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.
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| @@ -356,6 +356,9 @@ union bpf_attr { · 355 unmodified lines | ||
| 356 | 356 | __u32 func_info_rec_size; /* userspace bpf_func_info size */ |
| 357 | 357 | __aligned_u64 func_info; /* func info */ |
| 358 | 358 | __u32 func_info_cnt; /* number of bpf_func_info records */ |
| 359 | + __u32 line_info_rec_size; /* userspace bpf_line_info size */ | |
| 360 | + __aligned_u64 line_info; /* line info */ | |
| 361 | + __u32 line_info_cnt; /* number of bpf_line_info records */ | |
| 359 | 362 | }; |
| 360 | 363 | |
| 361 | 364 | struct { /* anonymous struct used by BPF_OBJ_* commands */ |
| @@ -2679,6 +2682,12 @@ struct bpf_prog_info { · 2317 unmodified lines | ||
| 2679 | 2682 | __u32 func_info_rec_size; |
| 2680 | 2683 | __aligned_u64 func_info; |
| 2681 | 2684 | __u32 func_info_cnt; |
| 2685 | + __u32 line_info_cnt; | |
| 2686 | + __aligned_u64 line_info; | |
| 2687 | + __aligned_u64 jited_line_info; | |
| 2688 | + __u32 jited_line_info_cnt; | |
| 2689 | + __u32 line_info_rec_size; | |
| 2690 | + __u32 jited_line_info_rec_size; | |
| 2682 | 2691 | } __attribute__((aligned(8))); |
| 2683 | 2692 | |
| 2684 | 2693 | struct bpf_map_info { |
| @@ -2995,4 +3004,14 @@ struct bpf_func_info { · 310 unmodified lines | ||
| 2995 | 3004 | __u32 type_id; |
| 2996 | 3005 | }; |
| 2997 | 3006 | |
| 3007 | +#define BPF_LINE_INFO_LINE_NUM(line_col) ((line_col) >> 10) | |
| 3008 | +#define BPF_LINE_INFO_LINE_COL(line_col) ((line_col) & 0x3ff) | |
| 3009 | + | |
| 3010 | +struct bpf_line_info { | |
| 3011 | + __u32 insn_off; | |
| 3012 | + __u32 file_name_off; | |
| 3013 | + __u32 line_off; | |
| 3014 | + __u32 line_col; | |
| 3015 | +}; | |
| 3016 | + | |
| 2998 | 3017 | #endif /* _UAPI__LINUX_BPF_H__ */ |