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[PATCH 02/11] reboot: reboot, not shutdown, on hw_protection_reboot timeout

Ahmad Fatoum posted 11 patches 12 months ago
There is a newer version of this series
[PATCH 02/11] reboot: reboot, not shutdown, on hw_protection_reboot timeout
Posted by Ahmad Fatoum 12 months ago 
hw_protection_shutdown() will kick off an orderly shutdown and if that
takes longer than a configurable amount of time, an emergency shutdown
will occur.

Recently, hw_protection_reboot() was added for those systems that don't
implement a proper shutdown and are better served by rebooting and
having the boot firmware worry about doing something about the critical
condition.

On timeout of the orderly reboot of hw_protection_reboot(), the system
would go into shutdown, instead of reboot. This is not a good idea, as
going into shutdown was explicitly not asked for.

Fix this by always doing an emergency reboot if hw_protection_reboot()
is called and the orderly reboot takes too long.

Fixes: 79fa723ba84c ("reboot: Introduce thermal_zone_device_critical_reboot()")
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 kernel/reboot.c | 46 +++++++++++++++++++++++++++++++++++-----------
 1 file changed, 35 insertions(+), 11 deletions(-)

diff --git a/kernel/reboot.c b/kernel/reboot.c
index f92aa66cbfec0f57ded43ba352a39c54d0c24a25..8e3680d36654587b57db44806a3d7b0228b10f67 100644
--- a/kernel/reboot.c
+++ b/kernel/reboot.c
@@ -932,6 +932,20 @@ void orderly_reboot(void)
 }
 EXPORT_SYMBOL_GPL(orderly_reboot);
 
+static const char *hw_protection_action_str(enum hw_protection_action action)
+{
+	switch (action) {
+	case HWPROT_ACT_SHUTDOWN:
+		return "shutdown";
+	case HWPROT_ACT_REBOOT:
+		return "reboot";
+	default:
+		return "undefined";
+	}
+}
+
+static enum hw_protection_action hw_failure_emergency_action;
+
 /**
  * hw_failure_emergency_poweroff_func - emergency poweroff work after a known delay
  * @work: work_struct associated with the emergency poweroff function
@@ -941,21 +955,29 @@ EXPORT_SYMBOL_GPL(orderly_reboot);
  */
 static void hw_failure_emergency_poweroff_func(struct work_struct *work)
 {
+	const char *action_str = hw_protection_action_str(hw_failure_emergency_action);
+
+	pr_emerg("Hardware protection timed-out. Trying forced %s\n",
+		 action_str);
+
 	/*
-	 * We have reached here after the emergency shutdown waiting period has
-	 * expired. This means orderly_poweroff has not been able to shut off
-	 * the system for some reason.
+	 * We have reached here after the emergency action waiting period has
+	 * expired. This means orderly_poweroff/reboot has not been able to
+	 * shut off the system for some reason.
 	 *
-	 * Try to shut down the system immediately using kernel_power_off
-	 * if populated
+	 * Try to shut off the system immediately if possible
 	 */
-	pr_emerg("Hardware protection timed-out. Trying forced poweroff\n");
-	kernel_power_off();
+
+	if (hw_failure_emergency_action == HWPROT_ACT_REBOOT)
+		kernel_restart(NULL);
+	else
+		kernel_power_off();
 
 	/*
 	 * Worst of the worst case trigger emergency restart
 	 */
-	pr_emerg("Hardware protection shutdown failed. Trying emergency restart\n");
+	pr_emerg("Hardware protection %s failed. Trying emergency restart\n",
+		 action_str);
 	emergency_restart();
 }
 
@@ -963,15 +985,17 @@ static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work,
 			    hw_failure_emergency_poweroff_func);
 
 /**
- * hw_failure_emergency_poweroff - Trigger an emergency system poweroff
+ * hw_failure_emergency_schedule - Schedule an emergency system shutdown or reboot
  *
  * This may be called from any critical situation to trigger a system shutdown
  * after a given period of time. If time is negative this is not scheduled.
  */
-static void hw_failure_emergency_poweroff(int poweroff_delay_ms)
+static void hw_failure_emergency_schedule(enum hw_protection_action action,
+					  int poweroff_delay_ms)
 {
 	if (poweroff_delay_ms <= 0)
 		return;
+	hw_failure_emergency_action = action;
 	schedule_delayed_work(&hw_failure_emergency_poweroff_work,
 			      msecs_to_jiffies(poweroff_delay_ms));
 }
@@ -1009,7 +1033,7 @@ void __hw_protection_shutdown(const char *reason, int ms_until_forced,
 	 * Queue a backup emergency shutdown in the event of
 	 * orderly_poweroff failure
 	 */
-	hw_failure_emergency_poweroff(ms_until_forced);
+	hw_failure_emergency_schedule(action, ms_until_forced);
 	if (action == HWPROT_ACT_REBOOT)
 		orderly_reboot();
 	else

-- 
2.39.5
Re: [PATCH 02/11] reboot: reboot, not shutdown, on hw_protection_reboot timeout
Posted by kernel test robot 12 months ago 
Hi Ahmad,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 78d4f34e2115b517bcbfe7ec0d018bbbb6f9b0b8]

url:    https://github.com/intel-lab-lkp/linux/commits/Ahmad-Fatoum/reboot-replace-__hw_protection_shutdown-bool-action-parameter-with-an-enum/20241219-155416
base:   78d4f34e2115b517bcbfe7ec0d018bbbb6f9b0b8
patch link:    https://lore.kernel.org/r/20241219-hw_protection-reboot-v1-2-263a0c1df802%40pengutronix.de
patch subject: [PATCH 02/11] reboot: reboot, not shutdown, on hw_protection_reboot timeout
config: i386-buildonly-randconfig-003-20241220 (https://download.01.org/0day-ci/archive/20241220/202412201310.JWkUQ9qf-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241220/202412201310.JWkUQ9qf-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202412201310.JWkUQ9qf-lkp@intel.com/

All warnings (new ones prefixed by >>):

   kernel/reboot.c:241: warning: Function parameter or struct member 'cmd' not described in 'do_kernel_restart'
>> kernel/reboot.c:995: warning: Function parameter or struct member 'action' not described in 'hw_failure_emergency_schedule'
>> kernel/reboot.c:995: warning: Function parameter or struct member 'poweroff_delay_ms' not described in 'hw_failure_emergency_schedule'
   kernel/reboot.c:1023: warning: Function parameter or struct member 'action' not described in '__hw_protection_shutdown'
   kernel/reboot.c:1023: warning: Excess function parameter 'shutdown' description in '__hw_protection_shutdown'


vim +995 kernel/reboot.c

dfa19b11385d4c Matti Vaittinen 2021-06-03   983  
dfa19b11385d4c Matti Vaittinen 2021-06-03   984  static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work,
dfa19b11385d4c Matti Vaittinen 2021-06-03   985  			    hw_failure_emergency_poweroff_func);
dfa19b11385d4c Matti Vaittinen 2021-06-03   986  
dfa19b11385d4c Matti Vaittinen 2021-06-03   987  /**
595ab92650cc28 Ahmad Fatoum    2024-12-19   988   * hw_failure_emergency_schedule - Schedule an emergency system shutdown or reboot
dfa19b11385d4c Matti Vaittinen 2021-06-03   989   *
dfa19b11385d4c Matti Vaittinen 2021-06-03   990   * This may be called from any critical situation to trigger a system shutdown
dfa19b11385d4c Matti Vaittinen 2021-06-03   991   * after a given period of time. If time is negative this is not scheduled.
dfa19b11385d4c Matti Vaittinen 2021-06-03   992   */
595ab92650cc28 Ahmad Fatoum    2024-12-19   993  static void hw_failure_emergency_schedule(enum hw_protection_action action,
595ab92650cc28 Ahmad Fatoum    2024-12-19   994  					  int poweroff_delay_ms)
dfa19b11385d4c Matti Vaittinen 2021-06-03  @995  {
dfa19b11385d4c Matti Vaittinen 2021-06-03   996  	if (poweroff_delay_ms <= 0)
dfa19b11385d4c Matti Vaittinen 2021-06-03   997  		return;
595ab92650cc28 Ahmad Fatoum    2024-12-19   998  	hw_failure_emergency_action = action;
dfa19b11385d4c Matti Vaittinen 2021-06-03   999  	schedule_delayed_work(&hw_failure_emergency_poweroff_work,
dfa19b11385d4c Matti Vaittinen 2021-06-03  1000  			      msecs_to_jiffies(poweroff_delay_ms));
dfa19b11385d4c Matti Vaittinen 2021-06-03  1001  }
dfa19b11385d4c Matti Vaittinen 2021-06-03  1002  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH 02/11] reboot: reboot, not shutdown, on hw_protection_reboot timeout
Posted by Ahmad Fatoum 11 months, 2 weeks ago 
On 20.12.24 07:12, kernel test robot wrote:
> Hi Ahmad,
> 
> kernel test robot noticed the following build warnings:
> 
> [auto build test WARNING on 78d4f34e2115b517bcbfe7ec0d018bbbb6f9b0b8]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Ahmad-Fatoum/reboot-replace-__hw_protection_shutdown-bool-action-parameter-with-an-enum/20241219-155416
> base:   78d4f34e2115b517bcbfe7ec0d018bbbb6f9b0b8
> patch link:    https://lore.kernel.org/r/20241219-hw_protection-reboot-v1-2-263a0c1df802%40pengutronix.de
> patch subject: [PATCH 02/11] reboot: reboot, not shutdown, on hw_protection_reboot timeout
> config: i386-buildonly-randconfig-003-20241220 (https://download.01.org/0day-ci/archive/20241220/202412201310.JWkUQ9qf-lkp@intel.com/config)
> compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241220/202412201310.JWkUQ9qf-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202412201310.JWkUQ9qf-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
>    kernel/reboot.c:241: warning: Function parameter or struct member 'cmd' not described in 'do_kernel_restart'
>>> kernel/reboot.c:995: warning: Function parameter or struct member 'action' not described in 'hw_failure_emergency_schedule'
>>> kernel/reboot.c:995: warning: Function parameter or struct member 'poweroff_delay_ms' not described in 'hw_failure_emergency_schedule'

Will fix the kernel doc issues for v2.

>    kernel/reboot.c:1023: warning: Function parameter or struct member 'action' not described in '__hw_protection_shutdown'
>    kernel/reboot.c:1023: warning: Excess function parameter 'shutdown' description in '__hw_protection_shutdown'
> 
> 
> vim +995 kernel/reboot.c
> 
> dfa19b11385d4c Matti Vaittinen 2021-06-03   983  
> dfa19b11385d4c Matti Vaittinen 2021-06-03   984  static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work,
> dfa19b11385d4c Matti Vaittinen 2021-06-03   985  			    hw_failure_emergency_poweroff_func);
> dfa19b11385d4c Matti Vaittinen 2021-06-03   986  
> dfa19b11385d4c Matti Vaittinen 2021-06-03   987  /**
> 595ab92650cc28 Ahmad Fatoum    2024-12-19   988   * hw_failure_emergency_schedule - Schedule an emergency system shutdown or reboot
> dfa19b11385d4c Matti Vaittinen 2021-06-03   989   *
> dfa19b11385d4c Matti Vaittinen 2021-06-03   990   * This may be called from any critical situation to trigger a system shutdown
> dfa19b11385d4c Matti Vaittinen 2021-06-03   991   * after a given period of time. If time is negative this is not scheduled.
> dfa19b11385d4c Matti Vaittinen 2021-06-03   992   */
> 595ab92650cc28 Ahmad Fatoum    2024-12-19   993  static void hw_failure_emergency_schedule(enum hw_protection_action action,
> 595ab92650cc28 Ahmad Fatoum    2024-12-19   994  					  int poweroff_delay_ms)
> dfa19b11385d4c Matti Vaittinen 2021-06-03  @995  {
> dfa19b11385d4c Matti Vaittinen 2021-06-03   996  	if (poweroff_delay_ms <= 0)
> dfa19b11385d4c Matti Vaittinen 2021-06-03   997  		return;
> 595ab92650cc28 Ahmad Fatoum    2024-12-19   998  	hw_failure_emergency_action = action;
> dfa19b11385d4c Matti Vaittinen 2021-06-03   999  	schedule_delayed_work(&hw_failure_emergency_poweroff_work,
> dfa19b11385d4c Matti Vaittinen 2021-06-03  1000  			      msecs_to_jiffies(poweroff_delay_ms));
> dfa19b11385d4c Matti Vaittinen 2021-06-03  1001  }
> dfa19b11385d4c Matti Vaittinen 2021-06-03  1002  
> 


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