platform_bionic/tests/libs/cfi_test_lib.cpp
Evgenii Stepanov 1dfd76ac2c Extend cfi test to verify a range of target pointers.
Test: bionic device tests
Bug: 63400743
Bug: 65590288
Change-Id: Ic4ef9630a2db709cf4edcc7f76c791df3f349192
2017-09-19 13:59:34 -07:00

87 lines
2.5 KiB
C++

/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <assert.h>
#include <stdint.h>
#include <stdlib.h>
// This library is built for all targets, including host tests, so __cfi_slowpath may not be
// present. But it is only used in the bionic loader tests.
extern "C" __attribute__((weak)) void __cfi_slowpath(uint64_t, void*);
static size_t g_count;
static uint64_t g_last_type_id;
static void* g_last_address;
static void* g_last_diag;
extern "C" {
// Make sure the library crosses at least one kLibraryAlignment(=256KB) boundary.
char bss[1024 * 1024];
// Mock a CFI-enabled library without relying on the compiler.
__attribute__((aligned(4096))) void __cfi_check(uint64_t CallSiteTypeId, void* TargetAddr,
void* Diag) {
++g_count;
g_last_type_id = CallSiteTypeId;
g_last_address = TargetAddr;
g_last_diag = Diag;
}
size_t get_count() {
return g_count;
}
uint64_t get_last_type_id() {
return g_last_type_id;
}
void* get_last_address() {
return g_last_address;
}
void* get_last_diag() {
return g_last_diag;
}
void* get_global_address() {
return &g_count;
}
}
// Check that CFI is set up in module constructors and destructors.
struct A {
void check_cfi_self() {
g_last_type_id = 0;
assert(&__cfi_slowpath);
// CFI check for an invalid address. Normally, this would kill the process by routing the call
// back to the calling module's __cfi_check, which does the right thing based on
// -fsanitize-recover / -fsanitize-trap. But this module has custom __cfi_check that does not do
// any of that, so the result looks like a passing check.
int zz;
__cfi_slowpath(13, static_cast<void*>(&zz));
assert(g_last_type_id == 13);
// CFI check for a libc function. This never goes into this module's __cfi_check, and must pass.
__cfi_slowpath(14, reinterpret_cast<void*>(&exit));
assert(g_last_type_id == 13);
}
A() {
check_cfi_self();
}
~A() {
check_cfi_self();
}
} a;