1 // SPDX-License-Identifier: GPL-2.0
2 #define _GNU_SOURCE
3 #include <stdio.h>
4 #include <signal.h>
5 #include <unistd.h>
6 #include <errno.h>
7 #include <linux/types.h>
8 #include <sys/wait.h>
9 #include <sys/syscall.h>
10 #include <sys/user.h>
11 #include <sys/mman.h>
12 
13 #include "linux/ptrace.h"
14 
15 static int sys_rt_sigqueueinfo(pid_t tgid, int sig, siginfo_t *uinfo)
16 {
17 	return syscall(SYS_rt_sigqueueinfo, tgid, sig, uinfo);
18 }
19 
20 static int sys_rt_tgsigqueueinfo(pid_t tgid, pid_t tid,
21 					int sig, siginfo_t *uinfo)
22 {
23 	return syscall(SYS_rt_tgsigqueueinfo, tgid, tid, sig, uinfo);
24 }
25 
26 static int sys_ptrace(int request, pid_t pid, void *addr, void *data)
27 {
28 	return syscall(SYS_ptrace, request, pid, addr, data);
29 }
30 
31 #define SIGNR 10
32 #define TEST_SICODE_PRIV	-1
33 #define TEST_SICODE_SHARE	-2
34 
35 #ifndef PAGE_SIZE
36 #define PAGE_SIZE sysconf(_SC_PAGESIZE)
37 #endif
38 
39 #define err(fmt, ...)						\
40 		fprintf(stderr,					\
41 			"Error (%s:%d): " fmt,			\
42 			__FILE__, __LINE__, ##__VA_ARGS__)
43 
44 static int check_error_paths(pid_t child)
45 {
46 	struct ptrace_peeksiginfo_args arg;
47 	int ret, exit_code = -1;
48 	void *addr_rw, *addr_ro;
49 
50 	/*
51 	 * Allocate two contiguous pages. The first one is for read-write,
52 	 * another is for read-only.
53 	 */
54 	addr_rw = mmap(NULL, 2 * PAGE_SIZE, PROT_READ | PROT_WRITE,
55 				MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
56 	if (addr_rw == MAP_FAILED) {
57 		err("mmap() failed: %m\n");
58 		return 1;
59 	}
60 
61 	addr_ro = mmap(addr_rw + PAGE_SIZE, PAGE_SIZE, PROT_READ,
62 			MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
63 	if (addr_ro == MAP_FAILED) {
64 		err("mmap() failed: %m\n");
65 		goto out;
66 	}
67 
68 	arg.nr = SIGNR;
69 	arg.off = 0;
70 
71 	/* Unsupported flags */
72 	arg.flags = ~0;
73 	ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg, addr_rw);
74 	if (ret != -1 || errno != EINVAL) {
75 		err("sys_ptrace() returns %d (expected -1),"
76 				" errno %d (expected %d): %m\n",
77 				ret, errno, EINVAL);
78 		goto out;
79 	}
80 	arg.flags = 0;
81 
82 	/* A part of the buffer is read-only */
83 	ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg,
84 					addr_ro - sizeof(siginfo_t) * 2);
85 	if (ret != 2) {
86 		err("sys_ptrace() returns %d (expected 2): %m\n", ret);
87 		goto out;
88 	}
89 
90 	/* Read-only buffer */
91 	ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg, addr_ro);
92 	if (ret != -1 && errno != EFAULT) {
93 		err("sys_ptrace() returns %d (expected -1),"
94 				" errno %d (expected %d): %m\n",
95 				ret, errno, EFAULT);
96 		goto out;
97 	}
98 
99 	exit_code = 0;
100 out:
101 	munmap(addr_rw, 2 * PAGE_SIZE);
102 	return exit_code;
103 }
104 
105 int check_direct_path(pid_t child, int shared, int nr)
106 {
107 	struct ptrace_peeksiginfo_args arg = {.flags = 0, .nr = nr, .off = 0};
108 	int i, j, ret, exit_code = -1;
109 	siginfo_t siginfo[SIGNR];
110 	int si_code;
111 
112 	if (shared == 1) {
113 		arg.flags = PTRACE_PEEKSIGINFO_SHARED;
114 		si_code = TEST_SICODE_SHARE;
115 	} else {
116 		arg.flags = 0;
117 		si_code = TEST_SICODE_PRIV;
118 	}
119 
120 	for (i = 0; i < SIGNR; ) {
121 		arg.off = i;
122 		ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg, siginfo);
123 		if (ret == -1) {
124 			err("ptrace() failed: %m\n");
125 			goto out;
126 		}
127 
128 		if (ret == 0)
129 			break;
130 
131 		for (j = 0; j < ret; j++, i++) {
132 			if (siginfo[j].si_code == si_code &&
133 			    siginfo[j].si_int == i)
134 				continue;
135 
136 			err("%d: Wrong siginfo i=%d si_code=%d si_int=%d\n",
137 			     shared, i, siginfo[j].si_code, siginfo[j].si_int);
138 			goto out;
139 		}
140 	}
141 
142 	if (i != SIGNR) {
143 		err("Only %d signals were read\n", i);
144 		goto out;
145 	}
146 
147 	exit_code = 0;
148 out:
149 	return exit_code;
150 }
151 
152 int main(int argc, char *argv[])
153 {
154 	siginfo_t siginfo[SIGNR];
155 	int i, exit_code = 1;
156 	sigset_t blockmask;
157 	pid_t child;
158 
159 	sigemptyset(&blockmask);
160 	sigaddset(&blockmask, SIGRTMIN);
161 	sigprocmask(SIG_BLOCK, &blockmask, NULL);
162 
163 	child = fork();
164 	if (child == -1) {
165 		err("fork() failed: %m");
166 		return 1;
167 	} else if (child == 0) {
168 		pid_t ppid = getppid();
169 		while (1) {
170 			if (ppid != getppid())
171 				break;
172 			sleep(1);
173 		}
174 		return 1;
175 	}
176 
177 	/* Send signals in process-wide and per-thread queues */
178 	for (i = 0; i < SIGNR; i++) {
179 		siginfo->si_code = TEST_SICODE_SHARE;
180 		siginfo->si_int = i;
181 		sys_rt_sigqueueinfo(child, SIGRTMIN, siginfo);
182 
183 		siginfo->si_code = TEST_SICODE_PRIV;
184 		siginfo->si_int = i;
185 		sys_rt_tgsigqueueinfo(child, child, SIGRTMIN, siginfo);
186 	}
187 
188 	if (sys_ptrace(PTRACE_ATTACH, child, NULL, NULL) == -1)
189 		return 1;
190 
191 	waitpid(child, NULL, 0);
192 
193 	/* Dump signals one by one*/
194 	if (check_direct_path(child, 0, 1))
195 		goto out;
196 	/* Dump all signals for one call */
197 	if (check_direct_path(child, 0, SIGNR))
198 		goto out;
199 
200 	/*
201 	 * Dump signal from the process-wide queue.
202 	 * The number of signals is not multible to the buffer size
203 	 */
204 	if (check_direct_path(child, 1, 3))
205 		goto out;
206 
207 	if (check_error_paths(child))
208 		goto out;
209 
210 	printf("PASS\n");
211 	exit_code = 0;
212 out:
213 	if (sys_ptrace(PTRACE_KILL, child, NULL, NULL) == -1)
214 		return 1;
215 
216 	waitpid(child, NULL, 0);
217 
218 	return exit_code;
219 }
220