Re: [PATCH] perf dwarf-regs: s390: Fix an off by one bug

[Ian Rogers]

On Thu, Apr 23, 2026 at 1:28 PM Dan Carpenter <error27@xxxxxxxxx> wrote:
>
> On Thu, Apr 23, 2026 at 01:24:50PM -0700, Ian Rogers wrote:
> > On Thu, Apr 23, 2026 at 12:07 AM Dan Carpenter <error27@xxxxxxxxx> wrote:
> > >
> > > Change the > comparison to >= to prevent an out of bounds access of
> > > the dwarf_s390_regnums[] array.
> > >
> > > Fixes: 1e452dd850f3 ("perf dwarf-regs: Add S390 perf to DWARF register number mapping functions")
> > > Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
> > > ---
> > >  tools/perf/util/dwarf-regs-arch/dwarf-regs-s390.c | 1 +-
> > >  1 files changed, 1 insertions(+), 1 deletions(-)
> > >
> > > diff --git a/tools/perf/util/dwarf-regs-arch/dwarf-regs-s390.c b/tools/perf/util/dwarf-regs-arch/dwarf-regs-s390.c
> > > index 310a37451bdc..f79216a7665a 100644
> > > --- a/tools/perf/util/dwarf-regs-arch/dwarf-regs-s390.c
> > > +++ b/tools/perf/util/dwarf-regs-arch/dwarf-regs-s390.c
> > > @@ -45,7 +45,7 @@ int __get_dwarf_regnum_for_perf_regnum_s390(int perf_regnum)
> > >         if (perf_regnum == 0)
> > >                 return 0;
> > >
> > > -       if (perf_regnum <  0 || perf_regnum > (int)ARRAY_SIZE(dwarf_s390_regnums) ||
> > > +       if (perf_regnum <  0 || perf_regnum >= (int)ARRAY_SIZE(dwarf_s390_regnums) ||
> >
> > It looks like this mistake was copy-pasted into these files as well:
> >  - tools/perf/util/dwarf-regs-arch/dwarf-regs-csky.c
> >  - tools/perf/util/dwarf-regs-arch/dwarf-regs-x86.c
> >  - tools/perf/util/dwarf-regs-arch/dwarf-regs-powerpc.c
> >
> > Could you fix them all?
>
> Sure.  Do you want that as four separate patches or just one patch with
> four Fixes tags?

Probably the latter as it will make backports easier. Thanks!
Ian

> regards,
> dan carpenter
>