Re: [PATCH] util/cacheinfo: fix crash when compiling with uClibc

[Carlos Santos <casantos@redhat.com>]

On Thu, Jan 16, 2020 at 9:04 PM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 12/16/19 1:18 AM, Carlos Santos wrote:
> > On Thu, Oct 17, 2019 at 8:06 PM Carlos Santos <casantos@redhat.com> wrote:
> >>
> >> On Thu, Oct 17, 2019 at 9:47 AM Peter Maydell <peter.maydell@linaro.org> wrote:
> >>>
> >>> On Thu, 17 Oct 2019 at 13:39, <casantos@redhat.com> wrote:
> >>>>
> >>>> From: Carlos Santos <casantos@redhat.com>
> >>>>
> >>>> uClibc defines _SC_LEVEL1_ICACHE_LINESIZE and _SC_LEVEL1_DCACHE_LINESIZE
> >>>> but the corresponding sysconf calls returns -1, which is a valid result,
> >>>> meaning that the limit is indeterminate.
> >>>>
> >>>> Handle this situation using the fallback values instead of crashing due
> >>>> to an assertion failure.
> >>>>
> >>>> Signed-off-by: Carlos Santos <casantos@redhat.com>
> >>>> ---
> >>>>  util/cacheinfo.c | 10 ++++++++--
> >>>>  1 file changed, 8 insertions(+), 2 deletions(-)
> >>>>
> >>>> diff --git a/util/cacheinfo.c b/util/cacheinfo.c
> >>>> index ea6f3e99bf..d94dc6adc8 100644
> >>>> --- a/util/cacheinfo.c
> >>>> +++ b/util/cacheinfo.c
> >>>> @@ -93,10 +93,16 @@ static void sys_cache_info(int *isize, int *dsize)
> >>>>  static void sys_cache_info(int *isize, int *dsize)
> >>>>  {
> >>>>  # ifdef _SC_LEVEL1_ICACHE_LINESIZE
> >>>> -    *isize = sysconf(_SC_LEVEL1_ICACHE_LINESIZE);
> >>>> +    int tmp_isize = (int) sysconf(_SC_LEVEL1_ICACHE_LINESIZE);
> >>>
> >>> Do we need the cast here ?
> >>
> >> It's there to remind the reader that a type coercion may occur, since
> >> sysconf() returns a long and isize is an int.
> >>
> >>>> +    if (tmp_isize > 0) {
> >>>> +        *isize = tmp_isize;
> >>>> +    }
> >>>>  # endif
> >>>>  # ifdef _SC_LEVEL1_DCACHE_LINESIZE
> >>>> -    *dsize = sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
> >>>> +    int tmp_dsize = (int) sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
> >>>> +    if (tmp_dsize > 0) {
> >>>> +        *dsize = tmp_dsize;
> >>>> +    }
> >>>>  # endif
> >>>>  }
> >>>>  #endif /* sys_cache_info */
> >>>> --
> >>>
> >>> thanks
> >>> -- PMM
> >>
> >> --
> >> Carlos Santos
> >> Senior Software Maintenance Engineer
> >> Red Hat
> >> casantos@redhat.com    T: +55-11-3534-6186
> >
> > Hi,
> >
> > Any chance to have this merged for Christmas? :-)
>
> No, but it's queued now.  ;-)
>
>
> r~
>

Ah, Easter, perhaps. :-)

-- 
Carlos Santos
Senior Software Maintenance Engineer
Red Hat
casantos@redhat.com    T: +55-11-3534-6186