Subject: Re: next: LTP: syscalls: epoll_clt() if fd is an invalid fd expected EBADF: EINVAL (22)

From: Jens Axboe <[email-masked]>
Date: Wed, 7 Dec 2022 09:22:45 -0700

On 12/7/22 8:58?AM, Naresh Kamboju wrote:
> LTP syscalls epoll_ctl02 is failing on Linux next master.
> The reported problem is always reproducible and starts from next-20221205.
> 
> GOOD tag: next-20221202
> BAD tag: next-20221205
> 
> tst_test.c:1524: TINFO: Timeout per run is 0h 05m 00s
> epoll_ctl02.c:87: TPASS: epoll_clt(...) if epfd is an invalid fd : EBADF (9)
> epoll_ctl02.c:87: TPASS: epoll_clt(...) if fd does not support epoll : EPERM (1)
> epoll_ctl02.c:87: TFAIL: epoll_clt(...) if fd is an invalid fd
> expected EBADF: EINVAL (22)
> epoll_ctl02.c:87: TPASS: epoll_clt(...) if op is not supported : EINVAL (22)
> epoll_ctl02.c:87: TPASS: epoll_clt(...) if fd is the same as epfd : EINVAL (22)
> epoll_ctl02.c:87: TPASS: epoll_clt(...) if events is NULL : EFAULT (14)
> epoll_ctl02.c:87: TPASS: epoll_clt(...) if fd is not registered with
> EPOLL_CTL_DEL : ENOENT (2)
> epoll_ctl02.c:87: TPASS: epoll_clt(...) if fd is not registered with
> EPOLL_CTL_MOD : ENOENT (2)
> epoll_ctl02.c:87: TPASS: epoll_clt(...) if fd is already registered
> with EPOLL_CTL_ADD : EEXIST (17)

This should fix it:

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index ec7ffce8265a..de9c551e1993 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -2195,6 +2195,7 @@ int do_epoll_ctl(int epfd, int op, int fd, struct epoll_event *epds,
 	}
 
 	/* Get the "struct file *" for the target file */
+	error = -EBADF;
 	tf = fdget(fd);
 	if (!tf.file)
 		goto error_fput;

-- 
Jens Axboe