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From: "H. Peter Anvin" <hpa@zytor.com>
To: Frantisek Hrbata <fhrbata@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	tglx@linutronix.de, mingo@redhat.com, x86@kernel.org,
	oleg@redhat.com, kamaleshb@in.ibm.com, hechjie@cn.ibm.com,
	akpm@linux-foundation.org, dave.hansen@intel.com
Subject: Re: [RESEND PATCH] x86: add phys addr validity check for /dev/mem mmap
Date: Wed, 02 Oct 2013 10:46:35 -0700	[thread overview]
Message-ID: <524C5BFB.5050501@zytor.com> (raw)
In-Reply-To: <20131002160514.GA25471@localhost.localdomain>

On 10/02/2013 09:05 AM, Frantisek Hrbata wrote:
> +
> +int valid_phys_addr_range(phys_addr_t addr, size_t count)
> +{
> +	return addr + count <= __pa(high_memory);
> +}
> +
> +int valid_mmap_phys_addr_range(unsigned long pfn, size_t count)
> +{
> +	resource_size_t addr = (pfn << PAGE_SHIFT) + count;
> +	return phys_addr_valid(addr);
> +}
> 

The latter has overflow problems.

The former I realize matches the current /dev/mem, but it is still just
plain wrong in multiple ways.

	-hpa

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  reply	other threads:[~2013-10-02 17:48 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-02 16:05 [RESEND PATCH] x86: add phys addr validity check for /dev/mem mmap Frantisek Hrbata
2013-10-02 17:46 ` H. Peter Anvin [this message]
2013-10-02 18:31   ` Frantisek Hrbata
2013-10-02 18:36     ` H. Peter Anvin
2013-10-02 18:48       ` Frantisek Hrbata
2013-10-02 18:54         ` H. Peter Anvin

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