[PATCH v2 09/14] ACPICA: Debugger: Fix "quit/exit" command by cleaning up user commands termination logic

From: Lv Zheng
Date: Sun Oct 18 2015 - 22:27:18 EST


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@xxxxxxxxx>
Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx>
---
drivers/acpi/acpica/acglobal.h | 3 ++-
drivers/acpi/acpica/dbinput.c | 16 ++++------------
drivers/acpi/acpica/dbxface.c | 20 ++++++++++++++++++++
drivers/acpi/acpica/utinit.c | 2 --
drivers/acpi/acpica/utxface.c | 4 ----
5 files changed, 26 insertions(+), 19 deletions(-)

diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
index 593de41..d82249c 100644
--- a/drivers/acpi/acpica/acglobal.h
+++ b/drivers/acpi/acpica/acglobal.h
@@ -324,7 +324,6 @@ ACPI_GLOBAL(struct acpi_external_file *, acpi_gbl_external_file_list);

#ifdef ACPI_DEBUGGER

-ACPI_INIT_GLOBAL(u8, acpi_gbl_db_terminate_threads, FALSE);
ACPI_INIT_GLOBAL(u8, acpi_gbl_abort_method, FALSE);
ACPI_INIT_GLOBAL(u8, acpi_gbl_method_executing, FALSE);

@@ -336,6 +335,8 @@ ACPI_GLOBAL(char *, acpi_gbl_db_filename);
ACPI_GLOBAL(u32, acpi_gbl_db_debug_level);
ACPI_GLOBAL(u32, acpi_gbl_db_console_debug_level);
ACPI_GLOBAL(struct acpi_namespace_node *, acpi_gbl_db_scope_node);
+ACPI_GLOBAL(u8, acpi_gbl_db_terminate_loop);
+ACPI_GLOBAL(u8, acpi_gbl_db_threads_terminated);

ACPI_GLOBAL(char *, acpi_gbl_db_args[ACPI_DEBUGGER_MAX_ARGS]);
ACPI_GLOBAL(acpi_object_type, acpi_gbl_db_arg_types[ACPI_DEBUGGER_MAX_ARGS]);
diff --git a/drivers/acpi/acpica/dbinput.c b/drivers/acpi/acpica/dbinput.c
index 7f1b6ec..f8cddd6 100644
--- a/drivers/acpi/acpica/dbinput.c
+++ b/drivers/acpi/acpica/dbinput.c
@@ -694,7 +694,7 @@ acpi_db_command_dispatch(char *input_buffer,

/* If acpi_terminate has been called, terminate this thread */

- if (acpi_gbl_db_terminate_threads) {
+ if (acpi_gbl_db_terminate_loop) {
return (AE_CTRL_TERMINATE);
}

@@ -1116,7 +1116,7 @@ acpi_db_command_dispatch(char *input_buffer,
#ifdef ACPI_APPLICATION
acpi_db_close_debug_file();
#endif
- acpi_gbl_db_terminate_threads = TRUE;
+ acpi_gbl_db_terminate_loop = TRUE;
return (AE_CTRL_TERMINATE);

case CMD_NOT_FOUND:
@@ -1166,6 +1166,7 @@ void ACPI_SYSTEM_XFACE acpi_db_execute_thread(void *context)

acpi_os_release_mutex(acpi_gbl_db_command_complete);
}
+ acpi_gbl_db_threads_terminated = TRUE;
}

/*******************************************************************************
@@ -1212,7 +1213,7 @@ acpi_status acpi_db_user_commands(char prompt, union acpi_parse_object *op)

/* TBD: [Restructure] Need a separate command line buffer for step mode */

- while (!acpi_gbl_db_terminate_threads) {
+ while (!acpi_gbl_db_terminate_loop) {

/* Force output to console until a command is entered */

@@ -1261,14 +1262,5 @@ acpi_status acpi_db_user_commands(char prompt, union acpi_parse_object *op)
}
}

- /* Shut down the debugger */
-
- acpi_terminate_debugger();
-
- /*
- * Only this thread (the original thread) should actually terminate the
- * subsystem, because all the semaphores are deleted during termination
- */
- status = acpi_terminate();
return (status);
}
diff --git a/drivers/acpi/acpica/dbxface.c b/drivers/acpi/acpica/dbxface.c
index 26023bd..bef5f4e 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;
diff --git a/drivers/acpi/acpica/utinit.c b/drivers/acpi/acpica/utinit.c
index 28ab3a1..d8699df 100644
--- a/drivers/acpi/acpica/utinit.c
+++ b/drivers/acpi/acpica/utinit.c
@@ -241,8 +241,6 @@ acpi_status acpi_ut_init_globals(void)
acpi_gbl_disable_mem_tracking = FALSE;
#endif

- ACPI_DEBUGGER_EXEC(acpi_gbl_db_terminate_threads = FALSE);
-
return_ACPI_STATUS(AE_OK);
}

diff --git a/drivers/acpi/acpica/utxface.c b/drivers/acpi/acpica/utxface.c
index 4f33281..f183daf 100644
--- a/drivers/acpi/acpica/utxface.c
+++ b/drivers/acpi/acpica/utxface.c
@@ -80,10 +80,6 @@ acpi_status __init acpi_terminate(void)
acpi_gbl_startup_flags = 0;
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Shutting down ACPI Subsystem\n"));

- /* Terminate the AML Debugger if present */
-
- ACPI_DEBUGGER_EXEC(acpi_gbl_db_terminate_threads = TRUE);
-
/* Shutdown and free all resources */

acpi_ut_subsystem_shutdown();
--
1.7.10

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