[Devel] [PATCH v3 07/10] IPC: message queue receive cleanup
Stanislav Kinsbursky
skinsbursky at parallels.com
Fri Aug 10 07:25:56 PDT 2012
This patch moves all message related manipulation into one function msg_fill().
Actually, two functions because of the compat one.
Signed-off-by: Stanislav Kinsbursky <skinsbursky at parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov at openvz.org>
Conflicts:
arch/tile/kernel/compat.c
include/linux/compat.h
---
arch/tile/kernel/compat.c | 29 +++++++++++++++++++++++++++++
include/linux/compat.h | 2 ++
include/linux/msg.h | 5 +++--
ipc/compat.c | 33 +++++++++++++++++----------------
ipc/msg.c | 44 +++++++++++++++++++++++---------------------
5 files changed, 74 insertions(+), 39 deletions(-)
diff --git a/arch/tile/kernel/compat.c b/arch/tile/kernel/compat.c
index d67459b..e74d61b 100644
--- a/arch/tile/kernel/compat.c
+++ b/arch/tile/kernel/compat.c
@@ -94,6 +94,35 @@ long compat_sys_sched_rr_get_interval(compat_pid_t pid,
return ret;
}
+/*
+ * The usual compat_sys_msgsnd() and _msgrcv() seem to be assuming
+ * some different calling convention than our normal 32-bit tile code.
+ */
+
+/* Already defined in ipc/compat.c, but we need it here. */
+struct compat_msgbuf {
+ compat_long_t mtype;
+ char mtext[1];
+};
+
+long tile_compat_sys_msgsnd(int msqid,
+ struct compat_msgbuf __user *msgp,
+ size_t msgsz, int msgflg)
+{
+ compat_long_t mtype;
+
+ if (get_user(mtype, &msgp->mtype))
+ return -EFAULT;
+ return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg);
+}
+
+long tile_compat_sys_msgrcv(int msqid,
+ struct compat_msgbuf __user *msgp,
+ size_t msgsz, long msgtyp, int msgflg)
+{
+ return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, compat_do_msg_fill);
+}
+
/* Provide the compat syscall number to call mapping. */
#undef __SYSCALL
#define __SYSCALL(nr, call) [nr] = (call),
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 4e89039..6e035dc 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -245,6 +245,7 @@ struct compat_sysctl_args;
struct compat_kexec_segment;
struct compat_mq_attr;
struct compat_msgbuf;
+struct msg_msg;
extern void compat_exit_robust_list(struct task_struct *curr);
@@ -258,6 +259,7 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr,
#ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
long compat_sys_semctl(int first, int second, int third, void __user *uptr);
long compat_sys_msgsnd(int first, int second, int third, void __user *uptr);
+long compat_do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz);
long compat_sys_msgrcv(int first, int second, int msgtyp, int third,
int version, void __user *uptr);
long compat_sys_shmat(int first, int second, compat_uptr_t third, int version,
diff --git a/include/linux/msg.h b/include/linux/msg.h
index 6689e73..9411b76 100644
--- a/include/linux/msg.h
+++ b/include/linux/msg.h
@@ -105,8 +105,9 @@ struct msg_queue {
/* Helper routines for sys_msgsnd and sys_msgrcv */
extern long do_msgsnd(int msqid, long mtype, void __user *mtext,
size_t msgsz, int msgflg);
-extern long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
- size_t msgsz, long msgtyp, int msgflg);
+extern long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
+ int msgflg,
+ long (*msg_fill)(void __user *, struct msg_msg *, size_t ));
#endif /* __KERNEL__ */
diff --git a/ipc/compat.c b/ipc/compat.c
index 7cfdb5b..6b07f5c 100644
--- a/ipc/compat.c
+++ b/ipc/compat.c
@@ -341,13 +341,23 @@ long compat_sys_msgsnd(int first, int second, int third, void __user *uptr)
return do_msgsnd(first, type, up->mtext, second, third);
}
+long compat_do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
+{
+ struct compat_msgbuf __user *msgp;
+ size_t msgsz;
+
+ if (put_user(msg->m_type, &msgp->mtype))
+ return -EFAULT;
+
+ msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
+ if (store_msg(msgp->mtext, msg, msgsz))
+ return -EFAULT;
+ return msgsz;
+}
+
long compat_sys_msgrcv(int first, int second, int msgtyp, int third,
int version, void __user *uptr)
{
- struct compat_msgbuf __user *up;
- long type;
- int err;
-
if (first < 0)
return -EINVAL;
if (second < 0)
@@ -355,23 +365,14 @@ long compat_sys_msgrcv(int first, int second, int msgtyp, int third,
if (!version) {
struct compat_ipc_kludge ipck;
- err = -EINVAL;
if (!uptr)
- goto out;
- err = -EFAULT;
+ return -EINVAL;
if (copy_from_user (&ipck, uptr, sizeof(ipck)))
- goto out;
+ return -EFAULT;
uptr = compat_ptr(ipck.msgp);
msgtyp = ipck.msgtyp;
}
- up = uptr;
- err = do_msgrcv(first, &type, up->mtext, second, msgtyp, third);
- if (err < 0)
- goto out;
- if (put_user(type, &up->mtype))
- err = -EFAULT;
-out:
- return err;
+ return do_msgrcv(first, uptr, second, msgtyp, third, compat_do_msg_fill);
}
#else
long compat_sys_semctl(int semid, int semnum, int cmd, int arg)
diff --git a/ipc/msg.c b/ipc/msg.c
index 6bd66d3..08009f5 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -762,15 +762,30 @@ static inline int convert_mode(long *msgtyp, int msgflg)
return SEARCH_EQUAL;
}
-long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
- size_t msgsz, long msgtyp, int msgflg)
+static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
+{
+ struct msgbuf __user *msgp = dest;
+ size_t msgsz;
+
+ if (put_user(msg->m_type, &msgp->mtype))
+ return -EFAULT;
+
+ msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
+ if (store_msg(msgp->mtext, msg, msgsz))
+ return -EFAULT;
+ return msgsz;
+}
+
+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 ))
{
struct msg_queue *msq;
struct msg_msg *msg;
int mode;
struct ipc_namespace *ns;
- if (msqid < 0 || (long) msgsz < 0)
+ if (msqid < 0 || (long) bufsz < 0)
return -EINVAL;
mode = convert_mode(&msgtyp, msgflg);
ns = current->nsproxy->ipc_ns;
@@ -813,7 +828,7 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
* Found a suitable message.
* Unlink it from the queue.
*/
- if ((msgsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
+ if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
msg = ERR_PTR(-E2BIG);
goto out_unlock;
}
@@ -840,7 +855,7 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
if (msgflg & MSG_NOERROR)
msr_d.r_maxsize = INT_MAX;
else
- msr_d.r_maxsize = msgsz;
+ msr_d.r_maxsize = bufsz;
msr_d.r_msg = ERR_PTR(-EAGAIN);
current->state = TASK_INTERRUPTIBLE;
msg_unlock(msq);
@@ -903,29 +918,16 @@ out_unlock:
if (IS_ERR(msg))
return PTR_ERR(msg);
- msgsz = (msgsz > msg->m_ts) ? msg->m_ts : msgsz;
- *pmtype = msg->m_type;
- if (store_msg(mtext, msg, msgsz))
- msgsz = -EFAULT;
-
+ bufsz = msg_handler(buf, msg, bufsz);
free_msg(msg);
- return msgsz;
+ return bufsz;
}
SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
long, msgtyp, int, msgflg)
{
- long err, mtype;
-
- err = do_msgrcv(msqid, &mtype, msgp->mtext, msgsz, msgtyp, msgflg);
- if (err < 0)
- goto out;
-
- if (put_user(mtype, &msgp->mtype))
- err = -EFAULT;
-out:
- return err;
+ return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
}
#ifdef CONFIG_PROC_FS
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