1. 01 Oct, 2018 1 commit
  2. 25 Sep, 2018 4 commits
    • Jun Yao's avatar
      arm64/mm: move runtime pgds to rodata · 8eb7e28d
      Jun Yao authored
      Now that deliberate writes to swapper_pg_dir are made via the fixmap, we
      can defend against errant writes by moving it into the rodata section.
      Since tramp_pg_dir and reserved_ttbr0 must be at a fixed offset from
      swapper_pg_dir, and are not modified at runtime, these are also moved
      into the rodata section. Likewise, idmap_pg_dir is not modified at
      runtime, and is moved into rodata.
      Signed-off-by: default avatarJun Yao <[email protected]>
      Reviewed-by: default avatarJames Morse <[email protected]>
      [Mark: simplify linker script, commit message]
      Signed-off-by: default avatarMark Rutland <[email protected]>
      Signed-off-by: default avatarCatalin Marinas <[email protected]>
      8eb7e28d
    • Jun Yao's avatar
      arm64/mm: use fixmap to modify swapper_pg_dir · 2330b7ca
      Jun Yao authored
      Once swapper_pg_dir is in the rodata section, it will not be possible to
      modify it directly, but we will need to modify it in some cases.
      
      To enable this, we can use the fixmap when deliberately modifying
      swapper_pg_dir. As the pgd is only transiently mapped, this provides
      some resilience against illicit modification of the pgd, e.g. for
      Kernel Space Mirror Attack (KSMA).
      Signed-off-by: default avatarJun Yao <[email protected]>
      Reviewed-by: default avatarJames Morse <[email protected]>
      [Mark: simplify ifdeffery, commit message]
      Signed-off-by: default avatarMark Rutland <[email protected]>
      Signed-off-by: default avatarCatalin Marinas <[email protected]>
      2330b7ca
    • Jun Yao's avatar
      arm64/mm: Separate boot-time page tables from swapper_pg_dir · 2b5548b6
      Jun Yao authored
      Since the address of swapper_pg_dir is fixed for a given kernel image,
      it is an attractive target for manipulation via an arbitrary write. To
      mitigate this we'd like to make it read-only by moving it into the
      rodata section.
      
      We require that swapper_pg_dir is at a fixed offset from tramp_pg_dir
      and reserved_ttbr0, so these will also need to move into rodata.
      However, swapper_pg_dir is allocated along with some transient page
      tables used for boot which we do not want to move into rodata.
      
      As a step towards this, this patch separates the boot-time page tables
      into a new init_pg_dir, and reduces swapper_pg_dir to the single page it
      needs to be. This allows us to retain the relationship between
      swapper_pg_dir, tramp_pg_dir, and swapper_pg_dir, while cleanly
      separating these from the boot-time page tables.
      
      The init_pg_dir holds all of the pgd/pud/pmd/pte levels needed during
      boot, and all of these levels will be freed when we switch to the
      swapper_pg_dir, which is initialized by the existing code in
      paging_init(). Since we start off on the init_pg_dir, we no longer need
      to allocate a transient page table in paging_init() in order to ensure
      that swapper_pg_dir isn't live while we initialize it.
      
      There should be no functional change as a result of this patch.
      Signed-off-by: default avatarJun Yao <[email protected]>
      Reviewed-by: default avatarJames Morse <[email protected]>
      [Mark: place init_pg_dir after BSS, fold mm changes, commit message]
      Signed-off-by: default avatarMark Rutland <[email protected]>
      Signed-off-by: default avatarCatalin Marinas <[email protected]>
      2b5548b6
    • Jun Yao's avatar
      arm64/mm: Pass ttbr1 as a parameter to __enable_mmu() · 693d5639
      Jun Yao authored
      In subsequent patches we'll use a transient pgd during the primary cpu's
      boot process. To make this work while allowing secondary cpus to use the
      swapper_pg_dir, we need to pass the relevant TTBR1 pgd as a parameter
      to __enable_mmu().
      
      This patch updates __enable__mmu() to take this as a parameter, updating
      callsites to pass swapper_pg_dir for now.
      
      There should be no functional change as a result of this patch.
      Signed-off-by: default avatarJun Yao <[email protected]>
      Reviewed-by: default avatarJames Morse <[email protected]>
      [Mark: simplify assembly, clarify commit message]
      Signed-off-by: default avatarMark Rutland <[email protected]>
      Signed-off-by: default avatarCatalin Marinas <[email protected]>
      693d5639
  3. 24 Sep, 2018 1 commit
  4. 21 Sep, 2018 5 commits
  5. 19 Sep, 2018 1 commit
  6. 18 Sep, 2018 2 commits
  7. 17 Sep, 2018 1 commit
    • Suzuki K Poulose's avatar
      arm64: sysreg: Clean up instructions for modifying PSTATE fields · 74e24828
      Suzuki K Poulose authored
      Instructions for modifying the PSTATE fields which were not supported
      in the older toolchains (e.g, PAN, UAO) are generated using macros.
      We have so far used the normal sys_reg() helper for defining the PSTATE
      fields. While this works fine, it is really difficult to correlate the
      code with the Arm ARM definition.
      
      As per Arm ARM, the PSTATE fields are defined only using Op1, Op2 fields,
      with fixed values for Op0, CRn. Also the CRm field has been reserved
      for the Immediate value for the instruction. So using the sys_reg()
      looks quite confusing.
      
      This patch cleans up the instruction helpers by bringing them
      in line with the Arm ARM definitions to make it easier to correlate
      code with the document. No functional changes.
      
      Cc: Will Deacon <[email protected]>
      Cc: Mark Rutland <[email protected]>
      Signed-off-by: default avatarSuzuki K Poulose <[email protected]>
      Signed-off-by: default avatarCatalin Marinas <[email protected]>
      74e24828
  8. 14 Sep, 2018 9 commits
  9. 11 Sep, 2018 9 commits
  10. 10 Sep, 2018 5 commits
  11. 07 Sep, 2018 2 commits