mem: fix undefined behavior in NUMA-aware mapping

When NUMA-aware hugepages config option is set, we rely on
libnuma to tell the kernel to allocate hugepages on a specific
NUMA node. However, we allocate node mask before we check if
NUMA is available in the first place, which, according to
the manpage [1], causes undefined behaviour.

Fix by only using nodemask when we have NUMA available.

[1] https://linux.die.net/man/3/numa_alloc_onnode

Bugzilla ID: 20
Fixes: 1b72605d2416 ("mem: balanced allocation of hugepages")
Cc: stable@dpdk.org
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Ilya Maximets <i.maximets@samsung.com>

diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c
index e3ac248..78bfa22 100644 (file)
--- a/lib/librte_eal/linuxapp/eal/eal_memory.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
@@ -264,7 +264,7 @@ map_all_hugepages(struct hugepage_file *hugepg_tbl, struct hugepage_info *hpi,
        int node_id = -1;
        int essential_prev = 0;
        int oldpolicy;
-       struct bitmask *oldmask = numa_allocate_nodemask();
+       struct bitmask *oldmask = NULL;
        bool have_numa = true;
        unsigned long maxnode = 0;
 
@@ -276,6 +276,7 @@ map_all_hugepages(struct hugepage_file *hugepg_tbl, struct hugepage_info *hpi,
 
        if (have_numa) {
                RTE_LOG(DEBUG, EAL, "Trying to obtain current memory policy.\n");
+               oldmask = numa_allocate_nodemask();
                if (get_mempolicy(&oldpolicy, oldmask->maskp,
                                  oldmask->size + 1, 0, 0) < 0) {
                        RTE_LOG(ERR, EAL,
@@ -403,7 +404,8 @@ out:
                        numa_set_localalloc();
                }
        }
-       numa_free_cpumask(oldmask);
+       if (oldmask != NULL)
+               numa_free_cpumask(oldmask);
 #endif
        return i;
 }