[PATCH 19/36] tty/vt: consolemap: extract dict unsharing to con_unshare_unimap()

Jiri Slaby
2022-06-07T10:51:49Z

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().

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/tty/vt/consolemap.c | 133 ++++++++++++++++++------------------
1 file changed, 68 insertions(+), 65 deletions(-)

diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c
index 733795a3dc68..eb5b4b519baf 100644
--- 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;
}
--
2.36.1