From: Lukas Sismis <lsismis@oisf.net>
Date: Tue, 22 Jul 2025 07:57:38 +0000 (+0200)
Subject: hyperscan: prevent LTO opmitizing out hash calculation
X-Git-Tag: suricata-8.0.1~93
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e4a406d375bad00ea4d73d49cb1ad777042c105c;p=thirdparty%2Fsuricata.git

hyperscan: prevent LTO opmitizing out hash calculation

Since cached_hash was updated through reference (hash), it seems
LTO did not notice this and optimized the whole code block, returning
zero.
This in turn caused all caches to have the same name and to overwrite.
On subsequent runs, only the last cache was loaded for all SGHs
causing wrong MPM assignment.

Ticket: 7824
---

diff --git a/src/util-mpm-hs-cache.c b/src/util-mpm-hs-cache.c
index 4aaf5da84c..2e58676fa9 100644
--- a/src/util-mpm-hs-cache.c
+++ b/src/util-mpm-hs-cache.c
@@ -222,14 +222,12 @@ cleanup:
 
 uint64_t HSHashDb(const PatternDatabase *pd)
 {
-    uint64_t cached_hash = 0;
-    uint32_t *hash = (uint32_t *)(&cached_hash);
+    uint32_t hash[2] = { 0 };
     hashword2(&pd->pattern_cnt, 1, &hash[0], &hash[1]);
     for (uint32_t i = 0; i < pd->pattern_cnt; i++) {
         SCHSCachePatternHash(pd->parray[i], &hash[0], &hash[1]);
     }
-
-    return cached_hash;
+    return ((uint64_t)hash[1] << 32) | hash[0];
 }
 
 void HSSaveCacheIterator(void *data, void *aux)