[PATCH] hwmon: (pmbus/core) Avoid race condition during probe

pmbus_write_smbalert_mask() is not guarded, which can cause race conditions
with concurrent sysfs attribute accesses.

Similar, PMBus accesses in pmbus_init_debugfs() are not guarded, also
resulting in potential race conditions.

Add guards to both functions to prevent the races.

Fixes: 221819ca4c36e ("hwmon: (pmbus/core) Add interrupt support")
Fixes: 1e069dfd96dfe ("hwmon: (pmbus) Add debugfs for status registers")
Signed-off-by: Guenter Roeck <[email protected]>
---
 drivers/hwmon/pmbus/pmbus_core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index ba3e9e9fc8bc..6991c7f8d125 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -3448,6 +3448,8 @@ static int pmbus_write_smbalert_mask(struct i2c_client *client, u8 page, u8 reg,
 {
 	int ret;
 
+	guard(pmbus_lock)(client);
+
 	ret = _pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8));
 
 	/*
@@ -3700,6 +3702,8 @@ static void pmbus_init_debugfs(struct i2c_client *client,
 	if (!entries)
 		return;
 
+	guard(pmbus_lock)(client);
+
 	/*
 	 * Add device-specific entries.
 	 * Please note that the PMBUS standard allows all registers to be
-- 
2.45.2