| Message ID | 20230424092313.178699-1-alexghiti@rivosinc.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | riscv: Allow to downgrade paging mode from the command line | expand |
On Mon, 24 Apr 2023 11:23:12 +0200, Alexandre Ghiti wrote: > his 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. > > [...] Applied, thanks! [1/1] riscv: Allow to downgrade paging mode from the command line https://git.kernel.org/palmer/c/26e7aacb83df Best regards,
his 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. This patchset is rebased on top: Introduce 64b relocatable kernel (https://patchwork.kernel.org/project/linux-riscv/list/?series=734847) base-commit-tag: v6.3-rc1 v10: - Compile kernel/pi with -fpie to fix llvm boot issues (arm64 does just that) - Rebase on top relocatable patchset that was merged - Add -z norelro to all kernels (not just relocatable) to quiet ld.lld warnings v9: - Fix medlow builds by marking pi/ medany, as reported by Palmer v8: - Fix LLVM ld warning by moving the section .init.sdata from kernel/pi/string.c into the newly created section .init.pidata v7: - Rebased on top of for-next which introduces lots of errors (thanks to the patchwork CI) - Add __NO_FORTIFY to avoid undefined __pi_fortify_panic - Add an alias to our newly introduced strlen - Remove __init as sections are already prefixed in the Makefile - Introduce new section for kernel/pi/string.c to quiet the following warnings (once we have all the string functions, we'll be able to get rid of this): warning: orphan section `.init__bug_table' from `arch/riscv/kernel/pi/string.pi.o' being placed in section `.init__bug_table' warning: orphan section `.init.srodata.cst8' from `arch/riscv/kernel/pi/string.pi.o' being placed in section `.init.srodata.cst8' v6: - Fix llvm warning by forward declaring set_satp_mode_from_cmdline 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/Makefile | 3 +- arch/riscv/kernel/Makefile | 2 + arch/riscv/kernel/pi/Makefile | 39 ++++++++++++ arch/riscv/kernel/pi/cmdline_early.c | 62 +++++++++++++++++++ arch/riscv/kernel/vmlinux.lds.S | 11 +++- arch/riscv/lib/memcpy.S | 2 + arch/riscv/lib/memmove.S | 2 + arch/riscv/lib/strlen.S | 1 + arch/riscv/mm/init.c | 36 +++++++++-- 10 files changed, 154 insertions(+), 9 deletions(-) create mode 100644 arch/riscv/kernel/pi/Makefile create mode 100644 arch/riscv/kernel/pi/cmdline_early.c