From: Yosry Ahmed <yosryahmed@google.com>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>, Hao Luo <haoluo@google.com>,
Tejun Heo <tj@kernel.org>, Zefan Li <lizefan.x@bytedance.com>
Cc: "Johannes Weiner" <hannes@cmpxchg.org>,
"Shuah Khan" <shuah@kernel.org>,
"Michal Hocko" <mhocko@kernel.org>,
"KP Singh" <kpsingh@kernel.org>,
"Benjamin Tissoires" <benjamin.tissoires@redhat.com>,
"John Fastabend" <john.fastabend@gmail.com>,
"Michal Koutný" <mkoutny@suse.com>,
"Roman Gushchin" <roman.gushchin@linux.dev>,
"David Rientjes" <rientjes@google.com>,
"Stanislav Fomichev" <sdf@google.com>,
"Greg Thelen" <gthelen@google.com>,
"Shakeel Butt" <shakeelb@google.com>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
bpf@vger.kernel.org, cgroups@vger.kernel.org,
"Yosry Ahmed" <yosryahmed@google.com>
Subject: [PATCH bpf-next v4 3/8] bpf, iter: Fix the condition on p when calling stop.
Date: Fri, 22 Jul 2022 02:13:08 +0000 [thread overview]
Message-ID: <20220722021313.3150035-4-yosryahmed@google.com> (raw)
In-Reply-To: <20220722021313.3150035-1-yosryahmed@google.com>
From: Hao Luo <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.
Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Yonghong Song <yhs@fb.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) {
--
2.37.1.359.gd136c6c3e2-goog
next prev parent reply other threads:[~2022-07-22 2:13 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-22 2:13 [PATCH bpf-next v4 0/8] bpf: rstat: cgroup hierarchical stats Yosry Ahmed
2022-07-22 2:13 ` [PATCH bpf-next v4 1/8] btf: Add a new kfunc set which allows to mark a function to be sleepable Yosry Ahmed
2022-07-22 16:20 ` Alexei Starovoitov
2022-07-22 17:49 ` Yosry Ahmed
2022-07-22 2:13 ` [PATCH bpf-next v4 2/8] cgroup: enable cgroup_get_from_file() on cgroup1 Yosry Ahmed
2022-07-22 2:13 ` Yosry Ahmed [this message]
2022-07-22 2:13 ` [PATCH bpf-next v4 4/8] bpf: Introduce cgroup iter Yosry Ahmed
2022-07-22 2:13 ` [PATCH bpf-next v4 5/8] selftests/bpf: Test cgroup_iter Yosry Ahmed
2022-07-22 2:13 ` [PATCH bpf-next v4 6/8] cgroup: bpf: enable bpf programs to integrate with rstat Yosry Ahmed
2022-07-22 2:13 ` [PATCH bpf-next v4 7/8] selftests/bpf: extend cgroup helpers Yosry Ahmed
2022-07-22 2:13 ` [PATCH bpf-next v4 8/8] bpf: add a selftest for cgroup hierarchical stats collection Yosry Ahmed
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