4.9-stable patches

added patches:
	hugetlb-take-pmd-sharing-into-account-when-flushing-tlb-caches.patch

diff --git a/queue-4.9/hugetlb-take-pmd-sharing-into-account-when-flushing-tlb-caches.patch b/queue-4.9/hugetlb-take-pmd-sharing-into-account-when-flushing-tlb-caches.patch
new file mode 100644 (file)
index 0000000..4670e27
--- /dev/null
+++ b/queue-4.9/hugetlb-take-pmd-sharing-into-account-when-flushing-tlb-caches.patch
@@ -0,0 +1,139 @@
+From dff11abe280b47c21b804a8ace318e0638bb9a49 Mon Sep 17 00:00:00 2001
+From: Mike Kravetz <mike.kravetz@oracle.com>
+Date: Fri, 5 Oct 2018 15:51:33 -0700
+Subject: hugetlb: take PMD sharing into account when flushing tlb/caches
+
+From: Mike Kravetz <mike.kravetz@oracle.com>
+
+commit dff11abe280b47c21b804a8ace318e0638bb9a49 upstream.
+
+When fixing an issue with PMD sharing and migration, it was discovered via
+code inspection that other callers of huge_pmd_unshare potentially have an
+issue with cache and tlb flushing.
+
+Use the routine adjust_range_if_pmd_sharing_possible() to calculate worst
+case ranges for mmu notifiers.  Ensure that this range is flushed if
+huge_pmd_unshare succeeds and unmaps a PUD_SUZE area.
+
+Link: http://lkml.kernel.org/r/20180823205917.16297-3-mike.kravetz@oracle.com
+Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
+Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
+Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
+Cc: Vlastimil Babka <vbabka@suse.cz>
+Cc: Davidlohr Bueso <dave@stgolabs.net>
+Cc: Michal Hocko <mhocko@kernel.org>
+Cc: Jerome Glisse <jglisse@redhat.com>
+Cc: Mike Kravetz <mike.kravetz@oracle.com>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ mm/hugetlb.c |   53 +++++++++++++++++++++++++++++++++++++++++++----------
+ 1 file changed, 43 insertions(+), 10 deletions(-)
+
+--- a/mm/hugetlb.c
++++ b/mm/hugetlb.c
+@@ -3393,8 +3393,8 @@ void __unmap_hugepage_range(struct mmu_g
+       struct page *page;
+       struct hstate *h = hstate_vma(vma);
+       unsigned long sz = huge_page_size(h);
+-      const unsigned long mmun_start = start; /* For mmu_notifiers */
+-      const unsigned long mmun_end   = end;   /* For mmu_notifiers */
++      unsigned long mmun_start = start;       /* For mmu_notifiers */
++      unsigned long mmun_end   = end;         /* For mmu_notifiers */
+       bool force_flush = false;
+ 
+       WARN_ON(!is_vm_hugetlb_page(vma));
+@@ -3402,6 +3402,11 @@ void __unmap_hugepage_range(struct mmu_g
+       BUG_ON(end & ~huge_page_mask(h));
+ 
+       tlb_start_vma(tlb, vma);
++
++      /*
++       * If sharing possible, alert mmu notifiers of worst case.
++       */
++      adjust_range_if_pmd_sharing_possible(vma, &mmun_start, &mmun_end);
+       mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+       address = start;
+       for (; address < end; address += sz) {
+@@ -3512,12 +3517,23 @@ void unmap_hugepage_range(struct vm_area
+ {
+       struct mm_struct *mm;
+       struct mmu_gather tlb;
++      unsigned long tlb_start = start;
++      unsigned long tlb_end = end;
++
++      /*
++       * If shared PMDs were possibly used within this vma range, adjust
++       * start/end for worst case tlb flushing.
++       * Note that we can not be sure if PMDs are shared until we try to
++       * unmap pages.  However, we want to make sure TLB flushing covers
++       * the largest possible range.
++       */
++      adjust_range_if_pmd_sharing_possible(vma, &tlb_start, &tlb_end);
+ 
+       mm = vma->vm_mm;
+ 
+-      tlb_gather_mmu(&tlb, mm, start, end);
++      tlb_gather_mmu(&tlb, mm, tlb_start, tlb_end);
+       __unmap_hugepage_range(&tlb, vma, start, end, ref_page);
+-      tlb_finish_mmu(&tlb, start, end);
++      tlb_finish_mmu(&tlb, tlb_start, tlb_end);
+ }
+ 
+ /*
+@@ -4205,11 +4221,21 @@ unsigned long hugetlb_change_protection(
+       pte_t pte;
+       struct hstate *h = hstate_vma(vma);
+       unsigned long pages = 0;
++      unsigned long f_start = start;
++      unsigned long f_end = end;
++      bool shared_pmd = false;
++
++      /*
++       * In the case of shared PMDs, the area to flush could be beyond
++       * start/end.  Set f_start/f_end to cover the maximum possible
++       * range if PMD sharing is possible.
++       */
++      adjust_range_if_pmd_sharing_possible(vma, &f_start, &f_end);
+ 
+       BUG_ON(address >= end);
+-      flush_cache_range(vma, address, end);
++      flush_cache_range(vma, f_start, f_end);
+ 
+-      mmu_notifier_invalidate_range_start(mm, start, end);
++      mmu_notifier_invalidate_range_start(mm, f_start, f_end);
+       i_mmap_lock_write(vma->vm_file->f_mapping);
+       for (; address < end; address += huge_page_size(h)) {
+               spinlock_t *ptl;
+@@ -4220,6 +4246,7 @@ unsigned long hugetlb_change_protection(
+               if (huge_pmd_unshare(mm, &address, ptep)) {
+                       pages++;
+                       spin_unlock(ptl);
++                      shared_pmd = true;
+                       continue;
+               }
+               pte = huge_ptep_get(ptep);
+@@ -4254,12 +4281,18 @@ unsigned long hugetlb_change_protection(
+        * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare
+        * may have cleared our pud entry and done put_page on the page table:
+        * once we release i_mmap_rwsem, another task can do the final put_page
+-       * and that page table be reused and filled with junk.
++       * and that page table be reused and filled with junk.  If we actually
++       * did unshare a page of pmds, flush the range corresponding to the pud.
+        */
+-      flush_hugetlb_tlb_range(vma, start, end);
+-      mmu_notifier_invalidate_range(mm, start, end);
++      if (shared_pmd) {
++              flush_hugetlb_tlb_range(vma, f_start, f_end);
++              mmu_notifier_invalidate_range(mm, f_start, f_end);
++      } else {
++              flush_hugetlb_tlb_range(vma, start, end);
++              mmu_notifier_invalidate_range(mm, start, end);
++      }
+       i_mmap_unlock_write(vma->vm_file->f_mapping);
+-      mmu_notifier_invalidate_range_end(mm, start, end);
++      mmu_notifier_invalidate_range_end(mm, f_start, f_end);
+ 
+       return pages << h->order;
+ }

diff --git a/queue-4.9/series b/queue-4.9/series
index d6dfabe04e6b3542acb3a4265ebbe37a37b4a8ca..9399875a6ba87da62d7462142d00195e47fb0e14 100644 (file)
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -36,3 +36,4 @@ xen-netfront-don-t-trust-the-backend-response-data-blindly.patch
 tty-hvc-replace-bug_on-with-negative-return-value.patch
 shm-extend-forced-shm-destroy-to-support-objects-from-several-ipc-nses.patch
 nfsv42-fix-pagecache-invalidation-after-copy-clone.patch
+hugetlb-take-pmd-sharing-into-account-when-flushing-tlb-caches.patch