[bug report] firmware: arm_ffa: Add schedule receiver callback mechanism
Dan Carpenter
dan.carpenter at linaro.org
Mon Oct 30 21:15:45 PDT 2023
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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