[IPV4]: fib_trie stats fix

fib_triestats has been buggy and caused oopses some platforms as
openwrt.  The patch below should cure those problems.

Signed-off-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 6 deletions

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 8aa31fe514ee..ccd3efc6a173 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -50,7 +50,7 @@
  *              Patrick McHardy <kaber@trash.net>
  */
 
-#define VERSION "0.405"
+#define VERSION "0.406"
 
 #include <linux/config.h>
 #include <asm/uaccess.h>
@@ -84,7 +84,7 @@
 #include "fib_lookup.h"
 
 #undef CONFIG_IP_FIB_TRIE_STATS
-#define MAX_CHILDS 16384
+#define MAX_STAT_DEPTH 32
 
 #define KEYLENGTH (8*sizeof(t_key))
 #define MASK_PFX(k, l) (((l)==0)?0:(k >> (KEYLENGTH-l)) << (KEYLENGTH-l))
@@ -154,7 +154,7 @@ struct trie_stat {
         unsigned int tnodes;
         unsigned int leaves;
         unsigned int nullpointers;
-        unsigned int nodesizes[MAX_CHILDS];
+        unsigned int nodesizes[MAX_STAT_DEPTH];
 };
 
 struct trie {
@@ -2080,7 +2080,9 @@ static void trie_collect_stats(struct trie *t, struct trie_stat *s)
                         int i;
 
                         s->tnodes++;
-                        s->nodesizes[tn->bits]++;
+                        if(tn->bits < MAX_STAT_DEPTH)
+                                s->nodesizes[tn->bits]++;
+
                         for (i = 0; i < (1<<tn->bits); i++)
                                 if (!tn->child[i])
                                         s->nullpointers++;
@@ -2110,8 +2112,8 @@ static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
         seq_printf(seq, "\tInternal nodes: %d\n\t", stat->tnodes);
         bytes += sizeof(struct tnode) * stat->tnodes;
 
-        max = MAX_CHILDS-1;
-        while (max >= 0 && stat->nodesizes[max] == 0)
+        max = MAX_STAT_DEPTH;
+        while (max > 0 && stat->nodesizes[max-1] == 0)
                 max--;
 
         pointers = 0;