From: Changcheng Deng <deng.changcheng@xxxxxxxxxx>
do_div() does a 64-by-32 division. Here the divisor is an unsigned long
which on some platforms is 64 bit wide. So use div64_ul instead of do_div
to avoid a possible truncation.
Reported-by: Zeal Robot <zealci@xxxxxxxxxx>
Signed-off-by: Changcheng Deng <deng.changcheng@xxxxxxxxxx>
---
mm/page_alloc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8dd6399bafb5..60469b616ac1 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8431,7 +8431,7 @@ static void __setup_per_zone_wmarks(void)
spin_lock_irqsave(&zone->lock, flags);
tmp = (u64)pages_min * zone_managed_pages(zone);
- do_div(tmp, lowmem_pages);
+ tmp = div64_ul(tmp, lowmem_pages);
if (is_highmem(zone)) {
/*
* __GFP_HIGH and PF_MEMALLOC allocations usually don't
@@ -8804,7 +8804,7 @@ void *__init alloc_large_system_hash(const char *tablename,
/* limit allocation size to 1/16 total memory by default */
if (max == 0) {
max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
- do_div(max, bucketsize);
+ max = div64_ul(max, bucketsize);
}
max = min(max, 0x80000000ULL);
--
2.25.1
