1. 17 Mar, 2022 3 commits
    • topjohnwu's avatar
      Reorganize magiskinit code · 8dbf9375
      topjohnwu authored
      8dbf9375
    • topjohnwu's avatar
      Remove unused code · e266a811
      topjohnwu authored
      e266a811
    • topjohnwu's avatar
      Add hijack sepolicy support for rootfs devices · e841aab9
      topjohnwu authored
      On older Android versions, pre-mounting selinuxfs will lead to errors,
      so we have to use a different method to block init's control flow.
      Since all devices that falls in this catagory must both:
      
      1. Be Android 8.0 - 9.0
      2. Have early mount fstab in its device tree
      
      We can actually use the same FIFO trick, but this time not on selinuxfs,
      but on the read-only device tree nodes in sysfs or procfs. By mocking
      the fstab/compatible node in the device tree, we can block init when
      it attempts to do early mount; at that point, we can then mock selinuxfs
      as we normally would, successfully hijack and inject patched sepolicy.
      e841aab9
  2. 16 Mar, 2022 1 commit
    • topjohnwu's avatar
      Introduce new sepolicy injection mechanism · 49f25906
      topjohnwu authored
      In the current implementation, Magisk will either have to recreate
      all early mount implementation (for legacy SAR and rootfs devices) or
      delegate early mount to first stage init (for 2SI devices) to access
      required partitions for loading sepolicy. It then has to recreate the
      split sepolicy loading implementation in-house, apply patches, then
      dump the compiled + patched policies into monolithic format somewhere.
      Finally, it patches the original init to force it to load the sepolicy
      file we just created.
      
      With the increasing complexity involved in early mount and split
      sepolicy (there is even APEX module involved in the future!),
      it is about time to rethink Magisk's sepolicy strategy as rebuilding
      init's functionality is not scalable and easy to maintain.
      
      In this commit, instead of building sepolicy ourselves, we mock
      selinuxfs with FIFO files connected to a pre-init daemon, waiting
      for the actual init process to directly write the sepolicy file into
      MagiskInit. We then patch the file and load it into the kernel. Some
      FIFO tricks has to be used to hijack the original init process's
      control flow and prevent race conditions, details are directly in the
      comments in code.
      
      At the moment, only system-as-root (read-only root) support is added.
      Support for legacy rootfs devices will come with a follow up commit.
      49f25906
  3. 14 Mar, 2022 1 commit
  4. 13 Mar, 2022 2 commits
    • topjohnwu's avatar
      Use /data as tmpfs mount point in 2SI setup · 810d27a6
      topjohnwu authored
      Design credit to @yujincheng08
      Close #5146. Fix #5491, fix #3752
      
      Previously, Magisk changes the mount point from /system to /system_root
      by patching fstab to prevent the original init from changing root.
      The reason why we want to prevent the original init from switching the
      root directory is because it will then be read-only, making patching
      and injecting magiskinit into the boot chain difficult.
      
      This commit (ab)uses the fact that the /data folder will never be part
      of early mount (because it is handled very late in the boot by vold),
      so that we can use it as the mount point of tmpfs to store files.
      
      Some advantages of this method:
      
      - No need to switch root manually
      - No need to modify fstab, which significantly improves compatibility
        e.g. avoid hacks for weird devices like those using oplus.fstab,
        and avoid hacking init to bypass fstab in device trees
      - Supports skip_mount.cfg
      - Support DSU
      810d27a6
    • topjohnwu's avatar
      Support multiple CPIO concatenated · 9b60c005
      topjohnwu authored
      9b60c005
  5. 10 Mar, 2022 8 commits
  6. 07 Mar, 2022 1 commit
  7. 04 Mar, 2022 1 commit
  8. 03 Mar, 2022 10 commits
  9. 02 Mar, 2022 12 commits
  10. 01 Mar, 2022 1 commit