cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

base.c (3478B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 *  This code maintains a list of active profiling data structures.
      4 *
      5 *    Copyright IBM Corp. 2009
      6 *    Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
      7 *
      8 *    Uses gcc-internal data definitions.
      9 *    Based on the gcov-kernel patch by:
     10 *		 Hubertus Franke <frankeh@us.ibm.com>
     11 *		 Nigel Hinds <nhinds@us.ibm.com>
     12 *		 Rajan Ravindran <rajancr@us.ibm.com>
     13 *		 Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
     14 *		 Paul Larson
     15 */
     16
     17#define pr_fmt(fmt)	"gcov: " fmt
     18
     19#include <linux/init.h>
     20#include <linux/module.h>
     21#include <linux/mutex.h>
     22#include <linux/sched.h>
     23#include "gcov.h"
     24
     25int gcov_events_enabled;
     26DEFINE_MUTEX(gcov_lock);
     27
     28/**
     29 * gcov_enable_events - enable event reporting through gcov_event()
     30 *
     31 * Turn on reporting of profiling data load/unload-events through the
     32 * gcov_event() callback. Also replay all previous events once. This function
     33 * is needed because some events are potentially generated too early for the
     34 * callback implementation to handle them initially.
     35 */
     36void gcov_enable_events(void)
     37{
     38	struct gcov_info *info = NULL;
     39
     40	mutex_lock(&gcov_lock);
     41	gcov_events_enabled = 1;
     42
     43	/* Perform event callback for previously registered entries. */
     44	while ((info = gcov_info_next(info))) {
     45		gcov_event(GCOV_ADD, info);
     46		cond_resched();
     47	}
     48
     49	mutex_unlock(&gcov_lock);
     50}
     51
     52/**
     53 * store_gcov_u32 - store 32 bit number in gcov format to buffer
     54 * @buffer: target buffer or NULL
     55 * @off: offset into the buffer
     56 * @v: value to be stored
     57 *
     58 * Number format defined by gcc: numbers are recorded in the 32 bit
     59 * unsigned binary form of the endianness of the machine generating the
     60 * file. Returns the number of bytes stored. If @buffer is %NULL, doesn't
     61 * store anything.
     62 */
     63size_t store_gcov_u32(void *buffer, size_t off, u32 v)
     64{
     65	u32 *data;
     66
     67	if (buffer) {
     68		data = buffer + off;
     69		*data = v;
     70	}
     71
     72	return sizeof(*data);
     73}
     74
     75/**
     76 * store_gcov_u64 - store 64 bit number in gcov format to buffer
     77 * @buffer: target buffer or NULL
     78 * @off: offset into the buffer
     79 * @v: value to be stored
     80 *
     81 * Number format defined by gcc: numbers are recorded in the 32 bit
     82 * unsigned binary form of the endianness of the machine generating the
     83 * file. 64 bit numbers are stored as two 32 bit numbers, the low part
     84 * first. Returns the number of bytes stored. If @buffer is %NULL, doesn't store
     85 * anything.
     86 */
     87size_t store_gcov_u64(void *buffer, size_t off, u64 v)
     88{
     89	u32 *data;
     90
     91	if (buffer) {
     92		data = buffer + off;
     93
     94		data[0] = (v & 0xffffffffUL);
     95		data[1] = (v >> 32);
     96	}
     97
     98	return sizeof(*data) * 2;
     99}
    100
    101#ifdef CONFIG_MODULES
    102/* Update list and generate events when modules are unloaded. */
    103static int gcov_module_notifier(struct notifier_block *nb, unsigned long event,
    104				void *data)
    105{
    106	struct module *mod = data;
    107	struct gcov_info *info = NULL;
    108	struct gcov_info *prev = NULL;
    109
    110	if (event != MODULE_STATE_GOING)
    111		return NOTIFY_OK;
    112	mutex_lock(&gcov_lock);
    113
    114	/* Remove entries located in module from linked list. */
    115	while ((info = gcov_info_next(info))) {
    116		if (gcov_info_within_module(info, mod)) {
    117			gcov_info_unlink(prev, info);
    118			if (gcov_events_enabled)
    119				gcov_event(GCOV_REMOVE, info);
    120		} else
    121			prev = info;
    122	}
    123
    124	mutex_unlock(&gcov_lock);
    125
    126	return NOTIFY_OK;
    127}
    128
    129static struct notifier_block gcov_nb = {
    130	.notifier_call	= gcov_module_notifier,
    131};
    132
    133static int __init gcov_init(void)
    134{
    135	return register_module_notifier(&gcov_nb);
    136}
    137device_initcall(gcov_init);
    138#endif /* CONFIG_MODULES */