[PATCH] iommu/dmar: Use struct_size() helper

[PATCH] iommu/dmar: Use struct_size() helper

[Gustavo A. R. Silva]

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.

So, replace code of the following form:

size = sizeof(*info) + level * sizeof(info->path[0]);

with:

size = struct_size(info, path, level);

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/iommu/dmar.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 9c49300e9fb7..6d969a172fbb 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -145,7 +145,7 @@ dmar_alloc_pci_notify_info(struct pci_dev *dev, unsigned long event)
 		for (tmp = dev; tmp; tmp = tmp->bus->self)
 			level++;
 
-	size = sizeof(*info) + level * sizeof(info->path[0]);
+	size = struct_size(info, path, level);
 	if (size <= sizeof(dmar_pci_notify_info_buf)) {
 		info = (struct dmar_pci_notify_info *)dmar_pci_notify_info_buf;
 	} else {
-- 
2.21.0

Re: [PATCH] iommu/dmar: Use struct_size() helper

[Joerg Roedel]

On Thu, Apr 18, 2019 at 01:46:24PM -0500, Gustavo A. R. Silva wrote:
> Make use of the struct_size() helper instead of an open-coded version
> in order to avoid any potential type mistakes, in particular in the
> context in which this code is being used.
> 
> So, replace code of the following form:
> 
> size = sizeof(*info) + level * sizeof(info->path[0]);
> 
> with:
> 
> size = struct_size(info, path, level);
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Applied, thanks.

Re: [PATCH] iommu/dmar: Use struct_size() helper

[Gustavo A. R. Silva]

On 4/26/19 9:44 AM, Joerg Roedel wrote:
> On Thu, Apr 18, 2019 at 01:46:24PM -0500, Gustavo A. R. Silva wrote:
>> Make use of the struct_size() helper instead of an open-coded version
>> in order to avoid any potential type mistakes, in particular in the
>> context in which this code is being used.
>>
>> So, replace code of the following form:
>>
>> size = sizeof(*info) + level * sizeof(info->path[0]);
>>
>> with:
>>
>> size = struct_size(info, path, level);
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> 
> Applied, thanks.
> 

Great. :)

Thanks, Joerg.
--
Gustavo