swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 1c163f4c7b3f621efff9b28a47abb36f7378d783 authored by Linus Torvalds on 03 March 2019, 23:21:29 UTC
Linux 5.0
Linux 5.0
Tip revision: 1c163f4
wp.c
// SPDX-License-Identifier: GPL-2.0
#include <stdlib.h>
#include <sys/ioctl.h>
#include <linux/hw_breakpoint.h>
#include "tests.h"
#include "debug.h"
#include "cloexec.h"
#define WP_TEST_ASSERT_VAL(fd, text, val) \
do { \
long long count; \
wp_read(fd, &count, sizeof(long long)); \
TEST_ASSERT_VAL(text, count == val); \
} while (0)
volatile u64 data1;
volatile u8 data2[3];
static int wp_read(int fd, long long *count, int size)
{
int ret = read(fd, count, size);
if (ret != size) {
pr_debug("failed to read: %d\n", ret);
return -1;
}
return 0;
}
static void get__perf_event_attr(struct perf_event_attr *attr, int wp_type,
void *wp_addr, unsigned long wp_len)
{
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 = wp_type;
attr->bp_addr = (unsigned long)wp_addr;
attr->bp_len = wp_len;
attr->sample_period = 1;
attr->sample_type = PERF_SAMPLE_IP;
attr->exclude_kernel = 1;
attr->exclude_hv = 1;
}
static int __event(int wp_type, void *wp_addr, unsigned long wp_len)
{
int fd;
struct perf_event_attr attr;
get__perf_event_attr(&attr, wp_type, wp_addr, wp_len);
fd = sys_perf_event_open(&attr, 0, -1, -1,
perf_event_open_cloexec_flag());
if (fd < 0)
pr_debug("failed opening event %x\n", attr.bp_type);
return fd;
}
static int wp_ro_test(void)
{
int fd;
unsigned long tmp, tmp1 = rand();
fd = __event(HW_BREAKPOINT_R, (void *)&data1, sizeof(data1));
if (fd < 0)
return -1;
tmp = data1;
WP_TEST_ASSERT_VAL(fd, "RO watchpoint", 1);
data1 = tmp1 + tmp;
WP_TEST_ASSERT_VAL(fd, "RO watchpoint", 1);
close(fd);
return 0;
}
static int wp_wo_test(void)
{
int fd;
unsigned long tmp, tmp1 = rand();
fd = __event(HW_BREAKPOINT_W, (void *)&data1, sizeof(data1));
if (fd < 0)
return -1;
tmp = data1;
WP_TEST_ASSERT_VAL(fd, "WO watchpoint", 0);
data1 = tmp1 + tmp;
WP_TEST_ASSERT_VAL(fd, "WO watchpoint", 1);
close(fd);
return 0;
}
static int wp_rw_test(void)
{
int fd;
unsigned long tmp, tmp1 = rand();
fd = __event(HW_BREAKPOINT_R | HW_BREAKPOINT_W, (void *)&data1,
sizeof(data1));
if (fd < 0)
return -1;
tmp = data1;
WP_TEST_ASSERT_VAL(fd, "RW watchpoint", 1);
data1 = tmp1 + tmp;
WP_TEST_ASSERT_VAL(fd, "RW watchpoint", 2);
close(fd);
return 0;
}
static int wp_modify_test(void)
{
int fd, ret;
unsigned long tmp = rand();
struct perf_event_attr new_attr;
fd = __event(HW_BREAKPOINT_W, (void *)&data1, sizeof(data1));
if (fd < 0)
return -1;
data1 = tmp;
WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 1);
/* Modify watchpoint with disabled = 1 */
get__perf_event_attr(&new_attr, HW_BREAKPOINT_W, (void *)&data2[0],
sizeof(u8) * 2);
new_attr.disabled = 1;
ret = ioctl(fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &new_attr);
if (ret < 0) {
pr_debug("ioctl(PERF_EVENT_IOC_MODIFY_ATTRIBUTES) failed\n");
close(fd);
return ret;
}
data2[1] = tmp; /* Not Counted */
WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 1);
/* Enable the event */
ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
if (ret < 0) {
pr_debug("Failed to enable event\n");
close(fd);
return ret;
}
data2[1] = tmp; /* Counted */
WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 2);
data2[2] = tmp; /* Not Counted */
WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 2);
close(fd);
return 0;
}
static bool wp_ro_supported(void)
{
#if defined (__x86_64__) || defined (__i386__)
return false;
#else
return true;
#endif
}
static void wp_ro_skip_msg(void)
{
#if defined (__x86_64__) || defined (__i386__)
pr_debug("Hardware does not support read only watchpoints.\n");
#endif
}
static struct {
const char *desc;
int (*target_func)(void);
bool (*is_supported)(void);
void (*skip_msg)(void);
} wp_testcase_table[] = {
{
.desc = "Read Only Watchpoint",
.target_func = &wp_ro_test,
.is_supported = &wp_ro_supported,
.skip_msg = &wp_ro_skip_msg,
},
{
.desc = "Write Only Watchpoint",
.target_func = &wp_wo_test,
},
{
.desc = "Read / Write Watchpoint",
.target_func = &wp_rw_test,
},
{
.desc = "Modify Watchpoint",
.target_func = &wp_modify_test,
},
};
int test__wp_subtest_get_nr(void)
{
return (int)ARRAY_SIZE(wp_testcase_table);
}
const char *test__wp_subtest_get_desc(int i)
{
if (i < 0 || i >= (int)ARRAY_SIZE(wp_testcase_table))
return NULL;
return wp_testcase_table[i].desc;
}
int test__wp(struct test *test __maybe_unused, int i)
{
if (i < 0 || i >= (int)ARRAY_SIZE(wp_testcase_table))
return TEST_FAIL;
if (wp_testcase_table[i].is_supported &&
!wp_testcase_table[i].is_supported()) {
wp_testcase_table[i].skip_msg();
return TEST_SKIP;
}
return !wp_testcase_table[i].target_func() ? TEST_OK : TEST_FAIL;
}
/* The s390 so far does not have support for
* instruction breakpoint using the perf_event_open() system call.
*/
bool test__wp_is_supported(void)
{
#if defined(__s390x__)
return false;
#else
return true;
#endif
}