Patch "media: v4l2-ctrls: fix sparse warning" has been added to the 3.18-stable tree

From: gregkh
Date: Wed Apr 04 2018 - 11:34:06 EST

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This is a note to let you know that I've just added the patch titled

media: v4l2-ctrls: fix sparse warning

to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
media-v4l2-ctrls-fix-sparse-warning.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.

>From foo@baz Wed Apr 4 17:30:18 CEST 2018
From: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Date: Wed, 28 Mar 2018 15:12:34 -0300
Subject: media: v4l2-ctrls: fix sparse warning
To: Linux Media Mailing List <linux-media@xxxxxxxxxxxxxxx>, stable@xxxxxxxxxxxxxxx
Cc: Hans Verkuil <hans.verkuil@xxxxxxxxx>, Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxx>, Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>, Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>, Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Message-ID: <d53d22eb0ea4cdbcb2e7f02d789a01892d8c36cf.1522260310.git.mchehab@xxxxxxxxxxxxxxxx>

From: Hans Verkuil <hans.verkuil@xxxxxxxxx>

The warning is simple:

drivers/media/v4l2-core/v4l2-ctrls.c:1685:15: warning: incorrect type in assignment (different address spaces)

but the fix isn't.

The core problem was that the conversion from user to kernelspace was
done at too low a level and that needed to be moved up. That made it possible
to drop pointers to v4l2_ext_control from set_ctrl and validate_new and
clean up this sparse warning because those functions now always operate
on kernelspace pointers.

Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-ctrls.c | 87 ++++++++++++++++++++---------------
1 file changed, 52 insertions(+), 35 deletions(-)

--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1668,10 +1668,8 @@ static int check_range(enum v4l2_ctrl_ty
}

/* Validate a new control */
-static int validate_new(const struct v4l2_ctrl *ctrl,
- struct v4l2_ext_control *c)
+static int validate_new(const struct v4l2_ctrl *ctrl, union v4l2_ctrl_ptr p_new)
{
- union v4l2_ctrl_ptr ptr;
unsigned idx;
int err = 0;

@@ -1684,19 +1682,14 @@ static int validate_new(const struct v4l
case V4L2_CTRL_TYPE_BOOLEAN:
case V4L2_CTRL_TYPE_BUTTON:
case V4L2_CTRL_TYPE_CTRL_CLASS:
- ptr.p_s32 = &c->value;
- return ctrl->type_ops->validate(ctrl, 0, ptr);
-
case V4L2_CTRL_TYPE_INTEGER64:
- ptr.p_s64 = &c->value64;
- return ctrl->type_ops->validate(ctrl, 0, ptr);
+ return ctrl->type_ops->validate(ctrl, 0, p_new);
default:
break;
}
}
- ptr.p = c->ptr;
- for (idx = 0; !err && idx < c->size / ctrl->elem_size; idx++)
- err = ctrl->type_ops->validate(ctrl, idx, ptr);
+ for (idx = 0; !err && idx < ctrl->elems; idx++)
+ err = ctrl->type_ops->validate(ctrl, idx, p_new);
return err;
}

@@ -3020,6 +3013,7 @@ static int validate_ctrls(struct v4l2_ex
cs->error_idx = cs->count;
for (i = 0; i < cs->count; i++) {
struct v4l2_ctrl *ctrl = helpers[i].ctrl;
+ union v4l2_ctrl_ptr p_new;

cs->error_idx = i;

@@ -3033,7 +3027,17 @@ static int validate_ctrls(struct v4l2_ex
best-effort to avoid that. */
if (set && (ctrl->flags & V4L2_CTRL_FLAG_GRABBED))
return -EBUSY;
- ret = validate_new(ctrl, &cs->controls[i]);
+ /*
+ * Skip validation for now if the payload needs to be copied
+ * from userspace into kernelspace. We'll validate those later.
+ */
+ if (ctrl->is_ptr)
+ continue;
+ if (ctrl->type == V4L2_CTRL_TYPE_INTEGER64)
+ p_new.p_s64 = &cs->controls[i].value64;
+ else
+ p_new.p_s32 = &cs->controls[i].value;
+ ret = validate_new(ctrl, p_new);
if (ret)
return ret;
}
@@ -3128,7 +3132,11 @@ static int try_set_ext_ctrls(struct v4l2
/* Copy the new caller-supplied control values.
user_to_new() sets 'is_new' to 1. */
do {
- ret = user_to_new(cs->controls + idx, helpers[idx].ctrl);
+ struct v4l2_ctrl *ctrl = helpers[idx].ctrl;
+
+ ret = user_to_new(cs->controls + idx, ctrl);
+ if (!ret && ctrl->is_ptr)
+ ret = validate_new(ctrl, ctrl->p_new);
idx = helpers[idx].next;
} while (!ret && idx);

@@ -3178,10 +3186,10 @@ int v4l2_subdev_s_ext_ctrls(struct v4l2_
EXPORT_SYMBOL(v4l2_subdev_s_ext_ctrls);

/* Helper function for VIDIOC_S_CTRL compatibility */
-static int set_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl,
- struct v4l2_ext_control *c, u32 ch_flags)
+static int set_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, u32 ch_flags)
{
struct v4l2_ctrl *master = ctrl->cluster[0];
+ int ret;
int i;

/* Reset the 'is_new' flags of the cluster */
@@ -3189,8 +3197,9 @@ static int set_ctrl(struct v4l2_fh *fh,
if (master->cluster[i])
master->cluster[i]->is_new = 0;

- if (c)
- user_to_new(c, ctrl);
+ ret = validate_new(ctrl, ctrl->p_new);
+ if (ret)
+ return ret;

/* For autoclusters with volatiles that are switched from auto to
manual mode we have to update the current volatile values since
@@ -3207,15 +3216,14 @@ static int set_ctrl(struct v4l2_fh *fh,
static int set_ctrl_lock(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl,
struct v4l2_ext_control *c)
{
- int ret = validate_new(ctrl, c);
+ int ret;

- if (!ret) {
- v4l2_ctrl_lock(ctrl);
- ret = set_ctrl(fh, ctrl, c, 0);
- if (!ret)
- cur_to_user(c, ctrl);
- v4l2_ctrl_unlock(ctrl);
- }
+ v4l2_ctrl_lock(ctrl);
+ user_to_new(c, ctrl);
+ ret = set_ctrl(fh, ctrl, 0);
+ if (!ret)
+ cur_to_user(c, ctrl);
+ v4l2_ctrl_unlock(ctrl);
return ret;
}

@@ -3223,7 +3231,7 @@ int v4l2_s_ctrl(struct v4l2_fh *fh, stru
struct v4l2_control *control)
{
struct v4l2_ctrl *ctrl = v4l2_ctrl_find(hdl, control->id);
- struct v4l2_ext_control c;
+ struct v4l2_ext_control c = { control->id };
int ret;

if (ctrl == NULL || !ctrl->is_int)
@@ -3252,7 +3260,7 @@ int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl
/* It's a driver bug if this happens. */
WARN_ON(!ctrl->is_int);
ctrl->val = val;
- return set_ctrl(NULL, ctrl, NULL, 0);
+ return set_ctrl(NULL, ctrl, 0);
}
EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl);

@@ -3263,7 +3271,7 @@ int __v4l2_ctrl_s_ctrl_int64(struct v4l2
/* It's a driver bug if this happens. */
WARN_ON(ctrl->is_ptr || ctrl->type != V4L2_CTRL_TYPE_INTEGER64);
*ctrl->p_new.p_s64 = val;
- return set_ctrl(NULL, ctrl, NULL, 0);
+ return set_ctrl(NULL, ctrl, 0);
}
EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_int64);

@@ -3274,7 +3282,7 @@ int __v4l2_ctrl_s_ctrl_string(struct v4l
/* It's a driver bug if this happens. */
WARN_ON(ctrl->type != V4L2_CTRL_TYPE_STRING);
strlcpy(ctrl->p_new.p_char, s, ctrl->maximum + 1);
- return set_ctrl(NULL, ctrl, NULL, 0);
+ return set_ctrl(NULL, ctrl, 0);
}
EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_string);

@@ -3297,8 +3305,8 @@ EXPORT_SYMBOL(v4l2_ctrl_notify);
int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
s64 min, s64 max, u64 step, s64 def)
{
+ bool changed;
int ret;
- struct v4l2_ext_control c;

lockdep_assert_held(ctrl->handler->lock);

@@ -3325,11 +3333,20 @@ int __v4l2_ctrl_modify_range(struct v4l2
ctrl->maximum = max;
ctrl->step = step;
ctrl->default_value = def;
- c.value = *ctrl->p_cur.p_s32;
- if (validate_new(ctrl, &c))
- c.value = def;
- if (c.value != *ctrl->p_cur.p_s32)
- ret = set_ctrl(NULL, ctrl, &c, V4L2_EVENT_CTRL_CH_RANGE);
+ cur_to_new(ctrl);
+ if (validate_new(ctrl, ctrl->p_new)) {
+ if (ctrl->type == V4L2_CTRL_TYPE_INTEGER64)
+ *ctrl->p_new.p_s64 = def;
+ else
+ *ctrl->p_new.p_s32 = def;
+ }
+
+ if (ctrl->type == V4L2_CTRL_TYPE_INTEGER64)
+ changed = *ctrl->p_new.p_s64 != *ctrl->p_cur.p_s64;
+ else
+ changed = *ctrl->p_new.p_s32 != *ctrl->p_cur.p_s32;
+ if (changed)
+ ret = set_ctrl(NULL, ctrl, V4L2_EVENT_CTRL_CH_RANGE);
else
send_event(NULL, ctrl, V4L2_EVENT_CTRL_CH_RANGE);
return ret;

Patches currently in stable-queue which might be from mchehab@xxxxxxxxxxxxxxxx are

queue-3.18/media-v4l2-compat-ioctl32.c-copy-m.userptr-in-put_v4l2_plane32.patch
queue-3.18/media-v4l2-compat-ioctl32.c-avoid-sizeof-type.patch
queue-3.18/media-v4l2-compat-ioctl32.c-drop-pr_info-for-unknown-buffer-type.patch
queue-3.18/media-v4l2-compat-ioctl32-use-compat_u64-for-video-standard.patch
queue-3.18/media-v4l2-compat-ioctl32.c-add-missing-vidioc_prepare_buf.patch
queue-3.18/vb2-v4l2_buf_flag_done-is-set-after-dqbuf.patch
queue-3.18/media-v4l2-compat-ioctl32.c-refactor-compat-ioctl32-logic.patch
queue-3.18/media-v4l2-ctrls-fix-sparse-warning.patch
queue-3.18/media-v4l2-compat-ioctl32.c-fix-ctrl_is_pointer.patch
queue-3.18/media-v4l2-compat-ioctl32.c-move-helper-functions-to-__get-put_v4l2_format32.patch
queue-3.18/media-media-v4l2-ctrls-volatiles-should-not-generate-ch_value.patch
queue-3.18/media-v4l2-compat-ioctl32.c-don-t-copy-back-the-result-for-certain-errors.patch
queue-3.18/media-v4l2-compat-ioctl32.c-make-ctrl_is_pointer-work-for-subdevs.patch
queue-3.18/media-v4l2-compat-ioctl32.c-fix-the-indentation.patch
queue-3.18/media-v4l2-compat-ioctl32-copy-v4l2_window-global_alpha.patch
queue-3.18/media-v4l2-ioctl.c-don-t-copy-back-the-result-for-enotty.patch
queue-3.18/media-v4l2-compat-ioctl32.c-copy-clip-list-in-put_v4l2_window32.patch
queue-3.18/media-v4l2-compat-ioctl32-initialize-a-reserved-field.patch

Next message: David Ahern: "Re: [PATCH] netdevsim: remove incorrect __net_initdata annotations"
Previous message: Alex G.: "Re: [RFC PATCH 3/4] acpi: apei: Do not panic() in NMI because of GHES messages"
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