Commit 791eb22e authored by Dominik Brodowski's avatar Dominik Brodowski
Browse files

fs: add do_epoll_*() helpers; remove internal calls to sys_epoll_*() 

Using the helper functions do_epoll_create() and do_epoll_wait() allows us
to remove in-kernel calls to the related syscall functions.

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 f1390358

fs/eventpoll.c

+17 −6
Original line number Diff line number Diff line
@@ -1936,7 +1936,7 @@ static void clear_tfile_check_list(void) 
/*

 * Open an eventpoll file descriptor.

 */

SYSCALL_DEFINE1(epoll_create1, int, flags)

static int do_epoll_create(int flags)

{

	int error, fd;

	struct eventpoll *ep = NULL;
@@ -1979,12 +1979,17 @@ SYSCALL_DEFINE1(epoll_create1, int, flags) 
	return error;

}



SYSCALL_DEFINE1(epoll_create1, int, flags)

{

	return do_epoll_create(flags);

}



SYSCALL_DEFINE1(epoll_create, int, size)

{

	if (size <= 0)

		return -EINVAL;



	return sys_epoll_create1(0);

	return do_epoll_create(0);

}



/*
@@ -2148,8 +2153,8 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd, 
 * Implement the event wait interface for the eventpoll file. It is the kernel

 * part of the user space epoll_wait(2).

 */

SYSCALL_DEFINE4(epoll_wait, int, epfd, struct epoll_event __user *, events,

		int, maxevents, int, timeout)

static int do_epoll_wait(int epfd, struct epoll_event __user *events,

			 int maxevents, int timeout)

{

	int error;

	struct fd f;
@@ -2190,6 +2195,12 @@ SYSCALL_DEFINE4(epoll_wait, int, epfd, struct epoll_event __user *, events, 
	return error;

}



SYSCALL_DEFINE4(epoll_wait, int, epfd, struct epoll_event __user *, events,

		int, maxevents, int, timeout)

{

	return do_epoll_wait(epfd, events, maxevents, timeout);

}



/*

 * Implement the event wait interface for the eventpoll file. It is the kernel

 * part of the user space epoll_pwait(2).
@@ -2214,7 +2225,7 @@ SYSCALL_DEFINE6(epoll_pwait, int, epfd, struct epoll_event __user *, events, 
		set_current_blocked(&ksigmask);

	}



	error = sys_epoll_wait(epfd, events, maxevents, timeout);

	error = do_epoll_wait(epfd, events, maxevents, timeout);



	/*

	 * If we changed the signal mask, we need to restore the original one.
@@ -2257,7 +2268,7 @@ COMPAT_SYSCALL_DEFINE6(epoll_pwait, int, epfd, 
		set_current_blocked(&ksigmask);

	}



	err = sys_epoll_wait(epfd, events, maxevents, timeout);

	err = do_epoll_wait(epfd, events, maxevents, timeout);



	/*

	 * If we changed the signal mask, we need to restore the original one.