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