Re: [PATCH v2 2/2] rusage: allow 64-bit times ru_utime/ru_stime

Ingo Molnar
2018-06-21T15:49:24Z

(belated reply)

* Arnd Bergmann <arnd@arndb.de> wrote:

> +int put_compat_rusage_time64(const struct __kernel_rusage *r,
> + struct compat_rusage_time64 __user *ru)
> +{
> + struct compat_rusage_time64 r32;
> + memset(&r32, 0, sizeof(r32));
> + r32.ru_utime.tv_sec = r->ru_utime.tv_sec;
> + r32.ru_utime.tv_usec = r->ru_utime.tv_usec;
> + r32.ru_stime.tv_sec = r->ru_stime.tv_sec;
> + r32.ru_stime.tv_usec = r->ru_stime.tv_usec;
> + r32.ru_maxrss = r->ru_maxrss;
> + r32.ru_ixrss = r->ru_ixrss;
> + r32.ru_idrss = r->ru_idrss;
> + r32.ru_isrss = r->ru_isrss;
> + r32.ru_minflt = r->ru_minflt;
> + r32.ru_majflt = r->ru_majflt;
> + r32.ru_nswap = r->ru_nswap;
> + r32.ru_inblock = r->ru_inblock;
> + r32.ru_oublock = r->ru_oublock;
> + r32.ru_msgsnd = r->ru_msgsnd;
> + r32.ru_msgrcv = r->ru_msgrcv;
> + r32.ru_nsignals = r->ru_nsignals;
> + r32.ru_nvcsw = r->ru_nvcsw;
> + r32.ru_nivcsw = r->ru_nivcsw;

Could you please vertically align the right side of the initialization as well?
Much easier to check at a glance.

> + user_access_begin();
> + unsafe_put_user(signo, &infop->si_signo, Efault);
> + unsafe_put_user(0, &infop->si_errno, Efault);
> + unsafe_put_user(info.cause, &infop->si_code, Efault);
> + unsafe_put_user(info.pid, &infop->si_pid, Efault);
> + unsafe_put_user(info.uid, &infop->si_uid, Efault);
> + unsafe_put_user(info.status, &infop->si_status, Efault);
> + user_access_end();

This too would look nicer the following way:

> + user_access_begin();
> + unsafe_put_user(signo, &infop->si_signo, Efault);
> + unsafe_put_user(0, &infop->si_errno, Efault);
> + unsafe_put_user(info.cause, &infop->si_code, Efault);
> + unsafe_put_user(info.pid, &infop->si_pid, Efault);
> + unsafe_put_user(info.uid, &infop->si_uid, Efault);
> + unsafe_put_user(info.status, &infop->si_status, Efault);
> + user_access_end();

Which tabulated form made me notice the info.cause / si_code asymmetry - and a
brief check of the source shows that it's correct. No way would I have noticed it
in the jumbled up form above, so I think aligning such mass-initializations makes
sense.

> + memset(&r, 0, sizeof(r));
> + r.ru_utime.tv_sec = rk->ru_utime.tv_sec;
> + r.ru_utime.tv_usec = rk->ru_utime.tv_usec;
> + r.ru_stime.tv_sec = rk->ru_stime.tv_sec;
> + r.ru_stime.tv_usec = rk->ru_stime.tv_usec;
> + r.ru_maxrss = rk->ru_maxrss;
> + r.ru_ixrss = rk->ru_ixrss;
> + r.ru_idrss = rk->ru_idrss;
> + r.ru_isrss = rk->ru_isrss;
> + r.ru_minflt = rk->ru_minflt;
> + r.ru_majflt = rk->ru_majflt;
> + r.ru_nswap = rk->ru_nswap;
> + r.ru_inblock = rk->ru_inblock;
> + r.ru_oublock = rk->ru_oublock;
> + r.ru_msgsnd = rk->ru_msgsnd;
> + r.ru_msgrcv = rk->ru_msgrcv;
> + r.ru_nsignals = rk->ru_nsignals;
> + r.ru_nvcsw = rk->ru_nvcsw;
> + r.ru_nivcsw = rk->ru_nivcsw;

Ditto.

Thanks,

Ingo