Messages in this thread Patch in this message | | | Date | Sat, 4 Aug 2012 21:21:14 +0200 | From | Ingo Molnar <> | Subject | [PATCH] time: Fix adjustment cleanup bug in timekeeping_adjust() |
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* Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> wrote:
> Hello. > > Bisected to 2a8c0883 "time: Move xtime_nsec adjustment > underflow handling timekeeping_adjust". > > Would you check?
probably caused by this stray return in timekeeping_adjust():
} else return;
which should really be a proper goto - like the (totally untested!) patch below.
Does this fix the bug for you?
Thanks,
Ingo
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Subject: time: Fix adjustment cleanup bug in timekeeping_adjust()
Also make the flow more readable by properly balancing curly braces.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 2988bc8..e16af19 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -923,20 +923,22 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset) if (likely(error <= interval)) adj = 1; else - adj = timekeeping_bigadjust(tk, error, &interval, - &offset); - } else if (error < -interval) { - /* See comment above, this is just switched for the negative */ - error >>= 2; - if (likely(error >= -interval)) { - adj = -1; - interval = -interval; - offset = -offset; - } else - adj = timekeeping_bigadjust(tk, error, &interval, - &offset); - } else - return; + adj = timekeeping_bigadjust(tk, error, &interval, &offset); + } else { + if (error < -interval) { + /* See comment above, this is just switched for the negative */ + error >>= 2; + if (likely(error >= -interval)) { + adj = -1; + interval = -interval; + offset = -offset; + } else { + adj = timekeeping_bigadjust(tk, error, &interval, &offset); + } + } else { + goto out_adjust; + } + } if (unlikely(tk->clock->maxadj && (tk->mult + adj > tk->clock->mult + tk->clock->maxadj))) { @@ -999,6 +1001,7 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset) tk->xtime_nsec -= offset; tk->ntp_error -= (interval - offset) << tk->ntp_error_shift; +out_adjust: /* * It may be possible that when we entered this function, xtime_nsec * was very small. Further, if we're slightly speeding the clocksource
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