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// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// Ensure that libunwind doesn't crash on invalid info; the Linux aarch64
// sigreturn frame check would previously attempt to access invalid memory in
// this scenario.
// REQUIRES: linux && (target={{aarch64-.+}} || target={{s390x-.+}} || target={{x86_64-.+}})
// GCC doesn't support __attribute__((naked)) on AArch64.
// UNSUPPORTED: gcc
// Inline assembly is incompatible with MSAN.
// UNSUPPORTED: msan
#undef NDEBUG
#include <assert.h>
#include <libunwind.h>
#include <stdio.h>
__attribute__((naked)) void bad_unwind_info() {
#if defined(__aarch64__)
__asm__("// not using 0 because unwinder was already resilient to that\n"
"mov x8, #4\n"
"stp x30, x8, [sp, #-16]!\n"
".cfi_def_cfa_offset 16\n"
"// purposely use incorrect offset for x30\n"
".cfi_offset x30, -8\n"
"bl stepper\n"
"ldr x30, [sp], #16\n"
".cfi_def_cfa_offset 0\n"
".cfi_restore x30\n"
"ret\n");
#elif defined(__s390x__)
__asm__("stmg %r14,%r15,112(%r15)\n"
"mvghi 104(%r15),4\n"
"# purposely use incorrect offset for %r14\n"
".cfi_offset 14, -56\n"
".cfi_offset 15, -40\n"
"lay %r15,-160(%r15)\n"
".cfi_def_cfa_offset 320\n"
"brasl %r14,stepper\n"
"lmg %r14,%r15,272(%r15)\n"
".cfi_restore 15\n"
".cfi_restore 14\n"
".cfi_def_cfa_offset 160\n"
"br %r14\n");
#elif defined(__x86_64__)
__asm__("pushq %rbx\n"
".cfi_def_cfa_offset 16\n"
"movq 8(%rsp), %rbx\n"
"# purposely corrupt return value on stack\n"
"movq $4, 8(%rsp)\n"
"callq stepper\n"
"movq %rbx, 8(%rsp)\n"
"popq %rbx\n"
".cfi_def_cfa_offset 8\n"
"ret\n");
#else
#error This test is only supported on aarch64, s390x, or x86-64
#endif
}
extern "C" void stepper() {
unw_cursor_t cursor;
unw_context_t uc;
unw_getcontext(&uc);
unw_init_local(&cursor, &uc);
// stepping to bad_unwind_info should succeed
assert(unw_step(&cursor) > 0);
// stepping past bad_unwind_info should fail but not crash
assert(unw_step(&cursor) <= 0);
}
int main() { bad_unwind_info(); }
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