Re: [PATCH v3] kdb: remove unnecessary null check of dbg_io_ops

Andy Shevchenko
2020-06-30T11:48:57Z

On Tue, Jun 30, 2020 at 05:06:31PM +0530, Sumit Garg wrote:
> On Tue, 30 Jun 2020 at 14:00, Cengiz Can <cengiz@kernel.wtf> wrote:
> >
> > `kdb_msg_write` operates on a global `struct kgdb_io *` called
> > `dbg_io_ops`.
> >
> > It's initialized in `debug_core.c` and checked throughout the debug
> > flow.
> >
> > There's a null check in `kdb_msg_write` which triggers static analyzers
> > and gives the (almost entirely wrong) impression that it can be null.
> >
> > Coverity scanner caught this as CID 1465042.
> >
> > I have removed the unnecessary null check and eliminated false-positive
> > forward null dereference warning.

> > - while (len--) {
> > - dbg_io_ops->write_char(*cp);
> > - cp++;
> > - }
> > + while (len--) {
> > + dbg_io_ops->write_char(*cp);
> > + cp++;
> > }

Despite being in the original code this can be simple done in two lines:

while (len--)
dbg_io_ops->write_char(*cp++);

--
With Best Regards,
Andy Shevchenko