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kern_sig_16.c revision 1.8
      1 /*	$NetBSD: kern_sig_16.c,v 1.8 2021/12/02 04:26:09 ryo Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Andrew Doran.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * Copyright (c) 1982, 1986, 1989, 1991, 1993
     34  *	The Regents of the University of California.  All rights reserved.
     35  * (c) UNIX System Laboratories, Inc.
     36  * All or some portions of this file are derived from material licensed
     37  * to the University of California by American Telephone and Telegraph
     38  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
     39  * the permission of UNIX System Laboratories, Inc.
     40  *
     41  * Redistribution and use in source and binary forms, with or without
     42  * modification, are permitted provided that the following conditions
     43  * are met:
     44  * 1. Redistributions of source code must retain the above copyright
     45  *    notice, this list of conditions and the following disclaimer.
     46  * 2. Redistributions in binary form must reproduce the above copyright
     47  *    notice, this list of conditions and the following disclaimer in the
     48  *    documentation and/or other materials provided with the distribution.
     49  * 3. Neither the name of the University nor the names of its contributors
     50  *    may be used to endorse or promote products derived from this software
     51  *    without specific prior written permission.
     52  *
     53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     63  * SUCH DAMAGE.
     64  *
     65  *	@(#)kern_sig.c	8.14 (Berkeley) 5/14/95
     66  */
     67 
     68 #include <sys/cdefs.h>
     69 __KERNEL_RCSID(0, "$NetBSD: kern_sig_16.c,v 1.8 2021/12/02 04:26:09 ryo Exp $");
     70 
     71 #if defined(_KERNEL_OPT)
     72 #include "opt_compat_netbsd.h"
     73 #endif
     74 
     75 #include <sys/param.h>
     76 #include <sys/exec.h>
     77 #include <sys/kernel.h>
     78 #include <sys/rwlock.h>
     79 #include <sys/signalvar.h>
     80 #include <sys/proc.h>
     81 #include <sys/pool.h>
     82 #include <sys/syscall.h>
     83 #include <sys/syscallvar.h>
     84 #include <sys/syscallargs.h>
     85 #include <sys/kauth.h>
     86 #include <sys/wait.h>
     87 #include <sys/kmem.h>
     88 #include <sys/compat_stub.h>
     89 
     90 #include <uvm/uvm_object.h>
     91 #include <uvm/uvm_prot.h>
     92 #include <uvm/uvm_pager.h>
     93 
     94 #include <compat/common/compat_mod.h>
     95 
     96 #if !defined(__amd64__) || defined(COMPAT_NETBSD32)
     97 #define COMPAT_SIGCONTEXT
     98 extern char sigcode[], esigcode[];
     99 struct uvm_object *emul_netbsd_object;
    100 #endif
    101 
    102 static const struct syscall_package kern_sig_16_syscalls[] = {
    103 #ifdef COMPAT_SIGCONTEXT
    104 	{ SYS_compat_16___sigaction14, 0,
    105 	    (sy_call_t *)compat_16_sys___sigaction14 },
    106 	/* compat_16_sigreturn14 is in MD code! */
    107 	{ SYS_compat_16___sigreturn14, 0,
    108 	    (sy_call_t *)compat_16_sys___sigreturn14 },
    109 #endif
    110 	{ 0, 0, NULL }
    111 };
    112 
    113 int
    114 compat_16_sys___sigaction14(struct lwp *l,
    115     const struct compat_16_sys___sigaction14_args *uap, register_t *retval)
    116 {
    117 	/* {
    118 		syscallarg(int)				signum;
    119 		syscallarg(const struct sigaction *)	nsa;
    120 		syscallarg(struct sigaction *)		osa;
    121 	} */
    122 	struct sigaction	nsa, osa;
    123 	int			error;
    124 
    125 	if (SCARG(uap, nsa)) {
    126 		error = copyin(SCARG(uap, nsa), &nsa, sizeof(nsa));
    127 		if (error)
    128 			return (error);
    129 	}
    130 	error = sigaction1(l, SCARG(uap, signum),
    131 	    SCARG(uap, nsa) ? &nsa : 0, SCARG(uap, osa) ? &osa : 0,
    132 	    NULL, 0);
    133 	if (error)
    134 		return (error);
    135 	if (SCARG(uap, osa)) {
    136 		error = copyout(&osa, SCARG(uap, osa), sizeof(osa));
    137 		if (error)
    138 			return (error);
    139 	}
    140 	return (0);
    141 }
    142 
    143 int
    144 kern_sig_16_init(void)
    145 {
    146 	int error;
    147 
    148 	error = syscall_establish(NULL, kern_sig_16_syscalls);
    149 	if (error)
    150 		return error;
    151 #if defined(COMPAT_SIGCONTEXT)
    152 	KASSERT(emul_netbsd.e_sigobject == NULL);
    153 	rw_enter(&exec_lock, RW_WRITER);
    154 	emul_netbsd.e_sigcode = sigcode;
    155 	emul_netbsd.e_esigcode = esigcode;
    156 	emul_netbsd.e_sigobject = &emul_netbsd_object;
    157 	error = exec_sigcode_alloc(&emul_netbsd);
    158 	if (error) {
    159 		emul_netbsd.e_sigcode = NULL;
    160 		emul_netbsd.e_esigcode = NULL;
    161 		emul_netbsd.e_sigobject = NULL;
    162 	}
    163 	rw_exit(&exec_lock);
    164 	if (error)
    165 		return error;
    166 	MODULE_HOOK_SET(sendsig_sigcontext_16_hook, sendsig_sigcontext);
    167 #endif
    168 
    169 	return 0;
    170 }
    171 
    172 int
    173 kern_sig_16_fini(void)
    174 {
    175 	proc_t *p;
    176 	int error;
    177 
    178 	error = syscall_disestablish(NULL, kern_sig_16_syscalls);
    179 	if (error)
    180 		return error;
    181 	/*
    182 	 * Ensure sendsig_sigcontext() is not being used.
    183 	 * module_lock prevents the flag being set on any
    184 	 * further processes while we are here.  See
    185 	 * sigaction1() for the opposing half.
    186 	 */
    187 	mutex_enter(&proc_lock);
    188 	PROCLIST_FOREACH(p, &allproc) {
    189 		if ((p->p_lflag & PL_SIGCOMPAT) != 0) {
    190 			break;
    191 		}
    192 	}
    193 	mutex_exit(&proc_lock);
    194 	if (p != NULL) {
    195 		syscall_establish(NULL, kern_sig_16_syscalls);
    196 		return EBUSY;
    197 	}
    198 
    199 #if defined(COMPAT_SIGCONTEXT)
    200 	/*
    201 	 * The sigobject may persist if still in use, but
    202 	 * is reference counted so will die eventually.
    203 	 */
    204 	rw_enter(&exec_lock, RW_WRITER);
    205 	exec_sigcode_free(&emul_netbsd);
    206 	emul_netbsd_object = NULL;
    207 	emul_netbsd.e_sigcode = NULL;
    208 	emul_netbsd.e_esigcode = NULL;
    209 	emul_netbsd.e_sigobject = NULL;
    210 	rw_exit(&exec_lock);
    211 
    212 	MODULE_HOOK_UNSET(sendsig_sigcontext_16_hook);
    213 #endif
    214 	return 0;
    215 }
    216 
    217