linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Robin Murphy <robin.murphy@arm.com>
To: Ajay Kumar <ajaykumar.rs@samsung.com>,
	linux-arm-kernel@lists.infradead.org, robh+dt@kernel.org,
	mark.rutland@arm.com, will@kernel.org
Cc: shaik.ameer@samsung.com, nleeder@codeaurora.org,
	shameerali.kolothum.thodi@huawei.com, alim.akhtar@samsung.com,
	Jay Chen <jkchen@linux.alibaba.com>,
	joro@8bytes.org
Subject: Re: [PATCH 4/4] perf/smmuv3: fix crash when platdata not specified
Date: Mon, 13 Jul 2020 10:46:06 +0100	[thread overview]
Message-ID: <54027eac-6d75-7da8-ebaa-fb554f40933c@arm.com> (raw)
In-Reply-To: <20200712163341.61410-5-ajaykumar.rs@samsung.com>

On 2020-07-12 17:33, Ajay Kumar wrote:
> The arm_smmuv3_pmu driver assumes platform data is always
> available and exposes a possible NULL pointer deferencing
> at the below line.
> 
> model = *(u32 *)dev_get_platdata(smmu_pmu->dev);
> 
> This patch fixes the bug by adding a check prior to the
> deferencing of the platform data pointer.
> 
> Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
> ---
>   drivers/perf/arm_smmuv3_pmu.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c
> index 25feab718c20..f7a27ae2f8d8 100644
> --- a/drivers/perf/arm_smmuv3_pmu.c
> +++ b/drivers/perf/arm_smmuv3_pmu.c
> @@ -710,9 +710,10 @@ static void smmu_pmu_reset(struct smmu_pmu *smmu_pmu)
>   
>   static void smmu_pmu_get_acpi_options(struct smmu_pmu *smmu_pmu)
>   {
> -	u32 model;
> +	u32 model = 0;
>   
> -	model = *(u32 *)dev_get_platdata(smmu_pmu->dev);
> +	if (dev_get_platdata(smmu_pmu->dev))
> +		model = *(u32 *)dev_get_platdata(smmu_pmu->dev);

As I commented on the other series, ideally this could be something like:

	if (dev->of_node)
		model = of_device_get_match_data(dev->of_node);
	else
		model = *(u32 *)dev_get_platdata(dev); /* from IORT */

(and lose the "acpi_" from the function name, obviously)

Robin.

>   
>   	switch (model) {
>   	case IORT_SMMU_V3_PMCG_HISI_HIP08:
> 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2020-07-13  9:47 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20200712165509epcas5p29e66777a4e0115420b9104ba5aa83f57@epcas5p2.samsung.com>
2020-07-12 16:33 ` [PATCH 0/4] Add DT support for arm_smmuv3_pmu driver Ajay Kumar
2020-07-12 16:33   ` [PATCH 1/4] perf/smmuv3: Remove dependency on CONFIG_ACPI Ajay Kumar
2020-07-12 16:33   ` [PATCH 2/4] Documentation: perf: Add documentation for arm-smmu-v3-pmcg Ajay Kumar
2020-07-13  8:41     ` Jonathan Cameron
2020-07-12 16:33   ` [PATCH 3/4] perf/smmuv3: add device tree support Ajay Kumar
2020-07-12 16:33   ` [PATCH 4/4] perf/smmuv3: fix crash when platdata not specified Ajay Kumar
2020-07-13  8:46     ` Jonathan Cameron
2020-07-13  9:46     ` Robin Murphy [this message]
2020-07-13  9:42   ` [PATCH 0/4] Add DT support for arm_smmuv3_pmu driver Robin Murphy
2020-07-13  9:57     ` John Garry
2020-07-13 10:17       ` Ajay kumar
2020-07-13 10:28       ` Robin Murphy

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=54027eac-6d75-7da8-ebaa-fb554f40933c@arm.com \
    --to=robin.murphy@arm.com \
    --cc=ajaykumar.rs@samsung.com \
    --cc=alim.akhtar@samsung.com \
    --cc=jkchen@linux.alibaba.com \
    --cc=joro@8bytes.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=mark.rutland@arm.com \
    --cc=nleeder@codeaurora.org \
    --cc=robh+dt@kernel.org \
    --cc=shaik.ameer@samsung.com \
    --cc=shameerali.kolothum.thodi@huawei.com \
    --cc=will@kernel.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;
as well as URLs for NNTP newsgroup(s).