media: v4l2-mem2mem: add lock to protect parameter num_rdy

[ Upstream commit 56b5c3e ] Getting below error when using KCSAN to check the driver. Adding lock to protect parameter num_rdy when getting the value with function: v4l2_m2m_num_src_bufs_ready/v4l2_m2m_num_dst_bufs_ready. kworker/u16:3: [name:report&]BUG: KCSAN: data-race in v4l2_m2m_buf_queue kworker/u16:3: [name:report&] kworker/u16:3: [name:report&]read-write to 0xffffff8105f35b94 of 1 bytes by task 20865 on cpu 7: kworker/u16:3: v4l2_m2m_buf_queue+0xd8/0x10c Signed-off-by: Pina Chen <pina.chen@mediatek.com> Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Sasha Levin <sashal@kernel.org>
xanmod · Aug 23, 2023 · c71aa5f · c71aa5f
1 parent 6c9317f
commit c71aa5f
Showing 1 changed file with 16 additions and 2 deletions.
diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2-mem2mem.h
@@ -593,7 +593,14 @@ void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx,
 static inline
 unsigned int v4l2_m2m_num_src_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
 {
-	return m2m_ctx->out_q_ctx.num_rdy;
+	unsigned int num_buf_rdy;
+	unsigned long flags;
+
+	spin_lock_irqsave(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
+	num_buf_rdy = m2m_ctx->out_q_ctx.num_rdy;
+	spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
+
+	return num_buf_rdy;
 }
 
 /**
@@ -605,7 +612,14 @@ unsigned int v4l2_m2m_num_src_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
 static inline
 unsigned int v4l2_m2m_num_dst_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
 {
-	return m2m_ctx->cap_q_ctx.num_rdy;
+	unsigned int num_buf_rdy;
+	unsigned long flags;
+
+	spin_lock_irqsave(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags);
+	num_buf_rdy = m2m_ctx->cap_q_ctx.num_rdy;
+	spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags);
+
+	return num_buf_rdy;
 }
 
 /**