On 8/4/23 3:57 AM, Yafang Shao wrote:
Add selftest for the fill_link_info of uprobe, kprobe and tracepoint.
The result:
$ tools/testing/selftests/bpf/test_progs --name=fill_link_info
#79/1 fill_link_info/kprobe_link_info:OK
#79/2 fill_link_info/kretprobe_link_info:OK
#79/3 fill_link_info/kprobe_fill_invalid_user_buff:OK
#79/4 fill_link_info/tracepoint_link_info:OK
#79/5 fill_link_info/uprobe_link_info:OK
#79/6 fill_link_info/uretprobe_link_info:OK
#79/7 fill_link_info/kprobe_multi_link_info:OK
#79/8 fill_link_info/kretprobe_multi_link_info:OK
#79/9 fill_link_info/kprobe_multi_ubuff:OK
#79 fill_link_info:OK
Summary: 1/9 PASSED, 0 SKIPPED, 0 FAILED
The test case for kprobe_multi won't be run on aarch64, as it is not
supported.
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
Ack with a few nits below.
Acked-by: Yonghong Song <yonghong.song@xxxxxxxxx>
---
tools/testing/selftests/bpf/DENYLIST.aarch64 | 3 +
.../selftests/bpf/prog_tests/fill_link_info.c | 337 +++++++++++++++++++++
.../selftests/bpf/progs/test_fill_link_info.c | 42 +++
3 files changed, 382 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/fill_link_info.c
create mode 100644 tools/testing/selftests/bpf/progs/test_fill_link_info.c
diff --git a/tools/testing/selftests/bpf/DENYLIST.aarch64 b/tools/testing/selftests/bpf/DENYLIST.aarch64
index 3b61e8b..b2f46b6 100644
--- a/tools/testing/selftests/bpf/DENYLIST.aarch64
+++ b/tools/testing/selftests/bpf/DENYLIST.aarch64
@@ -12,3 +12,6 @@ kprobe_multi_test/skel_api # libbpf: failed to load BPF sk
module_attach # prog 'kprobe_multi': failed to auto-attach: -95
fentry_test/fentry_many_args # fentry_many_args:FAIL:fentry_many_args_attach unexpected error: -524
fexit_test/fexit_many_args # fexit_many_args:FAIL:fexit_many_args_attach unexpected error: -524
+fill_link_info/kprobe_multi_link_info # bpf_program__attach_kprobe_multi_opts unexpected error: -95
+fill_link_info/kretprobe_multi_link_info # bpf_program__attach_kprobe_multi_opts unexpected error: -95
+fill_link_info/kprobe_multi_ubuff # bpf_program__attach_kprobe_multi_opts unexpected error: -95
diff --git a/tools/testing/selftests/bpf/prog_tests/fill_link_info.c b/tools/testing/selftests/bpf/prog_tests/fill_link_info.c
new file mode 100644
index 0000000..001a8b5
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/fill_link_info.c
@@ -0,0 +1,337 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2023 Yafang Shao <laoar.shao@xxxxxxxxx> */
+
+#include <string.h>
+#include <linux/bpf.h>
+#include <linux/limits.h>
+#include <test_progs.h>
+#include "trace_helpers.h"
+#include "test_fill_link_info.skel.h"
+
+#define TP_CAT "sched"
+#define TP_NAME "sched_switch"
+#define KPROBE_FUNC "tcp_rcv_established"
+#define UPROBE_FILE "/proc/self/exe"
+#define KMULTI_CNT (4)
+
+/* uprobe attach point */
+static noinline void uprobe_func(void)
+{
+ asm volatile ("");
+}
+
+static int verify_perf_link_info(int fd, enum bpf_perf_event_type type, long addr,
+ ssize_t offset, ssize_t entry_offset)
+{
+ struct bpf_link_info info;
+ __u32 len = sizeof(info);
+ char buf[PATH_MAX];
+ int err = 0;
+
+ memset(&info, 0, sizeof(info));
+ buf[0] = '\0';
+
+again:
+ err = bpf_link_get_info_by_fd(fd, &info, &len);
+ if (!ASSERT_OK(err, "get_link_info"))
+ return -1;
+
+ if (!ASSERT_EQ(info.type, BPF_LINK_TYPE_PERF_EVENT, "link_type"))
+ return -1;
+ if (!ASSERT_EQ(info.perf_event.type, type, "perf_type_match"))
+ return -1;
+
+ switch (info.perf_event.type) {
+ case BPF_PERF_EVENT_KPROBE:
+ case BPF_PERF_EVENT_KRETPROBE:
+ ASSERT_EQ(info.perf_event.kprobe.offset, offset, "kprobe_offset");
+
+ /* In case kernel.kptr_restrict is not permitted or MAX_SYMS is reached */
+ if (addr)
+ ASSERT_EQ(info.perf_event.kprobe.addr, addr + entry_offset,
+ "kprobe_addr");
+
+ if (!info.perf_event.kprobe.func_name) {
+ ASSERT_EQ(info.perf_event.kprobe.name_len, 0, "name_len");
+ info.perf_event.kprobe.func_name = ptr_to_u64(&buf);
+ info.perf_event.kprobe.name_len = sizeof(buf);
+ goto again;
+ }
+
+ err = strncmp(u64_to_ptr(info.perf_event.kprobe.func_name), KPROBE_FUNC,
+ strlen(KPROBE_FUNC));
+ ASSERT_EQ(err, 0, "cmp_kprobe_func_name");
+ break;
+ case BPF_PERF_EVENT_TRACEPOINT:
+ if (!info.perf_event.tracepoint.tp_name) {
+ ASSERT_EQ(info.perf_event.tracepoint.name_len, 0, "name_len");
+ info.perf_event.tracepoint.tp_name = ptr_to_u64(&buf);
+ info.perf_event.tracepoint.name_len = sizeof(buf);
+ goto again;
+ }
+
+ err = strncmp(u64_to_ptr(info.perf_event.tracepoint.tp_name), TP_NAME,
+ strlen(TP_NAME));
+ ASSERT_EQ(err, 0, "cmp_tp_name");
+ break;
+ case BPF_PERF_EVENT_UPROBE:
+ case BPF_PERF_EVENT_URETPROBE:
+ ASSERT_EQ(info.perf_event.uprobe.offset, offset, "uprobe_offset");
+
+ if (!info.perf_event.uprobe.file_name) {
+ ASSERT_EQ(info.perf_event.uprobe.name_len, 0, "name_len");
+ info.perf_event.uprobe.file_name = ptr_to_u64(&buf);
+ info.perf_event.uprobe.name_len = sizeof(buf);
+ goto again;
+ }
+
+ err = strncmp(u64_to_ptr(info.perf_event.uprobe.file_name), UPROBE_FILE,
+ strlen(UPROBE_FILE));
+ ASSERT_EQ(err, 0, "cmp_file_name");
+ break;
+ default:
Is the 'default' case possible? Probably not, right? Then
let us add
err = -1;
to indicate this path is not possible.
+ break;
+ }
+ return err;
+}
+
[...]
+
+static void test_kprobe_fill_link_info(struct test_fill_link_info *skel,
+ enum bpf_perf_event_type type,
+ bool retprobe, bool invalid)
+{
+ DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts,
+ .attach_mode = PROBE_ATTACH_MODE_LINK,
+ .retprobe = retprobe,
+ );
+ ssize_t offset = 0, entry_offset = 0;
Remove 'offset = 0'.
+ int link_fd, err;
+ long addr;
+
+ skel->links.kprobe_run = bpf_program__attach_kprobe_opts(skel->progs.kprobe_run,
+ KPROBE_FUNC, &opts);
+ if (!ASSERT_OK_PTR(skel->links.kprobe_run, "attach_kprobe"))
+ return;
+
+ link_fd = bpf_link__fd(skel->links.kprobe_run);
+ addr = ksym_get_addr(KPROBE_FUNC);
+ if (!invalid) {
+ /* See also arch_adjust_kprobe_addr(). */
+ if (skel->kconfig->CONFIG_X86_KERNEL_IBT)
+ entry_offset = 4;
+ err = verify_perf_link_info(link_fd, type, addr, offset, entry_offset);
Replease 'offset' with '0'.
+ ASSERT_OK(err, "verify_perf_link_info");
+ } else {
+ kprobe_fill_invalid_user_buffer(link_fd);
+ }
+ bpf_link__detach(skel->links.kprobe_run);
+}
+
[...]
+
+static void test_kprobe_multi_fill_link_info(struct test_fill_link_info *skel,
+ bool retprobe, bool buffer)
+{
+ LIBBPF_OPTS(bpf_kprobe_multi_opts, opts);
+ const char *syms[KMULTI_CNT] = {
+ "schedule_timeout_interruptible",
+ "schedule_timeout_uninterruptible",
+ "schedule_timeout_idle",
+ "schedule_timeout_killable",
+ };
+ __u64 addrs[KMULTI_CNT];
+ int link_fd, i, err = 0;
'err = 0' => 'err'.
+
+ qsort(syms, KMULTI_CNT, sizeof(syms[0]), symbols_cmp_r);
+ opts.syms = syms;
+ opts.cnt = KMULTI_CNT;
+ opts.retprobe = retprobe;
+ skel->links.kmulti_run = bpf_program__attach_kprobe_multi_opts(skel->progs.kmulti_run,
+ NULL, &opts);
+ if (!ASSERT_OK_PTR(skel->links.kmulti_run, "attach_kprobe_multi"))
+ return;
+
+ link_fd = bpf_link__fd(skel->links.kmulti_run);
+ for (i = 0; i < KMULTI_CNT; i++)
+ addrs[i] = ksym_get_addr(syms[i]);
+
+ if (!buffer)
+ err = verify_kmulti_link_info(link_fd, addrs, retprobe);
+ else
+ verify_kmulti_user_buffer(link_fd, addrs);
+ ASSERT_OK(err, "verify_kmulti_link_info");
if (!buffer) {
err = verify_kmulti_link_info(link_fd, addrs, retprobe);
ASSERT_OK(err, "verify_kmulti_link_info");
} else {
verify_kmulti_user_buffer(link_fd, addrs);
}
+ bpf_link__detach(skel->links.kmulti_run);
+}
+
[...]
