This tests perf hardware breakpoints (ie PERF_TYPE_BREAKPOINT) on
powerpc.
Signed-off-by: Michael Neuling <mi...@neuling.org>
---
.../selftests/powerpc/ptrace/.gitignore | 1 +
.../testing/selftests/powerpc/ptrace/Makefile | 3 +-
.../selftests/powerpc/ptrace/perf-hwbreak.c | 214 ++++++++++++++++++
3 files changed, 217 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c
diff --git a/tools/testing/selftests/powerpc/ptrace/.gitignore
b/tools/testing/selftests/powerpc/ptrace/.gitignore
index 9dcc16ea81..07ec449a27 100644
--- a/tools/testing/selftests/powerpc/ptrace/.gitignore
+++ b/tools/testing/selftests/powerpc/ptrace/.gitignore
@@ -9,3 +9,4 @@ ptrace-tm-vsx
ptrace-tm-spd-vsx
ptrace-tm-spr
ptrace-hwbreak
+perf-hwbreak
diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile
b/tools/testing/selftests/powerpc/ptrace/Makefile
index 0e2f4601d1..532f5dda37 100644
--- a/tools/testing/selftests/powerpc/ptrace/Makefile
+++ b/tools/testing/selftests/powerpc/ptrace/Makefile
@@ -1,13 +1,14 @@
# SPDX-License-Identifier: GPL-2.0
TEST_PROGS := ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr \
ptrace-tar ptrace-tm-tar ptrace-tm-spd-tar ptrace-vsx
ptrace-tm-vsx \
- ptrace-tm-spd-vsx ptrace-tm-spr ptrace-hwbreak
+ ptrace-tm-spd-vsx ptrace-tm-spr ptrace-hwbreak perf-hwbreak
include ../../lib.mk
all: $(TEST_PROGS)
CFLAGS += -m64 -I../../../../../usr/include -I../tm -mhtm -fno-pie
+LDLIBS += -lpthread
$(TEST_PROGS): ../harness.c ../utils.c ../lib/reg.S ptrace.h
diff --git a/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c
b/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c
new file mode 100644
index 0000000000..4ab7059029
--- /dev/null
+++ b/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c
@@ -0,0 +1,214 @@
+/*
+ * perf events self profiling example test case for hw breakpoints.
+ *
+ * Start an number of threads. In each thread setup a breakpoint with
+ * a number of variables:
+ * 1) number of times we loop over it
+ * 2) read, write or read&write match
+ * 3) exclude userspace
+ * setup this breakpoint, then read and write the data a number of times.
+ * Then check the output count from perf is as expected.
+ *
+ * Based on:
+ * http://ozlabs.org/~anton/junkcode/perf_events_example1.c
+ *
+ * Copyright (C) 2018 Michael Neuling, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <unistd.h>
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <pthread.h>
+#include <elf.h>
+#include <sys/syscall.h>
+#include <linux/perf_event.h>
+#include <linux/hw_breakpoint.h>
+#include "utils.h"
+
+int max_loops;
+int num_threads;
+int fail = 0;
+int arraytest;
+
+#define DAWR_LENGTH_MAX ((0x3f + 1) * 8)
+
+static inline int sys_perf_event_open(struct perf_event_attr *attr, pid_t pid,
+ int cpu, int group_fd,
+ unsigned long flags)
+{
+ attr->size = sizeof(*attr);
+ return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags);
+}
+
+static inline bool breakpoint_test(int len)
+{
+ struct perf_event_attr attr;
+ int fd;
+
+ /* setup counters */
+ memset(&attr, 0, sizeof(attr));
+ attr.disabled = 1;
+ attr.type = PERF_TYPE_BREAKPOINT;
+ attr.bp_type = HW_BREAKPOINT_R;
+ /* bp_addr can point anywhere but needs to be aligned */
+ attr.bp_addr = (__u64)(&attr) & 0xfffffffffffff800;
+ attr.bp_len = len;
+ fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
+ if (fd < 0)
+ return false;
+ close(fd);
+ return true;
+}
+
+static inline bool perf_breakpoint_supported(void)
+{
+ return breakpoint_test(4);
+}
+
+static inline bool dawr_supported(void)
+{
+ return breakpoint_test(DAWR_LENGTH_MAX);
+}
+
+/*
+ */
+static void *runtestsingle(void *vptr_args)
+{
+ int i,j;
+ struct perf_event_attr attr;
+ size_t res;
+ unsigned long long breaks, needed;
+ int readint; /* random stacks will give diff addr here */
+ int readintarraybig[2*DAWR_LENGTH_MAX/sizeof(int)];
+ int *readintalign;
+ volatile int *ptr;
+ int break_fd;
+ int loop_num = rand() % max_loops;
+ int readwriteflag = (rand() % 3) + 1; /* needs to be 1-3 */
+ int exclude_user = rand() % 2;
+ volatile int *k;
+
+ /* align to 0x400 boundary as required by DAWR */
+ readintalign = (int *)(((unsigned long)readintarraybig + 0x7ff) &
0xfffffffffffff800);
+
+ ptr = &readint;
+ if (arraytest)
+ ptr = &readintalign[0];
+
+ /* setup counters */
+ memset(&attr, 0, sizeof(attr));
+ attr.disabled = 1;
+ attr.type = PERF_TYPE_BREAKPOINT;
+ attr.bp_type = readwriteflag;
+ attr.bp_addr = (__u64)ptr;
+ attr.bp_len = sizeof(int);
+ if (arraytest)
+ attr.bp_len = DAWR_LENGTH_MAX;
+ attr.exclude_user = exclude_user;
+ break_fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
+ if (break_fd < 0) {
+ perror("sys_perf_event_open");
+ exit(1);
+ }
+
+ /* start counters */
+ ioctl(break_fd, PERF_EVENT_IOC_ENABLE);
+
+ /* Test a bunch of reads and writes */
+ k = &readint;
+ for (i = 0; i < loop_num; i++) {
+ if (arraytest)
+ k = &(readintalign[i % (DAWR_LENGTH_MAX/sizeof(int))]);
+
+ j = *k;
+ *k = j;
+ }
+
+ /* stop counters */
+ ioctl(break_fd, PERF_EVENT_IOC_DISABLE);
+
+ /* read and check counters */
+ res = read(break_fd, &breaks, sizeof(unsigned long long));
+ assert(res == sizeof(unsigned long long));
+ /* we read and write each loop, so subtract the ones we are counting */
+ needed = 0;
+ if (readwriteflag & HW_BREAKPOINT_R)
+ needed += loop_num;
+ if (readwriteflag & HW_BREAKPOINT_W)
+ needed += loop_num;
+ needed = needed * (1 - exclude_user);
+ if (breaks != needed) {
+ printf("FAILED: 0x%lx brks:%lld needed:%lli %i %i %i\n\n",
+ (unsigned long int)ptr, breaks, needed, loop_num,
readwriteflag, exclude_user);
+ fail = 1;
+ }
+ close(break_fd);
+
+ return NULL;
+}
+
+void runtest(void)
+{
+ pthread_t *threads;
+ int i;
+
+ if ((threads = malloc(num_threads * sizeof(pthread_t))) == NULL) {
+ perror("pthread malloc");
+ }
+
+ for (i = 0; i < num_threads; i++){
+ if (pthread_create(&threads[i], NULL, runtestsingle, NULL) !=
0) {
+ perror("pthreads_create");
+ fail = 1;
+ }
+ }
+
+ for (i = 0; i < num_threads; i++) {
+ pthread_join(threads[i], NULL);
+ }
+}
+
+int check_test(void)
+{
+ printf("threads=%i loops=%i %s test\n", num_threads, max_loops,
+ arraytest?"array":"scalar");
+
+ return fail;
+}
+
+static int perf_hwbreak(void)
+{
+ srand ( time(NULL) );
+ num_threads = sysconf(_SC_NPROCESSORS_ONLN) * 2;
+ max_loops = 1048576;
+
+ SKIP_IF(!perf_breakpoint_supported());
+
+ fail = 0;
+ arraytest = 0;
+ runtest();
+ if (check_test())
+ return 1;
+
+
+ if (!dawr_supported())
+ return 0;
+ fail = 0;
+ arraytest = 1;
+ runtest();
+ return check_test();
+}
+
+
+int main(int argc, char *argv[], char **envp)
+{
+ return test_harness(perf_hwbreak, "perf_hwbreak");
+}
--
2.17.0
