On 5/16/21 7:05 PM, Dennis Zhou wrote:
Hello, On Sat, May 15, 2021 at 11:08:17AM -0700, trix@xxxxxxxxxx wrote:From: Tom Rix <trix@xxxxxxxxxx> 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@xxxxxxxxxx> --- 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;--2.26.3I think the proper fix would be: best_upa = 0;
I was looking for initializing with something that would work.
for (...) { }
BUG_ON(!best_upa);
WARN_ON instead?
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.
Clang 10 Tom
Thanks, Dennis
