From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: + cfag12864b-fix-crash-when-built-in-and-no-parport.patch added to -mm tree Date: Mon, 12 Feb 2007 22:39:17 -0800 Message-ID: <200702130639.l1D6dHfO024095@shell0.pdx.osdl.net> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from smtp.osdl.org ([65.172.181.24]:56455 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030651AbXBMGjT (ORCPT ); Tue, 13 Feb 2007 01:39:19 -0500 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: mm-commits@vger.kernel.org Cc: maxextreme@gmail.com The patch titled cfag12864b: fix crash when built-in and no parport present has been added to the -mm tree. Its filename is cfag12864b-fix-crash-when-built-in-and-no-parport.patch *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this ------------------------------------------------------ Subject: cfag12864b: fix crash when built-in and no parport present From: Miguel Ojeda 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 Signed-off-by: Andrew Morton --- 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@gmail.com are origin.patch cfag12864b-fix-crash-when-built-in-and-no-parport.patch