mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to sys_mmap_pgoff()

Using this helper allows us to avoid the in-kernel calls to the
sys_mmap_pgoff() 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_mmap_pgoff().

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: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
This commit is contained in:
Dominik Brodowski
2018-03-11 11:34:46 +01:00
parent 9d5b7c956b
commit a90f590a1b
21 changed files with 60 additions and 41 deletions

View File

@@ -442,8 +442,8 @@ COMPAT_SYSCALL_DEFINE1(s390_old_mmap, struct mmap_arg_struct_emu31 __user *, arg
return -EFAULT;
if (a.offset & ~PAGE_MASK)
return -EINVAL;
return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
a.offset >> PAGE_SHIFT);
return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
a.offset >> PAGE_SHIFT);
}
COMPAT_SYSCALL_DEFINE1(s390_mmap2, struct mmap_arg_struct_emu31 __user *, arg)
@@ -452,7 +452,7 @@ COMPAT_SYSCALL_DEFINE1(s390_mmap2, struct mmap_arg_struct_emu31 __user *, arg)
if (copy_from_user(&a, arg, sizeof(a)))
return -EFAULT;
return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
}
COMPAT_SYSCALL_DEFINE3(s390_read, unsigned int, fd, char __user *, buf, compat_size_t, count)

View File

@@ -53,7 +53,7 @@ SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
if (copy_from_user(&a, arg, sizeof(a)))
goto out;
error = sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
error = ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
out:
return error;
}