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Commit 253b2380 authored by Lloyd Atkinson's avatar Lloyd Atkinson
Browse files

drm/msm: protect register dumps and debugfs with mutex 



Add a mutex to serialize sde debug register dumps for
back-to-back dumps, as well as any debugfs access.

Change-Id: I7f6186575df021ce48e18ea980f9c2108b756283
Signed-off-by: default avatarLloyd Atkinson <latkinso@codeaurora.org>
parent ce488494

drivers/gpu/drm/msm/sde_dbg.c

+52 −12
Original line number Diff line number Diff line
@@ -153,6 +153,7 @@ struct sde_dbg_vbif_debug_bus { 
 * @reg_base_list: list of register dumping regions

 * @root: base debugfs root

 * @dev: device pointer

 * @mutex: mutex to serialize access to serialze dumps, debugfs access

 * @power_ctrl: callback structure for enabling power for reading hw registers

 * @req_dump_blks: list of blocks requested for dumping

 * @panic_on_err: whether to kernel panic after triggering dump via debugfs
@@ -167,6 +168,7 @@ static struct sde_dbg_base { 
	struct list_head reg_base_list;

	struct dentry *root;

	struct device *dev;

	struct mutex mutex;

	struct sde_dbg_power_ctrl power_ctrl;



	struct sde_dbg_reg_base *req_dump_blks[SDE_DBG_BASE_MAX];
@@ -1450,6 +1452,8 @@ static void _sde_dump_array(struct sde_dbg_reg_base *blk_arr[], 
{

	int i;



	mutex_lock(&sde_dbg_base.mutex);



	for (i = 0; i < len; i++) {

		if (blk_arr[i] != NULL)

			_sde_dump_reg_by_ranges(blk_arr[i],
@@ -1466,6 +1470,8 @@ static void _sde_dump_array(struct sde_dbg_reg_base *blk_arr[], 


	if (do_panic && sde_dbg_base.panic_on_err)

		panic(name);



	mutex_unlock(&sde_dbg_base.mutex);

}



/**
@@ -1663,6 +1669,7 @@ int sde_dbg_init(struct dentry *debugfs_root, struct device *dev, 
{

	int i;



	mutex_init(&sde_dbg_base.mutex);

	INIT_LIST_HEAD(&sde_dbg_base.reg_base_list);

	sde_dbg_base.dev = dev;

	sde_dbg_base.power_ctrl = *power_ctrl;
@@ -1718,6 +1725,7 @@ void sde_dbg_destroy(void) 
	sde_dbg_base_evtlog = NULL;

	sde_evtlog_destroy(sde_dbg_base.evtlog);

	sde_dbg_base.evtlog = NULL;

	mutex_destroy(&sde_dbg_base.mutex);

}



/**
@@ -1730,11 +1738,14 @@ static int sde_dbg_reg_base_release(struct inode *inode, struct file *file) 
{

	struct sde_dbg_reg_base *dbg = file->private_data;



	mutex_lock(&sde_dbg_base.mutex);

	if (dbg && dbg->buf) {

		kfree(dbg->buf);

		dbg->buf_len = 0;

		dbg->buf = NULL;

	}

	mutex_unlock(&sde_dbg_base.mutex);



	return 0;

}
@@ -1753,6 +1764,7 @@ static ssize_t sde_dbg_reg_base_offset_write(struct file *file, 
	u32 off = 0;

	u32 cnt = DEFAULT_BASE_REG_CNT;

	char buf[24];

	ssize_t rc = count;



	if (!dbg)

		return -ENODEV;
@@ -1768,24 +1780,33 @@ static ssize_t sde_dbg_reg_base_offset_write(struct file *file, 
	if (sscanf(buf, "%x %x", &off, &cnt) != 2)

		return -EFAULT;



	if (off > dbg->max_offset)

		return -EINVAL;

	mutex_lock(&sde_dbg_base.mutex);

	if (off > dbg->max_offset) {

		rc = -EINVAL;

		goto exit;

	}



	if (off % sizeof(u32))

		return -EINVAL;

	if (off % sizeof(u32)) {

		rc = -EINVAL;

		goto exit;

	}



	if (cnt > (dbg->max_offset - off))

		cnt = dbg->max_offset - off;



	if (cnt % sizeof(u32))

		return -EINVAL;

	if (cnt % sizeof(u32)) {

		rc = -EINVAL;

		goto exit;

	}



	dbg->off = off;

	dbg->cnt = cnt;



exit:

	mutex_unlock(&sde_dbg_base.mutex);

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



	return count;

	return rc;

}



/**
@@ -1808,14 +1829,20 @@ static ssize_t sde_dbg_reg_base_offset_read(struct file *file, 
	if (*ppos)

		return 0;	/* the end */



	mutex_lock(&sde_dbg_base.mutex);

	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(&sde_dbg_base.mutex);

		return 0;

	}



	if ((count < sizeof(buf)) || copy_to_user(buff, buf, len))

	if ((count < sizeof(buf)) || copy_to_user(buff, buf, len)) {

		mutex_unlock(&sde_dbg_base.mutex);

		return -EFAULT;

	}



	*ppos += len;	/* increase offset */

	mutex_unlock(&sde_dbg_base.mutex);



	return len;

}
@@ -1851,8 +1878,11 @@ static ssize_t sde_dbg_reg_base_reg_write(struct file *file, 
	if (cnt < 2)

		return -EFAULT;



	if (off >= dbg->max_offset)

	mutex_lock(&sde_dbg_base.mutex);

	if (off >= dbg->max_offset) {

		mutex_unlock(&sde_dbg_base.mutex);

		return -EFAULT;

	}



	_sde_dbg_enable_power(true);
@@ -1860,6 +1890,8 @@ static ssize_t sde_dbg_reg_base_reg_write(struct file *file, 


	_sde_dbg_enable_power(false);



	mutex_unlock(&sde_dbg_base.mutex);



	pr_debug("addr=%zx data=%x\n", off, data);



	return count;
@@ -1883,6 +1915,7 @@ static ssize_t sde_dbg_reg_base_reg_read(struct file *file, 
		return -ENODEV;

	}



	mutex_lock(&sde_dbg_base.mutex);

	if (!dbg->buf) {

		char *hwbuf;

		char dump_buf[64];
@@ -1897,12 +1930,15 @@ static ssize_t sde_dbg_reg_base_reg_read(struct file *file, 


		dbg->buf = kzalloc(dbg->buf_len, GFP_KERNEL);



		if (!dbg->buf)

		if (!dbg->buf) {

			mutex_unlock(&sde_dbg_base.mutex);

			return -ENOMEM;

		}



		hwbuf = kzalloc(ROW_BYTES, GFP_KERNEL);

		if (!hwbuf) {

			kfree(dbg->buf);

			mutex_unlock(&sde_dbg_base.mutex);

			return -ENOMEM;

		}
@@ -1934,16 +1970,20 @@ static ssize_t sde_dbg_reg_base_reg_read(struct file *file, 
		kfree(hwbuf);

	}



	if (*ppos >= dbg->buf_len)

	if (*ppos >= dbg->buf_len) {

		mutex_unlock(&sde_dbg_base.mutex);

		return 0; /* done reading */

	}



	len = min(count, dbg->buf_len - (size_t) *ppos);

	if (copy_to_user(user_buf, dbg->buf + *ppos, len)) {

		mutex_unlock(&sde_dbg_base.mutex);

		pr_err("failed to copy to user\n");

		return -EFAULT;

	}



	*ppos += len; /* increase offset */

	mutex_unlock(&sde_dbg_base.mutex);



	return len;

}