diff mbox

[v2,13/19] remoteproc: core: Append resource only if spare resource present

Message ID 1472676622-32533-14-git-send-email-loic.pallardy@st.com
State New
Headers show

Commit Message

Loic Pallardy Aug. 31, 2016, 8:50 p.m. UTC
This patch renames rproc_add_resource_table_entry in __add_rsc_tbl_entry
to have shorter function name and adds spare resource support.
To guarantee remoteproc won't overwrite firmware data when copying
back modified resource table, __add_rsc_tbl_entry verifies first that
resource table owns a spare resource and uses spare bytes to create
a new resource entry. Spare resource is updated according to changes.

Signed-off-by: Loic Pallardy <loic.pallardy@st.com>

---
 drivers/remoteproc/remoteproc_core.c | 54 ++++++++++++++++++++----------------
 1 file changed, 30 insertions(+), 24 deletions(-)

-- 
1.9.1

Comments

Lee Jones Sept. 8, 2016, 9:33 a.m. UTC | #1
On Wed, 31 Aug 2016, Loic Pallardy wrote:

> This patch renames rproc_add_resource_table_entry in __add_rsc_tbl_entry

> to have shorter function name and adds spare resource support.

> To guarantee remoteproc won't overwrite firmware data when copying

> back modified resource table, __add_rsc_tbl_entry verifies first that

> resource table owns a spare resource and uses spare bytes to create

> a new resource entry. Spare resource is updated according to changes.

> 

> Signed-off-by: Loic Pallardy <loic.pallardy@st.com>

> ---

>  drivers/remoteproc/remoteproc_core.c | 54 ++++++++++++++++++++----------------

>  1 file changed, 30 insertions(+), 24 deletions(-)

> 

> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c

> index aff1a00..25a429b 100644

> --- a/drivers/remoteproc/remoteproc_core.c

> +++ b/drivers/remoteproc/remoteproc_core.c

> @@ -1107,39 +1107,34 @@ static int __update_rsc_tbl_entry(struct rproc *rproc,

>  	return !updated;

>  }

>  

> -static struct resource_table*

> -rproc_add_resource_table_entry(struct rproc *rproc,

> +static int __add_rsc_tbl_entry(struct rproc *rproc,


Once again, I prefer plain English over cryptic abbreviations.  Makes
things much more difficult for developers who are new to, or are just
dipping into RemoteProc code.

>  			       struct rproc_request_resource *request,

> -			       struct resource_table *old_table, int *tablesz)

> +			       struct resource_table *table, int tablesz)

>  {

> -	struct resource_table *table;

>  	struct fw_rsc_hdr h;

> +	struct fw_rsc_spare spare;

>  	void *new_rsc_loc;

>  	void *fw_header_loc;

>  	void *start_of_rscs;

>  	int new_rsc_offset;

> -	int size = *tablesz;

> -	int i;

> +	int new_spare_offset;

> +	int i, spare_index = 0;

>  

>  	h.type = request->type;

>  

> -	new_rsc_offset = size;

> +	/* check available spare size */


In keeping with the existing comments, please use correct grammar.

Capital letters to start and for names etc.

Much more professional IMO.

> +	spare.len = __get_rsc_tbl_spare_size(rproc, table, tablesz, &spare_index);

> +	if (spare.len < (sizeof(h) + request->size + 4)) /* new offset entry */


Not sure that comment makes the code any clearer?

All you're doing here is checking if we have enough space, right?

I think the 4 is a 'magic' number.  I'd either provide a comment (like
I did below), or define it.

> +		return -EPERM;


What does this have to do with permissions?

> -	/*

> -	 * Allocate another contiguous chunk of memory, large enough to

> -	 * contain the new, expanded resource table.

> -	 *

> -	 * The +4 is for the extra offset[] element in the top level header

> -	 */

> -	size += sizeof(struct fw_rsc_hdr) + request->size + 4;

> -	table = devm_kmemdup(&rproc->dev, old_table, size, GFP_KERNEL);

> -	if (!table)

> -		return ERR_PTR(-ENOMEM);

> +	new_rsc_offset = table->offset[spare_index];

>  

>  	/* Shunt table by 4 Bytes to account for the extra offset[] element */

>  	start_of_rscs = (void *)table + table->offset[0];

>  	memmove(start_of_rscs + 4,

>  		start_of_rscs, new_rsc_offset - table->offset[0]);

> +

> +	spare.len -= 4;


This probably deserves a comment too.

/*
 * The spare area is finite.  Since we are increasing the size of the
 * header and shunting the tables, we need to reduce the size of the
 * available 'spare' area by the shunt size.
 */

>  	new_rsc_offset += 4;

>  

>  	/* Update existing resource entry's offsets */

> @@ -1153,13 +1148,27 @@ rproc_add_resource_table_entry(struct rproc *rproc,

>  	/* Copy new firmware header into table */

>  	fw_header_loc = (void *)table + new_rsc_offset;

>  	memcpy(fw_header_loc, &h, sizeof(h));

> +	spare.len -= sizeof(h);

>  

>  	/* Copy new resource entry into table */

>  	new_rsc_loc = (void *)fw_header_loc + sizeof(h);

>  	memcpy(new_rsc_loc, request->resource, request->size);

> +	spare.len -= request->size;

>  

> -	*tablesz = size;

> -	return table;

> +	/* create new rsc spare resource at the end of remaining spare */


Same comment about using nice grammar in comments.

> +	new_spare_offset = new_rsc_offset + sizeof(h) + request->size;

> +	h.type = RSC_SPARE;

> +

> +	fw_header_loc = (void *)table + new_spare_offset;

> +	memcpy(fw_header_loc, &h, sizeof(h));

> +

> +	new_rsc_loc = (void *)fw_header_loc + sizeof(h);

> +	memcpy(new_rsc_loc, &spare, sizeof(spare));

> +

> +	/* update spare offset */

> +	table->offset[spare_index] = new_spare_offset;

> +

> +	return 0;

>  }

>  

>  static struct resource_table*

> @@ -1203,12 +1212,9 @@ rproc_apply_resource_overrides(struct rproc *rproc,

>  			continue;

>  

>  		/* Didn't find matching resource entry -- creating a new one. */

> -		table = rproc_add_resource_table_entry(rproc, resource,

> -						       table, &size);

> -		if (IS_ERR(table))

> +		updated = __add_rsc_tbl_entry(rproc, resource, table, size);

> +		if (updated)

>  			goto out;

> -

> -		*orig_table = table;

>  	}

>  

>  	rproc_dump_resource_table(rproc, table, size);


-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
Loic Pallardy Sept. 8, 2016, 9:54 a.m. UTC | #2
On 09/08/2016 11:33 AM, Lee Jones wrote:
> On Wed, 31 Aug 2016, Loic Pallardy wrote:

>

>> This patch renames rproc_add_resource_table_entry in __add_rsc_tbl_entry

>> to have shorter function name and adds spare resource support.

>> To guarantee remoteproc won't overwrite firmware data when copying

>> back modified resource table, __add_rsc_tbl_entry verifies first that

>> resource table owns a spare resource and uses spare bytes to create

>> a new resource entry. Spare resource is updated according to changes.

>>

>> Signed-off-by: Loic Pallardy <loic.pallardy@st.com>

>> ---

>>  drivers/remoteproc/remoteproc_core.c | 54 ++++++++++++++++++++----------------

>>  1 file changed, 30 insertions(+), 24 deletions(-)

>>

>> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c

>> index aff1a00..25a429b 100644

>> --- a/drivers/remoteproc/remoteproc_core.c

>> +++ b/drivers/remoteproc/remoteproc_core.c

>> @@ -1107,39 +1107,34 @@ static int __update_rsc_tbl_entry(struct rproc *rproc,

>>  	return !updated;

>>  }

>>

>> -static struct resource_table*

>> -rproc_add_resource_table_entry(struct rproc *rproc,

>> +static int __add_rsc_tbl_entry(struct rproc *rproc,

>

> Once again, I prefer plain English over cryptic abbreviations.  Makes

> things much more difficult for developers who are new to, or are just

> dipping into RemoteProc code.


OK
>

>>  			       struct rproc_request_resource *request,

>> -			       struct resource_table *old_table, int *tablesz)

>> +			       struct resource_table *table, int tablesz)

>>  {

>> -	struct resource_table *table;

>>  	struct fw_rsc_hdr h;

>> +	struct fw_rsc_spare spare;

>>  	void *new_rsc_loc;

>>  	void *fw_header_loc;

>>  	void *start_of_rscs;

>>  	int new_rsc_offset;

>> -	int size = *tablesz;

>> -	int i;

>> +	int new_spare_offset;

>> +	int i, spare_index = 0;

>>

>>  	h.type = request->type;

>>

>> -	new_rsc_offset = size;

>> +	/* check available spare size */

>

> In keeping with the existing comments, please use correct grammar.

>

> Capital letters to start and for names etc.

>

> Much more professional IMO.


I'll correct
>

>> +	spare.len = __get_rsc_tbl_spare_size(rproc, table, tablesz, &spare_index);

>> +	if (spare.len < (sizeof(h) + request->size + 4)) /* new offset entry */

>

> Not sure that comment makes the code any clearer?

>

> All you're doing here is checking if we have enough space, right?

>

> I think the 4 is a 'magic' number.  I'd either provide a comment (like

> I did below), or define it.

I'll add a comment as you did to explain the "4".

>

>> +		return -EPERM;

>

> What does this have to do with permissions?

Yes sure, I'll replaced by -EINVAL as resource too large compare to 
spare area capability.

>

>> -	/*

>> -	 * Allocate another contiguous chunk of memory, large enough to

>> -	 * contain the new, expanded resource table.

>> -	 *

>> -	 * The +4 is for the extra offset[] element in the top level header

>> -	 */

>> -	size += sizeof(struct fw_rsc_hdr) + request->size + 4;

>> -	table = devm_kmemdup(&rproc->dev, old_table, size, GFP_KERNEL);

>> -	if (!table)

>> -		return ERR_PTR(-ENOMEM);

>> +	new_rsc_offset = table->offset[spare_index];

>>

>>  	/* Shunt table by 4 Bytes to account for the extra offset[] element */

>>  	start_of_rscs = (void *)table + table->offset[0];

>>  	memmove(start_of_rscs + 4,

>>  		start_of_rscs, new_rsc_offset - table->offset[0]);

>> +

>> +	spare.len -= 4;

>

> This probably deserves a comment too.

I'll add a comment too
>

> /*

>  * The spare area is finite.  Since we are increasing the size of the

>  * header and shunting the tables, we need to reduce the size of the

>  * available 'spare' area by the shunt size.

>  */

>

>>  	new_rsc_offset += 4;

>>

>>  	/* Update existing resource entry's offsets */

>> @@ -1153,13 +1148,27 @@ rproc_add_resource_table_entry(struct rproc *rproc,

>>  	/* Copy new firmware header into table */

>>  	fw_header_loc = (void *)table + new_rsc_offset;

>>  	memcpy(fw_header_loc, &h, sizeof(h));

>> +	spare.len -= sizeof(h);

>>

>>  	/* Copy new resource entry into table */

>>  	new_rsc_loc = (void *)fw_header_loc + sizeof(h);

>>  	memcpy(new_rsc_loc, request->resource, request->size);

>> +	spare.len -= request->size;

>>

>> -	*tablesz = size;

>> -	return table;

>> +	/* create new rsc spare resource at the end of remaining spare */

>

> Same comment about using nice grammar in comments.

Ok
Thanks,
Loic
>

>> +	new_spare_offset = new_rsc_offset + sizeof(h) + request->size;

>> +	h.type = RSC_SPARE;

>> +

>> +	fw_header_loc = (void *)table + new_spare_offset;

>> +	memcpy(fw_header_loc, &h, sizeof(h));

>> +

>> +	new_rsc_loc = (void *)fw_header_loc + sizeof(h);

>> +	memcpy(new_rsc_loc, &spare, sizeof(spare));

>> +

>> +	/* update spare offset */

>> +	table->offset[spare_index] = new_spare_offset;

>> +

>> +	return 0;

>>  }

>>

>>  static struct resource_table*

>> @@ -1203,12 +1212,9 @@ rproc_apply_resource_overrides(struct rproc *rproc,

>>  			continue;

>>

>>  		/* Didn't find matching resource entry -- creating a new one. */

>> -		table = rproc_add_resource_table_entry(rproc, resource,

>> -						       table, &size);

>> -		if (IS_ERR(table))

>> +		updated = __add_rsc_tbl_entry(rproc, resource, table, size);

>> +		if (updated)

>>  			goto out;

>> -

>> -		*orig_table = table;

>>  	}

>>

>>  	rproc_dump_resource_table(rproc, table, size);

>
Lee Jones Sept. 8, 2016, 11 a.m. UTC | #3
On Thu, 08 Sep 2016, loic pallardy wrote:

> 

> 

> On 09/08/2016 11:33 AM, Lee Jones wrote:

> > On Wed, 31 Aug 2016, Loic Pallardy wrote:

> > 

> > > This patch renames rproc_add_resource_table_entry in __add_rsc_tbl_entry

> > > to have shorter function name and adds spare resource support.

> > > To guarantee remoteproc won't overwrite firmware data when copying

> > > back modified resource table, __add_rsc_tbl_entry verifies first that

> > > resource table owns a spare resource and uses spare bytes to create

> > > a new resource entry. Spare resource is updated according to changes.

> > > 

> > > Signed-off-by: Loic Pallardy <loic.pallardy@st.com>

> > > ---

> > >  drivers/remoteproc/remoteproc_core.c | 54 ++++++++++++++++++++----------------

> > >  1 file changed, 30 insertions(+), 24 deletions(-)

> > > 

> > > diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c

> > > index aff1a00..25a429b 100644

> > > --- a/drivers/remoteproc/remoteproc_core.c

> > > +++ b/drivers/remoteproc/remoteproc_core.c

> > > @@ -1107,39 +1107,34 @@ static int __update_rsc_tbl_entry(struct rproc *rproc,

> > >  	return !updated;

> > >  }


[...]

> > > +	spare.len = __get_rsc_tbl_spare_size(rproc, table, tablesz, &spare_index);

> > > +	if (spare.len < (sizeof(h) + request->size + 4)) /* new offset entry */

> > > +		return -EPERM;

> > 

> > What does this have to do with permissions?

> Yes sure, I'll replaced by -EINVAL as resource too large compare to spare

> area capability.


Yes, or perhaps -ENOSPC?

[...]

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
diff mbox

Patch

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index aff1a00..25a429b 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1107,39 +1107,34 @@  static int __update_rsc_tbl_entry(struct rproc *rproc,
 	return !updated;
 }
 
-static struct resource_table*
-rproc_add_resource_table_entry(struct rproc *rproc,
+static int __add_rsc_tbl_entry(struct rproc *rproc,
 			       struct rproc_request_resource *request,
-			       struct resource_table *old_table, int *tablesz)
+			       struct resource_table *table, int tablesz)
 {
-	struct resource_table *table;
 	struct fw_rsc_hdr h;
+	struct fw_rsc_spare spare;
 	void *new_rsc_loc;
 	void *fw_header_loc;
 	void *start_of_rscs;
 	int new_rsc_offset;
-	int size = *tablesz;
-	int i;
+	int new_spare_offset;
+	int i, spare_index = 0;
 
 	h.type = request->type;
 
-	new_rsc_offset = size;
+	/* check available spare size */
+	spare.len = __get_rsc_tbl_spare_size(rproc, table, tablesz, &spare_index);
+	if (spare.len < (sizeof(h) + request->size + 4)) /* new offset entry */
+		return -EPERM;
 
-	/*
-	 * Allocate another contiguous chunk of memory, large enough to
-	 * contain the new, expanded resource table.
-	 *
-	 * The +4 is for the extra offset[] element in the top level header
-	 */
-	size += sizeof(struct fw_rsc_hdr) + request->size + 4;
-	table = devm_kmemdup(&rproc->dev, old_table, size, GFP_KERNEL);
-	if (!table)
-		return ERR_PTR(-ENOMEM);
+	new_rsc_offset = table->offset[spare_index];
 
 	/* Shunt table by 4 Bytes to account for the extra offset[] element */
 	start_of_rscs = (void *)table + table->offset[0];
 	memmove(start_of_rscs + 4,
 		start_of_rscs, new_rsc_offset - table->offset[0]);
+
+	spare.len -= 4;
 	new_rsc_offset += 4;
 
 	/* Update existing resource entry's offsets */
@@ -1153,13 +1148,27 @@  rproc_add_resource_table_entry(struct rproc *rproc,
 	/* Copy new firmware header into table */
 	fw_header_loc = (void *)table + new_rsc_offset;
 	memcpy(fw_header_loc, &h, sizeof(h));
+	spare.len -= sizeof(h);
 
 	/* Copy new resource entry into table */
 	new_rsc_loc = (void *)fw_header_loc + sizeof(h);
 	memcpy(new_rsc_loc, request->resource, request->size);
+	spare.len -= request->size;
 
-	*tablesz = size;
-	return table;
+	/* create new rsc spare resource at the end of remaining spare */
+	new_spare_offset = new_rsc_offset + sizeof(h) + request->size;
+	h.type = RSC_SPARE;
+
+	fw_header_loc = (void *)table + new_spare_offset;
+	memcpy(fw_header_loc, &h, sizeof(h));
+
+	new_rsc_loc = (void *)fw_header_loc + sizeof(h);
+	memcpy(new_rsc_loc, &spare, sizeof(spare));
+
+	/* update spare offset */
+	table->offset[spare_index] = new_spare_offset;
+
+	return 0;
 }
 
 static struct resource_table*
@@ -1203,12 +1212,9 @@  rproc_apply_resource_overrides(struct rproc *rproc,
 			continue;
 
 		/* Didn't find matching resource entry -- creating a new one. */
-		table = rproc_add_resource_table_entry(rproc, resource,
-						       table, &size);
-		if (IS_ERR(table))
+		updated = __add_rsc_tbl_entry(rproc, resource, table, size);
+		if (updated)
 			goto out;
-
-		*orig_table = table;
 	}
 
 	rproc_dump_resource_table(rproc, table, size);