diff options
Diffstat (limited to 'ipc/util.c')
| -rw-r--r-- | ipc/util.c | 290 |
1 files changed, 132 insertions, 158 deletions
diff --git a/ipc/util.c b/ipc/util.c index 3ae17a4ace5..e1b4c6db8aa 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -110,15 +110,15 @@ static struct notifier_block ipc_memory_nb = { }; /** - * ipc_init - initialise IPC subsystem + * ipc_init - initialise ipc subsystem * - * The various system5 IPC resources (semaphores, messages and shared - * memory) are initialised - * A callback routine is registered into the memory hotplug notifier - * chain: since msgmni scales to lowmem this callback routine will be - * called upon successful memory add / remove to recompute msmgni. + * The various sysv ipc resources (semaphores, messages and shared + * memory) are initialised. + * + * A callback routine is registered into the memory hotplug notifier + * chain: since msgmni scales to lowmem this callback routine will be + * called upon successful memory add / remove to recompute msmgni. */ - static int __init ipc_init(void) { sem_init(); @@ -131,39 +131,29 @@ static int __init ipc_init(void) __initcall(ipc_init); /** - * ipc_init_ids - initialise IPC identifiers - * @ids: Identifier set + * ipc_init_ids - initialise ipc identifiers + * @ids: ipc identifier set * - * Set up the sequence range to use for the ipc identifier range (limited - * below IPCMNI) then initialise the ids idr. + * Set up the sequence range to use for the ipc identifier range (limited + * below IPCMNI) then initialise the ids idr. */ - void ipc_init_ids(struct ipc_ids *ids) { - init_rwsem(&ids->rwsem); - ids->in_use = 0; ids->seq = 0; ids->next_id = -1; - { - int seq_limit = INT_MAX/SEQ_MULTIPLIER; - if (seq_limit > USHRT_MAX) - ids->seq_max = USHRT_MAX; - else - ids->seq_max = seq_limit; - } - + init_rwsem(&ids->rwsem); idr_init(&ids->ipcs_idr); } #ifdef CONFIG_PROC_FS static const struct file_operations sysvipc_proc_fops; /** - * ipc_init_proc_interface - Create a proc interface for sysipc types using a seq_file interface. - * @path: Path in procfs - * @header: Banner to be printed at the beginning of the file. - * @ids: ipc id table to iterate. - * @show: show routine. + * ipc_init_proc_interface - create a proc interface for sysipc types using a seq_file interface. + * @path: Path in procfs + * @header: Banner to be printed at the beginning of the file. + * @ids: ipc id table to iterate. + * @show: show routine. */ void __init ipc_init_proc_interface(const char *path, const char *header, int ids, int (*show)(struct seq_file *, void *)) @@ -184,23 +174,21 @@ void __init ipc_init_proc_interface(const char *path, const char *header, NULL, /* parent dir */ &sysvipc_proc_fops, iface); - if (!pde) { + if (!pde) kfree(iface); - } } #endif /** - * ipc_findkey - find a key in an ipc identifier set - * @ids: Identifier set - * @key: The key to find + * ipc_findkey - find a key in an ipc identifier set + * @ids: ipc identifier set + * @key: key to find * - * Requires ipc_ids.rwsem locked. - * Returns the LOCKED pointer to the ipc structure if found or NULL - * if not. - * If key is found ipc points to the owning ipc structure + * Returns the locked pointer to the ipc structure if found or NULL + * otherwise. If key is found ipc points to the owning ipc structure + * + * Called with ipc_ids.rwsem held. */ - static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key) { struct kern_ipc_perm *ipc; @@ -227,12 +215,11 @@ static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key) } /** - * ipc_get_maxid - get the last assigned id - * @ids: IPC identifier set + * ipc_get_maxid - get the last assigned id + * @ids: ipc identifier set * - * Called with ipc_ids.rwsem held. + * Called with ipc_ids.rwsem held. */ - int ipc_get_maxid(struct ipc_ids *ids) { struct kern_ipc_perm *ipc; @@ -258,19 +245,19 @@ int ipc_get_maxid(struct ipc_ids *ids) } /** - * ipc_addid - add an IPC identifier - * @ids: IPC identifier set - * @new: new IPC permission set - * @size: limit for the number of used ids + * ipc_addid - add an ipc identifier + * @ids: ipc identifier set + * @new: new ipc permission set + * @size: limit for the number of used ids * - * Add an entry 'new' to the IPC ids idr. The permissions object is - * initialised and the first free entry is set up and the id assigned - * is returned. The 'new' entry is returned in a locked state on success. - * On failure the entry is not locked and a negative err-code is returned. + * Add an entry 'new' to the ipc ids idr. The permissions object is + * initialised and the first free entry is set up and the id assigned + * is returned. The 'new' entry is returned in a locked state on success. + * On failure the entry is not locked and a negative err-code is returned. * - * Called with writer ipc_ids.rwsem held. + * Called with writer ipc_ids.rwsem held. */ -int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size) +int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int size) { kuid_t euid; kgid_t egid; @@ -286,7 +273,7 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size) idr_preload(GFP_KERNEL); spin_lock_init(&new->lock); - new->deleted = 0; + new->deleted = false; rcu_read_lock(); spin_lock(&new->lock); @@ -308,7 +295,7 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size) if (next_id < 0) { new->seq = ids->seq++; - if (ids->seq > ids->seq_max) + if (ids->seq > IPCID_SEQ_MAX) ids->seq = 0; } else { new->seq = ipcid_to_seqx(next_id); @@ -320,14 +307,14 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size) } /** - * ipcget_new - create a new ipc object - * @ns: namespace - * @ids: IPC identifer set - * @ops: the actual creation routine to call - * @params: its parameters - * - * This routine is called by sys_msgget, sys_semget() and sys_shmget() - * when the key is IPC_PRIVATE. + * ipcget_new - create a new ipc object + * @ns: ipc namespace + * @ids: ipc identifer set + * @ops: the actual creation routine to call + * @params: its parameters + * + * This routine is called by sys_msgget, sys_semget() and sys_shmget() + * when the key is IPC_PRIVATE. */ static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids, struct ipc_ops *ops, struct ipc_params *params) @@ -341,19 +328,19 @@ static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids, } /** - * ipc_check_perms - check security and permissions for an IPC - * @ns: IPC namespace - * @ipcp: ipc permission set - * @ops: the actual security routine to call - * @params: its parameters + * ipc_check_perms - check security and permissions for an ipc object + * @ns: ipc namespace + * @ipcp: ipc permission set + * @ops: the actual security routine to call + * @params: its parameters * - * This routine is called by sys_msgget(), sys_semget() and sys_shmget() - * when the key is not IPC_PRIVATE and that key already exists in the - * ids IDR. + * This routine is called by sys_msgget(), sys_semget() and sys_shmget() + * when the key is not IPC_PRIVATE and that key already exists in the + * ds IDR. * - * On success, the IPC id is returned. + * On success, the ipc id is returned. * - * It is called with ipc_ids.rwsem and ipcp->lock held. + * It is called with ipc_ids.rwsem and ipcp->lock held. */ static int ipc_check_perms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, @@ -374,18 +361,18 @@ static int ipc_check_perms(struct ipc_namespace *ns, } /** - * ipcget_public - get an ipc object or create a new one - * @ns: namespace - * @ids: IPC identifer set - * @ops: the actual creation routine to call - * @params: its parameters - * - * This routine is called by sys_msgget, sys_semget() and sys_shmget() - * when the key is not IPC_PRIVATE. - * It adds a new entry if the key is not found and does some permission - * / security checkings if the key is found. - * - * On success, the ipc id is returned. + * ipcget_public - get an ipc object or create a new one + * @ns: ipc namespace + * @ids: ipc identifer set + * @ops: the actual creation routine to call + * @params: its parameters + * + * This routine is called by sys_msgget, sys_semget() and sys_shmget() + * when the key is not IPC_PRIVATE. + * It adds a new entry if the key is not found and does some permission + * / security checkings if the key is found. + * + * On success, the ipc id is returned. */ static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids, struct ipc_ops *ops, struct ipc_params *params) @@ -431,39 +418,33 @@ static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids, /** - * ipc_rmid - remove an IPC identifier - * @ids: IPC identifier set - * @ipcp: ipc perm structure containing the identifier to remove + * ipc_rmid - remove an ipc identifier + * @ids: ipc identifier set + * @ipcp: ipc perm structure containing the identifier to remove * - * ipc_ids.rwsem (as a writer) and the spinlock for this ID are held - * before this function is called, and remain locked on the exit. + * ipc_ids.rwsem (as a writer) and the spinlock for this ID are held + * before this function is called, and remain locked on the exit. */ - void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp) { int lid = ipcid_to_idx(ipcp->id); idr_remove(&ids->ipcs_idr, lid); - ids->in_use--; - - ipcp->deleted = 1; - - return; + ipcp->deleted = true; } /** - * ipc_alloc - allocate ipc space - * @size: size desired + * ipc_alloc - allocate ipc space + * @size: size desired * - * Allocate memory from the appropriate pools and return a pointer to it. - * NULL is returned if the allocation fails + * Allocate memory from the appropriate pools and return a pointer to it. + * NULL is returned if the allocation fails */ - void *ipc_alloc(int size) { void *out; - if(size > PAGE_SIZE) + if (size > PAGE_SIZE) out = vmalloc(size); else out = kmalloc(size, GFP_KERNEL); @@ -471,28 +452,27 @@ void *ipc_alloc(int size) } /** - * ipc_free - free ipc space - * @ptr: pointer returned by ipc_alloc - * @size: size of block + * ipc_free - free ipc space + * @ptr: pointer returned by ipc_alloc + * @size: size of block * - * Free a block created with ipc_alloc(). The caller must know the size - * used in the allocation call. + * Free a block created with ipc_alloc(). The caller must know the size + * used in the allocation call. */ - -void ipc_free(void* ptr, int size) +void ipc_free(void *ptr, int size) { - if(size > PAGE_SIZE) + if (size > PAGE_SIZE) vfree(ptr); else kfree(ptr); } /** - * ipc_rcu_alloc - allocate ipc and rcu space - * @size: size desired + * ipc_rcu_alloc - allocate ipc and rcu space + * @size: size desired * - * Allocate memory for the rcu header structure + the object. - * Returns the pointer to the object or NULL upon failure. + * Allocate memory for the rcu header structure + the object. + * Returns the pointer to the object or NULL upon failure. */ void *ipc_rcu_alloc(int size) { @@ -534,17 +514,16 @@ void ipc_rcu_free(struct rcu_head *head) } /** - * ipcperms - check IPC permissions - * @ns: IPC namespace - * @ipcp: IPC permission set - * @flag: desired permission set. + * ipcperms - check ipc permissions + * @ns: ipc namespace + * @ipcp: ipc permission set + * @flag: desired permission set * - * Check user, group, other permissions for access - * to ipc resources. return 0 if allowed + * Check user, group, other permissions for access + * to ipc resources. return 0 if allowed * - * @flag will most probably be 0 or S_...UGO from <linux/stat.h> + * @flag will most probably be 0 or S_...UGO from <linux/stat.h> */ - int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag) { kuid_t euid = current_euid(); @@ -572,16 +551,14 @@ int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag) */ /** - * kernel_to_ipc64_perm - convert kernel ipc permissions to user - * @in: kernel permissions - * @out: new style IPC permissions + * kernel_to_ipc64_perm - convert kernel ipc permissions to user + * @in: kernel permissions + * @out: new style ipc permissions * - * Turn the kernel object @in into a set of permissions descriptions - * for returning to userspace (@out). + * Turn the kernel object @in into a set of permissions descriptions + * for returning to userspace (@out). */ - - -void kernel_to_ipc64_perm (struct kern_ipc_perm *in, struct ipc64_perm *out) +void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out) { out->key = in->key; out->uid = from_kuid_munged(current_user_ns(), in->uid); @@ -593,15 +570,14 @@ void kernel_to_ipc64_perm (struct kern_ipc_perm *in, struct ipc64_perm *out) } /** - * ipc64_perm_to_ipc_perm - convert new ipc permissions to old - * @in: new style IPC permissions - * @out: old style IPC permissions + * ipc64_perm_to_ipc_perm - convert new ipc permissions to old + * @in: new style ipc permissions + * @out: old style ipc permissions * - * Turn the new style permissions object @in into a compatibility - * object and store it into the @out pointer. + * Turn the new style permissions object @in into a compatibility + * object and store it into the @out pointer. */ - -void ipc64_perm_to_ipc_perm (struct ipc64_perm *in, struct ipc_perm *out) +void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out) { out->key = in->key; SET_UID(out->uid, in->uid); @@ -635,8 +611,8 @@ struct kern_ipc_perm *ipc_obtain_object(struct ipc_ids *ids, int id) } /** - * ipc_lock - Lock an ipc structure without rwsem held - * @ids: IPC identifier set + * ipc_lock - lock an ipc structure without rwsem held + * @ids: ipc identifier set * @id: ipc id to look for * * Look for an id in the ipc ids idr and lock the associated ipc object. @@ -657,7 +633,7 @@ struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id) /* ipc_rmid() may have already freed the ID while ipc_lock * was spinning: here verify that the structure is still valid */ - if (!out->deleted) + if (ipc_valid_object(out)) return out; spin_unlock(&out->lock); @@ -693,11 +669,11 @@ out: /** * ipcget - Common sys_*get() code - * @ns : namsepace - * @ids : IPC identifier set - * @ops : operations to be called on ipc object creation, permission checks - * and further checks - * @params : the parameters needed by the previous operations. + * @ns: namsepace + * @ids: ipc identifier set + * @ops: operations to be called on ipc object creation, permission checks + * and further checks + * @params: the parameters needed by the previous operations. * * Common routine called by sys_msgget(), sys_semget() and sys_shmget(). */ @@ -711,7 +687,7 @@ int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, } /** - * ipc_update_perm - update the permissions of an IPC. + * ipc_update_perm - update the permissions of an ipc object * @in: the permission given as input. * @out: the permission of the ipc to set. */ @@ -732,7 +708,7 @@ int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out) /** * ipcctl_pre_down_nolock - retrieve an ipc and check permissions for some IPC_XXX cmd - * @ns: the ipc namespace + * @ns: ipc namespace * @ids: the table of ids where to look for the ipc * @id: the id of the ipc to retrieve * @cmd: the cmd to check @@ -779,15 +755,14 @@ err: /** - * ipc_parse_version - IPC call version - * @cmd: pointer to command + * ipc_parse_version - ipc call version + * @cmd: pointer to command * - * Return IPC_64 for new style IPC and IPC_OLD for old style IPC. - * The @cmd value is turned from an encoding command and version into - * just the command code. + * Return IPC_64 for new style IPC and IPC_OLD for old style IPC. + * The @cmd value is turned from an encoding command and version into + * just the command code. */ - -int ipc_parse_version (int *cmd) +int ipc_parse_version(int *cmd) { if (*cmd & IPC_64) { *cmd ^= IPC_64; @@ -824,7 +799,7 @@ static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos, if (total >= ids->in_use) return NULL; - for ( ; pos < IPCMNI; pos++) { + for (; pos < IPCMNI; pos++) { ipc = idr_find(&ids->ipcs_idr, pos); if (ipc != NULL) { *new_pos = pos + 1; @@ -927,8 +902,10 @@ static int sysvipc_proc_open(struct inode *inode, struct file *file) goto out; ret = seq_open(file, &sysvipc_proc_seqops); - if (ret) - goto out_kfree; + if (ret) { + kfree(iter); + goto out; + } seq = file->private_data; seq->private = iter; @@ -937,9 +914,6 @@ static int sysvipc_proc_open(struct inode *inode, struct file *file) iter->ns = get_ipc_ns(current->nsproxy->ipc_ns); out: return ret; -out_kfree: - kfree(iter); - goto out; } static int sysvipc_proc_release(struct inode *inode, struct file *file) |