From d14f6fced5f9360edca5a1325ddb7077aab1203b Mon Sep 17 00:00:00 2001
From: Jay Cornwall <jay@jcornwall.me>
Date: Wed, 16 Sep 2015 14:10:03 -0500
Subject: [PATCH 1/2] iommu/amd: Fix BUG when faulting a PROT_NONE VMA
handle_mm_fault indirectly triggers a BUG in do_numa_page
when given a VMA without read/write/execute access. Check
this condition in do_fault.
do_fault -> handle_mm_fault -> handle_pte_fault -> do_numa_page
mm/memory.c
3147 static int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
....
3159 /* A PROT_NONE fault should not end up here */
3160 BUG_ON(!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)));
Signed-off-by: Jay Cornwall <jay@jcornwall.me>
Cc: <stable@vger.kernel.org> # v4.1+
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/amd_iommu_v2.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 1131664b918b..d21d4edf7236 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -516,6 +516,13 @@ static void do_fault(struct work_struct *work)
goto out;
}
+ if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))) {
+ /* handle_mm_fault would BUG_ON() */
+ up_read(&mm->mmap_sem);
+ handle_fault_error(fault);
+ goto out;
+ }
+
ret = handle_mm_fault(mm, vma, address, write);
if (ret & VM_FAULT_ERROR) {
/* failed to service fault */
From cbf3ccd09d683abf1cacd36e3640872ee912d99b Mon Sep 17 00:00:00 2001
From: Joerg Roedel <jroedel@suse.de>
Date: Tue, 20 Oct 2015 14:59:36 +0200
Subject: [PATCH 2/2] iommu/amd: Don't clear DTE flags when modifying it
During device assignment/deassignment the flags in the DTE
get lost, which might cause spurious faults, for example
when the device tries to access the system management range.
Fix this by not clearing the flags with the rest of the DTE.
Reported-by: G. Richard Bellamy <rbellamy@pteradigm.com>
Tested-by: G. Richard Bellamy <rbellamy@pteradigm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/amd_iommu.c | 4 ++--
drivers/iommu/amd_iommu_types.h | 1 +
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 08d2775887f7..532e2a211fe1 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1974,8 +1974,8 @@ static void set_dte_entry(u16 devid, struct protection_domain *domain, bool ats)
static void clear_dte_entry(u16 devid)
{
/* remove entry from the device table seen by the hardware */
- amd_iommu_dev_table[devid].data[0] = IOMMU_PTE_P | IOMMU_PTE_TV;
- amd_iommu_dev_table[devid].data[1] = 0;
+ amd_iommu_dev_table[devid].data[0] = IOMMU_PTE_P | IOMMU_PTE_TV;
+ amd_iommu_dev_table[devid].data[1] &= DTE_FLAG_MASK;
amd_iommu_apply_erratum_63(devid);
}
diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index f65908841be0..c9b64722f623 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -295,6 +295,7 @@
#define IOMMU_PTE_IR (1ULL << 61)
#define IOMMU_PTE_IW (1ULL << 62)
+#define DTE_FLAG_MASK (0x3ffULL << 32)
#define DTE_FLAG_IOTLB (0x01UL << 32)
#define DTE_FLAG_GV (0x01ULL << 55)
#define DTE_GLX_SHIFT (56)