qcacmn: Add qdf_print_thread_trace API

Add an abstraction to QDF for printing the stack trace of a given
thread.

Change-Id: Ibea6e6bed7f3ebe67538b8ea8b6b437b643d5541
CRs-Fixed: 2088806

qdf/inc/qdf_threads.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2016 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2014-2017 The Linux Foundation. All rights reserved.
  *
  * Previously licensed under the ISC license by Qualcomm Atheros, Inc.
  *
@@ -34,7 +34,9 @@
 #define __QDF_THREADS_H
 
 #include <qdf_types.h>
-#include <qdf_util.h>
+#include "i_qdf_threads.h"
+
+typedef __qdf_thread_t qdf_thread_t;
 
 /* Function declarations and documenation */
 
@@ -71,4 +73,12 @@ qdf_thread_t *qdf_create_thread(int (*thread_handler)(void *data), void *data,
  */
 int qdf_wake_up_process(qdf_thread_t *thread);
 
+/**
+ * qdf_print_stack_trace_thread() - prints the stack trace of the given thread
+ * @thread: the thread for which the stack trace will be printed
+ *
+ * Return: None
+ */
+void qdf_print_thread_trace(qdf_thread_t *thread);
+
 #endif /* __QDF_THREADS_H */

qdf/inc/qdf_util.h

@@ -41,7 +41,6 @@
 #define QDF_MAX_AVAILABLE_CPU	1
 #endif
 
-typedef __qdf_thread_t qdf_thread_t;
 typedef __qdf_wait_queue_head_t qdf_wait_queue_head_t;
 
 /**

qdf/linux/src/i_qdf_threads.h

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2017 The Linux Foundation. All rights reserved.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for
+ * any purpose with or without fee is hereby granted, provided that the
+ * above copyright notice and this permission notice appear in all
+ * copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+ * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+ * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/**
+ * DOC: i_qdf_threads
+ * Header file for linux-specific thead abstractions
+ */
+
+#ifndef __I_QDF_THREADS_H
+#define __I_QDF_THREADS_H
+
+typedef struct task_struct __qdf_thread_t;
+
+#endif /* __I_QDF_THREADS_H */

qdf/linux/src/i_qdf_util.h

@@ -65,7 +65,6 @@
 #include <linux/byteorder/generic.h>
 #endif
 
-typedef struct task_struct __qdf_thread_t;
 typedef wait_queue_head_t __qdf_wait_queue_head_t;
 
 /* Generic compiler-dependent macros if defined by the OS */

qdf/linux/src/qdf_threads.c

@@ -44,6 +44,7 @@
 #include <linux/interrupt.h>
 #include <linux/export.h>
 #include <linux/kthread.h>
+#include <stacktrace.h>
 
 /* Function declarations and documenation */
 
@@ -129,3 +130,28 @@ int qdf_wake_up_process(qdf_thread_t *thread)
 	return wake_up_process(thread);
 }
 EXPORT_SYMBOL(qdf_wake_up_process);
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 13, 0)) ||\
+	defined(BACKPORTED_EXPORT_SAVE_STACK_TRACE_TSK)
+/* save_stack_trace_tsk is not generally exported for arm architectures */
+#define QDF_PRINT_TRACE_COUNT 32
+void qdf_print_thread_trace(qdf_thread_t *thread)
+{
+	const int spaces = 4;
+	struct task_struct *task = thread;
+	unsigned long entries[QDF_PRINT_TRACE_COUNT] = {0};
+	struct stack_trace trace = {
+		.nr_entries = 0,
+		.skip = 0,
+		.entries = &entries[0],
+		.max_entries = QDF_PRINT_TRACE_COUNT,
+	};
+
+	save_stack_trace_tsk(task, &trace);
+	print_stack_trace(&trace, spaces);
+}
+#else
+void qdf_print_thread_trace(qdf_thread_t *thread) { }
+#endif /* KERNEL_VERSION(4, 13, 0) */
+EXPORT_SYMBOL(qdf_print_thread_trace);
+