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authorAshok Raj <ashok.raj@intel.com>2017-08-08 23:29:27 +0300
committerJoerg Roedel <jroedel@suse.de>2017-08-30 18:48:18 +0300
commit9d8c3af31607819a61011d746e861b8096ac9761 (patch)
treec7ae280f333a27f154fa52168ad07293fbef3d2b /drivers/iommu
parentbc24c57159fac5f7e8df22ce3bc8069578684763 (diff)
downloadlinux-9d8c3af31607819a61011d746e861b8096ac9761.tar.xz
iommu/vt-d: IOMMU Page Request needs to check if address is canonical.
Page Request from devices that support device-tlb would request translation to pre-cache them in device to avoid overhead of IOMMU lookups. IOMMU needs to check for canonicallity of the address before performing page-fault processing. To: Joerg Roedel <joro@8bytes.org> To: linux-kernel@vger.kernel.org> Cc: iommu@lists.linux-foundation.org Cc: David Woodhouse <dwmw2@infradead.org> Cc: Jacob Pan <jacob.jun.pan@intel.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Ashok Raj <ashok.raj@intel.com> Reported-by: Sudeep Dutt <sudeep.dutt@intel.com> Acked-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/intel-svm.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index f167c0d84ebf..0c9f0773601d 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -24,6 +24,7 @@
#include <linux/pci-ats.h>
#include <linux/dmar.h>
#include <linux/interrupt.h>
+#include <asm/page.h>
static irqreturn_t prq_event_thread(int irq, void *d);
@@ -555,6 +556,14 @@ static bool access_error(struct vm_area_struct *vma, struct page_req_dsc *req)
return (requested & ~vma->vm_flags) != 0;
}
+static bool is_canonical_address(u64 addr)
+{
+ int shift = 64 - (__VIRTUAL_MASK_SHIFT + 1);
+ long saddr = (long) addr;
+
+ return (((saddr << shift) >> shift) == saddr);
+}
+
static irqreturn_t prq_event_thread(int irq, void *d)
{
struct intel_iommu *iommu = d;
@@ -612,6 +621,11 @@ static irqreturn_t prq_event_thread(int irq, void *d)
/* If the mm is already defunct, don't handle faults. */
if (!mmget_not_zero(svm->mm))
goto bad_req;
+
+ /* If address is not canonical, return invalid response */
+ if (!is_canonical_address(address))
+ goto bad_req;
+
down_read(&svm->mm->mmap_sem);
vma = find_extend_vma(svm->mm, address);
if (!vma || address < vma->vm_start)