malloc: protect stats with lock

When we're gathering statistics, we are traversing the freelist,
which may change under our feet in multithreaded scenario. This
is verified by occasional segfaults when running malloc autotest
on a machine with big amount of cores.

This patch protects malloc heap stats call with a lock. It changes
its definition in the process due to locking invalidating the
const-ness, but this isn't a public API, so that's OK.

Fixes: 2a5c356e177d ("memory: stats for malloc")
Cc: stable@dpdk.org
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>

diff --git a/lib/librte_eal/common/malloc_heap.c b/lib/librte_eal/common/malloc_heap.c
index b98b3af92191e6d6daf02bbc0aa59b806b331d72..7aafc880ae8f6523bca3dca62836368d6a89d9fc 100644 (file)
--- a/lib/librte_eal/common/malloc_heap.c
+++ b/lib/librte_eal/common/malloc_heap.c
@@ -149,12 +149,14 @@ malloc_heap_alloc(struct malloc_heap *heap,
  * Function to retrieve data for heap on given socket
  */
 int
-malloc_heap_get_stats(const struct malloc_heap *heap,
+malloc_heap_get_stats(struct malloc_heap *heap,
                struct rte_malloc_socket_stats *socket_stats)
 {
        size_t idx;
        struct malloc_elem *elem;
 
+       rte_spinlock_lock(&heap->lock);
+
        /* Initialise variables for heap */
        socket_stats->free_count = 0;
        socket_stats->heap_freesz_bytes = 0;
@@ -176,6 +178,8 @@ malloc_heap_get_stats(const struct malloc_heap *heap,
        socket_stats->heap_allocsz_bytes = (socket_stats->heap_totalsz_bytes -
                        socket_stats->heap_freesz_bytes);
        socket_stats->alloc_count = heap->alloc_count;
+
+       rte_spinlock_unlock(&heap->lock);
        return 0;
 }
 

diff --git a/lib/librte_eal/common/malloc_heap.h b/lib/librte_eal/common/malloc_heap.h
index be5e6e6613953405a055dc5f1639d483918644aa..e0defa709558c09f28ee40965df1024873751841 100644 (file)
--- a/lib/librte_eal/common/malloc_heap.h
+++ b/lib/librte_eal/common/malloc_heap.h
@@ -28,7 +28,7 @@ malloc_heap_alloc(struct malloc_heap *heap,   const char *type, size_t size,
                unsigned flags, size_t align, size_t bound);
 
 int
-malloc_heap_get_stats(const struct malloc_heap *heap,
+malloc_heap_get_stats(struct malloc_heap *heap,
                struct rte_malloc_socket_stats *socket_stats);
 
 int