diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2024-01-23 18:21:02 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-01-24 16:21:01 -0800 |
| commit | 9ea7c4bf17e39d463eb4782f948f401d9764b1b3 (patch) | |
| tree | 9cf0cc9d7b7ceb2ec8b7b2fe37baa0b5ce0bd30c | |
| parent | a177fc2bf6fd83704854feaf7aae926b1df4f0b9 (diff) | |
bpf: Add BPF token support to BPF_BTF_LOAD command
Accept BPF token FD in BPF_BTF_LOAD command to allow BTF data loading
through delegated BPF token. BPF_F_TOKEN_FD flag has to be specified
when passing BPF token FD. Given BPF_BTF_LOAD command didn't have flags
field before, we also add btf_flags field.
BTF loading is a pretty straightforward operation, so as long as BPF
token is created with allow_cmds granting BPF_BTF_LOAD command, kernel
proceeds to parsing BTF data and creating BTF object.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-6-andrii@kernel.org
| -rw-r--r-- | include/uapi/linux/bpf.h | 5 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 23 | ||||
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 5 |
3 files changed, 31 insertions, 2 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index c78cab8b462d..cb2c888e3bb4 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1632,6 +1632,11 @@ union bpf_attr { * truncated), or smaller (if log buffer wasn't filled completely). */ __u32 btf_log_true_size; + __u32 btf_flags; + /* BPF token FD to use with BPF_BTF_LOAD operation. + * If provided, btf_flags should have BPF_F_TOKEN_FD flag set. + */ + __s32 btf_token_fd; }; struct { diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index b13a4bdcd3a0..45b3a55896eb 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -4831,15 +4831,34 @@ static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, return err; } -#define BPF_BTF_LOAD_LAST_FIELD btf_log_true_size +#define BPF_BTF_LOAD_LAST_FIELD btf_token_fd static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size) { + struct bpf_token *token = NULL; + if (CHECK_ATTR(BPF_BTF_LOAD)) return -EINVAL; - if (!bpf_capable()) + if (attr->btf_flags & ~BPF_F_TOKEN_FD) + return -EINVAL; + + if (attr->btf_flags & BPF_F_TOKEN_FD) { + token = bpf_token_get_from_fd(attr->btf_token_fd); + if (IS_ERR(token)) + return PTR_ERR(token); + if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) { + bpf_token_put(token); + token = NULL; + } + } + + if (!bpf_token_capable(token, CAP_BPF)) { + bpf_token_put(token); return -EPERM; + } + + bpf_token_put(token); return btf_new_fd(attr, uattr, uattr_size); } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index c78cab8b462d..cb2c888e3bb4 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1632,6 +1632,11 @@ union bpf_attr { * truncated), or smaller (if log buffer wasn't filled completely). */ __u32 btf_log_true_size; + __u32 btf_flags; + /* BPF token FD to use with BPF_BTF_LOAD operation. + * If provided, btf_flags should have BPF_F_TOKEN_FD flag set. + */ + __s32 btf_token_fd; }; struct { |