| Message ID | 1356315256-6572-20-git-send-email-akinobu.mita@gmail.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Mon, Dec 24, 2012 at 11:14:06AM +0900, Akinobu Mita wrote: > batadv_iv_ogm_emit_send_time() attempts to calculates a random integer > in the range of 'orig_interval +- BATADV_JITTER' by the below lines. > > msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; > msecs += (random32() % 2 * BATADV_JITTER); > > But it actually gets 'orig_interval' or 'orig_interval - BATADV_JITTER' > because '%' and '*' have same precedence and associativity is > left-to-right. > > This adds the parentheses at the appropriate position so that it matches > original intension. > > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> > Cc: Marek Lindner <lindner_marek@yahoo.de> > Cc: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> > Cc: Antonio Quartulli <ordex@autistici.org> > Cc: b.a.t.m.a.n@lists.open-mesh.org > Cc: "David S. Miller" <davem@davemloft.net> > Cc: netdev@vger.kernel.org > --- Acked-by: Antonio Quartulli <ordex@autistici.org> But I would suggest to apply this change to net, since it is a fix. Cheers,
2012/12/25 Antonio Quartulli <ordex@autistici.org>: > On Mon, Dec 24, 2012 at 11:14:06AM +0900, Akinobu Mita wrote: >> batadv_iv_ogm_emit_send_time() attempts to calculates a random integer >> in the range of 'orig_interval +- BATADV_JITTER' by the below lines. >> >> msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; >> msecs += (random32() % 2 * BATADV_JITTER); >> >> But it actually gets 'orig_interval' or 'orig_interval - BATADV_JITTER' >> because '%' and '*' have same precedence and associativity is >> left-to-right. >> >> This adds the parentheses at the appropriate position so that it matches >> original intension. >> >> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> >> Cc: Marek Lindner <lindner_marek@yahoo.de> >> Cc: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> >> Cc: Antonio Quartulli <ordex@autistici.org> >> Cc: b.a.t.m.a.n@lists.open-mesh.org >> Cc: "David S. Miller" <davem@davemloft.net> >> Cc: netdev@vger.kernel.org >> --- > > Acked-by: Antonio Quartulli <ordex@autistici.org> > > But I would suggest to apply this change to net, since it is a fix. I agree. David, please consider to apply this patch for 3.8-rc*.
From: Akinobu Mita <akinobu.mita@gmail.com> Date: Wed, 26 Dec 2012 06:35:37 +0900 > 2012/12/25 Antonio Quartulli <ordex@autistici.org>: >> On Mon, Dec 24, 2012 at 11:14:06AM +0900, Akinobu Mita wrote: >>> batadv_iv_ogm_emit_send_time() attempts to calculates a random integer >>> in the range of 'orig_interval +- BATADV_JITTER' by the below lines. >>> >>> msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; >>> msecs += (random32() % 2 * BATADV_JITTER); >>> >>> But it actually gets 'orig_interval' or 'orig_interval - BATADV_JITTER' >>> because '%' and '*' have same precedence and associativity is >>> left-to-right. >>> >>> This adds the parentheses at the appropriate position so that it matches >>> original intension. >>> >>> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> >>> Cc: Marek Lindner <lindner_marek@yahoo.de> >>> Cc: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> >>> Cc: Antonio Quartulli <ordex@autistici.org> >>> Cc: b.a.t.m.a.n@lists.open-mesh.org >>> Cc: "David S. Miller" <davem@davemloft.net> >>> Cc: netdev@vger.kernel.org >>> --- >> >> Acked-by: Antonio Quartulli <ordex@autistici.org> >> >> But I would suggest to apply this change to net, since it is a fix. > > I agree. > David, please consider to apply this patch for 3.8-rc*. > All patches I should consider seriously should be properly reposted for review and inclusion.
diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index 9f3925a..7d02ebd 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -123,7 +123,7 @@ batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv) unsigned int msecs; msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; - msecs += (random32() % 2 * BATADV_JITTER); + msecs += random32() % (2 * BATADV_JITTER); return jiffies + msecs_to_jiffies(msecs); }
batadv_iv_ogm_emit_send_time() attempts to calculates a random integer in the range of 'orig_interval +- BATADV_JITTER' by the below lines. msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; msecs += (random32() % 2 * BATADV_JITTER); But it actually gets 'orig_interval' or 'orig_interval - BATADV_JITTER' because '%' and '*' have same precedence and associativity is left-to-right. This adds the parentheses at the appropriate position so that it matches original intension. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Marek Lindner <lindner_marek@yahoo.de> Cc: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> Cc: Antonio Quartulli <ordex@autistici.org> Cc: b.a.t.m.a.n@lists.open-mesh.org Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org --- net/batman-adv/bat_iv_ogm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)