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authorNadia Derbey <Nadia.Derbey@bull.net>2007-10-18 23:40:49 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-19 11:53:44 -0700
commit7748dbfaa010b12d5fb9ddf80199534c565c6bce (patch)
treec6756de4007c29fdcb405d54173a4322d48ff631 /ipc/util.c
parent7ca7e564e049d8b350ec9d958ff25eaa24226352 (diff)
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ipc: unify the syscalls code
This patch introduces a change into the sys_msgget(), sys_semget() and sys_shmget() routines: they now share a common code, which is better for maintainability. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> 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.c101
1 files changed, 100 insertions, 1 deletions
diff --git a/ipc/util.c b/ipc/util.c
index 2a205875d27..03b88798f71 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -197,7 +197,7 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
* If key is found ipc contains its ipc structure
*/
-struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
+static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
{
struct kern_ipc_perm *ipc;
int next_id;
@@ -301,6 +301,105 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
}
/**
+ * ipcget_new - create a new ipc object
+ * @ns: namespace
+ * @ids: identifer set
+ * @ops: the actual creation routine to call
+ * @params: its parameters
+ *
+ * This routine is called sys_msgget, sys_semget() and sys_shmget() when
+ * the key is IPC_PRIVATE
+ */
+int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
+ struct ipc_ops *ops, struct ipc_params *params)
+{
+ int err;
+
+ err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
+
+ if (!err)
+ return -ENOMEM;
+
+ mutex_lock(&ids->mutex);
+ err = ops->getnew(ns, params);
+ mutex_unlock(&ids->mutex);
+
+ return err;
+}
+
+/**
+ * ipc_check_perms - check security and permissions for an IPC
+ * @ipcp: ipc permission set
+ * @ids: identifer set
+ * @ops: the actual security routine to call
+ * @params: its parameters
+ */
+static int ipc_check_perms(struct kern_ipc_perm *ipcp, struct ipc_ops *ops,
+ struct ipc_params *params)
+{
+ int err;
+
+ if (ipcperms(ipcp, params->flg))
+ err = -EACCES;
+ else {
+ err = ops->associate(ipcp, params->flg);
+ if (!err)
+ err = ipcp->id;
+ }
+
+ return err;
+}
+
+/**
+ * ipcget_public - get an ipc object or create a new one
+ * @ns: namespace
+ * @ids: identifer set
+ * @ops: the actual creation routine to call
+ * @params: its parameters
+ *
+ * This routine is called sys_msgget, sys_semget() and sys_shmget() when
+ * the key is not IPC_PRIVATE
+ */
+int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
+ struct ipc_ops *ops, struct ipc_params *params)
+{
+ struct kern_ipc_perm *ipcp;
+ int flg = params->flg;
+ int err;
+
+ err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
+
+ mutex_lock(&ids->mutex);
+ ipcp = ipc_findkey(ids, params->key);
+ if (ipcp == NULL) {
+ /* key not used */
+ if (!(flg & IPC_CREAT))
+ err = -ENOENT;
+ else if (!err)
+ err = -ENOMEM;
+ else
+ err = ops->getnew(ns, params);
+ } else {
+ /* ipc object has been locked by ipc_findkey() */
+
+ if (flg & IPC_CREAT && flg & IPC_EXCL)
+ err = -EEXIST;
+ else {
+ err = 0;
+ if (ops->more_checks)
+ err = ops->more_checks(ipcp, params);
+ if (!err)
+ err = ipc_check_perms(ipcp, ops, params);
+ }
+ ipc_unlock(ipcp);
+ }
+ mutex_unlock(&ids->mutex);
+
+ return err;
+}
+
+
+/**
* ipc_rmid - remove an IPC identifier
* @ids: identifier set
* @id: ipc perm structure containing the identifier to remove