From 6690523bccb3e44cfcc4b2c995767e6814046e34 Mon Sep 17 00:00:00 2001 From: Joe Stringer Date: Tue, 2 Mar 2021 09:19:35 -0800 Subject: [PATCH] bpf: Document BPF_F_LOCK in syscall commands MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Document the meaning of the BPF_F_LOCK flag for the map lookup/update descriptions. Based on commit 96049f3afd50 ("bpf: introduce BPF_F_LOCK flag"). Signed-off-by: Joe Stringer Signed-off-by: Alexei Starovoitov Reviewed-by: Quentin Monnet Acked-by: Toke Høiland-Jørgensen Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20210302171947.2268128-4-joe@cilium.io --- include/uapi/linux/bpf.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 052bbfe65f774..eb9f059f0569f 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -123,6 +123,14 @@ union bpf_iter_link_info { * Look up an element with a given *key* in the map referred to * by the file descriptor *map_fd*. * + * The *flags* argument may be specified as one of the + * following: + * + * **BPF_F_LOCK** + * Look up the value of a spin-locked map without + * returning the lock. This must be specified if the + * elements contain a spinlock. + * * Return * Returns zero on success. On error, -1 is returned and *errno* * is set appropriately. @@ -140,6 +148,8 @@ union bpf_iter_link_info { * Create a new element only if it did not exist. * **BPF_EXIST** * Update an existing element. + * **BPF_F_LOCK** + * Update a spin_lock-ed map element. * * Return * Returns zero on success. On error, -1 is returned and *errno* -- 2.30.2