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From: Florian Lehner <dev@der-flo.net>
To: bpf@vger.kernel.org
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
	martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org,
	yonghong.song@linux.dev, john.fastabend@gmail.com,
	kpsingh@kernel.org, sdf@google.com, haoluo@google.com,
	jolsa@kernel.org, Florian Lehner <dev@der-flo.net>
Subject: [PATCH bpf-next] bpf: Return EINVAL instead of NULL for map_lookup_elem of queue
Date: Sat,  8 Jun 2024 11:29:12 +0200	[thread overview]
Message-ID: <20240608092912.11615-1-dev@der-flo.net> (raw)

Programs should use map_peek_elem over map_lookup_elem for queues. NULL is
also not a valid queue return nor a proper error, that could be handled.

Signed-off-by: Florian Lehner <dev@der-flo.net>
---
 kernel/bpf/queue_stack_maps.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/bpf/queue_stack_maps.c b/kernel/bpf/queue_stack_maps.c
index d869f51ea93a..85bead55024d 100644
--- a/kernel/bpf/queue_stack_maps.c
+++ b/kernel/bpf/queue_stack_maps.c
@@ -234,7 +234,8 @@ static long queue_stack_map_push_elem(struct bpf_map *map, void *value,
 /* Called from syscall or from eBPF program */
 static void *queue_stack_map_lookup_elem(struct bpf_map *map, void *key)
 {
-	return NULL;
+	/* The eBPF program should use map_peek_elem instead */
+	return ERR_PTR(-EINVAL);
 }
 
 /* Called from syscall or from eBPF program */
-- 
2.45.2


             reply	other threads:[~2024-06-08  9:35 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-06-08  9:29 Florian Lehner [this message]
2024-06-10  5:32 ` [PATCH bpf-next] bpf: Return EINVAL instead of NULL for map_lookup_elem of queue Yonghong Song
2024-06-11 19:14 ` Alexei Starovoitov

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