[NET]: Fix heavy stack usage in seq_file output routines.
Plan C: we can follow the Al Viro's proposal about %n like in this patch.
The same applies to udp, fib (the /proc/net/route file), rt_cache and
sctp debug. This is minus ~150-200 bytes for each.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index ea294ff..4b02d14 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -2602,15 +2602,16 @@
list_for_each_entry_rcu(fa, &li->falh, fa_list) {
const struct fib_info *fi = fa->fa_info;
unsigned flags = fib_flag_trans(fa->fa_type, mask, fi);
- char bf[128];
+ int len;
if (fa->fa_type == RTN_BROADCAST
|| fa->fa_type == RTN_MULTICAST)
continue;
if (fi)
- snprintf(bf, sizeof(bf),
- "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
+ seq_printf(seq,
+ "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
+ "%d\t%08X\t%d\t%u\t%u%n",
fi->fib_dev ? fi->fib_dev->name : "*",
prefix,
fi->fib_nh->nh_gw, flags, 0, 0,
@@ -2619,14 +2620,15 @@
(fi->fib_advmss ?
fi->fib_advmss + 40 : 0),
fi->fib_window,
- fi->fib_rtt >> 3);
+ fi->fib_rtt >> 3, &len);
else
- snprintf(bf, sizeof(bf),
- "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
+ seq_printf(seq,
+ "*\t%08X\t%08X\t%04X\t%d\t%u\t"
+ "%d\t%08X\t%d\t%u\t%u%n",
prefix, 0, flags, 0, 0, 0,
- mask, 0, 0, 0);
+ mask, 0, 0, 0, &len);
- seq_printf(seq, "%-127s\n", bf);
+ seq_printf(seq, "%*s\n", 127 - len, "");
}
}
