Re: [PATCH 06/10] cmdline: fix highest bit port list parsing

[David Marchand <david.marchand@redhat.com>]

On Fri, Jun 20, 2025 at 11:22 AM Bruce Richardson
<bruce.richardson@intel.com> wrote:
>
> On Thu, Jun 19, 2025 at 09:10:32AM +0200, David Marchand wrote:
> > pl->map is a uint32_t.
> >
> > Caught by UBSan:
> >
> > ../lib/cmdline/cmdline_parse_portlist.c:27:17: runtime error:
> >       left shift of 1 by 31 places cannot be represented in type 'int'
> > SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior
> >       ../lib/cmdline/cmdline_parse_portlist.c:27:17 in
> >
> > Fixes: af75078fece3 ("first public release")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: David Marchand <david.marchand@redhat.com>
> > ---
> >  lib/cmdline/cmdline_parse_portlist.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/lib/cmdline/cmdline_parse_portlist.c b/lib/cmdline/cmdline_parse_portlist.c
> > index 0c07cc02b5..3ef427d32a 100644
> > --- a/lib/cmdline/cmdline_parse_portlist.c
> > +++ b/lib/cmdline/cmdline_parse_portlist.c
> > @@ -11,7 +11,9 @@
> >  #include <errno.h>
> >
> >  #include <eal_export.h>
> > +#include <rte_bitops.h>
> >  #include <rte_string_fns.h>
> > +
> >  #include "cmdline_parse.h"
> >  #include "cmdline_parse_portlist.h"
> >
> > @@ -27,7 +29,7 @@ static void
> >  parse_set_list(cmdline_portlist_t *pl, size_t low, size_t high)
> >  {
> >       do {
> > -             pl->map |= (1 << low++);
> > +             pl->map |= RTE_BIT32(low++);
> >       } while (low <= high);
> >  }
> >
> While this is correct, the use of "++" in a call to a macro sets off some
> alarm bells for me!
> Can we put the "++" in the while instead, as "++low"?

It would be safer yes.


-- 
David Marchand