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Groups > linux.kernel > #1552205 > unrolled thread

[PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing

Started byLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
First post2017-01-05 19:40 +0100
Last post2017-01-09 09:10 +0100
Articles 6 — 4 participants

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Contents

  [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-01-05 19:40 +0100
    Re: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries  indexing Sinan Kaya <okaya@codeaurora.org> - 2017-01-07 22:20 +0100
      Re: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries  indexing Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-09 07:40 +0100
        Re: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries  indexing Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-09 07:50 +0100
        Re: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries  indexing okaya@codeaurora.org - 2017-01-09 12:30 +0100
    Re: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries  indexing Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-09 09:10 +0100

#1552205 — [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing

FromLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Date2017-01-05 19:40 +0100
Subject[PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing
Message-ID<sWl7c-6J7-9@gated-at.bofh.it>
Commit 618f535a6062 ("ACPI/IORT: Add single mapping function")
introduced a function (iort_node_get_id()) to retrieve ids for IORT
named components.

iort_node_get_id() takes an index as input to refer to a specific
mapping entry in the mapping array to retrieve the id at a specific
index provided the index is below the total mapping count; currently the
index is used to retrieve the mapping value from the correct entry but
not to dereference the correct entry while retrieving the mapping
output_reference (ie IORT parent pointer), which consequently always
resolves to the output_reference of the first entry in the mapping
array.

Update the map array entry pointer computation in iort_node_get_id() to
take into account the index value, fixing the issue.

Fixes: 618f535a6062 ("ACPI/IORT: Add single mapping function")
Reported-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Sinan Kaya <okaya@codeaurora.org>
Cc: Tomasz Nowicki <tn@semihalf.com>
Cc: Nate Watterson <nwatters@codeaurora.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
---
 drivers/acpi/arm64/iort.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index e0d2e6e..ba156c5 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -333,7 +333,7 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
 		return NULL;
 
 	map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
-			   node->mapping_offset);
+			   node->mapping_offset + index * sizeof(*map));
 
 	/* Firmware bug! */
 	if (!map->output_reference) {
@@ -348,10 +348,10 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
 	if (!(IORT_TYPE_MASK(parent->type) & type_mask))
 		return NULL;
 
-	if (map[index].flags & ACPI_IORT_ID_SINGLE_MAPPING) {
+	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
 		if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT ||
 		    node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
-			*id_out = map[index].output_base;
+			*id_out = map->output_base;
 			return parent;
 		}
 	}
-- 
2.10.0

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#1553742 — Re: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing

FromSinan Kaya <okaya@codeaurora.org>
Date2017-01-07 22:20 +0100
SubjectRe: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing
Message-ID<sX6z7-5CD-11@gated-at.bofh.it>
In reply to#1552205
On 1/5/2017 1:29 PM, Lorenzo Pieralisi wrote:
> Commit 618f535a6062 ("ACPI/IORT: Add single mapping function")
> introduced a function (iort_node_get_id()) to retrieve ids for IORT
> named components.
> 
> iort_node_get_id() takes an index as input to refer to a specific
> mapping entry in the mapping array to retrieve the id at a specific
> index provided the index is below the total mapping count; currently the
> index is used to retrieve the mapping value from the correct entry but
> not to dereference the correct entry while retrieving the mapping
> output_reference (ie IORT parent pointer), which consequently always
> resolves to the output_reference of the first entry in the mapping
> array.
> 
> Update the map array entry pointer computation in iort_node_get_id() to
> take into account the index value, fixing the issue.
> 
> Fixes: 618f535a6062 ("ACPI/IORT: Add single mapping function")
> Reported-by: Hanjun Guo <hanjun.guo@linaro.org>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Hanjun Guo <hanjun.guo@linaro.org>
> Cc: Sinan Kaya <okaya@codeaurora.org>
> Cc: Tomasz Nowicki <tn@semihalf.com>
> Cc: Nate Watterson <nwatters@codeaurora.org>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> ---
>  drivers/acpi/arm64/iort.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index e0d2e6e..ba156c5 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -333,7 +333,7 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
>  		return NULL;
>  
>  	map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
> -			   node->mapping_offset);
> +			   node->mapping_offset + index * sizeof(*map));

What does this give us that the previous code didn't do?

You are using map as a pointer and returning the offset of the first map entry above
and then accessing the map at the indexed offset with map[index]

The new code is using map as a plain pointer, calculating the pointer location with ACPI_ADD_PTR
instead and then collecting the output parameter with map->output_base.

>  
>  	/* Firmware bug! */
>  	if (!map->output_reference) {
> @@ -348,10 +348,10 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
>  	if (!(IORT_TYPE_MASK(parent->type) & type_mask))
>  		return NULL;
>  
> -	if (map[index].flags & ACPI_IORT_ID_SINGLE_MAPPING) {
> +	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
>  		if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT ||
>  		    node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
> -			*id_out = map[index].output_base;
> +			*id_out = map->output_base;

You are claiming that the existing code is collecting the output parameter from the first mapping.
I don't see this happening above.

What am I missing?

>  			return parent;
>  		}
>  	}
> 

If we are just doing a housekeeping, this is fine. I couldn't see an actual bug getting fixed.

-- 
Sinan Kaya
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.

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#1554082 — Re: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing

FromHanjun Guo <hanjun.guo@linaro.org>
Date2017-01-09 07:40 +0100
SubjectRe: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing
Message-ID<sXBMB-zF-31@gated-at.bofh.it>
In reply to#1553742
Hi Sinan,

On 2017/1/8 5:09, Sinan Kaya wrote:
> On 1/5/2017 1:29 PM, Lorenzo Pieralisi wrote:
>> Commit 618f535a6062 ("ACPI/IORT: Add single mapping function")
>> introduced a function (iort_node_get_id()) to retrieve ids for IORT
>> named components.
>>
>> iort_node_get_id() takes an index as input to refer to a specific
>> mapping entry in the mapping array to retrieve the id at a specific
>> index provided the index is below the total mapping count; currently the
>> index is used to retrieve the mapping value from the correct entry but
>> not to dereference the correct entry while retrieving the mapping
>> output_reference (ie IORT parent pointer), which consequently always
>> resolves to the output_reference of the first entry in the mapping
>> array.
>>
>> Update the map array entry pointer computation in iort_node_get_id() to
>> take into account the index value, fixing the issue.
>>
>> Fixes: 618f535a6062 ("ACPI/IORT: Add single mapping function")
>> Reported-by: Hanjun Guo <hanjun.guo@linaro.org>
>> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>> Cc: Hanjun Guo <hanjun.guo@linaro.org>
>> Cc: Sinan Kaya <okaya@codeaurora.org>
>> Cc: Tomasz Nowicki <tn@semihalf.com>
>> Cc: Nate Watterson <nwatters@codeaurora.org>
>> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
>> ---
>>  drivers/acpi/arm64/iort.c | 6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
>> index e0d2e6e..ba156c5 100644
>> --- a/drivers/acpi/arm64/iort.c
>> +++ b/drivers/acpi/arm64/iort.c
>> @@ -333,7 +333,7 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
>>  		return NULL;
>>
>>  	map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
>> -			   node->mapping_offset);
>> +			   node->mapping_offset + index * sizeof(*map));
>
> What does this give us that the previous code didn't do?

Fir example, if you have multi mappings ids under platform device:

|-------------|
|  SMMU  2    |<-------
|-------------|       |
                       |
                       |
|-------------|       |
|  SMMU 1     |<----  |
|-------------|    |  |
                    |  |
                    |  |
|-------------|    |  |
|  platform   |    |  |
|  device     |    |  |
|-------------|    |  |
| stream id   |    |  |
| 1           |    |  |
| parent------|----|  |
|-------------|       |
|  stream id  |       |
|  2          |       |
|  parent-----|-------|
|-------------|

For now, we just use the first entry in the mapping entry to get
the parent, and always point to the same parent, as above, we will
always map to SMMU 1 even if you connect to different SMMUs. (Although
we may don't have such device topology yet)


>
> You are using map as a pointer and returning the offset of the first map entry above
> and then accessing the map at the indexed offset with map[index]
>
> The new code is using map as a plain pointer, calculating the pointer location with ACPI_ADD_PTR
> instead and then collecting the output parameter with map->output_base.
>
>>
>>  	/* Firmware bug! */
>>  	if (!map->output_reference) {
>> @@ -348,10 +348,10 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
>>  	if (!(IORT_TYPE_MASK(parent->type) & type_mask))
>>  		return NULL;
>>
>> -	if (map[index].flags & ACPI_IORT_ID_SINGLE_MAPPING) {
>> +	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
>>  		if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT ||
>>  		    node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
>> -			*id_out = map[index].output_base;
>> +			*id_out = map->output_base;
>
> You are claiming that the existing code is collecting the output parameter from the first mapping.
> I don't see this happening above.
>
> What am I missing?

It's not about the output id but it's about the parent returned
by this function, it always return the first entry's parent in the
mapping entry.

>
>>  			return parent;
>>  		}
>>  	}
>>
>
> If we are just doing a housekeeping, this is fine. I couldn't see an actual bug getting fixed.

Although we may don't have such use cases for now, but I think we
need to prepare for it, it worth a bugfix I think :)

Thanks
Hanjun

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#1554108 — Re: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing

FromHanjun Guo <hanjun.guo@linaro.org>
Date2017-01-09 07:50 +0100
SubjectRe: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing
Message-ID<sXBWh-CV-9@gated-at.bofh.it>
In reply to#1554082
On 2017/1/9 14:34, Hanjun Guo wrote:
> Hi Sinan,
>
> On 2017/1/8 5:09, Sinan Kaya wrote:
>> On 1/5/2017 1:29 PM, Lorenzo Pieralisi wrote:
>>> Commit 618f535a6062 ("ACPI/IORT: Add single mapping function")
>>> introduced a function (iort_node_get_id()) to retrieve ids for IORT
>>> named components.
>>>
>>> iort_node_get_id() takes an index as input to refer to a specific
>>> mapping entry in the mapping array to retrieve the id at a specific
>>> index provided the index is below the total mapping count; currently the
>>> index is used to retrieve the mapping value from the correct entry but
>>> not to dereference the correct entry while retrieving the mapping
>>> output_reference (ie IORT parent pointer), which consequently always
>>> resolves to the output_reference of the first entry in the mapping
>>> array.
>>>
>>> Update the map array entry pointer computation in iort_node_get_id() to
>>> take into account the index value, fixing the issue.
>>>
>>> Fixes: 618f535a6062 ("ACPI/IORT: Add single mapping function")
>>> Reported-by: Hanjun Guo <hanjun.guo@linaro.org>
>>> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>>> Cc: Hanjun Guo <hanjun.guo@linaro.org>
>>> Cc: Sinan Kaya <okaya@codeaurora.org>
>>> Cc: Tomasz Nowicki <tn@semihalf.com>
>>> Cc: Nate Watterson <nwatters@codeaurora.org>
>>> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
>>> ---
>>>  drivers/acpi/arm64/iort.c | 6 +++---
>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
>>> index e0d2e6e..ba156c5 100644
>>> --- a/drivers/acpi/arm64/iort.c
>>> +++ b/drivers/acpi/arm64/iort.c
>>> @@ -333,7 +333,7 @@ struct acpi_iort_node *iort_node_get_id(struct
>>> acpi_iort_node *node,
>>>          return NULL;
>>>
>>>      map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
>>> -               node->mapping_offset);
>>> +               node->mapping_offset + index * sizeof(*map));
>>
>> What does this give us that the previous code didn't do?
>
> Fir example, if you have multi mappings ids under platform device:
>
> |-------------|
> |  SMMU  2    |<-------
> |-------------|       |
>                       |
>                       |
> |-------------|       |
> |  SMMU 1     |<----  |
> |-------------|    |  |
>                    |  |
>                    |  |
> |-------------|    |  |
> |  platform   |    |  |
> |  device     |    |  |
> |-------------|    |  |
> | stream id   |    |  |
> | 1           |    |  |
> | parent------|----|  |
> |-------------|       |
> |  stream id  |       |
> |  2          |       |
> |  parent-----|-------|
> |-------------|
>
> For now, we just use the first entry in the mapping entry to get
> the parent, and always point to the same parent, as above, we will
> always map to SMMU 1 even if you connect to different SMMUs. (Although
> we may don't have such device topology yet)
>
>
>>
>> You are using map as a pointer and returning the offset of the first
>> map entry above
>> and then accessing the map at the indexed offset with map[index]
>>
>> The new code is using map as a plain pointer, calculating the pointer
>> location with ACPI_ADD_PTR
>> instead and then collecting the output parameter with map->output_base.
>>
>>>
>>>      /* Firmware bug! */
>>>      if (!map->output_reference) {
>>> @@ -348,10 +348,10 @@ struct acpi_iort_node *iort_node_get_id(struct
>>> acpi_iort_node *node,
>>>      if (!(IORT_TYPE_MASK(parent->type) & type_mask))
>>>          return NULL;
>>>
>>> -    if (map[index].flags & ACPI_IORT_ID_SINGLE_MAPPING) {
>>> +    if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
>>>          if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT ||
>>>              node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
>>> -            *id_out = map[index].output_base;
>>> +            *id_out = map->output_base;
>>
>> You are claiming that the existing code is collecting the output
>> parameter from the first mapping.
>> I don't see this happening above.
>>
>> What am I missing?
>
> It's not about the output id but it's about the parent returned
> by this function, it always return the first entry's parent in the
> mapping entry.

And as Lorenzo said in the commit message:
"always resolves to the output_reference of the first entry in the
mapping array."

Then always judge the same entry for:

if (!map->output_reference)
	pr_err();

...

Thanks
Hanjun

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#1554232 — Re: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing

Fromokaya@codeaurora.org
Date2017-01-09 12:30 +0100
SubjectRe: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing
Message-ID<sXGjg-3xT-21@gated-at.bofh.it>
In reply to#1554082
On 2017-01-09 01:34, Hanjun Guo wrote:
> Hi Sinan,
> 
> On 2017/1/8 5:09, Sinan Kaya wrote:
>> On 1/5/2017 1:29 PM, Lorenzo Pieralisi wrote:
>>> Commit 618f535a6062 ("ACPI/IORT: Add single mapping function")
>>> introduced a function (iort_node_get_id()) to retrieve ids for IORT
>>> named components.
>>> 
>>> iort_node_get_id() takes an index as input to refer to a specific
>>> mapping entry in the mapping array to retrieve the id at a specific
>>> index provided the index is below the total mapping count; currently 
>>> the
>>> index is used to retrieve the mapping value from the correct entry 
>>> but
>>> not to dereference the correct entry while retrieving the mapping
>>> output_reference (ie IORT parent pointer), which consequently always
>>> resolves to the output_reference of the first entry in the mapping
>>> array.
>>> 
>>> Update the map array entry pointer computation in iort_node_get_id() 
>>> to
>>> take into account the index value, fixing the issue.
>>> 
>>> Fixes: 618f535a6062 ("ACPI/IORT: Add single mapping function")
>>> Reported-by: Hanjun Guo <hanjun.guo@linaro.org>
>>> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>>> Cc: Hanjun Guo <hanjun.guo@linaro.org>
>>> Cc: Sinan Kaya <okaya@codeaurora.org>
>>> Cc: Tomasz Nowicki <tn@semihalf.com>
>>> Cc: Nate Watterson <nwatters@codeaurora.org>
>>> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
>>> ---
>>>  drivers/acpi/arm64/iort.c | 6 +++---
>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>> 
>>> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
>>> index e0d2e6e..ba156c5 100644
>>> --- a/drivers/acpi/arm64/iort.c
>>> +++ b/drivers/acpi/arm64/iort.c
>>> @@ -333,7 +333,7 @@ struct acpi_iort_node *iort_node_get_id(struct 
>>> acpi_iort_node *node,
>>>  		return NULL;
>>> 
>>>  	map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
>>> -			   node->mapping_offset);
>>> +			   node->mapping_offset + index * sizeof(*map));
>> 
>> What does this give us that the previous code didn't do?
> 
> Fir example, if you have multi mappings ids under platform device:
> 
> |-------------|
> |  SMMU  2    |<-------
> |-------------|       |
>                       |
>                       |
> |-------------|       |
> |  SMMU 1     |<----  |
> |-------------|    |  |
>                    |  |
>                    |  |
> |-------------|    |  |
> |  platform   |    |  |
> |  device     |    |  |
> |-------------|    |  |
> | stream id   |    |  |
> | 1           |    |  |
> | parent------|----|  |
> |-------------|       |
> |  stream id  |       |
> |  2          |       |
> |  parent-----|-------|
> |-------------|
> 
> For now, we just use the first entry in the mapping entry to get
> the parent, and always point to the same parent, as above, we will
> always map to SMMU 1 even if you connect to different SMMUs. (Although
> we may don't have such device topology yet)

I see. This wasn't obvious from the commit message. Thanks for taking 
time to explain it.

I think the commit message needs to include some of your description.

> 
> 
>> 
>> You are using map as a pointer and returning the offset of the first 
>> map entry above
>> and then accessing the map at the indexed offset with map[index]
>> 
>> The new code is using map as a plain pointer, calculating the pointer 
>> location with ACPI_ADD_PTR
>> instead and then collecting the output parameter with 
>> map->output_base.
>> 
>>> 
>>>  	/* Firmware bug! */
>>>  	if (!map->output_reference) {
>>> @@ -348,10 +348,10 @@ struct acpi_iort_node *iort_node_get_id(struct 
>>> acpi_iort_node *node,
>>>  	if (!(IORT_TYPE_MASK(parent->type) & type_mask))
>>>  		return NULL;
>>> 
>>> -	if (map[index].flags & ACPI_IORT_ID_SINGLE_MAPPING) {
>>> +	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
>>>  		if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT ||
>>>  		    node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
>>> -			*id_out = map[index].output_base;
>>> +			*id_out = map->output_base;
>> 
>> You are claiming that the existing code is collecting the output 
>> parameter from the first mapping.
>> I don't see this happening above.
>> 
>> What am I missing?
> 
> It's not about the output id but it's about the parent returned
> by this function, it always return the first entry's parent in the
> mapping entry.

Ok, I was judt looking at the patch. I didn't realize ww are changing 
the return value.

This could have been mentioned.


> 
>> 
>>>  			return parent;
>>>  		}
>>>  	}
>>> 
>> 
>> If we are just doing a housekeeping, this is fine. I couldn't see an 
>> actual bug getting fixed.
> 
> Although we may don't have such use cases for now, but I think we
> need to prepare for it, it worth a bugfix I think :)
> 
> Thanks
> Hanjun

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#1554138 — Re: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing

FromHanjun Guo <hanjun.guo@linaro.org>
Date2017-01-09 09:10 +0100
SubjectRe: [PATCH] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing
Message-ID<sXDbI-1Ae-11@gated-at.bofh.it>
In reply to#1552205
On 2017/1/6 2:29, Lorenzo Pieralisi wrote:
> Commit 618f535a6062 ("ACPI/IORT: Add single mapping function")
> introduced a function (iort_node_get_id()) to retrieve ids for IORT
> named components.
>
> iort_node_get_id() takes an index as input to refer to a specific
> mapping entry in the mapping array to retrieve the id at a specific
> index provided the index is below the total mapping count; currently the
> index is used to retrieve the mapping value from the correct entry but
> not to dereference the correct entry while retrieving the mapping
> output_reference (ie IORT parent pointer), which consequently always
> resolves to the output_reference of the first entry in the mapping
> array.
>
> Update the map array entry pointer computation in iort_node_get_id() to
> take into account the index value, fixing the issue.
>
> Fixes: 618f535a6062 ("ACPI/IORT: Add single mapping function")
> Reported-by: Hanjun Guo <hanjun.guo@linaro.org>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Hanjun Guo <hanjun.guo@linaro.org>
> Cc: Sinan Kaya <okaya@codeaurora.org>
> Cc: Tomasz Nowicki <tn@semihalf.com>
> Cc: Nate Watterson <nwatters@codeaurora.org>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> ---
>  drivers/acpi/arm64/iort.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index e0d2e6e..ba156c5 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -333,7 +333,7 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
>  		return NULL;
>
>  	map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
> -			   node->mapping_offset);
> +			   node->mapping_offset + index * sizeof(*map));
>
>  	/* Firmware bug! */
>  	if (!map->output_reference) {
> @@ -348,10 +348,10 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
>  	if (!(IORT_TYPE_MASK(parent->type) & type_mask))
>  		return NULL;
>
> -	if (map[index].flags & ACPI_IORT_ID_SINGLE_MAPPING) {
> +	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
>  		if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT ||
>  		    node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
> -			*id_out = map[index].output_base;
> +			*id_out = map->output_base;
>  			return parent;
>  		}
>  	}

Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>

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