Commit d969c6fa authored by Dominik Brodowski's avatar Dominik Brodowski

ipc: add semctl syscall/compat_syscall wrappers

Provide ksys_semctl() and compat_ksys_semctl() 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_semctl() and compat_sys_semctl().

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: default avatarDominik Brodowski <linux@dominikbrodowski.net>
parent 69894718
......@@ -1581,7 +1581,7 @@ static int semctl_down(struct ipc_namespace *ns, int semid,
return err;
}
SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg)
{
int version;
struct ipc_namespace *ns;
......@@ -1635,6 +1635,11 @@ SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
}
}
SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
{
return ksys_semctl(semid, semnum, cmd, arg);
}
#ifdef CONFIG_COMPAT
struct compat_semid_ds {
......@@ -1683,7 +1688,7 @@ static int copy_compat_semid_to_user(void __user *buf, struct semid64_ds *in,
}
}
COMPAT_SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, int, arg)
long compat_ksys_semctl(int semid, int semnum, int cmd, int arg)
{
void __user *p = compat_ptr(arg);
struct ipc_namespace *ns;
......@@ -1727,6 +1732,11 @@ COMPAT_SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, int, arg)
return -EINVAL;
}
}
COMPAT_SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, int, arg)
{
return compat_ksys_semctl(semid, semnum, cmd, arg);
}
#endif
/* If the task doesn't already have a undo_list, then allocate one
......
......@@ -42,7 +42,7 @@ SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
return -EINVAL;
if (get_user(arg, (unsigned long __user *) ptr))
return -EFAULT;
return sys_semctl(first, second, third, arg);
return ksys_semctl(first, second, third, arg);
}
case MSGSND:
......@@ -138,7 +138,7 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
return -EINVAL;
if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
return -EFAULT;
return compat_sys_semctl(first, second, third, pad);
return compat_ksys_semctl(first, second, third, pad);
case MSGSND:
return compat_sys_msgsnd(first, ptr, second, third);
......
......@@ -241,12 +241,14 @@ long ksys_semtimedop(int semid, struct sembuf __user *tsops,
unsigned int nsops,
const struct timespec __user *timeout);
long ksys_semget(key_t key, int nsems, int semflg);
long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg);
/* for CONFIG_ARCH_WANT_OLD_COMPAT_IPC */
#ifdef CONFIG_COMPAT
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);
#endif /* CONFIG_COMPAT */
#endif
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