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linux-next/net/kcm/kcmproc.c
Madhuparna Bhowmik 1963507e62 net: kcm: kcmproc.c: Fix RCU list suspicious usage warning
This path fixes the suspicious RCU usage warning reported by
kernel test robot.

net/kcm/kcmproc.c:#RCU-list_traversed_in_non-reader_section

There is no need to use list_for_each_entry_rcu() in
kcm_stats_seq_show() as the list is always traversed under
knet->mutex held.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-16 17:14:02 -07:00

388 lines
8.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/proc_fs.h>
#include <linux/rculist.h>
#include <linux/seq_file.h>
#include <linux/socket.h>
#include <net/inet_sock.h>
#include <net/kcm.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/tcp.h>
#ifdef CONFIG_PROC_FS
static struct kcm_mux *kcm_get_first(struct seq_file *seq)
{
struct net *net = seq_file_net(seq);
struct kcm_net *knet = net_generic(net, kcm_net_id);
return list_first_or_null_rcu(&knet->mux_list,
struct kcm_mux, kcm_mux_list);
}
static struct kcm_mux *kcm_get_next(struct kcm_mux *mux)
{
struct kcm_net *knet = mux->knet;
return list_next_or_null_rcu(&knet->mux_list, &mux->kcm_mux_list,
struct kcm_mux, kcm_mux_list);
}
static struct kcm_mux *kcm_get_idx(struct seq_file *seq, loff_t pos)
{
struct net *net = seq_file_net(seq);
struct kcm_net *knet = net_generic(net, kcm_net_id);
struct kcm_mux *m;
list_for_each_entry_rcu(m, &knet->mux_list, kcm_mux_list) {
if (!pos)
return m;
--pos;
}
return NULL;
}
static void *kcm_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
void *p;
if (v == SEQ_START_TOKEN)
p = kcm_get_first(seq);
else
p = kcm_get_next(v);
++*pos;
return p;
}
static void *kcm_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(rcu)
{
rcu_read_lock();
if (!*pos)
return SEQ_START_TOKEN;
else
return kcm_get_idx(seq, *pos - 1);
}
static void kcm_seq_stop(struct seq_file *seq, void *v)
__releases(rcu)
{
rcu_read_unlock();
}
struct kcm_proc_mux_state {
struct seq_net_private p;
int idx;
};
static void kcm_format_mux_header(struct seq_file *seq)
{
struct net *net = seq_file_net(seq);
struct kcm_net *knet = net_generic(net, kcm_net_id);
seq_printf(seq,
"*** KCM statistics (%d MUX) ****\n",
knet->count);
seq_printf(seq,
"%-14s %-10s %-16s %-10s %-16s %-8s %-8s %-8s %-8s %s",
"Object",
"RX-Msgs",
"RX-Bytes",
"TX-Msgs",
"TX-Bytes",
"Recv-Q",
"Rmem",
"Send-Q",
"Smem",
"Status");
/* XXX: pdsts header stuff here */
seq_puts(seq, "\n");
}
static void kcm_format_sock(struct kcm_sock *kcm, struct seq_file *seq,
int i, int *len)
{
seq_printf(seq,
" kcm-%-7u %-10llu %-16llu %-10llu %-16llu %-8d %-8d %-8d %-8s ",
kcm->index,
kcm->stats.rx_msgs,
kcm->stats.rx_bytes,
kcm->stats.tx_msgs,
kcm->stats.tx_bytes,
kcm->sk.sk_receive_queue.qlen,
sk_rmem_alloc_get(&kcm->sk),
kcm->sk.sk_write_queue.qlen,
"-");
if (kcm->tx_psock)
seq_printf(seq, "Psck-%u ", kcm->tx_psock->index);
if (kcm->tx_wait)
seq_puts(seq, "TxWait ");
if (kcm->tx_wait_more)
seq_puts(seq, "WMore ");
if (kcm->rx_wait)
seq_puts(seq, "RxWait ");
seq_puts(seq, "\n");
}
static void kcm_format_psock(struct kcm_psock *psock, struct seq_file *seq,
int i, int *len)
{
seq_printf(seq,
" psock-%-5u %-10llu %-16llu %-10llu %-16llu %-8d %-8d %-8d %-8d ",
psock->index,
psock->strp.stats.msgs,
psock->strp.stats.bytes,
psock->stats.tx_msgs,
psock->stats.tx_bytes,
psock->sk->sk_receive_queue.qlen,
atomic_read(&psock->sk->sk_rmem_alloc),
psock->sk->sk_write_queue.qlen,
refcount_read(&psock->sk->sk_wmem_alloc));
if (psock->done)
seq_puts(seq, "Done ");
if (psock->tx_stopped)
seq_puts(seq, "TxStop ");
if (psock->strp.stopped)
seq_puts(seq, "RxStop ");
if (psock->tx_kcm)
seq_printf(seq, "Rsvd-%d ", psock->tx_kcm->index);
if (!psock->strp.paused && !psock->ready_rx_msg) {
if (psock->sk->sk_receive_queue.qlen) {
if (psock->strp.need_bytes)
seq_printf(seq, "RxWait=%u ",
psock->strp.need_bytes);
else
seq_printf(seq, "RxWait ");
}
} else {
if (psock->strp.paused)
seq_puts(seq, "RxPause ");
if (psock->ready_rx_msg)
seq_puts(seq, "RdyRx ");
}
seq_puts(seq, "\n");
}
static void
kcm_format_mux(struct kcm_mux *mux, loff_t idx, struct seq_file *seq)
{
int i, len;
struct kcm_sock *kcm;
struct kcm_psock *psock;
/* mux information */
seq_printf(seq,
"%-6s%-8s %-10llu %-16llu %-10llu %-16llu %-8s %-8s %-8s %-8s ",
"mux", "",
mux->stats.rx_msgs,
mux->stats.rx_bytes,
mux->stats.tx_msgs,
mux->stats.tx_bytes,
"-", "-", "-", "-");
seq_printf(seq, "KCMs: %d, Psocks %d\n",
mux->kcm_socks_cnt, mux->psocks_cnt);
/* kcm sock information */
i = 0;
spin_lock_bh(&mux->lock);
list_for_each_entry(kcm, &mux->kcm_socks, kcm_sock_list) {
kcm_format_sock(kcm, seq, i, &len);
i++;
}
i = 0;
list_for_each_entry(psock, &mux->psocks, psock_list) {
kcm_format_psock(psock, seq, i, &len);
i++;
}
spin_unlock_bh(&mux->lock);
}
static int kcm_seq_show(struct seq_file *seq, void *v)
{
struct kcm_proc_mux_state *mux_state;
mux_state = seq->private;
if (v == SEQ_START_TOKEN) {
mux_state->idx = 0;
kcm_format_mux_header(seq);
} else {
kcm_format_mux(v, mux_state->idx, seq);
mux_state->idx++;
}
return 0;
}
static const struct seq_operations kcm_seq_ops = {
.show = kcm_seq_show,
.start = kcm_seq_start,
.next = kcm_seq_next,
.stop = kcm_seq_stop,
};
static int kcm_stats_seq_show(struct seq_file *seq, void *v)
{
struct kcm_psock_stats psock_stats;
struct kcm_mux_stats mux_stats;
struct strp_aggr_stats strp_stats;
struct kcm_mux *mux;
struct kcm_psock *psock;
struct net *net = seq->private;
struct kcm_net *knet = net_generic(net, kcm_net_id);
memset(&mux_stats, 0, sizeof(mux_stats));
memset(&psock_stats, 0, sizeof(psock_stats));
memset(&strp_stats, 0, sizeof(strp_stats));
mutex_lock(&knet->mutex);
aggregate_mux_stats(&knet->aggregate_mux_stats, &mux_stats);
aggregate_psock_stats(&knet->aggregate_psock_stats,
&psock_stats);
aggregate_strp_stats(&knet->aggregate_strp_stats,
&strp_stats);
list_for_each_entry(mux, &knet->mux_list, kcm_mux_list) {
spin_lock_bh(&mux->lock);
aggregate_mux_stats(&mux->stats, &mux_stats);
aggregate_psock_stats(&mux->aggregate_psock_stats,
&psock_stats);
aggregate_strp_stats(&mux->aggregate_strp_stats,
&strp_stats);
list_for_each_entry(psock, &mux->psocks, psock_list) {
aggregate_psock_stats(&psock->stats, &psock_stats);
save_strp_stats(&psock->strp, &strp_stats);
}
spin_unlock_bh(&mux->lock);
}
mutex_unlock(&knet->mutex);
seq_printf(seq,
"%-8s %-10s %-16s %-10s %-16s %-10s %-10s %-10s %-10s %-10s\n",
"MUX",
"RX-Msgs",
"RX-Bytes",
"TX-Msgs",
"TX-Bytes",
"TX-Retries",
"Attach",
"Unattach",
"UnattchRsvd",
"RX-RdyDrops");
seq_printf(seq,
"%-8s %-10llu %-16llu %-10llu %-16llu %-10u %-10u %-10u %-10u %-10u\n",
"",
mux_stats.rx_msgs,
mux_stats.rx_bytes,
mux_stats.tx_msgs,
mux_stats.tx_bytes,
mux_stats.tx_retries,
mux_stats.psock_attach,
mux_stats.psock_unattach_rsvd,
mux_stats.psock_unattach,
mux_stats.rx_ready_drops);
seq_printf(seq,
"%-8s %-10s %-16s %-10s %-16s %-10s %-10s %-10s %-10s %-10s %-10s %-10s %-10s %-10s %-10s %-10s\n",
"Psock",
"RX-Msgs",
"RX-Bytes",
"TX-Msgs",
"TX-Bytes",
"Reserved",
"Unreserved",
"RX-Aborts",
"RX-Intr",
"RX-Unrecov",
"RX-MemFail",
"RX-NeedMor",
"RX-BadLen",
"RX-TooBig",
"RX-Timeout",
"TX-Aborts");
seq_printf(seq,
"%-8s %-10llu %-16llu %-10llu %-16llu %-10llu %-10llu %-10u %-10u %-10u %-10u %-10u %-10u %-10u %-10u %-10u\n",
"",
strp_stats.msgs,
strp_stats.bytes,
psock_stats.tx_msgs,
psock_stats.tx_bytes,
psock_stats.reserved,
psock_stats.unreserved,
strp_stats.aborts,
strp_stats.interrupted,
strp_stats.unrecov_intr,
strp_stats.mem_fail,
strp_stats.need_more_hdr,
strp_stats.bad_hdr_len,
strp_stats.msg_too_big,
strp_stats.msg_timeouts,
psock_stats.tx_aborts);
return 0;
}
static int kcm_proc_init_net(struct net *net)
{
if (!proc_create_net_single("kcm_stats", 0444, net->proc_net,
kcm_stats_seq_show, NULL))
goto out_kcm_stats;
if (!proc_create_net("kcm", 0444, net->proc_net, &kcm_seq_ops,
sizeof(struct kcm_proc_mux_state)))
goto out_kcm;
return 0;
out_kcm:
remove_proc_entry("kcm_stats", net->proc_net);
out_kcm_stats:
return -ENOMEM;
}
static void kcm_proc_exit_net(struct net *net)
{
remove_proc_entry("kcm", net->proc_net);
remove_proc_entry("kcm_stats", net->proc_net);
}
static struct pernet_operations kcm_net_ops = {
.init = kcm_proc_init_net,
.exit = kcm_proc_exit_net,
};
int __init kcm_proc_init(void)
{
return register_pernet_subsys(&kcm_net_ops);
}
void __exit kcm_proc_exit(void)
{
unregister_pernet_subsys(&kcm_net_ops);
}
#endif /* CONFIG_PROC_FS */