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From: Frederic Weisbecker <frederic@kernel.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Anna-Maria Behnsen <anna-maria@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	syzbot+5c54bd3eb218bb595aa9@syzkaller.appspotmail.com,
	Dmitry Vyukov <dvyukov@google.com>,
	Sebastian Siewior <bigeasy@linutronix.de>,
	Michael Kerrisk <mtk.manpages@gmail.com>
Subject: Re: [patch 02/20] posix-timers: Ensure timer ID search-loop limit is valid
Date: Tue, 9 May 2023 16:18:28 +0200	[thread overview]
Message-ID: <ZFpWNIoTo9FfO2t5@lothringen> (raw)
In-Reply-To: <877cth1xyd.ffs@tglx>

On Tue, May 09, 2023 at 02:38:50PM +0200, Thomas Gleixner wrote:
> On Tue, May 09 2023 at 11:42, Frederic Weisbecker wrote:
> > On Sat, May 06, 2023 at 01:36:22AM +0200, Thomas Gleixner wrote:
> >> Unless you think about the theoretical case of an unlimited number of
> >> threads sharing the signal_struct which all concurrently try to allocate
> >> a timer id and then releasing it immediately again (to avoid resource
> >> limit exhaustion). Theoretically possible, but is this a real concern
> >> with a timer ID space of 2G?
> >
> > I didn't go that far actually, it was just me misunderstanding that loop and
> > especially the (id =~start) part. Now I got it.
> >
> > I guess the for statement can just be:
> >
> > for (; start != id; id++)
> 
> My brain based compiler complains about uninitialized usage of @id. I'm
> pretty sure it's rightfully complaining and a real compiler would agree,
> no?

*sigh* I should think more before pressing answer these days :)

  reply	other threads:[~2023-05-09 14:18 UTC|newest]

Thread overview: 122+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-25 18:48 [patch 00/20] posix-timers: Fixes and cleanups Thomas Gleixner
2023-04-25 18:48 ` [patch 01/20] posix-timers: Prevent RT livelock in itimer_delete() Thomas Gleixner
2023-05-04 17:06   ` Frederic Weisbecker
2023-05-04 18:20     ` Thomas Gleixner
2023-05-05  7:57       ` Thomas Gleixner
2023-06-01 19:00         ` [patch v2 " Thomas Gleixner
2023-06-01 20:16           ` [patch v2a " Thomas Gleixner
2023-06-05 10:59             ` Frederic Weisbecker
2023-06-05 15:08             ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:50             ` tip-bot2 for Thomas Gleixner
2023-04-25 18:48 ` [patch 02/20] posix-timers: Ensure timer ID search-loop limit is valid Thomas Gleixner
2023-05-05 14:50   ` Frederic Weisbecker
2023-05-05 22:58     ` Thomas Gleixner
2023-05-05 23:36       ` Thomas Gleixner
2023-05-08 21:57         ` Thomas Gleixner
2023-05-09  9:30           ` Thomas Gleixner
2023-05-09 12:50             ` Thomas Gleixner
2023-05-09 21:42               ` [RFD] posix-timers: CRIU woes Thomas Gleixner
2023-05-10  4:36                 ` Pavel Tikhomirov
2023-05-10  8:30                   ` Thomas Gleixner
2023-05-11  4:12                     ` Pavel Tikhomirov
2023-05-11  7:56                       ` Peter Zijlstra
2023-05-11  9:32                       ` Thomas Gleixner
2023-05-11 10:13                   ` David Laight
2023-05-10  8:16                 ` Andrey Vagin
2023-05-11  3:17                   ` Pavel Tikhomirov
2023-05-11  9:36                     ` Thomas Gleixner
2023-05-11  9:52                       ` Pavel Tikhomirov
2023-05-11 13:42                         ` Thomas Gleixner
2023-05-11 14:54                           ` Pavel Tikhomirov
2023-05-11 15:25                           ` Pavel Tikhomirov
2023-05-12  1:21                       ` Andrey Vagin
2023-05-31 17:38                         ` Thomas Gleixner
2023-05-11  7:49                   ` Cyrill Gorcunov
2023-05-10  0:42               ` [patch 02/20] posix-timers: Ensure timer ID search-loop limit is valid Andrey Vagin
2023-05-09  9:42         ` Frederic Weisbecker
2023-05-09 12:04           ` Thomas Gleixner
2023-05-09 12:38           ` Thomas Gleixner
2023-05-09 14:18             ` Frederic Weisbecker [this message]
2023-06-01 18:58               ` [patch v2 " Thomas Gleixner
2023-06-05 14:17                 ` Frederic Weisbecker
2023-06-05 15:08                 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:50                 ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 03/20] posix-timers: Clarify timer_wait_running() comment Thomas Gleixner
2023-05-09  9:50   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:50   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 04/20] posix-timers: Cleanup comments about timer ID tracking Thomas Gleixner
2023-05-09  9:58   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:50   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 05/20] posix-timers: Add comments about timer lookup Thomas Gleixner
2023-05-09 10:58   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:50   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 06/20] posix-timers: Annotate concurrent access to k_itimer::it_signal Thomas Gleixner
2023-05-09 11:04   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] posix-timers: Annotate concurrent access to k_itimer:: It_signal tip-bot2 for Thomas Gleixner
2023-06-18 20:50   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 07/20] posix-timers: Set k_itimer::it_signal to NULL on exit() Thomas Gleixner
2023-06-01 10:09   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] posix-timers: Set k_itimer:: It_signal " tip-bot2 for Thomas Gleixner
2023-06-18 20:50   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 08/20] posix-timers: Remove pointless irqsafe from hash_lock Thomas Gleixner
2023-06-01 10:12   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:50   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 09/20] posix-timers: Split release_posix_timers() Thomas Gleixner
2023-06-01 10:25   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:50   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 10/20] posix-timers: Document sys_clock_getres() correctly Thomas Gleixner
2023-06-01 10:44   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:50   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 11/20] posix-timers: Document common_clock_get() correctly Thomas Gleixner
2023-06-01 11:00   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:50   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 12/20] posix-timers: Document sys_clock_getoverrun() Thomas Gleixner
2023-06-01 11:06   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:50   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 13/20] posix-timers: Document sys_clock_settime() permissions in place Thomas Gleixner
2023-06-01 11:22   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:50   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 14/20] posix-timers: Document nanosleep() details Thomas Gleixner
2023-06-01 12:30   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:49   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 15/20] posix-timers: Add proper comments in do_timer_create() Thomas Gleixner
2023-06-01 12:43   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:49   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 16/20] posix-timers: Comment SIGEV_THREAD_ID properly Thomas Gleixner
2023-06-01 12:47   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:49   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 17/20] posix-timers: Clarify posix_timer_rearm() comment Thomas Gleixner
2023-06-01 12:52   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-18 20:49   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 18/20] posix-timers: Clarify posix_timer_fn() comments Thomas Gleixner
2023-06-01 13:21   ` Frederic Weisbecker
2023-06-01 18:43     ` Thomas Gleixner
2023-06-01 19:07     ` Thomas Gleixner
2023-06-05 14:26       ` Frederic Weisbecker
2023-06-05 15:08       ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-05 22:17       ` tip-bot2 for Thomas Gleixner
2023-06-18 20:49       ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 19/20] posix-timers: Remove pointless comments Thomas Gleixner
2023-06-01 13:48   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-05 22:17   ` tip-bot2 for Thomas Gleixner
2023-06-18 20:49   ` tip-bot2 for Thomas Gleixner
2023-04-25 18:49 ` [patch 20/20] posix-timers: Polish coding style in a few places Thomas Gleixner
2023-06-01 13:50   ` Frederic Weisbecker
2023-06-05 15:08   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2023-06-05 22:17   ` tip-bot2 for Thomas Gleixner
2023-06-18 20:49   ` tip-bot2 for Thomas Gleixner
2023-06-05 14:32 ` [patch 00/20] posix-timers: Fixes and cleanups Frederic Weisbecker

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