linux-toradex.git/drivers/acpi/acpi_memhotplug.c, branch v3.10.78

ACPI / memhotplug: Fix a stale pointer in error path

2013-08-04T08:51:02+00:00

commit d19f503e22316a84c39bc19445e0e4fdd49b3532 upstream.

device->driver_data needs to be cleared when releasing its data,
mem_device, in an error path of acpi_memory_device_add().

The function evaluates the _CRS of memory device objects, and fails
when it gets an unexpected resource or cannot allocate memory.  A
kernel crash or data corruption may occur when the kernel accesses
the stale pointer.

Signed-off-by: Toshi Kani 
Reviewed-by: Yasuaki Ishimatsu 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

ACPI / memhotplug: Remove info->failed bit

2013-03-24T23:36:25+00:00

acpi_memory_info has enabled bit and failed bit for controlling memory
hotplug. But we don't need to keep both bits.

The patch removes acpi_memory_info->failed bit.

Signed-off-by: yasuaki ishimatsu 
Acked-by: Toshi Kani 
Signed-off-by: Rafael J. Wysocki

ACPI / memhotplug: set info->enabled for memory present at boot time

2013-03-24T23:34:36+00:00

At http://marc.info/?l=linux-acpi&m=135769405622667&w=2 thread,
Toshi Kani mentioned as follows:

"I have a question about the change you made in commit 65479472 in
acpi_memhotplug.c.  This change seems to require that
acpi_memory_enable_device() calls add_memory() to add all memory ranges
represented by memory device objects at boot-time, and keep the results
be used for hot-remove.

If I understand it right, this add_memory() call fails with EEXIST at
boot-time since all memory ranges should have been added from EFI memory
table (or e820) already.  This results all memory ranges be marked as !
enabled & !failed.  I think this means that we cannot hot-delete any
memory ranges presented at boot-time since acpi_memory_remove_memory()
only calls remove_memory() when the enabled flag is set.  Is that
correct?"

Above mention is correct. Thus even if memory device supports hotplug,
memory presented at boot-time cannot be hot removed since the memory
device's acpi_memory_info->enabled is always 0.

This patch changes to set 1 to "acpi_memory_info->enabled" of memory
device presented at boot-time for hot removing the memory device.

Signed-off-by: Yasuaki Ishimatsu 
Acked-by: Toshi Kani 
Signed-off-by: Rafael J. Wysocki

ACPI / scan: Make memory hotplug driver use struct acpi_scan_handler

2013-03-04T13:25:32+00:00

Make the ACPI memory hotplug driver use struct acpi_scan_handler
for representing the object used to set up ACPI memory hotplug
functionality and to remove hotplug memory ranges and data
structures used by the driver before unregistering ACPI device
nodes representing memory.  Register the new struct acpi_scan_handler
object with the help of acpi_scan_add_handler_with_hotplug() to allow
user space to manipulate the attributes of the memory hotplug
profile.

This results in a significant reduction of the drvier's code size
and removes some ACPI hotplug code duplication.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Toshi Kani 
Tested-by: Toshi Kani

memory-hotplug: remove sysfs file of node

2013-02-24T01:50:13+00:00

Introduce a new function try_offline_node() to remove sysfs file of node
when all memory sections of this node are removed.  If some memory
sections of this node are not removed, this function does nothing.

Signed-off-by: Wen Congyang 
Signed-off-by: Tang Chen 
Cc: KOSAKI Motohiro 
Cc: Jiang Liu 
Cc: Jianguo Wu 
Cc: Kamezawa Hiroyuki 
Cc: Lai Jiangshan 
Cc: Wu Jianguo 
Cc: Yasuaki Ishimatsu 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ACPI / hotplug: Fix concurrency issues and memory leaks

2013-02-13T13:36:47+00:00

This changeset is aimed at fixing a few different but related
problems in the ACPI hotplug infrastructure.

First of all, since notify handlers may be run in parallel with
acpi_bus_scan(), acpi_bus_trim() and acpi_bus_hot_remove_device()
and some of them are installed for ACPI handles that have no struct
acpi_device objects attached (i.e. before those objects are created),
those notify handlers have to take acpi_scan_lock to prevent races
from taking place (e.g. a struct acpi_device is found to be present
for the given ACPI handle, but right after that it is removed by
acpi_bus_trim() running in parallel to the given notify handler).
Moreover, since some of them call acpi_bus_scan() and
acpi_bus_trim(), this leads to the conclusion that acpi_scan_lock
should be acquired by the callers of these two funtions rather by
these functions themselves.

For these reasons, make all notify handlers that can handle device
addition and eject events take acpi_scan_lock and remove the
acpi_scan_lock locking from acpi_bus_scan() and acpi_bus_trim().
Accordingly, update all of their users to make sure that they
are always called under acpi_scan_lock.

Furthermore, since eject operations are carried out asynchronously
with respect to the notify events that trigger them, with the help
of acpi_bus_hot_remove_device(), even if notify handlers take the
ACPI scan lock, it still is possible that, for example,
acpi_bus_trim() will run between acpi_bus_hot_remove_device() and
the notify handler that scheduled its execution and that
acpi_bus_trim() will remove the device node passed to
acpi_bus_hot_remove_device() for ejection.  In that case, the struct
acpi_device object obtained by acpi_bus_hot_remove_device() will be
invalid and not-so-funny things will ensue.  To protect agaist that,
make the users of acpi_bus_hot_remove_device() run get_device() on
ACPI device node objects that are about to be passed to it and make
acpi_bus_hot_remove_device() run put_device() on them and check if
their ACPI handles are not NULL (make acpi_device_unregister() clear
the device nodes' ACPI handles for that check to work).

Finally, observe that acpi_os_hotplug_execute() actually can fail,
in which case its caller ought to free memory allocated for the
context object to prevent leaks from happening.  It also needs to
run put_device() on the device node that it ran get_device() on
previously in that case.  Modify the code accordingly.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Yinghai Lu

ACPI: Remove useless type argument of driver .remove() operation

2013-01-25T23:37:24+00:00

The second argument of ACPI driver .remove() operation is only used
by the ACPI processor driver and the value passed to that driver
through it is always available from the given struct acpi_device
object's removal_type field.  For this reason, the second ACPI driver
.remove() argument is in fact useless, so drop it.

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Jiang Liu 
Acked-by: Toshi Kani 
Acked-by: Yinghai Lu

Merge branch 'acpi-scan' into acpi-cleanup

2013-01-25T23:36:44+00:00

The following commits depend on the 'acpi-scan' material.

ACPI / scan: Drop acpi_bus_add() and use acpi_bus_scan() instead

2013-01-19T00:27:35+00:00

The only difference between acpi_bus_scan() and acpi_bus_add() is the
invocation of acpi_update_all_gpes() in the latter which in fact is
unnecessary, because acpi_update_all_gpes() has already been called
by acpi_scan_init() and the way it is implemented guarantees the next
invocations of it to do nothing.

For this reason, drop acpi_bus_add() and make all its callers use
acpi_bus_scan() directly instead of it.  Additionally, rearrange the
code in acpi_scan_init() slightly to improve the visibility of the
acpi_update_all_gpes() call in there.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Yinghai Lu

ACPI: update ej_event interface to take acpi_device

2013-01-15T12:24:59+00:00

Should use acpi_device pointer directly instead of use handle and
get the device pointer again later.

Signed-off-by: Yinghai Lu 
Signed-off-by: Rafael J. Wysocki