From: Michał Mirosław mirq-linux@rere.qmqm.pl
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: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking") Signed-off-by: Michał Mirosław mirq-linux@rere.qmqm.pl Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/6eebc99b2474f4ffaa0405b15178ece0e7e4f608.159719532... Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/regulator/core.c | 53 ++++++++++++++++++++++++----------------------- 1 file changed, 28 insertions(+), 25 deletions(-)
--- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1579,44 +1579,53 @@ static struct regulator *create_regulato const char *supply_name) { struct regulator *regulator; - char buf[REG_STR_SIZE]; - int err, size; + int err; + + if (dev) { + char buf[REG_STR_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(®ulator->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"); @@ -1641,13 +1650,7 @@ static struct regulator *create_regulato _regulator_is_enabled(rdev)) regulator->always_on = true;
- regulator_unlock(rdev); return regulator; -overflow_err: - list_del(®ulator->list); - kfree(regulator); - regulator_unlock(rdev); - return NULL; }
static int _regulator_get_enable_time(struct regulator_dev *rdev)