139 lines
3.4 KiB
C
139 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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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 <linux/sched.h>
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#include "gcov.h"
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int gcov_events_enabled;
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DEFINE_MUTEX(gcov_lock);
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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 = NULL;
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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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while ((info = gcov_info_next(info))) {
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gcov_event(GCOV_ADD, info);
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cond_resched();
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}
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mutex_unlock(&gcov_lock);
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}
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/**
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* store_gcov_u32 - store 32 bit number in gcov format to buffer
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* @buffer: target buffer or NULL
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* @off: offset into the buffer
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* @v: value to be stored
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*
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* Number format defined by gcc: numbers are recorded in the 32 bit
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* unsigned binary form of the endianness of the machine generating the
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* file. Returns the number of bytes stored. If @buffer is %NULL, doesn't
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* store anything.
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*/
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size_t store_gcov_u32(void *buffer, size_t off, u32 v)
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{
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u32 *data;
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if (buffer) {
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data = buffer + off;
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*data = v;
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}
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return sizeof(*data);
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}
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/**
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* store_gcov_u64 - store 64 bit number in gcov format to buffer
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* @buffer: target buffer or NULL
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* @off: offset into the buffer
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* @v: value to be stored
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*
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* Number format defined by gcc: numbers are recorded in the 32 bit
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* unsigned binary form of the endianness of the machine generating the
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* file. 64 bit numbers are stored as two 32 bit numbers, the low part
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* first. Returns the number of bytes stored. If @buffer is %NULL, doesn't store
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* anything.
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*/
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size_t store_gcov_u64(void *buffer, size_t off, u64 v)
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{
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u32 *data;
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if (buffer) {
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data = buffer + off;
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data[0] = (v & 0xffffffffUL);
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data[1] = (v >> 32);
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}
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return sizeof(*data) * 2;
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}
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#ifdef CONFIG_MODULES
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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 = NULL;
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struct gcov_info *prev = NULL;
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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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/* Remove entries located in module from linked list. */
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while ((info = gcov_info_next(info))) {
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if (gcov_info_within_module(info, mod)) {
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gcov_info_unlink(prev, info);
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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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