net: filter: x86: internal BPF JIT

Maps all internal BPF instructions into x86_64 instructions.
This patch replaces original BPF x64 JIT with internal BPF x64 JIT.
sysctl net.core.bpf_jit_enable is reused as on/off switch.

Performance:

1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code.
  No performance difference is observed for filters that were JIT-able before

Example assembler code for BPF filter "tcpdump port 22"

original BPF -> old JIT:            original BPF -> internal BPF -> new JIT:
   0:   push   %rbp                      0:     push   %rbp
   1:   mov    %rsp,%rbp                 1:     mov    %rsp,%rbp
   4:   sub    $0x60,%rsp                4:     sub    $0x228,%rsp
   8:   mov    %rbx,-0x8(%rbp)           b:     mov    %rbx,-0x228(%rbp) // prologue
                                        12:     mov    %r13,-0x220(%rbp)
                                        19:     mov    %r14,-0x218(%rbp)
                                        20:     mov    %r15,-0x210(%rbp)
                                        27:     xor    %eax,%eax         // clear A
   c:   xor    %ebx,%ebx                29:     xor    %r13,%r13         // clear X
   e:   mov    0x68(%rdi),%r9d          2c:     mov    0x68(%rdi),%r9d
  12:   sub    0x6c(%rdi),%r9d          30:     sub    0x6c(%rdi),%r9d
  16:   mov    0xd8(%rdi),%r8           34:     mov    0xd8(%rdi),%r10
                                        3b:     mov    %rdi,%rbx
  1d:   mov    $0xc,%esi                3e:     mov    $0xc,%esi
  22:   callq  0xffffffffe1021e15       43:     callq  0xffffffffe102bd75
  27:   cmp    $0x86dd,%eax             48:     cmp    $0x86dd,%rax
  2c:   jne    0x0000000000000069       4f:     jne    0x000000000000009a
  2e:   mov    $0x14,%esi               51:     mov    $0x14,%esi
  33:   callq  0xffffffffe1021e31       56:     callq  0xffffffffe102bd91
  38:   cmp    $0x84,%eax               5b:     cmp    $0x84,%rax
  3d:   je     0x0000000000000049       62:     je     0x0000000000000074
  3f:   cmp    $0x6,%eax                64:     cmp    $0x6,%rax
  42:   je     0x0000000000000049       68:     je     0x0000000000000074
  44:   cmp    $0x11,%eax               6a:     cmp    $0x11,%rax
  47:   jne    0x00000000000000c6       6e:     jne    0x0000000000000117
  49:   mov    $0x36,%esi               74:     mov    $0x36,%esi
  4e:   callq  0xffffffffe1021e15       79:     callq  0xffffffffe102bd75
  53:   cmp    $0x16,%eax               7e:     cmp    $0x16,%rax
  56:   je     0x00000000000000bf       82:     je     0x0000000000000110
  58:   mov    $0x38,%esi               88:     mov    $0x38,%esi
  5d:   callq  0xffffffffe1021e15       8d:     callq  0xffffffffe102bd75
  62:   cmp    $0x16,%eax               92:     cmp    $0x16,%rax
  65:   je     0x00000000000000bf       96:     je     0x0000000000000110
  67:   jmp    0x00000000000000c6       98:     jmp    0x0000000000000117
  69:   cmp    $0x800,%eax              9a:     cmp    $0x800,%rax
  6e:   jne    0x00000000000000c6       a1:     jne    0x0000000000000117
  70:   mov    $0x17,%esi               a3:     mov    $0x17,%esi
  75:   callq  0xffffffffe1021e31       a8:     callq  0xffffffffe102bd91
  7a:   cmp    $0x84,%eax               ad:     cmp    $0x84,%rax
  7f:   je     0x000000000000008b       b4:     je     0x00000000000000c2
  81:   cmp    $0x6,%eax                b6:     cmp    $0x6,%rax
  84:   je     0x000000000000008b       ba:     je     0x00000000000000c2
  86:   cmp    $0x11,%eax               bc:     cmp    $0x11,%rax
  89:   jne    0x00000000000000c6       c0:     jne    0x0000000000000117
  8b:   mov    $0x14,%esi               c2:     mov    $0x14,%esi
  90:   callq  0xffffffffe1021e15       c7:     callq  0xffffffffe102bd75
  95:   test   $0x1fff,%ax              cc:     test   $0x1fff,%rax
  99:   jne    0x00000000000000c6       d3:     jne    0x0000000000000117
                                        d5:     mov    %rax,%r14
  9b:   mov    $0xe,%esi                d8:     mov    $0xe,%esi
  a0:   callq  0xffffffffe1021e44       dd:     callq  0xffffffffe102bd91 // MSH
                                        e2:     and    $0xf,%eax
                                        e5:     shl    $0x2,%eax
                                        e8:     mov    %rax,%r13
                                        eb:     mov    %r14,%rax
                                        ee:     mov    %r13,%rsi
  a5:   lea    0xe(%rbx),%esi           f1:     add    $0xe,%esi
  a8:   callq  0xffffffffe1021e0d       f4:     callq  0xffffffffe102bd6d
  ad:   cmp    $0x16,%eax               f9:     cmp    $0x16,%rax
  b0:   je     0x00000000000000bf       fd:     je     0x0000000000000110
                                        ff:     mov    %r13,%rsi
  b2:   lea    0x10(%rbx),%esi         102:     add    $0x10,%esi
  b5:   callq  0xffffffffe1021e0d      105:     callq  0xffffffffe102bd6d
  ba:   cmp    $0x16,%eax              10a:     cmp    $0x16,%rax
  bd:   jne    0x00000000000000c6      10e:     jne    0x0000000000000117
  bf:   mov    $0xffff,%eax            110:     mov    $0xffff,%eax
  c4:   jmp    0x00000000000000c8      115:     jmp    0x000000000000011c
  c6:   xor    %eax,%eax               117:     mov    $0x0,%eax
  c8:   mov    -0x8(%rbp),%rbx         11c:     mov    -0x228(%rbp),%rbx // epilogue
  cc:   leaveq                         123:     mov    -0x220(%rbp),%r13
  cd:   retq                           12a:     mov    -0x218(%rbp),%r14
                                       131:     mov    -0x210(%rbp),%r15
                                       138:     leaveq
                                       139:     retq

On fully cached SKBs both JITed functions take 12 nsec to execute.
BPF interpreter executes the program in 30 nsec.

The difference in generated assembler is due to the following:

Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function
inside bpf_jit.S.
New JIT removes the helper and does it explicitly, so ldx_msh cost
is the same for both JITs, but generated code looks longer.

New JIT has 4 registers to save, so prologue/epilogue are larger,
but the cost is within noise on x64.

Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'.
New JIT clears %rax unconditionally.

2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM
  extensions. New JIT supports all BPF extensions.
  Performance of such filters improves 2-4 times depending on a filter.
  The longer the filter the higher performance gain.
  Synthetic benchmarks with many ancillary loads see 20x speedup
  which seems to be the maximum gain from JIT

Notes:

. net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional
  and can be used to see generated assembler

. there are two jit_compile() functions and code flow for classic filters is:
  sk_attach_filter() - load classic BPF
  bpf_jit_compile() - try to JIT from classic BPF
  sk_convert_filter() - convert classic to internal
  bpf_int_jit_compile() - JIT from internal BPF

  seccomp and tracing filters will just call bpf_int_jit_compile()

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 737 insertions, 654 deletions

diff --git a/arch/x86/net/bpf_jit.S b/arch/x86/net/bpf_jit.S
index 0149575..6440221 100644
--- a/arch/x86/net/bpf_jit.S
+++ b/arch/x86/net/bpf_jit.S
@@ -12,13 +12,16 @@
 
 /*
  * Calling convention :
- * rdi : skb pointer
+ * rbx : skb pointer (callee saved)
  * esi : offset of byte(s) to fetch in skb (can be scratched)
- * r8  : copy of skb->data
+ * r10 : copy of skb->data
  * r9d : hlen = skb->len - skb->data_len
  */
-#define SKBDATA	%r8
+#define SKBDATA	%r10
 #define SKF_MAX_NEG_OFF    $(-0x200000) /* SKF_LL_OFF from filter.h */
+#define MAX_BPF_STACK (512 /* from filter.h */ + \
+	32 /* space for rbx,r13,r14,r15 */ + \
+	8 /* space for skb_copy_bits */)
 
 sk_load_word:
 	.globl	sk_load_word
@@ -68,53 +71,31 @@ sk_load_byte_positive_offset:
 	movzbl	(SKBDATA,%rsi),%eax
 	ret
 
-/**
- * sk_load_byte_msh - BPF_S_LDX_B_MSH helper
- *
- * Implements BPF_S_LDX_B_MSH : ldxb  4*([offset]&0xf)
- * Must preserve A accumulator (%eax)
- * Inputs : %esi is the offset value
- */
-sk_load_byte_msh:
-	.globl	sk_load_byte_msh
-	test	%esi,%esi
-	js	bpf_slow_path_byte_msh_neg
-
-sk_load_byte_msh_positive_offset:
-	.globl	sk_load_byte_msh_positive_offset
-	cmp	%esi,%r9d      /* if (offset >= hlen) goto bpf_slow_path_byte_msh */
-	jle	bpf_slow_path_byte_msh
-	movzbl	(SKBDATA,%rsi),%ebx
-	and	$15,%bl
-	shl	$2,%bl
-	ret
-
 /* rsi contains offset and can be scratched */
 #define bpf_slow_path_common(LEN)		\
-	push	%rdi;    /* save skb */		\
+	mov	%rbx, %rdi; /* arg1 == skb */	\
 	push	%r9;				\
 	push	SKBDATA;			\
 /* rsi already has offset */			\
 	mov	$LEN,%ecx;	/* len */	\
-	lea	-12(%rbp),%rdx;			\
+	lea	- MAX_BPF_STACK + 32(%rbp),%rdx;			\
 	call	skb_copy_bits;			\
 	test    %eax,%eax;			\
 	pop	SKBDATA;			\
-	pop	%r9;				\
-	pop	%rdi
+	pop	%r9;
 
 
 bpf_slow_path_word:
 	bpf_slow_path_common(4)
 	js	bpf_error
-	mov	-12(%rbp),%eax
+	mov	- MAX_BPF_STACK + 32(%rbp),%eax
 	bswap	%eax
 	ret
 
 bpf_slow_path_half:
 	bpf_slow_path_common(2)
 	js	bpf_error
-	mov	-12(%rbp),%ax
+	mov	- MAX_BPF_STACK + 32(%rbp),%ax
 	rol	$8,%ax
 	movzwl	%ax,%eax
 	ret
@@ -122,21 +103,11 @@ bpf_slow_path_half:
 bpf_slow_path_byte:
 	bpf_slow_path_common(1)
 	js	bpf_error
-	movzbl	-12(%rbp),%eax
-	ret
-
-bpf_slow_path_byte_msh:
-	xchg	%eax,%ebx /* dont lose A , X is about to be scratched */
-	bpf_slow_path_common(1)
-	js	bpf_error
-	movzbl	-12(%rbp),%eax
-	and	$15,%al
-	shl	$2,%al
-	xchg	%eax,%ebx
+	movzbl	- MAX_BPF_STACK + 32(%rbp),%eax
 	ret
 
 #define sk_negative_common(SIZE)				\
-	push	%rdi;	/* save skb */				\
+	mov	%rbx, %rdi; /* arg1 == skb */			\
 	push	%r9;						\
 	push	SKBDATA;					\
 /* rsi already has offset */					\
@@ -145,10 +116,8 @@ bpf_slow_path_byte_msh:
 	test	%rax,%rax;					\
 	pop	SKBDATA;					\
 	pop	%r9;						\
-	pop	%rdi;						\
 	jz	bpf_error
 
-
 bpf_slow_path_word_neg:
 	cmp	SKF_MAX_NEG_OFF, %esi	/* test range */
 	jl	bpf_error	/* offset lower -> error  */
@@ -179,22 +148,12 @@ sk_load_byte_negative_offset:
 	movzbl	(%rax), %eax
 	ret
 
-bpf_slow_path_byte_msh_neg:
-	cmp	SKF_MAX_NEG_OFF, %esi
-	jl	bpf_error
-sk_load_byte_msh_negative_offset:
-	.globl	sk_load_byte_msh_negative_offset
-	xchg	%eax,%ebx /* dont lose A , X is about to be scratched */
-	sk_negative_common(1)
-	movzbl	(%rax),%eax
-	and	$15,%al
-	shl	$2,%al
-	xchg	%eax,%ebx
-	ret
-
 bpf_error:
 # force a return 0 from jit handler
-	xor		%eax,%eax
-	mov		-8(%rbp),%rbx
+	xor	%eax,%eax
+	mov	- MAX_BPF_STACK(%rbp),%rbx
+	mov	- MAX_BPF_STACK + 8(%rbp),%r13
+	mov	- MAX_BPF_STACK + 16(%rbp),%r14
+	mov	- MAX_BPF_STACK + 24(%rbp),%r15
 	leaveq
 	ret
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index c5fa7c9..92aef8fd 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -1,6 +1,7 @@
 /* bpf_jit_comp.c : BPF JIT compiler
  *
  * Copyright (C) 2011-2013 Eric Dumazet (eric.dumazet@gmail.com)
+ * Internal BPF Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -14,28 +15,16 @@
 #include <linux/if_vlan.h>
 #include <linux/random.h>
 
-/*
- * Conventions :
- *  EAX : BPF A accumulator
- *  EBX : BPF X accumulator
- *  RDI : pointer to skb   (first argument given to JIT function)
- *  RBP : frame pointer (even if CONFIG_FRAME_POINTER=n)
- *  ECX,EDX,ESI : scratch registers
- *  r9d : skb->len - skb->data_len (headlen)
- *  r8  : skb->data
- * -8(RBP) : saved RBX value
- * -16(RBP)..-80(RBP) : BPF_MEMWORDS values
- */
 int bpf_jit_enable __read_mostly;
 
 /*
  * assembly code in arch/x86/net/bpf_jit.S
  */
-extern u8 sk_load_word[], sk_load_half[], sk_load_byte[], sk_load_byte_msh[];
+extern u8 sk_load_word[], sk_load_half[], sk_load_byte[];
 extern u8 sk_load_word_positive_offset[], sk_load_half_positive_offset[];
-extern u8 sk_load_byte_positive_offset[], sk_load_byte_msh_positive_offset[];
+extern u8 sk_load_byte_positive_offset[];
 extern u8 sk_load_word_negative_offset[], sk_load_half_negative_offset[];
-extern u8 sk_load_byte_negative_offset[], sk_load_byte_msh_negative_offset[];
+extern u8 sk_load_byte_negative_offset[];
 
 static inline u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len)
 {
@@ -56,30 +45,44 @@ static inline u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len)
 #define EMIT2(b1, b2)		EMIT((b1) + ((b2) << 8), 2)
 #define EMIT3(b1, b2, b3)	EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3)
 #define EMIT4(b1, b2, b3, b4)   EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4)
-#define EMIT1_off32(b1, off)	do { EMIT1(b1); EMIT(off, 4);} while (0)
-
-#define CLEAR_A() EMIT2(0x31, 0xc0) /* xor %eax,%eax */
-#define CLEAR_X() EMIT2(0x31, 0xdb) /* xor %ebx,%ebx */
+#define EMIT1_off32(b1, off) \
+	do {EMIT1(b1); EMIT(off, 4); } while (0)
+#define EMIT2_off32(b1, b2, off) \
+	do {EMIT2(b1, b2); EMIT(off, 4); } while (0)
+#define EMIT3_off32(b1, b2, b3, off) \
+	do {EMIT3(b1, b2, b3); EMIT(off, 4); } while (0)
+#define EMIT4_off32(b1, b2, b3, b4, off) \
+	do {EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0)
 
 static inline bool is_imm8(int value)
 {
 	return value <= 127 && value >= -128;
 }
 
-static inline bool is_near(int offset)
+static inline bool is_simm32(s64 value)
 {
-	return offset <= 127 && offset >= -128;
+	return value == (s64) (s32) value;
 }
 
-#define EMIT_JMP(offset)						\
-do {									\
-	if (offset) {							\
-		if (is_near(offset))					\
-			EMIT2(0xeb, offset); /* jmp .+off8 */		\
-		else							\
-			EMIT1_off32(0xe9, offset); /* jmp .+off32 */	\
-	}								\
-} while (0)
+/* mov A, X */
+#define EMIT_mov(A, X) \
+	do {if (A != X) \
+		EMIT3(add_2mod(0x48, A, X), 0x89, add_2reg(0xC0, A, X)); \
+	} while (0)
+
+static int bpf_size_to_x86_bytes(int bpf_size)
+{
+	if (bpf_size == BPF_W)
+		return 4;
+	else if (bpf_size == BPF_H)
+		return 2;
+	else if (bpf_size == BPF_B)
+		return 1;
+	else if (bpf_size == BPF_DW)
+		return 4; /* imm32 */
+	else
+		return 0;
+}
 
 /* list of x86 cond jumps opcodes (. + s8)
  * Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32)
@@ -90,27 +93,8 @@ do {									\
 #define X86_JNE 0x75
 #define X86_JBE 0x76
 #define X86_JA  0x77
-
-#define EMIT_COND_JMP(op, offset)				\
-do {								\
-	if (is_near(offset))					\
-		EMIT2(op, offset); /* jxx .+off8 */		\
-	else {							\
-		EMIT2(0x0f, op + 0x10);				\
-		EMIT(offset, 4); /* jxx .+off32 */		\
-	}							\
-} while (0)
-
-#define COND_SEL(CODE, TOP, FOP)	\
-	case CODE:			\
-		t_op = TOP;		\
-		f_op = FOP;		\
-		goto cond_branch
-
-
-#define SEEN_DATAREF 1 /* might call external helpers */
-#define SEEN_XREG    2 /* ebx is used */
-#define SEEN_MEM     4 /* use mem[] for temporary storage */
+#define X86_JGE 0x7D
+#define X86_JG  0x7F
 
 static inline void bpf_flush_icache(void *start, void *end)
 {
@@ -125,26 +109,6 @@ static inline void bpf_flush_icache(void *start, void *end)
 #define CHOOSE_LOAD_FUNC(K, func) \
 	((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset)
 
-/* Helper to find the offset of pkt_type in sk_buff
- * We want to make sure its still a 3bit field starting at a byte boundary.
- */
-#define PKT_TYPE_MAX 7
-static int pkt_type_offset(void)
-{
-	struct sk_buff skb_probe = {
-		.pkt_type = ~0,
-	};
-	char *ct = (char *)&skb_probe;
-	unsigned int off;
-
-	for (off = 0; off < sizeof(struct sk_buff); off++) {
-		if (ct[off] == PKT_TYPE_MAX)
-			return off;
-	}
-	pr_err_once("Please fix pkt_type_offset(), as pkt_type couldn't be found\n");
-	return -1;
-}
-
 struct bpf_binary_header {
 	unsigned int	pages;
 	/* Note : for security reasons, bpf code will follow a randomly
@@ -178,546 +142,715 @@ static struct bpf_binary_header *bpf_alloc_binary(unsigned int proglen,
 	return header;
 }
 
+/* pick a register outside of BPF range for JIT internal work */
+#define AUX_REG (MAX_BPF_REG + 1)
+
+/* the following table maps BPF registers to x64 registers.
+ * x64 register r12 is unused, since if used as base address register
+ * in load/store instructions, it always needs an extra byte of encoding
+ */
+static const int reg2hex[] = {
+	[BPF_REG_0] = 0,  /* rax */
+	[BPF_REG_1] = 7,  /* rdi */
+	[BPF_REG_2] = 6,  /* rsi */
+	[BPF_REG_3] = 2,  /* rdx */
+	[BPF_REG_4] = 1,  /* rcx */
+	[BPF_REG_5] = 0,  /* r8 */
+	[BPF_REG_6] = 3,  /* rbx callee saved */
+	[BPF_REG_7] = 5,  /* r13 callee saved */
+	[BPF_REG_8] = 6,  /* r14 callee saved */
+	[BPF_REG_9] = 7,  /* r15 callee saved */
+	[BPF_REG_FP] = 5, /* rbp readonly */
+	[AUX_REG] = 3,    /* r11 temp register */
+};
+
+/* is_ereg() == true if BPF register 'reg' maps to x64 r8..r15
+ * which need extra byte of encoding.
+ * rax,rcx,...,rbp have simpler encoding
+ */
+static inline bool is_ereg(u32 reg)
+{
+	if (reg == BPF_REG_5 || reg == AUX_REG ||
+	    (reg >= BPF_REG_7 && reg <= BPF_REG_9))
+		return true;
+	else
+		return false;
+}
+
+/* add modifiers if 'reg' maps to x64 registers r8..r15 */
+static inline u8 add_1mod(u8 byte, u32 reg)
+{
+	if (is_ereg(reg))
+		byte |= 1;
+	return byte;
+}
+
+static inline u8 add_2mod(u8 byte, u32 r1, u32 r2)
+{
+	if (is_ereg(r1))
+		byte |= 1;
+	if (is_ereg(r2))
+		byte |= 4;
+	return byte;
+}
+
+/* encode dest register 'a_reg' into x64 opcode 'byte' */
+static inline u8 add_1reg(u8 byte, u32 a_reg)
+{
+	return byte + reg2hex[a_reg];
+}
+
+/* encode dest 'a_reg' and src 'x_reg' registers into x64 opcode 'byte' */
+static inline u8 add_2reg(u8 byte, u32 a_reg, u32 x_reg)
+{
+	return byte + reg2hex[a_reg] + (reg2hex[x_reg] << 3);
+}
+
 struct jit_context {
 	unsigned int cleanup_addr; /* epilogue code offset */
-	int pc_ret0; /* bpf index of first RET #0 instruction (if any) */
-	u8 seen;
+	bool seen_ld_abs;
 };
 
 static int do_jit(struct sk_filter *bpf_prog, int *addrs, u8 *image,
 		  int oldproglen, struct jit_context *ctx)
 {
-	const struct sock_filter *filter = bpf_prog->insns;
-	int flen = bpf_prog->len;
+	struct sock_filter_int *insn = bpf_prog->insnsi;
+	int insn_cnt = bpf_prog->len;
 	u8 temp[64];
-	u8 *prog;
-	int ilen, i, proglen;
-	int t_offset, f_offset;
-	u8 t_op, f_op, seen = 0;
-	u8 *func;
-	unsigned int cleanup_addr = ctx->cleanup_addr;
-	u8 seen_or_pass0 = ctx->seen;
-
-		/* no prologue/epilogue for trivial filters (RET something) */
-		proglen = 0;
-		prog = temp;
+	int i;
+	int proglen = 0;
+	u8 *prog = temp;
+	int stacksize = MAX_BPF_STACK +
+		32 /* space for rbx, r13, r14, r15 */ +
+		8 /* space for skb_copy_bits() buffer */;
 
-		if (seen_or_pass0) {
-			EMIT4(0x55, 0x48, 0x89, 0xe5); /* push %rbp; mov %rsp,%rbp */
-			EMIT4(0x48, 0x83, 0xec, 96);	/* subq  $96,%rsp	*/
-			/* note : must save %rbx in case bpf_error is hit */
-			if (seen_or_pass0 & (SEEN_XREG | SEEN_DATAREF))
-				EMIT4(0x48, 0x89, 0x5d, 0xf8); /* mov %rbx, -8(%rbp) */
-			if (seen_or_pass0 & SEEN_XREG)
-				CLEAR_X(); /* make sure we dont leek kernel memory */
-
-			/*
-			 * If this filter needs to access skb data,
-			 * loads r9 and r8 with :
-			 *  r9 = skb->len - skb->data_len
-			 *  r8 = skb->data
-			 */
-			if (seen_or_pass0 & SEEN_DATAREF) {
-				if (offsetof(struct sk_buff, len) <= 127)
-					/* mov    off8(%rdi),%r9d */
-					EMIT4(0x44, 0x8b, 0x4f, offsetof(struct sk_buff, len));
-				else {
-					/* mov    off32(%rdi),%r9d */
-					EMIT3(0x44, 0x8b, 0x8f);
-					EMIT(offsetof(struct sk_buff, len), 4);
-				}
-				if (is_imm8(offsetof(struct sk_buff, data_len)))
-					/* sub    off8(%rdi),%r9d */
-					EMIT4(0x44, 0x2b, 0x4f, offsetof(struct sk_buff, data_len));
-				else {
-					EMIT3(0x44, 0x2b, 0x8f);
-					EMIT(offsetof(struct sk_buff, data_len), 4);
-				}
+	EMIT1(0x55); /* push rbp */
+	EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */
 
-				if (is_imm8(offsetof(struct sk_buff, data)))
-					/* mov off8(%rdi),%r8 */
-					EMIT4(0x4c, 0x8b, 0x47, offsetof(struct sk_buff, data));
-				else {
-					/* mov off32(%rdi),%r8 */
-					EMIT3(0x4c, 0x8b, 0x87);
-					EMIT(offsetof(struct sk_buff, data), 4);
-				}
+	/* sub rsp, stacksize */
+	EMIT3_off32(0x48, 0x81, 0xEC, stacksize);
+
+	/* all classic BPF filters use R6(rbx) save it */
+
+	/* mov qword ptr [rbp-X],rbx */
+	EMIT3_off32(0x48, 0x89, 0x9D, -stacksize);
+
+	/* sk_convert_filter() maps classic BPF register X to R7 and uses R8
+	 * as temporary, so all tcpdump filters need to spill/fill R7(r13) and
+	 * R8(r14). R9(r15) spill could be made conditional, but there is only
+	 * one 'bpf_error' return path out of helper functions inside bpf_jit.S
+	 * The overhead of extra spill is negligible for any filter other
+	 * than synthetic ones. Therefore not worth adding complexity.
+	 */
+
+	/* mov qword ptr [rbp-X],r13 */
+	EMIT3_off32(0x4C, 0x89, 0xAD, -stacksize + 8);
+	/* mov qword ptr [rbp-X],r14 */
+	EMIT3_off32(0x4C, 0x89, 0xB5, -stacksize + 16);
+	/* mov qword ptr [rbp-X],r15 */
+	EMIT3_off32(0x4C, 0x89, 0xBD, -stacksize + 24);
+
+	/* clear A and X registers */
+	EMIT2(0x31, 0xc0); /* xor eax, eax */
+	EMIT3(0x4D, 0x31, 0xED); /* xor r13, r13 */
+
+	if (ctx->seen_ld_abs) {
+		/* r9d : skb->len - skb->data_len (headlen)
+		 * r10 : skb->data
+		 */
+		if (is_imm8(offsetof(struct sk_buff, len)))
+			/* mov %r9d, off8(%rdi) */
+			EMIT4(0x44, 0x8b, 0x4f,
+			      offsetof(struct sk_buff, len));
+		else
+			/* mov %r9d, off32(%rdi) */
+			EMIT3_off32(0x44, 0x8b, 0x8f,
+				    offsetof(struct sk_buff, len));
+
+		if (is_imm8(offsetof(struct sk_buff, data_len)))
+			/* sub %r9d, off8(%rdi) */
+			EMIT4(0x44, 0x2b, 0x4f,
+			      offsetof(struct sk_buff, data_len));
+		else
+			EMIT3_off32(0x44, 0x2b, 0x8f,
+				    offsetof(struct sk_buff, data_len));
+
+		if (is_imm8(offsetof(struct sk_buff, data)))
+			/* mov %r10, off8(%rdi) */
+			EMIT4(0x4c, 0x8b, 0x57,
+			      offsetof(struct sk_buff, data));
+		else
+			/* mov %r10, off32(%rdi) */
+			EMIT3_off32(0x4c, 0x8b, 0x97,
+				    offsetof(struct sk_buff, data));
+	}
+
+	for (i = 0; i < insn_cnt; i++, insn++) {
+		const s32 K = insn->imm;
+		u32 a_reg = insn->a_reg;
+		u32 x_reg = insn->x_reg;
+		u8 b1 = 0, b2 = 0, b3 = 0;
+		s64 jmp_offset;
+		u8 jmp_cond;
+		int ilen;
+		u8 *func;
+
+		switch (insn->code) {
+			/* ALU */
+		case BPF_ALU | BPF_ADD | BPF_X:
+		case BPF_ALU | BPF_SUB | BPF_X:
+		case BPF_ALU | BPF_AND | BPF_X:
+		case BPF_ALU | BPF_OR | BPF_X:
+		case BPF_ALU | BPF_XOR | BPF_X:
+		case BPF_ALU64 | BPF_ADD | BPF_X:
+		case BPF_ALU64 | BPF_SUB | BPF_X:
+		case BPF_ALU64 | BPF_AND | BPF_X:
+		case BPF_ALU64 | BPF_OR | BPF_X:
+		case BPF_ALU64 | BPF_XOR | BPF_X:
+			switch (BPF_OP(insn->code)) {
+			case BPF_ADD: b2 = 0x01; break;
+			case BPF_SUB: b2 = 0x29; break;
+			case BPF_AND: b2 = 0x21; break;
+			case BPF_OR: b2 = 0x09; break;
+			case BPF_XOR: b2 = 0x31; break;
 			}
-		}
+			if (BPF_CLASS(insn->code) == BPF_ALU64)
+				EMIT1(add_2mod(0x48, a_reg, x_reg));
+			else if (is_ereg(a_reg) || is_ereg(x_reg))
+				EMIT1(add_2mod(0x40, a_reg, x_reg));
+			EMIT2(b2, add_2reg(0xC0, a_reg, x_reg));
+			break;
 
-		switch (filter[0].code) {
-		case BPF_S_RET_K:
-		case BPF_S_LD_W_LEN:
-		case BPF_S_ANC_PROTOCOL:
-		case BPF_S_ANC_IFINDEX:
-		case BPF_S_ANC_MARK:
-		case BPF_S_ANC_RXHASH:
-		case BPF_S_ANC_CPU:
-		case BPF_S_ANC_VLAN_TAG:
-		case BPF_S_ANC_VLAN_TAG_PRESENT:
-		case BPF_S_ANC_QUEUE:
-		case BPF_S_ANC_PKTTYPE:
-		case BPF_S_LD_W_ABS:
-		case BPF_S_LD_H_ABS:
-		case BPF_S_LD_B_ABS:
-			/* first instruction sets A register (or is RET 'constant') */
+			/* mov A, X */
+		case BPF_ALU64 | BPF_MOV | BPF_X:
+			EMIT_mov(a_reg, x_reg);
 			break;
-		default:
-			/* make sure we dont leak kernel information to user */
-			CLEAR_A(); /* A = 0 */
-		}
 
-		for (i = 0; i < flen; i++) {
-			unsigned int K = filter[i].k;
+			/* mov32 A, X */
+		case BPF_ALU | BPF_MOV | BPF_X:
+			if (is_ereg(a_reg) || is_ereg(x_reg))
+				EMIT1(add_2mod(0x40, a_reg, x_reg));
+			EMIT2(0x89, add_2reg(0xC0, a_reg, x_reg));
+			break;
 
-			switch (filter[i].code) {
-			case BPF_S_ALU_ADD_X: /* A += X; */
-				seen |= SEEN_XREG;
-				EMIT2(0x01, 0xd8);		/* add %ebx,%eax */
-				break;
-			case BPF_S_ALU_ADD_K: /* A += K; */
-				if (!K)
-					break;
-				if (is_imm8(K))
-					EMIT3(0x83, 0xc0, K);	/* add imm8,%eax */
-				else
-					EMIT1_off32(0x05, K);	/* add imm32,%eax */
-				break;
-			case BPF_S_ALU_SUB_X: /* A -= X; */
-				seen |= SEEN_XREG;
-				EMIT2(0x29, 0xd8);		/* sub    %ebx,%eax */
-				break;
-			case BPF_S_ALU_SUB_K: /* A -= K */
-				if (!K)
-					break;
-				if (is_imm8(K))
-					EMIT3(0x83, 0xe8, K); /* sub imm8,%eax */
-				else
-					EMIT1_off32(0x2d, K); /* sub imm32,%eax */
-				break;
-			case BPF_S_ALU_MUL_X: /* A *= X; */
-				seen |= SEEN_XREG;
-				EMIT3(0x0f, 0xaf, 0xc3);	/* imul %ebx,%eax */
-				break;
-			case BPF_S_ALU_MUL_K: /* A *= K */
-				if (is_imm8(K))
-					EMIT3(0x6b, 0xc0, K); /* imul imm8,%eax,%eax */
-				else {
-					EMIT2(0x69, 0xc0);		/* imul imm32,%eax */
-					EMIT(K, 4);
-				}
-				break;
-			case BPF_S_ALU_DIV_X: /* A /= X; */
-				seen |= SEEN_XREG;
-				EMIT2(0x85, 0xdb);	/* test %ebx,%ebx */
-				if (ctx->pc_ret0 > 0) {
-					/* addrs[pc_ret0 - 1] is start address of target
-					 * (addrs[i] - 4) is the address following this jmp
-					 * ("xor %edx,%edx; div %ebx" being 4 bytes long)
-					 */
-					EMIT_COND_JMP(X86_JE, addrs[ctx->pc_ret0 - 1] -
-								(addrs[i] - 4));
-				} else {
-					EMIT_COND_JMP(X86_JNE, 2 + 5);
-					CLEAR_A();
-					EMIT1_off32(0xe9, cleanup_addr - (addrs[i] - 4)); /* jmp .+off32 */
-				}
-				EMIT4(0x31, 0xd2, 0xf7, 0xf3); /* xor %edx,%edx; div %ebx */
-				break;
-			case BPF_S_ALU_MOD_X: /* A %= X; */
-				seen |= SEEN_XREG;
-				EMIT2(0x85, 0xdb);	/* test %ebx,%ebx */
-				if (ctx->pc_ret0 > 0) {
-					/* addrs[pc_ret0 - 1] is start address of target
-					 * (addrs[i] - 6) is the address following this jmp
-					 * ("xor %edx,%edx; div %ebx;mov %edx,%eax" being 6 bytes long)
-					 */
-					EMIT_COND_JMP(X86_JE, addrs[ctx->pc_ret0 - 1] -
-								(addrs[i] - 6));
-				} else {
-					EMIT_COND_JMP(X86_JNE, 2 + 5);
-					CLEAR_A();
-					EMIT1_off32(0xe9, cleanup_addr - (addrs[i] - 6)); /* jmp .+off32 */
-				}
-				EMIT2(0x31, 0xd2);	/* xor %edx,%edx */
-				EMIT2(0xf7, 0xf3);	/* div %ebx */
-				EMIT2(0x89, 0xd0);	/* mov %edx,%eax */
-				break;
-			case BPF_S_ALU_MOD_K: /* A %= K; */
-				if (K == 1) {
-					CLEAR_A();
-					break;
-				}
-				EMIT2(0x31, 0xd2);	/* xor %edx,%edx */
-				EMIT1(0xb9);EMIT(K, 4);	/* mov imm32,%ecx */
-				EMIT2(0xf7, 0xf1);	/* div %ecx */
-				EMIT2(0x89, 0xd0);	/* mov %edx,%eax */
-				break;
-			case BPF_S_ALU_DIV_K: /* A /= K */
-				if (K == 1)
-					break;
-				EMIT2(0x31, 0xd2);	/* xor %edx,%edx */
-				EMIT1(0xb9);EMIT(K, 4);	/* mov imm32,%ecx */
-				EMIT2(0xf7, 0xf1);	/* div %ecx */
-				break;
-			case BPF_S_ALU_AND_X:
-				seen |= SEEN_XREG;
-				EMIT2(0x21, 0xd8);		/* and %ebx,%eax */
-				break;
-			case BPF_S_ALU_AND_K:
-				if (K >= 0xFFFFFF00) {
-					EMIT2(0x24, K & 0xFF); /* and imm8,%al */
-				} else if (K >= 0xFFFF0000) {
-					EMIT2(0x66, 0x25);	/* and imm16,%ax */
-					EMIT(K, 2);
-				} else {
-					EMIT1_off32(0x25, K);	/* and imm32,%eax */
-				}
-				break;
-			case BPF_S_ALU_OR_X:
-				seen |= SEEN_XREG;
-				EMIT2(0x09, 0xd8);		/* or %ebx,%eax */
-				break;
-			case BPF_S_ALU_OR_K:
-				if (is_imm8(K))
-					EMIT3(0x83, 0xc8, K); /* or imm8,%eax */
-				else
-					EMIT1_off32(0x0d, K);	/* or imm32,%eax */
-				break;
-			case BPF_S_ANC_ALU_XOR_X: /* A ^= X; */
-			case BPF_S_ALU_XOR_X:
-				seen |= SEEN_XREG;
-				EMIT2(0x31, 0xd8);		/* xor %ebx,%eax */
-				break;
-			case BPF_S_ALU_XOR_K: /* A ^= K; */
-				if (K == 0)
-					break;
-				if (is_imm8(K))
-					EMIT3(0x83, 0xf0, K);	/* xor imm8,%eax */
-				else
-					EMIT1_off32(0x35, K);	/* xor imm32,%eax */
-				break;
-			case BPF_S_ALU_LSH_X: /* A <<= X; */
-				seen |= SEEN_XREG;
-				EMIT4(0x89, 0xd9, 0xd3, 0xe0);	/* mov %ebx,%ecx; shl %cl,%eax */
-				break;
-			case BPF_S_ALU_LSH_K:
-				if (K == 0)
-					break;
-				else if (K == 1)
-					EMIT2(0xd1, 0xe0); /* shl %eax */
-				else
-					EMIT3(0xc1, 0xe0, K);
-				break;
-			case BPF_S_ALU_RSH_X: /* A >>= X; */
-				seen |= SEEN_XREG;
-				EMIT4(0x89, 0xd9, 0xd3, 0xe8);	/* mov %ebx,%ecx; shr %cl,%eax */
-				break;
-			case BPF_S_ALU_RSH_K: /* A >>= K; */
-				if (K == 0)
-					break;
-				else if (K == 1)
-					EMIT2(0xd1, 0xe8); /* shr %eax */
-				else
-					EMIT3(0xc1, 0xe8, K);
-				break;
-			case BPF_S_ALU_NEG:
-				EMIT2(0xf7, 0xd8);		/* neg %eax */
-				break;
-			case BPF_S_RET_K:
-				if (!K) {
-					if (ctx->pc_ret0 == -1)
-						ctx->pc_ret0 = i;
-					CLEAR_A();
-				} else {
-					EMIT1_off32(0xb8, K);	/* mov $imm32,%eax */
-				}
-				/* fallinto */
-			case BPF_S_RET_A:
-				if (seen_or_pass0) {
-					if (i != flen - 1) {
-						EMIT_JMP(cleanup_addr - addrs[i]);
-						break;
-					}
-					if (seen_or_pass0 & SEEN_XREG)
-						EMIT4(0x48, 0x8b, 0x5d, 0xf8);  /* mov  -8(%rbp),%rbx */
-					EMIT1(0xc9);		/* leaveq */
-				}
-				EMIT1(0xc3);		/* ret */
-				break;
-			case BPF_S_MISC_TAX: /* X = A */
-				seen |= SEEN_XREG;
-				EMIT2(0x89, 0xc3);	/* mov    %eax,%ebx */
-				break;
-			case BPF_S_MISC_TXA: /* A = X */
-				seen |= SEEN_XREG;
-				EMIT2(0x89, 0xd8);	/* mov    %ebx,%eax */
-				break;
-			case BPF_S_LD_IMM: /* A = K */
-				if (!K)
-					CLEAR_A();
-				else
-					EMIT1_off32(0xb8, K); /* mov $imm32,%eax */
+			/* neg A */
+		case BPF_ALU | BPF_NEG:
+		case BPF_ALU64 | BPF_NEG:
+			if (BPF_CLASS(insn->code) == BPF_ALU64)
+				EMIT1(add_1mod(0x48, a_reg));
+			else if (is_ereg(a_reg))
+				EMIT1(add_1mod(0x40, a_reg));
+			EMIT2(0xF7, add_1reg(0xD8, a_reg));
+			break;
+
+		case BPF_ALU | BPF_ADD | BPF_K:
+		case BPF_ALU | BPF_SUB | BPF_K:
+		case BPF_ALU | BPF_AND | BPF_K:
+		case BPF_ALU | BPF_OR | BPF_K:
+		case BPF_ALU | BPF_XOR | BPF_K:
+		case BPF_ALU64 | BPF_ADD | BPF_K:
+		case BPF_ALU64 | BPF_SUB | BPF_K:
+		case BPF_ALU64 | BPF_AND | BPF_K:
+		case BPF_ALU64 | BPF_OR | BPF_K:
+		case BPF_ALU64 | BPF_XOR | BPF_K:
+			if (BPF_CLASS(insn->code) == BPF_ALU64)
+				EMIT1(add_1mod(0x48, a_reg));
+			else if (is_ereg(a_reg))
+				EMIT1(add_1mod(0x40, a_reg));
+
+			switch (BPF_OP(insn->code)) {
+			case BPF_ADD: b3 = 0xC0; break;
+			case BPF_SUB: b3 = 0xE8; break;
+			case BPF_AND: b3 = 0xE0; break;
+			case BPF_OR: b3 = 0xC8; break;
+			case BPF_XOR: b3 = 0xF0; break;
+			}
+
+			if (is_imm8(K))
+				EMIT3(0x83, add_1reg(b3, a_reg), K);
+			else
+				EMIT2_off32(0x81, add_1reg(b3, a_reg), K);
+			break;
+
+		case BPF_ALU64 | BPF_MOV | BPF_K:
+			/* optimization: if imm32 is positive,
+			 * use 'mov eax, imm32' (which zero-extends imm32)
+			 * to save 2 bytes
+			 */
+			if (K < 0) {
+				/* 'mov rax, imm32' sign extends imm32 */
+				b1 = add_1mod(0x48, a_reg);
+				b2 = 0xC7;
+				b3 = 0xC0;
+				EMIT3_off32(b1, b2, add_1reg(b3, a_reg), K);
 				break;
-			case BPF_S_LDX_IMM: /* X = K */
-				seen |= SEEN_XREG;
-				if (!K)
-					CLEAR_X();
+			}
+
+		case BPF_ALU | BPF_MOV | BPF_K:
+			/* mov %eax, imm32 */
+			if (is_ereg(a_reg))
+				EMIT1(add_1mod(0x40, a_reg));
+			EMIT1_off32(add_1reg(0xB8, a_reg), K);
+			break;
+
+			/* A %= X, A /= X, A %= K, A /= K */
+		case BPF_ALU | BPF_MOD | BPF_X:
+		case BPF_ALU | BPF_DIV | BPF_X:
+		case BPF_ALU | BPF_MOD | BPF_K:
+		case BPF_ALU | BPF_DIV | BPF_K:
+		case BPF_ALU64 | BPF_MOD | BPF_X:
+		case BPF_ALU64 | BPF_DIV | BPF_X:
+		case BPF_ALU64 | BPF_MOD | BPF_K:
+		case BPF_ALU64 | BPF_DIV | BPF_K:
+			EMIT1(0x50); /* push rax */
+			EMIT1(0x52); /* push rdx */
+
+			if (BPF_SRC(insn->code) == BPF_X)
+				/* mov r11, X */
+				EMIT_mov(AUX_REG, x_reg);
+			else
+				/* mov r11, K */
+				EMIT3_off32(0x49, 0xC7, 0xC3, K);
+
+			/* mov rax, A */
+			EMIT_mov(BPF_REG_0, a_reg);
+
+			/* xor edx, edx
+			 * equivalent to 'xor rdx, rdx', but one byte less
+			 */
+			EMIT2(0x31, 0xd2);
+
+			if (BPF_SRC(insn->code) == BPF_X) {
+				/* if (X == 0) return 0 */
+
+				/* cmp r11, 0 */
+				EMIT4(0x49, 0x83, 0xFB, 0x00);
+
+				/* jne .+9 (skip over pop, pop, xor and jmp) */
+				EMIT2(X86_JNE, 1 + 1 + 2 + 5);
+				EMIT1(0x5A); /* pop rdx */
+				EMIT1(0x58); /* pop rax */
+				EMIT2(0x31, 0xc0); /* xor eax, eax */
+
+				/* jmp cleanup_addr
+				 * addrs[i] - 11, because there are 11 bytes
+				 * after this insn: div, mov, pop, pop, mov
+				 */
+				jmp_offset = ctx->cleanup_addr - (addrs[i] - 11);
+				EMIT1_off32(0xE9, jmp_offset);
+			}
+
+			if (BPF_CLASS(insn->code) == BPF_ALU64)
+				/* div r11 */
+				EMIT3(0x49, 0xF7, 0xF3);
+			else
+				/* div r11d */
+				EMIT3(0x41, 0xF7, 0xF3);
+
+			if (BPF_OP(insn->code) == BPF_MOD)
+				/* mov r11, rdx */
+				EMIT3(0x49, 0x89, 0xD3);
+			else
+				/* mov r11, rax */
+				EMIT3(0x49, 0x89, 0xC3);
+
+			EMIT1(0x5A); /* pop rdx */
+			EMIT1(0x58); /* pop rax */
+
+			/* mov A, r11 */
+			EMIT_mov(a_reg, AUX_REG);
+			break;
+
+		case BPF_ALU | BPF_MUL | BPF_K:
+		case BPF_ALU | BPF_MUL | BPF_X:
+		case BPF_ALU64 | BPF_MUL | BPF_K:
+		case BPF_ALU64 | BPF_MUL | BPF_X:
+			EMIT1(0x50); /* push rax */
+			EMIT1(0x52); /* push rdx */
+
+			/* mov r11, A */
+			EMIT_mov(AUX_REG, a_reg);
+
+			if (BPF_SRC(insn->code) == BPF_X)
+				/* mov rax, X */
+				EMIT_mov(BPF_REG_0, x_reg);
+			else
+				/* mov rax, K */
+				EMIT3_off32(0x48, 0xC7, 0xC0, K);
+
+			if (BPF_CLASS(insn->code) == BPF_ALU64)
+				EMIT1(add_1mod(0x48, AUX_REG));
+			else if (is_ereg(AUX_REG))
+				EMIT1(add_1mod(0x40, AUX_REG));
+			/* mul(q) r11 */
+			EMIT2(0xF7, add_1reg(0xE0, AUX_REG));
+
+			/* mov r11, rax */
+			EMIT_mov(AUX_REG, BPF_REG_0);
+
+			EMIT1(0x5A); /* pop rdx */
+			EMIT1(0x58); /* pop rax */
+
+			/* mov A, r11 */
+			EMIT_mov(a_reg, AUX_REG);
+			break;
+
+			/* shifts */
+		case BPF_ALU | BPF_LSH | BPF_K:
+		case BPF_ALU | BPF_RSH | BPF_K:
+		case BPF_ALU | BPF_ARSH | BPF_K:
+		case BPF_ALU64 | BPF_LSH | BPF_K:
+		case BPF_ALU64 | BPF_RSH | BPF_K:
+		case BPF_ALU64 | BPF_ARSH | BPF_K:
+			if (BPF_CLASS(insn->code) == BPF_ALU64)
+				EMIT1(add_1mod(0x48, a_reg));
+			else if (is_ereg(a_reg))
+				EMIT1(add_1mod(0x40, a_reg));
+
+			switch (BPF_OP(insn->code)) {
+			case BPF_LSH: b3 = 0xE0; break;
+			case BPF_RSH: b3 = 0xE8; break;
+			case BPF_ARSH: b3 = 0xF8; break;
+			}
+			EMIT3(0xC1, add_1reg(b3, a_reg), K);
+			break;
+
+		case BPF_ALU | BPF_END | BPF_FROM_BE:
+			switch (K) {
+			case 16:
+				/* emit 'ror %ax, 8' to swap lower 2 bytes */
+				EMIT1(0x66);
+				if (is_ereg(a_reg))
+					EMIT1(0x41);
+				EMIT3(0xC1, add_1reg(0xC8, a_reg), 8);
+				break;
+			case 32:
+				/* emit 'bswap eax' to swap lower 4 bytes */
+				if (is_ereg(a_reg))
+					EMIT2(0x41, 0x0F);
 				else
-					EMIT1_off32(0xbb, K); /* mov $imm32,%ebx */
-				break;
-			case BPF_S_LD_MEM: /* A = mem[K] : mov off8(%rbp),%eax */
-				seen |= SEEN_MEM;
-				EMIT3(0x8b, 0x45, 0xf0 - K*4);
+					EMIT1(0x0F);
+				EMIT1(add_1reg(0xC8, a_reg));
 				break;
-			case BPF_S_LDX_MEM: /* X = mem[K] : mov off8(%rbp),%ebx */
-				seen |= SEEN_XREG | SEEN_MEM;
-				EMIT3(0x8b, 0x5d, 0xf0 - K*4);
-				break;
-			case BPF_S_ST: /* mem[K] = A : mov %eax,off8(%rbp) */
-				seen |= SEEN_MEM;
-				EMIT3(0x89, 0x45, 0xf0 - K*4);
-				break;
-			case BPF_S_STX: /* mem[K] = X : mov %ebx,off8(%rbp) */
-				seen |= SEEN_XREG | SEEN_MEM;
-				EMIT3(0x89, 0x5d, 0xf0 - K*4);
-				break;
-			case BPF_S_LD_W_LEN: /*	A = skb->len; */
-				BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4);
-				if (is_imm8(offsetof(struct sk_buff, len)))
-					/* mov    off8(%rdi),%eax */
-					EMIT3(0x8b, 0x47, offsetof(struct sk_buff, len));
-				else {
-					EMIT2(0x8b, 0x87);
-					EMIT(offsetof(struct sk_buff, len), 4);
-				}
-				break;
-			case BPF_S_LDX_W_LEN: /* X = skb->len; */
-				seen |= SEEN_XREG;
-				if (is_imm8(offsetof(struct sk_buff, len)))
-					/* mov off8(%rdi),%ebx */
-					EMIT3(0x8b, 0x5f, offsetof(struct sk_buff, len));
-				else {
-					EMIT2(0x8b, 0x9f);
-					EMIT(offsetof(struct sk_buff, len), 4);
-				}
-				break;
-			case BPF_S_ANC_PROTOCOL: /* A = ntohs(skb->protocol); */
-				BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2);
-				if (is_imm8(offsetof(struct sk_buff, protocol))) {
-					/* movzwl off8(%rdi),%eax */
-					EMIT4(0x0f, 0xb7, 0x47, offsetof(struct sk_buff, protocol));
-				} else {
-					EMIT3(0x0f, 0xb7, 0x87); /* movzwl off32(%rdi),%eax */
-					EMIT(offsetof(struct sk_buff, protocol), 4);
-				}
-				EMIT2(0x86, 0xc4); /* ntohs() : xchg   %al,%ah */
-				break;
-			case BPF_S_ANC_IFINDEX:
-				if (is_imm8(offsetof(struct sk_buff, dev))) {
-					/* movq off8(%rdi),%rax */
-					EMIT4(0x48, 0x8b, 0x47, offsetof(struct sk_buff, dev));
-				} else {
-					EMIT3(0x48, 0x8b, 0x87); /* movq off32(%rdi),%rax */
-					EMIT(offsetof(struct sk_buff, dev), 4);
-				}
-				EMIT3(0x48, 0x85, 0xc0);	/* test %rax,%rax */
-				EMIT_COND_JMP(X86_JE, cleanup_addr - (addrs[i] - 6));
-				BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
-				EMIT2(0x8b, 0x80);	/* mov off32(%rax),%eax */
-				EMIT(offsetof(struct net_device, ifindex), 4);
-				break;
-			case BPF_S_ANC_MARK:
-				BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
-				if (is_imm8(offsetof(struct sk_buff, mark))) {
-					/* mov off8(%rdi),%eax */
-					EMIT3(0x8b, 0x47, offsetof(struct sk_buff, mark));
-				} else {
-					EMIT2(0x8b, 0x87);
-					EMIT(offsetof(struct sk_buff, mark), 4);
-				}
-				break;
-			case BPF_S_ANC_RXHASH:
-				BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4);
-				if (is_imm8(offsetof(struct sk_buff, hash))) {
-					/* mov off8(%rdi),%eax */
-					EMIT3(0x8b, 0x47, offsetof(struct sk_buff, hash));
-				} else {
-					EMIT2(0x8b, 0x87);
-					EMIT(offsetof(struct sk_buff, hash), 4);
-				}
-				break;
-			case BPF_S_ANC_QUEUE:
-				BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2);
-				if (is_imm8(offsetof(struct sk_buff, queue_mapping))) {
-					/* movzwl off8(%rdi),%eax */
-					EMIT4(0x0f, 0xb7, 0x47, offsetof(struct sk_buff, queue_mapping));
-				} else {
-					EMIT3(0x0f, 0xb7, 0x87); /* movzwl off32(%rdi),%eax */
-					EMIT(offsetof(struct sk_buff, queue_mapping), 4);
-				}
-				break;
-			case BPF_S_ANC_CPU:
-#ifdef CONFIG_SMP
-				EMIT4(0x65, 0x8b, 0x04, 0x25); /* mov %gs:off32,%eax */
-				EMIT((u32)(unsigned long)&cpu_number, 4); /* A = smp_processor_id(); */
-#else
-				CLEAR_A();
-#endif
-				break;
-			case BPF_S_ANC_VLAN_TAG:
-			case BPF_S_ANC_VLAN_TAG_PRESENT:
-				BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2);
-				if (is_imm8(offsetof(struct sk_buff, vlan_tci))) {
-					/* movzwl off8(%rdi),%eax */
-					EMIT4(0x0f, 0xb7, 0x47, offsetof(struct sk_buff, vlan_tci));
-				} else {
-					EMIT3(0x0f, 0xb7, 0x87); /* movzwl off32(%rdi),%eax */
-					EMIT(offsetof(struct sk_buff, vlan_tci), 4);
-				}
-				BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000);
-				if (filter[i].code == BPF_S_ANC_VLAN_TAG) {
-					EMIT3(0x80, 0xe4, 0xef); /* and    $0xef,%ah */
-				} else {
-					EMIT3(0xc1, 0xe8, 0x0c); /* shr    $0xc,%eax */
-					EMIT3(0x83, 0xe0, 0x01); /* and    $0x1,%eax */
-				}
-				break;
-			case BPF_S_ANC_PKTTYPE:
-			{
-				int off = pkt_type_offset();
-
-				if (off < 0)
-					return -EINVAL;
-				if (is_imm8(off)) {
-					/* movzbl off8(%rdi),%eax */
-					EMIT4(0x0f, 0xb6, 0x47, off);
-				} else {
-					/* movbl off32(%rdi),%eax */
-					EMIT3(0x0f, 0xb6, 0x87);
-					EMIT(off, 4);
-				}
-				EMIT3(0x83, 0xe0, PKT_TYPE_MAX); /* and    $0x7,%eax */
+			case 64:
+				/* emit 'bswap rax' to swap 8 bytes */
+				EMIT3(add_1mod(0x48, a_reg), 0x0F,
+				      add_1reg(0xC8, a_reg));
 				break;
 			}
-			case BPF_S_LD_W_ABS:
-				func = CHOOSE_LOAD_FUNC(K, sk_load_word);
-common_load:			seen |= SEEN_DATAREF;
-				t_offset = func - (image + addrs[i]);
-				EMIT1_off32(0xbe, K); /* mov imm32,%esi */
-				EMIT1_off32(0xe8, t_offset); /* call */
-				break;
-			case BPF_S_LD_H_ABS:
-				func = CHOOSE_LOAD_FUNC(K, sk_load_half);
-				goto common_load;
-			case BPF_S_LD_B_ABS:
-				func = CHOOSE_LOAD_FUNC(K, sk_load_byte);
-				goto common_load;
-			case BPF_S_LDX_B_MSH:
-				func = CHOOSE_LOAD_FUNC(K, sk_load_byte_msh);
-				seen |= SEEN_DATAREF | SEEN_XREG;
-				t_offset = func - (image + addrs[i]);
-				EMIT1_off32(0xbe, K);	/* mov imm32,%esi */
-				EMIT1_off32(0xe8, t_offset); /* call sk_load_byte_msh */
-				break;
-			case BPF_S_LD_W_IND:
-				func = sk_load_word;
-common_load_ind:		seen |= SEEN_DATAREF | SEEN_XREG;
-				t_offset = func - (image + addrs[i]);
-				if (K) {
-					if (is_imm8(K)) {
-						EMIT3(0x8d, 0x73, K); /* lea imm8(%rbx), %esi */
-					} else {
-						EMIT2(0x8d, 0xb3); /* lea imm32(%rbx),%esi */
-						EMIT(K, 4);
-					}
-				} else {
-					EMIT2(0x89,0xde); /* mov %ebx,%esi */
-				}
-				EMIT1_off32(0xe8, t_offset);	/* call sk_load_xxx_ind */
-				break;
-			case BPF_S_LD_H_IND:
-				func = sk_load_half;
-				goto common_load_ind;
-			case BPF_S_LD_B_IND:
-				func = sk_load_byte;
-				goto common_load_ind;
-			case BPF_S_JMP_JA:
-				t_offset = addrs[i + K] - addrs[i];
-				EMIT_JMP(t_offset);
-				break;
-			COND_SEL(BPF_S_JMP_JGT_K, X86_JA, X86_JBE);
-			COND_SEL(BPF_S_JMP_JGE_K, X86_JAE, X86_JB);
-			COND_SEL(BPF_S_JMP_JEQ_K, X86_JE, X86_JNE);
-			COND_SEL(BPF_S_JMP_JSET_K,X86_JNE, X86_JE);
-			COND_SEL(BPF_S_JMP_JGT_X, X86_JA, X86_JBE);
-			COND_SEL(BPF_S_JMP_JGE_X, X86_JAE, X86_JB);
-			COND_SEL(BPF_S_JMP_JEQ_X, X86_JE, X86_JNE);
-			COND_SEL(BPF_S_JMP_JSET_X,X86_JNE, X86_JE);
-
-cond_branch:			f_offset = addrs[i + filter[i].jf] - addrs[i];
-				t_offset = addrs[i + filter[i].jt] - addrs[i];
-
-				/* same targets, can avoid doing the test :) */
-				if (filter[i].jt == filter[i].jf) {
-					EMIT_JMP(t_offset);
-					break;
-				}
+			break;
+
+		case BPF_ALU | BPF_END | BPF_FROM_LE:
+			break;
+
+			/* ST: *(u8*)(a_reg + off) = imm */
+		case BPF_ST | BPF_MEM | BPF_B:
+			if (is_ereg(a_reg))
+				EMIT2(0x41, 0xC6);
+			else
+				EMIT1(0xC6);
+			goto st;
+		case BPF_ST | BPF_MEM | BPF_H:
+			if (is_ereg(a_reg))
+				EMIT3(0x66, 0x41, 0xC7);
+			else
+				EMIT2(0x66, 0xC7);
+			goto st;
+		case BPF_ST | BPF_MEM | BPF_W:
+			if (is_ereg(a_reg))
+				EMIT2(0x41, 0xC7);
+			else
+				EMIT1(0xC7);
+			goto st;
+		case BPF_ST | BPF_MEM | BPF_DW:
+			EMIT2(add_1mod(0x48, a_reg), 0xC7);
+
+st:			if (is_imm8(insn->off))
+				EMIT2(add_1reg(0x40, a_reg), insn->off);
+			else
+				EMIT1_off32(add_1reg(0x80, a_reg), insn->off);
+
+			EMIT(K, bpf_size_to_x86_bytes(BPF_SIZE(insn->code)));
+			break;
+
+			/* STX: *(u8*)(a_reg + off) = x_reg */
+		case BPF_STX | BPF_MEM | BPF_B:
+			/* emit 'mov byte ptr [rax + off], al' */
+			if (is_ereg(a_reg) || is_ereg(x_reg) ||
+			    /* have to add extra byte for x86 SIL, DIL regs */
+			    x_reg == BPF_REG_1 || x_reg == BPF_REG_2)
+				EMIT2(add_2mod(0x40, a_reg, x_reg), 0x88);
+			else
+				EMIT1(0x88);
+			goto stx;
+		case BPF_STX | BPF_MEM | BPF_H:
+			if (is_ereg(a_reg) || is_ereg(x_reg))
+				EMIT3(0x66, add_2mod(0x40, a_reg, x_reg), 0x89);
+			else
+				EMIT2(0x66, 0x89);
+			goto stx;
+		case BPF_STX | BPF_MEM | BPF_W:
+			if (is_ereg(a_reg) || is_ereg(x_reg))
+				EMIT2(add_2mod(0x40, a_reg, x_reg), 0x89);
+			else
+				EMIT1(0x89);
+			goto stx;
+		case BPF_STX | BPF_MEM | BPF_DW:
+			EMIT2(add_2mod(0x48, a_reg, x_reg), 0x89);
+stx:			if (is_imm8(insn->off))
+				EMIT2(add_2reg(0x40, a_reg, x_reg), insn->off);
+			else
+				EMIT1_off32(add_2reg(0x80, a_reg, x_reg),
+					    insn->off);
+			break;
+
+			/* LDX: a_reg = *(u8*)(x_reg + off) */
+		case BPF_LDX | BPF_MEM | BPF_B:
+			/* emit 'movzx rax, byte ptr [rax + off]' */
+			EMIT3(add_2mod(0x48, x_reg, a_reg), 0x0F, 0xB6);
+			goto ldx;
+		case BPF_LDX | BPF_MEM | BPF_H:
+			/* emit 'movzx rax, word ptr [rax + off]' */
+			EMIT3(add_2mod(0x48, x_reg, a_reg), 0x0F, 0xB7);
+			goto ldx;
+		case BPF_LDX | BPF_MEM | BPF_W:
+			/* emit 'mov eax, dword ptr [rax+0x14]' */
+			if (is_ereg(a_reg) || is_ereg(x_reg))
+				EMIT2(add_2mod(0x40, x_reg, a_reg), 0x8B);
+			else
+				EMIT1(0x8B);
+			goto ldx;
+		case BPF_LDX | BPF_MEM | BPF_DW:
+			/* emit 'mov rax, qword ptr [rax+0x14]' */
+			EMIT2(add_2mod(0x48, x_reg, a_reg), 0x8B);
+ldx:			/* if insn->off == 0 we can save one extra byte, but
+			 * special case of x86 r13 which always needs an offset
+			 * is not worth the hassle
+			 */
+			if (is_imm8(insn->off))
+				EMIT2(add_2reg(0x40, x_reg, a_reg), insn->off);
+			else
+				EMIT1_off32(add_2reg(0x80, x_reg, a_reg),
+					    insn->off);
+			break;
+
+			/* STX XADD: lock *(u32*)(a_reg + off) += x_reg */
+		case BPF_STX | BPF_XADD | BPF_W:
+			/* emit 'lock add dword ptr [rax + off], eax' */
+			if (is_ereg(a_reg) || is_ereg(x_reg))
+				EMIT3(0xF0, add_2mod(0x40, a_reg, x_reg), 0x01);
+			else
+				EMIT2(0xF0, 0x01);
+			goto xadd;
+		case BPF_STX | BPF_XADD | BPF_DW:
+			EMIT3(0xF0, add_2mod(0x48, a_reg, x_reg), 0x01);
+xadd:			if (is_imm8(insn->off))
+				EMIT2(add_2reg(0x40, a_reg, x_reg), insn->off);
+			else
+				EMIT1_off32(add_2reg(0x80, a_reg, x_reg),
+					    insn->off);
+			break;
+
+			/* call */
+		case BPF_JMP | BPF_CALL:
+			func = (u8 *) __bpf_call_base + K;
+			jmp_offset = func - (image + addrs[i]);
+			if (ctx->seen_ld_abs) {
+				EMIT2(0x41, 0x52); /* push %r10 */
+				EMIT2(0x41, 0x51); /* push %r9 */
+				/* need to adjust jmp offset, since
+				 * pop %r9, pop %r10 take 4 bytes after call insn
+				 */
+				jmp_offset += 4;
+			}
+			if (!K || !is_simm32(jmp_offset)) {
+				pr_err("unsupported bpf func %d addr %p image %p\n",
+				       K, func, image);
+				return -EINVAL;
+			}
+			EMIT1_off32(0xE8, jmp_offset);
+			if (ctx->seen_ld_abs) {
+				EMIT2(0x41, 0x59); /* pop %r9 */
+				EMIT2(0x41, 0x5A); /* pop %r10 */
+			}
+			break;
+
+			/* cond jump */
+		case BPF_JMP | BPF_JEQ | BPF_X:
+		case BPF_JMP | BPF_JNE | BPF_X:
+		case BPF_JMP | BPF_JGT | BPF_X:
+		case BPF_JMP | BPF_JGE | BPF_X:
+		case BPF_JMP | BPF_JSGT | BPF_X:
+		case BPF_JMP | BPF_JSGE | BPF_X:
+			/* cmp a_reg, x_reg */
+			EMIT3(add_2mod(0x48, a_reg, x_reg), 0x39,
+			      add_2reg(0xC0, a_reg, x_reg));
+			goto emit_cond_jmp;
+
+		case BPF_JMP | BPF_JSET | BPF_X:
+			/* test a_reg, x_reg */
+			EMIT3(add_2mod(0x48, a_reg, x_reg), 0x85,
+			      add_2reg(0xC0, a_reg, x_reg));
+			goto emit_cond_jmp;
+
+		case BPF_JMP | BPF_JSET | BPF_K:
+			/* test a_reg, imm32 */
+			EMIT1(add_1mod(0x48, a_reg));
+			EMIT2_off32(0xF7, add_1reg(0xC0, a_reg), K);
+			goto emit_cond_jmp;
+
+		case BPF_JMP | BPF_JEQ | BPF_K:
+		case BPF_JMP | BPF_JNE | BPF_K:
+		case BPF_JMP | BPF_JGT | BPF_K:
+		case BPF_JMP | BPF_JGE | BPF_K:
+		case BPF_JMP | BPF_JSGT | BPF_K:
+		case BPF_JMP | BPF_JSGE | BPF_K:
+			/* cmp a_reg, imm8/32 */
+			EMIT1(add_1mod(0x48, a_reg));
+
+			if (is_imm8(K))
+				EMIT3(0x83, add_1reg(0xF8, a_reg), K);
+			else
+				EMIT2_off32(0x81, add_1reg(0xF8, a_reg), K);
+
+emit_cond_jmp:		/* convert BPF opcode to x86 */
+			switch (BPF_OP(insn->code)) {
+			case BPF_JEQ:
+				jmp_cond = X86_JE;
+				break;
+			case BPF_JSET:
+			case BPF_JNE:
+				jmp_cond = X86_JNE;
+				break;
+			case BPF_JGT:
+				/* GT is unsigned '>', JA in x86 */
+				jmp_cond = X86_JA;
+				break;
+			case BPF_JGE:
+				/* GE is unsigned '>=', JAE in x86 */
+				jmp_cond = X86_JAE;
+				break;
+			case BPF_JSGT:
+				/* signed '>', GT in x86 */
+				jmp_cond = X86_JG;
+				break;
+			case BPF_JSGE:
+				/* signed '>=', GE in x86 */
+				jmp_cond = X86_JGE;
+				break;
+			default: /* to silence gcc warning */
+				return -EFAULT;
+			}
+			jmp_offset = addrs[i + insn->off] - addrs[i];
+			if (is_imm8(jmp_offset)) {
+				EMIT2(jmp_cond, jmp_offset);
+			} else if (is_simm32(jmp_offset)) {
+				EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset);
+			} else {
+				pr_err("cond_jmp gen bug %llx\n", jmp_offset);
+				return -EFAULT;
+			}
+
+			break;
 
-				switch (filter[i].code) {
-				case BPF_S_JMP_JGT_X:
-				case BPF_S_JMP_JGE_X:
-				case BPF_S_JMP_JEQ_X:
-					seen |= SEEN_XREG;
-					EMIT2(0x39, 0xd8); /* cmp %ebx,%eax */
-					break;
-				case BPF_S_JMP_JSET_X:
-					seen |= SEEN_XREG;
-					EMIT2(0x85, 0xd8); /* test %ebx,%eax */
-					break;
-				case BPF_S_JMP_JEQ_K:
-					if (K == 0) {
-						EMIT2(0x85, 0xc0); /* test   %eax,%eax */
-						break;
-					}
-				case BPF_S_JMP_JGT_K:
-				case BPF_S_JMP_JGE_K:
-					if (K <= 127)
-						EMIT3(0x83, 0xf8, K); /* cmp imm8,%eax */
+		case BPF_JMP | BPF_JA:
+			jmp_offset = addrs[i + insn->off] - addrs[i];
+			if (!jmp_offset)
+				/* optimize out nop jumps */
+				break;
+emit_jmp:
+			if (is_imm8(jmp_offset)) {
+				EMIT2(0xEB, jmp_offset);
+			} else if (is_simm32(jmp_offset)) {
+				EMIT1_off32(0xE9, jmp_offset);
+			} else {
+				pr_err("jmp gen bug %llx\n", jmp_offset);
+				return -EFAULT;
+			}
+			break;
+
+		case BPF_LD | BPF_IND | BPF_W:
+			func = sk_load_word;
+			goto common_load;
+		case BPF_LD | BPF_ABS | BPF_W:
+			func = CHOOSE_LOAD_FUNC(K, sk_load_word);
+common_load:		ctx->seen_ld_abs = true;
+			jmp_offset = func - (image + addrs[i]);
+			if (!func || !is_simm32(jmp_offset)) {
+				pr_err("unsupported bpf func %d addr %p image %p\n",
+				       K, func, image);
+				return -EINVAL;
+			}
+			if (BPF_MODE(insn->code) == BPF_ABS) {
+				/* mov %esi, imm32 */
+				EMIT1_off32(0xBE, K);
+			} else {
+				/* mov %rsi, x_reg */
+				EMIT_mov(BPF_REG_2, x_reg);
+				if (K) {
+					if (is_imm8(K))
+						/* add %esi, imm8 */
+						EMIT3(0x83, 0xC6, K);
 					else
-						EMIT1_off32(0x3d, K); /* cmp imm32,%eax */
-					break;
-				case BPF_S_JMP_JSET_K:
-					if (K <= 0xFF)
-						EMIT2(0xa8, K); /* test imm8,%al */
-					else if (!(K & 0xFFFF00FF))
-						EMIT3(0xf6, 0xc4, K >> 8); /* test imm8,%ah */
-					else if (K <= 0xFFFF) {
-						EMIT2(0x66, 0xa9); /* test imm16,%ax */
-						EMIT(K, 2);
-					} else {
-						EMIT1_off32(0xa9, K); /* test imm32,%eax */
-					}
-					break;
+						/* add %esi, imm32 */
+						EMIT2_off32(0x81, 0xC6, K);
 				}
-				if (filter[i].jt != 0) {
-					if (filter[i].jf && f_offset)
-						t_offset += is_near(f_offset) ? 2 : 5;
-					EMIT_COND_JMP(t_op, t_offset);
-					if (filter[i].jf)
-						EMIT_JMP(f_offset);
-					break;
-				}
-				EMIT_COND_JMP(f_op, f_offset);
-				break;
+			}
+			/* skb pointer is in R6 (%rbx), it will be copied into
+			 * %rdi if skb_copy_bits() call is necessary.
+			 * sk_load_* helpers also use %r10 and %r9d.
+			 * See bpf_jit.S
+			 */
+			EMIT1_off32(0xE8, jmp_offset); /* call */
+			break;
+
+		case BPF_LD | BPF_IND | BPF_H:
+			func = sk_load_half;
+			goto common_load;
+		case BPF_LD | BPF_ABS | BPF_H:
+			func = CHOOSE_LOAD_FUNC(K, sk_load_half);
+			goto common_load;
+		case BPF_LD | BPF_IND | BPF_B:
+			func = sk_load_byte;
+			goto common_load;
+		case BPF_LD | BPF_ABS | BPF_B:
+			func = CHOOSE_LOAD_FUNC(K, sk_load_byte);
+			goto common_load;
+
+		case BPF_JMP | BPF_EXIT:
+			if (i != insn_cnt - 1) {
+				jmp_offset = ctx->cleanup_addr - addrs[i];
+				goto emit_jmp;
+			}
+			/* update cleanup_addr */
+			ctx->cleanup_addr = proglen;
+			/* mov rbx, qword ptr [rbp-X] */
+			EMIT3_off32(0x48, 0x8B, 0x9D, -stacksize);
+			/* mov r13, qword ptr [rbp-X] */
+			EMIT3_off32(0x4C, 0x8B, 0xAD, -stacksize + 8);
+			/* mov r14, qword ptr [rbp-X] */
+			EMIT3_off32(0x4C, 0x8B, 0xB5, -stacksize + 16);
+			/* mov r15, qword ptr [rbp-X] */
+			EMIT3_off32(0x4C, 0x8B, 0xBD, -stacksize + 24);
+
+			EMIT1(0xC9); /* leave */
+			EMIT1(0xC3); /* ret */
+			break;
+
 		default:
-			/* hmm, too complex filter, give up with jit compiler */
+			/* By design x64 JIT should support all BPF instructions
+			 * This error will be seen if new instruction was added
+			 * to interpreter, but not to JIT
+			 * or if there is junk in sk_filter
+			 */
+			pr_err("bpf_jit: unknown opcode %02x\n", insn->code);
 			return -EINVAL;
 		}
+
 		ilen = prog - temp;
 		if (image) {
 			if (unlikely(proglen + ilen > oldproglen)) {
-				pr_err("bpb_jit_compile fatal error\n");
+				pr_err("bpf_jit_compile fatal error\n");
 				return -EFAULT;
 			}
 			memcpy(image + proglen, temp, ilen);
@@ -726,22 +859,15 @@ cond_branch:			f_offset = addrs[i + filter[i].jf] - addrs[i];
 		addrs[i] = proglen;
 		prog = temp;
 	}
-	/* last bpf instruction is always a RET :
-	 * use it to give the cleanup instruction(s) addr
-	 */
-	ctx->cleanup_addr = proglen - 1; /* ret */
-	if (seen_or_pass0)
-		ctx->cleanup_addr -= 1; /* leaveq */
-	if (seen_or_pass0 & SEEN_XREG)
-		ctx->cleanup_addr -= 4; /* mov  -8(%rbp),%rbx */
-
-	ctx->seen = seen;
-
 	return proglen;
 }
 
 void bpf_jit_compile(struct sk_filter *prog)
 {
+}
+
+void bpf_int_jit_compile(struct sk_filter *prog)
+{
 	struct bpf_binary_header *header = NULL;
 	int proglen, oldproglen = 0;
 	struct jit_context ctx = {};
@@ -768,8 +894,6 @@ void bpf_jit_compile(struct sk_filter *prog)
 		addrs[i] = proglen;
 	}
 	ctx.cleanup_addr = proglen;
-	ctx.seen = SEEN_XREG | SEEN_DATAREF | SEEN_MEM;
-	ctx.pc_ret0 = -1;
 
 	for (pass = 0; pass < 10; pass++) {
 		proglen = do_jit(prog, addrs, image, oldproglen, &ctx);