linux-kernel - [ 14/18] timer: Fix jiffies wrap behavior of round_jiffies

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20130719021049.936861329@linuxfoundation.org>
Date:	Thu, 18 Jul 2013 19:23:29 -0700
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org, Bart Van Assche <bvanassche@....org>,
	Arjan van de Ven <arjan@...radead.org>,
	Stephen Rothwell <sfr@...b.auug.org.au>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: [ 14/18] timer: Fix jiffies wrap behavior of round_jiffies_common()

3.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Bart Van Assche <bart.vanassche@...il.com>

commit 9e04d3804d3ac97d8c03a41d78d0f0674b5d01e1 upstream.

Direct compare of jiffies related values does not work in the wrap
around case. Replace it with time_is_after_jiffies().

Signed-off-by: Bart Van Assche <bvanassche@....org>
Cc: Arjan van de Ven <arjan@...radead.org>
Cc: Stephen Rothwell <sfr@...b.auug.org.au>
Link: http://lkml.kernel.org/r/519BC066.5080600@acm.org
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 kernel/timer.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -145,9 +145,11 @@ static unsigned long round_jiffies_commo
 	/* now that we have rounded, subtract the extra skew again */
 	j -= cpu * 3;
 
-	if (j <= jiffies) /* rounding ate our timeout entirely; */
-		return original;
-	return j;
+	/*
+	 * Make sure j is still in the future. Otherwise return the
+	 * unmodified value.
+	 */
+	return time_is_after_jiffies(j) ? j : original;
 }
 
 /**


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/