[PATCH v2 13/47] use clamp() for counts in csi_?() handlers

From: Jiri Slaby (SUSE)
Date: Mon Jan 22 2024 - 06:23:23 EST


The count to process is supposed to be between 1 and vc->vc_cols -
vc->state.x (or rows and .y). clamp() can be used exactly for this,
instead of ifs and min().

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@xxxxxxxxxx>
---

Notes:
[v2] new in v2.

drivers/tty/vt/vt.c | 27 +++++----------------------
1 file changed, 5 insertions(+), 22 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index bf77d962eeb4..05baf9ca23f2 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -1574,12 +1574,7 @@ static void csi_K(struct vc_data *vc, int vpar)
/* erase the following vpar positions */
static void csi_X(struct vc_data *vc, unsigned int vpar)
{ /* not vt100? */
- unsigned int count;
-
- if (!vpar)
- vpar++;
-
- count = min(vpar, vc->vc_cols - vc->state.x);
+ unsigned int count = clamp(vpar, 1, vc->vc_cols - vc->state.x);

vc_uniscr_clear_line(vc, vc->state.x, count);
scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
@@ -2010,20 +2005,14 @@ static void setterm_command(struct vc_data *vc)
/* console_lock is held */
static void csi_at(struct vc_data *vc, unsigned int nr)
{
- if (nr > vc->vc_cols - vc->state.x)
- nr = vc->vc_cols - vc->state.x;
- else if (!nr)
- nr = 1;
+ nr = clamp(nr, 1, vc->vc_cols - vc->state.x);
insert_char(vc, nr);
}

/* console_lock is held */
static void csi_L(struct vc_data *vc, unsigned int nr)
{
- if (nr > vc->vc_rows - vc->state.y)
- nr = vc->vc_rows - vc->state.y;
- else if (!nr)
- nr = 1;
+ nr = clamp(nr, 1, vc->vc_rows - vc->state.y);
con_scroll(vc, vc->state.y, vc->vc_bottom, SM_DOWN, nr);
vc->vc_need_wrap = 0;
}
@@ -2031,20 +2020,14 @@ static void csi_L(struct vc_data *vc, unsigned int nr)
/* console_lock is held */
static void csi_P(struct vc_data *vc, unsigned int nr)
{
- if (nr > vc->vc_cols - vc->state.x)
- nr = vc->vc_cols - vc->state.x;
- else if (!nr)
- nr = 1;
+ nr = clamp(nr, 1, vc->vc_cols - vc->state.x);
delete_char(vc, nr);
}

/* console_lock is held */
static void csi_M(struct vc_data *vc, unsigned int nr)
{
- if (nr > vc->vc_rows - vc->state.y)
- nr = vc->vc_rows - vc->state.y;
- else if (!nr)
- nr=1;
+ nr = clamp(nr, 1, vc->vc_rows - vc->state.y);
con_scroll(vc, vc->state.y, vc->vc_bottom, SM_UP, nr);
vc->vc_need_wrap = 0;
}
--
2.43.0