From: Joe Stringer Date: Tue, 2 Mar 2021 17:19:35 +0000 (-0800) Subject: bpf: Document BPF_F_LOCK in syscall commands X-Git-Tag: v5.13-rc1~94^2~619^2~12^2~12 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=6690523bccb3e44cfcc4b2c995767e6814046e34;p=linux-block.git bpf: Document BPF_F_LOCK in syscall commands 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 --- diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 052bbfe65f77..eb9f059f0569 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*