Commit 156d9ed1 authored by Al Viro's avatar Al Viro

msgctl(): split the actual work from copyin/copyout

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 553f770e
......@@ -361,23 +361,17 @@ copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
* NOTE: no locks must be held, the rwsem is taken inside this function.
*/
static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
struct msqid_ds __user *buf, int version)
struct msqid64_ds *msqid64)
{
struct kern_ipc_perm *ipcp;
struct msqid64_ds uninitialized_var(msqid64);
struct msg_queue *msq;
int err;
if (cmd == IPC_SET) {
if (copy_msqid_from_user(&msqid64, buf, version))
return -EFAULT;
}
down_write(&msg_ids(ns).rwsem);
rcu_read_lock();
ipcp = ipcctl_pre_down_nolock(ns, &msg_ids(ns), msqid, cmd,
&msqid64.msg_perm, msqid64.msg_qbytes);
&msqid64->msg_perm, msqid64->msg_qbytes);
if (IS_ERR(ipcp)) {
err = PTR_ERR(ipcp);
goto out_unlock1;
......@@ -399,18 +393,18 @@ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
{
DEFINE_WAKE_Q(wake_q);
if (msqid64.msg_qbytes > ns->msg_ctlmnb &&
if (msqid64->msg_qbytes > ns->msg_ctlmnb &&
!capable(CAP_SYS_RESOURCE)) {
err = -EPERM;
goto out_unlock1;
}
ipc_lock_object(&msq->q_perm);
err = ipc_update_perm(&msqid64.msg_perm, ipcp);
err = ipc_update_perm(&msqid64->msg_perm, ipcp);
if (err)
goto out_unlock0;
msq->q_qbytes = msqid64.msg_qbytes;
msq->q_qbytes = msqid64->msg_qbytes;
msq->q_ctime = get_seconds();
/*
......@@ -442,111 +436,89 @@ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
return err;
}
static int msgctl_nolock(struct ipc_namespace *ns, int msqid,
int cmd, int version, void __user *buf)
static int msgctl_info(struct ipc_namespace *ns, int msqid,
int cmd, struct msginfo *msginfo)
{
int err;
struct msg_queue *msq;
switch (cmd) {
case IPC_INFO:
case MSG_INFO:
{
struct msginfo msginfo;
int max_id;
if (!buf)
return -EFAULT;
int max_id;
/*
* We must not return kernel stack data.
* due to padding, it's not enough
* to set all member fields.
*/
err = security_msg_queue_msgctl(NULL, cmd);
if (err)
return err;
memset(&msginfo, 0, sizeof(msginfo));
msginfo.msgmni = ns->msg_ctlmni;
msginfo.msgmax = ns->msg_ctlmax;
msginfo.msgmnb = ns->msg_ctlmnb;
msginfo.msgssz = MSGSSZ;
msginfo.msgseg = MSGSEG;
down_read(&msg_ids(ns).rwsem);
if (cmd == MSG_INFO) {
msginfo.msgpool = msg_ids(ns).in_use;
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 = ipc_get_maxid(&msg_ids(ns));
up_read(&msg_ids(ns).rwsem);
if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
return -EFAULT;
return (max_id < 0) ? 0 : max_id;
/*
* We must not return kernel stack data.
* due to padding, it's not enough
* to set all member fields.
*/
err = security_msg_queue_msgctl(NULL, cmd);
if (err)
return err;
memset(msginfo, 0, sizeof(*msginfo));
msginfo->msgmni = ns->msg_ctlmni;
msginfo->msgmax = ns->msg_ctlmax;
msginfo->msgmnb = ns->msg_ctlmnb;
msginfo->msgssz = MSGSSZ;
msginfo->msgseg = MSGSEG;
down_read(&msg_ids(ns).rwsem);
if (cmd == MSG_INFO) {
msginfo->msgpool = msg_ids(ns).in_use;
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 = ipc_get_maxid(&msg_ids(ns));
up_read(&msg_ids(ns).rwsem);
return (max_id < 0) ? 0 : max_id;
}
case MSG_STAT:
case IPC_STAT:
{
struct msqid64_ds tbuf;
int success_return;
if (!buf)
return -EFAULT;
memset(&tbuf, 0, sizeof(tbuf));
static int msgctl_stat(struct ipc_namespace *ns, int msqid,
int cmd, struct msqid64_ds *p)
{
int err;
struct msg_queue *msq;
int success_return;
rcu_read_lock();
if (cmd == MSG_STAT) {
msq = msq_obtain_object(ns, msqid);
if (IS_ERR(msq)) {
err = PTR_ERR(msq);
goto out_unlock;
}
success_return = msq->q_perm.id;
} else {
msq = msq_obtain_object_check(ns, msqid);
if (IS_ERR(msq)) {
err = PTR_ERR(msq);
goto out_unlock;
}
success_return = 0;
}
memset(p, 0, sizeof(*p));
err = -EACCES;
if (ipcperms(ns, &msq->q_perm, S_IRUGO))
rcu_read_lock();
if (cmd == MSG_STAT) {
msq = msq_obtain_object(ns, msqid);
if (IS_ERR(msq)) {
err = PTR_ERR(msq);
goto out_unlock;
err = security_msg_queue_msgctl(msq, cmd);
if (err)
}
success_return = msq->q_perm.id;
} else {
msq = msq_obtain_object_check(ns, msqid);
if (IS_ERR(msq)) {
err = PTR_ERR(msq);
goto out_unlock;
}
success_return = 0;
}
kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm);
tbuf.msg_stime = msq->q_stime;
tbuf.msg_rtime = msq->q_rtime;
tbuf.msg_ctime = msq->q_ctime;
tbuf.msg_cbytes = msq->q_cbytes;
tbuf.msg_qnum = msq->q_qnum;
tbuf.msg_qbytes = msq->q_qbytes;
tbuf.msg_lspid = msq->q_lspid;
tbuf.msg_lrpid = msq->q_lrpid;
rcu_read_unlock();
err = -EACCES;
if (ipcperms(ns, &msq->q_perm, S_IRUGO))
goto out_unlock;
if (copy_msqid_to_user(buf, &tbuf, version))
return -EFAULT;
return success_return;
}
err = security_msg_queue_msgctl(msq, cmd);
if (err)
goto out_unlock;
kernel_to_ipc64_perm(&msq->q_perm, &p->msg_perm);
p->msg_stime = msq->q_stime;
p->msg_rtime = msq->q_rtime;
p->msg_ctime = msq->q_ctime;
p->msg_cbytes = msq->q_cbytes;
p->msg_qnum = msq->q_qnum;
p->msg_qbytes = msq->q_qbytes;
p->msg_lspid = msq->q_lspid;
p->msg_lrpid = msq->q_lrpid;
rcu_read_unlock();
default:
return -EINVAL;
}
return success_return;
return err;
out_unlock:
rcu_read_unlock();
return err;
......@@ -556,6 +528,8 @@ SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
{
int version;
struct ipc_namespace *ns;
struct msqid64_ds msqid64;
int err;
if (msqid < 0 || cmd < 0)
return -EINVAL;
......@@ -565,13 +539,29 @@ SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
switch (cmd) {
case IPC_INFO:
case MSG_INFO:
case MSG_INFO: {
struct msginfo msginfo;
err = msgctl_info(ns, msqid, cmd, &msginfo);
if (err < 0)
return err;
if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
err = -EFAULT;
return err;
}
case MSG_STAT: /* msqid is an index rather than a msg queue id */
case IPC_STAT:
return msgctl_nolock(ns, msqid, cmd, version, buf);
err = msgctl_stat(ns, msqid, cmd, &msqid64);
if (err < 0)
return err;
if (copy_msqid_to_user(buf, &msqid64, version))
err = -EFAULT;
return err;
case IPC_SET:
if (copy_msqid_from_user(&msqid64, buf, version))
return -EFAULT;
/* fallthru */
case IPC_RMID:
return msgctl_down(ns, msqid, cmd, buf, version);
return msgctl_down(ns, msqid, cmd, &msqid64);
default:
return -EINVAL;
}
......
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