diff options
Diffstat (limited to 'arch/arm/net/bpf_jit_32.c')
-rw-r--r-- | arch/arm/net/bpf_jit_32.c | 98 |
1 files changed, 83 insertions, 15 deletions
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index 4550d247e308..876060bcceeb 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -74,32 +74,52 @@ struct jit_ctx { int bpf_jit_enable __read_mostly; -static u64 jit_get_skb_b(struct sk_buff *skb, unsigned offset) +static inline int call_neg_helper(struct sk_buff *skb, int offset, void *ret, + unsigned int size) +{ + void *ptr = bpf_internal_load_pointer_neg_helper(skb, offset, size); + + if (!ptr) + return -EFAULT; + memcpy(ret, ptr, size); + return 0; +} + +static u64 jit_get_skb_b(struct sk_buff *skb, int offset) { u8 ret; int err; - err = skb_copy_bits(skb, offset, &ret, 1); + if (offset < 0) + err = call_neg_helper(skb, offset, &ret, 1); + else + err = skb_copy_bits(skb, offset, &ret, 1); return (u64)err << 32 | ret; } -static u64 jit_get_skb_h(struct sk_buff *skb, unsigned offset) +static u64 jit_get_skb_h(struct sk_buff *skb, int offset) { u16 ret; int err; - err = skb_copy_bits(skb, offset, &ret, 2); + if (offset < 0) + err = call_neg_helper(skb, offset, &ret, 2); + else + err = skb_copy_bits(skb, offset, &ret, 2); return (u64)err << 32 | ntohs(ret); } -static u64 jit_get_skb_w(struct sk_buff *skb, unsigned offset) +static u64 jit_get_skb_w(struct sk_buff *skb, int offset) { u32 ret; int err; - err = skb_copy_bits(skb, offset, &ret, 4); + if (offset < 0) + err = call_neg_helper(skb, offset, &ret, 4); + else + err = skb_copy_bits(skb, offset, &ret, 4); return (u64)err << 32 | ntohl(ret); } @@ -536,9 +556,6 @@ static int build_body(struct jit_ctx *ctx) case BPF_LD | BPF_B | BPF_ABS: load_order = 0; load: - /* the interpreter will deal with the negative K */ - if ((int)k < 0) - return -ENOTSUPP; emit_mov_i(r_off, k, ctx); load_common: ctx->seen |= SEEN_DATA | SEEN_CALL; @@ -547,12 +564,24 @@ load_common: emit(ARM_SUB_I(r_scratch, r_skb_hl, 1 << load_order), ctx); emit(ARM_CMP_R(r_scratch, r_off), ctx); - condt = ARM_COND_HS; + condt = ARM_COND_GE; } else { emit(ARM_CMP_R(r_skb_hl, r_off), ctx); condt = ARM_COND_HI; } + /* + * test for negative offset, only if we are + * currently scheduled to take the fast + * path. this will update the flags so that + * the slowpath instruction are ignored if the + * offset is negative. + * + * for loard_order == 0 the HI condition will + * make loads at offset 0 take the slow path too. + */ + _emit(condt, ARM_CMP_I(r_off, 0), ctx); + _emit(condt, ARM_ADD_R(r_scratch, r_off, r_skb_data), ctx); @@ -828,7 +857,9 @@ b_epilogue: emit(ARM_LDR_I(r_A, r_scratch, off), ctx); break; case BPF_ANC | SKF_AD_IFINDEX: + case BPF_ANC | SKF_AD_HATYPE: /* A = skb->dev->ifindex */ + /* A = skb->dev->type */ ctx->seen |= SEEN_SKB; off = offsetof(struct sk_buff, dev); emit(ARM_LDR_I(r_scratch, r_skb, off), ctx); @@ -838,8 +869,24 @@ b_epilogue: BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); - off = offsetof(struct net_device, ifindex); - emit(ARM_LDR_I(r_A, r_scratch, off), ctx); + BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, + type) != 2); + + if (code == (BPF_ANC | SKF_AD_IFINDEX)) { + off = offsetof(struct net_device, ifindex); + emit(ARM_LDR_I(r_A, r_scratch, off), ctx); + } else { + /* + * offset of field "type" in "struct + * net_device" is above what can be + * used in the ldrh rd, [rn, #imm] + * instruction, so load the offset in + * a register and use ldrh rd, [rn, rm] + */ + off = offsetof(struct net_device, type); + emit_mov_i(ARM_R3, off, ctx); + emit(ARM_LDRH_R(r_A, r_scratch, ARM_R3), ctx); + } break; case BPF_ANC | SKF_AD_MARK: ctx->seen |= SEEN_SKB; @@ -860,9 +907,22 @@ b_epilogue: off = offsetof(struct sk_buff, vlan_tci); emit(ARM_LDRH_I(r_A, r_skb, off), ctx); if (code == (BPF_ANC | SKF_AD_VLAN_TAG)) - OP_IMM3(ARM_AND, r_A, r_A, VLAN_VID_MASK, ctx); - else - OP_IMM3(ARM_AND, r_A, r_A, VLAN_TAG_PRESENT, ctx); + OP_IMM3(ARM_AND, r_A, r_A, ~VLAN_TAG_PRESENT, ctx); + else { + OP_IMM3(ARM_LSR, r_A, r_A, 12, ctx); + OP_IMM3(ARM_AND, r_A, r_A, 0x1, ctx); + } + break; + case BPF_ANC | SKF_AD_PKTTYPE: + ctx->seen |= SEEN_SKB; + BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, + __pkt_type_offset[0]) != 1); + off = PKT_TYPE_OFFSET(); + emit(ARM_LDRB_I(r_A, r_skb, off), ctx); + emit(ARM_AND_I(r_A, r_A, PKT_TYPE_MAX), ctx); +#ifdef __BIG_ENDIAN_BITFIELD + emit(ARM_LSR_I(r_A, r_A, 5), ctx); +#endif break; case BPF_ANC | SKF_AD_QUEUE: ctx->seen |= SEEN_SKB; @@ -873,6 +933,14 @@ b_epilogue: off = offsetof(struct sk_buff, queue_mapping); emit(ARM_LDRH_I(r_A, r_skb, off), ctx); break; + case BPF_ANC | SKF_AD_PAY_OFFSET: + ctx->seen |= SEEN_SKB | SEEN_CALL; + + emit(ARM_MOV_R(ARM_R0, r_skb), ctx); + emit_mov_i(ARM_R3, (unsigned int)skb_get_poff, ctx); + emit_blx_r(ARM_R3, ctx); + emit(ARM_MOV_R(r_A, ARM_R0), ctx); + break; case BPF_LDX | BPF_W | BPF_ABS: /* * load a 32bit word from struct seccomp_data. |