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authorDmitry Osipenko <dmitry.osipenko@collabora.com>2022-05-25 00:21:18 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2022-05-25 14:51:40 +0200
commitda007f171fc9dd993d03a360b515cac1c87921bb (patch)
tree290a6033a420fbba35dd2072c937472bab9476e0 /kernel/reboot.c
parentcfd6d63e596552e1a5bf38bb889997b656475032 (diff)
downloadlinux-da007f171fc9dd993d03a360b515cac1c87921bb.tar.bz2
kernel/reboot: Change registration order of legacy power-off handler
We're unconditionally registering sys-off handler for the legacy pm_power_off() callback, this causes problem for platforms that don't use power-off handlers at all and should be halted. Now reboot syscall assumes that there is a power-off handler installed and tries to power off system instead of halting it. To fix the trouble, move the handler's registration to the reboot syscall and check the pm_power_off() presence. Fixes: 0e2110d2e910 ("kernel/reboot: Add kernel_can_power_off()") Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'kernel/reboot.c')
-rw-r--r--kernel/reboot.c33
1 files changed, 17 insertions, 16 deletions
diff --git a/kernel/reboot.c b/kernel/reboot.c
index bdb635842ec8..d4aa372c0cdc 100644
--- a/kernel/reboot.c
+++ b/kernel/reboot.c
@@ -569,22 +569,6 @@ static int legacy_pm_power_off(struct sys_off_data *data)
return NOTIFY_DONE;
}
-/*
- * Register sys-off handlers for legacy PM callbacks. This allows legacy
- * PM callbacks co-exist with the new sys-off API.
- *
- * TODO: Remove legacy handlers once all legacy PM users will be switched
- * to the sys-off based APIs.
- */
-static int __init legacy_pm_init(void)
-{
- register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, SYS_OFF_PRIO_DEFAULT,
- legacy_pm_power_off, NULL);
-
- return 0;
-}
-core_initcall(legacy_pm_init);
-
static void do_kernel_power_off_prepare(void)
{
blocking_notifier_call_chain(&power_off_prep_handler_list, 0, NULL);
@@ -646,6 +630,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
void __user *, arg)
{
struct pid_namespace *pid_ns = task_active_pid_ns(current);
+ struct sys_off_handler *sys_off = NULL;
char buffer[256];
int ret = 0;
@@ -670,6 +655,21 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
if (ret)
return ret;
+ /*
+ * Register sys-off handlers for legacy PM callback. This allows
+ * legacy PM callbacks temporary co-exist with the new sys-off API.
+ *
+ * TODO: Remove legacy handlers once all legacy PM users will be
+ * switched to the sys-off based APIs.
+ */
+ if (pm_power_off) {
+ sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
+ SYS_OFF_PRIO_DEFAULT,
+ legacy_pm_power_off, NULL);
+ if (IS_ERR(sys_off))
+ return PTR_ERR(sys_off);
+ }
+
/* Instead of trying to make the power_off code look like
* halt when pm_power_off is not set do it the easy way.
*/
@@ -727,6 +727,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
break;
}
mutex_unlock(&system_transition_mutex);
+ unregister_sys_off_handler(sys_off);
return ret;
}