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| author | Alexandre Ghiti <alexghiti@rivosinc.com> | 2023-04-24 11:23:13 +0200 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-04-26 07:30:52 -0700 |
| commit | 26e7aacb83dfd04330673c5c9ac336560da52bb3 (patch) | |
| tree | 7e0e02de1026bb1c034e3048c706f56a352c97eb /arch/riscv/lib | |
| parent | d4dda690b44a5e36b4bf108c48177cef40c80d24 (diff) | |
riscv: Allow to downgrade paging mode from the command line
Add 2 early command line parameters that allow to downgrade satp mode
(using the same naming as x86):
- "no5lvl": use a 4-level page table (down from sv57 to sv48)
- "no4lvl": use a 3-level page table (down from sv57/sv48 to sv39)
Note that going through the device tree to get the kernel command line
works with ACPI too since the efi stub creates a device tree anyway with
the command line.
In KASAN kernels, we can't use the libfdt that early in the boot process
since we are not ready to execute instrumented functions. So instead of
using the "generic" libfdt, we compile our own versions of those functions
that are not instrumented and that are prefixed so that they do not
conflict with the generic ones. We also need the non-instrumented versions
of the string functions and the prefixed versions of memcpy/memmove.
This is largely inspired by commit aacd149b6238 ("arm64: head: avoid
relocating the kernel twice for KASLR") from which I removed compilation
flags that were not relevant to RISC-V at the moment (LTO, SCS). Also
note that we have to link with -z norelro to avoid ld.lld to throw a
warning with the new .got sections, like in commit 311bea3cb9ee ("arm64:
link with -z norelro for LLD or aarch64-elf").
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230424092313.178699-2-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/lib')
| -rw-r--r-- | arch/riscv/lib/memcpy.S | 2 | ||||
| -rw-r--r-- | arch/riscv/lib/memmove.S | 2 | ||||
| -rw-r--r-- | arch/riscv/lib/strlen.S | 1 |
3 files changed, 5 insertions, 0 deletions
diff --git a/arch/riscv/lib/memcpy.S b/arch/riscv/lib/memcpy.S index 51ab716253fa..1a40d01a9543 100644 --- a/arch/riscv/lib/memcpy.S +++ b/arch/riscv/lib/memcpy.S @@ -106,3 +106,5 @@ WEAK(memcpy) 6: ret END(__memcpy) +SYM_FUNC_ALIAS(__pi_memcpy, __memcpy) +SYM_FUNC_ALIAS(__pi___memcpy, __memcpy) diff --git a/arch/riscv/lib/memmove.S b/arch/riscv/lib/memmove.S index e0609e1f0864..838ff2022fe3 100644 --- a/arch/riscv/lib/memmove.S +++ b/arch/riscv/lib/memmove.S @@ -314,3 +314,5 @@ return_from_memmove: SYM_FUNC_END(memmove) SYM_FUNC_END(__memmove) +SYM_FUNC_ALIAS(__pi_memmove, __memmove) +SYM_FUNC_ALIAS(__pi___memmove, __memmove) diff --git a/arch/riscv/lib/strlen.S b/arch/riscv/lib/strlen.S index db3d42d99b78..8ae3064e45ff 100644 --- a/arch/riscv/lib/strlen.S +++ b/arch/riscv/lib/strlen.S @@ -130,3 +130,4 @@ strlen_zbb: .option pop #endif SYM_FUNC_END(strlen) +SYM_FUNC_ALIAS(__pi_strlen, strlen) |