From c454a46b5efd8eff8880e88ece2976e60a26bf35 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Fri, 7 Dec 2018 16:42:25 -0800 Subject: bpf: Add bpf_line_info support This patch adds bpf_line_info support. It accepts an array of bpf_line_info objects during BPF_PROG_LOAD. The "line_info", "line_info_cnt" and "line_info_rec_size" are added to the "union bpf_attr". The "line_info_rec_size" makes bpf_line_info extensible in the future. The new "check_btf_line()" ensures the userspace line_info is valid for the kernel to use. When the verifier is translating/patching the bpf_prog (through "bpf_patch_insn_single()"), the line_infos' insn_off is also adjusted by the newly added "bpf_adj_linfo()". If the bpf_prog is jited, this patch also provides the jited addrs (in aux->jited_linfo) for the corresponding line_info.insn_off. "bpf_prog_fill_jited_linfo()" is added to fill the aux->jited_linfo. It is currently called by the x86 jit. Other jits can also use "bpf_prog_fill_jited_linfo()" and it will be done in the followup patches. In the future, if it deemed necessary, a particular jit could also provide its own "bpf_prog_fill_jited_linfo()" implementation. A few "*line_info*" fields are added to the bpf_prog_info such that the user can get the xlated line_info back (i.e. the line_info with its insn_off reflecting the translated prog). The jited_line_info is available if the prog is jited. It is an array of __u64. If the prog is not jited, jited_line_info_cnt is 0. The verifier's verbose log with line_info will be done in a follow up patch. Signed-off-by: Martin KaFai Lau Acked-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- include/linux/btf.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/btf.h') diff --git a/include/linux/btf.h b/include/linux/btf.h index 8c2199b5d250..b98405a56383 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -46,6 +46,7 @@ void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, struct seq_file *m); int btf_get_fd_by_id(u32 id); u32 btf_id(const struct btf *btf); +bool btf_name_offset_valid(const struct btf *btf, u32 offset); #ifdef CONFIG_BPF_SYSCALL const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id); -- cgit v1.2.3-59-g8ed1b