net: filter: Just In Time compiler for sparc

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

4 files changed, 1040 insertions, 0 deletions

diff --git a/arch/sparc/net/Makefile b/arch/sparc/net/Makefile
new file mode 100644
index 000000000000..1306a58ac541
--- /dev/null
+++ b/arch/sparc/net/Makefile
@@ -0,0 +1,4 @@
+#
+# Arch-specific network modules
+#
+obj-$(CONFIG_BPF_JIT) += bpf_jit_asm.o bpf_jit_comp.o
diff --git a/arch/sparc/net/bpf_jit.h b/arch/sparc/net/bpf_jit.h
new file mode 100644
index 000000000000..74f048be739c
--- /dev/null
+++ b/arch/sparc/net/bpf_jit.h
@@ -0,0 +1,52 @@
+#ifndef _BPF_JIT_H
+#define _BPF_JIT_H
+
+/* Conventions:
+ *  %g1 : temporary
+ *  %g2 : Secondary temporary used by SKB data helper stubs.
+ *  %o0 : pointer to skb (first argument given to JIT function)
+ *  %o1 : BPF A accumulator
+ *  %o2 : BPF X accumulator
+ *  %o3 : Holds saved %o7 so we can call helper functions without needing
+ *        to allocate a register window.
+ *  %o4 : skb->data
+ *  %o5 : skb->len - skb->data_len
+ */
+
+#ifndef __ASSEMBLER__
+#define G0		0x00
+#define G1		0x01
+#define G3		0x03
+#define G6		0x06
+#define O0		0x08
+#define O1		0x09
+#define O2		0x0a
+#define O3		0x0b
+#define O4		0x0c
+#define O5		0x0d
+#define SP		0x0e
+#define O7		0x0f
+#define FP		0x1e
+
+#define r_SKB		O0
+#define r_A		O1
+#define r_X		O2
+#define r_saved_O7	O3
+#define r_HEADLEN	O4
+#define r_SKB_DATA	O5
+#define r_TMP		G1
+#define r_TMP2		G2
+#define r_OFF		G3
+#else
+#define r_SKB		%o0
+#define r_A		%o1
+#define r_X		%o2
+#define r_saved_O7	%o3
+#define r_HEADLEN	%o4
+#define r_SKB_DATA	%o5
+#define r_TMP		%g1
+#define r_TMP2		%g2
+#define r_OFF		%g3
+#endif
+
+#endif /* _BPF_JIT_H */
diff --git a/arch/sparc/net/bpf_jit_asm.S b/arch/sparc/net/bpf_jit_asm.S
new file mode 100644
index 000000000000..fdc69324aabc
--- /dev/null
+++ b/arch/sparc/net/bpf_jit_asm.S
@@ -0,0 +1,199 @@
+#include <asm/ptrace.h>
+
+#include "bpf_jit.h"
+
+#ifdef CONFIG_SPARC64
+#define SAVE_SZ		176
+#define SCRATCH_OFF	STACK_BIAS + 128
+#define BE_PTR(label)	be,pn %xcc, label
+#else
+#define SAVE_SZ		96
+#define SCRATCH_OFF	72
+#define BE_PTR(label)	be label
+#endif
+
+#define SKF_MAX_NEG_OFF	(-0x200000) /* SKF_LL_OFF from filter.h */
+
+	.text
+	.globl	bpf_jit_load_word
+bpf_jit_load_word:
+	cmp	r_OFF, 0
+	bl	bpf_slow_path_word_neg
+	 nop
+	.globl	bpf_jit_load_word_positive_offset
+bpf_jit_load_word_positive_offset:
+	sub	r_HEADLEN, r_OFF, r_TMP
+	cmp	r_TMP, 3
+	ble	bpf_slow_path_word
+	 add	r_SKB_DATA, r_OFF, r_TMP
+	andcc	r_TMP, 3, %g0
+	bne	load_word_unaligned
+	 nop
+	retl
+	 ld	[r_SKB_DATA + r_OFF], r_A
+load_word_unaligned:
+	ldub	[r_TMP + 0x0], r_OFF
+	ldub	[r_TMP + 0x1], r_TMP2
+	sll	r_OFF, 8, r_OFF
+	or	r_OFF, r_TMP2, r_OFF
+	ldub	[r_TMP + 0x2], r_TMP2
+	sll	r_OFF, 8, r_OFF
+	or	r_OFF, r_TMP2, r_OFF
+	ldub	[r_TMP + 0x3], r_TMP2
+	sll	r_OFF, 8, r_OFF
+	retl
+	 or	r_OFF, r_TMP2, r_A
+
+	.globl	bpf_jit_load_half
+bpf_jit_load_half:
+	cmp	r_OFF, 0
+	bl	bpf_slow_path_half_neg
+	 nop
+	.globl	bpf_jit_load_half_positive_offset
+bpf_jit_load_half_positive_offset:
+	sub	r_HEADLEN, r_OFF, r_TMP
+	cmp	r_TMP, 1
+	ble	bpf_slow_path_half
+	 add	r_SKB_DATA, r_OFF, r_TMP
+	andcc	r_TMP, 1, %g0
+	bne	load_half_unaligned
+	 nop
+	retl
+	 lduh	[r_SKB_DATA + r_OFF], r_A
+load_half_unaligned:
+	ldub	[r_TMP + 0x0], r_OFF
+	ldub	[r_TMP + 0x1], r_TMP2
+	sll	r_OFF, 8, r_OFF
+	retl
+	 or	r_OFF, r_TMP2, r_A
+
+	.globl	bpf_jit_load_byte
+bpf_jit_load_byte:
+	cmp	r_OFF, 0
+	bl	bpf_slow_path_byte_neg
+	 nop
+	.globl	bpf_jit_load_byte_positive_offset
+bpf_jit_load_byte_positive_offset:
+	cmp	r_OFF, r_HEADLEN
+	bge	bpf_slow_path_byte
+	 nop
+	retl
+	 ldub	[r_SKB_DATA + r_OFF], r_A
+
+	.globl	bpf_jit_load_byte_msh
+bpf_jit_load_byte_msh:
+	cmp	r_OFF, 0
+	bl	bpf_slow_path_byte_msh_neg
+	 nop
+	.globl	bpf_jit_load_byte_msh_positive_offset
+bpf_jit_load_byte_msh_positive_offset:
+	cmp	r_OFF, r_HEADLEN
+	bge	bpf_slow_path_byte_msh
+	 nop
+	ldub	[r_SKB_DATA + r_OFF], r_OFF
+	and	r_OFF, 0xf, r_OFF
+	retl
+	 sll	r_OFF, 2, r_X
+
+#define bpf_slow_path_common(LEN)	\
+	save	%sp, -SAVE_SZ, %sp;	\
+	mov	%i0, %o0;		\
+	mov	r_OFF, %o1;		\
+	add	%fp, SCRATCH_OFF, %o2;	\
+	call	skb_copy_bits;		\
+	 mov	(LEN), %o3;		\
+	cmp	%o0, 0;			\
+	restore;
+
+bpf_slow_path_word:
+	bpf_slow_path_common(4)
+	bl	bpf_error
+	 ld	[%sp + SCRATCH_OFF], r_A
+	retl
+	 nop
+bpf_slow_path_half:
+	bpf_slow_path_common(2)
+	bl	bpf_error
+	 lduh	[%sp + SCRATCH_OFF], r_A
+	retl
+	 nop
+bpf_slow_path_byte:
+	bpf_slow_path_common(1)
+	bl	bpf_error
+	 ldub	[%sp + SCRATCH_OFF], r_A
+	retl
+	 nop
+bpf_slow_path_byte_msh:
+	bpf_slow_path_common(1)
+	bl	bpf_error
+	 ldub	[%sp + SCRATCH_OFF], r_A
+	and	r_OFF, 0xf, r_OFF
+	retl
+	 sll	r_OFF, 2, r_X
+
+#define bpf_negative_common(LEN)			\
+	save	%sp, -SAVE_SZ, %sp;			\
+	mov	%i0, %o0;				\
+	mov	r_OFF, %o1;				\
+	call	bpf_internal_load_pointer_neg_helper;	\
+	 mov	(LEN), %o2;				\
+	mov	%o0, r_TMP;				\
+	cmp	%o0, 0;					\
+	BE_PTR(bpf_error);				\
+	 restore;
+
+bpf_slow_path_word_neg:
+	sethi	%hi(SKF_MAX_NEG_OFF), r_TMP
+	cmp	r_OFF, r_TMP
+	bl	bpf_error
+	 nop
+	.globl	bpf_jit_load_word_negative_offset
+bpf_jit_load_word_negative_offset:
+	bpf_negative_common(4)
+	andcc	r_TMP, 3, %g0
+	bne	load_word_unaligned
+	 nop
+	retl
+	 ld	[r_TMP], r_A
+
+bpf_slow_path_half_neg:
+	sethi	%hi(SKF_MAX_NEG_OFF), r_TMP
+	cmp	r_OFF, r_TMP
+	bl	bpf_error
+	 nop
+	.globl	bpf_jit_load_half_negative_offset
+bpf_jit_load_half_negative_offset:
+	bpf_negative_common(2)
+	andcc	r_TMP, 1, %g0
+	bne	load_half_unaligned
+	 nop
+	retl
+	 lduh	[r_TMP], r_A
+
+bpf_slow_path_byte_neg:
+	sethi	%hi(SKF_MAX_NEG_OFF), r_TMP
+	cmp	r_OFF, r_TMP
+	bl	bpf_error
+	 nop
+	.globl	bpf_jit_load_byte_negative_offset
+bpf_jit_load_byte_negative_offset:
+	bpf_negative_common(1)
+	retl
+	 ldub	[r_TMP], r_A
+
+bpf_slow_path_byte_msh_neg:
+	sethi	%hi(SKF_MAX_NEG_OFF), r_TMP
+	cmp	r_OFF, r_TMP
+	bl	bpf_error
+	 nop
+	.globl	bpf_jit_load_byte_msh_negative_offset
+bpf_jit_load_byte_msh_negative_offset:
+	bpf_negative_common(1)
+	ldub	[r_TMP], r_OFF
+	and	r_OFF, 0xf, r_OFF
+	retl
+	 sll	r_OFF, 2, r_X
+
+bpf_error:
+	jmpl	r_saved_O7 + 8, %g0
+	 clr	%o0
diff --git a/arch/sparc/net/bpf_jit_comp.c b/arch/sparc/net/bpf_jit_comp.c
new file mode 100644
index 000000000000..86349cab60c5
--- /dev/null
+++ b/arch/sparc/net/bpf_jit_comp.c
@@ -0,0 +1,785 @@
+#include <linux/moduleloader.h>
+#include <linux/workqueue.h>
+#include <linux/netdevice.h>
+#include <linux/filter.h>
+#include <linux/cache.h>
+
+#include <asm/cacheflush.h>
+#include <asm/ptrace.h>
+
+#include "bpf_jit.h"
+
+int bpf_jit_enable __read_mostly;
+
+/* assembly code in arch/sparc/net/bpf_jit_asm.S */
+extern u32 bpf_jit_load_word[];
+extern u32 bpf_jit_load_half[];
+extern u32 bpf_jit_load_byte[];
+extern u32 bpf_jit_load_byte_msh[];
+extern u32 bpf_jit_load_word_positive_offset[];
+extern u32 bpf_jit_load_half_positive_offset[];
+extern u32 bpf_jit_load_byte_positive_offset[];
+extern u32 bpf_jit_load_byte_msh_positive_offset[];
+extern u32 bpf_jit_load_word_negative_offset[];
+extern u32 bpf_jit_load_half_negative_offset[];
+extern u32 bpf_jit_load_byte_negative_offset[];
+extern u32 bpf_jit_load_byte_msh_negative_offset[];
+
+static inline bool is_simm13(unsigned int value)
+{
+	return value + 0x1000 < 0x2000;
+}
+
+static void bpf_flush_icache(void *start_, void *end_)
+{
+#ifdef CONFIG_SPARC64
+	/* Cheetah's I-cache is fully coherent.  */
+	if (tlb_type == spitfire) {
+		unsigned long start = (unsigned long) start_;
+		unsigned long end = (unsigned long) end_;
+
+		start &= ~7UL;
+		end = (end + 7UL) & ~7UL;
+		while (start < end) {
+			flushi(start);
+			start += 32;
+		}
+	}
+#endif
+}
+
+#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 S13(X)		((X) & 0x1fff)
+#define IMMED		0x00002000
+#define RD(X)		((X) << 25)
+#define RS1(X)		((X) << 14)
+#define RS2(X)		((X))
+#define OP(X)		((X) << 30)
+#define OP2(X)		((X) << 22)
+#define OP3(X)		((X) << 19)
+#define COND(X)		((X) << 25)
+#define F1(X)		OP(X)
+#define F2(X, Y)	(OP(X) | OP2(Y))
+#define F3(X, Y)	(OP(X) | OP3(Y))
+
+#define CONDN		COND (0x0)
+#define CONDE		COND (0x1)
+#define CONDLE		COND (0x2)
+#define CONDL		COND (0x3)
+#define CONDLEU		COND (0x4)
+#define CONDCS		COND (0x5)
+#define CONDNEG		COND (0x6)
+#define CONDVC		COND (0x7)
+#define CONDA		COND (0x8)
+#define CONDNE		COND (0x9)
+#define CONDG		COND (0xa)
+#define CONDGE		COND (0xb)
+#define CONDGU		COND (0xc)
+#define CONDCC		COND (0xd)
+#define CONDPOS		COND (0xe)
+#define CONDVS		COND (0xf)
+
+#define CONDGEU		CONDCC
+#define CONDLU		CONDCS
+
+#define WDISP22(X)	(((X) >> 2) & 0x3fffff)
+
+#define BA		(F2(0, 2) | CONDA)
+#define BGU		(F2(0, 2) | CONDGU)
+#define BLEU		(F2(0, 2) | CONDLEU)
+#define BGEU		(F2(0, 2) | CONDGEU)
+#define BLU		(F2(0, 2) | CONDLU)
+#define BE		(F2(0, 2) | CONDE)
+#define BNE		(F2(0, 2) | CONDNE)
+
+#ifdef CONFIG_SPARC64
+#define BNE_PTR		(F2(0, 1) | CONDNE | (2 << 20))
+#else
+#define BNE_PTR		BNE
+#endif
+
+#define SETHI(K, REG)	\
+	(F2(0, 0x4) | RD(REG) | (((K) >> 10) & 0x3fffff))
+#define OR_LO(K, REG)	\
+	(F3(2, 0x02) | IMMED | RS1(REG) | ((K) & 0x3ff) | RD(REG))
+
+#define ADD		F3(2, 0x00)
+#define AND		F3(2, 0x01)
+#define ANDCC		F3(2, 0x11)
+#define OR		F3(2, 0x02)
+#define SUB		F3(2, 0x04)
+#define SUBCC		F3(2, 0x14)
+#define MUL		F3(2, 0x0a)	/* umul */
+#define DIV		F3(2, 0x0e)	/* udiv */
+#define SLL		F3(2, 0x25)
+#define SRL		F3(2, 0x26)
+#define JMPL		F3(2, 0x38)
+#define CALL		F1(1)
+#define BR		F2(0, 0x01)
+#define RD_Y		F3(2, 0x28)
+#define WR_Y		F3(2, 0x30)
+
+#define LD32		F3(3, 0x00)
+#define LD8		F3(3, 0x01)
+#define LD16		F3(3, 0x02)
+#define LD64		F3(3, 0x0b)
+#define ST32		F3(3, 0x04)
+
+#ifdef CONFIG_SPARC64
+#define LDPTR		LD64
+#define BASE_STACKFRAME	176
+#else
+#define LDPTR		LD32
+#define BASE_STACKFRAME	96
+#endif
+
+#define LD32I		(LD32 | IMMED)
+#define LD8I		(LD8 | IMMED)
+#define LD16I		(LD16 | IMMED)
+#define LD64I		(LD64 | IMMED)
+#define LDPTRI		(LDPTR | IMMED)
+#define ST32I		(ST32 | IMMED)
+
+#define emit_nop()		\
+do {				\
+	*prog++ = SETHI(0, G0);	\
+} while (0)
+
+#define emit_neg()					\
+do {	/* sub %g0, r_A, r_A */				\
+	*prog++ = SUB | RS1(G0) | RS2(r_A) | RD(r_A);	\
+} while (0)
+
+#define emit_reg_move(FROM, TO)				\
+do {	/* or %g0, FROM, TO */				\
+	*prog++ = OR | RS1(G0) | RS2(FROM) | RD(TO);	\
+} while (0)
+
+#define emit_clear(REG)					\
+do {	/* or %g0, %g0, REG */				\
+	*prog++ = OR | RS1(G0) | RS2(G0) | RD(REG);	\
+} while (0)
+
+#define emit_set_const(K, REG)					\
+do {	/* sethi %hi(K), REG */					\
+	*prog++ = SETHI(K, REG);				\
+	/* or REG, %lo(K), REG */				\
+	*prog++ = OR_LO(K, REG);				\
+} while (0)
+
+	/* Emit
+	 *
+	 * 	OP	r_A, r_X, r_A
+	 */
+#define emit_alu_X(OPCODE)					\
+do {								\
+	seen |= SEEN_XREG;					\
+	*prog++ = OPCODE | RS1(r_A) | RS2(r_X) | RD(r_A);	\
+} while (0)
+
+	/* Emit either:
+	 *
+	 *	OP	r_A, K, r_A
+	 *
+	 * or
+	 *
+	 *	sethi	%hi(K), r_TMP
+	 *	or	r_TMP, %lo(K), r_TMP
+	 *	OP	r_A, r_TMP, r_A
+	 *
+	 * depending upon whether K fits in a signed 13-bit
+	 * immediate instruction field.  Emit nothing if K
+	 * is zero.
+	 */
+#define emit_alu_K(OPCODE, K)					\
+do {			   					\
+	if (K) {						\
+		unsigned int _insn = OPCODE;			\
+		_insn |= RS1(r_A) | RD(r_A);			\
+		if (is_simm13(K)) {				\
+			*prog++ = _insn | IMMED | S13(K);	\
+		} else {					\
+			emit_set_const(K, r_TMP);		\
+			*prog++ = _insn | RS2(r_TMP);		\
+		}		  	  			\
+	}							\
+} while (0)
+
+#define emit_loadimm(K, DEST)						\
+do {									\
+	if (is_simm13(K)) {						\
+		/* or %g0, K, DEST */					\
+		*prog++ = OR | IMMED | RS1(G0) | S13(K) | RD(DEST);	\
+	} else {							\
+		emit_set_const(K, DEST);				\
+	}								\
+} while (0)
+
+#define emit_loadptr(BASE, STRUCT, FIELD, DEST)				\
+do {	unsigned int _off = offsetof(STRUCT, FIELD);			\
+	BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(void *));	\
+	*prog++ = LDPTRI | RS1(BASE) | S13(_off) | RD(DEST);		\
+} while(0)
+
+#define emit_load32(BASE, STRUCT, FIELD, DEST)				\
+do {	unsigned int _off = offsetof(STRUCT, FIELD);			\
+	BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u32));	\
+	*prog++ = LD32I | RS1(BASE) | S13(_off) | RD(DEST);		\
+} while(0)
+
+#define emit_load16(BASE, STRUCT, FIELD, DEST)				\
+do {	unsigned int _off = offsetof(STRUCT, FIELD);			\
+	BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u16));	\
+	*prog++ = LD16I | RS1(BASE) | S13(_off) | RD(DEST);		\
+} while(0)
+
+#define __emit_load8(BASE, STRUCT, FIELD, DEST)				\
+do {	unsigned int _off = offsetof(STRUCT, FIELD);			\
+	*prog++ = LD8I | RS1(BASE) | S13(_off) | RD(DEST);		\
+} while(0)
+
+#define emit_load8(BASE, STRUCT, FIELD, DEST)				\
+do {	BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u8));	\
+	__emit_load8(BASE, STRUCT, FIELD, DEST);			\
+} while(0)
+
+#define emit_ldmem(OFF, DEST)					\
+do {	*prog++ = LD32I | RS1(FP) | S13(-(OFF)) | RD(DEST);	\
+} while(0)
+
+#define emit_stmem(OFF, SRC)					\
+do {	*prog++ = LD32I | RS1(FP) | S13(-(OFF)) | RD(SRC);	\
+} while(0)
+
+#define cpu_off		offsetof(struct thread_info, cpu)
+
+#ifdef CONFIG_SMP
+#ifdef CONFIG_SPARC64
+#define emit_load_cpu(REG)						\
+	emit_load16(G6, struct thread_info, cpu, REG)
+#else
+#define emit_load_cpu(REG)						\
+	emit_load32(G6, struct thread_info, cpu, REG)
+#endif
+#else
+#define emit_load_cpu(REG)	emit_clear(REG)
+#endif
+
+#define emit_skb_loadptr(FIELD, DEST) \
+	emit_loadptr(r_SKB, struct sk_buff, FIELD, DEST)
+#define emit_skb_load32(FIELD, DEST) \
+	emit_load32(r_SKB, struct sk_buff, FIELD, DEST)
+#define emit_skb_load16(FIELD, DEST) \
+	emit_load16(r_SKB, struct sk_buff, FIELD, DEST)
+#define __emit_skb_load8(FIELD, DEST) \
+	__emit_load8(r_SKB, struct sk_buff, FIELD, DEST)
+#define emit_skb_load8(FIELD, DEST) \
+	emit_load8(r_SKB, struct sk_buff, FIELD, DEST)
+
+#define emit_jmpl(BASE, IMM_OFF, LREG) \
+	*prog++ = (JMPL | IMMED | RS1(BASE) | S13(IMM_OFF) | RD(LREG))
+
+#define emit_call(FUNC)					\
+do {	void *_here = image + addrs[i] - 8;		\
+	unsigned int _off = (void *)(FUNC) - _here;	\
+	*prog++ = CALL | (((_off) >> 2) & 0x3fffffff);	\
+	emit_nop();					\
+} while (0)
+
+#define emit_branch(BR_OPC, DEST)			\
+do {	unsigned int _here = addrs[i] - 8;		\
+	*prog++ = BR_OPC | WDISP22((DEST) - _here);	\
+} while(0)
+
+#define emit_branch_off(BR_OPC, OFF)			\
+do {	*prog++ = BR_OPC | WDISP22(OFF);		\
+} while(0)
+
+#define emit_jump(DEST)		emit_branch(BA, DEST)
+
+#define emit_read_y(REG) 	*prog++ = RD_Y | RD(REG);
+#define emit_write_y(REG) 	*prog++ = WR_Y | IMMED | RS1(REG) | S13(0);
+
+#define emit_cmp(R1, R2) \
+	*prog++ = (SUBCC | RS1(R1) | RS2(R2) | RD(G0))
+
+#define emit_cmpi(R1, IMM) \
+	*prog++ = (SUBCC | IMMED | RS1(R1) | S13(IMM) | RD(G0));
+
+#define emit_btst(R1, R2) \
+	*prog++ = (ANDCC | RS1(R1) | RS2(R2) | RD(G0))
+
+#define emit_btsti(R1, IMM) \
+	*prog++ = (ANDCC | IMMED | RS1(R1) | S13(IMM) | RD(G0));
+
+#define emit_sub(R1, R2, R3) \
+	*prog++ = (SUB | RS1(R1) | RS2(R2) | RD(R3))
+
+#define emit_subi(R1, IMM, R3) \
+	*prog++ = (SUB | IMMED | RS1(R1) | S13(IMM) | RD(R3))
+
+#define emit_add(R1, R2, R3) \
+	*prog++ = (ADD | RS1(R1) | RS2(R2) | RD(R3))
+
+#define emit_addi(R1, IMM, R3) \
+	*prog++ = (ADD | IMMED | RS1(R1) | S13(IMM) | RD(R3))
+
+#define emit_alloc_stack(SZ) \
+	*prog++ = (SUB | IMMED | RS1(SP) | S13(SZ) | RD(SP))
+
+#define emit_release_stack(SZ) \
+	*prog++ = (ADD | IMMED | RS1(SP) | S13(SZ) | RD(SP))
+
+void bpf_jit_compile(struct sk_filter *fp)
+{
+	unsigned int cleanup_addr, proglen, oldproglen = 0;
+	u32 temp[8], *prog, *func, seen = 0, pass;
+	const struct sock_filter *filter = fp->insns;
+	int i, flen = fp->len, pc_ret0 = -1;
+	unsigned int *addrs;
+	void *image;
+
+	if (!bpf_jit_enable)
+		return;
+
+	addrs = kmalloc(flen * sizeof(*addrs), GFP_KERNEL);
+	if (addrs == NULL)
+		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 < flen; i++) {
+		proglen += 64;
+		addrs[i] = proglen;
+	}
+	cleanup_addr = proglen; /* epilogue address */
+	image = NULL;
+	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;
+
+		/* Prologue */
+		if (seen_or_pass0) {
+			if (seen_or_pass0 & SEEN_MEM) {
+				unsigned int sz = BASE_STACKFRAME;
+				sz += BPF_MEMWORDS * sizeof(u32);
+				emit_alloc_stack(sz);
+			}
+
+			/* Make sure we dont leek kernel memory. */
+			if (seen_or_pass0 & SEEN_XREG)
+				emit_clear(r_X);
+
+			/* If this filter needs to access skb data,
+			 * load %o4 and %o4 with:
+			 *  %o4 = skb->len - skb->data_len
+			 *  %o5 = skb->data
+			 * And also back up %o7 into r_saved_O7 so we can
+			 * invoke the stubs using 'call'.
+			 */
+			if (seen_or_pass0 & SEEN_DATAREF) {
+				emit_load32(r_SKB, struct sk_buff, len, r_HEADLEN);
+				emit_load32(r_SKB, struct sk_buff, data_len, r_TMP);
+				emit_sub(r_HEADLEN, r_TMP, r_HEADLEN);
+				emit_loadptr(r_SKB, struct sk_buff, data, r_SKB_DATA);
+			}
+		}
+		emit_reg_move(O7, r_saved_O7);
+
+		switch (filter[0].code) {
+		case BPF_S_RET_K:
+		case BPF_S_LD_W_LEN:
+		case BPF_S_ANC_PROTOCOL:
+		case BPF_S_ANC_PKTTYPE:
+		case BPF_S_ANC_IFINDEX:
+		case BPF_S_ANC_MARK:
+		case BPF_S_ANC_RXHASH:
+		case BPF_S_ANC_CPU:
+		case BPF_S_ANC_QUEUE:
+		case BPF_S_LD_W_ABS:
+		case BPF_S_LD_H_ABS:
+		case BPF_S_LD_B_ABS:
+			/* The first instruction sets the A register (or is
+			 * a "RET 'constant'")
+			 */
+			break;
+		default:
+			/* Make sure we dont leak kernel information to the
+			 * user.
+			 */
+			emit_clear(r_A); /* A = 0 */
+		}
+
+		for (i = 0; i < flen; i++) {
+			unsigned int K = filter[i].k;
+			unsigned int t_offset;
+			unsigned int f_offset;
+			u32 t_op, f_op;
+			int ilen;
+
+			switch (filter[i].code) {
+			case BPF_S_ALU_ADD_X:	/* A += X; */
+				emit_alu_X(ADD);
+				break;
+			case BPF_S_ALU_ADD_K:	/* A += K; */
+				emit_alu_K(ADD, K);
+				break;
+			case BPF_S_ALU_SUB_X:	/* A -= X; */
+				emit_alu_X(SUB);
+				break;
+			case BPF_S_ALU_SUB_K:	/* A -= K */
+				emit_alu_K(SUB, K);
+				break;
+			case BPF_S_ALU_AND_X:	/* A &= X */
+				emit_alu_X(AND);
+				break;
+			case BPF_S_ALU_AND_K:	/* A &= K */
+				emit_alu_K(AND, K);
+				break;
+			case BPF_S_ALU_OR_X:	/* A |= X */
+				emit_alu_X(OR);
+				break;
+			case BPF_S_ALU_OR_K:	/* A |= K */
+				emit_alu_K(OR, K);
+				break;
+			case BPF_S_ALU_LSH_X:	/* A <<= X */
+				emit_alu_X(SLL);
+				break;
+			case BPF_S_ALU_LSH_K:	/* A <<= K */
+				emit_alu_K(SLL, K);
+				break;
+			case BPF_S_ALU_RSH_X:	/* A >>= X */
+				emit_alu_X(SRL);
+				break;
+			case BPF_S_ALU_RSH_K:	/* A >>= K */
+				emit_alu_K(SRL, K);
+				break;
+			case BPF_S_ALU_MUL_X:	/* A *= X; */
+				emit_alu_X(MUL);
+				break;
+			case BPF_S_ALU_MUL_K:	/* A *= K */
+				emit_alu_K(MUL, K);
+				break;
+			case BPF_S_ALU_DIV_K:	/* A /= K */
+				emit_alu_K(MUL, K);
+				emit_read_y(r_A);
+				break;
+			case BPF_S_ALU_DIV_X:	/* A /= X; */
+				emit_cmpi(r_X, 0);
+				if (pc_ret0 > 0) {
+					t_offset = addrs[pc_ret0 - 1];
+#ifdef CONFIG_SPARC32
+					emit_branch(BE, t_offset + 20);
+#else
+					emit_branch(BE, t_offset + 8);
+#endif
+					emit_nop(); /* delay slot */
+				} else {
+					emit_branch_off(BNE, 16);
+					emit_nop();
+#ifdef CONFIG_SPARC32
+					emit_jump(cleanup_addr + 20);
+#else
+					emit_jump(cleanup_addr + 8);
+#endif
+					emit_clear(r_A);
+				}
+				emit_write_y(G0);
+#ifdef CONFIG_SPARC32
+				emit_nop();
+				emit_nop();
+				emit_nop();
+#endif
+				emit_alu_X(DIV);
+				break;
+			case BPF_S_ALU_NEG:
+				emit_neg();
+				break;
+			case BPF_S_RET_K:
+				if (!K) {
+					if (pc_ret0 == -1)
+						pc_ret0 = i;
+					emit_clear(r_A);
+				} else {
+					emit_loadimm(K, r_A);
+				}
+				/* Fallthrough */
+			case BPF_S_RET_A:
+				if (seen_or_pass0) {
+					if (i != flen - 1) {
+						emit_jump(cleanup_addr);
+						emit_nop();
+						break;
+					}
+					if (seen_or_pass0 & SEEN_MEM) {
+						unsigned int sz = BASE_STACKFRAME;
+						sz += BPF_MEMWORDS * sizeof(u32);
+						emit_release_stack(sz);
+					}
+				}
+				/* jmpl %r_saved_O7 + 8, %g0 */
+				emit_jmpl(r_saved_O7, 8, G0);
+				emit_reg_move(r_A, O0); /* delay slot */
+				break;
+			case BPF_S_MISC_TAX:
+				seen |= SEEN_XREG;
+				emit_reg_move(r_A, r_X);
+				break;
+			case BPF_S_MISC_TXA:
+				seen |= SEEN_XREG;
+				emit_reg_move(r_X, r_A);
+				break;
+			case BPF_S_ANC_CPU:
+				emit_load_cpu(r_A);
+				break;
+			case BPF_S_ANC_PROTOCOL:
+				emit_skb_load16(protocol, r_A);
+				break;
+#if 0
+				/* GCC won't let us take the address of
+				 * a bit field even though we very much
+				 * know what we are doing here.
+				 */
+			case BPF_S_ANC_PKTTYPE:
+				__emit_skb_load8(pkt_type, r_A);
+				emit_alu_K(SRL, 5);
+				break;
+#endif
+			case BPF_S_ANC_IFINDEX:
+				emit_skb_loadptr(dev, r_A);
+				emit_cmpi(r_A, 0);
+				emit_branch(BNE_PTR, cleanup_addr + 4);
+				emit_nop();
+				emit_load32(r_A, struct net_device, ifindex, r_A);
+				break;
+			case BPF_S_ANC_MARK:
+				emit_skb_load32(mark, r_A);
+				break;
+			case BPF_S_ANC_QUEUE:
+				emit_skb_load16(queue_mapping, r_A);
+				break;
+			case BPF_S_ANC_HATYPE:
+				emit_skb_loadptr(dev, r_A);
+				emit_cmpi(r_A, 0);
+				emit_branch(BNE_PTR, cleanup_addr + 4);
+				emit_nop();
+				emit_load16(r_A, struct net_device, type, r_A);
+				break;
+			case BPF_S_ANC_RXHASH:
+				emit_skb_load32(rxhash, r_A);
+				break;
+
+			case BPF_S_LD_IMM:
+				emit_loadimm(K, r_A);
+				break;
+			case BPF_S_LDX_IMM:
+				emit_loadimm(K, r_X);
+				break;
+			case BPF_S_LD_MEM:
+				emit_ldmem(K * 4, r_A);
+				break;
+			case BPF_S_LDX_MEM:
+				emit_ldmem(K * 4, r_X);
+				break;
+			case BPF_S_ST:
+				emit_stmem(K * 4, r_A);
+				break;
+			case BPF_S_STX:
+				emit_stmem(K * 4, r_X);
+				break;
+
+#define CHOOSE_LOAD_FUNC(K, func) \
+	((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset)
+
+			case BPF_S_LD_W_ABS:
+				func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_word);
+common_load:			seen |= SEEN_DATAREF;
+				emit_loadimm(K, r_OFF);
+				emit_call(func);
+				break;
+			case BPF_S_LD_H_ABS:
+				func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_half);
+				goto common_load;
+			case BPF_S_LD_B_ABS:
+				func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_byte);
+				goto common_load;
+			case BPF_S_LDX_B_MSH:
+				func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_byte_msh);
+				goto common_load;
+			case BPF_S_LD_W_IND:
+				func = bpf_jit_load_word;
+common_load_ind:		seen |= SEEN_DATAREF | SEEN_XREG;
+				if (K) {
+					if (is_simm13(K)) {
+						emit_addi(r_X, K, r_OFF);
+					} else {
+						emit_loadimm(K, r_TMP);
+						emit_add(r_X, r_TMP, r_OFF);
+					}
+				} else {
+					emit_reg_move(r_X, r_OFF);
+				}
+				emit_call(func);
+				break;
+			case BPF_S_LD_H_IND:
+				func = bpf_jit_load_half;
+				goto common_load_ind;
+			case BPF_S_LD_B_IND:
+				func = bpf_jit_load_byte;
+				goto common_load_ind;
+			case BPF_S_JMP_JA:
+				emit_jump(addrs[i + K]);
+				emit_nop();
+				break;
+
+#define COND_SEL(CODE, TOP, FOP)	\
+	case CODE:			\
+		t_op = TOP;		\
+		f_op = FOP;		\
+		goto cond_branch
+
+			COND_SEL(BPF_S_JMP_JGT_K, BGU, BLEU);
+			COND_SEL(BPF_S_JMP_JGE_K, BGEU, BLU);
+			COND_SEL(BPF_S_JMP_JEQ_K, BE, BNE);
+			COND_SEL(BPF_S_JMP_JSET_K, BNE, BE);
+			COND_SEL(BPF_S_JMP_JGT_X, BGU, BLEU);
+			COND_SEL(BPF_S_JMP_JGE_X, BGEU, BLU);
+			COND_SEL(BPF_S_JMP_JEQ_X, BE, BNE);
+			COND_SEL(BPF_S_JMP_JSET_X, BNE, BE);
+
+cond_branch:			f_offset = addrs[i + filter[i].jf];
+				t_offset = addrs[i + filter[i].jt];
+
+				/* same targets, can avoid doing the test :) */
+				if (filter[i].jt == filter[i].jf) {
+					emit_jump(t_offset);
+					emit_nop();
+					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;
+					emit_cmp(r_A, r_X);
+					break;
+				case BPF_S_JMP_JSET_X:
+					seen |= SEEN_XREG;
+					emit_btst(r_A, r_X);
+					break;
+				case BPF_S_JMP_JEQ_K:
+				case BPF_S_JMP_JGT_K:
+				case BPF_S_JMP_JGE_K:
+					if (is_simm13(K)) {
+						emit_cmpi(r_A, K);
+					} else {
+						emit_loadimm(K, r_TMP);
+						emit_cmp(r_A, r_TMP);
+					}
+					break;
+				case BPF_S_JMP_JSET_K:
+					if (is_simm13(K)) {
+						emit_btsti(r_A, K);
+					} else {
+						emit_loadimm(K, r_TMP);
+						emit_btst(r_A, r_TMP);
+					}
+					break;
+				}
+				if (filter[i].jt != 0) {
+					if (filter[i].jf)
+						t_offset += 8;
+					emit_branch(t_op, t_offset);
+					emit_nop(); /* delay slot */
+					if (filter[i].jf) {
+						emit_jump(f_offset);
+						emit_nop();
+					}
+					break;
+				}
+				emit_branch(f_op, f_offset);
+				emit_nop(); /* delay slot */
+				break;
+
+			default:
+				/* hmm, too complex filter, give up with jit compiler */
+				goto out;
+			}
+			ilen = (void *) prog - (void *) temp;
+			if (image) {
+				if (unlikely(proglen + ilen > oldproglen)) {
+					pr_err("bpb_jit_compile fatal error\n");
+					kfree(addrs);
+					module_free(NULL, image);
+					return;
+				}
+				memcpy(image + proglen, temp, ilen);
+			}
+			proglen += ilen;
+			addrs[i] = proglen;
+			prog = temp;
+		}
+		/* last bpf instruction is always a RET :
+		 * use it to give the cleanup instruction(s) addr
+		 */
+		cleanup_addr = proglen - 8; /* jmpl; mov r_A,%o0; */
+		if (seen_or_pass0 & SEEN_MEM)
+			cleanup_addr -= 4; /* add %sp, X, %sp; */
+
+		if (image) {
+			if (proglen != oldproglen)
+				pr_err("bpb_jit_compile proglen=%u != oldproglen=%u\n",
+				       proglen, oldproglen);
+			break;
+		}
+		if (proglen == oldproglen) {
+			image = module_alloc(max_t(unsigned int,
+						   proglen,
+						   sizeof(struct work_struct)));
+			if (!image)
+				goto out;
+		}
+		oldproglen = proglen;
+	}
+
+	if (bpf_jit_enable > 1)
+		pr_err("flen=%d proglen=%u pass=%d image=%p\n",
+		       flen, proglen, pass, image);
+
+	if (image) {
+		if (bpf_jit_enable > 1)
+			print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_ADDRESS,
+				       16, 1, image, proglen, false);
+		bpf_flush_icache(image, image + proglen);
+		fp->bpf_func = (void *)image;
+	}
+out:
+	kfree(addrs);
+	return;
+}
+
+static void jit_free_defer(struct work_struct *arg)
+{
+	module_free(NULL, arg);
+}
+
+/* run from softirq, we must use a work_struct to call
+ * module_free() from process context
+ */
+void bpf_jit_free(struct sk_filter *fp)
+{
+	if (fp->bpf_func != sk_run_filter) {
+		struct work_struct *work = (struct work_struct *)fp->bpf_func;
+
+		INIT_WORK(work, jit_free_defer);
+		schedule_work(work);
+	}
+}