ipc: add msgsnd syscall/compat_syscall wrappers
Provide ksys_msgsnd() and compat_ksys_msgsnd() wrappers to avoid in-kernel
calls to these syscalls. The ksys_ prefix denotes that these functions are
meant as a drop-in replacement for the syscalls. In particular, they use
the same calling convention as sys_msgsnd() and compat_sys_msgsnd().
This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
diff --git a/ipc/msg.c b/ipc/msg.c
index abc5826..9de4806 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -867,8 +867,8 @@ static long do_msgsnd(int msqid, long mtype, void __user *mtext,
return err;
}
-SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
- int, msgflg)
+long ksys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz,
+ int msgflg)
{
long mtype;
@@ -877,6 +877,12 @@ SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg);
}
+SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
+ int, msgflg)
+{
+ return ksys_msgsnd(msqid, msgp, msgsz, msgflg);
+}
+
#ifdef CONFIG_COMPAT
struct compat_msgbuf {
@@ -884,8 +890,8 @@ struct compat_msgbuf {
char mtext[1];
};
-COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp,
- compat_ssize_t, msgsz, int, msgflg)
+long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp,
+ compat_ssize_t msgsz, int msgflg)
{
struct compat_msgbuf __user *up = compat_ptr(msgp);
compat_long_t mtype;
@@ -894,6 +900,12 @@ COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp,
return -EFAULT;
return do_msgsnd(msqid, mtype, up->mtext, (ssize_t)msgsz, msgflg);
}
+
+COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp,
+ compat_ssize_t, msgsz, int, msgflg)
+{
+ return compat_ksys_msgsnd(msqid, msgp, msgsz, msgflg);
+}
#endif
static inline int convert_mode(long *msgtyp, int msgflg)