| 1 | /* probe.c |
| 2 | * |
| 3 | * Loads a function at a marker call site. |
| 4 | * |
| 5 | * (C) Copyright 2006 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> |
| 6 | * |
| 7 | * This file is released under the GPLv2. |
| 8 | * See the file COPYING for more details. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/marker.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/kallsyms.h> |
| 14 | |
| 15 | /* function to install */ |
| 16 | #define DO_MARK1_FORMAT "%d" |
| 17 | void do_mark1(const char *format, ...) |
| 18 | { |
| 19 | va_list ap; |
| 20 | int value; |
| 21 | |
| 22 | va_start(ap, format); |
| 23 | value = va_arg(ap, int); |
| 24 | printk("value is %d\n", value); |
| 25 | |
| 26 | va_end(ap); |
| 27 | } |
| 28 | |
| 29 | void do_mark2(const char *format, ...) |
| 30 | { |
| 31 | va_list ap; |
| 32 | |
| 33 | va_start(ap, format); |
| 34 | vprintk(format, ap); |
| 35 | va_end(ap); |
| 36 | printk("\n"); |
| 37 | } |
| 38 | |
| 39 | #define DO_MARK3_FORMAT "%d %s %s" |
| 40 | void do_mark3(const char *format, ...) |
| 41 | { |
| 42 | va_list ap; |
| 43 | int value; |
| 44 | const char *s1, *s2; |
| 45 | |
| 46 | va_start(ap, format); |
| 47 | value = va_arg(ap, int); |
| 48 | s1 = va_arg(ap, const char*); |
| 49 | s2 = va_arg(ap, const char *); |
| 50 | |
| 51 | printk("value is %d %s %s\n", |
| 52 | value, s1, s2); |
| 53 | va_end(ap); |
| 54 | } |
| 55 | |
| 56 | int init_module(void) |
| 57 | { |
| 58 | int result; |
| 59 | result = marker_set_probe("subsys_mark1", DO_MARK1_FORMAT, |
| 60 | (marker_probe_func*)do_mark1); |
| 61 | if(!result) goto end; |
| 62 | result = marker_set_probe("subsys_mark2", NULL, |
| 63 | (marker_probe_func*)do_mark2); |
| 64 | if(!result) goto cleanup1; |
| 65 | result = marker_set_probe("subsys_mark3", DO_MARK3_FORMAT, |
| 66 | (marker_probe_func*)do_mark3); |
| 67 | if(!result) goto cleanup2; |
| 68 | |
| 69 | return 0; |
| 70 | |
| 71 | cleanup2: |
| 72 | marker_remove_probe((marker_probe_func*)do_mark2); |
| 73 | cleanup1: |
| 74 | marker_remove_probe((marker_probe_func*)do_mark1); |
| 75 | end: |
| 76 | return -EPERM; |
| 77 | } |
| 78 | |
| 79 | void cleanup_module(void) |
| 80 | { |
| 81 | marker_remove_probe((marker_probe_func*)do_mark1); |
| 82 | marker_remove_probe((marker_probe_func*)do_mark2); |
| 83 | marker_remove_probe((marker_probe_func*)do_mark3); |
| 84 | } |
| 85 | |
| 86 | MODULE_LICENSE("GPL"); |
| 87 | MODULE_AUTHOR("Mathieu Desnoyers"); |
| 88 | MODULE_DESCRIPTION("Probe"); |