[PATCH v3 bpf-next 3/8] bpf: Remember BTF of inner maps.
From: Alexei Starovoitov <hidden>
Date: 2021-06-24 02:25:30
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
From: Alexei Starovoitov <ast@kernel.org>
BTF is required for 'struct bpf_timer' to be recognized inside map value.
The bpf timers are supported inside inner maps.
Remember 'struct btf *' in inner_map_meta to make it available
to the verifier in the sequence:
struct bpf_map *inner_map = bpf_map_lookup_elem(&outer_map, ...);
if (inner_map)
timer = bpf_map_lookup_elem(&inner_map, ...);
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
kernel/bpf/map_in_map.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c
index 2f961b941159..d737cff90922 100644
--- a/kernel/bpf/map_in_map.c
+++ b/kernel/bpf/map_in_map.c@@ -3,6 +3,7 @@ */ #include <linux/slab.h> #include <linux/bpf.h> +#include <linux/btf.h> #include "map_in_map.h"
@@ -51,6 +52,10 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) inner_map_meta->max_entries = inner_map->max_entries; inner_map_meta->spin_lock_off = inner_map->spin_lock_off; inner_map_meta->timer_off = inner_map->timer_off; + if (inner_map->btf) { + btf_get(inner_map->btf); + inner_map_meta->btf = inner_map->btf; + } /* Misc members not needed in bpf_map_meta_equal() check. */ inner_map_meta->ops = inner_map->ops;
@@ -66,6 +71,7 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) void bpf_map_meta_free(struct bpf_map *map_meta) { + btf_put(map_meta->btf); kfree(map_meta); }
--
2.30.2