From: Yang Jihong <yangjihong1@huawei.com>
To: <ast@kernel.org>, <daniel@iogearbox.net>, <andrii@kernel.org>,
<martin.lau@linux.dev>, <song@kernel.org>, <yhs@fb.com>,
<john.fastabend@gmail.com>, <kpsingh@kernel.org>,
<sdf@google.com>, <haoluo@google.com>, <jolsa@kernel.org>,
<illusionist.neo@gmail.com>, <linux@armlinux.org.uk>,
<davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
<pabeni@redhat.com>, <mykolal@fb.com>, <shuah@kernel.org>,
<benjamin.tissoires@redhat.com>, <memxor@gmail.com>,
<delyank@fb.com>, <asavkov@redhat.com>, <colin.i.king@gmail.com>,
<bpf@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <netdev@vger.kernel.org>,
<linux-kselftest@vger.kernel.org>
Cc: <yangjihong1@huawei.com>
Subject: [PATCH 1/4] bpf: Adapt 32-bit return value kfunc for 32-bit ARM when zext extension
Date: Thu, 3 Nov 2022 16:32:51 +0800 [thread overview]
Message-ID: <20221103083254.237646-2-yangjihong1@huawei.com> (raw)
In-Reply-To: <20221103083254.237646-1-yangjihong1@huawei.com>
For ARM32 architecture, if data width of kfunc return value is 32 bits,
need to do explicit zero extension for high 32-bit, insn_def_regno should
return dst_reg for BPF_JMP type of BPF_PSEUDO_KFUNC_CALL. Otherwise,
opt_subreg_zext_lo32_rnd_hi32 returns -EFAULT, resulting in BPF failure.
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
---
kernel/bpf/verifier.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 7f0a9f6cb889..bac37757ffca 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2404,6 +2404,9 @@ static int insn_def_regno(const struct bpf_insn *insn)
{
switch (BPF_CLASS(insn->code)) {
case BPF_JMP:
+ if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL)
+ return insn->dst_reg;
+ fallthrough;
case BPF_JMP32:
case BPF_ST:
return -1;
--
2.30.GIT
next prev parent reply other threads:[~2022-11-03 8:36 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-03 8:32 [PATCH 0/4] bpf: Support kernel function call in 32-bit ARM Yang Jihong
2022-11-03 8:32 ` Yang Jihong [this message]
2022-11-03 8:32 ` [PATCH 2/4] bpf: Remove size check for sk in bpf_skb_is_valid_access for 32-bit architecture Yang Jihong
2022-11-04 21:56 ` Andrii Nakryiko
2022-11-04 23:32 ` Alexei Starovoitov
2022-11-08 1:07 ` Andrii Nakryiko
2022-11-08 2:28 ` Martin KaFai Lau
2022-11-03 8:32 ` [PATCH 3/4] bpf: Add kernel function call support in 32-bit ARM Yang Jihong
2022-11-03 8:32 ` [PATCH 4/4] bpf:selftests: Add kfunc_call test for mixing 32-bit and 64-bit parameters Yang Jihong
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