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From:   Florent Revest <revest@chromium.org>
To:     bpf@vger.kernel.org
Cc:     viro@zeniv.linux.org.uk, davem@davemloft.net, kuba@kernel.org,
        ast@kernel.org, daniel@iogearbox.net, kafai@fb.com, yhs@fb.com,
        andrii@kernel.org, kpsingh@chromium.org, revest@google.com,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: [PATCH v2 3/5] bpf: Expose bpf_sk_storage_* to iterator programs
Date:   Thu, 19 Nov 2020 17:26:52 +0100
Message-Id: <20201119162654.2410685-3-revest@chromium.org>
In-Reply-To: <20201119162654.2410685-1-revest@chromium.org>
References: <20201119162654.2410685-1-revest@chromium.org>
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From: Florent Revest <revest@google.com>

Iterators are currently used to expose kernel information to userspace
over fast procfs-like files but iterators could also be used to
manipulate local storage. For example, the task_file iterator could be
used to initialize a socket local storage with associations between
processes and sockets or to selectively delete local storage values.

This exposes both socket local storage helpers to all iterators.
Alternatively we could expose it to only certain iterators with strcmps
on prog->aux->attach_func_name.

Signed-off-by: Florent Revest <revest@google.com>
---
 net/core/bpf_sk_storage.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index a32037daa933..4edd033e899c 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -394,6 +394,7 @@ static bool bpf_sk_storage_tracing_allowed(const struct bpf_prog *prog)
 	 * use the bpf_sk_storage_(get|delete) helper.
 	 */
 	switch (prog->expected_attach_type) {
+	case BPF_TRACE_ITER:
 	case BPF_TRACE_RAW_TP:
 		/* bpf_sk_storage has no trace point */
 		return true;
-- 
2.29.2.299.gdc1121823c-goog