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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>
hifive-unleashed-5.1
Ashok Raj 2017-08-08 13:29:27 -07:00 committed by Joerg Roedel
parent bc24c57159
commit 9d8c3af316
1 changed files with 14 additions and 0 deletions
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14
drivers/iommu/intel-svm.c
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@ -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)