Re: [PATCH net-next 2/6] net/bpf: split VLAN_PRESENT bit handling from VLAN_TCI
On Mon, Nov 19, 2018 at 12:26:46PM +0100, Daniel Borkmann wrote: > On 11/10/2018 07:58 PM, Michał Mirosław wrote: > > Signed-off-by: Michał Mirosław > > 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? I have only x86 boxes currently so didn't try to test others. I hope upstreaming the series through net-next will allow us to find any fallouts, if any. The changes are very simple, though: they move code around (the "splitting" part) and eventually change a vlan_present flag's position in a skbuff structure. Dependency on CPU endianness is removed by using byte loads for the flag. Best Regards, Michał Mirosław
Re: [PATCH net-next 2/6] net/bpf: split VLAN_PRESENT bit handling from VLAN_TCI
On 11/10/2018 07:58 PM, Michał Mirosław wrote:
> Signed-off-by: Michał Mirosław
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]) ...
>
[PATCH net-next 2/6] net/bpf: split VLAN_PRESENT bit handling from VLAN_TCI
Signed-off-by: Michał Mirosław
---
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]) ...
--
2.19.1
