From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55873) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1azlBb-00018N-NS for qemu-devel@nongnu.org; Mon, 09 May 2016 09:25:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1azlBW-00042J-IP for qemu-devel@nongnu.org; Mon, 09 May 2016 09:25:22 -0400 From: Laurent Vivier Date: Mon, 9 May 2016 15:24:59 +0200 Message-Id: <1462800299-12641-6-git-send-email-lvivier@redhat.com> In-Reply-To: <1462800299-12641-1-git-send-email-lvivier@redhat.com> References: <1462800299-12641-1-git-send-email-lvivier@redhat.com> Subject: [Qemu-devel] [PATCH v2 5/5] ppc: Remove a potential overflow in muldiv64() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, qemu-trivial@nongnu.org Cc: Richard Henderson , Laurent Vivier The coccinelle script: scripts/coccinelle/overflow_muldiv64.cocci gives us a list of potential overflows in muldiv64() (the two first parameters are 64bit values). This patch fixes one, as the fix seems obvious: replace muldiv64(a, b, c) by muldiv64(b, a, c) as "a" and "b" are 64bit values but a <= NANOSECONDS_PER_SECOND. (10^9 -> 30bit value). Signed-off-by: Laurent Vivier --- hw/ppc/ppc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c index 38ff2e1..07ea47c 100644 --- a/hw/ppc/ppc.c +++ b/hw/ppc/ppc.c @@ -880,7 +880,7 @@ static int timebase_post_load(void *opaque, int version_id) host_ns = qemu_clock_get_ns(QEMU_CLOCK_HOST); ns_diff = MAX(0, host_ns - tb_remote->time_of_the_day_ns); migration_duration_ns = MIN(NANOSECONDS_PER_SECOND, ns_diff); - migration_duration_tb = muldiv64(migration_duration_ns, freq, + migration_duration_tb = muldiv64(freq, migration_duration_ns, NANOSECONDS_PER_SECOND); guest_tb = tb_remote->guest_timebase + MIN(0, migration_duration_tb); -- 2.5.5