diff options
| author | Miguel Ojeda <maxextreme@gmail.com> | 2007-02-21 00:58:00 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-21 04:10:14 +0300 |
| commit | 34173a4aad7a641e72b70f9927ca797746fbce69 (patch) | |
| tree | e09d2fd33dc6e14d4b76210e471c47e8fed7b2a1 /drivers/auxdisplay | |
| parent | e627432c2948d500669a6c4522f22b66f5118d64 (diff) | |
| download | linux-34173a4aad7a641e72b70f9927ca797746fbce69.tar.xz | |
[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')
| -rw-r--r-- | drivers/auxdisplay/cfag12864b.c | 19 | ||||
| -rw-r--r-- | drivers/auxdisplay/cfag12864bfb.c | 10 | ||||
| -rw-r--r-- | drivers/auxdisplay/ks0108.c | 12 |
3 files changed, 40 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: |