From: Yonghong Song yhs@fb.com
mainline inclusion from mainline-v4.20-rc1 commit a7c19db38d62fc1ce797dba19936e9f81cf2b9fb category: feature bugzilla: 43460 CVE: NA
--------------------------------------- Added bpffs pretty print for program array map. For a particular array index, if the program array points to a valid program, the "<index>: <prog_id>" will be printed out like 0: 6 which means bpf program with id "6" is installed at index "0".
Signed-off-by: Yonghong Song yhs@fb.com Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: liuxin liuxin264@huawei.com Reviewed-by: Cheng Jian cj.chengjian@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- kernel/bpf/arraymap.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index f9d24121be99..dded84cbe814 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -553,6 +553,29 @@ static void bpf_fd_array_map_clear(struct bpf_map *map) fd_array_map_delete_elem(map, &i); }
+static void prog_array_map_seq_show_elem(struct bpf_map *map, void *key, + struct seq_file *m) +{ + void **elem, *ptr; + u32 prog_id; + + rcu_read_lock(); + + elem = array_map_lookup_elem(map, key); + if (elem) { + ptr = READ_ONCE(*elem); + if (ptr) { + seq_printf(m, "%u: ", *(u32 *)key); + prog_id = prog_fd_array_sys_lookup_elem(ptr); + btf_type_seq_show(map->btf, map->btf_value_type_id, + &prog_id, m); + seq_puts(m, "\n"); + } + } + + rcu_read_unlock(); +} + const struct bpf_map_ops prog_array_map_ops = { .map_alloc_check = fd_array_map_alloc_check, .map_alloc = array_map_alloc, @@ -564,7 +587,7 @@ const struct bpf_map_ops prog_array_map_ops = { .map_fd_put_ptr = prog_fd_array_put_ptr, .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem, .map_release_uref = bpf_fd_array_map_clear, - .map_check_btf = map_check_no_btf, + .map_seq_show_elem = prog_array_map_seq_show_elem, };
static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file,