xref: /llvm-project/compiler-rt/test/asan/TestCases/intercept-rethrow-exception.cpp (revision 38e9660eaa3478b003cbc48cb4ed0adcf22e053a)
1 // Regression test for
2 // https://bugs.llvm.org/show_bug.cgi?id=32434
3 
4 // REQUIRES: shared_cxxabi
5 
6 // RUN: %clangxx_asan -fexceptions -O0 %s -o %t
7 // RUN: %env_asan_opts=detect_stack_use_after_return=0 %run %t
8 
9 // The current implementation of this functionality requires special
10 // combination of libraries that are not used by default on NetBSD
11 // XFAIL: target={{.*netbsd.*}}
12 // FIXME: Bug 42703
13 // XFAIL: target={{.*solaris.*}}
14 
15 // https://reviews.llvm.org/D111703 made compiler incompatible with released NDK.
16 // UNSUPPORTED: android && arm-target-arch
17 
18 #include <assert.h>
19 #include <exception>
20 #include <sanitizer/asan_interface.h>
21 
22 namespace {
23 
24 // Not instrumented because std::rethrow_exception is a [[noreturn]] function,
25 // for which the compiler would emit a call to __asan_handle_no_return which
26 // unpoisons the stack.
27 // We emulate here some code not compiled with asan. This function is not
28 // [[noreturn]] because the scenario we're emulating doesn't always throw. If it
29 // were [[noreturn]], the calling code would emit a call to
30 // __asan_handle_no_return.
31 void __attribute__((no_sanitize("address")))
uninstrumented_rethrow_exception(std::exception_ptr const & exc_ptr)32 uninstrumented_rethrow_exception(std::exception_ptr const &exc_ptr) {
33   std::rethrow_exception(exc_ptr);
34 }
35 
36 char *poisoned1;
37 char *poisoned2;
38 
39 // Create redzones for stack variables in shadow memory and call
40 // std::rethrow_exception which should unpoison the entire stack.
create_redzones_and_throw(std::exception_ptr const & exc_ptr)41 void create_redzones_and_throw(std::exception_ptr const &exc_ptr) {
42   char a[100];
43   poisoned1 = a - 1;
44   poisoned2 = a + sizeof(a);
45   assert(__asan_address_is_poisoned(poisoned1));
46   assert(__asan_address_is_poisoned(poisoned2));
47   uninstrumented_rethrow_exception(exc_ptr);
48 }
49 
50 } // namespace
51 
52 // Check that std::rethrow_exception is intercepted by asan and the interception
53 // unpoisons the stack.
54 // If std::rethrow_exception is NOT intercepted, then calls to this function
55 // from instrumented code will still unpoison the stack because
56 // std::rethrow_exception is a [[noreturn]] function and any [[noreturn]]
57 // function call will be instrumented with __asan_handle_no_return.
58 // However, calls to std::rethrow_exception from UNinstrumented code will not
59 // unpoison the stack, so we need to intercept std::rethrow_exception to
60 // unpoison the stack.
main()61 int main() {
62   // In some implementations of std::make_exception_ptr, e.g. libstdc++ prior to
63   // gcc 7, this function calls __cxa_throw. The __cxa_throw is intercepted by
64   // asan to unpoison the entire stack; since this test essentially tests that
65   // the stack is unpoisoned by a call to std::rethrow_exception, we need to
66   // generate the exception_ptr BEFORE we have the local variables poison the
67   // stack.
68   std::exception_ptr my_exception_ptr = std::make_exception_ptr("up");
69 
70   try {
71     create_redzones_and_throw(my_exception_ptr);
72   } catch(char const *) {
73     assert(!__asan_region_is_poisoned(poisoned1, poisoned2 - poisoned1 + 1));
74   }
75 }
76