>From af11020b18f82458527b92c0280619d75881410b Mon Sep 17 00:00:00 2001
From: Lukas Slebodnik <lslebodn@redhat.com>
Date: Sat, 17 Aug 2013 09:13:34 +0200
Subject: [PATCH 1/2] check hash table

---
 src/responder/nss/nsssrv_mmap_cache.c | 72 +++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/src/responder/nss/nsssrv_mmap_cache.c b/src/responder/nss/nsssrv_mmap_cache.c
index c34997b8034d05796687ff7d380b367d5c7bba06..4afee22486cd45fd9a10d86b0eedc85d677ab5ee 100644
--- a/src/responder/nss/nsssrv_mmap_cache.c
+++ b/src/responder/nss/nsssrv_mmap_cache.c
@@ -161,6 +161,68 @@ static uint32_t sss_mc_hash(struct sss_mc_ctx *mcc,
     return murmurhash3(key, len, mcc->seed) % MC_HT_ELEMS(mcc->ht_size);
 }
 
+static char sync_var=0;
+
+#ifdef DEBUG_MCC
+static char seg_var=0;
+#define EXCEPTION do {\
+    seg_var+=1; \
+    return seg_var; \
+}while(0)
+
+#else /* !DEBUG_MCC */
+ #define EXCEPTION do {\
+     char *ptr =NULL;\
+     char b =0;\
+     return b + ptr[0];\
+ }while(0)
+#endif /* DEBUG_MCC */
+
+char sss_check_hash_table(struct sss_mc_ctx *mcc)
+{
+    volatile uint32_t i;
+
+    const uint32_t ht_elems = MC_HT_ELEMS(mcc->ht_size);
+    uint32_t *hash_table = mcc->hash_table;
+
+    volatile uint32_t slot;
+
+    const uint32_t dt_elems = mcc->dt_size / MC_SLOT_SIZE;
+
+    struct sss_mc_rec * volatile rec;
+    for (i=0; i<ht_elems; i++) {
+        slot = hash_table[i];
+        if (slot == MC_INVALID_VAL32) {
+            continue;
+        }
+
+        if (slot >= dt_elems) {
+            EXCEPTION;
+        }
+
+        rec = MC_SLOT_TO_PTR(mcc->data_table, slot, struct sss_mc_rec);
+        if ((rec->b1 == MC_INVALID_VAL) ||
+            (rec->b1 != rec->b2)) {
+            EXCEPTION;
+        }
+
+        if (!MC_CHECK_RECORD_LENGTH(mcc, rec)) {
+            EXCEPTION;
+        }
+
+        if (rec->hash1 >= ht_elems) {
+            EXCEPTION;
+        }
+
+        if (rec->hash2 >= ht_elems) {
+            EXCEPTION;
+        }
+    }
+
+    /* all tests passed */
+    return true;
+}
+
 static void sss_mc_add_rec_to_chain(struct sss_mc_ctx *mcc,
                                     struct sss_mc_rec *rec,
                                     uint32_t hash)
@@ -278,9 +340,15 @@ static void sss_mc_free_slots(struct sss_mc_ctx *mcc, struct sss_mc_rec *rec)
     }
 }
 
+static uint8_t backup_memory[6806312+1];
+
 static void sss_mc_invalidate_rec(struct sss_mc_ctx *mcc,
                                   struct sss_mc_rec *rec)
 {
+    static struct sss_mc_rec backup;
+    memcpy(&backup, rec, sizeof(backup));
+    memcpy(backup_memory, mcc->mmap_base, mcc->mmap_size);
+
     if (rec->b1 == MC_INVALID_VAL) {
         /* record already invalid */
         return;
@@ -305,6 +373,9 @@ static void sss_mc_invalidate_rec(struct sss_mc_ctx *mcc,
     rec->hash1 = MC_INVALID_VAL32;
     rec->hash2 = MC_INVALID_VAL32;
     MC_LOWER_BARRIER(rec);
+
+    sync_var += sss_check_hash_table(mcc);
+    (void) backup; /* unused, debug purpose */
 }
 
 static bool sss_mc_is_valid_rec(struct sss_mc_ctx *mcc, struct sss_mc_rec *rec)
@@ -733,6 +804,7 @@ errno_t sss_mmap_cache_pw_store(struct sss_mc_ctx **_mcc,
 
     /* finally chain the rec in the hash table */
     sss_mmap_chain_in_rec(mcc, rec);
+    sync_var += sss_check_hash_table(mcc);
 
     return EOK;
 }
-- 
1.8.3.1