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Diffstat (limited to 'ipc/msg.c')
-rw-r--r--ipc/msg.c124
1 files changed, 50 insertions, 74 deletions
diff --git a/ipc/msg.c b/ipc/msg.c
index fede1d06ef30..d0c6d967b390 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -66,6 +66,7 @@ struct msg_sender {
#define SEARCH_EQUAL 2
#define SEARCH_NOTEQUAL 3
#define SEARCH_LESSEQUAL 4
+#define SEARCH_NUMBER 5
#define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS])
@@ -237,14 +238,9 @@ static inline void ss_del(struct msg_sender *mss)
static void ss_wakeup(struct list_head *h, int kill)
{
- struct list_head *tmp;
+ struct msg_sender *mss, *t;
- tmp = h->next;
- while (tmp != h) {
- struct msg_sender *mss;
-
- mss = list_entry(tmp, struct msg_sender, list);
- tmp = tmp->next;
+ list_for_each_entry_safe(mss, t, h, list) {
if (kill)
mss->list.next = NULL;
wake_up_process(mss->tsk);
@@ -253,14 +249,9 @@ static void ss_wakeup(struct list_head *h, int kill)
static void expunge_all(struct msg_queue *msq, int res)
{
- struct list_head *tmp;
-
- tmp = msq->q_receivers.next;
- while (tmp != &msq->q_receivers) {
- struct msg_receiver *msr;
+ struct msg_receiver *msr, *t;
- msr = list_entry(tmp, struct msg_receiver, r_list);
- tmp = tmp->next;
+ list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
msr->r_msg = NULL;
wake_up_process(msr->r_tsk);
smp_mb();
@@ -278,7 +269,7 @@ static void expunge_all(struct msg_queue *msq, int res)
*/
static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
{
- struct list_head *tmp;
+ struct msg_msg *msg, *t;
struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
expunge_all(msq, -EIDRM);
@@ -286,11 +277,7 @@ static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
msg_rmid(ns, msq);
msg_unlock(msq);
- tmp = msq->q_messages.next;
- while (tmp != &msq->q_messages) {
- struct msg_msg *msg = list_entry(tmp, struct msg_msg, m_list);
-
- tmp = tmp->next;
+ list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) {
atomic_dec(&ns->msg_hdrs);
free_msg(msg);
}
@@ -583,6 +570,7 @@ static int testmsg(struct msg_msg *msg, long type, int mode)
switch(mode)
{
case SEARCH_ANY:
+ case SEARCH_NUMBER:
return 1;
case SEARCH_LESSEQUAL:
if (msg->m_type <=type)
@@ -602,14 +590,9 @@ static int testmsg(struct msg_msg *msg, long type, int mode)
static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
{
- struct list_head *tmp;
+ struct msg_receiver *msr, *t;
- tmp = msq->q_receivers.next;
- while (tmp != &msq->q_receivers) {
- struct msg_receiver *msr;
-
- msr = list_entry(tmp, struct msg_receiver, r_list);
- tmp = tmp->next;
+ list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
if (testmsg(msg, msr->r_msgtype, msr->r_mode) &&
!security_msg_queue_msgrcv(msq, msg, msr->r_tsk,
msr->r_msgtype, msr->r_mode)) {
@@ -685,7 +668,12 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
goto out_unlock_free;
}
ss_add(msq, &s);
- ipc_rcu_getref(msq);
+
+ if (!ipc_rcu_getref(msq)) {
+ err = -EIDRM;
+ goto out_unlock_free;
+ }
+
msg_unlock(msq);
schedule();
@@ -738,6 +726,8 @@ SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
static inline int convert_mode(long *msgtyp, int msgflg)
{
+ if (msgflg & MSG_COPY)
+ return SEARCH_NUMBER;
/*
* find message of correct type.
* msgtyp = 0 => get first.
@@ -774,14 +764,10 @@ static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
* This function creates new kernel message structure, large enough to store
* bufsz message bytes.
*/
-static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz,
- int msgflg, long *msgtyp,
- unsigned long *copy_number)
+static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
{
struct msg_msg *copy;
- *copy_number = *msgtyp;
- *msgtyp = 0;
/*
* Create dummy message to copy real message to.
*/
@@ -797,9 +783,7 @@ static inline void free_copy(struct msg_msg *copy)
free_msg(copy);
}
#else
-static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz,
- int msgflg, long *msgtyp,
- unsigned long *copy_number)
+static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
{
return ERR_PTR(-ENOSYS);
}
@@ -809,6 +793,30 @@ static inline void free_copy(struct msg_msg *copy)
}
#endif
+static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
+{
+ struct msg_msg *msg;
+ long count = 0;
+
+ list_for_each_entry(msg, &msq->q_messages, m_list) {
+ if (testmsg(msg, *msgtyp, mode) &&
+ !security_msg_queue_msgrcv(msq, msg, current,
+ *msgtyp, mode)) {
+ if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
+ *msgtyp = msg->m_type - 1;
+ } else if (mode == SEARCH_NUMBER) {
+ if (*msgtyp == count)
+ return msg;
+ } else
+ return msg;
+ count++;
+ }
+ }
+
+ return ERR_PTR(-EAGAIN);
+}
+
+
long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
int msgflg,
long (*msg_handler)(void __user *, struct msg_msg *, size_t))
@@ -818,15 +826,13 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
int mode;
struct ipc_namespace *ns;
struct msg_msg *copy = NULL;
- unsigned long copy_number = 0;
ns = current->nsproxy->ipc_ns;
if (msqid < 0 || (long) bufsz < 0)
return -EINVAL;
if (msgflg & MSG_COPY) {
- copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax),
- msgflg, &msgtyp, &copy_number);
+ copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
if (IS_ERR(copy))
return PTR_ERR(copy);
}
@@ -840,45 +846,13 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
for (;;) {
struct msg_receiver msr_d;
- struct list_head *tmp;
- long msg_counter = 0;
msg = ERR_PTR(-EACCES);
if (ipcperms(ns, &msq->q_perm, S_IRUGO))
goto out_unlock;
- msg = ERR_PTR(-EAGAIN);
- tmp = msq->q_messages.next;
- while (tmp != &msq->q_messages) {
- struct msg_msg *walk_msg;
-
- walk_msg = list_entry(tmp, struct msg_msg, m_list);
- if (testmsg(walk_msg, msgtyp, mode) &&
- !security_msg_queue_msgrcv(msq, walk_msg, current,
- msgtyp, mode)) {
-
- msg = walk_msg;
- if (mode == SEARCH_LESSEQUAL &&
- walk_msg->m_type != 1) {
- msgtyp = walk_msg->m_type - 1;
- } else if (msgflg & MSG_COPY) {
- if (copy_number == msg_counter) {
- /*
- * Found requested message.
- * Copy it.
- */
- msg = copy_msg(msg, copy);
- if (IS_ERR(msg))
- goto out_unlock;
- break;
- }
- msg = ERR_PTR(-EAGAIN);
- } else
- break;
- msg_counter++;
- }
- tmp = tmp->next;
- }
+ msg = find_msg(msq, &msgtyp, mode);
+
if (!IS_ERR(msg)) {
/*
* Found a suitable message.
@@ -892,8 +866,10 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
* If we are copying, then do not unlink message and do
* not update queue parameters.
*/
- if (msgflg & MSG_COPY)
+ if (msgflg & MSG_COPY) {
+ msg = copy_msg(msg, copy);
goto out_unlock;
+ }
list_del(&msg->m_list);
msq->q_qnum--;
msq->q_rtime = get_seconds();
generated by cgit v1.2.3 (git 2.0.4) at 2024-06-21 22:32:05 +0000