libunwind/test/bad_unwind_info.pass.cpp

   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
  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
  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
  80 int main() { bad_unwind_info(); }