From ea90228c7b2ae6646bb6381385229aabb6f14cd2 Mon Sep 17 00:00:00 2001 From: Raul E Rangel Date: Mon, 11 May 2020 10:33:36 -0600 Subject: iommu/amd: Fix get_acpihid_device_id() 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 Signed-off-by: Raul E Rangel Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20200511103229.v2.1.I6f1b6f973ee6c8af1348611370c73a0ec0ea53f1@changeid Signed-off-by: Joerg Roedel --- 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 1dc3718560d0..2883ac389abb 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; -- cgit