From edd7f49bb884139af9069dcf59d9f89f1f4ddf3f Mon Sep 17 00:00:00 2001 From: Yafang Shao Date: Sun, 9 Jul 2023 02:56:23 +0000 Subject: [PATCH] bpftool: Show kprobe_multi link info Show the already expose kprobe_multi link info in bpftool. The result as follows, $ tools/bpf/bpftool/bpftool link show 91: kprobe_multi prog 244 kprobe.multi func_cnt 7 addr func [module] ffffffff98c44f20 schedule_timeout_interruptible ffffffff98c44f60 schedule_timeout_killable ffffffff98c44fa0 schedule_timeout_uninterruptible ffffffff98c44fe0 schedule_timeout_idle ffffffffc075b8d0 xfs_trans_get_efd [xfs] ffffffffc0768a10 xfs_trans_get_buf_map [xfs] ffffffffc076c320 xfs_trans_get_dqtrx [xfs] pids kprobe_multi(188367) 92: kprobe_multi prog 244 kretprobe.multi func_cnt 7 addr func [module] ffffffff98c44f20 schedule_timeout_interruptible ffffffff98c44f60 schedule_timeout_killable ffffffff98c44fa0 schedule_timeout_uninterruptible ffffffff98c44fe0 schedule_timeout_idle ffffffffc075b8d0 xfs_trans_get_efd [xfs] ffffffffc0768a10 xfs_trans_get_buf_map [xfs] ffffffffc076c320 xfs_trans_get_dqtrx [xfs] pids kprobe_multi(188367) $ tools/bpf/bpftool/bpftool link show -j [{"id":91,"type":"kprobe_multi","prog_id":244,"retprobe":false,"func_cnt":7,"funcs":[{"addr":18446744071977586464,"func":"schedule_timeout_interruptible","module":null},{"addr":18446744071977586528,"func":"schedule_timeout_killable","module":null},{"addr":18446744071977586592,"func":"schedule_timeout_uninterruptible","module":null},{"addr":18446744071977586656,"func":"schedule_timeout_idle","module":null},{"addr":18446744072643524816,"func":"xfs_trans_get_efd","module":"xfs"},{"addr":18446744072643578384,"func":"xfs_trans_get_buf_map","module":"xfs"},{"addr":18446744072643592992,"func":"xfs_trans_get_dqtrx","module":"xfs"}],"pids":[{"pid":188367,"comm":"kprobe_multi"}]},{"id":92,"type":"kprobe_multi","prog_id":244,"retprobe":true,"func_cnt":7,"funcs":[{"addr":18446744071977586464,"func":"schedule_timeout_interruptible","module":null},{"addr":18446744071977586528,"func":"schedule_timeout_killable","module":null},{"addr":18446744071977586592,"func":"schedule_timeout_uninterruptible","module":null},{"addr":18446744071977586656,"func":"schedule_timeout_idle","module":null},{"addr":18446744072643524816,"func":"xfs_trans_get_efd","module":"xfs"},{"addr":18446744072643578384,"func":"xfs_trans_get_buf_map","module":"xfs"},{"addr":18446744072643592992,"func":"xfs_trans_get_dqtrx","module":"xfs"}],"pids":[{"pid":188367,"comm":"kprobe_multi"}]}] When kptr_restrict is 2, the result is, $ tools/bpf/bpftool/bpftool link show 91: kprobe_multi prog 244 kprobe.multi func_cnt 7 92: kprobe_multi prog 244 kretprobe.multi func_cnt 7 Signed-off-by: Yafang Shao Reviewed-by: Quentin Monnet Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20230709025630.3735-4-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov --- tools/bpf/bpftool/link.c | 118 +++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 115 insertions(+), 3 deletions(-) diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c index 2d78607..a4f5a43 100644 --- a/tools/bpf/bpftool/link.c +++ b/tools/bpf/bpftool/link.c @@ -14,8 +14,10 @@ #include "json_writer.h" #include "main.h" +#include "xlated_dumper.h" static struct hashmap *link_table; +static struct dump_data dd; static int link_parse_fd(int *argc, char ***argv) { @@ -166,6 +168,50 @@ static int get_prog_info(int prog_id, struct bpf_prog_info *info) return err; } +static int cmp_u64(const void *A, const void *B) +{ + const __u64 *a = A, *b = B; + + return *a - *b; +} + +static void +show_kprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + __u32 i, j = 0; + __u64 *addrs; + + jsonw_bool_field(json_wtr, "retprobe", + info->kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN); + jsonw_uint_field(json_wtr, "func_cnt", info->kprobe_multi.count); + jsonw_name(json_wtr, "funcs"); + jsonw_start_array(json_wtr); + addrs = u64_to_ptr(info->kprobe_multi.addrs); + qsort(addrs, info->kprobe_multi.count, sizeof(addrs[0]), cmp_u64); + + /* Load it once for all. */ + if (!dd.sym_count) + kernel_syms_load(&dd); + for (i = 0; i < dd.sym_count; i++) { + if (dd.sym_mapping[i].address != addrs[j]) + continue; + jsonw_start_object(json_wtr); + jsonw_uint_field(json_wtr, "addr", dd.sym_mapping[i].address); + jsonw_string_field(json_wtr, "func", dd.sym_mapping[i].name); + /* Print null if it is vmlinux */ + if (dd.sym_mapping[i].module[0] == '\0') { + jsonw_name(json_wtr, "module"); + jsonw_null(json_wtr); + } else { + jsonw_string_field(json_wtr, "module", dd.sym_mapping[i].module); + } + jsonw_end_object(json_wtr); + if (j++ == info->kprobe_multi.count) + break; + } + jsonw_end_array(json_wtr); +} + static int show_link_close_json(int fd, struct bpf_link_info *info) { struct bpf_prog_info prog_info; @@ -218,6 +264,9 @@ static int show_link_close_json(int fd, struct bpf_link_info *info) jsonw_uint_field(json_wtr, "map_id", info->struct_ops.map_id); break; + case BPF_LINK_TYPE_KPROBE_MULTI: + show_kprobe_multi_json(info, json_wtr); + break; default: break; } @@ -351,6 +400,44 @@ void netfilter_dump_plain(const struct bpf_link_info *info) printf(" flags 0x%x", info->netfilter.flags); } +static void show_kprobe_multi_plain(struct bpf_link_info *info) +{ + __u32 i, j = 0; + __u64 *addrs; + + if (!info->kprobe_multi.count) + return; + + if (info->kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN) + printf("\n\tkretprobe.multi "); + else + printf("\n\tkprobe.multi "); + printf("func_cnt %u ", info->kprobe_multi.count); + addrs = (__u64 *)u64_to_ptr(info->kprobe_multi.addrs); + qsort(addrs, info->kprobe_multi.count, sizeof(__u64), cmp_u64); + + /* Load it once for all. */ + if (!dd.sym_count) + kernel_syms_load(&dd); + if (!dd.sym_count) + return; + + printf("\n\t%-16s %s", "addr", "func [module]"); + for (i = 0; i < dd.sym_count; i++) { + if (dd.sym_mapping[i].address != addrs[j]) + continue; + printf("\n\t%016lx %s", + dd.sym_mapping[i].address, dd.sym_mapping[i].name); + if (dd.sym_mapping[i].module[0] != '\0') + printf(" [%s] ", dd.sym_mapping[i].module); + else + printf(" "); + + if (j++ == info->kprobe_multi.count) + break; + } +} + static int show_link_close_plain(int fd, struct bpf_link_info *info) { struct bpf_prog_info prog_info; @@ -396,6 +483,9 @@ static int show_link_close_plain(int fd, struct bpf_link_info *info) case BPF_LINK_TYPE_NETFILTER: netfilter_dump_plain(info); break; + case BPF_LINK_TYPE_KPROBE_MULTI: + show_kprobe_multi_plain(info); + break; default: break; } @@ -417,7 +507,9 @@ static int do_show_link(int fd) { struct bpf_link_info info; __u32 len = sizeof(info); + __u64 *addrs = NULL; char buf[256]; + int count; int err; memset(&info, 0, sizeof(info)); @@ -431,22 +523,38 @@ again: } if (info.type == BPF_LINK_TYPE_RAW_TRACEPOINT && !info.raw_tracepoint.tp_name) { - info.raw_tracepoint.tp_name = (unsigned long)&buf; + info.raw_tracepoint.tp_name = ptr_to_u64(&buf); info.raw_tracepoint.tp_name_len = sizeof(buf); goto again; } if (info.type == BPF_LINK_TYPE_ITER && !info.iter.target_name) { - info.iter.target_name = (unsigned long)&buf; + info.iter.target_name = ptr_to_u64(&buf); info.iter.target_name_len = sizeof(buf); goto again; } + if (info.type == BPF_LINK_TYPE_KPROBE_MULTI && + !info.kprobe_multi.addrs) { + count = info.kprobe_multi.count; + if (count) { + addrs = calloc(count, sizeof(__u64)); + if (!addrs) { + p_err("mem alloc failed"); + close(fd); + return -ENOMEM; + } + info.kprobe_multi.addrs = ptr_to_u64(addrs); + goto again; + } + } if (json_output) show_link_close_json(fd, &info); else show_link_close_plain(fd, &info); + if (addrs) + free(addrs); close(fd); return 0; } @@ -471,7 +579,8 @@ static int do_show(int argc, char **argv) fd = link_parse_fd(&argc, &argv); if (fd < 0) return fd; - return do_show_link(fd); + do_show_link(fd); + goto out; } if (argc) @@ -510,6 +619,9 @@ static int do_show(int argc, char **argv) if (show_pinned) delete_pinned_obj_table(link_table); +out: + if (dd.sym_count) + kernel_syms_destroy(&dd); return errno == ENOENT ? 0 : -1; } -- 2.7.4