Messages in this thread | | | Subject | Re: [PATCH] ipmi: fix unsigned long underflow | From | Weilong Chen <> | Date | Mon, 7 Aug 2017 16:41:09 +0800 |
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Hi Minyard,
I test this patch, it works.
Thanks.
On 2017/7/30 10:20, minyard@acm.org wrote: > From: Corey Minyard <cminyard@mvista.com> > > When I set the timeout to a specific value such as 500ms, the timeout > event will not happen in time due to the overflow in function > check_msg_timeout: > ... > ent->timeout -= timeout_period; > if (ent->timeout > 0) > return; > ... > > The type of timeout_period is long, but ent->timeout is unsigned long. > This patch makes the type consistent. > > Reported-by: Weilong Chen <chenweilong@huawei.com> > Signed-off-by: Corey Minyard <cminyard@mvista.com> > --- > I like to keep things consistent (though I obviously messed up here) > and keep variables that should be positive unsigned. > > But you are right, there is a bug here and some inconsistency. > This patch changes timeout_period to be unsigned and fixes the > check. Can you try this out? > > drivers/char/ipmi/ipmi_msghandler.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c > index 810b138..c82d9fd 100644 > --- a/drivers/char/ipmi/ipmi_msghandler.c > +++ b/drivers/char/ipmi/ipmi_msghandler.c > @@ -4030,7 +4030,8 @@ smi_from_recv_msg(ipmi_smi_t intf, struct ipmi_recv_msg *recv_msg, > } > > static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent, > - struct list_head *timeouts, long timeout_period, > + struct list_head *timeouts, > + unsigned long timeout_period, > int slot, unsigned long *flags, > unsigned int *waiting_msgs) > { > @@ -4043,8 +4044,8 @@ static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent, > if (!ent->inuse) > return; > > - ent->timeout -= timeout_period; > - if (ent->timeout > 0) { > + if (timeout_period < ent->timeout) { > + ent->timeout -= timeout_period; > (*waiting_msgs)++; > return; > } > @@ -4110,7 +4111,8 @@ static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent, > } > } > > -static unsigned int ipmi_timeout_handler(ipmi_smi_t intf, long timeout_period) > +static unsigned int ipmi_timeout_handler(ipmi_smi_t intf, > + unsigned long timeout_period) > { > struct list_head timeouts; > struct ipmi_recv_msg *msg, *msg2; >
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