5940dd9faa
For the example module hello_5, the book showed the incorrect output
in corresponding with its execution results.
In addition, this patch changes from myintArray[2] = {-1, -1} to
myintArray[2] = {420, 420}, which help the readers distinguish from
the kernel messages.
70 lines
2.1 KiB
C
70 lines
2.1 KiB
C
/*
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* hello-5.c - Demonstrates command line argument passing to a module.
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*/
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/stat.h>
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MODULE_LICENSE("GPL");
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static short int myshort = 1;
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static int myint = 420;
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static long int mylong = 9999;
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static char *mystring = "blah";
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static int myintArray[2] = {420, 420};
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static int arr_argc = 0;
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/*
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* module_param(foo, int, 0000)
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* The first param is the parameters name
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* The second param is it's data type
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* The final argument is the permissions bits,
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* for exposing parameters in sysfs (if non-zero) at a later stage.
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*/
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module_param(myshort, short, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
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MODULE_PARM_DESC(myshort, "A short integer");
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module_param(myint, int, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
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MODULE_PARM_DESC(myint, "An integer");
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module_param(mylong, long, S_IRUSR);
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MODULE_PARM_DESC(mylong, "A long integer");
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module_param(mystring, charp, 0000);
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MODULE_PARM_DESC(mystring, "A character string");
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/*
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* module_param_array(name, type, num, perm);
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* The first param is the parameter's (in this case the array's) name
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* The second param is the data type of the elements of the array
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* The third argument is a pointer to the variable that will store the number
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* of elements of the array initialized by the user at module loading time
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* The fourth argument is the permission bits
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*/
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module_param_array(myintArray, int, &arr_argc, 0000);
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MODULE_PARM_DESC(myintArray, "An array of integers");
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static int __init hello_5_init(void)
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{
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int i;
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pr_info("Hello, world 5\n=============\n");
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pr_info("myshort is a short integer: %hd\n", myshort);
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pr_info("myint is an integer: %d\n", myint);
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pr_info("mylong is a long integer: %ld\n", mylong);
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pr_info("mystring is a string: %s\n", mystring);
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for (i = 0; i < (sizeof myintArray / sizeof(int)); i++)
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pr_info("myintArray[%d] = %d\n", i, myintArray[i]);
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pr_info("got %d arguments for myintArray.\n", arr_argc);
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return 0;
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}
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static void __exit hello_5_exit(void)
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{
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pr_info("Goodbye, world 5\n");
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}
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module_init(hello_5_init);
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module_exit(hello_5_exit);
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