[PATCH v4 0/1] riscv: Allow to downgrade paging mode from the command line

From: Alexandre Ghiti
Date: Tue Jan 31 2023 - 10:13:58 EST


This new version gets rid of the limitation that prevented KASAN kernels
to use the newly introduced parameters.

While looking into KASLR, I fell onto commit aacd149b6238 ("arm64: head:
avoid relocating the kernel twice for KASLR"): it allows to use the fdt
functions very early in the boot process with KASAN enabled by simply
compiling a new version of those functions without instrumentation.

I had to change the handling of the command line parsing to make the
code self-contained in kernel/pi/cmd_early.c to avoid calling too many
__pi prefixed functions from outside this file.

I'll use this approach like arm64 to handle the extraction of the random
seedi from the device tree for KASLR.

@Ard: I copied the "pi" name but I have to admit I don't know what it
means.

Alexandre Ghiti (1):
riscv: Allow to downgrade paging mode from the command line

.../admin-guide/kernel-parameters.txt | 5 +-
arch/riscv/kernel/Makefile | 2 +
arch/riscv/kernel/pi/Makefile | 34 ++++++++++++
arch/riscv/kernel/pi/cmdline_early.c | 52 +++++++++++++++++++
arch/riscv/lib/memcpy.S | 2 +
arch/riscv/lib/memmove.S | 2 +
arch/riscv/mm/init.c | 36 ++++++++++---
7 files changed, 126 insertions(+), 7 deletions(-)
create mode 100644 arch/riscv/kernel/pi/Makefile
create mode 100644 arch/riscv/kernel/pi/cmdline_early.c

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2.37.2