acpi_dev_hid_uid_match() expects a null pointer for UID if it doesn't
exist. The acpihid_map_entry contains a char buffer for holding the
UID. If no UID was provided in the IVRS table, this buffer will be
zeroed. If we pass in a null string, acpi_dev_hid_uid_match() will
return false because it will try and match an empty string to the ACPI
UID of the device.
Fixes: ae5e6c6439c3 ("iommu/amd: Switch to use acpi_dev_hid_uid_match()")
Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Raul E Rangel <rrangel@xxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
---
Changes in v2:
- Added Suggested by
- Fixed commit description
- Decided to keep `p->uid[0]` instead of `*p->uid` since the data member is an array instead of a pointer.
- Used clang-format
drivers/iommu/amd_iommu.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 20cce366e951..06f603366cb1 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -125,7 +125,8 @@ static inline int get_acpihid_device_id(struct device *dev,
return -ENODEV;
list_for_each_entry(p, &acpihid_map, list) {
- if (acpi_dev_hid_uid_match(adev, p->hid, p->uid)) {
+ if (acpi_dev_hid_uid_match(adev, p->hid,
+ p->uid[0] ? p->uid : NULL)) {
if (entry)
*entry = p;
return p->devid;
--
2.26.2.645.ge9eca65c58-goog
