From: Martin KaFai Lau Date: Sat, 8 Dec 2018 00:42:32 +0000 (-0800) Subject: bpf: libbpf: bpftool: Print bpf_line_info during prog dump X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=b053b439b72ad152257ecc3f71cfb4c619b0137e;p=openwrt%2Fstaging%2Fblogic.git bpf: libbpf: bpftool: Print bpf_line_info during prog dump This patch adds print bpf_line_info function in 'prog dump jitted' and 'prog dump xlated': [root@arch-fb-vm1 bpf]# ~/devshare/fb-kernel/linux/tools/bpf/bpftool/bpftool prog dump jited pinned /sys/fs/bpf/test_btf_haskv [...] int test_long_fname_2(struct dummy_tracepoint_args * arg): bpf_prog_44a040bf25481309_test_long_fname_2: ; static int test_long_fname_2(struct dummy_tracepoint_args *arg) 0: push %rbp 1: mov %rsp,%rbp 4: sub $0x30,%rsp b: sub $0x28,%rbp f: mov %rbx,0x0(%rbp) 13: mov %r13,0x8(%rbp) 17: mov %r14,0x10(%rbp) 1b: mov %r15,0x18(%rbp) 1f: xor %eax,%eax 21: mov %rax,0x20(%rbp) 25: xor %esi,%esi ; int key = 0; 27: mov %esi,-0x4(%rbp) ; if (!arg->sock) 2a: mov 0x8(%rdi),%rdi ; if (!arg->sock) 2e: cmp $0x0,%rdi 32: je 0x0000000000000070 34: mov %rbp,%rsi ; counts = bpf_map_lookup_elem(&btf_map, &key); 37: add $0xfffffffffffffffc,%rsi 3b: movabs $0xffff8881139d7480,%rdi 45: add $0x110,%rdi 4c: mov 0x0(%rsi),%eax 4f: cmp $0x4,%rax 53: jae 0x000000000000005e 55: shl $0x3,%rax 59: add %rdi,%rax 5c: jmp 0x0000000000000060 5e: xor %eax,%eax ; if (!counts) 60: cmp $0x0,%rax 64: je 0x0000000000000070 ; counts->v6++; 66: mov 0x4(%rax),%edi 69: add $0x1,%rdi 6d: mov %edi,0x4(%rax) 70: mov 0x0(%rbp),%rbx 74: mov 0x8(%rbp),%r13 78: mov 0x10(%rbp),%r14 7c: mov 0x18(%rbp),%r15 80: add $0x28,%rbp 84: leaveq 85: retq [...] With linum: [root@arch-fb-vm1 bpf]# ~/devshare/fb-kernel/linux/tools/bpf/bpftool/bpftool prog dump jited pinned /sys/fs/bpf/test_btf_haskv linum int _dummy_tracepoint(struct dummy_tracepoint_args * arg): bpf_prog_b07ccb89267cf242__dummy_tracepoint: ; return test_long_fname_1(arg); [file:/data/users/kafai/fb-kernel/linux/tools/testing/selftests/bpf/test_btf_haskv.c line_num:54 line_col:9] 0: push %rbp 1: mov %rsp,%rbp 4: sub $0x28,%rsp b: sub $0x28,%rbp f: mov %rbx,0x0(%rbp) 13: mov %r13,0x8(%rbp) 17: mov %r14,0x10(%rbp) 1b: mov %r15,0x18(%rbp) 1f: xor %eax,%eax 21: mov %rax,0x20(%rbp) 25: callq 0x000000000000851e ; return test_long_fname_1(arg); [file:/data/users/kafai/fb-kernel/linux/tools/testing/selftests/bpf/test_btf_haskv.c line_num:54 line_col:2] 2a: xor %eax,%eax 2c: mov 0x0(%rbp),%rbx 30: mov 0x8(%rbp),%r13 34: mov 0x10(%rbp),%r14 38: mov 0x18(%rbp),%r15 3c: add $0x28,%rbp 40: leaveq 41: retq [...] Signed-off-by: Martin KaFai Lau Acked-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst index 5524b6dccd85..7c30731a9b73 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst @@ -22,8 +22,8 @@ MAP COMMANDS ============= | **bpftool** **prog { show | list }** [*PROG*] -| **bpftool** **prog dump xlated** *PROG* [{**file** *FILE* | **opcodes** | **visual**}] -| **bpftool** **prog dump jited** *PROG* [{**file** *FILE* | **opcodes**}] +| **bpftool** **prog dump xlated** *PROG* [{**file** *FILE* | **opcodes** | **visual** | **linum**}] +| **bpftool** **prog dump jited** *PROG* [{**file** *FILE* | **opcodes** | **linum**}] | **bpftool** **prog pin** *PROG* *FILE* | **bpftool** **prog { load | loadall }** *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*] | **bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*] @@ -56,7 +56,7 @@ DESCRIPTION Output will start with program ID followed by program type and zero or more named attributes (depending on kernel version). - **bpftool prog dump xlated** *PROG* [{ **file** *FILE* | **opcodes** | **visual** }] + **bpftool prog dump xlated** *PROG* [{ **file** *FILE* | **opcodes** | **visual** | **linum** }] Dump eBPF instructions of the program from the kernel. By default, eBPF will be disassembled and printed to standard output in human-readable format. In this case, **opcodes** @@ -69,13 +69,21 @@ DESCRIPTION built instead, and eBPF instructions will be presented with CFG in DOT format, on standard output. - **bpftool prog dump jited** *PROG* [{ **file** *FILE* | **opcodes** }] + If the prog has line_info available, the source line will + be displayed by default. If **linum** is specified, + the filename, line number and line column will also be + displayed on top of the source line. + **bpftool prog dump jited** *PROG* [{ **file** *FILE* | **opcodes** | **linum** }] Dump jited image (host machine code) of the program. If *FILE* is specified image will be written to a file, otherwise it will be disassembled and printed to stdout. **opcodes** controls if raw opcodes will be printed. + If the prog has line_info available, the source line will + be displayed by default. If **linum** is specified, + the filename, line number and line column will also be + displayed on top of the source line. **bpftool prog pin** *PROG* *FILE* Pin program *PROG* as *FILE*. diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool index 44c189ba072a..a57febd6abb1 100644 --- a/tools/bpf/bpftool/bash-completion/bpftool +++ b/tools/bpf/bpftool/bash-completion/bpftool @@ -191,7 +191,7 @@ _bpftool() # Deal with simplest keywords case $prev in - help|hex|opcodes|visual) + help|hex|opcodes|visual|linum) return 0 ;; tag) @@ -278,10 +278,10 @@ _bpftool() *) _bpftool_once_attr 'file' if _bpftool_search_list 'xlated'; then - COMPREPLY+=( $( compgen -W 'opcodes visual' -- \ + COMPREPLY+=( $( compgen -W 'opcodes visual linum' -- \ "$cur" ) ) else - COMPREPLY+=( $( compgen -W 'opcodes' -- \ + COMPREPLY+=( $( compgen -W 'opcodes linum' -- \ "$cur" ) ) fi return 0 diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c index c3fd3a7cb787..dbbf6ece6760 100644 --- a/tools/bpf/bpftool/btf_dumper.c +++ b/tools/bpf/bpftool/btf_dumper.c @@ -385,3 +385,67 @@ void btf_dumper_type_only(const struct btf *btf, __u32 type_id, char *func_sig, if (err < 0) func_sig[0] = '\0'; } + +static const char *ltrim(const char *s) +{ + while (isspace(*s)) + s++; + + return s; +} + +void btf_dump_linfo_plain(const struct btf *btf, + const struct bpf_line_info *linfo, + const char *prefix, bool linum) +{ + const char *line = btf__name_by_offset(btf, linfo->line_off); + + if (!line) + return; + line = ltrim(line); + + if (!prefix) + prefix = ""; + + if (linum) { + const char *file = btf__name_by_offset(btf, linfo->file_name_off); + + /* More forgiving on file because linum option is + * expected to provide more info than the already + * available src line. + */ + if (!file) + file = ""; + + printf("%s%s [file:%s line_num:%u line_col:%u]\n", + prefix, line, file, + BPF_LINE_INFO_LINE_NUM(linfo->line_col), + BPF_LINE_INFO_LINE_COL(linfo->line_col)); + } else { + printf("%s%s\n", prefix, line); + } +} + +void btf_dump_linfo_json(const struct btf *btf, + const struct bpf_line_info *linfo, bool linum) +{ + const char *line = btf__name_by_offset(btf, linfo->line_off); + + if (line) + jsonw_string_field(json_wtr, "src", ltrim(line)); + + if (linum) { + const char *file = btf__name_by_offset(btf, linfo->file_name_off); + + if (file) + jsonw_string_field(json_wtr, "file", file); + + if (BPF_LINE_INFO_LINE_NUM(linfo->line_col)) + jsonw_int_field(json_wtr, "line_num", + BPF_LINE_INFO_LINE_NUM(linfo->line_col)); + + if (BPF_LINE_INFO_LINE_COL(linfo->line_col)) + jsonw_int_field(json_wtr, "line_col", + BPF_LINE_INFO_LINE_COL(linfo->line_col)); + } +} diff --git a/tools/bpf/bpftool/jit_disasm.c b/tools/bpf/bpftool/jit_disasm.c index 545a92471c33..f381f8628ce9 100644 --- a/tools/bpf/bpftool/jit_disasm.c +++ b/tools/bpf/bpftool/jit_disasm.c @@ -21,6 +21,7 @@ #include #include #include +#include #include "json_writer.h" #include "main.h" @@ -68,10 +69,16 @@ static int fprintf_json(void *out, const char *fmt, ...) } void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes, - const char *arch, const char *disassembler_options) + const char *arch, const char *disassembler_options, + const struct btf *btf, + const struct bpf_prog_linfo *prog_linfo, + __u64 func_ksym, unsigned int func_idx, + bool linum) { + const struct bpf_line_info *linfo = NULL; disassembler_ftype disassemble; struct disassemble_info info; + unsigned int nr_skip = 0; int count, i, pc = 0; char tpath[PATH_MAX]; bfd *bfdf; @@ -127,12 +134,26 @@ void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes, if (json_output) jsonw_start_array(json_wtr); do { + if (prog_linfo) { + linfo = bpf_prog_linfo__lfind_addr_func(prog_linfo, + func_ksym + pc, + func_idx, + nr_skip); + if (linfo) + nr_skip++; + } + if (json_output) { jsonw_start_object(json_wtr); oper_count = 0; + if (linfo) + btf_dump_linfo_json(btf, linfo, linum); jsonw_name(json_wtr, "pc"); jsonw_printf(json_wtr, "\"0x%x\"", pc); } else { + if (linfo) + btf_dump_linfo_plain(btf, linfo, "; ", + linum); printf("%4x:\t", pc); } diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index 0be0dd8f467f..d9393abdba78 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -138,6 +138,9 @@ struct pinned_obj { struct hlist_node hash; }; +struct btf; +struct bpf_line_info; + int build_pinned_obj_table(struct pinned_obj_table *table, enum bpf_obj_type type); void delete_pinned_obj_table(struct pinned_obj_table *tab); @@ -175,13 +178,23 @@ int map_parse_fd(int *argc, char ***argv); int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len); #ifdef HAVE_LIBBFD_SUPPORT +struct bpf_prog_linfo; void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes, - const char *arch, const char *disassembler_options); + const char *arch, const char *disassembler_options, + const struct btf *btf, + const struct bpf_prog_linfo *prog_linfo, + __u64 func_ksym, unsigned int func_idx, + bool linum); int disasm_init(void); #else static inline void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes, - const char *arch, const char *disassembler_options) + const char *arch, const char *disassembler_options, + const struct btf *btf, + const struct bpf_prog_linfo *prog_linfo, + __u64 func_ksym, unsigned int func_idx, + bool linum) + { } static inline int disasm_init(void) @@ -217,6 +230,12 @@ int btf_dumper_type(const struct btf_dumper *d, __u32 type_id, void btf_dumper_type_only(const struct btf *btf, __u32 func_type_id, char *func_only, int size); +void btf_dump_linfo_plain(const struct btf *btf, + const struct bpf_line_info *linfo, + const char *prefix, bool linum); +void btf_dump_linfo_json(const struct btf *btf, + const struct bpf_line_info *linfo, bool linum); + struct nlattr; struct ifinfomsg; struct tcmsg; diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index a9a51123454c..65b921ffd10a 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -423,24 +423,26 @@ static int do_show(int argc, char **argv) static int do_dump(int argc, char **argv) { + unsigned int finfo_rec_size, linfo_rec_size, jited_linfo_rec_size; + void *func_info = NULL, *linfo = NULL, *jited_linfo = NULL; + unsigned int finfo_cnt, linfo_cnt = 0, jited_linfo_cnt = 0; + struct bpf_prog_linfo *prog_linfo = NULL; unsigned long *func_ksyms = NULL; struct bpf_prog_info info = {}; unsigned int *func_lens = NULL; const char *disasm_opt = NULL; - unsigned int finfo_rec_size; unsigned int nr_func_ksyms; unsigned int nr_func_lens; struct dump_data dd = {}; __u32 len = sizeof(info); struct btf *btf = NULL; - void *func_info = NULL; - unsigned int finfo_cnt; unsigned int buf_size; char *filepath = NULL; bool opcodes = false; bool visual = false; char func_sig[1024]; unsigned char *buf; + bool linum = false; __u32 *member_len; __u64 *member_ptr; ssize_t n; @@ -484,6 +486,9 @@ static int do_dump(int argc, char **argv) } else if (is_prefix(*argv, "visual")) { visual = true; NEXT_ARG(); + } else if (is_prefix(*argv, "linum")) { + linum = true; + NEXT_ARG(); } if (argc) { @@ -543,6 +548,32 @@ static int do_dump(int argc, char **argv) } } + linfo_rec_size = info.line_info_rec_size; + if (info.line_info_cnt && linfo_rec_size && info.btf_id) { + linfo_cnt = info.line_info_cnt; + linfo = malloc(linfo_cnt * linfo_rec_size); + if (!linfo) { + p_err("mem alloc failed"); + close(fd); + goto err_free; + } + } + + jited_linfo_rec_size = info.jited_line_info_rec_size; + if (info.jited_line_info_cnt && + jited_linfo_rec_size && + info.nr_jited_ksyms && + info.nr_jited_func_lens && + info.btf_id) { + jited_linfo_cnt = info.jited_line_info_cnt; + jited_linfo = malloc(jited_linfo_cnt * jited_linfo_rec_size); + if (!jited_linfo) { + p_err("mem alloc failed"); + close(fd); + goto err_free; + } + } + memset(&info, 0, sizeof(info)); *member_ptr = ptr_to_u64(buf); @@ -554,6 +585,13 @@ static int do_dump(int argc, char **argv) info.func_info_cnt = finfo_cnt; info.func_info_rec_size = finfo_rec_size; info.func_info = ptr_to_u64(func_info); + info.line_info_cnt = linfo_cnt; + info.line_info_rec_size = linfo_rec_size; + info.line_info = ptr_to_u64(linfo); + info.jited_line_info_cnt = jited_linfo_cnt; + info.jited_line_info_rec_size = jited_linfo_rec_size; + info.jited_line_info = ptr_to_u64(jited_linfo); + err = bpf_obj_get_info_by_fd(fd, &info, &len); close(fd); @@ -596,6 +634,30 @@ static int do_dump(int argc, char **argv) finfo_cnt = 0; } + if (linfo && info.line_info_cnt != linfo_cnt) { + p_err("incorrect line_info_cnt %u vs. expected %u", + info.line_info_cnt, linfo_cnt); + goto err_free; + } + + if (info.line_info_rec_size != linfo_rec_size) { + p_err("incorrect line_info_rec_size %u vs. expected %u", + info.line_info_rec_size, linfo_rec_size); + goto err_free; + } + + if (jited_linfo && info.jited_line_info_cnt != jited_linfo_cnt) { + p_err("incorrect jited_line_info_cnt %u vs. expected %u", + info.jited_line_info_cnt, jited_linfo_cnt); + goto err_free; + } + + if (info.jited_line_info_rec_size != jited_linfo_rec_size) { + p_err("incorrect jited_line_info_rec_size %u vs. expected %u", + info.jited_line_info_rec_size, jited_linfo_rec_size); + goto err_free; + } + if ((member_len == &info.jited_prog_len && info.jited_prog_insns == 0) || (member_len == &info.xlated_prog_len && @@ -609,6 +671,12 @@ static int do_dump(int argc, char **argv) goto err_free; } + if (linfo_cnt) { + prog_linfo = bpf_prog_linfo__new(&info); + if (!prog_linfo) + p_err("error in processing bpf_line_info. continue without it."); + } + if (filepath) { fd = open(filepath, O_WRONLY | O_CREAT | O_TRUNC, 0600); if (fd < 0) { @@ -690,8 +758,11 @@ static int do_dump(int argc, char **argv) printf("%s:\n", sym_name); } - disasm_print_insn(img, lens[i], opcodes, name, - disasm_opt); + disasm_print_insn(img, lens[i], opcodes, + name, disasm_opt, btf, + prog_linfo, ksyms[i], i, + linum); + img += lens[i]; if (json_output) @@ -704,7 +775,7 @@ static int do_dump(int argc, char **argv) jsonw_end_array(json_wtr); } else { disasm_print_insn(buf, *member_len, opcodes, name, - disasm_opt); + disasm_opt, btf, NULL, 0, 0, false); } } else if (visual) { if (json_output) @@ -718,11 +789,14 @@ static int do_dump(int argc, char **argv) dd.btf = btf; dd.func_info = func_info; dd.finfo_rec_size = finfo_rec_size; + dd.prog_linfo = prog_linfo; if (json_output) - dump_xlated_json(&dd, buf, *member_len, opcodes); + dump_xlated_json(&dd, buf, *member_len, opcodes, + linum); else - dump_xlated_plain(&dd, buf, *member_len, opcodes); + dump_xlated_plain(&dd, buf, *member_len, opcodes, + linum); kernel_syms_destroy(&dd); } @@ -730,6 +804,9 @@ static int do_dump(int argc, char **argv) free(func_ksyms); free(func_lens); free(func_info); + free(linfo); + free(jited_linfo); + bpf_prog_linfo__free(prog_linfo); return 0; err_free: @@ -737,6 +814,9 @@ err_free: free(func_ksyms); free(func_lens); free(func_info); + free(linfo); + free(jited_linfo); + bpf_prog_linfo__free(prog_linfo); return -1; } @@ -1138,8 +1218,8 @@ static int do_help(int argc, char **argv) fprintf(stderr, "Usage: %s %s { show | list } [PROG]\n" - " %s %s dump xlated PROG [{ file FILE | opcodes | visual }]\n" - " %s %s dump jited PROG [{ file FILE | opcodes }]\n" + " %s %s dump xlated PROG [{ file FILE | opcodes | visual | linum }]\n" + " %s %s dump jited PROG [{ file FILE | opcodes | linum }]\n" " %s %s pin PROG FILE\n" " %s %s { load | loadall } OBJ PATH \\\n" " [type TYPE] [dev NAME] \\\n" diff --git a/tools/bpf/bpftool/xlated_dumper.c b/tools/bpf/bpftool/xlated_dumper.c index 131ecd175533..aef628dcccb6 100644 --- a/tools/bpf/bpftool/xlated_dumper.c +++ b/tools/bpf/bpftool/xlated_dumper.c @@ -41,6 +41,7 @@ #include #include #include +#include #include "disasm.h" #include "json_writer.h" @@ -234,8 +235,9 @@ static const char *print_imm(void *private_data, } void dump_xlated_json(struct dump_data *dd, void *buf, unsigned int len, - bool opcodes) + bool opcodes, bool linum) { + const struct bpf_prog_linfo *prog_linfo = dd->prog_linfo; const struct bpf_insn_cbs cbs = { .cb_print = print_insn_json, .cb_call = print_call, @@ -246,6 +248,7 @@ void dump_xlated_json(struct dump_data *dd, void *buf, unsigned int len, struct bpf_insn *insn = buf; struct btf *btf = dd->btf; bool double_insn = false; + unsigned int nr_skip = 0; char func_sig[1024]; unsigned int i; @@ -273,6 +276,16 @@ void dump_xlated_json(struct dump_data *dd, void *buf, unsigned int len, } } + if (prog_linfo) { + const struct bpf_line_info *linfo; + + linfo = bpf_prog_linfo__lfind(prog_linfo, i, nr_skip); + if (linfo) { + btf_dump_linfo_json(btf, linfo, linum); + nr_skip++; + } + } + jsonw_name(json_wtr, "disasm"); print_bpf_insn(&cbs, insn + i, true); @@ -307,8 +320,9 @@ void dump_xlated_json(struct dump_data *dd, void *buf, unsigned int len, } void dump_xlated_plain(struct dump_data *dd, void *buf, unsigned int len, - bool opcodes) + bool opcodes, bool linum) { + const struct bpf_prog_linfo *prog_linfo = dd->prog_linfo; const struct bpf_insn_cbs cbs = { .cb_print = print_insn, .cb_call = print_call, @@ -318,6 +332,7 @@ void dump_xlated_plain(struct dump_data *dd, void *buf, unsigned int len, struct bpf_func_info *record; struct bpf_insn *insn = buf; struct btf *btf = dd->btf; + unsigned int nr_skip = 0; bool double_insn = false; char func_sig[1024]; unsigned int i; @@ -340,6 +355,17 @@ void dump_xlated_plain(struct dump_data *dd, void *buf, unsigned int len, } } + if (prog_linfo) { + const struct bpf_line_info *linfo; + + linfo = bpf_prog_linfo__lfind(prog_linfo, i, nr_skip); + if (linfo) { + btf_dump_linfo_plain(btf, linfo, "; ", + linum); + nr_skip++; + } + } + double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW); printf("% 4d: ", i); diff --git a/tools/bpf/bpftool/xlated_dumper.h b/tools/bpf/bpftool/xlated_dumper.h index aec31723e1e5..a24f89df8cb2 100644 --- a/tools/bpf/bpftool/xlated_dumper.h +++ b/tools/bpf/bpftool/xlated_dumper.h @@ -40,6 +40,8 @@ #define SYM_MAX_NAME 256 +struct bpf_prog_linfo; + struct kernel_sym { unsigned long address; char name[SYM_MAX_NAME]; @@ -54,6 +56,7 @@ struct dump_data { struct btf *btf; void *func_info; __u32 finfo_rec_size; + const struct bpf_prog_linfo *prog_linfo; char scratch_buff[SYM_MAX_NAME + 8]; }; @@ -61,9 +64,9 @@ void kernel_syms_load(struct dump_data *dd); void kernel_syms_destroy(struct dump_data *dd); struct kernel_sym *kernel_syms_search(struct dump_data *dd, unsigned long key); void dump_xlated_json(struct dump_data *dd, void *buf, unsigned int len, - bool opcodes); + bool opcodes, bool linum); void dump_xlated_plain(struct dump_data *dd, void *buf, unsigned int len, - bool opcodes); + bool opcodes, bool linum); void dump_xlated_for_graph(struct dump_data *dd, void *buf, void *buf_end, unsigned int start_index); diff --git a/tools/lib/bpf/Build b/tools/lib/bpf/Build index 7bc31c905018..197b40f5b5c6 100644 --- a/tools/lib/bpf/Build +++ b/tools/lib/bpf/Build @@ -1 +1 @@ -libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o str_error.o netlink.o +libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o str_error.o netlink.o bpf_prog_linfo.o diff --git a/tools/lib/bpf/bpf_prog_linfo.c b/tools/lib/bpf/bpf_prog_linfo.c new file mode 100644 index 000000000000..b8af65145408 --- /dev/null +++ b/tools/lib/bpf/bpf_prog_linfo.c @@ -0,0 +1,253 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) +/* Copyright (c) 2018 Facebook */ + +#include +#include +#include +#include +#include "libbpf.h" + +#ifndef min +#define min(x, y) ((x) < (y) ? (x) : (y)) +#endif + +struct bpf_prog_linfo { + void *raw_linfo; + void *raw_jited_linfo; + __u32 *nr_jited_linfo_per_func; + __u32 *jited_linfo_func_idx; + __u32 nr_linfo; + __u32 nr_jited_func; + __u32 rec_size; + __u32 jited_rec_size; +}; + +static int dissect_jited_func(struct bpf_prog_linfo *prog_linfo, + const __u64 *ksym_func, const __u32 *ksym_len) +{ + __u32 nr_jited_func, nr_linfo; + const void *raw_jited_linfo; + const __u64 *jited_linfo; + __u64 last_jited_linfo; + /* + * Index to raw_jited_linfo: + * i: Index for searching the next ksym_func + * prev_i: Index to the last found ksym_func + */ + __u32 i, prev_i; + __u32 f; /* Index to ksym_func */ + + raw_jited_linfo = prog_linfo->raw_jited_linfo; + jited_linfo = raw_jited_linfo; + if (ksym_func[0] != *jited_linfo) + goto errout; + + prog_linfo->jited_linfo_func_idx[0] = 0; + nr_jited_func = prog_linfo->nr_jited_func; + nr_linfo = prog_linfo->nr_linfo; + + for (prev_i = 0, i = 1, f = 1; + i < nr_linfo && f < nr_jited_func; + i++) { + raw_jited_linfo += prog_linfo->jited_rec_size; + last_jited_linfo = *jited_linfo; + jited_linfo = raw_jited_linfo; + + if (ksym_func[f] == *jited_linfo) { + prog_linfo->jited_linfo_func_idx[f] = i; + + /* Sanity check */ + if (last_jited_linfo - ksym_func[f - 1] + 1 > + ksym_len[f - 1]) + goto errout; + + prog_linfo->nr_jited_linfo_per_func[f - 1] = + i - prev_i; + prev_i = i; + + /* + * The ksym_func[f] is found in jited_linfo. + * Look for the next one. + */ + f++; + } else if (*jited_linfo <= last_jited_linfo) { + /* Ensure the addr is increasing _within_ a func */ + goto errout; + } + } + + if (f != nr_jited_func) + goto errout; + + prog_linfo->nr_jited_linfo_per_func[nr_jited_func - 1] = + nr_linfo - prev_i; + + return 0; + +errout: + return -EINVAL; +} + +void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo) +{ + if (!prog_linfo) + return; + + free(prog_linfo->raw_linfo); + free(prog_linfo->raw_jited_linfo); + free(prog_linfo->nr_jited_linfo_per_func); + free(prog_linfo->jited_linfo_func_idx); + free(prog_linfo); +} + +struct bpf_prog_linfo *bpf_prog_linfo__new(const struct bpf_prog_info *info) +{ + struct bpf_prog_linfo *prog_linfo; + __u32 nr_linfo, nr_jited_func; + + nr_linfo = info->line_info_cnt; + + /* + * Test !info->line_info because the kernel may NULL + * the ptr if kernel.kptr_restrict is set. + */ + if (!nr_linfo || !info->line_info) + return NULL; + + /* + * The min size that bpf_prog_linfo has to access for + * searching purpose. + */ + if (info->line_info_rec_size < + offsetof(struct bpf_line_info, file_name_off)) + return NULL; + + prog_linfo = calloc(1, sizeof(*prog_linfo)); + if (!prog_linfo) + return NULL; + + /* Copy xlated line_info */ + prog_linfo->nr_linfo = nr_linfo; + prog_linfo->rec_size = info->line_info_rec_size; + prog_linfo->raw_linfo = malloc(nr_linfo * prog_linfo->rec_size); + if (!prog_linfo->raw_linfo) + goto err_free; + memcpy(prog_linfo->raw_linfo, (void *)(long)info->line_info, + nr_linfo * prog_linfo->rec_size); + + nr_jited_func = info->nr_jited_ksyms; + if (!nr_jited_func || + !info->jited_line_info || + info->jited_line_info_cnt != nr_linfo || + info->jited_line_info_rec_size < sizeof(__u64) || + info->nr_jited_func_lens != nr_jited_func || + !info->jited_ksyms || + !info->jited_func_lens) + /* Not enough info to provide jited_line_info */ + return prog_linfo; + + /* Copy jited_line_info */ + prog_linfo->nr_jited_func = nr_jited_func; + prog_linfo->jited_rec_size = info->jited_line_info_rec_size; + prog_linfo->raw_jited_linfo = malloc(nr_linfo * + prog_linfo->jited_rec_size); + if (!prog_linfo->raw_jited_linfo) + goto err_free; + memcpy(prog_linfo->raw_jited_linfo, + (void *)(long)info->jited_line_info, + nr_linfo * prog_linfo->jited_rec_size); + + /* Number of jited_line_info per jited func */ + prog_linfo->nr_jited_linfo_per_func = malloc(nr_jited_func * + sizeof(__u32)); + if (!prog_linfo->nr_jited_linfo_per_func) + goto err_free; + + /* + * For each jited func, + * the start idx to the "linfo" and "jited_linfo" array, + */ + prog_linfo->jited_linfo_func_idx = malloc(nr_jited_func * + sizeof(__u32)); + if (!prog_linfo->jited_linfo_func_idx) + goto err_free; + + if (dissect_jited_func(prog_linfo, + (__u64 *)(long)info->jited_ksyms, + (__u32 *)(long)info->jited_func_lens)) + goto err_free; + + return prog_linfo; + +err_free: + bpf_prog_linfo__free(prog_linfo); + return NULL; +} + +const struct bpf_line_info * +bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo, + __u64 addr, __u32 func_idx, __u32 nr_skip) +{ + __u32 jited_rec_size, rec_size, nr_linfo, start, i; + const void *raw_jited_linfo, *raw_linfo; + const __u64 *jited_linfo; + + if (func_idx >= prog_linfo->nr_jited_func) + return NULL; + + nr_linfo = prog_linfo->nr_jited_linfo_per_func[func_idx]; + if (nr_skip >= nr_linfo) + return NULL; + + start = prog_linfo->jited_linfo_func_idx[func_idx] + nr_skip; + jited_rec_size = prog_linfo->jited_rec_size; + raw_jited_linfo = prog_linfo->raw_jited_linfo + + (start * jited_rec_size); + jited_linfo = raw_jited_linfo; + if (addr < *jited_linfo) + return NULL; + + nr_linfo -= nr_skip; + rec_size = prog_linfo->rec_size; + raw_linfo = prog_linfo->raw_linfo + (start * rec_size); + for (i = 0; i < nr_linfo; i++) { + if (addr < *jited_linfo) + break; + + raw_linfo += rec_size; + raw_jited_linfo += jited_rec_size; + jited_linfo = raw_jited_linfo; + } + + return raw_linfo - rec_size; +} + +const struct bpf_line_info * +bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo, + __u32 insn_off, __u32 nr_skip) +{ + const struct bpf_line_info *linfo; + __u32 rec_size, nr_linfo, i; + const void *raw_linfo; + + nr_linfo = prog_linfo->nr_linfo; + if (nr_skip >= nr_linfo) + return NULL; + + rec_size = prog_linfo->rec_size; + raw_linfo = prog_linfo->raw_linfo + (nr_skip * rec_size); + linfo = raw_linfo; + if (insn_off < linfo->insn_off) + return NULL; + + nr_linfo -= nr_skip; + for (i = 0; i < nr_linfo; i++) { + if (insn_off < linfo->insn_off) + break; + + raw_linfo += rec_size; + linfo = raw_linfo; + } + + return raw_linfo - rec_size; +} diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index f30c3d07bb7d..5f68d7b75215 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -342,6 +342,19 @@ int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex, int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle, libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie); +struct bpf_prog_linfo; +struct bpf_prog_info; + +LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo); +LIBBPF_API struct bpf_prog_linfo * +bpf_prog_linfo__new(const struct bpf_prog_info *info); +LIBBPF_API const struct bpf_line_info * +bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo, + __u64 addr, __u32 func_idx, __u32 nr_skip); +LIBBPF_API const struct bpf_line_info * +bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo, + __u32 insn_off, __u32 nr_skip); + #ifdef __cplusplus } /* extern "C" */ #endif diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 8deff22d61bb..cd02cd4e2cc3 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -99,6 +99,10 @@ LIBBPF_0.0.1 { bpf_program__unload; bpf_program__unpin; bpf_program__unpin_instance; + bpf_prog_linfo__free; + bpf_prog_linfo__new; + bpf_prog_linfo__lfind_addr_func; + bpf_prog_linfo__lfind; bpf_raw_tracepoint_open; bpf_set_link_xdp_fd; bpf_task_fd_query;