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@xxxxxxxxxxxx>
Signed-off-by: Yunfei Dong <yunfei.dong@xxxxxxxxxxxx>
---
include/media/v4l2-mem2mem.h | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2-mem2mem.h
index bb9de6a899e0..d6c8eb2b5201 100644
--- 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;
}
/**
--
2.18.0
