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: <20230119151935.013597162@ens-lyon.org>
Date:   Thu, 19 Jan 2023 16:19:16 +0100
From:   Samuel Thibault <samuel.thibault@...-lyon.org>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jirislaby@...nel.org>, kbd@...ts.altlinux.org
Cc:     linux-kernel@...r.kernel.org,
        "linux-kernel@...r.kernel.org, Samuel Thibault" 
        <samuel.thibault@...-lyon.org>
Subject: [PATCHv3 2/3] VT: Add KD_FONT_OP_SET/GET_TALL operations

The KD_FONT_OP_SET/GET operations hardcode vpitch to be 32 pixels,
which only dates from the old VGA hardware which as asserting this.

Drivers such as fbcon however do not have such limitation, so this
introduces KD_FONT_OP_SET/GET_TALL operations, which userland can try
to use to avoid this limitation, thus opening the patch to >32 pixels
font height.

Signed-off-by: Samuel Thibault <samuel.thibault@...-lyon.org>

Index: linux-6.0/drivers/tty/vt/vt.c
===================================================================
--- linux-6.0.orig/drivers/tty/vt/vt.c
+++ linux-6.0/drivers/tty/vt/vt.c
@@ -4592,6 +4592,7 @@ static int con_font_get(struct vc_data *
 	struct console_font font;
 	int rc = -EINVAL;
 	int c;
+	unsigned int vpitch = op->op == KD_FONT_OP_GET_TALL ? op->height : 32;
 
 	if (op->data) {
 		font.data = kmalloc(max_font_size, GFP_KERNEL);
@@ -4604,7 +4605,7 @@ static int con_font_get(struct vc_data *
 	if (vc->vc_mode != KD_TEXT)
 		rc = -EINVAL;
 	else if (vc->vc_sw->con_font_get)
-		rc = vc->vc_sw->con_font_get(vc, &font, 32);
+		rc = vc->vc_sw->con_font_get(vc, &font, vpitch);
 	else
 		rc = -ENOSYS;
 	console_unlock();
@@ -4612,7 +4613,7 @@ static int con_font_get(struct vc_data *
 	if (rc)
 		goto out;
 
-	c = (font.width+7)/8 * 32 * font.charcount;
+	c = (font.width+7)/8 * vpitch * font.charcount;
 
 	if (op->data && font.charcount > op->charcount)
 		rc = -ENOSPC;
@@ -4638,6 +4639,7 @@ static int con_font_set(struct vc_data *
 	struct console_font font;
 	int rc = -EINVAL;
 	int size;
+	unsigned int vpitch = op->op == KD_FONT_OP_SET_TALL ? op->height : 32;
 
 	if (vc->vc_mode != KD_TEXT)
 		return -EINVAL;
@@ -4647,7 +4649,9 @@ static int con_font_set(struct vc_data *
 		return -EINVAL;
 	if (op->width <= 0 || op->width > 32 || !op->height || op->height > 32)
 		return -EINVAL;
-	size = (op->width+7)/8 * 32 * op->charcount;
+	if (vpitch < op->height)
+		return -EINVAL;
+	size = (op->width+7)/8 * vpitch * op->charcount;
 	if (size > max_font_size)
 		return -ENOSPC;
 
@@ -4665,7 +4669,7 @@ static int con_font_set(struct vc_data *
 	else if (vc->vc_sw->con_font_set) {
 		if (vc_is_sel(vc))
 			clear_selection();
-		rc = vc->vc_sw->con_font_set(vc, &font, 32, op->flags);
+		rc = vc->vc_sw->con_font_set(vc, &font, vpitch, op->flags);
 	} else
 		rc = -ENOSYS;
 	console_unlock();
@@ -4711,8 +4715,10 @@ int con_font_op(struct vc_data *vc, stru
 {
 	switch (op->op) {
 	case KD_FONT_OP_SET:
+	case KD_FONT_OP_SET_TALL:
 		return con_font_set(vc, op);
 	case KD_FONT_OP_GET:
+	case KD_FONT_OP_GET_TALL:
 		return con_font_get(vc, op);
 	case KD_FONT_OP_SET_DEFAULT:
 		return con_font_default(vc, op);
Index: linux-6.0/include/uapi/linux/kd.h
===================================================================
--- linux-6.0.orig/include/uapi/linux/kd.h
+++ linux-6.0/include/uapi/linux/kd.h
@@ -161,19 +161,25 @@ struct console_font_op {
 	unsigned int flags;	/* KD_FONT_FLAG_* */
 	unsigned int width, height;	/* font size */
 	unsigned int charcount;
-	unsigned char __user *data;	/* font data with height fixed to 32 */
+	unsigned char __user *data;	/* font data with vpitch fixed to 32 for
+					 * KD_FONT_OP_SET/GET
+					 */
 };
 
 struct console_font {
 	unsigned int width, height;	/* font size */
 	unsigned int charcount;
-	unsigned char *data;	/* font data with height fixed to 32 */
+	unsigned char *data;	/* font data with vpitch fixed to 32 for
+				 * KD_FONT_OP_SET/GET
+				 */
 };
 
 #define KD_FONT_OP_SET		0	/* Set font */
 #define KD_FONT_OP_GET		1	/* Get font */
 #define KD_FONT_OP_SET_DEFAULT	2	/* Set font to default, data points to name / NULL */
 #define KD_FONT_OP_COPY		3	/* Obsolete, do not use */
+#define KD_FONT_OP_SET_TALL	4	/* Set font with vpitch = height */
+#define KD_FONT_OP_GET_TALL	5	/* Get font with vpitch = height */
 
 #define KD_FONT_FLAG_DONT_RECALC 	1	/* Don't recalculate hw charcell size [compat] */
 


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ