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 libunwind doesn't crash on invalid info; the Linux aarch64
11 // sigreturn frame check would previously attempt to access invalid memory in
12 // this scenario.
13 // REQUIRES: target={{(aarch64|s390x|x86_64)-.+linux.*}}
14
15 // GCC doesn't support __attribute__((naked)) on AArch64.
16 // UNSUPPORTED: gcc
17
18 // Inline assembly is incompatible with MSAN.
19 // UNSUPPORTED: msan
20
21 #undef NDEBUG
22 #include <assert.h>
23 #include <libunwind.h>
24 #include <stdio.h>
25
bad_unwind_info()26 __attribute__((naked)) void bad_unwind_info() {
27 #if defined(__aarch64__)
28 __asm__("// not using 0 because unwinder was already resilient to that\n"
29 "mov x8, #4\n"
30 "stp x30, x8, [sp, #-16]!\n"
31 ".cfi_def_cfa_offset 16\n"
32 "// purposely use incorrect offset for x30\n"
33 ".cfi_offset x30, -8\n"
34 "bl stepper\n"
35 "ldr x30, [sp], #16\n"
36 ".cfi_def_cfa_offset 0\n"
37 ".cfi_restore x30\n"
38 "ret\n");
39 #elif defined(__s390x__)
40 __asm__("stmg %r14,%r15,112(%r15)\n"
41 "mvghi 104(%r15),4\n"
42 "# purposely use incorrect offset for %r14\n"
43 ".cfi_offset 14, -56\n"
44 ".cfi_offset 15, -40\n"
45 "lay %r15,-160(%r15)\n"
46 ".cfi_def_cfa_offset 320\n"
47 "brasl %r14,stepper\n"
48 "lmg %r14,%r15,272(%r15)\n"
49 ".cfi_restore 15\n"
50 ".cfi_restore 14\n"
51 ".cfi_def_cfa_offset 160\n"
52 "br %r14\n");
53 #elif defined(__x86_64__)
54 __asm__("pushq %rbx\n"
55 ".cfi_def_cfa_offset 16\n"
56 "movq 8(%rsp), %rbx\n"
57 "# purposely corrupt return value on stack\n"
58 "movq $4, 8(%rsp)\n"
59 "callq stepper\n"
60 "movq %rbx, 8(%rsp)\n"
61 "popq %rbx\n"
62 ".cfi_def_cfa_offset 8\n"
63 "ret\n");
64 #else
65 #error This test is only supported on aarch64, s390x, or x86-64
66 #endif
67 }
68
stepper()69 extern "C" void stepper() {
70 unw_cursor_t cursor;
71 unw_context_t uc;
72 unw_getcontext(&uc);
73 unw_init_local(&cursor, &uc);
74 // stepping to bad_unwind_info should succeed
75 assert(unw_step(&cursor) > 0);
76 // stepping past bad_unwind_info should fail but not crash
77 assert(unw_step(&cursor) <= 0);
78 }
79
main()80 int main() { bad_unwind_info(); }
81