From: Hans de Goede <hdegoede@xxxxxxxxxx>
commit 81ee85d0462410de8eeeec1b9761941fd6ed8c7b upstream.
Quoting from the comment describing the WARN functions in
include/asm-generic/bug.h:
* WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
* significant kernel issues that need prompt attention if they should ever
* appear at runtime.
*
* Do not use these macros when checking for invalid external inputs
The (buggy) firmware tables which the dmar code was calling WARN_TAINT
for really are invalid external inputs. They are not under the kernel's
control and the issues in them cannot be fixed by a kernel update.
So logging a backtrace, which invites bug reports to be filed about this,
is not helpful.
Fixes: 556ab45f9a77 ("ioat2: catch and recover from broken vtd configurations v6")
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Acked-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200309182510.373875-1-hdegoede@xxxxxxxxxx
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=701847
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/iommu/intel-iommu.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4129,10 +4129,11 @@ static void quirk_ioat_snb_local_iommu(s
/* we know that the this iommu should be at offset 0xa000 from vtbar */
drhd = dmar_find_matched_drhd_unit(pdev);
- if (WARN_TAINT_ONCE(!drhd || drhd->reg_base_addr - vtbar != 0xa000,
- TAINT_FIRMWARE_WORKAROUND,
- "BIOS assigned incorrect VT-d unit for Intel(R) QuickData Technology device\n"))
+ if (!drhd || drhd->reg_base_addr - vtbar != 0xa000) {
+ pr_warn_once(FW_BUG "BIOS assigned incorrect VT-d unit for Intel(R) QuickData Technology device\n");
+ add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
pdev->dev.archdata.iommu = DUMMY_DEVICE_DOMAIN_INFO;
+ }
}
DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_SNB, quirk_ioat_snb_local_iommu);
