Handle false array-bounds warning

Signed-off-by: Paul Dagnelie <[email protected]>

module/zfs/spa.c

@@ -4867,8 +4867,26 @@ spa_load_chain_map(spa_t *spa)
 	    KM_SLEEP);
 	for (zap_cursor_init(&zc, os, chain_map_zap);
 	    zap_cursor_retrieve(&zc, &attr) == 0; zap_cursor_advance(&zc)) {
+
+		/*
+		 * Workaround for GCC 12+ with UBSan enabled deficencies.
+		 *
+		 * GCC 12+ invoked with -fsanitize=undefined incorrectly reports
+		 * the code below as violating -Warray-bounds
+		 */
+#if defined(__GNUC__) && !defined(__clang__) && \
+	((!defined(_KERNEL) && defined(ZFS_UBSAN_ENABLED)) || \
+	    defined(CONFIG_UBSAN))
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
+#endif
 		uint64_t pool_guid = ((uint64_t *)attr.za_name)[0];
 		uint64_t os_guid = ((uint64_t *)attr.za_name)[1];
+#if defined(__GNUC__) && !defined(__clang__) && \
+	((!defined(_KERNEL) && defined(ZFS_UBSAN_ENABLED)) || \
+	    defined(CONFIG_UBSAN))
+#pragma GCC diagnostic pop
+#endif
 		error = zap_lookup_uint64(os, chain_map_zap,
 		    (uint64_t *)attr.za_name, 2, sizeof (uint64_t),
 		    sizeof (*szcmv) / sizeof (uint64_t),