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Commit 5e659e4c authored by Pavel Emelyanov's avatar Pavel Emelyanov Committed by David S. Miller
Browse files

[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: default avatarPavel Emelyanov <xemul@openvz.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3d366960

net/ipv4/fib_hash.c

+9 −8
Original line number Diff line number Diff line
@@ -1003,7 +1003,7 @@ static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi) 
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 @@ static int fib_seq_show(struct seq_file *seq, void *v) 
	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;

}

net/ipv4/fib_trie.c

+10 −8
Original line number Diff line number Diff line
@@ -2602,15 +2602,16 @@ static int fib_route_seq_show(struct seq_file *seq, void *v) 
		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 @@ static int fib_route_seq_show(struct seq_file *seq, void *v) 
					 (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, "");

		}

	}

net/ipv4/route.c

+6 −5
Original line number Diff line number Diff line
@@ -367,10 +367,10 @@ static int rt_cache_seq_show(struct seq_file *seq, void *v) 
			   "HHUptod\tSpecDst");

	else {

		struct rtable *r = v;

		char temp[256];

		int len;



		sprintf(temp, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"

			      "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X",

		seq_printf(seq, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"

			      "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",

			r->u.dst.dev ? r->u.dst.dev->name : "*",

			(unsigned long)r->rt_dst, (unsigned long)r->rt_gateway,

			r->rt_flags, atomic_read(&r->u.dst.__refcnt),
@@ -384,8 +384,9 @@ static int rt_cache_seq_show(struct seq_file *seq, void *v) 
			r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1,

			r->u.dst.hh ? (r->u.dst.hh->hh_output ==

				       dev_queue_xmit) : 0,

			r->rt_spec_dst);

		seq_printf(seq, "%-127s\n", temp);

			r->rt_spec_dst, &len);



		seq_printf(seq, "%*s\n", 127 - len, "");

	}

	return 0;

}

net/ipv4/tcp_ipv4.c

+19 −17
Original line number Diff line number Diff line
@@ -2255,13 +2255,13 @@ void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo) 
}



static void get_openreq4(struct sock *sk, struct request_sock *req,

			 char *tmpbuf, int i, int uid)

			 struct seq_file *f, int i, int uid, int *len)

{

	const struct inet_request_sock *ireq = inet_rsk(req);

	int ttd = req->expires - jiffies;



	sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"

		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %p",

	seq_printf(f, "%4d: %08X:%04X %08X:%04X"

		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %p%n",

		i,

		ireq->loc_addr,

		ntohs(inet_sk(sk)->sport),
@@ -2276,10 +2276,11 @@ static void get_openreq4(struct sock *sk, struct request_sock *req, 
		0,  /* non standard timer */

		0, /* open_requests have no inode */

		atomic_read(&sk->sk_refcnt),

		req);

		req,

		len);

}



static void get_tcp4_sock(struct sock *sk, char *tmpbuf, int i)

static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len)

{

	int timer_active;

	unsigned long timer_expires;
@@ -2305,8 +2306,8 @@ static void get_tcp4_sock(struct sock *sk, char *tmpbuf, int i) 
		timer_expires = jiffies;

	}



	sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "

			"%08X %5d %8d %lu %d %p %u %u %u %u %d",

	seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "

			"%08X %5d %8d %lu %d %p %u %u %u %u %d%n",

		i, src, srcp, dest, destp, sk->sk_state,

		tp->write_seq - tp->snd_una,

		sk->sk_state == TCP_LISTEN ? sk->sk_ack_backlog :
@@ -2322,11 +2323,12 @@ static void get_tcp4_sock(struct sock *sk, char *tmpbuf, int i) 
		icsk->icsk_ack.ato,

		(icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,

		tp->snd_cwnd,

		tp->snd_ssthresh >= 0xFFFF ? -1 : tp->snd_ssthresh);

		tp->snd_ssthresh >= 0xFFFF ? -1 : tp->snd_ssthresh,

		len);

}



static void get_timewait4_sock(struct inet_timewait_sock *tw,

			       char *tmpbuf, int i)

			       struct seq_file *f, int i, int *len)

{

	__be32 dest, src;

	__u16 destp, srcp;
@@ -2340,11 +2342,11 @@ static void get_timewait4_sock(struct inet_timewait_sock *tw, 
	destp = ntohs(tw->tw_dport);

	srcp  = ntohs(tw->tw_sport);



	sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"

		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p",

	seq_printf(f, "%4d: %08X:%04X %08X:%04X"

		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p%n",

		i, src, srcp, dest, destp, tw->tw_substate, 0, 0,

		3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,

		atomic_read(&tw->tw_refcnt), tw);

		atomic_read(&tw->tw_refcnt), tw, len);

}



#define TMPSZ 150
@@ -2352,7 +2354,7 @@ static void get_timewait4_sock(struct inet_timewait_sock *tw, 
static int tcp4_seq_show(struct seq_file *seq, void *v)

{

	struct tcp_iter_state* st;

	char tmpbuf[TMPSZ + 1];

	int len;



	if (v == SEQ_START_TOKEN) {

		seq_printf(seq, "%-*s\n", TMPSZ - 1,
@@ -2366,16 +2368,16 @@ static int tcp4_seq_show(struct seq_file *seq, void *v) 
	switch (st->state) {

	case TCP_SEQ_STATE_LISTENING:

	case TCP_SEQ_STATE_ESTABLISHED:

		get_tcp4_sock(v, tmpbuf, st->num);

		get_tcp4_sock(v, seq, st->num, &len);

		break;

	case TCP_SEQ_STATE_OPENREQ:

		get_openreq4(st->syn_wait_sk, v, tmpbuf, st->num, st->uid);

		get_openreq4(st->syn_wait_sk, v, seq, st->num, st->uid, &len);

		break;

	case TCP_SEQ_STATE_TIME_WAIT:

		get_timewait4_sock(v, tmpbuf, st->num);

		get_timewait4_sock(v, seq, st->num, &len);

		break;

	}

	seq_printf(seq, "%-*s\n", TMPSZ - 1, tmpbuf);

	seq_printf(seq, "%*s\n", TMPSZ - 1 - len, "");

out:

	return 0;

}

net/ipv4/udp.c

+8 −7
Original line number Diff line number Diff line
@@ -1619,7 +1619,8 @@ void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo) 
}



/* ------------------------------------------------------------------------ */

static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket)

static void udp4_format_sock(struct sock *sp, struct seq_file *f,

		int bucket, int *len)

{

	struct inet_sock *inet = inet_sk(sp);

	__be32 dest = inet->daddr;
@@ -1627,13 +1628,13 @@ static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket) 
	__u16 destp	  = ntohs(inet->dport);

	__u16 srcp	  = ntohs(inet->sport);



	sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"

		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p",

	seq_printf(f, "%4d: %08X:%04X %08X:%04X"

		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p%n",

		bucket, src, srcp, dest, destp, sp->sk_state,

		atomic_read(&sp->sk_wmem_alloc),

		atomic_read(&sp->sk_rmem_alloc),

		0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),

		atomic_read(&sp->sk_refcnt), sp);

		atomic_read(&sp->sk_refcnt), sp, len);

}



int udp4_seq_show(struct seq_file *seq, void *v)
@@ -1644,11 +1645,11 @@ int udp4_seq_show(struct seq_file *seq, void *v) 
			   "rx_queue tr tm->when retrnsmt   uid  timeout "

			   "inode");

	else {

		char tmpbuf[129];

		struct udp_iter_state *state = seq->private;

		int len;



		udp4_format_sock(v, tmpbuf, state->bucket);

		seq_printf(seq, "%-127s\n", tmpbuf);

		udp4_format_sock(v, seq, state->bucket, &len);

		seq_printf(seq, "%*s\n", 127 - len ,"");

	}

	return 0;

}