[tip:timers/ptp 39/39] lib/vdso/gettimeofday.c:335:17: warning: shift count >= width of type

[tip:timers/ptp 39/39] lib/vdso/gettimeofday.c:335:17: warning: shift count >= width of type

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/ptp
head:   7893ea1006fcbb876ddf53ad4ebba4a054add4b2
commit: 7893ea1006fcbb876ddf53ad4ebba4a054add4b2 [39/39] vdso/gettimeofday: Add support for auxiliary clocks
config: powerpc-allyesconfig (https://download.01.org/0day-ci/archive/20250708/202507080348.hKtUspGk-lkp@intel.com/config)
compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project 01c97b4953e87ae455bd4c41e3de3f0f0f29c61c)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250708/202507080348.hKtUspGk-lkp@intel.com/reproduce)

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>
| Closes: https://lore.kernel.org/oe-kbuild-all/202507080348.hKtUspGk-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from <built-in>:4:
>> lib/vdso/gettimeofday.c:335:17: warning: shift count >= width of type [-Wshift-count-overflow]
     335 |         else if (msk & VDSO_AUX)
         |                        ^~~~~~~~
   include/vdso/datapage.h:50:18: note: expanded from macro 'VDSO_AUX'
      50 | #define VDSO_AUX        __GENMASK(CLOCK_AUX_LAST, CLOCK_AUX)
         |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/uapi/linux/bits.h:7:56: note: expanded from macro '__GENMASK'
       7 | #define __GENMASK(h, l) (((~_UL(0)) << (l)) & (~_UL(0) >> (BITS_PER_LONG - 1 - (h))))
         |                                                        ^  ~~~~~~~~~~~~~~~~~~~~~~~~~
   In file included from <built-in>:4:
   lib/vdso/gettimeofday.c:481:19: warning: shift count >= width of type [-Wshift-count-overflow]
     481 |         } else if (msk & VDSO_AUX) {
         |                          ^~~~~~~~
   include/vdso/datapage.h:50:18: note: expanded from macro 'VDSO_AUX'
      50 | #define VDSO_AUX        __GENMASK(CLOCK_AUX_LAST, CLOCK_AUX)
         |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/uapi/linux/bits.h:7:56: note: expanded from macro '__GENMASK'
       7 | #define __GENMASK(h, l) (((~_UL(0)) << (l)) & (~_UL(0) >> (BITS_PER_LONG - 1 - (h))))
         |                                                        ^  ~~~~~~~~~~~~~~~~~~~~~~~~~
   2 warnings generated.
--
   In file included from <built-in>:4:
>> lib/vdso/gettimeofday.c:335:17: warning: shift count >= width of type [-Wshift-count-overflow]
     335 |         else if (msk & VDSO_AUX)
         |                        ^~~~~~~~
   include/vdso/datapage.h:50:18: note: expanded from macro 'VDSO_AUX'
      50 | #define VDSO_AUX        __GENMASK(CLOCK_AUX_LAST, CLOCK_AUX)
         |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/uapi/linux/bits.h:7:56: note: expanded from macro '__GENMASK'
       7 | #define __GENMASK(h, l) (((~_UL(0)) << (l)) & (~_UL(0) >> (BITS_PER_LONG - 1 - (h))))
         |                                                        ^  ~~~~~~~~~~~~~~~~~~~~~~~~~
   In file included from <built-in>:4:
   lib/vdso/gettimeofday.c:481:19: warning: shift count >= width of type [-Wshift-count-overflow]
     481 |         } else if (msk & VDSO_AUX) {
         |                          ^~~~~~~~
   include/vdso/datapage.h:50:18: note: expanded from macro 'VDSO_AUX'
      50 | #define VDSO_AUX        __GENMASK(CLOCK_AUX_LAST, CLOCK_AUX)
         |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/uapi/linux/bits.h:7:56: note: expanded from macro '__GENMASK'
       7 | #define __GENMASK(h, l) (((~_UL(0)) << (l)) & (~_UL(0) >> (BITS_PER_LONG - 1 - (h))))
         |                                                        ^  ~~~~~~~~~~~~~~~~~~~~~~~~~
   2 warnings generated.


vim +335 lib/vdso/gettimeofday.c

   313	
   314	static __always_inline bool
   315	__cvdso_clock_gettime_common(const struct vdso_time_data *vd, clockid_t clock,
   316				     struct __kernel_timespec *ts)
   317	{
   318		const struct vdso_clock *vc = vd->clock_data;
   319		u32 msk;
   320	
   321		if (!vdso_clockid_valid(clock))
   322			return false;
   323	
   324		/*
   325		 * Convert the clockid to a bitmask and use it to check which
   326		 * clocks are handled in the VDSO directly.
   327		 */
   328		msk = 1U << clock;
   329		if (likely(msk & VDSO_HRES))
   330			vc = &vc[CS_HRES_COARSE];
   331		else if (msk & VDSO_COARSE)
   332			return do_coarse(vd, &vc[CS_HRES_COARSE], clock, ts);
   333		else if (msk & VDSO_RAW)
   334			vc = &vc[CS_RAW];
 > 335		else if (msk & VDSO_AUX)
   336			return do_aux(vd, clock, ts);
   337		else
   338			return false;
   339	
   340		return do_hres(vd, vc, clock, ts);
   341	}
   342	

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