All of lore.kernel.org
 help / color / mirror / Atom feed
From: Vasily Averin <vvs@virtuozzo.com>
To: linux-fsdevel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Subject: [PATCH] epoll: extra check in ep_item_poll()
Date: Sun, 7 Jun 2020 10:10:26 +0300	[thread overview]
Message-ID: <f56c28cb-565c-6cc0-8ed6-34492cacc300@virtuozzo.com> (raw)

reported by smatch:
fs/eventpoll.c:891 ep_item_poll() warn:
 variable dereferenced before check 'pt' (see line 885)

ep_item_poll() is newer called with empty 'pt' argument,
and it is dereferenced in the beginning of this function,
so 'pt' check in line 891 looks useless

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
---
 fs/eventpoll.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 12eebcd..5ddb549 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -888,7 +888,7 @@ static __poll_t ep_item_poll(const struct epitem *epi, poll_table *pt,
 
 	ep = epi->ffd.file->private_data;
 	poll_wait(epi->ffd.file, &ep->poll_wait, pt);
-	locked = pt && (pt->_qproc == ep_ptable_queue_proc);
+	locked = (pt->_qproc == ep_ptable_queue_proc);
 
 	return ep_scan_ready_list(epi->ffd.file->private_data,
 				  ep_read_events_proc, &depth, depth,
-- 
1.8.3.1


                 reply	other threads:[~2020-06-07  7:10 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=f56c28cb-565c-6cc0-8ed6-34492cacc300@virtuozzo.com \
    --to=vvs@virtuozzo.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=viro@zeniv.linux.org.uk \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.