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").
Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
Reviewed-by: Quentin Monnet <quentin@xxxxxxxxxxxxx>
Signed-off-by: Joe Stringer <joe@xxxxxxxxx>
---
CC: Alexei Starovoitov <ast@xxxxxxxxxx>
---
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 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*
--
2.27.0
