The patch titled
cfag12864b: fix crash when built-in and no parport present
has been removed from the -mm tree. Its filename was
cfag12864b-fix-crash-when-built-in-and-no-parport.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: cfag12864b: fix crash when built-in and no parport present
From: Miguel Ojeda <maxextreme@xxxxxxxxx>
The problem comes when ks0108/cfag12864b are built-in and no parallel port is
present. ks0108_init() is called first, as it should be, but fails to load
(as there is no parallel port to use).
After that, cfag12864b_init() gets called, without knowing anything about
ks0108 failed, and calls ks0108_writecontrol(), which dereferences an
uninitialized pointer.
Init order is OK, I think. The problem is how to stop cfag12864b_init() being
called if ks0108 failed to load. modprobe does it for us, but, how when
built-in?
Signed-off-by: Miguel Ojeda Sandonis <maxextreme@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/auxdisplay/cfag12864b.c | 19 +++++++++++++++++++
drivers/auxdisplay/cfag12864bfb.c | 10 +++++++++-
drivers/auxdisplay/ks0108.c | 12 ++++++++++++
include/linux/cfag12864b.h | 5 +++++
include/linux/ks0108.h | 3 +++
5 files changed, 48 insertions(+), 1 deletion(-)
diff -puN drivers/auxdisplay/cfag12864b.c~cfag12864b-fix-crash-when-built-in-and-no-parport drivers/auxdisplay/cfag12864b.c
--- a/drivers/auxdisplay/cfag12864b.c~cfag12864b-fix-crash-when-built-in-and-no-parport
+++ a/drivers/auxdisplay/cfag12864b.c
@@ -312,6 +312,17 @@ EXPORT_SYMBOL_GPL(cfag12864b_disable);
EXPORT_SYMBOL_GPL(cfag12864b_isenabled);
/*
+ * Is the module inited?
+ */
+
+static unsigned char cfag12864b_inited;
+unsigned char cfag12864b_isinited(void)
+{
+ return cfag12864b_inited;
+}
+EXPORT_SYMBOL_GPL(cfag12864b_isinited);
+
+/*
* Module Init & Exit
*/
@@ -319,6 +330,13 @@ static int __init cfag12864b_init(void)
{
int ret = -EINVAL;
+ /* ks0108_init() must be called first */
+ if (!ks0108_isinited()) {
+ printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
+ "ks0108 is not initialized\n");
+ goto none;
+ }
+
if (PAGE_SIZE < CFAG12864B_SIZE) {
printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
"page size (%i) < cfag12864b size (%i)\n",
@@ -354,6 +372,7 @@ static int __init cfag12864b_init(void)
cfag12864b_clear();
cfag12864b_on();
+ cfag12864b_inited = 1;
return 0;
cachealloced:
diff -puN drivers/auxdisplay/cfag12864bfb.c~cfag12864b-fix-crash-when-built-in-and-no-parport drivers/auxdisplay/cfag12864bfb.c
--- a/drivers/auxdisplay/cfag12864bfb.c~cfag12864b-fix-crash-when-built-in-and-no-parport
+++ a/drivers/auxdisplay/cfag12864bfb.c
@@ -137,7 +137,14 @@ static struct platform_device *cfag12864
static int __init cfag12864bfb_init(void)
{
- int ret;
+ int ret = -EINVAL;
+
+ /* cfag12864b_init() must be called first */
+ if (!cfag12864b_isinited()) {
+ printk(KERN_ERR CFAG12864BFB_NAME ": ERROR: "
+ "cfag12864b is not initialized\n");
+ goto none;
+ }
if (cfag12864b_enable()) {
printk(KERN_ERR CFAG12864BFB_NAME ": ERROR: "
@@ -162,6 +169,7 @@ static int __init cfag12864bfb_init(void
}
}
+none:
return ret;
}
diff -puN drivers/auxdisplay/ks0108.c~cfag12864b-fix-crash-when-built-in-and-no-parport drivers/auxdisplay/ks0108.c
--- a/drivers/auxdisplay/ks0108.c~cfag12864b-fix-crash-when-built-in-and-no-parport
+++ a/drivers/auxdisplay/ks0108.c
@@ -111,6 +111,17 @@ EXPORT_SYMBOL_GPL(ks0108_address);
EXPORT_SYMBOL_GPL(ks0108_page);
/*
+ * Is the module inited?
+ */
+
+static unsigned char ks0108_inited;
+unsigned char ks0108_isinited(void)
+{
+ return ks0108_inited;
+}
+EXPORT_SYMBOL_GPL(ks0108_isinited);
+
+/*
* Module Init & Exit
*/
@@ -142,6 +153,7 @@ static int __init ks0108_init(void)
goto registered;
}
+ ks0108_inited = 1;
return 0;
registered:
diff -puN include/linux/cfag12864b.h~cfag12864b-fix-crash-when-built-in-and-no-parport include/linux/cfag12864b.h
--- a/include/linux/cfag12864b.h~cfag12864b-fix-crash-when-built-in-and-no-parport
+++ a/include/linux/cfag12864b.h
@@ -73,5 +73,10 @@ extern void cfag12864b_disable(void);
*/
extern unsigned char cfag12864b_isenabled(void);
+/*
+ * Is the module inited?
+ */
+extern unsigned char cfag12864b_isinited(void);
+
#endif /* _CFAG12864B_H_ */
diff -puN include/linux/ks0108.h~cfag12864b-fix-crash-when-built-in-and-no-parport include/linux/ks0108.h
--- a/include/linux/ks0108.h~cfag12864b-fix-crash-when-built-in-and-no-parport
+++ a/include/linux/ks0108.h
@@ -43,4 +43,7 @@ extern void ks0108_address(unsigned char
/* Set the controller's current page (0..7) */
extern void ks0108_page(unsigned char page);
+/* Is the module inited? */
+extern unsigned char ks0108_isinited(void);
+
#endif /* _KS0108_H_ */
_
Patches currently in -mm which might be from maxextreme@xxxxxxxxx are
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
