ipc: add shmctl syscall/compat_syscall wrappers

Provide ksys_shmctl() and compat_ksys_shmctl() 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_shmctl() and compat_sys_shmctl().

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 20:12:33 +01:00
parent da1e274434
commit c84d0791df
3 changed files with 16 additions and 4 deletions

View File

@ -1045,7 +1045,7 @@ out_unlock1:
return err;
}
SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf)
{
int err, version;
struct ipc_namespace *ns;
@ -1099,6 +1099,11 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
}
}
SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
{
return ksys_shmctl(shmid, cmd, buf);
}
#ifdef CONFIG_COMPAT
struct compat_shmid_ds {
@ -1218,7 +1223,7 @@ static int copy_compat_shmid_from_user(struct shmid64_ds *out, void __user *buf,
}
}
COMPAT_SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, void __user *, uptr)
long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr)
{
struct ipc_namespace *ns;
struct shmid64_ds sem64;
@ -1273,6 +1278,11 @@ COMPAT_SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, void __user *, uptr)
}
return err;
}
COMPAT_SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, void __user *, uptr)
{
return compat_ksys_shmctl(shmid, cmd, uptr);
}
#endif
/*

View File

@ -94,7 +94,7 @@ SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
case SHMGET:
return ksys_shmget(first, second, third);
case SHMCTL:
return sys_shmctl(first, second,
return ksys_shmctl(first, second,
(struct shmid_ds __user *) ptr);
default:
return -ENOSYS;
@ -182,7 +182,7 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
case SHMGET:
return ksys_shmget(first, (unsigned int)second, third);
case SHMCTL:
return compat_sys_shmctl(first, second, compat_ptr(ptr));
return compat_ksys_shmctl(first, second, compat_ptr(ptr));
}
return -ENOSYS;

View File

@ -245,6 +245,7 @@ long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg);
long ksys_msgget(key_t key, int msgflg);
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);
/* for CONFIG_ARCH_WANT_OLD_COMPAT_IPC */
#ifdef CONFIG_COMPAT
@ -252,6 +253,7 @@ 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_shmctl(int shmid, int cmd, void __user *uptr);
#endif /* CONFIG_COMPAT */
#endif