[PATCH bpf] selftests/bpf: fix stacktrace_build_id with missing kprobe/urandom_read

From: Song Liu <song@kernel.org>
To: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>
Cc: <ast@kernel.org>, <daniel@iogearbox.net>, <andrii@kernel.org>,
	<kernel-team@fb.com>, Song Liu <song@kernel.org>,
	Mykola Lysenko <mykolal@fb.com>
Subject: [PATCH bpf] selftests/bpf: fix stacktrace_build_id with missing kprobe/urandom_read
Date: Thu, 26 May 2022 12:16:08 -0700	[thread overview]
Message-ID: <20220526191608.2364049-1-song@kernel.org> (raw)

Kernel function urandom_read is replaced with urandom_read_iter.
Therefore, kprobe on urandom_read is not working any more:

[root@eth50-1 bpf]# ./test_progs -n 161
test_stacktrace_build_id:PASS:skel_open_and_load 0 nsec
libbpf: kprobe perf_event_open() failed: No such file or directory
libbpf: prog 'oncpu': failed to create kprobe 'urandom_read+0x0' \
        perf event: No such file or directory
libbpf: prog 'oncpu': failed to auto-attach: -2
test_stacktrace_build_id:FAIL:attach_tp err -2
161     stacktrace_build_id:FAIL

Fix this by replacing urandom_read with urandom_read_iter in the test.

Fixes: 1b388e7765f2 ("random: convert to using fops->read_iter()")
Reported-by: Mykola Lysenko <mykolal@fb.com>
Signed-off-by: Song Liu <song@kernel.org>
---
 tools/testing/selftests/bpf/progs/test_stacktrace_build_id.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/progs/test_stacktrace_build_id.c b/tools/testing/selftests/bpf/progs/test_stacktrace_build_id.c
index 6c62bfb8bb6f..0c4426592a26 100644
--- a/tools/testing/selftests/bpf/progs/test_stacktrace_build_id.c
+++ b/tools/testing/selftests/bpf/progs/test_stacktrace_build_id.c
@@ -39,7 +39,7 @@ struct {
 	__type(value, stack_trace_t);
 } stack_amap SEC(".maps");
 
-SEC("kprobe/urandom_read")
+SEC("kprobe/urandom_read_iter")
 int oncpu(struct pt_regs *args)
 {
 	__u32 max_len = sizeof(struct bpf_stack_build_id)
-- 
2.30.2

