[PATCH 24/45] tty: vt: sanitize consw::con_putc() parameters

Jiri Slaby (SUSE)
2024-01-18T07:58:51Z

Make parameters of consw::con_putc() saner:
* x and y are unsigned now, as they cannot be negative, and
* ca is made u16, as it is composed of two 8bit values (character and
attribute). See the con_putcs() hook, u16/ushort is worked on there.

And document the hook.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
---
drivers/video/console/dummycon.c | 6 ++++--
drivers/video/console/newport_con.c | 4 ++--
include/linux/console.h | 5 ++++-
3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/video/console/dummycon.c b/drivers/video/console/dummycon.c
index 0a69d5c216ee..1874beed0325 100644
--- a/drivers/video/console/dummycon.c
+++ b/drivers/video/console/dummycon.c
@@ -50,7 +50,8 @@ void dummycon_unregister_output_notifier(struct notifier_block *nb)
raw_notifier_chain_unregister(&dummycon_output_nh, nb);
}

-static void dummycon_putc(struct vc_data *vc, int c, int ypos, int xpos)
+static void dummycon_putc(struct vc_data *vc, u16 c, unsigned int y,
+ unsigned int x)
{
WARN_CONSOLE_UNLOCKED();

@@ -84,7 +85,8 @@ static int dummycon_blank(struct vc_data *vc, int blank, int mode_switch)
return 1;
}
#else
-static void dummycon_putc(struct vc_data *vc, int c, int ypos, int xpos) { }
+static void dummycon_putc(struct vc_data *vc, u16 c, unsigned int y,
+ unsigned int x) { }
static void dummycon_putcs(struct vc_data *vc, const unsigned short *s,
int count, int ypos, int xpos) { }
static int dummycon_blank(struct vc_data *vc, int blank, int mode_switch)
diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index 55c6106b3507..9b5c0118873e 100644
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -367,8 +367,8 @@ static void newport_clear(struct vc_data *vc, unsigned int sy, unsigned int sx,
}
}

-static void newport_putc(struct vc_data *vc, int charattr, int ypos,
- int xpos)
+static void newport_putc(struct vc_data *vc, u16 charattr, unsigned int ypos,
+ unsigned int xpos)
{
unsigned char *p;

diff --git a/include/linux/console.h b/include/linux/console.h
index 8fd96a5fca5f..92d57e5b3009 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -39,6 +39,8 @@ enum vc_intensity;
* @con_init: initialize the console on @vc. @init is true for the very first
* call on this @vc.
* @con_clear: erase @count characters at [@x, @y] on @vc. @count >= 1.
+ * @con_putc: emit one character with attributes @ca to [@x, @y] on @vc.
+ * (optional -- @con_putcs would be called instead)
* @con_scroll: move lines from @top to @bottom in direction @dir by @lines.
* Return true if no generic handling should be done.
* Invoked by csi_M and printing to the console.
@@ -53,7 +55,8 @@ struct consw {
void (*con_deinit)(struct vc_data *vc);
void (*con_clear)(struct vc_data *vc, unsigned int y,
unsigned int x, unsigned int count);
- void (*con_putc)(struct vc_data *vc, int c, int ypos, int xpos);
+ void (*con_putc)(struct vc_data *vc, u16 ca, unsigned int y,
+ unsigned int x);
void (*con_putcs)(struct vc_data *vc, const unsigned short *s,
int count, int ypos, int xpos);
void (*con_cursor)(struct vc_data *vc, int mode);
--
2.43.0