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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 
     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 #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 
     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 
    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 
    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