tty/vt: consolemap: extract dict unsharing to con_unshare_unimap()

The code in con_set_unimap() is too nested. Extract its obvious part
into a separate function and name it after what the code does:
con_unshare_unimap().

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220607104946.18710-19-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c
index 733795a3dc68e0b195453d0f4e1198b16e351677..eb5b4b519baf4fa8153aea07807825143b2a7088 100644 (file)
--- a/drivers/tty/vt/consolemap.c
+++ b/drivers/tty/vt/consolemap.c
@@ -562,11 +562,73 @@ int con_clear_unimap(struct vc_data *vc)
        console_unlock();
        return ret;
 }
-       
+
+static struct uni_pagedict *con_unshare_unimap(struct vc_data *vc,
+               struct uni_pagedict *p)
+{
+       struct uni_pagedict *q;
+       u16 **p1, *p2, l;
+       int ret;
+       int i, j, k;
+
+       ret = con_do_clear_unimap(vc);
+       if (ret)
+               return ERR_PTR(ret);
+
+       /*
+        * Since refcount was > 1, con_clear_unimap() allocated a new
+        * uni_pagedict for this vc.  Re: p != q
+        */
+       q = *vc->vc_uni_pagedir_loc;
+
+       /*
+        * uni_pgdir is a 32*32*64 table with rows allocated when its first
+        * entry is added. The unicode value must still be incremented for
+        * empty rows. We are copying entries from "p" (old) to "q" (new).
+        */
+       l = 0;          /* unicode value */
+       for (i = 0; i < UNI_DIRS; i++) {
+               p1 = p->uni_pgdir[i];
+               if (!p1) {
+                       /* Account for empty table */
+                       l += UNI_DIR_ROWS * UNI_ROW_GLYPHS;
+                       continue;
+               }
+
+               for (j = 0; j < UNI_DIR_ROWS; j++) {
+                       p2 = p1[j];
+                       if (!p2) {
+                               /* Account for row of 64 empty entries */
+                               l += UNI_ROW_GLYPHS;
+                               continue;
+                       }
+
+                       for (k = 0; k < UNI_ROW_GLYPHS; k++, l++) {
+                               if (p2[k] == 0xffff)
+                                       continue;
+                               /*
+                                * Found one, copy entry for unicode l with
+                                * fontpos value p2[k].
+                                */
+                               ret = con_insert_unipair(q, l, p2[k]);
+                               if (ret) {
+                                       p->refcount++;
+                                       *vc->vc_uni_pagedir_loc = p;
+                                       con_release_unimap(q);
+                                       kfree(q);
+                                       return ERR_PTR(ret);
+                               }
+                       }
+               }
+       }
+
+       return q;
+}
+
 int con_set_unimap(struct vc_data *vc, ushort ct, struct unipair __user *list)
 {
-       int err = 0, err1, i;
-       struct uni_pagedict *p, *q;
+       int err = 0, err1;
+       struct uni_pagedict *p;
        struct unipair *unilist, *plist;
 
        if (!ct)
@@ -586,70 +648,11 @@ int con_set_unimap(struct vc_data *vc, ushort ct, struct unipair __user *list)
        }
 
        if (p->refcount > 1) {
-               int j, k;
-               u16 **p1, *p2, l;
-
-               err1 = con_do_clear_unimap(vc);
-               if (err1) {
-                       err = err1;
+               p = con_unshare_unimap(vc, p);
+               if (IS_ERR(p)) {
+                       err = PTR_ERR(p);
                        goto out_unlock;
                }
-
-               /*
-                * Since refcount was > 1, con_clear_unimap() allocated a
-                * a new uni_pagedict for this vc.  Re: p != q
-                */
-               q = *vc->vc_uni_pagedir_loc;
-
-               /*
-                * uni_pgdir is a 32*32*64 table with rows allocated
-                * when its first entry is added.  The unicode value must
-                * still be incremented for empty rows.  We are copying
-                * entries from "p" (old) to "q" (new).
-                */
-               l = 0;          /* unicode value */
-               for (i = 0; i < UNI_DIRS; i++) {
-                       p1 = p->uni_pgdir[i];
-                       if (!p1) {
-                               /* Account for empty table */
-                               l += UNI_DIR_ROWS * UNI_ROW_GLYPHS;
-                               continue;
-                       }
-
-                       for (j = 0; j < UNI_DIR_ROWS; j++) {
-                               p2 = p1[j];
-                               if (!p2) {
-                                       /*
-                                        * Account for row of 64 empty entries
-                                        */
-                                       l += UNI_ROW_GLYPHS;
-                                       continue;
-                               }
-
-                               for (k = 0; k < UNI_ROW_GLYPHS; k++, l++) {
-                                       if (p2[k] == 0xffff)
-                                               continue;
-                                       /*
-                                        * Found one, copy entry for unicode
-                                        * l with fontpos value p2[k].
-                                        */
-                                       err1 = con_insert_unipair(q, l, p2[k]);
-                                       if (err1) {
-                                               p->refcount++;
-                                               *vc->vc_uni_pagedir_loc = p;
-                                               con_release_unimap(q);
-                                               kfree(q);
-                                               err = err1;
-                                               goto out_unlock;
-                                       }
-                               }
-                       }
-               }
-
-               /*
-                * Finished copying font table, set vc_uni_pagedir to new table
-                */
-               p = q;
        } else if (p == dflt) {
                dflt = NULL;
        }