Re: [PATCH v2] of: Fix reserved-memory overlap detection

From: Rob Herring <robh@kernel.org>
To: Vincent Whitchurch <vincent.whitchurch@axis.com>
Cc: kernel@axis.com, Frank Rowand <frowand.list@gmail.com>,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	Rob Herring <robh+dt@kernel.org>
Subject: Re: [PATCH v2] of: Fix reserved-memory overlap detection
Date: Fri, 23 Oct 2020 11:50:30 -0500	[thread overview]
Message-ID: <20201023165030.GA2852897@bogus> (raw)
In-Reply-To: <ded6fd6b47b58741aabdcc6967f73eca6a3f311e.1603273666.git-series.vincent.whitchurch@axis.com>

On Wed, 21 Oct 2020 11:53:59 +0200, Vincent Whitchurch wrote:
> The reserved-memory overlap detection code fails to detect overlaps if
> either of the regions starts at address 0x0.  The code explicitly checks
> for and ignores such regions, apparently in order to ignore dynamically
> allocated regions which have an address of 0x0 at this point.  These
> dynamically allocated regions also have a size of 0x0 at this point, so
> fix this by removing the check and sorting the dynamically allocated
> regions ahead of any static regions at address 0x0.
> 
> For example, there are two overlaps in this case but they are not
> currently reported:
> 
> 	foo@0 {
> 	        reg = <0x0 0x2000>;
> 	};
> 
> 	bar@0 {
> 	        reg = <0x0 0x1000>;
> 	};
> 
> 	baz@1000 {
> 	        reg = <0x1000 0x1000>;
> 	};
> 
> 	quux {
> 	        size = <0x1000>;
> 	};
> 
> but they are after this patch:
> 
>  OF: reserved mem: OVERLAP DETECTED!
>  bar@0 (0x00000000--0x00001000) overlaps with foo@0 (0x00000000--0x00002000)
>  OF: reserved mem: OVERLAP DETECTED!
>  foo@0 (0x00000000--0x00002000) overlaps with baz@1000 (0x00001000--0x00002000)
> 
> Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
> ---
> v2: Fix handling of dynamically allocated regions.
> 
>  drivers/of/of_reserved_mem.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 

Applied, thanks!