mbox series

[v2,0/6] Fix page permission on arm64 architectures

Message ID 20250220135506.151894-1-ilias.apalodimas@linaro.org
Headers show
Series Fix page permission on arm64 architectures | expand

Message

Ilias Apalodimas Feb. 20, 2025, 1:54 p.m. UTC 
Hi this is v2 of [0] [1]

This is an attempt to map the U-Boot binary properly and enhance its
security posture but leave the area we load binaries unaffected and RWX.

What I have done but decided not to include was Simons suggestion of using
DM for the cpu ops. I've spent some time doing this but once I finished I
realised that the DM cpu ops are only present in a handful of boards.
Since we want this to work for all boards I've kept the DM branch here [2]
but still use the weak function approach on the patchset. I can resend
it once we have boards supporting the DM class.

Changes since v1:
- added r-b from Caleb.
- The memory map only gets dumped if CONFIG_CMD_MEMINFO_MAP is enabled as
  Simon asked
- reworded some patches and Kconfig messages according to Toms suggestions
- Fixed suggestions from Richard on linker scripts and added a Kconfig
  option to reduce the required page alignment if the feature is not
  selected
- Treating _u_boot_list as .rodata, they end up in RO memory now
- The function changing attributes returns an int instead of void so we can
  reuse it in EFI for the memory attribute protocol -- Heinrich
- Correctly cast the size as size_t instead of phys_addr_t in
  pgprot_set_attrs()

Change since RFC:
- Fixed the alignment of meminfo command when printing regions
- 'meminfo' now prints arch specific attributes e.g PXN, UXN etc for arm
  instead of RW, RO, RX
- Since we don't set the permissions of EFI runtime services yet and keep
  them as RWX, I removed the linker alignment changes which makes patch #3
  easier to review. It's worth noting that qemu-arm sbsa was crashing with
  the efi services page aligned. This is probably due to a mismatch of
  memory, since the crash is only reproducible with QEMU instances that
  have < 2 GB of RAM. I'll fix that along with the efi runtime services
- Defined memory attribute changes properly with an enum for RW, RO, RX
  instead of the hardcoded '1,2,3' I had on the RFC
- Enabling mappings is now under a Kconfig (CONFIG_MMU_PGPROT), since
  peope reported crashes when testing this, which are orthogonal to this
  patch. We still have places in U-Boot where we define and later write
  const variables. This will lead to a crash now as const variables are
  properly managed and places in RO memory
- Split patches to be easier to review
- Added a patch updating 'meminfo'
- Picked up acked-by tags from Jerome

[0] https://lore.kernel.org/u-boot/20250205071714.635518-1-ilias.apalodimas@linaro.org/
[1] https://lore.kernel.org/u-boot/20250130072100.27297-1-ilias.apalodimas@linaro.org/
[2] https://source.denx.de/u-boot/custodians/u-boot-tpm/-/tree/fix_memory_permissions_uclass

Neil tested a bunch of board as well so adding his tags here to be picked up for
the entire series

Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on AML-S905X-CC
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on AML-S805X-AC
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on BananaPi-M5
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on BananaPi-M2S
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-HDK
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-QRD
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-HDK

Cheers
/Ilias

Ilias Apalodimas (6):
  meminfo: add memory details for armv8
  doc: update meminfo with arch specific information
  arm: Prepare linker scripts for memory permissions
  arm64: mmu_change_region_attr() add an option not to break PTEs
  treewide: Add a function to change page permissions
  arm64: Enable RW, RX and RO mappings for the relocated binary

 arch/arc/lib/cache.c                    |  6 +++
 arch/arm/cpu/arm926ejs/cache.c          |  6 +++
 arch/arm/cpu/armv7/cache_v7.c           |  6 +++
 arch/arm/cpu/armv7m/cache.c             |  6 +++
 arch/arm/cpu/armv8/cache_v8.c           | 57 ++++++++++++++++++--
 arch/arm/cpu/armv8/fsl-layerscape/cpu.c | 10 ++--
 arch/arm/cpu/armv8/u-boot.lds           | 59 +++++++++++++-------
 arch/arm/include/asm/armv8/mmu.h        |  2 +
 arch/arm/include/asm/system.h           | 11 +++-
 arch/arm/lib/cache.c                    |  6 +++
 arch/arm/mach-snapdragon/board.c        |  2 +-
 arch/m68k/lib/cache.c                   |  6 +++
 arch/nios2/lib/cache.c                  |  6 +++
 arch/powerpc/lib/cache.c                |  6 +++
 arch/riscv/lib/cache.c                  |  6 +++
 arch/sh/cpu/sh4/cache.c                 |  6 +++
 arch/xtensa/lib/cache.c                 |  6 +++
 cmd/meminfo.c                           |  6 +++
 common/Kconfig                          | 13 +++++
 common/board_r.c                        | 20 +++++++
 doc/usage/cmd/meminfo.rst               | 71 ++++++++++++++++++-------
 include/asm-generic/sections.h          |  2 +
 include/cpu_func.h                      | 17 ++++++
 23 files changed, 288 insertions(+), 48 deletions(-)

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2.47.2