[ Upstream commit dbe954d8f1635f949a1d9a5d6e6fb749ae022b47 ]
Sometimes regulator_get() gets called twice for the same supply on the
same device. This may happen e.g. when a framework / library is used
which uses the regulator; and the driver itself also needs to enable
the regulator in some cases where the framework will not enable it.
Commit ff268b56ce8c ("regulator: core: Don't spew backtraces on
duplicate sysfs") already takes care of the backtrace which would
trigger when creating a duplicate consumer symlink under
/sys/class/regulator/regulator.%d in this scenario.
Commit c33d442328f5 ("debugfs: make error message a bit more verbose")
causes a new error to get logged in this scenario:
[ 26.938425] debugfs: Directory 'wm5102-codec-MICVDD' with parent 'spi-WM510204:00-MICVDD' already present!
There is no _nowarn variant of debugfs_create_dir(), but we can detect
and avoid this problem by checking the return value of the earlier
sysfs_create_link_nowarn() call.
Add a check for the earlier sysfs_create_link_nowarn() failing with
-EEXIST and skip the debugfs_create_dir() call in that case, avoiding
this error getting logged.
Fixes: c33d442328f5 ("debugfs: make error message a bit more verbose")
Cc: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20210122183250.370571-1-hdegoede@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 14a71d509ac809dcf56d7e3ca376b15d17bd0ddd ]
With commit eaa7995c529b54 (regulator: core: avoid
regulator_resolve_supply() race condition) we started holding the rdev
lock while resolving supplies, an operation that requires holding the
regulator_list_mutex. This results in lockdep warnings since in other
places we take the list mutex then the mutex on an individual rdev.
Since the goal is to make sure that we don't call set_supply() twice
rather than a concern about the cost of resolution pull the rdev lock
and check for duplicate resolution down to immediately before we do the
set_supply() and drop it again once the allocation is done.
Fixes: eaa7995c529b54 (regulator: core: avoid regulator_resolve_supply() race condition)
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210122132042.10306-1-broonie@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit eaa7995c529b54d68d97a30f6344cc6ca2f214a7 ]
The final step in regulator_register() is to call
regulator_resolve_supply() for each registered regulator
(including the one in the process of being registered). The
regulator_resolve_supply() function first checks if rdev->supply
is NULL, then it performs various steps to try to find the supply.
If successful, rdev->supply is set inside of set_supply().
This procedure can encounter a race condition if two concurrent
tasks call regulator_register() near to each other on separate CPUs
and one of the regulators has rdev->supply_name specified. There
is currently nothing guaranteeing atomicity between the rdev->supply
check and set steps. Thus, both tasks can observe rdev->supply==NULL
in their regulator_resolve_supply() calls. This then results in
both creating a struct regulator for the supply. One ends up
actually stored in rdev->supply and the other is lost (though still
present in the supply's consumer_list).
Here is a kernel log snippet showing the issue:
[ 12.421768] gpu_cc_gx_gdsc: supplied by pm8350_s5_level
[ 12.425854] gpu_cc_gx_gdsc: supplied by pm8350_s5_level
[ 12.429064] debugfs: Directory 'regulator.4-SUPPLY' with parent
'17a00000.rsc:rpmh-regulator-gfxlvl-pm8350_s5_level'
already present!
Avoid this race condition by holding the rdev->mutex lock inside
of regulator_resolve_supply() while checking and setting
rdev->supply.
Signed-off-by: David Collins <collinsd@codeaurora.org>
Link: https://lore.kernel.org/r/1610068562-4410-1-git-send-email-collinsd@codeaurora.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f5c042b23f7429e5c2ac987b01a31c69059a978b upstream.
Workaround regulators whose supply name happens to be the same as its
own name. This fixes boards that used to work before the early supply
resolving was removed. The error message is left in place so that
offending drivers can be detected.
Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Cc: stable@vger.kernel.org
Reported-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de> # stpmic1
Link: https://lore.kernel.org/r/d703acde2a93100c3c7a81059d716c50ad1b1f52.1605226675.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4b639e254d3d4f15ee4ff2b890a447204cfbeea9 upstream.
When a regulator's name equals its supply's name the
regulator_resolve_supply() recurses indefinitely. Add a check
so that debugging the problem is easier. The "fixed" commit
just exposed the problem.
Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Cc: stable@vger.kernel.org
Reported-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de> # stpmic1
Link: https://lore.kernel.org/r/c6171057cfc0896f950c4d8cb82df0f9f1b89ad9.1605226675.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 57a6ad482af256b2a13de14194fb8f67c1a65f10 upstream.
Fixed commit introduced a possible second call to
set_machine_constraints() and that allocates memory for
rdev->constraints. Move the allocation to the caller so
it's easier to manage and done once.
Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Cc: stable@vger.kernel.org
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de> # stpmic1
Link: https://lore.kernel.org/r/78c3d4016cebc08d441aad18cb924b4e4d9cf9df.1605226675.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cf1ad559a20d1930aa7b47a52f54e1f8718de301 upstream.
regulator_get_voltage_rdev() is called in regulator probe() when
applying machine constraints. The "fixed" commit exposed the problem
that non-bypassed regulators can forward the request to its parent
(like bypassed ones) supply. Return -EPROBE_DEFER when the supply
is expected but not resolved yet.
Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Cc: stable@vger.kernel.org
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reported-by: Ondřej Jirman <megous@megous.com>
Reported-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Tested-by: Ondřej Jirman <megous@megous.com>
Link: https://lore.kernel.org/r/a9041d68b4d35e4a2dd71629c8a6422662acb5ee.1604351936.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit aea6cb99703e17019e025aa71643b4d3e0a24413 ]
When creating a new regulator its supply cannot create the sysfs link
because the device is not yet published. Remove early supply resolving
since it will be done later anyway. This makes the following error
disappear and the symlinks get created instead.
DCDC_REG1: supplied by VSYS
VSYS: could not add device link regulator.3 err -2
Note: It doesn't fix the problem for bypassed regulators, though.
Fixes: 45389c47526d ("regulator: core: Add early supply resolution for regulators")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/ba09e0a8617ffeeb25cb4affffe6f3149319cef8.1601155770.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 0a7416f94707c60b9f66b01c0a505b7e41375f3a upstream.
The recent commit 7d8196641ee1 ("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: f8702f9e4aa7 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d3c731564e09b6c2ebefcd1344743a91a237d6dc upstream.
By calling device_initialize() earlier and noting that kfree(NULL) is
ok, we can save a bit of code in error handling and plug of_node leak.
Fixed commit already did part of the work.
Fixes: 9177514ce349 ("regulator: fix memory leak on error path of regulator_register()")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/f5035b1b4d40745e66bacd571bbbb5e4644d21a1.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
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/6eebc99b2474f4ffaa0405b15178ece0e7e4f608.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 73a32129f8ccb556704a26b422f54e048bf14bd0 upstream.
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: d8ca7d184b33 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a577f3456c0a2fac3dee037c483753e6e68f3e49 ]
The code modifies rdev, but locks c_rdev instead. Remove the lock
as this is held together by regulator_list_mutex taken in the caller.
Fixes: f9503385b187 ("regulator: core: Mutually resolve regulators coupling")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/25eb81cefb37a646f3e44eaaf1d8ae8881cfde52.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 467bf30142c64f2eb64e2ac67fa4595126230efd ]
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: 541d052d7215 ("regulator: core: Only support passing enable GPIO descriptors")
[this commit only changes context]
Fixes: f8702f9e4aa7 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9177514ce34902b3adb2abd490b6ad05d1cfcb43 ]
The change corrects registration and deregistration on error path
of a regulator, the problem was manifested by a reported memory
leak on deferred probe:
as3722-regulator as3722-regulator: regulator 13 register failed -517
# cat /sys/kernel/debug/kmemleak
unreferenced object 0xecc43740 (size 64):
comm "swapper/0", pid 1, jiffies 4294937640 (age 712.880s)
hex dump (first 32 bytes):
72 65 67 75 6c 61 74 6f 72 2e 32 34 00 5a 5a 5a regulator.24.ZZZ
5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
backtrace:
[<0c4c3d1c>] __kmalloc_track_caller+0x15c/0x2c0
[<40c0ad48>] kvasprintf+0x64/0xd4
[<109abd29>] kvasprintf_const+0x70/0x84
[<c4215946>] kobject_set_name_vargs+0x34/0xa8
[<62282ea2>] dev_set_name+0x40/0x64
[<a39b6757>] regulator_register+0x3a4/0x1344
[<16a9543f>] devm_regulator_register+0x4c/0x84
[<51a4c6a1>] as3722_regulator_probe+0x294/0x754
...
The memory leak problem was introduced as a side ef another fix in
regulator_register() error path, I believe that the proper fix is
to decouple device_register() function into its two compounds and
initialize a struct device before assigning any values to its fields
and then using it before actual registration of a device happens.
This lets to call put_device() safely after initialization, and, since
now a release callback is called, kfree(rdev->constraints) shall be
removed to exclude a double free condition.
Fixes: a3cde9534ebd ("regulator: core: fix regulator_register() error paths to properly release rdev")
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: Wen Yang <wenyang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20200724005013.23278-1-vz@mleia.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Hans de Goede