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| author |   Luke Nelson <lukenels@cs.washington.edu> | 2020-07-20 19:52:38 -0700 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2020-07-21 13:26:25 -0700 |
| commit | bfabff3cb0fef366086c64f24be8ab316a355b99 (patch) | |
| tree | 7e6e73a32c62c4ca261abbf0a570f758f3103a84 /arch/riscv/net/bpf_jit_comp64.c | |
| parent | tools/bpftool: Fix error handing in do_skeleton() (diff) | |
| download | wireguard-linux-bfabff3cb0fef366086c64f24be8ab316a355b99.tar.xz wireguard-linux-bfabff3cb0fef366086c64f24be8ab316a355b99.zip | |
bpf, riscv: Modify JIT ctx to support compressed instructions
This patch makes the necessary changes to struct rv_jit_context and to
bpf_int_jit_compile to support compressed riscv (RVC) instructions in
the BPF JIT.
It changes the JIT image to be u16 instead of u32, since RVC instructions
are 2 bytes as opposed to 4.
It also changes ctx->offset and ctx->ninsns to refer to 2-byte
instructions rather than 4-byte ones. The riscv PC is required to be
16-bit aligned with or without RVC, so this is sufficient to refer to
any valid riscv offset.
The code for computing jump offsets in bytes is updated accordingly,
and factored into a new "ninsns_rvoff" function to simplify the code.
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200721025241.8077-2-luke.r.nels@gmail.com
Diffstat (limited to 'arch/riscv/net/bpf_jit_comp64.c')
| -rw-r--r-- | arch/riscv/net/bpf_jit_comp64.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c index 6cfd164cbe88..55861269da2a 100644 --- a/arch/riscv/net/bpf_jit_comp64.c +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -304,14 +304,14 @@ static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx) if (is_12b_check(off, insn)) return -1; emit(rv_lwu(RV_REG_T1, off, RV_REG_A1), ctx); - off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2; + off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); emit_branch(BPF_JGE, RV_REG_A2, RV_REG_T1, off, ctx); /* if (TCC-- < 0) * goto out; */ emit(rv_addi(RV_REG_T1, tcc, -1), ctx); - off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2; + off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); emit_branch(BPF_JSLT, tcc, RV_REG_ZERO, off, ctx); /* prog = array->ptrs[index]; @@ -324,7 +324,7 @@ static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx) if (is_12b_check(off, insn)) return -1; emit(rv_ld(RV_REG_T2, off, RV_REG_T2), ctx); - off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2; + off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); emit_branch(BPF_JEQ, RV_REG_T2, RV_REG_ZERO, off, ctx); /* goto *(prog->bpf_func + 4); */ @@ -757,7 +757,7 @@ out_be: e = ctx->ninsns; /* Adjust for extra insns */ - rvoff -= (e - s) << 2; + rvoff -= ninsns_rvoff(e - s); } if (BPF_OP(code) == BPF_JSET) { @@ -810,7 +810,7 @@ out_be: e = ctx->ninsns; /* Adjust for extra insns */ - rvoff -= (e - s) << 2; + rvoff -= ninsns_rvoff(e - s); emit_branch(BPF_OP(code), rd, rs, rvoff, ctx); break; @@ -831,7 +831,7 @@ out_be: if (!is64 && imm < 0) emit(rv_addiw(RV_REG_T1, RV_REG_T1, 0), ctx); e = ctx->ninsns; - rvoff -= (e - s) << 2; + rvoff -= ninsns_rvoff(e - s); emit_branch(BPF_JNE, RV_REG_T1, RV_REG_ZERO, rvoff, ctx); break; |