1. 26 Sep, 2020 2 commits
    • Gao Xiang's avatar
      mm, THP, swap: fix allocating cluster for swapfile by mistake · 41663430
      Gao Xiang authored
      SWP_FS is used to make swap_{read,write}page() go through the
      filesystem, and it's only used for swap files over NFS.  So, !SWP_FS
      means non NFS for now, it could be either file backed or device backed.
      Something similar goes with legacy SWP_FILE.
      
      So in order to achieve the goal of the original patch, SWP_BLKDEV should
      be used instead.
      
      FS corruption can be observed with SSD device + XFS + fragmented
      swapfile due to CONFIG_THP_SWAP=y.
      
      I reproduced the issue with the following details:
      
      Environment:
      
        QEMU + upstream kernel + buildroot + NVMe (2 GB)
      
      Kernel config:
      
        CONFIG_BLK_DEV_NVME=y
        CONFIG_THP_SWAP=y
      
      Some reproducible steps:
      
        mkfs.xfs -f /dev/nvme0n1
        mkdir /tmp/mnt
        mount /dev/nvme0n1 /tmp/mnt
        bs="32k"
        sz="1024m"    # doesn't matter too much, I also tried 16m
        xfs_io -f -c "pwrite -R -b $bs 0 $sz" -c "fdatasync" /tmp/mnt/sw
        xfs_io -f -c "pwrite -R -b $bs 0 $sz" -c "fdatasync" /tmp/mnt/sw
        xfs_io -f -c "pwrite -R -b $bs 0 $sz" -c "fdatasync" /tmp/mnt/sw
        xfs_io -f -c "pwrite -F -S 0 -b $bs 0 $sz" -c "fdatasync" /tmp/mnt/sw
        xfs_io -f -c "pwrite -R -b $bs 0 $sz" -c "fsync" /tmp/mnt/sw
      
        mkswap /tmp/mnt/sw
        swapon /tmp/mnt/sw
      
        stress --vm 2 --vm-bytes 600M   # doesn't matter too much as well
      
      Symptoms:
       - FS corruption (e.g. checksum failure)
       - memory corruption at: 0xd2808010
       - segfault
      
      Fixes: f0eea189 ("mm, THP, swap: Don't allocate huge cluster for file backed swap device")
      Fixes: 38d8b4e6 ("mm, THP, swap: delay splitting THP during swap out")
      Signed-off-by: default avatarGao Xiang <hsiangkao@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Reviewed-by: default avatar"Huang, Ying" <ying.huang@intel.com>
      Reviewed-by: default avatarYang Shi <shy828301@gmail.com>
      Acked-by: default avatarRafael Aquini <aquini@redhat.com>
      Cc: Matthew Wilcox <willy@infradead.org>
      Cc: Carlos Maiolino <cmaiolino@redhat.com>
      Cc: Eric Sandeen <esandeen@redhat.com>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: <stable@vger.kernel.org>
      Link: https://lkml.kernel.org/r/20200820045323.7809-1-hsiangkao@redhat.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      41663430
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm · 7c7ec322
      Linus Torvalds authored
      Pull more kvm fixes from Paolo Bonzini:
       "Five small fixes.
      
        The nested migration bug will be fixed with a better API in 5.10 or
        5.11, for now this is a fix that works with existing userspace but
        keeps the current ugly API"
      
      * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
        KVM: SVM: Add a dedicated INVD intercept routine
        KVM: x86: Reset MMU context if guest toggles CR4.SMAP or CR4.PKE
        KVM: x86: fix MSR_IA32_TSC read for nested migration
        selftests: kvm: Fix assert failure in single-step test
        KVM: x86: VMX: Make smaller physical guest address space support user-configurable
      7c7ec322
  2. 25 Sep, 2020 15 commits
  3. 24 Sep, 2020 6 commits
  4. 23 Sep, 2020 16 commits
  5. 22 Sep, 2020 1 commit