linux/arch/arm64/net/bpf_jit.h
Xu Kuohai 042152c27c bpf, arm64: Sign return address for JITed code
Sign return address for JITed code when the kernel is built with pointer
authentication enabled:

1. Sign LR with paciasp instruction before LR is pushed to stack. Since
   paciasp acts like landing pads for function entry, no need to insert
   bti instruction before paciasp.

2. Authenticate LR with autiasp instruction after LR is popped from stack.

For BPF tail call, the stack frame constructed by the caller is reused by
the callee. That is, the stack frame is constructed by the caller and
destructed by the callee. Thus LR is signed and pushed to the stack in the
caller's prologue, and poped from the stack and authenticated in the
callee's epilogue.

For BPF2BPF call, the caller and callee construct their own stack frames,
and sign and authenticate their own LRs.

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://events.static.linuxfound.org/sites/events/files/slides/slides_23.pdf
Link: https://lore.kernel.org/bpf/20220402073942.3782529-1-xukuohai@huawei.com
2022-04-06 00:04:22 +02:00

278 lines
12 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* BPF JIT compiler for ARM64
*
* Copyright (C) 2014-2016 Zi Shen Lim <zlim.lnx@gmail.com>
*/
#ifndef _BPF_JIT_H
#define _BPF_JIT_H
#include <asm/insn.h>
/* 5-bit Register Operand */
#define A64_R(x) AARCH64_INSN_REG_##x
#define A64_FP AARCH64_INSN_REG_FP
#define A64_LR AARCH64_INSN_REG_LR
#define A64_ZR AARCH64_INSN_REG_ZR
#define A64_SP AARCH64_INSN_REG_SP
#define A64_VARIANT(sf) \
((sf) ? AARCH64_INSN_VARIANT_64BIT : AARCH64_INSN_VARIANT_32BIT)
/* Compare & branch (immediate) */
#define A64_COMP_BRANCH(sf, Rt, offset, type) \
aarch64_insn_gen_comp_branch_imm(0, offset, Rt, A64_VARIANT(sf), \
AARCH64_INSN_BRANCH_COMP_##type)
#define A64_CBZ(sf, Rt, imm19) A64_COMP_BRANCH(sf, Rt, (imm19) << 2, ZERO)
#define A64_CBNZ(sf, Rt, imm19) A64_COMP_BRANCH(sf, Rt, (imm19) << 2, NONZERO)
/* Conditional branch (immediate) */
#define A64_COND_BRANCH(cond, offset) \
aarch64_insn_gen_cond_branch_imm(0, offset, cond)
#define A64_COND_EQ AARCH64_INSN_COND_EQ /* == */
#define A64_COND_NE AARCH64_INSN_COND_NE /* != */
#define A64_COND_CS AARCH64_INSN_COND_CS /* unsigned >= */
#define A64_COND_HI AARCH64_INSN_COND_HI /* unsigned > */
#define A64_COND_LS AARCH64_INSN_COND_LS /* unsigned <= */
#define A64_COND_CC AARCH64_INSN_COND_CC /* unsigned < */
#define A64_COND_GE AARCH64_INSN_COND_GE /* signed >= */
#define A64_COND_GT AARCH64_INSN_COND_GT /* signed > */
#define A64_COND_LE AARCH64_INSN_COND_LE /* signed <= */
#define A64_COND_LT AARCH64_INSN_COND_LT /* signed < */
#define A64_B_(cond, imm19) A64_COND_BRANCH(cond, (imm19) << 2)
/* Unconditional branch (immediate) */
#define A64_BRANCH(offset, type) aarch64_insn_gen_branch_imm(0, offset, \
AARCH64_INSN_BRANCH_##type)
#define A64_B(imm26) A64_BRANCH((imm26) << 2, NOLINK)
#define A64_BL(imm26) A64_BRANCH((imm26) << 2, LINK)
/* Unconditional branch (register) */
#define A64_BR(Rn) aarch64_insn_gen_branch_reg(Rn, AARCH64_INSN_BRANCH_NOLINK)
#define A64_BLR(Rn) aarch64_insn_gen_branch_reg(Rn, AARCH64_INSN_BRANCH_LINK)
#define A64_RET(Rn) aarch64_insn_gen_branch_reg(Rn, AARCH64_INSN_BRANCH_RETURN)
/* Load/store register (register offset) */
#define A64_LS_REG(Rt, Rn, Rm, size, type) \
aarch64_insn_gen_load_store_reg(Rt, Rn, Rm, \
AARCH64_INSN_SIZE_##size, \
AARCH64_INSN_LDST_##type##_REG_OFFSET)
#define A64_STRB(Wt, Xn, Xm) A64_LS_REG(Wt, Xn, Xm, 8, STORE)
#define A64_LDRB(Wt, Xn, Xm) A64_LS_REG(Wt, Xn, Xm, 8, LOAD)
#define A64_STRH(Wt, Xn, Xm) A64_LS_REG(Wt, Xn, Xm, 16, STORE)
#define A64_LDRH(Wt, Xn, Xm) A64_LS_REG(Wt, Xn, Xm, 16, LOAD)
#define A64_STR32(Wt, Xn, Xm) A64_LS_REG(Wt, Xn, Xm, 32, STORE)
#define A64_LDR32(Wt, Xn, Xm) A64_LS_REG(Wt, Xn, Xm, 32, LOAD)
#define A64_STR64(Xt, Xn, Xm) A64_LS_REG(Xt, Xn, Xm, 64, STORE)
#define A64_LDR64(Xt, Xn, Xm) A64_LS_REG(Xt, Xn, Xm, 64, LOAD)
/* Load/store register (immediate offset) */
#define A64_LS_IMM(Rt, Rn, imm, size, type) \
aarch64_insn_gen_load_store_imm(Rt, Rn, imm, \
AARCH64_INSN_SIZE_##size, \
AARCH64_INSN_LDST_##type##_IMM_OFFSET)
#define A64_STRBI(Wt, Xn, imm) A64_LS_IMM(Wt, Xn, imm, 8, STORE)
#define A64_LDRBI(Wt, Xn, imm) A64_LS_IMM(Wt, Xn, imm, 8, LOAD)
#define A64_STRHI(Wt, Xn, imm) A64_LS_IMM(Wt, Xn, imm, 16, STORE)
#define A64_LDRHI(Wt, Xn, imm) A64_LS_IMM(Wt, Xn, imm, 16, LOAD)
#define A64_STR32I(Wt, Xn, imm) A64_LS_IMM(Wt, Xn, imm, 32, STORE)
#define A64_LDR32I(Wt, Xn, imm) A64_LS_IMM(Wt, Xn, imm, 32, LOAD)
#define A64_STR64I(Xt, Xn, imm) A64_LS_IMM(Xt, Xn, imm, 64, STORE)
#define A64_LDR64I(Xt, Xn, imm) A64_LS_IMM(Xt, Xn, imm, 64, LOAD)
/* Load/store register pair */
#define A64_LS_PAIR(Rt, Rt2, Rn, offset, ls, type) \
aarch64_insn_gen_load_store_pair(Rt, Rt2, Rn, offset, \
AARCH64_INSN_VARIANT_64BIT, \
AARCH64_INSN_LDST_##ls##_PAIR_##type)
/* Rn -= 16; Rn[0] = Rt; Rn[8] = Rt2; */
#define A64_PUSH(Rt, Rt2, Rn) A64_LS_PAIR(Rt, Rt2, Rn, -16, STORE, PRE_INDEX)
/* Rt = Rn[0]; Rt2 = Rn[8]; Rn += 16; */
#define A64_POP(Rt, Rt2, Rn) A64_LS_PAIR(Rt, Rt2, Rn, 16, LOAD, POST_INDEX)
/* Load/store exclusive */
#define A64_SIZE(sf) \
((sf) ? AARCH64_INSN_SIZE_64 : AARCH64_INSN_SIZE_32)
#define A64_LSX(sf, Rt, Rn, Rs, type) \
aarch64_insn_gen_load_store_ex(Rt, Rn, Rs, A64_SIZE(sf), \
AARCH64_INSN_LDST_##type)
/* Rt = [Rn]; (atomic) */
#define A64_LDXR(sf, Rt, Rn) \
A64_LSX(sf, Rt, Rn, A64_ZR, LOAD_EX)
/* [Rn] = Rt; (atomic) Rs = [state] */
#define A64_STXR(sf, Rt, Rn, Rs) \
A64_LSX(sf, Rt, Rn, Rs, STORE_EX)
/* [Rn] = Rt (store release); (atomic) Rs = [state] */
#define A64_STLXR(sf, Rt, Rn, Rs) \
aarch64_insn_gen_load_store_ex(Rt, Rn, Rs, A64_SIZE(sf), \
AARCH64_INSN_LDST_STORE_REL_EX)
/*
* LSE atomics
*
* ST{ADD,CLR,SET,EOR} is simply encoded as an alias for
* LDD{ADD,CLR,SET,EOR} with XZR as the destination register.
*/
#define A64_ST_OP(sf, Rn, Rs, op) \
aarch64_insn_gen_atomic_ld_op(A64_ZR, Rn, Rs, \
A64_SIZE(sf), AARCH64_INSN_MEM_ATOMIC_##op, \
AARCH64_INSN_MEM_ORDER_NONE)
/* [Rn] <op>= Rs */
#define A64_STADD(sf, Rn, Rs) A64_ST_OP(sf, Rn, Rs, ADD)
#define A64_STCLR(sf, Rn, Rs) A64_ST_OP(sf, Rn, Rs, CLR)
#define A64_STEOR(sf, Rn, Rs) A64_ST_OP(sf, Rn, Rs, EOR)
#define A64_STSET(sf, Rn, Rs) A64_ST_OP(sf, Rn, Rs, SET)
#define A64_LD_OP_AL(sf, Rt, Rn, Rs, op) \
aarch64_insn_gen_atomic_ld_op(Rt, Rn, Rs, \
A64_SIZE(sf), AARCH64_INSN_MEM_ATOMIC_##op, \
AARCH64_INSN_MEM_ORDER_ACQREL)
/* Rt = [Rn] (load acquire); [Rn] <op>= Rs (store release) */
#define A64_LDADDAL(sf, Rt, Rn, Rs) A64_LD_OP_AL(sf, Rt, Rn, Rs, ADD)
#define A64_LDCLRAL(sf, Rt, Rn, Rs) A64_LD_OP_AL(sf, Rt, Rn, Rs, CLR)
#define A64_LDEORAL(sf, Rt, Rn, Rs) A64_LD_OP_AL(sf, Rt, Rn, Rs, EOR)
#define A64_LDSETAL(sf, Rt, Rn, Rs) A64_LD_OP_AL(sf, Rt, Rn, Rs, SET)
/* Rt = [Rn] (load acquire); [Rn] = Rs (store release) */
#define A64_SWPAL(sf, Rt, Rn, Rs) A64_LD_OP_AL(sf, Rt, Rn, Rs, SWP)
/* Rs = CAS(Rn, Rs, Rt) (load acquire & store release) */
#define A64_CASAL(sf, Rt, Rn, Rs) \
aarch64_insn_gen_cas(Rt, Rn, Rs, A64_SIZE(sf), \
AARCH64_INSN_MEM_ORDER_ACQREL)
/* Add/subtract (immediate) */
#define A64_ADDSUB_IMM(sf, Rd, Rn, imm12, type) \
aarch64_insn_gen_add_sub_imm(Rd, Rn, imm12, \
A64_VARIANT(sf), AARCH64_INSN_ADSB_##type)
/* Rd = Rn OP imm12 */
#define A64_ADD_I(sf, Rd, Rn, imm12) A64_ADDSUB_IMM(sf, Rd, Rn, imm12, ADD)
#define A64_SUB_I(sf, Rd, Rn, imm12) A64_ADDSUB_IMM(sf, Rd, Rn, imm12, SUB)
#define A64_ADDS_I(sf, Rd, Rn, imm12) \
A64_ADDSUB_IMM(sf, Rd, Rn, imm12, ADD_SETFLAGS)
#define A64_SUBS_I(sf, Rd, Rn, imm12) \
A64_ADDSUB_IMM(sf, Rd, Rn, imm12, SUB_SETFLAGS)
/* Rn + imm12; set condition flags */
#define A64_CMN_I(sf, Rn, imm12) A64_ADDS_I(sf, A64_ZR, Rn, imm12)
/* Rn - imm12; set condition flags */
#define A64_CMP_I(sf, Rn, imm12) A64_SUBS_I(sf, A64_ZR, Rn, imm12)
/* Rd = Rn */
#define A64_MOV(sf, Rd, Rn) A64_ADD_I(sf, Rd, Rn, 0)
/* Bitfield move */
#define A64_BITFIELD(sf, Rd, Rn, immr, imms, type) \
aarch64_insn_gen_bitfield(Rd, Rn, immr, imms, \
A64_VARIANT(sf), AARCH64_INSN_BITFIELD_MOVE_##type)
/* Signed, with sign replication to left and zeros to right */
#define A64_SBFM(sf, Rd, Rn, ir, is) A64_BITFIELD(sf, Rd, Rn, ir, is, SIGNED)
/* Unsigned, with zeros to left and right */
#define A64_UBFM(sf, Rd, Rn, ir, is) A64_BITFIELD(sf, Rd, Rn, ir, is, UNSIGNED)
/* Rd = Rn << shift */
#define A64_LSL(sf, Rd, Rn, shift) ({ \
int sz = (sf) ? 64 : 32; \
A64_UBFM(sf, Rd, Rn, (unsigned)-(shift) % sz, sz - 1 - (shift)); \
})
/* Rd = Rn >> shift */
#define A64_LSR(sf, Rd, Rn, shift) A64_UBFM(sf, Rd, Rn, shift, (sf) ? 63 : 31)
/* Rd = Rn >> shift; signed */
#define A64_ASR(sf, Rd, Rn, shift) A64_SBFM(sf, Rd, Rn, shift, (sf) ? 63 : 31)
/* Zero extend */
#define A64_UXTH(sf, Rd, Rn) A64_UBFM(sf, Rd, Rn, 0, 15)
#define A64_UXTW(sf, Rd, Rn) A64_UBFM(sf, Rd, Rn, 0, 31)
/* Move wide (immediate) */
#define A64_MOVEW(sf, Rd, imm16, shift, type) \
aarch64_insn_gen_movewide(Rd, imm16, shift, \
A64_VARIANT(sf), AARCH64_INSN_MOVEWIDE_##type)
/* Rd = Zeros (for MOVZ);
* Rd |= imm16 << shift (where shift is {0, 16, 32, 48});
* Rd = ~Rd; (for MOVN); */
#define A64_MOVN(sf, Rd, imm16, shift) A64_MOVEW(sf, Rd, imm16, shift, INVERSE)
#define A64_MOVZ(sf, Rd, imm16, shift) A64_MOVEW(sf, Rd, imm16, shift, ZERO)
#define A64_MOVK(sf, Rd, imm16, shift) A64_MOVEW(sf, Rd, imm16, shift, KEEP)
/* Add/subtract (shifted register) */
#define A64_ADDSUB_SREG(sf, Rd, Rn, Rm, type) \
aarch64_insn_gen_add_sub_shifted_reg(Rd, Rn, Rm, 0, \
A64_VARIANT(sf), AARCH64_INSN_ADSB_##type)
/* Rd = Rn OP Rm */
#define A64_ADD(sf, Rd, Rn, Rm) A64_ADDSUB_SREG(sf, Rd, Rn, Rm, ADD)
#define A64_SUB(sf, Rd, Rn, Rm) A64_ADDSUB_SREG(sf, Rd, Rn, Rm, SUB)
#define A64_SUBS(sf, Rd, Rn, Rm) A64_ADDSUB_SREG(sf, Rd, Rn, Rm, SUB_SETFLAGS)
/* Rd = -Rm */
#define A64_NEG(sf, Rd, Rm) A64_SUB(sf, Rd, A64_ZR, Rm)
/* Rn - Rm; set condition flags */
#define A64_CMP(sf, Rn, Rm) A64_SUBS(sf, A64_ZR, Rn, Rm)
/* Data-processing (1 source) */
#define A64_DATA1(sf, Rd, Rn, type) aarch64_insn_gen_data1(Rd, Rn, \
A64_VARIANT(sf), AARCH64_INSN_DATA1_##type)
/* Rd = BSWAPx(Rn) */
#define A64_REV16(sf, Rd, Rn) A64_DATA1(sf, Rd, Rn, REVERSE_16)
#define A64_REV32(sf, Rd, Rn) A64_DATA1(sf, Rd, Rn, REVERSE_32)
#define A64_REV64(Rd, Rn) A64_DATA1(1, Rd, Rn, REVERSE_64)
/* Data-processing (2 source) */
/* Rd = Rn OP Rm */
#define A64_DATA2(sf, Rd, Rn, Rm, type) aarch64_insn_gen_data2(Rd, Rn, Rm, \
A64_VARIANT(sf), AARCH64_INSN_DATA2_##type)
#define A64_UDIV(sf, Rd, Rn, Rm) A64_DATA2(sf, Rd, Rn, Rm, UDIV)
#define A64_LSLV(sf, Rd, Rn, Rm) A64_DATA2(sf, Rd, Rn, Rm, LSLV)
#define A64_LSRV(sf, Rd, Rn, Rm) A64_DATA2(sf, Rd, Rn, Rm, LSRV)
#define A64_ASRV(sf, Rd, Rn, Rm) A64_DATA2(sf, Rd, Rn, Rm, ASRV)
/* Data-processing (3 source) */
/* Rd = Ra + Rn * Rm */
#define A64_MADD(sf, Rd, Ra, Rn, Rm) aarch64_insn_gen_data3(Rd, Ra, Rn, Rm, \
A64_VARIANT(sf), AARCH64_INSN_DATA3_MADD)
/* Rd = Ra - Rn * Rm */
#define A64_MSUB(sf, Rd, Ra, Rn, Rm) aarch64_insn_gen_data3(Rd, Ra, Rn, Rm, \
A64_VARIANT(sf), AARCH64_INSN_DATA3_MSUB)
/* Rd = Rn * Rm */
#define A64_MUL(sf, Rd, Rn, Rm) A64_MADD(sf, Rd, A64_ZR, Rn, Rm)
/* Logical (shifted register) */
#define A64_LOGIC_SREG(sf, Rd, Rn, Rm, type) \
aarch64_insn_gen_logical_shifted_reg(Rd, Rn, Rm, 0, \
A64_VARIANT(sf), AARCH64_INSN_LOGIC_##type)
/* Rd = Rn OP Rm */
#define A64_AND(sf, Rd, Rn, Rm) A64_LOGIC_SREG(sf, Rd, Rn, Rm, AND)
#define A64_ORR(sf, Rd, Rn, Rm) A64_LOGIC_SREG(sf, Rd, Rn, Rm, ORR)
#define A64_EOR(sf, Rd, Rn, Rm) A64_LOGIC_SREG(sf, Rd, Rn, Rm, EOR)
#define A64_ANDS(sf, Rd, Rn, Rm) A64_LOGIC_SREG(sf, Rd, Rn, Rm, AND_SETFLAGS)
/* Rn & Rm; set condition flags */
#define A64_TST(sf, Rn, Rm) A64_ANDS(sf, A64_ZR, Rn, Rm)
/* Rd = ~Rm (alias of ORN with A64_ZR as Rn) */
#define A64_MVN(sf, Rd, Rm) \
A64_LOGIC_SREG(sf, Rd, A64_ZR, Rm, ORN)
/* Logical (immediate) */
#define A64_LOGIC_IMM(sf, Rd, Rn, imm, type) ({ \
u64 imm64 = (sf) ? (u64)imm : (u64)(u32)imm; \
aarch64_insn_gen_logical_immediate(AARCH64_INSN_LOGIC_##type, \
A64_VARIANT(sf), Rn, Rd, imm64); \
})
/* Rd = Rn OP imm */
#define A64_AND_I(sf, Rd, Rn, imm) A64_LOGIC_IMM(sf, Rd, Rn, imm, AND)
#define A64_ORR_I(sf, Rd, Rn, imm) A64_LOGIC_IMM(sf, Rd, Rn, imm, ORR)
#define A64_EOR_I(sf, Rd, Rn, imm) A64_LOGIC_IMM(sf, Rd, Rn, imm, EOR)
#define A64_ANDS_I(sf, Rd, Rn, imm) A64_LOGIC_IMM(sf, Rd, Rn, imm, AND_SETFLAGS)
/* Rn & imm; set condition flags */
#define A64_TST_I(sf, Rn, imm) A64_ANDS_I(sf, A64_ZR, Rn, imm)
/* HINTs */
#define A64_HINT(x) aarch64_insn_gen_hint(x)
#define A64_PACIASP A64_HINT(AARCH64_INSN_HINT_PACIASP)
#define A64_AUTIASP A64_HINT(AARCH64_INSN_HINT_AUTIASP)
/* BTI */
#define A64_BTI_C A64_HINT(AARCH64_INSN_HINT_BTIC)
#define A64_BTI_J A64_HINT(AARCH64_INSN_HINT_BTIJ)
#define A64_BTI_JC A64_HINT(AARCH64_INSN_HINT_BTIJC)
/* DMB */
#define A64_DMB_ISH aarch64_insn_gen_dmb(AARCH64_INSN_MB_ISH)
#endif /* _BPF_JIT_H */