diff mbox series

Remove deductively redundant NULL pointer checks

Message ID 1551128631-19713-1-git-send-email-shaobo@cs.utah.edu (mailing list archive)
State New
Delegated to: Kieran Bingham
Headers show
Series Remove deductively redundant NULL pointer checks | expand

Commit Message

Shaobo He Feb. 25, 2019, 9:03 p.m. UTC 
The fixes included in this commit essentially removes NULL pointer
checks on the return values of function `get_queue_ctx` as well as
`v4l2_m2m_get_vq` defined in file v4l2-mem2mem.c.

Function `get_queue_ctx` is very unlikely to return a NULL pointer
because its return value is an address composed of the base address
pointed by `m2m_ctx` and an offset of field `out_q_ctx` or `cap_q_ctx`.
Since the offset of either field is not 0, for the return value to be
NULL, pointer `m2m_ctx` must be a very large unsigned value such that
its addition to the offset overflows to NULL which may be undefined
according to this post:
https://wdtz.org/catching-pointer-overflow-bugs.html. Moreover, even if
`m2m_ctx` is NULL, the return value cannot be NULL, either. Therefore, I
think it is reasonable to conclude that the return value of function
`get_queue_ctx` cannot be NULL.

Given the return values of `get_queue_ctx` not being NULL, we can follow
a similar reasoning to conclude that the return value of
`v4l2_mem_get_vq` cannot be NULL since its return value is the same
address as the return value of `get_queue_ctx`. Therefore, this patch
also removes NULL pointer checks on the return values of
`v4l2_mem_get_vq`.

Signed-off-by: Shaobo He <shaobo@cs.utah.edu>
---
 drivers/media/platform/coda/coda-common.c          |  4 ----
 drivers/media/platform/imx-pxp.c                   |  7 -------
 drivers/media/platform/m2m-deinterlace.c           |  7 -------
 drivers/media/platform/mtk-jpeg/mtk_jpeg_core.c    |  7 -------
 drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c |  7 -------
 drivers/media/platform/mtk-vcodec/mtk_vcodec_enc.c | 13 -------------
 drivers/media/platform/mx2_emmaprp.c               |  7 -------
 drivers/media/platform/rcar_fdp1.c                 |  3 ---
 drivers/media/platform/rcar_jpu.c                  |  8 --------
 drivers/media/platform/rockchip/rga/rga.c          |  4 ----
 drivers/media/platform/s5p-g2d/g2d.c               |  4 ----
 drivers/media/platform/s5p-jpeg/jpeg-core.c        |  7 -------
 drivers/media/platform/sh_veu.c                    |  2 --
 drivers/media/platform/ti-vpe/vpe.c                |  7 -------
 drivers/media/platform/vicodec/vicodec-core.c      |  5 -----
 drivers/media/platform/vim2m.c                     |  9 ---------
 drivers/media/v4l2-core/v4l2-mem2mem.c             |  4 ----
 17 files changed, 105 deletions(-)

Comments

kernel test robot Feb. 26, 2019, 8 a.m. UTC | #1 
Hi Shaobo,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linuxtv-media/master]
[also build test WARNING on v5.0-rc8 next-20190225]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Shaobo-He/Remove-deductively-redundant-NULL-pointer-checks/20190226-133616
base:   git://linuxtv.org/media_tree.git master
config: xtensa-allyesconfig (attached as .config)
compiler: xtensa-linux-gcc (GCC) 8.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=8.2.0 make.cross ARCH=xtensa 

Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings

All warnings (new ones prefixed by >>):

   In file included from include/media/videobuf2-v4l2.h:16,
                    from include/media/v4l2-mem2mem.h:20,
                    from drivers/media//platform/vim2m.c:27:
   drivers/media//platform/vim2m.c: In function 'vidioc_s_fmt':
>> include/media/videobuf2-core.h:1098:11: warning: 'vq' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return (q->num_buffers > 0);
             ~^~~~~~~~~~~~~
   drivers/media//platform/vim2m.c:683:20: note: 'vq' was declared here
     struct vb2_queue *vq;
                       ^~
--
   In file included from include/media/videobuf2-v4l2.h:16,
                    from include/media/v4l2-mem2mem.h:20,
                    from drivers/media/platform/vim2m.c:27:
   drivers/media/platform/vim2m.c: In function 'vidioc_s_fmt':
>> include/media/videobuf2-core.h:1098:11: warning: 'vq' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return (q->num_buffers > 0);
             ~^~~~~~~~~~~~~
   drivers/media/platform/vim2m.c:683:20: note: 'vq' was declared here
     struct vb2_queue *vq;
                       ^~

vim +/vq +1098 include/media/videobuf2-core.h

74753cff Hans Verkuil          2014-04-07  1089  
74753cff Hans Verkuil          2014-04-07  1090  /**
2b141324 Mauro Carvalho Chehab 2017-10-06  1091   * vb2_is_busy() - return busy status of the queue.
2b141324 Mauro Carvalho Chehab 2017-10-06  1092   * @q:		pointer to &struct vb2_queue with videobuf2 queue.
e23ccc0a Pawel Osciak          2010-10-11  1093   *
e23ccc0a Pawel Osciak          2010-10-11  1094   * This function checks if queue has any buffers allocated.
e23ccc0a Pawel Osciak          2010-10-11  1095   */
e23ccc0a Pawel Osciak          2010-10-11  1096  static inline bool vb2_is_busy(struct vb2_queue *q)
e23ccc0a Pawel Osciak          2010-10-11  1097  {
e23ccc0a Pawel Osciak          2010-10-11 @1098  	return (q->num_buffers > 0);
e23ccc0a Pawel Osciak          2010-10-11  1099  }
e23ccc0a Pawel Osciak          2010-10-11  1100  

:::::: The code at line 1098 was first introduced by commit
:::::: e23ccc0ad9258634e6d52cedf473b35dc34416c7 [media] v4l: add videobuf2 Video for Linux 2 driver framework

:::::: TO: Pawel Osciak <p.osciak@samsung.com>
:::::: CC: Mauro Carvalho Chehab <mchehab@redhat.com>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
kernel test robot Feb. 26, 2019, 8:47 a.m. UTC | #2 
Hi Shaobo,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linuxtv-media/master]
[also build test WARNING on v5.0-rc8 next-20190225]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Shaobo-He/Remove-deductively-redundant-NULL-pointer-checks/20190226-133616
base:   git://linuxtv.org/media_tree.git master
config: x86_64-allyesconfig (attached as .config)
compiler: gcc-8 (Debian 8.2.0-20) 8.2.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings

All warnings (new ones prefixed by >>):

   drivers/media//platform/vim2m.c: In function 'vidioc_s_fmt':
>> drivers/media//platform/vim2m.c:689:6: warning: 'vq' may be used uninitialized in this function [-Wmaybe-uninitialized]
     if (vb2_is_busy(vq)) {
         ^~~~~~~~~~~~~~~

vim +/vq +689 drivers/media//platform/vim2m.c

96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  679  
1f923a42 drivers/media/platform/vim2m.c        Hans Verkuil     2014-09-22  680  static int vidioc_s_fmt(struct vim2m_ctx *ctx, struct v4l2_format *f)
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  681  {
1f923a42 drivers/media/platform/vim2m.c        Hans Verkuil     2014-09-22  682  	struct vim2m_q_data *q_data;
d80ee38c drivers/media/video/mem2mem_testdev.c Marek Szyprowski 2011-01-12  683  	struct vb2_queue *vq;
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  684  
9f4161a6 drivers/media/video/mem2mem_testdev.c Tomasz Moń       2012-06-08  685  	q_data = get_q_data(ctx, f->type);
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  686  	if (!q_data)
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  687  		return -EINVAL;
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  688  
d80ee38c drivers/media/video/mem2mem_testdev.c Marek Szyprowski 2011-01-12 @689  	if (vb2_is_busy(vq)) {
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  690  		v4l2_err(&ctx->dev->v4l2_dev, "%s queue busy\n", __func__);
07e80305 drivers/media/video/mem2mem_testdev.c Marek Szyprowski 2010-12-20  691  		return -EBUSY;
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  692  	}
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  693  
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  694  	q_data->fmt		= find_format(f);
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  695  	q_data->width		= f->fmt.pix.width;
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  696  	q_data->height		= f->fmt.pix.height;
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  697  	q_data->sizeimage	= q_data->width * q_data->height
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  698  				* q_data->fmt->depth >> 3;
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  699  
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  700  	dprintk(ctx->dev,
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  701  		"Setting format for type %d, wxh: %dx%d, fmt: %d\n",
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  702  		f->type, q_data->width, q_data->height, q_data->fmt->fourcc);
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  703  
07e80305 drivers/media/video/mem2mem_testdev.c Marek Szyprowski 2010-12-20  704  	return 0;
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  705  }
96d8eab5 drivers/media/video/mem2mem_testdev.c Pawel Osciak     2010-04-23  706  

:::::: The code at line 689 was first introduced by commit
:::::: d80ee38cd845baadef175893b99df24e7a03ec40 [media] v4l: mem2mem: port m2m_testdev to vb2

:::::: TO: Marek Szyprowski <m.szyprowski@samsung.com>
:::::: CC: Mauro Carvalho Chehab <mchehab@redhat.com>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
diff mbox series

Patch

diff --git a/drivers/media/platform/coda/coda-common.c b/drivers/media/platform/coda/coda-common.c
index 7518f01..ee1e05b 100644
--- a/drivers/media/platform/coda/coda-common.c
+++ b/drivers/media/platform/coda/coda-common.c
@@ -696,8 +696,6 @@  static int coda_s_fmt(struct coda_ctx *ctx, struct v4l2_format *f,
 	struct vb2_queue *vq;
 
 	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
 
 	q_data = get_q_data(ctx, f->type);
 	if (!q_data)
@@ -817,8 +815,6 @@  static int coda_s_fmt_vid_out(struct file *file, void *priv,
 	ctx->quantization = f->fmt.pix.quantization;
 
 	dst_vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
-	if (!dst_vq)
-		return -EINVAL;
 
 	/*
 	 * Setting the capture queue format is not possible while the capture
diff --git a/drivers/media/platform/imx-pxp.c b/drivers/media/platform/imx-pxp.c
index c1c2554..d079b3c 100644
--- a/drivers/media/platform/imx-pxp.c
+++ b/drivers/media/platform/imx-pxp.c
@@ -1071,13 +1071,8 @@  static int pxp_enum_fmt_vid_out(struct file *file, void *priv,
 
 static int pxp_g_fmt(struct pxp_ctx *ctx, struct v4l2_format *f)
 {
-	struct vb2_queue *vq;
 	struct pxp_q_data *q_data;
 
-	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
-
 	q_data = get_q_data(ctx, f->type);
 
 	f->fmt.pix.width	= q_data->width;
@@ -1220,8 +1215,6 @@  static int pxp_s_fmt(struct pxp_ctx *ctx, struct v4l2_format *f)
 	struct vb2_queue *vq;
 
 	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
 
 	q_data = get_q_data(ctx, f->type);
 	if (!q_data)
diff --git a/drivers/media/platform/m2m-deinterlace.c b/drivers/media/platform/m2m-deinterlace.c
index c62e598..df03ffd 100644
--- a/drivers/media/platform/m2m-deinterlace.c
+++ b/drivers/media/platform/m2m-deinterlace.c
@@ -497,13 +497,8 @@  static int vidioc_enum_fmt_vid_out(struct file *file, void *priv,
 
 static int vidioc_g_fmt(struct deinterlace_ctx *ctx, struct v4l2_format *f)
 {
-	struct vb2_queue *vq;
 	struct deinterlace_q_data *q_data;
 
-	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
-
 	q_data = get_q_data(f->type);
 
 	f->fmt.pix.width	= q_data->width;
@@ -598,8 +593,6 @@  static int vidioc_s_fmt(struct deinterlace_ctx *ctx, struct v4l2_format *f)
 	struct vb2_queue *vq;
 
 	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
 
 	q_data = get_q_data(f->type);
 	if (!q_data)
diff --git a/drivers/media/platform/mtk-jpeg/mtk_jpeg_core.c b/drivers/media/platform/mtk-jpeg/mtk_jpeg_core.c
index 2a5d500..2da90ae 100644
--- a/drivers/media/platform/mtk-jpeg/mtk_jpeg_core.c
+++ b/drivers/media/platform/mtk-jpeg/mtk_jpeg_core.c
@@ -271,17 +271,12 @@  static int mtk_jpeg_try_fmt_mplane(struct v4l2_format *f,
 static int mtk_jpeg_g_fmt_vid_mplane(struct file *file, void *priv,
 				     struct v4l2_format *f)
 {
-	struct vb2_queue *vq;
 	struct mtk_jpeg_q_data *q_data = NULL;
 	struct v4l2_pix_format_mplane *pix_mp = &f->fmt.pix_mp;
 	struct mtk_jpeg_ctx *ctx = mtk_jpeg_fh_to_ctx(priv);
 	struct mtk_jpeg_dev *jpeg = ctx->jpeg;
 	int i;
 
-	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
-
 	q_data = mtk_jpeg_get_q_data(ctx, f->type);
 
 	memset(pix_mp->reserved, 0, sizeof(pix_mp->reserved));
@@ -372,8 +367,6 @@  static int mtk_jpeg_s_fmt_mplane(struct mtk_jpeg_ctx *ctx,
 	int i;
 
 	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
 
 	q_data = mtk_jpeg_get_q_data(ctx, f->type);
 
diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c b/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c
index ba61964..d4006e5 100644
--- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c
+++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c
@@ -955,15 +955,8 @@  static int vidioc_vdec_g_fmt(struct file *file, void *priv,
 {
 	struct mtk_vcodec_ctx *ctx = fh_to_ctx(priv);
 	struct v4l2_pix_format_mplane *pix_mp = &f->fmt.pix_mp;
-	struct vb2_queue *vq;
 	struct mtk_q_data *q_data;
 
-	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
-	if (!vq) {
-		mtk_v4l2_err("no vb2 queue for type=%d", f->type);
-		return -EINVAL;
-	}
-
 	q_data = mtk_vdec_get_q_data(ctx, f->type);
 
 	pix_mp->field = V4L2_FIELD_NONE;
diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc.c b/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc.c
index d1f1225..7c54690 100644
--- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc.c
+++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc.c
@@ -430,10 +430,6 @@  static int vidioc_venc_s_fmt_cap(struct file *file, void *priv,
 	struct mtk_video_fmt *fmt;
 
 	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
-	if (!vq) {
-		mtk_v4l2_err("fail to get vq");
-		return -EINVAL;
-	}
 
 	if (vb2_is_busy(vq)) {
 		mtk_v4l2_err("queue busy");
@@ -493,10 +489,6 @@  static int vidioc_venc_s_fmt_out(struct file *file, void *priv,
 	struct v4l2_pix_format_mplane *pix_fmt_mp = &f->fmt.pix_mp;
 
 	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
-	if (!vq) {
-		mtk_v4l2_err("fail to get vq");
-		return -EINVAL;
-	}
 
 	if (vb2_is_busy(vq)) {
 		mtk_v4l2_err("queue busy");
@@ -554,14 +546,9 @@  static int vidioc_venc_g_fmt(struct file *file, void *priv,
 {
 	struct v4l2_pix_format_mplane *pix = &f->fmt.pix_mp;
 	struct mtk_vcodec_ctx *ctx = fh_to_ctx(priv);
-	struct vb2_queue *vq;
 	struct mtk_q_data *q_data;
 	int i;
 
-	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
-
 	q_data = mtk_venc_get_q_data(ctx, f->type);
 
 	pix->width = q_data->coded_width;
diff --git a/drivers/media/platform/mx2_emmaprp.c b/drivers/media/platform/mx2_emmaprp.c
index 27b078c..1366fde 100644
--- a/drivers/media/platform/mx2_emmaprp.c
+++ b/drivers/media/platform/mx2_emmaprp.c
@@ -436,13 +436,8 @@  static int vidioc_enum_fmt_vid_out(struct file *file, void *priv,
 
 static int vidioc_g_fmt(struct emmaprp_ctx *ctx, struct v4l2_format *f)
 {
-	struct vb2_queue *vq;
 	struct emmaprp_q_data *q_data;
 
-	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
-
 	q_data = get_q_data(ctx, f->type);
 
 	f->fmt.pix.width	= q_data->width;
@@ -545,8 +540,6 @@  static int vidioc_s_fmt(struct emmaprp_ctx *ctx, struct v4l2_format *f)
 	int ret;
 
 	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
 
 	q_data = get_q_data(ctx, f->type);
 	if (!q_data)
diff --git a/drivers/media/platform/rcar_fdp1.c b/drivers/media/platform/rcar_fdp1.c
index 6bda1ee..ef747d3 100644
--- a/drivers/media/platform/rcar_fdp1.c
+++ b/drivers/media/platform/rcar_fdp1.c
@@ -1407,9 +1407,6 @@  static int fdp1_g_fmt(struct file *file, void *priv, struct v4l2_format *f)
 	struct fdp1_q_data *q_data;
 	struct fdp1_ctx *ctx = fh_to_ctx(priv);
 
-	if (!v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type))
-		return -EINVAL;
-
 	q_data = get_q_data(ctx, f->type);
 	f->fmt.pix_mp = q_data->format;
 
diff --git a/drivers/media/platform/rcar_jpu.c b/drivers/media/platform/rcar_jpu.c
index 1dfd2eb..a91664c 100644
--- a/drivers/media/platform/rcar_jpu.c
+++ b/drivers/media/platform/rcar_jpu.c
@@ -839,9 +839,6 @@  static int jpu_try_fmt(struct file *file, void *priv, struct v4l2_format *f)
 {
 	struct jpu_ctx *ctx = fh_to_ctx(priv);
 
-	if (!v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type))
-		return -EINVAL;
-
 	return __jpu_try_fmt(ctx, NULL, &f->fmt.pix_mp, f->type);
 }
 
@@ -855,8 +852,6 @@  static int jpu_s_fmt(struct file *file, void *priv, struct v4l2_format *f)
 	int ret;
 
 	vq = v4l2_m2m_get_vq(m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
 
 	if (vb2_is_busy(vq)) {
 		v4l2_err(&ctx->jpu->v4l2_dev, "%s queue busy\n", __func__);
@@ -880,9 +875,6 @@  static int jpu_g_fmt(struct file *file, void *priv, struct v4l2_format *f)
 	struct jpu_q_data *q_data;
 	struct jpu_ctx *ctx = fh_to_ctx(priv);
 
-	if (!v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type))
-		return -EINVAL;
-
 	q_data = jpu_get_q_data(ctx, f->type);
 	f->fmt.pix_mp = q_data->format;
 
diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
index 5c65328..74b8e9d 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -470,12 +470,8 @@  static int vidioc_enum_fmt(struct file *file, void *prv, struct v4l2_fmtdesc *f)
 static int vidioc_g_fmt(struct file *file, void *prv, struct v4l2_format *f)
 {
 	struct rga_ctx *ctx = prv;
-	struct vb2_queue *vq;
 	struct rga_frame *frm;
 
-	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
 	frm = rga_get_frame(ctx, f->type);
 	if (IS_ERR(frm))
 		return PTR_ERR(frm);
diff --git a/drivers/media/platform/s5p-g2d/g2d.c b/drivers/media/platform/s5p-g2d/g2d.c
index 57ab1d1..dda4159 100644
--- a/drivers/media/platform/s5p-g2d/g2d.c
+++ b/drivers/media/platform/s5p-g2d/g2d.c
@@ -319,12 +319,8 @@  static int vidioc_enum_fmt(struct file *file, void *prv, struct v4l2_fmtdesc *f)
 static int vidioc_g_fmt(struct file *file, void *prv, struct v4l2_format *f)
 {
 	struct g2d_ctx *ctx = prv;
-	struct vb2_queue *vq;
 	struct g2d_frame *frm;
 
-	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
 	frm = get_frame(ctx, f->type);
 	if (IS_ERR(frm))
 		return PTR_ERR(frm);
diff --git a/drivers/media/platform/s5p-jpeg/jpeg-core.c b/drivers/media/platform/s5p-jpeg/jpeg-core.c
index 3f9000b..4884725 100644
--- a/drivers/media/platform/s5p-jpeg/jpeg-core.c
+++ b/drivers/media/platform/s5p-jpeg/jpeg-core.c
@@ -1359,15 +1359,10 @@  static struct s5p_jpeg_q_data *get_q_data(struct s5p_jpeg_ctx *ctx,
 
 static int s5p_jpeg_g_fmt(struct file *file, void *priv, struct v4l2_format *f)
 {
-	struct vb2_queue *vq;
 	struct s5p_jpeg_q_data *q_data = NULL;
 	struct v4l2_pix_format *pix = &f->fmt.pix;
 	struct s5p_jpeg_ctx *ct = fh_to_ctx(priv);
 
-	vq = v4l2_m2m_get_vq(ct->fh.m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
-
 	if (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE &&
 	    ct->mode == S5P_JPEG_DECODE && !ct->hdr_parsed)
 		return -EINVAL;
@@ -1620,8 +1615,6 @@  static int s5p_jpeg_s_fmt(struct s5p_jpeg_ctx *ct, struct v4l2_format *f)
 	unsigned int f_type;
 
 	vq = v4l2_m2m_get_vq(ct->fh.m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
 
 	q_data = get_q_data(ct, f->type);
 	BUG_ON(q_data == NULL);
diff --git a/drivers/media/platform/sh_veu.c b/drivers/media/platform/sh_veu.c
index 09ae64a..6d59e16 100644
--- a/drivers/media/platform/sh_veu.c
+++ b/drivers/media/platform/sh_veu.c
@@ -554,8 +554,6 @@  static int sh_veu_s_fmt(struct sh_veu_file *veu_file, struct v4l2_format *f)
 		return ret;
 
 	vq = v4l2_m2m_get_vq(veu->m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
 
 	if (vb2_is_busy(vq)) {
 		v4l2_err(&veu_file->veu_dev->v4l2_dev, "%s queue busy\n", __func__);
diff --git a/drivers/media/platform/ti-vpe/vpe.c b/drivers/media/platform/ti-vpe/vpe.c
index d70871d0..1620168 100644
--- a/drivers/media/platform/ti-vpe/vpe.c
+++ b/drivers/media/platform/ti-vpe/vpe.c
@@ -1537,14 +1537,9 @@  static int vpe_g_fmt(struct file *file, void *priv, struct v4l2_format *f)
 {
 	struct v4l2_pix_format_mplane *pix = &f->fmt.pix_mp;
 	struct vpe_ctx *ctx = file2ctx(file);
-	struct vb2_queue *vq;
 	struct vpe_q_data *q_data;
 	int i;
 
-	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
-
 	q_data = get_q_data(ctx, f->type);
 
 	pix->width = q_data->width;
@@ -1714,8 +1709,6 @@  static int __vpe_s_fmt(struct vpe_ctx *ctx, struct v4l2_format *f)
 	int i;
 
 	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
 
 	if (vb2_is_busy(vq)) {
 		vpe_err(ctx->dev, "queue busy\n");
diff --git a/drivers/media/platform/vicodec/vicodec-core.c b/drivers/media/platform/vicodec/vicodec-core.c
index 0d7876f..9a2ab8b 100644
--- a/drivers/media/platform/vicodec/vicodec-core.c
+++ b/drivers/media/platform/vicodec/vicodec-core.c
@@ -445,16 +445,11 @@  static int vidioc_enum_fmt_vid_out(struct file *file, void *priv,
 
 static int vidioc_g_fmt(struct vicodec_ctx *ctx, struct v4l2_format *f)
 {
-	struct vb2_queue *vq;
 	struct vicodec_q_data *q_data;
 	struct v4l2_pix_format_mplane *pix_mp;
 	struct v4l2_pix_format *pix;
 	const struct v4l2_fwht_pixfmt_info *info;
 
-	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
-
 	q_data = get_q_data(ctx, f->type);
 	info = q_data->info;
 
diff --git a/drivers/media/platform/vim2m.c b/drivers/media/platform/vim2m.c
index 89d9c4c..dae8af5 100644
--- a/drivers/media/platform/vim2m.c
+++ b/drivers/media/platform/vim2m.c
@@ -484,13 +484,8 @@  static int vidioc_enum_fmt_vid_out(struct file *file, void *priv,
 
 static int vidioc_g_fmt(struct vim2m_ctx *ctx, struct v4l2_format *f)
 {
-	struct vb2_queue *vq;
 	struct vim2m_q_data *q_data;
 
-	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
-
 	q_data = get_q_data(ctx, f->type);
 
 	f->fmt.pix.width	= q_data->width;
@@ -594,10 +589,6 @@  static int vidioc_s_fmt(struct vim2m_ctx *ctx, struct v4l2_format *f)
 	struct vim2m_q_data *q_data;
 	struct vb2_queue *vq;
 
-	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
-	if (!vq)
-		return -EINVAL;
-
 	q_data = get_q_data(ctx, f->type);
 	if (!q_data)
 		return -EINVAL;
diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
index 5bbdec5..1bbf4b0 100644
--- a/drivers/media/v4l2-core/v4l2-mem2mem.c
+++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
@@ -124,8 +124,6 @@  struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
 	struct v4l2_m2m_queue_ctx *q_ctx;
 
 	q_ctx = get_queue_ctx(m2m_ctx, type);
-	if (!q_ctx)
-		return NULL;
 
 	return &q_ctx->q;
 }
@@ -965,8 +963,6 @@  void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx,
 	unsigned long flags;
 
 	q_ctx = get_queue_ctx(m2m_ctx, vbuf->vb2_buf.vb2_queue->type);
-	if (!q_ctx)
-		return;
 
 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 	list_add_tail(&b->list, &q_ctx->rdy_queue);