[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_hash.c b/net/ipv4/fib_hash.c
index 02088de..2e2fc33 100644
--- a/net/ipv4/fib_hash.c
+++ b/net/ipv4/fib_hash.c
@@ -1003,7 +1003,7 @@
static int fib_seq_show(struct seq_file *seq, void *v)
{
struct fib_iter_state *iter;
- char bf[128];
+ int len;
__be32 prefix, mask;
unsigned flags;
struct fib_node *f;
@@ -1025,18 +1025,19 @@
mask = FZ_MASK(iter->zone);
flags = fib_flag_trans(fa->fa_type, mask, fi);
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, fi->fib_priority,
mask, (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",
- prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0);
- seq_printf(seq, "%-127s\n", bf);
+ 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, &len);
+
+ seq_printf(seq, "%*s\n", 127 - len, "");
out:
return 0;
}