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

From: Dan Carpenter
Date: Wed Oct 18 2023 - 06:56:11 EST


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@xxxxxxxxx/config)
> > compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> > reproduce: (https://download.01.org/0day-ci/archive/20231017/202310171600.WCrsOwFj-lkp@xxxxxxxxx/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@xxxxxxxxx>
> > | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > | Closes: https://lore.kernel.org/r/202310171600.WCrsOwFj-lkp@xxxxxxxxx/
> >
> > 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

regards,
dan carpenter