ipc: add msgctl syscall/compat_syscall wrappers

Provide ksys_msgctl() and compat_ksys_msgctl() 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_msgctl() and compat_sys_msgctl().

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>
This commit is contained in:
Dominik Brodowski 2018-03-20 20:15:28 +01:00
parent c84d0791df
commit e340db5648
3 changed files with 17 additions and 4 deletions

View File

@ -538,7 +538,7 @@ out_unlock:
return err;
}
SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
{
int version;
struct ipc_namespace *ns;
@ -581,6 +581,11 @@ SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
}
}
SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
{
return ksys_msgctl(msqid, cmd, buf);
}
#ifdef CONFIG_COMPAT
struct compat_msqid_ds {
@ -651,7 +656,7 @@ static int copy_compat_msqid_to_user(void __user *buf, struct msqid64_ds *in,
}
}
COMPAT_SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, void __user *, uptr)
long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr)
{
struct ipc_namespace *ns;
int err;
@ -692,6 +697,11 @@ COMPAT_SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, void __user *, uptr)
return -EINVAL;
}
}
COMPAT_SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, void __user *, uptr)
{
return compat_ksys_msgctl(msqid, cmd, uptr);
}
#endif
static int testmsg(struct msg_msg *msg, long type, int mode)

View File

@ -70,7 +70,8 @@ SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
case MSGGET:
return ksys_msgget((key_t) first, second);
case MSGCTL:
return sys_msgctl(first, second, (struct msqid_ds __user *)ptr);
return ksys_msgctl(first, second,
(struct msqid_ds __user *)ptr);
case SHMAT:
switch (version) {
@ -163,7 +164,7 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
case MSGGET:
return ksys_msgget(first, second);
case MSGCTL:
return compat_sys_msgctl(first, second, compat_ptr(ptr));
return compat_ksys_msgctl(first, second, compat_ptr(ptr));
case SHMAT: {
int err;

View File

@ -243,6 +243,7 @@ long ksys_semtimedop(int semid, struct sembuf __user *tsops,
long ksys_semget(key_t key, int nsems, int semflg);
long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg);
long ksys_msgget(key_t key, int msgflg);
long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf);
long ksys_shmget(key_t key, size_t size, int shmflg);
long ksys_shmdt(char __user *shmaddr);
long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf);
@ -253,6 +254,7 @@ long compat_ksys_semtimedop(int semid, struct sembuf __user *tsems,
unsigned int nsops,
const struct compat_timespec __user *timeout);
long compat_ksys_semctl(int semid, int semnum, int cmd, int arg);
long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr);
long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr);
#endif /* CONFIG_COMPAT */