blob: 6e9470c43c24ada65f16ac115f4a51c41c97de94 [file] [log] [blame]
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build cgo,darwin cgo,linux
#include <stdint.h>
#include "libcgo.h"
#ifndef __has_feature
#define __has_feature(x) 0
#if __has_feature(memory_sanitizer)
#include <sanitizer/msan_interface.h>
// Call the user's traceback function and then call sigtramp.
// The runtime signal handler will jump to this code.
// We do it this way so that the user's traceback function will be called
// by a C function with proper unwind info.
x_cgo_callers(uintptr_t sig, void *info, void *context, void (*cgoTraceback)(struct cgoTracebackArg*), uintptr_t* cgoCallers, void (*sigtramp)(uintptr_t, void*, void*)) {
struct cgoTracebackArg arg;
arg.Context = 0;
arg.SigContext = (uintptr_t)(context);
arg.Buf = cgoCallers;
arg.Max = 32; // must match len(runtime.cgoCallers)
#if __has_feature(memory_sanitizer)
// This function is called directly from the signal handler.
// The arguments are passed in registers, so whether msan
// considers cgoCallers to be initialized depends on whether
// it considers the appropriate register to be initialized.
// That can cause false reports in rare cases.
// Explicitly unpoison the memory to avoid that.
// See issue #47543 for more details.
__msan_unpoison(&arg, sizeof arg);
sigtramp(sig, info, context);