1 | // SPDX-License-Identifier: GPL-2.0 |
2 | |
3 | #define _GNU_SOURCE |
4 | #include <errno.h> |
5 | #include <fcntl.h> |
6 | #include <inttypes.h> |
7 | #include <limits.h> |
8 | #include <linux/types.h> |
9 | #include <sched.h> |
10 | #include <signal.h> |
11 | #include <stdbool.h> |
12 | #include <stdio.h> |
13 | #include <stdlib.h> |
14 | #include <string.h> |
15 | #include <syscall.h> |
16 | #include <sys/mount.h> |
17 | #include <sys/prctl.h> |
18 | #include <sys/wait.h> |
19 | #include <unistd.h> |
20 | |
21 | #include "pidfd.h" |
22 | #include "../kselftest.h" |
23 | |
24 | static int safe_int(const char *numstr, int *converted) |
25 | { |
26 | char *err = NULL; |
27 | long sli; |
28 | |
29 | errno = 0; |
30 | sli = strtol(numstr, &err, 0); |
31 | if (errno == ERANGE && (sli == LONG_MAX || sli == LONG_MIN)) |
32 | return -ERANGE; |
33 | |
34 | if (errno != 0 && sli == 0) |
35 | return -EINVAL; |
36 | |
37 | if (err == numstr || *err != '\0') |
38 | return -EINVAL; |
39 | |
40 | if (sli > INT_MAX || sli < INT_MIN) |
41 | return -ERANGE; |
42 | |
43 | *converted = (int)sli; |
44 | return 0; |
45 | } |
46 | |
47 | static int char_left_gc(const char *buffer, size_t len) |
48 | { |
49 | size_t i; |
50 | |
51 | for (i = 0; i < len; i++) { |
52 | if (buffer[i] == ' ' || |
53 | buffer[i] == '\t') |
54 | continue; |
55 | |
56 | return i; |
57 | } |
58 | |
59 | return 0; |
60 | } |
61 | |
62 | static int char_right_gc(const char *buffer, size_t len) |
63 | { |
64 | int i; |
65 | |
66 | for (i = len - 1; i >= 0; i--) { |
67 | if (buffer[i] == ' ' || |
68 | buffer[i] == '\t' || |
69 | buffer[i] == '\n' || |
70 | buffer[i] == '\0') |
71 | continue; |
72 | |
73 | return i + 1; |
74 | } |
75 | |
76 | return 0; |
77 | } |
78 | |
79 | static char *trim_whitespace_in_place(char *buffer) |
80 | { |
81 | buffer += char_left_gc(buffer, len: strlen(buffer)); |
82 | buffer[char_right_gc(buffer, len: strlen(buffer))] = '\0'; |
83 | return buffer; |
84 | } |
85 | |
86 | static pid_t get_pid_from_fdinfo_file(int pidfd, const char *key, size_t keylen) |
87 | { |
88 | int ret; |
89 | char path[512]; |
90 | FILE *f; |
91 | size_t n = 0; |
92 | pid_t result = -1; |
93 | char *line = NULL; |
94 | |
95 | snprintf(path, sizeof(path), "/proc/self/fdinfo/%d" , pidfd); |
96 | |
97 | f = fopen(path, "re" ); |
98 | if (!f) |
99 | return -1; |
100 | |
101 | while (getline(&line, &n, f) != -1) { |
102 | char *numstr; |
103 | |
104 | if (strncmp(line, key, keylen)) |
105 | continue; |
106 | |
107 | numstr = trim_whitespace_in_place(buffer: line + 4); |
108 | ret = safe_int(numstr, converted: &result); |
109 | if (ret < 0) |
110 | goto out; |
111 | |
112 | break; |
113 | } |
114 | |
115 | out: |
116 | free(line); |
117 | fclose(f); |
118 | return result; |
119 | } |
120 | |
121 | int main(int argc, char **argv) |
122 | { |
123 | int pidfd = -1, ret = 1; |
124 | pid_t pid; |
125 | |
126 | ksft_set_plan(plan: 3); |
127 | |
128 | pidfd = sys_pidfd_open(pid: -1, flags: 0); |
129 | if (pidfd >= 0) { |
130 | ksft_print_msg( |
131 | msg: "%s - succeeded to open pidfd for invalid pid -1\n" , |
132 | strerror(errno)); |
133 | goto on_error; |
134 | } |
135 | ksft_test_result_pass(msg: "do not allow invalid pid test: passed\n" ); |
136 | |
137 | pidfd = sys_pidfd_open(pid: getpid(), flags: 1); |
138 | if (pidfd >= 0) { |
139 | ksft_print_msg( |
140 | msg: "%s - succeeded to open pidfd with invalid flag value specified\n" , |
141 | strerror(errno)); |
142 | goto on_error; |
143 | } |
144 | ksft_test_result_pass(msg: "do not allow invalid flag test: passed\n" ); |
145 | |
146 | pidfd = sys_pidfd_open(pid: getpid(), flags: 0); |
147 | if (pidfd < 0) { |
148 | ksft_print_msg(msg: "%s - failed to open pidfd\n" , strerror(errno)); |
149 | goto on_error; |
150 | } |
151 | ksft_test_result_pass(msg: "open a new pidfd test: passed\n" ); |
152 | |
153 | pid = get_pid_from_fdinfo_file(pidfd, key: "Pid:" , keylen: sizeof("Pid:" ) - 1); |
154 | ksft_print_msg(msg: "pidfd %d refers to process with pid %d\n" , pidfd, pid); |
155 | |
156 | ret = 0; |
157 | |
158 | on_error: |
159 | if (pidfd >= 0) |
160 | close(pidfd); |
161 | |
162 | return !ret ? ksft_exit_pass() : ksft_exit_fail(); |
163 | } |
164 | |