linux-toradex.git/kernel/power/user.c, branch v3.2.70

PM / Hibernate: Thaw kernel threads in SNAPSHOT_CREATE_IMAGE ioctl path

2012-02-13T19:16:56+00:00

commit fe9161db2e6053da21e4649d77bbefaf3030b11d upstream.

In the SNAPSHOT_CREATE_IMAGE ioctl, if the call to hibernation_snapshot()
fails, the frozen tasks are not thawed.

And in the case of success, if we happen to exit due to a successful freezer
test, all tasks (including those of userspace) are thawed, whereas actually
we should have thawed only the kernel threads at that point. Fix both these
issues.

Signed-off-by: Srivatsa S. Bhat 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PM / Hibernate: Thaw processes in SNAPSHOT_CREATE_IMAGE ioctl test path

2012-02-13T19:16:56+00:00

commit 97819a26224f019e73d88bb2fd4eb5a614860461 upstream.

Commit 2aede851ddf08666f68ffc17be446420e9d2a056 (PM / Hibernate: Freeze
kernel threads after preallocating memory) moved the freezing of kernel
threads to hibernation_snapshot() function.

So now, if the call to hibernation_snapshot() returns early due to a
successful hibernation test, the caller has to thaw processes to ensure
that the system gets back to its original state.

But in SNAPSHOT_CREATE_IMAGE hibernation ioctl, the caller does not thaw
processes in case hibernation_snapshot() returned due to a successful
freezer test. Fix this issue. But note we still send the value of 'in_suspend'
(which is now 0) to userspace, because we are not in an error path per-se,
and moreover, the value of in_suspend correctly depicts the situation here.

Signed-off-by: Srivatsa S. Bhat 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PM / Hibernate: Fix s2disk regression related to freezing workqueues

2012-02-13T19:16:55+00:00

commit 181e9bdef37bfcaa41f3ab6c948a2a0d60a268b5 upstream.

Commit 2aede851ddf08666f68ffc17be446420e9d2a056

  PM / Hibernate: Freeze kernel threads after preallocating memory

introduced a mechanism by which kernel threads were frozen after
the preallocation of hibernate image memory to avoid problems with
frozen kernel threads not responding to memory freeing requests.
However, it overlooked the s2disk code path in which the
SNAPSHOT_CREATE_IMAGE ioctl was run directly after SNAPSHOT_FREE,
which caused freeze_workqueues_begin() to BUG(), because it saw
that worqueues had been already frozen.

Although in principle this issue might be addressed by removing
the relevant BUG_ON() from freeze_workqueues_begin(), that would
reintroduce the very problem that commit 2aede851ddf08666f68ffc17be4
attempted to avoid into that particular code path.  For this reason,
to fix the issue at hand, introduce thaw_kernel_threads() and make
the SNAPSHOT_FREE ioctl execute it.

Special thanks to Srivatsa S. Bhat for detailed analysis of the
problem.

Reported-and-tested-by: Jiri Slaby 
Signed-off-by: Rafael J. Wysocki 
Acked-by: Srivatsa S. Bhat 
Signed-off-by: Greg Kroah-Hartman

kernel: fix several implicit usasges of kmod.h

2011-10-31T13:20:12+00:00

These files were implicitly relying on  coming in via
module.h, as without it we get things like:

kernel/power/suspend.c:100: error: implicit declaration of function ‘usermodehelper_disable’
kernel/power/suspend.c:109: error: implicit declaration of function ‘usermodehelper_enable’
kernel/power/user.c:254: error: implicit declaration of function ‘usermodehelper_disable’
kernel/power/user.c:261: error: implicit declaration of function ‘usermodehelper_enable’

kernel/sys.c:317: error: implicit declaration of function ‘usermodehelper_disable’
kernel/sys.c:1816: error: implicit declaration of function ‘call_usermodehelper_setup’
kernel/sys.c:1822: error: implicit declaration of function ‘call_usermodehelper_setfns’
kernel/sys.c:1824: error: implicit declaration of function ‘call_usermodehelper_exec’

Signed-off-by: Paul Gortmaker

PM: Free memory bitmaps if opening /dev/snapshot fails

2011-06-21T21:20:06+00:00

When opening /dev/snapshot device, snapshot_open() creates memory
bitmaps which are freed in snapshot_release(). But if any of the
callbacks called by pm_notifier_call_chain() returns NOTIFY_BAD, open()
fails, snapshot_release() is never called and bitmaps are not freed.
Next attempt to open /dev/snapshot then triggers BUG_ON() check in
create_basic_memory_bitmaps(). This happens e.g. when vmwatchdog module
is active on s390x.

Signed-off-by: Michal Kubecek 
Signed-off-by: Rafael J. Wysocki 
Cc: stable@kernel.org

PM / Hibernate: Fix ioctl SNAPSHOT_S2RAM

2011-05-11T19:10:58+00:00

The SNAPSHOT_S2RAM ioctl used for implementing the feature allowing
one to suspend to RAM after creating a hibernation image is currently
broken, because it doesn't clear the "ready" flag in the struct
snapshot_data object handled by it.  As a result, the
SNAPSHOT_UNFREEZE doesn't work correctly after SNAPSHOT_S2RAM has
returned and the user space hibernate task cannot thaw the other
processes as appropriate.  Make SNAPSHOT_S2RAM clear data->ready
to fix this problem.

Tested-by: Alexandre Felipe Muller de Souza 
Signed-off-by: Rafael J. Wysocki 
Cc: stable@kernel.org

PM / Hibernate: Make snapshot_release() restore GFP mask

2011-05-11T19:10:43+00:00

If the process using the hibernate user space interface closes
/dev/snapshot after creating a hibernation image without thawing
tasks, snapshot_release() should call pm_restore_gfp_mask() to
restore the GFP mask used before the creation of the image.  Make
that happen.

Tested-by: Alexandre Felipe Muller de Souza 
Signed-off-by: Rafael J. Wysocki 
Cc: stable@kernel.org

PM / Hibernate: Fix PM_POST_* notification with user-space suspend

2010-12-16T16:08:43+00:00

The user-space hibernation sends a wrong notification after the image
restoration because of thinko for the file flag check.  RDONLY
corresponds to hibernation and WRONLY to restoration, confusingly.

Signed-off-by: Takashi Iwai 
Signed-off-by: Rafael J. Wysocki 
Cc: stable@kernel.org

PM / Hibernate: Fix memory corruption related to swap

2010-12-06T22:52:08+00:00

There is a problem that swap pages allocated before the creation of
a hibernation image can be released and used for storing the contents
of different memory pages while the image is being saved.  Since the
kernel stored in the image doesn't know of that, it causes memory
corruption to occur after resume from hibernation, especially on
systems with relatively small RAM that need to swap often.

This issue can be addressed by keeping the GFP_IOFS bits clear
in gfp_allowed_mask during the entire hibernation, including the
saving of the image, until the system is finally turned off or
the hibernation is aborted.  Unfortunately, for this purpose
it's necessary to rework the way in which the hibernate and
suspend code manipulates gfp_allowed_mask.

This change is based on an earlier patch from Hugh Dickins.

Signed-off-by: Rafael J. Wysocki 
Reported-by: Ondrej Zary 
Acked-by: Hugh Dickins 
Reviewed-by: KAMEZAWA Hiroyuki 
Cc: stable@kernel.org

PM / Hibernate: Snapshot cleanup

2010-05-10T21:08:17+00:00

Remove support of reads with offset. This means snapshot_read/write_next
now does not accept count parameter. It allows to clean up the functions
and snapshot handle which no longer needs to care about offsets.

/dev/snapshot handler is converted to simple_{read_from,write_to}_buffer
which take care of offsets.

Signed-off-by: Jiri Slaby 
Acked-by: Pavel Machek 
Signed-off-by: Rafael J. Wysocki