Change the ownership of power_supply structure from each driver
implementing the class to the power supply core.
The patch changes power_supply_register() function thus all drivers
implementing power supply class are adjusted.
Each driver provides the implementation of power supply. However it
should not be the owner of power supply class instance because it is
exposed by core to other subsystems with power_supply_get_by_name().
These other subsystems have no knowledge when the driver will unregister
the power supply. This leads to several issues when driver is unbound -
mostly because user of power supply accesses freed memory.
Instead let the core own the instance of struct 'power_supply'. Other
users of this power supply will still access valid memory because it
will be freed when device reference count reaches 0. Currently this
means "it will leak" but power_supply_put() call in next patches will
solve it.
This solves invalid memory references in following race condition
scenario:
Thread 1: charger manager
Thread 2: power supply driver, used by charger manager
THREAD 1 (charger manager) THREAD 2 (power supply driver)
========================== ==============================
psy = power_supply_get_by_name()
Driver unbind, .remove
power_supply_unregister()
Device fully removed
psy->get_property()
The 'get_property' call is executed in invalid context because the driver was
unbound and struct 'power_supply' memory was freed.
This could be observed easily with charger manager driver (here compiled
with max17040 fuel gauge):
$ cat /sys/devices/virtual/power_supply/cm-battery/capacity &
$ echo "1-0036" > /sys/bus/i2c/drivers/max17040/unbind
[ 55.725123] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[ 55.732584] pgd = d98d4000
[ 55.734060] [00000000] *pgd=5afa2831, *pte=00000000, *ppte=00000000
[ 55.740318] Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM
[ 55.746210] Modules linked in:
[ 55.749259] CPU: 1 PID: 2936 Comm: cat Tainted: G W 3.19.0-rc1-next-20141226-00048-gf79f475f3c44-dirty #1496
[ 55.760190] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[ 55.766270] task: d9b76f00 ti: daf54000 task.ti: daf54000
[ 55.771647] PC is at 0x0
[ 55.774182] LR is at charger_get_property+0x2f4/0x36c
[ 55.779201] pc : [<00000000>] lr : [<c034b0b4>] psr: 60000013
[ 55.779201] sp : daf55e90 ip : 00000003 fp : 00000000
[ 55.790657] r10: 00000000 r9 : c06e2878 r8 : d9b26c68
[ 55.795865] r7 : dad81610 r6 : daec7410 r5 : daf55ebc r4 : 00000000
[ 55.802367] r3 : 00000000 r2 : daf55ebc r1 : 0000002a r0 : d9b26c68
[ 55.808879] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
[ 55.815994] Control: 10c5387d Table: 598d406a DAC: 00000015
[ 55.821723] Process cat (pid: 2936, stack limit = 0xdaf54210)
[ 55.827451] Stack: (0xdaf55e90 to 0xdaf56000)
[ 55.831795] 5e80: 60000013 c01459c4 0000002a c06f8ef8
[ 55.839956] 5ea0: db651000 c06f8ef8 daebac00 c04cb668 daebac08 c0346864 00000000 c01459c4
[ 55.848115] 5ec0: d99eaa80 c06f8ef8 00000fff 00001000 db651000 c027f25c c027f240 d99eaa80
[ 55.856274] 5ee0: d9a06c00 c0146218 daf55f18 00001000 d99eaa80 db4c18c0 00000001 00000001
[ 55.864468] 5f00: daf55f80 c0144c78 c0144c54 c0107f90 00015000 d99eaab0 00000000 00000000
[ 55.872603] 5f20: 000051c7 00000000 db4c18c0 c04a9370 00015000 00001000 daf55f80 00001000
[ 55.880763] 5f40: daf54000 00015000 00000000 c00e53dc db4c18c0 c00e548c 0000000d 00008124
[ 55.888937] 5f60: 00000001 00000000 00000000 db4c18c0 db4c18c0 00001000 00015000 c00e5550
[ 55.897099] 5f80: 00000000 00000000 00001000 00001000 00015000 00000003 00000003 c000f364
[ 55.905239] 5fa0: 00000000 c000f1a0 00001000 00015000 00000003 00015000 00001000 0001333c
[ 55.913399] 5fc0: 00001000 00015000 00000003 00000003 00000002 00000000 00000000 00000000
[ 55.921560] 5fe0: 7fffe000 be999850 0000a225 b6f3c19c 60000010 00000003 00000000 00000000
[ 55.929744] [<c034b0b4>] (charger_get_property) from [<c0346864>] (power_supply_show_property+0x48/0x20c)
[ 55.939286] [<c0346864>] (power_supply_show_property) from [<c027f25c>] (dev_attr_show+0x1c/0x48)
[ 55.948130] [<c027f25c>] (dev_attr_show) from [<c0146218>] (sysfs_kf_seq_show+0x84/0x104)
[ 55.956298] [<c0146218>] (sysfs_kf_seq_show) from [<c0144c78>] (kernfs_seq_show+0x24/0x28)
[ 55.964536] [<c0144c78>] (kernfs_seq_show) from [<c0107f90>] (seq_read+0x1b0/0x484)
[ 55.972172] [<c0107f90>] (seq_read) from [<c00e53dc>] (__vfs_read+0x18/0x4c)
[ 55.979188] [<c00e53dc>] (__vfs_read) from [<c00e548c>] (vfs_read+0x7c/0x100)
[ 55.986304] [<c00e548c>] (vfs_read) from [<c00e5550>] (SyS_read+0x40/0x8c)
[ 55.993164] [<c00e5550>] (SyS_read) from [<c000f1a0>] (ret_fast_syscall+0x0/0x48)
[ 56.000626] Code: bad PC value
[ 56.011652] ---[ end trace 7b64343fbdae8ef1 ]---
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
[for the nvec part]
Reviewed-by: Marc Dietrich <marvin24@gmx.de>
[for compal-laptop.c]
Acked-by: Darren Hart <dvhart@linux.intel.com>
[for the mfd part]
Acked-by: Lee Jones <lee.jones@linaro.org>
[for the hid part]
Acked-by: Jiri Kosina <jkosina@suse.cz>
[for the acpi part]
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Add new structure 'power_supply_config' for holding run-time
initialization data like of_node, supplies and private driver data.
The power_supply_register() function is changed so all power supply
drivers need updating.
When registering the power supply this new 'power_supply_config' should be
used instead of directly initializing 'struct power_supply'. This allows
changing the ownership of power_supply structure from driver to the
power supply core in next patches.
When a driver does not use of_node or supplies then it should use NULL
as config. If driver uses of_node or supplies then it should allocate
config on stack and initialize it with proper values.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
[for the nvec part]
Reviewed-by: Marc Dietrich <marvin24@gmx.de>
[for drivers/platform/x86/compal-laptop.c]
Reviewed-by: Darren Hart <dvhart@linux.intel.com>
[for drivers/hid/*]
Reviewed-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Prior to this patch, pmu_battery was unable to report battery full
status. This patch fixes the issue by adding a proper handling code
into pmu_bat_get_property(): if we're on AC and the battery isn't
charging, then the battery is considered full.
Signed-off-by: Thomas Champagne <lafeuil@gmail.com>
Acked-By: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
By changing drivers/power/pmu_battery.c I now have '_' instead of
' ' (spaces) in /sys:
/sys/devices/platform/pmu-battery.0/power_supply/PMU_battery_0
/sys/class/power_supply/PMU_battery_0
I'm still not sure if some userspace tool out there uses the old paths and
will break now.
Signed-off-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Krzysztof Kozlowski
Tejun Heo
Thomas Champagne
Christian Kujau
Anton Vorontsov
David Woodhouse