminfo64 shminfo;
531
532                 err = security_shm_shmctl(NULL, cmd);
533                 if (err)
534                         return err;
535
536                 memset(&shminfo,0,sizeof(shminfo));
537                 shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
538                 shminfo.shmmax = ns->shm_ctlmax;
539                 shminfo.shmall = ns->shm_ctlall;
540
541                 shminfo.shmmin = SHMMIN;
542                 if(copy_shminfo_to_user (buf, &shminfo, version))
543                         return -EFAULT;
544                 /* reading a integer is always atomic */
545                 err= shm_ids(ns).max_id;
546                 if(err<0)
547                         err = 0;
548                 goto out;
549         }
550         case SHM_INFO:
551         {
552                 struct shm_info shm_info;
553
554                 err = security_shm_shmctl(NULL, cmd);
555                 if (err)
556                         return err;
557
558                 memset(&shm_info,0,sizeof(shm_info));
559                 mutex_lock(&shm_ids(ns).mutex);
560                 shm_info.used_ids = shm_ids(ns).in_use;
561                 shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp);
562                 shm_info.shm_tot = ns->shm_tot;
563                 shm_info.swap_attempts = 0;
564                 shm_info.swap_successes = 0;
565                 err = shm_ids(ns).max_id;
566                 mutex_unlock(&shm_ids(ns).mutex);
567                 if(copy_to_user (buf, &shm_info, sizeof(shm_info))) {
568                         err = -EFAULT;
569                         goto out;
570                 }
571
572                 err = err < 0 ? 0 : err;
573                 goto out;
574         }
575         case SHM_STAT:
576         case IPC_STAT:
577         {
578                 struct shmid64_ds tbuf;
579                 int result;
580                 memset(&tbuf, 0, sizeof(tbuf));
581                 shp = shm_lock(ns, shmid);
582                 if(shp==NULL) {
583                         err = -EINVAL;
584                         goto out;
585                 } else if(cmd==SHM_STAT) {
586                         err = -EINVAL;
587                         if (shmid > shm_ids(ns).max_id)
588                                 goto out_unlock;
589                         result = shm_buildid(ns, shmid, shp->shm_perm.seq);
590                 } else {
591                         err = shm_checkid(ns, shp,shmid);
592                         if(err)
593                                 goto out_unlock;
594                         result = 0;
595                 }
596                 err=-EACCES;
597                 if (ipcperms (&shp->shm_perm, S_IRUGO))
598                         goto out_unlock;
599                 err = security_shm_shmctl(shp, cmd);
600                 if (err)
601                         goto out_unlock;
602                 kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
603                 tbuf.shm_segsz  = shp->shm_segsz;
604                 tbuf.shm_atime  = shp->shm_atim;
605                 tbuf.shm_dtime  = shp->shm_dtim;
606                 tbuf.shm_ctime  = shp->shm_ctim;
607                 tbuf.shm_cpid   = shp->shm_cprid;
608                 tbuf.shm_lpid   = shp->shm_lprid;
609                 if (!is_file_hugepages(shp->shm_file))
610                         tbuf.shm_nattch = shp->shm_nattch;
611                 else
612                         tbuf.shm_nattch = file_count(shp->shm_file) - 1;
613                 shm_unlock(shp);
614                 if(copy_shmid_to_user (buf, &tbuf, version))
615                         err = -EFAULT;
616                 else
617                         err = result;
618                 goto out;
619         }
620         case SHM_LOCK:
621         case SHM_UNLOCK:
622         {
623                 shp = shm_lock(ns, shmid);
624                 if(shp==NULL) {
625                         err = -EINVAL;
626                         goto out;
627                 }
628                 err = shm_checkid(ns, shp,shmid);
629                 if(err)
630                         goto out_unlock;
631
632                 err = audit_ipc_obj(&(shp->shm_perm));
633                 if (err)
634                         goto out_unlock;
635
636                 if (!capable(CAP_IPC_LOCK)) {
637                         err = -EPERM;
638                         if (current->euid != shp->shm_perm.uid &&
639                             current->euid != shp->shm_perm.cuid)
640                                 goto out_unlock;
641                         if (cmd == SHM_LOCK &&
642                             !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur)
643                                 goto out_unlock;
644                 }
645
646                 err = security_shm_shmctl(shp, cmd);
647                 if (err)
648                         goto out_unlock;
649                 
650                 if(cmd==SHM_LOCK) {
651                         struct user_struct * user = current->user;
652                         if (!is_file_hugepages(shp->shm_file)) {
653                                 err = shmem_lock(shp->shm_file, 1, user);
654                                 if (!err) {
655                                         shp->shm_perm.mode |= SHM_LOCKED;
656                                         shp->mlock_user = user;
657                                 }
658                         }
659                 } else if (!is_file_hugepages(shp->shm_file)) {
660                         shmem_lock(shp->shm_file, 0, shp->mlock_user);
661                         shp->shm_perm.mode &= ~SHM_LOCKED;
662                         shp->mlock_user = NULL;
663                 }
664                 shm_unlock(shp);
665                 goto out;
666         }
667         case IPC_RMID:
668         {
669                 /*
670                  *      We cannot simply remove the file. The SVID states
671                  *      that the block remains until the last person
672                  *      detaches from it, then is deleted. A shmat() on
673                  *      an RMID segment is legal in older Linux and if 
674                  *      we change it apps break...
675                  *
676                  *      Instead we set a destroyed flag, and then blow
677                  *      the name away when the usage hits zero.
678                  */
679                 mutex_lock(&shm_ids(ns).mutex);
680                 shp = shm_lock(ns, shmid);
681                 err = -EINVAL;
682                 if (shp == NULL) 
683                         goto out_up;
684                 err = shm_checkid(ns, shp, shmid);
685                 if(err)
686                         goto out_unlock_up;
687
688                 err = audit_ipc_obj(&(shp->shm_perm));
689                 if (err)
690                         goto out_unlock_up;
691
692                 if (current->euid != shp->shm_perm.uid &&
693                     current->euid != shp->shm_perm.cuid && 
694                     !capable(CAP_SYS_ADMIN)) {
695                         err=-EPERM;
696                         goto out_unlock_up;
697                 }
698
699                 err = security_shm_shmctl(shp, cmd);
700                 if (err)
701                         goto out_unlock_up;
702
703                 do_shm_rmid(ns, shp);
704                 mutex_unlock(&shm_ids(ns).mutex);
705                 goto out;
706         }
707
708         case IPC_SET:
709         {
710                 if (copy_shmid_from_user (&setbuf, buf, version)) {
711                         err = -EFAULT;
712                         goto out;
713                 }
714                 mutex_lock(&shm_ids(ns).mutex);
715                 shp = shm_lock(ns, shmid);
716                 err=-EINVAL;
717                 if(shp==NULL)
718                         goto out_up;
719                 err = shm_checkid(ns, shp,shmid);
720                 if(err)
721                         goto out_unlock_up;
722                 err = audit_ipc_obj(&(shp->shm_perm));
723                 if (err)
724                         goto out_unlock_up;
725                 err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode);
726                 if (err)
727                         goto out_unlock_up;
728                 err=-EPERM;
729                 if (current->euid != shp->shm_perm.uid &&
730                     current->euid != shp->shm_perm.cuid && 
731                     !capable(CAP_SYS_ADMIN)) {
732                         goto out_unlock_up;
733                 }
734
735                 err = security_shm_shmctl(shp, cmd);
736                 if (err)
737                         goto out_unlock_up;
738                 
739                 shp->shm_perm.uid = setbuf.uid;
740                 shp->shm_perm.gid = setbuf.gid;
741                 shp->shm_perm.mode = (shp->shm_perm.mode & ~S_IRWXUGO)
742                         | (setbuf.mode & S_IRWXUGO);
743                 shp->shm_ctim = get_seconds();
744                 break;
745         }
746
747         default:
748                 err = -EINVAL;
749                 goto out;
750         }
751
752         err = 0;
753 out_unlock_up:
754         shm_unlock(shp);
755 out_up:
756         mutex_unlock(&shm_ids(ns).mutex);
757         goto out;
758 out_unlock:
759         shm_unlock(shp);
760 out:
761         return err;
762 }
763
764 /*
765  * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
766  *
767  * NOTE! Despite the name, this is NOT a direct system call entrypoint. The
768  * "raddr" thing points to kernel space, and there has to be a wrapper around
769  * this.
770  */
771 long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
772 {
773         struct shmid_kernel *shp;
774         unsigned long addr;
775         unsigned long size;
776         struct file * file;
777         int    err;
778         unsigned long flags;
779         unsigned long prot;
780         int acc_mode;
781         void *user_addr;
782         struct ipc_namespace *ns;
783
784         if (shmid < 0) {
785                 err = -EINVAL;
786                 goto out;
787         } else if ((addr = (ulong)shmaddr)) {
788                 if (addr & (SHMLBA-1)) {
789                         if (shmflg & SHM_RND)
790                                 addr &= ~(SHMLBA-1);       /* round down */
791                         else
792 #ifndef __ARCH_FORCE_SHMLBA
793                                 if (addr & ~PAGE_MASK)
794 #endif
795                                         return -EINVAL;
796                 }
797                 flags = MAP_SHARED | MAP_FIXED;
798         } else {
799                 if ((shmflg & SHM_REMAP))
800                         return -EINVAL;
801
802                 flags = MAP_SHARED;
803         }
804
805         if (shmflg & SHM_RDONLY) {
806                 prot = PROT_READ;
807                 acc_mode = S_IRUGO;
808         } else {
809                 prot = PROT_READ | PROT_WRITE;
810                 acc_mode = S_IRUGO | S_IWUGO;
811         }
812         if (shmflg & SHM_EXEC) {
813                 prot |= PROT_EXEC;
814                 acc_mode |= S_IXUGO;
815         }
816
817         /*
818          * We cannot rely on the fs check since SYSV IPC does have an
819          * additional creator id...
820          */
821         ns = current->nsproxy->ipc_ns;
822         shp = shm_lock(ns, shmid);
823         if(shp == NULL) {
824                 err = -EINVAL;
825                 goto out;
826         }
827         err = shm_checkid(ns, shp,shmid);
828         if (err) {
829                 shm_unlock(shp);
830                 goto out;
831         }
832         if (ipcperms(&shp->shm_perm, acc_mode)) {
833                 shm_unlock(shp);
834                 err = -EACCES;
835                 goto out;
836         }
837
838         err = security_shm_shmat(shp, shmaddr, shmflg);
839         if (err) {
840                 shm_unlock(shp);
841                 return err;
842         }
843                 
844         file = shp->shm_file;
845         size = i_size_read(file->f_dentry->d_inode);
846         shp->shm_nattch++;
847         shm_unlock(shp);
848
849         down_write(&current->mm->mmap_sem);
850         if (addr && !(shmflg & SHM_REMAP)) {
851                 user_addr = ERR_PTR(-EINVAL);
852                 if (find_vma_intersection(current->mm, addr, addr + size))
853                         goto invalid;
854                 /*
855                  * If shm segment goes below stack, make sure there is some
856                  * space left for the stack to grow (at least 4 pages).
857                  */
858                 if (addr < current->mm->start_stack &&
859                     addr > current->mm->start_stack - size - PAGE_SIZE * 5)
860                         goto invalid;
861         }
862                 
863         user_addr = (void*) do_mmap (file, addr, size, prot, flags, 0);
864
865 invalid:
866         up_write(&current->mm->mmap_sem);
867
868         mutex_lock(&shm_ids(ns).mutex);
869         shp = shm_lock(ns, shmid);
870         BUG_ON(!shp);
871         shp->shm_nattch--;
872         if(shp->shm_nattch == 0 &&
873            shp->shm_perm.mode & SHM_DEST)
874                 shm_destroy(ns, shp);
875         else
876                 shm_unlock(shp);
877         mutex_unlock(&shm_ids(ns).mutex);
878
879         *raddr = (unsigned long) user_addr;
880         err = 0;
881         if (IS_ERR(user_addr))
882                 err = PTR_ERR(user_addr);
883 out:
884         return err;
885 }
886
887 asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg)
888 {
889         unsigned long ret;
890         long err;
891
892         err = do_shmat(shmid, shmaddr, shmflg, &ret);
893         if (err)
894                 return err;
895         force_successful_syscall_return();
896         return (long)ret;
897 }
898
899 /*
900  * detach and kill segment if marked destroyed.
901  * The work is done in shm_close.
902  */
903 asmlinkage long sys_shmdt(char __user *shmaddr)
904 {
905         struct mm_struct *mm = current->mm;
906         struct vm_area_struct *vma, *next;
907         unsigned long addr = (unsigned long)shmaddr;
908         loff_t size = 0;
909         int retval = -EINVAL;
910
911         if (addr & ~PAGE_MASK)
912                 return retval;
913
914         down_write(&mm->mmap_sem);
915
916         /*
917          * This function tries to be smart and unmap shm segments that
918          * were modified by partial mlock or munmap calls:
919          * - It first determines the size of the shm segment that should be
920          *   unmapped: It searches for a vma that is backed by shm and that
921          *   started at address shmaddr. It records it's size and then unmaps
922          *   it.
923          * - Then it unmaps all shm vmas that started at shmaddr and that
924          *   are within the initially determined size.
925          * Errors from do_munmap are ignored: the function only fails if
926          * it's called with invalid parameters or if it's called to unmap
927          * a part of a vma. Both calls in this function are for full vmas,
928          * the parameters are directly copied from the vma itself and always
929          * valid - therefore do_munmap cannot fail. (famous last words?)
930          */
931         /*
932          * If it had been mremap()'d, the starting address would not
933          * match the usual checks anyway. So assume all vma's are
934          * above the starting address given.
935          */
936         vma = find_vma(mm, addr);
937
938         while (vma) {
939                 next = vma->vm_next;
940
941                 /*
942                  * Check if the starting address would match, i.e. it's
943                  * a fragment created by mprotect() and/or munmap(), or it
944                  * otherwise it starts at this address with no hassles.
945                  */
946                 if ((vma->vm_ops == &shm_vm_ops || is_vm_hugetlb_page(vma)) &&
947                         (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
948
949
950                         size = vma->vm_file->f_dentry->d_inode->i_size;
951                         do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
952                         /*
953                          * We discovered the size of the shm segment, so
954                          * break out of here and fall through to the next
955                          * loop that uses the size information to stop
956                          * searching for matching vma's.
957                          */
958                         retval = 0;
959                         vma = next;
960                         break;
961                 }
962                 vma = next;
963         }
964
965         /*
966          * We need look no further than the maximum address a fragment
967          * could possibly have landed at. Also cast things to loff_t to
968          * prevent overflows and make comparisions vs. equal-width types.
969          */
970         size = PAGE_ALIGN(size);
971         while (vma && (loff_t)(vma->vm_end - addr) <= size) {
972                 next = vma->vm_next;
973
974                 /* finding a matching vma now does not alter retval */
975                 if ((vma->vm_ops == &shm_vm_ops || is_vm_hugetlb_page(vma)) &&
976                         (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff)
977
978                         do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
979                 vma = next;
980         }
981
982         up_write(&mm->mmap_sem);
983         return retval;
984 }
985
986 #ifdef CONFIG_PROC_FS
987 static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
988 {
989         struct shmid_kernel *shp = it;
990         char *format;
991
992 #define SMALL_STRING "%10d %10d  %4o %10u %5u %5u  %5d %5u %5u %5u %5u %10lu %10lu %10lu\n"
993 #define BIG_STRING   "%10d %10d  %4o %21u %5u %5u  %5d %5u %5u %5u %5u %10lu %10lu %10lu\n"
994
995         if (sizeof(size_t) <= sizeof(int))
996                 format = SMALL_STRING;
997         else
998                 format = BIG_STRING;
999         return seq_printf(s, format,
1000                           shp->shm_perm.key,
1001                           shp->id,
1002                           shp->shm_perm.mode,
1003                           shp->shm_segsz,
1004                           shp->shm_cprid,
1005                           shp->shm_lprid,
1006                           is_file_hugepages(shp->shm_file) ? (file_count(shp->shm_file) - 1) : shp->shm_nattch,
1007                           shp->shm_perm.uid,
1008                           shp->shm_perm.gid,
1009                           shp->shm_perm.cuid,
1010                           shp->shm_perm.cgid,
1011                           shp->shm_atim,
1012                           shp->shm_dtim,
1013                           shp->shm_ctim);
1014 }
1015 #endif