IOMMU Fixes for Linux v4.3-rc7

Two late fixes for the AMD IOMMU driver:
 
 	* One adds an additional check to the io page-fault handler to
 	  avoid a BUG_ON being hit in handle_mm_fault()
 
 	* Second patch fixes a problem with devices writing to the
 	  system management area and were blocked by the IOMMU because
 	  the driver wrongly cleared out the DTE flags allowing that
 	  access.
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Merge tag 'iommu-fixes-v4.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull iommu fixes from Joerg Roedel:
 "Two late fixes for the AMD IOMMU driver:

   - add an additional check to the io page-fault handler to avoid a
     BUG_ON being hit in handle_mm_fault()

   - fix a problem with devices writing to the system management area
     and were blocked by the IOMMU because the driver wrongly cleared
     out the DTE flags allowing that access"

* tag 'iommu-fixes-v4.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: Don't clear DTE flags when modifying it
  iommu/amd: Fix BUG when faulting a PROT_NONE VMA
This commit is contained in:
Linus Torvalds 2015-10-27 07:44:13 +09:00
commit 858e904bd7
3 changed files with 10 additions and 2 deletions

View file

@ -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);
}

View file

@ -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)

View file

@ -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 */