Commit Graph

3 Commits

Author SHA1 Message Date
Pu Lehui
5e57fb7b0b riscv: Extend patch_text for multiple instructions
Extend patch_text for multiple instructions. This is the preparaiton for
multiple instructions text patching in riscv BPF trampoline, and may be
useful for other scenario.

Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/bpf/20230215135205.1411105-2-pulehui@huaweicloud.com
2023-02-17 21:45:30 +01:00
Zong Li
b80b3d582e riscv: Remove the 'riscv_' prefix of function name
Refactor the function name by removing the 'riscv_' prefix, it would be
better unless it could mix up with arch-independent functions.

Signed-off-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-05-18 11:38:13 -07:00
Zong Li
043cb41a85 riscv: introduce interfaces to patch kernel code
On strict kernel memory permission, we couldn't patch code without
writable permission. Preserve two holes in fixmap area, so we can map
the kernel code temporarily to fixmap area, then patch the instructions.

We need two pages here because we support the compressed instruction, so
the instruction might be align to 2 bytes. When patching the 32-bit
length instruction which is 2 bytes alignment, it will across two pages.

Introduce two interfaces to patch kernel code:
riscv_patch_text_nosync:
 - patch code without synchronization, it's caller's responsibility to
   synchronize all CPUs if needed.
riscv_patch_text:
 - patch code and always synchronize with stop_machine()

Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-03-26 09:24:52 -07:00