On 11/10/2018 07:58 PM, Michał Mirosław wrote:
> Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
Why you have empty commit messages for non-trivial changes like this in
4 out of 6 of your patches ...
How was it tested on the JITs you were changing? Did you test on both,
big and little endian machines?
> ---
> net/core/filter.c | 40 +++++++++++++++++++++-------------------
> 1 file changed, 21 insertions(+), 19 deletions(-)
>
> diff --git a/net/core/filter.c b/net/core/filter.c
> index e521c5ebc7d1..c151b906df53 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -296,22 +296,21 @@ static u32 convert_skb_access(int skb_field, int dst_reg, int src_reg,
> break;
>
> case SKF_AD_VLAN_TAG:
> - case SKF_AD_VLAN_TAG_PRESENT:
> BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2);
> - BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000);
>
> /* dst_reg = *(u16 *) (src_reg + offsetof(vlan_tci)) */
> *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg,
> offsetof(struct sk_buff, vlan_tci));
> - if (skb_field == SKF_AD_VLAN_TAG) {
> - *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg,
> - ~VLAN_TAG_PRESENT);
> - } else {
> - /* dst_reg >>= 12 */
> - *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, 12);
> - /* dst_reg &= 1 */
> +#ifdef VLAN_TAG_PRESENT
> + *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, ~VLAN_TAG_PRESENT);
> +#endif
> + break;
> + case SKF_AD_VLAN_TAG_PRESENT:
> + *insn++ = BPF_LDX_MEM(BPF_B, dst_reg, src_reg, PKT_VLAN_PRESENT_OFFSET());
> + if (PKT_VLAN_PRESENT_BIT)
> + *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, PKT_VLAN_PRESENT_BIT);
> + if (PKT_VLAN_PRESENT_BIT < 7)
> *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, 1);
> - }
> break;
> }
>
> @@ -6140,19 +6139,22 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type,
> break;
>
> case offsetof(struct __sk_buff, vlan_present):
> + *target_size = 1;
> + *insn++ = BPF_LDX_MEM(BPF_B, si->dst_reg, si->src_reg,
> + PKT_VLAN_PRESENT_OFFSET());
> + if (PKT_VLAN_PRESENT_BIT)
> + *insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg, PKT_VLAN_PRESENT_BIT);
> + if (PKT_VLAN_PRESENT_BIT < 7)
> + *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, 1);
> + break;
> +
> case offsetof(struct __sk_buff, vlan_tci):
> - BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000);
> -
> *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg,
> bpf_target_off(struct sk_buff, vlan_tci, 2,
> target_size));
> - if (si->off == offsetof(struct __sk_buff, vlan_tci)) {
> - *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg,
> - ~VLAN_TAG_PRESENT);
> - } else {
> - *insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg, 12);
> - *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, 1);
> - }
> +#ifdef VLAN_TAG_PRESENT
> + *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, ~VLAN_TAG_PRESENT);
> +#endif
> break;
>
> case offsetof(struct __sk_buff, cb[0]) ...
>
