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| author | Eric Dumazet <edumazet@google.com> | 2012-08-08 23:13:53 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-08-10 01:17:03 +0200 |
| commit | a399a8053164ec8bcb06fed52be9941a26ecde11 (patch) | |
| tree | c60402a77d08c82630d63e972d32b038919b827f /net/ipv4/igmp.c | |
| parent | fib: use __fls() on non null argument (diff) | |
| download | linux-a399a8053164ec8bcb06fed52be9941a26ecde11.tar.xz linux-a399a8053164ec8bcb06fed52be9941a26ecde11.zip | |
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>
Diffstat (limited to 'net/ipv4/igmp.c')
| -rw-r--r-- | net/ipv4/igmp.c | 7 |
1 files changed, 5 insertions, 2 deletions
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; |