Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5c5fc156 authored by Pan Fang's avatar Pan Fang
Browse files

msm:rpm-log: add the mutex to protect read opertion 



This commit will protect rpm log read operation. Then multithread
read the same rpm log buffer will not corruption.

CRs-Fixed: 646485
Change-Id: I38b10c89902a9268fc0a4d649267d3a3df9a739a
Signed-off-by: default avatarPan Fang <fangpan@codeaurora.org>
parent c82bee2d

drivers/soc/qcom/rpm_log.c

+5 −0
Original line number Original line Diff line number Diff line
@@ -50,6 +50,7 @@ struct msm_rpm_log_buffer { 
	char *data;

	char *data;

	u32 len;

	u32 len;

	u32 pos;

	u32 pos;

	struct mutex mutex;

	u32 max_len;

	u32 max_len;

	u32 read_idx;

	u32 read_idx;

	struct msm_rpm_log_platform_data *pdata;

	struct msm_rpm_log_platform_data *pdata;
@@ -216,6 +217,7 @@ static ssize_t msm_rpm_log_file_read(struct file *file, char __user *bufu, 
	if (!access_ok(VERIFY_WRITE, bufu, count))

	if (!access_ok(VERIFY_WRITE, bufu, count))

		return -EFAULT;

		return -EFAULT;





	mutex_lock(&buf->mutex);

	/* check for more messages if local buffer empty */

	/* check for more messages if local buffer empty */

	if (buf->pos == buf->len) {

	if (buf->pos == buf->len) {

		buf->pos = 0;

		buf->pos = 0;
@@ -224,6 +226,7 @@ static ssize_t msm_rpm_log_file_read(struct file *file, char __user *bufu, 
	}

	}





	if ((file->f_flags & O_NONBLOCK) && buf->len == 0)

	if ((file->f_flags & O_NONBLOCK) && buf->len == 0)

		mutex_unlock(&buf->mutex);

		return -EAGAIN;

		return -EAGAIN;





	/* loop until new messages arrive */

	/* loop until new messages arrive */
@@ -239,6 +242,7 @@ static ssize_t msm_rpm_log_file_read(struct file *file, char __user *bufu, 




	remaining = __copy_to_user(bufu, &(buf->data[buf->pos]), out_len);

	remaining = __copy_to_user(bufu, &(buf->data[buf->pos]), out_len);

	buf->pos += out_len - remaining;

	buf->pos += out_len - remaining;

	mutex_unlock(&buf->mutex);





	return out_len - remaining;

	return out_len - remaining;

}

}
@@ -285,6 +289,7 @@ static int msm_rpm_log_file_open(struct inode *inode, struct file *file) 
	buf->pdata = pdata;

	buf->pdata = pdata;

	buf->len = 0;

	buf->len = 0;

	buf->pos = 0;

	buf->pos = 0;

	mutex_init(&buf->mutex);

	buf->max_len = PRINTED_LENGTH(pdata->log_len);

	buf->max_len = PRINTED_LENGTH(pdata->log_len);

	buf->read_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,

	buf->read_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,

					 MSM_RPM_LOG_HEAD);

					 MSM_RPM_LOG_HEAD);