From 078faac9e8b6c8124bc012bbf97cca59caf6d4ea Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Tue, 20 Mar 2018 21:25:57 +0100 Subject: ipc: add msgrcv syscall/compat_syscall wrappers Provide ksys_msgrcv() and compat_ksys_msgrcv() 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_msgrcv() and compat_sys_msgrcv(). 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 Cc: Andrew Morton Signed-off-by: Dominik Brodowski --- ipc/msg.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) (limited to 'ipc/msg.c') diff --git a/ipc/msg.c b/ipc/msg.c index 5b026868df07..abc5826270a6 100644 --- a/ipc/msg.c +++ b/ipc/msg.c @@ -1150,10 +1150,16 @@ out_unlock1: return bufsz; } +long ksys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz, + long msgtyp, int msgflg) +{ + return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill); +} + SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz, long, msgtyp, int, msgflg) { - return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill); + return ksys_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg); } #ifdef CONFIG_COMPAT @@ -1171,12 +1177,19 @@ static long compat_do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bu return msgsz; } -COMPAT_SYSCALL_DEFINE5(msgrcv, int, msqid, compat_uptr_t, msgp, - compat_ssize_t, msgsz, compat_long_t, msgtyp, int, msgflg) +long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz, + compat_long_t msgtyp, int msgflg) { return do_msgrcv(msqid, compat_ptr(msgp), (ssize_t)msgsz, (long)msgtyp, msgflg, compat_do_msg_fill); } + +COMPAT_SYSCALL_DEFINE5(msgrcv, int, msqid, compat_uptr_t, msgp, + compat_ssize_t, msgsz, compat_long_t, msgtyp, + int, msgflg) +{ + return compat_ksys_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg); +} #endif int msg_init_ns(struct ipc_namespace *ns) -- cgit v1.2.3-59-g8ed1b