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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Alexander Viro <viro@zeniv.linux.org.uk>,
	Chris Mason <clm@fb.com>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: linux-fsdevel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [patch -next] eventfd: type bug in eventfd_poll()
Date: Mon, 19 Jan 2015 22:33:19 +0300	[thread overview]
Message-ID: <20150119193319.GA32634@mwanda> (raw)

Since "count" is an unsigned int, then these conditions are never true:

        if (count == ULLONG_MAX)
                events |= POLLERR;
        if (ULLONG_MAX - 1 > count)
                events |= POLLOUT;

It should be a u64, because that's what ctx->count is.  Also GCC
complains that "flags" is unused.

Fixes: a90de8a54127 ('eventfd: don't take the spinlock in eventfd_poll')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/fs/eventfd.c b/fs/eventfd.c
index 439e6f0..8d0c0df 100644
--- a/fs/eventfd.c
+++ b/fs/eventfd.c
@@ -118,8 +118,7 @@ static unsigned int eventfd_poll(struct file *file, poll_table *wait)
 {
 	struct eventfd_ctx *ctx = file->private_data;
 	unsigned int events = 0;
-	unsigned long flags;
-	unsigned int count;
+	u64 count;
 
 	poll_wait(file, &ctx->wqh, wait);
 	smp_rmb();

WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Alexander Viro <viro@zeniv.linux.org.uk>,
	Chris Mason <clm@fb.com>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: linux-fsdevel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [patch -next] eventfd: type bug in eventfd_poll()
Date: Mon, 19 Jan 2015 19:33:19 +0000	[thread overview]
Message-ID: <20150119193319.GA32634@mwanda> (raw)

Since "count" is an unsigned int, then these conditions are never true:

        if (count = ULLONG_MAX)
                events |= POLLERR;
        if (ULLONG_MAX - 1 > count)
                events |= POLLOUT;

It should be a u64, because that's what ctx->count is.  Also GCC
complains that "flags" is unused.

Fixes: a90de8a54127 ('eventfd: don't take the spinlock in eventfd_poll')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/fs/eventfd.c b/fs/eventfd.c
index 439e6f0..8d0c0df 100644
--- a/fs/eventfd.c
+++ b/fs/eventfd.c
@@ -118,8 +118,7 @@ static unsigned int eventfd_poll(struct file *file, poll_table *wait)
 {
 	struct eventfd_ctx *ctx = file->private_data;
 	unsigned int events = 0;
-	unsigned long flags;
-	unsigned int count;
+	u64 count;
 
 	poll_wait(file, &ctx->wqh, wait);
 	smp_rmb();

             reply	other threads:[~2015-01-19 19:33 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-19 19:33 Dan Carpenter [this message]
2015-01-19 19:33 ` [patch -next] eventfd: type bug in eventfd_poll() Dan Carpenter
2015-01-19 19:41 ` Chris Mason
2015-01-19 19:41   ` Chris Mason
2015-01-29 18:56 ` Chris Mason
2015-01-29 18:56   ` Chris Mason
2015-01-30  8:28 ` walter harms

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