Re: [PATCH 4/7] regulator: push allocation in set_consumer_device_supply() out of lock

From: kernel test robot
Date: Tue Aug 11 2020 - 01:53:03 EST

Hi "Michał,

I love your patch! Perhaps something to improve:

[auto build test WARNING on regulator/for-next]
[also build test WARNING on v5.8 next-20200810]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/0day-ci/linux/commits/Micha-Miros-aw/regulator-fix-deadlock-vs-memory-reclaim/20200811-091414
base: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git for-next
config: x86_64-randconfig-m001-20200810 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

New smatch warnings:
drivers/regulator/core.c:1491 set_consumer_device_supply() warn: overwrite may leak 'node'

Old smatch warnings:
drivers/regulator/core.c:129 regulator_ops_is_valid() error: we previously assumed 'rdev->constraints' could be null (see line 128)
drivers/regulator/core.c:3051 regulator_get_hardware_vsel_register() warn: inconsistent indenting

vim +/node +1491 drivers/regulator/core.c

3801b86aa482d2 Mark Brown 2011-06-09 1448
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1449 /**
06c63f9396133f Randy Dunlap 2010-11-18 1450 * set_consumer_device_supply - Bind a regulator to a symbolic supply
69279fb9a95051 Mark Brown 2008-12-31 1451 * @rdev: regulator source
40f9244f4da897 Mark Brown 2009-06-17 1452 * @consumer_dev_name: dev_name() string for device supply applies to
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1453 * @supply: symbolic name for supply
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1454 *
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1455 * Allows platform initialisation code to map physical regulator
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1456 * sources to symbolic names for supplies for use by devices. Devices
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1457 * should use these symbolic names to request regulators, avoiding the
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1458 * need to provide board-specific regulator names as platform data.
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1459 */
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1460 static int set_consumer_device_supply(struct regulator_dev *rdev,
737f360d5bef5e Mark Brown 2012-02-02 1461 const char *consumer_dev_name,
40f9244f4da897 Mark Brown 2009-06-17 1462 const char *supply)
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1463 {
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1464 struct regulator_map *node;
9ed2099edca26d Mark Brown 2009-07-21 1465 int has_dev;
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1466
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1467 if (supply == NULL)
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1468 return -EINVAL;
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1469
9ed2099edca26d Mark Brown 2009-07-21 1470 if (consumer_dev_name != NULL)
9ed2099edca26d Mark Brown 2009-07-21 1471 has_dev = 1;
9ed2099edca26d Mark Brown 2009-07-21 1472 else
9ed2099edca26d Mark Brown 2009-07-21 1473 has_dev = 0;
9ed2099edca26d Mark Brown 2009-07-21 1474
bcadf558ba875d Michał Mirosław 2020-08-11 1475 node = kzalloc(sizeof(struct regulator_map), GFP_KERNEL);
bcadf558ba875d Michał Mirosław 2020-08-11 1476 if (node == NULL)
bcadf558ba875d Michał Mirosław 2020-08-11 1477 return -ENOMEM;
bcadf558ba875d Michał Mirosław 2020-08-11 1478
bcadf558ba875d Michał Mirosław 2020-08-11 1479 node->regulator = rdev;
bcadf558ba875d Michał Mirosław 2020-08-11 1480 node->supply = supply;
bcadf558ba875d Michał Mirosław 2020-08-11 1481
bcadf558ba875d Michał Mirosław 2020-08-11 1482 if (has_dev) {
bcadf558ba875d Michał Mirosław 2020-08-11 1483 node->dev_name = kstrdup(consumer_dev_name, GFP_KERNEL);
bcadf558ba875d Michał Mirosław 2020-08-11 1484 if (node->dev_name == NULL) {
bcadf558ba875d Michał Mirosław 2020-08-11 1485 kfree(node);
bcadf558ba875d Michał Mirosław 2020-08-11 1486 return -ENOMEM;
bcadf558ba875d Michał Mirosław 2020-08-11 1487 }
bcadf558ba875d Michał Mirosław 2020-08-11 1488 }
bcadf558ba875d Michał Mirosław 2020-08-11 1489
bcadf558ba875d Michał Mirosław 2020-08-11 1490 mutex_lock(&regulator_list_mutex);
6001e13c5f708e David Brownell 2008-12-31 @1491 list_for_each_entry(node, &regulator_map_list, list) {
23b5cc2ab67832 Jani Nikula 2010-04-29 1492 if (node->dev_name && consumer_dev_name) {
23b5cc2ab67832 Jani Nikula 2010-04-29 1493 if (strcmp(node->dev_name, consumer_dev_name) != 0)
6001e13c5f708e David Brownell 2008-12-31 1494 continue;
23b5cc2ab67832 Jani Nikula 2010-04-29 1495 } else if (node->dev_name || consumer_dev_name) {
23b5cc2ab67832 Jani Nikula 2010-04-29 1496 continue;
23b5cc2ab67832 Jani Nikula 2010-04-29 1497 }
23b5cc2ab67832 Jani Nikula 2010-04-29 1498
6001e13c5f708e David Brownell 2008-12-31 1499 if (strcmp(node->supply, supply) != 0)
6001e13c5f708e David Brownell 2008-12-31 1500 continue;
6001e13c5f708e David Brownell 2008-12-31 1501
737f360d5bef5e Mark Brown 2012-02-02 1502 pr_debug("%s: %s/%s is '%s' supply; fail %s/%s\n",
737f360d5bef5e Mark Brown 2012-02-02 1503 consumer_dev_name,
6001e13c5f708e David Brownell 2008-12-31 1504 dev_name(&node->regulator->dev),
6001e13c5f708e David Brownell 2008-12-31 1505 node->regulator->desc->name,
6001e13c5f708e David Brownell 2008-12-31 1506 supply,
1083c39346d482 Mark Brown 2009-10-22 1507 dev_name(&rdev->dev), rdev_get_name(rdev));
bcadf558ba875d Michał Mirosław 2020-08-11 1508 goto fail;
6001e13c5f708e David Brownell 2008-12-31 1509 }
6001e13c5f708e David Brownell 2008-12-31 1510
bcadf558ba875d Michał Mirosław 2020-08-11 1511 list_add(&node->list, &regulator_map_list);
bcadf558ba875d Michał Mirosław 2020-08-11 1512 mutex_unlock(&regulator_list_mutex);
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1513
bcadf558ba875d Michał Mirosław 2020-08-11 1514 return 0;
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1515
bcadf558ba875d Michał Mirosław 2020-08-11 1516 fail:
bcadf558ba875d Michał Mirosław 2020-08-11 1517 mutex_unlock(&regulator_list_mutex);
bcadf558ba875d Michał Mirosław 2020-08-11 1518 kfree(node->dev_name);
40f9244f4da897 Mark Brown 2009-06-17 1519 kfree(node);
bcadf558ba875d Michał Mirosław 2020-08-11 1520 return -EBUSY;
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1521 }
a5766f11cfd3a0 Liam Girdwood 2008-10-10 1522

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