On 6/28/23 1:53 PM, Yafang Shao wrote:
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 <laoar.shao@xxxxxxxxx>
Reviewed-by: Quentin Monnet <quentin@xxxxxxxxxxxxx>
Mainly small nits, but otherwise series lgtm, thanks for improving the visibility!
tools/bpf/bpftool/link.c | 114 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 113 insertions(+), 1 deletion(-)
diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c
index 2d786072ed0d..34fa17cd9d2a 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 = {};
Doesn't need explicit = {}
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 *)u64_to_ptr(info->kprobe_multi.addrs);
No need to explicitly cast.
+ qsort((void *)addrs, info->kprobe_multi.count, sizeof(__u64), cmp_u64);
Ditto wrt cast, also sizeof(addrs[0])
+ /* 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((void *)addrs, info->kprobe_multi.count, sizeof(__u64), cmp_u64);
Same.
+ /* 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));
@@ -441,12 +533,28 @@ 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;
-ENOMEM
+ }
+ info.kprobe_multi.addrs = (unsigned long)addrs;
ptr_to_u64()
(the same should also have been used for above (unsigned long)&buf)
+ 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;
}
