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Commit 7a987025 authored by Russell King's avatar Russell King Committed by Daniel Borkmann
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ARM: net: bpf: provide accessor functions for BPF registers 



Many of the code paths need to have knowledge about whether a register
is stacked or in a CPU register.  Move this decision making to a pair
of helper functions instead of having it scattered throughout the
code.

Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 47b9c3bf

arch/arm/net/bpf_jit_32.c

+128 −201
Original line number Diff line number Diff line
@@ -465,6 +465,31 @@ static bool is_stacked(s8 reg) 
	return reg < 0;

}



/* If a BPF register is on the stack (stk is true), load it to the

 * supplied temporary register and return the temporary register

 * for subsequent operations, otherwise just use the CPU register.

 */

static s8 arm_bpf_get_reg32(s8 reg, s8 tmp, struct jit_ctx *ctx)

{

	if (is_stacked(reg)) {

		emit(ARM_LDR_I(tmp, ARM_SP, STACK_VAR(reg)), ctx);

		reg = tmp;

	}

	return reg;

}



/* If a BPF register is on the stack (stk is true), save the register

 * back to the stack.  If the source register is not the same, then

 * move it into the correct register.

 */

static void arm_bpf_put_reg32(s8 reg, s8 src, struct jit_ctx *ctx)

{

	if (is_stacked(reg))

		emit(ARM_STR_I(src, ARM_SP, STACK_VAR(reg)), ctx);

	else if (reg != src)

		emit(ARM_MOV_R(reg, src), ctx);

}



static inline void emit_a32_mov_i(const s8 dst, const u32 val,

				  struct jit_ctx *ctx)

{
@@ -472,7 +497,7 @@ static inline void emit_a32_mov_i(const s8 dst, const u32 val, 


	if (is_stacked(dst)) {

		emit_mov_i(tmp[1], val, ctx);

		emit(ARM_STR_I(tmp[1], ARM_SP, STACK_VAR(dst)), ctx);

		arm_bpf_put_reg32(dst, tmp[1], ctx);

	} else {

		emit_mov_i(dst, val, ctx);

	}
@@ -572,19 +597,13 @@ static inline void emit_a32_alu_r(const s8 dst, const s8 src, 
				  struct jit_ctx *ctx, const bool is64,

				  const bool hi, const u8 op) {

	const s8 *tmp = bpf2a32[TMP_REG_1];

	s8 rn = is_stacked(src) ? tmp[1] : src;



	if (is_stacked(src))

		emit(ARM_LDR_I(rn, ARM_SP, STACK_VAR(src)), ctx);

	s8 rn, rd;



	rn = arm_bpf_get_reg32(src, tmp[1], ctx);

	rd = arm_bpf_get_reg32(dst, tmp[0], ctx);

	/* ALU operation */

	if (is_stacked(dst)) {

		emit(ARM_LDR_I(tmp[0], ARM_SP, STACK_VAR(dst)), ctx);

		emit_alu_r(tmp[0], rn, is64, hi, op, ctx);

		emit(ARM_STR_I(tmp[0], ARM_SP, STACK_VAR(dst)), ctx);

	} else {

		emit_alu_r(dst, rn, is64, hi, op, ctx);

	}

	emit_alu_r(rd, rn, is64, hi, op, ctx);

	arm_bpf_put_reg32(dst, rd, ctx);

}



/* ALU operation (64 bit) */
@@ -598,18 +617,14 @@ static inline void emit_a32_alu_r64(const bool is64, const s8 dst[], 
		emit_a32_mov_i(dst_hi, 0, ctx);

}



/* dst = imm (4 bytes)*/

/* dst = src (4 bytes)*/

static inline void emit_a32_mov_r(const s8 dst, const s8 src,

				  struct jit_ctx *ctx) {

	const s8 *tmp = bpf2a32[TMP_REG_1];

	s8 rt = is_stacked(src) ? tmp[0] : src;

	s8 rt;



	if (is_stacked(src))

		emit(ARM_LDR_I(tmp[0], ARM_SP, STACK_VAR(src)), ctx);

	if (is_stacked(dst))

		emit(ARM_STR_I(rt, ARM_SP, STACK_VAR(dst)), ctx);

	else

		emit(ARM_MOV_R(dst, rt), ctx);

	rt = arm_bpf_get_reg32(src, tmp[0], ctx);

	arm_bpf_put_reg32(dst, rt, ctx);

}



/* dst = src */
@@ -630,10 +645,9 @@ static inline void emit_a32_mov_r64(const bool is64, const s8 dst[], 
static inline void emit_a32_alu_i(const s8 dst, const u32 val,

				struct jit_ctx *ctx, const u8 op) {

	const s8 *tmp = bpf2a32[TMP_REG_1];

	s8 rd = is_stacked(dst) ? tmp[0] : dst;

	s8 rd;



	if (is_stacked(dst))

		emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst)), ctx);

	rd = arm_bpf_get_reg32(dst, tmp[0], ctx);



	/* Do shift operation */

	switch (op) {
@@ -648,31 +662,25 @@ static inline void emit_a32_alu_i(const s8 dst, const u32 val, 
		break;

	}



	if (is_stacked(dst))

		emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst)), ctx);

	arm_bpf_put_reg32(dst, rd, ctx);

}



/* dst = ~dst (64 bit) */

static inline void emit_a32_neg64(const s8 dst[],

				struct jit_ctx *ctx){

	const s8 *tmp = bpf2a32[TMP_REG_1];

	s8 rd = is_stacked(dst_lo) ? tmp[1] : dst[1];

	s8 rm = is_stacked(dst_lo) ? tmp[0] : dst[0];

	s8 rd, rm;



	/* Setup Operand */

	if (is_stacked(dst_lo)) {

		emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);

	}

	rd = arm_bpf_get_reg32(dst_lo, tmp[1], ctx);

	rm = arm_bpf_get_reg32(dst_hi, tmp[0], ctx);



	/* Do Negate Operation */

	emit(ARM_RSBS_I(rd, rd, 0), ctx);

	emit(ARM_RSC_I(rm, rm, 0), ctx);



	if (is_stacked(dst_lo)) {

		emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_STR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);

	}

	arm_bpf_put_reg32(dst_lo, rd, ctx);

	arm_bpf_put_reg32(dst_hi, rm, ctx);

}



/* dst = dst << src */
@@ -680,18 +688,12 @@ static inline void emit_a32_lsh_r64(const s8 dst[], const s8 src[], 
				    struct jit_ctx *ctx) {

	const s8 *tmp = bpf2a32[TMP_REG_1];

	const s8 *tmp2 = bpf2a32[TMP_REG_2];

	s8 rt, rd, rm;



	/* Setup Operands */

	s8 rt = is_stacked(src_lo) ? tmp2[1] : src_lo;

	s8 rd = is_stacked(dst_lo) ? tmp[1] : dst_lo;

	s8 rm = is_stacked(dst_lo) ? tmp[0] : dst_hi;



	if (is_stacked(src_lo))

		emit(ARM_LDR_I(rt, ARM_SP, STACK_VAR(src_lo)), ctx);

	if (is_stacked(dst_lo)) {

		emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);

	}

	rt = arm_bpf_get_reg32(src_lo, tmp2[1], ctx);

	rd = arm_bpf_get_reg32(dst_lo, tmp[1], ctx);

	rm = arm_bpf_get_reg32(dst_hi, tmp[0], ctx);



	/* Do LSH operation */

	emit(ARM_SUB_I(ARM_IP, rt, 32), ctx);
@@ -701,13 +703,8 @@ static inline void emit_a32_lsh_r64(const s8 dst[], const s8 src[], 
	emit(ARM_ORR_SR(ARM_IP, ARM_LR, rd, SRTYPE_LSR, tmp2[0]), ctx);

	emit(ARM_MOV_SR(ARM_LR, rd, SRTYPE_ASL, rt), ctx);



	if (is_stacked(dst_lo)) {

		emit(ARM_STR_I(ARM_LR, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_STR_I(ARM_IP, ARM_SP, STACK_VAR(dst_hi)), ctx);

	} else {

		emit(ARM_MOV_R(rd, ARM_LR), ctx);

		emit(ARM_MOV_R(rm, ARM_IP), ctx);

	}

	arm_bpf_put_reg32(dst_lo, ARM_LR, ctx);

	arm_bpf_put_reg32(dst_hi, ARM_IP, ctx);

}



/* dst = dst >> src (signed)*/
@@ -715,17 +712,12 @@ static inline void emit_a32_arsh_r64(const s8 dst[], const s8 src[], 
				     struct jit_ctx *ctx) {

	const s8 *tmp = bpf2a32[TMP_REG_1];

	const s8 *tmp2 = bpf2a32[TMP_REG_2];

	/* Setup Operands */

	s8 rt = is_stacked(src_lo) ? tmp2[1] : src_lo;

	s8 rd = is_stacked(dst_lo) ? tmp[1] : dst_lo;

	s8 rm = is_stacked(dst_lo) ? tmp[0] : dst_hi;

	s8 rt, rd, rm;



	if (is_stacked(src_lo))

		emit(ARM_LDR_I(rt, ARM_SP, STACK_VAR(src_lo)), ctx);

	if (is_stacked(dst_lo)) {

		emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);

	}

	/* Setup Operands */

	rt = arm_bpf_get_reg32(src_lo, tmp2[1], ctx);

	rd = arm_bpf_get_reg32(dst_lo, tmp[1], ctx);

	rm = arm_bpf_get_reg32(dst_hi, tmp[0], ctx);



	/* Do the ARSH operation */

	emit(ARM_RSB_I(ARM_IP, rt, 32), ctx);
@@ -735,13 +727,9 @@ static inline void emit_a32_arsh_r64(const s8 dst[], const s8 src[], 
	_emit(ARM_COND_MI, ARM_B(0), ctx);

	emit(ARM_ORR_SR(ARM_LR, ARM_LR, rm, SRTYPE_ASR, tmp2[0]), ctx);

	emit(ARM_MOV_SR(ARM_IP, rm, SRTYPE_ASR, rt), ctx);

	if (is_stacked(dst_lo)) {

		emit(ARM_STR_I(ARM_LR, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_STR_I(ARM_IP, ARM_SP, STACK_VAR(dst_hi)), ctx);

	} else {

		emit(ARM_MOV_R(rd, ARM_LR), ctx);

		emit(ARM_MOV_R(rm, ARM_IP), ctx);

	}



	arm_bpf_put_reg32(dst_lo, ARM_LR, ctx);

	arm_bpf_put_reg32(dst_hi, ARM_IP, ctx);

}



/* dst = dst >> src */
@@ -749,17 +737,12 @@ static inline void emit_a32_rsh_r64(const s8 dst[], const s8 src[], 
				    struct jit_ctx *ctx) {

	const s8 *tmp = bpf2a32[TMP_REG_1];

	const s8 *tmp2 = bpf2a32[TMP_REG_2];

	/* Setup Operands */

	s8 rt = is_stacked(src_lo) ? tmp2[1] : src_lo;

	s8 rd = is_stacked(dst_lo) ? tmp[1] : dst_lo;

	s8 rm = is_stacked(dst_lo) ? tmp[0] : dst_hi;

	s8 rt, rd, rm;



	if (is_stacked(src_lo))

		emit(ARM_LDR_I(rt, ARM_SP, STACK_VAR(src_lo)), ctx);

	if (is_stacked(dst_lo)) {

		emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);

	}

	/* Setup Operands */

	rt = arm_bpf_get_reg32(src_lo, tmp2[1], ctx);

	rd = arm_bpf_get_reg32(dst_lo, tmp[1], ctx);

	rm = arm_bpf_get_reg32(dst_hi, tmp[0], ctx);



	/* Do RSH operation */

	emit(ARM_RSB_I(ARM_IP, rt, 32), ctx);
@@ -768,13 +751,9 @@ static inline void emit_a32_rsh_r64(const s8 dst[], const s8 src[], 
	emit(ARM_ORR_SR(ARM_LR, ARM_LR, rm, SRTYPE_ASL, ARM_IP), ctx);

	emit(ARM_ORR_SR(ARM_LR, ARM_LR, rm, SRTYPE_LSR, tmp2[0]), ctx);

	emit(ARM_MOV_SR(ARM_IP, rm, SRTYPE_LSR, rt), ctx);

	if (is_stacked(dst_lo)) {

		emit(ARM_STR_I(ARM_LR, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_STR_I(ARM_IP, ARM_SP, STACK_VAR(dst_hi)), ctx);

	} else {

		emit(ARM_MOV_R(rd, ARM_LR), ctx);

		emit(ARM_MOV_R(rm, ARM_IP), ctx);

	}



	arm_bpf_put_reg32(dst_lo, ARM_LR, ctx);

	arm_bpf_put_reg32(dst_hi, ARM_IP, ctx);

}



/* dst = dst << val */
@@ -782,14 +761,11 @@ static inline void emit_a32_lsh_i64(const s8 dst[], 
				    const u32 val, struct jit_ctx *ctx){

	const s8 *tmp = bpf2a32[TMP_REG_1];

	const s8 *tmp2 = bpf2a32[TMP_REG_2];

	/* Setup operands */

	s8 rd = is_stacked(dst_lo) ? tmp[1] : dst_lo;

	s8 rm = is_stacked(dst_lo) ? tmp[0] : dst_hi;

	s8 rd, rm;



	if (is_stacked(dst_lo)) {

		emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);

	}

	/* Setup operands */

	rd = arm_bpf_get_reg32(dst_lo, tmp[1], ctx);

	rm = arm_bpf_get_reg32(dst_hi, tmp[0], ctx);



	/* Do LSH operation */

	if (val < 32) {
@@ -804,10 +780,8 @@ static inline void emit_a32_lsh_i64(const s8 dst[], 
		emit(ARM_EOR_R(rd, rd, rd), ctx);

	}



	if (is_stacked(dst_lo)) {

		emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_STR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);

	}

	arm_bpf_put_reg32(dst_lo, rd, ctx);

	arm_bpf_put_reg32(dst_hi, rm, ctx);

}



/* dst = dst >> val */
@@ -815,14 +789,11 @@ static inline void emit_a32_rsh_i64(const s8 dst[], 
				    const u32 val, struct jit_ctx *ctx) {

	const s8 *tmp = bpf2a32[TMP_REG_1];

	const s8 *tmp2 = bpf2a32[TMP_REG_2];

	/* Setup operands */

	s8 rd = is_stacked(dst_lo) ? tmp[1] : dst_lo;

	s8 rm = is_stacked(dst_lo) ? tmp[0] : dst_hi;

	s8 rd, rm;



	if (is_stacked(dst_lo)) {

		emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);

	}

	/* Setup operands */

	rd = arm_bpf_get_reg32(dst_lo, tmp[1], ctx);

	rm = arm_bpf_get_reg32(dst_hi, tmp[0], ctx);



	/* Do LSR operation */

	if (val < 32) {
@@ -837,10 +808,8 @@ static inline void emit_a32_rsh_i64(const s8 dst[], 
		emit(ARM_MOV_I(rm, 0), ctx);

	}



	if (is_stacked(dst_lo)) {

		emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_STR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);

	}

	arm_bpf_put_reg32(dst_lo, rd, ctx);

	arm_bpf_put_reg32(dst_hi, rm, ctx);

}



/* dst = dst >> val (signed) */
@@ -848,14 +817,11 @@ static inline void emit_a32_arsh_i64(const s8 dst[], 
				     const u32 val, struct jit_ctx *ctx){

	const s8 *tmp = bpf2a32[TMP_REG_1];

	const s8 *tmp2 = bpf2a32[TMP_REG_2];

	 /* Setup operands */

	s8 rd = is_stacked(dst_lo) ? tmp[1] : dst_lo;

	s8 rm = is_stacked(dst_lo) ? tmp[0] : dst_hi;

	s8 rd, rm;



	if (is_stacked(dst_lo)) {

		emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);

	}

	/* Setup operands */

	rd = arm_bpf_get_reg32(dst_lo, tmp[1], ctx);

	rm = arm_bpf_get_reg32(dst_hi, tmp[0], ctx);



	/* Do ARSH operation */

	if (val < 32) {
@@ -870,30 +836,21 @@ static inline void emit_a32_arsh_i64(const s8 dst[], 
		emit(ARM_MOV_SI(rm, rm, SRTYPE_ASR, 31), ctx);

	}



	if (is_stacked(dst_lo)) {

		emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_STR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);

	}

	arm_bpf_put_reg32(dst_lo, rd, ctx);

	arm_bpf_put_reg32(dst_hi, rm, ctx);

}



static inline void emit_a32_mul_r64(const s8 dst[], const s8 src[],

				    struct jit_ctx *ctx) {

	const s8 *tmp = bpf2a32[TMP_REG_1];

	const s8 *tmp2 = bpf2a32[TMP_REG_2];

	/* Setup operands for multiplication */

	s8 rd = is_stacked(dst_lo) ? tmp[1] : dst_lo;

	s8 rm = is_stacked(dst_lo) ? tmp[0] : dst_hi;

	s8 rt = is_stacked(src_lo) ? tmp2[1] : src_lo;

	s8 rn = is_stacked(src_lo) ? tmp2[0] : src_hi;

	s8 rd, rm, rt, rn;



	if (is_stacked(dst_lo)) {

		emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);

	}

	if (is_stacked(src_lo)) {

		emit(ARM_LDR_I(rt, ARM_SP, STACK_VAR(src_lo)), ctx);

		emit(ARM_LDR_I(rn, ARM_SP, STACK_VAR(src_hi)), ctx);

	}

	/* Setup operands for multiplication */

	rd = arm_bpf_get_reg32(dst_lo, tmp[1], ctx);

	rm = arm_bpf_get_reg32(dst_hi, tmp[0], ctx);

	rt = arm_bpf_get_reg32(src_lo, tmp2[1], ctx);

	rn = arm_bpf_get_reg32(src_hi, tmp2[0], ctx);



	/* Do Multiplication */

	emit(ARM_MUL(ARM_IP, rd, rn), ctx);
@@ -902,22 +859,18 @@ static inline void emit_a32_mul_r64(const s8 dst[], const s8 src[], 


	emit(ARM_UMULL(ARM_IP, rm, rd, rt), ctx);

	emit(ARM_ADD_R(rm, ARM_LR, rm), ctx);

	if (is_stacked(dst_lo)) {

		emit(ARM_STR_I(ARM_IP, ARM_SP, STACK_VAR(dst_lo)), ctx);

		emit(ARM_STR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);

	} else {

		emit(ARM_MOV_R(rd, ARM_IP), ctx);

	}



	arm_bpf_put_reg32(dst_lo, ARM_IP, ctx);

	arm_bpf_put_reg32(dst_hi, rm, ctx);

}



/* *(size *)(dst + off) = src */

static inline void emit_str_r(const s8 dst, const s8 src,

			      const s32 off, struct jit_ctx *ctx, const u8 sz){

	const s8 *tmp = bpf2a32[TMP_REG_1];

	s8 rd = is_stacked(dst) ? tmp[1] : dst;

	s8 rd;



	if (is_stacked(dst))

		emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst)), ctx);

	rd = arm_bpf_get_reg32(dst, tmp[1], ctx);

	if (off) {

		emit_a32_mov_i(tmp[0], off, ctx);

		emit(ARM_ADD_R(tmp[0], rd, tmp[0]), ctx);
@@ -983,10 +936,9 @@ static inline void emit_ldx_r(const s8 dst[], const s8 src, 
		emit(ARM_LDR_I(rd[0], rm, off + 4), ctx);

		break;

	}

	if (is_stacked(dst_lo))

		emit(ARM_STR_I(rd[1], ARM_SP, STACK_VAR(dst_lo)), ctx);

	if (is_stacked(dst_lo) && sz == BPF_DW)

		emit(ARM_STR_I(rd[0], ARM_SP, STACK_VAR(dst_hi)), ctx);

	arm_bpf_put_reg32(dst[1], rd[1], ctx);

	if (sz == BPF_DW)

		arm_bpf_put_reg32(dst[0], rd[0], ctx);

}



/* Arithmatic Operation */
@@ -1034,6 +986,7 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx) 
#define cur_offset (ctx->idx - idx0)

#define jmp_offset (out_offset - (cur_offset) - 2)

	u32 off, lo, hi;

	s8 r_array, r_index, r_tc_lo, r_tc_hi;



	/* if (index >= array->map.max_entries)

	 *	goto out;
@@ -1041,12 +994,12 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx) 
	off = offsetof(struct bpf_array, map.max_entries);

	/* array->map.max_entries */

	emit_a32_mov_i(tmp[1], off, ctx);

	emit(ARM_LDR_I(tmp2[1], ARM_SP, STACK_VAR(r2[1])), ctx);

	emit(ARM_LDR_R(tmp[1], tmp2[1], tmp[1]), ctx);

	r_array = arm_bpf_get_reg32(r2[1], tmp2[1], ctx);

	emit(ARM_LDR_R(tmp[1], r_array, tmp[1]), ctx);

	/* index is 32-bit for arrays */

	emit(ARM_LDR_I(tmp2[1], ARM_SP, STACK_VAR(r3[1])), ctx);

	r_index = arm_bpf_get_reg32(r3[1], tmp2[1], ctx);

	/* index >= array->map.max_entries */

	emit(ARM_CMP_R(tmp2[1], tmp[1]), ctx);

	emit(ARM_CMP_R(r_index, tmp[1]), ctx);

	_emit(ARM_COND_CS, ARM_B(jmp_offset), ctx);



	/* if (tail_call_cnt > MAX_TAIL_CALL_CNT)
@@ -1055,15 +1008,15 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx) 
	 */

	lo = (u32)MAX_TAIL_CALL_CNT;

	hi = (u32)((u64)MAX_TAIL_CALL_CNT >> 32);

	emit(ARM_LDR_I(tmp[1], ARM_SP, STACK_VAR(tcc[1])), ctx);

	emit(ARM_LDR_I(tmp[0], ARM_SP, STACK_VAR(tcc[0])), ctx);

	emit(ARM_CMP_I(tmp[0], hi), ctx);

	_emit(ARM_COND_EQ, ARM_CMP_I(tmp[1], lo), ctx);

	r_tc_lo = arm_bpf_get_reg32(tcc[1], tmp[1], ctx);

	r_tc_hi = arm_bpf_get_reg32(tcc[0], tmp[0], ctx);

	emit(ARM_CMP_I(r_tc_hi, hi), ctx);

	_emit(ARM_COND_EQ, ARM_CMP_I(r_tc_lo, lo), ctx);

	_emit(ARM_COND_HI, ARM_B(jmp_offset), ctx);

	emit(ARM_ADDS_I(tmp[1], tmp[1], 1), ctx);

	emit(ARM_ADC_I(tmp[0], tmp[0], 0), ctx);

	emit(ARM_STR_I(tmp[1], ARM_SP, STACK_VAR(tcc[1])), ctx);

	emit(ARM_STR_I(tmp[0], ARM_SP, STACK_VAR(tcc[0])), ctx);

	emit(ARM_ADDS_I(r_tc_lo, r_tc_lo, 1), ctx);

	emit(ARM_ADC_I(r_tc_hi, r_tc_hi, 0), ctx);

	arm_bpf_put_reg32(tcc[1], r_tc_lo, ctx);

	arm_bpf_put_reg32(tcc[0], r_tc_hi, ctx);



	/* prog = array->ptrs[index]

	 * if (prog == NULL)
@@ -1071,10 +1024,10 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx) 
	 */

	off = offsetof(struct bpf_array, ptrs);

	emit_a32_mov_i(tmp[1], off, ctx);

	emit(ARM_LDR_I(tmp2[1], ARM_SP, STACK_VAR(r2[1])), ctx);

	emit(ARM_ADD_R(tmp[1], tmp2[1], tmp[1]), ctx);

	emit(ARM_LDR_I(tmp2[1], ARM_SP, STACK_VAR(r3[1])), ctx);

	emit(ARM_MOV_SI(tmp[0], tmp2[1], SRTYPE_ASL, 2), ctx);

	r_array = arm_bpf_get_reg32(r2[1], tmp2[1], ctx);

	emit(ARM_ADD_R(tmp[1], r_array, tmp[1]), ctx);

	r_index = arm_bpf_get_reg32(r3[1], tmp2[1], ctx);

	emit(ARM_MOV_SI(tmp[0], r_index, SRTYPE_ASL, 2), ctx);

	emit(ARM_LDR_R(tmp[1], tmp[1], tmp[0]), ctx);

	emit(ARM_CMP_I(tmp[1], 0), ctx);

	_emit(ARM_COND_EQ, ARM_B(jmp_offset), ctx);
@@ -1317,15 +1270,10 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) 
	case BPF_ALU | BPF_DIV | BPF_X:

	case BPF_ALU | BPF_MOD | BPF_K:

	case BPF_ALU | BPF_MOD | BPF_X:

		rd = is_stacked(dst_lo) ? tmp2[1] : dst_lo;

		if (is_stacked(dst_lo))

			emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);

		rd = arm_bpf_get_reg32(dst_lo, tmp2[1], ctx);

		switch (BPF_SRC(code)) {

		case BPF_X:

			rt = is_stacked(rt) ? tmp2[0] : src_lo;

			if (is_stacked(src_lo))

				emit(ARM_LDR_I(rt, ARM_SP, STACK_VAR(src_lo)),

				     ctx);

			rt = arm_bpf_get_reg32(src_lo, tmp2[0], ctx);

			break;

		case BPF_K:

			rt = tmp2[0];
@@ -1336,8 +1284,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) 
			break;

		}

		emit_udivmod(rd, rd, rt, ctx, BPF_OP(code));

		if (is_stacked(dst_lo))

			emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst_lo)), ctx);

		arm_bpf_put_reg32(dst_lo, rd, ctx);

		emit_a32_mov_i(dst_hi, 0, ctx);

		break;

	case BPF_ALU64 | BPF_DIV | BPF_K:
@@ -1417,12 +1364,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) 
	/* dst = htobe(dst) */

	case BPF_ALU | BPF_END | BPF_FROM_LE:

	case BPF_ALU | BPF_END | BPF_FROM_BE:

		rd = is_stacked(dst_lo) ? tmp[0] : dst_hi;

		rt = is_stacked(dst_lo) ? tmp[1] : dst_lo;

		if (is_stacked(dst_lo)) {

			emit(ARM_LDR_I(rt, ARM_SP, STACK_VAR(dst_lo)), ctx);

			emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_hi)), ctx);

		}

		rt = arm_bpf_get_reg32(dst_lo, tmp[1], ctx);

		rd = arm_bpf_get_reg32(dst_hi, tmp[0], ctx);

		if (BPF_SRC(code) == BPF_FROM_LE)

			goto emit_bswap_uxt;

		switch (imm) {
@@ -1460,10 +1403,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) 
			break;

		}

exit:

		if (is_stacked(dst_lo)) {

			emit(ARM_STR_I(rt, ARM_SP, STACK_VAR(dst_lo)), ctx);

			emit(ARM_STR_I(rd, ARM_SP, STACK_VAR(dst_hi)), ctx);

		}

		arm_bpf_put_reg32(dst_lo, rt, ctx);

		arm_bpf_put_reg32(dst_hi, rd, ctx);

		break;

	/* dst = imm64 */

	case BPF_LD | BPF_IMM | BPF_DW:
@@ -1482,9 +1423,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) 
	case BPF_LDX | BPF_MEM | BPF_H:

	case BPF_LDX | BPF_MEM | BPF_B:

	case BPF_LDX | BPF_MEM | BPF_DW:

		rn = is_stacked(src_lo) ? tmp2[1] : src_lo;

		if (is_stacked(src_lo))

			emit(ARM_LDR_I(rn, ARM_SP, STACK_VAR(src_lo)), ctx);

		rn = arm_bpf_get_reg32(src_lo, tmp2[1], ctx);

		emit_ldx_r(dst, rn, off, ctx, BPF_SIZE(code));

		break;

	/* ST: *(size *)(dst + off) = imm */
@@ -1520,12 +1459,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) 
	{

		u8 sz = BPF_SIZE(code);



		rn = is_stacked(src_lo) ? tmp2[1] : src_lo;

		rm = is_stacked(src_lo) ? tmp2[0] : src_hi;

		if (is_stacked(src_lo)) {

			emit(ARM_LDR_I(rn, ARM_SP, STACK_VAR(src_lo)), ctx);

			emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(src_hi)), ctx);

		}

		rn = arm_bpf_get_reg32(src_lo, tmp2[1], ctx);

		rm = arm_bpf_get_reg32(src_hi, tmp2[0], ctx);



		/* Store the value */

		if (BPF_SIZE(code) == BPF_DW) {
@@ -1559,12 +1494,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) 
	case BPF_JMP | BPF_JSLT | BPF_X:

	case BPF_JMP | BPF_JSLE | BPF_X:

		/* Setup source registers */

		rm = is_stacked(src_lo) ? tmp2[0] : src_hi;

		rn = is_stacked(src_lo) ? tmp2[1] : src_lo;

		if (is_stacked(src_lo)) {

			emit(ARM_LDR_I(rn, ARM_SP, STACK_VAR(src_lo)), ctx);

			emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(src_hi)), ctx);

		}

		rm = arm_bpf_get_reg32(src_hi, tmp2[0], ctx);

		rn = arm_bpf_get_reg32(src_lo, tmp2[1], ctx);

		goto go_jmp;

	/* PC += off if dst == imm */

	/* PC += off if dst > imm */
@@ -1596,12 +1527,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) 
		emit_a32_mov_i64(true, tmp2, imm, ctx);

go_jmp:

		/* Setup destination register */

		rd = is_stacked(dst_lo) ? tmp[0] : dst_hi;

		rt = is_stacked(dst_lo) ? tmp[1] : dst_lo;

		if (is_stacked(dst_lo)) {

			emit(ARM_LDR_I(rt, ARM_SP, STACK_VAR(dst_lo)), ctx);

			emit(ARM_LDR_I(rd, ARM_SP, STACK_VAR(dst_hi)), ctx);

		}

		rt = arm_bpf_get_reg32(dst_lo, tmp[1], ctx);

		rd = arm_bpf_get_reg32(dst_hi, tmp[0], ctx);



		/* Check for the condition */

		emit_ar_r(rd, rt, rm, rn, ctx, BPF_OP(code));