linux/kernel/power
Vlastimil Babka df2f7cde73 PM: hibernate: fix resume_store() return value when hibernation not available
On a laptop with hibernation set up but not actively used, and with
secure boot and lockdown enabled kernel, 6.5-rc1 gets stuck on boot with
the following repeated messages:

  A start job is running for Resume from hibernation using device /dev/system/swap (24s / no limit)
  lockdown_is_locked_down: 25311154 callbacks suppressed
  Lockdown: systemd-hiberna: hibernation is restricted; see man kernel_lockdown.7
  ...

Checking the resume code leads to commit cc89c63e2f ("PM: hibernate:
move finding the resume device out of software_resume") which
inadvertently changed the return value from resume_store() to 0 when
!hibernation_available(). This apparently translates to userspace
write() returning 0 as in number of bytes written, and userspace looping
indefinitely in the attempt to write the intended value.

Fix this by returning the full number of bytes that were to be written,
as that's what was done before the commit.

Fixes: cc89c63e2f ("PM: hibernate: move finding the resume device out of software_resume")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-08-07 11:41:11 +02:00
..
autosleep.c
console.c
energy_model.c PM: EM: fix memory leak with using debugfs_lookup() 2023-02-09 20:36:10 +01:00
hibernate.c PM: hibernate: fix resume_store() return value when hibernation not available 2023-08-07 11:41:11 +02:00
Kconfig PM: sleep: Remove "select SRCU" 2023-01-20 17:53:07 +01:00
main.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
Makefile PM: sleep: Narrow down -DDEBUG on kernel/power/ files 2022-04-13 16:34:01 +02:00
power.h - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
poweroff.c
process.c workqueue: Introduce show_freezable_workqueues 2023-03-23 15:55:38 -10:00
qos.c PM: QoS: Restore support for default value on frequency QoS 2023-07-11 20:09:57 +02:00
snapshot.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
suspend_test.c PM: suspend: fix return value of __setup handler 2022-03-01 18:55:07 +01:00
suspend.c Scheduler changes for v6.1: 2022-10-10 09:10:28 -07:00
swap.c block: replace fmode_t with a block-specific type for block open flags 2023-06-12 08:04:05 -06:00
user.c freezer: Have {,un}lock_system_sleep() save/restore flags 2022-09-07 21:53:48 +02:00
wakelock.c PM: wakeup: simplify the output logic of pm_show_wakelocks() 2022-01-25 18:27:02 +01:00