| Message ID | 20230131151115.1972740-1-alexghiti@rivosinc.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | riscv: Allow to downgrade paging mode from the command line | expand |
Sorry, I forgot the changelog again: |v4: - Remove the kasan limitation by compiling 'local' fdt functions, as done in arm64 by Ard - Remove RB from Björn as the cmdline handling changed 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| On 1/31/23 16:11, Alexandre Ghiti wrote: > 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 >
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! 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 >
Hi Conor, On Tue, Jan 31, 2023 at 8:25 PM Conor Dooley <conor@kernel.org> 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 > >
On Thu, Feb 2, 2023 at 4:07 PM Alexandre Ghiti <alexghiti@rivosinc.com> wrote: > > Hi Conor, > > On Tue, Jan 31, 2023 at 8:25 PM Conor Dooley <conor@kernel.org> 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? And to answer your question: this patch applies nicely on top of v6.2-rc6 + my KASAN patchset (https://patchwork.kernel.org/project/linux-riscv/list/?series=715388) > > 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 > > >
Alexandre Ghiti <alexghiti@rivosinc.com> writes: > 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. __pi_ is for "position-independent" -- KASLR related. For the (tiny ;-)) series: Tested-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
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