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

From: Alexandre Ghiti
Date: Thu Feb 02 2023 - 10:08:53 EST


Hi Conor,

On Tue, Jan 31, 2023 at 8:25 PM Conor Dooley <conor@xxxxxxxxxx> wrote:
>
> Hey Alex,
>
> On Tue, Jan 31, 2023 at 04:11:14PM +0100, Alexandre Ghiti wrote:
> > This new version gets rid of the limitation that prevented KASAN kernels
> > to use the newly introduced parameters.
>
> What's the base commit for this version?
> Fails to apply for me on top of for-next, fixes, rc1, and linux-next :/
> I also tried it on top of your KASAN series, but no luck there either!

Really sorry about that, that's the second time it happens, I'll
improve my workflow: I'll include the base-commit sha1/tag + a link to
all needed-but-not-yet-upstreamed patches.

Thanks for your time,

Alex

>
> Thanks,
> Conor.
>
> > 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
> >
> > --
> > 2.37.2
> >