vbatts/mod_hello
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a bit of reorg and showing the jiffies around fib

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Vincent Batts 2014-09-18 11:48:25 -04:00
parent b090072939
commit bf92567e5f
1 changed files with 28 additions and 21 deletions
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49
mod_hello.c
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@ -2,22 +2,19 @@
#include <linux/init.h> /* provides initialization routines */ #include <linux/init.h> /* provides initialization routines */
#include <linux/kallsyms.h> #include <linux/kallsyms.h>
#include <linux/string.h>
static char __initdata hello_hellomsg[] = KERN_NOTICE "Hello, Kernel, I'm in\n"; MODULE_LICENSE("GPL");
static char __exitdata hello_byemsg[] = KERN_NOTICE "Bye, I'm out\n"; MODULE_AUTHOR("Vincent Batts <vbatts@hashbangbash.com>");
MODULE_DESCRIPTION("just getting familiar");
MODULE_VERSION("1.0");
//static char __initdata hello_hellomsg[] = KERN_NOTICE "Hello, Kernel, I'm in\n";
//static char __exitdata hello_byemsg[] = KERN_NOTICE "Bye, I'm out\n";
static int hello_print_hello(void) static int hello_print_hello(void)
{ {
unsigned long i; printk(KERN_INFO "[%s] module loaded.\n", __this_module.name);
char *symbol_name;
printk(hello_hellomsg);
symbol_name = "free_pages";
printk("looking up '%s'\n", symbol_name);
i = kallsyms_lookup_name(symbol_name);
printk("%s 0x%lx\n", symbol_name, i);
return 0; return 0;
} }
@ -39,32 +36,42 @@ long hello_fib(long times, long n1, long n2)
return next; return next;
} }
static int __init start_hello_world(void) static int __init hello_init(void)
{ {
long f_int, f_cap, f_start1, f_start2; long f_int, f_cap, f_start1, f_start2;
unsigned long sym_addr;
char *sym_name;
char filename[255];
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Vincent Batts <vbatts@hashbangbash.com>");
MODULE_DESCRIPTION("just getting familiar");
MODULE_VERSION("1.0");
hello_print_hello(); hello_print_hello();
sym_name = "files";
printk("looking up '%s'\n", sym_name);
sym_addr = kallsyms_lookup_name(sym_name);
printk("%s 0x%lx\n", sym_name, sym_addr);
strncpy(filename, (char *)sym_addr, 255);
printk(KERN_INFO "[%s] %s (0x%lx): %s\n", __this_module.name, sym_name, sym_addr, filename);
printk("[%s] jiffies: %lu\n", __this_module.name, jiffies);
f_cap = 10000000; f_cap = 10000000;
f_start1 = 0; f_start1 = 0;
f_start2 = 1; f_start2 = 1;
f_int = hello_fib(f_cap, f_start1, f_start2); f_int = hello_fib(f_cap, f_start1, f_start2);
printk("fib of %ld and %ld (up to %ld): %ld\n", f_start1, f_start2, f_cap, f_int); printk("fib of %ld and %ld (up to %ld): %ld\n", f_start1, f_start2, f_cap, f_int);
printk("[%s] jiffies: %lu\n", __this_module.name, jiffies);
return 0; return 0;
} }
static void __exit hello_go_away(void) static void __exit hello_cleanup(void)
{ {
printk(hello_byemsg); printk(KERN_INFO "[%s] module unloaded.\n", __this_module.name);
} }
module_init(start_hello_world); module_init(hello_init);
module_exit(hello_go_away); module_exit(hello_cleanup);
// vim:set shiftwidth=4 softtabstop=4 expandtab: // vim:set shiftwidth=4 softtabstop=4 expandtab: