The recent commit 7d8196641e ("regulator: Remove pointer table
overallocation") changed the size of coupled_rdevs and now KASAN is able
to detect slab-out-of-bounds problem in regulator_unlock_recursive(),
which is a legit problem caused by a typo in the code. The recursive
unlock function uses n_coupled value of a parent regulator for unlocking
supply regulator, while supply's n_coupled should be used. In practice
problem may only affect platforms that use coupled regulators.
Cc: stable@vger.kernel.org # 5.0+
Fixes: f8702f9e4a ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20200831204335.19489-1-digetx@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The following build warning is seen after commit 8bdaa43808 ("regulator:
dbx500: no need to check return value of debugfs_create functions"):
drivers/regulator/dbx500-prcmu.c:144:1: warning: label 'exit_no_debugfs' defined but not used [-Wunused-label]
Remove the unused label and its associated error message.
Fixes: 8bdaa43808 ("regulator: dbx500: no need to check return value of debugfs_create functions")
Reported-by: Olof's autobuilder <build@lixom.net>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/20200821144823.13404-1-festevam@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix below warning when CONFIG_OF=n:
drivers/regulator/qcom-rpmh-regulator.c:970:34: warning: ‘rpmh_regulator_match_table’ defined but not used [-Wunused-const-variable=]
970 | static const struct of_device_id rpmh_regulator_match_table[] = {
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Link: https://lore.kernel.org/r/20200821111913.1096f7cc@xhacker.debian
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix below warnings when CONFIG_OF=n:
drivers/regulator/fixed.c:48:36: warning: ‘fixed_clkenable_data’ defined but not used [-Wunused-const-variable=]
48 | static const struct fixed_dev_type fixed_clkenable_data = {
| ^~~~~~~~~~~~~~~~~~~~
drivers/regulator/fixed.c:44:36: warning: ‘fixed_voltage_data’ defined but not used [-Wunused-const-variable=]
44 | static const struct fixed_dev_type fixed_voltage_data = {
| ^~~~~~~~~~~~~~~~~~
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Link: https://lore.kernel.org/r/20200821111403.3e8b58a3@xhacker.debian
Signed-off-by: Mark Brown <broonie@kernel.org>
Jisheng Zhang <Jisheng.Zhang@synaptics.com>:
From: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
This is to improve the mp886x regulator driver support.
patch1 implments .set_ramp_delay
patch2 and patch3 support the switch freq setting
patch4 converts dt binding to json-schema
Since v2:
- put any schema conversions at the end of the series as Mark
suggested.
Jisheng Zhang (4):
regulator: mp886x: implement set_ramp_delay
dt-bindings: regulator: mp886x: support mps,switch-frequency
regulator: mp886x: support setting switch freq
dt-bindings: regulator: Convert mp886x to json-schema
.../devicetree/bindings/regulator/mp886x.txt | 27 -----
.../bindings/regulator/mps,mp886x.yaml | 58 ++++++++++
drivers/regulator/mp886x.c | 109 +++++++++++++++++-
3 files changed, 164 insertions(+), 30 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/regulator/mp886x.txt
create mode 100644 Documentation/devicetree/bindings/regulator/mps,mp886x.yaml
--
2.28.0.rc1
For systems that have eg. eMMC storage using voltage regulator, memory
reclaim path might call back into regulator subsystem. This means we
have to make sure no allocations happen with a regulator or regulator
list locked.
After this series I see no more lockdep complaints on my test system,
but please review and test further.
First four patches move allocations out of locked regions, next three
came as a drive-by cleanups.
---
v2: fix bug in patch #4 spotted by kernel test robot
reworded commit #7 description
Michał Mirosław (7):
regulator: push allocation in regulator_init_coupling() outside of
lock
regulator: push allocation in regulator_ena_gpio_request() out of lock
regulator: push allocations in create_regulator() outside of lock
regulator: push allocation in set_consumer_device_supply() out of lock
regulator: plug of_node leak in regulator_register()'s error path
regulator: cleanup regulator_ena_gpio_free()
regulator: remove superfluous lock in regulator_resolve_coupling()
drivers/regulator/core.c | 164 +++++++++++++++++++++------------------
1 file changed, 87 insertions(+), 77 deletions(-)
--
2.20.1
I see it takes about 5us per regulator to grab the lock, check that this
regulator isn't going to do anything for suspend, and then release the
lock. When that is combined with PMICs that have dozens of regulators we
get into a state where we spend a few miliseconds doing a bunch of
locking operations synchronously to figure out that there's nothing to
do. Let's reorganize the code here a bit so that we don't grab the lock
until we're actually going to do something so that suspend is a little
faster.
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200804070837.1084024-1-swboyd@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>
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: f8702f9e4a ("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/6eebc99b2474f4ffaa0405b15178ece0e7e4f608.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Move another allocation out of regulator_list_mutex-protected region, as
reclaim might want to take the same lock.
WARNING: possible circular locking dependency detected
5.7.13+ #534 Not tainted
------------------------------------------------------
kswapd0/383 is trying to acquire lock:
c0e5d920 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x54/0x2c0
but task is already holding lock:
c0e38518 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x0/0x50
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (fs_reclaim){+.+.}-{0:0}:
fs_reclaim_acquire.part.11+0x40/0x50
fs_reclaim_acquire+0x24/0x28
kmem_cache_alloc_trace+0x40/0x1e8
regulator_register+0x384/0x1630
devm_regulator_register+0x50/0x84
reg_fixed_voltage_probe+0x248/0x35c
[...]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(regulator_list_mutex);
lock(fs_reclaim);
lock(regulator_list_mutex);
*** DEADLOCK ***
[...]
2 locks held by kswapd0/383:
#0: c0e38518 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x0/0x50
#1: cb70e5e0 (hctx->srcu){....}-{0:0}, at: hctx_lock+0x60/0xb8
[...]
Fixes: 541d052d72 ("regulator: core: Only support passing enable GPIO descriptors")
[this commit only changes context]
Fixes: f8702f9e4a ("regulator: core: Use ww_mutex for regulators locking")
[this is when the regulator_list_mutex was introduced in reclaim locking path]
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/41fe6a9670335721b48e8f5195038c3d67a3bf92.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Allocating memory with regulator_list_mutex held makes lockdep unhappy
when memory pressure makes the system do fs_reclaim on eg. eMMC using
a regulator. Push the lock inside regulator_init_coupling() after the
allocation.
======================================================
WARNING: possible circular locking dependency detected
5.7.13+ #533 Not tainted
------------------------------------------------------
kswapd0/383 is trying to acquire lock:
cca78ca4 (&sbi->write_io[i][j].io_rwsem){++++}-{3:3}, at: __submit_merged_write_cond+0x104/0x154
but task is already holding lock:
c0e38518 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x0/0x50
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (fs_reclaim){+.+.}-{0:0}:
fs_reclaim_acquire.part.11+0x40/0x50
fs_reclaim_acquire+0x24/0x28
__kmalloc+0x54/0x218
regulator_register+0x860/0x1584
dummy_regulator_probe+0x60/0xa8
[...]
other info that might help us debug this:
Chain exists of:
&sbi->write_io[i][j].io_rwsem --> regulator_list_mutex --> fs_reclaim
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(regulator_list_mutex);
lock(fs_reclaim);
lock(&sbi->write_io[i][j].io_rwsem);
*** DEADLOCK ***
1 lock held by kswapd0/383:
#0: c0e38518 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x0/0x50
[...]
Fixes: d8ca7d184b ("regulator: core: Introduce API for regulators coupling customization")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1a889cf7f61c6429c9e6b34ddcdde99be77a26b6.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
