* Should the return value of the rlookup_amd_iommu be checked?
@ 2024-09-12 4:42 Qianqiang Liu
2024-09-12 4:49 ` Vasant Hegde
0 siblings, 1 reply; 3+ messages in thread
From: Qianqiang Liu @ 2024-09-12 4:42 UTC (permalink / raw)
To: suravee.suthikulpanit, will; +Cc: vasant.hegde, iommu, linux-kernel
Hi,
I reviewed the following code:
1592 void amd_iommu_update_and_flush_device_table(struct protection_domain *domain)
1593 {
1594 struct iommu_dev_data *dev_data;
1595
1596 list_for_each_entry(dev_data, &domain->dev_list, list) {
1597 struct amd_iommu *iommu = rlookup_amd_iommu(dev_data->dev); <-
1598
1599 set_dte_entry(iommu, dev_data); <-
1600 clone_aliases(iommu, dev_data->dev);
1601 }
1602
1603 list_for_each_entry(dev_data, &domain->dev_list, list)
1604 device_flush_dte(dev_data);
1605
1606 domain_flush_complete(domain);
1607 }
The "rlookup_amd_iommu" function may return NULL, and the "set_dte_entry" function
will call "get_dev_table" which will dereference the NULL pointer.
Is this an issue that may cause panic? Or will "rlookup_amd_iommu" function never
return NULL?
--
Best,
Qianqiang Liu
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Should the return value of the rlookup_amd_iommu be checked?
2024-09-12 4:42 Should the return value of the rlookup_amd_iommu be checked? Qianqiang Liu
@ 2024-09-12 4:49 ` Vasant Hegde
2024-09-12 4:53 ` Qianqiang Liu
0 siblings, 1 reply; 3+ messages in thread
From: Vasant Hegde @ 2024-09-12 4:49 UTC (permalink / raw)
To: Qianqiang Liu, suravee.suthikulpanit, will; +Cc: iommu, linux-kernel
Hi,
On 9/12/2024 10:12 AM, Qianqiang Liu wrote:
> Hi,
>
> I reviewed the following code:
>
> 1592 void amd_iommu_update_and_flush_device_table(struct protection_domain *domain)
> 1593 {
> 1594 struct iommu_dev_data *dev_data;
> 1595
> 1596 list_for_each_entry(dev_data, &domain->dev_list, list) {
> 1597 struct amd_iommu *iommu = rlookup_amd_iommu(dev_data->dev); <-
> 1598
> 1599 set_dte_entry(iommu, dev_data); <-
> 1600 clone_aliases(iommu, dev_data->dev);
> 1601 }
> 1602
> 1603 list_for_each_entry(dev_data, &domain->dev_list, list)
> 1604 device_flush_dte(dev_data);
> 1605
> 1606 domain_flush_complete(domain);
> 1607 }
>
> The "rlookup_amd_iommu" function may return NULL, and the "set_dte_entry" function
> will call "get_dev_table" which will dereference the NULL pointer.
>
> Is this an issue that may cause panic? Or will "rlookup_amd_iommu" function never
> return NULL?
During init driver will initialize rlookup_table. rlookup_amd_iommu will not
return NULL. So its fine.
-Vasant
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Should the return value of the rlookup_amd_iommu be checked?
2024-09-12 4:49 ` Vasant Hegde
@ 2024-09-12 4:53 ` Qianqiang Liu
0 siblings, 0 replies; 3+ messages in thread
From: Qianqiang Liu @ 2024-09-12 4:53 UTC (permalink / raw)
To: Vasant Hegde; +Cc: suravee.suthikulpanit, will, iommu, linux-kernel
On Thu, Sep 12, 2024 at 10:19:53AM +0530, Vasant Hegde wrote:
> During init driver will initialize rlookup_table. rlookup_amd_iommu will not
> return NULL. So its fine.
>
> -Vasant
OK, thanks!
--
Best,
Qianqiang Liu
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2024-09-12 4:53 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-09-12 4:42 Should the return value of the rlookup_amd_iommu be checked? Qianqiang Liu
2024-09-12 4:49 ` Vasant Hegde
2024-09-12 4:53 ` Qianqiang Liu
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®