Show the already expose kprobe_multi link info in bpftool. The result as
follows,
$ tools/bpf/bpftool/bpftool link show
1: kprobe_multi prog 5
func_cnt 4 addrs symbols
ffffffffb4d465b0 schedule_timeout_interruptible
ffffffffb4d465f0 schedule_timeout_killable
ffffffffb4d46630 schedule_timeout_uninterruptible
ffffffffb4d46670 schedule_timeout_idle
pids trace(8729)
$ tools/bpf/bpftool/bpftool link show -j
[{"id":1,"type":"kprobe_multi","prog_id":5,"func_cnt":4,"addrs":[{"addr":18446744072448402864,"symbol":"schedule_timeout_interruptible"},{"addr":18446744072448402928,"symbol":"schedule_timeout_killable"},{"addr":18446744072448402992,"symbol":"schedule_timeout_uninterruptible"},{"addr":18446744072448403056,"symbol":"schedule_timeout_idle"}],"pids":[{"pid":8729,"comm":"trace"}]}]
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
---
tools/bpf/bpftool/link.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 94 insertions(+)
diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c
index 2d78607..3b00c07 100644
--- a/tools/bpf/bpftool/link.c
+++ b/tools/bpf/bpftool/link.c
@@ -166,6 +166,57 @@ 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 kprobe_multi_print_plain(__u64 addr, char *sym, __u32 indent)
+{
+ printf("\n\t%*s %0*llx %s", indent, "", 16, addr, sym);
+}
+
+static void kprobe_multi_print_json(__u64 addr, char *sym)
+{
+ jsonw_start_object(json_wtr);
+ jsonw_uint_field(json_wtr, "addr", addr);
+ jsonw_string_field(json_wtr, "symbol", sym);
+ jsonw_end_object(json_wtr);
+}
+
+static void kernel_syms_show(const __u64 *addrs, __u32 cnt, __u32 indent)
+{
+ char buff[256], sym[256];
+ __u64 addr;
+ int i = 0;
+ FILE *fp;
+
+ fp = fopen("/proc/kallsyms", "r");
+ if (!fp)
+ return;
+
+ /* Each address is guaranteed to be unique. */
+ qsort((void *)addrs, cnt, sizeof(__u64), cmp_u64);
+ /* The addresses in /proc/kallsyms are already sorted. */
+ while (fgets(buff, sizeof(buff), fp)) {
+ if (sscanf(buff, "%llx %*c %s", &addr, sym) != 2)
+ continue;
+ /* The addr probed by kprobe_multi is always in
+ * /proc/kallsyms, so we can ignore some edge cases.
+ */
+ if (addr != addrs[i])
+ continue;
+ if (indent)
+ kprobe_multi_print_plain(addr, sym, indent);
+ else
+ kprobe_multi_print_json(addr, sym);
+ i++;
+ }
+ fclose(fp);
+}
+
static int show_link_close_json(int fd, struct bpf_link_info *info)
{
struct bpf_prog_info prog_info;
@@ -218,6 +269,17 @@ 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:
+ const __u64 *addrs;
+
+ jsonw_uint_field(json_wtr, "func_cnt", info->kprobe_multi.count);
+ jsonw_name(json_wtr, "addrs");
+ jsonw_start_array(json_wtr);
+ addrs = (const __u64 *)u64_to_ptr(info->kprobe_multi.addrs);
+ if (info->kprobe_multi.count)
+ kernel_syms_show(addrs, info->kprobe_multi.count, 0);
+ jsonw_end_array(json_wtr);
+ break;
default:
break;
}
@@ -396,6 +458,20 @@ 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:
+ __u32 indent, cnt, i;
+ const __u64 *addrs;
+
+ cnt = info->kprobe_multi.count;
+ if (!cnt)
+ break;
+ printf("\n\tfunc_cnt %d %-16s %s", cnt, "addrs", "symbols");
+ for (i = 0; cnt; i++)
+ cnt /= 10;
+ indent = strlen("func_cnt ") + i;
+ addrs = (const __u64 *)u64_to_ptr(info->kprobe_multi.addrs);
+ kernel_syms_show(addrs, cnt, indent);
+ break;
default:
break;
}
@@ -417,7 +493,9 @@ 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));
@@ -441,12 +519,28 @@ static int do_show_link(int fd)
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 -1;
+ }
+ info.kprobe_multi.addrs = (unsigned long)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;
}
--
1.8.3.1
