cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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bp_signal_overflow.c (3099B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Originally done by Vince Weaver <vincent.weaver@maine.edu> for
      4 * perf_event_tests (git://github.com/deater/perf_event_tests)
      5 */
      6
      7/*
      8 * Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
      9 * 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu.
     10 */
     11#define __SANE_USERSPACE_TYPES__
     12
     13#include <stdlib.h>
     14#include <stdio.h>
     15#include <unistd.h>
     16#include <string.h>
     17#include <sys/ioctl.h>
     18#include <time.h>
     19#include <fcntl.h>
     20#include <signal.h>
     21#include <sys/mman.h>
     22#include <linux/compiler.h>
     23#include <linux/hw_breakpoint.h>
     24
     25#include "tests.h"
     26#include "debug.h"
     27#include "event.h"
     28#include "../perf-sys.h"
     29#include "cloexec.h"
     30
     31static int overflows;
     32
     33static noinline int test_function(void)
     34{
     35	return time(NULL);
     36}
     37
     38static void sig_handler(int signum __maybe_unused,
     39			siginfo_t *oh __maybe_unused,
     40			void *uc __maybe_unused)
     41{
     42	overflows++;
     43}
     44
     45static long long bp_count(int fd)
     46{
     47	long long count;
     48	int ret;
     49
     50	ret = read(fd, &count, sizeof(long long));
     51	if (ret != sizeof(long long)) {
     52		pr_debug("failed to read: %d\n", ret);
     53		return TEST_FAIL;
     54	}
     55
     56	return count;
     57}
     58
     59#define EXECUTIONS 10000
     60#define THRESHOLD  100
     61
     62static int test__bp_signal_overflow(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
     63{
     64	struct perf_event_attr pe;
     65	struct sigaction sa;
     66	long long count;
     67	int fd, i, fails = 0;
     68
     69	if (!BP_SIGNAL_IS_SUPPORTED) {
     70		pr_debug("Test not supported on this architecture");
     71		return TEST_SKIP;
     72	}
     73
     74	/* setup SIGIO signal handler */
     75	memset(&sa, 0, sizeof(struct sigaction));
     76	sa.sa_sigaction = (void *) sig_handler;
     77	sa.sa_flags = SA_SIGINFO;
     78
     79	if (sigaction(SIGIO, &sa, NULL) < 0) {
     80		pr_debug("failed setting up signal handler\n");
     81		return TEST_FAIL;
     82	}
     83
     84	memset(&pe, 0, sizeof(struct perf_event_attr));
     85	pe.type = PERF_TYPE_BREAKPOINT;
     86	pe.size = sizeof(struct perf_event_attr);
     87
     88	pe.config = 0;
     89	pe.bp_type = HW_BREAKPOINT_X;
     90	pe.bp_addr = (unsigned long) test_function;
     91	pe.bp_len = sizeof(long);
     92
     93	pe.sample_period = THRESHOLD;
     94	pe.sample_type = PERF_SAMPLE_IP;
     95	pe.wakeup_events = 1;
     96
     97	pe.disabled = 1;
     98	pe.exclude_kernel = 1;
     99	pe.exclude_hv = 1;
    100
    101	fd = sys_perf_event_open(&pe, 0, -1, -1,
    102				 perf_event_open_cloexec_flag());
    103	if (fd < 0) {
    104		pr_debug("failed opening event %llx\n", pe.config);
    105		return TEST_FAIL;
    106	}
    107
    108	fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
    109	fcntl(fd, F_SETSIG, SIGIO);
    110	fcntl(fd, F_SETOWN, getpid());
    111
    112	ioctl(fd, PERF_EVENT_IOC_RESET, 0);
    113	ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
    114
    115	for (i = 0; i < EXECUTIONS; i++)
    116		test_function();
    117
    118	ioctl(fd, PERF_EVENT_IOC_DISABLE, 0);
    119
    120	count = bp_count(fd);
    121
    122	close(fd);
    123
    124	pr_debug("count %lld, overflow %d\n",
    125		 count, overflows);
    126
    127	if (count != EXECUTIONS) {
    128		pr_debug("\tWrong number of executions %lld != %d\n",
    129		count, EXECUTIONS);
    130		fails++;
    131	}
    132
    133	if (overflows != EXECUTIONS / THRESHOLD) {
    134		pr_debug("\tWrong number of overflows %d != %d\n",
    135		overflows, EXECUTIONS / THRESHOLD);
    136		fails++;
    137	}
    138
    139	return fails ? TEST_FAIL : TEST_OK;
    140}
    141
    142DEFINE_SUITE("Breakpoint overflow sampling", bp_signal_overflow);