time: jiffies_delta_to_clock_t() helper to the rescue

Various /proc/net files sometimes report crazy timer values, expressed
in clock_t units.

This happens when an expired timer delta (expires - jiffies) is passed
to jiffies_to_clock_t().

This function has an overflow in :

return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ);

commit cbbc719fcc (time: Change jiffies_to_clock_t() argument type
to unsigned long) only got around the problem.

As we cant output negative values in /proc/net/tcp without breaking
various tools, I suggest adding a jiffies_delta_to_clock_t() wrapper
that caps the negative delta to a 0 value.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Maciej Żenczykowski <maze@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: hank <pyu@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2012-08-08 21:13:53 +00:00 committed by David S. Miller
parent 79cda75a10
commit a399a80531
7 changed files with 22 additions and 19 deletions

View File

@ -303,7 +303,13 @@ extern void jiffies_to_timespec(const unsigned long jiffies,
extern unsigned long timeval_to_jiffies(const struct timeval *value);
extern void jiffies_to_timeval(const unsigned long jiffies,
struct timeval *value);
extern clock_t jiffies_to_clock_t(unsigned long x);
static inline clock_t jiffies_delta_to_clock_t(long delta)
{
return jiffies_to_clock_t(max(0L, delta));
}
extern unsigned long clock_t_to_jiffies(unsigned long x);
extern u64 jiffies_64_to_clock_t(u64 x);
extern u64 nsec_to_clock_t(u64 x);

View File

@ -312,7 +312,7 @@ int br_fdb_fillbuf(struct net_bridge *br, void *buf,
fe->is_local = f->is_local;
if (!f->is_static)
fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->updated);
fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
++fe;
++num;
}

View File

@ -170,5 +170,5 @@ void br_stp_port_timer_init(struct net_bridge_port *p)
unsigned long br_timer_value(const struct timer_list *timer)
{
return timer_pending(timer)
? jiffies_to_clock_t(timer->expires - jiffies) : 0;
? jiffies_delta_to_clock_t(timer->expires - jiffies) : 0;
}

View File

@ -618,7 +618,7 @@ int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id,
long expires, u32 error)
{
struct rta_cacheinfo ci = {
.rta_lastuse = jiffies_to_clock_t(jiffies - dst->lastuse),
.rta_lastuse = jiffies_delta_to_clock_t(jiffies - dst->lastuse),
.rta_used = dst->__use,
.rta_clntref = atomic_read(&(dst->__refcnt)),
.rta_error = error,

View File

@ -2435,6 +2435,8 @@ static int igmp_mc_seq_show(struct seq_file *seq, void *v)
struct ip_mc_list *im = (struct ip_mc_list *)v;
struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
char *querier;
long delta;
#ifdef CONFIG_IP_MULTICAST
querier = IGMP_V1_SEEN(state->in_dev) ? "V1" :
IGMP_V2_SEEN(state->in_dev) ? "V2" :
@ -2448,11 +2450,12 @@ static int igmp_mc_seq_show(struct seq_file *seq, void *v)
state->dev->ifindex, state->dev->name, state->in_dev->mc_count, querier);
}
delta = im->timer.expires - jiffies;
seq_printf(seq,
"\t\t\t\t%08X %5d %d:%08lX\t\t%d\n",
im->multiaddr, im->users,
im->tm_running, im->tm_running ?
jiffies_to_clock_t(im->timer.expires-jiffies) : 0,
im->tm_running,
im->tm_running ? jiffies_delta_to_clock_t(delta) : 0,
im->reporter);
}
return 0;

View File

@ -2385,7 +2385,7 @@ static void get_openreq4(const struct sock *sk, const struct request_sock *req,
struct seq_file *f, int i, int uid, int *len)
{
const struct inet_request_sock *ireq = inet_rsk(req);
int ttd = req->expires - jiffies;
long delta = req->expires - jiffies;
seq_printf(f, "%4d: %08X:%04X %08X:%04X"
" %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %pK%n",
@ -2397,7 +2397,7 @@ static void get_openreq4(const struct sock *sk, const struct request_sock *req,
TCP_SYN_RECV,
0, 0, /* could print option size, but that is af dependent. */
1, /* timers active (only the expire timer) */
jiffies_to_clock_t(ttd),
jiffies_delta_to_clock_t(delta),
req->retrans,
uid,
0, /* non standard timer */
@ -2448,7 +2448,7 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len)
tp->write_seq - tp->snd_una,
rx_queue,
timer_active,
jiffies_to_clock_t(timer_expires - jiffies),
jiffies_delta_to_clock_t(timer_expires - jiffies),
icsk->icsk_retransmits,
sock_i_uid(sk),
icsk->icsk_probes_out,
@ -2467,10 +2467,7 @@ static void get_timewait4_sock(const struct inet_timewait_sock *tw,
{
__be32 dest, src;
__u16 destp, srcp;
int ttd = tw->tw_ttd - jiffies;
if (ttd < 0)
ttd = 0;
long delta = tw->tw_ttd - jiffies;
dest = tw->tw_daddr;
src = tw->tw_rcv_saddr;
@ -2480,7 +2477,7 @@ static void get_timewait4_sock(const struct inet_timewait_sock *tw,
seq_printf(f, "%4d: %08X:%04X %08X:%04X"
" %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK%n",
i, src, srcp, dest, destp, tw->tw_substate, 0, 0,
3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
atomic_read(&tw->tw_refcnt), tw, len);
}

View File

@ -1875,7 +1875,7 @@ static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
tp->write_seq-tp->snd_una,
(sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
timer_active,
jiffies_to_clock_t(timer_expires - jiffies),
jiffies_delta_to_clock_t(timer_expires - jiffies),
icsk->icsk_retransmits,
sock_i_uid(sp),
icsk->icsk_probes_out,
@ -1895,10 +1895,7 @@ static void get_timewait6_sock(struct seq_file *seq,
const struct in6_addr *dest, *src;
__u16 destp, srcp;
const struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
int ttd = tw->tw_ttd - jiffies;
if (ttd < 0)
ttd = 0;
long delta = tw->tw_ttd - jiffies;
dest = &tw6->tw_v6_daddr;
src = &tw6->tw_v6_rcv_saddr;
@ -1914,7 +1911,7 @@ static void get_timewait6_sock(struct seq_file *seq,
dest->s6_addr32[0], dest->s6_addr32[1],
dest->s6_addr32[2], dest->s6_addr32[3], destp,
tw->tw_substate, 0, 0,
3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
atomic_read(&tw->tw_refcnt), tw);
}