Commit 6690523b authored by Joe Stringer's avatar Joe Stringer Committed by Alexei Starovoitov
Browse files

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 96049f3a ("bpf: introduce BPF_F_LOCK
flag").

Signed-off-by: default avatarJoe Stringer <joe@cilium.io>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Reviewed-by: default avatarQuentin Monnet <quentin@isovalent.com>
Acked-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210302171947.2268128-4-joe@cilium.io
parent f67c9cbf

include/uapi/linux/bpf.h

+10 −0
Original line number Diff line number Diff line
@@ -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*