linux-kernel - [PATCH 7/6] mm: pagewalk: add back missing variable initializations

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Message-ID: <2123960.ggj6I0NvhH@mobilepool36.emlix.com>
Date:   Wed, 24 Aug 2022 13:00:11 +0200
From:   Rolf Eike Beer <eb@...ix.com>
To:     Andrew Morton <akpm@...ux-foundation.org>
Cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        Dan Carpenter <dan.carpenter@...cle.com>,
        Nathan Chancellor <nathan@...nel.org>
Subject: [PATCH 7/6] mm: pagewalk: add back missing variable initializations

These initializations accidentially got lost during refactoring.

The first one can't actually be used without initialization, because
walk_p4d_range() is only called when one of the 4 callbacks is set, but relying
on this seems fragile.

Reported-by: Linux Kernel Functional Testing <lkft@...aro.org>
Reported-by: kernel test robot <lkp@...el.com>
Reported-by: Dan Carpenter <dan.carpenter@...cle.com>
Signed-off-by: Rolf Eike Beer <eb@...ix.com>
---
 mm/pagewalk.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Looks like my testing had just the right callbacks set so I never hit this. In 
case you want to have this squashed into the original one just drop me a note 
and I'll redo the whole series.

diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index d8be8a30b272..22e4bcca9bee 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -223,7 +223,7 @@ static int walk_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
 
 	p4d = p4d_offset(pgd, addr);
 	do {
-		int err;
+		int err = 0;
 
 		next = p4d_addr_end(addr, end);
 		if (p4d_none_or_clear_bad(p4d)) {
@@ -262,7 +262,7 @@ static int walk_pgd_range(unsigned long addr, unsigned long end,
 	else
 		pgd = pgd_offset(walk->mm, addr);
 	do {
-		int err;
+		int err = 0;
 
 		next = pgd_addr_end(addr, end);
 		if (pgd_none_or_clear_bad(pgd)) {
@@ -308,7 +308,7 @@ static int walk_hugetlb_range(unsigned long addr, unsigned long end,
 	const struct mm_walk_ops *ops = walk->ops;
 
 	for (; addr < end; addr = next) {
-		int err;
+		int err = 0;
 		pte_t *pte = huge_pte_offset(walk->mm, addr & hmask, sz);
 
 		next = hugetlb_entry_end(h, addr, end);
-- 
2.37.2

-- 
Rolf Eike Beer, emlix GmbH, https://www.emlix.com
Fon +49 551 30664-0, Fax +49 551 30664-11
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