From 3ce4a7bf66263748194b77ccefd284be963c6304 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Tue, 13 Mar 2018 21:56:26 +0100 Subject: fs: add ksys_read() helper; remove in-kernel calls to sys_read() Using this helper allows us to avoid the in-kernel calls to the sys_read() 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_read(). 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 Signed-off-by: Dominik Brodowski --- fs/read_write.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'fs/read_write.c') diff --git a/fs/read_write.c b/fs/read_write.c index b38b008a078e..fc441e1ac683 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -568,7 +568,7 @@ static inline void file_pos_write(struct file *file, loff_t pos) file->f_pos = pos; } -SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) +ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count) { struct fd f = fdget_pos(fd); ssize_t ret = -EBADF; @@ -583,6 +583,11 @@ SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) return ret; } +SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) +{ + return ksys_read(fd, buf, count); +} + ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count) { struct fd f = fdget_pos(fd); -- cgit v1.2.3