ACPICA: Debugger: Fix "quit/exit" command by cleaning up user commands termination logic

ACPICA commit 0dd68e16274cd38224aa4781eddc57dc2cbaa108

The quit/exit commands shouldn't invoke acpi_terminate_debugger() and
acpi_terminate() right in the user command loop, because when the debugger
exits, the kernel ACPI subsystem shouldn't be terminated (acpi_terminate())
and the debugger should only be terminated by its users
(acpi_terminate_debugger()) rather than being terminated itself. Leaving such
invocations causes kernel panic when the debugger is shipped in the Linux
kernel.

This patch fixes this issue. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/0dd68e16
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/dbxface.c b/drivers/acpi/acpica/dbxface.c
index 26023bd95f56..bef5f4ed22a0 100644
--- a/drivers/acpi/acpica/dbxface.c
+++ b/drivers/acpi/acpica/dbxface.c
@@ -401,6 +401,10 @@ acpi_status acpi_initialize_debugger(void)
 	acpi_gbl_db_scope_buf[1] = 0;
 	acpi_gbl_db_scope_node = acpi_gbl_root_node;
 
+	/* Initialize user commands loop */
+
+	acpi_gbl_db_terminate_loop = FALSE;
+
 	/*
 	 * If configured for multi-thread support, the debug executor runs in
 	 * a separate thread so that the front end can be in another address
@@ -426,11 +430,13 @@ acpi_status acpi_initialize_debugger(void)
 
 		/* Create the debug execution thread to execute commands */
 
+		acpi_gbl_db_threads_terminated = FALSE;
 		status = acpi_os_execute(OSL_DEBUGGER_THREAD,
 					 acpi_db_execute_thread, NULL);
 		if (ACPI_FAILURE(status)) {
 			ACPI_EXCEPTION((AE_INFO, status,
 					"Could not start debugger thread"));
+			acpi_gbl_db_threads_terminated = TRUE;
 			return_ACPI_STATUS(status);
 		}
 	}
@@ -454,6 +460,20 @@ ACPI_EXPORT_SYMBOL(acpi_initialize_debugger)
 void acpi_terminate_debugger(void)
 {
 
+	/* Terminate the AML Debugger */
+
+	acpi_gbl_db_terminate_loop = TRUE;
+
+	if (acpi_gbl_debugger_configuration & DEBUGGER_MULTI_THREADED) {
+		acpi_os_release_mutex(acpi_gbl_db_command_ready);
+
+		/* Wait the AML Debugger threads */
+
+		while (!acpi_gbl_db_threads_terminated) {
+			acpi_os_sleep(100);
+		}
+	}
+
 	if (acpi_gbl_db_buffer) {
 		acpi_os_free(acpi_gbl_db_buffer);
 		acpi_gbl_db_buffer = NULL;