From: Alexandre Ghiti <alexghiti@rivosinc.com>
To: "Jonathan Corbet" <corbet@lwn.net>,
"Paul Walmsley" <paul.walmsley@sifive.com>,
"Palmer Dabbelt" <palmer@dabbelt.com>,
"Albert Ou" <aou@eecs.berkeley.edu>,
"Conor Dooley" <conor@kernel.org>,
"Ard Biesheuvel" <ardb@kernel.org>,
"Björn Töpel" <bjorn@kernel.org>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-riscv@lists.infradead.org
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Subject: [PATCH v5 0/1] riscv: Allow to downgrade paging mode from the command line
Date: Wed, 22 Feb 2023 11:43:21 +0100 [thread overview]
Message-ID: <20230222104322.1197763-1-alexghiti@rivosinc.com> (raw)
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.
base-commit-tag: v6.2-rc7
v5:
- Handle null command line, Thanks Björn!
- Add RB/TB from Björn
v4:
- Introduce pi/ for KASAN to work
v3:
- Massage commit log to make no4lvl clearer, as asked by Conor
- Add a note to kernel-parameters.txt regarding the impossibility to use
those parameters when KASAN is enabled, as suggested by Conor
- Add RB from Björn
v2:
- Honor CMDLINE_EXTEND and CMDLINE_FORCE as noticed by Björn
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 | 55 +++++++++++++++++++
arch/riscv/lib/memcpy.S | 2 +
arch/riscv/lib/memmove.S | 2 +
arch/riscv/mm/init.c | 36 ++++++++++--
7 files changed, 129 insertions(+), 7 deletions(-)
create mode 100644 arch/riscv/kernel/pi/Makefile
create mode 100644 arch/riscv/kernel/pi/cmdline_early.c
--
2.37.2
WARNING: multiple messages have this Message-ID (diff)
From: Alexandre Ghiti <alexghiti@rivosinc.com>
To: "Jonathan Corbet" <corbet@lwn.net>,
"Paul Walmsley" <paul.walmsley@sifive.com>,
"Palmer Dabbelt" <palmer@dabbelt.com>,
"Albert Ou" <aou@eecs.berkeley.edu>,
"Conor Dooley" <conor@kernel.org>,
"Ard Biesheuvel" <ardb@kernel.org>,
"Björn Töpel" <bjorn@kernel.org>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-riscv@lists.infradead.org
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Subject: [PATCH v5 0/1] riscv: Allow to downgrade paging mode from the command line
Date: Wed, 22 Feb 2023 11:43:21 +0100 [thread overview]
Message-ID: <20230222104322.1197763-1-alexghiti@rivosinc.com> (raw)
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.
base-commit-tag: v6.2-rc7
v5:
- Handle null command line, Thanks Björn!
- Add RB/TB from Björn
v4:
- Introduce pi/ for KASAN to work
v3:
- Massage commit log to make no4lvl clearer, as asked by Conor
- Add a note to kernel-parameters.txt regarding the impossibility to use
those parameters when KASAN is enabled, as suggested by Conor
- Add RB from Björn
v2:
- Honor CMDLINE_EXTEND and CMDLINE_FORCE as noticed by Björn
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 | 55 +++++++++++++++++++
arch/riscv/lib/memcpy.S | 2 +
arch/riscv/lib/memmove.S | 2 +
arch/riscv/mm/init.c | 36 ++++++++++--
7 files changed, 129 insertions(+), 7 deletions(-)
create mode 100644 arch/riscv/kernel/pi/Makefile
create mode 100644 arch/riscv/kernel/pi/cmdline_early.c
--
2.37.2
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next reply other threads:[~2023-02-22 10:43 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-22 10:43 Alexandre Ghiti [this message]
2023-02-22 10:43 ` [PATCH v5 0/1] riscv: Allow to downgrade paging mode from the command line Alexandre Ghiti
2023-02-22 10:43 ` [PATCH v5 1/1] " Alexandre Ghiti
2023-02-22 10:43 ` Alexandre Ghiti
2023-02-22 15:37 ` kernel test robot
2023-02-22 15:37 ` kernel test robot
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