Hey Yunfei,
On 22.02.2024 17:26, Yunfei Dong wrote:
The ctx_list will be deleted when scp getting unexpected behavior, then the
ctx_list->next will be NULL, the kernel driver maybe access NULL pointer in
function vpu_enc_ipi_handler when going through each context, then reboot.
Need to add lock to protect the ctx_list to make sure the ctx_list->next isn't
NULL pointer.
Can we reword this slightly to make it grammatically correct?
My suggestion:
```
Add a lock for the ctx_list, to avoid accessing a NULL pointer within
the `vpu_enc_ipi_handler` function, when the ctx_list has been deleted
due to an unexpected behavior on the SCP IP block.
```
Greetings,
Sebastian
Fixes: 1972e32431ed ("media: mediatek: vcodec: Fix possible invalid memory access for encoder")
Signed-off-by: Yunfei Dong <yunfei.dong@xxxxxxxxxxxx>
---
.../platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c | 4 ++--
.../platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.c | 5 +++++
.../platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.h | 2 ++
drivers/media/platform/mediatek/vcodec/encoder/venc_vpu_if.c | 2 ++
4 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c b/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
index 9a11a2c248045..8d578b6902148 100644
--- a/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
+++ b/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
@@ -73,12 +73,12 @@ static void mtk_vcodec_vpu_reset_enc_handler(void *priv)
dev_err(&dev->plat_dev->dev, "Watchdog timeout!!");
- mutex_lock(&dev->dev_mutex);
+ mutex_lock(&dev->dev_ctx_lock);
list_for_each_entry(ctx, &dev->ctx_list, list) {
ctx->state = MTK_STATE_ABORT;
mtk_v4l2_vdec_dbg(0, ctx, "[%d] Change to state MTK_STATE_ABORT", ctx->id);
}
- mutex_unlock(&dev->dev_mutex);
+ mutex_unlock(&dev->dev_ctx_lock);
}
static const struct mtk_vcodec_fw_ops mtk_vcodec_vpu_msg = {
diff --git a/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.c b/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.c
index 5db2bf3db4c54..29524cd59ce8b 100644
--- a/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.c
+++ b/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.c
@@ -177,7 +177,9 @@ static int fops_vcodec_open(struct file *file)
mtk_v4l2_venc_dbg(2, ctx, "Create instance [%d]@%p m2m_ctx=%p ",
ctx->id, ctx, ctx->m2m_ctx);
+ mutex_lock(&dev->dev_ctx_lock);
list_add(&ctx->list, &dev->ctx_list);
+ mutex_unlock(&dev->dev_ctx_lock);
mutex_unlock(&dev->dev_mutex);
mtk_v4l2_venc_dbg(0, ctx, "%s encoder [%d]", dev_name(&dev->plat_dev->dev),
@@ -212,7 +214,9 @@ static int fops_vcodec_release(struct file *file)
v4l2_fh_exit(&ctx->fh);
v4l2_ctrl_handler_free(&ctx->ctrl_hdl);
+ mutex_lock(&dev->dev_ctx_lock);
list_del_init(&ctx->list);
+ mutex_unlock(&dev->dev_ctx_lock);
kfree(ctx);
mutex_unlock(&dev->dev_mutex);
return 0;
@@ -294,6 +298,7 @@ static int mtk_vcodec_probe(struct platform_device *pdev)
mutex_init(&dev->enc_mutex);
mutex_init(&dev->dev_mutex);
+ mutex_init(&dev->dev_ctx_lock);
spin_lock_init(&dev->irqlock);
snprintf(dev->v4l2_dev.name, sizeof(dev->v4l2_dev.name), "%s",
diff --git a/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.h b/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.h
index a042f607ed8d1..0bd85d0fb379a 100644
--- a/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.h
+++ b/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.h
@@ -178,6 +178,7 @@ struct mtk_vcodec_enc_ctx {
*
* @enc_mutex: encoder hardware lock.
* @dev_mutex: video_device lock
+ * @dev_ctx_lock: the lock of context list
* @encode_workqueue: encode work queue
*
* @enc_irq: h264 encoder irq resource
@@ -205,6 +206,7 @@ struct mtk_vcodec_enc_dev {
/* encoder hardware mutex lock */
struct mutex enc_mutex;
struct mutex dev_mutex;
+ struct mutex dev_ctx_lock;
struct workqueue_struct *encode_workqueue;
int enc_irq;
diff --git a/drivers/media/platform/mediatek/vcodec/encoder/venc_vpu_if.c b/drivers/media/platform/mediatek/vcodec/encoder/venc_vpu_if.c
index 84ad1cc6ad171..51bb7ee141b9e 100644
--- a/drivers/media/platform/mediatek/vcodec/encoder/venc_vpu_if.c
+++ b/drivers/media/platform/mediatek/vcodec/encoder/venc_vpu_if.c
@@ -47,12 +47,14 @@ static bool vpu_enc_check_ap_inst(struct mtk_vcodec_enc_dev *enc_dev, struct ven
struct mtk_vcodec_enc_ctx *ctx;
int ret = false;
+ mutex_lock(&enc_dev->dev_ctx_lock);
list_for_each_entry(ctx, &enc_dev->ctx_list, list) {
if (!IS_ERR_OR_NULL(ctx) && ctx->vpu_inst == vpu) {
ret = true;
break;
}
}
+ mutex_unlock(&enc_dev->dev_ctx_lock);
return ret;
}
--
2.18.0
