531d297569
Need a marker_synchronize_unregister() before the end of exit() to make sure every probe callers have exited the non preemptible section and thus are not executing the probe code anymore. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Ingo Molnar <mingo@elte.hu>
93 lines
2.1 KiB
C
93 lines
2.1 KiB
C
/* probe-example.c
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*
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* Connects two functions to marker call sites.
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*
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* (C) Copyright 2007 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
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*
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* This file is released under the GPLv2.
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* See the file COPYING for more details.
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*/
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/marker.h>
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#include <asm/atomic.h>
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struct probe_data {
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const char *name;
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const char *format;
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marker_probe_func *probe_func;
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};
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void probe_subsystem_event(void *probe_data, void *call_data,
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const char *format, va_list *args)
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{
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/* Declare args */
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unsigned int value;
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const char *mystr;
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/* Assign args */
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value = va_arg(*args, typeof(value));
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mystr = va_arg(*args, typeof(mystr));
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/* Call printk */
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printk(KERN_INFO "Value %u, string %s\n", value, mystr);
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/* or count, check rights, serialize data in a buffer */
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}
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atomic_t eventb_count = ATOMIC_INIT(0);
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void probe_subsystem_eventb(void *probe_data, void *call_data,
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const char *format, va_list *args)
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{
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/* Increment counter */
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atomic_inc(&eventb_count);
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}
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static struct probe_data probe_array[] =
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{
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{ .name = "subsystem_event",
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.format = "integer %d string %s",
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.probe_func = probe_subsystem_event },
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{ .name = "subsystem_eventb",
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.format = MARK_NOARGS,
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.probe_func = probe_subsystem_eventb },
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};
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static int __init probe_init(void)
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{
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int result;
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int i;
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for (i = 0; i < ARRAY_SIZE(probe_array); i++) {
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result = marker_probe_register(probe_array[i].name,
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probe_array[i].format,
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probe_array[i].probe_func, &probe_array[i]);
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if (result)
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printk(KERN_INFO "Unable to register probe %s\n",
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probe_array[i].name);
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}
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return 0;
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}
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static void __exit probe_fini(void)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(probe_array); i++)
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marker_probe_unregister(probe_array[i].name,
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probe_array[i].probe_func, &probe_array[i]);
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printk(KERN_INFO "Number of event b : %u\n",
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atomic_read(&eventb_count));
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marker_synchronize_unregister();
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}
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module_init(probe_init);
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module_exit(probe_fini);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Mathieu Desnoyers");
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MODULE_DESCRIPTION("SUBSYSTEM Probe");
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