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linux32_exec.c revision 1.10
      1 /*	$NetBSD: linux32_exec.c,v 1.10 2008/04/23 13:30:41 ad 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  * 3. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *        This product includes software developed by the NetBSD
     22  *        Foundation, Inc. and its contributors.
     23  * 4. Neither the name of The NetBSD Foundation nor the names of its
     24  *    contributors may be used to endorse or promote products derived
     25  *    from this software without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     37  * POSSIBILITY OF SUCH DAMAGE.
     38  */
     39 
     40 #include <sys/cdefs.h>
     41 __KERNEL_RCSID(0, "$NetBSD: linux32_exec.c,v 1.10 2008/04/23 13:30:41 ad Exp $");
     42 
     43 #include <sys/param.h>
     44 #include <sys/systm.h>
     45 #include <sys/kernel.h>
     46 #include <sys/proc.h>
     47 #include <sys/malloc.h>
     48 #include <sys/namei.h>
     49 #include <sys/vnode.h>
     50 #include <sys/mount.h>
     51 #include <sys/exec.h>
     52 #include <sys/exec_elf.h>
     53 
     54 #include <sys/mman.h>
     55 #include <sys/syscallargs.h>
     56 #include <sys/ptrace.h>		/* For proc_reparent() */
     57 
     58 #include <uvm/uvm_extern.h>
     59 
     60 #include <sys/cpu.h>
     61 #include <machine/reg.h>
     62 
     63 #include <compat/linux/common/linux_types.h>
     64 #include <compat/linux/common/linux_emuldata.h>
     65 
     66 #include <compat/linux32/common/linux32_exec.h>
     67 #include <compat/linux32/common/linux32_types.h>
     68 #include <compat/linux32/common/linux32_signal.h>
     69 #include <compat/linux32/common/linux32_machdep.h>
     70 
     71 #include <compat/linux32/linux32_syscallargs.h>
     72 #include <compat/linux32/linux32_syscall.h>
     73 
     74 extern char linux32_sigcode[1];
     75 extern char linux32_rt_sigcode[1];
     76 extern char linux32_esigcode[1];
     77 
     78 extern struct sysent linux32_sysent[];
     79 extern const char * const linux32_syscallnames[];
     80 
     81 static void linux32_e_proc_exec(struct proc *, struct exec_package *);
     82 static void linux32_e_proc_fork(struct proc *, struct proc *, int);
     83 static void linux32_e_proc_exit(struct proc *);
     84 static void linux32_e_proc_init(struct proc *, struct proc *, int);
     85 
     86 #ifdef LINUX32_NPTL
     87 void linux32_userret(void);
     88 void linux_nptl_proc_fork(struct proc *, struct proc *, void (*luserret)(void));
     89 void linux_nptl_proc_exit(struct proc *);
     90 void linux_nptl_proc_init(struct proc *, struct proc *);
     91 #endif
     92 
     93 /*
     94  * Emulation switch.
     95  */
     96 
     97 struct uvm_object *emul_linux32_object;
     98 
     99 const struct emul emul_linux32 = {
    100 	"linux32",
    101 	"/emul/linux32",
    102 #ifndef __HAVE_MINIMAL_EMUL
    103 	0,
    104 	NULL,
    105 	LINUX32_SYS_syscall,
    106 	LINUX32_SYS_NSYSENT,
    107 #endif
    108 	linux32_sysent,
    109 	linux32_syscallnames,
    110 	linux32_sendsig,
    111 	trapsignal,
    112 	NULL,
    113 	linux32_sigcode,
    114 	linux32_esigcode,
    115 	&emul_linux32_object,
    116 	linux32_setregs,
    117 	linux32_e_proc_exec,
    118 	linux32_e_proc_fork,
    119 	linux32_e_proc_exit,
    120 	NULL,
    121 	NULL,
    122 	linux32_syscall_intern,
    123 	NULL,
    124 	NULL,
    125 	netbsd32_vm_default_addr,
    126 };
    127 
    128 static void
    129 linux32_e_proc_init(p, parent, forkflags)
    130 	struct proc *p, *parent;
    131 	int forkflags;
    132 {
    133 	struct linux_emuldata *e = p->p_emuldata;
    134 	struct linux_emuldata_shared *s;
    135 	struct linux_emuldata *ep = NULL;
    136 
    137 	if (!e) {
    138 		/* allocate new Linux emuldata */
    139 		MALLOC(e, void *, sizeof(struct linux_emuldata),
    140 			M_EMULDATA, M_WAITOK);
    141 	} else  {
    142 		mutex_enter(&proclist_lock);
    143 		e->s->refs--;
    144 		if (e->s->refs == 0)
    145 			FREE(e->s, M_EMULDATA);
    146 		mutex_exit(&proclist_lock);
    147 	}
    148 
    149 	memset(e, '\0', sizeof(struct linux_emuldata));
    150 
    151 	e->proc = p;
    152 
    153 	if (parent)
    154 		ep = parent->p_emuldata;
    155 
    156 	if (forkflags & FORK_SHAREVM) {
    157 #ifdef DIAGNOSTIC
    158 		if (ep == NULL) {
    159 			killproc(p, "FORK_SHAREVM while emuldata is NULL\n");
    160 			return;
    161 		}
    162 #endif
    163 		mutex_enter(&proclist_lock);
    164 		s = ep->s;
    165 		s->refs++;
    166 	} else {
    167 		struct vmspace *vm;
    168 
    169 		MALLOC(s, void *, sizeof(struct linux_emuldata_shared),
    170 			M_EMULDATA, M_WAITOK);
    171 		s->refs = 1;
    172 
    173 		/*
    174 		 * Set the process idea of the break to the real value.
    175 		 * For fork, we use parent's vmspace since our's
    176 		 * is not setup at the time of this call and is going
    177 		 * to be copy of parent's anyway. For exec, just
    178 		 * use our own vmspace.
    179 		 */
    180 		vm = (parent) ? parent->p_vmspace : p->p_vmspace;
    181 		s->p_break = (char *)vm->vm_daddr + ctob(vm->vm_dsize);
    182 
    183 		/*
    184 		 * Linux threads are emulated as NetBSD processes (not lwp)
    185 		 * We use native PID for Linux TID. The Linux TID is the
    186 		 * PID of the first process in the group. It is stored
    187 		 * here
    188 		 */
    189 		s->group_pid = p->p_pid;
    190 
    191 		/*
    192 		 * Initialize the list of threads in the group
    193 		 */
    194 		LIST_INIT(&s->threads);
    195 
    196 		s->xstat = 0;
    197 		s->flags = 0;
    198 		mutex_enter(&proclist_lock);
    199 	}
    200 
    201 	e->s = s;
    202 
    203 	/*
    204 	 * Add this thread in the group thread list
    205 	 */
    206 	LIST_INSERT_HEAD(&s->threads, e, threads);
    207 	mutex_exit(&proclist_lock);
    208 
    209 #ifdef LINUX32_NPTL
    210 	linux_nptl_proc_init(p, parent);
    211 #endif /* LINUX32_NPTL */
    212 
    213 	p->p_emuldata = e;
    214 }
    215 
    216 /*
    217  * Allocate new per-process structures. Called when executing Linux
    218  * process. We can reuse the old emuldata - if it's not null,
    219  * the executed process is of same emulation as original forked one.
    220  */
    221 static void
    222 linux32_e_proc_exec(struct proc *p, struct exec_package *epp)
    223 {
    224 	/* exec, use our vmspace */
    225 	linux32_e_proc_init(p, NULL, 0);
    226 }
    227 
    228 /*
    229  * Emulation per-process exit hook.
    230  */
    231 static void
    232 linux32_e_proc_exit(struct proc *p)
    233 {
    234 	struct linux_emuldata *e = p->p_emuldata;
    235 
    236 #ifdef LINUX32_NPTL
    237 	linux_nptl_proc_exit(p);
    238 #endif /* LINUX32_NPTL */
    239 
    240 	/* Remove the thread for the group thread list */
    241 	mutex_enter(&proclist_lock);
    242 	LIST_REMOVE(e, threads);
    243 
    244 	/* free Linux emuldata and set the pointer to null */
    245 	e->s->refs--;
    246 	if (e->s->refs == 0)
    247 		FREE(e->s, M_EMULDATA);
    248 	p->p_emuldata = NULL;
    249 	mutex_exit(&proclist_lock);
    250 	FREE(e, M_EMULDATA);
    251 }
    252 
    253 /*
    254  * Emulation fork hook.
    255  */
    256 static void
    257 linux32_e_proc_fork(p, parent, forkflags)
    258 	struct proc *p, *parent;
    259 	int forkflags;
    260 {
    261 	/*
    262 	 * The new process might share some vmspace-related stuff
    263 	 * with parent, depending on fork flags (CLONE_VM et.al).
    264 	 * Force allocation of new base emuldata, and share the
    265 	 * VM-related parts only if necessary.
    266 	 */
    267 	p->p_emuldata = NULL;
    268 	linux32_e_proc_init(p, parent, forkflags);
    269 
    270 #ifdef LINUX32_NPTL
    271 	linux_nptl_proc_fork(p, parent, linux32_userret);
    272 #endif
    273 
    274 	return;
    275 }
    276 
    277 #ifdef LINUX32_NPTL
    278 void
    279 linux32_userret(void)
    280 {
    281 	struct lwp *l = curlwp;
    282 	struct proc *p = l->l_proc;
    283 	struct linux_emuldata *led = p->p_emuldata;
    284 	int error;
    285 
    286 	/* LINUX_CLONE_CHILD_SETTID: copy child's TID to child's memory  */
    287 	if (led->clone_flags & LINUX_CLONE_CHILD_SETTID) {
    288 		if ((error = copyout(&l->l_proc->p_pid,
    289 		    led->child_tidptr,  sizeof(l->l_proc->p_pid))) != 0)
    290 			printf("linux32_userret: LINUX_CLONE_CHILD_SETTID "
    291 			    "failed (led->child_tidptr = %p, p->p_pid = %d)\n",
    292 			    led->child_tidptr, p->p_pid);
    293 	}
    294 
    295 	/* LINUX_CLONE_SETTLS: allocate a new TLS */
    296 	if (led->clone_flags & LINUX_CLONE_SETTLS) {
    297 		if (linux32_set_newtls(l, linux32_get_newtls(l)) != 0)
    298 			printf("linux32_userret: linux32_set_tls failed");
    299 	}
    300 
    301 	return;
    302 }
    303 #endif /* LINUX32_NPTL */
    304