From: Hao Luo <haoluo@google.com>
To: linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
cgroups@vger.kernel.org, netdev@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <martin.lau@linux.dev>,
Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
Tejun Heo <tj@kernel.org>, Zefan Li <lizefan.x@bytedance.com>,
KP Singh <kpsingh@kernel.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Benjamin Tissoires <benjamin.tissoires@redhat.com>,
John Fastabend <john.fastabend@gmail.com>,
Michal Koutny <mkoutny@suse.com>,
Roman Gushchin <roman.gushchin@linux.dev>,
David Rientjes <rientjes@google.com>,
Stanislav Fomichev <sdf@google.com>,
Shakeel Butt <shakeelb@google.com>,
Yosry Ahmed <yosryahmed@google.com>, Hao Luo <haoluo@google.com>
Subject: [PATCH bpf-next v7 3/8] bpf, iter: Fix the condition on p when calling stop.
Date: Fri, 5 Aug 2022 14:48:16 -0700 [thread overview]
Message-ID: <20220805214821.1058337-4-haoluo@google.com> (raw)
In-Reply-To: <20220805214821.1058337-1-haoluo@google.com>
In bpf_seq_read, seq->op->next() could return an ERR and jump to
the label stop. However, the existing code in stop does not handle
the case when p (returned from next()) is an ERR. Adds the handling
of ERR of p by converting p into an error and jumping to done.
Because all the current implementations do not have a case that
returns ERR from next(), so this patch doesn't have behavior changes
right now.
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Hao Luo <haoluo@google.com>
---
kernel/bpf/bpf_iter.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
index 7e8fd49406f6..4688ba39ef25 100644
--- a/kernel/bpf/bpf_iter.c
+++ b/kernel/bpf/bpf_iter.c
@@ -198,6 +198,11 @@ static ssize_t bpf_seq_read(struct file *file, char __user *buf, size_t size,
}
stop:
offs = seq->count;
+ if (IS_ERR(p)) {
+ seq->op->stop(seq, NULL);
+ err = PTR_ERR(p);
+ goto done;
+ }
/* bpf program called if !p */
seq->op->stop(seq, p);
if (!p) {
--
2.37.1.559.g78731f0fdb-goog
next prev parent reply other threads:[~2022-08-05 21:49 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-05 21:48 [PATCH bpf-next v7 0/8] bpf: rstat: cgroup hierarchical stats Hao Luo
2022-08-05 21:48 ` [PATCH bpf-next v7 1/8] btf: Add a new kfunc flag which allows to mark a function to be sleepable Hao Luo
2022-08-05 21:48 ` [PATCH bpf-next v7 2/8] cgroup: enable cgroup_get_from_file() on cgroup1 Hao Luo
2022-08-05 21:48 ` Hao Luo [this message]
2022-08-05 21:48 ` [PATCH bpf-next v7 4/8] bpf: Introduce cgroup iter Hao Luo
2022-08-09 0:18 ` Andrii Nakryiko
2022-08-09 0:56 ` Hao Luo
2022-08-09 16:23 ` Alexei Starovoitov
2022-08-09 18:38 ` Hao Luo
2022-08-11 3:10 ` Hao Luo
2022-08-11 14:09 ` Yosry Ahmed
2022-08-16 4:12 ` Andrii Nakryiko
2022-08-16 4:19 ` Andrii Nakryiko
2022-08-16 6:52 ` Hao Luo
2022-08-16 17:17 ` Andrii Nakryiko
2022-08-16 17:22 ` Hao Luo
2022-08-05 21:48 ` [PATCH bpf-next v7 5/8] selftests/bpf: Test cgroup_iter Hao Luo
2022-08-09 0:20 ` Andrii Nakryiko
2022-08-09 1:18 ` Hao Luo
2022-08-05 21:48 ` [PATCH bpf-next v7 6/8] cgroup: bpf: enable bpf programs to integrate with rstat Hao Luo
2022-08-05 21:48 ` [PATCH bpf-next v7 7/8] selftests/bpf: extend cgroup helpers Hao Luo
2022-08-05 21:48 ` [PATCH bpf-next v7 8/8] selftests/bpf: add a selftest for cgroup hierarchical stats collection Hao Luo
2022-08-09 16:20 ` [PATCH bpf-next v7 0/8] bpf: rstat: cgroup hierarchical stats patchwork-bot+netdevbpf
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