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From: Leo Yan <leo.yan@arm.com>
To: Jie Gan <jie.gan@oss.qualcomm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>,
	Mike Leach <mike.leach@arm.com>,
	James Clark <james.clark@linaro.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Tingwei Zhang <tingwei.zhang@oss.qualcomm.com>,
	coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] coresight: tpdm: fix invalid MMIO access issue
Date: Tue, 7 Apr 2026 11:35:30 +0100	[thread overview]
Message-ID: <20260407103530.GL356832@e132581.arm.com> (raw)
In-Reply-To: <0a4911f4-168b-48c4-9554-3962d6e96efa@oss.qualcomm.com>

Hi Jie,

On Tue, Apr 07, 2026 at 04:33:22PM +0800, Jie Gan wrote:
> On 4/7/2026 4:10 PM, Leo Yan wrote:
> > On Tue, Apr 07, 2026 at 12:47:11PM +0800, Jie Gan wrote:
> > > Create the csdev_access struct only when a valid MMIO resource is
> > > available. In tpdm_probe(), base is uninitialized for static TPDM
> > > instances that lack an MMIO resource, causing csdev_access to be
> > > created with a garbage address and potentially leading to
> > > unexpected issues.
> > 
> > This patch itself is fine for me.  However, I am wandering if this
> > is sufficient.
> > 
> > As mentioned "potentially leading to unexpected issues", can I
> > understand some code pieces access register with uninitialized base?
> > If so, you would also explictly add coresight_is_static_tpdm() to
> > prevent register access.
> > 
> 
> Actually, we havent MMIO access for the static TPDM device, So no issues are
> observed. The commit message here may be misleading. do I need rephrase the
> commit message?

Yes, good to clarify a bit in commit log:

  "So far there has no register access for static instance, but this
   change helps mitigate potential risks in the future."

With this:

Reviewed-by: Leo Yan <leo.yan@arm.com>


  reply	other threads:[~2026-04-07 10:35 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-07  4:47 [PATCH] coresight: tpdm: fix invalid MMIO access issue Jie Gan
2026-04-07  8:10 ` Leo Yan
2026-04-07  8:33   ` Jie Gan
2026-04-07 10:35     ` Leo Yan [this message]
2026-04-07 10:59       ` Jie Gan

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