Re: Problem with VMAP_STACK=y

From	Jörg Otte <jrg.otte@gmail.com>
Newsgroups	linux.kernel
Subject	Re: Problem with VMAP_STACK=y
Date	2016-10-05 17:30 +0200
Message-ID	<soWiR-2Hq-15@gated-at.bofh.it> (permalink)
References	(2 earlier) <soABH-57P-7@gated-at.bofh.it> <soOOm-63B-7@gated-at.bofh.it> <soOY1-67p-13@gated-at.bofh.it> <soPho-6eP-11@gated-at.bofh.it> <soQn8-7dj-27@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

2016-10-05 11:04 GMT+02:00 Mauro Carvalho Chehab <mchehab@s-opensource.com>:
> Em Wed, 5 Oct 2016 09:50:42 +0200 (CEST)
> Jiri Kosina <jikos@kernel.org> escreveu:
>
>> On Wed, 5 Oct 2016, Patrick Boettcher wrote:
>>
>> > > > Thanks for the quick response.
>> > > > Drivers are:
>> > > > dvb_core, dvb_usb, dbv_usb_cynergyT2
>> > >
>> > > This dbv_usb_cynergyT2 is not from Linus' tree, is it? I don't seem
>> > > to be able to find it, and the only google hit I am getting is your
>> > > very mail to LKML :)
>> >
>> > It's a typo, it should say dvb_usb_cinergyT2.
>>
>> Ah, thanks. Same issues there in
>>
>>       cinergyt2_frontend_attach()
>>       cinergyt2_rc_query()
>>
>> I think this would require more in-depth review of all the media drivers
>> and having all this fixed for 4.9. It should be pretty straightforward;
>> all the instances I've seen so far should be just straightforward
>> conversion to kmalloc() + kfree(), as the buffer is not being embedded in
>> any structure etc.
>
> What we're doing on most cases is to put a buffer (usually with 80
> chars for USB drivers) inside the "state" struct (on DVB drivers),
> in order to avoid doing kmalloc/kfree all the times. One such patch is
> changeset c4a98793a63c4.
>
> I'm enclosing a non-tested patch fixing it for the cinergyT2-core.c
> driver.
>
> Thanks,
> Mauro
>
> [PATCH] cinergyT2-core: don't do DMA on stack
>

Tried the cinergyT2 patch. No success. When I select a TV channel
just nothing happens. There are no error messages.

Jörg

Thread

Problem with VMAP_STACK=y Jörg Otte <jrg.otte@gmail.com> - 2016-10-04 14:30 +0200
  Re: Problem with VMAP_STACK=y Jiri Kosina <jikos@kernel.org> - 2016-10-04 15:30 +0200
    Re: Problem with VMAP_STACK=y Jörg Otte <jrg.otte@gmail.com> - 2016-10-04 18:20 +0200
      Re: Problem with VMAP_STACK=y Jiri Kosina <jikos@kernel.org> - 2016-10-05 09:30 +0200
        Re: Problem with VMAP_STACK=y Patrick Boettcher <patrick.boettcher@posteo.de> - 2016-10-05 09:40 +0200
          Re: Problem with VMAP_STACK=y Jiri Kosina <jikos@kernel.org> - 2016-10-05 10:00 +0200
            Re: Problem with VMAP_STACK=y Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-05 11:10 +0200
              Re: Problem with VMAP_STACK=y Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-05 13:30 +0200
              Re: Problem with VMAP_STACK=y Jörg Otte <jrg.otte@gmail.com> - 2016-10-05 17:30 +0200
                Re: Problem with VMAP_STACK=y Andy Lutomirski <luto@amacapital.net> - 2016-10-05 18:00 +0200
                Re: Problem with VMAP_STACK=y Jörg Otte <jrg.otte@gmail.com> - 2016-10-05 18:50 +0200
                Re: Problem with VMAP_STACK=y Andy Lutomirski <luto@amacapital.net> - 2016-10-05 19:00 +0200
              Re: Problem with VMAP_STACK=y Johannes Stezenbach <js@linuxtv.org> - 2016-10-05 20:40 +0200
                Re: Problem with VMAP_STACK=y Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-05 21:00 +0200
                Re: Problem with VMAP_STACK=y Jörg Otte <jrg.otte@gmail.com> - 2016-10-06 10:40 +0200
                Re: Problem with VMAP_STACK=y Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-06 19:20 +0200
                Re: Problem with VMAP_STACK=y Jiri Kosina <jikos@kernel.org> - 2016-10-07 10:00 +0200
                Re: Problem with VMAP_STACK=y Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-07 13:20 +0200
    dvb-usb stack-memory used for URB-buffers (was: Re: Problem with  VMAP_STACK=y) Patrick Boettcher <patrick.boettcher@posteo.de> - 2016-10-05 09:50 +0200

csiph-web