I am sorry, I couldn't find answers to the two questions I have asked in the link you have given. Can someone kindly answer the two questions I have asked? I am a newbie in this field, hence I need a little help to get started with this. - Smith. On 12/12/06, Christophe Lucas <clucas@xxxxxxxxxxxxx> wrote:
Smith Norton (smith.norton@xxxxxxxxx) wrote: > I am trying the following kernel module in Ubuntu-6.06 LTS. I am using > the kernel that came along with Ubuntu. > > #include <linux/module.h> > #include <linux/kernel.h> > #include <linux/init.h> > > MODULE_LICENSE("GPL"); > > static int __init helloinit(void) > { > printk(KERN_ALERT, "[helloinit1]\n"); printk(KERN_ALERT "[helloinit1]\n"); => without coma. > printk("[helloinit2]\n"); > return 0; > } > > static void __exit helloexit(void) > { > printk(KERN_ALERT, "[helloexit1]\n"); > printk("[helloexit2]\n"); > } > > module_init(helloinit); > module_exit(helloexit); > > After compiling it with 'make', I 'insmod' it and then 'rmmod' it > twice. The last few lines of /var/log/kern.log are as follows:- > > Dec 11 23:14:40 localhost kernel: [4295711.583000] <1><1>[helloinit2] > Dec 11 23:14:45 localhost kernel: [4298099.296000] [helloexit2] > Dec 11 23:15:22 localhost kernel: [4298136.092000] [helloinit2] > Dec 11 23:15:27 localhost kernel: [4298141.000000] [helloexit2] > > 1. According to LKMPG '[helloinit1]' and '[helloexit1]' should have > been printed. Why weren't they printed. Instead the <1> (KERN_ALERT) > was printed. Here are all the macro defintions in my Ubuntu box:- > > smith@smithbox:~/kernel/exp$ grep "define" > /usr/src/linux-headers-`uname -r`/include/linux/kernel.h | grep > "KERN_" > #define KERN_EMERG "<0>" /* system is unusable */ > #define KERN_ALERT "<1>" /* action must be taken immediately */ > #define KERN_CRIT "<2>" /* critical conditions */ > #define KERN_ERR "<3>" /* error conditions */ > #define KERN_WARNING "<4>" /* warning conditions */ > #define KERN_NOTICE "<5>" /* normal but significant condition */ > #define KERN_INFO "<6>" /* informational */ > #define KERN_DEBUG "<7>" /* debug-level messages */ > > smith@smithbox:~/kernel/exp$ grep "int printk(" > /usr/src/linux-headers-`uname -r`/include/linux/kernel.h > asmlinkage int printk(const char * fmt, ...) > static inline int printk(const char *s, ...) > static inline int printk(const char *s, ...) { return 0; } > > Why aren't '[helloinit1]' and '[helloexit1]' getting printed? > > 2. According to the sequence of statements, the output should have been:- > > <1>[helloinit2] > <1>[helloexit2] > <1>[helloinit2] > <1>[helloexit2] > > But the output instead is:- > > <1><1>[helloinit2] > [helloexit2] > [helloinit2] > [helloexit2] > > Why? See : http://www.xml.com/ldd/chapter/book/ch04.html#t1 Have a nice day, Regards, Christophe
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