On 3/7/25 1:29 PM, Mykyta Yatsenko wrote:
From: Mykyta Yatsenko <yatsenko@xxxxxxxx>
Pass BPF token from bpf_program__set_attach_target to
BPF_BTF_GET_FD_BY_ID bpf command.
When freplace program attaches to target program, it needs to look up
for BTF of the target, this may require BPF token, if, for example,
running from user namespace.
LGTM with small nit below.
Acked-by: Yonghong Song <yonghong.song@xxxxxxxxx>
Signed-off-by: Mykyta Yatsenko <yatsenko@xxxxxxxx>
---
tools/lib/bpf/bpf.c | 3 ++-
tools/lib/bpf/bpf.h | 4 +++-
tools/lib/bpf/btf.c | 14 ++++++++++++--
tools/lib/bpf/libbpf.c | 10 +++++-----
tools/lib/bpf/libbpf_internal.h | 1 +
5 files changed, 23 insertions(+), 9 deletions(-)
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 359f73ead613..783274172e56 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -1097,7 +1097,7 @@ int bpf_map_get_fd_by_id(__u32 id)
int bpf_btf_get_fd_by_id_opts(__u32 id,
const struct bpf_get_fd_by_id_opts *opts)
{
- const size_t attr_sz = offsetofend(union bpf_attr, open_flags);
+ const size_t attr_sz = offsetofend(union bpf_attr, token_fd);
union bpf_attr attr;
int fd;
@@ -1107,6 +1107,7 @@ int bpf_btf_get_fd_by_id_opts(__u32 id,
memset(&attr, 0, attr_sz);
attr.btf_id = id;
attr.open_flags = OPTS_GET(opts, open_flags, 0);
+ attr.token_fd = OPTS_GET(opts, token_fd, 0);
fd = sys_bpf_fd(BPF_BTF_GET_FD_BY_ID, &attr, attr_sz);
return libbpf_err_errno(fd);
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 435da95d2058..544215d7137c 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -487,9 +487,11 @@ LIBBPF_API int bpf_link_get_next_id(__u32 start_id, __u32 *next_id);
struct bpf_get_fd_by_id_opts {
size_t sz; /* size of this struct for forward/backward compatibility */
__u32 open_flags; /* permissions requested for the operation on fd */
+ __u32 token_fd;
size_t :0;
};
-#define bpf_get_fd_by_id_opts__last_field open_flags
+
+#define bpf_get_fd_by_id_opts__last_field token_fd
LIBBPF_API int bpf_prog_get_fd_by_id(__u32 id);
LIBBPF_API int bpf_prog_get_fd_by_id_opts(__u32 id,
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index eea99c766a20..466336f16134 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -1619,12 +1619,17 @@ struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf)
return btf;
}
-struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf)
+struct btf *btf_load_from_kernel(__u32 id, struct btf *base_btf, int token_fd)
{
struct btf *btf;
int btf_fd;
+ LIBBPF_OPTS(bpf_get_fd_by_id_opts, opts);
+
+ opts.token_fd = token_fd;
+ if (token_fd)
+ opts.open_flags |= BPF_F_TOKEN_FD;
To 'move opts.token_fd = token_fd' under if condition? Something like
if (token_fd) {
opts.open_flags |= BPF_F_TOKEN_FD;
opts.token_fd = token_fd;
}
?
- btf_fd = bpf_btf_get_fd_by_id(id);
+ btf_fd = bpf_btf_get_fd_by_id_opts(id, &opts);
if (btf_fd < 0)
return libbpf_err_ptr(-errno);
[...]
