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[NET]: Fix heavy stack usage in seq_file output routines.
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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>
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Pavel Emelyanov authored and David S. Miller committed Apr 24, 2008
1 parent 3d36696 commit 5e659e4
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Showing 6 changed files with 56 additions and 50 deletions.
17 changes: 9 additions & 8 deletions net/ipv4/fib_hash.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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;
}
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18 changes: 10 additions & 8 deletions net/ipv4/fib_trie.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand All @@ -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, "");
}
}

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11 changes: 6 additions & 5 deletions net/ipv4/route.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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),
Expand All @@ -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;
}
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36 changes: 19 additions & 17 deletions net/ipv4/tcp_ipv4.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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),
Expand All @@ -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;
Expand All @@ -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 :
Expand All @@ -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;
Expand All @@ -2340,19 +2342,19 @@ 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

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,
Expand All @@ -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;
}
Expand Down
15 changes: 8 additions & 7 deletions net/ipv4/udp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1619,21 +1619,22 @@ 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;
__be32 src = inet->rcv_saddr;
__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)
Expand All @@ -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;
}
Expand Down
9 changes: 4 additions & 5 deletions net/sctp/objcnt.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -83,13 +83,12 @@ static sctp_dbg_objcnt_entry_t sctp_dbg_objcnt[] = {
*/
static int sctp_objcnt_seq_show(struct seq_file *seq, void *v)
{
int i;
char temp[128];
int i, len;

i = (int)*(loff_t *)v;
sprintf(temp, "%s: %d", sctp_dbg_objcnt[i].label,
atomic_read(sctp_dbg_objcnt[i].counter));
seq_printf(seq, "%-127s\n", temp);
seq_printf(seq, "%s: %d%n", sctp_dbg_objcnt[i].label,
atomic_read(sctp_dbg_objcnt[i].counter), &len);
seq_printf(seq, "%*s\n", 127 - len, "");
return 0;
}

Expand Down

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