summaryrefslogtreecommitdiff
path: root/kernel/bpf/btf.c
diff options
context:
space:
mode:
authorMartin KaFai Lau <kafai@fb.com>2018-05-04 14:49:52 -0700
committerDaniel Borkmann <daniel@iogearbox.net>2018-05-09 17:25:13 +0200
commit62dab84c81a487d946a5fc37c6df541dd95cca38 (patch)
treebcfa804c58e189bf89226ed0c7afa1e23dfeb24c /kernel/bpf/btf.c
parent78958fca7ead2f81b60a6827881c4866d1ed0c52 (diff)
bpf: btf: Add struct bpf_btf_info
During BPF_OBJ_GET_INFO_BY_FD on a btf_fd, the current bpf_attr's info.info is directly filled with the BTF binary data. It is not extensible. In this case, we want to add BTF ID. This patch adds "struct bpf_btf_info" which has the BTF ID as one of its member. The BTF binary data itself is exposed through the "btf" and "btf_size" members. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel/bpf/btf.c')
-rw-r--r--kernel/bpf/btf.c26
1 files changed, 21 insertions, 5 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 40950b6bf395..ded10ab47b8a 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -2114,12 +2114,28 @@ int btf_get_info_by_fd(const struct btf *btf,
const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
- void __user *udata = u64_to_user_ptr(attr->info.info);
- u32 copy_len = min_t(u32, btf->data_size,
- attr->info.info_len);
+ struct bpf_btf_info __user *uinfo;
+ struct bpf_btf_info info = {};
+ u32 info_copy, btf_copy;
+ void __user *ubtf;
+ u32 uinfo_len;
- if (copy_to_user(udata, btf->data, copy_len) ||
- put_user(btf->data_size, &uattr->info.info_len))
+ uinfo = u64_to_user_ptr(attr->info.info);
+ uinfo_len = attr->info.info_len;
+
+ info_copy = min_t(u32, uinfo_len, sizeof(info));
+ if (copy_from_user(&info, uinfo, info_copy))
+ return -EFAULT;
+
+ info.id = btf->id;
+ ubtf = u64_to_user_ptr(info.btf);
+ btf_copy = min_t(u32, btf->data_size, info.btf_size);
+ if (copy_to_user(ubtf, btf->data, btf_copy))
+ return -EFAULT;
+ info.btf_size = btf->data_size;
+
+ if (copy_to_user(uinfo, &info, info_copy) ||
+ put_user(info_copy, &uattr->info.info_len))
return -EFAULT;
return 0;