On Thu, May 26, 2022 at 12:16:08PM -0700, Song Liu wrote:
> 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@xxxxxx>
> Signed-off-by: Song Liu <song@xxxxxxxxxx>
> ---
> 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
>
Acked-by: David Vernet <void@xxxxxxxxxxxxx>
