1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/ipc/shm.c
4  * Copyright (C) 1992, 1993 Krishna Balasubramanian
5  *	 Many improvements/fixes by Bruno Haible.
6  * Replaced `struct shm_desc' by `struct vm_area_struct', July 1994.
7  * Fixed the shm swap deallocation (shm_unuse()), August 1998 Andrea Arcangeli.
8  *
9  * /proc/sysvipc/shm support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
10  * BIGMEM support, Andrea Arcangeli <andrea@suse.de>
11  * SMP thread shm, Jean-Luc Boyard <jean-luc.boyard@siemens.fr>
12  * HIGHMEM support, Ingo Molnar <mingo@redhat.com>
13  * Make shmmax, shmall, shmmni sysctl'able, Christoph Rohland <cr@sap.com>
14  * Shared /dev/zero support, Kanoj Sarcar <kanoj@sgi.com>
15  * Move the mm functionality over to mm/shmem.c, Christoph Rohland <cr@sap.com>
16  *
17  * support for audit of ipc object properties and permission changes
18  * Dustin Kirkland <dustin.kirkland@us.ibm.com>
19  *
20  * namespaces support
21  * OpenVZ, SWsoft Inc.
22  * Pavel Emelianov <xemul@openvz.org>
23  *
24  * Better ipc lock (kern_ipc_perm.lock) handling
25  * Davidlohr Bueso <davidlohr.bueso@hp.com>, June 2013.
26  */
27 
28 #include <linux/slab.h>
29 #include <linux/mm.h>
30 #include <linux/hugetlb.h>
31 #include <linux/shm.h>
32 #include <linux/init.h>
33 #include <linux/file.h>
34 #include <linux/mman.h>
35 #include <linux/shmem_fs.h>
36 #include <linux/security.h>
37 #include <linux/syscalls.h>
38 #include <linux/audit.h>
39 #include <linux/capability.h>
40 #include <linux/ptrace.h>
41 #include <linux/seq_file.h>
42 #include <linux/rwsem.h>
43 #include <linux/nsproxy.h>
44 #include <linux/mount.h>
45 #include <linux/ipc_namespace.h>
46 #include <linux/rhashtable.h>
47 
48 #include <linux/uaccess.h>
49 
50 #include "util.h"
51 
52 struct shmid_kernel /* private to the kernel */
53 {
54 	struct kern_ipc_perm	shm_perm;
55 	struct file		*shm_file;
56 	unsigned long		shm_nattch;
57 	unsigned long		shm_segsz;
58 	time64_t		shm_atim;
59 	time64_t		shm_dtim;
60 	time64_t		shm_ctim;
61 	struct pid		*shm_cprid;
62 	struct pid		*shm_lprid;
63 	struct ucounts		*mlock_ucounts;
64 
65 	/*
66 	 * The task created the shm object, for
67 	 * task_lock(shp->shm_creator)
68 	 */
69 	struct task_struct	*shm_creator;
70 
71 	/*
72 	 * List by creator. task_lock(->shm_creator) required for read/write.
73 	 * If list_empty(), then the creator is dead already.
74 	 */
75 	struct list_head	shm_clist;
76 	struct ipc_namespace	*ns;
77 } __randomize_layout;
78 
79 /* shm_mode upper byte flags */
80 #define SHM_DEST	01000	/* segment will be destroyed on last detach */
81 #define SHM_LOCKED	02000   /* segment will not be swapped */
82 
83 struct shm_file_data {
84 	int id;
85 	struct ipc_namespace *ns;
86 	struct file *file;
87 	const struct vm_operations_struct *vm_ops;
88 };
89 
90 #define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data))
91 
92 static const struct file_operations shm_file_operations;
93 static const struct vm_operations_struct shm_vm_ops;
94 
95 #define shm_ids(ns)	((ns)->ids[IPC_SHM_IDS])
96 
97 #define shm_unlock(shp)			\
98 	ipc_unlock(&(shp)->shm_perm)
99 
100 static int newseg(struct ipc_namespace *, struct ipc_params *);
101 static void shm_open(struct vm_area_struct *vma);
102 static void shm_close(struct vm_area_struct *vma);
103 static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp);
104 #ifdef CONFIG_PROC_FS
105 static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
106 #endif
107 
shm_init_ns(struct ipc_namespace * ns)108 void shm_init_ns(struct ipc_namespace *ns)
109 {
110 	ns->shm_ctlmax = SHMMAX;
111 	ns->shm_ctlall = SHMALL;
112 	ns->shm_ctlmni = SHMMNI;
113 	ns->shm_rmid_forced = 0;
114 	ns->shm_tot = 0;
115 	ipc_init_ids(&shm_ids(ns));
116 }
117 
118 /*
119  * Called with shm_ids.rwsem (writer) and the shp structure locked.
120  * Only shm_ids.rwsem remains locked on exit.
121  */
do_shm_rmid(struct ipc_namespace * ns,struct kern_ipc_perm * ipcp)122 static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
123 {
124 	struct shmid_kernel *shp;
125 
126 	shp = container_of(ipcp, struct shmid_kernel, shm_perm);
127 	WARN_ON(ns != shp->ns);
128 
129 	if (shp->shm_nattch) {
130 		shp->shm_perm.mode |= SHM_DEST;
131 		/* Do not find it any more */
132 		ipc_set_key_private(&shm_ids(ns), &shp->shm_perm);
133 		shm_unlock(shp);
134 	} else
135 		shm_destroy(ns, shp);
136 }
137 
138 #ifdef CONFIG_IPC_NS
shm_exit_ns(struct ipc_namespace * ns)139 void shm_exit_ns(struct ipc_namespace *ns)
140 {
141 	free_ipcs(ns, &shm_ids(ns), do_shm_rmid);
142 	idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr);
143 	rhashtable_destroy(&ns->ids[IPC_SHM_IDS].key_ht);
144 }
145 #endif
146 
ipc_ns_init(void)147 static int __init ipc_ns_init(void)
148 {
149 	shm_init_ns(&init_ipc_ns);
150 	return 0;
151 }
152 
153 pure_initcall(ipc_ns_init);
154 
shm_init(void)155 void __init shm_init(void)
156 {
157 	ipc_init_proc_interface("sysvipc/shm",
158 #if BITS_PER_LONG <= 32
159 				"       key      shmid perms       size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime        rss       swap\n",
160 #else
161 				"       key      shmid perms                  size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime                   rss                  swap\n",
162 #endif
163 				IPC_SHM_IDS, sysvipc_shm_proc_show);
164 }
165 
shm_obtain_object(struct ipc_namespace * ns,int id)166 static inline struct shmid_kernel *shm_obtain_object(struct ipc_namespace *ns, int id)
167 {
168 	struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&shm_ids(ns), id);
169 
170 	if (IS_ERR(ipcp))
171 		return ERR_CAST(ipcp);
172 
173 	return container_of(ipcp, struct shmid_kernel, shm_perm);
174 }
175 
shm_obtain_object_check(struct ipc_namespace * ns,int id)176 static inline struct shmid_kernel *shm_obtain_object_check(struct ipc_namespace *ns, int id)
177 {
178 	struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&shm_ids(ns), id);
179 
180 	if (IS_ERR(ipcp))
181 		return ERR_CAST(ipcp);
182 
183 	return container_of(ipcp, struct shmid_kernel, shm_perm);
184 }
185 
186 /*
187  * shm_lock_(check_) routines are called in the paths where the rwsem
188  * is not necessarily held.
189  */
shm_lock(struct ipc_namespace * ns,int id)190 static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
191 {
192 	struct kern_ipc_perm *ipcp;
193 
194 	rcu_read_lock();
195 	ipcp = ipc_obtain_object_idr(&shm_ids(ns), id);
196 	if (IS_ERR(ipcp))
197 		goto err;
198 
199 	ipc_lock_object(ipcp);
200 	/*
201 	 * ipc_rmid() may have already freed the ID while ipc_lock_object()
202 	 * was spinning: here verify that the structure is still valid.
203 	 * Upon races with RMID, return -EIDRM, thus indicating that
204 	 * the ID points to a removed identifier.
205 	 */
206 	if (ipc_valid_object(ipcp)) {
207 		/* return a locked ipc object upon success */
208 		return container_of(ipcp, struct shmid_kernel, shm_perm);
209 	}
210 
211 	ipc_unlock_object(ipcp);
212 	ipcp = ERR_PTR(-EIDRM);
213 err:
214 	rcu_read_unlock();
215 	/*
216 	 * Callers of shm_lock() must validate the status of the returned ipc
217 	 * object pointer and error out as appropriate.
218 	 */
219 	return ERR_CAST(ipcp);
220 }
221 
shm_lock_by_ptr(struct shmid_kernel * ipcp)222 static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp)
223 {
224 	rcu_read_lock();
225 	ipc_lock_object(&ipcp->shm_perm);
226 }
227 
shm_rcu_free(struct rcu_head * head)228 static void shm_rcu_free(struct rcu_head *head)
229 {
230 	struct kern_ipc_perm *ptr = container_of(head, struct kern_ipc_perm,
231 							rcu);
232 	struct shmid_kernel *shp = container_of(ptr, struct shmid_kernel,
233 							shm_perm);
234 	security_shm_free(&shp->shm_perm);
235 	kfree(shp);
236 }
237 
238 /*
239  * It has to be called with shp locked.
240  * It must be called before ipc_rmid()
241  */
shm_clist_rm(struct shmid_kernel * shp)242 static inline void shm_clist_rm(struct shmid_kernel *shp)
243 {
244 	struct task_struct *creator;
245 
246 	/* ensure that shm_creator does not disappear */
247 	rcu_read_lock();
248 
249 	/*
250 	 * A concurrent exit_shm may do a list_del_init() as well.
251 	 * Just do nothing if exit_shm already did the work
252 	 */
253 	if (!list_empty(&shp->shm_clist)) {
254 		/*
255 		 * shp->shm_creator is guaranteed to be valid *only*
256 		 * if shp->shm_clist is not empty.
257 		 */
258 		creator = shp->shm_creator;
259 
260 		task_lock(creator);
261 		/*
262 		 * list_del_init() is a nop if the entry was already removed
263 		 * from the list.
264 		 */
265 		list_del_init(&shp->shm_clist);
266 		task_unlock(creator);
267 	}
268 	rcu_read_unlock();
269 }
270 
shm_rmid(struct shmid_kernel * s)271 static inline void shm_rmid(struct shmid_kernel *s)
272 {
273 	shm_clist_rm(s);
274 	ipc_rmid(&shm_ids(s->ns), &s->shm_perm);
275 }
276 
277 
__shm_open(struct shm_file_data * sfd)278 static int __shm_open(struct shm_file_data *sfd)
279 {
280 	struct shmid_kernel *shp;
281 
282 	shp = shm_lock(sfd->ns, sfd->id);
283 
284 	if (IS_ERR(shp))
285 		return PTR_ERR(shp);
286 
287 	if (shp->shm_file != sfd->file) {
288 		/* ID was reused */
289 		shm_unlock(shp);
290 		return -EINVAL;
291 	}
292 
293 	shp->shm_atim = ktime_get_real_seconds();
294 	ipc_update_pid(&shp->shm_lprid, task_tgid(current));
295 	shp->shm_nattch++;
296 	shm_unlock(shp);
297 	return 0;
298 }
299 
300 /* This is called by fork, once for every shm attach. */
shm_open(struct vm_area_struct * vma)301 static void shm_open(struct vm_area_struct *vma)
302 {
303 	struct file *file = vma->vm_file;
304 	struct shm_file_data *sfd = shm_file_data(file);
305 	int err;
306 
307 	/* Always call underlying open if present */
308 	if (sfd->vm_ops->open)
309 		sfd->vm_ops->open(vma);
310 
311 	err = __shm_open(sfd);
312 	/*
313 	 * We raced in the idr lookup or with shm_destroy().
314 	 * Either way, the ID is busted.
315 	 */
316 	WARN_ON_ONCE(err);
317 }
318 
319 /*
320  * shm_destroy - free the struct shmid_kernel
321  *
322  * @ns: namespace
323  * @shp: struct to free
324  *
325  * It has to be called with shp and shm_ids.rwsem (writer) locked,
326  * but returns with shp unlocked and freed.
327  */
shm_destroy(struct ipc_namespace * ns,struct shmid_kernel * shp)328 static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
329 {
330 	struct file *shm_file;
331 
332 	shm_file = shp->shm_file;
333 	shp->shm_file = NULL;
334 	ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
335 	shm_rmid(shp);
336 	shm_unlock(shp);
337 	if (!is_file_hugepages(shm_file))
338 		shmem_lock(shm_file, 0, shp->mlock_ucounts);
339 	fput(shm_file);
340 	ipc_update_pid(&shp->shm_cprid, NULL);
341 	ipc_update_pid(&shp->shm_lprid, NULL);
342 	ipc_rcu_putref(&shp->shm_perm, shm_rcu_free);
343 }
344 
345 /*
346  * shm_may_destroy - identifies whether shm segment should be destroyed now
347  *
348  * Returns true if and only if there are no active users of the segment and
349  * one of the following is true:
350  *
351  * 1) shmctl(id, IPC_RMID, NULL) was called for this shp
352  *
353  * 2) sysctl kernel.shm_rmid_forced is set to 1.
354  */
shm_may_destroy(struct shmid_kernel * shp)355 static bool shm_may_destroy(struct shmid_kernel *shp)
356 {
357 	return (shp->shm_nattch == 0) &&
358 	       (shp->ns->shm_rmid_forced ||
359 		(shp->shm_perm.mode & SHM_DEST));
360 }
361 
362 /*
363  * remove the attach descriptor vma.
364  * free memory for segment if it is marked destroyed.
365  * The descriptor has already been removed from the current->mm->mmap list
366  * and will later be kfree()d.
367  */
__shm_close(struct shm_file_data * sfd)368 static void __shm_close(struct shm_file_data *sfd)
369 {
370 	struct shmid_kernel *shp;
371 	struct ipc_namespace *ns = sfd->ns;
372 
373 	down_write(&shm_ids(ns).rwsem);
374 	/* remove from the list of attaches of the shm segment */
375 	shp = shm_lock(ns, sfd->id);
376 
377 	/*
378 	 * We raced in the idr lookup or with shm_destroy().
379 	 * Either way, the ID is busted.
380 	 */
381 	if (WARN_ON_ONCE(IS_ERR(shp)))
382 		goto done; /* no-op */
383 
384 	ipc_update_pid(&shp->shm_lprid, task_tgid(current));
385 	shp->shm_dtim = ktime_get_real_seconds();
386 	shp->shm_nattch--;
387 	if (shm_may_destroy(shp))
388 		shm_destroy(ns, shp);
389 	else
390 		shm_unlock(shp);
391 done:
392 	up_write(&shm_ids(ns).rwsem);
393 }
394 
shm_close(struct vm_area_struct * vma)395 static void shm_close(struct vm_area_struct *vma)
396 {
397 	struct file *file = vma->vm_file;
398 	struct shm_file_data *sfd = shm_file_data(file);
399 
400 	/* Always call underlying close if present */
401 	if (sfd->vm_ops->close)
402 		sfd->vm_ops->close(vma);
403 
404 	__shm_close(sfd);
405 }
406 
407 /* Called with ns->shm_ids(ns).rwsem locked */
shm_try_destroy_orphaned(int id,void * p,void * data)408 static int shm_try_destroy_orphaned(int id, void *p, void *data)
409 {
410 	struct ipc_namespace *ns = data;
411 	struct kern_ipc_perm *ipcp = p;
412 	struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm);
413 
414 	/*
415 	 * We want to destroy segments without users and with already
416 	 * exit'ed originating process.
417 	 *
418 	 * As shp->* are changed under rwsem, it's safe to skip shp locking.
419 	 */
420 	if (!list_empty(&shp->shm_clist))
421 		return 0;
422 
423 	if (shm_may_destroy(shp)) {
424 		shm_lock_by_ptr(shp);
425 		shm_destroy(ns, shp);
426 	}
427 	return 0;
428 }
429 
shm_destroy_orphaned(struct ipc_namespace * ns)430 void shm_destroy_orphaned(struct ipc_namespace *ns)
431 {
432 	down_write(&shm_ids(ns).rwsem);
433 	if (shm_ids(ns).in_use)
434 		idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns);
435 	up_write(&shm_ids(ns).rwsem);
436 }
437 
438 /* Locking assumes this will only be called with task == current */
exit_shm(struct task_struct * task)439 void exit_shm(struct task_struct *task)
440 {
441 	for (;;) {
442 		struct shmid_kernel *shp;
443 		struct ipc_namespace *ns;
444 
445 		task_lock(task);
446 
447 		if (list_empty(&task->sysvshm.shm_clist)) {
448 			task_unlock(task);
449 			break;
450 		}
451 
452 		shp = list_first_entry(&task->sysvshm.shm_clist, struct shmid_kernel,
453 				shm_clist);
454 
455 		/*
456 		 * 1) Get pointer to the ipc namespace. It is worth to say
457 		 * that this pointer is guaranteed to be valid because
458 		 * shp lifetime is always shorter than namespace lifetime
459 		 * in which shp lives.
460 		 * We taken task_lock it means that shp won't be freed.
461 		 */
462 		ns = shp->ns;
463 
464 		/*
465 		 * 2) If kernel.shm_rmid_forced is not set then only keep track of
466 		 * which shmids are orphaned, so that a later set of the sysctl
467 		 * can clean them up.
468 		 */
469 		if (!ns->shm_rmid_forced)
470 			goto unlink_continue;
471 
472 		/*
473 		 * 3) get a reference to the namespace.
474 		 *    The refcount could be already 0. If it is 0, then
475 		 *    the shm objects will be free by free_ipc_work().
476 		 */
477 		ns = get_ipc_ns_not_zero(ns);
478 		if (!ns) {
479 unlink_continue:
480 			list_del_init(&shp->shm_clist);
481 			task_unlock(task);
482 			continue;
483 		}
484 
485 		/*
486 		 * 4) get a reference to shp.
487 		 *   This cannot fail: shm_clist_rm() is called before
488 		 *   ipc_rmid(), thus the refcount cannot be 0.
489 		 */
490 		WARN_ON(!ipc_rcu_getref(&shp->shm_perm));
491 
492 		/*
493 		 * 5) unlink the shm segment from the list of segments
494 		 *    created by current.
495 		 *    This must be done last. After unlinking,
496 		 *    only the refcounts obtained above prevent IPC_RMID
497 		 *    from destroying the segment or the namespace.
498 		 */
499 		list_del_init(&shp->shm_clist);
500 
501 		task_unlock(task);
502 
503 		/*
504 		 * 6) we have all references
505 		 *    Thus lock & if needed destroy shp.
506 		 */
507 		down_write(&shm_ids(ns).rwsem);
508 		shm_lock_by_ptr(shp);
509 		/*
510 		 * rcu_read_lock was implicitly taken in shm_lock_by_ptr, it's
511 		 * safe to call ipc_rcu_putref here
512 		 */
513 		ipc_rcu_putref(&shp->shm_perm, shm_rcu_free);
514 
515 		if (ipc_valid_object(&shp->shm_perm)) {
516 			if (shm_may_destroy(shp))
517 				shm_destroy(ns, shp);
518 			else
519 				shm_unlock(shp);
520 		} else {
521 			/*
522 			 * Someone else deleted the shp from namespace
523 			 * idr/kht while we have waited.
524 			 * Just unlock and continue.
525 			 */
526 			shm_unlock(shp);
527 		}
528 
529 		up_write(&shm_ids(ns).rwsem);
530 		put_ipc_ns(ns); /* paired with get_ipc_ns_not_zero */
531 	}
532 }
533 
shm_fault(struct vm_fault * vmf)534 static vm_fault_t shm_fault(struct vm_fault *vmf)
535 {
536 	struct file *file = vmf->vma->vm_file;
537 	struct shm_file_data *sfd = shm_file_data(file);
538 
539 	return sfd->vm_ops->fault(vmf);
540 }
541 
shm_may_split(struct vm_area_struct * vma,unsigned long addr)542 static int shm_may_split(struct vm_area_struct *vma, unsigned long addr)
543 {
544 	struct file *file = vma->vm_file;
545 	struct shm_file_data *sfd = shm_file_data(file);
546 
547 	if (sfd->vm_ops->may_split)
548 		return sfd->vm_ops->may_split(vma, addr);
549 
550 	return 0;
551 }
552 
shm_pagesize(struct vm_area_struct * vma)553 static unsigned long shm_pagesize(struct vm_area_struct *vma)
554 {
555 	struct file *file = vma->vm_file;
556 	struct shm_file_data *sfd = shm_file_data(file);
557 
558 	if (sfd->vm_ops->pagesize)
559 		return sfd->vm_ops->pagesize(vma);
560 
561 	return PAGE_SIZE;
562 }
563 
564 #ifdef CONFIG_NUMA
shm_set_policy(struct vm_area_struct * vma,struct mempolicy * new)565 static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
566 {
567 	struct file *file = vma->vm_file;
568 	struct shm_file_data *sfd = shm_file_data(file);
569 	int err = 0;
570 
571 	if (sfd->vm_ops->set_policy)
572 		err = sfd->vm_ops->set_policy(vma, new);
573 	return err;
574 }
575 
shm_get_policy(struct vm_area_struct * vma,unsigned long addr)576 static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
577 					unsigned long addr)
578 {
579 	struct file *file = vma->vm_file;
580 	struct shm_file_data *sfd = shm_file_data(file);
581 	struct mempolicy *pol = NULL;
582 
583 	if (sfd->vm_ops->get_policy)
584 		pol = sfd->vm_ops->get_policy(vma, addr);
585 	else if (vma->vm_policy)
586 		pol = vma->vm_policy;
587 
588 	return pol;
589 }
590 #endif
591 
shm_mmap(struct file * file,struct vm_area_struct * vma)592 static int shm_mmap(struct file *file, struct vm_area_struct *vma)
593 {
594 	struct shm_file_data *sfd = shm_file_data(file);
595 	int ret;
596 
597 	/*
598 	 * In case of remap_file_pages() emulation, the file can represent an
599 	 * IPC ID that was removed, and possibly even reused by another shm
600 	 * segment already.  Propagate this case as an error to caller.
601 	 */
602 	ret = __shm_open(sfd);
603 	if (ret)
604 		return ret;
605 
606 	ret = call_mmap(sfd->file, vma);
607 	if (ret) {
608 		__shm_close(sfd);
609 		return ret;
610 	}
611 	sfd->vm_ops = vma->vm_ops;
612 #ifdef CONFIG_MMU
613 	WARN_ON(!sfd->vm_ops->fault);
614 #endif
615 	vma->vm_ops = &shm_vm_ops;
616 	return 0;
617 }
618 
shm_release(struct inode * ino,struct file * file)619 static int shm_release(struct inode *ino, struct file *file)
620 {
621 	struct shm_file_data *sfd = shm_file_data(file);
622 
623 	put_ipc_ns(sfd->ns);
624 	fput(sfd->file);
625 	shm_file_data(file) = NULL;
626 	kfree(sfd);
627 	return 0;
628 }
629 
shm_fsync(struct file * file,loff_t start,loff_t end,int datasync)630 static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
631 {
632 	struct shm_file_data *sfd = shm_file_data(file);
633 
634 	if (!sfd->file->f_op->fsync)
635 		return -EINVAL;
636 	return sfd->file->f_op->fsync(sfd->file, start, end, datasync);
637 }
638 
shm_fallocate(struct file * file,int mode,loff_t offset,loff_t len)639 static long shm_fallocate(struct file *file, int mode, loff_t offset,
640 			  loff_t len)
641 {
642 	struct shm_file_data *sfd = shm_file_data(file);
643 
644 	if (!sfd->file->f_op->fallocate)
645 		return -EOPNOTSUPP;
646 	return sfd->file->f_op->fallocate(file, mode, offset, len);
647 }
648 
shm_get_unmapped_area(struct file * file,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)649 static unsigned long shm_get_unmapped_area(struct file *file,
650 	unsigned long addr, unsigned long len, unsigned long pgoff,
651 	unsigned long flags)
652 {
653 	struct shm_file_data *sfd = shm_file_data(file);
654 
655 	return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len,
656 						pgoff, flags);
657 }
658 
659 static const struct file_operations shm_file_operations = {
660 	.mmap		= shm_mmap,
661 	.fsync		= shm_fsync,
662 	.release	= shm_release,
663 	.get_unmapped_area	= shm_get_unmapped_area,
664 	.llseek		= noop_llseek,
665 	.fallocate	= shm_fallocate,
666 };
667 
668 /*
669  * shm_file_operations_huge is now identical to shm_file_operations,
670  * but we keep it distinct for the sake of is_file_shm_hugepages().
671  */
672 static const struct file_operations shm_file_operations_huge = {
673 	.mmap		= shm_mmap,
674 	.fsync		= shm_fsync,
675 	.release	= shm_release,
676 	.get_unmapped_area	= shm_get_unmapped_area,
677 	.llseek		= noop_llseek,
678 	.fallocate	= shm_fallocate,
679 };
680 
is_file_shm_hugepages(struct file * file)681 bool is_file_shm_hugepages(struct file *file)
682 {
683 	return file->f_op == &shm_file_operations_huge;
684 }
685 
686 static const struct vm_operations_struct shm_vm_ops = {
687 	.open	= shm_open,	/* callback for a new vm-area open */
688 	.close	= shm_close,	/* callback for when the vm-area is released */
689 	.fault	= shm_fault,
690 	.may_split = shm_may_split,
691 	.pagesize = shm_pagesize,
692 #if defined(CONFIG_NUMA)
693 	.set_policy = shm_set_policy,
694 	.get_policy = shm_get_policy,
695 #endif
696 };
697 
698 /**
699  * newseg - Create a new shared memory segment
700  * @ns: namespace
701  * @params: ptr to the structure that contains key, size and shmflg
702  *
703  * Called with shm_ids.rwsem held as a writer.
704  */
newseg(struct ipc_namespace * ns,struct ipc_params * params)705 static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
706 {
707 	key_t key = params->key;
708 	int shmflg = params->flg;
709 	size_t size = params->u.size;
710 	int error;
711 	struct shmid_kernel *shp;
712 	size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
713 	struct file *file;
714 	char name[13];
715 	vm_flags_t acctflag = 0;
716 
717 	if (size < SHMMIN || size > ns->shm_ctlmax)
718 		return -EINVAL;
719 
720 	if (numpages << PAGE_SHIFT < size)
721 		return -ENOSPC;
722 
723 	if (ns->shm_tot + numpages < ns->shm_tot ||
724 			ns->shm_tot + numpages > ns->shm_ctlall)
725 		return -ENOSPC;
726 
727 	shp = kmalloc(sizeof(*shp), GFP_KERNEL_ACCOUNT);
728 	if (unlikely(!shp))
729 		return -ENOMEM;
730 
731 	shp->shm_perm.key = key;
732 	shp->shm_perm.mode = (shmflg & S_IRWXUGO);
733 	shp->mlock_ucounts = NULL;
734 
735 	shp->shm_perm.security = NULL;
736 	error = security_shm_alloc(&shp->shm_perm);
737 	if (error) {
738 		kfree(shp);
739 		return error;
740 	}
741 
742 	sprintf(name, "SYSV%08x", key);
743 	if (shmflg & SHM_HUGETLB) {
744 		struct hstate *hs;
745 		size_t hugesize;
746 
747 		hs = hstate_sizelog((shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
748 		if (!hs) {
749 			error = -EINVAL;
750 			goto no_file;
751 		}
752 		hugesize = ALIGN(size, huge_page_size(hs));
753 
754 		/* hugetlb_file_setup applies strict accounting */
755 		if (shmflg & SHM_NORESERVE)
756 			acctflag = VM_NORESERVE;
757 		file = hugetlb_file_setup(name, hugesize, acctflag,
758 				HUGETLB_SHMFS_INODE, (shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
759 	} else {
760 		/*
761 		 * Do not allow no accounting for OVERCOMMIT_NEVER, even
762 		 * if it's asked for.
763 		 */
764 		if  ((shmflg & SHM_NORESERVE) &&
765 				sysctl_overcommit_memory != OVERCOMMIT_NEVER)
766 			acctflag = VM_NORESERVE;
767 		file = shmem_kernel_file_setup(name, size, acctflag);
768 	}
769 	error = PTR_ERR(file);
770 	if (IS_ERR(file))
771 		goto no_file;
772 
773 	shp->shm_cprid = get_pid(task_tgid(current));
774 	shp->shm_lprid = NULL;
775 	shp->shm_atim = shp->shm_dtim = 0;
776 	shp->shm_ctim = ktime_get_real_seconds();
777 	shp->shm_segsz = size;
778 	shp->shm_nattch = 0;
779 	shp->shm_file = file;
780 	shp->shm_creator = current;
781 
782 	/* ipc_addid() locks shp upon success. */
783 	error = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
784 	if (error < 0)
785 		goto no_id;
786 
787 	shp->ns = ns;
788 
789 	task_lock(current);
790 	list_add(&shp->shm_clist, &current->sysvshm.shm_clist);
791 	task_unlock(current);
792 
793 	/*
794 	 * shmid gets reported as "inode#" in /proc/pid/maps.
795 	 * proc-ps tools use this. Changing this will break them.
796 	 */
797 	file_inode(file)->i_ino = shp->shm_perm.id;
798 
799 	ns->shm_tot += numpages;
800 	error = shp->shm_perm.id;
801 
802 	ipc_unlock_object(&shp->shm_perm);
803 	rcu_read_unlock();
804 	return error;
805 
806 no_id:
807 	ipc_update_pid(&shp->shm_cprid, NULL);
808 	ipc_update_pid(&shp->shm_lprid, NULL);
809 	fput(file);
810 	ipc_rcu_putref(&shp->shm_perm, shm_rcu_free);
811 	return error;
812 no_file:
813 	call_rcu(&shp->shm_perm.rcu, shm_rcu_free);
814 	return error;
815 }
816 
817 /*
818  * Called with shm_ids.rwsem and ipcp locked.
819  */
shm_more_checks(struct kern_ipc_perm * ipcp,struct ipc_params * params)820 static int shm_more_checks(struct kern_ipc_perm *ipcp, struct ipc_params *params)
821 {
822 	struct shmid_kernel *shp;
823 
824 	shp = container_of(ipcp, struct shmid_kernel, shm_perm);
825 	if (shp->shm_segsz < params->u.size)
826 		return -EINVAL;
827 
828 	return 0;
829 }
830 
ksys_shmget(key_t key,size_t size,int shmflg)831 long ksys_shmget(key_t key, size_t size, int shmflg)
832 {
833 	struct ipc_namespace *ns;
834 	static const struct ipc_ops shm_ops = {
835 		.getnew = newseg,
836 		.associate = security_shm_associate,
837 		.more_checks = shm_more_checks,
838 	};
839 	struct ipc_params shm_params;
840 
841 	ns = current->nsproxy->ipc_ns;
842 
843 	shm_params.key = key;
844 	shm_params.flg = shmflg;
845 	shm_params.u.size = size;
846 
847 	return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params);
848 }
849 
SYSCALL_DEFINE3(shmget,key_t,key,size_t,size,int,shmflg)850 SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
851 {
852 	return ksys_shmget(key, size, shmflg);
853 }
854 
copy_shmid_to_user(void __user * buf,struct shmid64_ds * in,int version)855 static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
856 {
857 	switch (version) {
858 	case IPC_64:
859 		return copy_to_user(buf, in, sizeof(*in));
860 	case IPC_OLD:
861 	    {
862 		struct shmid_ds out;
863 
864 		memset(&out, 0, sizeof(out));
865 		ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
866 		out.shm_segsz	= in->shm_segsz;
867 		out.shm_atime	= in->shm_atime;
868 		out.shm_dtime	= in->shm_dtime;
869 		out.shm_ctime	= in->shm_ctime;
870 		out.shm_cpid	= in->shm_cpid;
871 		out.shm_lpid	= in->shm_lpid;
872 		out.shm_nattch	= in->shm_nattch;
873 
874 		return copy_to_user(buf, &out, sizeof(out));
875 	    }
876 	default:
877 		return -EINVAL;
878 	}
879 }
880 
881 static inline unsigned long
copy_shmid_from_user(struct shmid64_ds * out,void __user * buf,int version)882 copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
883 {
884 	switch (version) {
885 	case IPC_64:
886 		if (copy_from_user(out, buf, sizeof(*out)))
887 			return -EFAULT;
888 		return 0;
889 	case IPC_OLD:
890 	    {
891 		struct shmid_ds tbuf_old;
892 
893 		if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
894 			return -EFAULT;
895 
896 		out->shm_perm.uid	= tbuf_old.shm_perm.uid;
897 		out->shm_perm.gid	= tbuf_old.shm_perm.gid;
898 		out->shm_perm.mode	= tbuf_old.shm_perm.mode;
899 
900 		return 0;
901 	    }
902 	default:
903 		return -EINVAL;
904 	}
905 }
906 
copy_shminfo_to_user(void __user * buf,struct shminfo64 * in,int version)907 static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
908 {
909 	switch (version) {
910 	case IPC_64:
911 		return copy_to_user(buf, in, sizeof(*in));
912 	case IPC_OLD:
913 	    {
914 		struct shminfo out;
915 
916 		if (in->shmmax > INT_MAX)
917 			out.shmmax = INT_MAX;
918 		else
919 			out.shmmax = (int)in->shmmax;
920 
921 		out.shmmin	= in->shmmin;
922 		out.shmmni	= in->shmmni;
923 		out.shmseg	= in->shmseg;
924 		out.shmall	= in->shmall;
925 
926 		return copy_to_user(buf, &out, sizeof(out));
927 	    }
928 	default:
929 		return -EINVAL;
930 	}
931 }
932 
933 /*
934  * Calculate and add used RSS and swap pages of a shm.
935  * Called with shm_ids.rwsem held as a reader
936  */
shm_add_rss_swap(struct shmid_kernel * shp,unsigned long * rss_add,unsigned long * swp_add)937 static void shm_add_rss_swap(struct shmid_kernel *shp,
938 	unsigned long *rss_add, unsigned long *swp_add)
939 {
940 	struct inode *inode;
941 
942 	inode = file_inode(shp->shm_file);
943 
944 	if (is_file_hugepages(shp->shm_file)) {
945 		struct address_space *mapping = inode->i_mapping;
946 		struct hstate *h = hstate_file(shp->shm_file);
947 		*rss_add += pages_per_huge_page(h) * mapping->nrpages;
948 	} else {
949 #ifdef CONFIG_SHMEM
950 		struct shmem_inode_info *info = SHMEM_I(inode);
951 
952 		spin_lock_irq(&info->lock);
953 		*rss_add += inode->i_mapping->nrpages;
954 		*swp_add += info->swapped;
955 		spin_unlock_irq(&info->lock);
956 #else
957 		*rss_add += inode->i_mapping->nrpages;
958 #endif
959 	}
960 }
961 
962 /*
963  * Called with shm_ids.rwsem held as a reader
964  */
shm_get_stat(struct ipc_namespace * ns,unsigned long * rss,unsigned long * swp)965 static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
966 		unsigned long *swp)
967 {
968 	int next_id;
969 	int total, in_use;
970 
971 	*rss = 0;
972 	*swp = 0;
973 
974 	in_use = shm_ids(ns).in_use;
975 
976 	for (total = 0, next_id = 0; total < in_use; next_id++) {
977 		struct kern_ipc_perm *ipc;
978 		struct shmid_kernel *shp;
979 
980 		ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
981 		if (ipc == NULL)
982 			continue;
983 		shp = container_of(ipc, struct shmid_kernel, shm_perm);
984 
985 		shm_add_rss_swap(shp, rss, swp);
986 
987 		total++;
988 	}
989 }
990 
991 /*
992  * This function handles some shmctl commands which require the rwsem
993  * to be held in write mode.
994  * NOTE: no locks must be held, the rwsem is taken inside this function.
995  */
shmctl_down(struct ipc_namespace * ns,int shmid,int cmd,struct shmid64_ds * shmid64)996 static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
997 		       struct shmid64_ds *shmid64)
998 {
999 	struct kern_ipc_perm *ipcp;
1000 	struct shmid_kernel *shp;
1001 	int err;
1002 
1003 	down_write(&shm_ids(ns).rwsem);
1004 	rcu_read_lock();
1005 
1006 	ipcp = ipcctl_obtain_check(ns, &shm_ids(ns), shmid, cmd,
1007 				      &shmid64->shm_perm, 0);
1008 	if (IS_ERR(ipcp)) {
1009 		err = PTR_ERR(ipcp);
1010 		goto out_unlock1;
1011 	}
1012 
1013 	shp = container_of(ipcp, struct shmid_kernel, shm_perm);
1014 
1015 	err = security_shm_shmctl(&shp->shm_perm, cmd);
1016 	if (err)
1017 		goto out_unlock1;
1018 
1019 	switch (cmd) {
1020 	case IPC_RMID:
1021 		ipc_lock_object(&shp->shm_perm);
1022 		/* do_shm_rmid unlocks the ipc object and rcu */
1023 		do_shm_rmid(ns, ipcp);
1024 		goto out_up;
1025 	case IPC_SET:
1026 		ipc_lock_object(&shp->shm_perm);
1027 		err = ipc_update_perm(&shmid64->shm_perm, ipcp);
1028 		if (err)
1029 			goto out_unlock0;
1030 		shp->shm_ctim = ktime_get_real_seconds();
1031 		break;
1032 	default:
1033 		err = -EINVAL;
1034 		goto out_unlock1;
1035 	}
1036 
1037 out_unlock0:
1038 	ipc_unlock_object(&shp->shm_perm);
1039 out_unlock1:
1040 	rcu_read_unlock();
1041 out_up:
1042 	up_write(&shm_ids(ns).rwsem);
1043 	return err;
1044 }
1045 
shmctl_ipc_info(struct ipc_namespace * ns,struct shminfo64 * shminfo)1046 static int shmctl_ipc_info(struct ipc_namespace *ns,
1047 			   struct shminfo64 *shminfo)
1048 {
1049 	int err = security_shm_shmctl(NULL, IPC_INFO);
1050 	if (!err) {
1051 		memset(shminfo, 0, sizeof(*shminfo));
1052 		shminfo->shmmni = shminfo->shmseg = ns->shm_ctlmni;
1053 		shminfo->shmmax = ns->shm_ctlmax;
1054 		shminfo->shmall = ns->shm_ctlall;
1055 		shminfo->shmmin = SHMMIN;
1056 		down_read(&shm_ids(ns).rwsem);
1057 		err = ipc_get_maxidx(&shm_ids(ns));
1058 		up_read(&shm_ids(ns).rwsem);
1059 		if (err < 0)
1060 			err = 0;
1061 	}
1062 	return err;
1063 }
1064 
shmctl_shm_info(struct ipc_namespace * ns,struct shm_info * shm_info)1065 static int shmctl_shm_info(struct ipc_namespace *ns,
1066 			   struct shm_info *shm_info)
1067 {
1068 	int err = security_shm_shmctl(NULL, SHM_INFO);
1069 	if (!err) {
1070 		memset(shm_info, 0, sizeof(*shm_info));
1071 		down_read(&shm_ids(ns).rwsem);
1072 		shm_info->used_ids = shm_ids(ns).in_use;
1073 		shm_get_stat(ns, &shm_info->shm_rss, &shm_info->shm_swp);
1074 		shm_info->shm_tot = ns->shm_tot;
1075 		shm_info->swap_attempts = 0;
1076 		shm_info->swap_successes = 0;
1077 		err = ipc_get_maxidx(&shm_ids(ns));
1078 		up_read(&shm_ids(ns).rwsem);
1079 		if (err < 0)
1080 			err = 0;
1081 	}
1082 	return err;
1083 }
1084 
shmctl_stat(struct ipc_namespace * ns,int shmid,int cmd,struct shmid64_ds * tbuf)1085 static int shmctl_stat(struct ipc_namespace *ns, int shmid,
1086 			int cmd, struct shmid64_ds *tbuf)
1087 {
1088 	struct shmid_kernel *shp;
1089 	int err;
1090 
1091 	memset(tbuf, 0, sizeof(*tbuf));
1092 
1093 	rcu_read_lock();
1094 	if (cmd == SHM_STAT || cmd == SHM_STAT_ANY) {
1095 		shp = shm_obtain_object(ns, shmid);
1096 		if (IS_ERR(shp)) {
1097 			err = PTR_ERR(shp);
1098 			goto out_unlock;
1099 		}
1100 	} else { /* IPC_STAT */
1101 		shp = shm_obtain_object_check(ns, shmid);
1102 		if (IS_ERR(shp)) {
1103 			err = PTR_ERR(shp);
1104 			goto out_unlock;
1105 		}
1106 	}
1107 
1108 	/*
1109 	 * Semantically SHM_STAT_ANY ought to be identical to
1110 	 * that functionality provided by the /proc/sysvipc/
1111 	 * interface. As such, only audit these calls and
1112 	 * do not do traditional S_IRUGO permission checks on
1113 	 * the ipc object.
1114 	 */
1115 	if (cmd == SHM_STAT_ANY)
1116 		audit_ipc_obj(&shp->shm_perm);
1117 	else {
1118 		err = -EACCES;
1119 		if (ipcperms(ns, &shp->shm_perm, S_IRUGO))
1120 			goto out_unlock;
1121 	}
1122 
1123 	err = security_shm_shmctl(&shp->shm_perm, cmd);
1124 	if (err)
1125 		goto out_unlock;
1126 
1127 	ipc_lock_object(&shp->shm_perm);
1128 
1129 	if (!ipc_valid_object(&shp->shm_perm)) {
1130 		ipc_unlock_object(&shp->shm_perm);
1131 		err = -EIDRM;
1132 		goto out_unlock;
1133 	}
1134 
1135 	kernel_to_ipc64_perm(&shp->shm_perm, &tbuf->shm_perm);
1136 	tbuf->shm_segsz	= shp->shm_segsz;
1137 	tbuf->shm_atime	= shp->shm_atim;
1138 	tbuf->shm_dtime	= shp->shm_dtim;
1139 	tbuf->shm_ctime	= shp->shm_ctim;
1140 #ifndef CONFIG_64BIT
1141 	tbuf->shm_atime_high = shp->shm_atim >> 32;
1142 	tbuf->shm_dtime_high = shp->shm_dtim >> 32;
1143 	tbuf->shm_ctime_high = shp->shm_ctim >> 32;
1144 #endif
1145 	tbuf->shm_cpid	= pid_vnr(shp->shm_cprid);
1146 	tbuf->shm_lpid	= pid_vnr(shp->shm_lprid);
1147 	tbuf->shm_nattch = shp->shm_nattch;
1148 
1149 	if (cmd == IPC_STAT) {
1150 		/*
1151 		 * As defined in SUS:
1152 		 * Return 0 on success
1153 		 */
1154 		err = 0;
1155 	} else {
1156 		/*
1157 		 * SHM_STAT and SHM_STAT_ANY (both Linux specific)
1158 		 * Return the full id, including the sequence number
1159 		 */
1160 		err = shp->shm_perm.id;
1161 	}
1162 
1163 	ipc_unlock_object(&shp->shm_perm);
1164 out_unlock:
1165 	rcu_read_unlock();
1166 	return err;
1167 }
1168 
shmctl_do_lock(struct ipc_namespace * ns,int shmid,int cmd)1169 static int shmctl_do_lock(struct ipc_namespace *ns, int shmid, int cmd)
1170 {
1171 	struct shmid_kernel *shp;
1172 	struct file *shm_file;
1173 	int err;
1174 
1175 	rcu_read_lock();
1176 	shp = shm_obtain_object_check(ns, shmid);
1177 	if (IS_ERR(shp)) {
1178 		err = PTR_ERR(shp);
1179 		goto out_unlock1;
1180 	}
1181 
1182 	audit_ipc_obj(&(shp->shm_perm));
1183 	err = security_shm_shmctl(&shp->shm_perm, cmd);
1184 	if (err)
1185 		goto out_unlock1;
1186 
1187 	ipc_lock_object(&shp->shm_perm);
1188 
1189 	/* check if shm_destroy() is tearing down shp */
1190 	if (!ipc_valid_object(&shp->shm_perm)) {
1191 		err = -EIDRM;
1192 		goto out_unlock0;
1193 	}
1194 
1195 	if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
1196 		kuid_t euid = current_euid();
1197 
1198 		if (!uid_eq(euid, shp->shm_perm.uid) &&
1199 		    !uid_eq(euid, shp->shm_perm.cuid)) {
1200 			err = -EPERM;
1201 			goto out_unlock0;
1202 		}
1203 		if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) {
1204 			err = -EPERM;
1205 			goto out_unlock0;
1206 		}
1207 	}
1208 
1209 	shm_file = shp->shm_file;
1210 	if (is_file_hugepages(shm_file))
1211 		goto out_unlock0;
1212 
1213 	if (cmd == SHM_LOCK) {
1214 		struct ucounts *ucounts = current_ucounts();
1215 
1216 		err = shmem_lock(shm_file, 1, ucounts);
1217 		if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
1218 			shp->shm_perm.mode |= SHM_LOCKED;
1219 			shp->mlock_ucounts = ucounts;
1220 		}
1221 		goto out_unlock0;
1222 	}
1223 
1224 	/* SHM_UNLOCK */
1225 	if (!(shp->shm_perm.mode & SHM_LOCKED))
1226 		goto out_unlock0;
1227 	shmem_lock(shm_file, 0, shp->mlock_ucounts);
1228 	shp->shm_perm.mode &= ~SHM_LOCKED;
1229 	shp->mlock_ucounts = NULL;
1230 	get_file(shm_file);
1231 	ipc_unlock_object(&shp->shm_perm);
1232 	rcu_read_unlock();
1233 	shmem_unlock_mapping(shm_file->f_mapping);
1234 
1235 	fput(shm_file);
1236 	return err;
1237 
1238 out_unlock0:
1239 	ipc_unlock_object(&shp->shm_perm);
1240 out_unlock1:
1241 	rcu_read_unlock();
1242 	return err;
1243 }
1244 
ksys_shmctl(int shmid,int cmd,struct shmid_ds __user * buf,int version)1245 static long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf, int version)
1246 {
1247 	int err;
1248 	struct ipc_namespace *ns;
1249 	struct shmid64_ds sem64;
1250 
1251 	if (cmd < 0 || shmid < 0)
1252 		return -EINVAL;
1253 
1254 	ns = current->nsproxy->ipc_ns;
1255 
1256 	switch (cmd) {
1257 	case IPC_INFO: {
1258 		struct shminfo64 shminfo;
1259 		err = shmctl_ipc_info(ns, &shminfo);
1260 		if (err < 0)
1261 			return err;
1262 		if (copy_shminfo_to_user(buf, &shminfo, version))
1263 			err = -EFAULT;
1264 		return err;
1265 	}
1266 	case SHM_INFO: {
1267 		struct shm_info shm_info;
1268 		err = shmctl_shm_info(ns, &shm_info);
1269 		if (err < 0)
1270 			return err;
1271 		if (copy_to_user(buf, &shm_info, sizeof(shm_info)))
1272 			err = -EFAULT;
1273 		return err;
1274 	}
1275 	case SHM_STAT:
1276 	case SHM_STAT_ANY:
1277 	case IPC_STAT: {
1278 		err = shmctl_stat(ns, shmid, cmd, &sem64);
1279 		if (err < 0)
1280 			return err;
1281 		if (copy_shmid_to_user(buf, &sem64, version))
1282 			err = -EFAULT;
1283 		return err;
1284 	}
1285 	case IPC_SET:
1286 		if (copy_shmid_from_user(&sem64, buf, version))
1287 			return -EFAULT;
1288 		fallthrough;
1289 	case IPC_RMID:
1290 		return shmctl_down(ns, shmid, cmd, &sem64);
1291 	case SHM_LOCK:
1292 	case SHM_UNLOCK:
1293 		return shmctl_do_lock(ns, shmid, cmd);
1294 	default:
1295 		return -EINVAL;
1296 	}
1297 }
1298 
SYSCALL_DEFINE3(shmctl,int,shmid,int,cmd,struct shmid_ds __user *,buf)1299 SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
1300 {
1301 	return ksys_shmctl(shmid, cmd, buf, IPC_64);
1302 }
1303 
1304 #ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
ksys_old_shmctl(int shmid,int cmd,struct shmid_ds __user * buf)1305 long ksys_old_shmctl(int shmid, int cmd, struct shmid_ds __user *buf)
1306 {
1307 	int version = ipc_parse_version(&cmd);
1308 
1309 	return ksys_shmctl(shmid, cmd, buf, version);
1310 }
1311 
SYSCALL_DEFINE3(old_shmctl,int,shmid,int,cmd,struct shmid_ds __user *,buf)1312 SYSCALL_DEFINE3(old_shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
1313 {
1314 	return ksys_old_shmctl(shmid, cmd, buf);
1315 }
1316 #endif
1317 
1318 #ifdef CONFIG_COMPAT
1319 
1320 struct compat_shmid_ds {
1321 	struct compat_ipc_perm shm_perm;
1322 	int shm_segsz;
1323 	old_time32_t shm_atime;
1324 	old_time32_t shm_dtime;
1325 	old_time32_t shm_ctime;
1326 	compat_ipc_pid_t shm_cpid;
1327 	compat_ipc_pid_t shm_lpid;
1328 	unsigned short shm_nattch;
1329 	unsigned short shm_unused;
1330 	compat_uptr_t shm_unused2;
1331 	compat_uptr_t shm_unused3;
1332 };
1333 
1334 struct compat_shminfo64 {
1335 	compat_ulong_t shmmax;
1336 	compat_ulong_t shmmin;
1337 	compat_ulong_t shmmni;
1338 	compat_ulong_t shmseg;
1339 	compat_ulong_t shmall;
1340 	compat_ulong_t __unused1;
1341 	compat_ulong_t __unused2;
1342 	compat_ulong_t __unused3;
1343 	compat_ulong_t __unused4;
1344 };
1345 
1346 struct compat_shm_info {
1347 	compat_int_t used_ids;
1348 	compat_ulong_t shm_tot, shm_rss, shm_swp;
1349 	compat_ulong_t swap_attempts, swap_successes;
1350 };
1351 
copy_compat_shminfo_to_user(void __user * buf,struct shminfo64 * in,int version)1352 static int copy_compat_shminfo_to_user(void __user *buf, struct shminfo64 *in,
1353 					int version)
1354 {
1355 	if (in->shmmax > INT_MAX)
1356 		in->shmmax = INT_MAX;
1357 	if (version == IPC_64) {
1358 		struct compat_shminfo64 info;
1359 		memset(&info, 0, sizeof(info));
1360 		info.shmmax = in->shmmax;
1361 		info.shmmin = in->shmmin;
1362 		info.shmmni = in->shmmni;
1363 		info.shmseg = in->shmseg;
1364 		info.shmall = in->shmall;
1365 		return copy_to_user(buf, &info, sizeof(info));
1366 	} else {
1367 		struct shminfo info;
1368 		memset(&info, 0, sizeof(info));
1369 		info.shmmax = in->shmmax;
1370 		info.shmmin = in->shmmin;
1371 		info.shmmni = in->shmmni;
1372 		info.shmseg = in->shmseg;
1373 		info.shmall = in->shmall;
1374 		return copy_to_user(buf, &info, sizeof(info));
1375 	}
1376 }
1377 
put_compat_shm_info(struct shm_info * ip,struct compat_shm_info __user * uip)1378 static int put_compat_shm_info(struct shm_info *ip,
1379 				struct compat_shm_info __user *uip)
1380 {
1381 	struct compat_shm_info info;
1382 
1383 	memset(&info, 0, sizeof(info));
1384 	info.used_ids = ip->used_ids;
1385 	info.shm_tot = ip->shm_tot;
1386 	info.shm_rss = ip->shm_rss;
1387 	info.shm_swp = ip->shm_swp;
1388 	info.swap_attempts = ip->swap_attempts;
1389 	info.swap_successes = ip->swap_successes;
1390 	return copy_to_user(uip, &info, sizeof(info));
1391 }
1392 
copy_compat_shmid_to_user(void __user * buf,struct shmid64_ds * in,int version)1393 static int copy_compat_shmid_to_user(void __user *buf, struct shmid64_ds *in,
1394 					int version)
1395 {
1396 	if (version == IPC_64) {
1397 		struct compat_shmid64_ds v;
1398 		memset(&v, 0, sizeof(v));
1399 		to_compat_ipc64_perm(&v.shm_perm, &in->shm_perm);
1400 		v.shm_atime	 = lower_32_bits(in->shm_atime);
1401 		v.shm_atime_high = upper_32_bits(in->shm_atime);
1402 		v.shm_dtime	 = lower_32_bits(in->shm_dtime);
1403 		v.shm_dtime_high = upper_32_bits(in->shm_dtime);
1404 		v.shm_ctime	 = lower_32_bits(in->shm_ctime);
1405 		v.shm_ctime_high = upper_32_bits(in->shm_ctime);
1406 		v.shm_segsz = in->shm_segsz;
1407 		v.shm_nattch = in->shm_nattch;
1408 		v.shm_cpid = in->shm_cpid;
1409 		v.shm_lpid = in->shm_lpid;
1410 		return copy_to_user(buf, &v, sizeof(v));
1411 	} else {
1412 		struct compat_shmid_ds v;
1413 		memset(&v, 0, sizeof(v));
1414 		to_compat_ipc_perm(&v.shm_perm, &in->shm_perm);
1415 		v.shm_perm.key = in->shm_perm.key;
1416 		v.shm_atime = in->shm_atime;
1417 		v.shm_dtime = in->shm_dtime;
1418 		v.shm_ctime = in->shm_ctime;
1419 		v.shm_segsz = in->shm_segsz;
1420 		v.shm_nattch = in->shm_nattch;
1421 		v.shm_cpid = in->shm_cpid;
1422 		v.shm_lpid = in->shm_lpid;
1423 		return copy_to_user(buf, &v, sizeof(v));
1424 	}
1425 }
1426 
copy_compat_shmid_from_user(struct shmid64_ds * out,void __user * buf,int version)1427 static int copy_compat_shmid_from_user(struct shmid64_ds *out, void __user *buf,
1428 					int version)
1429 {
1430 	memset(out, 0, sizeof(*out));
1431 	if (version == IPC_64) {
1432 		struct compat_shmid64_ds __user *p = buf;
1433 		return get_compat_ipc64_perm(&out->shm_perm, &p->shm_perm);
1434 	} else {
1435 		struct compat_shmid_ds __user *p = buf;
1436 		return get_compat_ipc_perm(&out->shm_perm, &p->shm_perm);
1437 	}
1438 }
1439 
compat_ksys_shmctl(int shmid,int cmd,void __user * uptr,int version)1440 static long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr, int version)
1441 {
1442 	struct ipc_namespace *ns;
1443 	struct shmid64_ds sem64;
1444 	int err;
1445 
1446 	ns = current->nsproxy->ipc_ns;
1447 
1448 	if (cmd < 0 || shmid < 0)
1449 		return -EINVAL;
1450 
1451 	switch (cmd) {
1452 	case IPC_INFO: {
1453 		struct shminfo64 shminfo;
1454 		err = shmctl_ipc_info(ns, &shminfo);
1455 		if (err < 0)
1456 			return err;
1457 		if (copy_compat_shminfo_to_user(uptr, &shminfo, version))
1458 			err = -EFAULT;
1459 		return err;
1460 	}
1461 	case SHM_INFO: {
1462 		struct shm_info shm_info;
1463 		err = shmctl_shm_info(ns, &shm_info);
1464 		if (err < 0)
1465 			return err;
1466 		if (put_compat_shm_info(&shm_info, uptr))
1467 			err = -EFAULT;
1468 		return err;
1469 	}
1470 	case IPC_STAT:
1471 	case SHM_STAT_ANY:
1472 	case SHM_STAT:
1473 		err = shmctl_stat(ns, shmid, cmd, &sem64);
1474 		if (err < 0)
1475 			return err;
1476 		if (copy_compat_shmid_to_user(uptr, &sem64, version))
1477 			err = -EFAULT;
1478 		return err;
1479 
1480 	case IPC_SET:
1481 		if (copy_compat_shmid_from_user(&sem64, uptr, version))
1482 			return -EFAULT;
1483 		fallthrough;
1484 	case IPC_RMID:
1485 		return shmctl_down(ns, shmid, cmd, &sem64);
1486 	case SHM_LOCK:
1487 	case SHM_UNLOCK:
1488 		return shmctl_do_lock(ns, shmid, cmd);
1489 	default:
1490 		return -EINVAL;
1491 	}
1492 	return err;
1493 }
1494 
COMPAT_SYSCALL_DEFINE3(shmctl,int,shmid,int,cmd,void __user *,uptr)1495 COMPAT_SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, void __user *, uptr)
1496 {
1497 	return compat_ksys_shmctl(shmid, cmd, uptr, IPC_64);
1498 }
1499 
1500 #ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
compat_ksys_old_shmctl(int shmid,int cmd,void __user * uptr)1501 long compat_ksys_old_shmctl(int shmid, int cmd, void __user *uptr)
1502 {
1503 	int version = compat_ipc_parse_version(&cmd);
1504 
1505 	return compat_ksys_shmctl(shmid, cmd, uptr, version);
1506 }
1507 
COMPAT_SYSCALL_DEFINE3(old_shmctl,int,shmid,int,cmd,void __user *,uptr)1508 COMPAT_SYSCALL_DEFINE3(old_shmctl, int, shmid, int, cmd, void __user *, uptr)
1509 {
1510 	return compat_ksys_old_shmctl(shmid, cmd, uptr);
1511 }
1512 #endif
1513 #endif
1514 
1515 /*
1516  * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
1517  *
1518  * NOTE! Despite the name, this is NOT a direct system call entrypoint. The
1519  * "raddr" thing points to kernel space, and there has to be a wrapper around
1520  * this.
1521  */
do_shmat(int shmid,char __user * shmaddr,int shmflg,ulong * raddr,unsigned long shmlba)1522 long do_shmat(int shmid, char __user *shmaddr, int shmflg,
1523 	      ulong *raddr, unsigned long shmlba)
1524 {
1525 	struct shmid_kernel *shp;
1526 	unsigned long addr = (unsigned long)shmaddr;
1527 	unsigned long size;
1528 	struct file *file, *base;
1529 	int    err;
1530 	unsigned long flags = MAP_SHARED;
1531 	unsigned long prot;
1532 	int acc_mode;
1533 	struct ipc_namespace *ns;
1534 	struct shm_file_data *sfd;
1535 	int f_flags;
1536 	unsigned long populate = 0;
1537 
1538 	err = -EINVAL;
1539 	if (shmid < 0)
1540 		goto out;
1541 
1542 	if (addr) {
1543 		if (addr & (shmlba - 1)) {
1544 			if (shmflg & SHM_RND) {
1545 				addr &= ~(shmlba - 1);  /* round down */
1546 
1547 				/*
1548 				 * Ensure that the round-down is non-nil
1549 				 * when remapping. This can happen for
1550 				 * cases when addr < shmlba.
1551 				 */
1552 				if (!addr && (shmflg & SHM_REMAP))
1553 					goto out;
1554 			} else
1555 #ifndef __ARCH_FORCE_SHMLBA
1556 				if (addr & ~PAGE_MASK)
1557 #endif
1558 					goto out;
1559 		}
1560 
1561 		flags |= MAP_FIXED;
1562 	} else if ((shmflg & SHM_REMAP))
1563 		goto out;
1564 
1565 	if (shmflg & SHM_RDONLY) {
1566 		prot = PROT_READ;
1567 		acc_mode = S_IRUGO;
1568 		f_flags = O_RDONLY;
1569 	} else {
1570 		prot = PROT_READ | PROT_WRITE;
1571 		acc_mode = S_IRUGO | S_IWUGO;
1572 		f_flags = O_RDWR;
1573 	}
1574 	if (shmflg & SHM_EXEC) {
1575 		prot |= PROT_EXEC;
1576 		acc_mode |= S_IXUGO;
1577 	}
1578 
1579 	/*
1580 	 * We cannot rely on the fs check since SYSV IPC does have an
1581 	 * additional creator id...
1582 	 */
1583 	ns = current->nsproxy->ipc_ns;
1584 	rcu_read_lock();
1585 	shp = shm_obtain_object_check(ns, shmid);
1586 	if (IS_ERR(shp)) {
1587 		err = PTR_ERR(shp);
1588 		goto out_unlock;
1589 	}
1590 
1591 	err = -EACCES;
1592 	if (ipcperms(ns, &shp->shm_perm, acc_mode))
1593 		goto out_unlock;
1594 
1595 	err = security_shm_shmat(&shp->shm_perm, shmaddr, shmflg);
1596 	if (err)
1597 		goto out_unlock;
1598 
1599 	ipc_lock_object(&shp->shm_perm);
1600 
1601 	/* check if shm_destroy() is tearing down shp */
1602 	if (!ipc_valid_object(&shp->shm_perm)) {
1603 		ipc_unlock_object(&shp->shm_perm);
1604 		err = -EIDRM;
1605 		goto out_unlock;
1606 	}
1607 
1608 	/*
1609 	 * We need to take a reference to the real shm file to prevent the
1610 	 * pointer from becoming stale in cases where the lifetime of the outer
1611 	 * file extends beyond that of the shm segment.  It's not usually
1612 	 * possible, but it can happen during remap_file_pages() emulation as
1613 	 * that unmaps the memory, then does ->mmap() via file reference only.
1614 	 * We'll deny the ->mmap() if the shm segment was since removed, but to
1615 	 * detect shm ID reuse we need to compare the file pointers.
1616 	 */
1617 	base = get_file(shp->shm_file);
1618 	shp->shm_nattch++;
1619 	size = i_size_read(file_inode(base));
1620 	ipc_unlock_object(&shp->shm_perm);
1621 	rcu_read_unlock();
1622 
1623 	err = -ENOMEM;
1624 	sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
1625 	if (!sfd) {
1626 		fput(base);
1627 		goto out_nattch;
1628 	}
1629 
1630 	file = alloc_file_clone(base, f_flags,
1631 			  is_file_hugepages(base) ?
1632 				&shm_file_operations_huge :
1633 				&shm_file_operations);
1634 	err = PTR_ERR(file);
1635 	if (IS_ERR(file)) {
1636 		kfree(sfd);
1637 		fput(base);
1638 		goto out_nattch;
1639 	}
1640 
1641 	sfd->id = shp->shm_perm.id;
1642 	sfd->ns = get_ipc_ns(ns);
1643 	sfd->file = base;
1644 	sfd->vm_ops = NULL;
1645 	file->private_data = sfd;
1646 
1647 	err = security_mmap_file(file, prot, flags);
1648 	if (err)
1649 		goto out_fput;
1650 
1651 	if (mmap_write_lock_killable(current->mm)) {
1652 		err = -EINTR;
1653 		goto out_fput;
1654 	}
1655 
1656 	if (addr && !(shmflg & SHM_REMAP)) {
1657 		err = -EINVAL;
1658 		if (addr + size < addr)
1659 			goto invalid;
1660 
1661 		if (find_vma_intersection(current->mm, addr, addr + size))
1662 			goto invalid;
1663 	}
1664 
1665 	addr = do_mmap(file, addr, size, prot, flags, 0, &populate, NULL);
1666 	*raddr = addr;
1667 	err = 0;
1668 	if (IS_ERR_VALUE(addr))
1669 		err = (long)addr;
1670 invalid:
1671 	mmap_write_unlock(current->mm);
1672 	if (populate)
1673 		mm_populate(addr, populate);
1674 
1675 out_fput:
1676 	fput(file);
1677 
1678 out_nattch:
1679 	down_write(&shm_ids(ns).rwsem);
1680 	shp = shm_lock(ns, shmid);
1681 	shp->shm_nattch--;
1682 
1683 	if (shm_may_destroy(shp))
1684 		shm_destroy(ns, shp);
1685 	else
1686 		shm_unlock(shp);
1687 	up_write(&shm_ids(ns).rwsem);
1688 	return err;
1689 
1690 out_unlock:
1691 	rcu_read_unlock();
1692 out:
1693 	return err;
1694 }
1695 
SYSCALL_DEFINE3(shmat,int,shmid,char __user *,shmaddr,int,shmflg)1696 SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg)
1697 {
1698 	unsigned long ret;
1699 	long err;
1700 
1701 	err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
1702 	if (err)
1703 		return err;
1704 	force_successful_syscall_return();
1705 	return (long)ret;
1706 }
1707 
1708 #ifdef CONFIG_COMPAT
1709 
1710 #ifndef COMPAT_SHMLBA
1711 #define COMPAT_SHMLBA	SHMLBA
1712 #endif
1713 
COMPAT_SYSCALL_DEFINE3(shmat,int,shmid,compat_uptr_t,shmaddr,int,shmflg)1714 COMPAT_SYSCALL_DEFINE3(shmat, int, shmid, compat_uptr_t, shmaddr, int, shmflg)
1715 {
1716 	unsigned long ret;
1717 	long err;
1718 
1719 	err = do_shmat(shmid, compat_ptr(shmaddr), shmflg, &ret, COMPAT_SHMLBA);
1720 	if (err)
1721 		return err;
1722 	force_successful_syscall_return();
1723 	return (long)ret;
1724 }
1725 #endif
1726 
1727 /*
1728  * detach and kill segment if marked destroyed.
1729  * The work is done in shm_close.
1730  */
ksys_shmdt(char __user * shmaddr)1731 long ksys_shmdt(char __user *shmaddr)
1732 {
1733 	struct mm_struct *mm = current->mm;
1734 	struct vm_area_struct *vma;
1735 	unsigned long addr = (unsigned long)shmaddr;
1736 	int retval = -EINVAL;
1737 #ifdef CONFIG_MMU
1738 	loff_t size = 0;
1739 	struct file *file;
1740 	VMA_ITERATOR(vmi, mm, addr);
1741 #endif
1742 
1743 	if (addr & ~PAGE_MASK)
1744 		return retval;
1745 
1746 	if (mmap_write_lock_killable(mm))
1747 		return -EINTR;
1748 
1749 	/*
1750 	 * This function tries to be smart and unmap shm segments that
1751 	 * were modified by partial mlock or munmap calls:
1752 	 * - It first determines the size of the shm segment that should be
1753 	 *   unmapped: It searches for a vma that is backed by shm and that
1754 	 *   started at address shmaddr. It records it's size and then unmaps
1755 	 *   it.
1756 	 * - Then it unmaps all shm vmas that started at shmaddr and that
1757 	 *   are within the initially determined size and that are from the
1758 	 *   same shm segment from which we determined the size.
1759 	 * Errors from do_munmap are ignored: the function only fails if
1760 	 * it's called with invalid parameters or if it's called to unmap
1761 	 * a part of a vma. Both calls in this function are for full vmas,
1762 	 * the parameters are directly copied from the vma itself and always
1763 	 * valid - therefore do_munmap cannot fail. (famous last words?)
1764 	 */
1765 	/*
1766 	 * If it had been mremap()'d, the starting address would not
1767 	 * match the usual checks anyway. So assume all vma's are
1768 	 * above the starting address given.
1769 	 */
1770 
1771 #ifdef CONFIG_MMU
1772 	for_each_vma(vmi, vma) {
1773 		/*
1774 		 * Check if the starting address would match, i.e. it's
1775 		 * a fragment created by mprotect() and/or munmap(), or it
1776 		 * otherwise it starts at this address with no hassles.
1777 		 */
1778 		if ((vma->vm_ops == &shm_vm_ops) &&
1779 			(vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
1780 
1781 			/*
1782 			 * Record the file of the shm segment being
1783 			 * unmapped.  With mremap(), someone could place
1784 			 * page from another segment but with equal offsets
1785 			 * in the range we are unmapping.
1786 			 */
1787 			file = vma->vm_file;
1788 			size = i_size_read(file_inode(vma->vm_file));
1789 			do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
1790 			mas_pause(&vmi.mas);
1791 			/*
1792 			 * We discovered the size of the shm segment, so
1793 			 * break out of here and fall through to the next
1794 			 * loop that uses the size information to stop
1795 			 * searching for matching vma's.
1796 			 */
1797 			retval = 0;
1798 			vma = vma_next(&vmi);
1799 			break;
1800 		}
1801 	}
1802 
1803 	/*
1804 	 * We need look no further than the maximum address a fragment
1805 	 * could possibly have landed at. Also cast things to loff_t to
1806 	 * prevent overflows and make comparisons vs. equal-width types.
1807 	 */
1808 	size = PAGE_ALIGN(size);
1809 	while (vma && (loff_t)(vma->vm_end - addr) <= size) {
1810 		/* finding a matching vma now does not alter retval */
1811 		if ((vma->vm_ops == &shm_vm_ops) &&
1812 		    ((vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) &&
1813 		    (vma->vm_file == file)) {
1814 			do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
1815 			mas_pause(&vmi.mas);
1816 		}
1817 
1818 		vma = vma_next(&vmi);
1819 	}
1820 
1821 #else	/* CONFIG_MMU */
1822 	vma = vma_lookup(mm, addr);
1823 	/* under NOMMU conditions, the exact address to be destroyed must be
1824 	 * given
1825 	 */
1826 	if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
1827 		do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
1828 		retval = 0;
1829 	}
1830 
1831 #endif
1832 
1833 	mmap_write_unlock(mm);
1834 	return retval;
1835 }
1836 
SYSCALL_DEFINE1(shmdt,char __user *,shmaddr)1837 SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
1838 {
1839 	return ksys_shmdt(shmaddr);
1840 }
1841 
1842 #ifdef CONFIG_PROC_FS
sysvipc_shm_proc_show(struct seq_file * s,void * it)1843 static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
1844 {
1845 	struct pid_namespace *pid_ns = ipc_seq_pid_ns(s);
1846 	struct user_namespace *user_ns = seq_user_ns(s);
1847 	struct kern_ipc_perm *ipcp = it;
1848 	struct shmid_kernel *shp;
1849 	unsigned long rss = 0, swp = 0;
1850 
1851 	shp = container_of(ipcp, struct shmid_kernel, shm_perm);
1852 	shm_add_rss_swap(shp, &rss, &swp);
1853 
1854 #if BITS_PER_LONG <= 32
1855 #define SIZE_SPEC "%10lu"
1856 #else
1857 #define SIZE_SPEC "%21lu"
1858 #endif
1859 
1860 	seq_printf(s,
1861 		   "%10d %10d  %4o " SIZE_SPEC " %5u %5u  "
1862 		   "%5lu %5u %5u %5u %5u %10llu %10llu %10llu "
1863 		   SIZE_SPEC " " SIZE_SPEC "\n",
1864 		   shp->shm_perm.key,
1865 		   shp->shm_perm.id,
1866 		   shp->shm_perm.mode,
1867 		   shp->shm_segsz,
1868 		   pid_nr_ns(shp->shm_cprid, pid_ns),
1869 		   pid_nr_ns(shp->shm_lprid, pid_ns),
1870 		   shp->shm_nattch,
1871 		   from_kuid_munged(user_ns, shp->shm_perm.uid),
1872 		   from_kgid_munged(user_ns, shp->shm_perm.gid),
1873 		   from_kuid_munged(user_ns, shp->shm_perm.cuid),
1874 		   from_kgid_munged(user_ns, shp->shm_perm.cgid),
1875 		   shp->shm_atim,
1876 		   shp->shm_dtim,
1877 		   shp->shm_ctim,
1878 		   rss * PAGE_SIZE,
1879 		   swp * PAGE_SIZE);
1880 
1881 	return 0;
1882 }
1883 #endif
1884