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linux32_exec.c revision 1.12.2.3
      1 /*	$NetBSD: linux32_exec.c,v 1.12.2.3 2010/03/11 15:03:17 yamt Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 1994-2007 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Christos Zoulas, Frank van der Linden, Eric Haszlakiewicz,
      9  * Thor Lancelot Simon, and Emmanuel Dreyfus.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     30  * POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #include <sys/cdefs.h>
     34 __KERNEL_RCSID(0, "$NetBSD: linux32_exec.c,v 1.12.2.3 2010/03/11 15:03:17 yamt Exp $");
     35 
     36 #include <sys/param.h>
     37 #include <sys/systm.h>
     38 #include <sys/kernel.h>
     39 #include <sys/proc.h>
     40 #include <sys/malloc.h>
     41 #include <sys/namei.h>
     42 #include <sys/vnode.h>
     43 #include <sys/mount.h>
     44 #include <sys/exec.h>
     45 #include <sys/exec_elf.h>
     46 
     47 #include <sys/mman.h>
     48 #include <sys/syscallargs.h>
     49 #include <sys/ptrace.h>		/* For proc_reparent() */
     50 
     51 #include <uvm/uvm_extern.h>
     52 
     53 #include <sys/cpu.h>
     54 #include <machine/reg.h>
     55 
     56 #include <compat/linux/common/linux_types.h>
     57 #include <compat/linux/common/linux_emuldata.h>
     58 
     59 #include <compat/linux32/common/linux32_exec.h>
     60 #include <compat/linux32/common/linux32_types.h>
     61 #include <compat/linux32/common/linux32_signal.h>
     62 #include <compat/linux32/common/linux32_machdep.h>
     63 
     64 #include <compat/linux32/linux32_syscallargs.h>
     65 #include <compat/linux32/linux32_syscall.h>
     66 
     67 extern char linux32_sigcode[1];
     68 extern char linux32_rt_sigcode[1];
     69 extern char linux32_esigcode[1];
     70 
     71 extern struct sysent linux32_sysent[];
     72 extern const char * const linux32_syscallnames[];
     73 
     74 static void linux32_e_proc_exec(struct proc *, struct exec_package *);
     75 static void linux32_e_proc_fork(struct proc *, struct proc *, int);
     76 static void linux32_e_proc_exit(struct proc *);
     77 static void linux32_e_proc_init(struct proc *, struct proc *, int);
     78 
     79 #ifdef LINUX32_NPTL
     80 void linux32_userret(void);
     81 void linux_nptl_proc_fork(struct proc *, struct proc *, void (*luserret)(void));
     82 void linux_nptl_proc_exit(struct proc *);
     83 void linux_nptl_proc_init(struct proc *, struct proc *);
     84 #endif
     85 
     86 /*
     87  * Emulation switch.
     88  */
     89 
     90 struct uvm_object *emul_linux32_object;
     91 
     92 struct emul emul_linux32 = {
     93 	.e_name =		"linux32",
     94 	.e_path =		"/emul/linux32",
     95 #ifndef __HAVE_MINIMAL_EMUL
     96 	.e_flags =		0,
     97 	.e_errno =		NULL,
     98 	.e_nosys =		LINUX32_SYS_syscall,
     99 	.e_nsysent =		LINUX32_SYS_NSYSENT,
    100 #endif
    101 	.e_sysent =		linux32_sysent,
    102 	.e_syscallnames =	linux32_syscallnames,
    103 	.e_sendsig =		linux32_sendsig,
    104 	.e_trapsignal =		trapsignal,
    105 	.e_tracesig =		NULL,
    106 	.e_sigcode =		linux32_sigcode,
    107 	.e_esigcode =		linux32_esigcode,
    108 	.e_sigobject =		&emul_linux32_object,
    109 	.e_setregs =		linux32_setregs,
    110 	.e_proc_exec =		linux32_e_proc_exec,
    111 	.e_proc_fork =		linux32_e_proc_fork,
    112 	.e_proc_exit =		linux32_e_proc_exit,
    113 	.e_lwp_fork =		NULL,
    114 	.e_lwp_exit =		NULL,
    115 	.e_syscall_intern =	linux32_syscall_intern,
    116 	.e_sysctlovly =		NULL,
    117 	.e_fault =		NULL,
    118 	.e_vm_default_addr =	netbsd32_vm_default_addr,
    119 	.e_usertrap =		NULL,
    120 	.e_sa =			NULL,
    121 	.e_ucsize =		0,
    122 	.e_startlwp =		NULL
    123 };
    124 
    125 static void
    126 linux32_e_proc_init(struct proc *p, struct proc *parent, int forkflags)
    127 {
    128 	struct linux_emuldata *e = p->p_emuldata;
    129 	struct linux_emuldata_shared *s;
    130 	struct linux_emuldata *ep = NULL;
    131 
    132 	if (!e) {
    133 		/* allocate new Linux emuldata */
    134 		e = malloc(sizeof(struct linux_emuldata),
    135 			M_EMULDATA, M_WAITOK);
    136 	} else  {
    137 		mutex_enter(proc_lock);
    138 		e->s->refs--;
    139 		if (e->s->refs == 0)
    140 			free(e->s, M_EMULDATA);
    141 		mutex_exit(proc_lock);
    142 	}
    143 
    144 	memset(e, '\0', sizeof(struct linux_emuldata));
    145 
    146 	e->proc = p;
    147 
    148 	if (parent)
    149 		ep = parent->p_emuldata;
    150 
    151 	if (forkflags & FORK_SHAREVM) {
    152 		mutex_enter(proc_lock);
    153 #ifdef DIAGNOSTIC
    154 		if (ep == NULL) {
    155 			killproc(p, "FORK_SHAREVM while emuldata is NULL\n");
    156 			mutex_exit(proc_lock);
    157 			return;
    158 		}
    159 #endif
    160 		s = ep->s;
    161 		s->refs++;
    162 	} else {
    163 		struct vmspace *vm;
    164 
    165 		s = malloc(sizeof(struct linux_emuldata_shared),
    166 			M_EMULDATA, M_WAITOK);
    167 		s->refs = 1;
    168 
    169 		/*
    170 		 * Set the process idea of the break to the real value.
    171 		 * For fork, we use parent's vmspace since our's
    172 		 * is not setup at the time of this call and is going
    173 		 * to be copy of parent's anyway. For exec, just
    174 		 * use our own vmspace.
    175 		 */
    176 		vm = (parent) ? parent->p_vmspace : p->p_vmspace;
    177 		s->p_break = (char *)vm->vm_daddr + ctob(vm->vm_dsize);
    178 
    179 		/*
    180 		 * Linux threads are emulated as NetBSD processes (not lwp)
    181 		 * We use native PID for Linux TID. The Linux TID is the
    182 		 * PID of the first process in the group. It is stored
    183 		 * here
    184 		 */
    185 		s->group_pid = p->p_pid;
    186 
    187 		/*
    188 		 * Initialize the list of threads in the group
    189 		 */
    190 		LIST_INIT(&s->threads);
    191 
    192 		s->xstat = 0;
    193 		s->flags = 0;
    194 		mutex_enter(proc_lock);
    195 	}
    196 
    197 	e->s = s;
    198 
    199 	/*
    200 	 * Add this thread in the group thread list
    201 	 */
    202 	LIST_INSERT_HEAD(&s->threads, e, threads);
    203 	mutex_exit(proc_lock);
    204 
    205 #ifdef LINUX32_NPTL
    206 	linux_nptl_proc_init(p, parent);
    207 #endif /* LINUX32_NPTL */
    208 
    209 	p->p_emuldata = e;
    210 }
    211 
    212 /*
    213  * Allocate new per-process structures. Called when executing Linux
    214  * process. We can reuse the old emuldata - if it's not null,
    215  * the executed process is of same emulation as original forked one.
    216  */
    217 static void
    218 linux32_e_proc_exec(struct proc *p, struct exec_package *epp)
    219 {
    220 	/* exec, use our vmspace */
    221 	linux32_e_proc_init(p, NULL, 0);
    222 }
    223 
    224 /*
    225  * Emulation per-process exit hook.
    226  */
    227 static void
    228 linux32_e_proc_exit(struct proc *p)
    229 {
    230 	struct linux_emuldata *e = p->p_emuldata;
    231 
    232 #ifdef LINUX32_NPTL
    233 	linux_nptl_proc_exit(p);
    234 #endif /* LINUX32_NPTL */
    235 
    236 	/* Remove the thread for the group thread list */
    237 	mutex_enter(proc_lock);
    238 	LIST_REMOVE(e, threads);
    239 
    240 	/* free Linux emuldata and set the pointer to null */
    241 	e->s->refs--;
    242 	if (e->s->refs == 0)
    243 		free(e->s, M_EMULDATA);
    244 	p->p_emuldata = NULL;
    245 	mutex_exit(proc_lock);
    246 	free(e, M_EMULDATA);
    247 }
    248 
    249 /*
    250  * Emulation fork hook.
    251  */
    252 static void
    253 linux32_e_proc_fork(struct proc *p, struct proc *parent, int forkflags)
    254 {
    255 	/*
    256 	 * The new process might share some vmspace-related stuff
    257 	 * with parent, depending on fork flags (CLONE_VM et.al).
    258 	 * Force allocation of new base emuldata, and share the
    259 	 * VM-related parts only if necessary.
    260 	 */
    261 	p->p_emuldata = NULL;
    262 	linux32_e_proc_init(p, parent, forkflags);
    263 
    264 #ifdef LINUX32_NPTL
    265 	linux_nptl_proc_fork(p, parent, linux32_userret);
    266 #endif
    267 
    268 	return;
    269 }
    270 
    271 #ifdef LINUX32_NPTL
    272 void
    273 linux32_userret(void)
    274 {
    275 	struct lwp *l = curlwp;
    276 	struct proc *p = l->l_proc;
    277 	struct linux_emuldata *led = p->p_emuldata;
    278 	int error;
    279 
    280 	/* LINUX_CLONE_CHILD_SETTID: copy child's TID to child's memory  */
    281 	if (led->clone_flags & LINUX_CLONE_CHILD_SETTID) {
    282 		if ((error = copyout(&l->l_proc->p_pid,
    283 		    led->child_tidptr,  sizeof(l->l_proc->p_pid))) != 0)
    284 			printf("linux32_userret: LINUX_CLONE_CHILD_SETTID "
    285 			    "failed (led->child_tidptr = %p, p->p_pid = %d)\n",
    286 			    led->child_tidptr, p->p_pid);
    287 	}
    288 
    289 	/* LINUX_CLONE_SETTLS: allocate a new TLS */
    290 	if (led->clone_flags & LINUX_CLONE_SETTLS) {
    291 		if (linux32_set_newtls(l, linux32_get_newtls(l)) != 0)
    292 			printf("linux32_userret: linux32_set_tls failed");
    293 	}
    294 
    295 	return;
    296 }
    297 #endif /* LINUX32_NPTL */
    298