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 cbbc719fccdb8cb (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>
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index c66b90f..aa41b0e6 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1875,7 +1875,7 @@
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 @@
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 @@
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);
}