Messages in this thread | | | Date | Wed, 13 Mar 2024 14:44:56 +0100 | From | Sebastian Fricke <> | Subject | Re: [PATCH v3,2/2] media: mediatek: vcodec: adding lock to protect encoder context list |
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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@mediatek.com> >--- > .../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 > >
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