Merge branch 'journal_stack_overflow' into 'master'

journal: fixed stack overflow by hybrid static-dynamic array

See merge request !732

1 files changed, 14 insertions, 2 deletions

diff --git a/src/knot/journal/journal.c b/src/knot/journal/journal.c
index 8f7599944..ac94050e6 100644
--- a/src/knot/journal/journal.c
+++ b/src/knot/journal/journal.c
@@ -47,6 +47,15 @@
  * uint32_t serial_to + uint32_t chunk_count + 24B unused */
 #define JOURNAL_HEADER_SIZE (32)
 
+// eventually move to contrib and reuse as needed
+#define local_array_max_static_size (100)
+#define local_array(type, name, size, retval) \
+	type name ## _static__[local_array_max_static_size] = { 0 }; \
+	type *name ## _dynamic__ = ((size) > local_array_max_static_size ? calloc((size), sizeof(type)) : NULL); \
+	type *name = ((size) > local_array_max_static_size ? name ## _dynamic__ : name ## _static__); \
+	if ((retval) != 0 && (name) == NULL) { free(name ## _dynamic__); return (retval); }
+#define local_array_free(name) { free(name ## _dynamic__); }
+
 enum {
 	LAST_FLUSHED_VALID   = 1 << 0, /* "last flush is valid" flag. */
 	SERIAL_TO_VALID      = 1 << 1, /* "last serial_to is valid" flag. */
@@ -762,8 +771,9 @@ static int normal_iterkeycb(iteration_ctx_t *ctx)
 static int vals_to_changeset(knot_db_val_t *vals, int nvals,
                              const knot_dname_t *zone_name, changeset_t **ch, bool is_bootstrap)
 {
-	uint8_t *valps[nvals];
-	size_t vallens[nvals];
+	local_array(uint8_t *, valps, nvals, KNOT_ENOMEM)
+	local_array(size_t, vallens, nvals, KNOT_ENOMEM)
+
 	for (int i = 0; i < nvals; i++) {
 		valps[i] = vals[i].data + JOURNAL_HEADER_SIZE;
 		vallens[i] = vals[i].len - JOURNAL_HEADER_SIZE;
@@ -777,6 +787,8 @@ static int vals_to_changeset(knot_db_val_t *vals, int nvals,
 	int ret = is_bootstrap ? changeset_deserialize_bootstrap(t_ch, valps, vallens, nvals)
 	                       : changeset_deserialize(t_ch, valps, vallens, nvals);
 
+	local_array_free(valps)
+	local_array_free(vallens)
 	if (ret != KNOT_EOK) {
 		changeset_free(t_ch);
 		return ret;