1 // SPDX-License-Identifier: GPL-2.0
2 #define _GNU_SOURCE
3 
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <signal.h>
7 #include <limits.h>
8 #include <unistd.h>
9 #include <errno.h>
10 #include <string.h>
11 #include <fcntl.h>
12 #include <linux/unistd.h>
13 #include <linux/kcmp.h>
14 
15 #include <sys/syscall.h>
16 #include <sys/types.h>
17 #include <sys/stat.h>
18 #include <sys/wait.h>
19 #include <sys/epoll.h>
20 
21 #include "../kselftest.h"
22 
sys_kcmp(int pid1,int pid2,int type,unsigned long fd1,unsigned long fd2)23 static long sys_kcmp(int pid1, int pid2, int type, unsigned long fd1, unsigned long fd2)
24 {
25 	return syscall(__NR_kcmp, pid1, pid2, type, fd1, fd2);
26 }
27 
28 static const unsigned int duped_num = 64;
29 
main(int argc,char ** argv)30 int main(int argc, char **argv)
31 {
32 	const char kpath[] = "kcmp-test-file";
33 	struct kcmp_epoll_slot epoll_slot;
34 	struct epoll_event ev;
35 	int pid1, pid2;
36 	int pipefd[2];
37 	int fd1, fd2;
38 	int epollfd;
39 	int status;
40 	int fddup;
41 
42 	fd1 = open(kpath, O_RDWR | O_CREAT | O_TRUNC, 0644);
43 	pid1 = getpid();
44 
45 	if (fd1 < 0) {
46 		perror("Can't create file");
47 		ksft_exit_fail();
48 	}
49 
50 	if (pipe(pipefd)) {
51 		perror("Can't create pipe");
52 		ksft_exit_fail();
53 	}
54 
55 	epollfd = epoll_create1(0);
56 	if (epollfd < 0) {
57 		perror("epoll_create1 failed");
58 		ksft_exit_fail();
59 	}
60 
61 	memset(&ev, 0xff, sizeof(ev));
62 	ev.events = EPOLLIN | EPOLLOUT;
63 
64 	if (epoll_ctl(epollfd, EPOLL_CTL_ADD, pipefd[0], &ev)) {
65 		perror("epoll_ctl failed");
66 		ksft_exit_fail();
67 	}
68 
69 	fddup = dup2(pipefd[1], duped_num);
70 	if (fddup < 0) {
71 		perror("dup2 failed");
72 		ksft_exit_fail();
73 	}
74 
75 	if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fddup, &ev)) {
76 		perror("epoll_ctl failed");
77 		ksft_exit_fail();
78 	}
79 	close(fddup);
80 
81 	pid2 = fork();
82 	if (pid2 < 0) {
83 		perror("fork failed");
84 		ksft_exit_fail();
85 	}
86 
87 	if (!pid2) {
88 		int pid2 = getpid();
89 		int ret;
90 
91 		fd2 = open(kpath, O_RDWR, 0644);
92 		if (fd2 < 0) {
93 			perror("Can't open file");
94 			ksft_exit_fail();
95 		}
96 
97 		/* An example of output and arguments */
98 		printf("pid1: %6d pid2: %6d FD: %2ld FILES: %2ld VM: %2ld "
99 		       "FS: %2ld SIGHAND: %2ld IO: %2ld SYSVSEM: %2ld "
100 		       "INV: %2ld\n",
101 		       pid1, pid2,
102 		       sys_kcmp(pid1, pid2, KCMP_FILE,		fd1, fd2),
103 		       sys_kcmp(pid1, pid2, KCMP_FILES,		0, 0),
104 		       sys_kcmp(pid1, pid2, KCMP_VM,		0, 0),
105 		       sys_kcmp(pid1, pid2, KCMP_FS,		0, 0),
106 		       sys_kcmp(pid1, pid2, KCMP_SIGHAND,	0, 0),
107 		       sys_kcmp(pid1, pid2, KCMP_IO,		0, 0),
108 		       sys_kcmp(pid1, pid2, KCMP_SYSVSEM,	0, 0),
109 
110 			/* This one should fail */
111 		       sys_kcmp(pid1, pid2, KCMP_TYPES + 1,	0, 0));
112 
113 		/* This one should return same fd */
114 		ret = sys_kcmp(pid1, pid2, KCMP_FILE, fd1, fd1);
115 		if (ret) {
116 			printf("FAIL: 0 expected but %d returned (%s)\n",
117 				ret, strerror(errno));
118 			ksft_inc_fail_cnt();
119 			ret = -1;
120 		} else {
121 			printf("PASS: 0 returned as expected\n");
122 			ksft_inc_pass_cnt();
123 		}
124 
125 		/* Compare with self */
126 		ret = sys_kcmp(pid1, pid1, KCMP_VM, 0, 0);
127 		if (ret) {
128 			printf("FAIL: 0 expected but %d returned (%s)\n",
129 				ret, strerror(errno));
130 			ksft_inc_fail_cnt();
131 			ret = -1;
132 		} else {
133 			printf("PASS: 0 returned as expected\n");
134 			ksft_inc_pass_cnt();
135 		}
136 
137 		/* Compare epoll target */
138 		epoll_slot = (struct kcmp_epoll_slot) {
139 			.efd	= epollfd,
140 			.tfd	= duped_num,
141 			.toff	= 0,
142 		};
143 		ret = sys_kcmp(pid1, pid1, KCMP_EPOLL_TFD, pipefd[1],
144 			       (unsigned long)(void *)&epoll_slot);
145 		if (ret) {
146 			printf("FAIL: 0 expected but %d returned (%s)\n",
147 				ret, strerror(errno));
148 			ksft_inc_fail_cnt();
149 			ret = -1;
150 		} else {
151 			printf("PASS: 0 returned as expected\n");
152 			ksft_inc_pass_cnt();
153 		}
154 
155 		ksft_print_cnts();
156 
157 		if (ret)
158 			ksft_exit_fail();
159 		else
160 			ksft_exit_pass();
161 	}
162 
163 	waitpid(pid2, &status, P_ALL);
164 
165 	return ksft_exit_pass();
166 }
167