v4.19.13 snapshot.
diff --git a/tools/perf/tests/dwarf-unwind.c b/tools/perf/tests/dwarf-unwind.c
new file mode 100644
index 0000000..2f00806
--- /dev/null
+++ b/tools/perf/tests/dwarf-unwind.c
@@ -0,0 +1,213 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <inttypes.h>
+#include <unistd.h>
+#include "tests.h"
+#include "debug.h"
+#include "machine.h"
+#include "event.h"
+#include "../util/unwind.h"
+#include "perf_regs.h"
+#include "map.h"
+#include "thread.h"
+#include "callchain.h"
+
+#if defined (__x86_64__) || defined (__i386__) || defined (__powerpc__)
+#include "arch-tests.h"
+#endif
+
+/* For bsearch. We try to unwind functions in shared object. */
+#include <stdlib.h>
+
+static int mmap_handler(struct perf_tool *tool __maybe_unused,
+ union perf_event *event,
+ struct perf_sample *sample,
+ struct machine *machine)
+{
+ return machine__process_mmap2_event(machine, event, sample);
+}
+
+static int init_live_machine(struct machine *machine)
+{
+ union perf_event event;
+ pid_t pid = getpid();
+
+ return perf_event__synthesize_mmap_events(NULL, &event, pid, pid,
+ mmap_handler, machine, true, 500);
+}
+
+/*
+ * We need to keep these functions global, despite the
+ * fact that they are used only locally in this object,
+ * in order to keep them around even if the binary is
+ * stripped. If they are gone, the unwind check for
+ * symbol fails.
+ */
+int test_dwarf_unwind__thread(struct thread *thread);
+int test_dwarf_unwind__compare(void *p1, void *p2);
+int test_dwarf_unwind__krava_3(struct thread *thread);
+int test_dwarf_unwind__krava_2(struct thread *thread);
+int test_dwarf_unwind__krava_1(struct thread *thread);
+
+#define MAX_STACK 8
+
+static int unwind_entry(struct unwind_entry *entry, void *arg)
+{
+ unsigned long *cnt = (unsigned long *) arg;
+ char *symbol = entry->sym ? entry->sym->name : NULL;
+ static const char *funcs[MAX_STACK] = {
+ "test__arch_unwind_sample",
+ "test_dwarf_unwind__thread",
+ "test_dwarf_unwind__compare",
+ "bsearch",
+ "test_dwarf_unwind__krava_3",
+ "test_dwarf_unwind__krava_2",
+ "test_dwarf_unwind__krava_1",
+ "test__dwarf_unwind"
+ };
+ /*
+ * The funcs[MAX_STACK] array index, based on the
+ * callchain order setup.
+ */
+ int idx = callchain_param.order == ORDER_CALLER ?
+ MAX_STACK - *cnt - 1 : *cnt;
+
+ if (*cnt >= MAX_STACK) {
+ pr_debug("failed: crossed the max stack value %d\n", MAX_STACK);
+ return -1;
+ }
+
+ if (!symbol) {
+ pr_debug("failed: got unresolved address 0x%" PRIx64 "\n",
+ entry->ip);
+ return -1;
+ }
+
+ (*cnt)++;
+ pr_debug("got: %s 0x%" PRIx64 ", expecting %s\n",
+ symbol, entry->ip, funcs[idx]);
+ return strcmp((const char *) symbol, funcs[idx]);
+}
+
+noinline int test_dwarf_unwind__thread(struct thread *thread)
+{
+ struct perf_sample sample;
+ unsigned long cnt = 0;
+ int err = -1;
+
+ memset(&sample, 0, sizeof(sample));
+
+ if (test__arch_unwind_sample(&sample, thread)) {
+ pr_debug("failed to get unwind sample\n");
+ goto out;
+ }
+
+ err = unwind__get_entries(unwind_entry, &cnt, thread,
+ &sample, MAX_STACK);
+ if (err)
+ pr_debug("unwind failed\n");
+ else if (cnt != MAX_STACK) {
+ pr_debug("got wrong number of stack entries %lu != %d\n",
+ cnt, MAX_STACK);
+ err = -1;
+ }
+
+ out:
+ free(sample.user_stack.data);
+ free(sample.user_regs.regs);
+ return err;
+}
+
+static int global_unwind_retval = -INT_MAX;
+
+noinline int test_dwarf_unwind__compare(void *p1, void *p2)
+{
+ /* Any possible value should be 'thread' */
+ struct thread *thread = *(struct thread **)p1;
+
+ if (global_unwind_retval == -INT_MAX) {
+ /* Call unwinder twice for both callchain orders. */
+ callchain_param.order = ORDER_CALLER;
+
+ global_unwind_retval = test_dwarf_unwind__thread(thread);
+ if (!global_unwind_retval) {
+ callchain_param.order = ORDER_CALLEE;
+ global_unwind_retval = test_dwarf_unwind__thread(thread);
+ }
+ }
+
+ return p1 - p2;
+}
+
+noinline int test_dwarf_unwind__krava_3(struct thread *thread)
+{
+ struct thread *array[2] = {thread, thread};
+ void *fp = &bsearch;
+ /*
+ * make _bsearch a volatile function pointer to
+ * prevent potential optimization, which may expand
+ * bsearch and call compare directly from this function,
+ * instead of libc shared object.
+ */
+ void *(*volatile _bsearch)(void *, void *, size_t,
+ size_t, int (*)(void *, void *));
+
+ _bsearch = fp;
+ _bsearch(array, &thread, 2, sizeof(struct thread **),
+ test_dwarf_unwind__compare);
+ return global_unwind_retval;
+}
+
+noinline int test_dwarf_unwind__krava_2(struct thread *thread)
+{
+ return test_dwarf_unwind__krava_3(thread);
+}
+
+noinline int test_dwarf_unwind__krava_1(struct thread *thread)
+{
+ return test_dwarf_unwind__krava_2(thread);
+}
+
+int test__dwarf_unwind(struct test *test __maybe_unused, int subtest __maybe_unused)
+{
+ struct machine *machine;
+ struct thread *thread;
+ int err = -1;
+
+ machine = machine__new_host();
+ if (!machine) {
+ pr_err("Could not get machine\n");
+ return -1;
+ }
+
+ if (machine__create_kernel_maps(machine)) {
+ pr_err("Failed to create kernel maps\n");
+ return -1;
+ }
+
+ callchain_param.record_mode = CALLCHAIN_DWARF;
+ dwarf_callchain_users = true;
+
+ if (init_live_machine(machine)) {
+ pr_err("Could not init machine\n");
+ goto out;
+ }
+
+ if (verbose > 1)
+ machine__fprintf(machine, stderr);
+
+ thread = machine__find_thread(machine, getpid(), getpid());
+ if (!thread) {
+ pr_err("Could not get thread\n");
+ goto out;
+ }
+
+ err = test_dwarf_unwind__krava_1(thread);
+ thread__put(thread);
+
+ out:
+ machine__delete_threads(machine);
+ machine__delete(machine);
+ return err;
+}