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/tcp_ipv4.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) (limited to 'net/ipv4/tcp_ipv4.c') diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 42b2a6a73092..c660d2c19a2b 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -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); } -- cgit v1.2.3