Thanks for catching this.

On 9/11/20 12:16 AM, Joao Martins wrote:
After commit 26e495f34107 ("iommu/amd: Restore IRTE.RemapEn bit after
programming IRTE"), smatch warns:

        drivers/iommu/amd/iommu.c:3870 amd_iommu_deactivate_guest_mode()
         warn: variable dereferenced before check 'entry' (see line 3867)

Fix this by moving the @valid assignment to after @entry has been checked
for NULL.

Cc: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
Fixes: 26e495f34107 ("iommu/amd: Restore IRTE.RemapEn bit after programming 
IRTE")
Reported-by: Dan Carpenter <dan.carpen...@oracle.com>
Signed-off-by: Joao Martins <joao.m.mart...@oracle.com>
---
  drivers/iommu/amd/iommu.c | 4 +++-
  1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 07ae8b93887e..8abe1c7ad45b 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -3864,12 +3864,14 @@ int amd_iommu_deactivate_guest_mode(void *data)
        struct amd_ir_data *ir_data = (struct amd_ir_data *)data;
        struct irte_ga *entry = (struct irte_ga *) ir_data->entry;
        struct irq_cfg *cfg = ir_data->cfg;
-       u64 valid = entry->lo.fields_remap.valid;
+       u64 valid;
if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) ||
            !entry || !entry->lo.fields_vapic.guest_mode)
                return 0;
+ valid = entry->lo.fields_remap.valid;
+
        entry->lo.val = 0;
        entry->hi.val = 0;

Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>

Suravee
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