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/*
* 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 address inside this DSO. This goes to the current module's __cfi_check,
// which updates g_last_type_id.
__cfi_slowpath(13, static_cast<void*>(&g_last_type_id));
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;