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From: Martin KaFai Lau <kafai@fb.com>
To: <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	David Miller <davem@davemloft.net>, <kernel-team@fb.com>,
	<netdev@vger.kernel.org>
Subject: [PATCH bpf-next v2 04/11] bpf: Support bitfield read access in btf_struct_access
Date: Fri, 20 Dec 2019 22:26:04 -0800	[thread overview]
Message-ID: <20191221062604.1182843-1-kafai@fb.com> (raw)
In-Reply-To: <20191221062556.1182261-1-kafai@fb.com>

This patch allows bitfield access as a scalar.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
---
 kernel/bpf/btf.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 6e652643849b..da73b63acfc5 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -3744,10 +3744,6 @@ int btf_struct_access(struct bpf_verifier_log *log,
 	}
 
 	for_each_member(i, t, member) {
-		if (btf_member_bitfield_size(t, member))
-			/* bitfields are not supported yet */
-			continue;
-
 		/* offset of the field in bytes */
 		moff = btf_member_bit_offset(t, member) / 8;
 		if (off + size <= moff)
@@ -3757,6 +3753,12 @@ int btf_struct_access(struct bpf_verifier_log *log,
 		if (off < moff)
 			continue;
 
+		if (btf_member_bitfield_size(t, member)) {
+			if (off == moff && off + size <= t->size)
+				return SCALAR_VALUE;
+			continue;
+		}
+
 		/* type of the field */
 		mtype = btf_type_by_id(btf_vmlinux, member->type);
 		mname = __btf_name_by_offset(btf_vmlinux, member->name_off);
-- 
2.17.1


  parent reply	other threads:[~2019-12-21  6:26 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-21  6:25 [PATCH bpf-next v2 00/11] Introduce BPF STRUCT_OPS Martin KaFai Lau
2019-12-21  6:25 ` [PATCH bpf-next v2 01/11] bpf: Save PTR_TO_BTF_ID register state when spilling to stack Martin KaFai Lau
2019-12-21  6:25 ` [PATCH bpf-next v2 02/11] bpf: Avoid storing modifier to info->btf_id Martin KaFai Lau
2019-12-21  6:26 ` [PATCH bpf-next v2 03/11] bpf: Add enum support to btf_ctx_access() Martin KaFai Lau
2019-12-21  6:26 ` Martin KaFai Lau [this message]
2019-12-23  7:49   ` [PATCH bpf-next v2 04/11] bpf: Support bitfield read access in btf_struct_access Yonghong Song
2019-12-23 20:05   ` Andrii Nakryiko
2019-12-23 21:21     ` Yonghong Song
2019-12-21  6:26 ` [PATCH bpf-next v2 05/11] bpf: Introduce BPF_PROG_TYPE_STRUCT_OPS Martin KaFai Lau
2019-12-23 19:33   ` Yonghong Song
2019-12-23 20:29   ` Andrii Nakryiko
2019-12-23 22:29     ` Martin Lau
2019-12-23 22:55       ` Andrii Nakryiko
2019-12-24 11:46   ` kbuild test robot
2019-12-21  6:26 ` [PATCH bpf-next v2 06/11] bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS Martin KaFai Lau
2019-12-23 19:57   ` Yonghong Song
2019-12-23 21:44     ` Andrii Nakryiko
2019-12-23 22:15       ` Martin Lau
2019-12-27  6:16     ` Martin Lau
2019-12-23 23:05   ` Andrii Nakryiko
2019-12-28  1:47     ` Martin Lau
2019-12-28  2:24       ` Andrii Nakryiko
2019-12-28  5:16         ` Martin Lau
2019-12-24 12:28   ` kbuild test robot
2019-12-21  6:26 ` [PATCH bpf-next v2 07/11] bpf: tcp: Support tcp_congestion_ops in bpf Martin KaFai Lau
2019-12-23 20:18   ` Yonghong Song
2019-12-23 23:20   ` Andrii Nakryiko
2019-12-24  7:16   ` kbuild test robot
2019-12-24 13:06   ` kbuild test robot
2019-12-21  6:26 ` [PATCH bpf-next v2 08/11] bpf: Add BPF_FUNC_tcp_send_ack helper Martin KaFai Lau
2019-12-21  6:26 ` [PATCH bpf-next v2 09/11] bpf: Synch uapi bpf.h to tools/ Martin KaFai Lau
2019-12-21  6:26 ` [PATCH bpf-next v2 10/11] bpf: libbpf: Add STRUCT_OPS support Martin KaFai Lau
2019-12-23 19:54   ` Andrii Nakryiko
2019-12-26 22:47     ` Martin Lau
2019-12-21  6:26 ` [PATCH bpf-next v2 11/11] bpf: Add bpf_dctcp example Martin KaFai Lau
2019-12-23 23:26   ` Andrii Nakryiko
2019-12-24  1:31     ` Martin Lau
2019-12-24  7:01       ` Andrii Nakryiko
2019-12-24  7:32         ` Martin Lau
2019-12-24 16:50         ` Martin Lau
2019-12-26 19:02           ` Andrii Nakryiko
2019-12-26 20:25             ` Martin Lau
2019-12-26 20:48               ` Andrii Nakryiko
2019-12-26 22:20                 ` Martin Lau
2019-12-26 22:25                   ` Andrii Nakryiko

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