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    Subject[PATCH 4.19 58/78] regulator: push allocation in set_consumer_device_supply() out of lock
    Date
    From: Michał Mirosław <mirq-linux@rere.qmqm.pl>

    commit 5c06540165d443c6455123eb48e7f1a9b618ab34 upstream.

    Pull regulator_list_mutex into set_consumer_device_supply() and keep
    allocations outside of it. Fourth of the fs_reclaim deadlock case.

    Fixes: 45389c47526d ("regulator: core: Add early supply resolution for regulators")
    Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
    Cc: stable@vger.kernel.org
    Link: https://lore.kernel.org/r/f0380bdb3d60aeefa9693c4e234d2dcda7e56747.1597195321.git.mirq-linux@rere.qmqm.pl
    Signed-off-by: Mark Brown <broonie@kernel.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/regulator/core.c | 46 ++++++++++++++++++++++++++--------------------
    1 file changed, 26 insertions(+), 20 deletions(-)

    --- a/drivers/regulator/core.c
    +++ b/drivers/regulator/core.c
    @@ -1257,7 +1257,7 @@ static int set_consumer_device_supply(st
    const char *consumer_dev_name,
    const char *supply)
    {
    - struct regulator_map *node;
    + struct regulator_map *node, *new_node;
    int has_dev;

    if (supply == NULL)
    @@ -1268,6 +1268,22 @@ static int set_consumer_device_supply(st
    else
    has_dev = 0;

    + new_node = kzalloc(sizeof(struct regulator_map), GFP_KERNEL);
    + if (new_node == NULL)
    + return -ENOMEM;
    +
    + new_node->regulator = rdev;
    + new_node->supply = supply;
    +
    + if (has_dev) {
    + new_node->dev_name = kstrdup(consumer_dev_name, GFP_KERNEL);
    + if (new_node->dev_name == NULL) {
    + kfree(new_node);
    + return -ENOMEM;
    + }
    + }
    +
    + mutex_lock(&regulator_list_mutex);
    list_for_each_entry(node, &regulator_map_list, list) {
    if (node->dev_name && consumer_dev_name) {
    if (strcmp(node->dev_name, consumer_dev_name) != 0)
    @@ -1285,26 +1301,19 @@ static int set_consumer_device_supply(st
    node->regulator->desc->name,
    supply,
    dev_name(&rdev->dev), rdev_get_name(rdev));
    - return -EBUSY;
    + goto fail;
    }

    - node = kzalloc(sizeof(struct regulator_map), GFP_KERNEL);
    - if (node == NULL)
    - return -ENOMEM;
    -
    - node->regulator = rdev;
    - node->supply = supply;
    -
    - if (has_dev) {
    - node->dev_name = kstrdup(consumer_dev_name, GFP_KERNEL);
    - if (node->dev_name == NULL) {
    - kfree(node);
    - return -ENOMEM;
    - }
    - }
    + list_add(&new_node->list, &regulator_map_list);
    + mutex_unlock(&regulator_list_mutex);

    - list_add(&node->list, &regulator_map_list);
    return 0;
    +
    +fail:
    + mutex_unlock(&regulator_list_mutex);
    + kfree(new_node->dev_name);
    + kfree(new_node);
    + return -EBUSY;
    }

    static void unset_regulator_supplies(struct regulator_dev *rdev)
    @@ -4375,19 +4384,16 @@ regulator_register(const struct regulato

    /* add consumers devices */
    if (init_data) {
    - mutex_lock(&regulator_list_mutex);
    for (i = 0; i < init_data->num_consumer_supplies; i++) {
    ret = set_consumer_device_supply(rdev,
    init_data->consumer_supplies[i].dev_name,
    init_data->consumer_supplies[i].supply);
    if (ret < 0) {
    - mutex_unlock(&regulator_list_mutex);
    dev_err(dev, "Failed to set supply %s\n",
    init_data->consumer_supplies[i].supply);
    goto unset_supplies;
    }
    }
    - mutex_unlock(&regulator_list_mutex);
    }

    if (!rdev->desc->ops->get_voltage &&

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