Re: kernel/vmcore_info.c:117 paddr_vmcoreinfo_note() warn: unsigned '_x' is never less than zero.

[Philip Li <philip.li@intel.com>]

On Sat, Feb 15, 2025 at 06:24:50PM +0800, Baoquan He wrote:
> On 02/14/25 at 06:44pm, kernel test robot wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   128c8f96eb8638c060cd3532dc394d046ce64fe1
> > commit: 443cbaf9e2fdbef7d7cae457434a6cb8a679441b crash: split vmcoreinfo exporting code out from crash_core.c
> > date:   12 months ago
> > config: riscv-randconfig-r073-20250213 (https://download.01.org/0day-ci/archive/20250214/202502141843.5QoKdQ7g-lkp@intel.com/config)
> > compiler: riscv32-linux-gcc (GCC) 14.2.0
> > 
> > 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/202502141843.5QoKdQ7g-lkp@intel.com/
> > 
> > smatch warnings:
> > kernel/vmcore_info.c:117 paddr_vmcoreinfo_note() warn: unsigned '_x' is never less than zero.
> 
> Thanks for reporting this.
> 
> I am preparing to reproduce this issue, while I may not know what are
> the steps to reproduce.  Just run smatch or just build with the provided
> riscv-randconfig-r073-20250213?

Sorry for late reply, this is from smatch. There're multiple reports similar
to this, and one discussion is at [1], not sure whether this is a false positive.

[1] https://lore.kernel.org/oe-kbuild-all/Z7PWuSA4jtZnxp5J@rli9-mobl/T/#t

> 
> > 
> > vim +/_x +117 kernel/vmcore_info.c
> > 
> >    114	
> >    115	phys_addr_t __weak paddr_vmcoreinfo_note(void)
> >    116	{
> >  > 117		return __pa(vmcoreinfo_note);
> >    118	}
> >    119	EXPORT_SYMBOL(paddr_vmcoreinfo_note);
> >    120	
> > 
> > -- 
> > 0-DAY CI Kernel Test Service
> > https://github.com/intel/lkp-tests/wiki
> > 
> 
>