Re: [PATCH 27/65] media: Reset file->private_data to NULL in v4l2_fh_del()
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2025-08-07 08:50:24
Also in:
imx, linux-amlogic, linux-arm-msm, linux-media, linux-mediatek, linux-renesas-soc, linux-rockchip, linux-samsung-soc, linux-staging, linux-sunxi, linux-tegra, linux-usb, lkml
On Wed, Aug 06, 2025 at 02:45:14PM +0200, Hans Verkuil wrote:
On 02/08/2025 11:22, Jacopo Mondi wrote:quoted
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Multiple drivers that use v4l2_fh and call v4l2_fh_del() manually reset the file->private_data pointer to NULL in their video device .release() file operation handler. Move the code to the v4l2_fh_del() function to avoid direct access to file->private_data in drivers. This requires adding a file pointer argument to the function. Changes to drivers have been generated with the following coccinelle semantic patch: @@ expression fh; identifier filp; identifier release; type ret; @@ ret release(..., struct file *filp, ...) { <... - filp->private_data = NULL; ... - v4l2_fh_del(fh); + v4l2_fh_del(fh, filp); ...> } @@ expression fh; identifier filp; identifier release; type ret; @@ ret release(..., struct file *filp, ...) { <... - v4l2_fh_del(fh); + v4l2_fh_del(fh, filp); ... - filp->private_data = NULL; ...> } @@ expression fh; identifier filp; identifier release; type ret; @@ ret release(..., struct file *filp, ...) { <... - v4l2_fh_del(fh); + v4l2_fh_del(fh, filp); ...> } Manual changes have been applied to Documentation/ to update the usage patterns, to drivers/media/v4l2-core/v4l2-fh.c to update the v4l2_fh_del() prototype and reset file->private_data, and to include/media/v4l2-fh.h to update the v4l2_fh_del() function prototype and its documentation. Additionally, white space issues have been fixed manually in drivers/usb/gadget/function/uvc_v4l2.c Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com> --- Documentation/driver-api/media/v4l2-fh.rst | 4 ++-- Documentation/translations/zh_CN/video4linux/v4l2-framework.txt | 4 ++-- drivers/media/pci/cx18/cx18-fileops.c | 4 ++-- drivers/media/pci/ivtv/ivtv-fileops.c | 4 ++-- drivers/media/pci/saa7164/saa7164-encoder.c | 2 +- drivers/media/pci/saa7164/saa7164-vbi.c | 2 +- drivers/media/platform/allegro-dvt/allegro-core.c | 2 +- drivers/media/platform/amlogic/meson-ge2d/ge2d.c | 2 +- drivers/media/platform/amphion/vpu_v4l2.c | 4 ++-- drivers/media/platform/chips-media/coda/coda-common.c | 4 ++-- drivers/media/platform/chips-media/wave5/wave5-helper.c | 2 +- drivers/media/platform/imagination/e5010-jpeg-enc.c | 4 ++-- drivers/media/platform/m2m-deinterlace.c | 2 +- drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c | 4 ++-- drivers/media/platform/mediatek/mdp/mtk_mdp_m2m.c | 4 ++-- drivers/media/platform/mediatek/mdp3/mtk-mdp3-m2m.c | 4 ++-- .../media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c | 4 ++-- .../media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.c | 4 ++-- drivers/media/platform/nvidia/tegra-vde/v4l2.c | 2 +- drivers/media/platform/nxp/dw100/dw100.c | 2 +- drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c | 4 ++-- drivers/media/platform/nxp/imx-pxp.c | 2 +- drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c | 2 +- drivers/media/platform/nxp/mx2_emmaprp.c | 2 +- drivers/media/platform/qcom/iris/iris_vidc.c | 3 +-- drivers/media/platform/qcom/venus/core.c | 2 +- drivers/media/platform/renesas/rcar_fdp1.c | 2 +- drivers/media/platform/renesas/rcar_jpu.c | 4 ++-- drivers/media/platform/renesas/vsp1/vsp1_video.c | 2 +- drivers/media/platform/rockchip/rga/rga.c | 2 +- drivers/media/platform/rockchip/rkvdec/rkvdec.c | 2 +- drivers/media/platform/samsung/exynos-gsc/gsc-m2m.c | 4 ++-- drivers/media/platform/samsung/exynos4-is/fimc-m2m.c | 4 ++-- drivers/media/platform/samsung/s5p-g2d/g2d.c | 2 +- drivers/media/platform/samsung/s5p-jpeg/jpeg-core.c | 4 ++-- drivers/media/platform/samsung/s5p-mfc/s5p_mfc.c | 4 ++-- drivers/media/platform/st/sti/bdisp/bdisp-v4l2.c | 4 ++-- drivers/media/platform/st/sti/delta/delta-v4l2.c | 4 ++-- drivers/media/platform/st/sti/hva/hva-v4l2.c | 4 ++-- drivers/media/platform/st/stm32/dma2d/dma2d.c | 2 +- drivers/media/platform/sunxi/sun8i-di/sun8i-di.c | 2 +- drivers/media/platform/sunxi/sun8i-rotate/sun8i_rotate.c | 2 +- drivers/media/platform/ti/omap3isp/ispvideo.c | 5 ++--- drivers/media/platform/ti/vpe/vpe.c | 2 +- drivers/media/platform/verisilicon/hantro_drv.c | 4 ++-- drivers/media/test-drivers/vicodec/vicodec-core.c | 2 +- drivers/media/test-drivers/vim2m.c | 2 +- drivers/media/test-drivers/visl/visl-core.c | 2 +- drivers/media/usb/pvrusb2/pvrusb2-v4l2.c | 3 +-- drivers/media/v4l2-core/v4l2-fh.c | 7 ++++--- drivers/media/v4l2-core/v4l2-subdev.c | 5 ++--- drivers/staging/media/imx/imx-media-csc-scaler.c | 4 ++-- drivers/staging/media/meson/vdec/vdec.c | 2 +- drivers/staging/media/sunxi/cedrus/cedrus.c | 2 +- drivers/staging/most/video/video.c | 4 ++-- drivers/usb/gadget/function/uvc_v4l2.c | 3 +-- include/media/v4l2-fh.h | 5 ++++- 57 files changed, 89 insertions(+), 90 deletions(-)<snip>quoted
diff --git a/drivers/media/v4l2-core/v4l2-fh.c b/drivers/media/v4l2-core/v4l2-fh.c index b59b1084d8cdf1b62da12879e21dbe56c2109648..df3ba9d4674bd25626cfcddc2d0cb28c233e3cc3 100644 --- a/drivers/media/v4l2-core/v4l2-fh.c +++ b/drivers/media/v4l2-core/v4l2-fh.c@@ -67,7 +67,7 @@ int v4l2_fh_open(struct file *filp) } EXPORT_SYMBOL_GPL(v4l2_fh_open); -void v4l2_fh_del(struct v4l2_fh *fh) +void v4l2_fh_del(struct v4l2_fh *fh, struct file *filp)Instead of adding a second argument, perhaps it is better to just provide the filp pointer. After all, you can get the v4l2_fh from filp->private_data. It simplifies the code a bit.
That's an interesting idea. I'll give it a try.
quoted
{ unsigned long flags;@@ -75,6 +75,8 @@ void v4l2_fh_del(struct v4l2_fh *fh) list_del_init(&fh->list); spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); v4l2_prio_close(fh->vdev->prio, fh->prio); + + filp->private_data = NULL; } EXPORT_SYMBOL_GPL(v4l2_fh_del);@@ -94,10 +96,9 @@ int v4l2_fh_release(struct file *filp) struct v4l2_fh *fh = file_to_v4l2_fh(filp); if (fh) { - v4l2_fh_del(fh); + v4l2_fh_del(fh, filp); v4l2_fh_exit(fh); kfree(fh); - filp->private_data = NULL; } return 0; }<snip>quoted
diff --git a/include/media/v4l2-fh.h b/include/media/v4l2-fh.h index d8fcf49f10e09452b73499f4a9bd1285bc2835a5..5e4c761635120608e0b588e0b0daf63e69588d38 100644 --- a/include/media/v4l2-fh.h +++ b/include/media/v4l2-fh.h@@ -114,12 +114,15 @@ int v4l2_fh_open(struct file *filp); * v4l2_fh_del - Remove file handle from the list of file handles. * * @fh: pointer to &struct v4l2_fh + * @filp: pointer to &struct file associated with @fh + * + * The function resets filp->private_data to NULL. * * .. note:: * Must be called in v4l2_file_operations->release\(\) handler if the driver * uses &struct v4l2_fh. */ -void v4l2_fh_del(struct v4l2_fh *fh); +void v4l2_fh_del(struct v4l2_fh *fh, struct file *filp); /** * v4l2_fh_exit - Release resources related to a file handle.
-- Regards, Laurent Pinchart