Messages in this thread |  | | Date | Mon, 17 May 2021 02:05:11 +0000 | From | Dennis Zhou <> | Subject | Re: [PATCH] percpu: initialize best_upa variable |
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Hello,
On Sat, May 15, 2021 at 11:08:17AM -0700, trix@redhat.com wrote: > From: Tom Rix <trix@redhat.com> > > Static analysis reports this problem > percpu.c:2945:6: warning: Assigned value is garbage or undefined > upa = best_upa; > ^ ~~~~~~~~ > best_upa may not be set, so initialize it. > > Signed-off-by: Tom Rix <trix@redhat.com> > --- > mm/percpu.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/percpu.c b/mm/percpu.c > index a257c3efdf18b..6578b706fae81 100644 > --- a/mm/percpu.c > +++ b/mm/percpu.c > @@ -2916,6 +2916,7 @@ static struct pcpu_alloc_info * __init __flatten pcpu_build_alloc_info( > * Related to atom_size, which could be much larger than the unit_size. > */ > last_allocs = INT_MAX; > + best_upa = max_upa; > for (upa = max_upa; upa; upa--) { > int allocs = 0, wasted = 0; > > -- > 2.26.3 >
I think the proper fix would be:
best_upa = 0; for (...) { } BUG_ON(!best_upa); upa = best_upa;
If you're fine with this I'll make the changes and apply it to for-5.13-fixes.
Can you also tell me what static analysis tool produced this? I'm just a little curious because this code hasn't changed in several years so I'd have expected some static analyzer to have caught this by now.
Thanks, Dennis
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