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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/riscv/net/bpf_jit_comp64.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/riscv/net/bpf_jit_comp64.c')
-rw-r--r-- | arch/riscv/net/bpf_jit_comp64.c | 1870 |
1 files changed, 1870 insertions, 0 deletions
diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c new file mode 100644 index 0000000000..8581693e62 --- /dev/null +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -0,0 +1,1870 @@ +// SPDX-License-Identifier: GPL-2.0 +/* BPF JIT compiler for RV64G + * + * Copyright(c) 2019 Björn Töpel <bjorn.topel@gmail.com> + * + */ + +#include <linux/bitfield.h> +#include <linux/bpf.h> +#include <linux/filter.h> +#include <linux/memory.h> +#include <linux/stop_machine.h> +#include <asm/patch.h> +#include "bpf_jit.h" + +#define RV_FENTRY_NINSNS 2 + +#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, +}; + +static const int pt_regmap[] = { + [RV_REG_A0] = offsetof(struct pt_regs, a0), + [RV_REG_A1] = offsetof(struct pt_regs, a1), + [RV_REG_A2] = offsetof(struct pt_regs, a2), + [RV_REG_A3] = offsetof(struct pt_regs, a3), + [RV_REG_A4] = offsetof(struct pt_regs, a4), + [RV_REG_A5] = offsetof(struct pt_regs, a5), + [RV_REG_S1] = offsetof(struct pt_regs, s1), + [RV_REG_S2] = offsetof(struct pt_regs, s2), + [RV_REG_S3] = offsetof(struct pt_regs, s3), + [RV_REG_S4] = offsetof(struct pt_regs, s4), + [RV_REG_S5] = offsetof(struct pt_regs, s5), + [RV_REG_T0] = offsetof(struct pt_regs, 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)); +} + +/* Emit fixed-length instructions for address */ +static int emit_addr(u8 rd, u64 addr, bool extra_pass, struct rv_jit_context *ctx) +{ + /* + * Use the ro_insns(RX) to calculate the offset as the BPF program will + * finally run from this memory region. + */ + u64 ip = (u64)(ctx->ro_insns + ctx->ninsns); + s64 off = addr - ip; + s64 upper = (off + (1 << 11)) >> 12; + s64 lower = off & 0xfff; + + if (extra_pass && !in_auipc_jalr_range(off)) { + pr_err("bpf-jit: target offset 0x%llx is out of range\n", off); + return -ERANGE; + } + + emit(rv_auipc(rd, upper), ctx); + emit(rv_addi(rd, rd, lower), ctx); + return 0; +} + +/* Emit variable-length instructions for 32-bit and 64-bit imm */ +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; + /* Sign-extend lower 12 bits to 64 bits since immediates for li, addiw, + * and addi are signed and RVC checks will perform signed comparisons. + */ + s64 lower = ((val & 0xfff) << 52) >> 52; + int shift; + + if (is_32b_int(val)) { + if (upper) + emit_lui(rd, upper, ctx); + + if (!upper) { + emit_li(rd, lower, ctx); + return; + } + + emit_addiw(rd, rd, lower, ctx); + return; + } + + shift = __ffs(upper); + upper >>= shift; + shift += 12; + + emit_imm(rd, upper, ctx); + + emit_slli(rd, rd, shift, ctx); + if (lower) + emit_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_ld(RV_REG_RA, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } + emit_ld(RV_REG_FP, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + if (seen_reg(RV_REG_S1, ctx)) { + emit_ld(RV_REG_S1, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S2, ctx)) { + emit_ld(RV_REG_S2, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S3, ctx)) { + emit_ld(RV_REG_S3, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S4, ctx)) { + emit_ld(RV_REG_S4, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S5, ctx)) { + emit_ld(RV_REG_S5, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S6, ctx)) { + emit_ld(RV_REG_S6, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } + + emit_addi(RV_REG_SP, RV_REG_SP, stack_adjust, ctx); + /* Set return value. */ + if (!is_tail_call) + emit_addiw(RV_REG_A0, RV_REG_A5, 0, ctx); + emit_jalr(RV_REG_ZERO, is_tail_call ? RV_REG_T3 : RV_REG_RA, + is_tail_call ? (RV_FENTRY_NINSNS + 1) * 4 : 0, /* skip reserved nops and 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_slli(reg, reg, 32, ctx); + emit_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 = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); + emit_branch(BPF_JGE, RV_REG_A2, RV_REG_T1, off, ctx); + + /* if (--TCC < 0) + * goto out; + */ + emit_addi(RV_REG_TCC, tcc, -1, ctx); + off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); + emit_branch(BPF_JSLT, RV_REG_TCC, RV_REG_ZERO, off, ctx); + + /* prog = array->ptrs[index]; + * if (!prog) + * goto out; + */ + emit_slli(RV_REG_T2, RV_REG_A2, 3, ctx); + emit_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_ld(RV_REG_T2, off, RV_REG_T2, ctx); + off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); + 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_ld(RV_REG_T3, off, RV_REG_T2, 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_mv(RV_REG_T2, *rd, ctx); + emit_zext_32(RV_REG_T2, ctx); + emit_mv(RV_REG_T1, *rs, 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_addiw(RV_REG_T2, *rd, 0, ctx); + emit_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_mv(RV_REG_T2, *rd, 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_addiw(RV_REG_T2, *rd, 0, ctx); + *rd = RV_REG_T2; +} + +static int emit_jump_and_link(u8 rd, s64 rvoff, bool fixed_addr, + struct rv_jit_context *ctx) +{ + s64 upper, lower; + + if (rvoff && fixed_addr && is_21b_int(rvoff)) { + 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(u64 addr, bool fixed_addr, struct rv_jit_context *ctx) +{ + s64 off = 0; + u64 ip; + + if (addr && ctx->insns && ctx->ro_insns) { + /* + * Use the ro_insns(RX) to calculate the offset as the BPF + * program will finally run from this memory region. + */ + ip = (u64)(long)(ctx->ro_insns + ctx->ninsns); + off = addr - ip; + } + + return emit_jump_and_link(RV_REG_RA, off, fixed_addr, ctx); +} + +static void emit_atomic(u8 rd, u8 rs, s16 off, s32 imm, bool is64, + struct rv_jit_context *ctx) +{ + u8 r0; + int jmp_offset; + + if (off) { + if (is_12b_int(off)) { + emit_addi(RV_REG_T1, rd, off, ctx); + } else { + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rd, ctx); + } + rd = RV_REG_T1; + } + + switch (imm) { + /* lock *(u32/u64 *)(dst_reg + off16) <op>= src_reg */ + case BPF_ADD: + emit(is64 ? rv_amoadd_d(RV_REG_ZERO, rs, rd, 0, 0) : + rv_amoadd_w(RV_REG_ZERO, rs, rd, 0, 0), ctx); + break; + case BPF_AND: + emit(is64 ? rv_amoand_d(RV_REG_ZERO, rs, rd, 0, 0) : + rv_amoand_w(RV_REG_ZERO, rs, rd, 0, 0), ctx); + break; + case BPF_OR: + emit(is64 ? rv_amoor_d(RV_REG_ZERO, rs, rd, 0, 0) : + rv_amoor_w(RV_REG_ZERO, rs, rd, 0, 0), ctx); + break; + case BPF_XOR: + emit(is64 ? rv_amoxor_d(RV_REG_ZERO, rs, rd, 0, 0) : + rv_amoxor_w(RV_REG_ZERO, rs, rd, 0, 0), ctx); + break; + /* src_reg = atomic_fetch_<op>(dst_reg + off16, src_reg) */ + case BPF_ADD | BPF_FETCH: + emit(is64 ? rv_amoadd_d(rs, rs, rd, 0, 0) : + rv_amoadd_w(rs, rs, rd, 0, 0), ctx); + if (!is64) + emit_zext_32(rs, ctx); + break; + case BPF_AND | BPF_FETCH: + emit(is64 ? rv_amoand_d(rs, rs, rd, 0, 0) : + rv_amoand_w(rs, rs, rd, 0, 0), ctx); + if (!is64) + emit_zext_32(rs, ctx); + break; + case BPF_OR | BPF_FETCH: + emit(is64 ? rv_amoor_d(rs, rs, rd, 0, 0) : + rv_amoor_w(rs, rs, rd, 0, 0), ctx); + if (!is64) + emit_zext_32(rs, ctx); + break; + case BPF_XOR | BPF_FETCH: + emit(is64 ? rv_amoxor_d(rs, rs, rd, 0, 0) : + rv_amoxor_w(rs, rs, rd, 0, 0), ctx); + if (!is64) + emit_zext_32(rs, ctx); + break; + /* src_reg = atomic_xchg(dst_reg + off16, src_reg); */ + case BPF_XCHG: + emit(is64 ? rv_amoswap_d(rs, rs, rd, 0, 0) : + rv_amoswap_w(rs, rs, rd, 0, 0), ctx); + if (!is64) + emit_zext_32(rs, ctx); + break; + /* r0 = atomic_cmpxchg(dst_reg + off16, r0, src_reg); */ + case BPF_CMPXCHG: + r0 = bpf_to_rv_reg(BPF_REG_0, ctx); + emit(is64 ? rv_addi(RV_REG_T2, r0, 0) : + rv_addiw(RV_REG_T2, r0, 0), ctx); + emit(is64 ? rv_lr_d(r0, 0, rd, 0, 0) : + rv_lr_w(r0, 0, rd, 0, 0), ctx); + jmp_offset = ninsns_rvoff(8); + emit(rv_bne(RV_REG_T2, r0, jmp_offset >> 1), ctx); + emit(is64 ? rv_sc_d(RV_REG_T3, rs, rd, 0, 0) : + rv_sc_w(RV_REG_T3, rs, rd, 0, 0), ctx); + jmp_offset = ninsns_rvoff(-6); + emit(rv_bne(RV_REG_T3, 0, jmp_offset >> 1), ctx); + emit(rv_fence(0x3, 0x3), ctx); + break; + } +} + +#define BPF_FIXUP_OFFSET_MASK GENMASK(26, 0) +#define BPF_FIXUP_REG_MASK GENMASK(31, 27) + +bool ex_handler_bpf(const struct exception_table_entry *ex, + struct pt_regs *regs) +{ + off_t offset = FIELD_GET(BPF_FIXUP_OFFSET_MASK, ex->fixup); + int regs_offset = FIELD_GET(BPF_FIXUP_REG_MASK, ex->fixup); + + *(unsigned long *)((void *)regs + pt_regmap[regs_offset]) = 0; + regs->epc = (unsigned long)&ex->fixup - offset; + + return true; +} + +/* For accesses to BTF pointers, add an entry to the exception table */ +static int add_exception_handler(const struct bpf_insn *insn, + struct rv_jit_context *ctx, + int dst_reg, int insn_len) +{ + struct exception_table_entry *ex; + unsigned long pc; + off_t ins_offset; + off_t fixup_offset; + + if (!ctx->insns || !ctx->ro_insns || !ctx->prog->aux->extable || + (BPF_MODE(insn->code) != BPF_PROBE_MEM && BPF_MODE(insn->code) != BPF_PROBE_MEMSX)) + return 0; + + if (WARN_ON_ONCE(ctx->nexentries >= ctx->prog->aux->num_exentries)) + return -EINVAL; + + if (WARN_ON_ONCE(insn_len > ctx->ninsns)) + return -EINVAL; + + if (WARN_ON_ONCE(!rvc_enabled() && insn_len == 1)) + return -EINVAL; + + ex = &ctx->prog->aux->extable[ctx->nexentries]; + pc = (unsigned long)&ctx->ro_insns[ctx->ninsns - insn_len]; + + /* + * This is the relative offset of the instruction that may fault from + * the exception table itself. This will be written to the exception + * table and if this instruction faults, the destination register will + * be set to '0' and the execution will jump to the next instruction. + */ + ins_offset = pc - (long)&ex->insn; + if (WARN_ON_ONCE(ins_offset >= 0 || ins_offset < INT_MIN)) + return -ERANGE; + + /* + * Since the extable follows the program, the fixup offset is always + * negative and limited to BPF_JIT_REGION_SIZE. Store a positive value + * to keep things simple, and put the destination register in the upper + * bits. We don't need to worry about buildtime or runtime sort + * modifying the upper bits because the table is already sorted, and + * isn't part of the main exception table. + * + * The fixup_offset is set to the next instruction from the instruction + * that may fault. The execution will jump to this after handling the + * fault. + */ + fixup_offset = (long)&ex->fixup - (pc + insn_len * sizeof(u16)); + if (!FIELD_FIT(BPF_FIXUP_OFFSET_MASK, fixup_offset)) + return -ERANGE; + + /* + * The offsets above have been calculated using the RO buffer but we + * need to use the R/W buffer for writes. + * switch ex to rw buffer for writing. + */ + ex = (void *)ctx->insns + ((void *)ex - (void *)ctx->ro_insns); + + ex->insn = ins_offset; + + ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, fixup_offset) | + FIELD_PREP(BPF_FIXUP_REG_MASK, dst_reg); + ex->type = EX_TYPE_BPF; + + ctx->nexentries++; + return 0; +} + +static int gen_jump_or_nops(void *target, void *ip, u32 *insns, bool is_call) +{ + s64 rvoff; + struct rv_jit_context ctx; + + ctx.ninsns = 0; + ctx.insns = (u16 *)insns; + + if (!target) { + emit(rv_nop(), &ctx); + emit(rv_nop(), &ctx); + return 0; + } + + rvoff = (s64)(target - ip); + return emit_jump_and_link(is_call ? RV_REG_T0 : RV_REG_ZERO, rvoff, false, &ctx); +} + +int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type poke_type, + void *old_addr, void *new_addr) +{ + u32 old_insns[RV_FENTRY_NINSNS], new_insns[RV_FENTRY_NINSNS]; + bool is_call = poke_type == BPF_MOD_CALL; + int ret; + + if (!is_kernel_text((unsigned long)ip) && + !is_bpf_text_address((unsigned long)ip)) + return -ENOTSUPP; + + ret = gen_jump_or_nops(old_addr, ip, old_insns, is_call); + if (ret) + return ret; + + if (memcmp(ip, old_insns, RV_FENTRY_NINSNS * 4)) + return -EFAULT; + + ret = gen_jump_or_nops(new_addr, ip, new_insns, is_call); + if (ret) + return ret; + + cpus_read_lock(); + mutex_lock(&text_mutex); + if (memcmp(ip, new_insns, RV_FENTRY_NINSNS * 4)) + ret = patch_text(ip, new_insns, RV_FENTRY_NINSNS); + mutex_unlock(&text_mutex); + cpus_read_unlock(); + + return ret; +} + +static void store_args(int nregs, int args_off, struct rv_jit_context *ctx) +{ + int i; + + for (i = 0; i < nregs; i++) { + emit_sd(RV_REG_FP, -args_off, RV_REG_A0 + i, ctx); + args_off -= 8; + } +} + +static void restore_args(int nregs, int args_off, struct rv_jit_context *ctx) +{ + int i; + + for (i = 0; i < nregs; i++) { + emit_ld(RV_REG_A0 + i, -args_off, RV_REG_FP, ctx); + args_off -= 8; + } +} + +static int invoke_bpf_prog(struct bpf_tramp_link *l, int args_off, int retval_off, + int run_ctx_off, bool save_ret, struct rv_jit_context *ctx) +{ + int ret, branch_off; + struct bpf_prog *p = l->link.prog; + int cookie_off = offsetof(struct bpf_tramp_run_ctx, bpf_cookie); + + if (l->cookie) { + emit_imm(RV_REG_T1, l->cookie, ctx); + emit_sd(RV_REG_FP, -run_ctx_off + cookie_off, RV_REG_T1, ctx); + } else { + emit_sd(RV_REG_FP, -run_ctx_off + cookie_off, RV_REG_ZERO, ctx); + } + + /* arg1: prog */ + emit_imm(RV_REG_A0, (const s64)p, ctx); + /* arg2: &run_ctx */ + emit_addi(RV_REG_A1, RV_REG_FP, -run_ctx_off, ctx); + ret = emit_call((const u64)bpf_trampoline_enter(p), true, ctx); + if (ret) + return ret; + + /* if (__bpf_prog_enter(prog) == 0) + * goto skip_exec_of_prog; + */ + branch_off = ctx->ninsns; + /* nop reserved for conditional jump */ + emit(rv_nop(), ctx); + + /* store prog start time */ + emit_mv(RV_REG_S1, RV_REG_A0, ctx); + + /* arg1: &args_off */ + emit_addi(RV_REG_A0, RV_REG_FP, -args_off, ctx); + if (!p->jited) + /* arg2: progs[i]->insnsi for interpreter */ + emit_imm(RV_REG_A1, (const s64)p->insnsi, ctx); + ret = emit_call((const u64)p->bpf_func, true, ctx); + if (ret) + return ret; + + if (save_ret) { + emit_sd(RV_REG_FP, -retval_off, RV_REG_A0, ctx); + emit_sd(RV_REG_FP, -(retval_off - 8), regmap[BPF_REG_0], ctx); + } + + /* update branch with beqz */ + if (ctx->insns) { + int offset = ninsns_rvoff(ctx->ninsns - branch_off); + u32 insn = rv_beq(RV_REG_A0, RV_REG_ZERO, offset >> 1); + *(u32 *)(ctx->insns + branch_off) = insn; + } + + /* arg1: prog */ + emit_imm(RV_REG_A0, (const s64)p, ctx); + /* arg2: prog start time */ + emit_mv(RV_REG_A1, RV_REG_S1, ctx); + /* arg3: &run_ctx */ + emit_addi(RV_REG_A2, RV_REG_FP, -run_ctx_off, ctx); + ret = emit_call((const u64)bpf_trampoline_exit(p), true, ctx); + + return ret; +} + +static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, + const struct btf_func_model *m, + struct bpf_tramp_links *tlinks, + void *func_addr, u32 flags, + struct rv_jit_context *ctx) +{ + int i, ret, offset; + int *branches_off = NULL; + int stack_size = 0, nregs = m->nr_args; + int retval_off, args_off, nregs_off, ip_off, run_ctx_off, sreg_off; + struct bpf_tramp_links *fentry = &tlinks[BPF_TRAMP_FENTRY]; + struct bpf_tramp_links *fexit = &tlinks[BPF_TRAMP_FEXIT]; + struct bpf_tramp_links *fmod_ret = &tlinks[BPF_TRAMP_MODIFY_RETURN]; + void *orig_call = func_addr; + bool save_ret; + u32 insn; + + /* Two types of generated trampoline stack layout: + * + * 1. trampoline called from function entry + * -------------------------------------- + * FP + 8 [ RA to parent func ] return address to parent + * function + * FP + 0 [ FP of parent func ] frame pointer of parent + * function + * FP - 8 [ T0 to traced func ] return address of traced + * function + * FP - 16 [ FP of traced func ] frame pointer of traced + * function + * -------------------------------------- + * + * 2. trampoline called directly + * -------------------------------------- + * FP - 8 [ RA to caller func ] return address to caller + * function + * FP - 16 [ FP of caller func ] frame pointer of caller + * function + * -------------------------------------- + * + * FP - retval_off [ return value ] BPF_TRAMP_F_CALL_ORIG or + * BPF_TRAMP_F_RET_FENTRY_RET + * [ argN ] + * [ ... ] + * FP - args_off [ arg1 ] + * + * FP - nregs_off [ regs count ] + * + * FP - ip_off [ traced func ] BPF_TRAMP_F_IP_ARG + * + * FP - run_ctx_off [ bpf_tramp_run_ctx ] + * + * FP - sreg_off [ callee saved reg ] + * + * [ pads ] pads for 16 bytes alignment + */ + + if (flags & (BPF_TRAMP_F_ORIG_STACK | BPF_TRAMP_F_SHARE_IPMODIFY)) + return -ENOTSUPP; + + /* extra regiters for struct arguments */ + for (i = 0; i < m->nr_args; i++) + if (m->arg_flags[i] & BTF_FMODEL_STRUCT_ARG) + nregs += round_up(m->arg_size[i], 8) / 8 - 1; + + /* 8 arguments passed by registers */ + if (nregs > 8) + return -ENOTSUPP; + + /* room of trampoline frame to store return address and frame pointer */ + stack_size += 16; + + save_ret = flags & (BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_RET_FENTRY_RET); + if (save_ret) { + stack_size += 16; /* Save both A5 (BPF R0) and A0 */ + retval_off = stack_size; + } + + stack_size += nregs * 8; + args_off = stack_size; + + stack_size += 8; + nregs_off = stack_size; + + if (flags & BPF_TRAMP_F_IP_ARG) { + stack_size += 8; + ip_off = stack_size; + } + + stack_size += round_up(sizeof(struct bpf_tramp_run_ctx), 8); + run_ctx_off = stack_size; + + stack_size += 8; + sreg_off = stack_size; + + stack_size = round_up(stack_size, 16); + + if (func_addr) { + /* For the trampoline called from function entry, + * the frame of traced function and the frame of + * trampoline need to be considered. + */ + emit_addi(RV_REG_SP, RV_REG_SP, -16, ctx); + emit_sd(RV_REG_SP, 8, RV_REG_RA, ctx); + emit_sd(RV_REG_SP, 0, RV_REG_FP, ctx); + emit_addi(RV_REG_FP, RV_REG_SP, 16, ctx); + + emit_addi(RV_REG_SP, RV_REG_SP, -stack_size, ctx); + emit_sd(RV_REG_SP, stack_size - 8, RV_REG_T0, ctx); + emit_sd(RV_REG_SP, stack_size - 16, RV_REG_FP, ctx); + emit_addi(RV_REG_FP, RV_REG_SP, stack_size, ctx); + } else { + /* For the trampoline called directly, just handle + * the frame of trampoline. + */ + emit_addi(RV_REG_SP, RV_REG_SP, -stack_size, ctx); + emit_sd(RV_REG_SP, stack_size - 8, RV_REG_RA, ctx); + emit_sd(RV_REG_SP, stack_size - 16, RV_REG_FP, ctx); + emit_addi(RV_REG_FP, RV_REG_SP, stack_size, ctx); + } + + /* callee saved register S1 to pass start time */ + emit_sd(RV_REG_FP, -sreg_off, RV_REG_S1, ctx); + + /* store ip address of the traced function */ + if (flags & BPF_TRAMP_F_IP_ARG) { + emit_imm(RV_REG_T1, (const s64)func_addr, ctx); + emit_sd(RV_REG_FP, -ip_off, RV_REG_T1, ctx); + } + + emit_li(RV_REG_T1, nregs, ctx); + emit_sd(RV_REG_FP, -nregs_off, RV_REG_T1, ctx); + + store_args(nregs, args_off, ctx); + + /* skip to actual body of traced function */ + if (flags & BPF_TRAMP_F_SKIP_FRAME) + orig_call += RV_FENTRY_NINSNS * 4; + + if (flags & BPF_TRAMP_F_CALL_ORIG) { + emit_imm(RV_REG_A0, (const s64)im, ctx); + ret = emit_call((const u64)__bpf_tramp_enter, true, ctx); + if (ret) + return ret; + } + + for (i = 0; i < fentry->nr_links; i++) { + ret = invoke_bpf_prog(fentry->links[i], args_off, retval_off, run_ctx_off, + flags & BPF_TRAMP_F_RET_FENTRY_RET, ctx); + if (ret) + return ret; + } + + if (fmod_ret->nr_links) { + branches_off = kcalloc(fmod_ret->nr_links, sizeof(int), GFP_KERNEL); + if (!branches_off) + return -ENOMEM; + + /* cleanup to avoid garbage return value confusion */ + emit_sd(RV_REG_FP, -retval_off, RV_REG_ZERO, ctx); + for (i = 0; i < fmod_ret->nr_links; i++) { + ret = invoke_bpf_prog(fmod_ret->links[i], args_off, retval_off, + run_ctx_off, true, ctx); + if (ret) + goto out; + emit_ld(RV_REG_T1, -retval_off, RV_REG_FP, ctx); + branches_off[i] = ctx->ninsns; + /* nop reserved for conditional jump */ + emit(rv_nop(), ctx); + } + } + + if (flags & BPF_TRAMP_F_CALL_ORIG) { + restore_args(nregs, args_off, ctx); + ret = emit_call((const u64)orig_call, true, ctx); + if (ret) + goto out; + emit_sd(RV_REG_FP, -retval_off, RV_REG_A0, ctx); + emit_sd(RV_REG_FP, -(retval_off - 8), regmap[BPF_REG_0], ctx); + im->ip_after_call = ctx->insns + ctx->ninsns; + /* 2 nops reserved for auipc+jalr pair */ + emit(rv_nop(), ctx); + emit(rv_nop(), ctx); + } + + /* update branches saved in invoke_bpf_mod_ret with bnez */ + for (i = 0; ctx->insns && i < fmod_ret->nr_links; i++) { + offset = ninsns_rvoff(ctx->ninsns - branches_off[i]); + insn = rv_bne(RV_REG_T1, RV_REG_ZERO, offset >> 1); + *(u32 *)(ctx->insns + branches_off[i]) = insn; + } + + for (i = 0; i < fexit->nr_links; i++) { + ret = invoke_bpf_prog(fexit->links[i], args_off, retval_off, + run_ctx_off, false, ctx); + if (ret) + goto out; + } + + if (flags & BPF_TRAMP_F_CALL_ORIG) { + im->ip_epilogue = ctx->insns + ctx->ninsns; + emit_imm(RV_REG_A0, (const s64)im, ctx); + ret = emit_call((const u64)__bpf_tramp_exit, true, ctx); + if (ret) + goto out; + } + + if (flags & BPF_TRAMP_F_RESTORE_REGS) + restore_args(nregs, args_off, ctx); + + if (save_ret) { + emit_ld(RV_REG_A0, -retval_off, RV_REG_FP, ctx); + emit_ld(regmap[BPF_REG_0], -(retval_off - 8), RV_REG_FP, ctx); + } + + emit_ld(RV_REG_S1, -sreg_off, RV_REG_FP, ctx); + + if (func_addr) { + /* trampoline called from function entry */ + emit_ld(RV_REG_T0, stack_size - 8, RV_REG_SP, ctx); + emit_ld(RV_REG_FP, stack_size - 16, RV_REG_SP, ctx); + emit_addi(RV_REG_SP, RV_REG_SP, stack_size, ctx); + + emit_ld(RV_REG_RA, 8, RV_REG_SP, ctx); + emit_ld(RV_REG_FP, 0, RV_REG_SP, ctx); + emit_addi(RV_REG_SP, RV_REG_SP, 16, ctx); + + if (flags & BPF_TRAMP_F_SKIP_FRAME) + /* return to parent function */ + emit_jalr(RV_REG_ZERO, RV_REG_RA, 0, ctx); + else + /* return to traced function */ + emit_jalr(RV_REG_ZERO, RV_REG_T0, 0, ctx); + } else { + /* trampoline called directly */ + emit_ld(RV_REG_RA, stack_size - 8, RV_REG_SP, ctx); + emit_ld(RV_REG_FP, stack_size - 16, RV_REG_SP, ctx); + emit_addi(RV_REG_SP, RV_REG_SP, stack_size, ctx); + + emit_jalr(RV_REG_ZERO, RV_REG_RA, 0, ctx); + } + + ret = ctx->ninsns; +out: + kfree(branches_off); + return ret; +} + +int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, + void *image_end, const struct btf_func_model *m, + u32 flags, struct bpf_tramp_links *tlinks, + void *func_addr) +{ + int ret; + struct rv_jit_context ctx; + + ctx.ninsns = 0; + ctx.insns = NULL; + ctx.ro_insns = NULL; + ret = __arch_prepare_bpf_trampoline(im, m, tlinks, func_addr, flags, &ctx); + if (ret < 0) + return ret; + + if (ninsns_rvoff(ret) > (long)image_end - (long)image) + return -EFBIG; + + ctx.ninsns = 0; + /* + * The bpf_int_jit_compile() uses a RW buffer (ctx.insns) to write the + * JITed instructions and later copies it to a RX region (ctx.ro_insns). + * It also uses ctx.ro_insns to calculate offsets for jumps etc. As the + * trampoline image uses the same memory area for writing and execution, + * both ctx.insns and ctx.ro_insns can be set to image. + */ + ctx.insns = image; + ctx.ro_insns = image; + ret = __arch_prepare_bpf_trampoline(im, m, tlinks, func_addr, flags, &ctx); + if (ret < 0) + return ret; + + bpf_flush_icache(ctx.insns, ctx.insns + ctx.ninsns); + + return ninsns_rvoff(ret); +} + +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; + } + switch (insn->off) { + case 0: + emit_mv(rd, rs, ctx); + break; + case 8: + case 16: + emit_slli(RV_REG_T1, rs, 64 - insn->off, ctx); + emit_srai(rd, RV_REG_T1, 64 - insn->off, ctx); + break; + case 32: + emit_addiw(rd, rs, 0, ctx); + break; + } + 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_add(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: + if (is64) + emit_sub(rd, rd, rs, ctx); + else + emit_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_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_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_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: + if (off) + emit(is64 ? rv_div(rd, rd, rs) : rv_divw(rd, rd, rs), ctx); + else + 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: + if (off) + emit(is64 ? rv_rem(rd, rd, rs) : rv_remw(rd, rd, rs), ctx); + else + 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_sub(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_slli(rd, rd, 48, ctx); + emit_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: + case BPF_ALU64 | BPF_END | BPF_FROM_LE: + emit_li(RV_REG_T2, 0, ctx); + + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx); + emit_srli(rd, rd, 8, ctx); + if (imm == 16) + goto out_be; + + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx); + emit_srli(rd, rd, 8, ctx); + + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx); + emit_srli(rd, rd, 8, ctx); + if (imm == 32) + goto out_be; + + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx); + emit_srli(rd, rd, 8, ctx); + + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx); + emit_srli(rd, rd, 8, ctx); + + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx); + emit_srli(rd, rd, 8, ctx); + + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx); + emit_srli(rd, rd, 8, ctx); +out_be: + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + + emit_mv(rd, RV_REG_T2, 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_addi(rd, rd, imm, ctx); + } else { + emit_imm(RV_REG_T1, imm, ctx); + emit_add(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_addi(rd, rd, -imm, ctx); + } else { + emit_imm(RV_REG_T1, imm, ctx); + emit_sub(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_andi(rd, rd, imm, ctx); + } else { + emit_imm(RV_REG_T1, imm, ctx); + emit_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_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_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); + if (off) + emit(is64 ? rv_div(rd, rd, RV_REG_T1) : + rv_divw(rd, rd, RV_REG_T1), ctx); + else + 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); + if (off) + emit(is64 ? rv_rem(rd, rd, RV_REG_T1) : + rv_remw(rd, rd, RV_REG_T1), ctx); + else + 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_slli(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: + if (is64) + emit_srli(rd, rd, imm, ctx); + else + emit(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: + if (is64) + emit_srai(rd, rd, imm, ctx); + else + emit(rv_sraiw(rd, rd, imm), ctx); + + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + + /* JUMP off */ + case BPF_JMP | BPF_JA: + case BPF_JMP32 | BPF_JA: + if (BPF_CLASS(code) == BPF_JMP) + rvoff = rv_offset(i, off, ctx); + else + rvoff = rv_offset(i, imm, ctx); + ret = emit_jump_and_link(RV_REG_ZERO, rvoff, true, 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 -= ninsns_rvoff(e - s); + } + + if (BPF_OP(code) == BPF_JSET) { + /* Adjust for and */ + rvoff -= 4; + emit_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 -= ninsns_rvoff(e - s); + 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_andi(RV_REG_T1, rd, imm, ctx); + } else { + emit_imm(RV_REG_T1, imm, ctx); + emit_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_addiw(RV_REG_T1, RV_REG_T1, 0, ctx); + e = ctx->ninsns; + rvoff -= ninsns_rvoff(e - s); + emit_branch(BPF_JNE, RV_REG_T1, RV_REG_ZERO, rvoff, ctx); + break; + + /* function call */ + case BPF_JMP | BPF_CALL: + { + bool fixed_addr; + u64 addr; + + mark_call(ctx); + ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass, + &addr, &fixed_addr); + if (ret < 0) + return ret; + + ret = emit_call(addr, fixed_addr, ctx); + if (ret) + return ret; + + if (insn->src_reg != BPF_PSEUDO_CALL) + emit_mv(bpf_to_rv_reg(BPF_REG_0, ctx), RV_REG_A0, ctx); + 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, true, 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; + if (bpf_pseudo_func(insn)) { + /* fixed-length insns for extra jit pass */ + ret = emit_addr(rd, imm64, extra_pass, ctx); + if (ret) + return ret; + } else { + emit_imm(rd, imm64, ctx); + } + + return 1; + } + + /* LDX: dst = *(unsigned 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: + case BPF_LDX | BPF_PROBE_MEM | BPF_B: + case BPF_LDX | BPF_PROBE_MEM | BPF_H: + case BPF_LDX | BPF_PROBE_MEM | BPF_W: + case BPF_LDX | BPF_PROBE_MEM | BPF_DW: + /* LDSX: dst = *(signed size *)(src + off) */ + case BPF_LDX | BPF_MEMSX | BPF_B: + case BPF_LDX | BPF_MEMSX | BPF_H: + case BPF_LDX | BPF_MEMSX | BPF_W: + case BPF_LDX | BPF_PROBE_MEMSX | BPF_B: + case BPF_LDX | BPF_PROBE_MEMSX | BPF_H: + case BPF_LDX | BPF_PROBE_MEMSX | BPF_W: + { + int insn_len, insns_start; + bool sign_ext; + + sign_ext = BPF_MODE(insn->code) == BPF_MEMSX || + BPF_MODE(insn->code) == BPF_PROBE_MEMSX; + + switch (BPF_SIZE(code)) { + case BPF_B: + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + if (sign_ext) + emit(rv_lb(rd, off, rs), ctx); + else + emit(rv_lbu(rd, off, rs), ctx); + insn_len = ctx->ninsns - insns_start; + break; + } + + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rs, ctx); + insns_start = ctx->ninsns; + if (sign_ext) + emit(rv_lb(rd, 0, RV_REG_T1), ctx); + else + emit(rv_lbu(rd, 0, RV_REG_T1), ctx); + insn_len = ctx->ninsns - insns_start; + break; + case BPF_H: + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + if (sign_ext) + emit(rv_lh(rd, off, rs), ctx); + else + emit(rv_lhu(rd, off, rs), ctx); + insn_len = ctx->ninsns - insns_start; + break; + } + + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rs, ctx); + insns_start = ctx->ninsns; + if (sign_ext) + emit(rv_lh(rd, 0, RV_REG_T1), ctx); + else + emit(rv_lhu(rd, 0, RV_REG_T1), ctx); + insn_len = ctx->ninsns - insns_start; + break; + case BPF_W: + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + if (sign_ext) + emit(rv_lw(rd, off, rs), ctx); + else + emit(rv_lwu(rd, off, rs), ctx); + insn_len = ctx->ninsns - insns_start; + break; + } + + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rs, ctx); + insns_start = ctx->ninsns; + if (sign_ext) + emit(rv_lw(rd, 0, RV_REG_T1), ctx); + else + emit(rv_lwu(rd, 0, RV_REG_T1), ctx); + insn_len = ctx->ninsns - insns_start; + break; + case BPF_DW: + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + emit_ld(rd, off, rs, ctx); + insn_len = ctx->ninsns - insns_start; + break; + } + + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rs, ctx); + insns_start = ctx->ninsns; + emit_ld(rd, 0, RV_REG_T1, ctx); + insn_len = ctx->ninsns - insns_start; + break; + } + + ret = add_exception_handler(insn, ctx, rd, insn_len); + if (ret) + return ret; + + if (BPF_SIZE(code) != BPF_DW && insn_is_zext(&insn[1])) + return 1; + break; + } + /* speculation barrier */ + case BPF_ST | BPF_NOSPEC: + 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_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_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_sw(rd, off, RV_REG_T1, ctx); + break; + } + + emit_imm(RV_REG_T2, off, ctx); + emit_add(RV_REG_T2, RV_REG_T2, rd, ctx); + emit_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_sd(rd, off, RV_REG_T1, ctx); + break; + } + + emit_imm(RV_REG_T2, off, ctx); + emit_add(RV_REG_T2, RV_REG_T2, rd, ctx); + emit_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_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_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_sw(rd, off, rs, ctx); + break; + } + + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rd, ctx); + emit_sw(RV_REG_T1, 0, rs, ctx); + break; + case BPF_STX | BPF_MEM | BPF_DW: + if (is_12b_int(off)) { + emit_sd(rd, off, rs, ctx); + break; + } + + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rd, ctx); + emit_sd(RV_REG_T1, 0, rs, ctx); + break; + case BPF_STX | BPF_ATOMIC | BPF_W: + case BPF_STX | BPF_ATOMIC | BPF_DW: + emit_atomic(rd, rs, off, imm, + BPF_SIZE(code) == BPF_DW, 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 i, 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; + + /* nops reserved for auipc+jalr pair */ + for (i = 0; i < RV_FENTRY_NINSNS; i++) + emit(rv_nop(), ctx); + + /* First instruction is always setting the tail-call-counter + * (TCC) register. This instruction is skipped for tail calls. + * Force using a 4-byte (non-compressed) instruction. + */ + emit(rv_addi(RV_REG_TCC, RV_REG_ZERO, MAX_TAIL_CALL_CNT), ctx); + + emit_addi(RV_REG_SP, RV_REG_SP, -stack_adjust, ctx); + + if (seen_reg(RV_REG_RA, ctx)) { + emit_sd(RV_REG_SP, store_offset, RV_REG_RA, ctx); + store_offset -= 8; + } + emit_sd(RV_REG_SP, store_offset, RV_REG_FP, ctx); + store_offset -= 8; + if (seen_reg(RV_REG_S1, ctx)) { + emit_sd(RV_REG_SP, store_offset, RV_REG_S1, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S2, ctx)) { + emit_sd(RV_REG_SP, store_offset, RV_REG_S2, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S3, ctx)) { + emit_sd(RV_REG_SP, store_offset, RV_REG_S3, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S4, ctx)) { + emit_sd(RV_REG_SP, store_offset, RV_REG_S4, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S5, ctx)) { + emit_sd(RV_REG_SP, store_offset, RV_REG_S5, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S6, ctx)) { + emit_sd(RV_REG_SP, store_offset, RV_REG_S6, ctx); + store_offset -= 8; + } + + emit_addi(RV_REG_FP, RV_REG_SP, stack_adjust, ctx); + + if (bpf_stack_adjust) + emit_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_mv(RV_REG_TCC_SAVED, RV_REG_TCC, ctx); + + ctx->stack_size = stack_adjust; +} + +void bpf_jit_build_epilogue(struct rv_jit_context *ctx) +{ + __build_epilogue(false, ctx); +} + +bool bpf_jit_supports_kfunc_call(void) +{ + return true; +} |