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authorMiguel Ojeda <maxextreme@gmail.com>2007-02-20 13:58:00 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-02-20 17:10:14 -0800
commit34173a4aad7a641e72b70f9927ca797746fbce69 (patch)
treee09d2fd33dc6e14d4b76210e471c47e8fed7b2a1
parente627432c2948d500669a6c4522f22b66f5118d64 (diff)
downloadlinux-stericsson-34173a4aad7a641e72b70f9927ca797746fbce69.tar.gz
[PATCH] cfag12864b: fix crash when built-in and no parport present
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@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/auxdisplay/cfag12864b.c19
-rw-r--r--drivers/auxdisplay/cfag12864bfb.c10
-rw-r--r--drivers/auxdisplay/ks0108.c12
-rw-r--r--include/linux/cfag12864b.h5
-rw-r--r--include/linux/ks0108.h3
5 files changed, 48 insertions, 1 deletions
diff --git a/drivers/auxdisplay/cfag12864b.c b/drivers/auxdisplay/cfag12864b.c
index 889583dfc1a6..cb44cb4f6a47 100644
--- a/drivers/auxdisplay/cfag12864b.c
+++ b/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 --git a/drivers/auxdisplay/cfag12864bfb.c b/drivers/auxdisplay/cfag12864bfb.c
index 94765e78315f..66fafbb1d087 100644
--- a/drivers/auxdisplay/cfag12864bfb.c
+++ b/drivers/auxdisplay/cfag12864bfb.c
@@ -137,7 +137,14 @@ static struct platform_device *cfag12864bfb_device;
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 --git a/drivers/auxdisplay/ks0108.c b/drivers/auxdisplay/ks0108.c
index a637575b9106..e6c3646ef18c 100644
--- a/drivers/auxdisplay/ks0108.c
+++ b/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 --git a/include/linux/cfag12864b.h b/include/linux/cfag12864b.h
index 0bc45e69da5a..1605dd8aa646 100644
--- a/include/linux/cfag12864b.h
+++ b/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 --git a/include/linux/ks0108.h b/include/linux/ks0108.h
index 8047d4b17bf1..a2c54acceb4e 100644
--- a/include/linux/ks0108.h
+++ b/include/linux/ks0108.h
@@ -43,4 +43,7 @@ extern void ks0108_address(unsigned char address);
/* 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_ */