ipc: add semget syscall wrapper

Provide ksys_semget() wrapper to avoid in-kernel calls to this syscall.
The ksys_ prefix denotes that this function is meant as a drop-in
replacement for the syscall. In particular, it uses the same calling
convention as sys_semget().

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 19:53:58 +01:00
parent 41f4f0e2f5
commit 69894718a5
3 changed files with 9 additions and 3 deletions

View File

@ -556,7 +556,7 @@ static inline int sem_more_checks(struct kern_ipc_perm *ipcp,
return 0; return 0;
} }
SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg) long ksys_semget(key_t key, int nsems, int semflg)
{ {
struct ipc_namespace *ns; struct ipc_namespace *ns;
static const struct ipc_ops sem_ops = { static const struct ipc_ops sem_ops = {
@ -578,6 +578,11 @@ SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg)
return ipcget(ns, &sem_ids(ns), &sem_ops, &sem_params); return ipcget(ns, &sem_ids(ns), &sem_ops, &sem_params);
} }
SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg)
{
return ksys_semget(key, nsems, semflg);
}
/** /**
* perform_atomic_semop[_slow] - Attempt to perform semaphore * perform_atomic_semop[_slow] - Attempt to perform semaphore
* operations on a given array. * operations on a given array.

View File

@ -35,7 +35,7 @@ SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
(const struct timespec __user *)fifth); (const struct timespec __user *)fifth);
case SEMGET: case SEMGET:
return sys_semget(first, second, third); return ksys_semget(first, second, third);
case SEMCTL: { case SEMCTL: {
unsigned long arg; unsigned long arg;
if (!ptr) if (!ptr)
@ -132,7 +132,7 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
return compat_ksys_semtimedop(first, compat_ptr(ptr), second, return compat_ksys_semtimedop(first, compat_ptr(ptr), second,
compat_ptr(fifth)); compat_ptr(fifth));
case SEMGET: case SEMGET:
return sys_semget(first, second, third); return ksys_semget(first, second, third);
case SEMCTL: case SEMCTL:
if (!ptr) if (!ptr)
return -EINVAL; return -EINVAL;

View File

@ -240,6 +240,7 @@ static inline int compat_ipc_parse_version(int *cmd)
long ksys_semtimedop(int semid, struct sembuf __user *tsops, long ksys_semtimedop(int semid, struct sembuf __user *tsops,
unsigned int nsops, unsigned int nsops,
const struct timespec __user *timeout); const struct timespec __user *timeout);
long ksys_semget(key_t key, int nsems, int semflg);
/* for CONFIG_ARCH_WANT_OLD_COMPAT_IPC */ /* for CONFIG_ARCH_WANT_OLD_COMPAT_IPC */
#ifdef CONFIG_COMPAT #ifdef CONFIG_COMPAT