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From: Kefeng Wang <wangkefeng.wang@huawei.com>
To: Liang Wang <wangliang101@huawei.com>, <palmerdabbelt@google.com>,
	<mcgrof@kernel.org>, <linux-kernel@vger.kernel.org>,
	<gregkh@linuxfoundation.org>, <linux@armlinux.org.uk>,
	<linux-arm-kernel@lists.infradead.org>
Cc: <stable@vger.kernel.org>, <wangle6@huawei.com>,
	<kepler.chenxin@huawei.com>, <nixiaoming@huawei.com>
Subject: Re: [PATCH v2] lib: Use PFN_PHYS() in devmem_is_allowed()
Date: Fri, 30 Jul 2021 15:04:05 +0800	[thread overview]
Message-ID: <12e37243-0cdb-6765-c3ef-c98fd291591c@huawei.com> (raw)
In-Reply-To: <20210730064915.56249-1-wangliang101@huawei.com>


On 2021/7/30 14:49, Liang Wang wrote:
> The physical address may exceed 32 bits on ARM(when ARM_LPAE enabled),
> use PFN_PHYS() in devmem_is_allowed(), or the physical address may
> overflow and be truncated.
>
> This bug was initially introduced from v2.6.37, and the function was moved
> to lib when v5.10.
>
> Fixes: 087aaffcdf9c ("ARM: implement CONFIG_STRICT_DEVMEM by disabling access to RAM via /dev/mem")
> Fixes: 527701eda5f1 ("lib: Add a generic version of devmem_is_allowed()")
> Cc: stable@vger.kernel.org # v2.6.37
> Signed-off-by: Liang Wang <wangliang101@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
> v2: update subject and changelog
>   lib/devmem_is_allowed.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/devmem_is_allowed.c b/lib/devmem_is_allowed.c
> index c0d67c541849..60be9e24bd57 100644
> --- a/lib/devmem_is_allowed.c
> +++ b/lib/devmem_is_allowed.c
> @@ -19,7 +19,7 @@
>    */
>   int devmem_is_allowed(unsigned long pfn)
>   {
> -	if (iomem_is_exclusive(pfn << PAGE_SHIFT))
> +	if (iomem_is_exclusive(PFN_PHYS(pfn)))
>   		return 0;
>   	if (!page_is_ram(pfn))
>   		return 1;

       reply	other threads:[~2021-07-30  7:04 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20210730064915.56249-1-wangliang101@huawei.com>
2021-07-30  7:04 ` Kefeng Wang [this message]
2021-08-04  0:20   ` [PATCH v2] lib: Use PFN_PHYS() in devmem_is_allowed() Palmer Dabbelt
2021-08-04  5:03     ` Kefeng Wang
2021-07-30  7:43 Liang Wang
2021-07-30 19:36 ` Luis Chamberlain

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