1 files changed, 64 insertions, 11 deletions

diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index f9ef7d045c92..1dfa4d0eec4d 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -14,11 +14,19 @@
 #ifdef HAVE_BACKTRACE_SUPPORT
 #include <execinfo.h>
 #endif
+#include "addr_location.h"
 #include "color.h"
-#include "event.h"
 #include "debug.h"
+#include "env.h"
+#include "event.h"
+#include "machine.h"
+#include "map.h"
 #include "print_binary.h"
+#include "srcline.h"
+#include "symbol.h"
+#include "synthetic-events.h"
 #include "target.h"
+#include "thread.h"
 #include "trace-event.h"
 #include "ui/helpline.h"
 #include "ui/ui.h"
@@ -298,21 +306,66 @@ void perf_debug_setup(void)
 	libapi_set_print(pr_warning_wrapper, pr_warning_wrapper, pr_debug_wrapper);
 }
 
+void __dump_stack(FILE *file, void **stackdump, size_t stackdump_size)
+{
+	/* TODO: async safety. printf, malloc, etc. aren't safe inside a signal handler. */
+	pid_t pid = getpid();
+	struct machine *machine;
+	struct thread *thread = NULL;
+	struct perf_env host_env;
+
+	perf_env__init(&host_env);
+	machine = machine__new_live(&host_env, /*kernel_maps=*/false, pid);
+
+	if (machine)
+		thread = machine__find_thread(machine, pid, pid);
+
+#ifdef HAVE_BACKTRACE_SUPPORT
+	if (!machine || !thread) {
+		/*
+		 * Backtrace functions are async signal safe. Fall back on them
+		 * if machine/thread creation fails.
+		 */
+		backtrace_symbols_fd(stackdump, stackdump_size, fileno(file));
+		machine__delete(machine);
+		perf_env__exit(&host_env);
+		return;
+	}
+#endif
+
+	for (size_t i = 0; i < stackdump_size; i++) {
+		struct addr_location al;
+		u64 addr = (u64)(uintptr_t)stackdump[i];
+		bool printed = false;
+
+		addr_location__init(&al);
+		if (thread && thread__find_map(thread, PERF_RECORD_MISC_USER, addr, &al)) {
+			al.sym = map__find_symbol(al.map, al.addr);
+			if (al.sym) {
+				fprintf(file, "    #%zd %p in %s ", i, stackdump[i], al.sym->name);
+				printed = true;
+			}
+		}
+		if (!printed)
+			fprintf(file, "    #%zd %p ", i, stackdump[i]);
+
+		map__fprintf_srcline(al.map, al.addr, "", file);
+		fprintf(file, "\n");
+		addr_location__exit(&al);
+	}
+	thread__put(thread);
+	machine__delete(machine);
+	perf_env__exit(&host_env);
+}
+
 /* Obtain a backtrace and print it to stdout. */
 #ifdef HAVE_BACKTRACE_SUPPORT
 void dump_stack(void)
 {
-	void *array[16];
-	size_t size = backtrace(array, ARRAY_SIZE(array));
-	char **strings = backtrace_symbols(array, size);
-	size_t i;
-
-	printf("Obtained %zd stack frames.\n", size);
-
-	for (i = 0; i < size; i++)
-		printf("%s\n", strings[i]);
+	void *stackdump[32];
+	size_t size = backtrace(stackdump, ARRAY_SIZE(stackdump));
 
-	free(strings);
+	__dump_stack(stdout, stackdump, size);
 }
 #else
 void dump_stack(void) {}