diff options
| -rw-r--r-- | arch/riscv/net/bpf_jit_comp64.c | 49 |
1 files changed, 32 insertions, 17 deletions
diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c index cc1985d8750a..d208a9fd6c52 100644 --- a/arch/riscv/net/bpf_jit_comp64.c +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -110,6 +110,16 @@ static bool is_32b_int(s64 val) return -(1L << 31) <= val && val < (1L << 31); } +static bool in_auipc_jalr_range(s64 val) +{ + /* + * auipc+jalr can reach any signed PC-relative offset in the range + * [-2^31 - 2^11, 2^31 - 2^11). + */ + return (-(1L << 31) - (1L << 11)) <= val && + val < ((1L << 31) - (1L << 11)); +} + static void emit_imm(u8 rd, s64 val, struct rv_jit_context *ctx) { /* Note that the immediate from the add is sign-extended, @@ -380,20 +390,24 @@ static void emit_sext_32_rd(u8 *rd, struct rv_jit_context *ctx) *rd = RV_REG_T2; } -static void emit_jump_and_link(u8 rd, s64 rvoff, bool force_jalr, - struct rv_jit_context *ctx) +static int emit_jump_and_link(u8 rd, s64 rvoff, bool force_jalr, + struct rv_jit_context *ctx) { s64 upper, lower; if (rvoff && is_21b_int(rvoff) && !force_jalr) { emit(rv_jal(rd, rvoff >> 1), ctx); - return; + return 0; + } else if (in_auipc_jalr_range(rvoff)) { + upper = (rvoff + (1 << 11)) >> 12; + lower = rvoff & 0xfff; + emit(rv_auipc(RV_REG_T1, upper), ctx); + emit(rv_jalr(rd, RV_REG_T1, lower), ctx); + return 0; } - upper = (rvoff + (1 << 11)) >> 12; - lower = rvoff & 0xfff; - emit(rv_auipc(RV_REG_T1, upper), ctx); - emit(rv_jalr(rd, RV_REG_T1, lower), ctx); + pr_err("bpf-jit: target offset 0x%llx is out of range\n", rvoff); + return -ERANGE; } static bool is_signed_bpf_cond(u8 cond) @@ -407,18 +421,16 @@ static int emit_call(bool fixed, u64 addr, struct rv_jit_context *ctx) s64 off = 0; u64 ip; u8 rd; + int ret; if (addr && ctx->insns) { ip = (u64)(long)(ctx->insns + ctx->ninsns); off = addr - ip; - if (!is_32b_int(off)) { - pr_err("bpf-jit: target call addr %pK is out of range\n", - (void *)addr); - return -ERANGE; - } } - emit_jump_and_link(RV_REG_RA, off, !fixed, ctx); + ret = emit_jump_and_link(RV_REG_RA, off, !fixed, ctx); + if (ret) + return ret; rd = bpf_to_rv_reg(BPF_REG_0, ctx); emit(rv_addi(rd, RV_REG_A0, 0), ctx); return 0; @@ -429,7 +441,7 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, { bool is64 = BPF_CLASS(insn->code) == BPF_ALU64 || BPF_CLASS(insn->code) == BPF_JMP; - int s, e, rvoff, i = insn - ctx->prog->insnsi; + int s, e, rvoff, ret, i = insn - ctx->prog->insnsi; struct bpf_prog_aux *aux = ctx->prog->aux; u8 rd = -1, rs = -1, code = insn->code; s16 off = insn->off; @@ -699,7 +711,9 @@ out_be: /* JUMP off */ case BPF_JMP | BPF_JA: rvoff = rv_offset(i, off, ctx); - emit_jump_and_link(RV_REG_ZERO, rvoff, false, ctx); + ret = emit_jump_and_link(RV_REG_ZERO, rvoff, false, ctx); + if (ret) + return ret; break; /* IF (dst COND src) JUMP off */ @@ -801,7 +815,6 @@ out_be: case BPF_JMP | BPF_CALL: { bool fixed; - int ret; u64 addr; mark_call(ctx); @@ -826,7 +839,9 @@ out_be: break; rvoff = epilogue_offset(ctx); - emit_jump_and_link(RV_REG_ZERO, rvoff, false, ctx); + ret = emit_jump_and_link(RV_REG_ZERO, rvoff, false, ctx); + if (ret) + return ret; break; /* dst = imm64 */ |