1 files changed, 38 insertions, 13 deletions

diff --git a/tools/perf/tests/dwarf-unwind.c b/tools/perf/tests/dwarf-unwind.c
index 779ce280a0e9..afdca7f2959f 100644
--- a/tools/perf/tests/dwarf-unwind.c
+++ b/tools/perf/tests/dwarf-unwind.c
@@ -17,13 +17,26 @@
 #include "callchain.h"
 #include "util/synthetic-events.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>
 
+/*
+ * The test will assert frames are on the stack but tail call optimizations lose
+ * the frame of the caller. Clang can disable this optimization on a called
+ * function but GCC currently (11/2020) lacks this attribute. The barrier is
+ * used to inhibit tail calls in these cases.
+ */
+#ifdef __has_attribute
+#if __has_attribute(disable_tail_calls)
+#define NO_TAIL_CALL_ATTRIBUTE __attribute__((disable_tail_calls))
+#define NO_TAIL_CALL_BARRIER
+#endif
+#endif
+#ifndef NO_TAIL_CALL_ATTRIBUTE
+#define NO_TAIL_CALL_ATTRIBUTE
+#define NO_TAIL_CALL_BARRIER __asm__ __volatile__("" : : : "memory");
+#endif
+
 static int mmap_handler(struct perf_tool *tool __maybe_unused,
 			union perf_event *event,
 			struct perf_sample *sample,
@@ -37,6 +50,7 @@ static int init_live_machine(struct machine *machine)
 	union perf_event event;
 	pid_t pid = getpid();
 
+	memset(&event, 0, sizeof(event));
 	return perf_event__synthesize_mmap_events(NULL, &event, pid, pid,
 						  mmap_handler, machine, true);
 }
@@ -94,7 +108,7 @@ static int unwind_entry(struct unwind_entry *entry, void *arg)
 	return strcmp((const char *) symbol, funcs[idx]);
 }
 
-noinline int test_dwarf_unwind__thread(struct thread *thread)
+NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__thread(struct thread *thread)
 {
 	struct perf_sample sample;
 	unsigned long cnt = 0;
@@ -108,7 +122,7 @@ noinline int test_dwarf_unwind__thread(struct thread *thread)
 	}
 
 	err = unwind__get_entries(unwind_entry, &cnt, thread,
-				  &sample, MAX_STACK);
+				  &sample, MAX_STACK, false);
 	if (err)
 		pr_debug("unwind failed\n");
 	else if (cnt != MAX_STACK) {
@@ -125,7 +139,7 @@ noinline int test_dwarf_unwind__thread(struct thread *thread)
 
 static int global_unwind_retval = -INT_MAX;
 
-noinline int test_dwarf_unwind__compare(void *p1, void *p2)
+NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__compare(void *p1, void *p2)
 {
 	/* Any possible value should be 'thread' */
 	struct thread *thread = *(struct thread **)p1;
@@ -144,7 +158,7 @@ noinline int test_dwarf_unwind__compare(void *p1, void *p2)
 	return p1 - p2;
 }
 
-noinline int test_dwarf_unwind__krava_3(struct thread *thread)
+NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_3(struct thread *thread)
 {
 	struct thread *array[2] = {thread, thread};
 	void *fp = &bsearch;
@@ -163,17 +177,26 @@ noinline int test_dwarf_unwind__krava_3(struct thread *thread)
 	return global_unwind_retval;
 }
 
-noinline int test_dwarf_unwind__krava_2(struct thread *thread)
+NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_2(struct thread *thread)
 {
-	return test_dwarf_unwind__krava_3(thread);
+	int ret;
+
+	ret =  test_dwarf_unwind__krava_3(thread);
+	NO_TAIL_CALL_BARRIER;
+	return ret;
 }
 
-noinline int test_dwarf_unwind__krava_1(struct thread *thread)
+NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_1(struct thread *thread)
 {
-	return test_dwarf_unwind__krava_2(thread);
+	int ret;
+
+	ret =  test_dwarf_unwind__krava_2(thread);
+	NO_TAIL_CALL_BARRIER;
+	return ret;
 }
 
-int test__dwarf_unwind(struct test *test __maybe_unused, int subtest __maybe_unused)
+static int test__dwarf_unwind(struct test_suite *test __maybe_unused,
+			      int subtest __maybe_unused)
 {
 	struct machine *machine;
 	struct thread *thread;
@@ -215,3 +238,5 @@ int test__dwarf_unwind(struct test *test __maybe_unused, int subtest __maybe_unu
 	machine__delete(machine);
 	return err;
 }
+
+DEFINE_SUITE("Test dwarf unwind", dwarf_unwind);