1 #define _GNU_SOURCE
2 #include <stdio.h>
3 #include <signal.h>
4 #include <unistd.h>
5 #include <errno.h>
6 #include <linux/types.h>
7 #include <sys/wait.h>
8 #include <sys/syscall.h>
9 #include <sys/user.h>
10 #include <sys/mman.h>
11 
12 #include "linux/ptrace.h"
13 
14 static int sys_rt_sigqueueinfo(pid_t tgid, int sig, siginfo_t *uinfo)
15 {
16 	return syscall(SYS_rt_sigqueueinfo, tgid, sig, uinfo);
17 }
18 
19 static int sys_rt_tgsigqueueinfo(pid_t tgid, pid_t tid,
20 					int sig, siginfo_t *uinfo)
21 {
22 	return syscall(SYS_rt_tgsigqueueinfo, tgid, tid, sig, uinfo);
23 }
24 
25 static int sys_ptrace(int request, pid_t pid, void *addr, void *data)
26 {
27 	return syscall(SYS_ptrace, request, pid, addr, data);
28 }
29 
30 #define SIGNR 10
31 #define TEST_SICODE_PRIV	-1
32 #define TEST_SICODE_SHARE	-2
33 
34 #define err(fmt, ...)						\
35 		fprintf(stderr,					\
36 			"Error (%s:%d): " fmt,			\
37 			__FILE__, __LINE__, ##__VA_ARGS__)
38 
39 static int check_error_paths(pid_t child)
40 {
41 	struct ptrace_peeksiginfo_args arg;
42 	int ret, exit_code = -1;
43 	void *addr_rw, *addr_ro;
44 
45 	/*
46 	 * Allocate two contiguous pages. The first one is for read-write,
47 	 * another is for read-only.
48 	 */
49 	addr_rw = mmap(NULL, 2 * PAGE_SIZE, PROT_READ | PROT_WRITE,
50 				MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
51 	if (addr_rw == MAP_FAILED) {
52 		err("mmap() failed: %m\n");
53 		return 1;
54 	}
55 
56 	addr_ro = mmap(addr_rw + PAGE_SIZE, PAGE_SIZE, PROT_READ,
57 			MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
58 	if (addr_ro == MAP_FAILED) {
59 		err("mmap() failed: %m\n");
60 		goto out;
61 	}
62 
63 	arg.nr = SIGNR;
64 	arg.off = 0;
65 
66 	/* Unsupported flags */
67 	arg.flags = ~0;
68 	ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg, addr_rw);
69 	if (ret != -1 || errno != EINVAL) {
70 		err("sys_ptrace() returns %d (expected -1),"
71 				" errno %d (expected %d): %m\n",
72 				ret, errno, EINVAL);
73 		goto out;
74 	}
75 	arg.flags = 0;
76 
77 	/* A part of the buffer is read-only */
78 	ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg,
79 					addr_ro - sizeof(siginfo_t) * 2);
80 	if (ret != 2) {
81 		err("sys_ptrace() returns %d (expected 2): %m\n", ret);
82 		goto out;
83 	}
84 
85 	/* Read-only buffer */
86 	ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg, addr_ro);
87 	if (ret != -1 && errno != EFAULT) {
88 		err("sys_ptrace() returns %d (expected -1),"
89 				" errno %d (expected %d): %m\n",
90 				ret, errno, EFAULT);
91 		goto out;
92 	}
93 
94 	exit_code = 0;
95 out:
96 	munmap(addr_rw, 2 * PAGE_SIZE);
97 	return exit_code;
98 }
99 
100 int check_direct_path(pid_t child, int shared, int nr)
101 {
102 	struct ptrace_peeksiginfo_args arg = {.flags = 0, .nr = nr, .off = 0};
103 	int i, j, ret, exit_code = -1;
104 	siginfo_t siginfo[SIGNR];
105 	int si_code;
106 
107 	if (shared == 1) {
108 		arg.flags = PTRACE_PEEKSIGINFO_SHARED;
109 		si_code = TEST_SICODE_SHARE;
110 	} else {
111 		arg.flags = 0;
112 		si_code = TEST_SICODE_PRIV;
113 	}
114 
115 	for (i = 0; i < SIGNR; ) {
116 		arg.off = i;
117 		ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg, siginfo);
118 		if (ret == -1) {
119 			err("ptrace() failed: %m\n");
120 			goto out;
121 		}
122 
123 		if (ret == 0)
124 			break;
125 
126 		for (j = 0; j < ret; j++, i++) {
127 			if (siginfo[j].si_code == si_code &&
128 			    siginfo[j].si_int == i)
129 				continue;
130 
131 			err("%d: Wrong siginfo i=%d si_code=%d si_int=%d\n",
132 			     shared, i, siginfo[j].si_code, siginfo[j].si_int);
133 			goto out;
134 		}
135 	}
136 
137 	if (i != SIGNR) {
138 		err("Only %d signals were read\n", i);
139 		goto out;
140 	}
141 
142 	exit_code = 0;
143 out:
144 	return exit_code;
145 }
146 
147 int main(int argc, char *argv[])
148 {
149 	siginfo_t siginfo[SIGNR];
150 	int i, exit_code = 1;
151 	sigset_t blockmask;
152 	pid_t child;
153 
154 	sigemptyset(&blockmask);
155 	sigaddset(&blockmask, SIGRTMIN);
156 	sigprocmask(SIG_BLOCK, &blockmask, NULL);
157 
158 	child = fork();
159 	if (child == -1) {
160 		err("fork() failed: %m");
161 		return 1;
162 	} else if (child == 0) {
163 		pid_t ppid = getppid();
164 		while (1) {
165 			if (ppid != getppid())
166 				break;
167 			sleep(1);
168 		}
169 		return 1;
170 	}
171 
172 	/* Send signals in process-wide and per-thread queues */
173 	for (i = 0; i < SIGNR; i++) {
174 		siginfo->si_code = TEST_SICODE_SHARE;
175 		siginfo->si_int = i;
176 		sys_rt_sigqueueinfo(child, SIGRTMIN, siginfo);
177 
178 		siginfo->si_code = TEST_SICODE_PRIV;
179 		siginfo->si_int = i;
180 		sys_rt_tgsigqueueinfo(child, child, SIGRTMIN, siginfo);
181 	}
182 
183 	if (sys_ptrace(PTRACE_ATTACH, child, NULL, NULL) == -1)
184 		return 1;
185 
186 	waitpid(child, NULL, 0);
187 
188 	/* Dump signals one by one*/
189 	if (check_direct_path(child, 0, 1))
190 		goto out;
191 	/* Dump all signals for one call */
192 	if (check_direct_path(child, 0, SIGNR))
193 		goto out;
194 
195 	/*
196 	 * Dump signal from the process-wide queue.
197 	 * The number of signals is not multible to the buffer size
198 	 */
199 	if (check_direct_path(child, 1, 3))
200 		goto out;
201 
202 	if (check_error_paths(child))
203 		goto out;
204 
205 	printf("PASS\n");
206 	exit_code = 0;
207 out:
208 	if (sys_ptrace(PTRACE_KILL, child, NULL, NULL) == -1)
209 		return 1;
210 
211 	waitpid(child, NULL, 0);
212 
213 	return exit_code;
214 }
215