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linux32_exec.c revision 1.13.6.2
      1 /*	$NetBSD: linux32_exec.c,v 1.13.6.2 2008/12/13 01:13:57 haad 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 1.13.6.2 2008/12/13 01:13:57 haad 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 	"linux32",
     94 	"/emul/linux32",
     95 #ifndef __HAVE_MINIMAL_EMUL
     96 	0,
     97 	NULL,
     98 	LINUX32_SYS_syscall,
     99 	LINUX32_SYS_NSYSENT,
    100 #endif
    101 	linux32_sysent,
    102 	linux32_syscallnames,
    103 	linux32_sendsig,
    104 	trapsignal,
    105 	NULL,
    106 	linux32_sigcode,
    107 	linux32_esigcode,
    108 	&emul_linux32_object,
    109 	linux32_setregs,
    110 	linux32_e_proc_exec,
    111 	linux32_e_proc_fork,
    112 	linux32_e_proc_exit,
    113 	NULL,
    114 	NULL,
    115 	linux32_syscall_intern,
    116 	NULL,
    117 	NULL,
    118 	netbsd32_vm_default_addr,
    119 	NULL,
    120 	NULL,
    121 	0,
    122 	NULL
    123 };
    124 
    125 static void
    126 linux32_e_proc_init(p, parent, forkflags)
    127 	struct proc *p, *parent;
    128 	int forkflags;
    129 {
    130 	struct linux_emuldata *e = p->p_emuldata;
    131 	struct linux_emuldata_shared *s;
    132 	struct linux_emuldata *ep = NULL;
    133 
    134 	if (!e) {
    135 		/* allocate new Linux emuldata */
    136 		MALLOC(e, void *, sizeof(struct linux_emuldata),
    137 			M_EMULDATA, M_WAITOK);
    138 	} else  {
    139 		mutex_enter(proc_lock);
    140 		e->s->refs--;
    141 		if (e->s->refs == 0)
    142 			FREE(e->s, M_EMULDATA);
    143 		mutex_exit(proc_lock);
    144 	}
    145 
    146 	memset(e, '\0', sizeof(struct linux_emuldata));
    147 
    148 	e->proc = p;
    149 
    150 	if (parent)
    151 		ep = parent->p_emuldata;
    152 
    153 	if (forkflags & FORK_SHAREVM) {
    154 		mutex_enter(proc_lock);
    155 #ifdef DIAGNOSTIC
    156 		if (ep == NULL) {
    157 			killproc(p, "FORK_SHAREVM while emuldata is NULL\n");
    158 			mutex_exit(proc_lock);
    159 			return;
    160 		}
    161 #endif
    162 		s = ep->s;
    163 		s->refs++;
    164 	} else {
    165 		struct vmspace *vm;
    166 
    167 		MALLOC(s, void *, sizeof(struct linux_emuldata_shared),
    168 			M_EMULDATA, M_WAITOK);
    169 		s->refs = 1;
    170 
    171 		/*
    172 		 * Set the process idea of the break to the real value.
    173 		 * For fork, we use parent's vmspace since our's
    174 		 * is not setup at the time of this call and is going
    175 		 * to be copy of parent's anyway. For exec, just
    176 		 * use our own vmspace.
    177 		 */
    178 		vm = (parent) ? parent->p_vmspace : p->p_vmspace;
    179 		s->p_break = (char *)vm->vm_daddr + ctob(vm->vm_dsize);
    180 
    181 		/*
    182 		 * Linux threads are emulated as NetBSD processes (not lwp)
    183 		 * We use native PID for Linux TID. The Linux TID is the
    184 		 * PID of the first process in the group. It is stored
    185 		 * here
    186 		 */
    187 		s->group_pid = p->p_pid;
    188 
    189 		/*
    190 		 * Initialize the list of threads in the group
    191 		 */
    192 		LIST_INIT(&s->threads);
    193 
    194 		s->xstat = 0;
    195 		s->flags = 0;
    196 		mutex_enter(proc_lock);
    197 	}
    198 
    199 	e->s = s;
    200 
    201 	/*
    202 	 * Add this thread in the group thread list
    203 	 */
    204 	LIST_INSERT_HEAD(&s->threads, e, threads);
    205 	mutex_exit(proc_lock);
    206 
    207 #ifdef LINUX32_NPTL
    208 	linux_nptl_proc_init(p, parent);
    209 #endif /* LINUX32_NPTL */
    210 
    211 	p->p_emuldata = e;
    212 }
    213 
    214 /*
    215  * Allocate new per-process structures. Called when executing Linux
    216  * process. We can reuse the old emuldata - if it's not null,
    217  * the executed process is of same emulation as original forked one.
    218  */
    219 static void
    220 linux32_e_proc_exec(struct proc *p, struct exec_package *epp)
    221 {
    222 	/* exec, use our vmspace */
    223 	linux32_e_proc_init(p, NULL, 0);
    224 }
    225 
    226 /*
    227  * Emulation per-process exit hook.
    228  */
    229 static void
    230 linux32_e_proc_exit(struct proc *p)
    231 {
    232 	struct linux_emuldata *e = p->p_emuldata;
    233 
    234 #ifdef LINUX32_NPTL
    235 	linux_nptl_proc_exit(p);
    236 #endif /* LINUX32_NPTL */
    237 
    238 	/* Remove the thread for the group thread list */
    239 	mutex_enter(proc_lock);
    240 	LIST_REMOVE(e, threads);
    241 
    242 	/* free Linux emuldata and set the pointer to null */
    243 	e->s->refs--;
    244 	if (e->s->refs == 0)
    245 		FREE(e->s, M_EMULDATA);
    246 	p->p_emuldata = NULL;
    247 	mutex_exit(proc_lock);
    248 	FREE(e, M_EMULDATA);
    249 }
    250 
    251 /*
    252  * Emulation fork hook.
    253  */
    254 static void
    255 linux32_e_proc_fork(p, parent, forkflags)
    256 	struct proc *p, *parent;
    257 	int forkflags;
    258 {
    259 	/*
    260 	 * The new process might share some vmspace-related stuff
    261 	 * with parent, depending on fork flags (CLONE_VM et.al).
    262 	 * Force allocation of new base emuldata, and share the
    263 	 * VM-related parts only if necessary.
    264 	 */
    265 	p->p_emuldata = NULL;
    266 	linux32_e_proc_init(p, parent, forkflags);
    267 
    268 #ifdef LINUX32_NPTL
    269 	linux_nptl_proc_fork(p, parent, linux32_userret);
    270 #endif
    271 
    272 	return;
    273 }
    274 
    275 #ifdef LINUX32_NPTL
    276 void
    277 linux32_userret(void)
    278 {
    279 	struct lwp *l = curlwp;
    280 	struct proc *p = l->l_proc;
    281 	struct linux_emuldata *led = p->p_emuldata;
    282 	int error;
    283 
    284 	/* LINUX_CLONE_CHILD_SETTID: copy child's TID to child's memory  */
    285 	if (led->clone_flags & LINUX_CLONE_CHILD_SETTID) {
    286 		if ((error = copyout(&l->l_proc->p_pid,
    287 		    led->child_tidptr,  sizeof(l->l_proc->p_pid))) != 0)
    288 			printf("linux32_userret: LINUX_CLONE_CHILD_SETTID "
    289 			    "failed (led->child_tidptr = %p, p->p_pid = %d)\n",
    290 			    led->child_tidptr, p->p_pid);
    291 	}
    292 
    293 	/* LINUX_CLONE_SETTLS: allocate a new TLS */
    294 	if (led->clone_flags & LINUX_CLONE_SETTLS) {
    295 		if (linux32_set_newtls(l, linux32_get_newtls(l)) != 0)
    296 			printf("linux32_userret: linux32_set_tls failed");
    297 	}
    298 
    299 	return;
    300 }
    301 #endif /* LINUX32_NPTL */
    302