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149 lines
3.6 KiB
C
149 lines
3.6 KiB
C
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/*
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* This code maintains a list of active profiling data structures.
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*
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* Copyright IBM Corp. 2009
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* Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
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*
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* Uses gcc-internal data definitions.
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* Based on the gcov-kernel patch by:
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* Hubertus Franke <frankeh@us.ibm.com>
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* Nigel Hinds <nhinds@us.ibm.com>
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* Rajan Ravindran <rajancr@us.ibm.com>
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* Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
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* Paul Larson
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*/
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#define pr_fmt(fmt) "gcov: " fmt
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include "gcov.h"
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static struct gcov_info *gcov_info_head;
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static int gcov_events_enabled;
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static DEFINE_MUTEX(gcov_lock);
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/*
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* __gcov_init is called by gcc-generated constructor code for each object
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* file compiled with -fprofile-arcs.
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*/
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void __gcov_init(struct gcov_info *info)
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{
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static unsigned int gcov_version;
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mutex_lock(&gcov_lock);
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if (gcov_version == 0) {
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gcov_version = info->version;
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/*
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* Printing gcc's version magic may prove useful for debugging
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* incompatibility reports.
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*/
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pr_info("version magic: 0x%x\n", gcov_version);
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}
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/*
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* Add new profiling data structure to list and inform event
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* listener.
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*/
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info->next = gcov_info_head;
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gcov_info_head = info;
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if (gcov_events_enabled)
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gcov_event(GCOV_ADD, info);
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mutex_unlock(&gcov_lock);
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}
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EXPORT_SYMBOL(__gcov_init);
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/*
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* These functions may be referenced by gcc-generated profiling code but serve
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* no function for kernel profiling.
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*/
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void __gcov_flush(void)
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{
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/* Unused. */
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}
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EXPORT_SYMBOL(__gcov_flush);
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void __gcov_merge_add(gcov_type *counters, unsigned int n_counters)
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{
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/* Unused. */
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}
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EXPORT_SYMBOL(__gcov_merge_add);
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void __gcov_merge_single(gcov_type *counters, unsigned int n_counters)
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{
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/* Unused. */
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}
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EXPORT_SYMBOL(__gcov_merge_single);
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void __gcov_merge_delta(gcov_type *counters, unsigned int n_counters)
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{
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/* Unused. */
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}
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EXPORT_SYMBOL(__gcov_merge_delta);
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/**
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* gcov_enable_events - enable event reporting through gcov_event()
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*
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* Turn on reporting of profiling data load/unload-events through the
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* gcov_event() callback. Also replay all previous events once. This function
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* is needed because some events are potentially generated too early for the
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* callback implementation to handle them initially.
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*/
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void gcov_enable_events(void)
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{
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struct gcov_info *info;
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mutex_lock(&gcov_lock);
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gcov_events_enabled = 1;
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/* Perform event callback for previously registered entries. */
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for (info = gcov_info_head; info; info = info->next)
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gcov_event(GCOV_ADD, info);
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mutex_unlock(&gcov_lock);
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}
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#ifdef CONFIG_MODULES
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static inline int within(void *addr, void *start, unsigned long size)
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{
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return ((addr >= start) && (addr < start + size));
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}
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/* Update list and generate events when modules are unloaded. */
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static int gcov_module_notifier(struct notifier_block *nb, unsigned long event,
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void *data)
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{
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struct module *mod = data;
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struct gcov_info *info;
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struct gcov_info *prev;
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if (event != MODULE_STATE_GOING)
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return NOTIFY_OK;
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mutex_lock(&gcov_lock);
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prev = NULL;
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/* Remove entries located in module from linked list. */
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for (info = gcov_info_head; info; info = info->next) {
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if (within(info, mod->module_core, mod->core_size)) {
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if (prev)
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prev->next = info->next;
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else
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gcov_info_head = info->next;
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if (gcov_events_enabled)
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gcov_event(GCOV_REMOVE, info);
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} else
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prev = info;
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}
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mutex_unlock(&gcov_lock);
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return NOTIFY_OK;
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}
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static struct notifier_block gcov_nb = {
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.notifier_call = gcov_module_notifier,
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};
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static int __init gcov_init(void)
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{
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return register_module_notifier(&gcov_nb);
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}
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device_initcall(gcov_init);
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#endif /* CONFIG_MODULES */
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