On 9/29/20 9:00 PM, Alexei Starovoitov wrote:
On Tue, Sep 29, 2020 at 04:02:10PM +0200, Daniel Borkmann wrote:
+
+/* Share perf_event among processes */
+ BPF_F_SHARE_PE = (1U << 11),
nit but given UAPI: maybe name into something more self-descriptive
like BPF_F_SHAREABLE_EVENT ?
I'm not happy with either name.
It's not about sharing and not really about perf event.
I think the current behavior of perf_event_array is unusual and surprising.
Sadly we cannot fix it without breaking user space, so flag is needed.
How about BPF_F_STICKY_OBJECTS or BPF_F_PRESERVE_OBJECTS
or the same with s/OBJECTS/FILES/ ?
Sounds good to me, BPF_F_PRESERVE_OBJECTS or _ENTRIES seems reasonable.
+static void perf_event_fd_array_map_free(struct bpf_map *map)
+{
+ struct bpf_event_entry *ee;
+ struct bpf_array *array;
+ int i;
+
+ if ((map->map_flags & BPF_F_SHARE_PE) == 0) {
+ fd_array_map_free(map);
+ return;
+ }
+
+ array = container_of(map, struct bpf_array, map);
+ for (i = 0; i < array->map.max_entries; i++) {
+ ee = READ_ONCE(array->ptrs[i]);
+ if (ee)
+ fd_array_map_delete_elem(map, &i);
+ }
+ bpf_map_area_free(array);
Why not simplify into:
if (map->map_flags & BPF_F_SHAREABLE_EVENT)
bpf_fd_array_map_clear(map);
fd_array_map_free(map);
+1
+}
+
static void *prog_fd_array_get_ptr(struct bpf_map *map,
struct file *map_file, int fd)
{
@@ -1134,6 +1158,9 @@ static void perf_event_fd_array_release(struct bpf_map *map,
struct bpf_event_entry *ee;
int i;
add empty line pls.
+ if (map->map_flags & BPF_F_SHARE_PE)
+ return;
+
