From: Raul E Rangel rrangel@chromium.org
[ Upstream commit ea90228c7b2ae6646bb6381385229aabb6f14cd2 ]
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@linux.intel.com Signed-off-by: Raul E Rangel rrangel@chromium.org Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Link: https://lore.kernel.org/r/20200511103229.v2.1.I6f1b6f973ee6c8af1348611370c73... Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- 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 500d0a8c966f..1d8634250afc 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -127,7 +127,8 @@ 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;