From 23d128364de734e8dfd84145367bcd80fe06abd1 Mon Sep 17 00:00:00 2001
From: Yue Ma <yuem@qca.qualcomm.com>
Date: Tue, 15 Dec 2015 17:15:45 -0800
Subject: [PATCH] qcacld-3.0: Save call stack for each memory allocation in
 SLUB builds

qcacld-2.0 to qcacld-3.0 propagation

Currently only one level of information (file name and line number of
the caller who wants to allocate memory) is saved when each memory is
allocated. This may not be able to provide enough information for some
cases that multiple levels of callers are the same. Hence save call stack
as well for each memory allocation in SLUB builds for debug purpose.

Change-Id: I245d53ec3805217ca34d7c1f5e31b84cac73e395
CRs-fixed: 930557
---
 core/cdf/src/cdf_memory.c | 54 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/core/cdf/src/cdf_memory.c b/core/cdf/src/cdf_memory.c
index f32c56620f7f..874f5fb7a8fe 100644
--- a/core/cdf/src/cdf_memory.c
+++ b/core/cdf/src/cdf_memory.c
@@ -48,6 +48,7 @@
 
 #ifdef MEMORY_DEBUG
 #include <cdf_list.h>
+#include <linux/stacktrace.h>
 
 cdf_list_t cdf_mem_list;
 cdf_spinlock_t cdf_mem_list_lock;
@@ -57,11 +58,17 @@ static uint8_t WLAN_MEM_HEADER[] = { 0x61, 0x62, 0x63, 0x64, 0x65, 0x66,
 static uint8_t WLAN_MEM_TAIL[] = { 0x80, 0x81, 0x82, 0x83, 0x84, 0x85,
 					0x86, 0x87 };
 
+#define CDF_MEM_MAX_STACK_TRACE 16
+
 struct s_cdf_mem_struct {
 	cdf_list_node_t pNode;
 	char *fileName;
 	unsigned int lineNum;
 	unsigned int size;
+#ifdef WLAN_OPEN_SOURCE
+	unsigned long stack_trace[CDF_MEM_MAX_STACK_TRACE];
+	struct stack_trace trace;
+#endif
 	uint8_t header[8];
 };
 #endif
@@ -75,6 +82,51 @@ struct s_cdf_mem_struct {
 
 /* External Function implementation */
 #ifdef MEMORY_DEBUG
+#ifdef WLAN_OPEN_SOURCE
+/**
+ * cdf_mem_save_stack_trace() - Save stack trace of the caller
+ * @mem_struct: Pointer to the memory structure where to save the stack trace
+ *
+ * Return: None
+ */
+static inline void cdf_mem_save_stack_trace(struct s_cdf_mem_struct *mem_struct)
+{
+	struct stack_trace *trace = &mem_struct->trace;
+
+	trace->nr_entries = 0;
+	trace->max_entries = CDF_MEM_MAX_STACK_TRACE;
+	trace->entries = mem_struct->stack_trace;
+	trace->skip = 2;
+
+	save_stack_trace(trace);
+}
+
+/**
+ * cdf_mem_print_stack_trace() - Print saved stack trace
+ * @mem_struct: Pointer to the memory structure which has the saved stack trace
+ *              to be printed
+ *
+ * Return: None
+ */
+static inline void cdf_mem_print_stack_trace(struct s_cdf_mem_struct
+					     *mem_struct)
+{
+	CDF_TRACE(CDF_MODULE_ID_CDF, CDF_TRACE_LEVEL_FATAL,
+		  "Call stack for the source of leaked memory:");
+
+	print_stack_trace(&mem_struct->trace, 1);
+}
+#else
+static inline void cdf_mem_save_stack_trace(struct s_cdf_mem_struct *mem_struct)
+{
+
+}
+static inline void cdf_mem_print_stack_trace(struct s_cdf_mem_struct
+					     *mem_struct)
+{
+
+}
+#endif
 
 /**
  * cdf_mem_init() - initialize cdf memory debug functionality
@@ -144,6 +196,7 @@ void cdf_mem_clean(void)
 					mleak_cnt = 0;
 				}
 				mleak_cnt++;
+				cdf_mem_print_stack_trace(memStruct);
 				kfree((void *)memStruct);
 			}
 		} while (cdf_status == CDF_STATUS_SUCCESS);
@@ -240,6 +293,7 @@ void *cdf_mem_malloc_debug(size_t size, char *fileName, uint32_t lineNum)
 		memStruct->fileName = fileName;
 		memStruct->lineNum = lineNum;
 		memStruct->size = size;
+		cdf_mem_save_stack_trace(memStruct);
 
 		cdf_mem_copy(&memStruct->header[0],
 			     &WLAN_MEM_HEADER[0], sizeof(WLAN_MEM_HEADER));