[PATCH 1/6] vt: sort out locking for font handling

From: Alan Cox
Date: Fri Mar 02 2012 - 09:44:50 EST


From: Alan Cox <alan@xxxxxxxxxxxxxxx>

The font methods are console_lock covered. Unfortunately they don't extend
the lock over all the needed tests.

Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
---

drivers/tty/vt/vt.c | 23 +++++++++++++----------
1 files changed, 13 insertions(+), 10 deletions(-)


diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 8205578..8439303 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -3972,9 +3972,6 @@ static int con_font_get(struct vc_data *vc, struct console_font_op *op)
int rc = -EINVAL;
int c;

- if (vc->vc_mode != KD_TEXT)
- return -EINVAL;
-
if (op->data) {
font.data = kmalloc(max_font_size, GFP_KERNEL);
if (!font.data)
@@ -3983,7 +3980,9 @@ static int con_font_get(struct vc_data *vc, struct console_font_op *op)
font.data = NULL;

console_lock();
- if (vc->vc_sw->con_font_get)
+ if (vc->vc_mode != KD_TEXT)
+ rc = -EINVAL;
+ else if (vc->vc_sw->con_font_get)
rc = vc->vc_sw->con_font_get(vc, &font);
else
rc = -ENOSYS;
@@ -4065,7 +4064,9 @@ static int con_font_set(struct vc_data *vc, struct console_font_op *op)
if (IS_ERR(font.data))
return PTR_ERR(font.data);
console_lock();
- if (vc->vc_sw->con_font_set)
+ if (vc->vc_mode != KD_TEXT)
+ rc = -EINVAL;
+ else if (vc->vc_sw->con_font_set)
rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
else
rc = -ENOSYS;
@@ -4081,8 +4082,6 @@ static int con_font_default(struct vc_data *vc, struct console_font_op *op)
char *s = name;
int rc;

- if (vc->vc_mode != KD_TEXT)
- return -EINVAL;

if (!op->data)
s = NULL;
@@ -4092,6 +4091,10 @@ static int con_font_default(struct vc_data *vc, struct console_font_op *op)
name[MAX_FONT_NAME - 1] = 0;

console_lock();
+ if (vc->vc_mode != KD_TEXT) {
+ console_unlock();
+ return -EINVAL;
+ }
if (vc->vc_sw->con_font_default)
rc = vc->vc_sw->con_font_default(vc, &font, s);
else
@@ -4109,11 +4112,11 @@ static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
int con = op->height;
int rc;

- if (vc->vc_mode != KD_TEXT)
- return -EINVAL;

console_lock();
- if (!vc->vc_sw->con_font_copy)
+ if (vc->vc_mode != KD_TEXT)
+ rc = -EINVAL;
+ else if (!vc->vc_sw->con_font_copy)
rc = -ENOSYS;
else if (con < 0 || !vc_cons_allocated(con))
rc = -ENOTTY;

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