bionic/linker/tests/linker_allocator_test.cpp
Dmitriy Ivanov d597d263bc Refactor linker allocator
Makes it reusable for different fixed sized and not very
big structures (<PAGE_SIZE).

Change-Id: Id5ec13fc6541b1935ef7fe3671c22b98685abbae
2014-05-12 21:40:09 -07:00

162 lines
4.0 KiB
C++

/*
* Copyright (C) 2013 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 <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <gtest/gtest.h>
#include "../linker_allocator.h"
#include <unistd.h>
namespace {
struct test_struct_nominal {
void* pointer;
ssize_t value;
};
/*
* this one has size below allocator cap which is 2*sizeof(void*)
*/
struct test_struct_small {
char dummy_str[5];
};
/*
* 1009 byte struct (1009 is prime)
*/
struct test_struct_larger {
char dummy_str[1009];
};
static size_t kPageSize = sysconf(_SC_PAGE_SIZE);
};
TEST(linker_allocator, test_nominal) {
LinkerAllocator<test_struct_nominal> allocator;
allocator.init();
test_struct_nominal* ptr1 = allocator.alloc();
ASSERT_TRUE(ptr1 != nullptr);
test_struct_nominal* ptr2 = allocator.alloc();
ASSERT_TRUE(ptr2 != nullptr);
// they should be next to each other.
ASSERT_EQ(ptr1+1, ptr2);
ptr1->value = 42;
allocator.protect_page(ptr1, PROT_READ);
allocator.free(ptr1);
allocator.free(ptr2);
}
TEST(linker_allocator, test_small) {
LinkerAllocator<test_struct_small> allocator;
allocator.init();
char* ptr1 = reinterpret_cast<char*>(allocator.alloc());
char* ptr2 = reinterpret_cast<char*>(allocator.alloc());
ASSERT_TRUE(ptr1 != nullptr);
ASSERT_TRUE(ptr2 != nullptr);
ASSERT_EQ(ptr1+2*sizeof(void*), ptr2);
}
TEST(linker_allocator, test_larger) {
LinkerAllocator<test_struct_larger> allocator;
allocator.init();
test_struct_larger* ptr1 = allocator.alloc();
test_struct_larger* ptr2 = allocator.alloc();
ASSERT_TRUE(ptr1 != nullptr);
ASSERT_TRUE(ptr2 != nullptr);
ASSERT_EQ(ptr1+1, ptr2);
allocator.protect_page(ptr2, PROT_READ);
// lets allocate until we reach next page.
size_t n = kPageSize/sizeof(test_struct_larger) + 1 - 2;
for (size_t i=0; i<n; ++i) {
ASSERT_TRUE(allocator.alloc() != nullptr);
}
}
static void protect_one_page() {
LinkerAllocator<test_struct_larger> allocator;
allocator.init();
// number of allocs to reach the end of first page
size_t n = kPageSize/sizeof(test_struct_larger) - 1;
test_struct_larger* page1_ptr = allocator.alloc();
for (size_t i=0; i<n; ++i) {
allocator.alloc();
}
test_struct_larger* page2_ptr = allocator.alloc();
allocator.protect_page(page2_ptr, PROT_READ);
// check that we still have access to page1
page1_ptr->dummy_str[17] = 52;
fprintf(stderr, "trying to access protected page");
// this should result in segmentation fault
page2_ptr->dummy_str[12] = 3;
}
static void protect_all() {
LinkerAllocator<test_struct_larger> allocator;
allocator.init();
// number of allocs to reach the end of first page
size_t n = kPageSize/sizeof(test_struct_larger) - 1;
test_struct_larger* page1_ptr = allocator.alloc();
for (size_t i=0; i<n; ++i) {
allocator.alloc();
}
test_struct_larger* page2_ptr = allocator.alloc();
allocator.protect_all(PROT_READ);
allocator.protect_all(PROT_READ | PROT_WRITE);
// check access
page2_ptr->dummy_str[23] = 27;
page1_ptr->dummy_str[13] = 11;
allocator.protect_all(PROT_READ);
fprintf(stderr, "trying to access protected page");
// this should result in segmentation fault
page1_ptr->dummy_str[11] = 7;
}
TEST(linker_allocator, test_protect) {
testing::FLAGS_gtest_death_test_style = "threadsafe";
ASSERT_EXIT(protect_one_page(), testing::KilledBySignal(SIGSEGV), "trying to access protected page");
ASSERT_EXIT(protect_all(), testing::KilledBySignal(SIGSEGV), "trying to access protected page");
}