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Commit 31d89652 authored by Michał Mirosław's avatar Michał Mirosław Committed by Greg Kroah-Hartman
Browse files

regulator: push allocations in create_regulator() outside of lock 



commit 87fe29b61f9522a3d7b60a4580851f548558186f upstream.

Move all allocations outside of the regulator_lock()ed section.

======================================================
WARNING: possible circular locking dependency detected
5.7.13+ #535 Not tainted
------------------------------------------------------
f2fs_discard-179:7/702 is trying to acquire lock:
c0e5d920 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x54/0x2c0

but task is already holding lock:
cb95b080 (&dcc->cmd_lock){+.+.}-{3:3}, at: __issue_discard_cmd+0xec/0x5f8

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

[...]

-> #3 (fs_reclaim){+.+.}-{0:0}:
       fs_reclaim_acquire.part.11+0x40/0x50
       fs_reclaim_acquire+0x24/0x28
       __kmalloc_track_caller+0x54/0x218
       kstrdup+0x40/0x5c
       create_regulator+0xf4/0x368
       regulator_resolve_supply+0x1a0/0x200
       regulator_register+0x9c8/0x163c

[...]

other info that might help us debug this:

Chain exists of:
  regulator_list_mutex --> &sit_i->sentry_lock --> &dcc->cmd_lock

[...]

Fixes: f8702f9e ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: default avatarMichał Mirosław <mirq-linux@rere.qmqm.pl>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/6eebc99b2474f4ffaa0405b15178ece0e7e4f608.1597195321.git.mirq-linux@rere.qmqm.pl


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e7249ceb

drivers/regulator/core.c

+28 −25
Original line number Diff line number Diff line
@@ -1575,44 +1575,53 @@ static struct regulator *create_regulator(struct regulator_dev *rdev, 
					  const char *supply_name)

{

	struct regulator *regulator;

	int err;



	if (dev) {

		char buf[REG_STR_SIZE];

	int err, size;

		int size;



		size = snprintf(buf, REG_STR_SIZE, "%s-%s",

				dev->kobj.name, supply_name);

		if (size >= REG_STR_SIZE)

			return NULL;



		supply_name = kstrdup(buf, GFP_KERNEL);

		if (supply_name == NULL)

			return NULL;

	} else {

		supply_name = kstrdup_const(supply_name, GFP_KERNEL);

		if (supply_name == NULL)

			return NULL;

	}



	regulator = kzalloc(sizeof(*regulator), GFP_KERNEL);

	if (regulator == NULL)

	if (regulator == NULL) {

		kfree(supply_name);

		return NULL;

	}



	regulator_lock(rdev);

	regulator->rdev = rdev;

	regulator->supply_name = supply_name;



	regulator_lock(rdev);

	list_add(&regulator->list, &rdev->consumer_list);

	regulator_unlock(rdev);



	if (dev) {

		regulator->dev = dev;



		/* Add a link to the device sysfs entry */

		size = snprintf(buf, REG_STR_SIZE, "%s-%s",

				dev->kobj.name, supply_name);

		if (size >= REG_STR_SIZE)

			goto overflow_err;



		regulator->supply_name = kstrdup(buf, GFP_KERNEL);

		if (regulator->supply_name == NULL)

			goto overflow_err;



		err = sysfs_create_link_nowarn(&rdev->dev.kobj, &dev->kobj,

					buf);

					       supply_name);

		if (err) {

			rdev_dbg(rdev, "could not add device link %s err %d\n",

				  dev->kobj.name, err);

			/* non-fatal */

		}

	} else {

		regulator->supply_name = kstrdup_const(supply_name, GFP_KERNEL);

		if (regulator->supply_name == NULL)

			goto overflow_err;

	}



	regulator->debugfs = debugfs_create_dir(regulator->supply_name,

	regulator->debugfs = debugfs_create_dir(supply_name,

						rdev->debugfs);

	if (!regulator->debugfs) {

		rdev_dbg(rdev, "Failed to create debugfs directory\n");
@@ -1637,13 +1646,7 @@ static struct regulator *create_regulator(struct regulator_dev *rdev, 
	    _regulator_is_enabled(rdev))

		regulator->always_on = true;



	regulator_unlock(rdev);

	return regulator;

overflow_err:

	list_del(&regulator->list);

	kfree(regulator);

	regulator_unlock(rdev);

	return NULL;

}



static int _regulator_get_enable_time(struct regulator_dev *rdev)