Further robustify nscd database lookup.

We can compute an absolute maximum for the number of elements which
can fit into the currently mapped database.  Stop after that many
iterations.
(cherry picked from commit 831a40494d44045c0caaf8085ab1d35c0da23140)

diff --git a/ChangeLog b/ChangeLog
index a672e153bc4bf0e3de8a560ad2872dfc52433b16..9001fb73c4f82cd3b8519b4b8a9ea52d1b8b7cc2 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2009-05-15  Ulrich Drepper  <drepper@redhat.com>
+
+       * nscd/nscd.h: Move Definition for BLOCK_ALIGN_LOG, BLOCK_ALIGN, and
+       BLOCK_ALIGN_M1 to ...
+       * nscd/nscd-client.h: ...here.
+       * nscd/nscd_helper.c (__nscd_cache_search): Introduce loop counter.
+       Use it if we absolutely cannot reach any more correct list elements
+       because that many do not fit into the currently mapped database.
+
 2009-05-14  Jakub Jelinek  <jakub@redhat.com>
 
        * nscd/nscd_helper.c: Include stddef.h.

diff --git a/nscd/nscd-client.h b/nscd/nscd-client.h
index f66a658d2a8fb402d3f961ae74e96bd208184b3b..81ca3d56b940f209e973d6903cc6b3668dc1a8b4 100644 (file)
--- a/nscd/nscd-client.h
+++ b/nscd/nscd-client.h
@@ -44,9 +44,14 @@
 /* Path for the configuration file.  */
 #define _PATH_NSCDCONF  "/etc/nscd.conf"
 
-/* Maximu allowed length for the key.  */
+/* Maximum allowed length for the key.  */
 #define MAXKEYLEN 1024
 
+/* Maximum alignment requirement we will encounter.  */
+#define BLOCK_ALIGN_LOG 3
+#define BLOCK_ALIGN (1 << BLOCK_ALIGN_LOG)
+#define BLOCK_ALIGN_M1 (BLOCK_ALIGN - 1)
+
 
 /* Available services.  */
 typedef enum

diff --git a/nscd/nscd.h b/nscd/nscd.h
index 3279b8543266307e7f1f4c5dbf50a0d0dee2b767..632bf58dc5c70441739e7d992c3afe93d72801ac 100644 (file)
--- a/nscd/nscd.h
+++ b/nscd/nscd.h
@@ -111,11 +111,6 @@ struct database_dyn
 /* Path used when not using persistent storage.  */
 #define _PATH_NSCD_XYZ_DB_TMP  "/var/run/nscd/dbXXXXXX"
 
-/* Maximum alignment requirement we will encounter.  */
-#define BLOCK_ALIGN_LOG 3
-#define BLOCK_ALIGN (1 << BLOCK_ALIGN_LOG)
-#define BLOCK_ALIGN_M1 (BLOCK_ALIGN - 1)
-
 /* Default value for the maximum size of the database files.  */
 #define DEFAULT_MAX_DB_SIZE    (32 * 1024 * 1024)
 

diff --git a/nscd/nscd_helper.c b/nscd/nscd_helper.c
index db247962b95f77f3fcd562c7ba25f606f6cb1390..80ee3e1dd9769db0423c45705f0100495a4511f0 100644 (file)
--- a/nscd/nscd_helper.c
+++ b/nscd/nscd_helper.c
@@ -481,6 +481,7 @@ __nscd_cache_search (request_type type, const char *key, size_t keylen,
   ref_t trail = mapped->head->array[hash];
   trail = atomic_forced_read (trail);
   ref_t work = trail;
+  size_t loop_cnt = datasize / (offsetof (struct datahead, data) + datalen);
   int tick = 0;
 
   while (work != ENDREF && work + sizeof (struct hashentry) <= datasize)
@@ -527,7 +528,7 @@ __nscd_cache_search (request_type type, const char *key, size_t keylen,
       work = atomic_forced_read (here->next);
       /* Prevent endless loops.  This should never happen but perhaps
         the database got corrupted, accidentally or deliberately.  */
-      if (work == trail)
+      if (work == trail || loop_cnt-- > 0)
        break;
       if (tick)
        {