Re: mm/vmalloc.c:3689 vread_iter() error: we previously assumed 'vm' could be null (see line 3667)

[Baoquan He <bhe@redhat.com>]

Hi Dan,

On 10/18/23 at 01:32pm, Dan Carpenter wrote:
> On Wed, Oct 18, 2023 at 04:54:33PM +0800, Baoquan He wrote:
> > Hi,
> > 
> > On 10/17/23 at 05:26pm, Dan Carpenter wrote:
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > > head:   213f891525c222e8ed145ce1ce7ae1f47921cb9c
> > > commit: 4c91c07c93bbbdd7f2d9de2beb7ee5c2a48ad8e7 mm: vmalloc: convert vread() to vread_iter()
> > > config: x86_64-allnoconfig (https://download.01.org/0day-ci/archive/20231017/202310171600.WCrsOwFj-lkp@intel.com/config)
> > > compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> > > reproduce: (https://download.01.org/0day-ci/archive/20231017/202310171600.WCrsOwFj-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>
> > > | Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> > > | Closes: https://lore.kernel.org/r/202310171600.WCrsOwFj-lkp@intel.com/
> > > 
> > > smatch warnings:
> > > mm/vmalloc.c:3689 vread_iter() error: we previously assumed 'vm' could be null (see line 3667)
> > 
> > I see the code deficit, while the reproduce link seems to be unavilable.
> > Could you double check the link and provide a good one so that I can
> > verify the code fix?
> 
> Here's a link.  :)
> 
> https://repo.or.cz/smatch.git/blob/HEAD:/Documentation/smatch.txt
> 
> Just build it and run:
> 
> ~/smatch/smatch_scripts/kchecker drivers/whatever/file.c

I don't know smatch and lkp well, and have no idea on how to use above
smatch.txt to build the target file.c. I meant in this lkp report, the
config file is available, however, the reproduce file is empty. Could
you help add an available reproduce file link? or give a little more
detail guiding me how to make use of above smatch file to build .c file?
Thanks a lot in advance.

config: x86_64-allnoconfig (https://download.01.org/0day-ci/archive/20231017/202310171600.WCrsOwFj-lkp@intel.com/config)
reproduce: (https://download.01.org/0day-ci/archive/20231017/202310171600.WCrsOwFj-lkp@intel.com/reproduce)

Thanks
Baoquan