1/**
2 * Copyright (c) 2023 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 *   http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16#include <signal.h>
17#include <stdio.h>
18#include <sys/wait.h>
19#include "gwp_asan_test.h"
20#include "test.h"
21
22void buffer_underflow_handler()
23{
24    find_and_check_file(GWP_ASAN_LOG_DIR, GWP_ASAN_LOG_TAG, "Buffer Underflow");
25    clear_log(GWP_ASAN_LOG_DIR, GWP_ASAN_LOG_TAG);
26    cancel_gwp_asan_environment(true);
27    _exit(0);
28}
29
30static void install_sigv_handler()
31{
32    struct sigaction sigv = {
33        .sa_handler = buffer_underflow_handler,
34        .sa_flags = 0,
35    };
36    sigaction(SIGSEGV, &sigv, NULL);
37}
38
39void buffer_underflow_test()
40{
41    config_gwp_asan_environment(true);
42    clear_log(GWP_ASAN_LOG_DIR, GWP_ASAN_LOG_TAG);
43    install_sigv_handler();
44
45    char *ptr = (char *)malloc(sysconf(_SC_PAGE_SIZE));
46    if (!ptr) {
47        t_error("malloc failed.");
48        return;
49    }
50    if (!libc_gwp_asan_ptr_is_mine(ptr)) {
51        t_error("FAIL enter gwp_asan malloc failed!\n");
52        return;
53    }
54    char c = *(ptr - 1);
55    printf("c:%c", c);
56}
57
58/*
59 *
60 *|--guard area--|--malloc area--|--guard area--|
61 *              ^
62 */
63int main()
64{
65    pid_t pid = fork();
66    if (pid < 0) {
67        t_error("FAIL fork failed.");
68    } else if (pid == 0) { // child process
69        buffer_underflow_test();
70    } else { // parent process
71        int status;
72        if (waitpid(pid, &status, 0) != pid) {
73            t_error("gwp_asan_buffer_underflow_test waitpid failed.");
74        }
75
76        if (WIFEXITED(status) && WEXITSTATUS(status) != 0) {
77            t_error("gwp_asan_buffer_underflow_test failed.");
78        }
79
80        cancel_gwp_asan_environment(true);
81    }
82
83    return t_status;
84}