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From: Tim Deegan <tim@xen.org>
To: xen-devel@lists.xen.org
Cc: Liu Jinsong <jinsong.liu@intel.com>, Jan Beulich <jbeulich@suse.com>
Subject: [PATCH 5/9] cpufreq: avoid integer overflows.
Date: Thu, 12 Sep 2013 13:15:26 +0100	[thread overview]
Message-ID: <1378988130-24172-6-git-send-email-tim@xen.org> (raw)
In-Reply-To: <1378988130-24172-1-git-send-email-tim@xen.org>

The def_sampling_rate() one is, I think, a real bug.  The others were
spotted at the same time and are probably not bugs until we start
dealing with 40GHz CPus.

Coverity CID 1055682
Coverity CID 1055683

Signed-off-by: Tim Deegan <tim@xen.org>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Liu Jinsong <jinsong.liu@intel.com>
---
 xen/drivers/cpufreq/cpufreq_ondemand.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/xen/drivers/cpufreq/cpufreq_ondemand.c b/xen/drivers/cpufreq/cpufreq_ondemand.c
index b3f9ab8..7fdba03 100644
--- a/xen/drivers/cpufreq/cpufreq_ondemand.c
+++ b/xen/drivers/cpufreq/cpufreq_ondemand.c
@@ -144,7 +144,7 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
     }
 
     /* Check for frequency increase */
-    if (max_load_freq > dbs_tuners_ins.up_threshold * policy->cur) {
+    if (max_load_freq > (uint64_t) dbs_tuners_ins.up_threshold * policy->cur) {
         /* if we are already at full speed then break out early */
         if (policy->cur == max)
             return;
@@ -162,7 +162,8 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
      * can support the current CPU usage without triggering the up
      * policy. To be safe, we focus 10 points under the threshold.
      */
-    if (max_load_freq < (dbs_tuners_ins.up_threshold - 10) * policy->cur) {
+    if (max_load_freq
+        < (uint64_t) (dbs_tuners_ins.up_threshold - 10) * policy->cur) {
         uint64_t freq_next;
 
         freq_next = max_load_freq / (dbs_tuners_ins.up_threshold - 10);
@@ -246,7 +247,7 @@ int cpufreq_governor_dbs(struct cpufreq_policy *policy, unsigned int event)
          * is used for first time
          */
         if ((dbs_enable == 1) && !dbs_tuners_ins.sampling_rate) {
-            def_sampling_rate = policy->cpuinfo.transition_latency *
+            def_sampling_rate = (uint64_t) policy->cpuinfo.transition_latency *
                 DEF_SAMPLING_RATE_LATENCY_MULTIPLIER;
 
             if (def_sampling_rate < MIN_STAT_SAMPLING_RATE)
-- 
1.7.10.4

  parent reply	other threads:[~2013-09-12 12:15 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-12 12:15 More Coverity-reported issues Tim Deegan
2013-09-12 12:15 ` [PATCH 1/9] x86/mm: Don't dereference p2m pointer before NULL check Tim Deegan
2013-09-12 12:15 ` [PATCH 2/9] passthrough/amd: Drop unnecessary lock lookup Tim Deegan
2013-09-12 13:35   ` Jan Beulich
2013-09-12 12:15 ` [PATCH 3/9] passthrough/amd: Missing 'break' Tim Deegan
2013-09-17 15:04   ` Suravee Suthikulpanit
2013-09-12 12:15 ` [PATCH 4/9] passthrough/amd: Shuffle declaration Tim Deegan
2013-09-12 13:38   ` Jan Beulich
2013-09-12 13:44     ` Tim Deegan
2013-09-12 14:03       ` Jan Beulich
2013-09-17 15:19         ` Suravee Suthikulpanit
2013-09-12 12:15 ` Tim Deegan [this message]
2013-09-12 13:49   ` [PATCH 5/9] cpufreq: avoid integer overflows Jan Beulich
2013-09-13  7:18   ` Liu, Jinsong
2013-09-12 12:15 ` [PATCH 6/9] cpufreq: missing check of copy_from_guest() Tim Deegan
2013-09-12 13:54   ` Jan Beulich
2013-09-13  7:18   ` Liu, Jinsong
2013-09-12 12:15 ` [PATCH 7/9] ehci-dbgp: avoid division by zero Tim Deegan
2013-09-12 13:55   ` Jan Beulich
2013-09-12 12:15 ` [PATCH 8/9] ehci-dbgp: drop dead code Tim Deegan
2013-09-12 14:01   ` Jan Beulich
2013-09-12 12:15 ` [PATCH 9/9] acpi/pmstat: fix check for empty name strings Tim Deegan
2013-09-12 14:02   ` Jan Beulich
2013-09-12 13:11 ` More Coverity-reported issues Andrew Cooper

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