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From: walter harms <wharms@bfs.de>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [patch] edac i5000: fix pointer math in i5000_get_mc_regs()
Date: Fri, 02 Mar 2012 19:20:59 +0000	[thread overview]
Message-ID: <4F511D9B.10401@bfs.de> (raw)
In-Reply-To: <20120302190932.GI22598@mwanda>



Am 02.03.2012 20:09, schrieb Dan Carpenter:
> On Fri, Mar 02, 2012 at 10:00:06AM +0100, walter harms wrote:
>>> diff --git a/drivers/edac/i5000_edac.c b/drivers/edac/i5000_edac.c
>>> index 4dc3ac2..fcdc4ab 100644
>>> --- a/drivers/edac/i5000_edac.c
>>> +++ b/drivers/edac/i5000_edac.c
>>> @@ -1130,7 +1130,7 @@ static void i5000_get_mc_regs(struct mem_ctl_info *mci)
>>>  	pci_read_config_dword(pvt->system_address, AMBASE,
>>>  			(u32 *) & pvt->ambase);
>>>  	pci_read_config_dword(pvt->system_address, AMBASE + sizeof(u32),
>>> -			((u32 *) & pvt->ambase) + sizeof(u32));
>>> +			(u32 *)((char *) &pvt->ambase + sizeof(u32)));
>>>  
>>>  	maxdimmperch = pvt->maxdimmperch;
>>>  	maxch = pvt->maxch;
>>
>> i think this is hard to understand. personally i would prefer a union or other
>> more obvious solutions. my suggestion would be to get rid of this.
>>
>> u32 bottom,top;
>>  	pci_read_config_dword(pvt->system_address, AMBASE,
>>   			&bottom);
>> 	pci_read_config_dword(pvt->system_address, AMBASE+ sizeof(u32),
>>   			&top);
>> 	maxdimmperch=(u64)top<<32|bottom;
>> 	
>> you can find this pattern in other parts of the kernel also.
>>
> 
> Sure.  I want to do this again anyway because I see I've missed some
> other parts which have the same bug.  I'll resend a patch later.
> 
> regards,
> dan carpenter

I have no idea how ofter a64bit value is need but perhaps is pci_read_config_qword()
an option ?

re,
 wh

WARNING: multiple messages have this Message-ID (diff)
From: walter harms <wharms@bfs.de>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [patch] edac i5000: fix pointer math in i5000_get_mc_regs()
Date: Fri, 02 Mar 2012 20:20:59 +0100	[thread overview]
Message-ID: <4F511D9B.10401@bfs.de> (raw)
In-Reply-To: <20120302190932.GI22598@mwanda>



Am 02.03.2012 20:09, schrieb Dan Carpenter:
> On Fri, Mar 02, 2012 at 10:00:06AM +0100, walter harms wrote:
>>> diff --git a/drivers/edac/i5000_edac.c b/drivers/edac/i5000_edac.c
>>> index 4dc3ac2..fcdc4ab 100644
>>> --- a/drivers/edac/i5000_edac.c
>>> +++ b/drivers/edac/i5000_edac.c
>>> @@ -1130,7 +1130,7 @@ static void i5000_get_mc_regs(struct mem_ctl_info *mci)
>>>  	pci_read_config_dword(pvt->system_address, AMBASE,
>>>  			(u32 *) & pvt->ambase);
>>>  	pci_read_config_dword(pvt->system_address, AMBASE + sizeof(u32),
>>> -			((u32 *) & pvt->ambase) + sizeof(u32));
>>> +			(u32 *)((char *) &pvt->ambase + sizeof(u32)));
>>>  
>>>  	maxdimmperch = pvt->maxdimmperch;
>>>  	maxch = pvt->maxch;
>>
>> i think this is hard to understand. personally i would prefer a union or other
>> more obvious solutions. my suggestion would be to get rid of this.
>>
>> u32 bottom,top;
>>  	pci_read_config_dword(pvt->system_address, AMBASE,
>>   			&bottom);
>> 	pci_read_config_dword(pvt->system_address, AMBASE+ sizeof(u32),
>>   			&top);
>> 	maxdimmperch=(u64)top<<32|bottom;
>> 	
>> you can find this pattern in other parts of the kernel also.
>>
> 
> Sure.  I want to do this again anyway because I see I've missed some
> other parts which have the same bug.  I'll resend a patch later.
> 
> regards,
> dan carpenter

I have no idea how ofter a64bit value is need but perhaps is pci_read_config_qword()
an option ?

re,
 wh

  reply	other threads:[~2012-03-02 19:20 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-02  6:54 [patch] edac i5000: fix pointer math in i5000_get_mc_regs() Dan Carpenter
2012-03-02  6:54 ` Dan Carpenter
2012-03-02  9:00 ` walter harms
2012-03-02  9:00   ` walter harms
2012-03-02 19:09   ` Dan Carpenter
2012-03-02 19:09     ` Dan Carpenter
2012-03-02 19:20     ` walter harms [this message]
2012-03-02 19:20       ` walter harms
2012-03-05  8:59   ` [patch v2] edac i5000, i5400: " Dan Carpenter
2012-03-05  9:01     ` Dan Carpenter
2012-03-05  9:45     ` walter harms
2012-03-05  9:45       ` walter harms
2012-03-05  9:52       ` Dan Carpenter
2012-03-05  9:52         ` Dan Carpenter
2012-03-05 10:07         ` walter harms
2012-03-05 10:07           ` walter harms
2012-03-06  6:38         ` [patch v3] " Dan Carpenter
2012-03-06  6:38           ` Dan Carpenter
2012-03-06  8:50           ` walter harms
2012-03-06  8:50             ` walter harms

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