[v2,0/6] Improve kernel section protections

Message

Atish Patra Oct. 26, 2020, 11:02 p.m. UTC

This series aims at improving kernel permissions by doing following things.

1. Protect kernel sections early instead of after /init.
2. Protect .init.text & .init.data sections with appropriate permissions.
3. Move dynamic relocation section to _init.
4. Moved .init sections after .text. This is what most of the other archs
   are also doing.

After applying this patch, here are the linear mapped sections.

---[ Linear mapping ]---
0xffffffe000000000-0xffffffe000800000    0x0000000080200000         8M PMD     D A . . X . R V
0xffffffe000800000-0xffffffe000c00000    0x0000000080a00000         4M PMD     D A . . . W R V
0xffffffe000c00000-0xffffffe001200000    0x0000000080e00000         6M PMD     D A . . . . R V
0xffffffe001200000-0xffffffe03fe00000    0x0000000081400000      1004M PMD     D A . . . W R V

Changes from v1->v2:
1. .init.text section is aligned with SECTION_ALIGN.
2. .init.text is moved to below of .text so that .head.text & .text are in
   one section.
3. We don't need Guo's fix for static object issue.
4. Rebased on 5.10-rc1.

Atish Patra (6):
RISC-V: Move __start_kernel to .head.text
RISC-V: Initialize SBI early
RISC-V: Enforce protections for kernel sections early
RISC-V: Align the .init.text section
RISC-V: Protect .init.text & .init.data
RISC-V: Move dynamic relocation section under __init

arch/riscv/include/asm/sections.h   |  2 +
arch/riscv/include/asm/set_memory.h |  4 ++
arch/riscv/kernel/head.S            |  1 -
arch/riscv/kernel/setup.c           | 18 +++++++--
arch/riscv/kernel/vmlinux.lds.S     | 63 +++++++++++++++++------------
arch/riscv/mm/init.c                | 19 +++++++--
arch/riscv/mm/pageattr.c            |  6 +++
7 files changed, 79 insertions(+), 34 deletions(-)

--
2.25.1