[PATCH v3 1/3] eal/freebsd: do not use prev_ms_idx for hole detection

[Jake Freeland <jfree@FreeBSD.org>]

Use rte_fbarray_is_used() to check if the previous fbarray entry is
already empty.

Using prev_ms_idx to do this is flawed in cases where we loop through
multiple memseg lists. Each memseg list has its own count and length,
so using a prev_ms_idx from one memseg list to check for used entries
in another non-empty memseg list can lead to incorrect hole placement.

Signed-off-by: Jake Freeland <jfree@FreeBSD.org>
---
 lib/eal/freebsd/eal_memory.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/lib/eal/freebsd/eal_memory.c b/lib/eal/freebsd/eal_memory.c
index 6d3d46a390..8c315d97d5 100644
--- a/lib/eal/freebsd/eal_memory.c
+++ b/lib/eal/freebsd/eal_memory.c
@@ -103,7 +103,6 @@ rte_eal_hugepage_init(void)
 	for (i = 0; i < internal_conf->num_hugepage_sizes; i++) {
 		struct hugepage_info *hpi;
 		rte_iova_t prev_end = 0;
-		int prev_ms_idx = -1;
 		uint64_t page_sz, mem_needed;
 		unsigned int n_pages, max_pages;
 
@@ -167,9 +166,13 @@ rte_eal_hugepage_init(void)
 				if (ms_idx < 0)
 					continue;
 
-				if (need_hole && prev_ms_idx == ms_idx - 1)
+				/* ms_idx should never be 0 if we need a hole,
+				 * but include a check for static analysis.
+				 */
+				if (need_hole &&
+				    ms_idx > 0 &&
+				    rte_fbarray_is_used(arr, ms_idx - 1))
 					ms_idx++;
-				prev_ms_idx = ms_idx;
 
 				break;
 			}
-- 
2.51.0