From e7a3e8b2edf544ec28f689385c3adc2903f46ec0 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sun, 11 Mar 2018 11:34:41 +0100 Subject: fs: add ksys_write() helper; remove in-kernel calls to sys_write() Using this helper allows us to avoid the in-kernel calls to the sys_write() 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_write(). In the near future, the do_mounts / initramfs callers of ksys_write() should be converted to use filp_open() and vfs_write() instead. 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: Alexander Viro Cc: linux-s390@vger.kernel.org Signed-off-by: Dominik Brodowski --- fs/read_write.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'fs') diff --git a/fs/read_write.c b/fs/read_write.c index f8547b82dfb3..8e8f0b4f52e2 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -578,8 +578,7 @@ SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) return ret; } -SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, - size_t, count) +ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count) { struct fd f = fdget_pos(fd); ssize_t ret = -EBADF; @@ -595,6 +594,12 @@ SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, return ret; } +SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, + size_t, count) +{ + return ksys_write(fd, buf, count); +} + SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, size_t, count, loff_t, pos) { -- cgit v1.2.3