batman-adv: directly write tt entries without buffering

When the translation tables (global and local) are written for debugfs,
it is not neccesary to allocate a buffer, we can directly use
seq_printf() to print them out.

This might actually be safer if the table changes between size
calculation and traversal, and we can't estimate the required size
wrong.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>

1 files changed, 2 insertions, 55 deletions

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 5f28a7f0b03e..78b9528bfc2a 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -314,8 +314,6 @@ int tt_local_seq_print_text(struct seq_file *seq, void *offset)
         struct hard_iface *primary_if;
         struct hlist_node *node;
         struct hlist_head *head;
-        size_t buf_size, pos;
-        char *buff;
         uint32_t i;
         int ret = 0;
 
@@ -338,34 +336,13 @@ int tt_local_seq_print_text(struct seq_file *seq, void *offset)
                    "announced via TT (TTVN: %u):\n",
                    net_dev->name, (uint8_t)atomic_read(&bat_priv->ttvn));
 
-        buf_size = 1;
-        /* Estimate length for: " * xx:xx:xx:xx:xx:xx\n" */
-        for (i = 0; i < hash->size; i++) {
-                head = &hash->table[i];
-
-                rcu_read_lock();
-                __hlist_for_each_rcu(node, head)
-                        buf_size += 29;
-                rcu_read_unlock();
-        }
-
-        buff = kmalloc(buf_size, GFP_ATOMIC);
-        if (!buff) {
-                ret = -ENOMEM;
-                goto out;
-        }
-
-        buff[0] = '\0';
-        pos = 0;
-
         for (i = 0; i < hash->size; i++) {
                 head = &hash->table[i];
 
                 rcu_read_lock();
                 hlist_for_each_entry_rcu(tt_local_entry, node,
                                          head, hash_entry) {
-                        pos += snprintf(buff + pos, 30, " * %pM "
-                                        "[%c%c%c%c%c]\n",
+                        seq_printf(seq, " * %pM [%c%c%c%c%c]\n",
                                         tt_local_entry->addr,
                                         (tt_local_entry->flags &
                                          TT_CLIENT_ROAM ? 'R' : '.'),
@@ -380,9 +357,6 @@ int tt_local_seq_print_text(struct seq_file *seq, void *offset)
                 }
                 rcu_read_unlock();
         }
-
-        seq_printf(seq, "%s", buff);
-        kfree(buff);
 out:
         if (primary_if)
                 hardif_free_ref(primary_if);
@@ -591,8 +565,6 @@ int tt_global_seq_print_text(struct seq_file *seq, void *offset)
         struct hard_iface *primary_if;
         struct hlist_node *node;
         struct hlist_head *head;
-        size_t buf_size, pos;
-        char *buff;
         uint32_t i;
         int ret = 0;
 
@@ -617,35 +589,13 @@ int tt_global_seq_print_text(struct seq_file *seq, void *offset)
         seq_printf(seq, "       %-13s %s       %-15s %s %s\n",
                    "Client", "(TTVN)", "Originator", "(Curr TTVN)", "Flags");
 
-        buf_size = 1;
-        /* Estimate length for: " * xx:xx:xx:xx:xx:xx (ttvn) via
-         * xx:xx:xx:xx:xx:xx (cur_ttvn)\n"*/
-        for (i = 0; i < hash->size; i++) {
-                head = &hash->table[i];
-
-                rcu_read_lock();
-                __hlist_for_each_rcu(node, head)
-                        buf_size += 67;
-                rcu_read_unlock();
-        }
-
-        buff = kmalloc(buf_size, GFP_ATOMIC);
-        if (!buff) {
-                ret = -ENOMEM;
-                goto out;
-        }
-
-        buff[0] = '\0';
-        pos = 0;
-
         for (i = 0; i < hash->size; i++) {
                 head = &hash->table[i];
 
                 rcu_read_lock();
                 hlist_for_each_entry_rcu(tt_global_entry, node,
                                          head, hash_entry) {
-                        pos += snprintf(buff + pos, 69,
-                                        " * %pM  (%3u) via %pM     (%3u)   "
+                        seq_printf(seq, " * %pM  (%3u) via %pM     (%3u)   "
                                         "[%c%c%c]\n", tt_global_entry->addr,
                                         tt_global_entry->ttvn,
                                         tt_global_entry->orig_node->orig,
@@ -661,9 +611,6 @@ int tt_global_seq_print_text(struct seq_file *seq, void *offset)
                 }
                 rcu_read_unlock();
         }
-
-        seq_printf(seq, "%s", buff);
-        kfree(buff);
 out:
         if (primary_if)
                 hardif_free_ref(primary_if);