kernel/time/timekeeping.c:807:19-20: WARNING opportunity for min()

[kernel test robot <lkp@intel.com>]

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
CC: linux-kernel@vger.kernel.org
TO: Adrian Hunter <adrian.hunter@intel.com>
CC: Thomas Gleixner <tglx@linutronix.de>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   8c245fe7dde3bf776253550fc914a36293db4ff3
commit: fcf190c369149c3b04539797cedf28741eb14164 timekeeping: Make delta calculation overflow safe
date:   6 months ago
:::::: branch date: 7 hours ago
:::::: commit date: 6 months ago
config: mips-randconfig-r062-20241004 (https://download.01.org/0day-ci/archive/20241004/202410040856.IAPgOjON-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project fef3566a25ff0e34fb87339ba5e13eca17cec00f)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Julia Lawall <julia.lawall@inria.fr>
| Closes: https://lore.kernel.org/r/202410040856.IAPgOjON-lkp@intel.com/

cocci warnings: (new ones prefixed by >>)
>> kernel/time/timekeeping.c:807:19-20: WARNING opportunity for min()

vim +807 kernel/time/timekeeping.c

cc06268c6a87db1 Thomas Gleixner    2011-11-13  787  
8524070b7982d76 John Stultz        2007-05-08  788  /**
155ec60226ae0ae Martin Schwidefsky 2009-08-14  789   * timekeeping_forward_now - update clock to the current time
6e5a91901c2dff3 Alex Shi           2020-11-13  790   * @tk:		Pointer to the timekeeper to update
8524070b7982d76 John Stultz        2007-05-08  791   *
9a055117d3d9cb5 Roman Zippel       2008-08-20  792   * Forward the current clock to update its state since the last call to
9a055117d3d9cb5 Roman Zippel       2008-08-20  793   * update_wall_time(). This is useful before significant clock changes,
9a055117d3d9cb5 Roman Zippel       2008-08-20  794   * as it avoids having to deal with this time offset explicitly.
8524070b7982d76 John Stultz        2007-05-08  795   */
f726a697d06102e John Stultz        2012-07-13  796  static void timekeeping_forward_now(struct timekeeper *tk)
8524070b7982d76 John Stultz        2007-05-08  797  {
a5a1d1c2914b531 Thomas Gleixner    2016-12-21  798  	u64 cycle_now, delta;
8524070b7982d76 John Stultz        2007-05-08  799  
ceea5e3771ed237 John Stultz        2017-06-08  800  	cycle_now = tk_clock_read(&tk->tkr_mono);
876e78818def298 Peter Zijlstra     2015-03-19  801  	delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask);
876e78818def298 Peter Zijlstra     2015-03-19  802  	tk->tkr_mono.cycle_last = cycle_now;
4a4ad80d32cea69 Peter Zijlstra     2015-03-19  803  	tk->tkr_raw.cycle_last  = cycle_now;
8524070b7982d76 John Stultz        2007-05-08  804  
fcf190c369149c3 Adrian Hunter      2024-03-25  805  	while (delta > 0) {
fcf190c369149c3 Adrian Hunter      2024-03-25  806  		u64 max = tk->tkr_mono.clock->max_cycles;
fcf190c369149c3 Adrian Hunter      2024-03-25 @807  		u64 incr = delta < max ? delta : max;
fc6eead7c1e2e53 John Stultz        2017-05-22  808  
fcf190c369149c3 Adrian Hunter      2024-03-25  809  		tk->tkr_mono.xtime_nsec += incr * tk->tkr_mono.mult;
fcf190c369149c3 Adrian Hunter      2024-03-25  810  		tk->tkr_raw.xtime_nsec += incr * tk->tkr_raw.mult;
fc6eead7c1e2e53 John Stultz        2017-05-22  811  		tk_normalize_xtime(tk);
fcf190c369149c3 Adrian Hunter      2024-03-25  812  		delta -= incr;
fcf190c369149c3 Adrian Hunter      2024-03-25  813  	}
8524070b7982d76 John Stultz        2007-05-08  814  }
8524070b7982d76 John Stultz        2007-05-08  815  

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