6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Arnd Bergmann <arnd@xxxxxxxx>
[ Upstream commit 542440fd7b30983cae23e32bd22f69a076ec7ef4 ]
With gcc-14.1, there is a false-postive -Wuninitialized warning in
regcache_maple_drop:
drivers/base/regmap/regcache-maple.c: In function 'regcache_maple_drop':
drivers/base/regmap/regcache-maple.c:113:23: error: 'lower_index' is used uninitialized [-Werror=uninitialized]
113 | unsigned long lower_index, lower_last;
| ^~~~~~~~~~~
drivers/base/regmap/regcache-maple.c:113:36: error: 'lower_last' is used uninitialized [-Werror=uninitialized]
113 | unsigned long lower_index, lower_last;
| ^~~~~~~~~~
I've created a reduced test case to see if this needs to be reported
as a gcc, but it appears that the gcc-14.x branch already has a change
that turns this into a more sensible -Wmaybe-uninitialized warning, so
I ended up not reporting it so far.
The reduced test case also produces a warning for gcc-13 and gcc-12
but I don't see that with the version in the kernel.
Link: https://godbolt.org/z/oKbohKqd3
Link: https://lore.kernel.org/all/CAMuHMdWj=FLmkazPbYKPevDrcym2_HDb_U7Mb9YE9ovrP0jJfA@xxxxxxxxxxxxxx/
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Link: https://patch.msgid.link/20240719104030.1382465-1-arnd@xxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/base/regmap/regcache-maple.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/base/regmap/regcache-maple.c b/drivers/base/regmap/regcache-maple.c
index 55999a50ccc0..0b6c2277128b 100644
--- a/drivers/base/regmap/regcache-maple.c
+++ b/drivers/base/regmap/regcache-maple.c
@@ -110,7 +110,8 @@ static int regcache_maple_drop(struct regmap *map, unsigned int min,
struct maple_tree *mt = map->cache;
MA_STATE(mas, mt, min, max);
unsigned long *entry, *lower, *upper;
- unsigned long lower_index, lower_last;
+ /* initialized to work around false-positive -Wuninitialized warning */
+ unsigned long lower_index = 0, lower_last = 0;
unsigned long upper_index, upper_last;
int ret = 0;
--
2.43.0
