microsoft
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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/arch/riscv/net/bpf_jit_comp64.c

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28 KiB
C
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// SPDX-License-Identifier: GPL-2.0
/* BPF JIT compiler for RV64G
*
* Copyright(c) 2019 Björn Töpel <bjorn.topel@gmail.com>
*
*/
#include <linux/bpf.h>
#include <linux/filter.h>
#include "bpf_jit.h"
#define RV_REG_TCC RV_REG_A6
#define RV_REG_TCC_SAVED RV_REG_S6 /* Store A6 in S6 if program do calls */
static const int regmap[] = {
[BPF_REG_0] = RV_REG_A5,
[BPF_REG_1] = RV_REG_A0,
[BPF_REG_2] = RV_REG_A1,
[BPF_REG_3] = RV_REG_A2,
[BPF_REG_4] = RV_REG_A3,
[BPF_REG_5] = RV_REG_A4,
[BPF_REG_6] = RV_REG_S1,
[BPF_REG_7] = RV_REG_S2,
[BPF_REG_8] = RV_REG_S3,
[BPF_REG_9] = RV_REG_S4,
[BPF_REG_FP] = RV_REG_S5,
[BPF_REG_AX] = RV_REG_T0,
};
enum {
RV_CTX_F_SEEN_TAIL_CALL = 0,
RV_CTX_F_SEEN_CALL = RV_REG_RA,
RV_CTX_F_SEEN_S1 = RV_REG_S1,
RV_CTX_F_SEEN_S2 = RV_REG_S2,
RV_CTX_F_SEEN_S3 = RV_REG_S3,
RV_CTX_F_SEEN_S4 = RV_REG_S4,
RV_CTX_F_SEEN_S5 = RV_REG_S5,
RV_CTX_F_SEEN_S6 = RV_REG_S6,
};
static u8 bpf_to_rv_reg(int bpf_reg, struct rv_jit_context *ctx)
{
u8 reg = regmap[bpf_reg];
switch (reg) {
case RV_CTX_F_SEEN_S1:
case RV_CTX_F_SEEN_S2:
case RV_CTX_F_SEEN_S3:
case RV_CTX_F_SEEN_S4:
case RV_CTX_F_SEEN_S5:
case RV_CTX_F_SEEN_S6:
__set_bit(reg, &ctx->flags);
}
return reg;
};
static bool seen_reg(int reg, struct rv_jit_context *ctx)
{
switch (reg) {
case RV_CTX_F_SEEN_CALL:
case RV_CTX_F_SEEN_S1:
case RV_CTX_F_SEEN_S2:
case RV_CTX_F_SEEN_S3:
case RV_CTX_F_SEEN_S4:
case RV_CTX_F_SEEN_S5:
case RV_CTX_F_SEEN_S6:
return test_bit(reg, &ctx->flags);
}
return false;
}
static void mark_fp(struct rv_jit_context *ctx)
{
__set_bit(RV_CTX_F_SEEN_S5, &ctx->flags);
}
static void mark_call(struct rv_jit_context *ctx)
{
__set_bit(RV_CTX_F_SEEN_CALL, &ctx->flags);
}
static bool seen_call(struct rv_jit_context *ctx)
{
return test_bit(RV_CTX_F_SEEN_CALL, &ctx->flags);
}
static void mark_tail_call(struct rv_jit_context *ctx)
{
__set_bit(RV_CTX_F_SEEN_TAIL_CALL, &ctx->flags);
}
static bool seen_tail_call(struct rv_jit_context *ctx)
{
return test_bit(RV_CTX_F_SEEN_TAIL_CALL, &ctx->flags);
}
static u8 rv_tail_call_reg(struct rv_jit_context *ctx)
{
mark_tail_call(ctx);
if (seen_call(ctx)) {
__set_bit(RV_CTX_F_SEEN_S6, &ctx->flags);
return RV_REG_S6;
}
return RV_REG_A6;
}
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,
* which means that we need to compensate this by adding 2^12,
* when the 12th bit is set. A simpler way of doing this, and
* getting rid of the check, is to just add 2**11 before the
* shift. The "Loading a 32-Bit constant" example from the
* "Computer Organization and Design, RISC-V edition" book by
* Patterson/Hennessy highlights this fact.
*
* This also means that we need to process LSB to MSB.
*/
s64 upper = (val + (1 << 11)) >> 12, lower = val & 0xfff;
int shift;
if (is_32b_int(val)) {
if (upper)
emit(rv_lui(rd, upper), ctx);
if (!upper) {
emit(rv_addi(rd, RV_REG_ZERO, lower), ctx);
return;
}
emit(rv_addiw(rd, rd, lower), ctx);
return;
}
shift = __ffs(upper);
upper >>= shift;
shift += 12;
emit_imm(rd, upper, ctx);
emit(rv_slli(rd, rd, shift), ctx);
if (lower)
emit(rv_addi(rd, rd, lower), ctx);
}
static void __build_epilogue(bool is_tail_call, struct rv_jit_context *ctx)
{
int stack_adjust = ctx->stack_size, store_offset = stack_adjust - 8;
if (seen_reg(RV_REG_RA, ctx)) {
emit(rv_ld(RV_REG_RA, store_offset, RV_REG_SP), ctx);
store_offset -= 8;
}
emit(rv_ld(RV_REG_FP, store_offset, RV_REG_SP), ctx);
store_offset -= 8;
if (seen_reg(RV_REG_S1, ctx)) {
emit(rv_ld(RV_REG_S1, store_offset, RV_REG_SP), ctx);
store_offset -= 8;
}
if (seen_reg(RV_REG_S2, ctx)) {
emit(rv_ld(RV_REG_S2, store_offset, RV_REG_SP), ctx);
store_offset -= 8;
}
if (seen_reg(RV_REG_S3, ctx)) {
emit(rv_ld(RV_REG_S3, store_offset, RV_REG_SP), ctx);
store_offset -= 8;
}
if (seen_reg(RV_REG_S4, ctx)) {
emit(rv_ld(RV_REG_S4, store_offset, RV_REG_SP), ctx);
store_offset -= 8;
}
if (seen_reg(RV_REG_S5, ctx)) {
emit(rv_ld(RV_REG_S5, store_offset, RV_REG_SP), ctx);
store_offset -= 8;
}
if (seen_reg(RV_REG_S6, ctx)) {
emit(rv_ld(RV_REG_S6, store_offset, RV_REG_SP), ctx);
store_offset -= 8;
}
emit(rv_addi(RV_REG_SP, RV_REG_SP, stack_adjust), ctx);
/* Set return value. */
if (!is_tail_call)
emit(rv_addi(RV_REG_A0, RV_REG_A5, 0), ctx);
emit(rv_jalr(RV_REG_ZERO, is_tail_call ? RV_REG_T3 : RV_REG_RA,
is_tail_call ? 4 : 0), /* skip TCC init */
ctx);
}
static void emit_bcc(u8 cond, u8 rd, u8 rs, int rvoff,
struct rv_jit_context *ctx)
{
switch (cond) {
case BPF_JEQ:
emit(rv_beq(rd, rs, rvoff >> 1), ctx);
return;
case BPF_JGT:
emit(rv_bltu(rs, rd, rvoff >> 1), ctx);
return;
case BPF_JLT:
emit(rv_bltu(rd, rs, rvoff >> 1), ctx);
return;
case BPF_JGE:
emit(rv_bgeu(rd, rs, rvoff >> 1), ctx);
return;
case BPF_JLE:
emit(rv_bgeu(rs, rd, rvoff >> 1), ctx);
return;
case BPF_JNE:
emit(rv_bne(rd, rs, rvoff >> 1), ctx);
return;
case BPF_JSGT:
emit(rv_blt(rs, rd, rvoff >> 1), ctx);
return;
case BPF_JSLT:
emit(rv_blt(rd, rs, rvoff >> 1), ctx);
return;
case BPF_JSGE:
emit(rv_bge(rd, rs, rvoff >> 1), ctx);
return;
case BPF_JSLE:
emit(rv_bge(rs, rd, rvoff >> 1), ctx);
}
}
static void emit_branch(u8 cond, u8 rd, u8 rs, int rvoff,
struct rv_jit_context *ctx)
{
s64 upper, lower;
if (is_13b_int(rvoff)) {
emit_bcc(cond, rd, rs, rvoff, ctx);
return;
}
/* Adjust for jal */
rvoff -= 4;
/* Transform, e.g.:
* bne rd,rs,foo
* to
* beq rd,rs,<.L1>
* (auipc foo)
* jal(r) foo
* .L1
*/
cond = invert_bpf_cond(cond);
if (is_21b_int(rvoff)) {
emit_bcc(cond, rd, rs, 8, ctx);
emit(rv_jal(RV_REG_ZERO, rvoff >> 1), ctx);
return;
}
/* 32b No need for an additional rvoff adjustment, since we
* get that from the auipc at PC', where PC = PC' + 4.
*/
upper = (rvoff + (1 << 11)) >> 12;
lower = rvoff & 0xfff;
emit_bcc(cond, rd, rs, 12, ctx);
emit(rv_auipc(RV_REG_T1, upper), ctx);
emit(rv_jalr(RV_REG_ZERO, RV_REG_T1, lower), ctx);
}
static void emit_zext_32(u8 reg, struct rv_jit_context *ctx)
{
emit(rv_slli(reg, reg, 32), ctx);
emit(rv_srli(reg, reg, 32), ctx);
}
static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx)
{
int tc_ninsn, off, start_insn = ctx->ninsns;
u8 tcc = rv_tail_call_reg(ctx);
/* a0: &ctx
* a1: &array
* a2: index
*
* if (index >= array->map.max_entries)
* goto out;
*/
tc_ninsn = insn ? ctx->offset[insn] - ctx->offset[insn - 1] :
ctx->offset[0];
emit_zext_32(RV_REG_A2, ctx);
off = offsetof(struct bpf_array, map.max_entries);
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;
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;
emit_branch(BPF_JSLT, tcc, RV_REG_ZERO, off, ctx);
/* prog = array->ptrs[index];
* if (!prog)
* goto out;
*/
emit(rv_slli(RV_REG_T2, RV_REG_A2, 3), ctx);
emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_A1), ctx);
off = offsetof(struct bpf_array, ptrs);
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;
emit_branch(BPF_JEQ, RV_REG_T2, RV_REG_ZERO, off, ctx);
/* goto *(prog->bpf_func + 4); */
off = offsetof(struct bpf_prog, bpf_func);
if (is_12b_check(off, insn))
return -1;
emit(rv_ld(RV_REG_T3, off, RV_REG_T2), ctx);
emit(rv_addi(RV_REG_TCC, RV_REG_T1, 0), ctx);
__build_epilogue(true, ctx);
return 0;
}
static void init_regs(u8 *rd, u8 *rs, const struct bpf_insn *insn,
struct rv_jit_context *ctx)
{
u8 code = insn->code;
switch (code) {
case BPF_JMP | BPF_JA:
case BPF_JMP | BPF_CALL:
case BPF_JMP | BPF_EXIT:
case BPF_JMP | BPF_TAIL_CALL:
break;
default:
*rd = bpf_to_rv_reg(insn->dst_reg, ctx);
}
if (code & (BPF_ALU | BPF_X) || code & (BPF_ALU64 | BPF_X) ||
code & (BPF_JMP | BPF_X) || code & (BPF_JMP32 | BPF_X) ||
code & BPF_LDX || code & BPF_STX)
*rs = bpf_to_rv_reg(insn->src_reg, ctx);
}
static void emit_zext_32_rd_rs(u8 *rd, u8 *rs, struct rv_jit_context *ctx)
{
emit(rv_addi(RV_REG_T2, *rd, 0), ctx);
emit_zext_32(RV_REG_T2, ctx);
emit(rv_addi(RV_REG_T1, *rs, 0), ctx);
emit_zext_32(RV_REG_T1, ctx);
*rd = RV_REG_T2;
*rs = RV_REG_T1;
}
static void emit_sext_32_rd_rs(u8 *rd, u8 *rs, struct rv_jit_context *ctx)
{
emit(rv_addiw(RV_REG_T2, *rd, 0), ctx);
emit(rv_addiw(RV_REG_T1, *rs, 0), ctx);
*rd = RV_REG_T2;
*rs = RV_REG_T1;
}
static void emit_zext_32_rd_t1(u8 *rd, struct rv_jit_context *ctx)
{
emit(rv_addi(RV_REG_T2, *rd, 0), ctx);
emit_zext_32(RV_REG_T2, ctx);
emit_zext_32(RV_REG_T1, ctx);
*rd = RV_REG_T2;
}
static void emit_sext_32_rd(u8 *rd, struct rv_jit_context *ctx)
{
emit(rv_addiw(RV_REG_T2, *rd, 0), ctx);
*rd = RV_REG_T2;
}
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 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;
}
pr_err("bpf-jit: target offset 0x%llx is out of range\n", rvoff);
return -ERANGE;
}
static bool is_signed_bpf_cond(u8 cond)
{
return cond == BPF_JSGT || cond == BPF_JSLT ||
cond == BPF_JSGE || cond == BPF_JSLE;
}
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;
}
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;
}
int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx,
bool extra_pass)
{
bool is64 = BPF_CLASS(insn->code) == BPF_ALU64 ||
BPF_CLASS(insn->code) == BPF_JMP;
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;
s32 imm = insn->imm;
init_regs(&rd, &rs, insn, ctx);
switch (code) {
/* dst = src */
case BPF_ALU | BPF_MOV | BPF_X:
case BPF_ALU64 | BPF_MOV | BPF_X:
if (imm == 1) {
/* Special mov32 for zext */
emit_zext_32(rd, ctx);
break;
}
emit(is64 ? rv_addi(rd, rs, 0) : rv_addiw(rd, rs, 0), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
/* dst = dst OP src */
case BPF_ALU | BPF_ADD | BPF_X:
case BPF_ALU64 | BPF_ADD | BPF_X:
emit(is64 ? rv_add(rd, rd, rs) : rv_addw(rd, rd, rs), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_SUB | BPF_X:
case BPF_ALU64 | BPF_SUB | BPF_X:
emit(is64 ? rv_sub(rd, rd, rs) : rv_subw(rd, rd, rs), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_AND | BPF_X:
case BPF_ALU64 | BPF_AND | BPF_X:
emit(rv_and(rd, rd, rs), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_OR | BPF_X:
case BPF_ALU64 | BPF_OR | BPF_X:
emit(rv_or(rd, rd, rs), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_XOR | BPF_X:
case BPF_ALU64 | BPF_XOR | BPF_X:
emit(rv_xor(rd, rd, rs), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_MUL | BPF_X:
case BPF_ALU64 | BPF_MUL | BPF_X:
emit(is64 ? rv_mul(rd, rd, rs) : rv_mulw(rd, rd, rs), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_DIV | BPF_X:
case BPF_ALU64 | BPF_DIV | BPF_X:
emit(is64 ? rv_divu(rd, rd, rs) : rv_divuw(rd, rd, rs), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_MOD | BPF_X:
case BPF_ALU64 | BPF_MOD | BPF_X:
emit(is64 ? rv_remu(rd, rd, rs) : rv_remuw(rd, rd, rs), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_LSH | BPF_X:
case BPF_ALU64 | BPF_LSH | BPF_X:
emit(is64 ? rv_sll(rd, rd, rs) : rv_sllw(rd, rd, rs), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_RSH | BPF_X:
case BPF_ALU64 | BPF_RSH | BPF_X:
emit(is64 ? rv_srl(rd, rd, rs) : rv_srlw(rd, rd, rs), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_ARSH | BPF_X:
case BPF_ALU64 | BPF_ARSH | BPF_X:
emit(is64 ? rv_sra(rd, rd, rs) : rv_sraw(rd, rd, rs), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
/* dst = -dst */
case BPF_ALU | BPF_NEG:
case BPF_ALU64 | BPF_NEG:
emit(is64 ? rv_sub(rd, RV_REG_ZERO, rd) :
rv_subw(rd, RV_REG_ZERO, rd), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
/* dst = BSWAP##imm(dst) */
case BPF_ALU | BPF_END | BPF_FROM_LE:
switch (imm) {
case 16:
emit(rv_slli(rd, rd, 48), ctx);
emit(rv_srli(rd, rd, 48), ctx);
break;
case 32:
if (!aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case 64:
/* Do nothing */
break;
}
break;
case BPF_ALU | BPF_END | BPF_FROM_BE:
emit(rv_addi(RV_REG_T2, RV_REG_ZERO, 0), ctx);
emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
emit(rv_slli(RV_REG_T2, RV_REG_T2, 8), ctx);
emit(rv_srli(rd, rd, 8), ctx);
if (imm == 16)
goto out_be;
emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
emit(rv_slli(RV_REG_T2, RV_REG_T2, 8), ctx);
emit(rv_srli(rd, rd, 8), ctx);
emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
emit(rv_slli(RV_REG_T2, RV_REG_T2, 8), ctx);
emit(rv_srli(rd, rd, 8), ctx);
if (imm == 32)
goto out_be;
emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
emit(rv_slli(RV_REG_T2, RV_REG_T2, 8), ctx);
emit(rv_srli(rd, rd, 8), ctx);
emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
emit(rv_slli(RV_REG_T2, RV_REG_T2, 8), ctx);
emit(rv_srli(rd, rd, 8), ctx);
emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
emit(rv_slli(RV_REG_T2, RV_REG_T2, 8), ctx);
emit(rv_srli(rd, rd, 8), ctx);
emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
emit(rv_slli(RV_REG_T2, RV_REG_T2, 8), ctx);
emit(rv_srli(rd, rd, 8), ctx);
out_be:
emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
emit(rv_addi(rd, RV_REG_T2, 0), ctx);
break;
/* dst = imm */
case BPF_ALU | BPF_MOV | BPF_K:
case BPF_ALU64 | BPF_MOV | BPF_K:
emit_imm(rd, imm, ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
/* dst = dst OP imm */
case BPF_ALU | BPF_ADD | BPF_K:
case BPF_ALU64 | BPF_ADD | BPF_K:
if (is_12b_int(imm)) {
emit(is64 ? rv_addi(rd, rd, imm) :
rv_addiw(rd, rd, imm), ctx);
} else {
emit_imm(RV_REG_T1, imm, ctx);
emit(is64 ? rv_add(rd, rd, RV_REG_T1) :
rv_addw(rd, rd, RV_REG_T1), ctx);
}
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_SUB | BPF_K:
case BPF_ALU64 | BPF_SUB | BPF_K:
if (is_12b_int(-imm)) {
emit(is64 ? rv_addi(rd, rd, -imm) :
rv_addiw(rd, rd, -imm), ctx);
} else {
emit_imm(RV_REG_T1, imm, ctx);
emit(is64 ? rv_sub(rd, rd, RV_REG_T1) :
rv_subw(rd, rd, RV_REG_T1), ctx);
}
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_AND | BPF_K:
case BPF_ALU64 | BPF_AND | BPF_K:
if (is_12b_int(imm)) {
emit(rv_andi(rd, rd, imm), ctx);
} else {
emit_imm(RV_REG_T1, imm, ctx);
emit(rv_and(rd, rd, RV_REG_T1), ctx);
}
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_OR | BPF_K:
case BPF_ALU64 | BPF_OR | BPF_K:
if (is_12b_int(imm)) {
emit(rv_ori(rd, rd, imm), ctx);
} else {
emit_imm(RV_REG_T1, imm, ctx);
emit(rv_or(rd, rd, RV_REG_T1), ctx);
}
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_XOR | BPF_K:
case BPF_ALU64 | BPF_XOR | BPF_K:
if (is_12b_int(imm)) {
emit(rv_xori(rd, rd, imm), ctx);
} else {
emit_imm(RV_REG_T1, imm, ctx);
emit(rv_xor(rd, rd, RV_REG_T1), ctx);
}
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_MUL | BPF_K:
case BPF_ALU64 | BPF_MUL | BPF_K:
emit_imm(RV_REG_T1, imm, ctx);
emit(is64 ? rv_mul(rd, rd, RV_REG_T1) :
rv_mulw(rd, rd, RV_REG_T1), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_DIV | BPF_K:
case BPF_ALU64 | BPF_DIV | BPF_K:
emit_imm(RV_REG_T1, imm, ctx);
emit(is64 ? rv_divu(rd, rd, RV_REG_T1) :
rv_divuw(rd, rd, RV_REG_T1), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_MOD | BPF_K:
case BPF_ALU64 | BPF_MOD | BPF_K:
emit_imm(RV_REG_T1, imm, ctx);
emit(is64 ? rv_remu(rd, rd, RV_REG_T1) :
rv_remuw(rd, rd, RV_REG_T1), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_LSH | BPF_K:
case BPF_ALU64 | BPF_LSH | BPF_K:
emit(is64 ? rv_slli(rd, rd, imm) : rv_slliw(rd, rd, imm), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_RSH | BPF_K:
case BPF_ALU64 | BPF_RSH | BPF_K:
emit(is64 ? rv_srli(rd, rd, imm) : rv_srliw(rd, rd, imm), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
case BPF_ALU | BPF_ARSH | BPF_K:
case BPF_ALU64 | BPF_ARSH | BPF_K:
emit(is64 ? rv_srai(rd, rd, imm) : rv_sraiw(rd, rd, imm), ctx);
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
/* JUMP off */
case BPF_JMP | BPF_JA:
rvoff = rv_offset(i, off, ctx);
ret = emit_jump_and_link(RV_REG_ZERO, rvoff, false, ctx);
if (ret)
return ret;
break;
/* IF (dst COND src) JUMP off */
case BPF_JMP | BPF_JEQ | BPF_X:
case BPF_JMP32 | BPF_JEQ | BPF_X:
case BPF_JMP | BPF_JGT | BPF_X:
case BPF_JMP32 | BPF_JGT | BPF_X:
case BPF_JMP | BPF_JLT | BPF_X:
case BPF_JMP32 | BPF_JLT | BPF_X:
case BPF_JMP | BPF_JGE | BPF_X:
case BPF_JMP32 | BPF_JGE | BPF_X:
case BPF_JMP | BPF_JLE | BPF_X:
case BPF_JMP32 | BPF_JLE | BPF_X:
case BPF_JMP | BPF_JNE | BPF_X:
case BPF_JMP32 | BPF_JNE | BPF_X:
case BPF_JMP | BPF_JSGT | BPF_X:
case BPF_JMP32 | BPF_JSGT | BPF_X:
case BPF_JMP | BPF_JSLT | BPF_X:
case BPF_JMP32 | BPF_JSLT | BPF_X:
case BPF_JMP | BPF_JSGE | BPF_X:
case BPF_JMP32 | BPF_JSGE | BPF_X:
case BPF_JMP | BPF_JSLE | BPF_X:
case BPF_JMP32 | BPF_JSLE | BPF_X:
case BPF_JMP | BPF_JSET | BPF_X:
case BPF_JMP32 | BPF_JSET | BPF_X:
rvoff = rv_offset(i, off, ctx);
if (!is64) {
s = ctx->ninsns;
if (is_signed_bpf_cond(BPF_OP(code)))
emit_sext_32_rd_rs(&rd, &rs, ctx);
else
emit_zext_32_rd_rs(&rd, &rs, ctx);
e = ctx->ninsns;
/* Adjust for extra insns */
rvoff -= (e - s) << 2;
}
if (BPF_OP(code) == BPF_JSET) {
/* Adjust for and */
rvoff -= 4;
emit(rv_and(RV_REG_T1, rd, rs), ctx);
emit_branch(BPF_JNE, RV_REG_T1, RV_REG_ZERO, rvoff,
ctx);
} else {
emit_branch(BPF_OP(code), rd, rs, rvoff, ctx);
}
break;
/* IF (dst COND imm) JUMP off */
case BPF_JMP | BPF_JEQ | BPF_K:
case BPF_JMP32 | BPF_JEQ | BPF_K:
case BPF_JMP | BPF_JGT | BPF_K:
case BPF_JMP32 | BPF_JGT | BPF_K:
case BPF_JMP | BPF_JLT | BPF_K:
case BPF_JMP32 | BPF_JLT | BPF_K:
case BPF_JMP | BPF_JGE | BPF_K:
case BPF_JMP32 | BPF_JGE | BPF_K:
case BPF_JMP | BPF_JLE | BPF_K:
case BPF_JMP32 | BPF_JLE | BPF_K:
case BPF_JMP | BPF_JNE | BPF_K:
case BPF_JMP32 | BPF_JNE | BPF_K:
case BPF_JMP | BPF_JSGT | BPF_K:
case BPF_JMP32 | BPF_JSGT | BPF_K:
case BPF_JMP | BPF_JSLT | BPF_K:
case BPF_JMP32 | BPF_JSLT | BPF_K:
case BPF_JMP | BPF_JSGE | BPF_K:
case BPF_JMP32 | BPF_JSGE | BPF_K:
case BPF_JMP | BPF_JSLE | BPF_K:
case BPF_JMP32 | BPF_JSLE | BPF_K:
rvoff = rv_offset(i, off, ctx);
s = ctx->ninsns;
if (imm) {
emit_imm(RV_REG_T1, imm, ctx);
rs = RV_REG_T1;
} else {
/* If imm is 0, simply use zero register. */
rs = RV_REG_ZERO;
}
if (!is64) {
if (is_signed_bpf_cond(BPF_OP(code)))
emit_sext_32_rd(&rd, ctx);
else
emit_zext_32_rd_t1(&rd, ctx);
}
e = ctx->ninsns;
/* Adjust for extra insns */
rvoff -= (e - s) << 2;
emit_branch(BPF_OP(code), rd, rs, rvoff, ctx);
break;
case BPF_JMP | BPF_JSET | BPF_K:
case BPF_JMP32 | BPF_JSET | BPF_K:
rvoff = rv_offset(i, off, ctx);
s = ctx->ninsns;
if (is_12b_int(imm)) {
emit(rv_andi(RV_REG_T1, rd, imm), ctx);
} else {
emit_imm(RV_REG_T1, imm, ctx);
emit(rv_and(RV_REG_T1, rd, RV_REG_T1), ctx);
}
/* For jset32, we should clear the upper 32 bits of t1, but
* sign-extension is sufficient here and saves one instruction,
* as t1 is used only in comparison against zero.
*/
if (!is64 && imm < 0)
emit(rv_addiw(RV_REG_T1, RV_REG_T1, 0), ctx);
e = ctx->ninsns;
rvoff -= (e - s) << 2;
emit_branch(BPF_JNE, RV_REG_T1, RV_REG_ZERO, rvoff, ctx);
break;
/* function call */
case BPF_JMP | BPF_CALL:
{
bool fixed;
u64 addr;
mark_call(ctx);
ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass, &addr,
&fixed);
if (ret < 0)
return ret;
ret = emit_call(fixed, addr, ctx);
if (ret)
return ret;
break;
}
/* tail call */
case BPF_JMP | BPF_TAIL_CALL:
if (emit_bpf_tail_call(i, ctx))
return -1;
break;
/* function return */
case BPF_JMP | BPF_EXIT:
if (i == ctx->prog->len - 1)
break;
rvoff = epilogue_offset(ctx);
ret = emit_jump_and_link(RV_REG_ZERO, rvoff, false, ctx);
if (ret)
return ret;
break;
/* dst = imm64 */
case BPF_LD | BPF_IMM | BPF_DW:
{
struct bpf_insn insn1 = insn[1];
u64 imm64;
imm64 = (u64)insn1.imm << 32 | (u32)imm;
emit_imm(rd, imm64, ctx);
return 1;
}
/* LDX: dst = *(size *)(src + off) */
case BPF_LDX | BPF_MEM | BPF_B:
if (is_12b_int(off)) {
emit(rv_lbu(rd, off, rs), ctx);
break;
}
emit_imm(RV_REG_T1, off, ctx);
emit(rv_add(RV_REG_T1, RV_REG_T1, rs), ctx);
emit(rv_lbu(rd, 0, RV_REG_T1), ctx);
if (insn_is_zext(&insn[1]))
return 1;
break;
case BPF_LDX | BPF_MEM | BPF_H:
if (is_12b_int(off)) {
emit(rv_lhu(rd, off, rs), ctx);
break;
}
emit_imm(RV_REG_T1, off, ctx);
emit(rv_add(RV_REG_T1, RV_REG_T1, rs), ctx);
emit(rv_lhu(rd, 0, RV_REG_T1), ctx);
if (insn_is_zext(&insn[1]))
return 1;
break;
case BPF_LDX | BPF_MEM | BPF_W:
if (is_12b_int(off)) {
emit(rv_lwu(rd, off, rs), ctx);
break;
}
emit_imm(RV_REG_T1, off, ctx);
emit(rv_add(RV_REG_T1, RV_REG_T1, rs), ctx);
emit(rv_lwu(rd, 0, RV_REG_T1), ctx);
if (insn_is_zext(&insn[1]))
return 1;
break;
case BPF_LDX | BPF_MEM | BPF_DW:
if (is_12b_int(off)) {
emit(rv_ld(rd, off, rs), ctx);
break;
}
emit_imm(RV_REG_T1, off, ctx);
emit(rv_add(RV_REG_T1, RV_REG_T1, rs), ctx);
emit(rv_ld(rd, 0, RV_REG_T1), ctx);
break;
/* ST: *(size *)(dst + off) = imm */
case BPF_ST | BPF_MEM | BPF_B:
emit_imm(RV_REG_T1, imm, ctx);
if (is_12b_int(off)) {
emit(rv_sb(rd, off, RV_REG_T1), ctx);
break;
}
emit_imm(RV_REG_T2, off, ctx);
emit(rv_add(RV_REG_T2, RV_REG_T2, rd), ctx);
emit(rv_sb(RV_REG_T2, 0, RV_REG_T1), ctx);
break;
case BPF_ST | BPF_MEM | BPF_H:
emit_imm(RV_REG_T1, imm, ctx);
if (is_12b_int(off)) {
emit(rv_sh(rd, off, RV_REG_T1), ctx);
break;
}
emit_imm(RV_REG_T2, off, ctx);
emit(rv_add(RV_REG_T2, RV_REG_T2, rd), ctx);
emit(rv_sh(RV_REG_T2, 0, RV_REG_T1), ctx);
break;
case BPF_ST | BPF_MEM | BPF_W:
emit_imm(RV_REG_T1, imm, ctx);
if (is_12b_int(off)) {
emit(rv_sw(rd, off, RV_REG_T1), ctx);
break;
}
emit_imm(RV_REG_T2, off, ctx);
emit(rv_add(RV_REG_T2, RV_REG_T2, rd), ctx);
emit(rv_sw(RV_REG_T2, 0, RV_REG_T1), ctx);
break;
case BPF_ST | BPF_MEM | BPF_DW:
emit_imm(RV_REG_T1, imm, ctx);
if (is_12b_int(off)) {
emit(rv_sd(rd, off, RV_REG_T1), ctx);
break;
}
emit_imm(RV_REG_T2, off, ctx);
emit(rv_add(RV_REG_T2, RV_REG_T2, rd), ctx);
emit(rv_sd(RV_REG_T2, 0, RV_REG_T1), ctx);
break;
/* STX: *(size *)(dst + off) = src */
case BPF_STX | BPF_MEM | BPF_B:
if (is_12b_int(off)) {
emit(rv_sb(rd, off, rs), ctx);
break;
}
emit_imm(RV_REG_T1, off, ctx);
emit(rv_add(RV_REG_T1, RV_REG_T1, rd), ctx);
emit(rv_sb(RV_REG_T1, 0, rs), ctx);
break;
case BPF_STX | BPF_MEM | BPF_H:
if (is_12b_int(off)) {
emit(rv_sh(rd, off, rs), ctx);
break;
}
emit_imm(RV_REG_T1, off, ctx);
emit(rv_add(RV_REG_T1, RV_REG_T1, rd), ctx);
emit(rv_sh(RV_REG_T1, 0, rs), ctx);
break;
case BPF_STX | BPF_MEM | BPF_W:
if (is_12b_int(off)) {
emit(rv_sw(rd, off, rs), ctx);
break;
}
emit_imm(RV_REG_T1, off, ctx);
emit(rv_add(RV_REG_T1, RV_REG_T1, rd), ctx);
emit(rv_sw(RV_REG_T1, 0, rs), ctx);
break;
case BPF_STX | BPF_MEM | BPF_DW:
if (is_12b_int(off)) {
emit(rv_sd(rd, off, rs), ctx);
break;
}
emit_imm(RV_REG_T1, off, ctx);
emit(rv_add(RV_REG_T1, RV_REG_T1, rd), ctx);
emit(rv_sd(RV_REG_T1, 0, rs), ctx);
break;
/* STX XADD: lock *(u32 *)(dst + off) += src */
case BPF_STX | BPF_XADD | BPF_W:
/* STX XADD: lock *(u64 *)(dst + off) += src */
case BPF_STX | BPF_XADD | BPF_DW:
if (off) {
if (is_12b_int(off)) {
emit(rv_addi(RV_REG_T1, rd, off), ctx);
} else {
emit_imm(RV_REG_T1, off, ctx);
emit(rv_add(RV_REG_T1, RV_REG_T1, rd), ctx);
}
rd = RV_REG_T1;
}
emit(BPF_SIZE(code) == BPF_W ?
rv_amoadd_w(RV_REG_ZERO, rs, rd, 0, 0) :
rv_amoadd_d(RV_REG_ZERO, rs, rd, 0, 0), ctx);
break;
default:
pr_err("bpf-jit: unknown opcode %02x\n", code);
return -EINVAL;
}
return 0;
}
void bpf_jit_build_prologue(struct rv_jit_context *ctx)
{
int stack_adjust = 0, store_offset, bpf_stack_adjust;
bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 16);
if (bpf_stack_adjust)
mark_fp(ctx);
if (seen_reg(RV_REG_RA, ctx))
stack_adjust += 8;
stack_adjust += 8; /* RV_REG_FP */
if (seen_reg(RV_REG_S1, ctx))
stack_adjust += 8;
if (seen_reg(RV_REG_S2, ctx))
stack_adjust += 8;
if (seen_reg(RV_REG_S3, ctx))
stack_adjust += 8;
if (seen_reg(RV_REG_S4, ctx))
stack_adjust += 8;
if (seen_reg(RV_REG_S5, ctx))
stack_adjust += 8;
if (seen_reg(RV_REG_S6, ctx))
stack_adjust += 8;
stack_adjust = round_up(stack_adjust, 16);
stack_adjust += bpf_stack_adjust;
store_offset = stack_adjust - 8;
/* First instruction is always setting the tail-call-counter
* (TCC) register. This instruction is skipped for tail calls.
*/
emit(rv_addi(RV_REG_TCC, RV_REG_ZERO, MAX_TAIL_CALL_CNT), ctx);
emit(rv_addi(RV_REG_SP, RV_REG_SP, -stack_adjust), ctx);
if (seen_reg(RV_REG_RA, ctx)) {
emit(rv_sd(RV_REG_SP, store_offset, RV_REG_RA), ctx);
store_offset -= 8;
}
emit(rv_sd(RV_REG_SP, store_offset, RV_REG_FP), ctx);
store_offset -= 8;
if (seen_reg(RV_REG_S1, ctx)) {
emit(rv_sd(RV_REG_SP, store_offset, RV_REG_S1), ctx);
store_offset -= 8;
}
if (seen_reg(RV_REG_S2, ctx)) {
emit(rv_sd(RV_REG_SP, store_offset, RV_REG_S2), ctx);
store_offset -= 8;
}
if (seen_reg(RV_REG_S3, ctx)) {
emit(rv_sd(RV_REG_SP, store_offset, RV_REG_S3), ctx);
store_offset -= 8;
}
if (seen_reg(RV_REG_S4, ctx)) {
emit(rv_sd(RV_REG_SP, store_offset, RV_REG_S4), ctx);
store_offset -= 8;
}
if (seen_reg(RV_REG_S5, ctx)) {
emit(rv_sd(RV_REG_SP, store_offset, RV_REG_S5), ctx);
store_offset -= 8;
}
if (seen_reg(RV_REG_S6, ctx)) {
emit(rv_sd(RV_REG_SP, store_offset, RV_REG_S6), ctx);
store_offset -= 8;
}
emit(rv_addi(RV_REG_FP, RV_REG_SP, stack_adjust), ctx);
if (bpf_stack_adjust)
emit(rv_addi(RV_REG_S5, RV_REG_SP, bpf_stack_adjust), ctx);
/* Program contains calls and tail calls, so RV_REG_TCC need
* to be saved across calls.
*/
if (seen_tail_call(ctx) && seen_call(ctx))
emit(rv_addi(RV_REG_TCC_SAVED, RV_REG_TCC, 0), ctx);
ctx->stack_size = stack_adjust;
}
void bpf_jit_build_epilogue(struct rv_jit_context *ctx)
{
__build_epilogue(false, ctx);
}
void *bpf_jit_alloc_exec(unsigned long size)
{
return __vmalloc_node_range(size, PAGE_SIZE, BPF_JIT_REGION_START,
BPF_JIT_REGION_END, GFP_KERNEL,
PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
__builtin_return_address(0));
}
void bpf_jit_free_exec(void *addr)
{
return vfree(addr);
}
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