Commit c0ba8611 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by Martin KaFai Lau
Browse files

net: skbuff: move the fields BPF cares about directly next to the offset marker 



To avoid more possible BPF dependencies with moving bitfields
around keep the fields BPF cares about right next to the offset
marker.

Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230321014115.997841-4-kuba@kernel.org


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent b94e032b

include/linux/skbuff.h

+9 −9
Original line number Diff line number Diff line
@@ -947,15 +947,15 @@ struct sk_buff { 
	/* private: */

	__u8			__mono_tc_offset[0];

	/* public: */

	__u8			remcsum_offload:1;

	__u8			csum_complete_sw:1;

	__u8			csum_level:2;

	__u8			dst_pending_confirm:1;

	__u8			mono_delivery_time:1;	/* See SKB_MONO_DELIVERY_TIME_MASK */

#ifdef CONFIG_NET_CLS_ACT

	__u8			tc_skip_classify:1;

	__u8			tc_at_ingress:1;	/* See TC_AT_INGRESS_MASK */

	__u8			tc_skip_classify:1;

#endif

	__u8			remcsum_offload:1;

	__u8			csum_complete_sw:1;

	__u8			csum_level:2;

	__u8			dst_pending_confirm:1;



	__u8			l4_hash:1;

	__u8			sw_hash:1;
@@ -1072,11 +1072,11 @@ struct sk_buff { 
 * around, you also must adapt these constants.

 */

#ifdef __BIG_ENDIAN_BITFIELD

#define TC_AT_INGRESS_MASK		(1 << 0)

#define SKB_MONO_DELIVERY_TIME_MASK	(1 << 2)

#define SKB_MONO_DELIVERY_TIME_MASK	(1 << 7)

#define TC_AT_INGRESS_MASK		(1 << 6)

#else

#define TC_AT_INGRESS_MASK		(1 << 7)

#define SKB_MONO_DELIVERY_TIME_MASK	(1 << 5)

#define SKB_MONO_DELIVERY_TIME_MASK	(1 << 0)

#define TC_AT_INGRESS_MASK		(1 << 1)

#endif

#define SKB_BF_MONO_TC_OFFSET		offsetof(struct sk_buff, __mono_tc_offset)

tools/testing/selftests/bpf/prog_tests/ctx_rewrite.c

+4 −4
Original line number Diff line number Diff line
@@ -69,15 +69,15 @@ static struct test_case test_cases[] = { 
	{

		N(SCHED_CLS, struct __sk_buff, tstamp),

		.read  = "r11 = *(u8 *)($ctx + sk_buff::__mono_tc_offset);"

			 "w11 &= 160;"

			 "if w11 != 0xa0 goto pc+2;"

			 "w11 &= 3;"

			 "if w11 != 0x3 goto pc+2;"

			 "$dst = 0;"

			 "goto pc+1;"

			 "$dst = *(u64 *)($ctx + sk_buff::tstamp);",

		.write = "r11 = *(u8 *)($ctx + sk_buff::__mono_tc_offset);"

			 "if w11 & 0x80 goto pc+1;"

			 "if w11 & 0x2 goto pc+1;"

			 "goto pc+2;"

			 "w11 &= -33;"

			 "w11 &= -2;"

			 "*(u8 *)($ctx + sk_buff::__mono_tc_offset) = r11;"

			 "*(u64 *)($ctx + sk_buff::tstamp) = $src;",

	},