linux-kernel - [PATCH v2 6/6] media: imagination: Round to closest multiple for cropping region

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: <20240826150822.4057164-7-devarsht@ti.com>
Date: Mon, 26 Aug 2024 20:38:22 +0530
From: Devarsh Thakkar <devarsht@...com>
To: <mchehab@...nel.org>, <hverkuil-cisco@...all.nl>,
        <linux-media@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <sebastian.fricke@...labora.com>, <linux-doc@...r.kernel.org>
CC: <praneeth@...com>, <nm@...com>, <vigneshr@...com>, <s-jain1@...com>,
        <r-donadkar@...com>, <b-brnich@...com>, <detheridge@...com>,
        <p-mantena@...com>, <vijayp@...com>, <devarsht@...com>,
        <andi.shyti@...ux.intel.com>, <nicolas@...fresne.ca>,
        <andriy.shevchenko@...ux.intel.com>, <jirislaby@...nel.org>,
        <davidgow@...gle.com>, <dlatypov@...gle.com>, <corbet@....net>,
        <broonie@...nel.org>, <jani.nikula@...el.com>, <rdunlap@...radead.org>,
        <nik.borisov@...e.com>, <Dave.Martin@....com>
Subject: [PATCH v2 6/6] media: imagination: Round to closest multiple for cropping region

If neither of the flags to round down (V4L2_SEL_FLAG_LE) or round up
(V4L2_SEL_FLAG_GE) are specified by the user, then round to nearest
multiple of requested value while updating the crop rectangle coordinates.

Use the rounding macro which gives preference to rounding down in case two
nearest values (high and low) are possible to raise the probability of
cropping rectangle falling inside the bound region.

This complies with the VIDIOC_G_SELECTION, VIDIOC_S_SELECTION ioctl
description as documented in v4l uapi [1] which specifies that driver
should choose crop rectangle as close as possible if no flags are passed by
user-space, as quoted below :

"``0`` - The driver can adjust the rectangle size freely and shall choose a
crop/compose rectangle as close as possible to the requested
 one."

Link: https://www.kernel.org/doc/Documentation/userspace-api/media/v4l/vidioc-g-selection.rst [1]
Signed-off-by: Devarsh Thakkar <devarsht@...com>
---
V2: No change
---
 drivers/media/platform/imagination/e5010-jpeg-enc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/media/platform/imagination/e5010-jpeg-enc.c b/drivers/media/platform/imagination/e5010-jpeg-enc.c
index 187f2d8abfbb..6c3687445803 100644
--- a/drivers/media/platform/imagination/e5010-jpeg-enc.c
+++ b/drivers/media/platform/imagination/e5010-jpeg-enc.c
@@ -514,10 +514,10 @@ static int e5010_s_selection(struct file *file, void *fh, struct v4l2_selection
 
 	switch (s->flags) {
 	case 0:
-		s->r.width = round_down(s->r.width, queue->fmt->frmsize.step_width);
-		s->r.height = round_down(s->r.height, queue->fmt->frmsize.step_height);
-		s->r.left = round_down(s->r.left, queue->fmt->frmsize.step_width);
-		s->r.top = round_down(s->r.top, 2);
+		s->r.width = round_closest_down(s->r.width, queue->fmt->frmsize.step_width);
+		s->r.height = round_closest_down(s->r.height, queue->fmt->frmsize.step_height);
+		s->r.left = round_closest_down(s->r.left, queue->fmt->frmsize.step_width);
+		s->r.top = round_closest_down(s->r.top, 2);
 
 		if (s->r.left + s->r.width > queue->width)
 			s->r.width = round_down(s->r.width + s->r.left - queue->width,
-- 
2.39.1