Re: [bug report] firmware: arm_ffa: Add schedule receiver callback mechanism

[Dan Carpenter <dan.carpenter@linaro.org>]

On Mon, Oct 30, 2023 at 04:01:07PM +0000, Sudeep Holla wrote:
> On Mon, Oct 30, 2023 at 05:31:04PM +0300, Dan Carpenter wrote:
> > Hello Sudeep Holla,
> > 
> > The patch 0184450b8b1e: "firmware: arm_ffa: Add schedule receiver
> > callback mechanism" from Oct 5, 2023 (linux-next), leads to the
> > following Smatch static checker warning:
> > 
> > 	drivers/firmware/arm_ffa/driver.c:1251 ffa_partitions_cleanup()
> > 	warn: double check that we're allocating correct size: 8 vs 88
> > 
> > drivers/firmware/arm_ffa/driver.c
> >     1243 static void ffa_partitions_cleanup(void)
> >     1244 {
> >     1245         struct ffa_dev_part_info **info;
> >     1246         int idx, count = drv_info->partition_count;
> >     1247 
> >     1248         if (!count)
> >     1249                 return;
> >     1250 
> > --> 1251         info = kcalloc(count, sizeof(**info), GFP_KERNEL);
> > 
> > I *think* this should be sizeof(*info).  It ends up being a smaller
> > allocation (8 bytes instead of 88).
> 
> Not sure if I am following this warning properly. I am bit confused whether
> it suggest 8 is correct or 88 is correct. Anyways, the expectation is to
> just allocate 8 bytes for a pointer. We just fetch a list of stored pointer
> in XArray and free them.
> 
> One possible way to avoid any confusion is to use sizeof(struct ffa_dev_part_info *)
> or even sizeof(void *).

The static checker is saying that 8 is correct but we are allocating 88
bytes.  There is an extra * in the sizeof().

I don't necessarily like to make buffers smaller in case I have
misunderstood the code, but it seems like we should do that here.

regards,
dan carpenter


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