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      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