From da332b31effd204778ffc245184810f3b4137246 Mon Sep 17 00:00:00 2001
Message-Id: <da332b31effd204778ffc245184810f3b4137246.1386932211.git.jdenemar@redhat.com>
From: Bing Bu Cao <mars@linux.vnet.ibm.com>
Date: Tue, 10 Dec 2013 10:03:54 +0100
Subject: [PATCH] util: fix two virCompareLimitUlong bugs

https://bugzilla.redhat.com/show_bug.cgi?id=1024272

The helper function virCompareLimitUlong compares limit values,
where value of 0 is equal to unlimited. If the latter parameter is 0,
it should return -1 instead of 1, hence the user can only set hard_limit when
swap_hard_limit currently is unlimited.

Worse, all callers pass 2 64-bit values, but on 32-bit platforms,
the second argument was silently truncated to 32 bits, which
could lead to incorrect computations.

Signed-off-by: Bing Bu Cao <mars@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit 19e7c04dce34afeb9a762471e09777de7d219db8)
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/util/virutil.c | 5 ++++-
 src/util/virutil.h | 2 +-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/util/virutil.c b/src/util/virutil.c
index 21827f2..208d0b6 100644
--- a/src/util/virutil.c
+++ b/src/util/virutil.c
@@ -2030,11 +2030,14 @@ virFindFCHostCapableVport(const char *sysfs_prefix ATTRIBUTE_UNUSED)
  * Returns 0 if the numbers are equal, -1 if b is greater, 1 if a is greater.
  */
 int
-virCompareLimitUlong(unsigned long long a, unsigned long b)
+virCompareLimitUlong(unsigned long long a, unsigned long long b)
 {
     if (a == b)
         return 0;
 
+    if (!b)
+        return -1;
+
     if (a == 0 || a > b)
         return 1;
 
diff --git a/src/util/virutil.h b/src/util/virutil.h
index 2c8b0ec..2229c73 100644
--- a/src/util/virutil.h
+++ b/src/util/virutil.h
@@ -172,7 +172,7 @@ char *virGetFCHostNameByWWN(const char *sysfs_prefix,
 
 char *virFindFCHostCapableVport(const char *sysfs_prefix);
 
-int virCompareLimitUlong(unsigned long long a, unsigned long b);
+int virCompareLimitUlong(unsigned long long a, unsigned long long b);
 
 int virParseOwnershipIds(const char *label, uid_t *uidPtr, gid_t *gidPtr);
 
-- 
1.8.5.1