diff options
| author | Pu Lehui <[email protected]> | 2023-02-15 21:52:04 +0800 |
|---|---|---|
| committer | Daniel Borkmann <[email protected]> | 2023-02-17 21:45:30 +0100 |
| commit | 596f2e6f9cf41436a5512a3f278c86da5c5598fb (patch) | |
| tree | 379ec18fcd887274967b6b0d31c1ab3941b412c5 /arch/riscv/net/bpf_jit.h | |
| parent | 0fd1fd0104954380477353aea29c347e85dff16d (diff) | |
riscv, bpf: Add bpf_arch_text_poke support for RV64
Implement bpf_arch_text_poke for RV64. For call scenario, to make BPF
trampoline compatible with the kernel and BPF context, we follow the
framework of RV64 ftrace to reserve 4 nops for BPF programs as function
entry, and use auipc+jalr instructions for function call. However, since
auipc+jalr call instruction is non-atomic operation, we need to use
stop-machine to make sure instructions patching in atomic context. Also,
we use auipc+jalr pair and need to patch in stop-machine context for
jump scenario.
Signed-off-by: Pu Lehui <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Tested-by: Björn Töpel <[email protected]>
Acked-by: Björn Töpel <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Diffstat (limited to 'arch/riscv/net/bpf_jit.h')
| -rw-r--r-- | arch/riscv/net/bpf_jit.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/riscv/net/bpf_jit.h b/arch/riscv/net/bpf_jit.h index d926e0f7ef57..bf9802a63061 100644 --- a/arch/riscv/net/bpf_jit.h +++ b/arch/riscv/net/bpf_jit.h @@ -573,6 +573,11 @@ static inline u32 rv_fence(u8 pred, u8 succ) return rv_i_insn(imm11_0, 0, 0, 0, 0xf); } +static inline u32 rv_nop(void) +{ + return rv_i_insn(0, 0, 0, 0, 0x13); +} + /* RVC instrutions. */ static inline u16 rvc_addi4spn(u8 rd, u32 imm10) |