From: Anatoly Burakov <anatoly.burakov@intel.com>
Date: Thu, 3 May 2018 13:03:19 +0000 (+0100)
Subject: mem: fix potential underflow on mem size calculation
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=d2bd796d7bd45f6a14eeb68cd4b5faee244f11ec;p=dpdk.git

mem: fix potential underflow on mem size calculation

If total memory is already bigger than max memory, an underflow
will occur on subtraction. Fix it by simply stopping whenever
we already have amount of memory that is bigger than maximum.

Fixes: 66cc45e293ed ("mem: replace memseg with memseg lists")

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---

diff --git a/lib/librte_eal/common/eal_common_memory.c b/lib/librte_eal/common/eal_common_memory.c
index 4f13b58534..4f0688f9d5 100644
--- a/lib/librte_eal/common/eal_common_memory.c
+++ b/lib/librte_eal/common/eal_common_memory.c
@@ -458,6 +458,9 @@ memseg_primary_init(void)
 				break;
 #endif
 
+			if (total_mem >= max_mem)
+				break;
+
 			max_type_mem = RTE_MIN(max_mem - total_mem,
 				(uint64_t)RTE_MAX_MEM_MB_PER_TYPE << 20);
 			max_segs = RTE_MAX_MEMSEG_PER_TYPE;