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authorDavidlohr Bueso <davidlohr@hp.com>2014-01-27 20:07:05 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-28 00:02:39 -0500
commit8001c85810dd2277d75ae60376e840456afa9b7e (patch)
tree60a03cdecbbbb6e2bdca6b132b4b332f90a728ad /ipc/util.c
parent239521f31d7496a5322ee664ed8bbd1027b98c4b (diff)
ipc: standardize code comments
IPC commenting style is all over the place, *specially* in util.c. This patch orders things a bit. Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc/util.c')
-rw-r--r--ipc/util.c239
1 files changed, 114 insertions, 125 deletions
diff --git a/ipc/util.c b/ipc/util.c
index fdf03fa6869d..af976fc6a464 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -110,15 +110,15 @@ static struct notifier_block ipc_memory_nb = {
110}; 110};
111 111
112/** 112/**
113 * ipc_init - initialise IPC subsystem 113 * ipc_init - initialise ipc subsystem
114 * 114 *
115 * The various system5 IPC resources (semaphores, messages and shared 115 * The various sysv ipc resources (semaphores, messages and shared
116 * memory) are initialised 116 * memory) are initialised.
117 * A callback routine is registered into the memory hotplug notifier 117 *
118 * chain: since msgmni scales to lowmem this callback routine will be 118 * A callback routine is registered into the memory hotplug notifier
119 * called upon successful memory add / remove to recompute msmgni. 119 * chain: since msgmni scales to lowmem this callback routine will be
120 * called upon successful memory add / remove to recompute msmgni.
120 */ 121 */
121
122static int __init ipc_init(void) 122static int __init ipc_init(void)
123{ 123{
124 sem_init(); 124 sem_init();
@@ -131,13 +131,12 @@ static int __init ipc_init(void)
131__initcall(ipc_init); 131__initcall(ipc_init);
132 132
133/** 133/**
134 * ipc_init_ids - initialise IPC identifiers 134 * ipc_init_ids - initialise ipc identifiers
135 * @ids: Identifier set 135 * @ids: ipc identifier set
136 * 136 *
137 * Set up the sequence range to use for the ipc identifier range (limited 137 * Set up the sequence range to use for the ipc identifier range (limited
138 * below IPCMNI) then initialise the ids idr. 138 * below IPCMNI) then initialise the ids idr.
139 */ 139 */
140
141void ipc_init_ids(struct ipc_ids *ids) 140void ipc_init_ids(struct ipc_ids *ids)
142{ 141{
143 init_rwsem(&ids->rwsem); 142 init_rwsem(&ids->rwsem);
@@ -159,11 +158,11 @@ void ipc_init_ids(struct ipc_ids *ids)
159#ifdef CONFIG_PROC_FS 158#ifdef CONFIG_PROC_FS
160static const struct file_operations sysvipc_proc_fops; 159static const struct file_operations sysvipc_proc_fops;
161/** 160/**
162 * ipc_init_proc_interface - Create a proc interface for sysipc types using a seq_file interface. 161 * ipc_init_proc_interface - create a proc interface for sysipc types using a seq_file interface.
163 * @path: Path in procfs 162 * @path: Path in procfs
164 * @header: Banner to be printed at the beginning of the file. 163 * @header: Banner to be printed at the beginning of the file.
165 * @ids: ipc id table to iterate. 164 * @ids: ipc id table to iterate.
166 * @show: show routine. 165 * @show: show routine.
167 */ 166 */
168void __init ipc_init_proc_interface(const char *path, const char *header, 167void __init ipc_init_proc_interface(const char *path, const char *header,
169 int ids, int (*show)(struct seq_file *, void *)) 168 int ids, int (*show)(struct seq_file *, void *))
@@ -191,16 +190,15 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
191#endif 190#endif
192 191
193/** 192/**
194 * ipc_findkey - find a key in an ipc identifier set 193 * ipc_findkey - find a key in an ipc identifier set
195 * @ids: Identifier set 194 * @ids: ipc identifier set
196 * @key: The key to find 195 * @key: key to find
197 * 196 *
198 * Requires ipc_ids.rwsem locked. 197 * Returns the locked pointer to the ipc structure if found or NULL
199 * Returns the LOCKED pointer to the ipc structure if found or NULL 198 * otherwise. If key is found ipc points to the owning ipc structure
200 * if not. 199 *
201 * If key is found ipc points to the owning ipc structure 200 * Called with ipc_ids.rwsem held.
202 */ 201 */
203
204static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key) 202static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
205{ 203{
206 struct kern_ipc_perm *ipc; 204 struct kern_ipc_perm *ipc;
@@ -227,12 +225,11 @@ static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
227} 225}
228 226
229/** 227/**
230 * ipc_get_maxid - get the last assigned id 228 * ipc_get_maxid - get the last assigned id
231 * @ids: IPC identifier set 229 * @ids: ipc identifier set
232 * 230 *
233 * Called with ipc_ids.rwsem held. 231 * Called with ipc_ids.rwsem held.
234 */ 232 */
235
236int ipc_get_maxid(struct ipc_ids *ids) 233int ipc_get_maxid(struct ipc_ids *ids)
237{ 234{
238 struct kern_ipc_perm *ipc; 235 struct kern_ipc_perm *ipc;
@@ -258,17 +255,17 @@ int ipc_get_maxid(struct ipc_ids *ids)
258} 255}
259 256
260/** 257/**
261 * ipc_addid - add an IPC identifier 258 * ipc_addid - add an ipc identifier
262 * @ids: IPC identifier set 259 * @ids: ipc identifier set
263 * @new: new IPC permission set 260 * @new: new ipc permission set
264 * @size: limit for the number of used ids 261 * @size: limit for the number of used ids
265 * 262 *
266 * Add an entry 'new' to the IPC ids idr. The permissions object is 263 * Add an entry 'new' to the ipc ids idr. The permissions object is
267 * initialised and the first free entry is set up and the id assigned 264 * initialised and the first free entry is set up and the id assigned
268 * is returned. The 'new' entry is returned in a locked state on success. 265 * is returned. The 'new' entry is returned in a locked state on success.
269 * On failure the entry is not locked and a negative err-code is returned. 266 * On failure the entry is not locked and a negative err-code is returned.
270 * 267 *
271 * Called with writer ipc_ids.rwsem held. 268 * Called with writer ipc_ids.rwsem held.
272 */ 269 */
273int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int size) 270int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int size)
274{ 271{
@@ -320,14 +317,14 @@ int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int size)
320} 317}
321 318
322/** 319/**
323 * ipcget_new - create a new ipc object 320 * ipcget_new - create a new ipc object
324 * @ns: namespace 321 * @ns: ipc namespace
325 * @ids: IPC identifer set 322 * @ids: ipc identifer set
326 * @ops: the actual creation routine to call 323 * @ops: the actual creation routine to call
327 * @params: its parameters 324 * @params: its parameters
328 * 325 *
329 * This routine is called by sys_msgget, sys_semget() and sys_shmget() 326 * This routine is called by sys_msgget, sys_semget() and sys_shmget()
330 * when the key is IPC_PRIVATE. 327 * when the key is IPC_PRIVATE.
331 */ 328 */
332static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids, 329static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
333 struct ipc_ops *ops, struct ipc_params *params) 330 struct ipc_ops *ops, struct ipc_params *params)
@@ -341,19 +338,19 @@ static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
341} 338}
342 339
343/** 340/**
344 * ipc_check_perms - check security and permissions for an IPC 341 * ipc_check_perms - check security and permissions for an ipc object
345 * @ns: IPC namespace 342 * @ns: ipc namespace
346 * @ipcp: ipc permission set 343 * @ipcp: ipc permission set
347 * @ops: the actual security routine to call 344 * @ops: the actual security routine to call
348 * @params: its parameters 345 * @params: its parameters
349 * 346 *
350 * This routine is called by sys_msgget(), sys_semget() and sys_shmget() 347 * This routine is called by sys_msgget(), sys_semget() and sys_shmget()
351 * when the key is not IPC_PRIVATE and that key already exists in the 348 * when the key is not IPC_PRIVATE and that key already exists in the
352 * ids IDR. 349 * ds IDR.
353 * 350 *
354 * On success, the IPC id is returned. 351 * On success, the ipc id is returned.
355 * 352 *
356 * It is called with ipc_ids.rwsem and ipcp->lock held. 353 * It is called with ipc_ids.rwsem and ipcp->lock held.
357 */ 354 */
358static int ipc_check_perms(struct ipc_namespace *ns, 355static int ipc_check_perms(struct ipc_namespace *ns,
359 struct kern_ipc_perm *ipcp, 356 struct kern_ipc_perm *ipcp,
@@ -374,18 +371,18 @@ static int ipc_check_perms(struct ipc_namespace *ns,
374} 371}
375 372
376/** 373/**
377 * ipcget_public - get an ipc object or create a new one 374 * ipcget_public - get an ipc object or create a new one
378 * @ns: namespace 375 * @ns: ipc namespace
379 * @ids: IPC identifer set 376 * @ids: ipc identifer set
380 * @ops: the actual creation routine to call 377 * @ops: the actual creation routine to call
381 * @params: its parameters 378 * @params: its parameters
382 * 379 *
383 * This routine is called by sys_msgget, sys_semget() and sys_shmget() 380 * This routine is called by sys_msgget, sys_semget() and sys_shmget()
384 * when the key is not IPC_PRIVATE. 381 * when the key is not IPC_PRIVATE.
385 * It adds a new entry if the key is not found and does some permission 382 * It adds a new entry if the key is not found and does some permission
386 * / security checkings if the key is found. 383 * / security checkings if the key is found.
387 * 384 *
388 * On success, the ipc id is returned. 385 * On success, the ipc id is returned.
389 */ 386 */
390static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids, 387static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
391 struct ipc_ops *ops, struct ipc_params *params) 388 struct ipc_ops *ops, struct ipc_params *params)
@@ -431,14 +428,13 @@ static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
431 428
432 429
433/** 430/**
434 * ipc_rmid - remove an IPC identifier 431 * ipc_rmid - remove an ipc identifier
435 * @ids: IPC identifier set 432 * @ids: ipc identifier set
436 * @ipcp: ipc perm structure containing the identifier to remove 433 * @ipcp: ipc perm structure containing the identifier to remove
437 * 434 *
438 * ipc_ids.rwsem (as a writer) and the spinlock for this ID are held 435 * ipc_ids.rwsem (as a writer) and the spinlock for this ID are held
439 * before this function is called, and remain locked on the exit. 436 * before this function is called, and remain locked on the exit.
440 */ 437 */
441
442void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp) 438void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
443{ 439{
444 int lid = ipcid_to_idx(ipcp->id); 440 int lid = ipcid_to_idx(ipcp->id);
@@ -453,13 +449,12 @@ void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
453} 449}
454 450
455/** 451/**
456 * ipc_alloc - allocate ipc space 452 * ipc_alloc - allocate ipc space
457 * @size: size desired 453 * @size: size desired
458 * 454 *
459 * Allocate memory from the appropriate pools and return a pointer to it. 455 * Allocate memory from the appropriate pools and return a pointer to it.
460 * NULL is returned if the allocation fails 456 * NULL is returned if the allocation fails
461 */ 457 */
462
463void *ipc_alloc(int size) 458void *ipc_alloc(int size)
464{ 459{
465 void *out; 460 void *out;
@@ -471,14 +466,13 @@ void *ipc_alloc(int size)
471} 466}
472 467
473/** 468/**
474 * ipc_free - free ipc space 469 * ipc_free - free ipc space
475 * @ptr: pointer returned by ipc_alloc 470 * @ptr: pointer returned by ipc_alloc
476 * @size: size of block 471 * @size: size of block
477 * 472 *
478 * Free a block created with ipc_alloc(). The caller must know the size 473 * Free a block created with ipc_alloc(). The caller must know the size
479 * used in the allocation call. 474 * used in the allocation call.
480 */ 475 */
481
482void ipc_free(void *ptr, int size) 476void ipc_free(void *ptr, int size)
483{ 477{
484 if (size > PAGE_SIZE) 478 if (size > PAGE_SIZE)
@@ -488,11 +482,11 @@ void ipc_free(void *ptr, int size)
488} 482}
489 483
490/** 484/**
491 * ipc_rcu_alloc - allocate ipc and rcu space 485 * ipc_rcu_alloc - allocate ipc and rcu space
492 * @size: size desired 486 * @size: size desired
493 * 487 *
494 * Allocate memory for the rcu header structure + the object. 488 * Allocate memory for the rcu header structure + the object.
495 * Returns the pointer to the object or NULL upon failure. 489 * Returns the pointer to the object or NULL upon failure.
496 */ 490 */
497void *ipc_rcu_alloc(int size) 491void *ipc_rcu_alloc(int size)
498{ 492{
@@ -534,17 +528,16 @@ void ipc_rcu_free(struct rcu_head *head)
534} 528}
535 529
536/** 530/**
537 * ipcperms - check IPC permissions 531 * ipcperms - check ipc permissions
538 * @ns: IPC namespace 532 * @ns: ipc namespace
539 * @ipcp: IPC permission set 533 * @ipcp: ipc permission set
540 * @flag: desired permission set. 534 * @flag: desired permission set
541 * 535 *
542 * Check user, group, other permissions for access 536 * Check user, group, other permissions for access
543 * to ipc resources. return 0 if allowed 537 * to ipc resources. return 0 if allowed
544 * 538 *
545 * @flag will most probably be 0 or S_...UGO from <linux/stat.h> 539 * @flag will most probably be 0 or S_...UGO from <linux/stat.h>
546 */ 540 */
547
548int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag) 541int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
549{ 542{
550 kuid_t euid = current_euid(); 543 kuid_t euid = current_euid();
@@ -572,15 +565,13 @@ int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
572 */ 565 */
573 566
574/** 567/**
575 * kernel_to_ipc64_perm - convert kernel ipc permissions to user 568 * kernel_to_ipc64_perm - convert kernel ipc permissions to user
576 * @in: kernel permissions 569 * @in: kernel permissions
577 * @out: new style IPC permissions 570 * @out: new style ipc permissions
578 * 571 *
579 * Turn the kernel object @in into a set of permissions descriptions 572 * Turn the kernel object @in into a set of permissions descriptions
580 * for returning to userspace (@out). 573 * for returning to userspace (@out).
581 */ 574 */
582
583
584void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out) 575void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out)
585{ 576{
586 out->key = in->key; 577 out->key = in->key;
@@ -593,14 +584,13 @@ void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out)
593} 584}
594 585
595/** 586/**
596 * ipc64_perm_to_ipc_perm - convert new ipc permissions to old 587 * ipc64_perm_to_ipc_perm - convert new ipc permissions to old
597 * @in: new style IPC permissions 588 * @in: new style ipc permissions
598 * @out: old style IPC permissions 589 * @out: old style ipc permissions
599 * 590 *
600 * Turn the new style permissions object @in into a compatibility 591 * Turn the new style permissions object @in into a compatibility
601 * object and store it into the @out pointer. 592 * object and store it into the @out pointer.
602 */ 593 */
603
604void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out) 594void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out)
605{ 595{
606 out->key = in->key; 596 out->key = in->key;
@@ -635,8 +625,8 @@ struct kern_ipc_perm *ipc_obtain_object(struct ipc_ids *ids, int id)
635} 625}
636 626
637/** 627/**
638 * ipc_lock - Lock an ipc structure without rwsem held 628 * ipc_lock - lock an ipc structure without rwsem held
639 * @ids: IPC identifier set 629 * @ids: ipc identifier set
640 * @id: ipc id to look for 630 * @id: ipc id to look for
641 * 631 *
642 * Look for an id in the ipc ids idr and lock the associated ipc object. 632 * Look for an id in the ipc ids idr and lock the associated ipc object.
@@ -693,11 +683,11 @@ out:
693 683
694/** 684/**
695 * ipcget - Common sys_*get() code 685 * ipcget - Common sys_*get() code
696 * @ns : namsepace 686 * @ns: namsepace
697 * @ids : IPC identifier set 687 * @ids: ipc identifier set
698 * @ops : operations to be called on ipc object creation, permission checks 688 * @ops: operations to be called on ipc object creation, permission checks
699 * and further checks 689 * and further checks
700 * @params : the parameters needed by the previous operations. 690 * @params: the parameters needed by the previous operations.
701 * 691 *
702 * Common routine called by sys_msgget(), sys_semget() and sys_shmget(). 692 * Common routine called by sys_msgget(), sys_semget() and sys_shmget().
703 */ 693 */
@@ -711,7 +701,7 @@ int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
711} 701}
712 702
713/** 703/**
714 * ipc_update_perm - update the permissions of an IPC. 704 * ipc_update_perm - update the permissions of an ipc object
715 * @in: the permission given as input. 705 * @in: the permission given as input.
716 * @out: the permission of the ipc to set. 706 * @out: the permission of the ipc to set.
717 */ 707 */
@@ -732,7 +722,7 @@ int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
732 722
733/** 723/**
734 * ipcctl_pre_down_nolock - retrieve an ipc and check permissions for some IPC_XXX cmd 724 * ipcctl_pre_down_nolock - retrieve an ipc and check permissions for some IPC_XXX cmd
735 * @ns: the ipc namespace 725 * @ns: ipc namespace
736 * @ids: the table of ids where to look for the ipc 726 * @ids: the table of ids where to look for the ipc
737 * @id: the id of the ipc to retrieve 727 * @id: the id of the ipc to retrieve
738 * @cmd: the cmd to check 728 * @cmd: the cmd to check
@@ -779,14 +769,13 @@ err:
779 769
780 770
781/** 771/**
782 * ipc_parse_version - IPC call version 772 * ipc_parse_version - ipc call version
783 * @cmd: pointer to command 773 * @cmd: pointer to command
784 * 774 *
785 * Return IPC_64 for new style IPC and IPC_OLD for old style IPC. 775 * Return IPC_64 for new style IPC and IPC_OLD for old style IPC.
786 * The @cmd value is turned from an encoding command and version into 776 * The @cmd value is turned from an encoding command and version into
787 * just the command code. 777 * just the command code.
788 */ 778 */
789
790int ipc_parse_version(int *cmd) 779int ipc_parse_version(int *cmd)
791{ 780{
792 if (*cmd & IPC_64) { 781 if (*cmd & IPC_64) {