net: filter: get rid of BPF_S_* enum

This patch finally allows us to get rid of the BPF_S_* enum.
Currently, the code performs unnecessary encode and decode
workarounds in seccomp and filter migration itself when a filter
is being attached in order to overcome BPF_S_* encoding which
is not used anymore by the new interpreter resp. JIT compilers.

Keeping it around would mean that also in future we would need
to extend and maintain this enum and related encoders/decoders.
We can get rid of all that and save us these operations during
filter attaching. Naturally, also JIT compilers need to be updated
by this.

Before JIT conversion is being done, each compiler checks if A
is being loaded at startup to obtain information if it needs to
emit instructions to clear A first. Since BPF extensions are a
subset of BPF_LD | BPF_{W,H,B} | BPF_ABS variants, case statements
for extensions can be removed at that point. To ease and minimalize
code changes in the classic JITs, we have introduced bpf_anc_helper().

Tested with test_bpf on x86_64 (JIT, int), s390x (JIT, int),
arm (JIT, int), i368 (int), ppc64 (JIT, int); for sparc we
unfortunately didn't have access, but changes are analogous to
the rest.

Joint work with Alexei Starovoitov.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mircea Gherzan <mgherzan@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Chema Gonzalez <chemag@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 125 insertions, 216 deletions

diff --git a/net/core/filter.c b/net/core/filter.c
index 2c2d35d..328aaf6 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -536,11 +536,13 @@ load_word:
 		 * Output:
 		 *   BPF_R0 - 8/16/32-bit skb data converted to cpu endianness
 		 */
+
 		ptr = load_pointer((struct sk_buff *) ctx, off, 4, &tmp);
 		if (likely(ptr != NULL)) {
 			BPF_R0 = get_unaligned_be32(ptr);
 			CONT;
 		}
+
 		return 0;
 	LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + K)) */
 		off = K;
@@ -550,6 +552,7 @@ load_half:
 			BPF_R0 = get_unaligned_be16(ptr);
 			CONT;
 		}
+
 		return 0;
 	LD_ABS_B: /* BPF_R0 = *(u8 *) (ctx + K) */
 		off = K;
@@ -559,6 +562,7 @@ load_byte:
 			BPF_R0 = *(u8 *)ptr;
 			CONT;
 		}
+
 		return 0;
 	LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + X + K)) */
 		off = K + X;
@@ -1136,44 +1140,46 @@ err:
  */
 static int check_load_and_stores(struct sock_filter *filter, int flen)
 {
-	u16 *masks, memvalid = 0; /* one bit per cell, 16 cells */
+	u16 *masks, memvalid = 0; /* One bit per cell, 16 cells */
 	int pc, ret = 0;
 
 	BUILD_BUG_ON(BPF_MEMWORDS > 16);
+
 	masks = kmalloc(flen * sizeof(*masks), GFP_KERNEL);
 	if (!masks)
 		return -ENOMEM;
+
 	memset(masks, 0xff, flen * sizeof(*masks));
 
 	for (pc = 0; pc < flen; pc++) {
 		memvalid &= masks[pc];
 
 		switch (filter[pc].code) {
-		case BPF_S_ST:
-		case BPF_S_STX:
+		case BPF_ST:
+		case BPF_STX:
 			memvalid |= (1 << filter[pc].k);
 			break;
-		case BPF_S_LD_MEM:
-		case BPF_S_LDX_MEM:
+		case BPF_LD | BPF_MEM:
+		case BPF_LDX | BPF_MEM:
 			if (!(memvalid & (1 << filter[pc].k))) {
 				ret = -EINVAL;
 				goto error;
 			}
 			break;
-		case BPF_S_JMP_JA:
-			/* a jump must set masks on target */
+		case BPF_JMP | BPF_JA:
+			/* A jump must set masks on target */
 			masks[pc + 1 + filter[pc].k] &= memvalid;
 			memvalid = ~0;
 			break;
-		case BPF_S_JMP_JEQ_K:
-		case BPF_S_JMP_JEQ_X:
-		case BPF_S_JMP_JGE_K:
-		case BPF_S_JMP_JGE_X:
-		case BPF_S_JMP_JGT_K:
-		case BPF_S_JMP_JGT_X:
-		case BPF_S_JMP_JSET_X:
-		case BPF_S_JMP_JSET_K:
-			/* a jump must set masks on targets */
+		case BPF_JMP | BPF_JEQ | BPF_K:
+		case BPF_JMP | BPF_JEQ | BPF_X:
+		case BPF_JMP | BPF_JGE | BPF_K:
+		case BPF_JMP | BPF_JGE | BPF_X:
+		case BPF_JMP | BPF_JGT | BPF_K:
+		case BPF_JMP | BPF_JGT | BPF_X:
+		case BPF_JMP | BPF_JSET | BPF_K:
+		case BPF_JMP | BPF_JSET | BPF_X:
+			/* A jump must set masks on targets */
 			masks[pc + 1 + filter[pc].jt] &= memvalid;
 			masks[pc + 1 + filter[pc].jf] &= memvalid;
 			memvalid = ~0;
@@ -1185,6 +1191,72 @@ error:
 	return ret;
 }
 
+static bool chk_code_allowed(u16 code_to_probe)
+{
+	static const bool codes[] = {
+		/* 32 bit ALU operations */
+		[BPF_ALU | BPF_ADD | BPF_K] = true,
+		[BPF_ALU | BPF_ADD | BPF_X] = true,
+		[BPF_ALU | BPF_SUB | BPF_K] = true,
+		[BPF_ALU | BPF_SUB | BPF_X] = true,
+		[BPF_ALU | BPF_MUL | BPF_K] = true,
+		[BPF_ALU | BPF_MUL | BPF_X] = true,
+		[BPF_ALU | BPF_DIV | BPF_K] = true,
+		[BPF_ALU | BPF_DIV | BPF_X] = true,
+		[BPF_ALU | BPF_MOD | BPF_K] = true,
+		[BPF_ALU | BPF_MOD | BPF_X] = true,
+		[BPF_ALU | BPF_AND | BPF_K] = true,
+		[BPF_ALU | BPF_AND | BPF_X] = true,
+		[BPF_ALU | BPF_OR | BPF_K] = true,
+		[BPF_ALU | BPF_OR | BPF_X] = true,
+		[BPF_ALU | BPF_XOR | BPF_K] = true,
+		[BPF_ALU | BPF_XOR | BPF_X] = true,
+		[BPF_ALU | BPF_LSH | BPF_K] = true,
+		[BPF_ALU | BPF_LSH | BPF_X] = true,
+		[BPF_ALU | BPF_RSH | BPF_K] = true,
+		[BPF_ALU | BPF_RSH | BPF_X] = true,
+		[BPF_ALU | BPF_NEG] = true,
+		/* Load instructions */
+		[BPF_LD | BPF_W | BPF_ABS] = true,
+		[BPF_LD | BPF_H | BPF_ABS] = true,
+		[BPF_LD | BPF_B | BPF_ABS] = true,
+		[BPF_LD | BPF_W | BPF_LEN] = true,
+		[BPF_LD | BPF_W | BPF_IND] = true,
+		[BPF_LD | BPF_H | BPF_IND] = true,
+		[BPF_LD | BPF_B | BPF_IND] = true,
+		[BPF_LD | BPF_IMM] = true,
+		[BPF_LD | BPF_MEM] = true,
+		[BPF_LDX | BPF_W | BPF_LEN] = true,
+		[BPF_LDX | BPF_B | BPF_MSH] = true,
+		[BPF_LDX | BPF_IMM] = true,
+		[BPF_LDX | BPF_MEM] = true,
+		/* Store instructions */
+		[BPF_ST] = true,
+		[BPF_STX] = true,
+		/* Misc instructions */
+		[BPF_MISC | BPF_TAX] = true,
+		[BPF_MISC | BPF_TXA] = true,
+		/* Return instructions */
+		[BPF_RET | BPF_K] = true,
+		[BPF_RET | BPF_A] = true,
+		/* Jump instructions */
+		[BPF_JMP | BPF_JA] = true,
+		[BPF_JMP | BPF_JEQ | BPF_K] = true,
+		[BPF_JMP | BPF_JEQ | BPF_X] = true,
+		[BPF_JMP | BPF_JGE | BPF_K] = true,
+		[BPF_JMP | BPF_JGE | BPF_X] = true,
+		[BPF_JMP | BPF_JGT | BPF_K] = true,
+		[BPF_JMP | BPF_JGT | BPF_X] = true,
+		[BPF_JMP | BPF_JSET | BPF_K] = true,
+		[BPF_JMP | BPF_JSET | BPF_X] = true,
+	};
+
+	if (code_to_probe >= ARRAY_SIZE(codes))
+		return false;
+
+	return codes[code_to_probe];
+}
+
 /**
  *	sk_chk_filter - verify socket filter code
  *	@filter: filter to verify
@@ -1201,154 +1273,76 @@ error:
  */
 int sk_chk_filter(struct sock_filter *filter, unsigned int flen)
 {
-	/*
-	 * Valid instructions are initialized to non-0.
-	 * Invalid instructions are initialized to 0.
-	 */
-	static const u8 codes[] = {
-		[BPF_ALU|BPF_ADD|BPF_K]  = BPF_S_ALU_ADD_K,
-		[BPF_ALU|BPF_ADD|BPF_X]  = BPF_S_ALU_ADD_X,
-		[BPF_ALU|BPF_SUB|BPF_K]  = BPF_S_ALU_SUB_K,
-		[BPF_ALU|BPF_SUB|BPF_X]  = BPF_S_ALU_SUB_X,
-		[BPF_ALU|BPF_MUL|BPF_K]  = BPF_S_ALU_MUL_K,
-		[BPF_ALU|BPF_MUL|BPF_X]  = BPF_S_ALU_MUL_X,
-		[BPF_ALU|BPF_DIV|BPF_X]  = BPF_S_ALU_DIV_X,
-		[BPF_ALU|BPF_MOD|BPF_K]  = BPF_S_ALU_MOD_K,
-		[BPF_ALU|BPF_MOD|BPF_X]  = BPF_S_ALU_MOD_X,
-		[BPF_ALU|BPF_AND|BPF_K]  = BPF_S_ALU_AND_K,
-		[BPF_ALU|BPF_AND|BPF_X]  = BPF_S_ALU_AND_X,
-		[BPF_ALU|BPF_OR|BPF_K]   = BPF_S_ALU_OR_K,
-		[BPF_ALU|BPF_OR|BPF_X]   = BPF_S_ALU_OR_X,
-		[BPF_ALU|BPF_XOR|BPF_K]  = BPF_S_ALU_XOR_K,
-		[BPF_ALU|BPF_XOR|BPF_X]  = BPF_S_ALU_XOR_X,
-		[BPF_ALU|BPF_LSH|BPF_K]  = BPF_S_ALU_LSH_K,
-		[BPF_ALU|BPF_LSH|BPF_X]  = BPF_S_ALU_LSH_X,
-		[BPF_ALU|BPF_RSH|BPF_K]  = BPF_S_ALU_RSH_K,
-		[BPF_ALU|BPF_RSH|BPF_X]  = BPF_S_ALU_RSH_X,
-		[BPF_ALU|BPF_NEG]        = BPF_S_ALU_NEG,
-		[BPF_LD|BPF_W|BPF_ABS]   = BPF_S_LD_W_ABS,
-		[BPF_LD|BPF_H|BPF_ABS]   = BPF_S_LD_H_ABS,
-		[BPF_LD|BPF_B|BPF_ABS]   = BPF_S_LD_B_ABS,
-		[BPF_LD|BPF_W|BPF_LEN]   = BPF_S_LD_W_LEN,
-		[BPF_LD|BPF_W|BPF_IND]   = BPF_S_LD_W_IND,
-		[BPF_LD|BPF_H|BPF_IND]   = BPF_S_LD_H_IND,
-		[BPF_LD|BPF_B|BPF_IND]   = BPF_S_LD_B_IND,
-		[BPF_LD|BPF_IMM]         = BPF_S_LD_IMM,
-		[BPF_LDX|BPF_W|BPF_LEN]  = BPF_S_LDX_W_LEN,
-		[BPF_LDX|BPF_B|BPF_MSH]  = BPF_S_LDX_B_MSH,
-		[BPF_LDX|BPF_IMM]        = BPF_S_LDX_IMM,
-		[BPF_MISC|BPF_TAX]       = BPF_S_MISC_TAX,
-		[BPF_MISC|BPF_TXA]       = BPF_S_MISC_TXA,
-		[BPF_RET|BPF_K]          = BPF_S_RET_K,
-		[BPF_RET|BPF_A]          = BPF_S_RET_A,
-		[BPF_ALU|BPF_DIV|BPF_K]  = BPF_S_ALU_DIV_K,
-		[BPF_LD|BPF_MEM]         = BPF_S_LD_MEM,
-		[BPF_LDX|BPF_MEM]        = BPF_S_LDX_MEM,
-		[BPF_ST]                 = BPF_S_ST,
-		[BPF_STX]                = BPF_S_STX,
-		[BPF_JMP|BPF_JA]         = BPF_S_JMP_JA,
-		[BPF_JMP|BPF_JEQ|BPF_K]  = BPF_S_JMP_JEQ_K,
-		[BPF_JMP|BPF_JEQ|BPF_X]  = BPF_S_JMP_JEQ_X,
-		[BPF_JMP|BPF_JGE|BPF_K]  = BPF_S_JMP_JGE_K,
-		[BPF_JMP|BPF_JGE|BPF_X]  = BPF_S_JMP_JGE_X,
-		[BPF_JMP|BPF_JGT|BPF_K]  = BPF_S_JMP_JGT_K,
-		[BPF_JMP|BPF_JGT|BPF_X]  = BPF_S_JMP_JGT_X,
-		[BPF_JMP|BPF_JSET|BPF_K] = BPF_S_JMP_JSET_K,
-		[BPF_JMP|BPF_JSET|BPF_X] = BPF_S_JMP_JSET_X,
-	};
-	int pc;
 	bool anc_found;
+	int pc;
 
 	if (flen == 0 || flen > BPF_MAXINSNS)
 		return -EINVAL;
 
-	/* check the filter code now */
+	/* Check the filter code now */
 	for (pc = 0; pc < flen; pc++) {
 		struct sock_filter *ftest = &filter[pc];
-		u16 code = ftest->code;
 
-		if (code >= ARRAY_SIZE(codes))
-			return -EINVAL;
-		code = codes[code];
-		if (!code)
+		/* May we actually operate on this code? */
+		if (!chk_code_allowed(ftest->code))
 			return -EINVAL;
+
 		/* Some instructions need special checks */
-		switch (code) {
-		case BPF_S_ALU_DIV_K:
-		case BPF_S_ALU_MOD_K:
-			/* check for division by zero */
+		switch (ftest->code) {
+		case BPF_ALU | BPF_DIV | BPF_K:
+		case BPF_ALU | BPF_MOD | BPF_K:
+			/* Check for division by zero */
 			if (ftest->k == 0)
 				return -EINVAL;
 			break;
-		case BPF_S_LD_MEM:
-		case BPF_S_LDX_MEM:
-		case BPF_S_ST:
-		case BPF_S_STX:
-			/* check for invalid memory addresses */
+		case BPF_LD | BPF_MEM:
+		case BPF_LDX | BPF_MEM:
+		case BPF_ST:
+		case BPF_STX:
+			/* Check for invalid memory addresses */
 			if (ftest->k >= BPF_MEMWORDS)
 				return -EINVAL;
 			break;
-		case BPF_S_JMP_JA:
-			/*
-			 * Note, the large ftest->k might cause loops.
+		case BPF_JMP | BPF_JA:
+			/* Note, the large ftest->k might cause loops.
 			 * Compare this with conditional jumps below,
 			 * where offsets are limited. --ANK (981016)
 			 */
-			if (ftest->k >= (unsigned int)(flen-pc-1))
+			if (ftest->k >= (unsigned int)(flen - pc - 1))
 				return -EINVAL;
 			break;
-		case BPF_S_JMP_JEQ_K:
-		case BPF_S_JMP_JEQ_X:
-		case BPF_S_JMP_JGE_K:
-		case BPF_S_JMP_JGE_X:
-		case BPF_S_JMP_JGT_K:
-		case BPF_S_JMP_JGT_X:
-		case BPF_S_JMP_JSET_X:
-		case BPF_S_JMP_JSET_K:
-			/* for conditionals both must be safe */
+		case BPF_JMP | BPF_JEQ | BPF_K:
+		case BPF_JMP | BPF_JEQ | BPF_X:
+		case BPF_JMP | BPF_JGE | BPF_K:
+		case BPF_JMP | BPF_JGE | BPF_X:
+		case BPF_JMP | BPF_JGT | BPF_K:
+		case BPF_JMP | BPF_JGT | BPF_X:
+		case BPF_JMP | BPF_JSET | BPF_K:
+		case BPF_JMP | BPF_JSET | BPF_X:
+			/* Both conditionals must be safe */
 			if (pc + ftest->jt + 1 >= flen ||
 			    pc + ftest->jf + 1 >= flen)
 				return -EINVAL;
 			break;
-		case BPF_S_LD_W_ABS:
-		case BPF_S_LD_H_ABS:
-		case BPF_S_LD_B_ABS:
+		case BPF_LD | BPF_W | BPF_ABS:
+		case BPF_LD | BPF_H | BPF_ABS:
+		case BPF_LD | BPF_B | BPF_ABS:
 			anc_found = false;
-#define ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE:	\
-				code = BPF_S_ANC_##CODE;	\
-				anc_found = true;		\
-				break
-			switch (ftest->k) {
-			ANCILLARY(PROTOCOL);
-			ANCILLARY(PKTTYPE);
-			ANCILLARY(IFINDEX);
-			ANCILLARY(NLATTR);
-			ANCILLARY(NLATTR_NEST);
-			ANCILLARY(MARK);
-			ANCILLARY(QUEUE);
-			ANCILLARY(HATYPE);
-			ANCILLARY(RXHASH);
-			ANCILLARY(CPU);
-			ANCILLARY(ALU_XOR_X);
-			ANCILLARY(VLAN_TAG);
-			ANCILLARY(VLAN_TAG_PRESENT);
-			ANCILLARY(PAY_OFFSET);
-			ANCILLARY(RANDOM);
-			}
-
-			/* ancillary operation unknown or unsupported */
+			if (bpf_anc_helper(ftest) & BPF_ANC)
+				anc_found = true;
+			/* Ancillary operation unknown or unsupported */
 			if (anc_found == false && ftest->k >= SKF_AD_OFF)
 				return -EINVAL;
 		}
-		ftest->code = code;
 	}
 
-	/* last instruction must be a RET code */
+	/* Last instruction must be a RET code */
 	switch (filter[flen - 1].code) {
-	case BPF_S_RET_K:
-	case BPF_S_RET_A:
+	case BPF_RET | BPF_K:
+	case BPF_RET | BPF_A:
 		return check_load_and_stores(filter, flen);
 	}
+
 	return -EINVAL;
 }
 EXPORT_SYMBOL(sk_chk_filter);
@@ -1448,7 +1442,7 @@ static struct sk_filter *__sk_migrate_filter(struct sk_filter *fp,
 {
 	struct sock_filter *old_prog;
 	struct sk_filter *old_fp;
-	int i, err, new_len, old_len = fp->len;
+	int err, new_len, old_len = fp->len;
 
 	/* We are free to overwrite insns et al right here as it
 	 * won't be used at this point in time anymore internally
@@ -1458,13 +1452,6 @@ static struct sk_filter *__sk_migrate_filter(struct sk_filter *fp,
 	BUILD_BUG_ON(sizeof(struct sock_filter) !=
 		     sizeof(struct sock_filter_int));
 
-	/* For now, we need to unfiddle BPF_S_* identifiers in place.
-	 * This can sooner or later on be subject to removal, e.g. when
-	 * JITs have been converted.
-	 */
-	for (i = 0; i < fp->len; i++)
-		sk_decode_filter(&fp->insns[i], &fp->insns[i]);
-
 	/* Conversion cannot happen on overlapping memory areas,
 	 * so we need to keep the user BPF around until the 2nd
 	 * pass. At this time, the user BPF is stored in fp->insns.
@@ -1706,84 +1693,6 @@ int sk_detach_filter(struct sock *sk)
 }
 EXPORT_SYMBOL_GPL(sk_detach_filter);
 
-void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to)
-{
-	static const u16 decodes[] = {
-		[BPF_S_ALU_ADD_K]	= BPF_ALU|BPF_ADD|BPF_K,
-		[BPF_S_ALU_ADD_X]	= BPF_ALU|BPF_ADD|BPF_X,
-		[BPF_S_ALU_SUB_K]	= BPF_ALU|BPF_SUB|BPF_K,
-		[BPF_S_ALU_SUB_X]	= BPF_ALU|BPF_SUB|BPF_X,
-		[BPF_S_ALU_MUL_K]	= BPF_ALU|BPF_MUL|BPF_K,
-		[BPF_S_ALU_MUL_X]	= BPF_ALU|BPF_MUL|BPF_X,
-		[BPF_S_ALU_DIV_X]	= BPF_ALU|BPF_DIV|BPF_X,
-		[BPF_S_ALU_MOD_K]	= BPF_ALU|BPF_MOD|BPF_K,
-		[BPF_S_ALU_MOD_X]	= BPF_ALU|BPF_MOD|BPF_X,
-		[BPF_S_ALU_AND_K]	= BPF_ALU|BPF_AND|BPF_K,
-		[BPF_S_ALU_AND_X]	= BPF_ALU|BPF_AND|BPF_X,
-		[BPF_S_ALU_OR_K]	= BPF_ALU|BPF_OR|BPF_K,
-		[BPF_S_ALU_OR_X]	= BPF_ALU|BPF_OR|BPF_X,
-		[BPF_S_ALU_XOR_K]	= BPF_ALU|BPF_XOR|BPF_K,
-		[BPF_S_ALU_XOR_X]	= BPF_ALU|BPF_XOR|BPF_X,
-		[BPF_S_ALU_LSH_K]	= BPF_ALU|BPF_LSH|BPF_K,
-		[BPF_S_ALU_LSH_X]	= BPF_ALU|BPF_LSH|BPF_X,
-		[BPF_S_ALU_RSH_K]	= BPF_ALU|BPF_RSH|BPF_K,
-		[BPF_S_ALU_RSH_X]	= BPF_ALU|BPF_RSH|BPF_X,
-		[BPF_S_ALU_NEG]		= BPF_ALU|BPF_NEG,
-		[BPF_S_LD_W_ABS]	= BPF_LD|BPF_W|BPF_ABS,
-		[BPF_S_LD_H_ABS]	= BPF_LD|BPF_H|BPF_ABS,
-		[BPF_S_LD_B_ABS]	= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_PROTOCOL]	= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_PKTTYPE]	= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_IFINDEX]	= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_NLATTR]	= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_NLATTR_NEST]	= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_MARK]	= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_QUEUE]	= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_HATYPE]	= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_RXHASH]	= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_CPU]		= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_ALU_XOR_X]	= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_VLAN_TAG]	= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_VLAN_TAG_PRESENT] = BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_PAY_OFFSET]	= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_ANC_RANDOM]	= BPF_LD|BPF_B|BPF_ABS,
-		[BPF_S_LD_W_LEN]	= BPF_LD|BPF_W|BPF_LEN,
-		[BPF_S_LD_W_IND]	= BPF_LD|BPF_W|BPF_IND,
-		[BPF_S_LD_H_IND]	= BPF_LD|BPF_H|BPF_IND,
-		[BPF_S_LD_B_IND]	= BPF_LD|BPF_B|BPF_IND,
-		[BPF_S_LD_IMM]		= BPF_LD|BPF_IMM,
-		[BPF_S_LDX_W_LEN]	= BPF_LDX|BPF_W|BPF_LEN,
-		[BPF_S_LDX_B_MSH]	= BPF_LDX|BPF_B|BPF_MSH,
-		[BPF_S_LDX_IMM]		= BPF_LDX|BPF_IMM,
-		[BPF_S_MISC_TAX]	= BPF_MISC|BPF_TAX,
-		[BPF_S_MISC_TXA]	= BPF_MISC|BPF_TXA,
-		[BPF_S_RET_K]		= BPF_RET|BPF_K,
-		[BPF_S_RET_A]		= BPF_RET|BPF_A,
-		[BPF_S_ALU_DIV_K]	= BPF_ALU|BPF_DIV|BPF_K,
-		[BPF_S_LD_MEM]		= BPF_LD|BPF_MEM,
-		[BPF_S_LDX_MEM]		= BPF_LDX|BPF_MEM,
-		[BPF_S_ST]		= BPF_ST,
-		[BPF_S_STX]		= BPF_STX,
-		[BPF_S_JMP_JA]		= BPF_JMP|BPF_JA,
-		[BPF_S_JMP_JEQ_K]	= BPF_JMP|BPF_JEQ|BPF_K,
-		[BPF_S_JMP_JEQ_X]	= BPF_JMP|BPF_JEQ|BPF_X,
-		[BPF_S_JMP_JGE_K]	= BPF_JMP|BPF_JGE|BPF_K,
-		[BPF_S_JMP_JGE_X]	= BPF_JMP|BPF_JGE|BPF_X,
-		[BPF_S_JMP_JGT_K]	= BPF_JMP|BPF_JGT|BPF_K,
-		[BPF_S_JMP_JGT_X]	= BPF_JMP|BPF_JGT|BPF_X,
-		[BPF_S_JMP_JSET_K]	= BPF_JMP|BPF_JSET|BPF_K,
-		[BPF_S_JMP_JSET_X]	= BPF_JMP|BPF_JSET|BPF_X,
-	};
-	u16 code;
-
-	code = filt->code;
-
-	to->code = decodes[code];
-	to->jt = filt->jt;
-	to->jf = filt->jf;
-	to->k = filt->k;
-}
-
 int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf,
 		  unsigned int len)
 {