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| author | Björn Töpel <bjorn.topel@gmail.com> | 2019-12-16 10:13:37 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2019-12-19 16:03:30 +0100 |
| commit | 29d92edd9ee8b37bd8e9a0ba7fd549f874e0d069 (patch) | |
| tree | fe654fdcbe43e8f5ec7f7ca5825b66bcf4614b33 /arch/riscv | |
| parent | 7d1ef13fea2b66bb466592a7855b33181c85ec5f (diff) | |
| download | lwn-29d92edd9ee8b37bd8e9a0ba7fd549f874e0d069.tar.gz lwn-29d92edd9ee8b37bd8e9a0ba7fd549f874e0d069.zip | |
riscv, bpf: Add support for far branching when emitting tail call
Start use the emit_branch() function in the tail call emitter in order
to support far branching.
Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191216091343.23260-4-bjorn.topel@gmail.com
Diffstat (limited to 'arch/riscv')
| -rw-r--r-- | arch/riscv/net/bpf_jit_comp.c | 22 |
1 files 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); |