From: Feng zhou <zhoufeng.zf@bytedance.com>
To: martin.lau@linux.dev, ast@kernel.org, daniel@iogearbox.net,
andrii@kernel.org, song@kernel.org, yhs@fb.com,
john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
haoluo@google.com, jolsa@kernel.org, davem@davemloft.net,
edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
mykolal@fb.com, shuah@kernel.org
Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, linux-kselftest@vger.kernel.org,
yangzhenze@bytedance.com, wangdongdong.6@bytedance.com,
zhouchengming@bytedance.com, zhoufeng.zf@bytedance.com
Subject: [PATCH bpf-next v2 1/2] bpf: support access variable length array of integer type
Date: Thu, 20 Apr 2023 11:27:34 +0800 [thread overview]
Message-ID: <20230420032735.27760-2-zhoufeng.zf@bytedance.com> (raw)
In-Reply-To: <20230420032735.27760-1-zhoufeng.zf@bytedance.com>
From: Feng Zhou <zhoufeng.zf@bytedance.com>
After this commit:
bpf: Support variable length array in tracing programs (9c5f8a1008a1)
Trace programs can access variable length array, but for structure
type. This patch adds support for integer type.
Example:
Hook load_balance
struct sched_domain {
...
unsigned long span[];
}
The access: sd->span[0].
Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com>
---
kernel/bpf/btf.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 027f9f8a3551..a0887ee44e89 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -6157,11 +6157,13 @@ static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf,
if (off < moff)
goto error;
- /* Only allow structure for now, can be relaxed for
- * other types later.
- */
+ /* allow structure and integer */
t = btf_type_skip_modifiers(btf, array_elem->type,
NULL);
+
+ if (btf_type_is_int(t))
+ return WALK_SCALAR;
+
if (!btf_type_is_struct(t))
goto error;
--
2.20.1
next prev parent reply other threads:[~2023-04-20 3:28 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-20 3:27 [PATCH bpf-next v2 0/2] Access variable length array relaxed for integer type Feng zhou
2023-04-20 3:27 ` Feng zhou [this message]
2023-04-20 3:27 ` [PATCH bpf-next v2 2/2] selftests/bpf: Add test to access integer type of variable array Feng zhou
2023-04-20 4:40 ` [PATCH bpf-next v2 0/2] Access variable length array relaxed for integer type patchwork-bot+netdevbpf
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