[PATCH v3] ACPI: OSL: Poweroff when encountering a fatal ACPI error

[Armin Wolf <W_Armin@gmx.de>]

The ACPI spec states that the operating system should respond
to a fatal ACPI error by "performing a controlled OS shutdown in
a timely fashion". Comply with the ACPI specification by powering
off the system when ACPICA signals a fatal ACPI error. Users can
still disable this behavior by using the acpi.poweroff_on_fatal
kernel option to work around firmware bugs.

Link: https://uefi.org/specs/ACPI/6.6/19_ASL_Reference.html#fatal-fatal-error-check
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
---
Changes since v2:
- poweroff instead of triggering a kernel panic

Changes since v1:
- use IS_ENABLED() for checking the presence of CONFIG_ACPI_PANIC_ON_FATAL
---
 .../admin-guide/kernel-parameters.txt         |  9 +++++++++
 drivers/acpi/Kconfig                          | 11 +++++++++++
 drivers/acpi/osl.c                            | 19 ++++++++++++++++++-
 3 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 1058f2a6d6a8..1f2eaa0ec424 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -187,6 +187,15 @@ Kernel parameters
 			unusable.  The "log_buf_len" parameter may be useful
 			if you need to capture more output.
 
+	acpi.poweroff_on_fatal=	[ACPI]
+			{0 | 1}
+			Causes the system to poweroff when the ACPI bytecode signals
+			a fatal error. The default value of this setting can
+			be configured using CONFIG_ACPI_POWEROFF_ON_FATAL.
+			Overriding this value should only be done for diagnosing
+			ACPI firmware problems, as the system might behave erratically
+			after having encountered a fatal ACPI error.
+
 	acpi_enforce_resources=	[ACPI]
 			{ strict | lax | no }
 			Check for resource conflicts between native drivers
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index df0ff0764d0d..1610dd4c8278 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -65,6 +65,17 @@ config ACPI_THERMAL_LIB
        depends on THERMAL
        bool
 
+config ACPI_POWEROFF_ON_FATAL
+	bool "Poweroff on fatal ACPI error"
+	default y
+	help
+	  The ACPI bytecode can signal that a fatal error has occurred using the Fatal()
+	  ASL operator, normaly causing the system to poweroff. Disabling this option causes
+	  such a condition to be treated like a ordinary ACPI error.
+
+	  This setting can also be overridden during boot using the acpi.poweroff_on_fatal
+	  kernel parameter.
+
 config ACPI_DEBUGGER
 	bool "AML debugger interface"
 	select ACPI_DEBUG
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 05393a7315fe..f2b45fa4a752 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -11,8 +11,10 @@
 
 #define pr_fmt(fmt) "ACPI: OSL: " fmt
 
+#include <linux/kconfig.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
+#include <linux/reboot.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/highmem.h>
@@ -70,6 +72,10 @@ static bool acpi_os_initialized;
 unsigned int acpi_sci_irq = INVALID_ACPI_IRQ;
 bool acpi_permanent_mmap = false;
 
+static bool poweroff_on_fatal = IS_ENABLED(CONFIG_ACPI_POWEROFF_ON_FATAL);
+module_param(poweroff_on_fatal, bool, 0);
+MODULE_PARM_DESC(poweroff_on_fatal, "Poweroff when encountering a fatal ACPI error");
+
 /*
  * This list of permanent mappings is for memory that may be accessed from
  * interrupt context, where we can't do the ioremap().
@@ -1381,9 +1387,20 @@ acpi_status acpi_os_notify_command_complete(void)
 
 acpi_status acpi_os_signal(u32 function, void *info)
 {
+	struct acpi_signal_fatal_info *fatal_info;
+
 	switch (function) {
 	case ACPI_SIGNAL_FATAL:
-		pr_err("Fatal opcode executed\n");
+		fatal_info = info;
+		pr_emerg("Fatal error while evaluating ACPI control method\n");
+		pr_emerg("Type 0x%X Code 0x%X Argument 0x%X\n",
+			 fatal_info->type, fatal_info->code, fatal_info->argument);
+
+		if (poweroff_on_fatal)
+			orderly_poweroff(true);
+		else
+			add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
+
 		break;
 	case ACPI_SIGNAL_BREAKPOINT:
 		/*
-- 
2.39.5