diff options
Diffstat (limited to 'arch/loongarch/net/bpf_jit.c')
| -rw-r--r-- | arch/loongarch/net/bpf_jit.c | 1173 |
1 files changed, 1173 insertions, 0 deletions
diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c new file mode 100644 index 000000000..4e86441e6 --- /dev/null +++ b/arch/loongarch/net/bpf_jit.c @@ -0,0 +1,1173 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * BPF JIT compiler for LoongArch + * + * Copyright (C) 2022 Loongson Technology Corporation Limited + */ +#include "bpf_jit.h" + +#define REG_TCC LOONGARCH_GPR_A6 +#define TCC_SAVED LOONGARCH_GPR_S5 + +#define SAVE_RA BIT(0) +#define SAVE_TCC BIT(1) + +static const int regmap[] = { + /* return value from in-kernel function, and exit value for eBPF program */ + [BPF_REG_0] = LOONGARCH_GPR_A5, + /* arguments from eBPF program to in-kernel function */ + [BPF_REG_1] = LOONGARCH_GPR_A0, + [BPF_REG_2] = LOONGARCH_GPR_A1, + [BPF_REG_3] = LOONGARCH_GPR_A2, + [BPF_REG_4] = LOONGARCH_GPR_A3, + [BPF_REG_5] = LOONGARCH_GPR_A4, + /* callee saved registers that in-kernel function will preserve */ + [BPF_REG_6] = LOONGARCH_GPR_S0, + [BPF_REG_7] = LOONGARCH_GPR_S1, + [BPF_REG_8] = LOONGARCH_GPR_S2, + [BPF_REG_9] = LOONGARCH_GPR_S3, + /* read-only frame pointer to access stack */ + [BPF_REG_FP] = LOONGARCH_GPR_S4, + /* temporary register for blinding constants */ + [BPF_REG_AX] = LOONGARCH_GPR_T0, +}; + +static void mark_call(struct jit_ctx *ctx) +{ + ctx->flags |= SAVE_RA; +} + +static void mark_tail_call(struct jit_ctx *ctx) +{ + ctx->flags |= SAVE_TCC; +} + +static bool seen_call(struct jit_ctx *ctx) +{ + return (ctx->flags & SAVE_RA); +} + +static bool seen_tail_call(struct jit_ctx *ctx) +{ + return (ctx->flags & SAVE_TCC); +} + +static u8 tail_call_reg(struct jit_ctx *ctx) +{ + if (seen_call(ctx)) + return TCC_SAVED; + + return REG_TCC; +} + +/* + * eBPF prog stack layout: + * + * high + * original $sp ------------> +-------------------------+ <--LOONGARCH_GPR_FP + * | $ra | + * +-------------------------+ + * | $fp | + * +-------------------------+ + * | $s0 | + * +-------------------------+ + * | $s1 | + * +-------------------------+ + * | $s2 | + * +-------------------------+ + * | $s3 | + * +-------------------------+ + * | $s4 | + * +-------------------------+ + * | $s5 | + * +-------------------------+ <--BPF_REG_FP + * | prog->aux->stack_depth | + * | (optional) | + * current $sp -------------> +-------------------------+ + * low + */ +static void build_prologue(struct jit_ctx *ctx) +{ + int stack_adjust = 0, store_offset, bpf_stack_adjust; + + bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 16); + + /* To store ra, fp, s0, s1, s2, s3, s4 and s5. */ + stack_adjust += sizeof(long) * 8; + + stack_adjust = round_up(stack_adjust, 16); + stack_adjust += bpf_stack_adjust; + + /* + * First instruction initializes the tail call count (TCC). + * On tail call we skip this instruction, and the TCC is + * passed in REG_TCC from the caller. + */ + emit_insn(ctx, addid, REG_TCC, LOONGARCH_GPR_ZERO, MAX_TAIL_CALL_CNT); + + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -stack_adjust); + + store_offset = stack_adjust - sizeof(long); + emit_insn(ctx, std, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, store_offset); + + store_offset -= sizeof(long); + emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, store_offset); + + store_offset -= sizeof(long); + emit_insn(ctx, std, LOONGARCH_GPR_S0, LOONGARCH_GPR_SP, store_offset); + + store_offset -= sizeof(long); + emit_insn(ctx, std, LOONGARCH_GPR_S1, LOONGARCH_GPR_SP, store_offset); + + store_offset -= sizeof(long); + emit_insn(ctx, std, LOONGARCH_GPR_S2, LOONGARCH_GPR_SP, store_offset); + + store_offset -= sizeof(long); + emit_insn(ctx, std, LOONGARCH_GPR_S3, LOONGARCH_GPR_SP, store_offset); + + store_offset -= sizeof(long); + emit_insn(ctx, std, LOONGARCH_GPR_S4, LOONGARCH_GPR_SP, store_offset); + + store_offset -= sizeof(long); + emit_insn(ctx, std, LOONGARCH_GPR_S5, LOONGARCH_GPR_SP, store_offset); + + emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_adjust); + + if (bpf_stack_adjust) + emit_insn(ctx, addid, regmap[BPF_REG_FP], LOONGARCH_GPR_SP, bpf_stack_adjust); + + /* + * Program contains calls and tail calls, so REG_TCC need + * to be saved across calls. + */ + if (seen_tail_call(ctx) && seen_call(ctx)) + move_reg(ctx, TCC_SAVED, REG_TCC); + + ctx->stack_size = stack_adjust; +} + +static void __build_epilogue(struct jit_ctx *ctx, bool is_tail_call) +{ + int stack_adjust = ctx->stack_size; + int load_offset; + + load_offset = stack_adjust - sizeof(long); + emit_insn(ctx, ldd, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, load_offset); + + load_offset -= sizeof(long); + emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, load_offset); + + load_offset -= sizeof(long); + emit_insn(ctx, ldd, LOONGARCH_GPR_S0, LOONGARCH_GPR_SP, load_offset); + + load_offset -= sizeof(long); + emit_insn(ctx, ldd, LOONGARCH_GPR_S1, LOONGARCH_GPR_SP, load_offset); + + load_offset -= sizeof(long); + emit_insn(ctx, ldd, LOONGARCH_GPR_S2, LOONGARCH_GPR_SP, load_offset); + + load_offset -= sizeof(long); + emit_insn(ctx, ldd, LOONGARCH_GPR_S3, LOONGARCH_GPR_SP, load_offset); + + load_offset -= sizeof(long); + emit_insn(ctx, ldd, LOONGARCH_GPR_S4, LOONGARCH_GPR_SP, load_offset); + + load_offset -= sizeof(long); + emit_insn(ctx, ldd, LOONGARCH_GPR_S5, LOONGARCH_GPR_SP, load_offset); + + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, stack_adjust); + + if (!is_tail_call) { + /* Set return value */ + move_reg(ctx, LOONGARCH_GPR_A0, regmap[BPF_REG_0]); + /* Return to the caller */ + emit_insn(ctx, jirl, LOONGARCH_GPR_RA, LOONGARCH_GPR_ZERO, 0); + } else { + /* + * Call the next bpf prog and skip the first instruction + * of TCC initialization. + */ + emit_insn(ctx, jirl, LOONGARCH_GPR_T3, LOONGARCH_GPR_ZERO, 1); + } +} + +static void build_epilogue(struct jit_ctx *ctx) +{ + __build_epilogue(ctx, false); +} + +bool bpf_jit_supports_kfunc_call(void) +{ + return true; +} + +/* initialized on the first pass of build_body() */ +static int out_offset = -1; +static int emit_bpf_tail_call(struct jit_ctx *ctx) +{ + int off; + u8 tcc = tail_call_reg(ctx); + u8 a1 = LOONGARCH_GPR_A1; + u8 a2 = LOONGARCH_GPR_A2; + u8 t1 = LOONGARCH_GPR_T1; + u8 t2 = LOONGARCH_GPR_T2; + u8 t3 = LOONGARCH_GPR_T3; + const int idx0 = ctx->idx; + +#define cur_offset (ctx->idx - idx0) +#define jmp_offset (out_offset - (cur_offset)) + + /* + * a0: &ctx + * a1: &array + * a2: index + * + * if (index >= array->map.max_entries) + * goto out; + */ + off = offsetof(struct bpf_array, map.max_entries); + emit_insn(ctx, ldwu, t1, a1, off); + /* bgeu $a2, $t1, jmp_offset */ + if (emit_tailcall_jmp(ctx, BPF_JGE, a2, t1, jmp_offset) < 0) + goto toofar; + + /* + * if (--TCC < 0) + * goto out; + */ + emit_insn(ctx, addid, REG_TCC, tcc, -1); + if (emit_tailcall_jmp(ctx, BPF_JSLT, REG_TCC, LOONGARCH_GPR_ZERO, jmp_offset) < 0) + goto toofar; + + /* + * prog = array->ptrs[index]; + * if (!prog) + * goto out; + */ + emit_insn(ctx, alsld, t2, a2, a1, 2); + off = offsetof(struct bpf_array, ptrs); + emit_insn(ctx, ldd, t2, t2, off); + /* beq $t2, $zero, jmp_offset */ + if (emit_tailcall_jmp(ctx, BPF_JEQ, t2, LOONGARCH_GPR_ZERO, jmp_offset) < 0) + goto toofar; + + /* goto *(prog->bpf_func + 4); */ + off = offsetof(struct bpf_prog, bpf_func); + emit_insn(ctx, ldd, t3, t2, off); + __build_epilogue(ctx, true); + + /* out: */ + if (out_offset == -1) + out_offset = cur_offset; + if (cur_offset != out_offset) { + pr_err_once("tail_call out_offset = %d, expected %d!\n", + cur_offset, out_offset); + return -1; + } + + return 0; + +toofar: + pr_info_once("tail_call: jump too far\n"); + return -1; +#undef cur_offset +#undef jmp_offset +} + +static void emit_atomic(const struct bpf_insn *insn, struct jit_ctx *ctx) +{ + const u8 t1 = LOONGARCH_GPR_T1; + const u8 t2 = LOONGARCH_GPR_T2; + const u8 t3 = LOONGARCH_GPR_T3; + const u8 r0 = regmap[BPF_REG_0]; + const u8 src = regmap[insn->src_reg]; + const u8 dst = regmap[insn->dst_reg]; + const s16 off = insn->off; + const s32 imm = insn->imm; + const bool isdw = BPF_SIZE(insn->code) == BPF_DW; + + move_imm(ctx, t1, off, false); + emit_insn(ctx, addd, t1, dst, t1); + move_reg(ctx, t3, src); + + switch (imm) { + /* lock *(size *)(dst + off) <op>= src */ + case BPF_ADD: + if (isdw) + emit_insn(ctx, amaddd, t2, t1, src); + else + emit_insn(ctx, amaddw, t2, t1, src); + break; + case BPF_AND: + if (isdw) + emit_insn(ctx, amandd, t2, t1, src); + else + emit_insn(ctx, amandw, t2, t1, src); + break; + case BPF_OR: + if (isdw) + emit_insn(ctx, amord, t2, t1, src); + else + emit_insn(ctx, amorw, t2, t1, src); + break; + case BPF_XOR: + if (isdw) + emit_insn(ctx, amxord, t2, t1, src); + else + emit_insn(ctx, amxorw, t2, t1, src); + break; + /* src = atomic_fetch_<op>(dst + off, src) */ + case BPF_ADD | BPF_FETCH: + if (isdw) { + emit_insn(ctx, amaddd, src, t1, t3); + } else { + emit_insn(ctx, amaddw, src, t1, t3); + emit_zext_32(ctx, src, true); + } + break; + case BPF_AND | BPF_FETCH: + if (isdw) { + emit_insn(ctx, amandd, src, t1, t3); + } else { + emit_insn(ctx, amandw, src, t1, t3); + emit_zext_32(ctx, src, true); + } + break; + case BPF_OR | BPF_FETCH: + if (isdw) { + emit_insn(ctx, amord, src, t1, t3); + } else { + emit_insn(ctx, amorw, src, t1, t3); + emit_zext_32(ctx, src, true); + } + break; + case BPF_XOR | BPF_FETCH: + if (isdw) { + emit_insn(ctx, amxord, src, t1, t3); + } else { + emit_insn(ctx, amxorw, src, t1, t3); + emit_zext_32(ctx, src, true); + } + break; + /* src = atomic_xchg(dst + off, src); */ + case BPF_XCHG: + if (isdw) { + emit_insn(ctx, amswapd, src, t1, t3); + } else { + emit_insn(ctx, amswapw, src, t1, t3); + emit_zext_32(ctx, src, true); + } + break; + /* r0 = atomic_cmpxchg(dst + off, r0, src); */ + case BPF_CMPXCHG: + move_reg(ctx, t2, r0); + if (isdw) { + emit_insn(ctx, lld, r0, t1, 0); + emit_insn(ctx, bne, t2, r0, 4); + move_reg(ctx, t3, src); + emit_insn(ctx, scd, t3, t1, 0); + emit_insn(ctx, beq, t3, LOONGARCH_GPR_ZERO, -4); + } else { + emit_insn(ctx, llw, r0, t1, 0); + emit_zext_32(ctx, t2, true); + emit_zext_32(ctx, r0, true); + emit_insn(ctx, bne, t2, r0, 4); + move_reg(ctx, t3, src); + emit_insn(ctx, scw, t3, t1, 0); + emit_insn(ctx, beq, t3, LOONGARCH_GPR_ZERO, -6); + emit_zext_32(ctx, r0, true); + } + break; + } +} + +static bool is_signed_bpf_cond(u8 cond) +{ + return cond == BPF_JSGT || cond == BPF_JSLT || + cond == BPF_JSGE || cond == BPF_JSLE; +} + +static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool extra_pass) +{ + u8 tm = -1; + u64 func_addr; + bool func_addr_fixed; + int i = insn - ctx->prog->insnsi; + int ret, jmp_offset; + const u8 code = insn->code; + const u8 cond = BPF_OP(code); + const u8 t1 = LOONGARCH_GPR_T1; + const u8 t2 = LOONGARCH_GPR_T2; + const u8 src = regmap[insn->src_reg]; + const u8 dst = regmap[insn->dst_reg]; + const s16 off = insn->off; + const s32 imm = insn->imm; + const bool is32 = BPF_CLASS(insn->code) == BPF_ALU || BPF_CLASS(insn->code) == BPF_JMP32; + + switch (code) { + /* dst = src */ + case BPF_ALU | BPF_MOV | BPF_X: + case BPF_ALU64 | BPF_MOV | BPF_X: + move_reg(ctx, dst, src); + emit_zext_32(ctx, dst, is32); + break; + + /* dst = imm */ + case BPF_ALU | BPF_MOV | BPF_K: + case BPF_ALU64 | BPF_MOV | BPF_K: + move_imm(ctx, dst, imm, is32); + break; + + /* dst = dst + src */ + case BPF_ALU | BPF_ADD | BPF_X: + case BPF_ALU64 | BPF_ADD | BPF_X: + emit_insn(ctx, addd, dst, dst, src); + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst + imm */ + case BPF_ALU | BPF_ADD | BPF_K: + case BPF_ALU64 | BPF_ADD | BPF_K: + if (is_signed_imm12(imm)) { + emit_insn(ctx, addid, dst, dst, imm); + } else { + move_imm(ctx, t1, imm, is32); + emit_insn(ctx, addd, dst, dst, t1); + } + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst - src */ + case BPF_ALU | BPF_SUB | BPF_X: + case BPF_ALU64 | BPF_SUB | BPF_X: + emit_insn(ctx, subd, dst, dst, src); + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst - imm */ + case BPF_ALU | BPF_SUB | BPF_K: + case BPF_ALU64 | BPF_SUB | BPF_K: + if (is_signed_imm12(-imm)) { + emit_insn(ctx, addid, dst, dst, -imm); + } else { + move_imm(ctx, t1, imm, is32); + emit_insn(ctx, subd, dst, dst, t1); + } + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst * src */ + case BPF_ALU | BPF_MUL | BPF_X: + case BPF_ALU64 | BPF_MUL | BPF_X: + emit_insn(ctx, muld, dst, dst, src); + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst * imm */ + case BPF_ALU | BPF_MUL | BPF_K: + case BPF_ALU64 | BPF_MUL | BPF_K: + move_imm(ctx, t1, imm, is32); + emit_insn(ctx, muld, dst, dst, t1); + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst / src */ + case BPF_ALU | BPF_DIV | BPF_X: + case BPF_ALU64 | BPF_DIV | BPF_X: + emit_zext_32(ctx, dst, is32); + move_reg(ctx, t1, src); + emit_zext_32(ctx, t1, is32); + emit_insn(ctx, divdu, dst, dst, t1); + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst / imm */ + case BPF_ALU | BPF_DIV | BPF_K: + case BPF_ALU64 | BPF_DIV | BPF_K: + move_imm(ctx, t1, imm, is32); + emit_zext_32(ctx, dst, is32); + emit_insn(ctx, divdu, dst, dst, t1); + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst % src */ + case BPF_ALU | BPF_MOD | BPF_X: + case BPF_ALU64 | BPF_MOD | BPF_X: + emit_zext_32(ctx, dst, is32); + move_reg(ctx, t1, src); + emit_zext_32(ctx, t1, is32); + emit_insn(ctx, moddu, dst, dst, t1); + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst % imm */ + case BPF_ALU | BPF_MOD | BPF_K: + case BPF_ALU64 | BPF_MOD | BPF_K: + move_imm(ctx, t1, imm, is32); + emit_zext_32(ctx, dst, is32); + emit_insn(ctx, moddu, dst, dst, t1); + emit_zext_32(ctx, dst, is32); + break; + + /* dst = -dst */ + case BPF_ALU | BPF_NEG: + case BPF_ALU64 | BPF_NEG: + move_imm(ctx, t1, imm, is32); + emit_insn(ctx, subd, dst, LOONGARCH_GPR_ZERO, dst); + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst & src */ + case BPF_ALU | BPF_AND | BPF_X: + case BPF_ALU64 | BPF_AND | BPF_X: + emit_insn(ctx, and, dst, dst, src); + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst & imm */ + case BPF_ALU | BPF_AND | BPF_K: + case BPF_ALU64 | BPF_AND | BPF_K: + if (is_unsigned_imm12(imm)) { + emit_insn(ctx, andi, dst, dst, imm); + } else { + move_imm(ctx, t1, imm, is32); + emit_insn(ctx, and, dst, dst, t1); + } + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst | src */ + case BPF_ALU | BPF_OR | BPF_X: + case BPF_ALU64 | BPF_OR | BPF_X: + emit_insn(ctx, or, dst, dst, src); + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst | imm */ + case BPF_ALU | BPF_OR | BPF_K: + case BPF_ALU64 | BPF_OR | BPF_K: + if (is_unsigned_imm12(imm)) { + emit_insn(ctx, ori, dst, dst, imm); + } else { + move_imm(ctx, t1, imm, is32); + emit_insn(ctx, or, dst, dst, t1); + } + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst ^ src */ + case BPF_ALU | BPF_XOR | BPF_X: + case BPF_ALU64 | BPF_XOR | BPF_X: + emit_insn(ctx, xor, dst, dst, src); + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst ^ imm */ + case BPF_ALU | BPF_XOR | BPF_K: + case BPF_ALU64 | BPF_XOR | BPF_K: + if (is_unsigned_imm12(imm)) { + emit_insn(ctx, xori, dst, dst, imm); + } else { + move_imm(ctx, t1, imm, is32); + emit_insn(ctx, xor, dst, dst, t1); + } + emit_zext_32(ctx, dst, is32); + break; + + /* dst = dst << src (logical) */ + case BPF_ALU | BPF_LSH | BPF_X: + emit_insn(ctx, sllw, dst, dst, src); + emit_zext_32(ctx, dst, is32); + break; + + case BPF_ALU64 | BPF_LSH | BPF_X: + emit_insn(ctx, slld, dst, dst, src); + break; + + /* dst = dst << imm (logical) */ + case BPF_ALU | BPF_LSH | BPF_K: + emit_insn(ctx, slliw, dst, dst, imm); + emit_zext_32(ctx, dst, is32); + break; + + case BPF_ALU64 | BPF_LSH | BPF_K: + emit_insn(ctx, sllid, dst, dst, imm); + break; + + /* dst = dst >> src (logical) */ + case BPF_ALU | BPF_RSH | BPF_X: + emit_insn(ctx, srlw, dst, dst, src); + emit_zext_32(ctx, dst, is32); + break; + + case BPF_ALU64 | BPF_RSH | BPF_X: + emit_insn(ctx, srld, dst, dst, src); + break; + + /* dst = dst >> imm (logical) */ + case BPF_ALU | BPF_RSH | BPF_K: + emit_insn(ctx, srliw, dst, dst, imm); + emit_zext_32(ctx, dst, is32); + break; + + case BPF_ALU64 | BPF_RSH | BPF_K: + emit_insn(ctx, srlid, dst, dst, imm); + break; + + /* dst = dst >> src (arithmetic) */ + case BPF_ALU | BPF_ARSH | BPF_X: + emit_insn(ctx, sraw, dst, dst, src); + emit_zext_32(ctx, dst, is32); + break; + + case BPF_ALU64 | BPF_ARSH | BPF_X: + emit_insn(ctx, srad, dst, dst, src); + break; + + /* dst = dst >> imm (arithmetic) */ + case BPF_ALU | BPF_ARSH | BPF_K: + emit_insn(ctx, sraiw, dst, dst, imm); + emit_zext_32(ctx, dst, is32); + break; + + case BPF_ALU64 | BPF_ARSH | BPF_K: + emit_insn(ctx, sraid, dst, dst, imm); + break; + + /* dst = BSWAP##imm(dst) */ + case BPF_ALU | BPF_END | BPF_FROM_LE: + switch (imm) { + case 16: + /* zero-extend 16 bits into 64 bits */ + emit_insn(ctx, bstrpickd, dst, dst, 15, 0); + break; + case 32: + /* zero-extend 32 bits into 64 bits */ + emit_zext_32(ctx, dst, is32); + break; + case 64: + /* do nothing */ + break; + } + break; + + case BPF_ALU | BPF_END | BPF_FROM_BE: + switch (imm) { + case 16: + emit_insn(ctx, revb2h, dst, dst); + /* zero-extend 16 bits into 64 bits */ + emit_insn(ctx, bstrpickd, dst, dst, 15, 0); + break; + case 32: + emit_insn(ctx, revb2w, dst, dst); + /* zero-extend 32 bits into 64 bits */ + emit_zext_32(ctx, dst, is32); + break; + case 64: + emit_insn(ctx, revbd, dst, dst); + break; + } + break; + + /* PC += off if dst cond src */ + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP | BPF_JNE | BPF_X: + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JLT | BPF_X: + case BPF_JMP | BPF_JLE | BPF_X: + case BPF_JMP | BPF_JSGT | BPF_X: + case BPF_JMP | BPF_JSGE | BPF_X: + case BPF_JMP | BPF_JSLT | BPF_X: + case BPF_JMP | BPF_JSLE | BPF_X: + case BPF_JMP32 | BPF_JEQ | BPF_X: + case BPF_JMP32 | BPF_JNE | BPF_X: + case BPF_JMP32 | BPF_JGT | BPF_X: + case BPF_JMP32 | BPF_JGE | BPF_X: + case BPF_JMP32 | BPF_JLT | BPF_X: + case BPF_JMP32 | BPF_JLE | BPF_X: + case BPF_JMP32 | BPF_JSGT | BPF_X: + case BPF_JMP32 | BPF_JSGE | BPF_X: + case BPF_JMP32 | BPF_JSLT | BPF_X: + case BPF_JMP32 | BPF_JSLE | BPF_X: + jmp_offset = bpf2la_offset(i, off, ctx); + move_reg(ctx, t1, dst); + move_reg(ctx, t2, src); + if (is_signed_bpf_cond(BPF_OP(code))) { + emit_sext_32(ctx, t1, is32); + emit_sext_32(ctx, t2, is32); + } else { + emit_zext_32(ctx, t1, is32); + emit_zext_32(ctx, t2, is32); + } + if (emit_cond_jmp(ctx, cond, t1, t2, jmp_offset) < 0) + goto toofar; + break; + + /* PC += off if dst cond imm */ + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JNE | BPF_K: + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JLT | BPF_K: + case BPF_JMP | BPF_JLE | BPF_K: + case BPF_JMP | BPF_JSGT | BPF_K: + case BPF_JMP | BPF_JSGE | BPF_K: + case BPF_JMP | BPF_JSLT | BPF_K: + case BPF_JMP | BPF_JSLE | BPF_K: + case BPF_JMP32 | BPF_JEQ | BPF_K: + case BPF_JMP32 | BPF_JNE | BPF_K: + case BPF_JMP32 | BPF_JGT | BPF_K: + case BPF_JMP32 | BPF_JGE | BPF_K: + case BPF_JMP32 | BPF_JLT | BPF_K: + case BPF_JMP32 | BPF_JLE | BPF_K: + case BPF_JMP32 | BPF_JSGT | BPF_K: + case BPF_JMP32 | BPF_JSGE | BPF_K: + case BPF_JMP32 | BPF_JSLT | BPF_K: + case BPF_JMP32 | BPF_JSLE | BPF_K: + jmp_offset = bpf2la_offset(i, off, ctx); + if (imm) { + move_imm(ctx, t1, imm, false); + tm = t1; + } else { + /* If imm is 0, simply use zero register. */ + tm = LOONGARCH_GPR_ZERO; + } + move_reg(ctx, t2, dst); + if (is_signed_bpf_cond(BPF_OP(code))) { + emit_sext_32(ctx, tm, is32); + emit_sext_32(ctx, t2, is32); + } else { + emit_zext_32(ctx, tm, is32); + emit_zext_32(ctx, t2, is32); + } + if (emit_cond_jmp(ctx, cond, t2, tm, jmp_offset) < 0) + goto toofar; + break; + + /* PC += off if dst & src */ + case BPF_JMP | BPF_JSET | BPF_X: + case BPF_JMP32 | BPF_JSET | BPF_X: + jmp_offset = bpf2la_offset(i, off, ctx); + emit_insn(ctx, and, t1, dst, src); + emit_zext_32(ctx, t1, is32); + if (emit_cond_jmp(ctx, cond, t1, LOONGARCH_GPR_ZERO, jmp_offset) < 0) + goto toofar; + break; + + /* PC += off if dst & imm */ + case BPF_JMP | BPF_JSET | BPF_K: + case BPF_JMP32 | BPF_JSET | BPF_K: + jmp_offset = bpf2la_offset(i, off, ctx); + move_imm(ctx, t1, imm, is32); + emit_insn(ctx, and, t1, dst, t1); + emit_zext_32(ctx, t1, is32); + if (emit_cond_jmp(ctx, cond, t1, LOONGARCH_GPR_ZERO, jmp_offset) < 0) + goto toofar; + break; + + /* PC += off */ + case BPF_JMP | BPF_JA: + jmp_offset = bpf2la_offset(i, off, ctx); + if (emit_uncond_jmp(ctx, jmp_offset) < 0) + goto toofar; + break; + + /* function call */ + case BPF_JMP | BPF_CALL: + mark_call(ctx); + ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass, + &func_addr, &func_addr_fixed); + if (ret < 0) + return ret; + + move_addr(ctx, t1, func_addr); + emit_insn(ctx, jirl, t1, LOONGARCH_GPR_RA, 0); + move_reg(ctx, regmap[BPF_REG_0], LOONGARCH_GPR_A0); + break; + + /* tail call */ + case BPF_JMP | BPF_TAIL_CALL: + mark_tail_call(ctx); + if (emit_bpf_tail_call(ctx) < 0) + return -EINVAL; + break; + + /* function return */ + case BPF_JMP | BPF_EXIT: + if (i == ctx->prog->len - 1) + break; + + jmp_offset = epilogue_offset(ctx); + if (emit_uncond_jmp(ctx, jmp_offset) < 0) + goto toofar; + break; + + /* dst = imm64 */ + case BPF_LD | BPF_IMM | BPF_DW: + { + const u64 imm64 = (u64)(insn + 1)->imm << 32 | (u32)insn->imm; + + move_imm(ctx, dst, imm64, is32); + return 1; + } + + /* dst = *(size *)(src + off) */ + case BPF_LDX | BPF_MEM | BPF_B: + case BPF_LDX | BPF_MEM | BPF_H: + case BPF_LDX | BPF_MEM | BPF_W: + case BPF_LDX | BPF_MEM | BPF_DW: + switch (BPF_SIZE(code)) { + case BPF_B: + if (is_signed_imm12(off)) { + emit_insn(ctx, ldbu, dst, src, off); + } else { + move_imm(ctx, t1, off, is32); + emit_insn(ctx, ldxbu, dst, src, t1); + } + break; + case BPF_H: + if (is_signed_imm12(off)) { + emit_insn(ctx, ldhu, dst, src, off); + } else { + move_imm(ctx, t1, off, is32); + emit_insn(ctx, ldxhu, dst, src, t1); + } + break; + case BPF_W: + if (is_signed_imm12(off)) { + emit_insn(ctx, ldwu, dst, src, off); + } else if (is_signed_imm14(off)) { + emit_insn(ctx, ldptrw, dst, src, off); + } else { + move_imm(ctx, t1, off, is32); + emit_insn(ctx, ldxwu, dst, src, t1); + } + break; + case BPF_DW: + move_imm(ctx, t1, off, is32); + emit_insn(ctx, ldxd, dst, src, t1); + break; + } + break; + + /* *(size *)(dst + off) = imm */ + case BPF_ST | BPF_MEM | BPF_B: + case BPF_ST | BPF_MEM | BPF_H: + case BPF_ST | BPF_MEM | BPF_W: + case BPF_ST | BPF_MEM | BPF_DW: + switch (BPF_SIZE(code)) { + case BPF_B: + move_imm(ctx, t1, imm, is32); + if (is_signed_imm12(off)) { + emit_insn(ctx, stb, t1, dst, off); + } else { + move_imm(ctx, t2, off, is32); + emit_insn(ctx, stxb, t1, dst, t2); + } + break; + case BPF_H: + move_imm(ctx, t1, imm, is32); + if (is_signed_imm12(off)) { + emit_insn(ctx, sth, t1, dst, off); + } else { + move_imm(ctx, t2, off, is32); + emit_insn(ctx, stxh, t1, dst, t2); + } + break; + case BPF_W: + move_imm(ctx, t1, imm, is32); + if (is_signed_imm12(off)) { + emit_insn(ctx, stw, t1, dst, off); + } else if (is_signed_imm14(off)) { + emit_insn(ctx, stptrw, t1, dst, off); + } else { + move_imm(ctx, t2, off, is32); + emit_insn(ctx, stxw, t1, dst, t2); + } + break; + case BPF_DW: + move_imm(ctx, t1, imm, is32); + if (is_signed_imm12(off)) { + emit_insn(ctx, std, t1, dst, off); + } else if (is_signed_imm14(off)) { + emit_insn(ctx, stptrd, t1, dst, off); + } else { + move_imm(ctx, t2, off, is32); + emit_insn(ctx, stxd, t1, dst, t2); + } + break; + } + break; + + /* *(size *)(dst + off) = src */ + case BPF_STX | BPF_MEM | BPF_B: + case BPF_STX | BPF_MEM | BPF_H: + case BPF_STX | BPF_MEM | BPF_W: + case BPF_STX | BPF_MEM | BPF_DW: + switch (BPF_SIZE(code)) { + case BPF_B: + if (is_signed_imm12(off)) { + emit_insn(ctx, stb, src, dst, off); + } else { + move_imm(ctx, t1, off, is32); + emit_insn(ctx, stxb, src, dst, t1); + } + break; + case BPF_H: + if (is_signed_imm12(off)) { + emit_insn(ctx, sth, src, dst, off); + } else { + move_imm(ctx, t1, off, is32); + emit_insn(ctx, stxh, src, dst, t1); + } + break; + case BPF_W: + if (is_signed_imm12(off)) { + emit_insn(ctx, stw, src, dst, off); + } else if (is_signed_imm14(off)) { + emit_insn(ctx, stptrw, src, dst, off); + } else { + move_imm(ctx, t1, off, is32); + emit_insn(ctx, stxw, src, dst, t1); + } + break; + case BPF_DW: + if (is_signed_imm12(off)) { + emit_insn(ctx, std, src, dst, off); + } else if (is_signed_imm14(off)) { + emit_insn(ctx, stptrd, src, dst, off); + } else { + move_imm(ctx, t1, off, is32); + emit_insn(ctx, stxd, src, dst, t1); + } + break; + } + break; + + case BPF_STX | BPF_ATOMIC | BPF_W: + case BPF_STX | BPF_ATOMIC | BPF_DW: + emit_atomic(insn, ctx); + break; + + /* Speculation barrier */ + case BPF_ST | BPF_NOSPEC: + break; + + default: + pr_err("bpf_jit: unknown opcode %02x\n", code); + return -EINVAL; + } + + return 0; + +toofar: + pr_info_once("bpf_jit: opcode %02x, jump too far\n", code); + return -E2BIG; +} + +static int build_body(struct jit_ctx *ctx, bool extra_pass) +{ + int i; + const struct bpf_prog *prog = ctx->prog; + + for (i = 0; i < prog->len; i++) { + const struct bpf_insn *insn = &prog->insnsi[i]; + int ret; + + if (ctx->image == NULL) + ctx->offset[i] = ctx->idx; + + ret = build_insn(insn, ctx, extra_pass); + if (ret > 0) { + i++; + if (ctx->image == NULL) + ctx->offset[i] = ctx->idx; + continue; + } + if (ret) + return ret; + } + + if (ctx->image == NULL) + ctx->offset[i] = ctx->idx; + + return 0; +} + +/* Fill space with break instructions */ +static void jit_fill_hole(void *area, unsigned int size) +{ + u32 *ptr; + + /* We are guaranteed to have aligned memory */ + for (ptr = area; size >= sizeof(u32); size -= sizeof(u32)) + *ptr++ = INSN_BREAK; +} + +static int validate_code(struct jit_ctx *ctx) +{ + int i; + union loongarch_instruction insn; + + for (i = 0; i < ctx->idx; i++) { + insn = ctx->image[i]; + /* Check INSN_BREAK */ + if (insn.word == INSN_BREAK) + return -1; + } + + return 0; +} + +struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) +{ + bool tmp_blinded = false, extra_pass = false; + u8 *image_ptr; + int image_size; + struct jit_ctx ctx; + struct jit_data *jit_data; + struct bpf_binary_header *header; + struct bpf_prog *tmp, *orig_prog = prog; + + /* + * If BPF JIT was not enabled then we must fall back to + * the interpreter. + */ + if (!prog->jit_requested) + return orig_prog; + + tmp = bpf_jit_blind_constants(prog); + /* + * If blinding was requested and we failed during blinding, + * we must fall back to the interpreter. Otherwise, we save + * the new JITed code. + */ + if (IS_ERR(tmp)) + return orig_prog; + + if (tmp != prog) { + tmp_blinded = true; + prog = tmp; + } + + jit_data = prog->aux->jit_data; + if (!jit_data) { + jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); + if (!jit_data) { + prog = orig_prog; + goto out; + } + prog->aux->jit_data = jit_data; + } + if (jit_data->ctx.offset) { + ctx = jit_data->ctx; + image_ptr = jit_data->image; + header = jit_data->header; + extra_pass = true; + image_size = sizeof(u32) * ctx.idx; + goto skip_init_ctx; + } + + memset(&ctx, 0, sizeof(ctx)); + ctx.prog = prog; + + ctx.offset = kvcalloc(prog->len + 1, sizeof(u32), GFP_KERNEL); + if (ctx.offset == NULL) { + prog = orig_prog; + goto out_offset; + } + + /* 1. Initial fake pass to compute ctx->idx and set ctx->flags */ + build_prologue(&ctx); + if (build_body(&ctx, extra_pass)) { + prog = orig_prog; + goto out_offset; + } + ctx.epilogue_offset = ctx.idx; + build_epilogue(&ctx); + + /* Now we know the actual image size. + * As each LoongArch instruction is of length 32bit, + * we are translating number of JITed intructions into + * the size required to store these JITed code. + */ + image_size = sizeof(u32) * ctx.idx; + /* Now we know the size of the structure to make */ + header = bpf_jit_binary_alloc(image_size, &image_ptr, + sizeof(u32), jit_fill_hole); + if (header == NULL) { + prog = orig_prog; + goto out_offset; + } + + /* 2. Now, the actual pass to generate final JIT code */ + ctx.image = (union loongarch_instruction *)image_ptr; + +skip_init_ctx: + ctx.idx = 0; + + build_prologue(&ctx); + if (build_body(&ctx, extra_pass)) { + bpf_jit_binary_free(header); + prog = orig_prog; + goto out_offset; + } + build_epilogue(&ctx); + + /* 3. Extra pass to validate JITed code */ + if (validate_code(&ctx)) { + bpf_jit_binary_free(header); + prog = orig_prog; + goto out_offset; + } + + /* And we're done */ + if (bpf_jit_enable > 1) + bpf_jit_dump(prog->len, image_size, 2, ctx.image); + + /* Update the icache */ + flush_icache_range((unsigned long)header, (unsigned long)(ctx.image + ctx.idx)); + + if (!prog->is_func || extra_pass) { + if (extra_pass && ctx.idx != jit_data->ctx.idx) { + pr_err_once("multi-func JIT bug %d != %d\n", + ctx.idx, jit_data->ctx.idx); + bpf_jit_binary_free(header); + prog->bpf_func = NULL; + prog->jited = 0; + prog->jited_len = 0; + goto out_offset; + } + bpf_jit_binary_lock_ro(header); + } else { + jit_data->ctx = ctx; + jit_data->image = image_ptr; + jit_data->header = header; + } + prog->jited = 1; + prog->jited_len = image_size; + prog->bpf_func = (void *)ctx.image; + + if (!prog->is_func || extra_pass) { + int i; + + /* offset[prog->len] is the size of program */ + for (i = 0; i <= prog->len; i++) + ctx.offset[i] *= LOONGARCH_INSN_SIZE; + bpf_prog_fill_jited_linfo(prog, ctx.offset + 1); + +out_offset: + kvfree(ctx.offset); + kfree(jit_data); + prog->aux->jit_data = NULL; + } + +out: + if (tmp_blinded) + bpf_jit_prog_release_other(prog, prog == orig_prog ? tmp : orig_prog); + + out_offset = -1; + + return prog; +} |