[Outreachy kernel] [PATCH 4/5] gpu: drm: amdgpu: Replace snprintf() with sysfs_emit()

[Sumera Priyadarsini]

On Thu, Oct 22, 2020 at 7:24 PM Greg KH <gregkh at linuxfoundation.org> wrote:

> On Thu, Oct 22, 2020 at 07:17:56PM +0530, Sumera Priyadarsini wrote:
> > Using snprintf() for show() methods holds the risk of buffer overrun
> > as snprintf() does not know the PAGE_SIZE maximum of the temporary
> > buffer used to output sysfs content.
> >
> > Modify amdgpu_psp.c to use sysfs_emit() instead which knows the
> > size of the temporary buffer.
> >
> > Issue found with Coccinelle.
> >
> > Signed-off-by: Sumera Priyadarsini <sylphrenadin at gmail.com>
> > ---
> >  drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
> > index d6c38e24f130..4d1d1e1b005d 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
> > @@ -2621,7 +2621,7 @@ static ssize_t psp_usbc_pd_fw_sysfs_read(struct
> device *dev,
> >               return ret;
> >       }
> >
> > -     return snprintf(buf, PAGE_SIZE, "%x\n", fw_ver);
> > +     return sysfs_emit(buf, PAGE_SIZE, "%x\n", fw_ver);
>
> Did you build this code?  I don't think it is correct...
>

Yes, you are right. I compiled all of them again separately. I had based
them off the usual drm tree
but that is wrong because sysfs_emit has been added only in the 5.10. I
will send a v2 with the proper
corrections.

regards,
sumera


> thanks,
>
> greg k-h
>
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