All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [patch] hangcheck-timer: cleanup casting in hangcheck_init()
Date: Wed, 29 Oct 2014 08:42:50 +0000	[thread overview]
Message-ID: <20141029084250.GA8939@mwanda> (raw)

The 32 bit addition "(hangcheck_margin + hangcheck_tick)" could
potentially overflow.  It triggers a static checker warning to have an
overflowed addition followed by a no-op cast.  I have moved the cast so
that the addition can't overflow.

Also I removed the unneeded cast on the following line since both
"hangcheck_tsc_margin" and "TIMER_FREQ" are already 64 bit types.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/char/hangcheck-timer.c b/drivers/char/hangcheck-timer.c
index ebc4c73..a7c5c59 100644
--- a/drivers/char/hangcheck-timer.c
+++ b/drivers/char/hangcheck-timer.c
@@ -168,8 +168,8 @@ static int __init hangcheck_init(void)
 	printk("Hangcheck: starting hangcheck timer %s (tick is %d seconds, margin is %d seconds).\n",
 	       VERSION_STR, hangcheck_tick, hangcheck_margin);
 	hangcheck_tsc_margin -		(unsigned long long)(hangcheck_margin + hangcheck_tick);
-	hangcheck_tsc_margin *= (unsigned long long)TIMER_FREQ;
+		(unsigned long long)hangcheck_margin + hangcheck_tick;
+	hangcheck_tsc_margin *= TIMER_FREQ;
 
 	hangcheck_tsc = ktime_get_ns();
 	mod_timer(&hangcheck_ticktock, jiffies + (hangcheck_tick*HZ));

WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [patch] hangcheck-timer: cleanup casting in hangcheck_init()
Date: Wed, 29 Oct 2014 11:42:50 +0300	[thread overview]
Message-ID: <20141029084250.GA8939@mwanda> (raw)

The 32 bit addition "(hangcheck_margin + hangcheck_tick)" could
potentially overflow.  It triggers a static checker warning to have an
overflowed addition followed by a no-op cast.  I have moved the cast so
that the addition can't overflow.

Also I removed the unneeded cast on the following line since both
"hangcheck_tsc_margin" and "TIMER_FREQ" are already 64 bit types.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/char/hangcheck-timer.c b/drivers/char/hangcheck-timer.c
index ebc4c73..a7c5c59 100644
--- a/drivers/char/hangcheck-timer.c
+++ b/drivers/char/hangcheck-timer.c
@@ -168,8 +168,8 @@ static int __init hangcheck_init(void)
 	printk("Hangcheck: starting hangcheck timer %s (tick is %d seconds, margin is %d seconds).\n",
 	       VERSION_STR, hangcheck_tick, hangcheck_margin);
 	hangcheck_tsc_margin =
-		(unsigned long long)(hangcheck_margin + hangcheck_tick);
-	hangcheck_tsc_margin *= (unsigned long long)TIMER_FREQ;
+		(unsigned long long)hangcheck_margin + hangcheck_tick;
+	hangcheck_tsc_margin *= TIMER_FREQ;
 
 	hangcheck_tsc = ktime_get_ns();
 	mod_timer(&hangcheck_ticktock, jiffies + (hangcheck_tick*HZ));

             reply	other threads:[~2014-10-29  8:42 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-29  8:42 Dan Carpenter [this message]
2014-10-29  8:42 ` [patch] hangcheck-timer: cleanup casting in hangcheck_init() Dan Carpenter

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=20141029084250.GA8939@mwanda \
    --to=dan.carpenter@oracle.com \
    --cc=arnd@arndb.de \
    --cc=gregkh@linuxfoundation.org \
    --cc=kernel-janitors@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    /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.