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virtualization of sysv msg queues is incomplete
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Virtualization of sysv msg queues is incomplete: msg_hdrs and msg_bytes
variables visible from userspace are global.  Let's make them
per-namespace.

Signed-off-by: Alexey Kuznetsov <[email protected]>
Signed-off-by: Kirill Korotaev <[email protected]>
Cc: Pierre Peiffer <[email protected]>
Cc: Nadia Derbey <[email protected]>
Cc: Serge Hallyn <[email protected]>
Acked-by: "Eric W. Biederman" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Kirill Korotaev authored and Linus Torvalds committed Oct 19, 2007
1 parent c530c6a commit 3ac88a4
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Showing 2 changed files with 12 additions and 11 deletions.
2 changes: 2 additions & 0 deletions include/linux/ipc.h
Original file line number Diff line number Diff line change
Expand Up @@ -111,6 +111,8 @@ struct ipc_namespace {
int msg_ctlmax;
int msg_ctlmnb;
int msg_ctlmni;
atomic_t msg_bytes;
atomic_t msg_hdrs;

size_t shm_ctlmax;
size_t shm_ctlall;
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21 changes: 10 additions & 11 deletions ipc/msg.c
Original file line number Diff line number Diff line change
Expand Up @@ -66,9 +66,6 @@ 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]))
Expand All @@ -88,6 +85,8 @@ 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;
atomic_set(&ns->msg_bytes, 0);
atomic_set(&ns->msg_hdrs, 0);
ipc_init_ids(ids);
}

Expand Down Expand Up @@ -293,10 +292,10 @@ static void freeque(struct ipc_namespace *ns, struct msg_queue *msq)
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);
}
Expand Down Expand Up @@ -463,8 +462,8 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
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;
Expand Down Expand Up @@ -735,8 +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;
Expand Down Expand Up @@ -840,8 +839,8 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
msq->q_rtime = get_seconds();
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;
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