1// SPDX-License-Identifier: GPL-2.0
  2#include <stdlib.h>
  3#include <string.h>
  4#include <unistd.h>
  5#include <errno.h>
  6#include <sys/ioctl.h>
  7#include <linux/compiler.h>
  8#include <linux/hw_breakpoint.h>
  9#include <linux/kernel.h>
 10#include "tests.h"
 11#include "debug.h"
 12#include "event.h"
 13#include "cloexec.h"
 14#include "../perf-sys.h"
 15
 16#define WP_TEST_ASSERT_VAL(fd, text, val)       \
 17do {                                            \
 18	long long count;                        \
 19	wp_read(fd, &count, sizeof(long long)); \
 20	TEST_ASSERT_VAL(text, count == val);    \
 21} while (0)
 22
 23#ifdef __i386__
 24/* Only breakpoint length less-than 8 has hardware support on i386. */
 25volatile u32 data1;
 26#else
 27volatile u64 data1;
 28#endif
 29volatile u8 data2[3];
 30
 31#ifndef __s390x__
 32static int wp_read(int fd, long long *count, int size)
 33{
 34	int ret = read(fd, count, size);
 35
 36	if (ret != size) {
 37		pr_debug("failed to read: %d\n", ret);
 38		return -1;
 39	}
 40	return 0;
 41}
 42
 43static void get__perf_event_attr(struct perf_event_attr *attr, int wp_type,
 44				 void *wp_addr, unsigned long wp_len)
 45{
 46	memset(attr, 0, sizeof(struct perf_event_attr));
 47	attr->type           = PERF_TYPE_BREAKPOINT;
 48	attr->size           = sizeof(struct perf_event_attr);
 49	attr->config         = 0;
 50	attr->bp_type        = wp_type;
 51	attr->bp_addr        = (unsigned long)wp_addr;
 52	attr->bp_len         = wp_len;
 53	attr->sample_period  = 1;
 54	attr->sample_type    = PERF_SAMPLE_IP;
 55	attr->exclude_kernel = 1;
 56	attr->exclude_hv     = 1;
 57}
 58
 59static int __event(int wp_type, void *wp_addr, unsigned long wp_len)
 60{
 61	int fd;
 62	struct perf_event_attr attr;
 63
 64	get__perf_event_attr(&attr, wp_type, wp_addr, wp_len);
 65	fd = sys_perf_event_open(&attr, 0, -1, -1,
 66				 perf_event_open_cloexec_flag());
 67	if (fd < 0) {
 68		fd = -errno;
 69		pr_debug("failed opening event %x\n", attr.bp_type);
 70	}
 71
 72	return fd;
 73}
 74#endif
 75
 76static int test__wp_ro(struct test_suite *test __maybe_unused,
 77		       int subtest __maybe_unused)
 78{
 79#if defined(__s390x__) || defined(__x86_64__) || defined(__i386__)
 80	return TEST_SKIP;
 81#else
 82	int fd;
 83	unsigned long tmp, tmp1 = rand();
 84
 85	fd = __event(HW_BREAKPOINT_R, (void *)&data1, sizeof(data1));
 86	if (fd < 0)
 87		return fd == -ENODEV ? TEST_SKIP : -1;
 88
 89	tmp = data1;
 90	WP_TEST_ASSERT_VAL(fd, "RO watchpoint", 1);
 91
 92	data1 = tmp1 + tmp;
 93	WP_TEST_ASSERT_VAL(fd, "RO watchpoint", 1);
 94
 95	close(fd);
 96	return 0;
 97#endif
 98}
 99
100static int test__wp_wo(struct test_suite *test __maybe_unused,
101		       int subtest __maybe_unused)
102{
103#if defined(__s390x__)
104	return TEST_SKIP;
105#else
106	int fd;
107	unsigned long tmp, tmp1 = rand();
108
109	fd = __event(HW_BREAKPOINT_W, (void *)&data1, sizeof(data1));
110	if (fd < 0)
111		return fd == -ENODEV ? TEST_SKIP : -1;
112
113	tmp = data1;
114	WP_TEST_ASSERT_VAL(fd, "WO watchpoint", 0);
115
116	data1 = tmp1 + tmp;
117	WP_TEST_ASSERT_VAL(fd, "WO watchpoint", 1);
118
119	close(fd);
120	return 0;
121#endif
122}
123
124static int test__wp_rw(struct test_suite *test __maybe_unused,
125		       int subtest __maybe_unused)
126{
127#if defined(__s390x__)
128	return TEST_SKIP;
129#else
130	int fd;
131	unsigned long tmp, tmp1 = rand();
132
133	fd = __event(HW_BREAKPOINT_R | HW_BREAKPOINT_W, (void *)&data1,
134		     sizeof(data1));
135	if (fd < 0)
136		return fd == -ENODEV ? TEST_SKIP : -1;
137
138	tmp = data1;
139	WP_TEST_ASSERT_VAL(fd, "RW watchpoint", 1);
140
141	data1 = tmp1 + tmp;
142	WP_TEST_ASSERT_VAL(fd, "RW watchpoint", 2);
143
144	close(fd);
145	return 0;
146#endif
147}
148
149static int test__wp_modify(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
150{
151#if defined(__s390x__)
152	return TEST_SKIP;
153#else
154	int fd, ret;
155	unsigned long tmp = rand();
156	struct perf_event_attr new_attr;
157
158	fd = __event(HW_BREAKPOINT_W, (void *)&data1, sizeof(data1));
159	if (fd < 0)
160		return fd == -ENODEV ? TEST_SKIP : -1;
161
162	data1 = tmp;
163	WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 1);
164
165	/* Modify watchpoint with disabled = 1 */
166	get__perf_event_attr(&new_attr, HW_BREAKPOINT_W, (void *)&data2[0],
167			     sizeof(u8) * 2);
168	new_attr.disabled = 1;
169	ret = ioctl(fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &new_attr);
170	if (ret < 0) {
171		if (errno == ENOTTY) {
172			test->test_cases[subtest].skip_reason = "missing kernel support";
173			ret = TEST_SKIP;
174		}
175
176		pr_debug("ioctl(PERF_EVENT_IOC_MODIFY_ATTRIBUTES) failed\n");
177		close(fd);
178		return ret;
179	}
180
181	data2[1] = tmp; /* Not Counted */
182	WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 1);
183
184	/* Enable the event */
185	ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
186	if (ret < 0) {
187		pr_debug("Failed to enable event\n");
188		close(fd);
189		return ret;
190	}
191
192	data2[1] = tmp; /* Counted */
193	WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 2);
194
195	data2[2] = tmp; /* Not Counted */
196	WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 2);
197
198	close(fd);
199	return 0;
200#endif
201}
202
203static struct test_case wp_tests[] = {
204	TEST_CASE_REASON("Read Only Watchpoint", wp_ro, "missing hardware support"),
205	TEST_CASE_REASON("Write Only Watchpoint", wp_wo, "missing hardware support"),
206	TEST_CASE_REASON("Read / Write Watchpoint", wp_rw, "missing hardware support"),
207	TEST_CASE_REASON("Modify Watchpoint", wp_modify, "missing hardware support"),
208	{ .name = NULL, }
209};
210
211struct test_suite suite__wp = {
212	.desc = "Watchpoint",
213	.test_cases = wp_tests,
214};