diff options
| author | Miguel Ojeda <maxextreme@gmail.com> | 2007-02-20 13:58:00 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-20 17:10:14 -0800 |
| commit | 34173a4aad7a641e72b70f9927ca797746fbce69 (patch) | |
| tree | e09d2fd33dc6e14d4b76210e471c47e8fed7b2a1 /drivers/auxdisplay/cfag12864b.c | |
| parent | e627432c2948d500669a6c4522f22b66f5118d64 (diff) | |
[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>
Diffstat (limited to 'drivers/auxdisplay/cfag12864b.c')
| -rw-r--r-- | drivers/auxdisplay/cfag12864b.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/auxdisplay/cfag12864b.c b/drivers/auxdisplay/cfag12864b.c index 889583dfc1a..cb44cb4f6a4 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: |