mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Tomi Valkeinen <tomi.valkeinen@ti.com>
To: Linux Media Mailing List <linux-media@vger.kernel.org>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Bad kfree of dma_parms in v5.7-rc5
Date: Wed, 20 May 2020 12:00:14 +0300	[thread overview]
Message-ID: <a9df7155-dd7a-752b-6d1c-3426837756b1@ti.com> (raw)

Hi,

Commit 9495b7e92f716ab2bd6814fab5e97ab4a39adfdd ("driver core: platform: Initialize dma_parms for 
platform devices") v5.7-rc5 causes at least some v4l2 platform drivers to break when freeing resources.

E.g. drivers/media/platform/ti-vpe/cal.c uses vb2_dma_contig_set_max_seg_size() and 
vb2_dma_contig_clear_max_seg_size() to manage the dma_params, and similar pattern is seen in other 
drivers too.

After 9495b7e92f716ab2, vb2_dma_contig_set_max_seg_size() will not allocate anything, but 
vb2_dma_contig_clear_max_seg_size() will still kfree the dma_params.

I'm not sure what's the proper fix here. A flag somewhere to indicate that 
vb2_dma_contig_set_max_seg_size() did allocate, and thus vb2_dma_contig_clear_max_seg_size() must free?

Or drop the kzalloc and kfree totally, if dma_params is now supposed to always be there?

Or revert 9495b7e92f716ab2, as it was added so late?

  Tomi

-- 
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

             reply	other threads:[~2020-05-20  9:01 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20200520090109eucas1p17270805f81f6958cd5084a7b910efc6c@eucas1p1.samsung.com>
2020-05-20  9:00 ` Tomi Valkeinen [this message]
2020-05-20  9:13   ` Marek Szyprowski
2020-05-20  9:18     ` Tomi Valkeinen
     [not found]       ` <e3fa0b35-7cca-1e37-c2fa-63cc07e6bfda@samsung.com>
2020-05-20 12:43         ` Tomi Valkeinen
2020-05-20 12:54           ` Marek Szyprowski
2020-05-20 13:12             ` Ulf Hansson
2020-05-20 13:28               ` Marek Szyprowski
2020-05-20 15:14                 ` Ulf Hansson
2020-05-20 16:01                   ` Ulf Hansson

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=a9df7155-dd7a-752b-6d1c-3426837756b1@ti.com \
    --to=tomi.valkeinen@ti.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=m.szyprowski@samsung.com \
    --cc=mchehab@kernel.org \
    --cc=ulf.hansson@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®