Commit 2dae0248 authored by Dominik Brodowski's avatar Dominik Brodowski
Browse files

fs: add do_readlinkat() helper; remove internal call to sys_readlinkat() 

Using the do_readlinkat() helper removes an in-kernel call to the
sys_readlinkat() syscall.

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 <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarDominik Brodowski <linux@dominikbrodowski.net>
parent af03c4ac

fs/stat.c

+9 −3
Original line number Diff line number Diff line
@@ -379,8 +379,8 @@ SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf) 
	return error;

}



SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,

		char __user *, buf, int, bufsiz)

static int do_readlinkat(int dfd, const char __user *pathname,

			 char __user *buf, int bufsiz)

{

	struct path path;

	int error;
@@ -415,10 +415,16 @@ SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname, 
	return error;

}



SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,

		char __user *, buf, int, bufsiz)

{

	return do_readlinkat(dfd, pathname, buf, bufsiz);

}



SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,

		int, bufsiz)

{

	return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);

	return do_readlinkat(AT_FDCWD, path, buf, bufsiz);

}