Re: [PATCH 01/11] media: tm6000: fix potential Spectre variant 1

From: Mauro Carvalho Chehab
Date: Thu May 17 2018 - 06:37:58 EST


Em Thu, 17 May 2018 05:36:03 -0500
"Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx> escreveu:

>
>
> On 05/16/2018 08:14 PM, Gustavo A. R. Silva wrote:
> >
> >
> > On 05/15/2018 02:39 PM, Dan Carpenter wrote:

> >> You'd need to rebuild the db (possibly twice but definitely once).

How? Here, I just pull from your git tree and do a "make". At most,
make clean; make.

> >>
> >
> > Hi Dan,
> >
> > After rebuilding the db (once), these are all the Spectre media warnings
> > I get:
> >
> > drivers/media/pci/ddbridge/ddbridge-core.c:233 ddb_redirect() warn:
> > potential spectre issue 'ddbs'
> > drivers/media/pci/ddbridge/ddbridge-core.c:243 ddb_redirect() warn:
> > potential spectre issue 'pdev->port'
> > drivers/media/pci/ddbridge/ddbridge-core.c:252 ddb_redirect() warn:
> > potential spectre issue 'idev->input'
> > drivers/media/dvb-core/dvb_ca_en50221.c:1400
> > dvb_ca_en50221_io_do_ioctl() warn: potential spectre issue
> > 'ca->slot_info' (local cap)
> > drivers/media/dvb-core/dvb_ca_en50221.c:1479 dvb_ca_en50221_io_write()
> > warn: potential spectre issue 'ca->slot_info' (local cap)
> > drivers/media/dvb-core/dvb_net.c:252 handle_one_ule_extension() warn:
> > potential spectre issue 'p->ule_next_hdr'
> > drivers/media/dvb-core/dvb_net.c:1483 dvb_net_do_ioctl() warn: potential
> > spectre issue 'dvbnet->device' (local cap)
> > drivers/media/cec/cec-pin-error-inj.c:170 cec_pin_error_inj_parse_line()
> > warn: potential spectre issue 'pin->error_inj_args'
> >
> > I just want to double check if you are getting the same output. In case
> > you are getting the same, then what Mauro commented about these issues:
> >
> > https://patchwork.linuxtv.org/project/linux-media/list/?submitter=7277
> >
> > being resolved by commit 3ad3b7a2ebaefae37a7eafed0779324987ca5e56 seems
> > to be correct.
> >
>
> Interesting, I've rebuild the db twice and now I get a total of 75
> Spectre warnings in drivers/media

That makes more sense to me, as the same pattern is used by almost all
VIDIOC_ENUM_foo ioctls.

Thanks,
Mauro