vt: selection, create struct from console selection globals

Move all the selection global variables to a structure vc_selection,
instantiated as vc_sel. This helps to group all the variables together
and see what should be protected by the embedded lock too.

It might be used later also for per-console selection support.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200219073951.16151-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
index 33f9429..0cd7072 100644 (file)
--- a/drivers/tty/vt/selection.c
+++ b/drivers/tty/vt/selection.c
@@ -38,14 +38,17 @@
 extern void poke_blanked_console(void);
 
 /* FIXME: all this needs locking */
-/* Variables for selection control. */
-/* Use a dynamic buffer, instead of static (Dec 1994) */
-struct vc_data *sel_cons;              /* must not be deallocated */
-static volatile int sel_start = -1;    /* cleared by clear_selection */
-static int sel_end;
-static int sel_buffer_lth;
-static char *sel_buffer;
-static DEFINE_MUTEX(sel_lock);
+static struct vc_selection {
+       struct mutex lock;
+       struct vc_data *cons;                   /* must not be deallocated */
+       char *buffer;
+       unsigned int buf_len;
+       volatile int start;                     /* cleared by clear_selection */
+       int end;
+} vc_sel = {
+       .lock = __MUTEX_INITIALIZER(vc_sel.lock),
+       .start = -1,
+};
 
 /* clear_selection, highlight and highlight_pointer can be called
    from interrupt (via scrollback/front) */
@@ -53,22 +56,21 @@ static DEFINE_MUTEX(sel_lock);
 /* set reverse video on characters s-e of console with selection. */
 static inline void highlight(const int s, const int e)
 {
-       invert_screen(sel_cons, s, e-s+2, 1);
+       invert_screen(vc_sel.cons, s, e-s+2, 1);
 }
 
 /* use complementary color to show the pointer */
 static inline void highlight_pointer(const int where)
 {
-       complement_pos(sel_cons, where);
+       complement_pos(vc_sel.cons, where);
 }
 
 static u32
 sel_pos(int n, bool unicode)
 {
        if (unicode)
-               return screen_glyph_unicode(sel_cons, n / 2);
-       return inverse_translate(sel_cons, screen_glyph(sel_cons, n),
-                               0);
+               return screen_glyph_unicode(vc_sel.cons, n / 2);
+       return inverse_translate(vc_sel.cons, screen_glyph(vc_sel.cons, n), 0);
 }
 
 /**
@@ -80,16 +82,16 @@ sel_pos(int n, bool unicode)
 void clear_selection(void)
 {
        highlight_pointer(-1); /* hide the pointer */
-       if (sel_start != -1) {
-               highlight(sel_start, sel_end);
-               sel_start = -1;
+       if (vc_sel.start != -1) {
+               highlight(vc_sel.start, vc_sel.end);
+               vc_sel.start = -1;
        }
 }
 EXPORT_SYMBOL_GPL(clear_selection);
 
 bool vc_is_sel(struct vc_data *vc)
 {
-       return vc == sel_cons;
+       return vc == vc_sel.cons;
 }
 
 /*
@@ -216,13 +218,13 @@ int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty)
                return 0;
        }
 
-       if (ps > pe)    /* make sel_start <= sel_end */
+       if (ps > pe)    /* make vc_sel.start <= vc_sel.end */
                swap(ps, pe);
 
-       mutex_lock(&sel_lock);
-       if (sel_cons != vc_cons[fg_console].d) {
+       mutex_lock(&vc_sel.lock);
+       if (vc_sel.cons != vc_cons[fg_console].d) {
                clear_selection();
-               sel_cons = vc_cons[fg_console].d;
+               vc_sel.cons = vc_cons[fg_console].d;
        }
        unicode = vt_do_kdgkbmode(fg_console) == K_UNICODE;
 
@@ -281,35 +283,35 @@ int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty)
                if (isspace(sel_pos(pe, unicode)))
                        new_sel_end = pe;
        }
-       if (sel_start == -1)    /* no current selection */
+       if (vc_sel.start == -1) /* no current selection */
                highlight(new_sel_start, new_sel_end);
-       else if (new_sel_start == sel_start)
+       else if (new_sel_start == vc_sel.start)
        {
-               if (new_sel_end == sel_end)     /* no action required */
+               if (new_sel_end == vc_sel.end)  /* no action required */
                        goto unlock;
-               else if (new_sel_end > sel_end) /* extend to right */
-                       highlight(sel_end + 2, new_sel_end);
+               else if (new_sel_end > vc_sel.end)      /* extend to right */
+                       highlight(vc_sel.end + 2, new_sel_end);
                else                            /* contract from right */
-                       highlight(new_sel_end + 2, sel_end);
+                       highlight(new_sel_end + 2, vc_sel.end);
        }
-       else if (new_sel_end == sel_end)
+       else if (new_sel_end == vc_sel.end)
        {
-               if (new_sel_start < sel_start)  /* extend to left */
-                       highlight(new_sel_start, sel_start - 2);
+               if (new_sel_start < vc_sel.start) /* extend to left */
+                       highlight(new_sel_start, vc_sel.start - 2);
                else                            /* contract from left */
-                       highlight(sel_start, new_sel_start - 2);
+                       highlight(vc_sel.start, new_sel_start - 2);
        }
        else    /* some other case; start selection from scratch */
        {
                clear_selection();
                highlight(new_sel_start, new_sel_end);
        }
-       sel_start = new_sel_start;
-       sel_end = new_sel_end;
+       vc_sel.start = new_sel_start;
+       vc_sel.end = new_sel_end;
 
        /* Allocate a new buffer before freeing the old one ... */
        /* chars can take up to 4 bytes with unicode */
-       bp = kmalloc_array((sel_end - sel_start) / 2 + 1, unicode ? 4 : 1,
+       bp = kmalloc_array((vc_sel.end - vc_sel.start) / 2 + 1, unicode ? 4 : 1,
                           GFP_KERNEL);
        if (!bp) {
                printk(KERN_WARNING "selection: kmalloc() failed\n");
@@ -317,11 +319,11 @@ int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty)
                ret = -ENOMEM;
                goto unlock;
        }
-       kfree(sel_buffer);
-       sel_buffer = bp;
+       kfree(vc_sel.buffer);
+       vc_sel.buffer = bp;
 
        obp = bp;
-       for (i = sel_start; i <= sel_end; i += 2) {
+       for (i = vc_sel.start; i <= vc_sel.end; i += 2) {
                c = sel_pos(i, unicode);
                if (unicode)
                        bp += store_utf8(c, bp);
@@ -339,9 +341,9 @@ int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty)
                        obp = bp;
                }
        }
-       sel_buffer_lth = bp - sel_buffer;
+       vc_sel.buf_len = bp - vc_sel.buffer;
 unlock:
-       mutex_unlock(&sel_lock);
+       mutex_unlock(&vc_sel.lock);
        return ret;
 }
 EXPORT_SYMBOL_GPL(set_selection_kernel);
@@ -372,26 +374,26 @@ int paste_selection(struct tty_struct *tty)
        tty_buffer_lock_exclusive(&vc->port);
 
        add_wait_queue(&vc->paste_wait, &wait);
-       mutex_lock(&sel_lock);
-       while (sel_buffer && sel_buffer_lth > pasted) {
+       mutex_lock(&vc_sel.lock);
+       while (vc_sel.buffer && vc_sel.buf_len > pasted) {
                set_current_state(TASK_INTERRUPTIBLE);
                if (signal_pending(current)) {
                        ret = -EINTR;
                        break;
                }
                if (tty_throttled(tty)) {
-                       mutex_unlock(&sel_lock);
+                       mutex_unlock(&vc_sel.lock);
                        schedule();
-                       mutex_lock(&sel_lock);
+                       mutex_lock(&vc_sel.lock);
                        continue;
                }
                __set_current_state(TASK_RUNNING);
-               count = sel_buffer_lth - pasted;
-               count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL,
+               count = vc_sel.buf_len - pasted;
+               count = tty_ldisc_receive_buf(ld, vc_sel.buffer + pasted, NULL,
                                              count);
                pasted += count;
        }
-       mutex_unlock(&sel_lock);
+       mutex_unlock(&vc_sel.lock);
        remove_wait_queue(&vc->paste_wait, &wait);
        __set_current_state(TASK_RUNNING);