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* [PATCH v3 0/2] media: vimc: upon streaming, check that the pipeline starts with a source entity
@ 2019-10-09 15:53 Dafna Hirschfeld
  2019-10-09 15:53 ` [PATCH v3 1/2] media: vimc: move the dev field of each entity to vimc_ent_dev Dafna Hirschfeld
  2019-10-09 15:53 ` [PATCH v3 2/2] media: vimc: upon streaming, check that the pipeline starts with a source entity Dafna Hirschfeld
  0 siblings, 2 replies; 6+ messages in thread
From: Dafna Hirschfeld @ 2019-10-09 15:53 UTC (permalink / raw)
  To: linux-media
  Cc: dafna.hirschfeld, helen.koike, ezequiel, andre.almeida, skhan,
	hverkuil, kernel, dafna3

The first patch in this patchset moves the dev field of each
entity struct to the common sturct vimc_ent_device, this is
used by the first and the second patch to have access to 'dev'
in the streamer and replace pr_err with dev_err.

The second patch was first sent alone, then it was sent again
as part of the patchset
"media: vimc: use configfs in order to configure devices topologies"
I send it now again since it is not directly related to that patchset
and it fixes a crashing bug.

It has the following fixes due to Shuah Khan's comments:
- add the panic message to the commit message
- move the function vimc_is_source to the vimc-common.c file
- replace pr_err with dev_err

Dafna Hirschfeld (2):
  media: vimc: move the dev field of each entity to vimc_ent_dev
  media: vimc: upon streaming, check that the pipeline starts with a
    source entity

 drivers/media/platform/vimc/vimc-capture.c  |  7 +++--
 drivers/media/platform/vimc/vimc-common.c   | 10 +++++++
 drivers/media/platform/vimc/vimc-common.h   |  7 +++++
 drivers/media/platform/vimc/vimc-debayer.c  | 15 +++++------
 drivers/media/platform/vimc/vimc-scaler.c   | 11 ++++----
 drivers/media/platform/vimc/vimc-sensor.c   |  5 ++--
 drivers/media/platform/vimc/vimc-streamer.c | 29 ++++++++++++---------
 7 files changed, 51 insertions(+), 33 deletions(-)

-- 
2.20.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v3 1/2] media: vimc: move the dev field of each entity to vimc_ent_dev
  2019-10-09 15:53 [PATCH v3 0/2] media: vimc: upon streaming, check that the pipeline starts with a source entity Dafna Hirschfeld
@ 2019-10-09 15:53 ` Dafna Hirschfeld
  2019-10-09 15:53 ` [PATCH v3 2/2] media: vimc: upon streaming, check that the pipeline starts with a source entity Dafna Hirschfeld
  1 sibling, 0 replies; 6+ messages in thread
From: Dafna Hirschfeld @ 2019-10-09 15:53 UTC (permalink / raw)
  To: linux-media
  Cc: dafna.hirschfeld, helen.koike, ezequiel, andre.almeida, skhan,
	hverkuil, kernel, dafna3

Since the 'struct device *dev' field exists in each of the
entity structs, it can be moved to the common struct vimc_ent_devevice.
It is then used to replace 'pr_err' with 'dev_err' in the streamer
code.

Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
---
 drivers/media/platform/vimc/vimc-capture.c  |  7 +++----
 drivers/media/platform/vimc/vimc-common.h   |  2 ++
 drivers/media/platform/vimc/vimc-debayer.c  | 15 +++++++--------
 drivers/media/platform/vimc/vimc-scaler.c   | 11 +++++------
 drivers/media/platform/vimc/vimc-sensor.c   |  5 ++---
 drivers/media/platform/vimc/vimc-streamer.c |  2 +-
 6 files changed, 20 insertions(+), 22 deletions(-)

diff --git a/drivers/media/platform/vimc/vimc-capture.c b/drivers/media/platform/vimc/vimc-capture.c
index 602f80323031..d9cd6525ba22 100644
--- a/drivers/media/platform/vimc/vimc-capture.c
+++ b/drivers/media/platform/vimc/vimc-capture.c
@@ -15,7 +15,6 @@
 struct vimc_cap_device {
 	struct vimc_ent_device ved;
 	struct video_device vdev;
-	struct device *dev;
 	struct v4l2_pix_format format;
 	struct vb2_queue queue;
 	struct list_head buf_list;
@@ -124,7 +123,7 @@ static int vimc_cap_s_fmt_vid_cap(struct file *file, void *priv,
 	if (ret)
 		return ret;
 
-	dev_dbg(vcap->dev, "%s: format update: "
+	dev_dbg(vcap->ved.dev, "%s: format update: "
 		"old:%dx%d (0x%x, %d, %d, %d, %d) "
 		"new:%dx%d (0x%x, %d, %d, %d, %d)\n", vcap->vdev.name,
 		/* old */
@@ -300,7 +299,7 @@ static int vimc_cap_buffer_prepare(struct vb2_buffer *vb)
 	unsigned long size = vcap->format.sizeimage;
 
 	if (vb2_plane_size(vb, 0) < size) {
-		dev_err(vcap->dev, "%s: buffer too small (%lu < %lu)\n",
+		dev_err(vcap->ved.dev, "%s: buffer too small (%lu < %lu)\n",
 			vcap->vdev.name, vb2_plane_size(vb, 0), size);
 		return -EINVAL;
 	}
@@ -451,7 +450,7 @@ struct vimc_ent_device *vimc_cap_add(struct vimc_device *vimc,
 	vcap->ved.ent = &vcap->vdev.entity;
 	vcap->ved.process_frame = vimc_cap_process_frame;
 	vcap->ved.vdev_get_format = vimc_cap_get_format;
-	vcap->dev = &vimc->pdev.dev;
+	vcap->ved.dev = &vimc->pdev.dev;
 
 	/* Initialize the video_device struct */
 	vdev = &vcap->vdev;
diff --git a/drivers/media/platform/vimc/vimc-common.h b/drivers/media/platform/vimc/vimc-common.h
index 698db7c07645..8349e3c68a49 100644
--- a/drivers/media/platform/vimc/vimc-common.h
+++ b/drivers/media/platform/vimc/vimc-common.h
@@ -92,6 +92,7 @@ struct vimc_pix_map {
 /**
  * struct vimc_ent_device - core struct that represents a node in the topology
  *
+ * @dev:		a pointer of the device struct of the driver
  * @ent:		the pointer to struct media_entity for the node
  * @pads:		the list of pads of the node
  * @process_frame:	callback send a frame to that node
@@ -108,6 +109,7 @@ struct vimc_pix_map {
  * media_entity
  */
 struct vimc_ent_device {
+	struct device *dev;
 	struct media_entity *ent;
 	struct media_pad *pads;
 	void * (*process_frame)(struct vimc_ent_device *ved,
diff --git a/drivers/media/platform/vimc/vimc-debayer.c b/drivers/media/platform/vimc/vimc-debayer.c
index feac47d79449..ff7f8b763860 100644
--- a/drivers/media/platform/vimc/vimc-debayer.c
+++ b/drivers/media/platform/vimc/vimc-debayer.c
@@ -34,7 +34,6 @@ struct vimc_deb_pix_map {
 struct vimc_deb_device {
 	struct vimc_ent_device ved;
 	struct v4l2_subdev sd;
-	struct device *dev;
 	/* The active format */
 	struct v4l2_mbus_framefmt sink_fmt;
 	u32 src_code;
@@ -263,7 +262,7 @@ static int vimc_deb_set_fmt(struct v4l2_subdev *sd,
 		/* Set the new format in the sink pad */
 		vimc_deb_adjust_sink_fmt(&fmt->format);
 
-		dev_dbg(vdeb->dev, "%s: sink format update: "
+		dev_dbg(vdeb->ved.dev, "%s: sink format update: "
 			"old:%dx%d (0x%x, %d, %d, %d, %d) "
 			"new:%dx%d (0x%x, %d, %d, %d, %d)\n", vdeb->sd.name,
 			/* old */
@@ -386,7 +385,7 @@ static void vimc_deb_calc_rgb_sink(struct vimc_deb_device *vdeb,
 
 	/* Sum the values of the colors in the mean window */
 
-	dev_dbg(vdeb->dev,
+	dev_dbg(vdeb->ved.dev,
 		"deb: %s: --- Calc pixel %dx%d, window mean %d, seek %d ---\n",
 		vdeb->sd.name, lin, col, vdeb->sink_fmt.height, seek);
 
@@ -419,7 +418,7 @@ static void vimc_deb_calc_rgb_sink(struct vimc_deb_device *vdeb,
 						 vdeb->sink_fmt.width,
 						 vdeb->sink_bpp);
 
-			dev_dbg(vdeb->dev,
+			dev_dbg(vdeb->ved.dev,
 				"deb: %s: RGB CALC: frame index %d, win pos %dx%d, color %d\n",
 				vdeb->sd.name, index, wlin, wcol, color);
 
@@ -430,21 +429,21 @@ static void vimc_deb_calc_rgb_sink(struct vimc_deb_device *vdeb,
 			/* Save how many values we already added */
 			n_rgb[color]++;
 
-			dev_dbg(vdeb->dev, "deb: %s: RGB CALC: val %d, n %d\n",
+			dev_dbg(vdeb->ved.dev, "deb: %s: RGB CALC: val %d, n %d\n",
 				vdeb->sd.name, rgb[color], n_rgb[color]);
 		}
 	}
 
 	/* Calculate the mean */
 	for (i = 0; i < 3; i++) {
-		dev_dbg(vdeb->dev,
+		dev_dbg(vdeb->ved.dev,
 			"deb: %s: PRE CALC: %dx%d Color %d, val %d, n %d\n",
 			vdeb->sd.name, lin, col, i, rgb[i], n_rgb[i]);
 
 		if (n_rgb[i])
 			rgb[i] = rgb[i] / n_rgb[i];
 
-		dev_dbg(vdeb->dev,
+		dev_dbg(vdeb->ved.dev,
 			"deb: %s: FINAL CALC: %dx%d Color %d, val %d\n",
 			vdeb->sd.name, lin, col, i, rgb[i]);
 	}
@@ -518,7 +517,7 @@ struct vimc_ent_device *vimc_deb_add(struct vimc_device *vimc,
 	}
 
 	vdeb->ved.process_frame = vimc_deb_process_frame;
-	vdeb->dev = &vimc->pdev.dev;
+	vdeb->ved.dev = &vimc->pdev.dev;
 
 	/* Initialize the frame format */
 	vdeb->sink_fmt = sink_fmt_default;
diff --git a/drivers/media/platform/vimc/vimc-scaler.c b/drivers/media/platform/vimc/vimc-scaler.c
index a6a3cc5be872..9b1023525920 100644
--- a/drivers/media/platform/vimc/vimc-scaler.c
+++ b/drivers/media/platform/vimc/vimc-scaler.c
@@ -21,7 +21,6 @@ MODULE_PARM_DESC(sca_mult, " the image size multiplier");
 struct vimc_sca_device {
 	struct vimc_ent_device ved;
 	struct v4l2_subdev sd;
-	struct device *dev;
 	/* NOTE: the source fmt is the same as the sink
 	 * with the width and hight multiplied by mult
 	 */
@@ -171,7 +170,7 @@ static int vimc_sca_set_fmt(struct v4l2_subdev *sd,
 		/* Set the new format in the sink pad */
 		vimc_sca_adjust_sink_fmt(&fmt->format);
 
-		dev_dbg(vsca->dev, "%s: sink format update: "
+		dev_dbg(vsca->ved.dev, "%s: sink format update: "
 			"old:%dx%d (0x%x, %d, %d, %d, %d) "
 			"new:%dx%d (0x%x, %d, %d, %d, %d)\n", vsca->sd.name,
 			/* old */
@@ -271,7 +270,7 @@ static void vimc_sca_scale_pix(const struct vimc_sca_device *const vsca,
 				 vsca->bpp);
 	pixel = &sink_frame[index];
 
-	dev_dbg(vsca->dev,
+	dev_dbg(vsca->ved.dev,
 		"sca: %s: --- scale_pix sink pos %dx%d, index %d ---\n",
 		vsca->sd.name, lin, col, index);
 
@@ -281,7 +280,7 @@ static void vimc_sca_scale_pix(const struct vimc_sca_device *const vsca,
 	index = VIMC_FRAME_INDEX(lin * sca_mult, col * sca_mult,
 				 vsca->sink_fmt.width * sca_mult, vsca->bpp);
 
-	dev_dbg(vsca->dev, "sca: %s: scale_pix src pos %dx%d, index %d\n",
+	dev_dbg(vsca->ved.dev, "sca: %s: scale_pix src pos %dx%d, index %d\n",
 		vsca->sd.name, lin * sca_mult, col * sca_mult, index);
 
 	/* Repeat this pixel mult times */
@@ -290,7 +289,7 @@ static void vimc_sca_scale_pix(const struct vimc_sca_device *const vsca,
 		 * pixel repetition in a line
 		 */
 		for (j = 0; j < sca_mult * vsca->bpp; j += vsca->bpp) {
-			dev_dbg(vsca->dev,
+			dev_dbg(vsca->ved.dev,
 				"sca: %s: sca: scale_pix src pos %d\n",
 				vsca->sd.name, index + j);
 
@@ -377,7 +376,7 @@ struct vimc_ent_device *vimc_sca_add(struct vimc_device *vimc,
 	}
 
 	vsca->ved.process_frame = vimc_sca_process_frame;
-	vsca->dev = &vimc->pdev.dev;
+	vsca->ved.dev = &vimc->pdev.dev;
 
 	/* Initialize the frame format */
 	vsca->sink_fmt = sink_fmt_default;
diff --git a/drivers/media/platform/vimc/vimc-sensor.c b/drivers/media/platform/vimc/vimc-sensor.c
index 46dc6a535abe..9921993a2b73 100644
--- a/drivers/media/platform/vimc/vimc-sensor.c
+++ b/drivers/media/platform/vimc/vimc-sensor.c
@@ -17,7 +17,6 @@
 struct vimc_sen_device {
 	struct vimc_ent_device ved;
 	struct v4l2_subdev sd;
-	struct device *dev;
 	struct tpg_data tpg;
 	struct task_struct *kthread_sen;
 	u8 *frame;
@@ -158,7 +157,7 @@ static int vimc_sen_set_fmt(struct v4l2_subdev *sd,
 	/* Set the new format */
 	vimc_sen_adjust_fmt(&fmt->format);
 
-	dev_dbg(vsen->dev, "%s: format update: "
+	dev_dbg(vsen->ved.dev, "%s: format update: "
 		"old:%dx%d (0x%x, %d, %d, %d, %d) "
 		"new:%dx%d (0x%x, %d, %d, %d, %d)\n", vsen->sd.name,
 		/* old */
@@ -368,7 +367,7 @@ struct vimc_ent_device *vimc_sen_add(struct vimc_device *vimc,
 		goto err_free_hdl;
 
 	vsen->ved.process_frame = vimc_sen_process_frame;
-	vsen->dev = &vimc->pdev.dev;
+	vsen->ved.dev = &vimc->pdev.dev;
 
 	/* Initialize the frame format */
 	vsen->mbus_format = fmt_default;
diff --git a/drivers/media/platform/vimc/vimc-streamer.c b/drivers/media/platform/vimc/vimc-streamer.c
index faa2879c25df..37150c919fcb 100644
--- a/drivers/media/platform/vimc/vimc-streamer.c
+++ b/drivers/media/platform/vimc/vimc-streamer.c
@@ -96,7 +96,7 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
 			sd = media_entity_to_v4l2_subdev(ved->ent);
 			ret = v4l2_subdev_call(sd, video, s_stream, 1);
 			if (ret && ret != -ENOIOCTLCMD) {
-				pr_err("subdev_call error %s\n",
+				dev_err(ved->dev, "subdev_call error %s\n",
 				       ved->ent->name);
 				vimc_streamer_pipeline_terminate(stream);
 				return ret;
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v3 2/2] media: vimc: upon streaming, check that the pipeline starts with a source entity
  2019-10-09 15:53 [PATCH v3 0/2] media: vimc: upon streaming, check that the pipeline starts with a source entity Dafna Hirschfeld
  2019-10-09 15:53 ` [PATCH v3 1/2] media: vimc: move the dev field of each entity to vimc_ent_dev Dafna Hirschfeld
@ 2019-10-09 15:53 ` Dafna Hirschfeld
  2019-10-23  7:26   ` Hans Verkuil
  1 sibling, 1 reply; 6+ messages in thread
From: Dafna Hirschfeld @ 2019-10-09 15:53 UTC (permalink / raw)
  To: linux-media
  Cc: dafna.hirschfeld, helen.koike, ezequiel, andre.almeida, skhan,
	hverkuil, kernel, dafna3

Userspace can disable links and create pipelines that
do not start with a source entity. Trying to stream
from such a pipeline should fail with -EPIPE
currently this is not handled and cause kernel crash.

Reproducing the crash:
media-ctl -d0 -l "5:1->21:0[0]" -v
v4l2-ctl -z platform:vimc -d "RGB/YUV Capture" -v width=1920,height=1440
v4l2-ctl --stream-mmap --stream-count=100 -d /dev/video2

Panic message:
[   39.078841][  T248] BUG: kernel NULL pointer dereference, address: 0000000000000000
[   39.079338][  T248] #PF: supervisor read access in kernel mode
[   39.079704][  T248] #PF: error_code(0x0000) - not-present page
[   39.080071][  T248] PGD 0 P4D 0
[   39.080279][  T248] Oops: 0000 [#1] SMP PTI
[   39.080546][  T248] CPU: 0 PID: 248 Comm: vimc-streamer t Not tainted 5.4.0-rc1+ #17
[   39.081030][  T248] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
[   39.081779][  T248] RIP: 0010:vimc_sca_process_frame+0xdb/0x210 [vimc]
[   39.082191][  T248] Code: 44 8d 0c 28 8b 93 a4 01 00 00 48 8b 8b 98 01 00 00 85 d2 74 40 48 8b 74 24 10 8d 7a ff 4c 01 c9 31 d2 4c 01 fe eb 03 4c 89 c2 <44> 0f b6 04 16 44 88 04 11 4c 8d 42 01 48 39 fa 75 eb 8b 93 a4 01
[   39.083436][  T248] RSP: 0018:ffffb15a005abe90 EFLAGS: 00010246
[   39.083808][  T248] RAX: 0000000000000000 RBX: ffffa3fdc46d2e00 RCX: ffffb15a02579000
[   39.084298][  T248] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
[   39.084792][  T248] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[   39.085280][  T248] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
[   39.085770][  T248] R13: ffffa3fdc46d2ee0 R14: 0000000000000000 R15: 0000000000000000
[   39.086258][  T248] FS:  0000000000000000(0000) GS:ffffa3fdc7800000(0000) knlGS:0000000000000000
[   39.086806][  T248] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   39.087217][  T248] CR2: 0000000000000000 CR3: 0000000003c92005 CR4: 0000000000360ef0
[   39.087706][  T248] Call Trace:
[   39.087909][  T248]  ? vimc_streamer_pipeline_terminate+0x90/0x90 [vimc]
[   39.088318][  T248]  vimc_streamer_thread+0x7c/0xe0 [vimc]
[   39.088663][  T248]  kthread+0x10d/0x130
[   39.088919][  T248]  ? kthread_park+0x80/0x80
[   39.089205][  T248]  ret_from_fork+0x35/0x40
[   39.089475][  T248] Modules linked in: vimc videobuf2_vmalloc videobuf2_memops v4l2_tpg videobuf2_v4l2 videobuf2_common videodev mc
[   39.090208][  T248] CR2: 0000000000000000
[   39.090463][  T248] ---[ end trace 697650fefbf78bee ]---
[   39.090796][  T248] RIP: 0010:vimc_sca_process_frame+0xdb/0x210 [vimc]
[   39.091209][  T248] Code: 44 8d 0c 28 8b 93 a4 01 00 00 48 8b 8b 98 01 00 00 85 d2 74 40 48 8b 74 24 10 8d 7a ff 4c 01 c9 31 d2 4c 01 fe eb 03 4c 89 c2 <44> 0f b6 04 16 44 88 04 11 4c 8d 42 01 48 39 fa 75 eb 8b 93 a4 01
[   39.092417][  T248] RSP: 0018:ffffb15a005abe90 EFLAGS: 00010246
[   39.092789][  T248] RAX: 0000000000000000 RBX: ffffa3fdc46d2e00 RCX: ffffb15a02579000
[   39.093278][  T248] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
[   39.093766][  T248] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[   39.094254][  T248] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
[   39.094742][  T248] R13: ffffa3fdc46d2ee0 R14: 0000000000000000 R15: 0000000000000000
[   39.095309][  T248] FS:  0000000000000000(0000) GS:ffffa3fdc7800000(0000) knlGS:0000000000000000
[   39.095974][  T248] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   39.096372][  T248] CR2: 0000000000000000 CR3: 0000000003c92005 CR4: 0000000000360ef0

Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
---
 drivers/media/platform/vimc/vimc-common.c   | 10 ++++++++
 drivers/media/platform/vimc/vimc-common.h   |  5 ++++
 drivers/media/platform/vimc/vimc-streamer.c | 27 ++++++++++++---------
 3 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/drivers/media/platform/vimc/vimc-common.c b/drivers/media/platform/vimc/vimc-common.c
index a3120f4f7a90..e8ad3199ffbf 100644
--- a/drivers/media/platform/vimc/vimc-common.c
+++ b/drivers/media/platform/vimc/vimc-common.c
@@ -164,6 +164,16 @@ static const struct vimc_pix_map vimc_pix_map_list[] = {
 	},
 };
 
+bool vimc_is_source(struct media_entity *ent)
+{
+	unsigned int i;
+
+	for (i = 0; i < ent->num_pads; i++)
+		if (ent->pads[i].flags & MEDIA_PAD_FL_SINK)
+			return false;
+	return true;
+}
+
 const struct vimc_pix_map *vimc_pix_map_by_index(unsigned int i)
 {
 	if (i >= ARRAY_SIZE(vimc_pix_map_list))
diff --git a/drivers/media/platform/vimc/vimc-common.h b/drivers/media/platform/vimc/vimc-common.h
index 8349e3c68a49..112574bc3089 100644
--- a/drivers/media/platform/vimc/vimc-common.h
+++ b/drivers/media/platform/vimc/vimc-common.h
@@ -154,6 +154,11 @@ struct vimc_ent_config {
 	void (*rm)(struct vimc_device *vimc, struct vimc_ent_device *ved);
 };
 
+/**
+ * vimc_is_source - returns true iff the entity has only source pads
+ */
+bool vimc_is_source(struct media_entity *ent);
+
 /* prototypes for vimc_ent_config add and rm hooks */
 struct vimc_ent_device *vimc_cap_add(struct vimc_device *vimc,
 				     const char *vcfg_name);
diff --git a/drivers/media/platform/vimc/vimc-streamer.c b/drivers/media/platform/vimc/vimc-streamer.c
index 37150c919fcb..680614851a14 100644
--- a/drivers/media/platform/vimc/vimc-streamer.c
+++ b/drivers/media/platform/vimc/vimc-streamer.c
@@ -82,14 +82,12 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
 	struct media_entity *entity;
 	struct video_device *vdev;
 	struct v4l2_subdev *sd;
-	int ret = 0;
+	int ret = -EINVAL;
 
 	stream->pipe_size = 0;
 	while (stream->pipe_size < VIMC_STREAMER_PIPELINE_MAX_SIZE) {
-		if (!ved) {
-			vimc_streamer_pipeline_terminate(stream);
-			return -EINVAL;
-		}
+		if (!ved)
+			break;
 		stream->ved_pipeline[stream->pipe_size++] = ved;
 
 		if (is_media_entity_v4l2_subdev(ved->ent)) {
@@ -98,15 +96,23 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
 			if (ret && ret != -ENOIOCTLCMD) {
 				dev_err(ved->dev, "subdev_call error %s\n",
 				       ved->ent->name);
-				vimc_streamer_pipeline_terminate(stream);
-				return ret;
+				break;
 			}
 		}
 
 		entity = vimc_get_source_entity(ved->ent);
-		/* Check if the end of the pipeline was reached*/
-		if (!entity)
+		/* Check if the end of the pipeline was reached */
+		if (!entity) {
+			/* the first entity of the pipe should be source only */
+			if (!vimc_is_source(ved->ent)) {
+				dev_err(ved->dev,
+					"first entity in the pipe '%s' is not a source\n",
+					ved->ent->name);
+				ret = -EPIPE;
+				break;
+			}
 			return 0;
+		}
 
 		/* Get the next device in the pipeline */
 		if (is_media_entity_v4l2_subdev(entity)) {
@@ -119,9 +125,8 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
 			ved = video_get_drvdata(vdev);
 		}
 	}
-
 	vimc_streamer_pipeline_terminate(stream);
-	return -EINVAL;
+	return ret;
 }
 
 /**
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v3 2/2] media: vimc: upon streaming, check that the pipeline starts with a source entity
  2019-10-09 15:53 ` [PATCH v3 2/2] media: vimc: upon streaming, check that the pipeline starts with a source entity Dafna Hirschfeld
@ 2019-10-23  7:26   ` Hans Verkuil
  2019-10-24  8:36     ` Dafna Hirschfeld
  0 siblings, 1 reply; 6+ messages in thread
From: Hans Verkuil @ 2019-10-23  7:26 UTC (permalink / raw)
  To: Dafna Hirschfeld, linux-media
  Cc: helen.koike, ezequiel, andre.almeida, skhan, kernel, dafna3

On 10/9/19 5:53 PM, Dafna Hirschfeld wrote:
> Userspace can disable links and create pipelines that
> do not start with a source entity. Trying to stream
> from such a pipeline should fail with -EPIPE
> currently this is not handled and cause kernel crash.
> 
> Reproducing the crash:
> media-ctl -d0 -l "5:1->21:0[0]" -v
> v4l2-ctl -z platform:vimc -d "RGB/YUV Capture" -v width=1920,height=1440
> v4l2-ctl --stream-mmap --stream-count=100 -d /dev/video2
> 
> Panic message:
> [   39.078841][  T248] BUG: kernel NULL pointer dereference, address: 0000000000000000
> [   39.079338][  T248] #PF: supervisor read access in kernel mode
> [   39.079704][  T248] #PF: error_code(0x0000) - not-present page
> [   39.080071][  T248] PGD 0 P4D 0
> [   39.080279][  T248] Oops: 0000 [#1] SMP PTI
> [   39.080546][  T248] CPU: 0 PID: 248 Comm: vimc-streamer t Not tainted 5.4.0-rc1+ #17
> [   39.081030][  T248] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
> [   39.081779][  T248] RIP: 0010:vimc_sca_process_frame+0xdb/0x210 [vimc]
> [   39.082191][  T248] Code: 44 8d 0c 28 8b 93 a4 01 00 00 48 8b 8b 98 01 00 00 85 d2 74 40 48 8b 74 24 10 8d 7a ff 4c 01 c9 31 d2 4c 01 fe eb 03 4c 89 c2 <44> 0f b6 04 16 44 88 04 11 4c 8d 42 01 48 39 fa 75 eb 8b 93 a4 01
> [   39.083436][  T248] RSP: 0018:ffffb15a005abe90 EFLAGS: 00010246
> [   39.083808][  T248] RAX: 0000000000000000 RBX: ffffa3fdc46d2e00 RCX: ffffb15a02579000
> [   39.084298][  T248] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
> [   39.084792][  T248] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
> [   39.085280][  T248] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
> [   39.085770][  T248] R13: ffffa3fdc46d2ee0 R14: 0000000000000000 R15: 0000000000000000
> [   39.086258][  T248] FS:  0000000000000000(0000) GS:ffffa3fdc7800000(0000) knlGS:0000000000000000
> [   39.086806][  T248] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   39.087217][  T248] CR2: 0000000000000000 CR3: 0000000003c92005 CR4: 0000000000360ef0
> [   39.087706][  T248] Call Trace:
> [   39.087909][  T248]  ? vimc_streamer_pipeline_terminate+0x90/0x90 [vimc]
> [   39.088318][  T248]  vimc_streamer_thread+0x7c/0xe0 [vimc]
> [   39.088663][  T248]  kthread+0x10d/0x130
> [   39.088919][  T248]  ? kthread_park+0x80/0x80
> [   39.089205][  T248]  ret_from_fork+0x35/0x40
> [   39.089475][  T248] Modules linked in: vimc videobuf2_vmalloc videobuf2_memops v4l2_tpg videobuf2_v4l2 videobuf2_common videodev mc
> [   39.090208][  T248] CR2: 0000000000000000
> [   39.090463][  T248] ---[ end trace 697650fefbf78bee ]---
> [   39.090796][  T248] RIP: 0010:vimc_sca_process_frame+0xdb/0x210 [vimc]
> [   39.091209][  T248] Code: 44 8d 0c 28 8b 93 a4 01 00 00 48 8b 8b 98 01 00 00 85 d2 74 40 48 8b 74 24 10 8d 7a ff 4c 01 c9 31 d2 4c 01 fe eb 03 4c 89 c2 <44> 0f b6 04 16 44 88 04 11 4c 8d 42 01 48 39 fa 75 eb 8b 93 a4 01
> [   39.092417][  T248] RSP: 0018:ffffb15a005abe90 EFLAGS: 00010246
> [   39.092789][  T248] RAX: 0000000000000000 RBX: ffffa3fdc46d2e00 RCX: ffffb15a02579000
> [   39.093278][  T248] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
> [   39.093766][  T248] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
> [   39.094254][  T248] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
> [   39.094742][  T248] R13: ffffa3fdc46d2ee0 R14: 0000000000000000 R15: 0000000000000000
> [   39.095309][  T248] FS:  0000000000000000(0000) GS:ffffa3fdc7800000(0000) knlGS:0000000000000000
> [   39.095974][  T248] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   39.096372][  T248] CR2: 0000000000000000 CR3: 0000000003c92005 CR4: 0000000000360ef0
> 
> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
> ---
>  drivers/media/platform/vimc/vimc-common.c   | 10 ++++++++
>  drivers/media/platform/vimc/vimc-common.h   |  5 ++++
>  drivers/media/platform/vimc/vimc-streamer.c | 27 ++++++++++++---------
>  3 files changed, 31 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/media/platform/vimc/vimc-common.c b/drivers/media/platform/vimc/vimc-common.c
> index a3120f4f7a90..e8ad3199ffbf 100644
> --- a/drivers/media/platform/vimc/vimc-common.c
> +++ b/drivers/media/platform/vimc/vimc-common.c
> @@ -164,6 +164,16 @@ static const struct vimc_pix_map vimc_pix_map_list[] = {
>  	},
>  };
>  
> +bool vimc_is_source(struct media_entity *ent)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < ent->num_pads; i++)
> +		if (ent->pads[i].flags & MEDIA_PAD_FL_SINK)
> +			return false;
> +	return true;
> +}
> +
>  const struct vimc_pix_map *vimc_pix_map_by_index(unsigned int i)
>  {
>  	if (i >= ARRAY_SIZE(vimc_pix_map_list))
> diff --git a/drivers/media/platform/vimc/vimc-common.h b/drivers/media/platform/vimc/vimc-common.h
> index 8349e3c68a49..112574bc3089 100644
> --- a/drivers/media/platform/vimc/vimc-common.h
> +++ b/drivers/media/platform/vimc/vimc-common.h
> @@ -154,6 +154,11 @@ struct vimc_ent_config {
>  	void (*rm)(struct vimc_device *vimc, struct vimc_ent_device *ved);
>  };
>  
> +/**
> + * vimc_is_source - returns true iff the entity has only source pads
> + */
> +bool vimc_is_source(struct media_entity *ent);
> +
>  /* prototypes for vimc_ent_config add and rm hooks */
>  struct vimc_ent_device *vimc_cap_add(struct vimc_device *vimc,
>  				     const char *vcfg_name);
> diff --git a/drivers/media/platform/vimc/vimc-streamer.c b/drivers/media/platform/vimc/vimc-streamer.c
> index 37150c919fcb..680614851a14 100644
> --- a/drivers/media/platform/vimc/vimc-streamer.c
> +++ b/drivers/media/platform/vimc/vimc-streamer.c
> @@ -82,14 +82,12 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
>  	struct media_entity *entity;
>  	struct video_device *vdev;
>  	struct v4l2_subdev *sd;
> -	int ret = 0;
> +	int ret = -EINVAL;
>  
>  	stream->pipe_size = 0;
>  	while (stream->pipe_size < VIMC_STREAMER_PIPELINE_MAX_SIZE) {
> -		if (!ved) {
> -			vimc_streamer_pipeline_terminate(stream);
> -			return -EINVAL;
> -		}
> +		if (!ved)
> +			break;

This doesn't work, you need to set ret to -EINVAL explicitly since ret can
be set elsewhere as well in the while loop, so there is no guarantee that
ret is -EINVAL.

>  		stream->ved_pipeline[stream->pipe_size++] = ved;
>  
>  		if (is_media_entity_v4l2_subdev(ved->ent)) {
> @@ -98,15 +96,23 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
>  			if (ret && ret != -ENOIOCTLCMD) {
>  				dev_err(ved->dev, "subdev_call error %s\n",
>  				       ved->ent->name);
> -				vimc_streamer_pipeline_terminate(stream);
> -				return ret;
> +				break;

And here ret can end up being -ENOIOCTLCMD, so returning 'ret' at the end
may not be the value you expect.

Regards,

	Hans

>  			}
>  		}
>  
>  		entity = vimc_get_source_entity(ved->ent);
> -		/* Check if the end of the pipeline was reached*/
> -		if (!entity)
> +		/* Check if the end of the pipeline was reached */
> +		if (!entity) {
> +			/* the first entity of the pipe should be source only */
> +			if (!vimc_is_source(ved->ent)) {
> +				dev_err(ved->dev,
> +					"first entity in the pipe '%s' is not a source\n",
> +					ved->ent->name);
> +				ret = -EPIPE;
> +				break;
> +			}
>  			return 0;
> +		}
>  
>  		/* Get the next device in the pipeline */
>  		if (is_media_entity_v4l2_subdev(entity)) {
> @@ -119,9 +125,8 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
>  			ved = video_get_drvdata(vdev);
>  		}
>  	}
> -
>  	vimc_streamer_pipeline_terminate(stream);
> -	return -EINVAL;
> +	return ret;
>  }
>  
>  /**
> 


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v3 2/2] media: vimc: upon streaming, check that the pipeline starts with a source entity
  2019-10-23  7:26   ` Hans Verkuil
@ 2019-10-24  8:36     ` Dafna Hirschfeld
  2019-10-24  9:27       ` Hans Verkuil
  0 siblings, 1 reply; 6+ messages in thread
From: Dafna Hirschfeld @ 2019-10-24  8:36 UTC (permalink / raw)
  To: Hans Verkuil, linux-media
  Cc: helen.koike, ezequiel, andre.almeida, skhan, kernel, dafna3



On 10/23/19 9:26 AM, Hans Verkuil wrote:
> On 10/9/19 5:53 PM, Dafna Hirschfeld wrote:
>> Userspace can disable links and create pipelines that
>> do not start with a source entity. Trying to stream
>> from such a pipeline should fail with -EPIPE
>> currently this is not handled and cause kernel crash.
>>
>> Reproducing the crash:
>> media-ctl -d0 -l "5:1->21:0[0]" -v
>> v4l2-ctl -z platform:vimc -d "RGB/YUV Capture" -v width=1920,height=1440
>> v4l2-ctl --stream-mmap --stream-count=100 -d /dev/video2
>>
>> Panic message:
>> [   39.078841][  T248] BUG: kernel NULL pointer dereference, address: 0000000000000000
>> [   39.079338][  T248] #PF: supervisor read access in kernel mode
>> [   39.079704][  T248] #PF: error_code(0x0000) - not-present page
>> [   39.080071][  T248] PGD 0 P4D 0
>> [   39.080279][  T248] Oops: 0000 [#1] SMP PTI
>> [   39.080546][  T248] CPU: 0 PID: 248 Comm: vimc-streamer t Not tainted 5.4.0-rc1+ #17
>> [   39.081030][  T248] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
>> [   39.081779][  T248] RIP: 0010:vimc_sca_process_frame+0xdb/0x210 [vimc]
>> [   39.082191][  T248] Code: 44 8d 0c 28 8b 93 a4 01 00 00 48 8b 8b 98 01 00 00 85 d2 74 40 48 8b 74 24 10 8d 7a ff 4c 01 c9 31 d2 4c 01 fe eb 03 4c 89 c2 <44> 0f b6 04 16 44 88 04 11 4c 8d 42 01 48 39 fa 75 eb 8b 93 a4 01
>> [   39.083436][  T248] RSP: 0018:ffffb15a005abe90 EFLAGS: 00010246
>> [   39.083808][  T248] RAX: 0000000000000000 RBX: ffffa3fdc46d2e00 RCX: ffffb15a02579000
>> [   39.084298][  T248] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
>> [   39.084792][  T248] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
>> [   39.085280][  T248] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
>> [   39.085770][  T248] R13: ffffa3fdc46d2ee0 R14: 0000000000000000 R15: 0000000000000000
>> [   39.086258][  T248] FS:  0000000000000000(0000) GS:ffffa3fdc7800000(0000) knlGS:0000000000000000
>> [   39.086806][  T248] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [   39.087217][  T248] CR2: 0000000000000000 CR3: 0000000003c92005 CR4: 0000000000360ef0
>> [   39.087706][  T248] Call Trace:
>> [   39.087909][  T248]  ? vimc_streamer_pipeline_terminate+0x90/0x90 [vimc]
>> [   39.088318][  T248]  vimc_streamer_thread+0x7c/0xe0 [vimc]
>> [   39.088663][  T248]  kthread+0x10d/0x130
>> [   39.088919][  T248]  ? kthread_park+0x80/0x80
>> [   39.089205][  T248]  ret_from_fork+0x35/0x40
>> [   39.089475][  T248] Modules linked in: vimc videobuf2_vmalloc videobuf2_memops v4l2_tpg videobuf2_v4l2 videobuf2_common videodev mc
>> [   39.090208][  T248] CR2: 0000000000000000
>> [   39.090463][  T248] ---[ end trace 697650fefbf78bee ]---
>> [   39.090796][  T248] RIP: 0010:vimc_sca_process_frame+0xdb/0x210 [vimc]
>> [   39.091209][  T248] Code: 44 8d 0c 28 8b 93 a4 01 00 00 48 8b 8b 98 01 00 00 85 d2 74 40 48 8b 74 24 10 8d 7a ff 4c 01 c9 31 d2 4c 01 fe eb 03 4c 89 c2 <44> 0f b6 04 16 44 88 04 11 4c 8d 42 01 48 39 fa 75 eb 8b 93 a4 01
>> [   39.092417][  T248] RSP: 0018:ffffb15a005abe90 EFLAGS: 00010246
>> [   39.092789][  T248] RAX: 0000000000000000 RBX: ffffa3fdc46d2e00 RCX: ffffb15a02579000
>> [   39.093278][  T248] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
>> [   39.093766][  T248] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
>> [   39.094254][  T248] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
>> [   39.094742][  T248] R13: ffffa3fdc46d2ee0 R14: 0000000000000000 R15: 0000000000000000
>> [   39.095309][  T248] FS:  0000000000000000(0000) GS:ffffa3fdc7800000(0000) knlGS:0000000000000000
>> [   39.095974][  T248] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [   39.096372][  T248] CR2: 0000000000000000 CR3: 0000000003c92005 CR4: 0000000000360ef0
>>
>> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
>> ---
>>   drivers/media/platform/vimc/vimc-common.c   | 10 ++++++++
>>   drivers/media/platform/vimc/vimc-common.h   |  5 ++++
>>   drivers/media/platform/vimc/vimc-streamer.c | 27 ++++++++++++---------
>>   3 files changed, 31 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/media/platform/vimc/vimc-common.c b/drivers/media/platform/vimc/vimc-common.c
>> index a3120f4f7a90..e8ad3199ffbf 100644
>> --- a/drivers/media/platform/vimc/vimc-common.c
>> +++ b/drivers/media/platform/vimc/vimc-common.c
>> @@ -164,6 +164,16 @@ static const struct vimc_pix_map vimc_pix_map_list[] = {
>>   	},
>>   };
>>   
>> +bool vimc_is_source(struct media_entity *ent)
>> +{
>> +	unsigned int i;
>> +
>> +	for (i = 0; i < ent->num_pads; i++)
>> +		if (ent->pads[i].flags & MEDIA_PAD_FL_SINK)
>> +			return false;
>> +	return true;
>> +}
>> +
>>   const struct vimc_pix_map *vimc_pix_map_by_index(unsigned int i)
>>   {
>>   	if (i >= ARRAY_SIZE(vimc_pix_map_list))
>> diff --git a/drivers/media/platform/vimc/vimc-common.h b/drivers/media/platform/vimc/vimc-common.h
>> index 8349e3c68a49..112574bc3089 100644
>> --- a/drivers/media/platform/vimc/vimc-common.h
>> +++ b/drivers/media/platform/vimc/vimc-common.h
>> @@ -154,6 +154,11 @@ struct vimc_ent_config {
>>   	void (*rm)(struct vimc_device *vimc, struct vimc_ent_device *ved);
>>   };
>>   
>> +/**
>> + * vimc_is_source - returns true iff the entity has only source pads
>> + */
>> +bool vimc_is_source(struct media_entity *ent);
>> +
>>   /* prototypes for vimc_ent_config add and rm hooks */
>>   struct vimc_ent_device *vimc_cap_add(struct vimc_device *vimc,
>>   				     const char *vcfg_name);
>> diff --git a/drivers/media/platform/vimc/vimc-streamer.c b/drivers/media/platform/vimc/vimc-streamer.c
>> index 37150c919fcb..680614851a14 100644
>> --- a/drivers/media/platform/vimc/vimc-streamer.c
>> +++ b/drivers/media/platform/vimc/vimc-streamer.c
>> @@ -82,14 +82,12 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
>>   	struct media_entity *entity;
>>   	struct video_device *vdev;
>>   	struct v4l2_subdev *sd;
>> -	int ret = 0;
>> +	int ret = -EINVAL;
>>   
>>   	stream->pipe_size = 0;
>>   	while (stream->pipe_size < VIMC_STREAMER_PIPELINE_MAX_SIZE) {
>> -		if (!ved) {
>> -			vimc_streamer_pipeline_terminate(stream);
>> -			return -EINVAL;
>> -		}
>> +		if (!ved)
>> +			break;
> 
> This doesn't work, you need to set ret to -EINVAL explicitly since ret can
> be set elsewhere as well in the while loop, so there is no guarantee that
> ret is -EINVAL.
> 
>>   		stream->ved_pipeline[stream->pipe_size++] = ved;
>>   
>>   		if (is_media_entity_v4l2_subdev(ved->ent)) {
>> @@ -98,15 +96,23 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
>>   			if (ret && ret != -ENOIOCTLCMD) {
>>   				dev_err(ved->dev, "subdev_call error %s\n",
>>   				       ved->ent->name);
>> -				vimc_streamer_pipeline_terminate(stream);
>> -				return ret;
>> +				break;
> 
> And here ret can end up being -ENOIOCTLCMD, so returning 'ret' at the end
> may not be the value you expect.
> 

Hi,
But the condition "if (ret && ret != -ENOIOCTLCMD)" ensures it is not 
-ENOIOCTLCMD

Regards,
Dafna

> Regards,
> 
> 	Hans
> 
>>   			}
>>   		}
>>   
>>   		entity = vimc_get_source_entity(ved->ent);
>> -		/* Check if the end of the pipeline was reached*/
>> -		if (!entity)
>> +		/* Check if the end of the pipeline was reached */
>> +		if (!entity) {
>> +			/* the first entity of the pipe should be source only */
>> +			if (!vimc_is_source(ved->ent)) {
>> +				dev_err(ved->dev,
>> +					"first entity in the pipe '%s' is not a source\n",
>> +					ved->ent->name);
>> +				ret = -EPIPE;
>> +				break;
>> +			}
>>   			return 0;
>> +		}
>>   
>>   		/* Get the next device in the pipeline */
>>   		if (is_media_entity_v4l2_subdev(entity)) {
>> @@ -119,9 +125,8 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
>>   			ved = video_get_drvdata(vdev);
>>   		}
>>   	}
>> -
>>   	vimc_streamer_pipeline_terminate(stream);
>> -	return -EINVAL;
>> +	return ret;
>>   }
>>   
>>   /**
>>
> 
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v3 2/2] media: vimc: upon streaming, check that the pipeline starts with a source entity
  2019-10-24  8:36     ` Dafna Hirschfeld
@ 2019-10-24  9:27       ` Hans Verkuil
  0 siblings, 0 replies; 6+ messages in thread
From: Hans Verkuil @ 2019-10-24  9:27 UTC (permalink / raw)
  To: Dafna Hirschfeld, linux-media
  Cc: helen.koike, ezequiel, andre.almeida, skhan, kernel, dafna3

On 10/24/19 10:36 AM, Dafna Hirschfeld wrote:
> 
> 
> On 10/23/19 9:26 AM, Hans Verkuil wrote:
>> On 10/9/19 5:53 PM, Dafna Hirschfeld wrote:
>>> Userspace can disable links and create pipelines that
>>> do not start with a source entity. Trying to stream
>>> from such a pipeline should fail with -EPIPE
>>> currently this is not handled and cause kernel crash.
>>>
>>> Reproducing the crash:
>>> media-ctl -d0 -l "5:1->21:0[0]" -v
>>> v4l2-ctl -z platform:vimc -d "RGB/YUV Capture" -v width=1920,height=1440
>>> v4l2-ctl --stream-mmap --stream-count=100 -d /dev/video2
>>>
>>> Panic message:
>>> [   39.078841][  T248] BUG: kernel NULL pointer dereference, address: 0000000000000000
>>> [   39.079338][  T248] #PF: supervisor read access in kernel mode
>>> [   39.079704][  T248] #PF: error_code(0x0000) - not-present page
>>> [   39.080071][  T248] PGD 0 P4D 0
>>> [   39.080279][  T248] Oops: 0000 [#1] SMP PTI
>>> [   39.080546][  T248] CPU: 0 PID: 248 Comm: vimc-streamer t Not tainted 5.4.0-rc1+ #17
>>> [   39.081030][  T248] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
>>> [   39.081779][  T248] RIP: 0010:vimc_sca_process_frame+0xdb/0x210 [vimc]
>>> [   39.082191][  T248] Code: 44 8d 0c 28 8b 93 a4 01 00 00 48 8b 8b 98 01 00 00 85 d2 74 40 48 8b 74 24 10 8d 7a ff 4c 01 c9 31 d2 4c 01 fe eb 03 4c 89 c2 <44> 0f b6 04 16 44 88 04 11 4c 8d 42 01 48 39 fa 75 eb 8b 93 a4 01
>>> [   39.083436][  T248] RSP: 0018:ffffb15a005abe90 EFLAGS: 00010246
>>> [   39.083808][  T248] RAX: 0000000000000000 RBX: ffffa3fdc46d2e00 RCX: ffffb15a02579000
>>> [   39.084298][  T248] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
>>> [   39.084792][  T248] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
>>> [   39.085280][  T248] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
>>> [   39.085770][  T248] R13: ffffa3fdc46d2ee0 R14: 0000000000000000 R15: 0000000000000000
>>> [   39.086258][  T248] FS:  0000000000000000(0000) GS:ffffa3fdc7800000(0000) knlGS:0000000000000000
>>> [   39.086806][  T248] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> [   39.087217][  T248] CR2: 0000000000000000 CR3: 0000000003c92005 CR4: 0000000000360ef0
>>> [   39.087706][  T248] Call Trace:
>>> [   39.087909][  T248]  ? vimc_streamer_pipeline_terminate+0x90/0x90 [vimc]
>>> [   39.088318][  T248]  vimc_streamer_thread+0x7c/0xe0 [vimc]
>>> [   39.088663][  T248]  kthread+0x10d/0x130
>>> [   39.088919][  T248]  ? kthread_park+0x80/0x80
>>> [   39.089205][  T248]  ret_from_fork+0x35/0x40
>>> [   39.089475][  T248] Modules linked in: vimc videobuf2_vmalloc videobuf2_memops v4l2_tpg videobuf2_v4l2 videobuf2_common videodev mc
>>> [   39.090208][  T248] CR2: 0000000000000000
>>> [   39.090463][  T248] ---[ end trace 697650fefbf78bee ]---
>>> [   39.090796][  T248] RIP: 0010:vimc_sca_process_frame+0xdb/0x210 [vimc]
>>> [   39.091209][  T248] Code: 44 8d 0c 28 8b 93 a4 01 00 00 48 8b 8b 98 01 00 00 85 d2 74 40 48 8b 74 24 10 8d 7a ff 4c 01 c9 31 d2 4c 01 fe eb 03 4c 89 c2 <44> 0f b6 04 16 44 88 04 11 4c 8d 42 01 48 39 fa 75 eb 8b 93 a4 01
>>> [   39.092417][  T248] RSP: 0018:ffffb15a005abe90 EFLAGS: 00010246
>>> [   39.092789][  T248] RAX: 0000000000000000 RBX: ffffa3fdc46d2e00 RCX: ffffb15a02579000
>>> [   39.093278][  T248] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
>>> [   39.093766][  T248] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
>>> [   39.094254][  T248] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
>>> [   39.094742][  T248] R13: ffffa3fdc46d2ee0 R14: 0000000000000000 R15: 0000000000000000
>>> [   39.095309][  T248] FS:  0000000000000000(0000) GS:ffffa3fdc7800000(0000) knlGS:0000000000000000
>>> [   39.095974][  T248] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> [   39.096372][  T248] CR2: 0000000000000000 CR3: 0000000003c92005 CR4: 0000000000360ef0
>>>
>>> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
>>> ---
>>>   drivers/media/platform/vimc/vimc-common.c   | 10 ++++++++
>>>   drivers/media/platform/vimc/vimc-common.h   |  5 ++++
>>>   drivers/media/platform/vimc/vimc-streamer.c | 27 ++++++++++++---------
>>>   3 files changed, 31 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/drivers/media/platform/vimc/vimc-common.c b/drivers/media/platform/vimc/vimc-common.c
>>> index a3120f4f7a90..e8ad3199ffbf 100644
>>> --- a/drivers/media/platform/vimc/vimc-common.c
>>> +++ b/drivers/media/platform/vimc/vimc-common.c
>>> @@ -164,6 +164,16 @@ static const struct vimc_pix_map vimc_pix_map_list[] = {
>>>   	},
>>>   };
>>>   
>>> +bool vimc_is_source(struct media_entity *ent)
>>> +{
>>> +	unsigned int i;
>>> +
>>> +	for (i = 0; i < ent->num_pads; i++)
>>> +		if (ent->pads[i].flags & MEDIA_PAD_FL_SINK)
>>> +			return false;
>>> +	return true;
>>> +}
>>> +
>>>   const struct vimc_pix_map *vimc_pix_map_by_index(unsigned int i)
>>>   {
>>>   	if (i >= ARRAY_SIZE(vimc_pix_map_list))
>>> diff --git a/drivers/media/platform/vimc/vimc-common.h b/drivers/media/platform/vimc/vimc-common.h
>>> index 8349e3c68a49..112574bc3089 100644
>>> --- a/drivers/media/platform/vimc/vimc-common.h
>>> +++ b/drivers/media/platform/vimc/vimc-common.h
>>> @@ -154,6 +154,11 @@ struct vimc_ent_config {
>>>   	void (*rm)(struct vimc_device *vimc, struct vimc_ent_device *ved);
>>>   };
>>>   
>>> +/**
>>> + * vimc_is_source - returns true iff the entity has only source pads
>>> + */
>>> +bool vimc_is_source(struct media_entity *ent);
>>> +
>>>   /* prototypes for vimc_ent_config add and rm hooks */
>>>   struct vimc_ent_device *vimc_cap_add(struct vimc_device *vimc,
>>>   				     const char *vcfg_name);
>>> diff --git a/drivers/media/platform/vimc/vimc-streamer.c b/drivers/media/platform/vimc/vimc-streamer.c
>>> index 37150c919fcb..680614851a14 100644
>>> --- a/drivers/media/platform/vimc/vimc-streamer.c
>>> +++ b/drivers/media/platform/vimc/vimc-streamer.c
>>> @@ -82,14 +82,12 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
>>>   	struct media_entity *entity;
>>>   	struct video_device *vdev;
>>>   	struct v4l2_subdev *sd;
>>> -	int ret = 0;
>>> +	int ret = -EINVAL;
>>>   
>>>   	stream->pipe_size = 0;
>>>   	while (stream->pipe_size < VIMC_STREAMER_PIPELINE_MAX_SIZE) {
>>> -		if (!ved) {
>>> -			vimc_streamer_pipeline_terminate(stream);
>>> -			return -EINVAL;
>>> -		}
>>> +		if (!ved)
>>> +			break;
>>
>> This doesn't work, you need to set ret to -EINVAL explicitly since ret can
>> be set elsewhere as well in the while loop, so there is no guarantee that
>> ret is -EINVAL.
>>
>>>   		stream->ved_pipeline[stream->pipe_size++] = ved;
>>>   
>>>   		if (is_media_entity_v4l2_subdev(ved->ent)) {
>>> @@ -98,15 +96,23 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
>>>   			if (ret && ret != -ENOIOCTLCMD) {
>>>   				dev_err(ved->dev, "subdev_call error %s\n",
>>>   				       ved->ent->name);
>>> -				vimc_streamer_pipeline_terminate(stream);
>>> -				return ret;
>>> +				break;
>>
>> And here ret can end up being -ENOIOCTLCMD, so returning 'ret' at the end
>> may not be the value you expect.
>>
> 
> Hi,
> But the condition "if (ret && ret != -ENOIOCTLCMD)" ensures it is not 
> -ENOIOCTLCMD

But if v4l2_subdev_call DID return -ENOIOCTLCMD, then ret now has that value.
If the while now exits or ved becomes NULL, then you fall to the return ret
which now returns -ENOIOCTLCMD.

This code is messy w.r.t. the return value, it should be cleaned up a bit.

Even if the code is correct (as in that the scenario I described above cannot
actually happen in practice), it is still hard to follow.

Regards,

	Hans

> 
> Regards,
> Dafna
> 
>> Regards,
>>
>> 	Hans
>>
>>>   			}
>>>   		}
>>>   
>>>   		entity = vimc_get_source_entity(ved->ent);
>>> -		/* Check if the end of the pipeline was reached*/
>>> -		if (!entity)
>>> +		/* Check if the end of the pipeline was reached */
>>> +		if (!entity) {
>>> +			/* the first entity of the pipe should be source only */
>>> +			if (!vimc_is_source(ved->ent)) {
>>> +				dev_err(ved->dev,
>>> +					"first entity in the pipe '%s' is not a source\n",
>>> +					ved->ent->name);
>>> +				ret = -EPIPE;
>>> +				break;
>>> +			}
>>>   			return 0;
>>> +		}
>>>   
>>>   		/* Get the next device in the pipeline */
>>>   		if (is_media_entity_v4l2_subdev(entity)) {
>>> @@ -119,9 +125,8 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
>>>   			ved = video_get_drvdata(vdev);
>>>   		}
>>>   	}
>>> -
>>>   	vimc_streamer_pipeline_terminate(stream);
>>> -	return -EINVAL;
>>> +	return ret;
>>>   }
>>>   
>>>   /**
>>>
>>
>>


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2019-10-24  9:27 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-09 15:53 [PATCH v3 0/2] media: vimc: upon streaming, check that the pipeline starts with a source entity Dafna Hirschfeld
2019-10-09 15:53 ` [PATCH v3 1/2] media: vimc: move the dev field of each entity to vimc_ent_dev Dafna Hirschfeld
2019-10-09 15:53 ` [PATCH v3 2/2] media: vimc: upon streaming, check that the pipeline starts with a source entity Dafna Hirschfeld
2019-10-23  7:26   ` Hans Verkuil
2019-10-24  8:36     ` Dafna Hirschfeld
2019-10-24  9:27       ` Hans Verkuil

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