From a399a8053164ec8bcb06fed52be9941a26ecde11 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 8 Aug 2012 21:13:53 +0000 Subject: time: jiffies_delta_to_clock_t() helper to the rescue MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reported-by: Maciej Żenczykowski Cc: Thomas Gleixner Cc: Paul Gortmaker Cc: Andrew Morton Cc: hank Signed-off-by: David S. Miller --- net/ipv4/igmp.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'net/ipv4/igmp.c') diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index 6699f23e6f55..0b5580c69f2d 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -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; -- cgit v1.2.1