From: "H. Peter Anvin" <hpa@zytor.com>
To: Dave Hansen <dave.hansen@intel.com>,
Frantisek Hrbata <fhrbata@redhat.com>,
linux-kernel@vger.kernel.org
Cc: 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,
dvlasenk@redhat.com, prarit@redhat.com, lwoodman@redhat.com,
hannsj_uhl@de.ibm.com
Subject: Re: [PATCH 1/1] x86: add phys addr validity check for /dev/mem mmap
Date: Thu, 14 Aug 2014 10:20:53 -0700 [thread overview]
Message-ID: <53ECEFF5.1040800@zytor.com> (raw)
In-Reply-To: <53ECE573.1030405@intel.com>
On 08/14/2014 09:36 AM, Dave Hansen wrote:
> Thanks for dredging this back up!
>
> On 08/14/2014 07:18 AM, Frantisek Hrbata wrote:
>> +int valid_phys_addr_range(phys_addr_t addr, size_t count)
>> +{
>> + return addr + count <= __pa(high_memory);
>> +}
>
> Is this correct on 32-bit? It would limit /dev/mem to memory below 896MB.
>
Last I checked, /dev/mem was already broken for highmem... which is
actually a problem. I would prefer to see it fixed.
-hpa
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WARNING: multiple messages have this Message-ID (diff)
From: "H. Peter Anvin" <hpa@zytor.com>
To: Dave Hansen <dave.hansen@intel.com>,
Frantisek Hrbata <fhrbata@redhat.com>,
linux-kernel@vger.kernel.org
Cc: 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,
dvlasenk@redhat.com, prarit@redhat.com, lwoodman@redhat.com,
hannsj_uhl@de.ibm.com
Subject: Re: [PATCH 1/1] x86: add phys addr validity check for /dev/mem mmap
Date: Thu, 14 Aug 2014 10:20:53 -0700 [thread overview]
Message-ID: <53ECEFF5.1040800@zytor.com> (raw)
In-Reply-To: <53ECE573.1030405@intel.com>
On 08/14/2014 09:36 AM, Dave Hansen wrote:
> Thanks for dredging this back up!
>
> On 08/14/2014 07:18 AM, Frantisek Hrbata wrote:
>> +int valid_phys_addr_range(phys_addr_t addr, size_t count)
>> +{
>> + return addr + count <= __pa(high_memory);
>> +}
>
> Is this correct on 32-bit? It would limit /dev/mem to memory below 896MB.
>
Last I checked, /dev/mem was already broken for highmem... which is
actually a problem. I would prefer to see it fixed.
-hpa
next prev parent reply other threads:[~2014-08-14 17:21 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-14 14:18 [PATCH 0/1] Prevent possible PTE corruption with /dev/mem mmap Frantisek Hrbata
2014-08-14 14:18 ` Frantisek Hrbata
2014-08-14 14:18 ` [PATCH 1/1] x86: add phys addr validity check for " Frantisek Hrbata
2014-08-14 14:18 ` Frantisek Hrbata
2014-08-14 16:36 ` Dave Hansen
2014-08-14 16:36 ` Dave Hansen
2014-08-14 17:20 ` H. Peter Anvin [this message]
2014-08-14 17:20 ` H. Peter Anvin
2014-08-14 17:53 ` Frantisek Hrbata
2014-08-14 17:53 ` Frantisek Hrbata
2014-08-14 17:40 ` Frantisek Hrbata
2014-08-14 17:40 ` Frantisek Hrbata
2014-08-15 10:17 ` Frantisek Hrbata
2014-08-15 10:17 ` Frantisek Hrbata
2014-08-15 11:44 ` [PATCH V2 0/2] Prevent possible PTE corruption with " Frantisek Hrbata
2014-08-15 11:44 ` Frantisek Hrbata
2014-08-15 11:44 ` [PATCH V2 1/2] x86: add arch_pfn_possible helper Frantisek Hrbata
2014-08-15 11:44 ` Frantisek Hrbata
2014-08-15 11:44 ` [PATCH V2 2/2] x86: add phys addr validity check for /dev/mem mmap Frantisek Hrbata
2014-08-15 11:44 ` Frantisek Hrbata
2014-08-15 18:10 ` Dave Hansen
2014-08-15 18:10 ` Dave Hansen
2014-08-18 11:26 ` Frantisek Hrbata
2014-08-18 11:26 ` Frantisek Hrbata
2014-08-20 15:25 ` [PATCH 0/2] x86: allow read/write /dev/mem to access non-system RAM above high_memory Frantisek Hrbata
2014-08-20 15:25 ` Frantisek Hrbata
2014-08-20 15:25 ` [PATCH 1/2] x86: add high_memory check to (xlate|unxlate)_dev_mem_ptr Frantisek Hrbata
2014-08-20 15:25 ` Frantisek Hrbata
2014-08-20 15:25 ` [PATCH 2/2] x86: remove high_memory check from valid_phys_addr_range Frantisek Hrbata
2014-08-20 15:25 ` Frantisek Hrbata
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