[PATCH v2] perf test: Add watchpoint test

From: Ravi Bangoria
Date: Wed Sep 12 2018 - 02:12:52 EST


We don't have perf test available to test watchpoint functionality.
Add simple set of tests:
- Read only watchpoint
- Write only watchpoint
- Read / Write watchpoint
- Runtime watchpoint modification

Ex on powerpc:
$ sudo ./perf test 22
22: Watchpoint :
22.1: Read Only Watchpoint : Ok
22.2: Write Only Watchpoint : Ok
22.3: Read / Write Watchpoint : Ok
22.4: Modify Watchpoint : Ok

Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
v1 -> v2:
- Fix build failure for mips and other archs.
- Show debug message if subtest is not supported.

tools/perf/tests/Build | 1 +
tools/perf/tests/builtin-test.c | 9 ++
tools/perf/tests/tests.h | 3 +
tools/perf/tests/wp.c | 229 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 242 insertions(+)
create mode 100644 tools/perf/tests/wp.c

diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build
index 6c108fa79ae3..0b2b8305c965 100644
--- a/tools/perf/tests/Build
+++ b/tools/perf/tests/Build
@@ -21,6 +21,7 @@ perf-y += python-use.o
perf-y += bp_signal.o
perf-y += bp_signal_overflow.o
perf-y += bp_account.o
+perf-y += wp.o
perf-y += task-exit.o
perf-y += sw-clock.o
perf-y += mmap-thread-lookup.o
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index d7a5e1b9aa6f..54ca7d87236f 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -120,6 +120,15 @@ static struct test generic_tests[] = {
.func = test__bp_accounting,
.is_supported = test__bp_signal_is_supported,
},
+ {
+ .desc = "Watchpoint",
+ .func = test__wp,
+ .subtest = {
+ .skip_if_fail = false,
+ .get_nr = test__wp_subtest_get_nr,
+ .get_desc = test__wp_subtest_get_desc,
+ },
+ },
{
.desc = "Number of exit events of a simple workload",
.func = test__task_exit,
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index a9760e790563..8e26a4148f30 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -59,6 +59,9 @@ int test__python_use(struct test *test, int subtest);
int test__bp_signal(struct test *test, int subtest);
int test__bp_signal_overflow(struct test *test, int subtest);
int test__bp_accounting(struct test *test, int subtest);
+int test__wp(struct test *test, int subtest);
+const char *test__wp_subtest_get_desc(int subtest);
+int test__wp_subtest_get_nr(void);
int test__task_exit(struct test *test, int subtest);
int test__mem(struct test *test, int subtest);
int test__sw_clock_freq(struct test *test, int subtest);
diff --git a/tools/perf/tests/wp.c b/tools/perf/tests/wp.c
new file mode 100644
index 000000000000..017a99317f94
--- /dev/null
+++ b/tools/perf/tests/wp.c
@@ -0,0 +1,229 @@
+// 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;
+}
--
2.14.4