[PATCH 6.19 058/844] tools/power cpupower: Reset errno before strtoull()

[Sasha Levin]

From: Kaushlendra Kumar <kaushlendra.kumar@xxxxxxxxx>

[ Upstream commit f9bd3762cf1bd0c2465f2e6121b340883471d1bf ]

cpuidle_state_get_one_value() never cleared errno before calling
strtoull(), so a prior ERANGE caused every cpuidle counter read to
return zero. Reset errno to 0 before the conversion so each sysfs read
is evaluated independently.

Link: https://lore.kernel.org/r/20251201121745.3776703-1-kaushlendra.kumar@xxxxxxxxx
Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@xxxxxxxxx>
Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 tools/power/cpupower/lib/cpuidle.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/power/cpupower/lib/cpuidle.c b/tools/power/cpupower/lib/cpuidle.c
index f2c1139adf716..bd857ee7541a7 100644
--- a/tools/power/cpupower/lib/cpuidle.c
+++ b/tools/power/cpupower/lib/cpuidle.c
@@ -150,6 +150,7 @@ unsigned long long cpuidle_state_get_one_value(unsigned int cpu,
 	if (len == 0)
 		return 0;
 
+	errno = 0;
 	value = strtoull(linebuf, &endp, 0);
 
 	if (endp == linebuf || errno == ERANGE)
-- 
2.51.0