[LTP] [PATCH 4/5] syscalls: Don't pass struct timespec to tst_syscall()

[Arnd Bergmann]

On Wed, May 20, 2020 at 11:05 AM Viresh Kumar <viresh.kumar@linaro.org> wrote:
> On 20-05-20, 10:47, Arnd Bergmann wrote:
> > On Wed, May 20, 2020 at 9:31 AM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> > int tst_clock_gettime(clockid_t clk_id, struct timespec *ts)
> >  {
> >        int ret;
> >
> > #ifdef(__NR_clock_gettime64)
> >         struct __kernel_timespec newts;
> >         ret = tst_syscall(__NR_clock_gettime64, clk_id, &newts);
> >         *ts = (struct timespec) { .tv_sec = newts.tv_sec, .tv_nsec =
> > newts.tv_nsec };
> >         if (ret != -ENOSYS)
> >               return ret;
> > #endif
> >
> > #ifdef __NR_clock_gettime
> >         struct __kernel_old_timespec oldts;
> >         ret = tst_syscall(__NR_clock_gettime, clk_id, &oldts);
> >         *ts = (struct timespec) { .tv_sec = oldts.tv_sec, .tv_nsec =
> > oldts.tv_nsec };
> >         if (ret != -ENOSYS)
> >               return ret;
> > #endif
> >
> >        /* fallback for prehistoric linux */
> >         struct timeval tv;
> >         ret = gettimeofday(&tv, NULL);
> >         *ts = (struct timespec) { .tv_sec = newts.tv_sec, .tv_usec =
> > newts.tv_nsec / 1000};
> >
> >         return ret;
> > }
>
> This is used only for the internal working of the library and so we may not need
> to support all these timespec types TBH and make it complex.

Well, the point here is that you need the function to reliably return the
current time in the right format, and I don't think a simpler implementation
would be correct. In fact, I just realized that your patch version cannot work
on riscv32 since it only has __NR_clock_gettime64 but not __NR_clock_gettime.

         Arnd