gpu: nvgpu: check for null priv in channel_release

gk20a_channel_release can still get called even if the open_channel call failed
(e.g., if we ran out of hw chids), in which case priv is null. Check for this
case and return if null.

Bug 1964531

Change-Id: I48bc88e4dbd88a1c30fc399de629d8f8b344cfd9
Signed-off-by: Peter Daifuku <pdaifuku@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1526544
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/ioctl_channel.c b/drivers/gpu/nvgpu/common/linux/ioctl_channel.c
index 2242e19e..ab02dc42 100644
--- a/drivers/gpu/nvgpu/common/linux/ioctl_channel.c
+++ b/drivers/gpu/nvgpu/common/linux/ioctl_channel.c
@@ -281,11 +281,20 @@ struct channel_gk20a *gk20a_get_channel_from_file(int fd)
 int gk20a_channel_release(struct inode *inode, struct file *filp)
 {
         struct channel_priv *priv = filp->private_data;
-        struct channel_gk20a *ch = priv->c;
-        struct gk20a *g = priv->g;
+        struct channel_gk20a *ch;
+        struct gk20a *g;
 
         int err;
 
+        /* We could still end up here even if the channel_open failed, e.g.
+         * if we ran out of hw channel IDs.
+         */
+        if (!priv)
+                return 0;
+
+        ch = priv->c;
+        g = priv->g;
+
         err = gk20a_busy(g);
         if (err) {
                 nvgpu_err(g, "failed to release a channel!");