Merge "msm: mdss: fix race condition in mdp debugfs" (becfd28d) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/video/msm/mdss/mdss_debug.c

+40 −8

Original line number	Diff line number	Diff line
		/* Copyright (c) 2009-2016, The Linux Foundation. All rights reserved.
		/* Copyright (c) 2009-2017, 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
		@@ -44,6 +44,8 @@

		#define INVALID_XIN_ID 0xFF

		static DEFINE_MUTEX(mdss_debug_lock);

		static char panel_reg[2] = {DEFAULT_READ_PANEL_POWER_MODE_REG, 0x00};

		static int panel_debug_base_open(struct inode inode, struct file file)
		@@ -93,8 +95,10 @@ static ssize_t panel_debug_base_offset_write(struct file *file,
		if (cnt > (dbg->max_offset - off))
		cnt = dbg->max_offset - off;

		mutex_lock(&mdss_debug_lock);
		dbg->off = off;
		dbg->cnt = cnt;
		mutex_unlock(&mdss_debug_lock);

		pr_debug("offset=%x cnt=%d\n", off, cnt);

		@@ -114,15 +118,21 @@ static ssize_t panel_debug_base_offset_read(struct file *file,
		if (*ppos)
		return 0; /* the end */

		mutex_lock(&mdss_debug_lock);
		len = snprintf(buf, sizeof(buf), "0x%02zx %zx\n", dbg->off, dbg->cnt);
		if (len < 0 \|\| len >= sizeof(buf))
		if (len < 0 \|\| len >= sizeof(buf)) {
		mutex_unlock(&mdss_debug_lock);
		return 0;
		}

		if ((count < sizeof(buf)) \|\| copy_to_user(buff, buf, len))
		if ((count < sizeof(buf)) \|\| copy_to_user(buff, buf, len)) {
		mutex_unlock(&mdss_debug_lock);
		return -EFAULT;
		}

		ppos += len; / increase offset */

		mutex_unlock(&mdss_debug_lock);
		return len;
		}

		@@ -220,11 +230,16 @@ static ssize_t panel_debug_base_reg_read(struct file *file,
		if (!dbg)
		return -ENODEV;

		if (!dbg->cnt)
		mutex_lock(&mdss_debug_lock);
		if (!dbg->cnt) {
		mutex_unlock(&mdss_debug_lock);
		return 0;
		}

		if (*ppos)
		if (*ppos) {
		mutex_unlock(&mdss_debug_lock);
		return 0; /* the end */
		}

		/* '0x' + 2 digit + blank = 5 bytes for each number */
		reg_buf_len = (dbg->cnt * PANEL_REG_FORMAT_LEN)
		@@ -265,11 +280,13 @@ static ssize_t panel_debug_base_reg_read(struct file *file,
		kfree(panel_reg_buf);

		ppos += len; / increase offset */
		mutex_unlock(&mdss_debug_lock);
		return len;

		read_reg_fail:
		kfree(rx_buf);
		kfree(panel_reg_buf);
		mutex_unlock(&mdss_debug_lock);
		return rc;
		}

		@@ -403,8 +420,10 @@ static ssize_t mdss_debug_base_offset_write(struct file *file,
		if (cnt > (dbg->max_offset - off))
		cnt = dbg->max_offset - off;

		mutex_lock(&mdss_debug_lock);
		dbg->off = off;
		dbg->cnt = cnt;
		mutex_unlock(&mdss_debug_lock);

		pr_debug("offset=%x cnt=%x\n", off, cnt);

		@@ -424,15 +443,21 @@ static ssize_t mdss_debug_base_offset_read(struct file *file,
		if (*ppos)
		return 0; /* the end */

		mutex_lock(&mdss_debug_lock);
		len = snprintf(buf, sizeof(buf), "0x%08zx %zx\n", dbg->off, dbg->cnt);
		if (len < 0 \|\| len >= sizeof(buf))
		if (len < 0 \|\| len >= sizeof(buf)) {
		mutex_unlock(&mdss_debug_lock);
		return 0;
		}

		if ((count < sizeof(buf)) \|\| copy_to_user(buff, buf, len))
		if ((count < sizeof(buf)) \|\| copy_to_user(buff, buf, len)) {
		mutex_unlock(&mdss_debug_lock);
		return -EFAULT;
		}

		ppos += len; / increase offset */

		mutex_unlock(&mdss_debug_lock);
		return len;
		}

		@@ -489,6 +514,8 @@ static ssize_t mdss_debug_base_reg_read(struct file *file,
		return -ENODEV;
		}

		mutex_lock(&mdss_debug_lock);

		if (!dbg->buf) {
		char dump_buf[64];
		char *ptr;
		@@ -500,6 +527,7 @@ static ssize_t mdss_debug_base_reg_read(struct file *file,

		if (!dbg->buf) {
		pr_err("not enough memory to hold reg dump\n");
		mutex_unlock(&mdss_debug_lock);
		return -ENOMEM;
		}

		@@ -530,17 +558,21 @@ static ssize_t mdss_debug_base_reg_read(struct file *file,
		dbg->buf_len = tot;
		}

		if (*ppos >= dbg->buf_len)
		if (*ppos >= dbg->buf_len) {
		mutex_unlock(&mdss_debug_lock);
		return 0; /* done reading */
		}

		len = min(count, dbg->buf_len - (size_t) *ppos);
		if (copy_to_user(user_buf, dbg->buf + *ppos, len)) {
		pr_err("failed to copy to user\n");
		mutex_unlock(&mdss_debug_lock);
		return -EFAULT;
		}

		ppos += len; / increase offset */

		mutex_unlock(&mdss_debug_lock);
		return len;
		}