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authorKui-Feng Lee <thinker.li@gmail.com>2024-01-19 14:49:57 -0800
committerMartin KaFai Lau <martin.lau@kernel.org>2024-01-23 16:37:44 -0800
commit1338b93346587a2a6ac79bbcf55ef5b357745573 (patch)
tree3200810e4d2c138d8ecec7ab4303446db88a1bf7
parent47f4f657acd5d04c78c5c5ac7022cba9ce3b4a7d (diff)
bpf: pass btf object id in bpf_map_info.
Include btf object id (btf_obj_id) in bpf_map_info so that tools (ex: bpftools struct_ops dump) know the correct btf from the kernel to look up type information of struct_ops types. Since struct_ops types can be defined and registered in a module. The type information of a struct_ops type are defined in the btf of the module defining it. The userspace tools need to know which btf is for the module defining a struct_ops type. Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Link: https://lore.kernel.org/r/20240119225005.668602-7-thinker.li@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
-rw-r--r--include/linux/bpf.h4
-rw-r--r--include/uapi/linux/bpf.h2
-rw-r--r--kernel/bpf/bpf_struct_ops.c7
-rw-r--r--kernel/bpf/syscall.c2
-rw-r--r--tools/include/uapi/linux/bpf.h2
5 files changed, 15 insertions, 2 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 7fc95e7babab..29fcae9fa8ed 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1732,6 +1732,7 @@ struct bpf_dummy_ops {
int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr,
union bpf_attr __user *uattr);
#endif
+void bpf_map_struct_ops_info_fill(struct bpf_map_info *info, struct bpf_map *map);
#else
static inline const struct bpf_struct_ops_desc *bpf_struct_ops_find(u32 type_id)
{
@@ -1759,6 +1760,9 @@ static inline int bpf_struct_ops_link_create(union bpf_attr *attr)
{
return -EOPNOTSUPP;
}
+static inline void bpf_map_struct_ops_info_fill(struct bpf_map_info *info, struct bpf_map *map)
+{
+}
#endif
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 287d05732668..a380047c86af 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -6487,7 +6487,7 @@ struct bpf_map_info {
__u32 btf_id;
__u32 btf_key_type_id;
__u32 btf_value_type_id;
- __u32 :32; /* alignment pad */
+ __u32 btf_vmlinux_id;
__u64 map_extra;
} __attribute__((aligned(8)));
diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index 5ddcca4c4fba..5e98af4fc2e2 100644
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -947,3 +947,10 @@ err_out:
kfree(link);
return err;
}
+
+void bpf_map_struct_ops_info_fill(struct bpf_map_info *info, struct bpf_map *map)
+{
+ struct bpf_struct_ops_map *st_map = (struct bpf_struct_ops_map *)map;
+
+ info->btf_vmlinux_id = btf_obj_id(st_map->btf);
+}
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 13193aaafb64..55b458429705 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -4691,6 +4691,8 @@ static int bpf_map_get_info_by_fd(struct file *file,
info.btf_value_type_id = map->btf_value_type_id;
}
info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
+ if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS)
+ bpf_map_struct_ops_info_fill(&info, map);
if (bpf_map_is_offloaded(map)) {
err = bpf_map_offload_info_fill(&info, map);
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 287d05732668..a380047c86af 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -6487,7 +6487,7 @@ struct bpf_map_info {
__u32 btf_id;
__u32 btf_key_type_id;
__u32 btf_value_type_id;
- __u32 :32; /* alignment pad */
+ __u32 btf_vmlinux_id;
__u64 map_extra;
} __attribute__((aligned(8)));