tools/perf/tests/bp_signal_overflow.c

Source file repositories/reference/linux-study-clean/tools/perf/tests/bp_signal_overflow.c

File Facts

System
Linux kernel
Corpus path
tools/perf/tests/bp_signal_overflow.c
Extension
.c
Size
3137 bytes
Lines
144
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * Originally done by Vince Weaver <vincent.weaver@maine.edu> for
 * perf_event_tests (git://github.com/deater/perf_event_tests)
 */

/*
 * Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
 * 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu.
 */
#define __SANE_USERSPACE_TYPES__

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>
#include <time.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/mman.h>
#include <linux/compiler.h>
#include <linux/hw_breakpoint.h>

#include "tests.h"
#include "debug.h"
#include "event.h"
#include "parse-events.h"
#include "../perf-sys.h"
#include "cloexec.h"

static int overflows;

static noinline int test_function(void)
{
	return time(NULL);
}

static void sig_handler(int signum __maybe_unused,
			siginfo_t *oh __maybe_unused,
			void *uc __maybe_unused)
{
	overflows++;
}

static long long bp_count(int fd)
{
	long long count;
	int ret;

	ret = read(fd, &count, sizeof(long long));
	if (ret != sizeof(long long)) {
		pr_debug("failed to read: %d\n", ret);
		return TEST_FAIL;
	}

	return count;
}

#define EXECUTIONS 10000
#define THRESHOLD  100

static int test__bp_signal_overflow(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
{
	struct perf_event_attr pe;
	struct sigaction sa;
	long long count;
	int fd, i, fails = 0;

	if (!BP_SIGNAL_IS_SUPPORTED) {
		pr_debug("Test not supported on this architecture");
		return TEST_SKIP;
	}

	/* setup SIGIO signal handler */
	memset(&sa, 0, sizeof(struct sigaction));
	sa.sa_sigaction = (void *) sig_handler;
	sa.sa_flags = SA_SIGINFO;

	if (sigaction(SIGIO, &sa, NULL) < 0) {
		pr_debug("failed setting up signal handler\n");
		return TEST_FAIL;
	}

	memset(&pe, 0, sizeof(struct perf_event_attr));
	pe.type = PERF_TYPE_BREAKPOINT;
	pe.size = sizeof(struct perf_event_attr);

	pe.config = 0;
	pe.bp_type = HW_BREAKPOINT_X;

Annotation

Implementation Notes