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authorShengjiu Wang2022-05-21 11:35:05 +0800
committerMathieu Poirier2022-06-14 14:58:10 -0600
commitabe13e9a561d6b3e82b21362c0d6dd3ecd8a5b13 (patch)
tree8f964772405ec041206ea18b0f55434b03b19625 /drivers/rpmsg
parentb13baccc3850ca8b8cccbf8ed9912dbaa0fdf7f3 (diff)
rpmsg: char: Add mutex protection for rpmsg_eptdev_open()
There is no mutex protection for rpmsg_eptdev_open(), especially for eptdev->ept read and write operation. It may cause issues when multiple instances call rpmsg_eptdev_open() in parallel,the return state may be success or EBUSY. Fixes: 964e8bedd5a1 ("rpmsg: char: Return an error if device already open") Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com> Link: https://lore.kernel.org/r/1653104105-16779-1-git-send-email-shengjiu.wang@nxp.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Diffstat (limited to 'drivers/rpmsg')
-rw-r--r--drivers/rpmsg/rpmsg_char.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index b6183d4f62a2..4f2189111494 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -120,8 +120,11 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp)
struct rpmsg_device *rpdev = eptdev->rpdev;
struct device *dev = &eptdev->dev;
- if (eptdev->ept)
+ mutex_lock(&eptdev->ept_lock);
+ if (eptdev->ept) {
+ mutex_unlock(&eptdev->ept_lock);
return -EBUSY;
+ }
get_device(dev);
@@ -137,11 +140,13 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp)
if (!ept) {
dev_err(dev, "failed to open %s\n", eptdev->chinfo.name);
put_device(dev);
+ mutex_unlock(&eptdev->ept_lock);
return -EINVAL;
}
eptdev->ept = ept;
filp->private_data = eptdev;
+ mutex_unlock(&eptdev->ept_lock);
return 0;
}