linux-kernel - [PATCH v2 05/10] media/v4l2-core: struct struct v4l2_ext

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1440163169-18047-6-git-send-email-ricardo.ribalda@gmail.com>
Date:	Fri, 21 Aug 2015 15:19:24 +0200
From:	Ricardo Ribalda Delgado <ricardo.ribalda@...il.com>
To:	Mauro Carvalho Chehab <mchehab@....samsung.com>,
	Mike Isely <isely@...ox.com>,
	Laurent Pinchart <laurent.pinchart@...asonboard.com>,
	Hans Verkuil <hans.verkuil@...co.com>,
	Steven Toth <stoth@...nellabs.com>,
	Sakari Ailus <sakari.ailus@...ux.intel.com>,
	Vincent Palatin <vpalatin@...omium.org>,
	linux-media@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:	Ricardo Ribalda Delgado <ricardo.ribalda@...il.com>
Subject: [PATCH v2 05/10] media/v4l2-core: struct struct v4l2_ext_controls param which

Support for new field which on v4l2_ext_controls, used to get the
default value of one or more controls.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@...il.com>
---
 drivers/media/v4l2-core/v4l2-ctrls.c | 34 +++++++++++++++++++++++++++++-----
 1 file changed, 29 insertions(+), 5 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 580098ba5c0b..8f1a5d3cbf7f 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1489,6 +1489,17 @@ static int new_to_user(struct v4l2_ext_control *c,
 	return ptr_to_user(c, ctrl, ctrl->p_new);
 }
 
+/* Helper function: copy the initial control value back to the caller */
+static int def_to_user(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl)
+{
+	int idx;
+
+	for (idx = 0; idx < ctrl->elems; idx++)
+		ctrl->type_ops->init(ctrl, idx, ctrl->p_new);
+
+	return ptr_to_user(c, ctrl, ctrl->p_new);
+}
+
 /* Helper function: copy the caller-provider value to the given control value */
 static int user_to_ptr(struct v4l2_ext_control *c,
 		       struct v4l2_ctrl *ctrl,
@@ -2708,7 +2719,9 @@ static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
 
 		cs->error_idx = i;
 
-		if (cs->which && V4L2_CTRL_ID2WHICH(id) != cs->which)
+		if (cs->which &&
+		    cs->which != V4L2_CTRL_WHICH_DEF_VAL &&
+		    V4L2_CTRL_ID2WHICH(id) != cs->which)
 			return -EINVAL;
 
 		/* Old-style private controls are not allowed for
@@ -2787,7 +2800,7 @@ static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
    whether there are any controls at all. */
 static int class_check(struct v4l2_ctrl_handler *hdl, u32 which)
 {
-	if (!which)
+	if (which == 0 || which == V4L2_CTRL_WHICH_DEF_VAL)
 		return list_empty(&hdl->ctrl_refs) ? -EINVAL : 0;
 	return find_ref_lock(hdl, which | 1) ? 0 : -EINVAL;
 }
@@ -2801,6 +2814,9 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
 	struct v4l2_ctrl_helper *helpers = helper;
 	int ret;
 	int i, j;
+	bool def_value;
+
+	def_value = (cs->which == V4L2_CTRL_WHICH_DEF_VAL)
 
 	cs->error_idx = cs->count;
 	cs->which = V4L2_CTRL_ID2WHICH(cs->which);
@@ -2827,9 +2843,11 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
 
 	for (i = 0; !ret && i < cs->count; i++) {
 		int (*ctrl_to_user)(struct v4l2_ext_control *c,
-				    struct v4l2_ctrl *ctrl) = cur_to_user;
+				    struct v4l2_ctrl *ctrl);
 		struct v4l2_ctrl *master;
 
+		ctrl_to_user = def_value ? def_to_user : cur_to_user;
+
 		if (helpers[i].mref == NULL)
 			continue;
 
@@ -2839,8 +2857,9 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
 		v4l2_ctrl_lock(master);
 
 		/* g_volatile_ctrl will update the new control values */
-		if ((master->flags & V4L2_CTRL_FLAG_VOLATILE) ||
-			(master->has_volatiles && !is_cur_manual(master))) {
+		if (!def_value &&
+		    ((master->flags & V4L2_CTRL_FLAG_VOLATILE) ||
+		    (master->has_volatiles && !is_cur_manual(master)))) {
 			for (j = 0; j < master->ncontrols; j++)
 				cur_to_new(master->cluster[j]);
 			ret = call_op(master, g_volatile_ctrl);
@@ -3062,6 +3081,11 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
 	int ret;
 
 	cs->error_idx = cs->count;
+
+	/* Default value cannot be changed */
+	if (cs->which == V4L2_CTRL_WHICH_DEF_VAL)
+		return -EINVAL;
+
 	cs->which = V4L2_CTRL_ID2WHICH(cs->which);
 
 	if (hdl == NULL)
-- 
2.5.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/