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SubjectRe: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.
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On Tue, 2011-04-19 at 18:25 -0700, David Rientjes wrote:
> On Tue, 19 Apr 2011, james_p_freyensee@linux.intel.com wrote:
>
> > +static void pti_control_frame_built_and_sent(struct pti_masterchannel *mc)
> > +{
> > + struct pti_masterchannel mccontrol = {.master = CONTROL_ID,
> > + .channel = 0};
> > + const char *control_format = "%3d %3d %s";
> > +
> > + char comm[sizeof(current->comm) + 1];
> > + u8 control_frame[CONTROL_FRAME_LEN];
> > +
> > + if (!in_interrupt())
> > + get_task_comm(comm, current);
> > + else
> > + strcpy(comm, "Interrupt");
> > +
> > + /* Ensure our buffer is zero terminated */
> > + comm[sizeof(current->comm)] = 0;
> > +
>
> You definitely need to use get_task_comm() here, but that means you can't
> allocate char comm[] on the stack with anything but TASK_COMM_LEN, which
> is small enough that it shouldn't be an issue. Otherwise there's nothing
> protecting sizeof(current->comm) from changing without holding
> task_lock(current).

I'm going to look at utilizing get_task_comm() more in this function,
but I think I am okay even if I miss one, as I am just doing a read from
it. What is written in set_task_comm() states that threads may read
from current->comm without holding the task_lock(). The name could be
incomplete, which would be non-ideal (but acceptable), but it's supposed
to be safe from non-terminating string reads.

And it seems like the fix for

> + comm[sizeof(current->comm)] = 0;

can just be comm[TASK_COMM_LEN].



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