[PATCH v2 1/2] vt: selection: allow functions to be called from inside kernel
Okash Khawaja
okash.khawaja at gmail.com
Wed Apr 17 08:21:13 EDT 2019
This patch breaks set_selection() into two functions so that when
called from kernel, copy_from_user() can be avoided. The two functions
are called set_selection_user() and set_selection_kernel() in order to
be explicit about their purposes. This also means updating any
references to set_selection() and fixing for name change. It also
exports set_selection_kernel() and paste_selection().
These changes are used the following patch where speakup's selection
functionality calls into the above functions, thereby doing away with
parallel implementation.
Signed-off-by: Okash Khawaja <okash.khawaja at gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault at ens-lyon.org>
Tested-by: Gregory Nowak <greg at gregn.net>
---
drivers/tty/vt/selection.c | 46 ++++++++++++++++++++++++++++++----------------
drivers/tty/vt/vt.c | 7 ++++---
include/linux/selection.h | 7 ++++---
3 files changed, 38 insertions(+), 22 deletions(-)
diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
index 07496c7..78732fe 100644
--- a/drivers/tty/vt/selection.c
+++ b/drivers/tty/vt/selection.c
@@ -2,7 +2,9 @@
/*
* This module exports the functions:
*
- * 'int set_selection(struct tiocl_selection __user *, struct tty_struct *)'
+ * 'int set_selection_user(struct tiocl_selection __user *,
+ * struct tty_struct *)'
+ * '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 *)'
@@ -80,6 +82,7 @@ void clear_selection(void)
sel_start = -1;
}
}
+EXPORT_SYMBOL_GPL(clear_selection);
/*
* User settable table: what characters are to be considered alphabetic?
@@ -154,7 +157,7 @@ static int store_utf8(u32 c, char *p)
}
/**
- * set_selection - set the current selection.
+ * set_selection_user - set the current selection.
* @sel: user selection info
* @tty: the console tty
*
@@ -163,35 +166,44 @@ static int store_utf8(u32 c, char *p)
* The entire selection process is managed under the console_lock. It's
* a lot under the lock but its hardly a performance path
*/
-int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
+int set_selection_user(const struct tiocl_selection __user *sel,
+ struct tty_struct *tty)
+{
+ struct tiocl_selection v;
+
+ if (copy_from_user(&v, sel, sizeof(*sel)))
+ return -EFAULT;
+
+ return set_selection_kernel(&v, tty);
+}
+
+int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty)
{
struct vc_data *vc = vc_cons[fg_console].d;
int new_sel_start, new_sel_end, spc;
- struct tiocl_selection v;
char *bp, *obp;
int i, ps, pe, multiplier;
u32 c;
int mode;
poke_blanked_console();
- if (copy_from_user(&v, sel, sizeof(*sel)))
- return -EFAULT;
- v.xs = min_t(u16, v.xs - 1, vc->vc_cols - 1);
- v.ys = min_t(u16, v.ys - 1, vc->vc_rows - 1);
- v.xe = min_t(u16, v.xe - 1, vc->vc_cols - 1);
- v.ye = min_t(u16, v.ye - 1, vc->vc_rows - 1);
- ps = v.ys * vc->vc_size_row + (v.xs << 1);
- pe = v.ye * vc->vc_size_row + (v.xe << 1);
+ v->xs = min_t(u16, v->xs - 1, vc->vc_cols - 1);
+ v->ys = min_t(u16, v->ys - 1, vc->vc_rows - 1);
+ v->xe = min_t(u16, v->xe - 1, vc->vc_cols - 1);
+ v->ye = min_t(u16, v->ye - 1, vc->vc_rows - 1);
+ ps = v->ys * vc->vc_size_row + (v->xs << 1);
+ pe = v->ye * vc->vc_size_row + (v->xe << 1);
- if (v.sel_mode == TIOCL_SELCLEAR) {
+ if (v->sel_mode == TIOCL_SELCLEAR) {
/* useful for screendump without selection highlights */
clear_selection();
return 0;
}
- if (mouse_reporting() && (v.sel_mode & TIOCL_SELMOUSEREPORT)) {
- mouse_report(tty, v.sel_mode & TIOCL_SELBUTTONMASK, v.xs, v.ys);
+ if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) {
+ mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs,
+ v->ys);
return 0;
}
@@ -208,7 +220,7 @@ int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *t
else
use_unicode = 0;
- switch (v.sel_mode)
+ switch (v->sel_mode)
{
case TIOCL_SELCHAR: /* character-by-character selection */
new_sel_start = ps;
@@ -322,6 +334,7 @@ int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *t
sel_buffer_lth = bp - sel_buffer;
return 0;
}
+EXPORT_SYMBOL_GPL(set_selection_kernel);
/* Insert the contents of the selection buffer into the
* queue of the tty associated with the current console.
@@ -367,3 +380,4 @@ int paste_selection(struct tty_struct *tty)
tty_ldisc_deref(ld);
return 0;
}
+EXPORT_SYMBOL_GPL(paste_selection);
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index d34984a..f3c369a 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -1804,7 +1804,7 @@ void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
respond_string(buf, tty->port);
}
-/* invoked via ioctl(TIOCLINUX) and through set_selection */
+/* invoked via ioctl(TIOCLINUX) and through set_selection_user */
int mouse_reporting(void)
{
return vc_cons[fg_console].d->vc_report_mouse;
@@ -3008,7 +3008,7 @@ static struct tty_driver *vt_console_device(struct console *c, int *index)
* There are some functions which can sleep for arbitrary periods
* (paste_selection) but we don't need the lock there anyway.
*
- * set_selection has locking, and definitely needs it
+ * set_selection_user has locking, and definitely needs it
*/
int tioclinux(struct tty_struct *tty, unsigned long arg)
@@ -3028,7 +3028,8 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
{
case TIOCL_SETSEL:
console_lock();
- ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
+ ret = set_selection_user((struct tiocl_selection
+ __user *)(p+1), tty);
console_unlock();
break;
case TIOCL_PASTESEL:
diff --git a/include/linux/selection.h b/include/linux/selection.h
index a8f5b97..e2c1f96 100644
--- a/include/linux/selection.h
+++ b/include/linux/selection.h
@@ -11,13 +11,14 @@
#include <linux/tiocl.h>
#include <linux/vt_buffer.h>
-struct tty_struct;
-
extern struct vc_data *sel_cons;
struct tty_struct;
extern void clear_selection(void);
-extern int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty);
+extern int set_selection_user(const struct tiocl_selection __user *sel,
+ struct tty_struct *tty);
+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 mouse_reporting(void);
--
1.8.3.1
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