On Fri, Mar 13, 2020 at 04:35:35PM -0700, Andrii Nakryiko wrote:
> Amazingly, some libc implementations don't call __NR_nanosleep syscall from
> their nanosleep() APIs. Hammer it down with explicit syscall() call and never
> get back to it again. Also simplify code for timespec initialization.
>
> I verified that nanosleep is called w/ printk and in exactly same Linux image
> that is used in Travis CI. So it should both sleep and call correct syscall.
>
> Fixes: 4e1fd25d19e8 ("selftests/bpf: Fix usleep() implementation")
> Signed-off-by: Andrii Nakryiko <andriin@xxxxxx>
> ---
> tools/testing/selftests/bpf/test_progs.c | 16 ++++++----------
> 1 file changed, 6 insertions(+), 10 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
> index f85a06512541..6956d722a463 100644
> --- a/tools/testing/selftests/bpf/test_progs.c
> +++ b/tools/testing/selftests/bpf/test_progs.c
> @@ -35,16 +35,12 @@ struct prog_test_def {
> */
> int usleep(useconds_t usec)
> {
> - struct timespec ts;
> -
> - if (usec > 999999) {
> - ts.tv_sec = usec / 1000000;
> - ts.tv_nsec = usec % 1000000;
> - } else {
> - ts.tv_sec = 0;
> - ts.tv_nsec = usec;
> - }
> - return nanosleep(&ts, NULL);
> + struct timespec ts = {
> + .tv_sec = usec / 1000000,
> + .tv_nsec = usec % 1000000,
usec is in micro and tv_nsec is in nano?
> + };
> +
> + return syscall(__NR_nanosleep, &ts, NULL);
> }
>
