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* [PATCH] ACPI: fix APEI related table size checking
@ 2012-10-16 14:46 Jan Beulich
  2012-10-16 15:12 ` Keir Fraser
  2012-10-17  6:49 ` Huang Ying
  0 siblings, 2 replies; 5+ messages in thread
From: Jan Beulich @ 2012-10-16 14:46 UTC (permalink / raw)
  To: xen-devel; +Cc: ying.huang

[-- Attachment #1: Type: text/plain, Size: 1817 bytes --]

On Huang Ying's machine:

erst_tab->header_length == sizeof(struct acpi_table_einj)

but Yinghai reported that on his machine,

erst_tab->header_length == sizeof(struct acpi_table_einj) -
sizeof(struct acpi_table_header)

To make erst table size checking code works on all systems, both
testing are treated as PASS.

Same situation applies to einj_tab->header_length, so corresponding
table size checking is changed in similar way too.

Originally-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Huang Ying <ying.huang@intel.com>

- use switch() for better readability
- add comment explaining why a formally invalid size it also being
  accepted
- check erst_tab->header.length before even looking at
  erst_tab->header_length
- prefer sizeof(*erst_tab) over sizeof(struct acpi_table_erst)

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/drivers/acpi/apei/erst.c
+++ b/xen/drivers/acpi/apei/erst.c
@@ -715,12 +715,23 @@ int erst_clear(u64 record_id)
 
 static int __init erst_check_table(struct acpi_table_erst *erst_tab)
 {
-	if (erst_tab->header_length != sizeof(struct acpi_table_erst))
+	if (erst_tab->header.length < sizeof(*erst_tab))
 		return -EINVAL;
-	if (erst_tab->header.length < sizeof(struct acpi_table_erst))
+
+	switch (erst_tab->header_length) {
+	case sizeof(*erst_tab) - sizeof(erst_tab->header):
+	/*
+	 * While invalid per specification, there are (early?) systems
+	 * indicating the full header size here, so accept that value too.
+	 */
+	case sizeof(*erst_tab):
+		break;
+	default:
 		return -EINVAL;
+	}
+
 	if (erst_tab->entries !=
-	    (erst_tab->header.length - sizeof(struct acpi_table_erst)) /
+	    (erst_tab->header.length - sizeof(*erst_tab)) /
 	    sizeof(struct acpi_erst_entry))
 		return -EINVAL;
 




[-- Attachment #2: ACPI-ERST-header-length.patch --]
[-- Type: text/plain, Size: 1857 bytes --]

ACPI: fix APEI related table size checking

On Huang Ying's machine:

erst_tab->header_length == sizeof(struct acpi_table_einj)

but Yinghai reported that on his machine,

erst_tab->header_length == sizeof(struct acpi_table_einj) -
sizeof(struct acpi_table_header)

To make erst table size checking code works on all systems, both
testing are treated as PASS.

Same situation applies to einj_tab->header_length, so corresponding
table size checking is changed in similar way too.

Originally-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Huang Ying <ying.huang@intel.com>

- use switch() for better readability
- add comment explaining why a formally invalid size it also being
  accepted
- check erst_tab->header.length before even looking at
  erst_tab->header_length
- prefer sizeof(*erst_tab) over sizeof(struct acpi_table_erst)

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/drivers/acpi/apei/erst.c
+++ b/xen/drivers/acpi/apei/erst.c
@@ -715,12 +715,23 @@ int erst_clear(u64 record_id)
 
 static int __init erst_check_table(struct acpi_table_erst *erst_tab)
 {
-	if (erst_tab->header_length != sizeof(struct acpi_table_erst))
+	if (erst_tab->header.length < sizeof(*erst_tab))
 		return -EINVAL;
-	if (erst_tab->header.length < sizeof(struct acpi_table_erst))
+
+	switch (erst_tab->header_length) {
+	case sizeof(*erst_tab) - sizeof(erst_tab->header):
+	/*
+	 * While invalid per specification, there are (early?) systems
+	 * indicating the full header size here, so accept that value too.
+	 */
+	case sizeof(*erst_tab):
+		break;
+	default:
 		return -EINVAL;
+	}
+
 	if (erst_tab->entries !=
-	    (erst_tab->header.length - sizeof(struct acpi_table_erst)) /
+	    (erst_tab->header.length - sizeof(*erst_tab)) /
 	    sizeof(struct acpi_erst_entry))
 		return -EINVAL;
 

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] ACPI: fix APEI related table size checking
  2012-10-16 14:46 [PATCH] ACPI: fix APEI related table size checking Jan Beulich
@ 2012-10-16 15:12 ` Keir Fraser
  2012-10-17  6:49 ` Huang Ying
  1 sibling, 0 replies; 5+ messages in thread
From: Keir Fraser @ 2012-10-16 15:12 UTC (permalink / raw)
  To: Jan Beulich, xen-devel; +Cc: ying.huang

On 16/10/2012 15:46, "Jan Beulich" <JBeulich@suse.com> wrote:

> On Huang Ying's machine:
> 
> erst_tab->header_length == sizeof(struct acpi_table_einj)
> 
> but Yinghai reported that on his machine,
> 
> erst_tab->header_length == sizeof(struct acpi_table_einj) -
> sizeof(struct acpi_table_header)
> 
> To make erst table size checking code works on all systems, both
> testing are treated as PASS.
> 
> Same situation applies to einj_tab->header_length, so corresponding
> table size checking is changed in similar way too.
> 
> Originally-by: Yinghai Lu <yinghai@kernel.org>
> Signed-off-by: Huang Ying <ying.huang@intel.com>
> 
> - use switch() for better readability
> - add comment explaining why a formally invalid size it also being
>   accepted
> - check erst_tab->header.length before even looking at
>   erst_tab->header_length
> - prefer sizeof(*erst_tab) over sizeof(struct acpi_table_erst)
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Acked-by: Keir Fraser <keir@xen.org>

> --- a/xen/drivers/acpi/apei/erst.c
> +++ b/xen/drivers/acpi/apei/erst.c
> @@ -715,12 +715,23 @@ int erst_clear(u64 record_id)
>  
>  static int __init erst_check_table(struct acpi_table_erst *erst_tab)
>  {
> - if (erst_tab->header_length != sizeof(struct acpi_table_erst))
> + if (erst_tab->header.length < sizeof(*erst_tab))
> return -EINVAL;
> - if (erst_tab->header.length < sizeof(struct acpi_table_erst))
> +
> + switch (erst_tab->header_length) {
> + case sizeof(*erst_tab) - sizeof(erst_tab->header):
> + /*
> +  * While invalid per specification, there are (early?) systems
> +  * indicating the full header size here, so accept that value too.
> +  */
> + case sizeof(*erst_tab):
> +  break;
> + default:
> return -EINVAL;
> + }
> +
> if (erst_tab->entries !=
> -     (erst_tab->header.length - sizeof(struct acpi_table_erst)) /
> +     (erst_tab->header.length - sizeof(*erst_tab)) /
>    sizeof(struct acpi_erst_entry))
> return -EINVAL;
>  
> 
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] ACPI: fix APEI related table size checking
  2012-10-16 14:46 [PATCH] ACPI: fix APEI related table size checking Jan Beulich
  2012-10-16 15:12 ` Keir Fraser
@ 2012-10-17  6:49 ` Huang Ying
  2012-10-17  6:56   ` Jan Beulich
  1 sibling, 1 reply; 5+ messages in thread
From: Huang Ying @ 2012-10-17  6:49 UTC (permalink / raw)
  To: Jan Beulich; +Cc: xen-devel

On Tue, 2012-10-16 at 15:46 +0100, Jan Beulich wrote:
> On Huang Ying's machine:
> 
> erst_tab->header_length == sizeof(struct acpi_table_einj)
  ~~~~                                                ~~~~

Typo?

Best Regards,
Huang Ying

> but Yinghai reported that on his machine,
> 
> erst_tab->header_length == sizeof(struct acpi_table_einj) -
> sizeof(struct acpi_table_header)
> 
> To make erst table size checking code works on all systems, both
> testing are treated as PASS.
> 
> Same situation applies to einj_tab->header_length, so corresponding
> table size checking is changed in similar way too.
> 
> Originally-by: Yinghai Lu <yinghai@kernel.org>
> Signed-off-by: Huang Ying <ying.huang@intel.com>
> 
> - use switch() for better readability
> - add comment explaining why a formally invalid size it also being
>   accepted
> - check erst_tab->header.length before even looking at
>   erst_tab->header_length
> - prefer sizeof(*erst_tab) over sizeof(struct acpi_table_erst)
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> 
> --- a/xen/drivers/acpi/apei/erst.c
> +++ b/xen/drivers/acpi/apei/erst.c
> @@ -715,12 +715,23 @@ int erst_clear(u64 record_id)
>  
>  static int __init erst_check_table(struct acpi_table_erst *erst_tab)
>  {
> -	if (erst_tab->header_length != sizeof(struct acpi_table_erst))
> +	if (erst_tab->header.length < sizeof(*erst_tab))
>  		return -EINVAL;
> -	if (erst_tab->header.length < sizeof(struct acpi_table_erst))
> +
> +	switch (erst_tab->header_length) {
> +	case sizeof(*erst_tab) - sizeof(erst_tab->header):
> +	/*
> +	 * While invalid per specification, there are (early?) systems
> +	 * indicating the full header size here, so accept that value too.
> +	 */
> +	case sizeof(*erst_tab):
> +		break;
> +	default:
>  		return -EINVAL;
> +	}
> +
>  	if (erst_tab->entries !=
> -	    (erst_tab->header.length - sizeof(struct acpi_table_erst)) /
> +	    (erst_tab->header.length - sizeof(*erst_tab)) /
>  	    sizeof(struct acpi_erst_entry))
>  		return -EINVAL;
>  
> 
> 
> 

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] ACPI: fix APEI related table size checking
  2012-10-17  6:49 ` Huang Ying
@ 2012-10-17  6:56   ` Jan Beulich
  2012-10-17  8:52     ` Huang Ying
  0 siblings, 1 reply; 5+ messages in thread
From: Jan Beulich @ 2012-10-17  6:56 UTC (permalink / raw)
  To: Huang Ying; +Cc: xen-devel

>>> On 17.10.12 at 08:49, Huang Ying <ying.huang@intel.com> wrote:
> On Tue, 2012-10-16 at 15:46 +0100, Jan Beulich wrote:
>> On Huang Ying's machine:
>> 
>> erst_tab->header_length == sizeof(struct acpi_table_einj)
>   ~~~~                                                ~~~~
> 
> Typo?

Your typo: I copied the Linux commit message verbatim, to make
it possible to match the two commits. The adjustments done in
the actual patch eliminate the copy-n-paste mistake corrected by
Linux commit 7ed28f2ed43ece424ff2fa4dedac7928bb37a23a.

Jan

>> but Yinghai reported that on his machine,
>> 
>> erst_tab->header_length == sizeof(struct acpi_table_einj) -
>> sizeof(struct acpi_table_header)
>> 
>> To make erst table size checking code works on all systems, both
>> testing are treated as PASS.
>> 
>> Same situation applies to einj_tab->header_length, so corresponding
>> table size checking is changed in similar way too.
>> 
>> Originally-by: Yinghai Lu <yinghai@kernel.org>
>> Signed-off-by: Huang Ying <ying.huang@intel.com>
>> 
>> - use switch() for better readability
>> - add comment explaining why a formally invalid size it also being
>>   accepted
>> - check erst_tab->header.length before even looking at
>>   erst_tab->header_length
>> - prefer sizeof(*erst_tab) over sizeof(struct acpi_table_erst)
>> 
>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
>> 
>> --- a/xen/drivers/acpi/apei/erst.c
>> +++ b/xen/drivers/acpi/apei/erst.c
>> @@ -715,12 +715,23 @@ int erst_clear(u64 record_id)
>>  
>>  static int __init erst_check_table(struct acpi_table_erst *erst_tab)
>>  {
>> -	if (erst_tab->header_length != sizeof(struct acpi_table_erst))
>> +	if (erst_tab->header.length < sizeof(*erst_tab))
>>  		return -EINVAL;
>> -	if (erst_tab->header.length < sizeof(struct acpi_table_erst))
>> +
>> +	switch (erst_tab->header_length) {
>> +	case sizeof(*erst_tab) - sizeof(erst_tab->header):
>> +	/*
>> +	 * While invalid per specification, there are (early?) systems
>> +	 * indicating the full header size here, so accept that value too.
>> +	 */
>> +	case sizeof(*erst_tab):
>> +		break;
>> +	default:
>>  		return -EINVAL;
>> +	}
>> +
>>  	if (erst_tab->entries !=
>> -	    (erst_tab->header.length - sizeof(struct acpi_table_erst)) /
>> +	    (erst_tab->header.length - sizeof(*erst_tab)) /
>>  	    sizeof(struct acpi_erst_entry))
>>  		return -EINVAL;
>>  
>> 
>> 
>> 

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] ACPI: fix APEI related table size checking
  2012-10-17  6:56   ` Jan Beulich
@ 2012-10-17  8:52     ` Huang Ying
  0 siblings, 0 replies; 5+ messages in thread
From: Huang Ying @ 2012-10-17  8:52 UTC (permalink / raw)
  To: Jan Beulich; +Cc: xen-devel

On Wed, 2012-10-17 at 07:56 +0100, Jan Beulich wrote:
> >>> On 17.10.12 at 08:49, Huang Ying <ying.huang@intel.com> wrote:
> > On Tue, 2012-10-16 at 15:46 +0100, Jan Beulich wrote:
> >> On Huang Ying's machine:
> >> 
> >> erst_tab->header_length == sizeof(struct acpi_table_einj)
> >   ~~~~                                                ~~~~
> > 
> > Typo?
> 
> Your typo: I copied the Linux commit message verbatim, to make
> it possible to match the two commits. The adjustments done in
> the actual patch eliminate the copy-n-paste mistake corrected by
> Linux commit 7ed28f2ed43ece424ff2fa4dedac7928bb37a23a.

Sorry, my bad.

Best Regards,
Huang Ying

> 
> >> but Yinghai reported that on his machine,
> >> 
> >> erst_tab->header_length == sizeof(struct acpi_table_einj) -
> >> sizeof(struct acpi_table_header)
> >> 
> >> To make erst table size checking code works on all systems, both
> >> testing are treated as PASS.
> >> 
> >> Same situation applies to einj_tab->header_length, so corresponding
> >> table size checking is changed in similar way too.
> >> 
> >> Originally-by: Yinghai Lu <yinghai@kernel.org>
> >> Signed-off-by: Huang Ying <ying.huang@intel.com>
> >> 
> >> - use switch() for better readability
> >> - add comment explaining why a formally invalid size it also being
> >>   accepted
> >> - check erst_tab->header.length before even looking at
> >>   erst_tab->header_length
> >> - prefer sizeof(*erst_tab) over sizeof(struct acpi_table_erst)
> >> 
> >> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> >> 
> >> --- a/xen/drivers/acpi/apei/erst.c
> >> +++ b/xen/drivers/acpi/apei/erst.c
> >> @@ -715,12 +715,23 @@ int erst_clear(u64 record_id)
> >>  
> >>  static int __init erst_check_table(struct acpi_table_erst *erst_tab)
> >>  {
> >> -	if (erst_tab->header_length != sizeof(struct acpi_table_erst))
> >> +	if (erst_tab->header.length < sizeof(*erst_tab))
> >>  		return -EINVAL;
> >> -	if (erst_tab->header.length < sizeof(struct acpi_table_erst))
> >> +
> >> +	switch (erst_tab->header_length) {
> >> +	case sizeof(*erst_tab) - sizeof(erst_tab->header):
> >> +	/*
> >> +	 * While invalid per specification, there are (early?) systems
> >> +	 * indicating the full header size here, so accept that value too.
> >> +	 */
> >> +	case sizeof(*erst_tab):
> >> +		break;
> >> +	default:
> >>  		return -EINVAL;
> >> +	}
> >> +
> >>  	if (erst_tab->entries !=
> >> -	    (erst_tab->header.length - sizeof(struct acpi_table_erst)) /
> >> +	    (erst_tab->header.length - sizeof(*erst_tab)) /
> >>  	    sizeof(struct acpi_erst_entry))
> >>  		return -EINVAL;
> >>  
> >> 
> >> 
> >> 
> 
> 
> 

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2012-10-17  8:52 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-10-16 14:46 [PATCH] ACPI: fix APEI related table size checking Jan Beulich
2012-10-16 15:12 ` Keir Fraser
2012-10-17  6:49 ` Huang Ying
2012-10-17  6:56   ` Jan Beulich
2012-10-17  8:52     ` Huang Ying

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