mips:allmodconfig build failure in 3.16-rc1 due to bpf_jit code

mips:allmodconfig build failure in 3.16-rc1 due to bpf_jit code

[Guenter Roeck]

mips:allmodconfig fails in 3.16-rc1 with lots of undefined symbols.

arch/mips/net/bpf_jit.c: In function 'is_load_to_a':
arch/mips/net/bpf_jit.c:559:7: error: 'BPF_S_LD_W_LEN' undeclared (first use in this function)
arch/mips/net/bpf_jit.c:559:7: note: each undeclared identifier is reported only once for each function it appears in
arch/mips/net/bpf_jit.c:560:7: error: 'BPF_S_LD_W_ABS' undeclared (first use in this function)
arch/mips/net/bpf_jit.c:561:7: error: 'BPF_S_LD_H_ABS' undeclared (first use in this function)
arch/mips/net/bpf_jit.c:562:7: error: 'BPF_S_LD_B_ABS' undeclared (first use in this function)
arch/mips/net/bpf_jit.c:563:7: error: 'BPF_S_ANC_CPU' undeclared (first use in this function)
arch/mips/net/bpf_jit.c:564:7: error: 'BPF_S_ANC_IFINDEX' undeclared (first use in this function)
arch/mips/net/bpf_jit.c:565:7: error: 'BPF_S_ANC_MARK' undeclared (first use in this function)

and so on.

Those symbols are not defined anywhere.

The problem is due to a conflict with commit 348059313 (net: filter: get rid of BPF_S_*
enum), which removed those definitions.

Guenter

Re: mips:allmodconfig build failure in 3.16-rc1 due to bpf_jit code

[Daniel Borkmann]

On 06/17/2014 04:24 AM, Guenter Roeck wrote:
> mips:allmodconfig fails in 3.16-rc1 with lots of undefined symbols.
>
> arch/mips/net/bpf_jit.c: In function 'is_load_to_a':
> arch/mips/net/bpf_jit.c:559:7: error: 'BPF_S_LD_W_LEN' undeclared (first use in this function)
> arch/mips/net/bpf_jit.c:559:7: note: each undeclared identifier is reported only once for each function it appears in
> arch/mips/net/bpf_jit.c:560:7: error: 'BPF_S_LD_W_ABS' undeclared (first use in this function)
> arch/mips/net/bpf_jit.c:561:7: error: 'BPF_S_LD_H_ABS' undeclared (first use in this function)
> arch/mips/net/bpf_jit.c:562:7: error: 'BPF_S_LD_B_ABS' undeclared (first use in this function)
> arch/mips/net/bpf_jit.c:563:7: error: 'BPF_S_ANC_CPU' undeclared (first use in this function)
> arch/mips/net/bpf_jit.c:564:7: error: 'BPF_S_ANC_IFINDEX' undeclared (first use in this function)
> arch/mips/net/bpf_jit.c:565:7: error: 'BPF_S_ANC_MARK' undeclared (first use in this function)
>
> and so on.
>
> Those symbols are not defined anywhere.
>
> The problem is due to a conflict with commit 348059313 (net: filter: get rid of BPF_S_*
> enum), which removed those definitions.

Yep, it seems both got in this merge window from different trees. Don't have mips, but
I'll have a look, and send you a patch.

Re: mips:allmodconfig build failure in 3.16-rc1 due to bpf_jit code

[Daniel Borkmann]

[-- Attachment #1: Type: text/plain, Size: 1425 bytes --]

On 06/17/2014 10:20 AM, Daniel Borkmann wrote:
> On 06/17/2014 04:24 AM, Guenter Roeck wrote:
>> mips:allmodconfig fails in 3.16-rc1 with lots of undefined symbols.
>>
>> arch/mips/net/bpf_jit.c: In function 'is_load_to_a':
>> arch/mips/net/bpf_jit.c:559:7: error: 'BPF_S_LD_W_LEN' undeclared (first use in this function)
>> arch/mips/net/bpf_jit.c:559:7: note: each undeclared identifier is reported only once for each function it appears in
>> arch/mips/net/bpf_jit.c:560:7: error: 'BPF_S_LD_W_ABS' undeclared (first use in this function)
>> arch/mips/net/bpf_jit.c:561:7: error: 'BPF_S_LD_H_ABS' undeclared (first use in this function)
>> arch/mips/net/bpf_jit.c:562:7: error: 'BPF_S_LD_B_ABS' undeclared (first use in this function)
>> arch/mips/net/bpf_jit.c:563:7: error: 'BPF_S_ANC_CPU' undeclared (first use in this function)
>> arch/mips/net/bpf_jit.c:564:7: error: 'BPF_S_ANC_IFINDEX' undeclared (first use in this function)
>> arch/mips/net/bpf_jit.c:565:7: error: 'BPF_S_ANC_MARK' undeclared (first use in this function)
>>
>> and so on.
>>
>> Those symbols are not defined anywhere.
>>
>> The problem is due to a conflict with commit 348059313 (net: filter: get rid of BPF_S_*
>> enum), which removed those definitions.
>
> Yep, it seems both got in this merge window from different trees. Don't have mips, but
> I'll have a look, and send you a patch.

Could you give the attached patch a try?

Thanks,

Daniel

[-- Attachment #2: 0001-mips-filter-fix-build-error-in-BPF-JIT.patch --]
[-- Type: text/x-patch, Size: 14466 bytes --]

>From 12b5040eebd51f5efd6ffe04b1bec8ebbe5a9caf Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <dborkman@redhat.com>
Date: Tue, 17 Jun 2014 11:48:28 +0200
Subject: [PATCH] mips: filter: fix build error in BPF JIT

Guenter reported that on MIPS, the following build error occurs when
BPF JIT is enabled:

  mips: allmodconfig fails in 3.16-rc1 with lots of undefined symbols.

  arch/mips/net/bpf_jit.c: In function 'is_load_to_a':
  arch/mips/net/bpf_jit.c:559:7: error: 'BPF_S_LD_W_LEN' undeclared (first use in this function)
  arch/mips/net/bpf_jit.c:559:7: note: each undeclared identifier is reported only once for each function it appears in
  arch/mips/net/bpf_jit.c:560:7: error: 'BPF_S_LD_W_ABS' undeclared (first use in this function)
  [...]

The reason behind this is that 3480593131e0 ("net: filter: get rid of
BPF_S_* enum") was routed via net-next tree, that takes all BPF-related
changes, at a time where MIPS BPF JIT was not part of net-next, while
c6610de353da ("MIPS: net: Add BPF JIT") was routed via mips arch tree
and went into mainline within the same merge window. Thus, fix it up by
converting BPF_S_* in a similar fashion as in 3480593131e0 for MIPS.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
---
 arch/mips/net/bpf_jit.c | 143 +++++++++++++++++++++++-------------------------
 1 file changed, 69 insertions(+), 74 deletions(-)

diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c
index a67b975..f7c2064 100644
--- a/arch/mips/net/bpf_jit.c
+++ b/arch/mips/net/bpf_jit.c
@@ -556,18 +556,10 @@ static inline void update_on_xread(struct jit_ctx *ctx)
 static bool is_load_to_a(u16 inst)
 {
 	switch (inst) {
-	case BPF_S_LD_W_LEN:
-	case BPF_S_LD_W_ABS:
-	case BPF_S_LD_H_ABS:
-	case BPF_S_LD_B_ABS:
-	case BPF_S_ANC_CPU:
-	case BPF_S_ANC_IFINDEX:
-	case BPF_S_ANC_MARK:
-	case BPF_S_ANC_PROTOCOL:
-	case BPF_S_ANC_RXHASH:
-	case BPF_S_ANC_VLAN_TAG:
-	case BPF_S_ANC_VLAN_TAG_PRESENT:
-	case BPF_S_ANC_QUEUE:
+	case BPF_LD | BPF_W | BPF_LEN:
+	case BPF_LD | BPF_W | BPF_ABS:
+	case BPF_LD | BPF_H | BPF_ABS:
+	case BPF_LD | BPF_B | BPF_ABS:
 		return true;
 	default:
 		return false;
@@ -709,7 +701,7 @@ static void build_prologue(struct jit_ctx *ctx)
 		emit_jit_reg_move(r_X, r_zero, ctx);
 
 	/* Do not leak kernel data to userspace */
-	if ((first_inst != BPF_S_RET_K) && !(is_load_to_a(first_inst)))
+	if ((first_inst != (BPF_RET | BPF_K)) && !(is_load_to_a(first_inst)))
 		emit_jit_reg_move(r_A, r_zero, ctx);
 }
 
@@ -783,41 +775,44 @@ static int build_body(struct jit_ctx *ctx)
 	u32 k, b_off __maybe_unused;
 
 	for (i = 0; i < prog->len; i++) {
+		u16 code;
+
 		inst = &(prog->insns[i]);
 		pr_debug("%s: code->0x%02x, jt->0x%x, jf->0x%x, k->0x%x\n",
 			 __func__, inst->code, inst->jt, inst->jf, inst->k);
 		k = inst->k;
+		code = bpf_anc_helper(inst);
 
 		if (ctx->target == NULL)
 			ctx->offsets[i] = ctx->idx * 4;
 
-		switch (inst->code) {
-		case BPF_S_LD_IMM:
+		switch (code) {
+		case BPF_LD | BPF_IMM:
 			/* A <- k ==> li r_A, k */
 			ctx->flags |= SEEN_A;
 			emit_load_imm(r_A, k, ctx);
 			break;
-		case BPF_S_LD_W_LEN:
+		case BPF_LD | BPF_W | BPF_LEN:
 			BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4);
 			/* A <- len ==> lw r_A, offset(skb) */
 			ctx->flags |= SEEN_SKB | SEEN_A;
 			off = offsetof(struct sk_buff, len);
 			emit_load(r_A, r_skb, off, ctx);
 			break;
-		case BPF_S_LD_MEM:
+		case BPF_LD | BPF_MEM:
 			/* A <- M[k] ==> lw r_A, offset(M) */
 			ctx->flags |= SEEN_MEM | SEEN_A;
 			emit_load(r_A, r_M, SCRATCH_OFF(k), ctx);
 			break;
-		case BPF_S_LD_W_ABS:
+		case BPF_LD | BPF_W | BPF_ABS:
 			/* A <- P[k:4] */
 			load_order = 2;
 			goto load;
-		case BPF_S_LD_H_ABS:
+		case BPF_LD | BPF_H | BPF_ABS:
 			/* A <- P[k:2] */
 			load_order = 1;
 			goto load;
-		case BPF_S_LD_B_ABS:
+		case BPF_LD | BPF_B | BPF_ABS:
 			/* A <- P[k:1] */
 			load_order = 0;
 load:
@@ -852,15 +847,15 @@ load_common:
 			emit_b(b_imm(prog->len, ctx), ctx);
 			emit_reg_move(r_ret, r_zero, ctx);
 			break;
-		case BPF_S_LD_W_IND:
+		case BPF_LD | BPF_W | BPF_IND:
 			/* A <- P[X + k:4] */
 			load_order = 2;
 			goto load_ind;
-		case BPF_S_LD_H_IND:
+		case BPF_LD | BPF_H | BPF_IND:
 			/* A <- P[X + k:2] */
 			load_order = 1;
 			goto load_ind;
-		case BPF_S_LD_B_IND:
+		case BPF_LD | BPF_B | BPF_IND:
 			/* A <- P[X + k:1] */
 			load_order = 0;
 load_ind:
@@ -868,23 +863,23 @@ load_ind:
 			ctx->flags |= SEEN_OFF | SEEN_X;
 			emit_addiu(r_off, r_X, k, ctx);
 			goto load_common;
-		case BPF_S_LDX_IMM:
+		case BPF_LDX | BPF_IMM:
 			/* X <- k */
 			ctx->flags |= SEEN_X;
 			emit_load_imm(r_X, k, ctx);
 			break;
-		case BPF_S_LDX_MEM:
+		case BPF_LDX | BPF_MEM:
 			/* X <- M[k] */
 			ctx->flags |= SEEN_X | SEEN_MEM;
 			emit_load(r_X, r_M, SCRATCH_OFF(k), ctx);
 			break;
-		case BPF_S_LDX_W_LEN:
+		case BPF_LDX | BPF_W | BPF_LEN:
 			/* X <- len */
 			ctx->flags |= SEEN_X | SEEN_SKB;
 			off = offsetof(struct sk_buff, len);
 			emit_load(r_X, r_skb, off, ctx);
 			break;
-		case BPF_S_LDX_B_MSH:
+		case BPF_LDX | BPF_B | BPF_MSH:
 			/* X <- 4 * (P[k:1] & 0xf) */
 			ctx->flags |= SEEN_X | SEEN_CALL | SEEN_S0 | SEEN_SKB;
 			/* Load offset to a1 */
@@ -917,50 +912,50 @@ load_ind:
 			emit_b(b_imm(prog->len, ctx), ctx);
 			emit_load_imm(r_ret, 0, ctx); /* delay slot */
 			break;
-		case BPF_S_ST:
+		case BPF_ST:
 			/* M[k] <- A */
 			ctx->flags |= SEEN_MEM | SEEN_A;
 			emit_store(r_A, r_M, SCRATCH_OFF(k), ctx);
 			break;
-		case BPF_S_STX:
+		case BPF_STX:
 			/* M[k] <- X */
 			ctx->flags |= SEEN_MEM | SEEN_X;
 			emit_store(r_X, r_M, SCRATCH_OFF(k), ctx);
 			break;
-		case BPF_S_ALU_ADD_K:
+		case BPF_ALU | BPF_ADD | BPF_K:
 			/* A += K */
 			ctx->flags |= SEEN_A;
 			emit_addiu(r_A, r_A, k, ctx);
 			break;
-		case BPF_S_ALU_ADD_X:
+		case BPF_ALU | BPF_ADD | BPF_X:
 			/* A += X */
 			ctx->flags |= SEEN_A | SEEN_X;
 			emit_addu(r_A, r_A, r_X, ctx);
 			break;
-		case BPF_S_ALU_SUB_K:
+		case BPF_ALU | BPF_SUB | BPF_K:
 			/* A -= K */
 			ctx->flags |= SEEN_A;
 			emit_addiu(r_A, r_A, -k, ctx);
 			break;
-		case BPF_S_ALU_SUB_X:
+		case BPF_ALU | BPF_SUB | BPF_X:
 			/* A -= X */
 			ctx->flags |= SEEN_A | SEEN_X;
 			emit_subu(r_A, r_A, r_X, ctx);
 			break;
-		case BPF_S_ALU_MUL_K:
+		case BPF_ALU | BPF_MUL | BPF_K:
 			/* A *= K */
 			/* Load K to scratch register before MUL */
 			ctx->flags |= SEEN_A | SEEN_S0;
 			emit_load_imm(r_s0, k, ctx);
 			emit_mul(r_A, r_A, r_s0, ctx);
 			break;
-		case BPF_S_ALU_MUL_X:
+		case BPF_ALU | BPF_MUL | BPF_X:
 			/* A *= X */
 			update_on_xread(ctx);
 			ctx->flags |= SEEN_A | SEEN_X;
 			emit_mul(r_A, r_A, r_X, ctx);
 			break;
-		case BPF_S_ALU_DIV_K:
+		case BPF_ALU | BPF_DIV | BPF_K:
 			/* A /= k */
 			if (k == 1)
 				break;
@@ -973,7 +968,7 @@ load_ind:
 			emit_load_imm(r_s0, k, ctx);
 			emit_div(r_A, r_s0, ctx);
 			break;
-		case BPF_S_ALU_MOD_K:
+		case BPF_ALU | BPF_MOD | BPF_K:
 			/* A %= k */
 			if (k == 1 || optimize_div(&k)) {
 				ctx->flags |= SEEN_A;
@@ -984,7 +979,7 @@ load_ind:
 				emit_mod(r_A, r_s0, ctx);
 			}
 			break;
-		case BPF_S_ALU_DIV_X:
+		case BPF_ALU | BPF_DIV | BPF_X:
 			/* A /= X */
 			update_on_xread(ctx);
 			ctx->flags |= SEEN_X | SEEN_A;
@@ -994,7 +989,7 @@ load_ind:
 			emit_load_imm(r_val, 0, ctx); /* delay slot */
 			emit_div(r_A, r_X, ctx);
 			break;
-		case BPF_S_ALU_MOD_X:
+		case BPF_ALU | BPF_MOD | BPF_X:
 			/* A %= X */
 			update_on_xread(ctx);
 			ctx->flags |= SEEN_X | SEEN_A;
@@ -1004,94 +999,94 @@ load_ind:
 			emit_load_imm(r_val, 0, ctx); /* delay slot */
 			emit_mod(r_A, r_X, ctx);
 			break;
-		case BPF_S_ALU_OR_K:
+		case BPF_ALU | BPF_OR | BPF_K:
 			/* A |= K */
 			ctx->flags |= SEEN_A;
 			emit_ori(r_A, r_A, k, ctx);
 			break;
-		case BPF_S_ALU_OR_X:
+		case BPF_ALU | BPF_OR | BPF_X:
 			/* A |= X */
 			update_on_xread(ctx);
 			ctx->flags |= SEEN_A;
 			emit_ori(r_A, r_A, r_X, ctx);
 			break;
-		case BPF_S_ALU_XOR_K:
+		case BPF_ALU | BPF_XOR | BPF_K:
 			/* A ^= k */
 			ctx->flags |= SEEN_A;
 			emit_xori(r_A, r_A, k, ctx);
 			break;
-		case BPF_S_ANC_ALU_XOR_X:
-		case BPF_S_ALU_XOR_X:
+		case BPF_ANC | SKF_AD_ALU_XOR_X:
+		case BPF_ALU | BPF_XOR | BPF_X:
 			/* A ^= X */
 			update_on_xread(ctx);
 			ctx->flags |= SEEN_A;
 			emit_xor(r_A, r_A, r_X, ctx);
 			break;
-		case BPF_S_ALU_AND_K:
+		case BPF_ALU | BPF_AND | BPF_K:
 			/* A &= K */
 			ctx->flags |= SEEN_A;
 			emit_andi(r_A, r_A, k, ctx);
 			break;
-		case BPF_S_ALU_AND_X:
+		case BPF_ALU | BPF_AND | BPF_X:
 			/* A &= X */
 			update_on_xread(ctx);
 			ctx->flags |= SEEN_A | SEEN_X;
 			emit_and(r_A, r_A, r_X, ctx);
 			break;
-		case BPF_S_ALU_LSH_K:
+		case BPF_ALU | BPF_LSH | BPF_K:
 			/* A <<= K */
 			ctx->flags |= SEEN_A;
 			emit_sll(r_A, r_A, k, ctx);
 			break;
-		case BPF_S_ALU_LSH_X:
+		case BPF_ALU | BPF_LSH | BPF_X:
 			/* A <<= X */
 			ctx->flags |= SEEN_A | SEEN_X;
 			update_on_xread(ctx);
 			emit_sllv(r_A, r_A, r_X, ctx);
 			break;
-		case BPF_S_ALU_RSH_K:
+		case BPF_ALU | BPF_RSH | BPF_K:
 			/* A >>= K */
 			ctx->flags |= SEEN_A;
 			emit_srl(r_A, r_A, k, ctx);
 			break;
-		case BPF_S_ALU_RSH_X:
+		case BPF_ALU | BPF_RSH | BPF_X:
 			ctx->flags |= SEEN_A | SEEN_X;
 			update_on_xread(ctx);
 			emit_srlv(r_A, r_A, r_X, ctx);
 			break;
-		case BPF_S_ALU_NEG:
+		case BPF_ALU | BPF_NEG:
 			/* A = -A */
 			ctx->flags |= SEEN_A;
 			emit_neg(r_A, ctx);
 			break;
-		case BPF_S_JMP_JA:
+		case BPF_JMP | BPF_JA:
 			/* pc += K */
 			emit_b(b_imm(i + k + 1, ctx), ctx);
 			emit_nop(ctx);
 			break;
-		case BPF_S_JMP_JEQ_K:
+		case BPF_JMP | BPF_JEQ | BPF_K:
 			/* pc += ( A == K ) ? pc->jt : pc->jf */
 			condt = MIPS_COND_EQ | MIPS_COND_K;
 			goto jmp_cmp;
-		case BPF_S_JMP_JEQ_X:
+		case BPF_JMP | BPF_JEQ | BPF_X:
 			ctx->flags |= SEEN_X;
 			/* pc += ( A == X ) ? pc->jt : pc->jf */
 			condt = MIPS_COND_EQ | MIPS_COND_X;
 			goto jmp_cmp;
-		case BPF_S_JMP_JGE_K:
+		case BPF_JMP | BPF_JGE | BPF_K:
 			/* pc += ( A >= K ) ? pc->jt : pc->jf */
 			condt = MIPS_COND_GE | MIPS_COND_K;
 			goto jmp_cmp;
-		case BPF_S_JMP_JGE_X:
+		case BPF_JMP | BPF_JGE | BPF_X:
 			ctx->flags |= SEEN_X;
 			/* pc += ( A >= X ) ? pc->jt : pc->jf */
 			condt = MIPS_COND_GE | MIPS_COND_X;
 			goto jmp_cmp;
-		case BPF_S_JMP_JGT_K:
+		case BPF_JMP | BPF_JGT | BPF_K:
 			/* pc += ( A > K ) ? pc->jt : pc->jf */
 			condt = MIPS_COND_GT | MIPS_COND_K;
 			goto jmp_cmp;
-		case BPF_S_JMP_JGT_X:
+		case BPF_JMP | BPF_JGT | BPF_X:
 			ctx->flags |= SEEN_X;
 			/* pc += ( A > X ) ? pc->jt : pc->jf */
 			condt = MIPS_COND_GT | MIPS_COND_X;
@@ -1167,7 +1162,7 @@ jmp_cmp:
 				}
 			}
 			break;
-		case BPF_S_JMP_JSET_K:
+		case BPF_JMP | BPF_JSET | BPF_K:
 			ctx->flags |= SEEN_S0 | SEEN_S1 | SEEN_A;
 			/* pc += (A & K) ? pc -> jt : pc -> jf */
 			emit_load_imm(r_s1, k, ctx);
@@ -1181,7 +1176,7 @@ jmp_cmp:
 			emit_b(b_off, ctx);
 			emit_nop(ctx);
 			break;
-		case BPF_S_JMP_JSET_X:
+		case BPF_JMP | BPF_JSET | BPF_X:
 			ctx->flags |= SEEN_S0 | SEEN_X | SEEN_A;
 			/* pc += (A & X) ? pc -> jt : pc -> jf */
 			emit_and(r_s0, r_A, r_X, ctx);
@@ -1194,7 +1189,7 @@ jmp_cmp:
 			emit_b(b_off, ctx);
 			emit_nop(ctx);
 			break;
-		case BPF_S_RET_A:
+		case BPF_RET | BPF_A:
 			ctx->flags |= SEEN_A;
 			if (i != prog->len - 1)
 				/*
@@ -1204,7 +1199,7 @@ jmp_cmp:
 				emit_b(b_imm(prog->len, ctx), ctx);
 			emit_reg_move(r_ret, r_A, ctx); /* delay slot */
 			break;
-		case BPF_S_RET_K:
+		case BPF_RET | BPF_K:
 			/*
 			 * It can emit two instructions so it does not fit on
 			 * the delay slot.
@@ -1219,19 +1214,19 @@ jmp_cmp:
 				emit_nop(ctx);
 			}
 			break;
-		case BPF_S_MISC_TAX:
+		case BPF_MISC | BPF_TAX:
 			/* X = A */
 			ctx->flags |= SEEN_X | SEEN_A;
 			emit_jit_reg_move(r_X, r_A, ctx);
 			break;
-		case BPF_S_MISC_TXA:
+		case BPF_MISC | BPF_TXA:
 			/* A = X */
 			ctx->flags |= SEEN_A | SEEN_X;
 			update_on_xread(ctx);
 			emit_jit_reg_move(r_A, r_X, ctx);
 			break;
 		/* AUX */
-		case BPF_S_ANC_PROTOCOL:
+		case BPF_ANC | SKF_AD_PROTOCOL:
 			/* A = ntohs(skb->protocol */
 			ctx->flags |= SEEN_SKB | SEEN_OFF | SEEN_A;
 			BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff,
@@ -1256,7 +1251,7 @@ jmp_cmp:
 			}
 #endif
 			break;
-		case BPF_S_ANC_CPU:
+		case BPF_ANC | SKF_AD_CPU:
 			ctx->flags |= SEEN_A | SEEN_OFF;
 			/* A = current_thread_info()->cpu */
 			BUILD_BUG_ON(FIELD_SIZEOF(struct thread_info,
@@ -1265,7 +1260,7 @@ jmp_cmp:
 			/* $28/gp points to the thread_info struct */
 			emit_load(r_A, 28, off, ctx);
 			break;
-		case BPF_S_ANC_IFINDEX:
+		case BPF_ANC | SKF_AD_IFINDEX:
 			/* A = skb->dev->ifindex */
 			ctx->flags |= SEEN_SKB | SEEN_A | SEEN_S0;
 			off = offsetof(struct sk_buff, dev);
@@ -1279,31 +1274,31 @@ jmp_cmp:
 			off = offsetof(struct net_device, ifindex);
 			emit_load(r_A, r_s0, off, ctx);
 			break;
-		case BPF_S_ANC_MARK:
+		case BPF_ANC | SKF_AD_MARK:
 			ctx->flags |= SEEN_SKB | SEEN_A;
 			BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
 			off = offsetof(struct sk_buff, mark);
 			emit_load(r_A, r_skb, off, ctx);
 			break;
-		case BPF_S_ANC_RXHASH:
+		case BPF_ANC | SKF_AD_RXHASH:
 			ctx->flags |= SEEN_SKB | SEEN_A;
 			BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4);
 			off = offsetof(struct sk_buff, hash);
 			emit_load(r_A, r_skb, off, ctx);
 			break;
-		case BPF_S_ANC_VLAN_TAG:
-		case BPF_S_ANC_VLAN_TAG_PRESENT:
+		case BPF_ANC | SKF_AD_VLAN_TAG:
+		case BPF_ANC | SKF_AD_VLAN_TAG_PRESENT:
 			ctx->flags |= SEEN_SKB | SEEN_S0 | SEEN_A;
 			BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff,
 						  vlan_tci) != 2);
 			off = offsetof(struct sk_buff, vlan_tci);
 			emit_half_load(r_s0, r_skb, off, ctx);
-			if (inst->code == BPF_S_ANC_VLAN_TAG)
+			if (code == (BPF_ANC | SKF_AD_VLAN_TAG))
 				emit_and(r_A, r_s0, VLAN_VID_MASK, ctx);
 			else
 				emit_and(r_A, r_s0, VLAN_TAG_PRESENT, ctx);
 			break;
-		case BPF_S_ANC_PKTTYPE:
+		case BPF_ANC | SKF_AD_PKTTYPE:
 			off = pkt_type_offset();
 
 			if (off < 0)
@@ -1312,7 +1307,7 @@ jmp_cmp:
 			/* Keep only the last 3 bits */
 			emit_andi(r_A, r_tmp, PKT_TYPE_MAX, ctx);
 			break;
-		case BPF_S_ANC_QUEUE:
+		case BPF_ANC | SKF_AD_QUEUE:
 			ctx->flags |= SEEN_SKB | SEEN_A;
 			BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff,
 						  queue_mapping) != 2);
-- 
1.7.11.7

Re: mips:allmodconfig build failure in 3.16-rc1 due to bpf_jit code

[Guenter Roeck]

On 06/17/2014 03:16 AM, Daniel Borkmann wrote:
> On 06/17/2014 10:20 AM, Daniel Borkmann wrote:
>> On 06/17/2014 04:24 AM, Guenter Roeck wrote:
>>> mips:allmodconfig fails in 3.16-rc1 with lots of undefined symbols.
>>>
>>> arch/mips/net/bpf_jit.c: In function 'is_load_to_a':
>>> arch/mips/net/bpf_jit.c:559:7: error: 'BPF_S_LD_W_LEN' undeclared (first use in this function)
>>> arch/mips/net/bpf_jit.c:559:7: note: each undeclared identifier is reported only once for each function it appears in
>>> arch/mips/net/bpf_jit.c:560:7: error: 'BPF_S_LD_W_ABS' undeclared (first use in this function)
>>> arch/mips/net/bpf_jit.c:561:7: error: 'BPF_S_LD_H_ABS' undeclared (first use in this function)
>>> arch/mips/net/bpf_jit.c:562:7: error: 'BPF_S_LD_B_ABS' undeclared (first use in this function)
>>> arch/mips/net/bpf_jit.c:563:7: error: 'BPF_S_ANC_CPU' undeclared (first use in this function)
>>> arch/mips/net/bpf_jit.c:564:7: error: 'BPF_S_ANC_IFINDEX' undeclared (first use in this function)
>>> arch/mips/net/bpf_jit.c:565:7: error: 'BPF_S_ANC_MARK' undeclared (first use in this function)
>>>
>>> and so on.
>>>
>>> Those symbols are not defined anywhere.
>>>
>>> The problem is due to a conflict with commit 348059313 (net: filter: get rid of BPF_S_*
>>> enum), which removed those definitions.
>>
>> Yep, it seems both got in this merge window from different trees. Don't have mips, but
>> I'll have a look, and send you a patch.
>
> Could you give the attached patch a try?
>

Yes, this fixes the build problem. Obviously I have no idea if it works ;-)

Guenter

Re: mips:allmodconfig build failure in 3.16-rc1 due to bpf_jit code

[Markos Chandras]

On 06/17/2014 11:16 AM, Daniel Borkmann wrote:
> On 06/17/2014 10:20 AM, Daniel Borkmann wrote:
>> On 06/17/2014 04:24 AM, Guenter Roeck wrote:
>>> mips:allmodconfig fails in 3.16-rc1 with lots of undefined symbols.
>>>
>>> arch/mips/net/bpf_jit.c: In function 'is_load_to_a':
>>> arch/mips/net/bpf_jit.c:559:7: error: 'BPF_S_LD_W_LEN' undeclared
>>> (first use in this function)
>>> arch/mips/net/bpf_jit.c:559:7: note: each undeclared identifier is
>>> reported only once for each function it appears in
>>> arch/mips/net/bpf_jit.c:560:7: error: 'BPF_S_LD_W_ABS' undeclared
>>> (first use in this function)
>>> arch/mips/net/bpf_jit.c:561:7: error: 'BPF_S_LD_H_ABS' undeclared
>>> (first use in this function)
>>> arch/mips/net/bpf_jit.c:562:7: error: 'BPF_S_LD_B_ABS' undeclared
>>> (first use in this function)
>>> arch/mips/net/bpf_jit.c:563:7: error: 'BPF_S_ANC_CPU' undeclared
>>> (first use in this function)
>>> arch/mips/net/bpf_jit.c:564:7: error: 'BPF_S_ANC_IFINDEX' undeclared
>>> (first use in this function)
>>> arch/mips/net/bpf_jit.c:565:7: error: 'BPF_S_ANC_MARK' undeclared
>>> (first use in this function)
>>>
>>> and so on.
>>>
>>> Those symbols are not defined anywhere.
>>>
>>> The problem is due to a conflict with commit 348059313 (net: filter:
>>> get rid of BPF_S_*
>>> enum), which removed those definitions.
>>
>> Yep, it seems both got in this merge window from different trees.
>> Don't have mips, but
>> I'll have a look, and send you a patch.
> 
> Could you give the attached patch a try?
> 
> Thanks,
> 
> Daniel

Hi Daniel,

This fixes the build and seems to work ok (tried with dhcp and tcpdump).
Thanks for fixing it.

Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Tested-by: Markos Chandras <markos.chandras@imgtec.com>

-- 
markos

Re: mips:allmodconfig build failure in 3.16-rc1 due to bpf_jit code

[Daniel Borkmann]

On 06/17/2014 12:39 PM, Guenter Roeck wrote:
> On 06/17/2014 03:16 AM, Daniel Borkmann wrote:
>> On 06/17/2014 10:20 AM, Daniel Borkmann wrote:
>>> On 06/17/2014 04:24 AM, Guenter Roeck wrote:
>>>> mips:allmodconfig fails in 3.16-rc1 with lots of undefined symbols.
>>>>
>>>> arch/mips/net/bpf_jit.c: In function 'is_load_to_a':
>>>> arch/mips/net/bpf_jit.c:559:7: error: 'BPF_S_LD_W_LEN' undeclared (first use in this function)
>>>> arch/mips/net/bpf_jit.c:559:7: note: each undeclared identifier is reported only once for each function it appears in
>>>> arch/mips/net/bpf_jit.c:560:7: error: 'BPF_S_LD_W_ABS' undeclared (first use in this function)
>>>> arch/mips/net/bpf_jit.c:561:7: error: 'BPF_S_LD_H_ABS' undeclared (first use in this function)
>>>> arch/mips/net/bpf_jit.c:562:7: error: 'BPF_S_LD_B_ABS' undeclared (first use in this function)
>>>> arch/mips/net/bpf_jit.c:563:7: error: 'BPF_S_ANC_CPU' undeclared (first use in this function)
>>>> arch/mips/net/bpf_jit.c:564:7: error: 'BPF_S_ANC_IFINDEX' undeclared (first use in this function)
>>>> arch/mips/net/bpf_jit.c:565:7: error: 'BPF_S_ANC_MARK' undeclared (first use in this function)
>>>>
>>>> and so on.
>>>>
>>>> Those symbols are not defined anywhere.
>>>>
>>>> The problem is due to a conflict with commit 348059313 (net: filter: get rid of BPF_S_*
>>>> enum), which removed those definitions.
>>>
>>> Yep, it seems both got in this merge window from different trees. Don't have mips, but
>>> I'll have a look, and send you a patch.
>>
>> Could you give the attached patch a try?
>
> Yes, this fixes the build problem. Obviously I have no idea if it works ;-)

Thanks Guenter!

We have a test suite for BPF under lib/test_bpf.c that was designed for the
interpreter and for BPF JIT developers in mind and pretty much covers most
cases. E.g. one possibility to run it would be:

   0) compile module test_bpf (Kernel Hacking -> Test BPF filter functionality)
   1) echo 1 > /proc/sys/net/core/bpf_jit_enable           [<- enables BPF JIT]
   2) modprobe test_bpf                                    [<- runs test suite]

The results will be visible in the klog via dmesg (if at least one test fails,
the module init handler will return an error).

Best,

Daniel

Re: mips:allmodconfig build failure in 3.16-rc1 due to bpf_jit code

[Daniel Borkmann]

On 06/17/2014 12:54 PM, Markos Chandras wrote:
...
> This fixes the build and seems to work ok (tried with dhcp and tcpdump).
> Thanks for fixing it.
>
> Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
> Tested-by: Markos Chandras <markos.chandras@imgtec.com>

Great, thanks for your help!

Re: mips:allmodconfig build failure in 3.16-rc1 due to bpf_jit code

[Markos Chandras]

On 06/17/2014 11:56 AM, Daniel Borkmann wrote:
> On 06/17/2014 12:39 PM, Guenter Roeck wrote:
>> On 06/17/2014 03:16 AM, Daniel Borkmann wrote:
>>> On 06/17/2014 10:20 AM, Daniel Borkmann wrote:
>>>> On 06/17/2014 04:24 AM, Guenter Roeck wrote:
>>>>> mips:allmodconfig fails in 3.16-rc1 with lots of undefined symbols.
>>>>>
>>>>> arch/mips/net/bpf_jit.c: In function 'is_load_to_a':
>>>>> arch/mips/net/bpf_jit.c:559:7: error: 'BPF_S_LD_W_LEN' undeclared
>>>>> (first use in this function)
>>>>> arch/mips/net/bpf_jit.c:559:7: note: each undeclared identifier is
>>>>> reported only once for each function it appears in
>>>>> arch/mips/net/bpf_jit.c:560:7: error: 'BPF_S_LD_W_ABS' undeclared
>>>>> (first use in this function)
>>>>> arch/mips/net/bpf_jit.c:561:7: error: 'BPF_S_LD_H_ABS' undeclared
>>>>> (first use in this function)
>>>>> arch/mips/net/bpf_jit.c:562:7: error: 'BPF_S_LD_B_ABS' undeclared
>>>>> (first use in this function)
>>>>> arch/mips/net/bpf_jit.c:563:7: error: 'BPF_S_ANC_CPU' undeclared
>>>>> (first use in this function)
>>>>> arch/mips/net/bpf_jit.c:564:7: error: 'BPF_S_ANC_IFINDEX'
>>>>> undeclared (first use in this function)
>>>>> arch/mips/net/bpf_jit.c:565:7: error: 'BPF_S_ANC_MARK' undeclared
>>>>> (first use in this function)
>>>>>
>>>>> and so on.
>>>>>
>>>>> Those symbols are not defined anywhere.
>>>>>
>>>>> The problem is due to a conflict with commit 348059313 (net:
>>>>> filter: get rid of BPF_S_*
>>>>> enum), which removed those definitions.
>>>>
>>>> Yep, it seems both got in this merge window from different trees.
>>>> Don't have mips, but
>>>> I'll have a look, and send you a patch.
>>>
>>> Could you give the attached patch a try?
>>
>> Yes, this fixes the build problem. Obviously I have no idea if it
>> works ;-)
> 
> Thanks Guenter!
> 
> We have a test suite for BPF under lib/test_bpf.c that was designed for the
> interpreter and for BPF JIT developers in mind and pretty much covers most
> cases. E.g. one possibility to run it would be:
> 
>   0) compile module test_bpf (Kernel Hacking -> Test BPF filter
> functionality)
>   1) echo 1 > /proc/sys/net/core/bpf_jit_enable           [<- enables
> BPF JIT]
>   2) modprobe test_bpf                                    [<- runs test
> suite]
> 
> The results will be visible in the klog via dmesg (if at least one test
> fails,
> the module init handler will return an error).
> 
> Best,
> 
> Daniel
Hi Daniel,

Thanks for these instructions. I will try them myself once I find some
time since I don't think bpf_jit for MIPS has ever been tested with all
the opcodes.

-- 
markos

Re: mips:allmodconfig build failure in 3.16-rc1 due to bpf_jit code

[Daniel Borkmann]

On 06/17/2014 01:09 PM, Markos Chandras wrote:
...
> Thanks for these instructions. I will try them myself once I find some
> time since I don't think bpf_jit for MIPS has ever been tested with all
> the opcodes.

Sounds great! If you find some tests are missing, please feel free to
submit them as well via netdev.

Best,

Daniel

Re: mips:allmodconfig build failure in 3.16-rc1 due to bpf_jit code

[Alexei Starovoitov]

On Tue, Jun 17, 2014 at 4:21 AM, Daniel Borkmann <dborkman@redhat.com> wrote:
> On 06/17/2014 01:09 PM, Markos Chandras wrote:
> ...
>>
>> Thanks for these instructions. I will try them myself once I find some
>>
>> time since I don't think bpf_jit for MIPS has ever been tested with all
>> the opcodes.
>
>
> Sounds great! If you find some tests are missing, please feel free to
> submit them as well via netdev.
>
> Best,
>
> Daniel

Daniel,

thank you for taking care of it so quickly :)
from the BPF perspective the fix looks good:
Acked-by: Alexei Starovoitov <ast@plumgrid.com>

Markos,

please do run the testsuite.
Doing quick code review of mips jit, it looks like:

- your version of pkt_type_offset() will work for little endian only.
  (we've recently fixed it in net/core/filter.c)

- vlan tag handling is incorrect, since it's missing shifts.
  classic BPF standard for vlan_tag_present has to return 1 or 0
  and not just emit_and(r_A, r_s0, VLAN_TAG_PRESENT, ctx);

- pr_warn("%s: Unhandled opcode: 0x%02x\n", __FILE__,
  is way too heavy, since when jit is on, unprivileged user can spam log.

- /* sa is 5-bits long */
  BUG_ON(sa >= BIT(5));
is wrong too. Malicious user can cause kernel crash…
Also shift A>>=33 was always allowed by classic BPF checker, so
JITs have to silently do C-equivalent version of such shift.

- /* Determine if immediate is within the 16-bit signed range */
static inline bool is_range16(s32 imm)
{
        if (imm >= SBIT(15) || imm < -SBIT(15))
                return true;
the function name and comment are doing the opposite of
actual code, which makes harder to follow.

- the rest looks pretty good!

Also you'll get a lot more mileage out of mips jit if you use eBPF
instruction set as a base for JITing. You wouldn't need to worry
about vlan, pkt_type and other classic extensions. You'll get all
extensions for free, plus seccomp, tracing, etc.

Thanks
Alexei

Re: mips:allmodconfig build failure in 3.16-rc1 due to bpf_jit code

[Markos Chandras]

On 06/17/2014 08:38 PM, Alexei Starovoitov wrote:
> On Tue, Jun 17, 2014 at 4:21 AM, Daniel Borkmann <dborkman@redhat.com> wrote:
>> On 06/17/2014 01:09 PM, Markos Chandras wrote:
>> ...
>>>
>>> Thanks for these instructions. I will try them myself once I find some
>>>
>>> time since I don't think bpf_jit for MIPS has ever been tested with all
>>> the opcodes.
>>
>>
>> Sounds great! If you find some tests are missing, please feel free to
>> submit them as well via netdev.
>>
>> Best,
>>
>> Daniel
> 
> Daniel,
> 
> thank you for taking care of it so quickly :)
> from the BPF perspective the fix looks good:
> Acked-by: Alexei Starovoitov <ast@plumgrid.com>
> 
> Markos,
> 
> please do run the testsuite.
> Doing quick code review of mips jit, it looks like:
> 
> - your version of pkt_type_offset() will work for little endian only.
>   (we've recently fixed it in net/core/filter.c)
> 
> - vlan tag handling is incorrect, since it's missing shifts.
>   classic BPF standard for vlan_tag_present has to return 1 or 0
>   and not just emit_and(r_A, r_s0, VLAN_TAG_PRESENT, ctx);
> 
> - pr_warn("%s: Unhandled opcode: 0x%02x\n", __FILE__,
>   is way too heavy, since when jit is on, unprivileged user can spam log.
> 
> - /* sa is 5-bits long */
>   BUG_ON(sa >= BIT(5));
> is wrong too. Malicious user can cause kernel crash…
> Also shift A>>=33 was always allowed by classic BPF checker, so
> JITs have to silently do C-equivalent version of such shift.
> 
> - /* Determine if immediate is within the 16-bit signed range */
> static inline bool is_range16(s32 imm)
> {
>         if (imm >= SBIT(15) || imm < -SBIT(15))
>                 return true;
> the function name and comment are doing the opposite of
> actual code, which makes harder to follow.
> 
> - the rest looks pretty good!
> 
> Also you'll get a lot more mileage out of mips jit if you use eBPF
> instruction set as a base for JITing. You wouldn't need to worry
> about vlan, pkt_type and other classic extensions. You'll get all
> extensions for free, plus seccomp, tracing, etc.
> 
> Thanks
> Alexei
> 
Hi Alexei,

Thanks a lot for the feedback. I have already identified a few problems
which I have already fixed. I would like to move to eBPF but I can't
promise I can do it soon, so i think it's best to make sure that classic
BPF works fine for 3.16 and then I will make my plans for eBPF.

-- 
markos