| Message ID | 20230228154629.240541-1-alexghiti@rivosinc.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | riscv: Allow to downgrade paging mode from the command line | expand |
On Tue, 28 Feb 2023 07:46:28 PST (-0800), alexghiti@rivosinc.com 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. > > base-commit: eb9be8310c58 ("RISC-V: add a spin_shadow_stack declaration") I have that in my tree, I'm still getting a bunch of boot failures though. I can try to get a list if you're not seeing any, but I'm kind of stuck on some other stuff for a bit... > 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/kernel/Makefile | 2 + > arch/riscv/kernel/pi/Makefile | 37 +++++++++++ > arch/riscv/kernel/pi/cmdline_early.c | 62 +++++++++++++++++++ > arch/riscv/kernel/vmlinux.lds.S | 8 +++ > arch/riscv/lib/memcpy.S | 2 + > arch/riscv/lib/memmove.S | 2 + > arch/riscv/lib/strlen.S | 1 + > arch/riscv/mm/init.c | 36 +++++++++-- > 9 files changed, 148 insertions(+), 7 deletions(-) > create mode 100644 arch/riscv/kernel/pi/Makefile > create mode 100644 arch/riscv/kernel/pi/cmdline_early.c
On 3/29/23 19:59, Palmer Dabbelt wrote: > On Tue, 28 Feb 2023 07:46:28 PST (-0800), alexghiti@rivosinc.com 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. >> >> base-commit: eb9be8310c58 ("RISC-V: add a spin_shadow_stack >> declaration") > > I have that in my tree, I'm still getting a bunch of boot failures > though. I can try to get a list if you're not seeing any, but I'm > kind of stuck on some other stuff for a bit... I sent yesterday a v9 which fixes the medlow boot issues you mentioned, I did not have any boot failures after that on my side. > >> 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/kernel/Makefile | 2 + >> arch/riscv/kernel/pi/Makefile | 37 +++++++++++ >> arch/riscv/kernel/pi/cmdline_early.c | 62 +++++++++++++++++++ >> arch/riscv/kernel/vmlinux.lds.S | 8 +++ >> arch/riscv/lib/memcpy.S | 2 + >> arch/riscv/lib/memmove.S | 2 + >> arch/riscv/lib/strlen.S | 1 + >> arch/riscv/mm/init.c | 36 +++++++++-- >> 9 files changed, 148 insertions(+), 7 deletions(-) >> create mode 100644 arch/riscv/kernel/pi/Makefile >> create mode 100644 arch/riscv/kernel/pi/cmdline_early.c > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv
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: eb9be8310c58 ("RISC-V: add a spin_shadow_stack declaration") 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/kernel/Makefile | 2 + arch/riscv/kernel/pi/Makefile | 37 +++++++++++ arch/riscv/kernel/pi/cmdline_early.c | 62 +++++++++++++++++++ arch/riscv/kernel/vmlinux.lds.S | 8 +++ arch/riscv/lib/memcpy.S | 2 + arch/riscv/lib/memmove.S | 2 + arch/riscv/lib/strlen.S | 1 + arch/riscv/mm/init.c | 36 +++++++++-- 9 files changed, 148 insertions(+), 7 deletions(-) create mode 100644 arch/riscv/kernel/pi/Makefile create mode 100644 arch/riscv/kernel/pi/cmdline_early.c