xref: /llvm-project/libunwind/test/signal_unwind.pass.cpp (revision fe1301b5d846e96655ae6981789f677de6c7572d)
1 // -*- C++ -*-
2 //===----------------------------------------------------------------------===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // Ensure that the unwinder can cope with the signal handler.
11 // REQUIRES: target={{(aarch64|riscv64|s390x|x86_64)-.+linux.*}}
12 
13 // TODO: Figure out why this fails with Memory Sanitizer.
14 // XFAIL: msan
15 
16 // Note: this test fails on musl because:
17 //
18 //  (a) musl disables emission of unwind information for its build, and
19 //  (b) musl's signal trampolines don't include unwind information
20 //
21 // XFAIL: target={{.*}}-musl
22 
23 #undef NDEBUG
24 #include <assert.h>
25 #include <signal.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <sys/types.h>
30 #include <unistd.h>
31 #include <unwind.h>
32 
33 // Using __attribute__((section("main_func"))) is ELF specific, but then
34 // this entire test is marked as requiring Linux, so we should be good.
35 //
36 // We don't use dladdr() because on musl it's a no-op when statically linked.
37 extern char __start_main_func;
38 extern char __stop_main_func;
39 
frame_handler(struct _Unwind_Context * ctx,void * arg)40 _Unwind_Reason_Code frame_handler(struct _Unwind_Context* ctx, void* arg) {
41   (void)arg;
42 
43   // Unwind until the main is reached, above frames depend on the platform and
44   // architecture.
45   uintptr_t ip = _Unwind_GetIP(ctx);
46   if (ip >= (uintptr_t)&__start_main_func &&
47       ip < (uintptr_t)&__stop_main_func) {
48     _Exit(0);
49   }
50 
51   return _URC_NO_REASON;
52 }
53 
signal_handler(int signum)54 void signal_handler(int signum) {
55   (void)signum;
56   _Unwind_Backtrace(frame_handler, NULL);
57   _Exit(-1);
58 }
59 
main(int,char **)60 __attribute__((section("main_func"))) int main(int, char **) {
61   signal(SIGUSR1, signal_handler);
62   kill(getpid(), SIGUSR1);
63   return -2;
64 }
65