Alexandre Ghiti <alexghiti@rivosinc.com> says:
The following KASLR implementation allows to randomize the kernel mapping:
- virtually: we expect the bootloader to provide a seed in the device-tree
- physically: only implemented in the EFI stub, it relies on the firmware to
provide a seed using EFI_RNG_PROTOCOL. arm64 has a similar implementation
hence the patch 3 factorizes KASLR related functions for riscv to take
advantage.
The new virtual kernel location is limited by the early page table that only
has one PUD and with the PMD alignment constraint, the kernel can only take
< 512 positions.
* b4-shazam-merge:
riscv: libstub: Implement KASLR by using generic functions
libstub: Fix compilation warning for rv32
arm64: libstub: Move KASLR handling functions to kaslr.c
riscv: Dump out kernel offset information on panic
riscv: Introduce virtual kernel mapping KASLR
Link: https://lore.kernel.org/r/20230722123850.634544-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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