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* Re: [PATCH net-next] net: stmmac: Add support for U32 TC filter using Flexible RX Parser
From: Jakub Kicinski @ 2018-05-04  0:57 UTC (permalink / raw)
  To: Jose Abreu
  Cc: netdev, David S. Miller, Joao Pinto, Vitor Soares,
	Giuseppe Cavallaro, Alexandre Torgue
In-Reply-To: <9f57f98ef35360619001882fdcf0d7ef0558863f.1525351447.git.joabreu@synopsys.com>

On Thu,  3 May 2018 13:45:30 +0100, Jose Abreu wrote:
> +	case TC_SETUP_CLSU32:
> +		if (!(priv->dev->hw_features & NETIF_F_HW_TC))
> +			ret = -EOPNOTSUPP;
> +		else
> +			ret = stmmac_tc_setup_cls_u32(priv, priv, type_data);
> +		break;

Please just use tc_cls_can_offload_and_chain0().  The extack message it
sets is useful for debugging and you don't support chains other than 0
either.

^ permalink raw reply

* Re: [bpf-next v1 8/9] bpf: Provide helper to do lookups in kernel FIB table
From: David Ahern @ 2018-05-04  0:47 UTC (permalink / raw)
  To: Daniel Borkmann, netdev, borkmann, ast
  Cc: davem, shm, roopa, brouer, toke, john.fastabend
In-Reply-To: <df3ac0c5-de3c-f47d-2d8b-1b3b42a51187@iogearbox.net>

On 5/3/18 6:45 PM, Daniel Borkmann wrote:
>> +	.ret_type	= RET_INTEGER,
>> +	.arg1_type      = ARG_PTR_TO_CTX,
>> +	.arg2_type      = ARG_PTR_TO_MEM,
>> +	.arg3_type      = ARG_CONST_SIZE,
>> +	.arg4_type	= ARG_ANYTHING,
>> +};
>> +
>> +BPF_CALL_4(bpf_skb_fib_lookup, struct sk_buff *, skb,
>> +	   struct bpf_fib_lookup *, params, int, plen, u32, flags)
>> +{
>> +	if (plen < sizeof(*params))
>> +		return -EINVAL;
>> +
>> +	switch (params->family) {
>> +#if IS_ENABLED(CONFIG_INET)
>> +	case AF_INET:
>> +		return bpf_ipv4_fib_lookup(dev_net(skb->dev), params, flags);
>> +#endif
>> +#if IS_ENABLED(CONFIG_IPV6)
>> +	case AF_INET6:
>> +		return bpf_ipv6_fib_lookup(dev_net(skb->dev), params, flags);
>> +#endif
>> +	}
>> +	return -ENOTSUPP;
>> +}
>> +
>> +static const struct bpf_func_proto bpf_skb_fib_lookup_proto = {
>> +	.func		= bpf_skb_fib_lookup,
>> +	.gpl_only	= true,
>> +	.pkt_access	= true,
> 
> ... this should both not be marked as pkt_access = true. What this means is that
> arg2, which is the struct bpf_fib_lookup, could come from the raw packet buffer.

leftover from the first version which did pass in the packet. Will remove.

^ permalink raw reply

* Re: [bpf-next v1 8/9] bpf: Provide helper to do lookups in kernel FIB table
From: Daniel Borkmann @ 2018-05-04  0:45 UTC (permalink / raw)
  To: David Ahern, netdev, borkmann, ast
  Cc: davem, shm, roopa, brouer, toke, john.fastabend
In-Reply-To: <20180503035319.18290-9-dsahern@gmail.com>

On 05/03/2018 05:53 AM, David Ahern wrote:
[...]
> +
> +BPF_CALL_4(bpf_xdp_fib_lookup, struct xdp_buff *, ctx,
> +	   struct bpf_fib_lookup *, params, int, plen, u32, flags)
> +{
> +	if (plen < sizeof(*params))
> +		return -EINVAL;
> +
> +	switch (params->family) {
> +#if IS_ENABLED(CONFIG_INET)
> +	case AF_INET:
> +		return bpf_ipv4_fib_lookup(dev_net(ctx->rxq->dev), params,
> +					   flags);
> +#endif
> +#if IS_ENABLED(CONFIG_IPV6)
> +	case AF_INET6:
> +		return bpf_ipv6_fib_lookup(dev_net(ctx->rxq->dev), params,
> +					   flags);
> +#endif
> +	}
> +	return -ENOTSUPP;
> +}
> +
> +static const struct bpf_func_proto bpf_xdp_fib_lookup_proto = {
> +	.func		= bpf_xdp_fib_lookup,
> +	.gpl_only	= true,
> +	.pkt_access	= true,

Hmm, this one and ...

> +	.ret_type	= RET_INTEGER,
> +	.arg1_type      = ARG_PTR_TO_CTX,
> +	.arg2_type      = ARG_PTR_TO_MEM,
> +	.arg3_type      = ARG_CONST_SIZE,
> +	.arg4_type	= ARG_ANYTHING,
> +};
> +
> +BPF_CALL_4(bpf_skb_fib_lookup, struct sk_buff *, skb,
> +	   struct bpf_fib_lookup *, params, int, plen, u32, flags)
> +{
> +	if (plen < sizeof(*params))
> +		return -EINVAL;
> +
> +	switch (params->family) {
> +#if IS_ENABLED(CONFIG_INET)
> +	case AF_INET:
> +		return bpf_ipv4_fib_lookup(dev_net(skb->dev), params, flags);
> +#endif
> +#if IS_ENABLED(CONFIG_IPV6)
> +	case AF_INET6:
> +		return bpf_ipv6_fib_lookup(dev_net(skb->dev), params, flags);
> +#endif
> +	}
> +	return -ENOTSUPP;
> +}
> +
> +static const struct bpf_func_proto bpf_skb_fib_lookup_proto = {
> +	.func		= bpf_skb_fib_lookup,
> +	.gpl_only	= true,
> +	.pkt_access	= true,

... this should both not be marked as pkt_access = true. What this means is that
arg2, which is the struct bpf_fib_lookup, could come from the raw packet buffer.
Meaning instead of the struct sitting on stack it could in that case be passed
out of the packet directly. We have this enabled in helpers like csum_diff() or
map lookup/update where it would make sense to pass raw buffer there, but here
it seems unintentional and should be removed instead. See also description in
last paragraph in 36bbef52c7eb ("bpf: direct packet write and access for helpers
for clsact progs").

> +	.ret_type	= RET_INTEGER,
> +	.arg1_type      = ARG_PTR_TO_CTX,
> +	.arg2_type      = ARG_PTR_TO_MEM,
> +	.arg3_type      = ARG_CONST_SIZE,
> +	.arg4_type	= ARG_ANYTHING,
> +};
> +
>  static const struct bpf_func_proto *
>  bpf_base_func_proto(enum bpf_func_id func_id)
>  {
> @@ -3933,6 +4192,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
>  	case BPF_FUNC_skb_get_xfrm_state:
>  		return &bpf_skb_get_xfrm_state_proto;
>  #endif
> +	case BPF_FUNC_fib_lookup:
> +		return &bpf_skb_fib_lookup_proto;
>  	default:
>  		return bpf_base_func_proto(func_id);
>  	}
> @@ -3958,6 +4219,8 @@ xdp_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
>  		return &bpf_xdp_redirect_map_proto;
>  	case BPF_FUNC_xdp_adjust_tail:
>  		return &bpf_xdp_adjust_tail_proto;
> +	case BPF_FUNC_fib_lookup:
> +		return &bpf_xdp_fib_lookup_proto;
>  	default:
>  		return bpf_base_func_proto(func_id);
>  	}
> 

^ permalink raw reply

* [RFC PATCH 2/2] ixgbevf: Add support for UDP segmentation offload
From: Alexander Duyck @ 2018-05-04  0:39 UTC (permalink / raw)
  To: netdev, willemb, intel-wired-lan
In-Reply-To: <20180504003556.4769.11407.stgit@localhost.localdomain>

From: Alexander Duyck <alexander.h.duyck@intel.com>

This patch adds support for UDP segmentation offload. Relatively few
changes were needed to add this support as it functions much like the TCP
segmentation offload.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
 drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c |   25 ++++++++++++++++-----
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 9a939dcaf727..c2986142c98a 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -3709,6 +3709,7 @@ static int ixgbevf_tso(struct ixgbevf_ring *tx_ring,
 	} ip;
 	union {
 		struct tcphdr *tcp;
+		struct udphdr *udp;
 		unsigned char *hdr;
 	} l4;
 	u32 paylen, l4_offset;
@@ -3731,7 +3732,8 @@ static int ixgbevf_tso(struct ixgbevf_ring *tx_ring,
 	l4.hdr = skb_checksum_start(skb);
 
 	/* ADV DTYP TUCMD MKRLOC/ISCSIHEDLEN */
-	type_tucmd = IXGBE_ADVTXD_TUCMD_L4T_TCP;
+	type_tucmd = (skb->csum_offset == offsetof(struct tcphdr, check)) ?
+		     IXGBE_ADVTXD_TUCMD_L4T_TCP : IXGBE_ADVTXD_TUCMD_L4T_UDP;
 
 	/* initialize outer IP header fields */
 	if (ip.v4->version == 4) {
@@ -3759,12 +3761,20 @@ static int ixgbevf_tso(struct ixgbevf_ring *tx_ring,
 	/* determine offset of inner transport header */
 	l4_offset = l4.hdr - skb->data;
 
-	/* compute length of segmentation header */
-	*hdr_len = (l4.tcp->doff * 4) + l4_offset;
-
 	/* remove payload length from inner checksum */
 	paylen = skb->len - l4_offset;
-	csum_replace_by_diff(&l4.tcp->check, htonl(paylen));
+
+	if (type_tucmd & IXGBE_ADVTXD_TUCMD_L4T_TCP) {
+		/* compute length of segmentation header */
+		*hdr_len = (l4.tcp->doff * 4) + l4_offset;
+		csum_replace_by_diff(&l4.tcp->check,
+				     (__force __wsum)htonl(paylen));
+	} else {
+		/* compute length of segmentation header */
+		*hdr_len = sizeof(*l4.udp) + l4_offset;
+		csum_replace_by_diff(&l4.udp->check,
+				     (__force __wsum)htonl(paylen));
+	}
 
 	/* update gso size and bytecount with header size */
 	first->gso_segs = skb_shinfo(skb)->gso_segs;
@@ -4368,6 +4378,7 @@ static void ixgbevf_get_stats(struct net_device *netdev,
 	if (unlikely(mac_hdr_len > IXGBEVF_MAX_MAC_HDR_LEN))
 		return features & ~(NETIF_F_HW_CSUM |
 				    NETIF_F_SCTP_CRC |
+				    NETIF_F_GSO_UDP_L4 |
 				    NETIF_F_HW_VLAN_CTAG_TX |
 				    NETIF_F_TSO |
 				    NETIF_F_TSO6);
@@ -4376,6 +4387,7 @@ static void ixgbevf_get_stats(struct net_device *netdev,
 	if (unlikely(network_hdr_len >  IXGBEVF_MAX_NETWORK_HDR_LEN))
 		return features & ~(NETIF_F_HW_CSUM |
 				    NETIF_F_SCTP_CRC |
+				    NETIF_F_GSO_UDP_L4 |
 				    NETIF_F_TSO |
 				    NETIF_F_TSO6);
 
@@ -4571,7 +4583,8 @@ static int ixgbevf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 			      NETIF_F_TSO6 |
 			      NETIF_F_RXCSUM |
 			      NETIF_F_HW_CSUM |
-			      NETIF_F_SCTP_CRC;
+			      NETIF_F_SCTP_CRC |
+			      NETIF_F_GSO_UDP_L4;
 
 #define IXGBEVF_GSO_PARTIAL_FEATURES (NETIF_F_GSO_GRE | \
 				      NETIF_F_GSO_GRE_CSUM | \

^ permalink raw reply related

* [RFC PATCH 1/2] ixgbe: Add support for UDP segmentation offload
From: Alexander Duyck @ 2018-05-04  0:39 UTC (permalink / raw)
  To: netdev, willemb, intel-wired-lan
In-Reply-To: <20180504003556.4769.11407.stgit@localhost.localdomain>

From: Alexander Duyck <alexander.h.duyck@intel.com>

This patch adds support for UDP segmentation offload. Relatively few
changes were needed to add this support as it functions much like the TCP
segmentation offload.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c |   24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index a52d92e182ee..0bed3350a795 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -7693,6 +7693,7 @@ static int ixgbe_tso(struct ixgbe_ring *tx_ring,
 	} ip;
 	union {
 		struct tcphdr *tcp;
+		struct udphdr *udp;
 		unsigned char *hdr;
 	} l4;
 	u32 paylen, l4_offset;
@@ -7716,7 +7717,8 @@ static int ixgbe_tso(struct ixgbe_ring *tx_ring,
 	l4.hdr = skb_checksum_start(skb);
 
 	/* ADV DTYP TUCMD MKRLOC/ISCSIHEDLEN */
-	type_tucmd = IXGBE_ADVTXD_TUCMD_L4T_TCP;
+	type_tucmd = (skb->csum_offset == offsetof(struct tcphdr, check)) ?
+		     IXGBE_ADVTXD_TUCMD_L4T_TCP : IXGBE_ADVTXD_TUCMD_L4T_UDP;
 
 	/* initialize outer IP header fields */
 	if (ip.v4->version == 4) {
@@ -7746,12 +7748,20 @@ static int ixgbe_tso(struct ixgbe_ring *tx_ring,
 	/* determine offset of inner transport header */
 	l4_offset = l4.hdr - skb->data;
 
-	/* compute length of segmentation header */
-	*hdr_len = (l4.tcp->doff * 4) + l4_offset;
-
 	/* remove payload length from inner checksum */
 	paylen = skb->len - l4_offset;
-	csum_replace_by_diff(&l4.tcp->check, (__force __wsum)htonl(paylen));
+
+	if (type_tucmd & IXGBE_ADVTXD_TUCMD_L4T_TCP) {
+		/* compute length of segmentation header */
+		*hdr_len = (l4.tcp->doff * 4) + l4_offset;
+		csum_replace_by_diff(&l4.tcp->check,
+				     (__force __wsum)htonl(paylen));
+	} else {
+		/* compute length of segmentation header */
+		*hdr_len = sizeof(*l4.udp) + l4_offset;
+		csum_replace_by_diff(&l4.udp->check,
+				     (__force __wsum)htonl(paylen));
+	}
 
 	/* update gso size and bytecount with header size */
 	first->gso_segs = skb_shinfo(skb)->gso_segs;
@@ -9931,6 +9941,7 @@ static void ixgbe_fwd_del(struct net_device *pdev, void *priv)
 	if (unlikely(mac_hdr_len > IXGBE_MAX_MAC_HDR_LEN))
 		return features & ~(NETIF_F_HW_CSUM |
 				    NETIF_F_SCTP_CRC |
+				    NETIF_F_GSO_UDP_L4 |
 				    NETIF_F_HW_VLAN_CTAG_TX |
 				    NETIF_F_TSO |
 				    NETIF_F_TSO6);
@@ -9939,6 +9950,7 @@ static void ixgbe_fwd_del(struct net_device *pdev, void *priv)
 	if (unlikely(network_hdr_len >  IXGBE_MAX_NETWORK_HDR_LEN))
 		return features & ~(NETIF_F_HW_CSUM |
 				    NETIF_F_SCTP_CRC |
+				    NETIF_F_GSO_UDP_L4 |
 				    NETIF_F_TSO |
 				    NETIF_F_TSO6);
 
@@ -10480,7 +10492,7 @@ static int ixgbe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 			    IXGBE_GSO_PARTIAL_FEATURES;
 
 	if (hw->mac.type >= ixgbe_mac_82599EB)
-		netdev->features |= NETIF_F_SCTP_CRC;
+		netdev->features |= NETIF_F_SCTP_CRC | NETIF_F_GSO_UDP_L4;
 
 	/* copy netdev features into list of user selectable features */
 	netdev->hw_features |= netdev->features |

^ permalink raw reply related

* [RFC PATCH 0/2] ixgbe/ixgbevf: Add support for UDP segmentation offload
From: Alexander Duyck @ 2018-05-04  0:39 UTC (permalink / raw)
  To: netdev, willemb, intel-wired-lan

These patches are meant to be a follow-up to the following series:
https://patchwork.ozlabs.org/project/netdev/list/?series=42476&archive=both&state=*

These patches enable driver support for the new UDP segmentation offload
feature. For now I am pushing them as an RFC as they haven't been
officially productized or validated and I was using these mostly as a test
vehicle to verify the offload could be supported generically by drivers.

---

Alexander Duyck (2):
      ixgbe: Add support for UDP segmentation offload
      ixgbevf: Add support for UDP segmentation offload


 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c     |   24 +++++++++++++++-----
 drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c |   25 ++++++++++++++++-----
 2 files changed, 37 insertions(+), 12 deletions(-)

^ permalink raw reply

* [net-next PATCH 5/5] net: Add NETIF_F_GSO_UDP_L4 to list of GSO offloads with fallback
From: Alexander Duyck @ 2018-05-04  0:33 UTC (permalink / raw)
  To: netdev, willemb, davem
In-Reply-To: <20180504002817.4496.64616.stgit@localhost.localdomain>

From: Alexander Duyck <alexander.h.duyck@intel.com>

Enable UDP offload as a generic software offload since we can now handle it
for multiple cases including if the checksum isn't present and via
gso_partial in the case of tunnels.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
 include/linux/netdev_features.h |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
index c87c3a3453c1..efbd8b2c0197 100644
--- a/include/linux/netdev_features.h
+++ b/include/linux/netdev_features.h
@@ -184,7 +184,8 @@ enum {
 
 /* List of features with software fallbacks. */
 #define NETIF_F_GSO_SOFTWARE	(NETIF_F_ALL_TSO | \
-				 NETIF_F_GSO_SCTP)
+				 NETIF_F_GSO_SCTP| \
+				 NETIF_F_GSO_UDP_L4)
 
 /*
  * If one device supports one of these features, then enable them

^ permalink raw reply related

* [net-next PATCH 4/5] udp: Do not copy destructor if one is not present
From: Alexander Duyck @ 2018-05-04  0:33 UTC (permalink / raw)
  To: netdev, willemb, davem
In-Reply-To: <20180504002817.4496.64616.stgit@localhost.localdomain>

From: Alexander Duyck <alexander.h.duyck@intel.com>

This patch makes it so that if a destructor is not present we avoid trying
to update the skb socket or any reference counting that would be associated
with the NULL socket and/or descriptor. By doing this we can support
traffic coming from another namespace without any issues.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
 net/ipv4/udp_offload.c |   19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index fd94bbb369b2..52760660d674 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -195,6 +195,7 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
 	unsigned int sum_truesize = 0;
 	struct udphdr *uh;
 	unsigned int mss;
+	bool copy_dtor;
 	__sum16 check;
 	__be16 newlen;
 
@@ -208,12 +209,14 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
 	skb_pull(gso_skb, sizeof(*uh));
 
 	/* clear destructor to avoid skb_segment assigning it to tail */
-	WARN_ON_ONCE(gso_skb->destructor != sock_wfree);
+	copy_dtor = gso_skb->destructor == sock_wfree;
+	WARN_ON_ONCE(gso_skb->destructor && !copy_dtor);
 	gso_skb->destructor = NULL;
 
 	segs = skb_segment(gso_skb, features);
 	if (unlikely(IS_ERR_OR_NULL(segs))) {
-		gso_skb->destructor = sock_wfree;
+		if (copy_dtor)
+			gso_skb->destructor = sock_wfree;
 		return segs;
 	}
 
@@ -234,9 +237,11 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
 					    (__force u32)newlen));
 
 	for (;;) {
-		seg->destructor = sock_wfree;
-		seg->sk = sk;
-		sum_truesize += seg->truesize;
+		if (copy_dtor) {
+			seg->destructor = sock_wfree;
+			seg->sk = sk;
+			sum_truesize += seg->truesize;
+		}
 
 		if (!seg->next)
 			break;
@@ -268,7 +273,9 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
 		uh->check = gso_make_checksum(seg, ~check);
 
 	/* update refcount for the packet */
-	refcount_add(sum_truesize - gso_skb->truesize, &sk->sk_wmem_alloc);
+	if (copy_dtor)
+		refcount_add(sum_truesize - gso_skb->truesize,
+			     &sk->sk_wmem_alloc);
 out:
 	return segs;
 }

^ permalink raw reply related

* [net-next PATCH 3/5] udp: Add support for software checksum and GSO_PARTIAL with GSO offload
From: Alexander Duyck @ 2018-05-04  0:33 UTC (permalink / raw)
  To: netdev, willemb, davem
In-Reply-To: <20180504002817.4496.64616.stgit@localhost.localdomain>

From: Alexander Duyck <alexander.h.duyck@intel.com>

This patch adds support for a software provided checksum and GSO_PARTIAL
segmentation support. With this we can offload UDP segmentation on devices
that only have partial support for tunnels.

Since we are no longer needing the hardware checksum we can drop the checks
in the segmentation code that were verifying if it was present.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
 net/ipv4/udp_offload.c |   28 ++++++++++++++++++----------
 net/ipv6/udp_offload.c |   11 +----------
 2 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 946d06d2aa0c..fd94bbb369b2 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -217,6 +217,13 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
 		return segs;
 	}
 
+	/* GSO partial and frag_list segmentation only requires splitting
+	 * the frame into an MSS multiple and possibly a remainder, both
+	 * cases return a GSO skb. So update the mss now.
+	 */
+	if (skb_is_gso(segs))
+		mss *= skb_shinfo(segs)->gso_segs;
+
 	seg = segs;
 	uh = udp_hdr(seg);
 
@@ -237,6 +244,11 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
 		uh->len = newlen;
 		uh->check = check;
 
+		if (seg->ip_summed == CHECKSUM_PARTIAL)
+			gso_reset_checksum(seg, ~check);
+		else
+			uh->check = gso_make_checksum(seg, ~check);
+
 		seg = seg->next;
 		uh = udp_hdr(seg);
 	}
@@ -250,6 +262,11 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
 	uh->len = newlen;
 	uh->check = check;
 
+	if (seg->ip_summed == CHECKSUM_PARTIAL)
+		gso_reset_checksum(seg, ~check);
+	else
+		uh->check = gso_make_checksum(seg, ~check);
+
 	/* update refcount for the packet */
 	refcount_add(sum_truesize - gso_skb->truesize, &sk->sk_wmem_alloc);
 out:
@@ -257,15 +274,6 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
 }
 EXPORT_SYMBOL_GPL(__udp_gso_segment);
 
-static struct sk_buff *__udp4_gso_segment(struct sk_buff *gso_skb,
-					  netdev_features_t features)
-{
-	if (!can_checksum_protocol(features, htons(ETH_P_IP)))
-		return ERR_PTR(-EIO);
-
-	return __udp_gso_segment(gso_skb, features);
-}
-
 static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
 					 netdev_features_t features)
 {
@@ -289,7 +297,7 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
 		goto out;
 
 	if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
-		return __udp4_gso_segment(skb, features);
+		return __udp_gso_segment(skb, features);
 
 	mss = skb_shinfo(skb)->gso_size;
 	if (unlikely(skb->len <= mss))
diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index 61e34f1d2fa2..03a2ff3fe1e6 100644
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -17,15 +17,6 @@
 #include <net/ip6_checksum.h>
 #include "ip6_offload.h"
 
-static struct sk_buff *__udp6_gso_segment(struct sk_buff *gso_skb,
-					  netdev_features_t features)
-{
-	if (!can_checksum_protocol(features, htons(ETH_P_IPV6)))
-		return ERR_PTR(-EIO);
-
-	return __udp_gso_segment(gso_skb, features);
-}
-
 static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
 					 netdev_features_t features)
 {
@@ -58,7 +49,7 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
 			goto out;
 
 		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
-			return __udp6_gso_segment(skb, features);
+			return __udp_gso_segment(skb, features);
 
 		/* Do software UFO. Complete and fill in the UDP checksum as HW cannot
 		 * do checksum of UDP packets sent as multiple IP fragments.

^ permalink raw reply related

* [net-next PATCH 2/5] udp: Do not pass checksum or MSS as parameters
From: Alexander Duyck @ 2018-05-04  0:33 UTC (permalink / raw)
  To: netdev, willemb, davem
In-Reply-To: <20180504002817.4496.64616.stgit@localhost.localdomain>

From: Alexander Duyck <alexander.h.duyck@intel.com>

This patch is meant to be a start at cleaning up some of the UDP GSO
segmentation code. Specifically we were passing mss and a recomputed
checksum when we really didn't need to. The function itself could derive
that information based on the already provided checksum, the length of the
packet stored in the UDP header, and the gso_size.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
 include/net/udp.h      |    3 +-
 net/ipv4/udp_offload.c |   61 +++++++++++++++++++++++++++++++-----------------
 net/ipv6/udp_offload.c |    7 +-----
 3 files changed, 41 insertions(+), 30 deletions(-)

diff --git a/include/net/udp.h b/include/net/udp.h
index 05990746810e..9289b6425032 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -175,8 +175,7 @@ struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb,
 int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup);
 
 struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
-				  netdev_features_t features,
-				  unsigned int mss, __sum16 check);
+				  netdev_features_t features);
 
 static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb)
 {
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 006257092f06..946d06d2aa0c 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -188,19 +188,23 @@ struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
 EXPORT_SYMBOL(skb_udp_tunnel_segment);
 
 struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
-				  netdev_features_t features,
-				  unsigned int mss, __sum16 check)
+				  netdev_features_t features)
 {
+	struct sk_buff *seg, *segs = ERR_PTR(-EINVAL);
 	struct sock *sk = gso_skb->sk;
 	unsigned int sum_truesize = 0;
-	struct sk_buff *segs, *seg;
-	unsigned int hdrlen;
 	struct udphdr *uh;
+	unsigned int mss;
+	__sum16 check;
+	__be16 newlen;
 
+	mss = skb_shinfo(gso_skb)->gso_size;
 	if (gso_skb->len <= sizeof(*uh) + mss)
-		return ERR_PTR(-EINVAL);
+		goto out;
+
+	if (!pskb_may_pull(gso_skb, sizeof(*uh)))
+		goto out;
 
-	hdrlen = gso_skb->data - skb_mac_header(gso_skb);
 	skb_pull(gso_skb, sizeof(*uh));
 
 	/* clear destructor to avoid skb_segment assigning it to tail */
@@ -213,24 +217,42 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
 		return segs;
 	}
 
-	for (seg = segs; seg; seg = seg->next) {
-		uh = udp_hdr(seg);
-		uh->len = htons(seg->len - hdrlen);
-		uh->check = check;
+	seg = segs;
+	uh = udp_hdr(seg);
 
-		/* last packet can be partial gso_size */
-		if (!seg->next)
-			csum_replace2(&uh->check, htons(mss),
-				      htons(seg->len - hdrlen - sizeof(*uh)));
+	/* compute checksum adjustment based on old length versus new */
+	newlen = htons(sizeof(*uh) + mss);
+	check = ~csum_fold((__force __wsum)((__force u32)uh->check +
+					    ((__force u32)uh->len ^ 0xFFFF) +
+					    (__force u32)newlen));
 
-		uh->check = ~uh->check;
+	for (;;) {
 		seg->destructor = sock_wfree;
 		seg->sk = sk;
 		sum_truesize += seg->truesize;
+
+		if (!seg->next)
+			break;
+
+		uh->len = newlen;
+		uh->check = check;
+
+		seg = seg->next;
+		uh = udp_hdr(seg);
 	}
 
-	refcount_add(sum_truesize - gso_skb->truesize, &sk->sk_wmem_alloc);
+	/* last packet can be partial gso_size, account for that in checksum */
+	newlen = htons(skb_tail_pointer(seg) - skb_transport_header(seg) +
+		       seg->data_len);
+	check = ~csum_fold((__force __wsum)((__force u32)uh->check +
+					    ((__force u32)uh->len ^ 0xFFFF)  +
+					    (__force u32)newlen));
+	uh->len = newlen;
+	uh->check = check;
 
+	/* update refcount for the packet */
+	refcount_add(sum_truesize - gso_skb->truesize, &sk->sk_wmem_alloc);
+out:
 	return segs;
 }
 EXPORT_SYMBOL_GPL(__udp_gso_segment);
@@ -238,15 +260,10 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
 static struct sk_buff *__udp4_gso_segment(struct sk_buff *gso_skb,
 					  netdev_features_t features)
 {
-	const struct iphdr *iph = ip_hdr(gso_skb);
-	unsigned int mss = skb_shinfo(gso_skb)->gso_size;
-
 	if (!can_checksum_protocol(features, htons(ETH_P_IP)))
 		return ERR_PTR(-EIO);
 
-	return __udp_gso_segment(gso_skb, features, mss,
-				 udp_v4_check(sizeof(struct udphdr) + mss,
-					      iph->saddr, iph->daddr, 0));
+	return __udp_gso_segment(gso_skb, features);
 }
 
 static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index f7b85b1e6b3e..61e34f1d2fa2 100644
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -20,15 +20,10 @@
 static struct sk_buff *__udp6_gso_segment(struct sk_buff *gso_skb,
 					  netdev_features_t features)
 {
-	const struct ipv6hdr *ip6h = ipv6_hdr(gso_skb);
-	unsigned int mss = skb_shinfo(gso_skb)->gso_size;
-
 	if (!can_checksum_protocol(features, htons(ETH_P_IPV6)))
 		return ERR_PTR(-EIO);
 
-	return __udp_gso_segment(gso_skb, features, mss,
-				 udp_v6_check(sizeof(struct udphdr) + mss,
-					      &ip6h->saddr, &ip6h->daddr, 0));
+	return __udp_gso_segment(gso_skb, features);
 }
 
 static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,

^ permalink raw reply related

* [net-next PATCH 1/5] udp: Record gso_segs when supporting UDP segmentation offload
From: Alexander Duyck @ 2018-05-04  0:33 UTC (permalink / raw)
  To: netdev, willemb, davem
In-Reply-To: <20180504002817.4496.64616.stgit@localhost.localdomain>

From: Alexander Duyck <alexander.h.duyck@intel.com>

We need to record the number of segments that will be generated when this
frame is segmented. The expectation is that if gso_size is set then
gso_segs is set as well. Without this some drivers such as ixgbe get
confused if they attempt to offload this as they record 0 segments for the
entire packet instead of the correct value.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
 net/ipv4/udp.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index dd3102a37ef9..e07db83b311e 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -793,6 +793,8 @@ static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4,
 
 		skb_shinfo(skb)->gso_size = cork->gso_size;
 		skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
+		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(len - sizeof(uh),
+							 cork->gso_size);
 		goto csum_partial;
 	}
 

^ permalink raw reply related

* [net-next PATCH 0/5] UDP GSO Segmentation clean-ups
From: Alexander Duyck @ 2018-05-04  0:33 UTC (permalink / raw)
  To: netdev, willemb, davem

This patch set addresses a number of issues I found while sorting out
enabling UDP GSO Segmentation support for ixgbe/ixgbevf. Specifically there
were a number of issues related to the checksum and such that seemed to
cause either minor irregularities or kernel panics in the case of the
offload request being allowed to traverse between name spaces.

With this set applied I am was able to get UDP GSO traffic to pass over
vxlan tunnels in both offloaded modes and non-offloaded modes for ixgbe and
ixgbevf.

I will include the driver patches as a seperate RFC following this series.

---

Alexander Duyck (5):
      udp: Record gso_segs when supporting UDP segmentation offload
      udp: Do not pass checksum or MSS as parameters
      udp: Add support for software checksum and GSO_PARTIAL with GSO offload
      udp: Do not copy destructor if one is not present
      net: Add NETIF_F_GSO_UDP_L4 to list of GSO offloads with fallback


 include/linux/netdev_features.h |    3 +
 include/net/udp.h               |    3 -
 net/ipv4/udp.c                  |    2 +
 net/ipv4/udp_offload.c          |  102 ++++++++++++++++++++++++++-------------
 net/ipv6/udp_offload.c          |   16 ------
 5 files changed, 73 insertions(+), 53 deletions(-)

^ permalink raw reply

* Re: [PATCH] bpf: fix possible spectre-v1 in find_and_alloc_map()
From: Daniel Borkmann @ 2018-05-04  0:16 UTC (permalink / raw)
  To: Mark Rutland, linux-kernel
  Cc: Alexei Starovoitov, Dan Carpenter, Peter Zijlstra, netdev
In-Reply-To: <20180503160459.4111-1-mark.rutland@arm.com>

On 05/03/2018 06:04 PM, Mark Rutland wrote:
> It's possible for userspace to control attr->map_type. Sanitize it when
> using it as an array index to prevent an out-of-bounds value being used
> under speculation.
> 
> Found by smatch.
> 
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Cc: Alexei Starovoitov <ast@kernel.org>
> Cc: Dan Carpenter <dan.carpenter@oracle.com>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: netdev@vger.kernel.org

Applied to bpf tree, thanks Mark! I've also just submitted one for
BPF progs (http://patchwork.ozlabs.org/patch/908385/) which is same
situation.

^ permalink raw reply

* [PATCH bpf] bpf: use array_index_nospec in find_prog_type
From: Daniel Borkmann @ 2018-05-04  0:13 UTC (permalink / raw)
  To: alexei.starovoitov; +Cc: netdev, Daniel Borkmann, Mark Rutland

Commit 9ef09e35e521 ("bpf: fix possible spectre-v1 in find_and_alloc_map()")
converted find_and_alloc_map() over to use array_index_nospec() to sanitize
map type that user space passes on map creation, and this patch does an
analogous conversion for progs in find_prog_type() as it's also passed from
user space when loading progs as attr->prog_type.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Mark Rutland <mark.rutland@arm.com>
---
 kernel/bpf/syscall.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 8f43448..016ef90 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -874,11 +874,17 @@ static const struct bpf_prog_ops * const bpf_prog_types[] = {
 
 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
 {
-	if (type >= ARRAY_SIZE(bpf_prog_types) || !bpf_prog_types[type])
+	const struct bpf_prog_ops *ops;
+
+	if (type >= ARRAY_SIZE(bpf_prog_types))
+		return -EINVAL;
+	type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
+	ops = bpf_prog_types[type];
+	if (!ops)
 		return -EINVAL;
 
 	if (!bpf_prog_is_dev_bound(prog->aux))
-		prog->aux->ops = bpf_prog_types[type];
+		prog->aux->ops = ops;
 	else
 		prog->aux->ops = &bpf_offload_prog_ops;
 	prog->type = type;
-- 
2.9.5

^ permalink raw reply related

* Re: [PATCH net-next] net/mlx4_en: optimizes get_fixed_ipv6_csum()
From: Eric Dumazet @ 2018-05-04  0:05 UTC (permalink / raw)
  To: Tariq Toukan, Saeed Mahameed, davem@davemloft.net,
	edumazet@google.com
  Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com
In-Reply-To: <ea3acf65-6d9c-e169-f784-07ec42715e17@mellanox.com>



On 05/02/2018 07:18 AM, Tariq Toukan wrote:
> 
> 
> On 27/04/2018 1:56 AM, Saeed Mahameed wrote:

>> LGTM,
>>
>> Reviewed-by: Saeed Mahameed <saeedm@mellanox.com>
>>
> 
> Acked-by: Tariq Toukan <tariqt@mellanox.com>
> 
> Thanks Eric.

Thanks guys. 

I see this patch  ( http://patchwork.ozlabs.org/patch/901336/ ) in
a state I do not know : "Awaiting Upstream"

^ permalink raw reply

* [PATCH net] tg3: Fix vunmap() BUG_ON() triggered from tg3_free_consistent().
From: Michael Chan @ 2018-05-04  0:04 UTC (permalink / raw)
  To: davem; +Cc: netdev, siva.kallam, zumeng.chen

tg3_free_consistent() calls dma_free_coherent() to free tp->hw_stats
under spinlock and can trigger BUG_ON() in vunmap() because vunmap()
may sleep.  Fix it by removing the spinlock and relying on the
TG3_FLAG_INIT_COMPLETE flag to prevent race conditions between
tg3_get_stats64() and tg3_free_consistent().  TG3_FLAG_INIT_COMPLETE
is always cleared under tp->lock before tg3_free_consistent()
and therefore tg3_get_stats64() can safely access tp->hw_stats
under tp->lock if TG3_FLAG_INIT_COMPLETE is set.

Fixes: f5992b72ebe0 ("tg3: Fix race condition in tg3_get_stats64().")
Reported-by: Zumeng Chen <zumeng.chen@gmail.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 drivers/net/ethernet/broadcom/tg3.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 08bbb63..9f59b12 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -8733,14 +8733,15 @@ static void tg3_free_consistent(struct tg3 *tp)
 	tg3_mem_rx_release(tp);
 	tg3_mem_tx_release(tp);
 
-	/* Protect tg3_get_stats64() from reading freed tp->hw_stats. */
-	tg3_full_lock(tp, 0);
+	/* tp->hw_stats can be referenced safely:
+	 *     1. under rtnl_lock
+	 *     2. or under tp->lock if TG3_FLAG_INIT_COMPLETE is set.
+	 */
 	if (tp->hw_stats) {
 		dma_free_coherent(&tp->pdev->dev, sizeof(struct tg3_hw_stats),
 				  tp->hw_stats, tp->stats_mapping);
 		tp->hw_stats = NULL;
 	}
-	tg3_full_unlock(tp);
 }
 
 /*
@@ -14178,7 +14179,7 @@ static void tg3_get_stats64(struct net_device *dev,
 	struct tg3 *tp = netdev_priv(dev);
 
 	spin_lock_bh(&tp->lock);
-	if (!tp->hw_stats) {
+	if (!tp->hw_stats || !tg3_flag(tp, INIT_COMPLETE)) {
 		*stats = tp->net_stats_prev;
 		spin_unlock_bh(&tp->lock);
 		return;
-- 
1.8.3.1

^ permalink raw reply related

* Re: [PATCH bpf-next v2 00/13] Move ld_abs/ld_ind to native BPF
From: Alexei Starovoitov @ 2018-05-04  0:02 UTC (permalink / raw)
  To: Daniel Borkmann; +Cc: ast, netdev
In-Reply-To: <20180503230824.3462-1-daniel@iogearbox.net>

On Fri, May 04, 2018 at 01:08:11AM +0200, Daniel Borkmann wrote:
> This set simplifies BPF JITs significantly by moving ld_abs/ld_ind
> to native BPF, for details see individual patches. Main rationale
> is in patch 'implement ld_abs/ld_ind in native bpf'. Thanks!
> 
> v1 -> v2:
>   - Added missing seen_lds_abs in LDX_MSH and use X = A
>     initially due to being preserved on func call.
>   - Added a large batch of cBPF tests into test_bpf.
>   - Added x32 removal of LD_ABS/LD_IND, so all JITs are
>     covered.

Applied to bpf-next, Thanks Daniel.

^ permalink raw reply

* Re: [PATCH bpf-next v3 00/15] Introducing AF_XDP support
From: Alexei Starovoitov @ 2018-05-03 23:38 UTC (permalink / raw)
  To: Daniel Borkmann
  Cc: Björn Töpel, magnus.karlsson, alexander.h.duyck,
	alexander.duyck, john.fastabend, ast, brouer,
	willemdebruijn.kernel, mst, netdev, Björn Töpel,
	michael.lundkvist, jesse.brandeburg, anjali.singhai, qi.z.zhang
In-Reply-To: <c93fd33b-2fde-783b-7953-4673171e2f48@iogearbox.net>

On Fri, May 04, 2018 at 12:49:09AM +0200, Daniel Borkmann wrote:
> On 05/02/2018 01:01 PM, Björn Töpel wrote:
> > From: Björn Töpel <bjorn.topel@intel.com>
> > 
> > This patch set introduces a new address family called AF_XDP that is
> > optimized for high performance packet processing and, in upcoming
> > patch sets, zero-copy semantics. In this patch set, we have removed
> > all zero-copy related code in order to make it smaller, simpler and
> > hopefully more review friendly. This patch set only supports copy-mode
> > for the generic XDP path (XDP_SKB) for both RX and TX and copy-mode
> > for RX using the XDP_DRV path. Zero-copy support requires XDP and
> > driver changes that Jesper Dangaard Brouer is working on. Some of his
> > work has already been accepted. We will publish our zero-copy support
> > for RX and TX on top of his patch sets at a later point in time.
> 
> +1, would be great to see it land this cycle. Saw few minor nits here
> and there but nothing to hold it up, for the series:
> 
> Acked-by: Daniel Borkmann <daniel@iogearbox.net>
> 
> Thanks everyone!

Great stuff!

Applied to bpf-next, with one condition.
Upcoming zero-copy patches for both RX and TX need to be posted
and reviewed within this release window.
If netdev community as a whole won't be able to agree on the zero-copy
bits we'd need to revert this feature before the next merge window.

Few other minor nits:
patch 3:
+struct xdp_ring {
+       __u32 producer __attribute__((aligned(64)));
+       __u32 consumer __attribute__((aligned(64)));
+};
It kinda begs for ____cacheline_aligned_in_smp to be introduced for uapi headers.

patch 5:
+struct sockaddr_xdp {
+       __u16 sxdp_family;
+       __u32 sxdp_ifindex;
Not great to have a hole in uapi struct. Please fix it in the follow up.

patch 7:
Has a lot of synchronize_net(). I think udpate/delete side
can be improved to avoid them. Otherwise users may unknowingly DoS.

As the next steps I suggest to prioritize the highest to ship
zero-copy rx/tx patches and to add selftests.

Thanks!

^ permalink raw reply

* [PATCH bpf-next v2 13/13] bpf: sync tools bpf.h uapi header
From: Daniel Borkmann @ 2018-05-03 23:08 UTC (permalink / raw)
  To: ast; +Cc: netdev, Daniel Borkmann
In-Reply-To: <20180503230824.3462-1-daniel@iogearbox.net>

Only sync the header from include/uapi/linux/bpf.h.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
---
 tools/include/uapi/linux/bpf.h | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 8daef73..83a95ae 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1801,6 +1801,30 @@ union bpf_attr {
  * 	Return
  * 		a non-negative value equal to or less than size on success, or
  * 		a negative error in case of failure.
+ *
+ * int skb_load_bytes_relative(const struct sk_buff *skb, u32 offset, void *to, u32 len, u32 start_header)
+ * 	Description
+ * 		This helper is similar to **bpf_skb_load_bytes**\ () in that
+ * 		it provides an easy way to load *len* bytes from *offset*
+ * 		from the packet associated to *skb*, into the buffer pointed
+ * 		by *to*. The difference to **bpf_skb_load_bytes**\ () is that
+ * 		a fifth argument *start_header* exists in order to select a
+ * 		base offset to start from. *start_header* can be one of:
+ *
+ * 		**BPF_HDR_START_MAC**
+ * 			Base offset to load data from is *skb*'s mac header.
+ * 		**BPF_HDR_START_NET**
+ * 			Base offset to load data from is *skb*'s network header.
+ *
+ * 		In general, "direct packet access" is the preferred method to
+ * 		access packet data, however, this helper is in particular useful
+ * 		in socket filters where *skb*\ **->data** does not always point
+ * 		to the start of the mac header and where "direct packet access"
+ * 		is not available.
+ *
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -1870,7 +1894,8 @@ union bpf_attr {
 	FN(bind),			\
 	FN(xdp_adjust_tail),		\
 	FN(skb_get_xfrm_state),		\
-	FN(get_stack),
+	FN(get_stack),			\
+	FN(skb_load_bytes_relative),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -1931,6 +1956,12 @@ enum bpf_adj_room_mode {
 	BPF_ADJ_ROOM_NET,
 };
 
+/* Mode for BPF_FUNC_skb_load_bytes_relative helper. */
+enum bpf_hdr_start_off {
+	BPF_HDR_START_MAC,
+	BPF_HDR_START_NET,
+};
+
 /* user accessible mirror of in-kernel sk_buff.
  * new fields can only be added to the end of this structure
  */
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v2 12/13] bpf, x32: remove ld_abs/ld_ind
From: Daniel Borkmann @ 2018-05-03 23:08 UTC (permalink / raw)
  To: ast; +Cc: netdev, Daniel Borkmann
In-Reply-To: <20180503230824.3462-1-daniel@iogearbox.net>

Since LD_ABS/LD_IND instructions are now removed from the core and
reimplemented through a combination of inlined BPF instructions and
a slow-path helper, we can get rid of the complexity from x32 JIT.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
---
 arch/x86/net/bpf_jit_comp32.c | 136 +-----------------------------------------
 1 file changed, 1 insertion(+), 135 deletions(-)

diff --git a/arch/x86/net/bpf_jit_comp32.c b/arch/x86/net/bpf_jit_comp32.c
index 61e6134..0cc04e3 100644
--- a/arch/x86/net/bpf_jit_comp32.c
+++ b/arch/x86/net/bpf_jit_comp32.c
@@ -175,19 +175,13 @@ static const u8 bpf2ia32[][2] = {
 #define SCRATCH_SIZE 96
 
 /* Total stack size used in JITed code */
-#define _STACK_SIZE \
-	(stack_depth + \
-	 + SCRATCH_SIZE + \
-	 + 4 /* Extra space for skb_copy_bits buffer */)
+#define _STACK_SIZE	(stack_depth + SCRATCH_SIZE)
 
 #define STACK_SIZE ALIGN(_STACK_SIZE, STACK_ALIGNMENT)
 
 /* Get the offset of eBPF REGISTERs stored on scratch space. */
 #define STACK_VAR(off) (off)
 
-/* Offset of skb_copy_bits buffer */
-#define SKB_BUFFER STACK_VAR(SCRATCH_SIZE)
-
 /* Encode 'dst_reg' register into IA32 opcode 'byte' */
 static u8 add_1reg(u8 byte, u32 dst_reg)
 {
@@ -2276,134 +2270,6 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
 				return -EFAULT;
 			}
 			break;
-
-		case BPF_LD | BPF_ABS | BPF_W:
-		case BPF_LD | BPF_ABS | BPF_H:
-		case BPF_LD | BPF_ABS | BPF_B:
-		case BPF_LD | BPF_IND | BPF_W:
-		case BPF_LD | BPF_IND | BPF_H:
-		case BPF_LD | BPF_IND | BPF_B:
-		{
-			int size;
-			const u8 *r6 = bpf2ia32[BPF_REG_6];
-
-			/* Setting up first argument */
-			/* mov eax,dword ptr [ebp+off] */
-			EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX),
-			      STACK_VAR(r6[0]));
-
-			/* Setting up second argument */
-			if (BPF_MODE(code) == BPF_ABS) {
-				/* mov %edx, imm32 */
-				EMIT1_off32(0xBA, imm32);
-			} else {
-				if (sstk)
-					/* mov edx,dword ptr [ebp+off] */
-					EMIT3(0x8B, add_2reg(0x40, IA32_EBP,
-							     IA32_EDX),
-					      STACK_VAR(src_lo));
-				else
-					/* mov edx,src_lo */
-					EMIT2(0x8B, add_2reg(0xC0, src_lo,
-							     IA32_EDX));
-				if (imm32) {
-					if (is_imm8(imm32))
-						/* add %edx,imm8 */
-						EMIT3(0x83, 0xC2, imm32);
-					else
-						/* add %edx,imm32 */
-						EMIT2_off32(0x81, 0xC2, imm32);
-				}
-			}
-
-			/* Setting up third argument */
-			switch (BPF_SIZE(code)) {
-			case BPF_W:
-				size = 4;
-				break;
-			case BPF_H:
-				size = 2;
-				break;
-			case BPF_B:
-				size = 1;
-				break;
-			default:
-				return -EINVAL;
-			}
-			/* mov ecx,val */
-			EMIT2(0xB1, size);
-			/* movzx ecx,ecx */
-			EMIT3(0x0F, 0xB6, add_2reg(0xC0, IA32_ECX, IA32_ECX));
-
-			/* mov ebx,ebp */
-			EMIT2(0x8B, add_2reg(0xC0, IA32_EBP, IA32_EBX));
-			/* add %ebx,imm8 */
-			EMIT3(0x83, add_1reg(0xC0, IA32_EBX), SKB_BUFFER);
-			/* push ebx */
-			EMIT1(0x53);
-
-			/* Setting up function pointer to call */
-			/* mov ebx,imm32*/
-			EMIT2_off32(0xC7, add_1reg(0xC0, IA32_EBX),
-				    (unsigned int)bpf_load_pointer);
-
-			EMIT2(0xFF, add_1reg(0xD0, IA32_EBX));
-			/* add %esp,4 */
-			EMIT3(0x83, add_1reg(0xC0, IA32_ESP), 4);
-			/* xor edx,edx */
-			EMIT2(0x33, add_2reg(0xC0, IA32_EDX, IA32_EDX));
-
-			/* mov dword ptr [ebp+off],eax */
-			EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EDX),
-			      STACK_VAR(r0[0]));
-			/* mov dword ptr [ebp+off],edx */
-			EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EDX),
-			      STACK_VAR(r0[1]));
-
-			/*
-			 * Check if return address is NULL or not.
-			 * If NULL then jump to epilogue else continue
-			 * to load the value from retn address
-			 */
-			EMIT3(0x83, add_1reg(0xF8, IA32_EAX), 0);
-			jmp_offset = ctx->cleanup_addr - addrs[i];
-
-			switch (BPF_SIZE(code)) {
-			case BPF_W:
-				jmp_offset += 7;
-				break;
-			case BPF_H:
-				jmp_offset += 10;
-				break;
-			case BPF_B:
-				jmp_offset += 6;
-				break;
-			}
-
-			EMIT2_off32(0x0F, IA32_JE + 0x10, jmp_offset);
-			/* Load value from the address */
-			switch (BPF_SIZE(code)) {
-			case BPF_W:
-				/* mov eax,[eax] */
-				EMIT2(0x8B, 0x0);
-				/* Emit 'bswap eax' */
-				EMIT2(0x0F, add_1reg(0xC8, IA32_EAX));
-				break;
-			case BPF_H:
-				EMIT3(0x0F, 0xB7, 0x0);
-				EMIT1(0x66);
-				EMIT3(0xC1, add_1reg(0xC8, IA32_EAX), 8);
-				break;
-			case BPF_B:
-				EMIT3(0x0F, 0xB6, 0x0);
-				break;
-			}
-
-			/* mov dword ptr [ebp+off],eax */
-			EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EAX),
-			      STACK_VAR(r0[0]));
-			break;
-		}
 		/* STX XADD: lock *(u32 *)(dst + off) += src */
 		case BPF_STX | BPF_XADD | BPF_W:
 		/* STX XADD: lock *(u64 *)(dst + off) += src */
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v2 10/13] bpf, ppc64: remove ld_abs/ld_ind
From: Daniel Borkmann @ 2018-05-03 23:08 UTC (permalink / raw)
  To: ast; +Cc: netdev, Daniel Borkmann
In-Reply-To: <20180503230824.3462-1-daniel@iogearbox.net>

Since LD_ABS/LD_IND instructions are now removed from the core and
reimplemented through a combination of inlined BPF instructions and
a slow-path helper, we can get rid of the complexity from ppc64 JIT.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
---
 arch/powerpc/net/Makefile         |   2 +-
 arch/powerpc/net/bpf_jit64.h      |  37 ++------
 arch/powerpc/net/bpf_jit_asm64.S  | 180 --------------------------------------
 arch/powerpc/net/bpf_jit_comp64.c | 109 +----------------------
 4 files changed, 11 insertions(+), 317 deletions(-)
 delete mode 100644 arch/powerpc/net/bpf_jit_asm64.S

diff --git a/arch/powerpc/net/Makefile b/arch/powerpc/net/Makefile
index 02d369c..809f019 100644
--- a/arch/powerpc/net/Makefile
+++ b/arch/powerpc/net/Makefile
@@ -3,7 +3,7 @@
 # Arch-specific network modules
 #
 ifeq ($(CONFIG_PPC64),y)
-obj-$(CONFIG_BPF_JIT) += bpf_jit_asm64.o bpf_jit_comp64.o
+obj-$(CONFIG_BPF_JIT) += bpf_jit_comp64.o
 else
 obj-$(CONFIG_BPF_JIT) += bpf_jit_asm.o bpf_jit_comp.o
 endif
diff --git a/arch/powerpc/net/bpf_jit64.h b/arch/powerpc/net/bpf_jit64.h
index 8bdef7e..3609be4 100644
--- a/arch/powerpc/net/bpf_jit64.h
+++ b/arch/powerpc/net/bpf_jit64.h
@@ -20,7 +20,7 @@
  * with our redzone usage.
  *
  *		[	prev sp		] <-------------
- *		[   nv gpr save area	] 8*8		|
+ *		[   nv gpr save area	] 6*8		|
  *		[    tail_call_cnt	] 8		|
  *		[    local_tmp_var	] 8		|
  * fp (r31) -->	[   ebpf stack space	] upto 512	|
@@ -28,8 +28,8 @@
  * sp (r1) --->	[    stack pointer	] --------------
  */
 
-/* for gpr non volatile registers BPG_REG_6 to 10, plus skb cache registers */
-#define BPF_PPC_STACK_SAVE	(8*8)
+/* for gpr non volatile registers BPG_REG_6 to 10 */
+#define BPF_PPC_STACK_SAVE	(6*8)
 /* for bpf JIT code internal usage */
 #define BPF_PPC_STACK_LOCALS	16
 /* stack frame excluding BPF stack, ensure this is quadword aligned */
@@ -39,10 +39,8 @@
 #ifndef __ASSEMBLY__
 
 /* BPF register usage */
-#define SKB_HLEN_REG	(MAX_BPF_JIT_REG + 0)
-#define SKB_DATA_REG	(MAX_BPF_JIT_REG + 1)
-#define TMP_REG_1	(MAX_BPF_JIT_REG + 2)
-#define TMP_REG_2	(MAX_BPF_JIT_REG + 3)
+#define TMP_REG_1	(MAX_BPF_JIT_REG + 0)
+#define TMP_REG_2	(MAX_BPF_JIT_REG + 1)
 
 /* BPF to ppc register mappings */
 static const int b2p[] = {
@@ -63,40 +61,23 @@ static const int b2p[] = {
 	[BPF_REG_FP] = 31,
 	/* eBPF jit internal registers */
 	[BPF_REG_AX] = 2,
-	[SKB_HLEN_REG] = 25,
-	[SKB_DATA_REG] = 26,
 	[TMP_REG_1] = 9,
 	[TMP_REG_2] = 10
 };
 
-/* PPC NVR range -- update this if we ever use NVRs below r24 */
-#define BPF_PPC_NVR_MIN		24
-
-/* Assembly helpers */
-#define DECLARE_LOAD_FUNC(func)	u64 func(u64 r3, u64 r4);			\
-				u64 func##_negative_offset(u64 r3, u64 r4);	\
-				u64 func##_positive_offset(u64 r3, u64 r4);
-
-DECLARE_LOAD_FUNC(sk_load_word);
-DECLARE_LOAD_FUNC(sk_load_half);
-DECLARE_LOAD_FUNC(sk_load_byte);
-
-#define CHOOSE_LOAD_FUNC(imm, func)						\
-			(imm < 0 ?						\
-			(imm >= SKF_LL_OFF ? func##_negative_offset : func) :	\
-			func##_positive_offset)
+/* PPC NVR range -- update this if we ever use NVRs below r27 */
+#define BPF_PPC_NVR_MIN		27
 
 #define SEEN_FUNC	0x1000 /* might call external helpers */
 #define SEEN_STACK	0x2000 /* uses BPF stack */
-#define SEEN_SKB	0x4000 /* uses sk_buff */
-#define SEEN_TAILCALL	0x8000 /* uses tail calls */
+#define SEEN_TAILCALL	0x4000 /* uses tail calls */
 
 struct codegen_context {
 	/*
 	 * This is used to track register usage as well
 	 * as calls to external helpers.
 	 * - register usage is tracked with corresponding
-	 *   bits (r3-r10 and r25-r31)
+	 *   bits (r3-r10 and r27-r31)
 	 * - rest of the bits can be used to track other
 	 *   things -- for now, we use bits 16 to 23
 	 *   encoded in SEEN_* macros above
diff --git a/arch/powerpc/net/bpf_jit_asm64.S b/arch/powerpc/net/bpf_jit_asm64.S
deleted file mode 100644
index 7e4c514..0000000
--- a/arch/powerpc/net/bpf_jit_asm64.S
+++ /dev/null
@@ -1,180 +0,0 @@
-/*
- * bpf_jit_asm64.S: Packet/header access helper functions
- * for PPC64 BPF compiler.
- *
- * Copyright 2016, Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
- * 		   IBM Corporation
- *
- * Based on bpf_jit_asm.S by Matt Evans
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; version 2
- * of the License.
- */
-
-#include <asm/ppc_asm.h>
-#include <asm/ptrace.h>
-#include "bpf_jit64.h"
-
-/*
- * All of these routines are called directly from generated code,
- * with the below register usage:
- * r27		skb pointer (ctx)
- * r25		skb header length
- * r26		skb->data pointer
- * r4		offset
- *
- * Result is passed back in:
- * r8		data read in host endian format (accumulator)
- *
- * r9 is used as a temporary register
- */
-
-#define r_skb	r27
-#define r_hlen	r25
-#define r_data	r26
-#define r_off	r4
-#define r_val	r8
-#define r_tmp	r9
-
-_GLOBAL_TOC(sk_load_word)
-	cmpdi	r_off, 0
-	blt	bpf_slow_path_word_neg
-	b	sk_load_word_positive_offset
-
-_GLOBAL_TOC(sk_load_word_positive_offset)
-	/* Are we accessing past headlen? */
-	subi	r_tmp, r_hlen, 4
-	cmpd	r_tmp, r_off
-	blt	bpf_slow_path_word
-	/* Nope, just hitting the header.  cr0 here is eq or gt! */
-	LWZX_BE	r_val, r_data, r_off
-	blr	/* Return success, cr0 != LT */
-
-_GLOBAL_TOC(sk_load_half)
-	cmpdi	r_off, 0
-	blt	bpf_slow_path_half_neg
-	b	sk_load_half_positive_offset
-
-_GLOBAL_TOC(sk_load_half_positive_offset)
-	subi	r_tmp, r_hlen, 2
-	cmpd	r_tmp, r_off
-	blt	bpf_slow_path_half
-	LHZX_BE	r_val, r_data, r_off
-	blr
-
-_GLOBAL_TOC(sk_load_byte)
-	cmpdi	r_off, 0
-	blt	bpf_slow_path_byte_neg
-	b	sk_load_byte_positive_offset
-
-_GLOBAL_TOC(sk_load_byte_positive_offset)
-	cmpd	r_hlen, r_off
-	ble	bpf_slow_path_byte
-	lbzx	r_val, r_data, r_off
-	blr
-
-/*
- * Call out to skb_copy_bits:
- * Allocate a new stack frame here to remain ABI-compliant in
- * stashing LR.
- */
-#define bpf_slow_path_common(SIZE)					\
-	mflr	r0;							\
-	std	r0, PPC_LR_STKOFF(r1);					\
-	stdu	r1, -(STACK_FRAME_MIN_SIZE + BPF_PPC_STACK_LOCALS)(r1);	\
-	mr	r3, r_skb;						\
-	/* r4 = r_off as passed */					\
-	addi	r5, r1, STACK_FRAME_MIN_SIZE;				\
-	li	r6, SIZE;						\
-	bl	skb_copy_bits;						\
-	nop;								\
-	/* save r5 */							\
-	addi	r5, r1, STACK_FRAME_MIN_SIZE;				\
-	/* r3 = 0 on success */						\
-	addi	r1, r1, STACK_FRAME_MIN_SIZE + BPF_PPC_STACK_LOCALS;	\
-	ld	r0, PPC_LR_STKOFF(r1);					\
-	mtlr	r0;							\
-	cmpdi	r3, 0;							\
-	blt	bpf_error;	/* cr0 = LT */
-
-bpf_slow_path_word:
-	bpf_slow_path_common(4)
-	/* Data value is on stack, and cr0 != LT */
-	LWZX_BE	r_val, 0, r5
-	blr
-
-bpf_slow_path_half:
-	bpf_slow_path_common(2)
-	LHZX_BE	r_val, 0, r5
-	blr
-
-bpf_slow_path_byte:
-	bpf_slow_path_common(1)
-	lbzx	r_val, 0, r5
-	blr
-
-/*
- * Call out to bpf_internal_load_pointer_neg_helper
- */
-#define sk_negative_common(SIZE)				\
-	mflr	r0;						\
-	std	r0, PPC_LR_STKOFF(r1);				\
-	stdu	r1, -STACK_FRAME_MIN_SIZE(r1);			\
-	mr	r3, r_skb;					\
-	/* r4 = r_off, as passed */				\
-	li	r5, SIZE;					\
-	bl	bpf_internal_load_pointer_neg_helper;		\
-	nop;							\
-	addi	r1, r1, STACK_FRAME_MIN_SIZE;			\
-	ld	r0, PPC_LR_STKOFF(r1);				\
-	mtlr	r0;						\
-	/* R3 != 0 on success */				\
-	cmpldi	r3, 0;						\
-	beq	bpf_error_slow;	/* cr0 = EQ */
-
-bpf_slow_path_word_neg:
-	lis     r_tmp, -32	/* SKF_LL_OFF */
-	cmpd	r_off, r_tmp	/* addr < SKF_* */
-	blt	bpf_error	/* cr0 = LT */
-	b	sk_load_word_negative_offset
-
-_GLOBAL_TOC(sk_load_word_negative_offset)
-	sk_negative_common(4)
-	LWZX_BE	r_val, 0, r3
-	blr
-
-bpf_slow_path_half_neg:
-	lis     r_tmp, -32	/* SKF_LL_OFF */
-	cmpd	r_off, r_tmp	/* addr < SKF_* */
-	blt	bpf_error	/* cr0 = LT */
-	b	sk_load_half_negative_offset
-
-_GLOBAL_TOC(sk_load_half_negative_offset)
-	sk_negative_common(2)
-	LHZX_BE	r_val, 0, r3
-	blr
-
-bpf_slow_path_byte_neg:
-	lis     r_tmp, -32	/* SKF_LL_OFF */
-	cmpd	r_off, r_tmp	/* addr < SKF_* */
-	blt	bpf_error	/* cr0 = LT */
-	b	sk_load_byte_negative_offset
-
-_GLOBAL_TOC(sk_load_byte_negative_offset)
-	sk_negative_common(1)
-	lbzx	r_val, 0, r3
-	blr
-
-bpf_error_slow:
-	/* fabricate a cr0 = lt */
-	li	r_tmp, -1
-	cmpdi	r_tmp, 0
-bpf_error:
-	/*
-	 * Entered with cr0 = lt
-	 * Generated code will 'blt epilogue', returning 0.
-	 */
-	li	r_val, 0
-	blr
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 0ef3d95..1bdb1af 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -59,7 +59,7 @@ static inline bool bpf_has_stack_frame(struct codegen_context *ctx)
  *		[	prev sp		] <-------------
  *		[	  ...       	] 		|
  * sp (r1) --->	[    stack pointer	] --------------
- *		[   nv gpr save area	] 8*8
+ *		[   nv gpr save area	] 6*8
  *		[    tail_call_cnt	] 8
  *		[    local_tmp_var	] 8
  *		[   unused red zone	] 208 bytes protected
@@ -88,21 +88,6 @@ static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg)
 	BUG();
 }
 
-static void bpf_jit_emit_skb_loads(u32 *image, struct codegen_context *ctx)
-{
-	/*
-	 * Load skb->len and skb->data_len
-	 * r3 points to skb
-	 */
-	PPC_LWZ(b2p[SKB_HLEN_REG], 3, offsetof(struct sk_buff, len));
-	PPC_LWZ(b2p[TMP_REG_1], 3, offsetof(struct sk_buff, data_len));
-	/* header_len = len - data_len */
-	PPC_SUB(b2p[SKB_HLEN_REG], b2p[SKB_HLEN_REG], b2p[TMP_REG_1]);
-
-	/* skb->data pointer */
-	PPC_BPF_LL(b2p[SKB_DATA_REG], 3, offsetof(struct sk_buff, data));
-}
-
 static void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
 {
 	int i;
@@ -145,18 +130,6 @@ static void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
 		if (bpf_is_seen_register(ctx, i))
 			PPC_BPF_STL(b2p[i], 1, bpf_jit_stack_offsetof(ctx, b2p[i]));
 
-	/*
-	 * Save additional non-volatile regs if we cache skb
-	 * Also, setup skb data
-	 */
-	if (ctx->seen & SEEN_SKB) {
-		PPC_BPF_STL(b2p[SKB_HLEN_REG], 1,
-				bpf_jit_stack_offsetof(ctx, b2p[SKB_HLEN_REG]));
-		PPC_BPF_STL(b2p[SKB_DATA_REG], 1,
-				bpf_jit_stack_offsetof(ctx, b2p[SKB_DATA_REG]));
-		bpf_jit_emit_skb_loads(image, ctx);
-	}
-
 	/* Setup frame pointer to point to the bpf stack area */
 	if (bpf_is_seen_register(ctx, BPF_REG_FP))
 		PPC_ADDI(b2p[BPF_REG_FP], 1,
@@ -172,14 +145,6 @@ static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx
 		if (bpf_is_seen_register(ctx, i))
 			PPC_BPF_LL(b2p[i], 1, bpf_jit_stack_offsetof(ctx, b2p[i]));
 
-	/* Restore non-volatile registers used for skb cache */
-	if (ctx->seen & SEEN_SKB) {
-		PPC_BPF_LL(b2p[SKB_HLEN_REG], 1,
-				bpf_jit_stack_offsetof(ctx, b2p[SKB_HLEN_REG]));
-		PPC_BPF_LL(b2p[SKB_DATA_REG], 1,
-				bpf_jit_stack_offsetof(ctx, b2p[SKB_DATA_REG]));
-	}
-
 	/* Tear down our stack frame */
 	if (bpf_has_stack_frame(ctx)) {
 		PPC_ADDI(1, 1, BPF_PPC_STACKFRAME + ctx->stack_size);
@@ -753,23 +718,10 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
 			ctx->seen |= SEEN_FUNC;
 			func = (u8 *) __bpf_call_base + imm;
 
-			/* Save skb pointer if we need to re-cache skb data */
-			if ((ctx->seen & SEEN_SKB) &&
-			    bpf_helper_changes_pkt_data(func))
-				PPC_BPF_STL(3, 1, bpf_jit_stack_local(ctx));
-
 			bpf_jit_emit_func_call(image, ctx, (u64)func);
 
 			/* move return value from r3 to BPF_REG_0 */
 			PPC_MR(b2p[BPF_REG_0], 3);
-
-			/* refresh skb cache */
-			if ((ctx->seen & SEEN_SKB) &&
-			    bpf_helper_changes_pkt_data(func)) {
-				/* reload skb pointer to r3 */
-				PPC_BPF_LL(3, 1, bpf_jit_stack_local(ctx));
-				bpf_jit_emit_skb_loads(image, ctx);
-			}
 			break;
 
 		/*
@@ -887,65 +839,6 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
 			break;
 
 		/*
-		 * Loads from packet header/data
-		 * Assume 32-bit input value in imm and X (src_reg)
-		 */
-
-		/* Absolute loads */
-		case BPF_LD | BPF_W | BPF_ABS:
-			func = (u8 *)CHOOSE_LOAD_FUNC(imm, sk_load_word);
-			goto common_load_abs;
-		case BPF_LD | BPF_H | BPF_ABS:
-			func = (u8 *)CHOOSE_LOAD_FUNC(imm, sk_load_half);
-			goto common_load_abs;
-		case BPF_LD | BPF_B | BPF_ABS:
-			func = (u8 *)CHOOSE_LOAD_FUNC(imm, sk_load_byte);
-common_load_abs:
-			/*
-			 * Load from [imm]
-			 * Load into r4, which can just be passed onto
-			 *  skb load helpers as the second parameter
-			 */
-			PPC_LI32(4, imm);
-			goto common_load;
-
-		/* Indirect loads */
-		case BPF_LD | BPF_W | BPF_IND:
-			func = (u8 *)sk_load_word;
-			goto common_load_ind;
-		case BPF_LD | BPF_H | BPF_IND:
-			func = (u8 *)sk_load_half;
-			goto common_load_ind;
-		case BPF_LD | BPF_B | BPF_IND:
-			func = (u8 *)sk_load_byte;
-common_load_ind:
-			/*
-			 * Load from [src_reg + imm]
-			 * Treat src_reg as a 32-bit value
-			 */
-			PPC_EXTSW(4, src_reg);
-			if (imm) {
-				if (imm >= -32768 && imm < 32768)
-					PPC_ADDI(4, 4, IMM_L(imm));
-				else {
-					PPC_LI32(b2p[TMP_REG_1], imm);
-					PPC_ADD(4, 4, b2p[TMP_REG_1]);
-				}
-			}
-
-common_load:
-			ctx->seen |= SEEN_SKB;
-			ctx->seen |= SEEN_FUNC;
-			bpf_jit_emit_func_call(image, ctx, (u64)func);
-
-			/*
-			 * Helper returns 'lt' condition on error, and an
-			 * appropriate return value in BPF_REG_0
-			 */
-			PPC_BCC(COND_LT, exit_addr);
-			break;
-
-		/*
 		 * Tail call
 		 */
 		case BPF_JMP | BPF_TAIL_CALL:
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v2 11/13] bpf, s390x: remove ld_abs/ld_ind
From: Daniel Borkmann @ 2018-05-03 23:08 UTC (permalink / raw)
  To: ast; +Cc: netdev, Daniel Borkmann, Michael Holzheu
In-Reply-To: <20180503230824.3462-1-daniel@iogearbox.net>

Since LD_ABS/LD_IND instructions are now removed from the core and
reimplemented through a combination of inlined BPF instructions and
a slow-path helper, we can get rid of the complexity from s390x JIT.
Tested on s390x instance on LinuxONE.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
---
 arch/s390/net/Makefile       |   2 +-
 arch/s390/net/bpf_jit.S      | 116 ---------------------------------------
 arch/s390/net/bpf_jit.h      |  20 +------
 arch/s390/net/bpf_jit_comp.c | 127 ++++---------------------------------------
 4 files changed, 13 insertions(+), 252 deletions(-)
 delete mode 100644 arch/s390/net/bpf_jit.S

diff --git a/arch/s390/net/Makefile b/arch/s390/net/Makefile
index e0d5f24..d4663b4 100644
--- a/arch/s390/net/Makefile
+++ b/arch/s390/net/Makefile
@@ -2,4 +2,4 @@
 #
 # Arch-specific network modules
 #
-obj-$(CONFIG_BPF_JIT) += bpf_jit.o bpf_jit_comp.o
+obj-$(CONFIG_BPF_JIT) += bpf_jit_comp.o
diff --git a/arch/s390/net/bpf_jit.S b/arch/s390/net/bpf_jit.S
deleted file mode 100644
index 25bb464..0000000
--- a/arch/s390/net/bpf_jit.S
+++ /dev/null
@@ -1,116 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * BPF Jit compiler for s390, help functions.
- *
- * Copyright IBM Corp. 2012,2015
- *
- * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
- *	      Michael Holzheu <holzheu@linux.vnet.ibm.com>
- */
-
-#include <linux/linkage.h>
-#include "bpf_jit.h"
-
-/*
- * Calling convention:
- * registers %r7-%r10, %r11,%r13, and %r15 are call saved
- *
- * Input (64 bit):
- *   %r3 (%b2) = offset into skb data
- *   %r6 (%b5) = return address
- *   %r7 (%b6) = skb pointer
- *   %r12      = skb data pointer
- *
- * Output:
- *   %r14= %b0 = return value (read skb value)
- *
- * Work registers: %r2,%r4,%r5,%r14
- *
- * skb_copy_bits takes 4 parameters:
- *   %r2 = skb pointer
- *   %r3 = offset into skb data
- *   %r4 = pointer to temp buffer
- *   %r5 = length to copy
- *   Return value in %r2: 0 = ok
- *
- * bpf_internal_load_pointer_neg_helper takes 3 parameters:
- *   %r2 = skb pointer
- *   %r3 = offset into data
- *   %r4 = length to copy
- *   Return value in %r2: Pointer to data
- */
-
-#define SKF_MAX_NEG_OFF	-0x200000	/* SKF_LL_OFF from filter.h */
-
-/*
- * Load SIZE bytes from SKB
- */
-#define sk_load_common(NAME, SIZE, LOAD)				\
-ENTRY(sk_load_##NAME);							\
-	ltgr	%r3,%r3;		/* Is offset negative? */	\
-	jl	sk_load_##NAME##_slow_neg;				\
-ENTRY(sk_load_##NAME##_pos);						\
-	aghi	%r3,SIZE;		/* Offset + SIZE */		\
-	clg	%r3,STK_OFF_HLEN(%r15);	/* Offset + SIZE > hlen? */	\
-	jh	sk_load_##NAME##_slow;					\
-	LOAD	%r14,-SIZE(%r3,%r12);	/* Get data from skb */		\
-	b	OFF_OK(%r6);		/* Return */			\
-									\
-sk_load_##NAME##_slow:;							\
-	lgr	%r2,%r7;		/* Arg1 = skb pointer */	\
-	aghi	%r3,-SIZE;		/* Arg2 = offset */		\
-	la	%r4,STK_OFF_TMP(%r15);	/* Arg3 = temp bufffer */	\
-	lghi	%r5,SIZE;		/* Arg4 = size */		\
-	brasl	%r14,skb_copy_bits;	/* Get data from skb */		\
-	LOAD	%r14,STK_OFF_TMP(%r15);	/* Load from temp bufffer */	\
-	ltgr	%r2,%r2;		/* Set cc to (%r2 != 0) */	\
-	br	%r6;			/* Return */
-
-sk_load_common(word, 4, llgf)	/* r14 = *(u32 *) (skb->data+offset) */
-sk_load_common(half, 2, llgh)	/* r14 = *(u16 *) (skb->data+offset) */
-
-/*
- * Load 1 byte from SKB (optimized version)
- */
-	/* r14 = *(u8 *) (skb->data+offset) */
-ENTRY(sk_load_byte)
-	ltgr	%r3,%r3			# Is offset negative?
-	jl	sk_load_byte_slow_neg
-ENTRY(sk_load_byte_pos)
-	clg	%r3,STK_OFF_HLEN(%r15)	# Offset >= hlen?
-	jnl	sk_load_byte_slow
-	llgc	%r14,0(%r3,%r12)	# Get byte from skb
-	b	OFF_OK(%r6)		# Return OK
-
-sk_load_byte_slow:
-	lgr	%r2,%r7			# Arg1 = skb pointer
-					# Arg2 = offset
-	la	%r4,STK_OFF_TMP(%r15)	# Arg3 = pointer to temp buffer
-	lghi	%r5,1			# Arg4 = size (1 byte)
-	brasl	%r14,skb_copy_bits	# Get data from skb
-	llgc	%r14,STK_OFF_TMP(%r15)	# Load result from temp buffer
-	ltgr	%r2,%r2			# Set cc to (%r2 != 0)
-	br	%r6			# Return cc
-
-#define sk_negative_common(NAME, SIZE, LOAD)				\
-sk_load_##NAME##_slow_neg:;						\
-	cgfi	%r3,SKF_MAX_NEG_OFF;					\
-	jl	bpf_error;						\
-	lgr	%r2,%r7;		/* Arg1 = skb pointer */	\
-					/* Arg2 = offset */		\
-	lghi	%r4,SIZE;		/* Arg3 = size */		\
-	brasl	%r14,bpf_internal_load_pointer_neg_helper;		\
-	ltgr	%r2,%r2;						\
-	jz	bpf_error;						\
-	LOAD	%r14,0(%r2);		/* Get data from pointer */	\
-	xr	%r3,%r3;		/* Set cc to zero */		\
-	br	%r6;			/* Return cc */
-
-sk_negative_common(word, 4, llgf)
-sk_negative_common(half, 2, llgh)
-sk_negative_common(byte, 1, llgc)
-
-bpf_error:
-# force a return 0 from jit handler
-	ltgr	%r15,%r15	# Set condition code
-	br	%r6
diff --git a/arch/s390/net/bpf_jit.h b/arch/s390/net/bpf_jit.h
index 5e1e513..7822ea9 100644
--- a/arch/s390/net/bpf_jit.h
+++ b/arch/s390/net/bpf_jit.h
@@ -16,9 +16,6 @@
 #include <linux/filter.h>
 #include <linux/types.h>
 
-extern u8 sk_load_word_pos[], sk_load_half_pos[], sk_load_byte_pos[];
-extern u8 sk_load_word[], sk_load_half[], sk_load_byte[];
-
 #endif /* __ASSEMBLY__ */
 
 /*
@@ -36,15 +33,6 @@ extern u8 sk_load_word[], sk_load_half[], sk_load_byte[];
  *	      |		      |     |
  *	      |   BPF stack   |     |
  *	      |		      |     |
- *	      +---------------+     |
- *	      | 8 byte skbp   |     |
- * R15+176 -> +---------------+     |
- *	      | 8 byte hlen   |     |
- * R15+168 -> +---------------+     |
- *	      | 4 byte align  |     |
- *	      +---------------+     |
- *	      | 4 byte temp   |     |
- *	      | for bpf_jit.S |     |
  * R15+160 -> +---------------+     |
  *	      | new backchain |     |
  * R15+152 -> +---------------+     |
@@ -57,17 +45,11 @@ extern u8 sk_load_word[], sk_load_half[], sk_load_byte[];
  * The stack size used by the BPF program ("BPF stack" above) is passed
  * via "aux->stack_depth".
  */
-#define STK_SPACE_ADD (8 + 8 + 4 + 4 + 160)
+#define STK_SPACE_ADD	(160)
 #define STK_160_UNUSED	(160 - 12 * 8)
 #define STK_OFF		(STK_SPACE_ADD - STK_160_UNUSED)
-#define STK_OFF_TMP	160	/* Offset of tmp buffer on stack */
-#define STK_OFF_HLEN	168	/* Offset of SKB header length on stack */
-#define STK_OFF_SKBP	176	/* Offset of SKB pointer on stack */
 
 #define STK_OFF_R6	(160 - 11 * 8)	/* Offset of r6 on stack */
 #define STK_OFF_TCCNT	(160 - 12 * 8)	/* Offset of tail_call_cnt on stack */
 
-/* Offset to skip condition code check */
-#define OFF_OK		4
-
 #endif /* __ARCH_S390_NET_BPF_JIT_H */
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index 78a19c9..b020bea 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -47,23 +47,21 @@ struct bpf_jit {
 
 #define BPF_SIZE_MAX	0xffff	/* Max size for program (16 bit branches) */
 
-#define SEEN_SKB	1	/* skb access */
-#define SEEN_MEM	2	/* use mem[] for temporary storage */
-#define SEEN_RET0	4	/* ret0_ip points to a valid return 0 */
-#define SEEN_LITERAL	8	/* code uses literals */
-#define SEEN_FUNC	16	/* calls C functions */
-#define SEEN_TAIL_CALL	32	/* code uses tail calls */
-#define SEEN_REG_AX	64	/* code uses constant blinding */
-#define SEEN_STACK	(SEEN_FUNC | SEEN_MEM | SEEN_SKB)
+#define SEEN_MEM	(1 << 0)	/* use mem[] for temporary storage */
+#define SEEN_RET0	(1 << 1)	/* ret0_ip points to a valid return 0 */
+#define SEEN_LITERAL	(1 << 2)	/* code uses literals */
+#define SEEN_FUNC	(1 << 3)	/* calls C functions */
+#define SEEN_TAIL_CALL	(1 << 4)	/* code uses tail calls */
+#define SEEN_REG_AX	(1 << 5)	/* code uses constant blinding */
+#define SEEN_STACK	(SEEN_FUNC | SEEN_MEM)
 
 /*
  * s390 registers
  */
 #define REG_W0		(MAX_BPF_JIT_REG + 0)	/* Work register 1 (even) */
 #define REG_W1		(MAX_BPF_JIT_REG + 1)	/* Work register 2 (odd) */
-#define REG_SKB_DATA	(MAX_BPF_JIT_REG + 2)	/* SKB data register */
-#define REG_L		(MAX_BPF_JIT_REG + 3)	/* Literal pool register */
-#define REG_15		(MAX_BPF_JIT_REG + 4)	/* Register 15 */
+#define REG_L		(MAX_BPF_JIT_REG + 2)	/* Literal pool register */
+#define REG_15		(MAX_BPF_JIT_REG + 3)	/* Register 15 */
 #define REG_0		REG_W0			/* Register 0 */
 #define REG_1		REG_W1			/* Register 1 */
 #define REG_2		BPF_REG_1		/* Register 2 */
@@ -88,10 +86,8 @@ static const int reg2hex[] = {
 	[BPF_REG_9]	= 10,
 	/* BPF stack pointer */
 	[BPF_REG_FP]	= 13,
-	/* Register for blinding (shared with REG_SKB_DATA) */
+	/* Register for blinding */
 	[BPF_REG_AX]	= 12,
-	/* SKB data pointer */
-	[REG_SKB_DATA]	= 12,
 	/* Work registers for s390x backend */
 	[REG_W0]	= 0,
 	[REG_W1]	= 1,
@@ -385,27 +381,6 @@ static void save_restore_regs(struct bpf_jit *jit, int op, u32 stack_depth)
 }
 
 /*
- * For SKB access %b1 contains the SKB pointer. For "bpf_jit.S"
- * we store the SKB header length on the stack and the SKB data
- * pointer in REG_SKB_DATA if BPF_REG_AX is not used.
- */
-static void emit_load_skb_data_hlen(struct bpf_jit *jit)
-{
-	/* Header length: llgf %w1,<len>(%b1) */
-	EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_1,
-		      offsetof(struct sk_buff, len));
-	/* s %w1,<data_len>(%b1) */
-	EMIT4_DISP(0x5b000000, REG_W1, BPF_REG_1,
-		   offsetof(struct sk_buff, data_len));
-	/* stg %w1,ST_OFF_HLEN(%r0,%r15) */
-	EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0, REG_15, STK_OFF_HLEN);
-	if (!(jit->seen & SEEN_REG_AX))
-		/* lg %skb_data,data_off(%b1) */
-		EMIT6_DISP_LH(0xe3000000, 0x0004, REG_SKB_DATA, REG_0,
-			      BPF_REG_1, offsetof(struct sk_buff, data));
-}
-
-/*
  * Emit function prologue
  *
  * Save registers and create stack frame if necessary.
@@ -445,12 +420,6 @@ static void bpf_jit_prologue(struct bpf_jit *jit, u32 stack_depth)
 			EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0,
 				      REG_15, 152);
 	}
-	if (jit->seen & SEEN_SKB) {
-		emit_load_skb_data_hlen(jit);
-		/* stg %b1,ST_OFF_SKBP(%r0,%r15) */
-		EMIT6_DISP_LH(0xe3000000, 0x0024, BPF_REG_1, REG_0, REG_15,
-			      STK_OFF_SKBP);
-	}
 }
 
 /*
@@ -483,12 +452,12 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
 {
 	struct bpf_insn *insn = &fp->insnsi[i];
 	int jmp_off, last, insn_count = 1;
-	unsigned int func_addr, mask;
 	u32 dst_reg = insn->dst_reg;
 	u32 src_reg = insn->src_reg;
 	u32 *addrs = jit->addrs;
 	s32 imm = insn->imm;
 	s16 off = insn->off;
+	unsigned int mask;
 
 	if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX)
 		jit->seen |= SEEN_REG_AX;
@@ -970,13 +939,6 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
 		EMIT2(0x0d00, REG_14, REG_W1);
 		/* lgr %b0,%r2: load return value into %b0 */
 		EMIT4(0xb9040000, BPF_REG_0, REG_2);
-		if ((jit->seen & SEEN_SKB) &&
-		    bpf_helper_changes_pkt_data((void *)func)) {
-			/* lg %b1,ST_OFF_SKBP(%r15) */
-			EMIT6_DISP_LH(0xe3000000, 0x0004, BPF_REG_1, REG_0,
-				      REG_15, STK_OFF_SKBP);
-			emit_load_skb_data_hlen(jit);
-		}
 		break;
 	}
 	case BPF_JMP | BPF_TAIL_CALL:
@@ -1176,73 +1138,6 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
 		jmp_off = addrs[i + off + 1] - (addrs[i + 1] - 4);
 		EMIT4_PCREL(0xa7040000 | mask << 8, jmp_off);
 		break;
-	/*
-	 * BPF_LD
-	 */
-	case BPF_LD | BPF_ABS | BPF_B: /* b0 = *(u8 *) (skb->data+imm) */
-	case BPF_LD | BPF_IND | BPF_B: /* b0 = *(u8 *) (skb->data+imm+src) */
-		if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
-			func_addr = __pa(sk_load_byte_pos);
-		else
-			func_addr = __pa(sk_load_byte);
-		goto call_fn;
-	case BPF_LD | BPF_ABS | BPF_H: /* b0 = *(u16 *) (skb->data+imm) */
-	case BPF_LD | BPF_IND | BPF_H: /* b0 = *(u16 *) (skb->data+imm+src) */
-		if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
-			func_addr = __pa(sk_load_half_pos);
-		else
-			func_addr = __pa(sk_load_half);
-		goto call_fn;
-	case BPF_LD | BPF_ABS | BPF_W: /* b0 = *(u32 *) (skb->data+imm) */
-	case BPF_LD | BPF_IND | BPF_W: /* b0 = *(u32 *) (skb->data+imm+src) */
-		if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
-			func_addr = __pa(sk_load_word_pos);
-		else
-			func_addr = __pa(sk_load_word);
-		goto call_fn;
-call_fn:
-		jit->seen |= SEEN_SKB | SEEN_RET0 | SEEN_FUNC;
-		REG_SET_SEEN(REG_14); /* Return address of possible func call */
-
-		/*
-		 * Implicit input:
-		 *  BPF_REG_6	 (R7) : skb pointer
-		 *  REG_SKB_DATA (R12): skb data pointer (if no BPF_REG_AX)
-		 *
-		 * Calculated input:
-		 *  BPF_REG_2	 (R3) : offset of byte(s) to fetch in skb
-		 *  BPF_REG_5	 (R6) : return address
-		 *
-		 * Output:
-		 *  BPF_REG_0	 (R14): data read from skb
-		 *
-		 * Scratch registers (BPF_REG_1-5)
-		 */
-
-		/* Call function: llilf %w1,func_addr  */
-		EMIT6_IMM(0xc00f0000, REG_W1, func_addr);
-
-		/* Offset: lgfi %b2,imm */
-		EMIT6_IMM(0xc0010000, BPF_REG_2, imm);
-		if (BPF_MODE(insn->code) == BPF_IND)
-			/* agfr %b2,%src (%src is s32 here) */
-			EMIT4(0xb9180000, BPF_REG_2, src_reg);
-
-		/* Reload REG_SKB_DATA if BPF_REG_AX is used */
-		if (jit->seen & SEEN_REG_AX)
-			/* lg %skb_data,data_off(%b6) */
-			EMIT6_DISP_LH(0xe3000000, 0x0004, REG_SKB_DATA, REG_0,
-				      BPF_REG_6, offsetof(struct sk_buff, data));
-		/* basr %b5,%w1 (%b5 is call saved) */
-		EMIT2(0x0d00, BPF_REG_5, REG_W1);
-
-		/*
-		 * Note: For fast access we jump directly after the
-		 * jnz instruction from bpf_jit.S
-		 */
-		/* jnz <ret0> */
-		EMIT4_PCREL(0xa7740000, jit->ret0_ip - jit->prg);
-		break;
 	default: /* too complex, give up */
 		pr_err("Unknown opcode %02x\n", insn->code);
 		return -1;
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v2 07/13] bpf, sparc64: remove ld_abs/ld_ind
From: Daniel Borkmann @ 2018-05-03 23:08 UTC (permalink / raw)
  To: ast; +Cc: netdev, Daniel Borkmann
In-Reply-To: <20180503230824.3462-1-daniel@iogearbox.net>

Since LD_ABS/LD_IND instructions are now removed from the core and
reimplemented through a combination of inlined BPF instructions and
a slow-path helper, we can get rid of the complexity from sparc64 JIT.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
---
 arch/sparc/net/Makefile          |   5 +-
 arch/sparc/net/bpf_jit_64.h      |  29 -------
 arch/sparc/net/bpf_jit_asm_64.S  | 162 ---------------------------------------
 arch/sparc/net/bpf_jit_comp_64.c |  79 +------------------
 4 files changed, 6 insertions(+), 269 deletions(-)
 delete mode 100644 arch/sparc/net/bpf_jit_asm_64.S

diff --git a/arch/sparc/net/Makefile b/arch/sparc/net/Makefile
index 76fa8e9..d32aac3 100644
--- a/arch/sparc/net/Makefile
+++ b/arch/sparc/net/Makefile
@@ -1,4 +1,7 @@
 #
 # Arch-specific network modules
 #
-obj-$(CONFIG_BPF_JIT) += bpf_jit_asm_$(BITS).o bpf_jit_comp_$(BITS).o
+obj-$(CONFIG_BPF_JIT) += bpf_jit_comp_$(BITS).o
+ifeq ($(BITS),32)
+obj-$(CONFIG_BPF_JIT) += bpf_jit_asm_32.o
+endif
diff --git a/arch/sparc/net/bpf_jit_64.h b/arch/sparc/net/bpf_jit_64.h
index 428f7fd..fbc836f 100644
--- a/arch/sparc/net/bpf_jit_64.h
+++ b/arch/sparc/net/bpf_jit_64.h
@@ -33,35 +33,6 @@
 #define I5		0x1d
 #define FP		0x1e
 #define I7		0x1f
-
-#define r_SKB		L0
-#define r_HEADLEN	L4
-#define r_SKB_DATA	L5
-#define r_TMP		G1
-#define r_TMP2		G3
-
-/* assembly code in arch/sparc/net/bpf_jit_asm_64.S */
-extern u32 bpf_jit_load_word[];
-extern u32 bpf_jit_load_half[];
-extern u32 bpf_jit_load_byte[];
-extern u32 bpf_jit_load_byte_msh[];
-extern u32 bpf_jit_load_word_positive_offset[];
-extern u32 bpf_jit_load_half_positive_offset[];
-extern u32 bpf_jit_load_byte_positive_offset[];
-extern u32 bpf_jit_load_byte_msh_positive_offset[];
-extern u32 bpf_jit_load_word_negative_offset[];
-extern u32 bpf_jit_load_half_negative_offset[];
-extern u32 bpf_jit_load_byte_negative_offset[];
-extern u32 bpf_jit_load_byte_msh_negative_offset[];
-
-#else
-#define r_RESULT	%o0
-#define r_SKB		%o0
-#define r_OFF		%o1
-#define r_HEADLEN	%l4
-#define r_SKB_DATA	%l5
-#define r_TMP		%g1
-#define r_TMP2		%g3
 #endif
 
 #endif /* _BPF_JIT_H */
diff --git a/arch/sparc/net/bpf_jit_asm_64.S b/arch/sparc/net/bpf_jit_asm_64.S
deleted file mode 100644
index 7177867..0000000
--- a/arch/sparc/net/bpf_jit_asm_64.S
+++ /dev/null
@@ -1,162 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#include <asm/ptrace.h>
-
-#include "bpf_jit_64.h"
-
-#define SAVE_SZ		176
-#define SCRATCH_OFF	STACK_BIAS + 128
-#define BE_PTR(label)	be,pn %xcc, label
-#define SIGN_EXTEND(reg)	sra reg, 0, reg
-
-#define SKF_MAX_NEG_OFF	(-0x200000) /* SKF_LL_OFF from filter.h */
-
-	.text
-	.globl	bpf_jit_load_word
-bpf_jit_load_word:
-	cmp	r_OFF, 0
-	bl	bpf_slow_path_word_neg
-	 nop
-	.globl	bpf_jit_load_word_positive_offset
-bpf_jit_load_word_positive_offset:
-	sub	r_HEADLEN, r_OFF, r_TMP
-	cmp	r_TMP, 3
-	ble	bpf_slow_path_word
-	 add	r_SKB_DATA, r_OFF, r_TMP
-	andcc	r_TMP, 3, %g0
-	bne	load_word_unaligned
-	 nop
-	retl
-	 ld	[r_TMP], r_RESULT
-load_word_unaligned:
-	ldub	[r_TMP + 0x0], r_OFF
-	ldub	[r_TMP + 0x1], r_TMP2
-	sll	r_OFF, 8, r_OFF
-	or	r_OFF, r_TMP2, r_OFF
-	ldub	[r_TMP + 0x2], r_TMP2
-	sll	r_OFF, 8, r_OFF
-	or	r_OFF, r_TMP2, r_OFF
-	ldub	[r_TMP + 0x3], r_TMP2
-	sll	r_OFF, 8, r_OFF
-	retl
-	 or	r_OFF, r_TMP2, r_RESULT
-
-	.globl	bpf_jit_load_half
-bpf_jit_load_half:
-	cmp	r_OFF, 0
-	bl	bpf_slow_path_half_neg
-	 nop
-	.globl	bpf_jit_load_half_positive_offset
-bpf_jit_load_half_positive_offset:
-	sub	r_HEADLEN, r_OFF, r_TMP
-	cmp	r_TMP, 1
-	ble	bpf_slow_path_half
-	 add	r_SKB_DATA, r_OFF, r_TMP
-	andcc	r_TMP, 1, %g0
-	bne	load_half_unaligned
-	 nop
-	retl
-	 lduh	[r_TMP], r_RESULT
-load_half_unaligned:
-	ldub	[r_TMP + 0x0], r_OFF
-	ldub	[r_TMP + 0x1], r_TMP2
-	sll	r_OFF, 8, r_OFF
-	retl
-	 or	r_OFF, r_TMP2, r_RESULT
-
-	.globl	bpf_jit_load_byte
-bpf_jit_load_byte:
-	cmp	r_OFF, 0
-	bl	bpf_slow_path_byte_neg
-	 nop
-	.globl	bpf_jit_load_byte_positive_offset
-bpf_jit_load_byte_positive_offset:
-	cmp	r_OFF, r_HEADLEN
-	bge	bpf_slow_path_byte
-	 nop
-	retl
-	 ldub	[r_SKB_DATA + r_OFF], r_RESULT
-
-#define bpf_slow_path_common(LEN)	\
-	save	%sp, -SAVE_SZ, %sp;	\
-	mov	%i0, %o0;		\
-	mov	%i1, %o1;		\
-	add	%fp, SCRATCH_OFF, %o2;	\
-	call	skb_copy_bits;		\
-	 mov	(LEN), %o3;		\
-	cmp	%o0, 0;			\
-	restore;
-
-bpf_slow_path_word:
-	bpf_slow_path_common(4)
-	bl	bpf_error
-	 ld	[%sp + SCRATCH_OFF], r_RESULT
-	retl
-	 nop
-bpf_slow_path_half:
-	bpf_slow_path_common(2)
-	bl	bpf_error
-	 lduh	[%sp + SCRATCH_OFF], r_RESULT
-	retl
-	 nop
-bpf_slow_path_byte:
-	bpf_slow_path_common(1)
-	bl	bpf_error
-	 ldub	[%sp + SCRATCH_OFF], r_RESULT
-	retl
-	 nop
-
-#define bpf_negative_common(LEN)			\
-	save	%sp, -SAVE_SZ, %sp;			\
-	mov	%i0, %o0;				\
-	mov	%i1, %o1;				\
-	SIGN_EXTEND(%o1);				\
-	call	bpf_internal_load_pointer_neg_helper;	\
-	 mov	(LEN), %o2;				\
-	mov	%o0, r_TMP;				\
-	cmp	%o0, 0;					\
-	BE_PTR(bpf_error);				\
-	 restore;
-
-bpf_slow_path_word_neg:
-	sethi	%hi(SKF_MAX_NEG_OFF), r_TMP
-	cmp	r_OFF, r_TMP
-	bl	bpf_error
-	 nop
-	.globl	bpf_jit_load_word_negative_offset
-bpf_jit_load_word_negative_offset:
-	bpf_negative_common(4)
-	andcc	r_TMP, 3, %g0
-	bne	load_word_unaligned
-	 nop
-	retl
-	 ld	[r_TMP], r_RESULT
-
-bpf_slow_path_half_neg:
-	sethi	%hi(SKF_MAX_NEG_OFF), r_TMP
-	cmp	r_OFF, r_TMP
-	bl	bpf_error
-	 nop
-	.globl	bpf_jit_load_half_negative_offset
-bpf_jit_load_half_negative_offset:
-	bpf_negative_common(2)
-	andcc	r_TMP, 1, %g0
-	bne	load_half_unaligned
-	 nop
-	retl
-	 lduh	[r_TMP], r_RESULT
-
-bpf_slow_path_byte_neg:
-	sethi	%hi(SKF_MAX_NEG_OFF), r_TMP
-	cmp	r_OFF, r_TMP
-	bl	bpf_error
-	 nop
-	.globl	bpf_jit_load_byte_negative_offset
-bpf_jit_load_byte_negative_offset:
-	bpf_negative_common(1)
-	retl
-	 ldub	[r_TMP], r_RESULT
-
-bpf_error:
-	/* Make the JIT program itself return zero. */
-	ret
-	restore	%g0, %g0, %o0
diff --git a/arch/sparc/net/bpf_jit_comp_64.c b/arch/sparc/net/bpf_jit_comp_64.c
index 48a2586..9f5918e 100644
--- a/arch/sparc/net/bpf_jit_comp_64.c
+++ b/arch/sparc/net/bpf_jit_comp_64.c
@@ -48,10 +48,6 @@ static void bpf_flush_icache(void *start_, void *end_)
 	}
 }
 
-#define SEEN_DATAREF 1 /* might call external helpers */
-#define SEEN_XREG    2 /* ebx is used */
-#define SEEN_MEM     4 /* use mem[] for temporary storage */
-
 #define S13(X)		((X) & 0x1fff)
 #define S5(X)		((X) & 0x1f)
 #define IMMED		0x00002000
@@ -198,7 +194,6 @@ struct jit_ctx {
 	bool 			tmp_1_used;
 	bool 			tmp_2_used;
 	bool 			tmp_3_used;
-	bool			saw_ld_abs_ind;
 	bool			saw_frame_pointer;
 	bool			saw_call;
 	bool			saw_tail_call;
@@ -207,9 +202,7 @@ struct jit_ctx {
 
 #define TMP_REG_1	(MAX_BPF_JIT_REG + 0)
 #define TMP_REG_2	(MAX_BPF_JIT_REG + 1)
-#define SKB_HLEN_REG	(MAX_BPF_JIT_REG + 2)
-#define SKB_DATA_REG	(MAX_BPF_JIT_REG + 3)
-#define TMP_REG_3	(MAX_BPF_JIT_REG + 4)
+#define TMP_REG_3	(MAX_BPF_JIT_REG + 2)
 
 /* Map BPF registers to SPARC registers */
 static const int bpf2sparc[] = {
@@ -238,9 +231,6 @@ static const int bpf2sparc[] = {
 	[TMP_REG_1] = G1,
 	[TMP_REG_2] = G2,
 	[TMP_REG_3] = G3,
-
-	[SKB_HLEN_REG] = L4,
-	[SKB_DATA_REG] = L5,
 };
 
 static void emit(const u32 insn, struct jit_ctx *ctx)
@@ -800,25 +790,6 @@ static int emit_compare_and_branch(const u8 code, const u8 dst, u8 src,
 	return 0;
 }
 
-static void load_skb_regs(struct jit_ctx *ctx, u8 r_skb)
-{
-	const u8 r_headlen = bpf2sparc[SKB_HLEN_REG];
-	const u8 r_data = bpf2sparc[SKB_DATA_REG];
-	const u8 r_tmp = bpf2sparc[TMP_REG_1];
-	unsigned int off;
-
-	off = offsetof(struct sk_buff, len);
-	emit(LD32I | RS1(r_skb) | S13(off) | RD(r_headlen), ctx);
-
-	off = offsetof(struct sk_buff, data_len);
-	emit(LD32I | RS1(r_skb) | S13(off) | RD(r_tmp), ctx);
-
-	emit(SUB | RS1(r_headlen) | RS2(r_tmp) | RD(r_headlen), ctx);
-
-	off = offsetof(struct sk_buff, data);
-	emit(LDPTRI | RS1(r_skb) | S13(off) | RD(r_data), ctx);
-}
-
 /* Just skip the save instruction and the ctx register move.  */
 #define BPF_TAILCALL_PROLOGUE_SKIP	16
 #define BPF_TAILCALL_CNT_SP_OFF		(STACK_BIAS + 128)
@@ -857,9 +828,6 @@ static void build_prologue(struct jit_ctx *ctx)
 
 	emit_reg_move(I0, O0, ctx);
 	/* If you add anything here, adjust BPF_TAILCALL_PROLOGUE_SKIP above. */
-
-	if (ctx->saw_ld_abs_ind)
-		load_skb_regs(ctx, bpf2sparc[BPF_REG_1]);
 }
 
 static void build_epilogue(struct jit_ctx *ctx)
@@ -1225,16 +1193,11 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
 		u8 *func = ((u8 *)__bpf_call_base) + imm;
 
 		ctx->saw_call = true;
-		if (ctx->saw_ld_abs_ind && bpf_helper_changes_pkt_data(func))
-			emit_reg_move(bpf2sparc[BPF_REG_1], L7, ctx);
 
 		emit_call((u32 *)func, ctx);
 		emit_nop(ctx);
 
 		emit_reg_move(O0, bpf2sparc[BPF_REG_0], ctx);
-
-		if (ctx->saw_ld_abs_ind && bpf_helper_changes_pkt_data(func))
-			load_skb_regs(ctx, L7);
 		break;
 	}
 
@@ -1412,43 +1375,6 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
 		emit_nop(ctx);
 		break;
 	}
-#define CHOOSE_LOAD_FUNC(K, func) \
-		((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset)
-
-	/* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + imm)) */
-	case BPF_LD | BPF_ABS | BPF_W:
-		func = CHOOSE_LOAD_FUNC(imm, bpf_jit_load_word);
-		goto common_load;
-	case BPF_LD | BPF_ABS | BPF_H:
-		func = CHOOSE_LOAD_FUNC(imm, bpf_jit_load_half);
-		goto common_load;
-	case BPF_LD | BPF_ABS | BPF_B:
-		func = CHOOSE_LOAD_FUNC(imm, bpf_jit_load_byte);
-		goto common_load;
-	/* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + src + imm)) */
-	case BPF_LD | BPF_IND | BPF_W:
-		func = bpf_jit_load_word;
-		goto common_load;
-	case BPF_LD | BPF_IND | BPF_H:
-		func = bpf_jit_load_half;
-		goto common_load;
-
-	case BPF_LD | BPF_IND | BPF_B:
-		func = bpf_jit_load_byte;
-	common_load:
-		ctx->saw_ld_abs_ind = true;
-
-		emit_reg_move(bpf2sparc[BPF_REG_6], O0, ctx);
-		emit_loadimm(imm, O1, ctx);
-
-		if (BPF_MODE(code) == BPF_IND)
-			emit_alu(ADD, src, O1, ctx);
-
-		emit_call(func, ctx);
-		emit_alu_K(SRA, O1, 0, ctx);
-
-		emit_reg_move(O0, bpf2sparc[BPF_REG_0], ctx);
-		break;
 
 	default:
 		pr_err_once("unknown opcode %02x\n", code);
@@ -1583,12 +1509,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 		build_epilogue(&ctx);
 
 		if (bpf_jit_enable > 1)
-			pr_info("Pass %d: shrink = %d, seen = [%c%c%c%c%c%c%c]\n", pass,
+			pr_info("Pass %d: shrink = %d, seen = [%c%c%c%c%c%c]\n", pass,
 				image_size - (ctx.idx * 4),
 				ctx.tmp_1_used ? '1' : ' ',
 				ctx.tmp_2_used ? '2' : ' ',
 				ctx.tmp_3_used ? '3' : ' ',
-				ctx.saw_ld_abs_ind ? 'L' : ' ',
 				ctx.saw_frame_pointer ? 'F' : ' ',
 				ctx.saw_call ? 'C' : ' ',
 				ctx.saw_tail_call ? 'T' : ' ');
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v2 08/13] bpf, arm32: remove ld_abs/ld_ind
From: Daniel Borkmann @ 2018-05-03 23:08 UTC (permalink / raw)
  To: ast; +Cc: netdev, Daniel Borkmann
In-Reply-To: <20180503230824.3462-1-daniel@iogearbox.net>

Since LD_ABS/LD_IND instructions are now removed from the core and
reimplemented through a combination of inlined BPF instructions and
a slow-path helper, we can get rid of the complexity from arm32 JIT.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
---
 arch/arm/net/bpf_jit_32.c | 77 -----------------------------------------------
 1 file changed, 77 deletions(-)

diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index b5030e1..82689b9 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -1452,83 +1452,6 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
 			emit(ARM_LDR_I(rn, ARM_SP, STACK_VAR(src_lo)), ctx);
 		emit_ldx_r(dst, rn, dstk, off, ctx, BPF_SIZE(code));
 		break;
-	/* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + imm)) */
-	case BPF_LD | BPF_ABS | BPF_W:
-	case BPF_LD | BPF_ABS | BPF_H:
-	case BPF_LD | BPF_ABS | BPF_B:
-	/* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + src + imm)) */
-	case BPF_LD | BPF_IND | BPF_W:
-	case BPF_LD | BPF_IND | BPF_H:
-	case BPF_LD | BPF_IND | BPF_B:
-	{
-		const u8 r4 = bpf2a32[BPF_REG_6][1]; /* r4 = ptr to sk_buff */
-		const u8 r0 = bpf2a32[BPF_REG_0][1]; /*r0: struct sk_buff *skb*/
-						     /* rtn value */
-		const u8 r1 = bpf2a32[BPF_REG_0][0]; /* r1: int k */
-		const u8 r2 = bpf2a32[BPF_REG_1][1]; /* r2: unsigned int size */
-		const u8 r3 = bpf2a32[BPF_REG_1][0]; /* r3: void *buffer */
-		const u8 r6 = bpf2a32[TMP_REG_1][1]; /* r6: void *(*func)(..) */
-		int size;
-
-		/* Setting up first argument */
-		emit(ARM_MOV_R(r0, r4), ctx);
-
-		/* Setting up second argument */
-		emit_a32_mov_i(r1, imm, false, ctx);
-		if (BPF_MODE(code) == BPF_IND)
-			emit_a32_alu_r(r1, src_lo, false, sstk, ctx,
-				       false, false, BPF_ADD);
-
-		/* Setting up third argument */
-		switch (BPF_SIZE(code)) {
-		case BPF_W:
-			size = 4;
-			break;
-		case BPF_H:
-			size = 2;
-			break;
-		case BPF_B:
-			size = 1;
-			break;
-		default:
-			return -EINVAL;
-		}
-		emit_a32_mov_i(r2, size, false, ctx);
-
-		/* Setting up fourth argument */
-		emit(ARM_ADD_I(r3, ARM_SP, imm8m(SKB_BUFFER)), ctx);
-
-		/* Setting up function pointer to call */
-		emit_a32_mov_i(r6, (unsigned int)bpf_load_pointer, false, ctx);
-		emit_blx_r(r6, ctx);
-
-		emit(ARM_EOR_R(r1, r1, r1), ctx);
-		/* Check if return address is NULL or not.
-		 * if NULL then jump to epilogue
-		 * else continue to load the value from retn address
-		 */
-		emit(ARM_CMP_I(r0, 0), ctx);
-		jmp_offset = epilogue_offset(ctx);
-		check_imm24(jmp_offset);
-		_emit(ARM_COND_EQ, ARM_B(jmp_offset), ctx);
-
-		/* Load value from the address */
-		switch (BPF_SIZE(code)) {
-		case BPF_W:
-			emit(ARM_LDR_I(r0, r0, 0), ctx);
-			emit_rev32(r0, r0, ctx);
-			break;
-		case BPF_H:
-			emit(ARM_LDRH_I(r0, r0, 0), ctx);
-			emit_rev16(r0, r0, ctx);
-			break;
-		case BPF_B:
-			emit(ARM_LDRB_I(r0, r0, 0), ctx);
-			/* No need to reverse */
-			break;
-		}
-		break;
-	}
 	/* ST: *(size *)(dst + off) = imm */
 	case BPF_ST | BPF_MEM | BPF_W:
 	case BPF_ST | BPF_MEM | BPF_H:
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v2 09/13] bpf, mips64: remove ld_abs/ld_ind
From: Daniel Borkmann @ 2018-05-03 23:08 UTC (permalink / raw)
  To: ast; +Cc: netdev, Daniel Borkmann
In-Reply-To: <20180503230824.3462-1-daniel@iogearbox.net>

Since LD_ABS/LD_IND instructions are now removed from the core and
reimplemented through a combination of inlined BPF instructions and
a slow-path helper, we can get rid of the complexity from mips64 JIT.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
---
 arch/mips/net/ebpf_jit.c | 104 -----------------------------------------------
 1 file changed, 104 deletions(-)

diff --git a/arch/mips/net/ebpf_jit.c b/arch/mips/net/ebpf_jit.c
index 3e2798b..7ba7df9 100644
--- a/arch/mips/net/ebpf_jit.c
+++ b/arch/mips/net/ebpf_jit.c
@@ -1267,110 +1267,6 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
 			return -EINVAL;
 		break;
 
-	case BPF_LD | BPF_B | BPF_ABS:
-	case BPF_LD | BPF_H | BPF_ABS:
-	case BPF_LD | BPF_W | BPF_ABS:
-	case BPF_LD | BPF_DW | BPF_ABS:
-		ctx->flags |= EBPF_SAVE_RA;
-
-		gen_imm_to_reg(insn, MIPS_R_A1, ctx);
-		emit_instr(ctx, addiu, MIPS_R_A2, MIPS_R_ZERO, size_to_len(insn));
-
-		if (insn->imm < 0) {
-			emit_const_to_reg(ctx, MIPS_R_T9, (u64)bpf_internal_load_pointer_neg_helper);
-		} else {
-			emit_const_to_reg(ctx, MIPS_R_T9, (u64)ool_skb_header_pointer);
-			emit_instr(ctx, daddiu, MIPS_R_A3, MIPS_R_SP, ctx->tmp_offset);
-		}
-		goto ld_skb_common;
-
-	case BPF_LD | BPF_B | BPF_IND:
-	case BPF_LD | BPF_H | BPF_IND:
-	case BPF_LD | BPF_W | BPF_IND:
-	case BPF_LD | BPF_DW | BPF_IND:
-		ctx->flags |= EBPF_SAVE_RA;
-		src = ebpf_to_mips_reg(ctx, insn, src_reg_no_fp);
-		if (src < 0)
-			return src;
-		ts = get_reg_val_type(ctx, this_idx, insn->src_reg);
-		if (ts == REG_32BIT_ZERO_EX) {
-			/* sign extend */
-			emit_instr(ctx, sll, MIPS_R_A1, src, 0);
-			src = MIPS_R_A1;
-		}
-		if (insn->imm >= S16_MIN && insn->imm <= S16_MAX) {
-			emit_instr(ctx, daddiu, MIPS_R_A1, src, insn->imm);
-		} else {
-			gen_imm_to_reg(insn, MIPS_R_AT, ctx);
-			emit_instr(ctx, daddu, MIPS_R_A1, MIPS_R_AT, src);
-		}
-		/* truncate to 32-bit int */
-		emit_instr(ctx, sll, MIPS_R_A1, MIPS_R_A1, 0);
-		emit_instr(ctx, daddiu, MIPS_R_A3, MIPS_R_SP, ctx->tmp_offset);
-		emit_instr(ctx, slt, MIPS_R_AT, MIPS_R_A1, MIPS_R_ZERO);
-
-		emit_const_to_reg(ctx, MIPS_R_T8, (u64)bpf_internal_load_pointer_neg_helper);
-		emit_const_to_reg(ctx, MIPS_R_T9, (u64)ool_skb_header_pointer);
-		emit_instr(ctx, addiu, MIPS_R_A2, MIPS_R_ZERO, size_to_len(insn));
-		emit_instr(ctx, movn, MIPS_R_T9, MIPS_R_T8, MIPS_R_AT);
-
-ld_skb_common:
-		emit_instr(ctx, jalr, MIPS_R_RA, MIPS_R_T9);
-		/* delay slot move */
-		emit_instr(ctx, daddu, MIPS_R_A0, MIPS_R_S0, MIPS_R_ZERO);
-
-		/* Check the error value */
-		b_off = b_imm(exit_idx, ctx);
-		if (is_bad_offset(b_off)) {
-			target = j_target(ctx, exit_idx);
-			if (target == (unsigned int)-1)
-				return -E2BIG;
-
-			if (!(ctx->offsets[this_idx] & OFFSETS_B_CONV)) {
-				ctx->offsets[this_idx] |= OFFSETS_B_CONV;
-				ctx->long_b_conversion = 1;
-			}
-			emit_instr(ctx, bne, MIPS_R_V0, MIPS_R_ZERO, 4 * 3);
-			emit_instr(ctx, nop);
-			emit_instr(ctx, j, target);
-			emit_instr(ctx, nop);
-		} else {
-			emit_instr(ctx, beq, MIPS_R_V0, MIPS_R_ZERO, b_off);
-			emit_instr(ctx, nop);
-		}
-
-#ifdef __BIG_ENDIAN
-		need_swap = false;
-#else
-		need_swap = true;
-#endif
-		dst = MIPS_R_V0;
-		switch (BPF_SIZE(insn->code)) {
-		case BPF_B:
-			emit_instr(ctx, lbu, dst, 0, MIPS_R_V0);
-			break;
-		case BPF_H:
-			emit_instr(ctx, lhu, dst, 0, MIPS_R_V0);
-			if (need_swap)
-				emit_instr(ctx, wsbh, dst, dst);
-			break;
-		case BPF_W:
-			emit_instr(ctx, lw, dst, 0, MIPS_R_V0);
-			if (need_swap) {
-				emit_instr(ctx, wsbh, dst, dst);
-				emit_instr(ctx, rotr, dst, dst, 16);
-			}
-			break;
-		case BPF_DW:
-			emit_instr(ctx, ld, dst, 0, MIPS_R_V0);
-			if (need_swap) {
-				emit_instr(ctx, dsbh, dst, dst);
-				emit_instr(ctx, dshd, dst, dst);
-			}
-			break;
-		}
-
-		break;
 	case BPF_ALU | BPF_END | BPF_FROM_BE:
 	case BPF_ALU | BPF_END | BPF_FROM_LE:
 		dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
-- 
2.9.5

^ permalink raw reply related


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