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Diffstat (limited to 'ipc/msg.c')
-rw-r--r--ipc/msg.c253
1 files changed, 140 insertions, 113 deletions
diff --git a/ipc/msg.c b/ipc/msg.c
index a03fcb522fff..fdf3db5731ce 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -34,7 +34,7 @@
#include <linux/syscalls.h>
#include <linux/audit.h>
#include <linux/seq_file.h>
-#include <linux/mutex.h>
+#include <linux/rwsem.h>
#include <linux/nsproxy.h>
#include <asm/current.h>
@@ -66,23 +66,15 @@ struct msg_sender {
#define SEARCH_NOTEQUAL 3
#define SEARCH_LESSEQUAL 4
-static atomic_t msg_bytes = ATOMIC_INIT(0);
-static atomic_t msg_hdrs = ATOMIC_INIT(0);
-
static struct ipc_ids init_msg_ids;
#define msg_ids(ns) (*((ns)->ids[IPC_MSG_IDS]))
-#define msg_lock(ns, id) ((struct msg_queue*)ipc_lock(&msg_ids(ns), id))
#define msg_unlock(msq) ipc_unlock(&(msq)->q_perm)
-#define msg_rmid(ns, id) ((struct msg_queue*)ipc_rmid(&msg_ids(ns), id))
-#define msg_checkid(ns, msq, msgid) \
- ipc_checkid(&msg_ids(ns), &msq->q_perm, msgid)
-#define msg_buildid(ns, id, seq) \
- ipc_buildid(&msg_ids(ns), id, seq)
-
-static void freeque (struct ipc_namespace *ns, struct msg_queue *msq, int id);
-static int newque (struct ipc_namespace *ns, key_t key, int msgflg);
+#define msg_buildid(id, seq) ipc_buildid(id, seq)
+
+static void freeque(struct ipc_namespace *, struct msg_queue *);
+static int newque(struct ipc_namespace *, struct ipc_params *);
#ifdef CONFIG_PROC_FS
static int sysvipc_msg_proc_show(struct seq_file *s, void *it);
#endif
@@ -93,7 +85,9 @@ static void __msg_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
ns->msg_ctlmax = MSGMAX;
ns->msg_ctlmnb = MSGMNB;
ns->msg_ctlmni = MSGMNI;
- ipc_init_ids(ids, ns->msg_ctlmni);
+ atomic_set(&ns->msg_bytes, 0);
+ atomic_set(&ns->msg_hdrs, 0);
+ ipc_init_ids(ids);
}
int msg_init_ns(struct ipc_namespace *ns)
@@ -110,20 +104,25 @@ int msg_init_ns(struct ipc_namespace *ns)
void msg_exit_ns(struct ipc_namespace *ns)
{
- int i;
struct msg_queue *msq;
+ int next_id;
+ int total, in_use;
+
+ down_write(&msg_ids(ns).rw_mutex);
+
+ in_use = msg_ids(ns).in_use;
- mutex_lock(&msg_ids(ns).mutex);
- for (i = 0; i <= msg_ids(ns).max_id; i++) {
- msq = msg_lock(ns, i);
+ for (total = 0, next_id = 0; total < in_use; next_id++) {
+ msq = idr_find(&msg_ids(ns).ipcs_idr, next_id);
if (msq == NULL)
continue;
-
- freeque(ns, msq, i);
+ ipc_lock_by_ptr(&msq->q_perm);
+ freeque(ns, msq);
+ total++;
}
- mutex_unlock(&msg_ids(ns).mutex);
- ipc_fini_ids(ns->ids[IPC_MSG_IDS]);
+ up_write(&msg_ids(ns).rw_mutex);
+
kfree(ns->ids[IPC_MSG_IDS]);
ns->ids[IPC_MSG_IDS] = NULL;
}
@@ -136,10 +135,55 @@ void __init msg_init(void)
IPC_MSG_IDS, sysvipc_msg_proc_show);
}
-static int newque (struct ipc_namespace *ns, key_t key, int msgflg)
+/*
+ * This routine is called in the paths where the rw_mutex is held to protect
+ * access to the idr tree.
+ */
+static inline struct msg_queue *msg_lock_check_down(struct ipc_namespace *ns,
+ int id)
+{
+ struct kern_ipc_perm *ipcp = ipc_lock_check_down(&msg_ids(ns), id);
+
+ return container_of(ipcp, struct msg_queue, q_perm);
+}
+
+/*
+ * msg_lock_(check_) routines are called in the paths where the rw_mutex
+ * is not held.
+ */
+static inline struct msg_queue *msg_lock(struct ipc_namespace *ns, int id)
+{
+ struct kern_ipc_perm *ipcp = ipc_lock(&msg_ids(ns), id);
+
+ return container_of(ipcp, struct msg_queue, q_perm);
+}
+
+static inline struct msg_queue *msg_lock_check(struct ipc_namespace *ns,
+ int id)
+{
+ struct kern_ipc_perm *ipcp = ipc_lock_check(&msg_ids(ns), id);
+
+ return container_of(ipcp, struct msg_queue, q_perm);
+}
+
+static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
+{
+ ipc_rmid(&msg_ids(ns), &s->q_perm);
+}
+
+/**
+ * newque - Create a new msg queue
+ * @ns: namespace
+ * @params: ptr to the structure that contains the key and msgflg
+ *
+ * Called with msg_ids.rw_mutex held (writer)
+ */
+static int newque(struct ipc_namespace *ns, struct ipc_params *params)
{
struct msg_queue *msq;
int id, retval;
+ key_t key = params->key;
+ int msgflg = params->flg;
msq = ipc_rcu_alloc(sizeof(*msq));
if (!msq)
@@ -155,14 +199,17 @@ static int newque (struct ipc_namespace *ns, key_t key, int msgflg)
return retval;
}
+ /*
+ * ipc_addid() locks msq
+ */
id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
- if (id == -1) {
+ if (id < 0) {
security_msg_queue_free(msq);
ipc_rcu_putref(msq);
- return -ENOSPC;
+ return id;
}
- msq->q_id = msg_buildid(ns, id, msq->q_perm.seq);
+ msq->q_perm.id = msg_buildid(id, msq->q_perm.seq);
msq->q_stime = msq->q_rtime = 0;
msq->q_ctime = get_seconds();
msq->q_cbytes = msq->q_qnum = 0;
@@ -171,9 +218,10 @@ static int newque (struct ipc_namespace *ns, key_t key, int msgflg)
INIT_LIST_HEAD(&msq->q_messages);
INIT_LIST_HEAD(&msq->q_receivers);
INIT_LIST_HEAD(&msq->q_senders);
+
msg_unlock(msq);
- return msq->q_id;
+ return msq->q_perm.id;
}
static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss)
@@ -224,19 +272,19 @@ static void expunge_all(struct msg_queue *msq, int res)
/*
* freeque() wakes up waiters on the sender and receiver waiting queue,
- * removes the message queue from message queue ID
- * array, and cleans up all the messages associated with this queue.
+ * removes the message queue from message queue ID IDR, and cleans up all the
+ * messages associated with this queue.
*
- * msg_ids.mutex and the spinlock for this message queue is hold
- * before freeque() is called. msg_ids.mutex remains locked on exit.
+ * msg_ids.rw_mutex (writer) and the spinlock for this message queue are held
+ * before freeque() is called. msg_ids.rw_mutex remains locked on exit.
*/
-static void freeque(struct ipc_namespace *ns, struct msg_queue *msq, int id)
+static void freeque(struct ipc_namespace *ns, struct msg_queue *msq)
{
struct list_head *tmp;
expunge_all(msq, -EIDRM);
ss_wakeup(&msq->q_senders, 1);
- msq = msg_rmid(ns, id);
+ msg_rmid(ns, msq);
msg_unlock(msq);
tmp = msq->q_messages.next;
@@ -244,49 +292,40 @@ static void freeque(struct ipc_namespace *ns, struct msg_queue *msq, int id)
struct msg_msg *msg = list_entry(tmp, struct msg_msg, m_list);
tmp = tmp->next;
- atomic_dec(&msg_hdrs);
+ atomic_dec(&ns->msg_hdrs);
free_msg(msg);
}
- atomic_sub(msq->q_cbytes, &msg_bytes);
+ atomic_sub(msq->q_cbytes, &ns->msg_bytes);
security_msg_queue_free(msq);
ipc_rcu_putref(msq);
}
+/*
+ * Called with msg_ids.rw_mutex and ipcp locked.
+ */
+static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg)
+{
+ struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
+
+ return security_msg_queue_associate(msq, msgflg);
+}
+
asmlinkage long sys_msgget(key_t key, int msgflg)
{
- struct msg_queue *msq;
- int id, ret = -EPERM;
struct ipc_namespace *ns;
+ struct ipc_ops msg_ops;
+ struct ipc_params msg_params;
ns = current->nsproxy->ipc_ns;
-
- mutex_lock(&msg_ids(ns).mutex);
- if (key == IPC_PRIVATE)
- ret = newque(ns, key, msgflg);
- else if ((id = ipc_findkey(&msg_ids(ns), key)) == -1) { /* key not used */
- if (!(msgflg & IPC_CREAT))
- ret = -ENOENT;
- else
- ret = newque(ns, key, msgflg);
- } else if (msgflg & IPC_CREAT && msgflg & IPC_EXCL) {
- ret = -EEXIST;
- } else {
- msq = msg_lock(ns, id);
- BUG_ON(msq == NULL);
- if (ipcperms(&msq->q_perm, msgflg))
- ret = -EACCES;
- else {
- int qid = msg_buildid(ns, id, msq->q_perm.seq);
-
- ret = security_msg_queue_associate(msq, msgflg);
- if (!ret)
- ret = qid;
- }
- msg_unlock(msq);
- }
- mutex_unlock(&msg_ids(ns).mutex);
- return ret;
+ msg_ops.getnew = newque;
+ msg_ops.associate = msg_security;
+ msg_ops.more_checks = NULL;
+
+ msg_params.key = key;
+ msg_params.flg = msgflg;
+
+ return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params);
}
static inline unsigned long
@@ -420,23 +459,23 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
msginfo.msgmnb = ns->msg_ctlmnb;
msginfo.msgssz = MSGSSZ;
msginfo.msgseg = MSGSEG;
- mutex_lock(&msg_ids(ns).mutex);
+ down_read(&msg_ids(ns).rw_mutex);
if (cmd == MSG_INFO) {
msginfo.msgpool = msg_ids(ns).in_use;
- msginfo.msgmap = atomic_read(&msg_hdrs);
- msginfo.msgtql = atomic_read(&msg_bytes);
+ msginfo.msgmap = atomic_read(&ns->msg_hdrs);
+ msginfo.msgtql = atomic_read(&ns->msg_bytes);
} else {
msginfo.msgmap = MSGMAP;
msginfo.msgpool = MSGPOOL;
msginfo.msgtql = MSGTQL;
}
- max_id = msg_ids(ns).max_id;
- mutex_unlock(&msg_ids(ns).mutex);
+ max_id = ipc_get_maxid(&msg_ids(ns));
+ up_read(&msg_ids(ns).rw_mutex);
if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
return -EFAULT;
return (max_id < 0) ? 0 : max_id;
}
- case MSG_STAT:
+ case MSG_STAT: /* msqid is an index rather than a msg queue id */
case IPC_STAT:
{
struct msqid64_ds tbuf;
@@ -444,21 +483,16 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
if (!buf)
return -EFAULT;
- if (cmd == MSG_STAT && msqid >= msg_ids(ns).entries->size)
- return -EINVAL;
-
- memset(&tbuf, 0, sizeof(tbuf));
-
- msq = msg_lock(ns, msqid);
- if (msq == NULL)
- return -EINVAL;
if (cmd == MSG_STAT) {
- success_return = msg_buildid(ns, msqid, msq->q_perm.seq);
+ msq = msg_lock(ns, msqid);
+ if (IS_ERR(msq))
+ return PTR_ERR(msq);
+ success_return = msq->q_perm.id;
} else {
- err = -EIDRM;
- if (msg_checkid(ns, msq, msqid))
- goto out_unlock;
+ msq = msg_lock_check(ns, msqid);
+ if (IS_ERR(msq))
+ return PTR_ERR(msq);
success_return = 0;
}
err = -EACCES;
@@ -469,6 +503,8 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
if (err)
goto out_unlock;
+ memset(&tbuf, 0, sizeof(tbuf));
+
kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm);
tbuf.msg_stime = msq->q_stime;
tbuf.msg_rtime = msq->q_rtime;
@@ -495,15 +531,13 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
return -EINVAL;
}
- mutex_lock(&msg_ids(ns).mutex);
- msq = msg_lock(ns, msqid);
- err = -EINVAL;
- if (msq == NULL)
+ down_write(&msg_ids(ns).rw_mutex);
+ msq = msg_lock_check_down(ns, msqid);
+ if (IS_ERR(msq)) {
+ err = PTR_ERR(msq);
goto out_up;
+ }
- err = -EIDRM;
- if (msg_checkid(ns, msq, msqid))
- goto out_unlock_up;
ipcp = &msq->q_perm;
err = audit_ipc_obj(ipcp);
@@ -552,12 +586,12 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
break;
}
case IPC_RMID:
- freeque(ns, msq, msqid);
+ freeque(ns, msq);
break;
}
err = 0;
out_up:
- mutex_unlock(&msg_ids(ns).mutex);
+ up_write(&msg_ids(ns).rw_mutex);
return err;
out_unlock_up:
msg_unlock(msq);
@@ -611,7 +645,7 @@ static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
msr->r_msg = ERR_PTR(-E2BIG);
} else {
msr->r_msg = NULL;
- msq->q_lrpid = msr->r_tsk->pid;
+ msq->q_lrpid = task_pid_vnr(msr->r_tsk);
msq->q_rtime = get_seconds();
wake_up_process(msr->r_tsk);
smp_mb();
@@ -646,14 +680,11 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
msg->m_type = mtype;
msg->m_ts = msgsz;
- msq = msg_lock(ns, msqid);
- err = -EINVAL;
- if (msq == NULL)
+ msq = msg_lock_check(ns, msqid);
+ if (IS_ERR(msq)) {
+ err = PTR_ERR(msq);
goto out_free;
-
- err= -EIDRM;
- if (msg_checkid(ns, msq, msqid))
- goto out_unlock_free;
+ }
for (;;) {
struct msg_sender s;
@@ -695,7 +726,7 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
}
}
- msq->q_lspid = current->tgid;
+ msq->q_lspid = task_tgid_vnr(current);
msq->q_stime = get_seconds();
if (!pipelined_send(msq, msg)) {
@@ -703,8 +734,8 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
list_add_tail(&msg->m_list, &msq->q_messages);
msq->q_cbytes += msgsz;
msq->q_qnum++;
- atomic_add(msgsz, &msg_bytes);
- atomic_inc(&msg_hdrs);
+ atomic_add(msgsz, &ns->msg_bytes);
+ atomic_inc(&ns->msg_hdrs);
}
err = 0;
@@ -760,13 +791,9 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
mode = convert_mode(&msgtyp, msgflg);
ns = current->nsproxy->ipc_ns;
- msq = msg_lock(ns, msqid);
- if (msq == NULL)
- return -EINVAL;
-
- msg = ERR_PTR(-EIDRM);
- if (msg_checkid(ns, msq, msqid))
- goto out_unlock;
+ msq = msg_lock_check(ns, msqid);
+ if (IS_ERR(msq))
+ return PTR_ERR(msq);
for (;;) {
struct msg_receiver msr_d;
@@ -810,10 +837,10 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
list_del(&msg->m_list);
msq->q_qnum--;
msq->q_rtime = get_seconds();
- msq->q_lrpid = current->tgid;
+ msq->q_lrpid = task_tgid_vnr(current);
msq->q_cbytes -= msg->m_ts;
- atomic_sub(msg->m_ts, &msg_bytes);
- atomic_dec(&msg_hdrs);
+ atomic_sub(msg->m_ts, &ns->msg_bytes);
+ atomic_dec(&ns->msg_hdrs);
ss_wakeup(&msq->q_senders, 0);
msg_unlock(msq);
break;
@@ -926,7 +953,7 @@ static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
return seq_printf(s,
"%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n",
msq->q_perm.key,
- msq->q_id,
+ msq->q_perm.id,
msq->q_perm.mode,
msq->q_cbytes,
msq->q_qnum,
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