In function walk_hugetlb_range, the local variable err may
be used uninitialzed when:
ops->pte_hole in side of "else if (ops->pte_hole)" is false.
Signed-off-by: Zhouyi Zhou <zhouzhouyi@xxxxxxxxx>
---
Dear mm Developers:
When I build kernel using "make CC=clang-14"
the compiler complains following:
CC mm/pagewalk.o
mm/pagewalk.c:318:12: error: variable 'err' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
else if (ops->pte_hole)
^~~~~~~~~~~~~
mm/pagewalk.c:321:7: note: uninitialized use occurs here
if (err)
^~~
mm/pagewalk.c:318:8: note: remove the 'if' if its condition is always true
else if (ops->pte_hole)
^~~~~~~~~~~~~~~~~~
mm/pagewalk.c:311:10: note: initialize the variable 'err' to silence this warning
int err;
^
= 0
1 error generated.
make[1]: *** [scripts/Makefile.build:250: mm/pagewalk.o] Error 1
make: *** [Makefile:2006: mm] Error 2
I initialize that variable outside of the for loop because we can assign 0 to err
only once in this function.
After my fix, I can compile the kernel.
Many Thanks
Zhouyi
--
mm/pagewalk.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 54b2a1beeeb3..b6eb330e8ecd 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -306,9 +306,9 @@ static int walk_hugetlb_range(unsigned long addr, unsigned long end,
unsigned long hmask = huge_page_mask(h);
unsigned long sz = huge_page_size(h);
const struct mm_walk_ops *ops = walk->ops;
+ int err = 0;
for (; addr < end; addr = next) {
- int err;
pte_t *pte = huge_pte_offset(walk->mm, addr & hmask, sz);
next = hugetlb_entry_end(h, addr, end);
--
2.34.1
