[PATCH 05/45] tty: vt: pass proper pointers from tioclinux()

Jiri Slaby (SUSE)
2024-01-18T07:58:12Z

Pass proper types and proper pointers (the data with an offset) to the
TIOCL_* handlers. So that they need not to cast or add anything to the
passed pointer.

This makes obvious what is passed/consumed.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
---
drivers/tty/vt/selection.c | 8 ++++----
drivers/tty/vt/vt.c | 19 ++++++++++---------
include/linux/selection.h | 2 +-
3 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
index 8967c3a0d916..e172ede235a0 100644
--- a/drivers/tty/vt/selection.c
+++ b/drivers/tty/vt/selection.c
@@ -7,7 +7,7 @@
* 'int set_selection_kernel(struct tiocl_selection *, struct tty_struct *)'
* 'void clear_selection(void)'
* 'int paste_selection(struct tty_struct *)'
- * 'int sel_loadlut(char __user *)'
+ * 'int sel_loadlut(u32 __user *)'
*
* Now that /dev/vcs exists, most of this can disappear again.
*/
@@ -111,15 +111,15 @@ static inline int inword(const u32 c)

/**
* sel_loadlut() - load the LUT table
- * @p: user table
+ * @lut: user table
*
* Load the LUT table from user space. The caller must hold the console
* lock. Make a temporary copy so a partial update doesn't make a mess.
*/
-int sel_loadlut(char __user *p)
+int sel_loadlut(u32 __user *lut)
{
u32 tmplut[ARRAY_SIZE(inwordLut)];
- if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut)))
+ if (copy_from_user(tmplut, lut, sizeof(inwordLut)))
return -EFAULT;
memcpy(inwordLut, tmplut, sizeof(inwordLut));
return 0;
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index e131edea00da..079dbff562fd 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -145,7 +145,7 @@ static void gotoxy(struct vc_data *vc, int new_x, int new_y);
static void save_cur(struct vc_data *vc);
static void reset_terminal(struct vc_data *vc, int do_clear);
static void con_flush_chars(struct tty_struct *tty);
-static int set_vesa_blanking(char __user *p);
+static int set_vesa_blanking(u8 __user *mode);
static void set_cursor(struct vc_data *vc);
static void hide_cursor(struct vc_data *vc);
static void console_callback(struct work_struct *ignored);
@@ -3134,6 +3134,8 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
{
char type, data;
char __user *p = (char __user *)arg;
+ void __user *param_aligned32 = (u32 __user *)arg + 1;
+ void __user *param = (void __user *)arg + 1;
int lines;
int ret;

@@ -3147,8 +3149,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
case TIOCL_SETSEL:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- return set_selection_user((struct tiocl_selection
- __user *)(p+1), tty);
+ return set_selection_user(param, tty);
case TIOCL_PASTESEL:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
@@ -3162,7 +3163,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
console_lock();
- ret = sel_loadlut(p);
+ ret = sel_loadlut(param_aligned32);
console_unlock();
break;
case TIOCL_GETSHIFTSTATE:
@@ -3181,7 +3182,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
return put_user(data, p);
case TIOCL_SETVESABLANK:
console_lock();
- ret = set_vesa_blanking(p);
+ ret = set_vesa_blanking(param);
console_unlock();
break;
case TIOCL_GETKMSGREDIRECT:
@@ -3204,7 +3205,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
*/
return fg_console;
case TIOCL_SCROLLCONSOLE:
- if (get_user(lines, (s32 __user *)(p+4)))
+ if (get_user(lines, (s32 __user *)param_aligned32))
return -EFAULT;

/*
@@ -4262,11 +4263,11 @@ postcore_initcall(vtconsole_class_init);
* Screen blanking
*/

-static int set_vesa_blanking(char __user *p)
+static int set_vesa_blanking(u8 __user *mode_user)
{
- unsigned int mode;
+ u8 mode;

- if (get_user(mode, p + 1))
+ if (get_user(mode, mode_user))
return -EFAULT;

vesa_blank_mode = (mode < 4) ? mode : 0;
diff --git a/include/linux/selection.h b/include/linux/selection.h
index 170ef28ff26b..b7cd23e56a2b 100644
--- a/include/linux/selection.h
+++ b/include/linux/selection.h
@@ -20,7 +20,7 @@ extern int set_selection_user(const struct tiocl_selection __user *sel,
extern int set_selection_kernel(struct tiocl_selection *v,
struct tty_struct *tty);
extern int paste_selection(struct tty_struct *tty);
-extern int sel_loadlut(char __user *p);
+extern int sel_loadlut(u32 __user *lut);
extern int mouse_reporting(void);
extern void mouse_report(struct tty_struct * tty, int butt, int mrx, int mry);

--
2.43.0