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_dec_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. Hardware name: Google juniper sku16 board (DT) pstate: 20400005 (nzCv daif +PAN -UAO -TCO BTYPE=--) pc : vpu_dec_ipi_handler+0x58/0x1f8 [mtk_vcodec_dec] lr : scp_ipi_handler+0xd0/0x194 [mtk_scp] sp : ffffffc0131dbbd0 x29: ffffffc0131dbbd0 x28: 0000000000000000 x27: ffffff9bb277f348 x26: ffffff9bb242ad00 x25: ffffffd2d440d3b8 x24: ffffffd2a13ff1d4 x23: ffffff9bb7fe85a0 x22: ffffffc0133fbdb0 x21: 0000000000000010 x20: ffffff9b050ea328 x19: ffffffc0131dbc08 x18: 0000000000001000 x17: 0000000000000000 x16: ffffffd2d461c6e0 x15: 0000000000000242 x14: 000000000000018f x13: 000000000000004d x12: 0000000000000000 x11: 0000000000000001 x10: fffffffffffffff0 x9 : ffffff9bb6e793a8 x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f x5 : 0000000000000040 x4 : fffffffffffffff0 x3 : 0000000000000020 x2 : ffffff9bb6e79080 x1 : 0000000000000010 x0 : ffffffc0131dbc08 Call trace: vpu_dec_ipi_handler+0x58/0x1f8 [mtk_vcodec_dec (HASH:6c3f 2)] scp_ipi_handler+0xd0/0x194 [mtk_scp (HASH:7046 3)] mt8183_scp_irq_handler+0x44/0x88 [mtk_scp (HASH:7046 3)] scp_irq_handler+0x48/0x90 [mtk_scp (HASH:7046 3)] irq_thread_fn+0x38/0x94 irq_thread+0x100/0x1c0 kthread+0x140/0x1fc ret_from_fork+0x10/0x30 Code: 54000088 f94ca50a eb14015f 54000060 (f9400108) ---[ end trace ace43ce36cbd5c93 ]--- Kernel panic - not syncing: Oops: Fatal exception SMP: stopping secondary CPUs Kernel Offset: 0x12c4000000 from 0xffffffc010000000 PHYS_OFFSET: 0xffffffe580000000 CPU features: 0x08240002,2188200c Memory Limit: none Fixes: 655b86e52eac ("media: mediatek: vcodec: Fix possible invalid memory access for decoder") Signed-off-by: Yunfei Dong <yunfei.dong@xxxxxxxxxxxx> --- .../platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c | 4 ++-- .../platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c | 5 +++++ .../platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h | 2 ++ drivers/media/platform/mediatek/vcodec/decoder/vdec_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 9f6e4b59455da..9a11a2c248045 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 @@ -58,12 +58,12 @@ static void mtk_vcodec_vpu_reset_dec_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 void mtk_vcodec_vpu_reset_enc_handler(void *priv) diff --git a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c index ad9b68380692f..d69c9fe2af6f3 100644 --- a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c +++ b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c @@ -267,7 +267,9 @@ static int fops_vcodec_open(struct file *file) ctx->dev->vdec_pdata->init_vdec_params(ctx); + mutex_lock(&dev->dev_ctx_lock); list_add(&ctx->list, &dev->ctx_list); + mutex_unlock(&dev->dev_ctx_lock); mtk_vcodec_dbgfs_create(ctx); mutex_unlock(&dev->dev_mutex); @@ -310,7 +312,9 @@ static int fops_vcodec_release(struct file *file) v4l2_ctrl_handler_free(&ctx->ctrl_hdl); mtk_vcodec_dbgfs_remove(dev, ctx->id); + 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; @@ -403,6 +407,7 @@ static int mtk_vcodec_probe(struct platform_device *pdev) for (i = 0; i < MTK_VDEC_HW_MAX; i++) mutex_init(&dev->dec_mutex[i]); 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/decoder/mtk_vcodec_dec_drv.h b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h index 849b89dd205c2..85b2c0d3d8bcd 100644 --- a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h +++ b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h @@ -241,6 +241,7 @@ struct mtk_vcodec_dec_ctx { * * @dec_mutex: decoder hardware lock * @dev_mutex: video_device lock + * @dev_ctx_lock: the lock of context list * @decode_workqueue: decode work queue * * @irqlock: protect data access by irq handler and work thread @@ -282,6 +283,7 @@ struct mtk_vcodec_dec_dev { /* decoder hardware mutex lock */ struct mutex dec_mutex[MTK_VDEC_HW_MAX]; struct mutex dev_mutex; + struct mutex dev_ctx_lock; struct workqueue_struct *decode_workqueue; spinlock_t irqlock; diff --git a/drivers/media/platform/mediatek/vcodec/decoder/vdec_vpu_if.c b/drivers/media/platform/mediatek/vcodec/decoder/vdec_vpu_if.c index 82e57ae983d55..da6be556727bb 100644 --- a/drivers/media/platform/mediatek/vcodec/decoder/vdec_vpu_if.c +++ b/drivers/media/platform/mediatek/vcodec/decoder/vdec_vpu_if.c @@ -77,12 +77,14 @@ static bool vpu_dec_check_ap_inst(struct mtk_vcodec_dec_dev *dec_dev, struct vde struct mtk_vcodec_dec_ctx *ctx; int ret = false; + mutex_lock(&dec_dev->dev_ctx_lock); list_for_each_entry(ctx, &dec_dev->ctx_list, list) { if (!IS_ERR_OR_NULL(ctx) && ctx->vpu_inst == vpu) { ret = true; break; } } + mutex_unlock(&dec_dev->dev_ctx_lock); return ret; } -- 2.18.0