Merge branch 'filter-next'

Alexei Starovoitov says:

====================
internal BPF jit for x64 and JITed seccomp

Internal BPF JIT compiler for x86_64 replaces classic BPF JIT.
Use it in seccomp and in tracing filters (sent as separate patch)
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

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

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
@@ -178,583 +142,771 @@ static struct bpf_binary_header *bpf_alloc_binary(unsigned int proglen,
 	return header;
 }
 
-void bpf_jit_compile(struct sk_filter *fp)
+/* 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)
 {
-	u8 temp[64];
-	u8 *prog;
-	unsigned int proglen, oldproglen = 0;
-	int ilen, i;
-	int t_offset, f_offset;
-	u8 t_op, f_op, seen = 0, pass;
-	u8 *image = NULL;
-	struct bpf_binary_header *header = NULL;
-	u8 *func;
-	int pc_ret0 = -1; /* bpf index of first RET #0 instruction (if any) */
-	unsigned int cleanup_addr; /* epilogue code offset */
-	unsigned int *addrs;
-	const struct sock_filter *filter = fp->insns;
-	int flen = fp->len;
+	if (reg == BPF_REG_5 || reg == AUX_REG ||
+	    (reg >= BPF_REG_7 && reg <= BPF_REG_9))
+		return true;
+	else
+		return false;
+}
 
-	if (!bpf_jit_enable)
-		return;
+/* 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;
+}
 
-	addrs = kmalloc(flen * sizeof(*addrs), GFP_KERNEL);
-	if (addrs == NULL)
-		return;
+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;
+}
 
-	/* Before first pass, make a rough estimation of addrs[]
-	 * each bpf instruction is translated to less than 64 bytes
+/* 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 */
+	bool seen_ld_abs;
+};
+
+static int do_jit(struct sk_filter *bpf_prog, int *addrs, u8 *image,
+		  int oldproglen, struct jit_context *ctx)
+{
+	struct sock_filter_int *insn = bpf_prog->insnsi;
+	int insn_cnt = bpf_prog->len;
+	u8 temp[64];
+	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 */;
+
+	EMIT1(0x55); /* push rbp */
+	EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */
+
+	/* 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.
 	 */
-	for (proglen = 0, i = 0; i < flen; i++) {
-		proglen += 64;
-		addrs[i] = proglen;
+
+	/* 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));
 	}
-	cleanup_addr = proglen; /* epilogue address */
 
-	for (pass = 0; pass < 10; pass++) {
-		u8 seen_or_pass0 = (pass == 0) ? (SEEN_XREG | SEEN_DATAREF | SEEN_MEM) : seen;
-		/* no prologue/epilogue for trivial filters (RET something) */
-		proglen = 0;
-		prog = temp;
+	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;
 
-		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
+			/* mov A, X */
+		case BPF_ALU64 | BPF_MOV | BPF_X:
+			EMIT_mov(a_reg, x_reg);
+			break;
+
+			/* 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;
+
+			/* 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 (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);
-				}
+			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;
+			}
 
-				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);
-				}
+		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);
 			}
-		}
 
-		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') */
+			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;
-		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;
+		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;
 
-			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 (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[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 (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[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 (pc_ret0 == -1)
-						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 */
-				break;
-			case BPF_S_LDX_IMM: /* X = K */
-				seen |= SEEN_XREG;
-				if (!K)
-					CLEAR_X();
+			/* 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);
-				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);
+					EMIT1(0x0F);
+				EMIT1(add_1reg(0xC8, a_reg));
 				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)
-					goto out;
-				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;
 
-				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 */
+			/* 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;
+
+		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;
-			default:
-				/* hmm, too complex filter, give up with jit compiler */
-				goto out;
 			}
-			ilen = prog - temp;
-			if (image) {
-				if (unlikely(proglen + ilen > oldproglen)) {
-					pr_err("bpb_jit_compile fatal error\n");
-					kfree(addrs);
-					module_free(NULL, header);
-					return;
-				}
-				memcpy(image + proglen, temp, ilen);
+			/* 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;
 			}
-			proglen += ilen;
-			addrs[i] = proglen;
-			prog = temp;
+			/* 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:
+			/* 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;
 		}
-		/* last bpf instruction is always a RET :
-		 * use it to give the cleanup instruction(s) addr
-		 */
-		cleanup_addr = proglen - 1; /* ret */
-		if (seen_or_pass0)
-			cleanup_addr -= 1; /* leaveq */
-		if (seen_or_pass0 & SEEN_XREG)
-			cleanup_addr -= 4; /* mov  -8(%rbp),%rbx */
 
+		ilen = prog - temp;
+		if (image) {
+			if (unlikely(proglen + ilen > oldproglen)) {
+				pr_err("bpf_jit_compile fatal error\n");
+				return -EFAULT;
+			}
+			memcpy(image + proglen, temp, ilen);
+		}
+		proglen += ilen;
+		addrs[i] = proglen;
+		prog = temp;
+	}
+	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 = {};
+	u8 *image = NULL;
+	int *addrs;
+	int pass;
+	int i;
+
+	if (!bpf_jit_enable)
+		return;
+
+	if (!prog || !prog->len)
+		return;
+
+	addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL);
+	if (!addrs)
+		return;
+
+	/* Before first pass, make a rough estimation of addrs[]
+	 * each bpf instruction is translated to less than 64 bytes
+	 */
+	for (proglen = 0, i = 0; i < prog->len; i++) {
+		proglen += 64;
+		addrs[i] = proglen;
+	}
+	ctx.cleanup_addr = proglen;
+
+	for (pass = 0; pass < 10; pass++) {
+		proglen = do_jit(prog, addrs, image, oldproglen, &ctx);
+		if (proglen <= 0) {
+			image = NULL;
+			if (header)
+				module_free(NULL, header);
+			goto out;
+		}
 		if (image) {
 			if (proglen != oldproglen)
-				pr_err("bpb_jit_compile proglen=%u != oldproglen=%u\n", proglen, oldproglen);
+				pr_err("bpf_jit: proglen=%d != oldproglen=%d\n",
+				       proglen, oldproglen);
 			break;
 		}
 		if (proglen == oldproglen) {
@@ -766,17 +918,16 @@ cond_branch:			f_offset = addrs[i + filter[i].jf] - addrs[i];
 	}
 
 	if (bpf_jit_enable > 1)
-		bpf_jit_dump(flen, proglen, pass, image);
+		bpf_jit_dump(prog->len, proglen, 0, image);
 
 	if (image) {
 		bpf_flush_icache(header, image + proglen);
 		set_memory_ro((unsigned long)header, header->pages);
-		fp->bpf_func = (void *)image;
-		fp->jited = 1;
+		prog->bpf_func = (void *)image;
+		prog->jited = 1;
 	}
 out:
 	kfree(addrs);
-	return;
 }
 
 static void bpf_jit_free_deferred(struct work_struct *work)

include/linux/filter.h

@@ -207,6 +207,9 @@ void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to);
 void sk_filter_charge(struct sock *sk, struct sk_filter *fp);
 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
 
+u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
+void bpf_int_jit_compile(struct sk_filter *fp);
+
 #ifdef CONFIG_BPF_JIT
 #include <stdarg.h>
 #include <linux/linkage.h>

kernel/seccomp.c

@@ -54,8 +54,7 @@
 struct seccomp_filter {
 	atomic_t usage;
 	struct seccomp_filter *prev;
-	unsigned short len;  /* Instruction count */
-	struct sock_filter_int insnsi[];
+	struct sk_filter *prog;
 };
 
 /* Limit any path through the tree to 256KB worth of instructions. */
@@ -189,7 +188,8 @@ static u32 seccomp_run_filters(int syscall)
 	 * value always takes priority (ignoring the DATA).
 	 */
 	for (f = current->seccomp.filter; f; f = f->prev) {
-		u32 cur_ret = sk_run_filter_int_seccomp(&sd, f->insnsi);
+		u32 cur_ret = SK_RUN_FILTER(f->prog, (void *)&sd);
+
 		if ((cur_ret & SECCOMP_RET_ACTION) < (ret & SECCOMP_RET_ACTION))
 			ret = cur_ret;
 	}
@@ -215,7 +215,7 @@ static long seccomp_attach_filter(struct sock_fprog *fprog)
 		return -EINVAL;
 
 	for (filter = current->seccomp.filter; filter; filter = filter->prev)
-		total_insns += filter->len + 4;  /* include a 4 instr penalty */
+		total_insns += filter->prog->len + 4;  /* include a 4 instr penalty */
 	if (total_insns > MAX_INSNS_PER_PATH)
 		return -ENOMEM;
 
@@ -256,19 +256,27 @@ static long seccomp_attach_filter(struct sock_fprog *fprog)
 
 	/* Allocate a new seccomp_filter */
 	ret = -ENOMEM;
-	filter = kzalloc(sizeof(struct seccomp_filter) +
-			 sizeof(struct sock_filter_int) * new_len,
+	filter = kzalloc(sizeof(struct seccomp_filter),
 			 GFP_KERNEL|__GFP_NOWARN);
 	if (!filter)
 		goto free_prog;
 
-	ret = sk_convert_filter(fp, fprog->len, filter->insnsi, &new_len);
-	if (ret)
+	filter->prog = kzalloc(sk_filter_size(new_len),
+			       GFP_KERNEL|__GFP_NOWARN);
+	if (!filter->prog)
 		goto free_filter;
+
+	ret = sk_convert_filter(fp, fprog->len, filter->prog->insnsi, &new_len);
+	if (ret)
+		goto free_filter_prog;
 	kfree(fp);
 
 	atomic_set(&filter->usage, 1);
-	filter->len = new_len;
+	filter->prog->len = new_len;
+	filter->prog->bpf_func = (void *)sk_run_filter_int_seccomp;
+
+	/* JIT internal BPF into native HW instructions */
+	bpf_int_jit_compile(filter->prog);
 
 	/*
 	 * If there is an existing filter, make it the prev and don't drop its
@@ -278,6 +286,8 @@ static long seccomp_attach_filter(struct sock_fprog *fprog)
 	current->seccomp.filter = filter;
 	return 0;
 
+free_filter_prog:
+	kfree(filter->prog);
 free_filter:
 	kfree(filter);
 free_prog:
@@ -330,6 +340,7 @@ void put_seccomp_filter(struct task_struct *tsk)
 	while (orig && atomic_dec_and_test(&orig->usage)) {
 		struct seccomp_filter *freeme = orig;
 		orig = orig->prev;
+		bpf_jit_free(freeme->prog);
 		kfree(freeme);
 	}
 }

net/core/filter.c

@@ -1524,6 +1524,10 @@ out_err:
 	return ERR_PTR(err);
 }
 
+void __weak bpf_int_jit_compile(struct sk_filter *prog)
+{
+}
+
 static struct sk_filter *__sk_prepare_filter(struct sk_filter *fp,
 					     struct sock *sk)
 {
@@ -1544,9 +1548,12 @@ static struct sk_filter *__sk_prepare_filter(struct sk_filter *fp,
 	/* JIT compiler couldn't process this filter, so do the
 	 * internal BPF translation for the optimized interpreter.
 	 */
-	if (!fp->jited)
+	if (!fp->jited) {
 		fp = __sk_migrate_filter(fp, sk);
 
+		/* Probe if internal BPF can be jit-ed */
+		bpf_int_jit_compile(fp);
+	}
 	return fp;
 }