Re: [tip:timers/vdso] BUILD SUCCESS WITH UNVERIFIED WARNING 4c6736970fbf35aa65512ce7f82abd970f133c8e

From: Thomas Weißschuh

Date: Fri Nov 07 2025 - 09:54:42 EST


On Mon, Nov 03, 2025 at 12:58:28AM +0800, kernel test robot wrote:
> tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/vdso
> branch HEAD: 4c6736970fbf35aa65512ce7f82abd970f133c8e clocksource: Remove ARCH_CLOCKSOURCE_DATA
>
> Unverified Warning (likely false positive, kindly check if interested):
>
> arch/sparc/include/uapi/../../../../lib/vdso/gettimeofday.c:325 __cvdso_clock_gettime_common() warn: bitwise AND condition is false here
> arch/sparc/include/uapi/../../../../lib/vdso/gettimeofday.c:325 __cvdso_clock_gettime_common() warn: right shifting more than type allows 32 vs 40

While I can't reproduce this specific warning, this is most likely an issue in
the sparse configuration in the kernel. The CHECKFLAGS are not adapted for the
compat vDSO. Therefore sparse runs with a mixed 32-bit and 64-bit configuration.
Other architectures are also affected.

There are a few different aproaches for cleaning this up, but I'm not sure yet
which to use.

(...)