Merge "msm: sps: Fix race condition in SPS debugfs APIs"

2 files changed, 15 insertions, 19 deletions

diff --git a/drivers/platform/msm/sps/sps.c b/drivers/platform/msm/sps/sps.c
index 2f11c6dd7e05..ddb2388c5006 100644
--- a/drivers/platform/msm/sps/sps.c
+++ b/drivers/platform/msm/sps/sps.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2011-2016	, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2011-2017, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -67,6 +67,7 @@ static char *debugfs_buf;
 static u32 debugfs_buf_size;
 static u32 debugfs_buf_used;
 static int wraparound;
+static struct mutex sps_debugfs_lock;
 
 struct dentry *dent;
 struct dentry *dfile_info;
@@ -85,6 +86,7 @@ static struct sps_bam *phy2bam(phys_addr_t phys_addr);
 /* record debug info for debugfs */
 void sps_debugfs_record(const char *msg)
 {
+	mutex_lock(&sps_debugfs_lock);
 	if (debugfs_record_enabled) {
 		if (debugfs_buf_used + MAX_MSG_LEN >= debugfs_buf_size) {
 			debugfs_buf_used = 0;
@@ -98,6 +100,7 @@ void sps_debugfs_record(const char *msg)
 					debugfs_buf_size - debugfs_buf_used,
 					"\n**** end line of sps log ****\n\n");
 	}
+	mutex_unlock(&sps_debugfs_lock);
 }
 
 /* read the recorded debug info to userspace */
@@ -107,6 +110,7 @@ static ssize_t sps_read_info(struct file *file, char __user *ubuf,
 	int ret = 0;
 	int size;
 
+	mutex_lock(&sps_debugfs_lock);
 	if (debugfs_record_enabled) {
 		if (wraparound)
 			size = debugfs_buf_size - MAX_MSG_LEN;
@@ -116,6 +120,7 @@ static ssize_t sps_read_info(struct file *file, char __user *ubuf,
 		ret = simple_read_from_buffer(ubuf, count, ppos,
 				debugfs_buf, size);
 	}
+	mutex_unlock(&sps_debugfs_lock);
 
 	return ret;
 }
@@ -161,11 +166,13 @@ static ssize_t sps_set_info(struct file *file, const char __user *buf,
 
 	new_buf_size = buf_size_kb * SZ_1K;
 
+	mutex_lock(&sps_debugfs_lock);
 	if (debugfs_record_enabled) {
 		if (debugfs_buf_size == new_buf_size) {
 			/* need do nothing */
 			pr_info("sps:debugfs: input buffer size "
 				"is the same as before.\n");
+			mutex_unlock(&sps_debugfs_lock);
 			return count;
 		} else {
 			/* release the current buffer */
@@ -185,12 +192,14 @@ static ssize_t sps_set_info(struct file *file, const char __user *buf,
 	if (!debugfs_buf) {
 		debugfs_buf_size = 0;
 		pr_err("sps:fail to allocate memory for debug_fs.\n");
+		mutex_unlock(&sps_debugfs_lock);
 		return -ENOMEM;
 	}
 
 	debugfs_buf_used = 0;
 	wraparound = false;
 	debugfs_record_enabled = true;
+	mutex_unlock(&sps_debugfs_lock);
 
 	return count;
 }
@@ -239,6 +248,7 @@ static ssize_t sps_set_logging_option(struct file *file, const char __user *buf,
 		return count;
 	}
 
+	mutex_lock(&sps_debugfs_lock);
 	if (((option == 0) || (option == 2)) &&
 		((logging_option == 1) || (logging_option == 3))) {
 		debugfs_record_enabled = false;
@@ -250,6 +260,7 @@ static ssize_t sps_set_logging_option(struct file *file, const char __user *buf,
 	}
 
 	logging_option = option;
+	mutex_unlock(&sps_debugfs_lock);
 
 	return count;
 }
@@ -587,6 +598,8 @@ static void sps_debugfs_init(void)
 		goto bam_log_level_err;
 	}
 
+	mutex_init(&sps_debugfs_lock);
+
 	return;
 
 bam_log_level_err:
diff --git a/drivers/platform/msm/sps/spsi.h b/drivers/platform/msm/sps/spsi.h
index 1b4ca69bee16..38ee76be13c1 100644
--- a/drivers/platform/msm/sps/spsi.h
+++ b/drivers/platform/msm/sps/spsi.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2011-2016, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2011-2017, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -145,11 +145,6 @@ extern u8 print_limit_option;
 				pr_info(msg, ##args);	\
 		} \
 	} while (0)
-#define SPS_DEBUGFS(msg, args...) do {					\
-		char buf[MAX_MSG_LEN];		\
-		snprintf(buf, MAX_MSG_LEN, msg"\n", ##args);	\
-		sps_debugfs_record(buf);	\
-	} while (0)
 #define SPS_ERR(dev, msg, args...) do {					\
 		if (logging_option != 1) {	\
 			if (unlikely(print_limit_option > 2))	\
@@ -157,8 +152,6 @@ extern u8 print_limit_option;
 			else	\
 				pr_err(msg, ##args);	\
 		}	\
-		if (unlikely(debugfs_record_enabled))	\
-			SPS_DEBUGFS(msg, ##args);	\
 		SPS_IPC(3, dev, msg, args); \
 	} while (0)
 #define SPS_INFO(dev, msg, args...) do {				\
@@ -168,8 +161,6 @@ extern u8 print_limit_option;
 			else	\
 				pr_info(msg, ##args);	\
 		}	\
-		if (unlikely(debugfs_record_enabled))	\
-			SPS_DEBUGFS(msg, ##args);	\
 		SPS_IPC(3, dev, msg, args); \
 	} while (0)
 #define SPS_DBG(dev, msg, args...) do {					\
@@ -181,8 +172,6 @@ extern u8 print_limit_option;
 				pr_info(msg, ##args);	\
 		} else	\
 			pr_debug(msg, ##args);	\
-		if (unlikely(debugfs_record_enabled))	\
-			SPS_DEBUGFS(msg, ##args);	\
 		if (dev) { \
 			if ((dev)->ipc_loglevel <= 0)	\
 				SPS_IPC(0, dev, msg, args); \
@@ -197,8 +186,6 @@ extern u8 print_limit_option;
 				pr_info(msg, ##args);	\
 		} else	\
 			pr_debug(msg, ##args);	\
-		if (unlikely(debugfs_record_enabled))	\
-			SPS_DEBUGFS(msg, ##args);	\
 		if (dev) { \
 			if ((dev)->ipc_loglevel <= 1)	\
 				SPS_IPC(1, dev, msg, args);	\
@@ -213,8 +200,6 @@ extern u8 print_limit_option;
 				pr_info(msg, ##args);	\
 		} else	\
 			pr_debug(msg, ##args);	\
-		if (unlikely(debugfs_record_enabled))	\
-			SPS_DEBUGFS(msg, ##args);	\
 		if (dev) { \
 			if ((dev)->ipc_loglevel <= 2)	\
 				SPS_IPC(2, dev, msg, args); \
@@ -229,8 +214,6 @@ extern u8 print_limit_option;
 				pr_info(msg, ##args);	\
 		} else	\
 			pr_debug(msg, ##args);	\
-		if (unlikely(debugfs_record_enabled))	\
-			SPS_DEBUGFS(msg, ##args);	\
 		if (dev) { \
 			if ((dev)->ipc_loglevel <= 3)	\
 				SPS_IPC(3, dev, msg, args); \