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

Commit 025196c4 authored by Sreelakshmi Gownipalli's avatar Sreelakshmi Gownipalli
Browse files

diag: Avoid race while closing and opening mhi channels 



Add protection while closing mhi channels to ensure that close
has finished completely before calling open.

Change-Id: Ib112f5b7d38aee154f2938dab8b314eb1c3b7e7a
Signed-off-by: default avatarSreelakshmi Gownipalli <sgownipa@codeaurora.org>
parent a5c36deb

drivers/char/diag/diagfwd_mhi.c

+7 −2
Original line number Diff line number Diff line
@@ -225,9 +225,11 @@ static int __mhi_close(struct diag_mhi_info *mhi_info, int close_flag) 


	flush_workqueue(mhi_info->mhi_wq);



	if (close_flag == CLOSE_CHANNELS)

	if (close_flag == CLOSE_CHANNELS) {

		mutex_lock(&mhi_info->ch_mutex);

		mhi_unprepare_from_transfer(mhi_info->mhi_dev);



		mutex_unlock(&mhi_info->ch_mutex);

	}

	mhi_buf_tbl_clear(mhi_info);

	diag_remote_dev_close(mhi_info->dev_id);

	return 0;
@@ -276,7 +278,9 @@ static int __mhi_open(struct diag_mhi_info *mhi_info, int open_flag) 
		if ((atomic_read(&(mhi_info->read_ch.opened))) &&

			(atomic_read(&(mhi_info->write_ch.opened))))

			return 0;

		mutex_lock(&mhi_info->ch_mutex);

		err = mhi_prepare_for_transfer(mhi_info->mhi_dev);

		mutex_unlock(&mhi_info->ch_mutex);

		if (err) {

			pr_err("diag: In %s, unable to open ch, err: %d\n",

				__func__, err);
@@ -693,6 +697,7 @@ int diag_mhi_init(void) 
		spin_lock_init(&mhi_info->lock);

		spin_lock_init(&mhi_info->read_ch.lock);

		spin_lock_init(&mhi_info->write_ch.lock);

		mutex_init(&mhi_info->ch_mutex);

		INIT_LIST_HEAD(&mhi_info->read_ch.buf_tbl);

		INIT_LIST_HEAD(&mhi_info->write_ch.buf_tbl);

		atomic_set(&(mhi_info->read_ch.opened), 0);

drivers/char/diag/diagfwd_mhi.h

+1 −0
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ struct diag_mhi_info { 
	wait_queue_head_t mhi_wait_q;

	struct diag_mhi_ch_t read_ch;

	struct diag_mhi_ch_t write_ch;

	struct mutex ch_mutex;

	spinlock_t lock;

};