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      1 /*	$NetBSD: t_ptrace_sigchld.c,v 1.7 2025/05/02 02:37:07 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2020 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __RCSID("$NetBSD: t_ptrace_sigchld.c,v 1.7 2025/05/02 02:37:07 riastradh Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/types.h>
     34 #include <sys/exec_elf.h>
     35 #include <sys/mman.h>
     36 #include <sys/ptrace.h>
     37 #include <sys/resource.h>
     38 #include <sys/stat.h>
     39 #include <sys/syscall.h>
     40 #include <sys/sysctl.h>
     41 #include <sys/uio.h>
     42 #include <sys/wait.h>
     43 #include <machine/reg.h>
     44 #include <assert.h>
     45 #include <elf.h>
     46 #include <err.h>
     47 #include <errno.h>
     48 #include <fcntl.h>
     49 #include <lwp.h>
     50 #include <pthread.h>
     51 #include <sched.h>
     52 #include <signal.h>
     53 #include <spawn.h>
     54 #include <stdint.h>
     55 #include <stdio.h>
     56 #include <stdlib.h>
     57 #include <strings.h>
     58 #include <time.h>
     59 #include <unistd.h>
     60 
     61 #include <atf-c.h>
     62 
     63 #include "h_macros.h"
     64 #include "msg.h"
     65 
     66 #include "t_ptrace_wait.h"
     67 
     68 #define SYSCALL_REQUIRE(expr) ATF_REQUIRE_MSG(expr, "%s: %s", # expr, \
     69     strerror(errno))
     70 #define SYSCALL_REQUIRE_ERRNO(res, exp) ATF_REQUIRE_MSG(res == exp, \
     71     "%d(%s) != %d", res, strerror(res), exp)
     72 
     73 static int debug = 0;
     74 
     75 #define DPRINTF(a, ...)	do  \
     76 	if (debug) { \
     77 		const char *file = __FILE__, *slash = strrchr(file, '/'); \
     78 		if (slash) \
     79 			file = slash + 1; \
     80 		printf("%s() %d.%d %s:%d " a, \
     81        		    __func__, getpid(), _lwp_self(), file, __LINE__, \
     82 		    ##__VA_ARGS__); \
     83 	} \
     84     while (/*CONSTCOND*/0)
     85 
     86 /// ----------------------------------------------------------------------------
     87 
     88 static int expected_signo;
     89 static int expected_code;
     90 static int expected_status;
     91 static pid_t expected_pid;
     92 
     93 static void
     94 sigchld_action(int sig, siginfo_t *info, void *ctx)
     95 {
     96 
     97 	FORKEE_ASSERT_EQ(info->si_signo, expected_signo);
     98 	FORKEE_ASSERT_EQ(info->si_code, expected_code);
     99 	FORKEE_ASSERT_EQ(info->si_uid, getuid());
    100 	FORKEE_ASSERT_EQ(info->si_pid, expected_pid);
    101 
    102 	if (WIFEXITED(info->si_status))
    103 		ATF_REQUIRE_EQ(WEXITSTATUS(info->si_status), expected_status);
    104 	else if (WIFSTOPPED(info->si_status))
    105 		ATF_REQUIRE_EQ(WSTOPSIG(info->si_status), expected_status);
    106 	else if (WIFSIGNALED(info->si_status))
    107 		ATF_REQUIRE_EQ(WTERMSIG(info->si_status), expected_status);
    108 /*
    109 	else if (WIFCONTINUED(info->si_status))
    110 		;
    111 */
    112 }
    113 
    114 static void
    115 traceme_raise(int sigval)
    116 {
    117 	const int exitval = 5;
    118 	struct sigaction sa;
    119 	pid_t child;
    120 	struct msg_fds parent_child;
    121 	uint8_t msg = 0xde; /* dummy message for IPC based on pipe(2) */
    122 
    123 	struct ptrace_siginfo info;
    124 	memset(&info, 0, sizeof(info));
    125 
    126 	memset(&sa, 0, sizeof(sa));
    127 	sa.sa_sigaction = sigchld_action;
    128 	sa.sa_flags = SA_SIGINFO | SA_NOCLDWAIT;
    129 	sigemptyset(&sa.sa_mask);
    130 
    131 	atf_tc_skip("XXX: zombie is not collected before tracer's death");
    132 
    133 	SYSCALL_REQUIRE(sigaction(SIGCHLD, &sa, NULL) == 0);
    134 
    135 	SYSCALL_REQUIRE(msg_open(&parent_child) == 0);
    136 
    137 	DPRINTF("Before forking process PID=%d\n", getpid());
    138 	SYSCALL_REQUIRE((child = fork()) != -1);
    139 	if (child == 0) {
    140 		DPRINTF("Before calling PT_TRACE_ME from child %d\n", getpid());
    141 		FORKEE_ASSERT(ptrace(PT_TRACE_ME, 0, NULL, 0) != -1);
    142 
    143 		CHILD_FROM_PARENT("raise1 child", parent_child, msg);
    144 
    145 		raise(sigval);
    146 
    147 		CHILD_TO_PARENT("raise2 child", parent_child, msg);
    148 
    149 		switch (sigval) {
    150 		case SIGKILL:
    151 			/* NOTREACHED */
    152 			FORKEE_ASSERTX(0 && "This shall not be reached");
    153 			__unreachable();
    154 		default:
    155 			DPRINTF("Before exiting of the child process\n");
    156 			_exit(exitval);
    157 		}
    158 	}
    159 	DPRINTF("Parent process PID=%d, child's PID=%d\n", getpid(), child);
    160 
    161 	expected_signo = SIGCHLD;
    162 	expected_pid = child;
    163 	switch (sigval) {
    164 	case SIGKILL:
    165 		expected_code = CLD_KILLED;
    166 		expected_status = SIGKILL;
    167 		break;
    168 	case SIGSTOP:
    169 		expected_code = CLD_STOPPED;
    170 		expected_status = SIGSTOP;
    171 		break;
    172 	default:
    173 		break;
    174 	}
    175 
    176 	PARENT_TO_CHILD("raise1 child", parent_child, msg);
    177 
    178 	switch (sigval) {
    179 	case SIGKILL:
    180 		break;
    181 	default:
    182 		PARENT_FROM_CHILD("raise2 child", parent_child, msg);
    183 
    184 		DPRINTF("Before calling ptrace(2) with PT_GET_SIGINFO for "
    185 			"child\n");
    186 		SYSCALL_REQUIRE(ptrace(PT_GET_SIGINFO, child, &info,
    187 			sizeof(info)) != -1);
    188 
    189 		DPRINTF("Signal traced to lwpid=%d\n", info.psi_lwpid);
    190 		DPRINTF("Signal properties: si_signo=%#x si_code=%#x "
    191 			"si_errno=%#x\n",
    192 			info.psi_siginfo.si_signo, info.psi_siginfo.si_code,
    193 			info.psi_siginfo.si_errno);
    194 
    195 		ATF_REQUIRE_EQ(info.psi_siginfo.si_signo, sigval);
    196 		ATF_REQUIRE_EQ(info.psi_siginfo.si_code, SI_LWP);
    197 
    198 		expected_code = CLD_EXITED;
    199 		expected_status = exitval;
    200 
    201 		SYSCALL_REQUIRE(ptrace(PT_CONTINUE, child, (void *)1, 0));
    202 
    203 		break;
    204 	}
    205 
    206 	await_collected(child); /* XXX: Process is never collected */
    207 }
    208 
    209 #define TRACEME_RAISE(test, sig)					\
    210 ATF_TC(test);								\
    211 ATF_TC_HEAD(test, tc)							\
    212 {									\
    213 	atf_tc_set_md_var(tc, "descr",					\
    214 	    "Verify " #sig " followed by _exit(2) in a child");		\
    215 	atf_tc_set_md_var(tc, "timeout", "10");				\
    216 }									\
    217 									\
    218 ATF_TC_BODY(test, tc)							\
    219 {									\
    220 									\
    221 	traceme_raise(sig);						\
    222 }
    223 
    224 TRACEME_RAISE(traceme_raise1, SIGKILL) /* non-maskable */
    225 #if notyet
    226 TRACEME_RAISE(traceme_raise2, SIGSTOP) /* non-maskable */
    227 TRACEME_RAISE(traceme_raise3, SIGABRT) /* regular abort trap */
    228 TRACEME_RAISE(traceme_raise4, SIGHUP)  /* hangup */
    229 TRACEME_RAISE(traceme_raise5, SIGCONT) /* continued? */
    230 TRACEME_RAISE(traceme_raise6, SIGTRAP) /* crash signal */
    231 TRACEME_RAISE(traceme_raise7, SIGBUS) /* crash signal */
    232 TRACEME_RAISE(traceme_raise8, SIGILL) /* crash signal */
    233 TRACEME_RAISE(traceme_raise9, SIGFPE) /* crash signal */
    234 TRACEME_RAISE(traceme_raise10, SIGSEGV) /* crash signal */
    235 #endif
    236 
    237 ATF_TP_ADD_TCS(tp)
    238 {
    239 	setvbuf(stdout, NULL, _IONBF, 0);
    240 	setvbuf(stderr, NULL, _IONBF, 0);
    241 
    242 	ATF_TP_ADD_TC(tp, traceme_raise1);
    243 #if notyet
    244 	ATF_TP_ADD_TC(tp, traceme_raise2);
    245 	ATF_TP_ADD_TC(tp, traceme_raise3);
    246 	ATF_TP_ADD_TC(tp, traceme_raise4);
    247 	ATF_TP_ADD_TC(tp, traceme_raise5);
    248 	ATF_TP_ADD_TC(tp, traceme_raise6);
    249 	ATF_TP_ADD_TC(tp, traceme_raise7);
    250 	ATF_TP_ADD_TC(tp, traceme_raise8);
    251 	ATF_TP_ADD_TC(tp, traceme_raise9);
    252 	ATF_TP_ADD_TC(tp, traceme_raise10);
    253 #endif
    254 
    255 	return atf_no_error();
    256 }
    257