Messages in this thread | | | Date | Sat, 19 Sep 2015 10:39:20 -0700 | From | Dmitry Torokhov <> | Subject | Re: [PATCH v5] Input: Add userio module |
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Hi Stephen,
On Thu, Sep 17, 2015 at 07:00:10PM -0400, cpaul@redhat.com wrote: > Responses > * Re: if (!userio) in userio_device_write(): it happens if we close the file > descriptor while the input driver is trying to talk to the device, since we > can't immediately bring down the driver. Removing the condition breaks the > driver
...
> +/** > + * userio_device_write - Write data from serio to a userio device in userspace > + * @id: The serio port for the userio device > + * @val: The data to write to the device > + */ > +static int userio_device_write(struct serio *id, unsigned char val) > +{ > + struct userio_device *userio = id->port_data; > + > + if (!userio) > + return -1;
1. I do not see where we reset port data. 2. I do not see what prevents object to which you now have a pointer to from disappearing at any moment past your check.
> + > + mutex_lock(&userio->lock);
serio_write() must allow to be called from interrupt context, so you can't use mutex here.
Thanks.
-- Dmitry
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