tile should be: [PATCH] x86: ....
On Tue, Nov 25, 2014 at 11:14 AM, Louis Langholtz <[email protected]> wrote: > The cmp_range function (in kernel/range.c) is returning the difference > between two s64 values (actually coming from u64 typed variables) in an int > which can overflow (depending on the size of int). This function is used as a > compare function for linux's sort function (in lib/sort.c). Linux's sort > function however only cares if the compare function returns a value less > than, equal to, or greater than zero. > > As sort doesn't need the actual difference, this overflow potential is > avoided with the following patch (against linux kernel 3.18 code from Linus's > git repo and commit 0541881502a1276149889fe468662ff6a8fc8f6d): > > commit 641362d32fef0cfd7b12e1821c1139d75dd23330 > Author: Lou Langholtz <[email protected]> > Date: Mon Nov 24 09:31:01 2014 -0700 do not need 6 lines. > > Avoid overflow possibility You need Signed-off-by: .... Please check Documentation/SubmittingPatches for more info. > > diff --git a/kernel/range.c b/kernel/range.c > index 322ea8e..86337e2 100644 > --- a/kernel/range.c > +++ b/kernel/range.c > @@ -113,12 +113,17 @@ static int cmp_range(const void *x1, const void *x2) > { > const struct range *r1 = x1; > const struct range *r2 = x2; > - s64 start1, start2; > + u64 start1, start2; > > start1 = r1->start; > start2 = r2->start; > > - return start1 - start2; > + /* avoid any overflow possibilities and don't just return start1 - > start2 */ > + if (start1 > start2) > + return 1; > + if (start2 > start1) > + return -1; > + return 0; > } > > int clean_sort_range(struct range *range, int az) > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
