On Mon, 16 Dec 2019 01:13:37 PST (-0800), Bjorn Topel wrote:
Start use the emit_branch() function in the tail call emitter in order
to support far branching.
Signed-off-by: Björn Töpel <bjorn.topel@xxxxxxxxx>
---
arch/riscv/net/bpf_jit_comp.c | 22 +++-------------------
1 file changed, 3 insertions(+), 19 deletions(-)
diff --git a/arch/riscv/net/bpf_jit_comp.c b/arch/riscv/net/bpf_jit_comp.c
index e599458a9bcd..c38c95df3440 100644
--- a/arch/riscv/net/bpf_jit_comp.c
+++ b/arch/riscv/net/bpf_jit_comp.c
@@ -496,16 +496,6 @@ static int is_12b_check(int off, int insn)
return 0;
}
-static int is_13b_check(int off, int insn)
-{
- if (!is_13b_int(off)) {
- pr_err("bpf-jit: insn=%d 13b < offset=%d not supported yet!\n",
- insn, (int)off);
- return -1;
- }
- return 0;
-}
-
static int is_21b_check(int off, int insn)
{
if (!is_21b_int(off)) {
@@ -744,18 +734,14 @@ static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx)
return -1;
emit(rv_lwu(RV_REG_T1, off, RV_REG_A1), ctx);
off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2;
- if (is_13b_check(off, insn))
- return -1;
- emit(rv_bgeu(RV_REG_A2, RV_REG_T1, off >> 1), ctx);
+ 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;
- if (is_13b_check(off, insn))
- return -1;
- emit(rv_blt(RV_REG_T1, RV_REG_ZERO, off >> 1), ctx);
+ emit_branch(BPF_JSLT, RV_REG_T1, RV_REG_ZERO, off, ctx);
/* prog = array->ptrs[index];
* if (!prog)
@@ -768,9 +754,7 @@ static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx)
return -1;
emit(rv_ld(RV_REG_T2, off, RV_REG_T2), ctx);
off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2;
- if (is_13b_check(off, insn))
- return -1;
- emit(rv_beq(RV_REG_T2, RV_REG_ZERO, off >> 1), ctx);
+ emit_branch(BPF_JEQ, RV_REG_T2, RV_REG_ZERO, off, ctx);
/* goto *(prog->bpf_func + 4); */
off = offsetof(struct bpf_prog, bpf_func);
Reviewed-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
Acked-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
