From: Arnd Bergmann <arnd@arndb.de>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: y2038 Mailman List <y2038@lists.linaro.org>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Anna-Maria Gleixner <anna-maria@linutronix.de>,
Frederic Weisbecker <frederic@kernel.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH 21/23] y2038: itimer: change implementation to timespec64
Date: Thu, 14 Nov 2019 11:51:15 +0100 [thread overview]
Message-ID: <CAK8P3a27OV864GfvLK_wjO7dK__r59dZ_dNQACp4G00gJrAwMw@mail.gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.21.1911132306070.2507@nanos.tec.linutronix.de>
On Wed, Nov 13, 2019 at 11:28 PM Thomas Gleixner <tglx@linutronix.de> wrote:
> On Fri, 8 Nov 2019, Arnd Bergmann wrote:
> > @@ -321,12 +321,12 @@ TRACE_EVENT(itimer_state,
> > __entry->which = which;
> > __entry->expires = expires;
> > __entry->value_sec = value->it_value.tv_sec;
> > - __entry->value_usec = value->it_value.tv_usec;
> > + __entry->value_usec = value->it_value.tv_nsec / NSEC_PER_USEC;
> > __entry->interval_sec = value->it_interval.tv_sec;
> > - __entry->interval_usec = value->it_interval.tv_usec;
> > + __entry->interval_usec = value->it_interval.tv_nsec / NSEC_PER_USEC;
>
> Hmm, having a division in a tracepoint is clearly suboptimal.
Ok, moving it to the TP_printk() as Steven suggested.
> > - TP_printk("which=%d expires=%llu it_value=%ld.%ld it_interval=%ld.%ld",
> > + TP_printk("which=%d expires=%llu it_value=%ld.%06ld it_interval=%ld.%06ld",
>
> We print only 6 digits after the . so that would be even correct w/o a
> division. But it probably does not matter much.
This is just a cosmetic fix, it can be a separate patch if you care. The idea
is to print the numbers as normal decimal representation, e.g. 0.001000
for a millisecond instead of the nonstandard 0.1000.
> > @@ -197,19 +207,13 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
> > #define timeval_valid(t) \
> > (((t)->tv_sec >= 0) && (((unsigned long) (t)->tv_usec) < USEC_PER_SEC))
>
> Hrm, why do we have yet another incarnation of timeval_valid()?
No idea, you have to ask the author of commit 7d99b7d634d8 ("[PATCH]
Validate and
sanitze itimer timeval from userspace") ;-)
> Can we please have only one (the inline version)?
I'm removing the inline version in a later patch along with most of the rest of
include/linux/time32.h.
Having the macro version is convenient for this patch, since I'm using it
on two different structures (itimerval/__kernel_old_timeval and
old_itimerval32/old_timeval32), neither of which is the type used in the
inline function.
I could use two local inline functions instead of the macro, or just open
code both call sites if you prefer that.
Arnd
next prev parent reply other threads:[~2019-11-14 10:51 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-08 21:02 [PATCH 00/23] y2038 cleanups Arnd Bergmann
2019-11-08 21:07 ` [PATCH 01/23] y2038: remove CONFIG_64BIT_TIME Arnd Bergmann
2019-11-20 22:28 ` [Y2038] " Ben Hutchings
2019-11-20 22:58 ` Dmitry Safonov
2019-11-08 21:07 ` [PATCH 02/23] y2038: add __kernel_old_timespec and __kernel_old_time_t Arnd Bergmann
2019-11-09 19:02 ` Deepa Dinamani
2019-11-20 22:30 ` [Y2038] " Ben Hutchings
2019-11-21 14:17 ` Arnd Bergmann
2019-11-08 21:07 ` [PATCH 03/23] y2038: vdso: change timeval to __kernel_old_timeval Arnd Bergmann
2019-11-13 21:56 ` Thomas Gleixner
2019-11-08 21:07 ` [PATCH 04/23] y2038: vdso: change timespec to __kernel_old_timespec Arnd Bergmann
2019-11-08 21:07 ` [PATCH 05/23] y2038: vdso: change time_t to __kernel_old_time_t Arnd Bergmann
2019-11-13 21:57 ` Thomas Gleixner
2019-11-08 21:07 ` [PATCH 06/23] y2038: vdso: nds32: open-code timespec_add_ns() Arnd Bergmann
2019-11-08 21:07 ` [PATCH 07/23] y2038: vdso: powerpc: avoid timespec references Arnd Bergmann
2019-11-20 22:43 ` [Y2038] " Ben Hutchings
2019-11-21 14:23 ` Arnd Bergmann
2019-11-21 16:25 ` Christophe Leroy
2019-11-27 11:03 ` Arnd Bergmann
2019-12-02 12:55 ` Christophe Leroy
2019-12-02 14:03 ` Arnd Bergmann
2019-11-08 21:07 ` [PATCH 08/23] y2038: ipc: remove __kernel_time_t reference from headers Arnd Bergmann
2019-11-20 22:49 ` [Y2038] " Ben Hutchings
2019-11-21 14:28 ` Arnd Bergmann
2019-11-08 21:07 ` [PATCH 09/23] y2038: stat: avoid 'time_t' in 'struct stat' Arnd Bergmann
2019-11-08 21:12 ` [PATCH 10/23] y2038: uapi: change __kernel_time_t to __kernel_old_time_t Arnd Bergmann
2019-11-09 19:03 ` Deepa Dinamani
2019-11-11 12:38 ` Christian Brauner
2019-11-08 21:12 ` [PATCH 11/23] y2038: rusage: use __kernel_old_timeval Arnd Bergmann
2019-11-12 21:09 ` Cyrill Gorcunov
2019-11-13 10:02 ` Arnd Bergmann
2019-11-13 17:22 ` Cyrill Gorcunov
2019-11-14 0:38 ` Christian Brauner
2019-11-14 10:18 ` Arnd Bergmann
2019-11-14 10:23 ` Christian Brauner
2019-11-08 21:12 ` [PATCH 12/23] y2038: syscalls: change remaining timeval to __kernel_old_timeval Arnd Bergmann
2019-11-11 12:44 ` Christian Brauner
2019-11-13 22:39 ` Rafael J. Wysocki
2019-11-08 21:12 ` [PATCH 13/23] y2038: socket: remove timespec reference in timestamping Arnd Bergmann
2019-11-09 19:03 ` Deepa Dinamani
2019-11-11 20:24 ` Arnd Bergmann
2019-11-08 21:12 ` [PATCH 14/23] y2038: make ns_to_compat_timeval use __kernel_old_timeval Arnd Bergmann
2019-11-08 21:12 ` [PATCH 15/23] y2038: elfcore: Use __kernel_old_timeval for process times Arnd Bergmann
2019-11-08 21:12 ` [PATCH 16/23] y2038: timerfd: Use timespec64 internally Arnd Bergmann
2019-11-13 21:49 ` Thomas Gleixner
2019-11-08 21:12 ` [PATCH 17/23] y2038: time: avoid timespec usage in settimeofday() Arnd Bergmann
2019-11-13 21:53 ` Thomas Gleixner
2019-11-14 11:06 ` Arnd Bergmann
2019-11-14 14:04 ` Thomas Gleixner
2019-11-14 14:35 ` Arnd Bergmann
2019-11-14 23:01 ` Abel Vesa
2019-11-15 7:58 ` Arnd Bergmann
2019-11-15 10:27 ` Rasmus Villemoes
2019-11-15 13:50 ` Arnd Bergmann
2019-11-08 21:12 ` [PATCH 18/23] y2038: itimer: compat handling to itimer.c Arnd Bergmann
2019-11-13 21:54 ` Thomas Gleixner
2019-11-08 21:12 ` [PATCH 19/23] y2038: use compat_{get,set}_itimer on alpha Arnd Bergmann
2019-12-02 13:13 ` Guenter Roeck
2019-11-08 21:12 ` [PATCH 20/23] y2038: move itimer reset into itimer.c Arnd Bergmann
2019-11-09 13:43 ` Ondrej Mosnacek
2019-11-09 21:02 ` Arnd Bergmann
2019-11-09 23:07 ` Ondrej Mosnacek
2019-11-11 10:57 ` Arnd Bergmann
2019-11-14 8:51 ` Ondrej Mosnacek
2019-11-14 10:51 ` Thomas Gleixner
2019-11-13 22:03 ` Thomas Gleixner
2019-11-08 21:12 ` [PATCH 21/23] y2038: itimer: change implementation to timespec64 Arnd Bergmann
2019-11-13 22:28 ` Thomas Gleixner
2019-11-14 2:06 ` Steven Rostedt
2019-11-14 10:48 ` Thomas Gleixner
2019-11-14 10:52 ` Arnd Bergmann
2019-11-14 10:51 ` Arnd Bergmann [this message]
2019-11-14 10:57 ` Thomas Gleixner
2019-11-21 16:52 ` [Y2038] " Ben Hutchings
2019-11-25 20:26 ` Arnd Bergmann
2019-11-08 21:12 ` [PATCH 22/23] [RFC] y2038: itimer: use ktime_t internally Arnd Bergmann
2019-11-13 22:30 ` Thomas Gleixner
2019-11-08 21:12 ` [PATCH 23/23] y2038: allow disabling time32 system calls Arnd Bergmann
2019-11-11 12:31 ` Christian Brauner
2019-11-13 21:40 ` [PATCH 00/23] y2038 cleanups Arnd Bergmann
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