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// SPDX-License-Identifier: GPL-2.0
/*
* 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 <fcntl.h>
#include <linux/hw_breakpoint.h>
#include "tests.h"
#include "debug.h"
#include "event.h"
#include "../perf-sys.h"
#include "cloexec.h"
/*
* PowerPC and S390 do not support creation of instruction breakpoints using the
* perf_event interface.
*
* Just disable the test for these architectures until these issues are
* resolved.
*/
#if defined(__powerpc__) || defined(__s390x__)
#define BP_ACCOUNT_IS_SUPPORTED 0
#else
#define BP_ACCOUNT_IS_SUPPORTED 1
#endif
static volatile long the_var;
static noinline int test_function(void)
{
return 0;
}
static int __event(bool is_x, void *addr, struct perf_event_attr *attr)
{
int fd;
memset(attr, 0, sizeof(struct perf_event_attr));
attr->type = PERF_TYPE_BREAKPOINT;
attr->size = sizeof(struct perf_event_attr);
attr->config = 0;
attr->bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W;
attr->bp_addr = (unsigned long) addr;
attr->bp_len = sizeof(long);
attr->sample_period = 1;
attr->sample_type = PERF_SAMPLE_IP;
attr->exclude_kernel = 1;
attr->exclude_hv = 1;
fd = sys_perf_event_open(attr, -1, 0, -1,
perf_event_open_cloexec_flag());
if (fd < 0) {
pr_debug("failed opening event %llx\n", attr->config);
return TEST_FAIL;
}
return fd;
}
static int wp_event(void *addr, struct perf_event_attr *attr)
{
return __event(false, addr, attr);
}
static int bp_event(void *addr, struct perf_event_attr *attr)
{
return __event(true, addr, attr);
}
static int bp_accounting(int wp_cnt, int share)
{
struct perf_event_attr attr, attr_mod, attr_new;
int i, fd[wp_cnt], fd_wp, ret;
for (i = 0; i < wp_cnt; i++) {
fd[i] = wp_event((void *)&the_var, &attr);
TEST_ASSERT_VAL("failed to create wp\n", fd[i] != -1);
pr_debug("wp %d created\n", i);
}
attr_mod = attr;
attr_mod.bp_type = HW_BREAKPOINT_X;
attr_mod.bp_addr = (unsigned long) test_function;
ret = ioctl(fd[0], PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr_mod);
TEST_ASSERT_VAL("failed to modify wp\n", ret == 0);
pr_debug("wp 0 modified to bp\n");
if (!share) {
fd_wp = wp_event((void *)&the_var, &attr_new);
TEST_ASSERT_VAL("failed to create max wp\n", fd_wp != -1);
pr_debug("wp max created\n");
}
for (i = 0; i < wp_cnt; i++)
close(fd[i]);
return 0;
}
static int detect_cnt(bool is_x)
{
struct perf_event_attr attr;
void *addr = is_x ? (void *)test_function : (void *)&the_var;
int fd[100], cnt = 0, i;
while (1) {
if (cnt == 100) {
pr_debug("way too many debug registers, fix the test\n");
return 0;
}
fd[cnt] = __event(is_x, addr, &attr);
if (fd[cnt] < 0)
break;
cnt++;
}
for (i = 0; i < cnt; i++)
close(fd[i]);
return cnt;
}
static int detect_ioctl(void)
{
struct perf_event_attr attr;
int fd, ret = 1;
fd = wp_event((void *) &the_var, &attr);
if (fd > 0) {
ret = ioctl(fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr);
close(fd);
}
return ret ? 0 : 1;
}
static int detect_share(int wp_cnt, int bp_cnt)
{
struct perf_event_attr attr;
int i, *fd = NULL, ret = -1;
if (wp_cnt + bp_cnt == 0)
return 0;
fd = malloc(sizeof(int) * (wp_cnt + bp_cnt));
if (!fd)
return -1;
for (i = 0; i < wp_cnt; i++) {
fd[i] = wp_event((void *)&the_var, &attr);
if (fd[i] == -1) {
pr_err("failed to create wp\n");
goto out;
}
}
for (; i < (bp_cnt + wp_cnt); i++) {
fd[i] = bp_event((void *)test_function, &attr);
if (fd[i] == -1)
break;
}
ret = i != (bp_cnt + wp_cnt);
out:
while (i--)
close(fd[i]);
free(fd);
return ret;
}
/*
* This test does following:
* - detects the number of watch/break-points,
* skip test if any is missing
* - detects PERF_EVENT_IOC_MODIFY_ATTRIBUTES ioctl,
* skip test if it's missing
* - detects if watchpoints and breakpoints share
* same slots
* - create all possible watchpoints on cpu 0
* - change one of it to breakpoint
* - in case wp and bp do not share slots,
* we create another watchpoint to ensure
* the slot accounting is correct
*/
static int test__bp_accounting(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
{
int has_ioctl = detect_ioctl();
int wp_cnt = detect_cnt(false);
int bp_cnt = detect_cnt(true);
int share = detect_share(wp_cnt, bp_cnt);
if (!BP_ACCOUNT_IS_SUPPORTED) {
pr_debug("Test not supported on this architecture");
return TEST_SKIP;
}
pr_debug("watchpoints count %d, breakpoints count %d, has_ioctl %d, share %d\n",
wp_cnt, bp_cnt, has_ioctl, share);
if (!wp_cnt || !bp_cnt || !has_ioctl)
return TEST_SKIP;
return bp_accounting(wp_cnt, share);
}
DEFINE_SUITE("Breakpoint accounting", bp_accounting);
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