From 2ca2a09d6215fd9621aa3e2db7cc9428a61f2911 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sun, 11 Mar 2018 11:34:55 +0100 Subject: fs: add ksys_close() wrapper; remove in-kernel calls to sys_close() Using the ksys_close() wrapper allows us to get rid of in-kernel calls to the sys_close() 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_close(), with one subtle difference: The few places which checked the return value did not care about the return value re-writing in sys_close(), so simply use a wrapper around __close_fd(). 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 Cc: Andrew Morton Signed-off-by: Dominik Brodowski --- include/linux/syscalls.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/linux/syscalls.h') diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 41023177c8ec..38805f3447ea 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1045,4 +1045,16 @@ static inline long ksys_ftruncate(unsigned int fd, unsigned long length) return do_sys_ftruncate(fd, length, 1); } +extern int __close_fd(struct files_struct *files, unsigned int fd); + +/* + * In contrast to sys_close(), this stub does not check whether the syscall + * should or should not be restarted, but returns the raw error codes from + * __close_fd(). + */ +static inline int ksys_close(unsigned int fd) +{ + return __close_fd(current->files, fd); +} + #endif -- cgit v1.2.3