1 /*
2  * Copyright (c) International Business Machines  Corp., 2012
3  * Copyright (c) Linux Test Project, 2012
4  *
5  * This program is free software;  you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  * the GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program;  if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18  */
19 
20 #define _GNU_SOURCE
21 #include <sys/types.h>
22 #include <sys/uio.h>
23 #include <sys/wait.h>
24 #include <errno.h>
25 #include <limits.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <time.h>
30 #include <unistd.h>
31 
32 #include "test.h"
33 #include "safe_macros.h"
34 #include "process_vm.h"
35 
36 char *TCID = "process_vm_readv03";
37 int TST_TOTAL = 1;
38 
39 #define NUM_LOCAL_VECS 4
40 
41 static int nflag, sflag;
42 static char *nr_opt, *sz_opt;
43 static option_t options[] = {
44 	{"n:", &nflag, &nr_opt},
45 	{"s:", &sflag, &sz_opt},
46 	{NULL, NULL, NULL}
47 };
48 
49 static int nr_iovecs;
50 static long bufsz;
51 static int pipe_fd[2];
52 static pid_t pids[2];
53 static int semid;
54 
55 static void gen_random_arr(int *arr, int arr_sz);
56 static void child_alloc(int *bufsz_arr);
57 static void child_invoke(int *bufsz_arr);
58 static long *fetch_remote_addrs(void);
59 static void setup(void);
60 static void cleanup(void);
61 static void help(void);
62 
main(int argc,char ** argv)63 int main(int argc, char **argv)
64 {
65 	int lc, status;
66 	int *bufsz_arr;
67 
68 	tst_parse_opts(argc, argv, options, &help);
69 
70 	setup();
71 	for (lc = 0; TEST_LOOPING(lc); lc++) {
72 		tst_count = 0;
73 
74 		if (pipe(pipe_fd) < 0)
75 			tst_brkm(TBROK | TERRNO, cleanup, "pipe");
76 
77 		bufsz_arr = SAFE_MALLOC(cleanup, nr_iovecs * sizeof(int));
78 		gen_random_arr(bufsz_arr, nr_iovecs);
79 
80 		/* the start of child_alloc and child_invoke is already
81 		 * synchronized via pipe */
82 		pids[0] = fork();
83 		switch (pids[0]) {
84 		case -1:
85 			tst_brkm(TBROK | TERRNO, cleanup, "fork #0");
86 		case 0:
87 			child_alloc(bufsz_arr);
88 			exit(0);
89 		}
90 
91 		pids[1] = fork();
92 		switch (pids[1]) {
93 		case -1:
94 			tst_brkm(TBROK | TERRNO, cleanup, "fork #1");
95 		case 0:
96 			child_invoke(bufsz_arr);
97 			exit(0);
98 		}
99 
100 		/* wait until child_invoke reads from child_alloc's VM */
101 		if (waitpid(pids[1], &status, 0) == -1)
102 			tst_brkm(TBROK | TERRNO, cleanup, "waitpid");
103 		if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
104 			tst_resm(TFAIL, "child 1 returns %d", status);
105 
106 		/* child_alloc is free to exit now */
107 		safe_semop(semid, 0, 1);
108 
109 		if (waitpid(pids[0], &status, 0) == -1)
110 			tst_brkm(TBROK | TERRNO, cleanup, "waitpid");
111 		if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
112 			tst_resm(TFAIL, "child 0 returns %d", status);
113 
114 		free(bufsz_arr);
115 	}
116 
117 	cleanup();
118 	tst_exit();
119 }
120 
gen_random_arr(int * arr,int arr_sz)121 static void gen_random_arr(int *arr, int arr_sz)
122 {
123 	long bufsz_left, bufsz_single;
124 	int i;
125 
126 	bufsz_left = bufsz;
127 	for (i = 0; i < arr_sz - 1; i++) {
128 		bufsz_single = rand() % (bufsz_left / 2) + 1;
129 		arr[i] = bufsz_single;
130 		bufsz_left -= bufsz_single;
131 	}
132 	arr[arr_sz - 1] = bufsz_left;
133 }
134 
child_alloc(int * bufsz_arr)135 static void child_alloc(int *bufsz_arr)
136 {
137 	char **foo;
138 	int i, j;
139 	char buf[BUFSIZ];
140 	long count;
141 
142 	foo = SAFE_MALLOC(tst_exit, nr_iovecs * sizeof(char *));
143 
144 	count = 0;
145 	for (i = 0; i < nr_iovecs; i++) {
146 		foo[i] = SAFE_MALLOC(tst_exit, bufsz_arr[i]);
147 		for (j = 0; j < bufsz_arr[i]; j++) {
148 			foo[i][j] = count % 256;
149 			count++;
150 		}
151 	}
152 	tst_resm(TINFO, "child 0: %d iovecs allocated and initialized.",
153 		 nr_iovecs);
154 
155 	/* passing addr via pipe */
156 	SAFE_CLOSE(tst_exit, pipe_fd[0]);
157 	snprintf(buf, BUFSIZ, "%p", (void *)foo);
158 	SAFE_WRITE(tst_exit, 1, pipe_fd[1], buf, strlen(buf));
159 	SAFE_CLOSE(tst_exit, pipe_fd[1]);
160 
161 	/* wait until child_invoke is done reading from our VM */
162 	safe_semop(semid, 0, -1);
163 }
164 
fetch_remote_addrs(void)165 static long *fetch_remote_addrs(void)
166 {
167 	long *foo, *bar;
168 	char buf[BUFSIZ];
169 	long len;
170 	struct iovec local, remote;
171 
172 	/* get addr from pipe */
173 	SAFE_CLOSE(tst_exit, pipe_fd[1]);
174 	SAFE_READ(tst_exit, 0, pipe_fd[0], buf, BUFSIZ);
175 	SAFE_CLOSE(tst_exit, pipe_fd[0]);
176 	if (sscanf(buf, "%p", &foo) != 1)
177 		tst_brkm(TBROK | TERRNO, tst_exit, "sscanf");
178 
179 	len = nr_iovecs * sizeof(long);
180 	bar = SAFE_MALLOC(tst_exit, len);
181 	local.iov_base = bar;
182 	local.iov_len = len;
183 	remote.iov_base = foo;
184 	remote.iov_len = len;
185 
186 	TEST(test_process_vm_readv(pids[0], &local, 1, &remote, 1, 0));
187 	if (TEST_RETURN != len)
188 		tst_brkm(TFAIL | TERRNO, tst_exit, "process_vm_readv");
189 
190 	return local.iov_base;
191 }
192 
child_invoke(int * bufsz_arr)193 static void child_invoke(int *bufsz_arr)
194 {
195 	int i, j, count, nr_error;
196 	unsigned char expect, actual;
197 	long *addrs;
198 	struct iovec local[NUM_LOCAL_VECS], *remote;
199 	int rcv_arr[NUM_LOCAL_VECS];
200 
201 	addrs = fetch_remote_addrs();
202 
203 	remote = SAFE_MALLOC(tst_exit, nr_iovecs * sizeof(struct iovec));
204 	for (i = 0; i < nr_iovecs; i++) {
205 		remote[i].iov_base = (void *)addrs[i];
206 		remote[i].iov_len = bufsz_arr[i];
207 	}
208 	tst_resm(TINFO, "child 1: %d remote iovecs received.", nr_iovecs);
209 
210 	gen_random_arr(rcv_arr, NUM_LOCAL_VECS);
211 	for (i = 0; i < NUM_LOCAL_VECS; i++) {
212 		local[i].iov_base = SAFE_MALLOC(tst_exit, rcv_arr[i]);
213 		local[i].iov_len = rcv_arr[i];
214 	}
215 	tst_resm(TINFO, "child 1: %d local iovecs initialized.",
216 		 NUM_LOCAL_VECS);
217 
218 	TEST(test_process_vm_readv(pids[0], local, NUM_LOCAL_VECS,
219 				   remote, nr_iovecs, 0));
220 	if (TEST_RETURN != bufsz)
221 		tst_brkm(TBROK | TERRNO, tst_exit, "process_vm_readv");
222 
223 	/* verify every byte */
224 	count = 0;
225 	nr_error = 0;
226 	for (i = 0; i < NUM_LOCAL_VECS; i++) {
227 		for (j = 0; j < local[i].iov_len; j++) {
228 			expect = count % 256;
229 			actual = ((unsigned char *)local[i].iov_base)[j];
230 			if (expect != actual) {
231 #if DEBUG
232 				tst_resm(TFAIL, "child 1: expected %i, got %i "
233 					 "for byte seq %d",
234 					 expect, actual, count);
235 #endif
236 				nr_error++;
237 			}
238 			count++;
239 		}
240 	}
241 	if (nr_error)
242 		tst_brkm(TFAIL, tst_exit, "child 1: %d incorrect bytes "
243 			 "received.", nr_error);
244 	else
245 		tst_resm(TPASS, "child 1: all bytes are correctly received.");
246 }
247 
setup(void)248 static void setup(void)
249 {
250 	tst_require_root();
251 
252 	nr_iovecs = nflag ? SAFE_STRTOL(NULL, nr_opt, 1, IOV_MAX) : 10;
253 	bufsz = sflag ? SAFE_STRTOL(NULL, sz_opt, NUM_LOCAL_VECS, LONG_MAX)
254 	    : 100000;
255 
256 #if !defined(__NR_process_vm_readv)
257 	tst_brkm(TCONF, NULL, "process_vm_readv does not exist "
258 		 "on your system");
259 #endif
260 	semid = init_sem(1);
261 	srand(time(NULL));
262 
263 	TEST_PAUSE;
264 }
265 
cleanup(void)266 static void cleanup(void)
267 {
268 	clean_sem(semid);
269 }
270 
help(void)271 static void help(void)
272 {
273 	printf("    -n NUM  Set the number of iovecs to be allocated.\n");
274 	printf("    -s NUM  Set the size of total buffer size.\n");
275 }
276