linux-toradex.git/kernel/power/user.c, branch v5.1-rc1

PM / reboot: Eliminate race between reboot and suspend

2018-08-06T10:35:20+00:00

At present, "systemctl suspend" and "shutdown" can run in parrallel. A
system can suspend after devices_shutdown(), and resume. Then the shutdown
task goes on to power off. This causes many devices are not really shut
off. Hence replacing reboot_mutex with system_transition_mutex (renamed
from pm_mutex) to achieve the exclusion. The renaming of pm_mutex as
system_transition_mutex can be better to reflect the purpose of the mutex.

Signed-off-by: Pingfan Liu 
Acked-by: Pavel Machek 
Signed-off-by: Rafael J. Wysocki

PM / hibernate: Fix oops at snapshot_write()

2018-05-27T10:00:02+00:00

syzbot is reporting NULL pointer dereference at snapshot_write() [1].
This is because data->handle is zero-cleared by ioctl(SNAPSHOT_FREE).
Fix this by checking data_of(data->handle) != NULL before using it.

[1] https://syzkaller.appspot.com/bug?id=828a3c71bd344a6de8b6a31233d51a72099f27fd

Signed-off-by: Tetsuo Handa 
Reported-by: syzbot 
Signed-off-by: Rafael J. Wysocki

fs: add ksys_sync() helper; remove in-kernel calls to sys_sync()

2018-04-02T18:16:05+00:00

Using this helper allows us to avoid the in-kernel calls to the
sys_sync() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it
uses the same calling convention as sys_sync().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Alexander Viro 
Signed-off-by: Dominik Brodowski

Replace with globally

2016-12-24T19:46:01+00:00

This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*'
  sed -i -e "s!$PATT!#include !" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro 
Signed-off-by: Linus Torvalds

PM / sleep: make PM notifiers called symmetrically

2016-06-27T22:38:55+00:00

This makes pm notifier PREPARE/POST symmetrical: if PREPARE
fails, we will only undo what ever happened on PREPARE.

It fixes the unbalanced CPU hotplug enable in CPU PM notifier.

Signed-off-by: Lianwei Wang 
Signed-off-by: Rafael J. Wysocki

PM / hibernate: introduce "nohibernate" boot parameter

2014-06-16T21:29:39+00:00

To support using kernel features that are not compatible with hibernation,
this creates the "nohibernate" kernel boot parameter to disable both
hibernation and resume. This allows hibernation support to be a boot-time
choice instead of only a compile-time choice.

Signed-off-by: Kees Cook 
Acked-by: Pavel Machek 
Signed-off-by: Rafael J. Wysocki

Merge branch 'pm-sleep'

2013-11-19T00:07:08+00:00

* pm-sleep:
  PM / Hibernate: Do not crash kernel in free_basic_memory_bitmaps()

PM / Hibernate: Do not crash kernel in free_basic_memory_bitmaps()

2013-11-14T22:26:58+00:00

I have received a report about the BUG_ON() in free_basic_memory_bitmaps()
triggering mysteriously during an aborted s2disk hibernation attempt.
The only way I can explain that is that /dev/snapshot was first
opened for writing (resume mode), then closed and then opened again
for reading and closed again without freezing tasks.  In that case
the first invocation of snapshot_open() would set the free_bitmaps
flag in snapshot_state, which is a static variable.  That flag
wouldn't be cleared later and the second invocation of snapshot_open()
would just leave it like that, so the subsequent snapshot_release()
would see data->frozen set and free_basic_memory_bitmaps() would be
called unnecessarily.

To prevent that from happening clear data->free_bitmaps in
snapshot_open() when the file is being opened for reading (hibernate
mode).

In addition to that, replace the BUG_ON() in free_basic_memory_bitmaps()
with a WARN_ON() as the kernel can continue just fine if the condition
checked by that macro occurs.

Fixes: aab172891542 (PM / hibernate: Fix user space driven resume regression)
Reported-by: Oliver Lorenz 
Signed-off-by: Rafael J. Wysocki 
Cc: 3.12+  # 3.12+

PM / Hibernate: Use bool for boolean fields of struct snapshot_data

2013-10-18T20:20:40+00:00

The snapshot_data structure used internally by the hibernate user
space interface code in user.c has three char fields that are used
to store boolean values.  Change their data type to bool and use
true and false instead of 1 and 0, respectively, in assignments
involving those fields.

Signed-off-by: Rafael J. Wysocki

PM / hibernate: Fix user space driven resume regression

2013-09-30T17:40:56+00:00

Recent commit 8fd37a4 (PM / hibernate: Create memory bitmaps after
freezing user space) broke the resume part of the user space driven
hibernation (s2disk), because I forgot that the resume utility
loaded the image into memory without freezing user space (it still
freezes tasks after loading the image).  This means that during user
space driven resume we need to create the memory bitmaps at the
"device open" time rather than at the "freeze tasks" time, so make
that happen (that's a special case anyway, so it needs to be treated
in a special way).

Reported-and-tested-by: Ronald 
Signed-off-by: Rafael J. Wysocki